...Drying Agents Drying agents (also called desiccants) come in various forms and have found widespread use in the food, pharmaceuticals, packing, electronics and many manufacturing industries. Every time an organic compound is in contact with water, a small amount of substance will be dissolved in it and also a quantity of water will be found in that organic compound. It is considered that water is hard to be removed from the compounds because they are forming strong bonds with water molecules (e.g. alcohols) or the compound is volatile. A desiccant is a hygroscopic substance that induces or sustains a state of dryness in its vicinity. Ideally, it is chemically stable and chemically inert (i.e., silica). Unfortunately, this is not always the case in the chemistry lab because the drying agent comes into direct contact with the solvent and the chemical. Types of desiccators Little white packets of silica often are used in various types of consumer packaging to absorb moisture in the air in sealed packages of foods. These desiccators help keep foods fresher by keeping the air in the packaging as dry as possible. Foods such as beef jerky and freeze-dried foods often have a little packet of this material included in order to extend shelf life. They also are sometimes found in clothing packages and shoe boxes, because excessive moisture can cause mould or fungal growth on these consumer goods. Electronics also commonly have these packets included as a way to keep their sensitive...
Words: 489 - Pages: 2
...especially in leaves but also in stems, flowers and roots. Stomata are dots with openings on top of the leaves surfaces, which in many plants have numerous on the undersides of the foliage. The stomas are boarded by guard cells that open and close the pore. Leaf transpiration happens through stomata, it is considered as a necessary need associated with the opening of the stomata to allow the diffusion of carbon dioxide gas from the air for photosynthesis. Transpiration is very important for plants because it cools them and enables the mass flow of mineral nutrients and water from roots and shoots. The amount of water vapor within the plant tissue, air humidity, and air temperature all play a roll in the rate of transpiration. The rate of transpiration can be measured using the mass of water lost per unit area of leaf tissue relative to time. When you take a leaf from a plant it is obvious that water is lost from the tissue, however it has no source of water to compensate for its negative water potential, which keeps increasing. When cuticles are waxy that helps the leaf to slow the loss of water vapor. High cuticular pathway resistance is indicated when there is a low rate of water; on the other hand this means that the leaf has a high resistance to water loss. In this lab we were suppose to determine the rate of transpiration from a cut segment of citrus leaves. We are to test their resistance to the...
Words: 1511 - Pages: 7
...Airmass : Meaning and Characteristics “An air mass may be defined as a large body of air whose physical properties, especially temperature, moisture content, and lapse rate, are more or less uniform horizontally for hundreds of kilometres.” According to A N Strahler and A. H. Strahler: “a body of air in which the upward gradients of temperature and moisture are fairly uniform over a large area is known as an air mass.” * An air mass may be so extensive that it may cover a large portion of a continent and it may be so thick in vertical dimension that it may vertically extend through the troposphere. An air mass is designated as cold air mass when its temperature is lower than the underlying surface while an air mass is termed warm air mass when its temperature is higher than the underlying surface. * The boundary between two different air masses is called front. Source Regions * The extensive areas over which air masses originate or form are called surface regions whose nature and properties largely determine the temperature and moisture characteristics of air masses. * An ideal source region of air mass must possess the following essential conditions: * There must be extensive and homogenous earth's surface so that it may possess uniform temperature and moisture conditions * There should not be convergence of air; rather there should be divergence of air flow so that the air may attain the physical properties of the region...
Words: 8685 - Pages: 35
...AECT 350 Passivhaus on a Budget http://www.greenbuildingadvisor.com/homes/passivhaus-budget The article is about Jason and Stephanie Specht’s first time having a house built for them. They wanted a builder who would satisfy them with the quality of the construction, and wound not charge too much to do so. The Specht’s chose the company Structures Design/Build to be their builders for their house. While meeting with their consultant for the first time, the consultant, Adam Cohen, asked the couple if they had any interest in Passiyhaus. The Specht’s did not know what Passiyhaus was and assumed that energy efficiency was too expensive for them. Cohen believed that if they were to create an optimized Passiyhaus design, that they could achieve the cost parity with a traditional construction. He argued that by constructing a Passiyhaus, it would not be any more expensive than constructing a house that would meet the existing energy codes. The articile states that “it is the idea that a builder can leverage their knowledge and experience to produce a Passiyhaus at a price equal to standard construction, if the energy costs are included in the calculation.” It also states that the additional costs of the Passiyhaus construction ends up paying for itself through the savings in the monthly utility bill. The Spechts’ agreed on the idea of designing a Passiyhaus. As the building process began, The Specht’s continued with their research on the Passiyhaus design. They found that the Passiyhaus...
