Electrodynamics of a low-pressure electrode microwave discharge

Results are given of self-consistent two-dimensional simulation of self-sustained steady electrode microwave discharge in a chamber at the end of central conductor of a coaxial line. The discharge parameters are calculated in the diffusion mode in hydrogen at pressures of 0.5, 2, and 8 torr and incident power of 30–200 W. The dependence of matching between the discharge chamber and delivery path on the geometric dimensions of the chamber is investigated in the presence of plasma. It is demonstrated that the length of central electrode is the key factor affecting the structure of plasma formation and its matching with the pumping wave. The maxima and minima of matching alternate when the central electrode is elongated by quarter wave. The maxima and minima of matching for the case of low pressure (< 2 torr) are shifted by λ/4 relative to those for high pressure (> 2 torr). The problem of maximal energy input to the discharge region at the end of antenna-type electrode is analyzed. It is demonstrated that a restriction exists on the maximal energy input to such a discharge (and, accordingly, on the size of plasma formation). These restrictions are associated either with the runaway of discharge toward the generator or with the ignition of discharge in the region of entry of antenna into the chamber.     

Can we trust PRA?

The Fault-Tree/Event-Tree method is widely used in industry as the underlying formalism of probabilistic risk assessment. Almost all of the tools available to assess Event-Tree models implement the ‘classical’ assessment technique based on minimal cutsets and the rare event approximation. Binary decision diagrams (BDDs) are an alternative approach, but they were up to now limited to medium size models because of the exponential blow up of the memory requirements. We have designed a set of heuristics, which make it possible to quantify, by means of BDD, all of the sequences of a large Event-Tree model coming from the nuclear industry. For the first time, it was possible to compare results of the classical approach with those of the BDD approach, i.e. with exact results. This article reports this comparison and shows that the minimal cutsets technique gives overestimated results in a significant proportion of cases and underestimated results in some cases as well. Hence, the (indeed provocative) question in the title of this article.     

Pragmatic navigation: reactivity, heuristics, and search

FORR (FOr the Right Reasons) is an architecture for learning and problem solving that integrates a possibly incomplete and overlapping set of solution methods to address complex problems. Each method, although it represents some facet of domain expertise, may vary in reliability and speed. The principal contribution of this paper is the extension of FORR to include situation-based behavior (the serial testing of known, triggered techniques for problem solving in a domain) with reactivity and heuristic reasoning. FORR categorizes methods as reactive, heuristic, or situationbased, and addresses problem solving with one category of methods at a time. A hierarchical reasoner first has the opportunity to react correctly. If no ready reaction is computed, the reasoner activates a set of reactive triggers for time-limited search procedures tailored to specific situations. If they, too, fail to produce a response, the reasoner resorts to collaboration among heuristic rationales. All three components reference knowledge learned from experience. In a series of experiments, this architecture is shown to be effective and efficient. Ablation experiments demonstrate how each component plays an important role in problem solving. Additional contributions of this paper include a FORR-based, pragmatic, cognitively plausible approach to navigation with learned heuristic approximations that describe two-dimensional territory and travel experience through it, and a careful study of how situation-based behavior, reactivity, and heuristics interact there. Empirical evidence demonstrates that the resultant system is both effective and efficient, and guidelines for generalization to other domains are provided.     

Alcoholics Anonymous and Relapse Prevention as Maintenance Strategies After Conjoint Behavioral Alcohol Treatment for Men: 18-Month Outcomes.

Ninety men with alcohol problems and their female partners were randomly assigned to 1 of 3 outpatient conjoint treatments: alcohol behavioral couples therapy (ABCT), ABCT with relapse prevention techniques (RP/ABCT), or ABCT with interventions encouraging Alcoholics Anonymous (AA) involvement (AA/ABCT). Couples were followed for 18 months after treatment. Across the 3 treatments, drinkers who provided follow-up data maintained abstinence on almost 80% of days during follow-up, with no differences in drinking or marital happiness outcomes between groups. AA/ABCT participants attended AA meetings more often than ABCT or RP/ABCT participants, and their drinking outcomes were more strongly related to concurrent AA attendance. For the entire sample, AA attendance was positively related to abstinence during follow-up in both concurrent and time-lagged analyses. In the RP/ABCT treatment, attendance at posttreatment booster sessions was related to posttreatment abstinence. Across treatment conditions, marital happiness was related positively to abstinence in concurrent but not time-lagged analyses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A survey on makespan minimization in semi-online environments

We discuss variants of online scheduling on identical and uniformly related machines, where the objective is to minimize the makespan. All variants are such that some information regarding the input is provided in advance, and therefore these models are known as semi-online problems. Algorithms are analyzed with respect to the competitive ratio. We discuss the benefit arising from different kinds of available information and find that almost all variants allow one to reduce the competitive ratio significantly compared to the best possible competitive ratio for the corresponding pure online problem.     

