5,057 research outputs found
Study of the effects of gaseous environments on the hot corrosion of superalloy materials
The effect of the gaseous corrodent NaCl on the high temperature oxidation and sodium sulfate induced hot corrosion behavior of alumina formers, chromia formers, and the superalloy B-1900 was examined. Isothermal experiments were conducted at 900 C and 1050 C in air in the presence and absence of NaCl vapors. Microstructural changes in oxide morphology and increased rates of oxidation were observed when NaCl(g) was present. It is hypothesized that the accelerated rates of oxidation are the result of removal of aluminum from the scale substrate interface and the weakening of the scale substrate bonds. The aluminum removed was redeposited on the surfaces in the form of alumina whiskers. For the superalloy B-1900, alumina whiskers are also formed, and the alloy oxidizes at catastrophic rates. In the case of Ni-25Cr alloy, NaCl vapors interact with the scale depleting it of chromium
The ship of the desert. The dromedary camel (Camelus dromedarius), a domesticated animal species well adapted to extreme conditions of aridness and heat
The dromedary camel (Camel dromedarius) is extremely well adapted to life in hot and arid lands. In terms of physiological adaptation to heat and water deprivation it surpasses by far every other large animal of which data have been collected. None of the adaptive mechanisms to cope with the environmental stresses are unique to the Arabian camel, but the efficiency of its adaptation is superior. At high ambient temperatures the camels adapt to the scarcity of water by reducing their faecal, urinary and evaporative water losses. During dehydration, the kidneys reduce water losses both by decreasing the glomerual filtration rate and by increasing the tubular reabsorption of water. Also their ability of regulating their body temperature from 34.5-40.7 °C conserves a lot of water, when most needed
The Facts of Stigma: What\u27s Missing from the Procedural Due Process of Mental Health Commitment
This is the first systematic review of federal, judicial opinions that engage the stigma of mental health commitment in the context of procedural due process. In 1979, in Addington v. Texas, the Supreme Court held that the stigma, or adverse social consequences, of civil commitment is relevant to the procedural due process analysis. The following year, in Vitek v. Jones, the Court held that the stigmatizing consequences of a transfer from a prison to a mental health facility, coupled with mandatory treatment, triggered procedural protections
The future of the timeshare industry : will the brands dominate? : A summary of the vacation ownership industry and an analysis of the advantages that the brands have over smaller independent developers
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2002.Includes bibliographical references (leaves 42-44).The timeshare industry has transformed since its introduction to the United States nearly thirty years ago. Suffering from its early beginnings of dubious business practices and negative consumer perception, timesharing has evolved into a credible and growing source to the real estate industry. The concept of timeshare, at its simplest level, is dividing up condominium style residences into weekly increments, commonly referred to as intervals, which are sold to consumers in perpetuity or for a period of time. Timesharing has experienced explosive growth reaching four billion dollars in U.S sales in 2001 with compounded annual growth of over fourteen percent during the past twenty years. Over eighty-five percent of all timeshare owners are satisfied with their purchases. It is estimated that less than two percent of the U.S population own timeshares. With the convergence of the baby-boomer generation fueled with disposable income to spend on vacation experiences, the potential for growth is enormous. Industry insiders and the public mainly credit growth and consumer acceptance of timesharing due to the entry of large branded companies such as Marriott, Starwood, Disney, and Hilton. These companies have brought a degree of credibility and innovation to the industry that was lacking in the earlier part of its existence. Today, the industry is dominated by smaller independent companies who account for seventy-five percent of the market, but the brands continue to increase their market share. Will the timeshare industry mimic the consolidation of the hotel industry thirty years ago? This thesis paper will synthesize the pertinent aspects of the timeshare industry in order to establish a framework for those readers unfamiliar with the industry. It will also investigate and analyze the key reasons and competitive advantages that brands have over smaller independent developers. The thesis concludes that brands will dominate the timeshare industry due to five key factors: credibility/quality/ brand awareness; financial and economic advantages; sales and marketing; liquidity and flexibility; and consolidation.by Ethan S. Bornstein.S.M