Words: 873 - Pages: 4
...* Forming Dew Radiational cooling of the surface- Outgoing longwave radiation emitted to space Surfaces (grass,trees,cars) cool to the “dew” “point” Air is cooled by “conduction” and reaches its dew point condensation of liquid droplets on surfaces Dew Formation More likely to form on nights with clear skies and calm winds Objects near the ground will emit infradred radiation (clear nights) coldest air is located near the ground (calm winds) Frost Formation Radiational cooling of the Surface surfaces (grass,trees,cars) cool below frost point (below freezing). Air temp reaches frost point (air becomes saturated) (temp and dew point are equal) deposition of ice onto surfaces also known as hoarfrost or white frost exhibits “tree-like branching pattern.” FROST IS NOT FROZEN DEW! Frost forms on objects that are below freezing (vapor) Frozen dew is dew (liquid) that freezes as temperatures drop Haze…What Is It? Dust or salt particles suspended in the air Morning – Distant objects on the horizon are harder to see RH is much higher, therefore, water vapor condenses more readily and fills the air Afternoon – Distant objects on the horizon are easier to see RH is much lower, therefore, water vapor doesn’t condense as it would in the morning Hygoscopic – “Water-Seeking.” Ocean salt Hydrophobic – “water-repelling.” Oils, wax, and gas Wet haze – tiny liquid drops scatter light and appears dull grey or white Dry haze – non-water particles appear orange or yellowish ...
Words: 634 - Pages: 3
...For the hardcore outdoors person, the transition to the colder and harsher seasons of late fall and winter is nothing more than a change in venue in the activities you pursue and the equipment you use. Fall and winter, and the outdoors environment in general, can be hard on the eyes and your eyeglasses. The outdoors is an uncontrolled environment that can damage the eyes in a number of ways depending on the activity you are doing. For the person who wears prescription glasses, protecting his eyeglasses from damage is an additional concern. When choosing your prescription Wiley-X glasses, keep these four safety considerations in mind: Protection from Mechanical and Thermal Damage By this we mean protecting the eyes from wind-blown dust and grit, as well as from branches and thickets that you may encounter when hiking off trail. Cross country skiing along rugged terrain can subject the eyes to injury from passing branches. Cooking over a fire made with damp wood produces lots of sparks that cause both mechanical and thermal (heat) injury to the eyes. Leaving your indoor glasses at home and using prescription goggles, protects your eyes in all of these circumstances. Goggles also have a headband, which prevents their falling off. Goggles for the outdoors should be scratch resistant. Abrasion from wind-blown grit, dropping them, and setting them down on rough surfaces are common occurrences. If you are not using goggles, your prescription glasses should have a scratch resistant...
Words: 583 - Pages: 3
...Class Project #1 - Climate Profiles of Cities Around The World Luis Gonzalez GEOG 1301 - Physical Geography Bryant Evans This essay will discuss three cities, Houston, Texas, Alice Springs, Australia and Bridgetown, Barbados. It will emphasize the similarities and differences between them. There will be five factors that will be discussed which are average monthly high and annual temperatures, average monthly low and annual temperatures, average monthly and annual precipitation, average monthly and annual wind speeds, and average monthly and annual evening relative humidity readings. Houston Texas is my birth place. In Houston we have nearly four hundred events throughout the year. There’s fun for all the family from and is a diverse city which contains many cultures. Here are some of the interesting places that this wonderful city has to offer; there is NASA which is 25 miles southeast of downtown. It is like a museum for me but of things from present times, communications and space artifacts. Also, we have Discovery Green which is in downtown Houston. This park is in down town which attract all ages to gather and enjoy the outdoors. Facts: * Houston was founded on August 30, 1836 by brothers Augustus Chapman Allen and John Kirby Allen * Population-2,099,451 * Houston's latitude is 29 degrees 45 minutes north and its longitude is 95 degrees 22 minutes west * Houston is 43 feet above sea level. Sites- http://www.houstontx.gov/abouthouston/houstonfacts...
