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#1 Re: Ganesh's Puzzles » 10 second questions » Today 01:01:02

Hi,

.

#7126. Find the value of p.

.

#2 Re: Ganesh's Puzzles » Oral puzzles » Today 00:43:47

Hi,

#4290. The height of 5 boys is recorded as 146 centimeters, 154 centimeters, 164 centimeters, 148 centimeters, and 158 centimeters. What is the average height of all these boys?

#3 Jokes » Monkey Jokes - 2 » Today 00:31:22

ganesh
Replies: 0

Q: What does a logger say before he cuts down a tree?
A: Let the chimps fall where they may.
* * *
Q: Where should a monkey go when he loses his tail?
A: To a retailer!
* * *
Q: What did the banana do when he saw a monkey?
A: The banana split!
* * *
Q: What is a monkey's favorite game?
A: Hangman!
* * *
Q: Why don't monkeys play cards in the jungle?
A: There are too many cheetahs there!
* * *
Q: Why shouldn't you get into a fight with a monkey?
A: They use gorilla warfare.
* * *
Q: What do you call a monkey that succeeds at every sport?
A: A chimpion!
* * *
Q: Where do chimps get their gossip?
A: On the ape vine!
* * *
Q: How do you get an escaped lion back into his habitat?
A: With a bargaining chimp.
* * *
Q: What do you call a restaurant that throws food in your face?
A: A Monkey Business.
* * *
Q: How do you catch a monkey?
A: Climb a tree and act like a banana!
* * *

#4 Re: This is Cool » Miscellany » Today 00:18:41

256) Banana

Bananas are one of the world's most appealing fruits. Global banana exports reached about 18 million tons in 2015, according to the United Nations. About half of them went to the United States and the European market. In the United States, each person eats 11.4 lbs. of bananas per year, according to the U.S. Department of Agriculture, making it Americans' favorite fresh fruit.

A wide variety of health benefits are associated with the curvy yellow fruit. Bananas are high in potassium and pectin, a form of fiber, said Laura Flores, a San Diego-based nutritionist. They can also be a good way to get magnesium and vitamins C and B6.

"Bananas are known to reduce swelling, protect against developing type-2 diabetes, aid in weight loss, strengthen the nervous system and help with production of white blood cells, all due to the high level of vitamin B6 that bananas contain," Flores told Live Science.

"Bananas are high in antioxidants, which can provide protection from free radicals, which we come into contact with every day, from the sunlight to the lotion you put on your skin," Flores added.

From green to black

A 2017 meta-analysis published by Prilozi Section of Medical Sciences suggested that unripe green bananas offer some health benefits. They may help with controlling gastrointestinal problems such as diarrhea and ulcers, and may lower cholesterol and blood pressure. Some studies have suggested that the lectins in green bananas could provide treatment for HIV patients.

At the other end of a banana's life, research has shown that the levels of nutrients rise in bananas as they ripen. Bananas with dark spots were eight times more effective in enhancing the power of white blood cells than green-skin bananas, according to a 2009 study published in Food Science and Technology Research. White blood cells fight infections from bacteria, fungi, viruses and other pathogens.

Health benefits

Heart health

Bananas are good for your heart. They are packed with potassium, a mineral electrolyte that keeps electricity flowing throughout your body, which is required to keep your heart beating. Bananas' high potassium and low sodium content may also help protect your cardiovascular system against high blood pressure, according to the FDA.

A 2017 animal study conducted by researchers at the University of Alabama found that the potassium in bananas is also linked to arterial effectiveness; the more potassium you have, the less likely your arteries are to harden. In the study, mice with lower-potassium diet had harder arteries than mice consuming a normal amount of potassium. Arterial stiffness in humans is linked to heart disease.

Depression and mood

Bananas can be helpful in overcoming depression "due to high levels of tryptophan, which the body converts to serotonin, the mood-elevating brain neurotransmitter," Flores said. Plus, vitamin B6 can help you sleep well, and magnesium helps to relax muscles. Additionally, the tryptophan in bananas is well known for its sleep-inducing properties.

Digestion and weight loss

Bananas are high in fiber, which can help keep you regular. One banana can provide nearly 10 percent of your daily fiber requirement. Vitamin B6 can also help protect against type 2 diabetes and aid in weight loss, according to Flores. In general, bananas are a great weight loss food because they taste sweet and are filling, which helps curb cravings.

Bananas are particularly high in resistant starch, a form of dietary fiber in which researchers have recently become interested. A 2017 review published in Nutrition Bulletin found that the resistant starch in bananas may support gut health and control blood sugar. Resistant starch increases the production of short chain fatty acids in the gut, which are necessary to gut health.

Exercise

For replenishing energy and electrolytes, bananas can be more effective than sports drinks. A 2012 study published in PLOS One looked at male athletes competing in long-distance cycling races. They compared athletes refueling with Gatorade every 15 minutes to athletes refueling with a banana and water. Researchers saw that the athletes' performance times and body physiology were the same in both cases. But the banana's serotonin and dopamine improved the athletes' antioxidant capacity and helped with oxidative stress, improving performance overall.

Vision

Carrots may get all the glory for helping your eyes, but bananas do their share as well. The fruits contain a small but significant amount of vitamin A, which is essential for protecting your eyes, maintaining normal vision and improving vision at night, according to the National Institutes of Health. Vitamin A contains compounds that preserve the membranes around your eyes and are an element in the proteins that bring light to your corneas. Like other fruits, bananas can help prevent macular degeneration, an incurable condition, which blurs central vision.

