Frother is added in the froth floatation cell used in ore beneficiation to stabilise the air bubbles (i.e., froth), which will hold the ore particles, but it does not affect the floatability of minerals. Which of the following is not used as a frothe ?->(Show Answer!)

1. Frother is added in the froth floatation cell used in ore beneficiation to stabilise the air bubbles (i.e., froth), which will hold the ore particles, but it does not affect the floatability of minerals. Which of the following is not used as a frother?

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MCQ->Frother is added in the froth floatation cell used in ore beneficiation to stabilise the air bubbles (i.e., froth), which will hold the ore particles, but it does not affect the floatability of minerals. Which of the following is not used as a frother?....

MCQ-> The membrane-bound nucleus is the most prominent feature of the eukaryotic cell. Schleiden and Schwann, when setting forth the cell doctrine in the 1830s, considered that it had a central role in growth and development. Their belief has been fully supported even though they had only vague notions as to what that role might be, and how the role was to be expressed in some cellular action. The membraneless nuclear area of the prokaryotic cell, with its tangle of fine threads, is now known to play a similar role.Some cells, like the sieve tubes of vascular plants and the red blood cells of mammals, do not possess nuclei during the greater part of their existence, although they had nuclei when in a less differentiated state. Such cells can no longer divide and their life span is limited Other cells are regularly multinucleate. Some, like the cells of striated muscles or the latex vessels of higher plants, become so through cell fusion. Some, like the unicellular protozoan paramecium, are normally binucleate, one of the nuclei serving as a source of hereditary information for the next generation, the other governing the day-to-day metabolic activities of the cell. Still other organisms, such as some fungi, are multinucleate because cross walls, dividing the mycelium into specific cells, are absent or irregularly present. The uninucleate situation, however, is typical for the vast majority of cells, and it would appear that this is the most efficient and most economical manner of partitioning living substance into manageable units. This point of view is given credence not only by the prevalence of uninucleate cells, but because for each kind of cell there is a ratio maintained between the volume of the nucleus and that of the cytoplasm. If we think of the nucleus as the control centre of the cell, this would suggest that for a given kind of cell performing a given kind of work, one nucleus can ‘take care of’ a specific volume of cytoplasm and keep it in functioning order. In terms of material and energy, this must mean providing the kind of information needed to keep flow of materials and energy moving at the correct rate and in the proper channels. With the multitude of enzymes in the cell, materials and energy can of course be channelled in a multitude of ways; it is the function of some information molecules to make channels of use more preferred than others at any given time. How this regulatory control is exercised is not entirely clear.The nucleus is generally a rounded body. In plant cells, however, where the centre of the cell is often occupied by a large vacuole, the nucleus may be pushed against the cell wall, causing it to assume a lens shape. In some white blood cells, such as polymorphonucleated leukocytes, and in cells of the spinning gland of some insects and spiders, the nucleus is very much lobed The reason for this is not clear, but it may relate to the fact that for a given volume of nucleus, a lobate form provides a much greater surface area for nuclear-cytoplasmic exchanges, possibly affecting both the rate and the amount of metabolic reactions. The nucleus, whatever its shape, is segregated from the cytoplasm by a double membrane, the nuclear envelope, with the two membranes separated from each other by a perinuclear space of varying width. The envelope is absent only during the time of cell division, and then just for a brief period The outer membrane is often continuous with the membranes of the endoplasmic reticulum, a possible retention of an earlier relationship, since the envelope, at least in part, is formed at the end cell division by coalescing fragments of the endoplasmic reticulum. The cytoplasmic side of the nucleus is frequently coated with ribosomes, another fact that stresses the similarity and relation of the nuclear envelope to the endoplasmic reticulum. The inner membrane seems to posses a crystalline layer where it abuts the nucleoplasm, but its function remains to be determined.Everything that passes between the cytoplasm and the nucleus in the eukaryotic cell must transverse the nuclear envelope. This includes some fairly large molecules as well as bodies such as ribosomes, which measure about 25 mm in diameter. Some passageway is, therefore, obviously necessary since there is no indication of dissolution of the nuclear envelope in order to make such movement possible. The nuclear pores appear to be reasonable candidates for such passageways. In plant cells these are irregularly, rather sparsely distributed over the surface of the nucleus, but in the amphibian oocyte, for example, the pores are numerous, regularly arranged, and octagonal and are formed by the fusion of the outer and inner membrane.Which of the following kinds of cells never have a nuclei?
