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Armenian Patriarchate of Jerusalem

Public Radio of Armenia

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The Armenian Patriarchate of Jerusalem announces that a letter was sent on October 26, 2023 to Xana Gardens Ltd. whereby the Patriarchate informed Xana Gardens of the cancellation of the agreement si

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Armenian Patriarchate of Jerusalem cancels land deal

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Dental caries

Bariatric surgery

Those who have had surgical obesity treatment have a higher risk of dental caries than before surgery. They also often experience a general decline in oral health. This has been shown by a thesis from the University of Gothenburg.

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Research finds higher risk of dental caries after bariatric surgery

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Resilience

Excluded by inheritance and ignored by big business, women farmers in Kenya are turning to innovative methods to become independent food producers.

Women Correct Historical Injustices, Build Climate Resilience Through Cash Pooling

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Ultima IX: Ascension

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Silent Hill

Ascension kicks off on Halloween night – with one million pre-registrations, it's set to offer a unique look at the titular terror town

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Silent Hill Ascension is the horror origins story we've always wanted, and its Telltale-style public votes promise chaos

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AI-enabled B2B fintech marketplace Janover Inc (NASDAQ: JNVR), and Xchange.Loans Inc, an online marketplace for commercial loans, announced a strategic partnership whereby the two companies plan to br

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Great Central Railway

The Rail Accident Investigation Branch has released a report into an incident at the Great Central Railway whereby a passenger sustained serious injuries when alighting from a train at Loughborough Central.

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Great Central Railway: RAIB release report after passenger sustains serious injuries in incident

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THIS DEED OF TRANSFER MADE AT _____, this _____ day of _____ BETWEEN M/S. ABC & SONS, a registered Partnership Firm carrying on business at ...

Deed of Transfer whereby the Partnership Firm is Transferring the Unit in the Society to the Retiring Partner

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or to provoke the immediate use of unlawful violence by him whereby that person was likely to believe that such violence would be used, or it was likely that such violence would be provoked ...

Court round-up: Latest convictions at Doncaster Magistrates' Court

Doncaster Free Press

...the system whereby Britons choose their family doctors and the government pays those doctors. They voted to accept a deal whereby the union will receive nearly three-quarters of a million pounds from the International Miners Organisation.