Bones

Bananas may not be overflowing with calcium, but they are still helpful in keeping bones strong. According to a 2009 article in the Journal of Physiology and Biochemistry, bananas contain an abundance of fructooligosaccharides. These are nondigestive carbohydrates that encourage digestive-friendly priobotics and enhance the body's ability to absorb calcium.

Cancer

Some evidence suggests that moderate consumption of bananas may be protective against kidney cancer. A 2005 Swedish study found that women who ate more than 75 servings of fruits and vegetables cut their risk of kidney cancer by 40 percent, and that bananas were especially effective. Women eating four to six bananas a week halved their risk of developing kidney cancer.

Bananas may be helpful in preventing kidney cancer because of their high levels of antioxidant phenolic compounds.

Pregnancy

Bananas may also help prevent gestational diabetes. Lack of sleep during pregnancy can contribute to gestational diabetes, according to a meta-analysis published in Sleep Medicine Reviews. But the magnesium and tryptophan in bananas can help ensure a good night's rest.

Health risks

Eaten in moderation, there are no significant side effects associated with eating bananas. However, eating the fruits in excess may trigger headaches and sleepiness, Flores said. She said that such headaches are caused by "the amino acids in bananas that dilate blood vessels." Overripe bananas contain more of these amino acids than other bananas. "Bananas can also contribute to sleepiness when eaten in excess due to the high amount of tryptophan found in them," she said. Magnesium also relaxes the muscles — another sometimes-benefit, sometimes-risk.

Bananas are a sugary fruit, so eating too many and not maintaining proper dental hygiene practices can lead to tooth decay. They also do not contain enough fat or protein to be a healthy meal on their own, or an effective post-workout snack.

Eating bananas becomes significantly risky only if you eat too many. The USDA recommends that adults eat about two cups of fruit a day, or about two bananas. If you eat dozens of bananas every day, there may be a risk of excessively high vitamin and mineral levels.

The University of Maryland Medical Center reported that potassium overconsumption can lead to hyperkalemia, which is characterized by muscle weakness, temporary paralysis and an irregular heartbeat. It can have serious consequences, but you would have to eat about 43 bananas in a short time for any symptoms of hyperkalemia to occur.

According to the NIH, consuming more than 500 milligrams of vitamin B6 daily can possibly lead to nerve damage in the arms and legs. You would have to eat thousands of bananas to reach that level of vitamin B6.

Banana peels: edible or poisonous?

It turns out that the biggest risk from a banana peel might really be slipping on it. Banana peels are not poisonous. In fact, they're edible, and packed with nutrients. "Banana peel is eaten in many parts of the world, though [it's] not very common in the West," Flores said. "It contains high amounts of vitamin B6 and B12, as well as magnesium and potassium. It also contains some fiber and protein." According to a 2011 article in the journal of Applied Biochemistry and Biotechnology, banana peels also have "various bioactive compounds like polyphenols, carotenoids and others."

It is important to carefully wash a banana peel before eating it due to the pesticides that may be sprayed in banana groves.

Banana peels are usually served cooked, boiled or fried, though they can be eaten raw or put in a blender with other fruits. They are not as sweet as banana flesh. Riper peels will be sweeter than unripe ones.

Other banana facts

Bananas may have been the world's first cultivated fruit. Archaeologists have found evidence of banana cultivation in New Guinea as far back as 8000 B.C.
The banana plant is classified as an arborescent (tree-like) perennial herb, and the banana itself is considered a berry. A bunch of bananas is called a hand; a single banana is a finger.

There are almost 1,000 varieties of bananas, according to the Food and Agriculture Organization of the United Nations (FAO). Nearly all the bananas sold in stores are cloned from just one variety, the Cavendish banana plant, originally native to Southeast Asia. The Cavendish replaced the Gros Michel after that variety was wiped out by fungus in the 1950s. The Gros Michel reportedly was bigger, had a longer shelf life and tasted better. The Cavendish are resistant to the fungus that killed off the Gros Michel, but they are susceptible to another fungus and may face the same fate within the next 20 years, botanists say.

Botanically, there is no difference between plantains and bananas. But in general use, "banana" refers to the sweeter form of the fruit, which is often eaten uncooked, while "plantain" refers to a starchier fruit that is often cooked before eating.

Ecuador is the leading producer of bananas worldwide, followed by the Philippines. Bananas are produced in other tropical and subtropical areas of Asia, Africa, and the Americas, as well as the Canary Islands and Australia.

Wild bananas grow throughout Southeast Asia, but most are inedible for humans, as they are studded with hard seeds.

Banana-3-bananas-34512812-398-302.jpg

#6 Re: Ganesh's Puzzles » Oral puzzles » Yesterday 00:45:51

Hi,

#4289. The average age of 80 girls was 20 years, the average age of 20 of them was 22 years and that of another 20 was 24 years. Find the average age age of the remaining girls.

#7 Re: Dark Discussions at Cafe Infinity » crème de la crème » Yesterday 00:23:14

435) Anders Knutsson Ångström

Anders Knutsson Ångström (1888, Stockholm – 1981) was a Swedish physicist and meteorologist who was known primarily for his contributions to the field of atmospheric radiation. However, his scientific interests encompassed many diverse topics.

