Vi. Properties of Nitrogen Contents
Total Page：16
File Type：pdf, Size：1020Kb
Load more
Recommended publications
-
Chapter 5 Measures of Humidity Phases of Water
Chapter 5 Atmospheric Moisture Measures of Humidity 1. Absolute humidity 2. Specific humidity 3. Actual vapor pressure 4. Saturation vapor pressure 5. Relative humidity 6. Dew point Phases of Water Water Vapor n o su ti b ra li o n m p io d a a at ep t v s o io e en s n d it n io o n c freezing Liquid Water Ice melting 1 Coexistence of Water & Vapor • Even below the boiling point, some water molecules leave the liquid (evaporation). • Similarly, some water molecules from the air enter the liquid (condense). • The behavior happens over ice too (sublimation and condensation). Saturation • If we cap the air over the water, then more and more water molecules will enter the air until saturation is reached. • At saturation there is a balance between the number of water molecules leaving the liquid and entering it. • Saturation can occur over ice too. Hydrologic Cycle 2 Air Parcel • Enclose a volume of air in an imaginary thin elastic container, which we will call an air parcel. • It contains oxygen, nitrogen, water vapor, and other molecules in the air. 1. Absolute Humidity Mass of water vapor Absolute humidity = Volume of air The absolute humidity changes with the volume of the parcel, which can change with temperature or pressure. 2. Specific Humidity Mass of water vapor Specific humidity = Total mass of air The specific humidity does not change with parcel volume. 3 Specific Humidity vs. Latitude • The highest specific humidities are observed in the tropics and the lowest values in the polar regions. -
Physics, Chapter 17: the Phases of Matter
University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Robert Katz Publications Research Papers in Physics and Astronomy 1-1958 Physics, Chapter 17: The Phases of Matter Henry Semat City College of New York Robert Katz University of Nebraska-Lincoln, [email protected] Follow this and additional works at: https://digitalcommons.unl.edu/physicskatz Part of the Physics Commons Semat, Henry and Katz, Robert, "Physics, Chapter 17: The Phases of Matter" (1958). Robert Katz Publications. 165. https://digitalcommons.unl.edu/physicskatz/165 This Article is brought to you for free and open access by the Research Papers in Physics and Astronomy at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Robert Katz Publications by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. 17 The Phases of Matter 17-1 Phases of a Substance A substance which has a definite chemical composition can exist in one or more phases, such as the vapor phase, the liquid phase, or the solid phase. When two or more such phases are in equilibrium at any given temperature and pressure, there are always surfaces of separation between the two phases. In the solid phase a pure substance generally exhibits a well-defined crystal structure in which the atoms or molecules of the substance are arranged in a repetitive lattice. Many substances are known to exist in several different solid phases at different conditions of temperature and pressure. These solid phases differ in their crystal structure. Thus ice is known to have six different solid phases, while sulphur has four different solid phases. -
Compressed Liquid Gases (Cryogens) Laboratory Safe Work Practices
Compressed Liquid Gases (Cryogens) Laboratory Safe Work Practices Source: Section 3.9 of Guidelines for Safe Work Practices in Human and Animal Medical Diagnostic Laboratories: Recommendations of a CDC-convened, Biosafety Blue Ribbon Panel; excerpted by Vanderbilt OCRS, 10.2020. Compressed Liquid Gases (Cryogens) Cryogenic liquids are liquefied gases that have a normal boiling point below -238°F (-150°C). Liquid nitrogen is used in the microbiology laboratory to freeze and preserve cells and virus stocks. The electron microscopy laboratory, frozen section suites, and grossing stations for surgical pathology frequently use liquid