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MCQ-> Cells are the ultimate multi-taskers: they can switch on genes and carry out their orders, talk to each other, divide in two, and much more, all at the same time. But they couldn’t do any of these tricks without a power source to generate movement. The inside of a cell bustles with more traffic than Delhi roads, and, like all vehicles, the cell’s moving parts need engines. Physicists and biologists have looked ‘under the hood’ of the cell and laid out the nuts and bolts of molecular engines.The ability of such engines to convert chemical energy into motion is the envy nanotechnology researchers looking for ways to power molecule-sized devices. Medical researchers also want to understand how these engines work. Because these molecules are essential for cell division, scientists hope to shut down the rampant growth of cancer cells by deactivating certain motors. Improving motor-driven transport in nerve cells may also be helpful for treating diseases such as Alzheimer’s, Parkinson’s or ALS, also known as Lou Gehrig’s disease.We wouldn’t make it far in life without motor proteins. Our muscles wouldn’t contract. We couldn’t grow, because the growth process requires cells to duplicate their machinery and pull the copies apart. And our genes would be silent without the services of messenger RNA, which carries genetic instructions over to the cell’s protein-making factories. The movements that make these cellular activities possible occur along a complex network of threadlike fibers, or polymers, along which bundles of molecules travel like trams. The engines that power the cell’s freight are three families of proteins, called myosin, kinesin and dynein. For fuel, these proteins burn molecules of ATP, which cells make when they break down the carbohydrates and fats from the foods we eat. The energy from burning ATP causes changes in the proteins’ shape that allow them to heave themselves along the polymer track. The results are impressive: In one second, these molecules can travel between 50 and 100 times their own diameter. If a car with a five-foot-wide engine were as efficient, it would travel 170 to 340 kilometres per hour.Ronald Vale, a researcher at the Howard Hughes Medical Institute and the University of California at San Francisco, and Ronald Milligan of the Scripps Research Institute have realized a long-awaited goal by reconstructing the process by which myosin and kinesin move, almost down to the atom. The dynein motor, on the other hand, is still poorly understood. Myosin molecules, best known for their role in muscle contraction, form chains that lie between filaments of another protein called actin. Each myosin molecule has a tiny head that pokes out from the chain like oars from a canoe. Just as rowers propel their boat by stroking their oars through the water, the myosin molecules stick their heads into the actin and hoist themselves forward along the filament. While myosin moves along in short strokes, its cousin kinesin walks steadily along a different type of filament called a microtubule. Instead of using a projecting head as a lever, kinesin walks on two ‘legs’. Based on these differences, researchers used to think that myosin and kinesin were virtually unrelated. But newly discovered similarities in the motors’ ATP-processing machinery now suggest that they share a common ancestor — molecule. At this point, scientists can only speculate as to what type of primitive cell-like structure this ancestor occupied as it learned to burn ATP and use the energy to change shape. “We’ll never really know, because we can’t dig up the remains of ancient proteins, but that was probably a big evolutionary leap,” says Vale.On a slightly larger scale, loner cells like sperm or infectious bacteria are prime movers that resolutely push their way through to other cells. As L. Mahadevan and Paul Matsudaira of the Massachusetts Institute of Technology explain, the engines in this case are springs or ratchets that are clusters of molecules, rather than single proteins like myosin and kinesin. Researchers don’t yet fully understand these engines’ fueling process or the details of how they move, but the result is a force to be reckoned with. For example, one such engine is a spring-like stalk connecting a single-celled organism called a vorticellid to the leaf fragment it calls home. When exposed to calcium, the spring contracts, yanking the vorticellid down at speeds approaching three inches (eight centimetres) per second.Springs like this are coiled bundles of filaments that expand or contract in response to chemical cues. A wave of positively charged calcium ions, for example, neutralizes the negative charges that keep the filaments extended. Some sperm use spring-like engines made of actin filaments to shoot out a barb that penetrates the layers that surround an egg. And certain viruses use a similar apparatus to shoot their DNA into the host’s cell. Ratchets are also useful for moving whole cells, including some other sperm and pathogens. These engines are filaments that simply grow at one end, attracting chemical building blocks from nearby. Because the other end is anchored in place, the growing end pushes against any barrier that gets in its way.Both springs and ratchets are made up of small units that each move just slightly, but collectively produce a powerful movement. Ultimately, Mahadevan and Matsudaira hope to better understand just how these particles create an effect that seems to be so much more than the sum of its parts. Might such an understanding provide inspiration for ways to power artificial nano-sized devices in the future? “The short answer is absolutely,” says Mahadevan. “Biology has had a lot more time to evolve enormous richness in design for different organisms. Hopefully, studying these structures will not only improve our understanding of the biological world, it will also enable us to copy them, take apart their components and recreate them for other purpose.”According to the author, research on the power source of movement in cells can contribute to
