A hydrometer or areometer is an instrument that measures the specific gravity of liquids—the ratio of the density of the liquid to the density of water. A hydrometer is usually made of glass, and consists of a cylindrical stem, the liquid to test is poured into a tall container, often a graduated cylinder, and the hydrometer is gently lowered into the liquid until it floats freely. The point at which the surface of the liquid touches the stem of the hydrometer correlates to specific gravity, Hydrometers usually contain a scale inside the stem, so that the person using it can read specific gravity. A variety of scales exist for different contexts, principle Operation of the hydrometer is based on that a solid suspended in a fluid is buoyed by a force equal to the weight of the fluid displaced by the submerged part of the suspended solid. Thus, the lower the density of the substance, the farther the hydrometer sinks, thus, it is based on the principle of floatation. An early description of a hydrometer appears in a letter from Synesius of Cyrene to the Greek scholar Hypatia of Alexandria, in Synesius fifteenth letter, he requests Hypatia to make a hydrometer for him.
Hypatia is given credit for inventing the hydrometer sometime in the late 4th century or early 5th century, the instrument in question is a cylindrical tube, which has the shape of a flute and is about the same size. It has notches in a line, by means of which we are able to test the weight of the waters. A cone forms a lid at one of the extremities, closely fitted to the tube, the cone and the tube have one base only. Whenever you place the tube in water, it remains erect and you can count the notches at your ease, and in this way ascertain the weight of the water. According to the Encyclopedia of the History of Arabic Science, it was used by Abū Rayhān al-Bīrūnī in the 11th century and it appeared again in the work of Jacques Alexandre César Charles in the 18th century. In low-density liquids such as kerosene and alcohol, the hydrometer sinks deeper, and in high-density liquids such as brine and acids it doesnt sink so far. In many industries a set of hydrometers is used — covering specific gravity ranges of 1. 0–0.95,0. 95–0.9 etc. — to provide precise measurements.
Modern hydrometers usually measure specific gravity but different scales were used in certain industries, examples include, API gravity, universally used worldwide by the petroleum industry. A lactometer is used to check purity of cows milk, the specific gravity of milk does not give a conclusive indication of its composition since milk contains a variety of substances that are either heavier or lighter than water. Additional tests for fat content are necessary to determine overall composition, the instrument is graduated into a hundred parts. Milk is poured in and allowed to stand until the cream has formed, the device works on the principle of Archimedes principle that a solid suspended in a fluid is buoyed by a force equal to the weight of the fluid displaced. If the milk sample is pure, the lactometer floats on it and if it is adulterated or impure, an alcoholmeter is a hydrometer that indicates the alcoholic strength of liquids
Meat is animal flesh that is eaten as food. Humans have hunted and killed animals for meat since prehistoric times, the advent of civilization allowed the domestication of animals such as chickens, sheep and cattle. This eventually led to their use in production on an industrial scale with the aid of slaughterhouses. Meat is mainly composed of water and fat and it is edible raw, but is normally eaten after it has been cooked and seasoned or processed in a variety of ways. Unprocessed meat will spoil or rot within hours or days as a result of infection with and decomposition by bacteria, most often, meat refers to skeletal muscle and associated fat and other tissues, but it may describe other edible tissues such as offal. The word meat comes from the Old English word mete, which referred to food in general, the term is related to mad in Danish, mat in Swedish and Norwegian, and matur in Icelandic and Faroese, which mean food. The word mete exists in Old Frisian to denote important food, differentiating it from swiets, paleontological evidence suggests that meat constituted a substantial proportion of the diet of even the earliest humans.
