Mortar and pestle
Mortar and pestle are implements used since ancient times to prepare ingredients or substances by crushing and grinding them into a fine paste or powder in the kitchen and pharmacy. The mortar is a bowl made of hard wood, ceramic, or hard stone, such as granite; the pestle is a blunt club-shaped object. The substance to be ground, which may be wet or dry, is placed in the mortar, where the pestle is pressed and rotated onto it until the desired texture is achieved. Scientists have found ancient mortars and pestles that date back to 35000 BC; the English word mortar derives from classical Latin mortarium, among several other usages, "receptacle for pounding" and "product of grinding or pounding". The classical Latin pistillum, meaning "pounder", led to English pestle; the Roman poet Juvenal applied both mortarium and pistillum to articles used in the preparation of drugs, reflecting the early use of the mortar and pestle as a symbol of a pharmacist or apothecary. The antiquity of these tools is well documented in early writing, such as the Egyptian Ebers Papyrus of ~1550 BC and the Old Testament.
Mortars and pestles were traditionally used in pharmacies to crush various ingredients prior to preparing an extemporaneous prescription. The mortar and pestle, with the Rod of Asclepius, the Green Cross, others, is one of the most pervasive symbols of pharmacology, along with the show globe. For pharmaceutical use, the mortar and the head of the pestle are made of porcelain, while the handle of the pestle is made of wood; this is known as a Wedgwood mortar and pestle and originated in 1759. Today the act of reducing the particle size is known as trituration. Mortars and pestles are used as drug paraphernalia to grind up pills to speed up absorption when they are ingested, or in preparation for insufflation. To finely ground drugs, not available in liquid dosage form is used if patients need artificial nutrition such as parenteral nutrition or by nasogastric tube. Mortars are used in cooking to prepare wet or oily ingredients such as guacamole and pesto, as well as grinding spices into powder.
The molcajete, a version used by pre-Hispanic Mesoamerican cultures including the Aztec and Maya, stretching back several thousand years, is made of basalt and is used in Mexican cooking. Other Native American nations use mortars carved into the bedrock to other nuts. Many such depressions can be found in their territories. In Japan large mortars are used with wooden mallets to prepare mochi. A regular sized Japanese mortar and pestle are called surikogi, respectively. Granite mortars and pestles are used in Southeast Asia, as well as India. In India, it is used extensively to make spice mixtures for various delicacies as well as day to day dishes. With the advent of motorized grinders, use of the mortar and pestle has decreased, it is traditional in various Hindu ceremonies to crush turmeric in these mortars. In Malay, it is known as batu lesung. Large stone mortars, with long wood pestles were used in West Asia to grind meat for a type of meatloaf, or kibbeh, as well as the hummus variety known as masabcha.
In Indonesia and the Netherlands mortar is known as Cobek or Tjobek and pestle is known as Ulekan or Oelekan. It is used to make fresh sambal, a spicy chili condiment, hence the sambal ulek/oelek denote its process using pestle, it is used to grind peanut and other ingredients to make peanut sauce for gado-gado. Large mortars and pestles are used in developing countries to husk and dehull grain; these are made of wood, operated by one or more persons. Good mortar and pestle-making materials must be hard enough to crush the substance rather than be worn away by it, they can not be too brittle either. The material should be cohesive, so that small bits of the mortar or pestle do not mix in with the ingredients. Smooth and non-porous materials are trap the substances being ground. In food preparation, a rough or absorbent material may cause the strong flavour of a past ingredient to be tasted in food prepared later; the food particles left in the mortar and on the pestle may support the growth of microorganisms.
When dealing with medications, the prepared drugs may interact or mix, contaminating the used ingredients. Rough ceramic mortar and pestle sets can be used to reduce substances to fine powders, but stain and are brittle. Porcelain mortars are sometimes conditioned for use by grinding some sand to give them a rougher surface which helps to reduce the particle size. Glass mortars and pestles are fragile, but suitable for use with liquids. However, they do not grind as finely as the ceramic type. Other materials used include stone marble or agate, bamboo, steel and basalt. Mortar and pestle sets made from the wood of old grape vines have proved reliable for grinding salt and pepper at the dinner table. Uncooked rice is sometimes ground in mortars to clean them; this process must be repeated until the rice comes out white. Some stones, such as molcajete, need to be seasoned first before use. Metal mortars are kept oiled. Since the results obtained with hand grinding are neither reproducible nor reliable, most laboratories work with automatic mortar grinders.