He was the son of physicist Knut Ångström. He graduated with a BS from the University of Upsala in 1909. Then he completed his MS at the University of Upsala in 1911. He taught at the University of Stockholm Later, he was the department head of the Meteorology department at State Meteorological and Hydrological Institute (SMHI) of Sweden 1945–1949 and SMHI's chancellor 1949–1954.

He is credited with the invention of the pyranometer, the first device to accurately measure direct and indirect solar radiation.

In 1962 he was awarded the International Meteorological Organization Prize by the World Meteorological Organization.

Pyranometer

A pyranometer is a type of actinometer used for measuring solar irradiance on a planar surface and it is designed to measure the solar radiation flux density (W/m²) from the hemisphere above within a wavelength range 0.3 μm to 3 μm.

A typical pyranometer does not require any power to operate. However, recent technical development includes use of electronics in pyranometers, which do require (low) external power.

Explanation

The solar radiation spectrum that reaches earth's surface extends its wavelength approximately from 300 nm to 2800 nm. Depending on the type of pyranometer used, irradiance measurements with different degrees of spectral sensitivity will be obtained.

To make a measurement of irradiance, it is required by definition that the response to “beam” radiation varies with the cosine of the angle of incidence. This ensures a full response when the solar radiation hits the sensor perpendicularly (normal to the surface, sun at zenith, 0° angle of incidence), zero response when the sun is at the horizon (90° angle of incidence, 90° zenith angle), and 0.5 at a 60° angle of incidence. It follows that a pyranometer should have a so-called “directional response” or “cosine response” that is as close as possible to the ideal cosine characteristic.

Actinometer

Actinometers are instruments used to measure the heating power of radiation. They are used in meteorology to measure solar radiation as pyranometers, pyrheliometers and net radiometers.

An actinometer is a chemical system or physical device which determines the number of photons in a beam integrally or per unit time. This name is commonly applied to devices used in the ultraviolet and visible wavelength ranges. For example, solutions of iron(III) oxalate can be used as a chemical actinometer, while bolometers, thermopiles, and photodiodes are physical devices giving a reading that can be correlated to the number of photons detected.

anders_knutsson_angstrom_medium.jpg

#8 Re: Ganesh's Puzzles » 10 second questions » 2018-12-07 15:59:56

Hi,

Good work, Monox D. I-Fly! The solution #7123 is correct!

#7124. Find the value of j.

.

#9 Re: This is Cool » Miscellany » 2018-12-07 02:00:58

255) Inverter

One of the most significant battles of the 19th century was fought not over land or resources but to establish the type of electricity that powers our buildings.
At the very end of the 1800s, American electrical pioneer Thomas Edison (1847–1931) went out of his way to demonstrate that direct current (DC) was a better way to supply electrical power than alternating current (AC), a system backed by his Serbian-born arch-rival Nikola Tesla (1856–1943).  Tesla's system won the day and the world has pretty much run on AC power ever since.

The only trouble is, though many of our appliances are designed to work with AC, small-scale power generators often produce DC. That means if you want to run something like an AC-powered gadget from a DC car battery in a mobile home, you need a device that will convert DC to AC—an inverter, as it's called. Let's take a closer look at these gadgets and find out how they work!

What's the difference between DC and AC electricity?

When science teachers explain the basic idea of electricity to us as a flow of electrons, they're usually talking about direct current (DC). We learn that the electrons work a bit like a line of ants, marching along with packets of electrical energy in the same way that ants carry leaves. That's a good enough analogy for something like a basic flashlight, where we have a circuit (an unbroken electrical loop) linking a battery, a lamp, and a switch and electrical energy is systematically transported from the battery to the lamp until all the battery's energy is depleted.

In bigger household appliances, electricity works a different way. The power supply that comes from the outlet in your wall is based on alternating current (AC), where the electricity switches direction around 50–60 times each second (in other words, at a frequency of 50–60 Hz). It can be hard to understand how AC delivers energy when it's constantly changing its mind about where it's going! If the electrons coming out of your wall outlet get, let's say, a few millimeters down the cable then have to reverse direction and go back again, how do they ever get to the lamp on your table to make it light up?

The answer is actually quite simple. Imagine the cables running between the lamp and the wall packed full of electrons. When you flick on the switch, all the electrons filling the cable vibrate back and forth in the lamp's filament—and that rapid shuffling about converts electrical energy into heat and makes the lamp bulb glow. The electrons don't necessarily have to run in circle to transport energy: in AC, they simply "run on the spot."

What is an inverter?

One of Tesla's legacies (and that of his business partner George Westinghouse, boss of the Westinghouse Electrical Company) is that most of the appliances we have in our homes are specifically designed to run from AC power. Appliances that need DC but have to take power from AC outlets need an extra piece of equipment called a rectifier, typically built from electronic components called diodes, to convert from AC to DC.

An inverter does the opposite job and it's quite easy to understand the essence of how it works. Suppose you have a battery in a flashlight and the switch is closed so DC flows around the circuit, always in the same direction, like a race car around a track. Now what if you take the battery out and turn it around. Assuming it fits the other way, it'll almost certainly still power the flashlight and you won't notice any difference in the light you get—but the electric current will actually be flowing the opposite way. Suppose you had lightning-fast hands and were deft enough to keep reversing the battery 50–60 times a second. You'd then be a kind of mechanical inverter, turning the battery's DC power into AC at a frequency of 50–60 hertz.

