|
Humidity Buffering
Humidity buffering refers to the ability of materials to moderate changes in relative humidity by absorbing and desorbing water vapour from surrounding air. This is also referred to as moisture buffering. The phenomenon has long been exploited for preserving items from damage that could be caused by either excessively moist or dry conditions. Examples * Cigars are usually kept in a wooden box called a humidor. A pan of water is placed in the humidor so that the wood will absorb water vapor at close to 100% relative humidity. It is then used to store the cigars at fairly constant relative humidity, between 55-70%. * Silica gel is widely used to buffer relative humidity inside museum display cases, packaged clothing, electronics and anything that might be damaged by condensation, or in the example of museum display cases, being too low an RH (relative humidity) as the silica will help protect the objects displayed from mechanical damage due to shrinking and growing with RH changes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relative Humidity
Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present. Humidity depends on the temperature and pressure of the system of interest. The same amount of water vapor results in higher relative humidity in cool air than warm air. A related parameter is the dew point. The amount of water vapor needed to achieve saturation increases as the temperature increases. As the temperature of a parcel of air decreases it will eventually reach the saturation point without adding or losing water mass. The amount of water vapor contained within a parcel of air can vary significantly. For example, a parcel of air near saturation may contain 28 g of water per cubic metre of air at , but only 8 g of water per cubic metre of air at . Three primary measurements of humidity are widely employed: absolute, relative, and specific. Ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cigars
A cigar is a rolled bundle of dried and fermented tobacco leaves made to be smoked. Cigars are produced in a variety of sizes and shapes. Since the 20th century, almost all cigars are made of three distinct components: the filler, the binder leaf which holds the filler together, and a wrapper leaf, which is often the highest quality leaf used. Often there will be a cigar band printed with the cigar manufacturer's logo. Modern cigars often come with two bands, especially Cuban cigar bands, showing Limited Edition (''Edición Limitada'') bands displaying the year of production. Cigar tobacco is grown in significant quantities primarily in Central America and the islands of the Caribbean, including Cuba, the Dominican Republic, Haiti, Honduras, Mexico, Ecuador, Nicaragua, Guatemala, Costa Rica, Panama, and Puerto Rico; it is also produced in the Eastern United States, Brazil and in the Mediterranean countries of Italy and Spain (in the Canary Islands), and in Indonesia and the Phi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Humidor
A humidor is a humidity-controlled box or room used primarily for storing cigars, cigarettes, cannabis, or pipe tobacco. Either too much or too little humidity can be harmful to tobacco products; a humidor's primary function is to maintain a steady, desirable moisture level inside; secondarily it protects its contents from physical damage and deterioration from sunlight. For private use, small wooden boxes holding a few dozen or fewer cigars are common, while cigar shops may have walk-in humidors. Many humidors use hygrometers to monitor their humidity levels. Another use for a humidor is controlling the moisture level in a baseball, which can have a pronounced effect on its response when hit with a baseball bat. This phenomenon was so great that in order to put an end to much controversy, in 2002, nine years after joining the league, the Colorado Rockies started storing their game balls in a large walk-in humidor at their home stadium, thus counteracting the effects of the low ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cigars
A cigar is a rolled bundle of dried and fermented tobacco leaves made to be smoked. Cigars are produced in a variety of sizes and shapes. Since the 20th century, almost all cigars are made of three distinct components: the filler, the binder leaf which holds the filler together, and a wrapper leaf, which is often the highest quality leaf used. Often there will be a cigar band printed with the cigar manufacturer's logo. Modern cigars often come with two bands, especially Cuban cigar bands, showing Limited Edition (''Edición Limitada'') bands displaying the year of production. Cigar tobacco is grown in significant quantities primarily in Central America and the islands of the Caribbean, including Cuba, the Dominican Republic, Haiti, Honduras, Mexico, Ecuador, Nicaragua, Guatemala, Costa Rica, Panama, and Puerto Rico; it is also produced in the Eastern United States, Brazil and in the Mediterranean countries of Italy and Spain (in the Canary Islands), and in Indonesia and the Phi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silica Gel
Silica gel is an amorphous and porous form of silicon dioxide (silica), consisting of an irregular tridimensional framework of alternating silicon and oxygen atoms with nanometer-scale voids and pores. The voids may contain water or some other liquids, or may be filled by gas or vacuum. In the last case, the material is properly called silica xerogel. Silica xerogel with an average pore size of 2.4 nanometers has a strong affinity for water molecules and is widely used as a desiccant. It is hard and translucent, but considerably softer than massive silica glass or quartz; and remains hard when saturated with water. Silica xerogel is usually commercialized as coarse granules or beads, a few millimeters in diameter. Some grains may contain small amounts of indicator substance that changes color when they have absorbed some water. Small paper envelopes containing silica xerogel pellets, usually with a "do not eat" warning, are often included in dry food packages to absorb any h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Building Science
Building science is the science and technology-driven collection of knowledge in order to provide better indoor environmental quality (IEQ), energy-efficient built environments, and occupant comfort and satisfaction. ''Building physics, architectural science'', and ''applied physics'' are terms used for the knowledge domain that overlaps with building science. In building science, the methods used in natural and hard sciences are widely applied, which may include controlled and quasi-experiments, randomized control, physical measurements, remote sensing, and simulations. On the other hand, methods from social and soft sciences, such as case study, interviews & focus group, observational method, surveys, and experience sampling, are also widely used in building science to understand occupant satisfaction, comfort, and experiences by acquiring qualitative data. One of the recent trends in building science is a combination of the two different methods. For instance, it is widely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Architecture