Uniform flux heat transfer in concentric laminar flow of two immiscible liquids

The energy equation was solved exactly for fully developed steady laminar flow in a circular pipe of two immncible Newton liquids with a concentric cylindrical interface between them, assuming invariant physical properties of the liquids, uniform heat flux at the wall and fully developed temperature profiles. It is shown that, even if the viscosity of the annular liquid is orders of magnitude smaller than that of the core liquid, the improvement in heat transfer to the core liquid by infection of the annular liquid cannot exceed a factor of 1 8     

Testing a mathematical model for initial chemical reaction fouling using a dilute protein solution

A 1 wt% lysozyme solution was used as a model fluid to test a previously formulated mathematical model for the initial chemical reaction fouling rate of a heat transfer surface. The experimental results showed that, at a given wall temperature, a maximum initial fouling rate existed over a range of fluid velocities. The maximum rate and the fluid velocity at which it occurred both increased as the wall temperature increased. These observations were consistent with the model. Quantitatively, the average absolute percent deviation between the experimental results and the optimum model predictions was 23,3%. The decrease in initial fouling rate with increasing velocity at high fluid velocities was even greater than predicted by the model.     

Role of cytosolic calcium balance on cell injury in cultured bovine aortic endothelial cells during hypoxia and reoxygenation]

The integration of pharmacological therapies for comorbid disorders requires an acceptance of independence and interactions of respective addictive and psychiatric disorders. At the same time, alcohol and other drugs induce psychiatric states that are indistinguishable from psychiatric disorders. On the other hand, while psychiatric disorders do not induce addictive use of alcohol and drugs, they do pose vulnerabilities to the development of addictive disorders. Generally, the treatment of comorbid disorders begins with abstinence and evaluation of the effects of alcohol and other drugs in contributing to the psychiatric picture. In the case of comorbid disorders, stabilization and standard treatments can be employed with certain cautions, namely, to avoid the use of addicting medications such as benzodiazepines and opiates beyond the detoxification stage. High potency neuroleptics and antidepressants, particularly selective serotonin reuptake inhibitors (SSRIs) can be used to treat continuing psychiatric states after the exclusionary criteria in DSM-IV for substance-related disorders have been applied to the clinical case. If the psychiatric symptoms clear with sustained abstinence, little or no medications may be required. Specific treatment of the addictive disorders will often determine the extent that addictive disorders are responsible for psychiatric symptomatology. Alternatively, treatment of the psychiatric disorder will enhance compliance with addiction treatment.     

The appropriateness of use of percutaneous transluminal coronary angioplasty in New York State

Between 1974 and 1989 we prospectively observed 530 patients with brucellosis. The findings for 62 patients (42 males and 20 females; mean age, 34.7 years) with 63 episodes in which the sacroiliac joint was involved (the most frequent osteoarticular location [11.7%]) were analyzed. Ten of the older patients (mean age, 55.3 years) had concomitant spondylitis. Systemic symptoms were usually important, and characteristic pain and findings of sacroiliitis were observed in approximately 75% of cases. Blood cultures were positive for Brucella melitensis for 44 patients. The most frequent radiographic findings were blurring of articular margins (42 cases) and widening of the sacroiliac space (20 cases). No radiographic anomalies were detected in 13 cases. Results of 99mTc and gallium-67 bone scans were abnormal in approximately 90% of cases (abnormalities were often mild). Overall, clinical, radiographic, and isotopic bone scan findings were sensitive and useful, although they were occasionally minimal or difficult to evaluate, making diagnostic findings confusing or misleading. Brucellar sacroiliitis is a mild disease associated with a good outcome similar to that observed for patients with uncomplicated brucellosis.