Words: 1556 - Pages: 7
...available for remote operation, which reduces human effort and increases the efficiency and effectiveness of the system.A comfortable environment can increase the productivity multi-folds. So it is important that the environment variables, such as temperature, relative humidity, dew point, light intensity and air quality (gas/smoke), are continuously monitored and corresponding systems adjusted to maintain a comfortable working environment. Presented here is an Arduino-based hand-held environment monitoring system that senses these parameters and shows on an LCD display. All the mentioned parameters are displayed in a cyclic manner. BLOCK DIAGRAM A R D U I N O GSM MODEM TEMP SENSOR AIR QUALITY SENSOR HUMIDITY SENSOR LIGHT SENSOR POWER SUPPLY SERIAL LCD DISPLAY antenna Fig above shows the block diagram of the environment monitoring system. The heart of the system is Arduino Uno board with microcontroller ATmega 328. The used components are: 1. Arduino Uno 2. Regulator 7805(Power supply) 3. Serial 16×2 lcd display 4. Global system for mobile 5. light-dependent resistor NORP12 6. gas sensor(Air quality sensor) MQ135 7. temperature sensor LM35 8. Humidity sensor SY-HS-220. Arduino uno : Arduino UNO is an open source prototyping platform based on ATmega328 microcontroller. It consists of 14 digital input/output (I/O) pins, six analogue inputs, a USB connection...
Words: 836 - Pages: 4
...Solid to Liquid | MELTING | Absorbed . | Solid to Gas | Sublimation . | ABSORBED | Liquid to Gas | Evaporation . | Absorbed . | Liquid to Solid | Freezing. | Released . | Gas to Liquid | Condensation . | Released . | Gas to Solid | Deposition . | Released. | 2) Humidity, water in the atmosphere, is VERY important in the atmosphere. Fill in the following table relating to humidity. Answers for some are given in ( ). A measure of actual amount of water in air (Dew Point, Relative Humidity, or Specific Humidity) | Relative Humanity . | Measured in g of water per kg of air(Dew Point, Relative Humidity, or Specific Humidity) | Dew Point . | A ratio of air's actual water vapor content to its capacity to hold water vapor(Dew Point, Relative Humidity, or Specific Humidity) | Relative Humanity . | Air's relative humidity when air is "full" | 100 % | Two ways relative humidity can change: | 1) amount of water vapor available .2) the temperature of the air . | Temperature to which air must be cooled to reach saturation: (Dew Point, Relative Humidity, or Specific Humidity) | Dew Point . | Temperature at which dew...
Words: 382 - Pages: 2
...What is Humidity?? * Humidity is the state of atmosphere in relation to amount of water vapor it contains. Humidity is closely related to its temperature – higher the air temperature, more vapor the air can hold. * For this reason, saturation vapor pressure (ew) goes up with air temperature; i.e., as temperature goes up ew also goes up. Significance of Humidity The amount of water vapor in air effectively controls the weather condition by controlling evapotranspiration from land and water surfaces. Evaporation rate is proportional to difference between saturated vapor pressure at water temperature (ew) and actual vapor pressure in air (ea). EL = C (ew – ea), Where, EL is lake evaporation rate, C is a constant of proportionality. Causes of Humidity Molecules of water having sufficient kinetic energy to overcome attractive forces tending to hold them within the body of liquid water are projected through the water surface into the air. The process by which liquid water is converted into vapor is called vaporization or evaporation. Since the kinetic energy increases and surface tension decrease as temperature rises, evaporation rate increases with temperature. Most of the atmospheric vapor is the product of evaporation from water surfaces. The direct transformation from ice to vapor, and vice versa, is called sublimation. The process by which vapor changes to the liquid or solid state is called condensation. Properties of Water Vapor The partial pressure exerted by water...
Words: 2242 - Pages: 9
...Research and Development agency, Abuja As a result of these, majority of the farmers end up bankrupt while some incur huge debt from banks, relatives or committee of friends in the process [3]. With the proposed drying system, farmers would be able to dry their farm produce using appropriate temperature and humidity control system. Abstract— this paper presents the design and implementation of a microcontroller based Seed Dryer Machine for farm produce interfaced with PC. Drying of farm produce and seeds in large quantity such as; melon, beans, corn, cocoa seeds, pumpkin seeds, rice, pepper seeds, tomato seeds etc., has been very challenging due to lack of drying facilities, drying space and poor weather. This gives low lifespan to the seeds and reduced quantity of stored seeds, which in turn could discourage farmers from further cultivations. In view of this problem, a microcontroller based Seed Dryer Machine is designed to aid and encourage farmers to dry in large scale different farm produce within a set time. The system is divided into nine units namely power supply, Liquid crystal display (LCD), temperature & Humidity sensors, system controller, ADC, PC, Relay driver, Heater & Fan and Alarm. The system is designed to dry any farm produce, activate an alarm when done and display the temperature and humidity values on LCD. The program codes for the controller is...