Early hunter-gatherers depended on the hunting of large animals such as bison. Several breeds of sheep were established in ancient Mesopotamia and Egypt by 3500–3000 BC, more than 200 sheep-breeds exist. Cattle were domesticated in Mesopotamia after settled agriculture was established about 5000 BC, modern domesticated cattle fall into the groups Bos taurus and Bos indicus, both descended from the now-extinct aurochs. The breeding of cattle, cattle optimized for meat production as opposed to animals best suited for draught or dairy purposes. Domestic pigs, which are descended from boars, are known to have existed about 2500 BC in modern-day Hungary and in Troy, earlier pottery from Jericho. Pork sausages and hams were of commercial importance in Greco-Roman times. Pigs continue to be bred intensively as they are being optimized to produce meat best suited for meat products. Other animals are or have raised or hunted for their flesh. The type of meat consumed varies much between different cultures, changes over time, depending on such as tradition and the availability of the animals.
The amount and kind of meat consumed varies by income, horses are commonly eaten in France, Italy and Japan, among other countries. Horses and other mammals such as reindeer were hunted during the late Paleolithic in western Europe
Salt evaporation pond
Salt evaporation ponds, called salterns, salt works or salt pans, are shallow artificial ponds designed to extract salts from sea water or other brines. The seawater or brine is fed into large ponds and water is drawn out through natural evaporation which allows the salt to be subsequently harvested, the ponds provide a productive resting and feeding ground for many species of waterbirds, which may include endangered species. The ponds are separated by levees. Natural salt pans are geological formations that are created by water evaporating and leaving behind salts. Due to variable algal concentrations, vivid colors – from pale green to bright red – are created in the evaporation ponds, the color indicates the salinity of the ponds. Microorganisms change their hues as the salinity of the pond increases, in low- to mid-salinity ponds, green algae such as Dunaliella salina are predominant, although these algae can take on an orange hue. In middle- to high-salinity ponds, which is actually a group of halophilic Archaea, shift the colour to pink, other bacteria such as Stichococcus contribute tints.
Notable salt ponds include, the Salterns of Guérande, in Brittany, until World War II, salt was extracted from sea water in a unique way in Egypt near Alexandria. Posts were set out on the pans and covered with several feet of sea water. In time the sea water evaporated, leaving the salt behind on the post, salt pans are shallow open, often metal, pans used to evaporate brine for the production of salts. They are usually close to the source of the salt. In this case, extra heat is provided by lighting fires underneath
Seawater, or salt water, is water from a sea or ocean. On average, seawater in the oceans has a salinity of about 3. 5% This means that every kilogram of seawater has approximately 35 grams of dissolved salts. Average density at the surface is 1.025 kg/l, seawater is denser than both fresh water and pure water because the dissolved salts increase the mass by a larger proportion than the volume. The freezing point of seawater decreases as salt concentration increases, at typical salinity, it freezes at about −2 °C. The coldest seawater ever recorded was in 2010, in a stream under an Antarctic glacier, seawater pH is typically limited to a range between 7.5 and 8.4. However, there is no universally accepted reference pH-scale for seawater, although the vast majority of seawater has a salinity of between 31 g/kg and 38 g/kg, seawater is not uniformly saline throughout the world. Where mixing occurs with fresh water runoff from river mouths, near melting glaciers or vast amounts precipitation, the most saline open sea is the Red Sea, where high rates of evaporation, low precipitation and low river run-off, and confined circulation result in unusually salty water.
The salinity in isolated bodies of water can be considerably greater still, several salinity scales were used to approximate the absolute salinity of seawater. A popular scale was the Practical Salinity Scale where salinity was measured in practical salinity units, the current standard for salinity is the Reference Salinity scale with the salinity expressed in units of g/kg. The density of surface seawater ranges from about 1020 to 1029 kg/m3, depending on the temperature, at a temperature of 25 °C, salinity of 35 g/kg and 1 atm pressure, the density of seawater is 1023.6 kg/m3. Deep in the ocean, under pressure, seawater can reach a density of 1050 kg/m3 or higher. The density of seawater changes with salinity, brines generated by seawater desalination plants can have salinities up to 120 g/kg. The density of typical seawater brine of 120 g/kg salinity at 25 °C, seawater pH is limited to the range 7.5 to 8.4. The speed of sound in seawater is about 1,500 m/s, and varies with temperature, salinity.
