Academic literature on the topic 'STATIC ATC DETERMINATION'

The ATC determination method in this study uses line thermal constraints by calculating reactive power flow, and using Linear Power Transfer Distribution Factor. The ATC determination considers the magnitude of the voltage magnitude and the static voltage stability of each bus after the power transfer simulation is performed. Static voltage stability is calculated using the L Index. The results showed that the transfer of power equal to the ATC value in an electric power system caused a decrease in voltage stability or an increase in the L index value on the receiving bus on average 19 times the initial loading condition, even though it was still at a stable level. While the receiver bus voltage magnitude has decreased

The Applied Technology Council (ATC), with funding from the California Seismic Safety Commission developed the document, Seismic Evaluation and Retrofit of Concrete Buildings, commonly referred to as ATC 40. This two-volume, 612-page report provides a recommended procedure for the seismic evaluation and retrofit of concrete buildings. Although the focus is specifically on concrete buildings, the document provides information on emerging techniques applicable to most building types. This paper provides an introduction and overview of the document. The conceptual basis of the procedures is performance-based design using nonlinear static structural analysis. The ATC 40 document comprises a practical guide to the entire evaluation and retrofit process. Topics include performance objectives, seismic hazard, determination of deficiencies, retrofit strategies, quality assurance procedures, nonlinear static analysis using the capacity spectrum method, modeling recommendations, foundation effects, and response limits.

The article presents universal mathematical static current-voltage characteristics- based models of electric arc and indicates primary issues concerned with arc diagnostics related to the determination of the above-named models. Particular attention was paid to the experimental determination of AC-powered arc voltage. Diagnostics-related purposes involved the use of bridge systems with one or two sources of current. Computer-aided simulations involving sinusoidal and trapezoidal current-based excitations made it possible to demonstrate the possibility of obtaining minimum values of bridge unbalance voltage. Such a condition indicated the proper determination of AC-powered arc ignition voltage.

In the conditions of TIG welding, the magnitude of the current is set, but not the voltage of the arc. To determine the arc voltage at a set current, arc length, type of electrode, sharpening angle and others, it is necessary to know the static characteristics of the welding arc. This dependence facilitates the use of simulation modelling methods of welding processes. In the proposed study, the static characteristics of the welding arc in TIG process with 4 types of electrodes were determined experimentally. The magnitude of the current was set in the range of 20 to 200A and the arc voltage was measured. All parameters are measured remotely by a real-time welding monitoring system and transferred to a remote computer via the Internet. Graphs were built based on the recordings, and the numerical results were processed and regression relationships were obtained.

ABSTRACTInvasive pulmonary aspergillosis (IPA) is a devastating disease of immunocompromised patients. Pharmacodynamic (PD) examination of antifungal drug therapy in IPA is one strategy that may improve outcomes. The current study explored the PD target of posaconazole in an immunocompromised murine model of IPA against 10A. fumigatusisolates, including 4Cyp51wild-type isolates and 6 isolates carryingCyp51mutations conferring azole resistance. The posaconazole MIC range was 0.25 to 8 mg/liter. Following infection, mice were given 0.156 to 160 mg/kg of body weight of oral posaconazole daily for 7 days. Efficacy was assessed by quantitative PCR (qPCR) of lung homogenate and survival. At the start of therapy, mice had 5.59 ± 0.19 log10Aspergillusconidial equivalents (CE)/ml of lung homogenate, which increased to 7.11 ± 0.29 log10CE/ml of lung homogenate in untreated animals. The infection was uniformly lethal prior to the study endpoint in control mice. A Hill-type dose response function was used to model the relationship between posaconazole free drug area under the concentration-time curve (AUC)/MIC and qPCR lung burden. The static dose range was 1.09 to 51.9 mg/kg/24 h. The free drug AUC/MIC PD target was 1.09 ± 0.63 for the group of strains. The 1-log kill free drug AUC/MIC was 2.07 ± 1.02. The PD target was not significantly different for the wild-type and mutant organism groups. Mortality mirrored qPCR results, with the greatest improvement in survival noted at the same dosing regimens that produced static or cidal activity. Consideration of human pharmacokinetic data and the current static dose PD target would predict a clinical MIC threshold of 0.25 to 0.5 mg/liter.