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MCQ-> The second plan to have to examine is that of giving to each person what she deserves. Many people, especially those who are comfortably off, think this is what happens at present: that the industrious and sober and thrifty are never in want, and that poverty is due to idleness, improvidence, drinking, betting, dishonesty, and bad character generally. They can point to the fact that a labour whose character is bad finds it more difficult to get employment than one whose character is good; that a farmer or country gentleman who gambles and bets heavily, and mortgages his land to live wastefully and extravagantly, is soon reduced to poverty; and that a man of business who is lazy and does not attend to it becomes bankrupt. But this proves nothing that you cannot eat your cake and have it too; it does not prove that your share of the cake was a fair one. It shows that certain vices make us rich. People who are hard, grasping, selfish, cruel, and always ready to take advantage of their neighbours, become very rich if they are clever enough not to overreach themselves. On the other hand, people who are generous, public spirited, friendly, and not always thinking of the main chance, stay poor when they are born poor unless they have extraordinary talents. Also as things are today, some are born poor and others are born with silver spoons in their mouths: that is to say, they are divided into rich and poor before they are old enough to have any character at all. The notion that our present system distributes wealth according to merit, even roughly, may be dismissed at once as ridiculous. Everyone can see that it generally has the contrary effect; it makes a few idle people very rich, and a great many hardworking people very poor.On this, intelligent Lady, your first thought may be that if wealth is not distributed according to merit, it ought to be; and that we should at once set to work to alter our laws so that in future the good people shall be rich in proportion to their goodness and the bad people poor in proportion to their badness. There are several objections to this; but the very first one settles the question for good and all. It is, that the proposal is impossible and impractical. How are you going to measure anyone's merit in money? Choose any pair of human beings you like, male or female, and see whether you can decide how much each of them should have on her or his merits. If you live in the country, take the village blacksmith and the village clergyman, or the village washerwoman and the village schoolmistress, to begin with. At present, the clergyman often gets less pay than the blacksmith; it is only in some villages he gets more. But never mind what they get at present: you are trying whether you can set up a new order of things in which each will get what he deserves. You need not fix a sum of money for them: all you have to do is to settle the proportion between them. Is the blacksmith to have as much as the clergyman? Or twice as much as the clergyman? Or half as much as the clergyman? Or how much more or less? It is no use saying that one ought to have more the other less; you must be prepared to say exactly how much more or less in calculable proportion.Well, think it out. The clergyman has had a college education; but that is not any merit on his part: he owns it to his father; so you cannot allow him anything for that. But through it he is able to read the New Testament in Greek; so that he can do something the blacksmith cannot do. On the other hand, the blacksmith can make a horse-shoe, which the parson cannot. How many verses of the Greek Testament are worth one horse-shoe? You have only to ask the silly question to see that nobody can answer it.Since measuring their merits is no use, why not try to measure their faults? Suppose the blacksmith swears a good deal, and gets drunk occasionally! Everybody in the village knows this; but the parson has to keep his faults to himself. His wife knows them; but she will not tell you what they are if she knows that you intend to cut off some of his pay for them. You know that as he is only a mortal human being, he must have some faults; but you cannot find them out. However, suppose he has some faults he is a snob; that he cares more for sport and fashionable society than for religion! Does that make him as bad as the blacksmith, or twice as bad, or twice and quarter as bad, or only half as bad? In other words, if the blacksmith is to have a shilling, is the parson to have six pence, or five pence and one-third, or two shillings? Clearly these are fools' questions: the moment they bring us down from moral generalities to business particulars it becomes plain to every sensible person that no relation can be established between human qualities, good or bad, and sums of money, large or small.It may seem scandalous that a prize-fighter, for hitting another prize-fighter so hard at Wembley that he fell down and could not rise within ten seconds, received the same sum that was paid to the Archbishop of Canterbury for acting as Primate of the Church of England for nine months; but none of those who cry out against the scandal can express any better in money the difference between the two. Not one of the persons who think that the prize-fighter should get less than the Archbishop can say how much less. What the prize- fighter got for his six or seven months' boxing would pay a judge's salary for two years; and we all agree that nothing could be more ridiculous, and that any system of distributing wealth which leads to such absurdities must be wrong. But to suppose that it could be changed by any possible calculation that an ounce of archbishop of three ounces of judge is worth a pound of prize-fighter would be sillier still. You can find out how many candles are worth a pound of butter in the market on any particular day; but when you try to estimate the worth of human souls the utmost you can say is that they are all of equal value before the throne of God:And that will not help you in the least to settle how much money they should have. You must simply give it up, and admit that distributing money according to merit is beyond mortal measurement and judgement.Which of the following is not a vice attributed to the poor by the rich?