The thermal conductivity of seawater is 0.6 W/mK at 25 °C, the thermal conductivity decreases with increasing salinity and increases with increasing temperature. Seawater contains more dissolved ions than all types of freshwater, the ratios of solutes differ dramatically. Bicarbonate ions constitute 48% of river water solutes but only 0. 14% of all seawater ions, differences like these are due to the varying residence times of seawater solutes and chlorine have very long residence times, while calcium tends to precipitate much more quickly. The most abundant dissolved ions in seawater are sodium, magnesium and its osmolarity is about 1000 mOsm/l
Saline water is water that contains a significant concentration of dissolved salts. The salt concentration is expressed in parts per thousand or parts per million. The United States Geological Survey classifies saline water in three salinity categories. Salt concentration in slightly saline water is around 1,000 to 3,000 ppm, in saline water 3,000 to 10,000 ppm. Seawater has a salinity of roughly 35,000 ppm, equivalent to 35 grams of salt per one liter of water, the saturation level is dependent on the temperature of the water. At 20 °C one milliliter of water can dissolve about 0.357 grams of salt, at boiling the amount that can be dissolved in one milliliter of water increases to about 0.391 grams or 28. 1% saline solution. Some industries make use of water, such as mining. In the United States,14 percent of all used in 2000 was saline. Almost all saline withdrawals, over 92 percent, were used by the power industry to cool electricity-generating equipment. About three percent of the saline water was used for mining and other industrial purposes.
Due to their proximity to the Atlantic and Pacific Oceans, states near the coast make the most use of saline water, almost 40% of all saline water use in 2000 occurred in California and Maryland. The use of water, as with freshwater, has been trending downward since a peak in 1968. But, in the period between 1950 and 1968, the use of water increased at a much higher rate than freshwater use. The thermal conductivity of seawater is 0.6 W/mK at 25 °C, brackish water Brine Media related to Saline water at Wikimedia Commons
Total dissolved solids
Total dissolved solids is a measure of the combined content of all inorganic and organic substances contained in a liquid in molecular, ionized or micro-granular suspended form. Generally the operational definition is that the solids must be enough to survive filtration through a filter with two-micrometer pores. Total dissolved solids are normally discussed only for systems, as salinity includes some of the ions constituting the definition of TDS. The chemicals may be cations, molecules or agglomerations on the order of one thousand or fewer molecules, more exotic and harmful elements of TDS are pesticides arising from surface runoff. Certain naturally occurring total dissolved solids arise from the weathering and dissolution of rocks, the United States has established a secondary water quality standard of 500 mg/l to provide for palatability of drinking water. Total dissolved solids are differentiated from total suspended solids, in that the latter cannot pass through a sieve of two micrometers and yet are indefinitely suspended in solution.
The term settleable solids refers to material of any size that will not remain suspended or dissolved in a holding tank not subject to motion, settleable solids may include larger particulate matter or insoluble molecules. The two principal methods of measuring total dissolved solids are gravimetric analysis and conductivity, gravimetric methods are the most accurate and involve evaporating the liquid solvent and measuring the mass of residues left. This method is generally the best, although it is time-consuming, if inorganic salts comprise the great majority of TDS, gravimetric methods are appropriate. Electrical conductivity of water is related to the concentration of dissolved ionized solids in the water. Ions from the solids in water create the ability for that water to conduct an electric current. When correlated with laboratory TDS measurements, conductivity provides a value for the TDS concentration. The correlation factor ke varies between 0.55 and 0.8, hydrologic transport models are used to mathematically analyze movement of TDS within river systems.