Grinding time and pressure of the mortar can be adjusted and fixed, saving time and labor. The first automatic Mortar Grinder was invented by F. Kurt
A clamp is a fastening device used to hold or secure objects together to prevent movement or separation through the application of inward pressure. In the United Kingdom and Australia, the term cramp is used instead when the tool is for temporary use for positioning components during construction and woodworking. There are many types of clamps available for many different purposes; some are temporary, as used to position components while fixing them together, others are intended to be permanent. In the field of animal husbandry, using a clamp to attach an animal to a stationary object is known as "rounded clamping." A physical clamp of this type is used to refer to an obscure investment banking term. Anything that performs the action of clamping may be called a clamp, so this gives rise to a wide variety of terms across many fields; these clamps are used to position components temporarily for various tasks: Band clamp or web clamp Bar clamp, F-clamp or sliding clamp Bench clamp The bench forms the fixed jaw.
Cardellini clamp – jaw-style clamp that clamps onto round, square, or rectangular tubing. Forked clamp stainless steel for ST ground glass joints with/without setscrew. Sizes for: ST 14, 19, 24, 29 and 45. Gripe Handscrew Kant-Twist clamp Magnetic clamp Mitre clamp Pipe clamp Sash clamp Set screw Spring clamp Speed clamp Step clamp, a type of serrated-edged clamp used in conjunction with step blocks when machining or milling parts in metalworking Toggle clamp Toolmakers' clamp Pinch Dog Clip hangers are a subset of clothes hangers Hose clamp Marman clamp Wire rope clamp Joiner's dog Foerster clamp Hemostatic clamp Pennington clamp Gomco clamp Mogen clamp Wheel clamp Pandrol clip Tube clamp Nipple clamp Fixture Vise Patrick Spielman. Gluing and Clamping: A Woodworker’s Handbook. Sterling Publishing. ISBN 0-8069-6274-7 Lee Jesberger. Pro Woodworking Tips
Test tube holder
A test tube holder is used to hold test tubes. It should not be touched. For example, a test tube holder can be used to hold a test tube. Moreover, when heating the tube with liquid or solid contained inside, the tube holder ought to hold a test tube in order for the tube to be safely held while heating. For liquid heating, when holding a test tube holder with a test tube, hold it such that it aligns with the lab bench and point the open end of the tube away from yourself or anyone nearby. Additionally, while using a test tube holder, the proper distance between the test tube holder and the top of the test tube is 3 centimetres. Structurally, jaws of a test tube holder are self-closed by a spring; the purpose of a test tube holder is to be used only to hold a test tube as it is not structured for flasks or other heavier objects. Test tube Test tube rack
Laboratory rubber stopper
A laboratory rubber stopper or a rubber bung is used in chemical laboratory in combination with flasks and test tube and for fermentation in winery. In laboratory, the sizes of rubber stopper can be varied up to 16 sizes and each of it is specific to certain type of container; as the rubber stopper is used in many experiment, some specific experiment requires a specific material. For example, the M35 Green Neoprene is for chemical resistance. For food fermentation, M18 white natural gum is preferred. For high temperature application, red or white silicone rubber stopper should be used. Rubber bung can have one or more hole for plugging in tube depending on the specification of the procedures. To prevent the liquid chemical leaks or escape the container, the rubber bung should fit to the container's opening; these are some of the sizes that are seen in chemical laboratory. Bung Cork borer
A ceramic is a solid material comprising an inorganic compound of metal, non-metal or metalloid atoms held in ionic and covalent bonds. Common examples are earthenware and brick; the crystallinity of ceramic materials ranges from oriented to semi-crystalline and completely amorphous. Most fired ceramics are either vitrified or semi-vitrified as is the case with earthenware and porcelain. Varying crystallinity and electron composition in the ionic and covalent bonds cause most ceramic materials to be good thermal and electrical insulators. With such a large range of possible options for the composition/structure of a ceramic, the breadth of the subject is vast, identifiable attributes are difficult to specify for the group as a whole. General properties such as high melting temperature, high hardness, poor conductivity, high moduli of elasticity, chemical resistance and low ductility are the norm, with known exceptions to each of these rules. Many composites, such as fiberglass and carbon fiber, while containing ceramic materials, are not considered to be part of the ceramic family.
The earliest ceramics made by humans were pottery objects or figurines made from clay, either by itself or mixed with other materials like silica and sintered in fire. Ceramics were glazed and fired to create smooth, colored surfaces, decreasing porosity through the use of glassy, amorphous ceramic coatings on top of the crystalline ceramic substrates. Ceramics now include domestic and building products, as well as a wide range of ceramic art. In the 20th century, new ceramic materials were developed for use in advanced ceramic engineering, such as in semiconductors; the word "ceramic" comes from the Greek word κεραμικός, "of pottery" or "for pottery", from κέραμος, "potter's clay, pottery". The earliest known mention of the root "ceram-" is the Mycenaean Greek ke-ra-me-we, "workers of ceramics", written in Linear B syllabic script; the word "ceramic" may be used as an adjective to describe a material, product or process, or it may be used as a noun, either singular, or, more as the plural noun "ceramics".