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MCQ-> Read the following passage carefully and answer the questions given at the end.The movement to expel the Austrians from Italy and unite Italy under a republican government had been gaining momentum while Garibaldi was away. There was a growing clamour, not just from Giuseppe Mazzini's republicans, but from moderates as well, for a General capable of leading Italy to independence. Even the King of Piedmont, for whom Garibaldi was still an outlaw under sentence of death, subscribed to an appeal for a sword for the returning hero. Meanwhile, the 'year of revolutions', 1848, had occurred in which Louis Philippe had been toppled from the French throne. In Austria, an uprising triggered off insurrections in Venice and Milan, and the Austrian garrisons were forced out. The King of Piedmont, Charles Albert ordered his troops to occupy these cities. There had also been insurrections in Sicily, causing the King Ferdinand II, to grant major constitutional freedoms in 1849, prompting both the Pope and Charles Albert to grant further concessions.Meanwhile, largely ignorant of these developments, Garibaldi was approaching Italy at a leisurely pace, arriving at Nice on 23 June 1848 to a tumultuous reception. The hero declared himself willing to fight and lay down his life for Charles Albert, who he now regarded as a bastion of Italian nationalism.Mazzini and the republicans were horrified, regarding this as outright betrayal: did it reflect Garibaldi's innate simple-mindedness, his patriotism in the war against Austria, or was it part of a deal with the monarchy? Charles Albert had pardoned Garibaldi, but to outward appearances he was still very wary of the General and the Italian Legion he had amassed of 150 'brigands'. The two men met near Mantua, and the King appeared to dislike him instantly. He suggested that Garibaldi's men should join his army and that Garibaldi should go to Venice and captain a ship as a privateer against the Austrians.Garibaldi, meanwhile, met his former hero Mazzini for the first time, and again the encounter was frosty. Seemingly rebuffed on all sides, Garibaldi considered going to Sicily to fight King Ferdinand II of Naples, but changed his mind when the Milanese offered him the post of General - something they badly needed when Charles Albert's Piedmontese army was defeated at Custoza by the Austrians. With around 1,000 men, Garibaldi marched into the mountains at Varese, commenting bitterly: 'The King of Sardinia may have a crown that he holds on to by dint of misdeeds and cowardice, but my comrades and I do not wish to hold on to our lives by shameful actions'.The King of Piedmont offered an armistice to the Austrians and all the gains in northern Italy were lost again. Garibaldi returned to Nice and then across to Genoa, where he learned that, in September 1848, Ferdinand II had bombed Messina as a prelude to invasion - an atrocity which caused him to be dubbed 'King Bomba'. Reaching Livorno he was diverted yet again and set off across the Italian peninsula with 350 men to come to Venice's assistance, but on the way, in Bologna, he learned that the Pope had taken refuge with King Bomba. Garibaldi promptly altered course southwards towards Rome where he was greeted once again as a hero. Rome proclaimed itself a Republic. Garibaldi's Legion had swollen to nearly 1,300 men, and the Grand Duke of Tuscany fled Florence before the advancing republican force.However, the Austrians marched southwards to place the Grand Duke of Tuscany back on his throne. Prince Louis Napoleon of France despatched an army of 7,000 men under General Charles Oudinot to the port of Civitavecchia to seize the city. Garibaldi was appointed as a General to defend Rome.The republicans had around 9,000 men, and Garibaldi was given control of more than 4,000 to defend the Janiculum Hill, which was crucial to the defence of Rome, as it commanded the city over the Tiber. Some 5,000 well-equipped French troops arrived on 30 April 1849 at Porta Cavallegeri in the old walls of Rome, but tailed to get through, and were attacked from behind by Garibaldi, who led a baton charge and was grazed by a bullet slightly on his side. The French lost 500 dead and wounded, along with some 350 prisoners, to the Italians, 200 dead and wounded. It was a famous victory, wildly celebrated by the Romans into the night, and the French signed a tactical truce.However, other armies were on the march: Bomba's 