nitrogen; some laboratories also use liquid helium. The principal hazards associated with handling cryogenic fluids include cold contact burns and freezing, asphyxiation, explosion and material embrittlement. Cold contact burns and freezing • Liquid nitrogen is dangerously cold (-320°F [-196°C]), and • Wear loose-fitting thermal gloves with elbow-length cuffs skin contact with either the liquid or gas phase can when filling dewars. Ensure that gloves are loose enough to immediately cause frostbite. At -450°F (-268°C), liquid be thrown off quickly if they contact the liquid. helium is dangerous and cold enough to solidify atmospheric • Never place gloved hands into liquid nitrogen or into the air. liquid nitrogen stream when filling dewars. Gloves are not • Always wear eye protection (face shield over safety goggles). rated for this type of exposure. Insulated gloves are The eyes are extremely sensitive to freezing, and liquid designed to provide short-term protection during handling of nitrogen or liquid nitrogen vapors can cause eye damage. hoses or dispensers and during incidental contact with the • Do not allow any unprotected skin to contact uninsulated liquid. -
Cryogenics – the Basics Or Pre-Basics Lesson 1 D
Cryogenics – The Basics or Pre-Basics Lesson 1 D. Kashy Version 3 Lesson 1 - Objectives • Look at common liquids and gases to get a feeling for their properties • Look at Nitrogen and Helium • Discuss Pressure and Temperature Scales • Learn more about different phases of these fluids • Become familiar with some cryogenic fluids properties Liquids – Water (a good reference) H2O density is 1 g/cc 10cm Total weight 1000g or 1kg (2.2lbs) Cube of water – volume 1000cc = 1 liter Liquids – Motor Oil 10cm 15W30 density is 0.9 g/cc Total weight 900g or 0.9 kg (2lbs) Cube of motor oil – volume 1000cc = 1 liter Density can and usually does change with temperature 15W30 Oil Properties Density Curve Density scale Viscosity scale Viscosity Curve Water density vs temperature What happens here? What happens here? Note: This plot is for SATURATED Water – Discussed soon Water and Ice Water Phase Diagram Temperature and Pressure scales • Fahrenheit: 32F water freezes 212 water boils (at atmospheric pressure) • Celsius: 0C water freezes and 100C water boils (again at atmospheric pressure) • Kelvin: 273.15 water freezes and 373.15 water boils (0K is absolute zero – All motion would stop even electrons around a nucleus) • psi (pounds per square in) one can reference absolute pressure or “gage” pressure (psia or psig) • 14.7psia is one Atmosphere • 0 Atmosphere is absolute vacuum, and 0psia and -14.7psig • Standard Temperature and Pressure (STP) is 20C (68F) and 1 atm Temperature Scales Gases– Air Air density is 1.2kg/m3 => NO Kidding! 100cm =1m Total weight -
Cryogenic Liquid Nitrogen Vehicles (ZEV's)
International Journal of Scientific and Research Publications, Volume 6, Issue 9, September 2016 562 ISSN 2250-3153 Cryogenic Liquid Nitrogen Vehicles (ZEV’S) K J Yogesh Department Of Mechanical Engineering, Jain Engineering College, Belagavi Abstract- As a result of widely increasing air pollution available zero emission vehicle (ZEV) meeting it's standards are throughout the world & vehicle emissions having a major the electrically recharged ones, however these vehicles are also contribution towards the same, it makes its very essential to not a great success in the society due to its own limitations like engineer or design an alternative to the present traditional initial cost, slow recharge, speeds etc. Lead acid & Ni-Cd gasoline vehicles. Liquid nitrogen fueled vehicles can act as an batteries are the past of major technologies in the electric excellent alternative for the same. Liquefied N2 at cryogenic vehicles. They exhibit specific energy in the range of 30-40 W- temperatures can replace conventional fuels in cryogenic heat hr/kg. Lead- acid batteries take hours to recharge & the major engines used as a propellant. The ambient temperature of the