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What are some cases that forensic entomology has been used to solve?

Udemy, an online education platform, cites a few 1990s cases in which forensic entomology was used to investigate death. In the so-called "Ken and Barbie" murder that took place in Canada in 1991, a forensic entomologist was able to narrow down the possible time of death from 15 days to just four days. The time frame helped identify the two murderers, Udemy states. The Ohio case of Kevin Neal, who was convicted of killing his two stepchildren, hinged on a forensic entomologist's testimony of the presence or absence of certain bugs at the crime scene.\nThere are many cases in which the lif..

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How many arcseconds are in a full circle?

Arcminutes and arcseconds are used in fields that involve precise measurements and very small angles, such as astronomy, optometry, optics and navigation. In astronomy, where calculations often involve vast distances, the difference made by a tiny discrepancy in angle measure can create significant error. Astronomers sometimes use even smaller subdivisions of the arcsecond, referred to milliarcseconds and microarcseconds. Measurements as small as an arcminute are also commonly used in the firearms industry when evaluating and adjusting the accuracy of a rifle.

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How does a battery work?

There are three major components inside a battery. The anode is the negatively charged terminal of the battery, while the cathode is the positively charged terminal. The anode and cathode are not directly connected, but both are in contact with an electrolyte liquid or paste that allows electrons to pass from one to the other. When connected in a circuit, the anode reacts with the electrolyte to release electrons, and the cathode reacts with the electrolyte to absorb them. This produces a one-way flow of electricity through the circuit until the electrolyte medium is exhausted.\nIn batteries t..

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How is cellophane made?

According to Prism Pak, Inc., a producer of cellophane bags, some cellophane bags are made from a man-made polymer known as BOPP, or bi-axially oriented polypropylene. However, the cellophane bags made from cellulose that have been derived from plants, such as wood or cotton, are biodegradable.\nSince cellulose is a natural fiber that forms the rigid cell wall of plants, it biodegrades. This natural cellulose undergoes a series of chemical baths, which remove the impurities. Then, as the cellulose film begins to form, chemicals are added to make the material more flexible. Since this form of c..

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What is the difference between specific heat and heat capacity?

Temperatures of a substance rise when it is heated but decrease when a substance is cooled. The difference in temperature is proportional to the amount of heat supplied. Specific heat and heat capacity are two proportionality constants relating the temperature change and the amount of heat. The temperature of an object is a measure of the energy of each individual particle within it. On the other hand, heat energy is a measure of the total energy of the substance as a whole. This explains why a candle flame (750 degrees Celsius) can be put out with moist fingers without getting hurt, but it is..

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Why does sound travel faster in water than in air?

A sound is a wave that is transferred by particles. Since particles are spread so far apart in gas, it takes longer for them to bump into each other and transport the sound. In water, however, particles are right next to each other. This is why sound can travel over 3,280 feet per second in water, but only about 1,083 feet per second in air.

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What enzymes digest fats?

The pancreas secretes the enzyme lipase that breaks down various lipids or fat nutrients, such as triglycerides found in the foods people eat. Lipase breaks down and converts large fat molecules into smaller molecules called glycerol and fatty acids. This process takes place in the small intestine. The blood then absorbs the glycerol and fatty acids.\nThe pancreas is an important part of the digestive system because it also produces other types of enzymes, such as amylase and trypsin. While amylase breaks down carbohydrates, trypsin digests proteins. The pancreas also produces the hormone insu..

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What color is shale?

Shale colors fall in the neutral color palette and can be paired with blues for a country look, soft pinks for romantic style or gray tones for classic decor. When accented with gold accessories or gold-toned furniture, shale colors have a luxurious, elegant feel. Mixing shale tones with wood furniture or accents gives a room an earthy feel. Bright green or teal accents liven up a room that is decorated mainly with shale tones.

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How does meiosis contribute to genetic variation?

Meiosis is a way in which cells divide that distributes half of the usual 46 human chromosomes to sperm and half to an egg, according to Wikipedia. Together, the egg and sperm result in a fertilized egg, known as a zygote, which contains all 46 chromosomes. Half the chromosomes come from the father, and half come from the mother. The process of meiosis and fertilization result in every generation having the same number of 46 chromosomes. The process also takes place in animals and plants.\nOscar Hertwig, a German biologist, first observed the process of meiosis in 1876 as he studied the eggs o..

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What is the term that describes the bending of rock layers due to stress?

When a rock formation experiences significant stress, the formation typically either folds or faults. Folding refers to the rock formation bending either in a syncline formation or an anticline formation. A syncline formation is concave up and resembles a "U" shape, while an anticline formation is concave down and resembles an "A" shape. The stress that forms folding in rocks is typically caused by a strong force placed on the rock formation.

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