Definizione di whereby

Collins Dictionary

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How to Write Clearly: Rules and Exercises on English Composition by Edwin Abbott Abbott, is part of the HackerNoon Books Series. You can jump to any chapter in this book . WORDS. here WORDS. 1. Use words in their proper sense. Write, not "His apparent guilt justified his friends in disowning him," but "his evident guilt." "Conscious" and "aware," "unnatural" and "supernatural," "transpire" and "occur," "circumstance" and "event," "reverse" and "converse," "eliminate" and "elicit," are often confused together. This rule forbids the use of the same word in different senses. "It is in my power to refuse your request, and since I have power to do this, I may lawfully do it." Here the second "power" is used for "authority." This rule also forbids the slovenly use of "nice," "awfully," "delicious," "glorious," &c. See (2). 2. Avoid exaggerations. "The boundless plains in the heart of the empire furnished inexhaustible supplies of corn, that would have almost sufficed for twice the population." Here "inexhaustible" is inconsistent with what follows. The words "unprecedented," "incalculable," "very," and "stupendous" are often used in the same loose way. 3. Avoid useless circumlocution and "fine writing." "Her Majesty here partook of lunch." Write "lunched." "Partook of" implies sharing, and is incorrect as well as lengthy. So, do not use "apex" for "top," "species" for "kind," "individual" for "man," "assist" for "help," &c. [5] 4. Be careful how you use the following words: "not … and," "any," "only," "not … or," "that." See below, "Or." And. —"I am not bound to receive any messenger that you send."
Does this mean every, or a single? Use "every" or "a single." —(1) "I do not intend to help you, because you are my enemy &c." ought to mean (2), "I intend not to help you, and my reason for not helping you is, because you are my enemy." But it is often wrongly used to mean (3), "I intend to help you, not because you are my enemy (but because you are poor, blind, &c.)." In the latter case, not ought to be separated from intend. By distinctly marking the limits to which the influence of not extends, the ambiguity may be removed. Any. Not. is often used ambiguously for alone. "The rest help me to revenge myself; you only advise me to wait." This ought to mean, "you only advise, instead of helping;" but in similar sentences "you only" is often used for "you alone." But see 21. Only —When "or" is preceded by a negative, as "I do not want butter or honey," "or" ought not, strictly speaking, to be used like "and," nor like "nor." The strict use of "not … or" would be as follows:— Or. "You say you don't want both butter and honey—you want butter or honey; I, on the contrary, do not want butter or honey—I want them both." Practically, however, this meaning is so rare, that "I don't want butter or honey" is regularly used for "I want neither butter nor honey." But where there is the slightest danger of ambiguity, it is desirable to use nor. The same ambiguity attends "not … and." "I do not see Thomas and John" is commonly used for "I see neither Thomas nor John;" but it might mean, "I do not see them both—I see only one of them." —The different uses of "that" produce much ambiguity, e.g. "I am so much surprised by this statement that I am desirous of resigning, that I scarcely know what reply to make." Here it is impossible to tell, till one has read past "resigning," whether the first "that" depends upon "so" or "statement." Write: "The statement that I am desirous of resigning surprises me so much that I scarcely know &c." That. 4 a. Be careful in the use of ambiguous words, e.g. "certain." "Certain" is often used for "some," as in "Independently of his earnings, he has a certain property," where the meaning might be "unfailing." Under this head may be mentioned the double use of words, such as "left" in the same form and sound, but different in meaning. Even where there is no obscurity, the juxtaposition of the same word twice used in two senses is inelegant, e.g. (Bain), "He turned to the left and left the room." I have known the following slovenly sentence misunderstood: "Our object is that, with the aid of practice, we may sometime arrive at the point where we think eloquence in its most praiseworthy form to lie." "To lie" has been supposed to mean "to deceive." (For "which" see 8.) The ambiguity arising from the use of he applying to different persons is well known. 5. Be careful how you use "he," "it," "they," "these," &c. "He told his friend that if he did not feel better in half an hour he thought he had better return." See (6) for remedy. Much ambiguity is also caused by excessive use of such phrases as in this way, of this sort, &c. "God, foreseeing the disorders of human nature, has given us certain passions and affections which arise from, or whose objects are, these disorders. Of this sort are fear, resentment, compassion." Repeat the noun: "Among these passions and affections are fear &c." Two distinct uses of it may be noted. It, when referring to something that precedes, may be called "retrospective;" but when to something that follows, "prospective." In "Avoid indiscriminate charity: it is a crime," "it" is retrospective.[6] In "It is a crime to give indiscriminately," "it" is prospective. The prospective "it," if productive of ambiguity, can often be omitted by using the infinitive as a subject: "To give indiscriminately is a crime." Speeches in the third person afford a particular, though very common case, of the general ambiguity mentioned in (5). Instead of "He told his friend that if he did not feel better &c.," write "He said to his friend, 'If, I (or you) don't feel better &c.'" 6. Report a speech in the First, not the Third Person, where necessary to avoid ambiguity. Thus, where Essex is asking Sir Robert Cecil that Francis Bacon may be appointed Attorney-General, the dialogue is (as it almost always is in Lord Macaulay's writings) in the First Person, except where it becomes tedious and uninteresting so as to require condensation, and then it drops into the Third Person: 6 a. Sometimes, where the writer cannot know the exact words, or where the exact words are unimportant, or lengthy and uninteresting, the Third Person is preferable. "Sir Robert had nothing to say but that he thought his own abilities equal to the place which he hoped to obtain, and that his father's long services deserved such a mark of gratitude from the Queen." —Even when a speech is reported in the third person, "that" need not always be inserted before the dependent verb. Thus, instead of "He said that he took it ill that his promises were not believed," we may write, "'He took it ill,' he said, 'that &c.'" This gives a little more life, and sometimes more clearness also. 6 b. Omission of "that" in a speech reported in the Third Person. 7. When you use a Participle, as "walking," implying "when," "while," "though," "that," make it clear by the context what is implied. "Republics, in the first instance, are never desired for their own sakes. I do not think they will finally be desired at all, unaccompanied by courtly graces and good breeding." Here there is a little doubt whether the meaning is "since they are, or, if they are, unaccompanied." —"Men walking (that walk, or when they walk) on ice sometimes fall." That or when. It is better to use "men walking" to mean "men when they walk." If the relative is meant, use "men that walk," instead of the participle. (1) "While he was } Walking on { (1) the road, } he fell." (2) "Because he was } { (2) the ice, } When the participle precedes the subject, it generally implies a cause: "Seeing this, he retired." Otherwise it generally has its proper participial meaning, e.g. "He retired, keeping his face towards us." If there is any ambiguity, write "on seeing,"—"at the same time, or while, keeping." (1) "Though he was} {(1) he nevertheless stood
