A Comparison of Trace Organic Vapor Analysis - Static SPME, Dynamic SPME, and Thermal Desorption Methods

This undergraduate project focuses on comparing sampling methods for detecting 2,3-dimethyl-2,3-dinitrobutane (DMNB), a common taggant in some commercial explosives. Solid phase microextraction (SPME), both static and dynamic, and thermal desorption from Tenax® are compared for precision (RSD) and for the limit of detection (LOD) and limit of quantitation (LOQ) using a GC/MS in the negative chemical ionization mode. The static SPME was found to be the least sensitive method, with dynamic SPME approximately 6X and thermal desorption approximately 25X more sensitive. Full details of the SPME and thermal desorption sampling techniques will be illustrated.

Advanced Decline Curve Analysis in Vapor-Dominated Geothermal Reservoirs

The Fetkovich decline curve analysis method was extended for application to vapor-dominated geothermal reservoirs to estimate the permeability-thickness product (kh) from a well's transient production response. The analytic dimensionless terms for pressure, steam flowrate, decline rate, and decline time were derived for saturated steam using the real gas pseudopressure and customary geothermal production units of pounds-mass per hour. The derived terms were numerically validated using "Geysers-like" reservoir properties at permeabilities of 1, 10, and 100 mD and at a range of initial matrix liquid saturations from 0 to 100%. The rate-time responses collapsed onto a single set of curves using the derived dimensionless terms, validating the derived dimensionless equations. This collapse was accomplished by including the effective compressibility of a boiling liquid or by an alternative formulation considering an apparent time. This technique was applied to actual field production data at The Geysers, California, the world's largest developed geothermal, vapor-dominated reservoir. The production data for over 100 wells in the southeast Geysers were analyzed and the permeability-thickness products determined by application of the derived analytic dimensionless terms and the Fetkovich production decline type curve.

Analysis of Fuel Vapor Characteristics in an Aircraft Fuel Tank Ullage.

As a prerequisite to a comprehensive analysis of aircraft fuel tank fire and explosion hazards, a vapor-liquid equilibrium thermodynamic analysis was developed to assess the fuel vapor behavior in an aircraft fuel tank ullage. The analysis was based on the Peng-Robinson equation of state and the extended corresponding-states method. Jet-A fuel was treated as a pseudo single-component fluid. The calculated fuel/air mass ratios followed the trend observed in previous measurements.

Analysis Of Phosphorus In Chemical Vapor Deposited Films For Semiconductor Device Fabrication

A semiconductor is a crystalline material having a conductivity between that of a conductor and an insulator. The conductivity of semiconductors can be varied by changes in temperature, optical excitation, and impurity content. This variability of electrical properties makes the semiconductor material of elementary crystalline silicon an ideal material for electronic device fabrication. Silicon has the ability of undergoing a large variety of processing steps without the problems of decomposition. One such process involved in fabrication is the chemical vapor deposition of silicon dioxide films on the silicon. Chemical vapor deposition (CVD) can be defined as a material synthesis method in which the constituents of the vapor phase react to form a solid film at the surface of a silicon wafer. Dielectric layers such as the deposited silicon dioxide, and phosphorus doped oxides, silicon dioxide rich with phosphorus pentoxide, are used in semiconductor device fabrication for the insulation between conducting layers, for diffusion and ion implantation masks, and for passification to protect devices from impurities, scratches, and moisture.

The Water Vapor Fraud

Supposedly, only 0.2°C temperature increase is due to CO2, but it causes more water to evaporate, which multiplies the result to 0.6°C. If multiplying were possible, there would be thermal runaway, as all temperature increases would have to be multiplied. Every calorie of heat does the same thing.

If water vapor is doing most of the heating, why replace carbon dioxide with water vapor in tailpipes and smoke stacks? Because the propagandists couldn’t care less whether carbon dioxide exists; they are fighting a war against the lower classes by making energy and transportation less available. Otherwise they wouldn’t be shutting down coal plants and replacing them with cryogenic natural gas and obstructing nuclear energy.

Analysis of the formation of vapor-deposited organic thin films using quartz crystal microbalance

An optimization of preparation parameters and a detailed study on growth kinetics for organic thin film are required to obtain high functional devices, coatings and sensors. In this study, the deposition behavior of organic molecules during physical vapor deposition was observed in real time by a quartz crystal microbalance technique which is widely used as a thickness monitor method. Moreover, the mean adsorption time of vapor-deposited organic molecules on substrate was estimated from the result of fitting of a theoretical rate equation based on a physisorption model to experimental data.