drawback of the batteries in all the cases is their replacement surrounding vaporizes the liquid form of N2 under pressure & periodically. This directly/indirectly increases the operating cost leads to the formation of compressed N2 gas. This gas actuates a when studied carefully & thereby not 100% acceptable. pneumatic motor. A combination of multiple reheat open Recent studies make it clear that the vehicles using liquid Rankine cycle & closed Brayton cycle are involved in the nitrogen as their means provide an excellent alternative before process to make use of liquid N2 as a non-polluting fuel. -
Pressure Vs Temperature (Boiling Point)
Boiling Points and Vapor Pressure Background Boiling Points and Vapor Pressure Background: Definitions Vapor Pressure: The equilibrium pressure of a vapor above its liquid; the pressure of the vapor resulting from the evaporation of a liquid above a sample of the liquid in a closed container. Boiling Point: The temperature at which the vapor pressure of a liquid is equal to the atmospheric (or applied) pressure. As the temperature of the liquid increases, the vapor pressure will increase, as seen below: https://www.chem.purdue.edu/gchelp/liquids/vpress.html Vapor pressure is interpreted in terms of molecules of liquid converting to the gaseous phase and escaping into the empty space above the liquid. In order for the molecules to escape, the intermolecular forces (Van der Waals, dipole- dipole, and hydrogen bonding) have to be overcome, which requires energy. This energy can come in the form of heat, aka increase in temperature. Due to this relationship between vapor pressure and temperature, the boiling point of a liquid decreases as the atmospheric pressure decreases since there is more room above the liquid for molecules to escape into at lower pressure. The graph below illustrates this relationship using common solvents and some terpenes: Pressure vs Temperature (boiling point) Ethanol Heptane Isopropyl Alcohol B-myrcene 290.0 B-caryophyllene d-Limonene Linalool Pulegone 270.0 250.0 1,8-cineole (eucalyptol) a-pinene a-terpineol terpineol-4-ol 230.0 p-cymene 210.0 190.0 170.0 150.0 130.0 110.0 90.0 Temperature (˚C) Temperature 70.0 50.0 30.0 10 20 30 40 50 60 70 80 90 100 200 300 400 500 600 760 10.0 -10.0 -30.0 Pressure (torr) 1 Boiling Points and Vapor Pressure Background As a very general rule of thumb, the boiling point of many liquids will drop about 0.5˚C for a 10mmHg decrease in pressure when operating in the region of 760 mmHg (atmospheric pressure). -
ESSENTIALS of METEOROLOGY (7Th Ed.) GLOSSARY
ESSENTIALS OF METEOROLOGY (7th ed.) GLOSSARY Chapter 1 Aerosols Tiny suspended solid particles (dust, smoke, etc.) or liquid droplets that enter the atmosphere from either natural or human (anthropogenic) sources, such as the burning of fossil fuels. Sulfur-containing fossil fuels, such as coal, produce sulfate aerosols. Air density The ratio of the mass of a substance to the volume occupied by it. Air density is usually expressed as g/cm3 or kg/m3. Also See Density. Air pressure The pressure exerted by the mass of air above a given point, usually expressed in millibars (mb), inches of (atmospheric mercury (Hg) or in hectopascals (hPa). pressure) Atmosphere The envelope of gases that surround a planet and are held to it by the planet's gravitational attraction. The earth's atmosphere is mainly nitrogen and oxygen. Carbon dioxide (CO2) A colorless, odorless gas whose concentration is about 0.039 percent (390 ppm) in a volume of air near sea level. It is a selective absorber of infrared radiation and, consequently, it is important in the earth's atmospheric greenhouse effect. Solid CO2 is called dry ice. Climate The accumulation of daily and seasonal weather events over a long period of time. Front The transition zone between two distinct air masses. Hurricane A tropical cyclone having winds in excess of 64 knots (74 mi/hr). Ionosphere An electrified region of the upper atmosphere where fairly large concentrations of ions and free electrons exist. Lapse rate The rate at which an atmospheric variable (usually temperature) decreases with height. (See Environmental lapse rate.) Mesosphere The atmospheric layer between the stratosphere and the thermosphere. -