} { his ground." (2) "Since he was } Struck with terror, {(2) he rapidly retreated." (3) "If he is } {(3) he will soon retreat.” 8. When using the Relative Pronoun, use "who" and "which" where the meaning is "and he, it, &c.," "for he, it, &c." In other cases use "that," if euphony allows. "I heard this from the inspector, who (and he) heard it from the guard that travelled with the train." "Fetch me (all) the books that lie on the table, and also the pamphlets, which (and these) you will find on the floor." An adherence to this rule would remove much ambiguity. Thus: "There was a public-house next door, which was a great nuisance," means "and this (i.e. the fact of its being next door) was a great nuisance;" whereas that would have meant "Next door was a public-house that (i.e. the public-house) was a great nuisance." Thus, in the first example above, "inspector" is complete in itself, and "who" introduces a new fact about him; "guard" is incomplete, and requires "that travelled with the train" to complete the meaning. "Who," "which," &c. introduce a new fact about the antecedent, whereas "that" introduces something without which the antecedent is incomplete or undefined. It is not, and cannot be, maintained that this rule, though observed in Elizabethan English, is observed by our best modern authors. (Probably a general impression that "that" cannot be used to refer to persons has assisted "who" in supplanting "that" as a relative.) But the convenience of the rule is so great that beginners in composition may with advantage adhere to the rule. The following are some of the cases where who and which are mostly used, contrary to the rule, instead of that. — Exceptions: (a) When the antecedent is defined, e.g. by a possessive case, modern English uses who instead of that. It is rare, though it would be useful,[7] to say "His English friends that had not seen him" for "the English friends, or those of his English friends, that had not seen him." (b) That sounds ill when separated from its verb and from its antecedents, and emphasized by isolation: "There are many persons that, though unscrupulous, are commonly good-tempered, and that, if not strongly incited by self-interest, are ready for the most part to think of the interest of their neighbours." Shakespeare frequently uses who after that when the relative is repeated. See "Shakespearian Grammar," par. 260. (c) If the antecedent is qualified by that, the relative must not be that. Besides other considerations, the repetition is disagreeable. Addison ridicules such language as "That remark that I made yesterday is not that that I said that I regretted that I had made." (d) That cannot be preceded by a preposition, and hence throws the preposition to the end. "This is the rule that I adhere to." This is perfectly good English, though sometimes unnecessarily avoided. But, with some prepositions, the construction is harsh and objectionable, e.g. "This is the mark that I jumped beyond," "Such were the prejudices that he rose above." The reason is that some of these disyllabic prepositions are used as adverbs, and, when separated from their nouns, give one the impression that they are used as adverbs. (e) After pronominal adjectives used for personal pronouns, modern English prefers who. "There are many, others, several, those, who can testify &c." (f) After that used as a conjunction there is sometimes a dislike to use that as a relative. See (c). 9. Do not use redundant "and" before "which."[8] "I gave him a very interesting book for a present, and which cost me five shillings." In short sentences the absurdity is evident, but in long sentences it is less evident, and very common. "A petition was presented for rescinding that portion of the bye-laws which permits application of public money to support sectarian schools over which ratepayers have no control, this being a violation of the principle of civil and religious liberty, and which the memorialists believe would provoke a determined and conscientious resistance." Here which ought grammatically to refer to "portion" or "schools." But it seems intended to refer to "violation." Omit "and," or repeat "a violation" before "which," or turn the sentence otherwise. 10. Equivalents for Relative. —"Men thirsting (for 'men that thirst') for revenge are not indifferent to plunder." The objection to the participle is that here, as often, it creates a little ambiguity. The above sentence may mean, "men, when they thirst," or "though they thirst," as well as "men that thirst." Often however there is no ambiguity: "I have documents proving this conclusively." (a) Participle. —Instead of "He was the first that entered" you can write "to enter;" for "He is not a man who will act dishonestly," "to act." This equivalent cannot often be used. (b) Infinitive. can sometimes be used for "by which," "in which," so as to avoid a harsh repetition of "which." "The means whereby this may be effected." But this use is somewhat antiquated. (c) Whereby, wherein, &c., —"The man that does not care for music is to be pitied" can be written (though not so forcibly), "If a man does not care for music, he is to be pitied." It is in long sentences that this equivalent will be found most useful. (d) If. —"He did his best, which was all that could be expected," can be written, "and this was all that, &c." (e) And this. —"Let me repeat that which[9] you ought to know, that that which is worth doing is worth doing well." "Let me repeat, what you ought to know, that what is worth doing is worth doing well." (f) What. —It is sometimes thought ungrammatical to omit the relative, as in "The man (that) you speak of." On the contrary, that when an object (not when a subject) may be omitted, wherever the antecedent and the subject of the relative sentence are brought into juxtaposition by the omission. (g) Omission of Relative. This is particularly useful after a negative: "He said that he would not even hear me, which I confess I had expected." Here the meaning may be, "I had expected that he would," or "that he would not, hear me." Write, "a refusal, or, a favour, that I confess I had expected." See (38). 10 a'. Repeat the Antecedent in some new form, where there is any ambiguity. —This is a most important rule. Instead of "I have neither the necessaries of life nor the means of procuring them," write (if you can with truth), "I have not a crust of bread, nor a penny to buy one." 11. Use particular for general terms. CAUTION.—There is a danger in this use. The meaning is vividly expressed but sometimes may be exaggerated or imperfect. Crust of bread may be an exaggeration; on the other hand, if the speaker is destitute not only of bread, but also of shelter and clothing, then crust of bread is an imperfect expression of the meaning. In philosophy and science, where the language ought very often to be inclusive and brief, general and not particular terms must be used. The disadvantage of the use of Verbal Nouns is this, that, unless they are immediately preceded by prepositions, they are sometimes liable to be confounded with participles. The following is an instance of an excessive use of Verbal Nouns: 11 a. Avoid Verbal Nouns where Verbs can be used instead. "The pretended confession of the secretary was only collusion to lay the jealousies of the king's favouring popery, which still hung upon him, notwithstanding his writing on the Revelation, and affecting to enter on all occasions into controversy, asserting in particular that the Pope was Antichrist." Write "notwithstanding that he wrote and affected &c." 12. Use a particular Person instead of a class. "What is the splendour of the greatest monarch compared with the beauty of a flower?" "What is the splendour of Solomon compared with the beauty of a daisy?" Under this head may come the forcible use of Noun for Adjective: "This fortress is weakness itself." An excess of this use is lengthy and pedantically bombastic, e.g., the following paraphrase for "in every British colony:"—"under Indian palm-groves, amid Australian gum-trees, in the shadow of African mimosas, and beneath Canadian pines." 13. Use Metaphor instead of literal statement. "The ship ploughs the sea" is clearer than "the ship cleaves the sea," and shorter than "the ship cleaves the sea as a plough cleaves the land." Of course there are some subjects for which Metaphor should not be used. See (14 a) and (14 b). 14. Do not confuse Metaphor. "In a moment the thunderbolt was upon them, deluging their country with invaders." The following is attributed to Sir Boyle Roche: "Mr. Speaker, I smell a rat, I see him brewing in the air; but, mark me, I shall yet nip him in the bud." Some words, once metaphorical, have ceased to be so regarded. Hence many good writers say "under these circumstances" instead of "in these circumstances." An excessive regard for disused metaphor savours of pedantry: disregard is inelegant. Write, not, "unparalleled complications," but "unprecedented complications;" and "he threw light on obscurities," instead of "he unravelled obscurities." 14 a. Do not introduce literal statement immediately after Metaphor. "He was the father of Chemistry, and brother to the Earl of Cork." "He was a very thunderbolt of war,
And was lieutenant to the Earl of Mar." Thus, we may say "a poet soars," or even, though rarely, "a nation soars to greatness," but you could not say "Consols soared to 94-1/2." Even commonplace subjects may be illustrated by metaphor: for it is a metaphor, and quite unobjectionable, to say "Consols mounted, or jumped to 94-1/2." But commonplace subjects must be illustrated by metaphor that is commonplace. 14 b. Do not use poetic metaphor to illustrate a prosaic subject. About HackerNoon Book Series: We bring you the most important technical, scientific, and insightful public domain books. This book is part of the public domain. Edwin Abbott Abbott (2007). How to Write Clearly: Rules and Exercises on English Composition. Urbana, Illinois: Project Gutenberg. Retrieved https://www.gutenberg.org/cache/epub/22600/pg22600.html This eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at , located at . www.gutenberg.org https://www.gutenberg.org/policy/license.html