Of course the kind of inverters you buy in electrical stores don't work quite this way, though some are indeed mechanical: they use electromagnetic switches that flick on and off at high speed to reverse the current direction. Inverters like this often produce what's known as a square-wave output: the current is either flowing one way or the opposite way or it's instantly swapping over between the two states.

These kind of sudden power reversals are quite brutal for some forms of electrical equipment. In normal AC power, the current gradually swaps from one direction to the other in a sine-wave pattern.

Electronic inverters can be used to produce this kind of smoothly varying AC output from a DC input. They use electronic components called inductors and capacitors to make the output current rise and fall more gradually than the abrupt, on/off-switching square wave output you get with a basic inverter.

Inverters can also be used with transformers to change a certain DC input voltage into a completely different AC output voltage (either higher or lower) but the output power must always be less than the input power: it follows from the conservation of energy that an inverter and transformer can't give out more power than they take in and some energy is bound to be lost as heat as electricity flows through the various electrical and electronic components. In practice, the efficiency of an inverter is often over 90 percent, though basic physics tells us some energy—however little—is always being wasted somewhere!

How does an inverter work?

We've just had a very basic overview of inverters—and now let's go over it again in a little bit more detail.

Imagine you're a DC battery and someone taps you on the shoulder and asks you to produce AC instead. How would you do it? If all the current you produce flows out in one direction, what about adding a simple switch to your output lead? Switching your current on and off, very rapidly, would give pulses of direct current—which would do at least half the job. To make proper AC, you'd need a switch that allowed you to reverse the current completely and do it about 50‐60 times every second. Visualize yourself as a human battery swapping your contacts back and forth over 3000 times a minute. That's some neat fingerwork you'd need!

In essence, an old-fashioned mechanical inverter boils down to a switching unit connected to an electricity transformer. If you've studied our article on transformers, you'll know that they're electromagnetic devices that change low-voltage AC to high-voltage AC, or vice-versa, using two coils of wire (called the primary and secondary) wound around a common iron core. In a mechanical inverter, either an electric motor or some other kind of automated switching mechanism flips the incoming direct current back and forth in the primary, simply by reversing the contacts, and that produces alternating current in the secondary—so it's not so very different from the imaginary inverter I sketched out above. The switching device works a bit like the one in an electric doorbell. When the power is connected, it magnetizes the switch, pulling it open and switching it off very briefly. A spring pulls the switch back into position, turning it on again and repeating the process—over and over again.

Types of inverters

If you simply switch a DC current on and off, or flip it back and forth so its direction keeps reversing, what you end up with is very abrupt changes of current: all in one direction, all in the other direction, and back again. Draw a chart of the current (or voltage) against time and you'll get a square wave. Although electricity varying in that fashion is, technically, an alternating current, it's not at all like the alternating current supplied to our homes, which varies in a much more smoothly undulating sine wave). Generally speaking, hefty appliances in our homes that use raw power (things like electric heaters, incandescent lamps, kettles, or fridges) don't much care what shape wave they receive: all they want is energy and lots of it—so square waves really don't bother them. Electronic devices, on the other hand, are much more fussy and prefer the smoother input they get from a sine wave.

This explains why inverters come in two distinct flavors: true/pure sine wave inverters (often shortened to PSW) and modified/quasi sine wave inverters (shortened to MSW). As their name suggests, true inverters use what are called toroidal (donut-shaped) transformers and electronic circuits to transform direct current into a smoothly varying alternating current very similar to the kind of genuine sine wave normally supplied to our homes. They can be used to power any kind of AC appliance from a DC source, including TVs, computers, video games, radios, and stereos. Modified sine wave inverters, on the other hand, use relatively inexpensive electronics (thyristors,diodes, and other simple components) to produce a kind of "rounded-off" square wave (a much rougher approximation to a sine wave) and while they're fine for delivering power to hefty electric appliances, they can and do cause problems with delicate electronics (or anything with an electronic or microprocessor controller). Also, if you think about it, their rounded-off square waves are delivering more power to the appliance overall than a pure sine wave (there's more area under a square than a curve), so there's some risk of overheating with MSW inverters. On the positive side, they tend to be quite a bit cheaper than true inverters and often work more efficiently (which is important if you want to run something off a battery with a limited charge—because it will run for longer).

Although many inverters work as standalone units, with battery storage, that are totally independent from the grid, others (known as utility-interactive inverters or grid-tied inverters) are specifically designed to be connected to the grid all the time; typically they're used to send electricity from something like a solar panel back to the grid at exactly the right voltage and frequency. That's fine if your main objective is to generate your own power. It's not so helpful if you want to be independent of the grid sometimes or you want a backup power source in case of an outage, because if your connection to the grid goes down, and you're not making any electricity of your own (for example, it's night-time and your solar panels are inactive), the inverter goes down too, and you're completely without power—as helpless as you would be whether you were generating your own power or not. For this reason, some people use bimodal or birectional inverters, which can either work in standalone or grid-tied mode (though not both at the same time). Since they have extra bits and pieces, they tend to be more bulky and more expensive.

What are inverters like?