Problem Set #10 Assigned November 8, 2013 – Due Friday, November 15, 2013 Please Show All Work for Credit
Problem Set #10 Assigned November 8, 2013 – Due Friday, November 15, 2013 Please show all work for credit To Hand in 1. 1 2. –1 A least squares fit of ln P versus 1/T gives the result Hvaporization = 25.28 kJ mol . 3. Assuming constant pressure and temperature, and that the surface area of the protein is reduced by 25% due to the hydrophobic interaction: 2 G 0.25 N A 4 r Convert to per mole, ↓determine size per molecule 4 r 3 V M N 0.73mL/ g 60000g / mol (6.02 1023) 3 2 2 A r 2.52 109 m 2 23 9 2 G 0.25 N A 4 r 0.0720N / m 0.25 6.02 10 / mol (4 ) (2.52 10 m) 865kJ / mol We think this is a reasonable approach, but the value seems high 2 4. The vapor pressure of an unknown solid is approximately given by ln(P/Torr) = 22.413 – 2035(K/T), and the vapor pressure of the liquid phase of the same substance is approximately given by ln(P/Torr) = 18.352 – 1736(K/T). a. Calculate Hvaporization and Hsublimation. b. Calculate Hfusion. c. Calculate the triple point temperature and pressure. a) Calculate Hvaporization and Hsublimation. From Equation (8.16) dPln H sublimation dT RT 2 dln P d ln P dT d ln P H T 2 sublimation 11 dT dT R dd TT For this specific case H sublimation 2035 H 16.92 103 J mol –1 R sublimation Following the same proedure as above, H vaporization 1736 H 14.43 103 J mol –1 R vaporization b. -
Chapter Two Properties of Ammonia
Chapter Two Properties of Ammonia Physical Properties General Anhydrous ammonia exists as either a colorless gas, colorless liquid, or white solid, depending on its pressure and temperature. In nearly all commonly encountered situations, it exists as either a liquid or a gas. The gas is less dense than air and the liquid is less dense than water at standard conditions. Ammonia gas (vapor) diffuses readily in air and the liquid is highly soluble in water with an accompanying release of heat. Ammonia exhibits classical saturation relationships whereby pressure and temperature are directly related so long as both the vapor and liquid phase are present. It does have a critical pressure and temperature. At atmospheric pressure, a closed container of ammonia vapor and liquid will be in equilibrium at a temperature of –28°F [–33°C]. It should be noted however that if liquid ammonia is spilled or released to the atmosphere at normal temperatures, the resultant pool of boiling liquid will be significantly colder than –28°F due to the law of partial pressures (the partial pressure of the ammonia vapor in the air near the liquid surface will be less than atmospheric pressure). The following table provides some of the important physical properties of ammonia. TABLE 2-1 Physical Properties of Ammonia Property Condition Value (IP) Value (SI) Molecular Weight 17.03 17.03 Color None None Physical State Room Temp Gas Gas Freezing Point P=1 atm –108°F –78°C Boiling Point P=1 atm –28.1°F –33.3°C Critical Pressure 1657 psia 11,410 kPa Critical Temp 271°F -
The Thermodynamic Properties of Nitrogen from 64 to 300* K Between
Lonal Bureau of btaudaj a.^ Lilarary, M.W. Bldg JUIV 6 1962 PB 161630 ^ecknlcciL ^^ote 129 THE THERMODYNAMIC PROPERTIES OF NITROGEN FROM 64 TO 300^ K BETWEEN 0.1 AND 200 ATMOSPHERES THOMAS R. STROBRIDGE U. S. DEPARTMENT OF COMMERCE NATIONAL BUREAU OF STANDARDS THE NATIONAL BUREAU OF STANDARDS Functions and Activities The functions of the National Bureau of Standards are set forth in the Act of Congress, March 3, 1901, as amended by Congress in Public Law 619, 1950. These include the development and maintenance of the na- tional standards of measurement and the provision of means and methods for making measurements consistent with these standards; the determination of physical