Use words in their proper sense

Scientific American, Vol. XXXVII.—No. 2. [New Series.], July 14, 1877 by Various, is part of the HackerNoon Books Series. You can jump to any chapter in this book . SETTING LOCOMOTIVE SLIDE VALVES. here SETTING LOCOMOTIVE SLIDE VALVES. BY JOSHUA ROSE. E. G. asks: "How can I set the slide valves of a locomotive when she is on the road?" J. H. S. asks: "What is the method of setting locomotive slide valves from marks on the slide spindle?" And F. O. asks: "How are the valves of inside cylinder locomotives set, since the back ports are out of sight and you cannot measure the lead?" Our correspondent will find these questions answered in full below. It is presumed that the lengths of the eccentric rod, reverse rod, and other parts are correct, and they are properly connected and oiled so as to be in working order. The first thing to do is to place the reverse lever in the forward full-gear notch of the quadrants, or sectors, as they are sometimes called. The next procedure is to place the crank on its forward dead center as near as can be ascertained by the eye, and loosening the set screw of the forward eccentric, that is to say, the eccentric which connects with the upper end of the link, move that eccentric round on the shaft until the valve leaves the port at the front end of the cylinder open to the amount of whatever lead it is desired to give the valve. In moving the eccentric round on the shaft, it is necessary to move it in the direction in which it will turn when in operation. This is done in order to take up any lost motion there may be in the eccentric straps, in the eccentric rod eyebolts, or other working parts or joints between the eccentric and the slide valve rod or spindle. If the eccentric was turned backward instead of forward, all the lost motion would operate to vitiate the set of the valve, because, when the eccentric begins to move, its motion will have no effect in moving the slide valve spindle, until all the lost motion in the various parts is taken up by the eccentric movement. In considering this part of the operation, we must bear in mind that, to set the valve, we must move the wheels of the engine, it being impracticable to move the piston itself. Now, in moving the wheels, we are confronted with the fact that the crank pin is pulling the connecting rod; hence, if there is any lost motion in the brasses at either end of the connecting rod, the piston will not be at the end of its stroke when the crank is on its dead center. Suppose, for instance, that we have moved the driving wheel forward until the crank stands upright at a right angle to the bore of the cylinder, the resistance to motion of the piston and crosshead has caused the crank pin to bed against the half-brass nearest to the cylinder, all the play or lost motion is then between the other half-brass and the crank pin. When, however, the engine is at work and the piston is driving the crank pin, instead of being driven by it, the lost motion will exist between the crank pin and the half-brass nearest to the cylinder, and the contact will exist between the crank pin and the other brass. The difference in the position of the piston, caused by this lost motion, may be ascertained by moving the piston back and forth until the crank pin contacts with first one and then the other half-brass. It is sometimes attempted to remedy the defect due to this lost motion by moving the crank pin past the dead center and then moving it back to the dead center, so that while on that center the play or lost motion in the connecting rod is taken up. This is all very well so far as the connecting rod and piston is concerned, and will cause them both to stand on their respective dead centers with the lost motion taken up; but, in moving the wheel back to the dead center, we have given full liberty to all the lost motion in the various parts of the valve motion or gear, as already explained, in reference to moving the eccentric upon the shaft. As there are so many more parts in the valve gear, in which lost motion may occur, it is manifestly preferable to take up that play by moving the driving wheel in a continuous direction, rather than to move the latter back to accommodate any play there may be in the connecting rod. The crank being placed by the eye upon its forward dead center, and the eccentric connected to the top of the link being moved round on the axle (in the direction in which the wheels will run when the engine is going forward) until the steam port at the front end of the cylinder is open to the amount of the lead, we fasten the eccentric to hold in that position. We then throw the reverse lever over into the last notch at the other end of the sector, lifting the link up so that the eccentric connected to the lower end of the link may be approximately adjusted, which is done by moving the eccentric round upon the axle (in the direction in which the axle will revolve when the engine is running backward) until the crank stands upon the same dead center, and the front port is open to the amount of the lead. This being done, we have the eccentrics approximately adjusted and may proceed to the final adjustment, in which the first thing to do is to find the exact dead centers of the crank. It is obvious that a line drawn through the center of the crank pin and the center of the wheel axle, will stand horizontally true and level when the crank is on either of the dead centers, but the presence of the crank pin makes it impracticable to draw such a line. We can therefore draw one which will be parallel to those centers; and to do this we draw a circle upon the end of the wheel axle (and from its center) of the same diameter as that of the crank pin, and then resting a straight-edge upon the bearing of the crank pin (taking care to avoid the round corner upon the pin, if there is one), we place the other end of the straight-edge even with the top of the circle drawn upon the axle; and then, using the straight-edge as a guide, we draw a line across the end of the axle and the wheel face. When this line is level the crank will be upon its dead center. This plan is sometimes employed, but is not a very accurate one, because the length of the line is very short as compared to the circumference of the driving wheel; hence, an error of the thickness of the line becomes one equal to several thicknesses of the line when carried out to the wheel circumference. Furthermore, if the line of the cylinder does not stand horizontally level, as is sometimes the case, the result of the whole proceeding will be inaccurate. Again, the connecting rod end and the coupling rod is in the way, rendering it awkward to both draw and level the line. A better and more accurate method to find the dead centers is as follows: Place the reverse lever into the end notch of the sector at the forward end, and then move the driving wheel forward until the guide block is within about a quarter of an inch of the end of its travel, then place a straight-edge against the end of the guide block, and draw, on the outside face of the guide bar, a line even with the end of the guide block. Bend a piece of wire (pointed at both ends) to a right angle, make a center punch mark either in the rail, under the driving wheel, or in some stationary, solid part contiguous to the wheel, or at such distance from it that when one end of the bent wire is placed in the center punch mark, the operator with the other end will be able to draw a line across the rim of the driving wheel. Here, however, arises another consideration, that it is better to set the valves with the wheel axle in its proper position in the pedestal shoes, and in order to do this the wheel should rest upon the rail with its proper proportion of the weight of the engine resting upon it. The springs will then be deflected to their proper amount, and the axle box will have passed its proper distance up the pedestals. It is obvious that if the engine is blocked up so that the driving wheels clear the rails (which is done in order to avoid having the weight of the engine to move while setting the valve), the axle boxes will drop in the pedestal and the valve will be set incorrectly, as the wheels are in a wrong position. To avoid this, and at the same time to avoid having to move the whole engine while setting the valve, the engine is blocked up from the rails, and the axle boxes of the driving wheels are wedged up so as to be lifted up into their proper position. In this case there is no very accurate means of ascertaining what is the exact proper height, save it be by first marking upon the outside faces of the shoes or pedestal a line even with the top of the axle box when the load is upon the wheels, and then, after blocking up the engine from the rails, wedging up the axle boxes till the face again comes even with the line. Whatever plan is pursued, one end of the piece of wire is rested in the fixed center punch mark, and with the other a line is drawn across the outside face of the wheel rim. The driving wheel is then revolved forward until the guide block returns, having passed to the end of its travel. When its end again stands exactly even with the mark made upon the guide bar, the piece of wire is again brought into requisition, one end being rested in the fixed center punch mark as before, and with the other end another line is drawn across the outside rim of the wheel. It is obvious that by taking a pair of compasses and finding a point exactly equidistant between the two lines thus marked upon the wheel rim, and then marking that point with a center punch mark, the crank will be upon its exact dead center, when one end of the piece of bent wire rests in the fixed center punch mark, the other end rests in the center punch mark upon the wheel rim. To find the other dead center, the wheel must be moved about halfway round and the process repeated with the motion block at the other end of the guide bars. Thus, whenever the piece of wire will stand with one end resting in the fixed center punch mark and the other end in either of the center punch marks upon the wheel run, the crank is upon a dead center. Having thus placed the crank upon either dead center, we measure the valve lead, and if in temporarily fixing our eccentrics we gave it too much lead, we mark where it stands upon the shaft by means of a line drawn on the axle and carried up on the side face of the eccentric; then move the eccentric back some little distance more than is necessary to make the adjustment, and then move it forward again a little at a time, noting when the valve has the proper amount of lead, and thus fasten the eccentric upon the axle by means of the set screw. The object of moving the eccentric too far back and then moving it forward is to make the adjustment so that the latter may be made with the lost motion of the valve gear all taken up. The next proceeding is to move the driving wheel halfway round and try the lead at that end of the stroke. If the lead at the two ends is not equal, it shows that either the slide valve spindle or the eccentric rods are not of the proper length and must be rectified; this being done, the crank must be again placed upon first one and then the other dead center, the valve lead being measured at each end. When the lead is equal at each end, the rods are of correct length, and the amount of the lead must be regulated by moving the eccentrics as already directed. If the link block does not come opposite the end of the eccentric rod when the reverse lever is in the end notch of the sector, the length of the reverse rod is wrong and should be corrected. If the link block comes right, under the above conditions, for the forward but not for the backward eccentric rod, the notches in the sector are not cut in their proper positions, or the link hanger is not of the proper length. In either case the error may be remedied by altering the length of the latter. But, as doing this would alter the amount of the valve lead, it is well, if there is any prospect of such errors, to correct them before setting the valves. Instead of measuring the lead of the valve with a rule, or by a wedge, the following plan is very often adopted: After the valve and spindle are in position, the valve is placed with the proper amount of lead upon the front port. A center punch mark is then made upon the face of the steam chest. A piece of quarter inch iron wire is then bent at right angles and each end filed to a point. One end of this wire is placed in the fixed center punch mark in the steam chest, and with the other a mark is made upon the slide spindle. Upon this latter mark a center punch mark is also made sufficiently deep to be very plainly visible when the burr raised by center punching is filed off, which is necessary to prevent this burr from cutting the packing. It follows that whenever the bent piece of wire will rest with one end in the center punch mark in the steam chest, and the other end in the center punch mark in the slide spindle, the valve is in its proper position when the crank is on the corresponding dead center. This plan is a very old one and possesses the advantage that the valve may be set without seeing it, that is to say, with the steam chest cover on. If the length of the piece of wire measured direct from point to point is known, the valve may be set when the engine is upon the road without taking off the steam chest cover. The center punch mark upon the steam chest should, however, always be placed in about the same spot, so as to avoid mistakes in case of there being other similar marks upon the chest. It should always be made deep, so as not to get filled up with paint and be difficult to find. In course of time the mark upon the slide valve spindle is apt to disappear from the wear of the spindle, hence the center punch with which it is made should have a long conical point. To mark the position of the eccentric upon the axle, it is an excellent plan, after the eccentrics are finally adjusted, to take a chisel with the cutting end ground to the form of a fiddle drill, one cutting edge being at a right angle to the other. The chisel must be held so that while one edge rests upon the axle, the other edge will bear against the radial face of the eccentric. A sharp blow with a hammer upon the chisel-head will make a clean indented cut upon the axle and the eccentric, the two cuts exactly meeting at their junction and denoting the position of the eccentrics. In setting the valves of inside cylinder locomotives, the back ports being out of sight, the amount of lead is ascertained by making a wooden wedge about three inches long, a thirty-second of an inch thick at one end and three eighths of an inch thick at the other end. The faces of this wedge are chalked, and the lead is measured by inserting it between the edge of the valve and the edge of the port until its thickness just fills the space, and then moving it edgeways so that the valve and port edges will just mark it. By measuring the thickness of the wedge at the mark, the amount of lead is ascertained. After the valves are set, it is still desirable to mark the position by center punch marks upon the outside of the steam chests and upon the valve spindles, as already described. If an eccentric should slip when the engine is upon the road, and there are no marks whereby to readjust them, it may be done approximately as follows: Put the reverse lever in the end notch of the forward gear, then place the crank as nearly on a dead center as the eye will direct, and open both the cylinder cocks, then disconnect the slide valve spindle from the rocker arm, and move the valve spindle until the opening of the port corresponding to the dead center on which the crank stands will be shown by steam blowing through the cylinder cock, the throttle valve being opened a trifle. The position of the valve being thus determined, the eccentric must be moved upon the shaft until the valve spindle will connect with the rocker arm without being moved at all. The throttle valve should be very slightly opened, otherwise so much steam will be admitted into the cylinder that it will pass through any leak in the piston and blow through both cylinder cocks before there is time to ascertain which cock gives first exit to the steam. About HackerNoon Book Series: We bring you the most important technical, scientific, and insightful public domain books. This book is part of the public domain. Various (2012). Scientific American, Vol. XXXVII. —No. 2. [New Series.], July 14, 1877. Urbana, Illinois: Project Gutenberg. Retrieved https://www.gutenberg.org/cache/epub/38481/pg38481-images.html This eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at , located at . www.gutenberg.org https://www.gutenberg.org/policy/license.html