A ceramic material is an inorganic, non-metallic crystalline oxide, nitride or carbide material. Some elements, such as carbon or silicon, may be considered ceramics. Ceramic materials are brittle, strong in compression, weak in shearing and tension, they withstand chemical erosion that occurs in other materials subjected to acidic or caustic environments. Ceramics can withstand high temperatures, ranging from 1,000 °C to 1,600 °C. Glass is not considered a ceramic because of its amorphous character. However, glassmaking involves several steps of the ceramic process, its mechanical properties are similar to ceramic materials. Traditional ceramic raw materials include clay minerals such as kaolinite, whereas more recent materials include aluminium oxide, more known as alumina; the modern ceramic materials, which are classified as advanced ceramics, include silicon carbide and tungsten carbide. Both are valued for their abrasion resistance and hence find use in applications such as the wear plates of crushing equipment in mining operations.
Advanced ceramics are used in the medicine, electronics industries and body armor. Crystalline ceramic materials are not amenable to a great range of processing. Methods for dealing with them tend to fall into one of two categories – either make the ceramic in the desired shape, by reaction in situ, or by "forming" powders into the desired shape, sintering to form a solid body. Ceramic forming techniques include shaping by hand, slip casting, tape casting, injection molding, dry pressing, other variations. Noncrystalline ceramics, being glass, tend to be formed from melts; the glass is shaped when either molten, by casting, or when in a state of toffee-like viscosity, by methods such as blowing into a mold. If heat treatments cause this glass to become crystalline, the resulting material is known as a glass-ceramic used as cook-tops and as a glass composite material for nuclear waste disposal; the physical properties of any ceramic substance are a direct result of its crystalline structure and chemical composition.
Solid-state chemistry reveals the fundamental connection between microstructure and properties such as localized density variations, grain size distribution, type of porosity and second-phase content, which can all be correlated with ceramic properties such as mechanical strength σ by the Hall-Petch equation, toughness, dielectric constant, the optical properties exhibited by transparent materials. Ceramography is the art and science of preparation and evaluation of ceramic microstructures. Evaluation and characterization of ceramic microstructures is implemented on similar spatial scales to that used in the emerging field of nanotechnology: from tens of angstroms to tens of micrometers; this is somewhere between the minimum wavelength of visible light and the resolution limit of the naked eye. The microstructure includes most grains, secondary phases, grain boundaries, micro-
A kiln is a thermally insulated chamber, a type of oven, that produces temperatures sufficient to complete some process, such as hardening, drying, or chemical changes. Kilns have been used for millennia to turn objects made from clay into pottery and bricks. Various industries use rotary kilns for pyroprocessing—to calcinate ores, to calcinate limestone to lime for cement, to transform many other materials; the word kiln descends from the Old English cylene (/ˈkylene/, adapted from the Latin culīna "kitchen, cooking-stove, burning-place". During the Middle English Period, the "n" was not pronounced, as evidenced by kiln having been spelled without the "n", Another word, "miln", a place where wheat is ground had a silent "n". Whereas the spelling of "miln" was changed to "mill" to match its pronunciation, "kiln" maintained its spelling, which most led to a common mispronunciation, which has now become used. However, there are small bastions. Kiln, Mississippi, a small town known for its wood drying kilns that once served the timber industry, is still referred to as "the Kill" by locals.
Unwittingly adding the "n" sound at the end of "kiln" is due to people being introduced to the word through the written language before hearing the actual pronunciation. Linguists call this phenomenon "reading pronunciation" where an incorrect pronunciation is read aloud, becomes widespread reported by dictionaries, the "original pronunciation, passed from parent to child, mouth to ear, for many generations is lost."Phonetically, the "ln" in "kiln" is categorized as a digraph: a combination of two letters that make only one sound, such as the "mn" in "hymn". From English Words as Spoken and Written for Upper Grades by James A. Bowen 1900: "The digraph ln, n silent, occurs in kiln. A fall down the kiln can kill you." Bowen was pointing out the humorous fact. Pit fired pottery was produced for thousands of years before the earliest known kiln, which dates to around 6000 BC, was found at the Yarim Tepe site in modern Iraq. Neolithic kilns were able to produce temperatures greater than 900 °C. Uses include: Annealing and deforming glass, or fusing metallic oxide paints to the surface of glass Heat treatment for metallic workpieces Ceramics Brickworks Melting metal for casting Smelting ore to extract metal Pyrolysis of chemical materials Heating limestone with clay in the manufacture of Portland cement, the Cement kiln Heating limestone to make quicklime or calcium oxide, the Lime kiln Heating gypsum to make plaster of Paris For cremation Drying of tobacco leaves Drying malted barley for brewing and other fermentations Drying hops for brewing Drying corn before grinding or storage, sometimes called a corn kiln, corn drying kiln.