This research developed and optimized the methods for simultaneous determination of tetracycline (TCs), macrolide (MLs) and sulfonamide (SAs) antibiotics in soils using accelerated solvent extraction (ASE)- solid-phase extraction (SPE)-high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). Methanol-citric acid (pH=4.7) was used as extraction solvent, diatomite (washed by EDTA) was used as dispersing agent. Firstly, soil was extracted by ASE with the parameter conditions: pressure 1500 psi, temperature 70°C, static 10 min, 1 circle, then pre-concentration by SPE and followed by HPLC-MS/MS analysis. Recovery was 86.3%~97.4% for SAs, 67.3%~87.4% for TCs and 68.4%~78.3% for MLs. RSD < 9 % and r > 0.99. Limits of detection (LOD) was 0.5~0.9 ug/kg for SAs, 0.2~1.1 ug/kg for TCs and 0.2~0.3 ug/kg for MLs. This method determined 9 kinds of antibiotics within 15 min, the determination accuracy can meet the requirements of actual analysis.

Object The purpose of this study was to determine the effect of static and dynamic collimator optimization when using a micromultileaf collimator (mMLC) in dynamic-arc stereotactic radiosurgery (SRS) by evaluating the dose to healthy peritumoral tissue. Methods Thirty patients previously treated for intracranial lesions with the BrainLAB mMLC underwent retrospective replanning. Three collimator optimization strategies were compared for a simulated SRS treatment plan, as follows: Strategy 1, static collimation fixed at 90° throughout arcs; Strategy 2, static collimator settings optimized for each arc; and Strategy 3, dynamic collimator settings optimized every 10° throughout treatment arcs. Dose–volume histograms for a 0.7-cm shell of healthy peritumoral tissue were quantitatively compared. Collimator optimization schemes (Strategies 2 and 3) significantly decreased the volume of peritumoral tissue that is irradiated when compared with static collimation at 90° (Strategy 1). The volume was reduced by 40.6% for Strategy 2 (95% confidence interval [CI] ± 11) and by 47.1% for Strategy 3 (95% CI ± 8.1) at the 95% isodose; by 28.4% for Strategy 2 (95% CI ± 4.9) and 39.1% for Strategy 3 (95% CI ± 6) at the 90% isodose; and by 18.2% for Strategy 2 (95% CI ± 8.1) and 25.4% for Strategy 3 (95% CI ± 7.1) at the 80% isodose. Serial collimator optimization throughout the treatment arcs (Strategy 3) reduced the mean volume of peritumoral tissue irradiated when compared with static collimator optimization (Strategy 2), by 16.1% (95% CI ± 1.5) at 95% isodose, by 11.7% (95% CI ± 1) at 90% isodose, and by 8.2% (95% CI ± 1.2) at 80% isodose regions. In specific cases, linear or polynomial functions were formulated to optimize collimator settings dynamically throughout treatment arcs. Conclusions Dynamic collimator optimization during arc-based SRS decreases the volume of healthy peritumoral tissue treated with high doses of radiation and appears to be an effective method of improving target conformality. This study is the first step toward determination of a smoothing function algorithm to allow for true dynamic collimation during SRS.

Autoclaved aerated concrete (AAC) and its hygric parameters are a highly important issue in the field of building physics. There are several methods currently available to determine the equilibrium moisture content of building materials. Beside the conventional ones, new methods are constantly being introduced. This study explores the sorption/desorption properties of of three types of commercially produced AACs with three different bulk densities and demonstrates the application of the relevant methods available to characterize these parameters. The reliable characterization of the studied material was done through the conventional static approach, using the desiccator and an environmental chamber, and a new automated method of dynamic vapor sorption is implemented. The goal is to compare and identify the reliability of all methods used with respect to the efficiency of the data measurement process. Sound consistency between the results of the conventional methods and the experimental data obtained indicates the dynamic vapor sorption technique is highly reliable when measuring the equilibrium moisture content—particularly exemplified during the AAC sample testing. Therefore, the methodology developed in this study is expected to provide the reference for measuring the sorption/desorption isotherms of building materials with both static and automated techniques.