SETTING LOCOMOTIVE SLIDE VALVES

How to Write Clearly: Rules and Exercises on English Composition by Edwin Abbott Abbott, is part of the HackerNoon Books Series. You can jump to any chapter in this book . WORDS. here WORDS. Use words in their proper sense. Avoid exaggerations. Avoid useless circumlocution and "fine writing." Be careful in the use of "not … and," "any," "but," "only," "not … or," "that." 4 a. Be careful in the use of ambiguous words, e.g. "certain." Be careful in the use of "he," "it," "they," "these," &c. Report a speech in the First Person, where necessary to avoid ambiguity. 6 a. Use the Third Person where the exact words of the speaker are not intended to be given. 6 b. Omission of "that" in a speech in the Third Person. When you use a Participle implying "when," "while," "though," or "that," show clearly by the context what is implied. When using the Relative Pronoun, use "who" or "which," if the meaning is "and he" or "and it," "for he" or "for it." In other cases use "that," if euphony allows. Exceptions. Do not use "and which" for "which." Equivalents for the Relative: (a) Participle or Adjective; (b) Infinitive; (c) "Whereby," "whereto," &c.; (d) "If a man;" (e) "And he," "and this," &c.; (f) "what;" (g) omission of Relative. 10 a'. Repeat the Antecedent before the Relative, where the non-repetition causes any ambiguity. See 38. Use particular for general terms. Avoid abstract Nouns. 11 a. Avoid Verbal Nouns where Verbs can be used. Use particular persons instead of a class. Use metaphor instead of literal statement. Do not confuse metaphor. 14 a. Do not mix metaphor with literal statement. 14 b. Do not use poetic metaphor to illustrate a prosaic subject. About HackerNoon Book Series: We bring you the most important technical, scientific, and insightful public domain books. This book is part of the public domain. Edwin Abbott Abbott (2007). How to Write Clearly: Rules and Exercises on English Composition. Urbana, Illinois: Project Gutenberg. Retrieved https://www.gutenberg.org/cache/epub/22600/pg22600.html This eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at , located at . www.gutenberg.org https://www.gutenberg.org/policy/license.html

WORDS

found that human behavior was 93% predictable. This figure is quite incredible when you think about it, and the director of the study said at the time that spontaneous people were mostly absent from the population: A 2010 Northeastern University College of Science study “Spontaneous individuals are largely absent from the population. Despite the significant differences in travel patterns, we found that most people are equally predictable.” The director of the study refers to travel patterns here because the study focused on the mobility patterns of anonymous users. While the common perception is that our actions are random and unpredictable, this study established the opposite. This predictability of human behavior can be exploited in many other domains. It can be exploited in a field that will be of great interest to you: the prediction of asset movements in financial markets. When we carefully study the way an asset's price evolves, we realize that certain patterns frequently recur and, more interestingly, that the way the asset's price evolves afterward is identical to what happened previously. This is where Mark Twain's famous quote comes into play: “History doesn't repeat itself, but it often rhymes.” By thoroughly analyzing an asset's price movement, you can bring out these chart patterns that will allow you to make better decisions on what to do next. While some fundamental investors are very critical of trading patterns as being nothing more or less than astrology, this is wrong in my opinion. If the charts of an asset's evolution are not magical in themselves, the way the human mind will interpret and react to these charts can be predicted in a more refined way. This is where the study of human behavior I mentioned in the preamble comes into its own. It is the psychology of human beings that plays a major role in determining how markets will evolve. Since human behavior is mostly the same, you can define more or less precise strategies after having identified certain chart patterns. In the following, I will present you with the most common chart patterns that you need to know to better anticipate future developments in the price of Bitcoin. Note that this also applies to Altcoins if that's what you're interested in. Finally, be aware that these patterns become more effective the larger the number of participants in a market. What applies to Bitcoin will not be as accurate on an Altcoin with very few participants. The support and resistance lines are the fundamental notions to know before going further Before going any further, I would like to define some fundamental notions that will be used later. A Bullish move means a potential uptrend for the price of an asset. A Bearish move means a potential downward trend in the price of an asset. Once you have determined these patterns, you can better position yourself to trade the asset in question. In addition, to identify these patterns, you need to do a technical analysis of the price of an asset by drawing support lines and resistance lines. A support line is a line where the price of an asset stops falling. Resistance is a line where the price of an asset stops rising. Finally, you need to look at trading volume before confirming how accurate the chart pattern you identify is. For example, a strong upward movement that is not supported by a proportional increase in trading volume means that the asset in question may not be able to sustain this upward trajectory. Ascending Triangle An ascending triangle is a bullish continuation chart pattern that means a breakout is likely where the triangle lines converge. To draw this pattern, you would place a horizontal resistance line on several resistance points, then draw an ascending line along with the support points: The upside projection after the breakout is the same as the size of the triangle you may have drawn. You can place a stop-loss order below the breakout level. Descending Triangle Unlike an ascending triangle, the descending triangle represents a bearish market downtrend. The support line is horizontal, and the resistance line is descending, signifying the possibility of a downward breakout: The downward projection after the breakout is identical to the size of the triangle you may have drawn. Symmetrical Triangle For a symmetrical triangle, two trend lines start to meet which means a breakout is coming up or down. The support line is drawn with a bullish trend and the resistance line is drawn with a bearish trend. Although the breakout can go either way, the price generally follows the general market trend: Pennant Pennants are represented by two lines that meet a set of points. They are often formed after strong upward or downward movements as traders pause and the price begins to consolidate before the trend continues in the same direction: Flag The flag chart pattern forms a sloping rectangle, where the support and resistance lines progress in parallel until there is a breakout. The breakout is usually in the opposite direction of the trend lines, which means that it is a reversal pattern: Wedge A wedge pattern represents a tightening movement as the price moves between support and resistance lines. It can be a Rising Wedge or a Falling Wedge. Unlike the triangle, the wedge has no horizontal trend line and is characterized by either two uptrend lines or two downtrend lines. For a Falling Wedge, it is generally anticipated that the price will break through resistance to rise: For a Rising Wedge, the expectation is that support will be broken, which will cause the price of the asset to fall. This means the wedge is a reversal pattern as the breakout is opposite to the general trend. Double Bottom A Double Bottom is similar to the letter W and indicates when the price has failed twice to break the support level. This is a reversal chart pattern and it indicates a trend reversal. After unsuccessfully breaking through the support twice, the market price shifts towards an uptrend: Double Top In contrast to the Double Bottom, the Double Top looks more like the letter M. The trend enters a reversal phase after failing to break through the resistance twice. The trend then follows back to the support threshold and starts a downward trend breaking through the support line: Head and Shoulders The Head and Shoulders pattern tries to predict a market reversal from Bull to Bear. This pattern is characterized by a large peak with two similar peaks on both sides. Both three levels fall on the same support line. This pattern is likely to give a downward breakout: On the other hand, you have the Inverted Head and Shoulder pattern which is a Bullish signal and indicates a reversal from Bear to Bull. Rounding Top or Bottom A Rounding Bottom, also called a cup, usually indicates a bullish upward trend, while a Rounding Top indicates a bearish downward trend: Some traders are taking advantage of the middle of the U-shape forming a Rounding Bottom to buy, capitalizing on the upcoming break on resistance levels. Cup and Handle The Cup and Handle pattern is a well-known continuation pattern that signals an uptrend in the market. It is the same pattern as the rounding bottom above, but it has a handle after the rounding bottom. The handle looks like a flag or pennant, and once it is complete, you can see the market break out into an upward trend: Final Thoughts The 11 chart patterns that I have just revealed are the ones that come up most often. The fact that all traders know and use them increases the probability that the outcome will be the one expected. A sort of self-prophecy occurs, as everyone expects a certain outcome when the chart pattern appears. With time and practice, you will be able to spot these different chart patterns. This will allow you to better anticipate the evolution of the Bitcoin price. You will be able to make your own decisions based on your technical analysis rather than listening to others point out these patterns. I don't trade Bitcoin, because I am a HODLer. But I like to study these chart patterns for my readers. It's also exciting to see how market psychology can predict certain short-term price movements of an asset. Of course, you can also use these chart patterns on the stock market. That's where they were first highlighted. Also published . here