Inverters can be very big and hefty—especially if they have built-in battery packs so they can work in a standalone way. They also generate lots of heat, which is why they have large heat sinks (metal fins) and often cooling fans as well. As you can see from our top photo, typical ones are about as big as a car battery or car battery charger; larger units look like a bit like a bank of car batteries in a vertical stack. The smallest inverters are more portable boxes the size of a car radio that you can plug into your cigarette lighter socket to produce AC for charging laptop computers or cellphones.

Just as appliances vary in the power they consume, so inverters vary in the power they produce. Typically, to be on the safe side, you'll need an inverter rated about a quarter higher than the maximum power of the appliance you want to drive. That allows for the fact that some appliances (such as fridges and freezers or fluorescent lamps) consume peak power when they're first switched on. While inverters can deliver peak power for short periods of time, it's important to note that they're not really designed to operate at peak power for long periods.

What is an uninterruptible power supply?

One very common use for inverters is in emergency power supplies, also called uninterruptible power supplies or uninterruptible power sources (both going by the acronym UPS). If your household power fails in an outage (blackout), you might have a UPS as a backup—but how does it work?

A typical UPS stores energy in electrical form using rechargeable batteries (some UPS systems store energy in mechanical form using a high-speed flywheel, spun to high speed by an electric motor). When the power is flowing normally, the batteries are being trickle charged by DC, which is produced from the AC power supply using a transformer and rectifier circuit. If the power fails, what you have at your disposal is charged-up batteries that will produce direct current, but which need to produce alternating current to power your home. So when the UPS is supplying energy, the batteries pump DC through an inverter to produce AC.

A UPS is often combined with a surge protector and voltage optimization equipment to produce a resilient power supply capable of surviving spikes, surges, over-voltage, under-voltage, or a complete loss of power.

microtek-jumbo-ups-jm1250-va-250x250.png

#11 Re: Ganesh's Puzzles » Oral puzzles » 2018-12-07 00:40:00

Hi,

The solution #4287 is correct. Neat work,  Monox D. I-Fly!

#4288. Ronit's age is 10 years more that Rohit's age. Also, Ronit was twice old as Rohit 15 years ago. What will be the age of Ronit 6 years after?

#12 Jokes » Monkey Jokes - 1 » 2018-12-07 00:16:48

ganesh
Replies: 0

Q: How do monkeys get down the stairs?
A: They slide down the banana-ster!
* * *
Q: What do you call a monkey that sells potato chips?
A: A chipmunk.
* * *
Q: What kind of a key opens a banana?
A: A monkey!
* * *
Q: Why did the monkey like the banana?
A: Because it had appeal!
* * *
Q: What do monkeys do for laughs?
A: They tell jokes about people!
* * *
Q: What do you call a baby monkey?
A: A Chimp off the old block.
* * *
Q: What do you tell a bad monkey?
A: Stop chimping about.
* * *
Q: What do you call a monkey with a banana in each ear?
A: Anything you want, it can't hear you!
* * *
Q: What did the monkey say when he cut off his tail?
A: It won't be long now.
* * *
Q: Where do monkeys go to drink?
A: The monkey bars!
* * *

#13 Re: Jokes » Lion Jokes - 2 » 2018-12-07 00:13:09

Thought-provoking, Monox D. I-Fly! smile smile

#14 Re: Ganesh's Puzzles » Oral puzzles » 2018-12-06 16:39:25

Hi,

The solution #4286 is correct. Excellent,  Monox D. I-Fly!

#4287. The average weight of 25 students is 16 kilograms. The average weight of the first 12 students is 14 kilograms and the last 12 students is 17 kilograms. Find the weight of the thirteenth student.

#15 Re: Dark Discussions at Cafe Infinity » crème de la crème » 2018-12-06 00:53:32

434) Eugen Baumann

Eugen Baumann (12 December 1846 – 3 November 1896) was a German chemist. He was one of the first people to create polyvinyl chloride (PVC), and, together with Carl Schotten, he discovered the Schotten-Baumann reaction.

Life

Baumann was born in Cannstatt, which is now part of Stuttgart. After he attended a gymnasium in Stuttgart, he was educated in the pharmacy of his father. During his time in Stuttgart, he already attended the lectures of Hermann von Fehling at the University of Stuttgart.

To broaden his education, he went to Lübeck and Gothenburg to work in pharmacies there. Later, he studied pharmacy at the University of Tübingen. He passed his first exam in 1870 and received his PhD in 1872 for work with Felix Hoppe-Seyler. He followed Hoppe-Seyler to the University of Straßburg where did his habilitation in 1876. The same year, Emil Heinrich Du Bois-Reymond offered him a position as the Head of the Chemistry Department of the Institute of Physiology in Berlin. In 1882, Baumann became professor of medicine at that institute, and subsequently obtained professor position at the University of Freiburg.

In 1895, he took over the management of Hoppe-Seyler's Zeitschrift für Physiologische Chemie with Albrecht Kossel.

From 1883 till his death, Baumann was married to Theresa Kopp, the daughter of chemist Hermann Kopp, and they had five children. He died at the age of 49 due to a heart problem.

Work

The organosulfur compounds of the urine were his starting point into the physiological chemistry. He identified the source for aromatic compounds in urine being the aromatic amino acids, such as tyrosine. He influenced the organosulfur chemistry by the synthesis of thioacetals and thioketals. These substances were subsequently used by other scientists, for example for anesthesia. Together with his coworkers, he was able to prove that thyroxine was the active ingredient in the thyroid gland.