The Complexity of Helly- EPG Graph Recognition
Golumbic, Lipshteyn, and Stern defined in 2009 the class of EPG graphs, the
intersection graph class of edge paths on a grid. An EPG graph is a graph
that admits a representation where its vertices correspond to paths in a grid
, such that two vertices of are adjacent if and only if their
corresponding paths in have a common edge. If the paths in the
representation have at most bends, we say that it is a -EPG
representation. A collection of sets satisfies the Helly property when
every sub-collection of that is pairwise intersecting has at least one
common element. In this paper, we show that given a graph and an integer
, the problem of determining whether admits a -EPG representation
whose edge-intersections of paths satisfy the Helly property, so-called
Helly--EPG representation, is in NP, for every bounded by a polynomial
function of . Moreover, we show that the problem of recognizing
Helly--EPG graphs is NP-complete, and it remains NP-complete even when
restricted to 2-apex and 3-degenerate graphs
SBML models and MathSBML
MathSBML is an open-source, freely-downloadable Mathematica package that facilitates working with Systems Biology Markup Language (SBML) models. SBML is a toolneutral,computer-readable format for representing models of biochemical reaction networks, applicable to metabolic networks, cell-signaling pathways, genomic regulatory networks, and other modeling problems in systems biology that is widely supported by the systems biology community. SBML is based on XML, a standard medium for representing and transporting data that is widely supported on the internet as well as in computational biology and bioinformatics. Because SBML is tool-independent, it enables model transportability, reuse, publication and survival. In addition to MathSBML, a number of other tools that support SBML model examination and manipulation are provided on the sbml.org website, including libSBML, a C/C++ library for reading SBML models; an SBML Toolbox for MatLab; file conversion programs; an SBML model validator and visualizer; and SBML specifications and schemas. MathSBML enables SBML file import to and export from Mathematica as well as providing an API for model manipulation and simulation
Trust in the Jury System as a Predictor of Juror/Jury Decisions
To determine whether jurors’ attitudes are correlated with their verdicts and judgments at trial, the present experiments examined the relationship between individuals’ trust in the jury system, other legal attitudes, and their verdict judgments, at both the individual (juror) and group (jury) level. We used a binary logistic regression model to examine the factors—jury instructions and individual difference measures—that contribute to a juror’s verdict. The results indicate that jurors with higher PJAQ and JUST scores had a higher likelihood of voting guilty on a homicide trial involving a mercy killing. It was also found that the majority of juries in the second study took a verdict-based approach, and jurors with less trust in the jury system participated more in deliberation than high trust jurors
The resection angle in apical surgery: a CBCT assessment.
OBJECTIVES
The primary objective of the present radiographic study was to analyse the resection angle in apical surgery and its correlation with treatment outcome, type of treated tooth, surgical depth and level of root-end filling.
MATERIALS AND METHODS
In the context of a prospective clinical study, cone beam computed tomography (CBCT) scans were taken before and 1Â year after apical surgery to measure the angle of the resection plane relative to the longitudinal axis of the root. Further, the surgical depth (distance from the buccal cortex to the most lingual/palatal point of the resection plane) as well as the level of the root-end filling relative to the most coronal point of the cut root face was determined. Treated teeth were categorized into four groups (maxillary and mandibular anterior and posterior teeth). The final material comprised 62 treated roots in 55 teeth.
RESULTS
The mean calculated resection angle of all roots was 17.7° ± 11.4° (range -9.6° to 43.4°). Anterior maxillary roots presented the highest mean angle (25.8° ± 10.3°) that was significantly different from the mean angle in posterior maxillary roots (10.7° ± 9.4°; p 20°), however without reaching statistical significance (p = 0.0905). Angles did not correlate either with the surgical depth or with the retrofilling length.
CONCLUSIONS
Statistically significant differences were observed comparing resection angles of different tooth groups. However, the angle had no significant effect on treatment outcome.
CLINICAL RELEVANCE
Contrary to common belief, the resection angle in maxillary anterior teeth was greater than in the other teeth. The surgeon is advised to pay attention to the resection angle when bevelling maxillary anterior teeth in apical surgery
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