Drying green lumber so it can be used Drying wood for use as firewood Heating wood to the point of pyrolysis to produce charcoal Kilns are an essential part of the manufacture of all ceramics. Ceramics require high temperatures so chemical and physical reactions will occur to permanently alter the unfired body. In the case of pottery, clay materials are shaped and fired in a kiln; the final characteristics are determined by the composition and preparation of the clay body and the temperature at which it is fired. After a first firing, glazes may be used and the ware is fired a second time to fuse the glaze into the body. A third firing at a lower temperature may be required to fix overglaze decoration. Modern kilns have sophisticated electrical control systems to firing regime, although pyrometric devices are also used. Clay consists of fine-grained particles, that are weak and porous. Clay is combined with other minerals to create a workable clay body. Part of the firing process includes sintering.
This heats the clay until the particles melt and flow together, creating a strong, single mass, composed of a glassy phase interspersed with pores and crystalline material. Through firing, the pores are reduced in size; this crystalline material predominantly consists of aluminium oxides. In the broadest terms, there are two types of kiln: intermittent and continuous, both sharing the same basic characteristics of being an insulated box with a controlled inner temperature and atmosphere. A continuous kiln, sometimes called a tunnel kiln, is a long structure in which only the central portion is directly heated. From the cool entrance, ware is transported through the kiln, its temperature is increased as it approaches the central, hottest part of the kiln. From there, it continues through the kiln, the surrounding temperature is reduced until it exits the kiln nearly at room temperature. A continuous kiln is energy-efficient, because heat given off during cooling is recycled to pre-heat the incoming ware.
In some designs, the ware is left in one place. Kilns in this type include: Hoffmann kiln Bull’s Trench kiln Habla kiln Roller kiln: A special type of kiln, common in tableware and tile manufacture, is the roller-hearth kiln, in which wares placed on bats are carried through the kiln on rollers. In the intermittent kiln. the ware to be fired is placed into the kiln. The kiln is closed, the internal temperature increased according to a schedule. After the firing is completed, both the kiln and the ware are cooled; the ware is removed, the kiln is cleaned and the next cycle begins. Kilns in this type include: Clamp kiln Skove kiln Scotch kiln Down-Draft kiln Shuttle Kilns: this is a car-bottom kiln with a door
Laboratory water bath
A water bath is laboratory equipment made from a container filled with heated water. It is used to incubate samples in water at a constant temperature over a long period of time. All water baths have an analogue interface to allow users to set a desired temperature. Utilisations include melting of substrates or incubation of cell cultures, it is used to enable certain chemical reactions to occur at high temperature. Water bath is a preferred heat source for heating flammable chemicals instead of an open flame to prevent ignition. Different types of water baths are used depending on application. For all water baths, it can be used up to 99.9 °C. When temperature is above 100 °C, alternative methods such as oil bath, silicone bath or sand bath may be used. Use with caution, it is not recommended to use water bath with moisture pyrophoric reactions. Do not heat a bath fluid above its flash point. Water level should be monitored, filled with distilled water only; this is required to prevent salts from depositing on the heater.
Disinfectants can be added to prevent growth of organisms. Raise the temperature to 90 °C or higher to once a week for half an hour for the purpose of decontamination. Markers tend to come off in water baths. Use water resistant ones. If application involves liquids that give off fumes, it is recommended to operate water bath in fume hood or in a well ventilated area; the cover is closed to help reaching high temperatures. Set up on a steady surface away from flammable materials. Circulating the water baths are ideal for applications when temperature uniformity and consistency are critical, such as enzymatic and serologic experiments. Water is circulated throughout the bath resulting in a more uniform temperature; this type of water bath relies on convection instead of water being uniformly heated. Therefore, it is less accurate in terms of temperature control. In addition, there are add-ons that provide stirring to non-circulating water baths to create more uniform heat transfer; this type of water bath has extra control for shaking.
This shaking feature can be turned off. In microbiological practices, constant shaking allows liquid-grown cell cultures grown to mix with the air; some key benefits of shaking water bath are user-friendly operation via keypad, convenient bath drains, adjustable shaking frequencies, bright LED-display, optional lift-up bath cover, power switch integrated in keypad and warning and cut-off protection for low/high temperature. Thermal immersion circulator Heated bath Hot plate Sand bath Oil bath