Schotten-Baumann reaction

During his work at the physiological institute, Baumann, together with Carl Schotten, discovered a method to synthesize amides from amines and acid chlorides; this method is still known as the Schotten-Baumann reaction.

eugen_baumann.jpg

#17 Re: Ganesh's Puzzles » Oral puzzles » 2018-12-06 00:19:13

Hi,

#4286. The respective ratio of the ages of son, mother, father, and grandfather is 2:7:8:12. The average of the son and mother is 27 years. What will be the mother's age after 7 years?

#18 Jokes » Lion Jokes - 2 » 2018-12-05 16:20:19

ganesh
Replies: 2

Q: What's a lion running a copy machine called?
A: A copycat!
* * *
Q: What do you call a lion with chicken pox?
A: A dotted lion.
* * *
Q: What do you call a lion who chases camels across the desert?
A: A chameleon.
* * *
Q: What do you call a lion wearing a stylish hat?
A: A dandy lion.
* * *
Q: What job does a lion do at a newspaper?
A: Run the lionotype machine!
* * *
Q: Why are lions religious?
A: Because they prey frequently, and prey as a family!
* * *
Q: What does a lion do on a canoe?
A: Use his Roar!
* * *
Q: What happened when the lion ate the comedian?
A: He felt funny!
* * *
Q: What does the lion say to his friends before they go out hunting for food ?
A: 'Let us prey'.
* * *
Q: What do you get if you cross a lion with a watchdog ?
A: A terrified postman!
* * *
Q: What's the difference between a tiger and a lion?
A: A tiger has the mane part missing.
* * *
Q: What is lion's favorite food?
A: Baked being !
* * *

#19 Re: This is Cool » Miscellany » 2018-12-05 00:31:57

254) Seismograph

Seismograph, instrument that makes a record of seismic waves caused by an earthquake, explosion, or other Earth-shaking phenomenon. Seismographs are equipped with electromagnetic sensors that translate ground motions into electrical changes, which are processed and recorded by the instruments’ analog or digital circuits. The terms seismograph and seismometer are often used interchangeably; however, whereas both devices may detect and measure seismic waves, only a seismograph possesses the capacity to record the phenomena. A record produced by a seismograph on a display screen or paper printout is called a seismogram.

Although originally designed to locate natural earthquakes, seismographs have many other uses, such as petroleum exploration, investigation of Earth’s crust and lower layers, and monitoring of volcanic activity.

Development Of The First Seismographs

An early seismic instrument called the seismoscope made no time record of ground oscillations but simply indicated that shaking had occurred. A Chinese scholar, Zhang Heng, invented such an instrument as early as 132 CE. It was cylindrical in shape with eight dragon heads arranged around its upper circumference, each with a ball in its mouth. Around the lower circumference were eight frogs, each directly under a dragon head. When an earthquake occurred, balls were released from a dragon’s mouth, probably by an internal pendulum that moved back and forth according to the direction of vibration, and were caught by a frog’s mouth, which produced noise.

In 1855 Italian scientist Luigi Palmieri designed a seismograph that consisted of several U-shaped tubes filled with mercury and oriented toward the different points of the compass. When the ground shook, the motion of the mercury made an electrical contact that stopped a clock and simultaneously started a recording drum on which the motion of a float on the surface of mercury was registered. This device thus indicated time of occurrence and the relative intensity and duration of the ground motion.
The basic problem in measuring ground motions is to attain a steady point that remains fixed when the ground moves. Various types of pendulums have been used for that purpose. The simplest type is a common pendulum in which a heavy mass is suspended by a wire or rod from a fixed point (as in a clock). Other forms are the inverted pendulum, in which a heavy mass is fixed to the upper end of a vertical rod pointed at its lower end, and the horizontal pendulum, in which a rod with a mass on its end is suspended at two points so as to swing in a nearly horizontal plane instead of a vertical plane. After a series of earthquakes struck near Perthshire, Scotland, in 1839, a seismometer with an inverted pendulum was installed near Comrie in 1840.

The first true seismograph, according to Italian seismologists, was created in 1875 by Italian physicist Filippo Cecchi. The Cecchi seismograph also used pendulums, but it was the first to record the relative motion of the pendulums with respect to Earth’s ground motions as a function of time. The motions produced by seismic waves would activate a clock, and the recording surface (which tracked ground motion) advanced 1 cm (0.04 inch) per second, which would allow a reader to establish the timing of an earthquake’s onset as well as its duration.

Seismograph developments occurred rapidly in 1880 when Scottish physicist Sir James Alfred Ewing, Scottish engineer Thomas Gray, and English geologist John Milne, who were working in Japan at the time, began to study earthquakes. Following a severe earthquake that occurred at Yokohama near Tokyo in that year, they organized the Seismological Society of Japan. Under its auspices various devices, forerunners of today’s seismograph, were invented. Among the instruments constructed in that period was Milne’s famous horizontal pendulum seismograph. Milne successfully used that seismograph to record several earthquakes in Japan. Then, after returning to England, he established a small worldwide seismographic network using such instruments.

The horizontal pendulum seismograph was improved greatly after World War II. The Press-Ewing seismograph, developed in the United States for recording long-period waves, was widely used throughout the world. That device employed a Milne-type pendulum, but the pivot supporting the pendulum was replaced by an elastic wire to avoid friction.