Architecture is the art and technique of designing and building, as distinguished from the skills associated with construction. It is both the process and the product of sketching, conceiving, planning, designing, and constructing buildings or other structures. The term comes ; ; . Architectural works, in the material form of buildings, are often perceived as cultural symbols and as works of art. Historical civilizations are often identified with their surviving architectural achievements. The practice, which began in the prehistoric era, has been used as a way of expressing culture for civilizations on all seven continents. For this reason, architecture is considered to be a form of art. Texts on architecture have been written since ancient times. The earliest surviving text on architectural theories is the 1st century AD treatise '' De architectura'' by the Roman architect Vitruvius, according to whom a good building embodies , and (durability, utility, and beauty). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Conditioning
Air conditioning, often abbreviated as A/C or AC, is the process of removing heat from an enclosed space to achieve a more comfortable interior environment (sometimes referred to as 'comfort cooling') and in some cases also strictly controlling the humidity of internal air. Air conditioning can be achieved using a mechanical 'air conditioner' or alternatively a variety of other methods, including passive cooling or ventilative cooling. Air conditioning is a member of a family of systems and techniques that provide heating, ventilation, and air conditioning (HVAC). Heat pumps are similar in many ways to air conditioners, but use a reversing valve to allow them to both heat and also cool an enclosed space. Air conditioners, which typically use vapor-compression refrigeration, range in size from small units used within vehicles or single rooms to massive units that can cool large buildings. Air source heat pumps, which can be used for heating as well as cooling, are becoming incre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ventilation (architecture)
Ventilation is the intentional introduction of outdoor air into a space. Ventilation is mainly used to control indoor air quality by diluting and displacing indoor pollutants; it can also be used to control indoor temperature, humidity, and air motion to benefit thermal comfort, satisfaction with other aspects of indoor environment, or other objectives. The intentional introduction of outdoor air is usually categorized as either mechanical ventilation, natural ventilation, or mixed-mode ventilation (hybrid ventilation). * Mechanical ventilation is the intentional fan driven flow of outdoor air into a building. Mechanical ventilation systems may include supply fans (which push outdoor air into a building), exhaust fans (which draw air out of building and thereby cause equal ventilation flow into a building), or a combination of both. Mechanical ventilation is often provided by equipment that is also used to heat and cool a space. * Natural ventilation is the intentional passive fl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desiccant
A desiccant is a hygroscopic substance that is used to induce or sustain a state of dryness (desiccation) in its vicinity; it is the opposite of a humectant. Commonly encountered pre-packaged desiccants are solids that absorb water. Desiccants for specialized purposes may be in forms other than solid, and may work through other principles, such as chemical bonding of water molecules. They are commonly encountered in foods to retain crispness. Industrially, desiccants are widely used to control the level of water in gas streams. Types of desiccants Although some desiccants are chemically inert, others are extremely reactive and require specialized handling techniques. The most common desiccant is silica gel, an otherwise inert, nontoxic, water-insoluble white solid. Tens of thousands of tons are produced annually for this purpose. Other common desiccants include activated charcoal, calcium sulfate, calcium chloride, and molecular sieves (typically, zeolites). Desiccants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Humectant
A humectant is a hygroscopic (water-absorbing) substance used to keep things moist. They are used in many products, including food, cosmetics, medicines and pesticides. When used as a food additive, a humectant has the effect of keeping moisture in the food. Humectants are sometimes used as a component of antistatic coatings for plastics. A humectant attracts and retains the moisture in the air nearby via absorption, drawing the water vapor into or beneath the organism's or object's surface. This is the opposite use of a hygroscopic material where it is used as a desiccant used to draw moisture away. In pharmaceuticals and cosmetics, humectants can be used in topical dosage forms to increase the solubility of a chemical compound's active ingredients, increasing the active ingredients' ability to penetrate skin, or its activity time. This hydrating property can also be needed to counteract a dehydrating active ingredient (e.g., soaps, corticoids, and some alcohols), which is why ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Thermodynamics
Atmospheric thermodynamics is the study of heat-to-work transformations (and their reverse) that take place in the earth's atmosphere and manifest as weather or climate. Atmospheric thermodynamics use the laws of classical thermodynamics, to describe and explain such phenomena as the properties of moist air, the formation of clouds, atmospheric convection, boundary layer meteorology, and vertical instabilities in the atmosphere. Atmospheric thermodynamic diagrams are used as tools in the forecasting of storm development. Atmospheric thermodynamics forms a basis for cloud microphysics and convection parameterizations used in numerical weather models and is used in many climate considerations, including convective-equilibrium climate models. Overview The atmosphere is an example of a non-equilibrium system. Atmospheric thermodynamics describes the effect of buoyant forces that cause the rise of less dense (warmer) air, the descent of more dense air, and the transformation of water ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