12,500-strong Neapolitan army was approaching from the south, while the Austrians had attacked Bologna in the north. Garibaldi too, a force out of Rome and engaged in a flanking movement across the Neapolitan army's rear at Castelli Romani; the Neapolitans attacked and were driven off leaving 50 dead. Garibaldi accompanied the Roman General, Piero Roselli, in an attack on the retreating Neapolitan army. Foolishly leading a patrol of his men right out in front of his forces, he tried to stop a group of his cavalry retreating and fell under their horses, with the enemy slashing at him with their sabres. He was rescued by his legionnaires, narrowly having avoided being killed, but Roselli had missed the chance to encircle the Neapolitan army.Garibaldi boldly wanted to carry the fight down into the Kingdom of Naples, but Mazzini, who by now was effectively in charge of Rome, ordered him back to the capital to face the danger of Austrian attack from the north. In fact, it was the French who arrived on the outskirts of Rome first, with an army now reinforced by 30,000. Mazzini realized that Rome could not resist and ordered a symbolic stand within the city itself, rather than surrender, for the purposes of international propaganda and to keep the struggle alive, whatever the cost. On 3 June the French arrived in force and seized the strategic country house, Villa Pamphili.Garibaldi rallied his forces and fought feverishly to retake the villa up narrow and steep city streets, capturing it, then losing it again. By the end of the day, the sides had 1,000 dead between them. Garibaldi once again had been in the thick of the fray, giving orders to his troops and - fighting, it was said, like a lion. Although beaten 'off for the moment, the French imposed a siege in the morning, starving the city of provisions and bombarding its beautiful centre.On 30 June the French attacked again in force, while Garibaldi, at the head of his troops, fought back ferociously. But there was no prospect of holding the French off indefinitely, and Garibaldi, decided to take his men out of the city to continue resistance in the mountains. Mazzini fled to Britain while Garibaldi remained to fight for the cause. He had just 4,000 men, divided into two legions, and faced some 17,000 Austrians and Tuscans in the north, 30,000 Neapolitans and Spanish in the south, and 40,000 French in the west. He was being directly pursued by 8,000 French and was approaching Neapolitan and Spanish divisions of some 18,000 men. He stood no chance whatever. The rugged hill country was ideal, however, for his style of irregular guerrilla warfare, and he manoeuvred skilfully, marching and counter-marching in different directions, confounding his pursuers before finally aiming for Arezzo in the north. But his men were deserting in droves and local people were hostile to his army: he was soon reduced to 1500 men who struggled across the high mountain passes to San Marino where he found temporary. refuge.The Austrians, now approaching, demanded that he go into exile in America. He was determined to fight on and urged the ill and pregnant Anita, his wife, to stay behind in San Marino, but she would not hear of it. The pair set off with 200 loyal soldiers along the mountain tracks to the Adriatic coast, from where Garibaldi intended to embark for Venice which was still valiantly holding out against the Austrians. They embarked aboard 13 fishing boats and managed to sail to within 50 miles of the Venetian lagoon before being spotted by an Austrian flotilla and fired upon.Only two of Garibaldi's boats escaped. He carried Anita through the shallows to a beach and they moved further inland. The ailing Anita was placed in a cart and they reached a farmhouse, where she died. Her husband broke down into inconsolable wailing and she was buried in a shallow grave near the farmhouse, but was transferred to a churchyard a few days later. Garibaldi had no time to lose; he and his faithful companion Leggero escaped across the Po towards Ravenna.At last Garibaldi was persuaded to abandon his insane attempts to reach Venice by sea and to return along less guarded routes on the perilous mountain paths across the Apennines towards the western coast of Italy. He visited his family in Nice for an emotional reunion with his mother and his three children - but lacked the courage to tell them what had happened to their mother.Find the correct statement:
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