Anticipate Bullish or Bearish Movements in Bitcoin's Price With These 11 Chart Patterns

Scientific American, Vol. XXXIX. No. 6. [New Series.], August 10, 1878, by Various, is part of the HackerNoon Books Series. You can jump to any chapter in this book . NEW STEAM VALVE. here NEW STEAM VALVE. The improved valve shown partly in section in the engraving is designed for removing the water of condensation from steam pipes, so that dry steam may be furnished. In the engraving, the globe valve, A, is of the usual form, except that the casing below the valve seat is enlarged, forming a pocket, B, which communicates through an aperture at the bottom with a small valve, C. The steam, in passing through the valve, fills the pocket and there deposits any water that may have condensed from the steam in its passage through the steam pipe. The increased depth of the lower portion of the valve prevents siphoning, which takes place in valves of the ordinary form. The valve, C, is kept slightly open to discharge the water at the moment it collects in the pocket; the water is thus prevented from passing onward to the engine or other point of use. This valve affords a ready means of supplying dry steam to sulphuric acid chambers. We are informed that by its use a chamber in ordinary working order will produce acid 3° to 5° Baumé stronger than can be obtained with ordinary globe valves. Thirty steam pipes, arranged at different points, are found to deliver into a chamber in the space of five minutes from 4 to 16 ounces of condense water (according to the circumstances of distance, temperature of the air, size of pipe, etc.). These valves, being placed close to the chamber separating all the condense water, deliver with certainty uniformly dry steam, without the inconvenience of ordinary steam traps or other expensive appliances. This valve was patented through the Scientific American Patent Agency, May 21, 1878. For further particulars address Mr. Joseph Saunders, 975 Third avenue, Brooklyn, N. Y. A Hint from the Mormons. Ex-Governor Hendricks, in a recent industrial address, alluded to the highly prosperous condition of the Mormons as existing previous to the influx of the Gentiles into Utah, saying that "to the fact that they produced all they consumed I attribute their wonderful prosperity." This remark, associated with the prosperity of other communities in different parts of the country, would suggest the query of "Why the principle cannot be more largely applied to the whole nation?" Certainly the resources of the whole country would indicate a much greater diversity of production, and if there was the same regard for a uniform building up of our industrial system there would seem to be need of but little importation, certainly of goods which can be readily made, and which our people need the labor to produce. New Agricultural Inventions. Joseph George, of Springfield, Greene Co., Mo., has patented an improved form of Cultivator or Shovel Plow, designed to be convertible into either a single, double, or triple shovel plow as occasion may require. It consists in two detachable clamping plates, which hold the plow beams, and their arrangement with respect to the said beams and the handles of the plow, whereby a single bolt is made to secure the forward ends of the handles and clamp the plates to hold the plow beams in place. Russel O. Bean, of Macedonia, Miss., is the inventor of an improved Seed Planter for planting cotton and other seeds, and for distributing fertilizers. The details of the construction of this planter cannot be explained without engravings. Rutus Sarlls and Alexander Kelman, of Navasota, Texas, have invented an improved combined Planter, Cultivator, and Cotton Chopper, which may be readily adjusted for use in planting seed, cultivating plants, and chopping cotton to a stand, and is effective and reliable in operation in either capacity. William H. Akens, of Penn Line, Pa., is the inventor of an improved Dropper, for attachment to the finger bar of a reaper, to receive the grain and deliver it in gavels at the side of the machine, so as to be out of the way when making the next round. It is so constructed that when attached to the finger bar of a mower it will convert it into a harvester. James Goodheart, of Matawan, N. J., has devised an improved machine for Distributing Poison upon potato plants to destroy the potato bug. It may also be used for sowing seeds. William V. McConnell and Charles M. Dickerson, of Crockett, Texas, have invented an improved Fruit Picker, having cup-shaped self-opening spring jaws attached to its handle, and operated by a cord to close upon and clamp the fruit. It also has a hollow extensible adjustable handle and a fruit receiver. Quick Work. Two years ago a farmer-miller and his wife, at Carrolton, Mo., furnished some invited guests with bread baked in eight and a quarter minutes from the time the wheat was standing in the field. This year it was determined to make still better time. Accordingly elaborate preparations were made to reap, thrash, grind, and bake the grain with the least possible loss of time. In 1 minute 15 seconds the wheat, about a peck, was cut and thrashed, and put on the back of a swift horse to be carried to the mill, 16 rods away. In 2 minutes 17 seconds the flour was delivered to Mrs. Lawton, and in 3m. 55s. from the starting of the reaper the first griddle cake was done. In 4 minutes 37 seconds from the starting of the reaper, a pan of biscuits was delivered to the assembled guests. After that, according to the Carrolton , other pans of delicious "one minute" biscuits were baked more at leisure, and eagerly devoured, with the usual accompaniment of boiled ham and speech making. Democrat About HackerNoon Book Series: We bring you the most important technical, scientific, and insightful public domain books. This book is part of the public domain. Various (2013). Scientific American, Vol. XXXIX. No. 6. [New Series.], August 10, 1878. Urbana, Illinois: Project Gutenberg. Retrieved https://www.gutenberg.org/cache/epub/19406/pg19406-images.html This eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at , located at www.gutenberg.org https://www.gutenberg.org/policy/license.html