constants and properties of materials; the development of methods and instruments for testing materials,- devices, and structures; advisory services to government agen- cies on scientific and technical problems; invention and development of devices to serve special needs of the Government; and the development of standard practices, codes, and specifications. The work includes basic and applied research, development, engineering, instrumentation, testing, evaluation, calibration services, and various consultation and information services. Reseeirch projects are also performed for other government agencies when the work relates to and supplements the basic program of the Bureau or when the Bureau's unique competence is required. The scope of activities is suggested by the listing of divisions and sections on the inside of the back cover. Publications The results of the Bureau's research are published either in the Bureau's own series of publications or in the journals of professional and scientific societies. -
Protocol for Use and Maintenance of Oxygen Monitoring Devices 2021
National Institutes of Health Protocol for Use and Maintenance of Oxygen Monitoring Devices 2021 Authored by the Division of Occupational Health and Safety (DOHS) Oxygen Monitoring Program Manager. CONTENTS INTRODUCTION………………………………………………………………... 2 I. PURPOSE………………………………………………………………… 2 II. SCOPE……………………………………………………………………. 2 III. APPLICABLE REGULATORY, POLICY, AND INDUSTRY STANDARDS………………………………………... 3 IV. RESPONSIBILITIES …………………………………………….………. 4 V. TECHNICAL INFORMATION………………………………………….. 6 VI. REFERENCES…………………………………………………….……… 9 APPENDIX A – MANDATORY SIGNAGE………………………………….… 11 APPENDIX B – RECOMMENDED SIGNAGE………………………………… 13 ACRONYMS BAS Building Automation System DOHS Division of Occupational Health and Safety DRM Design Requirements Manual IC Institute/Center MRI Magnetic Resonance Imaging NMR Nuclear Magnetic Resonance OSHA Occupational Safety and Health Administration PI Principal Investigator TEM Transmission Electron Microscope TAB Technical Assistance Branch Disclaimer of Endorsement: Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government, and shall not be used for advertising or product endorsement purposes. 1 INTRODUCTION Compressed gases and cryogenic liquids (e.g. nitrogen, helium, carbon dioxide, oxygen and argon) -
Liquid Nitrogen Safety
Michigan Technological University, Department of Physics Liquid Nitrogen Safety Adapted from Department of Chemical Engineering Safety Manual and: http://engineering.dartmouth.edu/microengineering/ln2.html Properties of Liquid Nitrogen (LN2) 1. It is extremely cold: 77.3K = -196C = -320F at atmospheric pressure. This can cause severe frost bite 2. On vaporization it expands by a factor of 700; one liter of liquid nitrogen becomes 24.6 cubic feet of nitrogen gas. This can cause explosion of a sealed container, or it can displace oxygen in the room and cause suffocation without warning. 3. It can become oxygen enriched and cause ordinarily noncombustible materials to burn rapidly. Personal Protection When Handling LN2 1. When handling LN2 you should maximize the protection offered by clothing. Wear full sleeves, long pants and non-porous closed-toe shoes. 2. Splashing is common, so safety goggles or a face shield should be worn at all times when working with LN2. 3. Wear protective gloves when touching any object cooled by liquid nitrogen. However, the gloves should be loose fitting, so they could be thrown off if liquid were to pour inside them. 4. Care must be taken to prevent uninsulated containers from contacting unprotected skin since they may become bonded to the skin and will serious injury. 5. Contact of the skin with LN2 can cause severe cryogenic burns (tissue damage is similar to frostbite or thermal burns). Although small amounts of LN2 quickly evaporate when on the skin surface, if the liquid becomes trapped under jewelry, watches, or inside gloves or folds of clothing, it can result in serious and painful burns.