The most common models address surface runoff, allowing variation in land use type, soil type, vegetative cover, runoff models have evolved to a good degree of accuracy and permit the evaluation of alternative land management practices upon impacts to stream water quality. Basin models are used to more comprehensively evaluate total dissolved solids within a catchment basin, the DSSAM model was developed by the U. S. Environmental Protection Agency. This hydrology transport model is based upon the pollutant-loading metric called Total Maximum Daily Load. The success of this contributed to the Agency’s broadened commitment to the use of the underlying TMDL protocol in its national policy for management of many river systems in the United States. High levels of dissolved solids do not correlate to hard water
Marination is the process of soaking foods in a seasoned, often acidic, liquid before cooking. The origin of the word alludes to the use of brine in the pickling process, the liquid in question, the marinade, can be either acidic or enzymatic. In addition to ingredients, a marinade often contains oils, herbs. It is commonly used to flavor foods and to tenderize tougher cuts of meat, the process may last seconds or days. Different marinades are used in different cuisines, for example, in Indian cuisine the marinade is usually prepared with a mixture of spices. In meats, the causes the tissue to break down. A good marinade has a balance of acid, oil, if raw marinated meat is frozen, the marinade can break down the surface and turn the outer layer mushy. Often confused with marinating, macerating is a form of food preparation. Raw pork, seafood and poultry may contain harmful bacteria which may contaminate the marinade, marinating should be done in the refrigerator to inhibit bacterial growth. Used marinade should not be made into a sauce unless rendered safe by boiling directly before use, the container used for marinating should be glass or food safe plastic.
Metal, including pottery glazes which can lead, reacts with the acid in the marinade
Anhydrite is a mineral—anhydrous calcium sulfate, CaSO4. It is in the crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the orthorhombic barium and strontium sulfates, distinctly developed crystals are somewhat rare, the mineral usually presenting the form of cleavage masses. The Mohs hardness is 3.5 and the gravity is 2.9. The color is white, sometimes greyish, bluish, or purple, on the best developed of the three cleavages, the lustre is pearly, on other surfaces it is glassy. When exposed to water, anhydrite readily transforms to the commonly occurring gypsum. This transformation is reversible, with gypsum or calcium sulfate hemihydrate forming anhydrite by heating to around 200 °C under normal atmospheric conditions, anhydrite is commonly associated with calcite and sulfides such as galena, chalcopyrite and pyrite in vein deposits. Anhydrite is most frequently found in deposits with gypsum, it was, for instance, first discovered, in 1794.
In this occurrence, depth is critical since nearer the surface anhydrite has been altered to gypsum by absorption of circulating ground water and this is one of the several methods by which the mineral has been prepared artificially, and is identical with its mode of origin in nature. The mineral is common in salt basins, anhydrite occurs in a tidal flat environment in the Persian Gulf sabkhas as massive diagenetic replacement nodules. Cross sections of these nodular masses have an appearance and have been referred to as chicken-wire anhydrite. Nodular anhydrite occurs as replacement of gypsum in a variety of depositional environments. Massive amounts of anhydrite occur when salt domes form a caprock, anhydrite is 1–3% of the salt in salt domes and is generally left as a cap at the top of the salt when the halite is removed by pore waters. The typical cap rock is a salt, topped by a layer of anhydrite, topped by patches of gypsum, interaction with oil can reduce SO4 creating calcite and hydrogen sulfide.
Anhydrite has been found in igneous rocks, for example in the intrusive dioritic pluton of El Teniente, Chile and in trachyandesite pumice erupted by El Chichón volcano. The name anhydrite was given by A. G. Werner in 1804, because of the absence of water of crystallization, as contrasted with the presence of water in gypsum. Some obsolete names for the species are muriacite and karstenite, the former, the Catalyst Science Discovery Centre, has a relief carving of an anhydrite kiln, made from a piece of anhydrite, for the United Sulphuric Acid Corporation
Water is a transparent and nearly colorless chemical substance that is the main constituent of Earths streams and oceans, and the fluids of most living organisms. Its chemical formula is H2O, meaning that its molecule contains one oxygen, Water strictly refers to the liquid state of that substance, that prevails at standard ambient temperature and pressure, but it often refers to its solid state or its gaseous state. It occurs in nature as snow, ice packs and icebergs, fog, aquifers, Water covers 71% of the Earths surface. It is vital for all forms of life. Only 2. 5% of this water is freshwater, and 98. 8% of that water is in ice and groundwater. Less than 0. 3% of all freshwater is in rivers and the atmosphere, a greater quantity of water is found in the earths interior. Water on Earth moves continually through the cycle of evaporation and transpiration, precipitation. Evaporation and transpiration contribute to the precipitation over land, large amounts of water are chemically combined or adsorbed in hydrated minerals.
