Introductory study of the chemical behavior of jet emissions in photochemical smog

Jet aircraft emissions data from the literature were used as initial conditions for a series of computer simulations of photochemical smog formation in static air. The chemical kinetics mechanism used in these simulations was an updated version which contains certain parameters designed to account for hydrocarbon reactivity. These parameters were varied to simulate the reaction rate constants and average carbon numbers associated with the jet emissions. The roles of surface effects, variable light sources, NO/NO2 ratio, continuous emissions, and untested mechanistic parameters were also assessed. The results of these calculations indicate that the present jet emissions are capable of producing oxidant by themselves. The hydrocarbon/nitrous oxides ratio of present jet aircraft emissions is much higher than that of automobiles. These two ratios appear to bracket the hydrocarbon/nitrous oxides ratio that maximizes ozone production. Hence an enhanced effect is seen in the simulation when jet exhaust emissions are mixed with automobile emissions

The application development outsourcing contract decision: The effect of service quality, relationship quality, satisfaction, and switching costs on continuation and discontinuation decisions

Although the popularity of IT outsourcing has grown over the last two decades, approximately one third of outsourcing contracts are discontinued. This discontinuation of contracts has resulted in renegotiations with the original outsourcing vendor, switching to another vendor, and backsourcing, or the return of previously outsourced functions in-house. IT outsourcing is expected to grow to a $160 billion industry in the United States alone by 2005. Given the conclusion by some researchers that so many outsourcing arrangements end in vendor switches or backsourcing, it is apparent that a large amount of money is being needlessly wasted. By better understanding the factors that may lead to the discontinuation of outsourcing contracts, perhaps outsourcing vendors can increase the success rate of outsourcing agreements and companies can make better outsourcing decisions. Thus, the objective of this research is to determine what factors may be associated with the decision to switch vendors or backsource. IT application development managers were surveyed and 160 responses are analyzed. This data set was subjected to logistic regression analysis to determine the factors associated with application development outsourcing discontinuations. Constructs utilized include service quality, satisfaction, relationship quality, and switching costs. These constructs were chosen as a result of a broad review of the IT and marketing literatures for factors associated with bringing services in-house or switching to another service provider. Overall, poor communication, lack of timeliness, low user understanding, low reliability, high lost performance costs, high pre-switching costs, high sunk costs, and high management costs are significantly related to the decision to discontinue an application development outsourcing contract. These factors span across the four constructs proposed. This research answers a call by Lacity and Willcocks (2001) to investigate backsourcing, as well as a similar outsourcing outcome, switching vendors. The results not only help fill a void in the academic IT outsourcing literature related to outsourcing contract discontinuations, but also provide practitioners with a valuable indication of the factors associated with outsourcing contract discontinuation

Statistical applications of the walsh transform

This paper introduces a linear operator on the vector space spanned by the discrete sequency ordered Walsh functions

An assessment of the effect of supersonic aircraft operations on the stratospheric ozone content

An assessment of the potential effect on stratospheric ozone of an advanced supersonic transport operations is presented. This assessment, which was undertaken because of NASA's desire for an up-to-date evaluation to guide programs for the development of supersonic technology and improved aircraft engine designs, uses the most recent chemical reaction rate data. From the results of the present assessment it would appear that realistic fleet sizes should not cause concern with regard to the depletion of the total ozone overburden. For example, the NOx emission of one type designed to cruise at 20 km altitude will cause the ozone overburden to increase by 0.03% to 0.12%, depending upon which vertical transport is used. These ozone changes can be compared with the predictions of a 1.74% ozone decrease (for 100 Large SST's flying at 20 km) made in 1974 by the FAA's Climatic Impact Assessment Program

Blockchain in the Role of Emancipatory Technology

Historically, women miners have been at a disadvantage in the mining industries due to factors outside of their control. This has caused them problems related to less income and worse working conditions as compared to their male counterparts. This research demonstrates how blockchain can be used as an emancipatory technology that can help improve the economic and ultimately social impact of these marginalized workers. Specifically, the paper demonstrates how mediating economic opportunity through an emancipatory technology such as blockchain can reduce negative influences of gender bias, ASM involvement, poor market conditions, and ethical consumption and ultimately provide greater benefits for women miners

Two-dimensional model studies of the effect of supersonic aircraft operations on the stratospheric ozone content

For a fleet of 250 aircraft, the change in the ozone column is predicted to be very close to zero; in fact, the ozone overburden may actually increase as a result of show that above 25 to 30 km the ozone abundance decreases via catalytic destruction, but at lower heights it increases, mainly as a result of coupling with odd hydrogen species. Water vapor released in the engine exhaust is predicted to cause ozone decreases; for the hypothetical engines used in the study, the total column ozone changes due to water vapor emission largely offset the predicted ozone increases due to NOx emission. The actual effect of water vapor may be less than calculated because present models do not include thermal feedback. Feedback refers to the cooling effect of additional water vapor that would tend to slow the NOx reactions which destroy ozone

The Impact of Information Technology Outsourcing on Firm Profitability Measures

Some researchers have concluded that outsourcing of information technology (IT) provides benefits to firms including cost advantages, economies of scale and allowing more of a focus on core competencies. This paper attempts to determine if these benefits actually exist by comparing three financial measures, return on equity (ROE), return on assets (ROA) and profit margin, affirms that have varying levels of outsourcing. To empirically test for the existence of a difference between firms that outsource differing amounts of IT spending, data from 104 companies was gathered. Analysis of variance was selected as the primary statistical tool to test the relationship between the level of outsourcing and the profitability measures. The results of this study lead to the conclusion that there is not a significant difference between the amounts of IT outsourcing companies perform and any of the profitability measures used during the sample period. Further discussion continues related to the implications of the results

Stratospheric aerosol modification by supersonic transport operations with climate implications

The potential effects on stratospheric aerosois of supersonic transport emissions of sulfur dioxide gas and submicron size soot granules are estimated. An interactive particle-gas model of the stratospheric aerosol is used to compute particle changes due to exhaust emissions, and an accurate radiation transport model is used to compute the attendant surface temperature changes. It is shown that a fleet of several hundred supersonic aircraft, operating daily at 20 km, could produce about a 20% increase in the concentration of large particles in the stratosphere. Aerosol increases of this magnitude would reduce the global surface temperature by less than 0.01 K

Binding of Steroid Hormones In Vitro by Water-Insoluble Dietary Fiber

Previous work conducted in our laboratory has shown that steroid hormones bind to natural (e.g., brans, oat hulls) and purified (e.g., cellulose, lignin) fiber components. To explore this relationship further, we assessed the in vitro binding of estrone, estradiol-17β, and testosterone to a water-insoluble fiber fraction obtained from composite food samples of 18 Seventh-day Adventist (SDA) nonvegetarian (NV), 20 SDA lacto-ovovegetarian (LOV), and 15 SDA vegan (V) men. Three-day dietary food records and 72-hr food composites were obtained contemporaneously from each subject. The LOV and V subjects consumed significantly more crude, dietary and water-insoluble fiber than the NV subjects. Water-insoluble fiber bound an average of 73% of all estrogens tested, and 56% of the testosterone. Binding levels of testosterone were significantly higher in the Vs than in the LOVs and omnivores. Additionally, there was a significant relationship, for all groups combined, between water insoluble fiber intakes and binding of estrone and testosterone. These results suggest that diet may modify hormonal status, possibly through binding of steroid hormones by dietary fiber, leading to altered enterohepatic circulation of these hormones