Words: 6253 - Pages: 26
...Mohd Zarifi Bin Bakar 2010214722 Discussions: During the cooling process, the specific humidity of air is constant, but the relative humidity was increases and the dry-bulb temperature will decreases. Such a cooling process proceeds in the direction of decreasing dry-bulb temperature following a line of constant specific humidity on the psychometric chart, which appears as a horizontal line. If the relative humidity reaches undesirably high levels, it may be necessary to remove some moisture from the air, that is, to dehumidify it. This requires cooling the air below its dew-point temperature. The cooling process with dehumidifying is shown on figure 1. First, moist air will enter the cooling section at state 1. As it passes through the cooling coils, its temperature decreases and its relative humidity increases at constant specific humidity. If cooling section is sufficiently long, air reaches its dew point (state x, saturated air). Air remains saturated during the entire condensation process, which follows a line 100% relative humidity until final state (state2) reached. The water vapor that condenses out the air during this process is removed from the cooling section through a separate channel. The condensate is usually assumed to leave the cooling section at T2. From this experiment, we get the reading for AT3, RH3, AT4 and RH4. From the reading obtain, then we plotted this two states on the psychometric chart. The linear line was present when the two points is connected...
Words: 343 - Pages: 2
...UDE 1123 ORGANIZATIONAL BEHAVIOUR AND DEVELOPMENT Semester I Session 2013/2014 INDIVIDUAL ASSIGNMENT EXPLORE THE ORGANIZATIONAL BEHAVIOUR/ISSUES FACING YOUR ORGANIZATION AND SUGGEST SOLUTIONS. “WORKING INDOOR BUT THE SUN IS JUST ABOVE YOUR HEAD” NAME : NUR RAHIDA BINTI RAHMAN MATRIC’S NO. : MR131002 LECTURER’S NAME : DR. BATIAH MAHADI “WORKING INDOOR BUT THE SUN IS JUST ABOVE YOUR HEAD” Introduction A work environment can be identified as the place that one works, which means the milieus around a person. The work environment has a significant impact upon employee performance and productivity. By work environment we mean those processes, systems, structures, tools or conditions in the workplace that impact favourably or unfavourably individual perform. The work environment also includes policies, rules, culture, resources, working relationships, work location, and internal and external environmental factors, all of which influence the ways those employees perform their job functions. It is the quality of the employee’s workplace environment that most impacts on the level of employee’s motivation and subsequent performance. How well they engage with the organization, especially with their immediate environment, influences to a great extent their error rate, level of innovation and collaboration with other employees, absenteeism and, ultimately, how long they stay in the job. The environment that people are required to work in can have a significant impact on their...
Words: 4882 - Pages: 20
...enough to sustain life. 2. (8pts) Draw the atmosphere’s vertical temperature profile from the surface to about 75 miles high. Clearly label the different layers and the boundaries between the layers. (Be sure to properly label the axes of your graph). 3. (9pts) Discuss three different types of “apparent temperature”. (Do not give three examples of the same type of apparent temperature). For each type, explain why the “how-it-feels” temperature differs from the actual air temperature. 1. Due to the serious effects on your health that weather can have on a person, the Heat Index was developed. The heat index takes into account air temperature and relative humidity to determine the apparent temperature of what it feels like outside. This differs from the actual air temperature as it can feel hotter outside when there is less humidity in the air. 2. How the wind makes us feel can be explained by the wind chill index. When the wind blows, it moves the warm insulating air away from you and heat is rapidly lost. When the wind blows faster, we lose heat even faster...
Words: 2090 - Pages: 9
...Impact of different window types in regulating natural ventilation of residential buildings of Dhaka, Bangladesh |Md. Nymul Haque¹ |Jinia Sharmeen² | |haque.nymul@gmail.com |jinia_lima@hotmail.com | Abstract Natural ventilation is most desirable for cooling and providing fresh air in residential buildings for better indoor air quality and thermal comfort. The natural ventilation performance is affected by a combination of internal and external factors. External factors include the location, the orientation, the prevailing wind speeds and the building forms of the residential development, which are subject to constraints beyond the control of site planners and architects. Whilst for internal factors like the openings configurations and window types, site planners and architects are always given free hand for a proper design. Dhaka, a city in the Tropics, has become such a city where with rapid urbanization users are moving towards mechanically ventilated buildings putting ever increasing demand on the dwindling energy resources. This paper focuses on the influences of window types on the natural ventilation of residential units in Dhaka in order to improve quality of indoor living environment. Primary objective of the study is an attempt to investigate...
Words: 3285 - Pages: 14
