Thermal Stability of Distillate Hydrocarbon Fuels

Thermal stability of fuels is expected to become a severe problem in the future due to the anticipated use of broadened specification and alternative fuels. Future fuels will have higher contents of heteroatomic species which are reactive constituents and are known to influence fuel degradation. To study the degradation chemistry of selected model fuels, n-dodecane and n-dodecane plus heteroatoms were aerated by bubbling air through the fuels amd stressed on a modified Jet Fuel Thermal Oxidation Tester facility operating at heater tube temperatures between 200 to 400 C. The resulting samples were fractionated to concentrate the soluble products and then analyzed using gas chromatographic and mass spectrometric techniques to quantify and identify the stable reaction intermediate and product specifically. Heteroatom addition showed that the major soluble products were always the same, with and without heteroatoms, but their distributions varied considerably

The use of logarithmic transformation and numerical derivatives for business performance data

The value of plotting business performance data over time on a semi-logarithmic graph has been advocated, but in a somewhat off-hand and intuitive way. While examples have been discussed, no mathematical justification has been given. In this paper, we give such a justification in order to underscore, and perhaps acquaint the reader with this simple yet powerful graphics tool. We also discuss and illustrate an extension of the idea underlying this technique. These methods are particularly useful with spreadsheet packages which inculude graphics capabilities

Exploring the impact of stakeholder pressure on environmental management strategies at the plant level: What does industry have to do with it?

Stakeholder theory and empirical evidence confirm the positive relationship between stakeholder pressure and the implementation of environmental practices and strategies. However, the specific mechanisms and impact of selected stakeholder groups on environmental management strategies are relatively underexplored. In this paper, this shortcoming is addressed by exploring the impact of selected stakeholder groups on environmental management strategies taking the contingency factor industry into consideration (i.e., dynamic vs. static industries). Basing the arguments primarily on stakeholder theory, it is suggested that stakeholder pressures are perceived differently in plants in dynamic versus static industries. Similarly, it is suggested that the influence of stakeholder pressures on the implementation of environmental strategies is influenced by industry type. To test the proposed research model, primary survey data from 502 plants collected in the United States across multiple industries is used. Thus, this paper contributes to the sustainability operations management literature through exploring the relationship between stakeholder pressure, environmental strategy implementation and contextual factors (i.e., industry type) through hypotheses testing. Results indicate that industry type does indeed affect stakeholder pressure, and the relationship between stakeholder pressure and environmental strategy implementation. Plants situated in dynamic industries experience a significantly higher level of stakeholder pressures as opposed to plants situated in static industries across an array of environmental strategies

Improved Customer Service Using RFID Technology

Customer service is an important aspect of the service supply chain. Radio frequency identification (RFID) can be used to improve customer service in the service supply chain.  This paper examines the use of RFID in the service supply chain by examining case studies and illustrating RFID usage with respect to both internal and external customer service

Temperature and bias voltage dependence of Co/Pd multilayer-based magnetic tunnel junctions with perpendicular magnetic anisotropy

Temperature- and bias voltage-dependent transport measurements of magnetic tunnel junctions (MTJs) with perpendicularly magnetized Co/Pd electrodes are presented. Magnetization measurements of the Co/Pd multilayers are performed to characterize the electrodes. The effects of the Co layer thickness in the Co/Pd bilayers, the annealing temperature, the Co thickness at the MgO barrier interface, and the number of bilayers on the tunneling magneto resistance (TMR) effect are investigated. TMR-ratios of about 11 % at room temperature and 18.5 % at 13 K are measured and two well-defined switching fields are observed. The results are compared to measurements of MTJs with Co-Fe-B electrodes and in-plane anisotropy

Operational Research in Education

Operational Research (OR) techniques have been applied, from the early stages of the discipline, to a wide variety of issues in education. At the government level, these include questions of what resources should be allocated to education as a whole and how these should be divided amongst the individual sectors of education and the institutions within the sectors. Another pertinent issue concerns the efficient operation of institutions, how to measure it, and whether resource allocation can be used to incentivise efficiency savings. Local governments, as well as being concerned with issues of resource allocation, may also need to make decisions regarding, for example, the creation and location of new institutions or closure of existing ones, as well as the day-to-day logistics of getting pupils to schools. Issues of concern for managers within schools and colleges include allocating the budgets, scheduling lessons and the assignment of students to courses. This survey provides an overview of the diverse problems faced by government, managers and consumers of education, and the OR techniques which have typically been applied in an effort to improve operations and provide solutions

Multiple Symmetric Lipomatosis: New Classification System Based on the Largest German Patient Cohort

Background: Multiple symmetric lipomatosis (MSL) is defined as a disorder of nonencapsulated adipose tissue growth. Its prevalence is indicated as 1:25,000 and affects, as stated in the literature, mainly Mediterranean males (male:female ratio of 15:1). Phenotypes are still classified as defined by Donhauser in 1991. We report clinical and phenotypic data of the largest patient cohort investigated in Germany so far. Methods: Forty-five patients diagnosed with MSL at the University Hospital Regensburg between 2007 and 2017 were photographed, clinically examined, and blood samples were taken. Based on the photographs (n = 33), 11 independent observers assessed patients using the Donhauser classification. Furthermore, the bodies of all patients were subdivided into 12 body areas, and the viewers had to indicate all MSL-affected areas per patient. Prevalence was calculated, comorbidities were assessed, and blood samples were analyzed. Results: According to the established Donhauser classification, less than 50% of the patients could be classified. Therefore, based on the constellations of MSL-affected body areas, a new classification that divides phenotypes of MSL into 5 types (Ia, Ib, Ic, II, and III) was set up and was able to cover 100% of our patients. The male to female ratio was found to be 1:2.5 (male:female). Prevalence of MSL in the catchment area was found to be 1:25,000. Hypercholesterinemia and hypothyroidism were frequent comorbidities, and blood analyses were normal besides a hypercholesterinemia. Discussion: The new proposed classification system describes 5 subtypes and allowed to classify all assessed patients. Male to female ratio (1:2.5) contradicted most previous publications