Basic Principles Of The Modern Seismograph

If a common pendulum is free to swing in one direction and if the ground moves rapidly in the direction of freedom of the pendulum while the pendulum is motionless, the pendulum will tend to remain in place through inertia. If the ground moves back and forth (oscillates) and if the period of ground motion (the time necessary for one complete oscillation) is sufficiently shorter than the period of free oscillation of the pendulum, the pendulum will lag, and the movement of the ground relative to the pendulum can be recorded. The magnitude of that movement is commonly amplified electrically. When the period of the pendulum is comparable to that of the ground motion, the seismograph will not exactly record Earth’s movement. The correction, however, can readily be computed mathematically.

The ground can move in any of three directions, two horizontal and one vertical. Because each kind of movement must be separately recorded, three pendulums, one for each direction, are needed for a complete seismograph.

In general, then, the seismograph is an instrument in which the relative motion of pendulum and ground is recorded. It is equally possible to take the ratio between the deflection of the pendulum and the velocity (or acceleration) of the ground. That ratio is called the velocity (or acceleration) sensitivity of the seismograph.

If free oscillation of the pendulum is not minimized, it will mask the proper recording of seismic waves. The simplest way to reduce (damp out) the free oscillation of a pendulum is to suspend it in a viscous (thick) liquid of which the resisting force is proportional to the velocity of the pendulum. In practice, the required resisting force is exerted by a special device called a damper. In an electromagnetic damper, the resisting force is created by electrical currents induced in a copper plate moving in a strong magnetic field.

Various methods of recording pendulum motion have been developed. In the mechanical method (now of historical interest only), a sheet of smoked paper was wrapped around a rotating drum, so mounted as to move with Earth. A moving pen connected to the pendulum pressed lightly on the paper. The rotating drum shifted slightly with each revolution so that recorded lines were not superimposed on each other. The drum rotated without interruption; one sheet of paper usually lasted 24 hours. Though that method was simple and economical, the seismograph had to have a heavy mass to overcome the friction between pen and paper. In consequence, some mechanical seismographs weighed one ton or more. In the more-modern optical method, pendulum motion causes a mirror to move. Light is reflected by the mirror onto photosensitive paper wrapped on a drum. Thus, there is no friction to affect the pendulum.

In the electromagnetic method, widely used today, a coil fixed to the mass of the pendulum moves in a magnetic field and creates an electric current. When the current is amplified electronically, high magnification is obtainable. Certain short-period seismographs of that type used for the observation of microearthquakes attain a magnification as high as 1,000,000 or more. In ordinary seismographic observation, the time of initiation of ground oscillations is recorded. Marks are placed on the seismogram once a minute; an extra one identifies the hour.

All the seismographs described so far measure oscillatory motions of the ground at a given point. The strain seismograph, in contrast, employs no pendulum, and its operation depends on changes in the distance between two points on the ground. That type of seismograph was devised in 1935 by American seismologist Hugo Benioff.

Strong-motion seismographs, called accelerographs, are designed particularly to register intense movements of the ground, mainly for engineering purposes—i.e., antiseismic construction in earthquake-prone areas such as Japan. Strong-motion seismographs employ accelerometers as sensors, record digitally directly on magnetic tape or memory chips, and can measure ground acceleration up to twice gravity. Networks of accelerographs are now operative in several earthquake regions (e.g., California, Japan, Taiwan, Mexico), offering continuous direct recording linked to computers and the Internet. Data on ground shaking are thus available within seconds of a local damaging earthquake.

Applications Of The Seismograph

A seismograph records oscillation of the ground caused by seismic waves that travel from their point of origin through Earth or along its surface. The seismogram of a nearby small earthquake has a simple pattern, showing the arrival of P waves (longitudinal waves, which vibrate in the direction of propagation), S waves (transverse waves—that is, waves that vibrate at right angles to the direction of propagation), and surface waves (compression waves with no vertical or longitudinal components). In the case of distant earthquakes or of nearby very large earthquakes, the seismogram pattern is more complicated because it shows various sorts of seismic waves that originate from one or many points but then may be reflected or refracted within Earth’s crust before reaching the seismograph. The relation between the arrival time of the P and S waves and the epicentral distance—i.e., the distance from the point of origin—is expressed by a time-distance curve, in which the arrival time is read on the vertical axis and the epicentral distance on the horizontal axis. If the arrival times of various seismic waves are read on the seismogram at a station and compared with the standard time-distance curves, the epicentral distance from that station (the distance of the centre of the earthquake from the recording station) can be determined. If the epicentral distance from at least three stations is known, the origin of the earthquake can be calculated by simple trigonometric methods.

The eruption of a volcano is commonly accompanied by many small earthquakes, especially when a volcano resumes activity after a long dormant period. Observation with sensitive seismographs therefore plays an important role in predicting volcanic activity.

Often a strong earthquake is preceded by small earthquakes. Observation of very small tremors with sensitive seismographs is helpful in predicting disastrous earthquakes.

Seismographs sometimes detect small and long-continuing oscillations of the ground, called microseisms, that do not originate as earthquakes. The occurrence of some microseisms is related to storms at sea.