NEW STEAM VALVE

THE PRODUCTION OF AMMONIA FROM COAL

ATOMS, MOLECULES, AND ETHER WAVES

This paper is available on arxiv under CC 4.0 license. Authors: (1) Ruta Jawale; (2) Dakshita Khurana. Table of Links Abstract and Introduction Technical Overview Preliminaries Unclonable Non-Interactive Zero-Knowledge in the CRS Model Unclonable NIZK in the Quantum Ramdon Oracle Model Unclonable Signatures of Knowledge References Abstract A non-interactive ZK (NIZK) proof enables verification of NP statements without revealing secrets about them. However, an adversary that obtains a NIZK proof may be able to clone this proof and distribute arbitrarily many copies of it to various entities: this is inevitable for any proof that takes the form of a classical string. In this paper, we ask whether it is possible to rely on quantum information in order to build NIZK proof systems that are impossible to clone. We define and construct unclonable non-interactive zero-knowledge proofs (of knowledge) for NP. Besides satisfying the zero-knowledge and proof of knowledge properties, these proofs additionally satisfy unclonability. Very roughly, this ensures that no adversary can split an honestly generated proof of membership of an instance x in an NP language L and distribute copies to multiple entities that all obtain accepting proofs of membership of x in L. Our result has applications to unclonable signatures of knowledge, which we define and construct in this work; these non-interactively prevent replay attacks. 1 Introduction Zero-knowledge (ZK) [GMR89] proofs allow a prover to convince a verifier about the truth of an (NP) statement, without revealing secrets about it. These are among the most widely used cryptographic primitives, with a rich history of study. . ZK proofs for NP are typically defined via the simulation paradigm. A simulator is a polynomial-time algorithm that mimics the interaction of an adversarial verifier with an honest prover, given only the statement, i.e., x ∈ L, for an instance x of an NP language L. A protocol satisfies zero-knowledge if it admits a simulator that generates a view for the verifier, which is indistinguishable from the real view generated by an honest prover. This captures the intuition that any information obtained by a verifier upon observing an honestly generated proof, could have been generated by the verifier “on its own” by running the simulator. Enhancing Zero-knowledge Despite being widely useful and popular, there are desirable properties of proof systems that (standard) simulation-based security does not capture. For example, consider (distributions over) instances x of an NP language L where it is hard to find an NP witness w corresponding to a given instance x. In an “ideal” world, given just the description of one such NP statement x ∈ L, it is difficult for an adversary to find an NP witness w, and therefore to output any proofs of membership of x ∈ L. And yet, upon obtaining a single proof of membership of x ∈ L, it may suddenly become feasible for an adversary to make many copies of this proof, thereby generating several correct proofs of membership of x ∈ L. Unfortunately, this attack is inevitable for classical non-interactive proofs: given any proof string, an adversary can always make multiple copies of it. And yet, there is hope to prevent such an attack quantumly, by relying on the no-cloning principle. Indeed, a recent series of exciting works have combined cryptography with the no-cloning principle to develop quantum money [Wie83, AC13, FGH+12, Zha19a, Kan18], quantum tokens for digital signatures [BS16], quantum copy-protection [Aar09, AP21, ALL+21, CLLZ21], unclonable encryption [Got03, BL20, AK21, MST21, AKL+22], unclonable decryption [GZ20], one-outof-many unclonable security [KN23], and more. In this work, we combine zero-knowledge and unclonability to address a question first posed by Aaronson [Aar09]: Can we construct unclonable quantum proofs? How do these proofs relate to quantum money or copy-protection? 1.1 Our Results We define and construct unclonable non-interactive zero-knowledge proofs of knowledge (NIZKPoK). We obtain a construction in the common reference string (CRS) model, as well as one in the quantum(-accessible) random oracle model (QROM). The CRS model allows a trusted third-party to set up a structured string that is provided to both the prover and verifier. On the other hand, the QROM allows both parties quantum access to a truly random function O. In what follows, we describe our contributions in more detail. 1.1.1 Definitional Contributions Before discussing how we formalize the concept of unclonability for NIZKs, it will be helpful to define hard distributions over NP instance-witness pairs. . Informally, an efficiently samplable distribution over instance-witness pairs of a language L is a “hard” distribution if given an instance sampled randomly from this distribution, it is hard to find a witness. Then, unclonable security requires that no adversary given an instance x sampled randomly from the distribution, together with an honestly generated proof, can output two accepting proofs of membership of x ∈ L. Hard Distributions over Instance-Witness Pairs More specifically, a hard distribution (X ,W) over RL satisfies the following: for any polynomialsized (quantum) circuit family {Cλ}λ∈N, For the sake of simplifying our subsequent discussions and definitions, let us fix a NP language L with corresponding relation R. Let (X ,W) be some hard distribution over R. For NIZKs satisfying standard completeness, soundness and ZK, we define a simple, natural variant of unclonable security as follows. Informally, a proof system satisfies unclonable security if, given an honest proof for an instance and witness pair (x, w) sampled from a hard distribution (X ,W), no adversary can produce two proofs that verify with respect to x except with negligible probability. A Weaker Definition: Unclonable Security. (Unclonable Security of NIZK). A NIZK proof (Setup, Prove,Verify) satisfies unclonable security if for every language L and every hard distribution (X ,W) over RL, for every poly-sized circuit family {Cλ}λ∈N, Definition 1.1. In the definition above, we aim to capture the intuition that one of the two proofs output by the adversary can be the honest proof they received, but the adversary cannot output any other correct proof for the same statement. Of course, such a proof is easy to generate if the adversary is able to find the witness w for x, which is exactly why we require hardness of the distribution (X ,W) to make the definition non-trivial. We also remark that unclonable security of proofs necessitates that the proof π keep hidden any witnesses w certifying membership of x in L, as otherwise an adversary can always clone the proof π by generating (from scratch) another proof for x given the witness w. A Stronger Definition: Unclonable Extractability. We can further strengthen the definition above to require that any adversary generating two (or more) accepting proofs of membership of x ∈ L given a single proof, must have generated one of the two proofs “from scratch” and must therefore “know” a valid witness w for x. This will remove the need to refer to hard languages. In more detail, we will say that a proof system satisfies unclonable extractability if, from any adversary A that on input a single proof of membership of x ∈ L outputs two proofs for x, then we can extract a valid witness w from A for at least one of these statements with high probability. Our (still, simplified) definition of unclonable extractability is as follows. (Unclonable Extractability.). A proof (Setup, Prove,Verify) satisfies unclonable security there exists a QPT extractor E which is an oracle-aided circuit such that for every language L with corresponding relation RL and for every non-uniform polynomial-time quantum adversary A, for every instance-witness pair (x, w) ∈ RL and λ = λ(|x|), such that there is a polynomial p(·) satisfying: Definition 1.2 there is also a polynomial q(·) such that In fact, in the technical sections, we further generalize this definition to consider a setting where the adversary obtains an even larger number (say k−1) input proofs on instances x1, . . . , xk−1, and outputs k or more proofs. Then we require the extraction of an NP witness corresponding to any proofs that attempt to “clone” honestly generated proofs (i.e. the adversary outputs two or more proofs w.r.t. the same instance xi ∈ {x1, . . . , xk−1}). All our theorem statements hold w.r.t. this general definition. Finally, we also consider definitions and constructions in the quantum-accessible random oracle model (QROM); these are natural generalizations of the definitions above, so we do not discuss them here. We also show that the latter definition of unclonable extractability implies the former, i.e. unclonable security. Informally, this follows because the extractor guaranteed by the definition of extractability is able to obtain a witness w for x from any adversary, which contradicts hardness of the distribution (X ,W). We refer the reader to Appendix A for a formal proof of this claim. 