ABSTRACTInvasive pulmonary aspergillosis (IPA) continues to rise in concert with increasing numbers of immune suppression techniques to treat other medical conditions and transplantation. Despite these advances, morbidity and mortality rates remain unacceptably high. One strategy used to optimize outcomes is antifungal pharmacodynamic (PD) examination. We explored the pharmacodynamics of a new triazole in development, isavuconazole, in a murine neutropenic IPA model. TenA. fumigatusisolates were used, including four wild-type isolates and sixcyp51mutants. The MIC range was 0.125 to 8 mg/liter. Following infection, groups of mice were treated orally with the prodrug (BAL8557) at 40 to 640 mg/kg/12 h for 7 days. Efficacy was determined by quantitative PCR of lung homogenates. At the start of therapy, mice had 4.97 log10conidial equivalents (CE)/ml of lung homogenate, and this increased to 6.82 log10CE/ml of lung homogenate in untreated animals. The infection model was uniformly lethal in untreated control mice. The PD target endpoints examined included the static-dose AUC/MIC ratio and the 1-log10killing AUC/MIC ratio. A stasis endpoint was achieved for all isolates with an MIC of ≤1 mg/liter and 1-log10killing in all isolates with an MIC of ≤0.5 mg/liter, regardless of the presence or absence of thecyp51mutation. The static-dose range was 65 to 617 mg/kg/12 h. The corresponding median free-drug AUC/MIC ratio was near 5. The 1-log10killing dose range was 147 to 455 mg/kg/12 h, and the corresponding median free-drug AUC/MIC ratio was 11.1. These values are similar to those previously reported for other triazoles.

The mechanical properties of square section (up to 350 mm) forgings made of domestic steel VKS-9M (obtained by the duplex process of vacuum induction melting plus vacuum arc remelting) are studied. The mechanical properties of steel VKS-9M and American high-strength structural steel 300M are compared in terms of the calculated characteristics of materials. We extend the concept of «design characteristics of materials» to all the mechanical properties of materials used in determination of the strength and durability of structures. The design characteristics of materials include the strength characteristics under quasi-static tension, compression, crushing and shearing, as well as the strength under variable loads and the crack resistance of the material. The correctness of comparing the calculated values of the static strength of steels VKS-9M and 300M is based on the identity of test methods and the equivalence of processing and presentation of test results. The determination of the strength characteristics was carried out according to domestic standards, which are basically harmonized with the American standards. A difficult situation arises when determining the strength indicators of a newly developed material. Nowel material, as a rule, is developed in laboratory conditions, produced on experimental equipment in small volumes, and, therefore, the statistical assessment of the general population at the development stage is unreliable. In conditions of the full-scale manufacture of industrial semi-finished products, a statistical assessment of their strength characteristics becomes necessary. In the aviation industry, a statistical assessment of the calculated values of the strength characteristics of the material is prescribed by the law. The airworthiness standards set the levels of the calculated values of strength characteristics with a certain probability of non-destruction. For parts, the destruction of which can lead to an accident, the calculated values of the strength characteristics of materials should be selected in such a way that the strength of the material is to be ensured with a probability of 99% — with a 95% confidence interval (basis «A»). Statistical evaluation of the static strength characteristics of two heats of VKS-9M steel on the basis of «A» revealed their insignificant excess in comparison with steel 300M. The data obtained allow us to believe that the calculated values of the static strength characteristics of VKS-9M steel will not be lower than the calculated values for 300M steel. Large-scale fatigue tests of VKS-9M steel were carried out, which proved that the fatigue characteristics of VKS-9M and 300M steels practically coincide, as well as the arrays of their determinations. The equivalence of the strength characteristics of the VKS-9M and 300M steels allows replacement of the American 300M steel by the domestic VKS-9M steel.