Seismographs are used for detecting remote underground tests of nuclear weapons, in which the relatively faint seismic waves generated by an underground explosion must be distinguished from natural tremors. If the seismic waves generated by an explosive charge are recorded by sensitive seismographs installed at various points in the neighbourhood of the explosion, the underground structure of the site can be determined by analyzing the time-distance curves of the P waves, using both direct waves and those reflected or refracted at the boundaries of underground layers.

The depths of underground layers, their angle of inclination, and the speed of seismic waves in each layer can be also determined by using seismographs. Since the discovery of a large oil field in Texas by that method in 1923, seismic surveying has made rapid progress and is now used for oil and gas exploration. The improvement in the instruments and techniques achieved after World War II made it possible to determine the structure of Earth’s crust to a depth of 40–50 km (about 25–30 miles) by detonation of a small amount of explosive.

Ground motions caused by injecting fracking water into underground disposal wells and dynamiteblasts in mines, quarries, and public works also can be measured by the seismograph. Preliminary examinations based on seismographic measurements make it possible to estimate the intensity of shocks and, thus, evaluate the amount of damage caused by a given amount of dynamite. Rock bursts, in which rocks are ejected suddenly in deep pits or tunnels, are caused by increase of stress in the surrounding rocks. Experience in mines shows that an increase of small shocks detectable by highly sensitive geophones—portable seismometers for field use—generally indicates a rock burst hazard.

Detection of vibrations on the lunar surface by seismographs is of fundamental importance in determining the internal structure, physical state, and tectonic (crustal) activity of the Moon. Moon seismographs were installed during the Apollo program starting in 1969. They contained three long-period seismometers and a single-component, short-period, vertical seismometer. Many moonquakes were recorded by those instruments. Similar instruments were first placed on Mars by the Viking 2 lander in 1976 to determine the extent of seismic activity on that planet.

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#20 Re: Ganesh's Puzzles » Oral puzzles » 2018-12-05 00:23:36

Hi,

.

#4285. The average height of 16 students is 142 centimeters. If the heights of the teacher is included, the average height increases by 1 centimeter. Find the heights of the teacher.

#22 Re: Dark Discussions at Cafe Infinity » crème de la crème » 2018-12-04 02:32:41

433) Benoît Fourneyron

Benoît Fourneyron, (born Oct. 31, 1802, Saint-Étienne, Fr.—died July 31, 1867, Paris), French inventor of the water turbine.

The son of a mathematician, he graduated in the first class of the new Saint-Étienne engineering school in 1816. While working in the ironworks at Le Creusot, he studied a proposal advanced by his former professor, Claude Burdin, for a new type of waterwheel that Burdin named a “turbine.” Though neither the Academy of Sciences nor the Society for the Encouragement of Industry accepted Burdin’s paper, Fourneyron recognized its importance and undertook its realization. He built in 1827 a small, six-horsepower unit in which water was directed outward from a central source onto blades or vanes set at angles in a rotor.

By 1837 Fourneyron had produced a turbine capable of 2,300 revolutions per minute, 80 percent efficiency, and 60 horsepower, with a wheel a foot in diameter and weighing only 40 pounds (18 kilograms). Besides its more obvious advantages over the waterwheel, Fourneyron’s turbine could be installed as a horizontal wheel with a vertical shaft. It achieved immediate international success, powering industry in continental Europe and in the United States, notably the New England textile industry. But the real significance of the invention did not emerge until 1895, when Fourneyron turbines were installed on the American side of Niagara Falls to turn generators for electric-power production.

Fourneyron perceived the potential of steam-driven turbines, but his attempts to make a satisfactory steam turbine were thwarted by the inadequacy of available materials and workmanship.

fourneyron.jpg

#23 Re: Ganesh's Puzzles » 10 second questions » 2018-12-04 01:56:39

Hi,

.

#7120. Find the value of m.

.

#24 Re: Ganesh's Puzzles » Oral puzzles » 2018-12-04 01:42:40

Hi,

.

#4284. The average weight of 15 oarsman in a boat is increased by 1.6 kilograms when one of the crew , who weighs 42 kilograms is replaced by a new man. Find the weight of the new man in kilograms.

#25 Jokes » Lion Jokes - 1 » 2018-12-04 01:21:00

ganesh
Replies: 0

Q: How do you take a lion's temperature?
A: Very carefully!
* * *
Q: On which day do lions eat people ?
A: Chewsday!
* * *
Q: Why don't lions like fast food?
A: Because they can't catch it!
* * *
Q: Would you rather have a tiger eat you or a lion?
A: I would rather have a tiger eat a lion.
* * *
Q: Why do lions always eat raw meat?
A: Because they don't know how to cook.
* * *
Q: How much does a lion trainer have to know?
A: More than the lion!
* * *
Q: Why did the lion trainer buy new clothes for working with his lions?
A: He wanted to take 'pride' in his appearance!
* * *
Q: What is a lions favorite cookie?
A: Chocolate Chimp.
* * *
Q: What is a lions favorite state?
A: Maine.
* * *
Q: What street do lions live on?
A: Mane St.
* * *
Q: Why didn't the lion eat the detective?
A: Because he was under cover.
* * *
Q: Why do lions always eat raw meat?
A: They can't cook!
* * *
Q: What animals do you need to make a square?
A: 4 Lions.
* * *
Q: Why did the lion spit out the clown?
A: Because he tasted funny.
* * *

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