1.1.2 Realizations of Unclonable NIZK, and Relationship with Quantum Money We obtain realizations of unclonable NIZKs in both the common reference string (CRS) and the quantum random oracle (QRO) models, assuming public-key quantum money mini-scheme and other (post-quantum) standard assumptions. We summarize these results below. (Informal). Theorem 1.3 Assuming public-key quantum money mini-scheme, public-key encryption, perfectly binding and computationally hiding commitments, and adaptively sound NIZK proofs for NP, there exists an unclonable NIZKPoK scheme in the CRS model. (Informal). Theorem 1.4 Assuming public-key quantum money mini-scheme and honest verifier zeroknowledge proofs of knowledge (HVZKPoKs) for NP, there exists an unclonable NIZKPoK scheme in the QROM. (Informal). Theorem 1.5 Assuming public-key quantum money mini-scheme, public-key encryption, postquantum perfectly binding and computationally hiding commitments, and simulation-sound NIZK proofs for NP, there exists an unclonable signature of knowledge in the CRS model. Our work builds unclonable NIZKs for NP by relying on any (public-key) quantum money scheme (mini-scheme), in conjuction with other assumptions such as NIZKs for NP. Since constructions of public-key quantum money minischeme are only known based on post-quantum indistinguishability obfuscation [AC13, Zha19b], it is natural to wonder whether the reliance on quantum money is inherent. We show that this is indeed the case, by proving that unclonable NIZKs in fact imply public-key quantum money mini-scheme. Is Quantum Money necessary for Unclonable NIZKs? (Informal). Theorem 1.6 Unclonable NIZKs for NP imply public-key quantum money mini-scheme. 1.1.3 Applications A (classical) signature scheme asserts that a message m has been signed on behalf of a public key pk. However, in order for this signature to be authenticated, the public key pk must be proven trustworthy through a certification chain rooted at a trusted public key PK. However, as [CL06] argue, this reveals too much information; it should be sufficient for the recipient to only know that there exists a public key pk with a chain of trust from PK. To solve this problem, [CL06] propose signatures of knowledge which allow a signer to sign on behalf of an instance x of an NP-hard language without revealing its corresponding witness w. Such signatures provide an anonymity guarantee by hiding the pk of the sender. Unclonable Signatures of Knowledge. While this is ideal for many applications, anonymity presents the following downside: a receiver cannot determine whether they were the intended recipient of this signature. In particular, anonymous signatures are more susceptible to replay attacks. Replay attacks are a form of passive attack whereby an adversary observes a signature and retains a copy. The adversary then leverages this signature, either at a later point in time or to a different party, to impersonate the original signer. The privacy and financial consequences of replay attacks are steep. They can lead to data breach attacks which cost millions of dollars annually and world-wide [IBM23]. In this work, we construct a signature of knowledge scheme which is the first non-interactive signature in the CRS model that is naturally secure against replay attacks. Non-interactive, replay attack secure signatures have seen a lot of recent interest including a line of works in the bounded quantum storage model [BS23b] and the quantum random oracle model [BS23a]. Our construction is in the CRS model and relies on the hardness of NP problems, plausible cryptographic assumptions, and the axioms of quantum mechanics. We accomplish this by defining unclonable signatures of knowledge: if an adversary, given a signature of a message m with respect to an instance x, can produce two signatures for m which verify with respect to the same instance x, then our extractor is able to extract a witness for x. Our construction involves showing that an existing compiler can be augmented using unclonable NIZKs to construct unclonable signatures of knowledge. The authors of [CL06] construct signatures of knowledge from CPA secure dense cryptosystems [SP92, SCP00] and simulationsound NIZKs for NP [Sah99, SCO+01]. Signatures of knowledge are signature schemes in the CRS model for which we associate an instance x in a language L. This signature is simulatable, so there exists a simulator which can create valid signatures without knowledge of a witness for x. Additionally, the signature is extractable which means there is an extractor which is given a trapdoor for the CRS and a signature, and is able to produce a witness for x. We show that, by switching the simulation-sound NIZKs for unclonable simulation-extractable NIZKs (and slightly modifying the compiler), we can construct unclonable signatures of knowledge. . A recent exciting line of work obtains certified deletion for time-lock puzzles [Unr14], non-local games [FM18], information-theoretic proofs of deletion with partial security [CW19], encryption schemes [BI20, BK23], device-independent security of one-time pad encryption with certified deletion [KT20], public-key encryption with certified deletion [HMNY21], commitments and zero-knowledge with certified everlasting hiding [HMNY22], and fully-homomorphic encryption with certified deletion [Por22, BK23, BKP23, BGG+23]. While certified everlasting deletion of secrets has been explored in the context of interactive zero-knowledge proofs [HMNY22], there are no existing proposals for non-interactive ZK satisfying variants of certified deletion. Our work provides a pathway to building such proofs. Relationship with Revocation In this work, we construct a quantum revocable anonymous credentials protocol by way of the hardness of NP problems, plausible cryptographic assumptions, and the axioms of quantum mechanics. Our work follows a line of work on (classical) revocation for anonymous credentials schemes [BCC+09, CKS10, AN11]. In particular, our construction involves noting that NIZK proof systems that are unclonable can also be viewed as supporting a form of certified deletion/revocation, where in order to delete, an adversary must simply return the entire proof. In other words, the (quantum) certificate of deletion is the proof itself, and this certificate can be verified by running the NIZK verification procedure on the proof. The unclonability guarantee implies that an adversary cannot keep with itself or later have the ability to generate another proof for the same instance x. In the other direction, in order to offer certifiable deletion, a NIZK must necessarily be unclonable. To see why, note that if there was an adversary who could clone the NIZK, we could use this adversary to obtain two copies, and provably delete one of them. Even though the challenger for the certifiable deletion game would be convinced that its proof was deleted, we would still be left with another correct proof. 1.2 Related Works This work was built upon the foundations of and novel concepts introduced by prior literature. We will briefly touch upon some notable such results in this section. Unclonable encryption [Got03, BL20, AK21, MST21, AKL+22] imagines an interaction between three parties in which one party receives a quantum ciphertext and splits this ciphertext in some manner between the two remaining parties. At some later point, the key of the encryption scheme is revealed, yet both parties should not be able to simultaneouly recover the underlying message. While our proof systems share the ideology of unclonability, we do not have a similar game-based definition of security. This is mainly due to proof systems offering more structure which can take advantage of to express unclonability in terms of simulators and extractors. Unclonable Encryptions. Prior work [BS17] defines and constructs signature tokens which are signatures which involve a quantum signing token which can only be used once before it becomes inert. The setting they consider is where a client wishes to delegate the signing process to a server, but does not wish the server to be able to sign more than one message. They rely on quantum money [AC13] and the no-cloning principle to ensure the signature can only be computed once. For our unclonable signatures of knowledge result, we focus on the setting where a client wishes to authenticate themselves to a server and wants to prevent an adversary from simultaneously, or later, masquerading as them. Signature Tokens. The authors of [AGKZ20] introduce the notion of one-shot signatures which extend the concept of signature tokens to a scenario where the client and server only exchange classical information to create a one-use quantum signature token. They show that these signatures can be plausibly constructed in the CRS model from post-quantum indistinguishability obfuscation. Unless additional measures for security, which we discussed in our applications section, are employed, classical communication can be easily copied and replayed at a later point. In contrast, we prevent an adversary from simultaneously, or later, authenticating with the client’s identity. One-shot Signatures. Our QROM results are heavily inspired by the recent post-quantum Fiat-Shamir result [LZ19] which proves the post-quantum security of NIZKs in the compressed quantum(-accessible) random oracle model (compressed QROM). These classical NIZKs are the result of applying Fiat-Shamir to post-quantum sigma protocols which are HVZKPoKs. We further extend, and crucially rely upon, their novel proof techniques to prove extractability (for PoK) and programmability (for ZK) to achieve extractability and programmability for some protocols which output quantum proofs. Post-quantum Fiat-Shamir.

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