Safe drinking water is essential to humans and other even though it provides no calories or organic nutrients. There is a correlation between access to safe water and gross domestic product per capita. However, some observers have estimated that by 2025 more than half of the population will be facing water-based vulnerability. A report, issued in November 2009, suggests that by 2030, in developing regions of the world. Water plays an important role in the world economy, approximately 70% of the freshwater used by humans goes to agriculture. Fishing in salt and fresh water bodies is a source of food for many parts of the world. Much of long-distance trade of commodities and manufactured products is transported by boats through seas, lakes, large quantities of water and steam are used for cooling and heating, in industry and homes. Water is an excellent solvent for a variety of chemical substances, as such it is widely used in industrial processes. Water is central to many sports and other forms of entertainment, such as swimming, pleasure boating, boat racing, sport fishing, Water is a liquid at the temperatures and pressures that are most adequate for life.
Specifically, at atmospheric pressure of 1 bar, water is a liquid between the temperatures of 273.15 K and 373.15 K
Halite, commonly known as rock salt, is a type of salt, the mineral form of sodium chloride. The mineral is colorless or white, but may be light blue, dark blue, pink, orange, yellow or gray depending on the amount. It commonly occurs with other evaporite minerals such as several of the sulfates, halides. Halite occurs in vast beds of sedimentary evaporite minerals that result from the drying up of enclosed lakes, salt beds may be hundreds of meters thick and underlie broad areas. In the United States and Canada extensive underground beds extend from the Appalachian basin of western New York through parts of Ontario, other deposits are in Ohio, New Mexico, Nova Scotia and Saskatchewan. The Khewra salt mine is a deposit of halite near Islamabad. In the United Kingdom there are three mines, the largest of these is at Winsford in Cheshire producing on average a million tonnes per year. Salt domes are vertical diapirs or pipe-like masses of salt that have been squeezed up from underlying salt beds by mobilization due to the weight of overlying rock.
Salt domes contain anhydrite and native sulfur, in addition to halite and sylvite and they are common along the Gulf coasts of Texas and Louisiana and are often associated with petroleum deposits. Germany, the Netherlands and Iran have salt domes, salt glaciers exist in arid Iran where the salt has broken through the surface at high elevation and flows downhill. In all of these cases, halite is said to be behaving in the manner of a rheid, purple, fibrous vein filling halite is found in France and a few other localities. Halite crystals termed hopper crystals appear to be skeletons of the cubes, with the edges present and stairstep depressions on, or rather in. In a rapidly crystallizing environment, the edges of the cubes simply grow faster than the centers, halite crystals form very quickly in some rapidly evaporating lakes resulting in modern artifacts with a coating or encrustation of halite crystals. Halite flowers are rare stalactites of curling fibers of halite that are found in certain arid caves of Australias Nullarbor Plain, halite stalactites and encrustations are reported in the Quincy native copper mine of Hancock, Michigan.
Halite is often used both residentially and municipally for managing ice, because brine has a lower freezing point than pure water, putting salt or saltwater on ice that is near 0 °C will cause it to melt. It is common for homeowners in cold climates to spread salt on their sidewalks and driveways after a snow storm to melt the ice. It is not necessary to use so much salt that the ice is melted, rather. Also, many cities will spread a mixture of sand and salt on roads during, in addition to de-icing, rock salt is occasionally used in agriculture