Vapor Generation and Analysis Parameters of the Petroleum

Over a decade ago (1973-1983), a series of long-term inhalation exposures were performed to study the toxicity of a number of aviation and marine fuels derived from petroleum and compare results with those derived from shale. These included JP-4, JP-5, and diesel fuel marine, as well as some specialty petroleum derived fuels W-7, JP-8, and JP-TS. The Thomas Domes located in the Armstrong Laboratory at Wright-Patterson Air Force Base (Dayton), Ohio, were ideally suited for these studies because of both the large capacity for inhalation exposure of the mixed animal complement and the convenience of entry without interrupting continuous exposures. The target total hydrocarbon (TH) concentrations ranged from 0.05 to 5.0 mg/L. The concentration levels of TH vapors were limited by the effective vapor pressure of the type of fuel and, if exceeded, the formation of condensate aerosols in the exposure chamber. The Th vapor generation and analytical equipment is described. Advances in gas chromatographic technology during the period covered provided a variety of qualitative pictures of the fuel, vapor, and waste TH components. Hydrocarbons above C14 existed only in very low concentrations in any of the vapors. (MM)

MULTICOMPONENT ANALYSIS OF VOLATILE ORGANIC COMPOSITIONS IN VAPOR SAMPLES

Amounts of volatile organic compositions can be evaluated from vapor samples based on the time dependent response of a fuel cell contacted with the vapor sample at its anode. The time response of the fuel cell signal, e.g., voltage or current, is de-convoluted using a set of standard curves for an equivalent fuel cell configuration obtained separately for each of the volatile organic compositions of a fuel cell with an equivalent construction as the sample-evaluation fuel cell. The methodology can be implemented on a system with an appropriate vapor collection device suitable for the particular application. The method and system can be used to analyze breath samples to evaluate ethanol levels or other volatile organic composition. The system can be a breathalyzer, a vehicle interlock, a medical analysis device or a sensor of environmental or industrial interest.

Application of GPS Slant Water Vapor Tomography to an IHOP Storm Case with Simple Constraints

It has been demonstrated that GPS slants can be used to reconstruct a three-dimensional water vapor distribution and have strong impact on water vapor forecasts if they are accurate measurements of integrated water vapor along GPS ray paths through a GPS tomography technique based upon Observation System Simulation Experiments (OSSE). For real time GPS data, there have been some 3DVAR and 4DVAR case studies showing the GPS data impact associated with other observations, backgrounds and/or numerical models. A real time GPS tomography analysis is a direct and independent verification of the GPS impact on water vapor analysis.

The International H2O Project (IHOP) 2002 is a field experiment over the Southern Great Plains (SGP) of the United States aiming at improvement of four-dimensional water vapor distribution analysis and applications for prediction of convection. In addition to other observation instruments, there is a relatively dense ground-based GPS network covering the right center of IHOP region. This GPS network makes a real time analysis of GPS slant observations possible. For the June 12-13, 2002 storm case over this IHOP area, a GPS tomography technique is applied to GPS slants processed using the Bernese 4.2 GPS Software. By adding proper constraints, the tomography analyses resemble some major water vapor patterns of satellite water vapor images over this region. After comparison to sounding data, we believe that these real time GPS slants contain important information regarding the water vapor distribution.

Vapor Pressure Data Analysis Methodology, Statistics, and Applications

A method of fitting vapor pressure temperature data to the Antoine equation is described along with a detailed statistical analysis of the fits and calculations of vapor pressures, enthalpies of vaporization, volatilities (concentration of saturated vapors), and boiling points with the Antoine constants. It is shown that the number of digits required to accurately perform vapor pressure calculations is greater than previously believed. The system permits calculation of the limits of error for any level of confidence. A program is used to analyze and plot the available vapor pressure data for diethyl malonate. Vapor pressure, Antoine equation, Volatility, Temperature, Statistics, Plotting, Enthalpy of Vaporization, Concentration of saturated vapor, Experimental methods, Diethyl malonate, Confidence limits, Confidence level.

New Method for Water Vapor Permeability Testing of Medicine Package- Electrolytic Analysis Method

Water vapor permeability testing of package material is of great significance to medicine quality insurance. Based on the latest standards of medicine package, this article briefs on testing principle of water vapor permeability testing of electrolytic analysis method and its application in the testing of medicine package materials.