Wave Profile for Anti-force Waves with Maximum Possible Currents

In the theoretical investigation of the electrical breakdown of a gas, we apply a one-dimensional, steady state, constant velocity, three component fluid model and consider the electrons to be the main element in propagation of the wave. The electron gas temperature, and therefore the electron gas partial pressure, is considered to be large enough to provide the driving force. The wave is considered to have a shock front, followed by a thin dynamical transition region. Our set of electron fluid-dynamical equations consists of the equations of conservation of mass, momentum, and energy, plus the Poisson\u27s equation. The set of equations is referred to as the electron fluid dynamical equations; and a successful solution therefor must meet a set of acceptable physical conditions at the trailing edge of the wave. For breakdown waves with a significant current behind the shock front, modifications must be made to the set of electron fluid dynamical equations, as well as the shock condition on electron temperature. Considering existence of current behind the shock front, we have derived the shock condition on electron temperature, and for a set of experimentally measured wave speeds, we have been able to find maximum current values for which solutions to our set of electron velocity, electron temperature, and electron number density within the dynamical transition region of the wave

Relationship between the communication skill of nurse - patient with patient safety in the critical care units

زمینه و هدف: تمرکز روی ایمنی بیمار در بخش های مراقبت ویژه موضوعی مهم است و در این بین یکی از مهم ترین عوامل مربوط به ایمنی بیمار، مهارت های ارتباطی بین پرستار و بیمار می باشد. این مطالعه با هدف تعیین رابطه بین مهارت ارتباطی پرستار - بیمار با وضعیت ایمنی بیماران در بخش های ویژه بیمارستان های شهر ارومیه از دیدگاه پرستاران انجام شد. روش بررسی: در این مطالعه توصیفی - همبستگی، 167 پرستار شاغل در بخش های ویژه بیمارستان های آموزشی و غیر آموزشی شهر ارومیه با روش تمام سرشماری شرکت کردند. جهت جمع آوری داده ها از پرسشنامه های روا و پایا شده ی مهارت ارتباطی پرستار - بیمار و وضعیت ایمنی بیمار استفاده شد و مهارت ارتباطی پرستار - بیمار ارزیابی و ارتباط آن با وضعیت ایمنی بیماران تعیین شد. یافته ها: اکثریت پرستاران شاغل در بیمارستان های آموزشی و غیر آموزشی (به ترتیب 5/97 و 8/97 درصد) مهارت ارتباطی خود را در سطح خوب ارزیابی کردند. همچنین 6/87 درصد پرستاران بیمارستان های آموزشی و 8/84 پرستاران بیمارستان های غیر آموزشی ایمنی بیماران را در سطح خوب ارزیابی کردند. بین مهارت ارتباطی پرستاران با وضعیت ایمنی بیماران در بخش ویژه رابطه معنی دار آماری وجود داشت (001/0>P). نتیجه گیری: با توجه به نتایج این مطالعه پرستاران می توانند با بکارگیری مهارت های ارتباطی مناسب با بیماران بستری در بخش های ویژه، ایمنی آن ها را حفظ و ارتقاء بخشند

Momentum analysis of complex time-periodic flows

Several methods have been proposed to characterize the complex interactions in turbulent wakes, especially for flows with strong cyclic dynamics. This paper introduces the concept of Fourier-Averaged Navier-Stokes (FANS) equations as a framework to obtain direct insights into the dynamics of complex coherent wake interactions. The method simplifies the interpretations of flow physics by identifying terms contributing to momentum transport at different timescales. The method also allows for direct interpretation of non-linear interactions of the terms in the Navier-Stokes equations. By analysing well-known cases, the characteristics of FANS are evaluated. Particularly, we focus on physical interpretation of the terms as they relate to the interactions between modes at different timescales. Through comparison with established physics and other methods, FANS is shown to provide insight into the transfer of momentum between modes by extracting information about the contributing pressure, convective, and diffusive forces. FANS provides a simply calculated and easily interpreted set of equations to analyse flow physics by leveraging momentum conservation principles and Fourier analysis. The method is applicable to flows with complex cyclic waveforms, including broadband spectral energy distributions.Comment: 28 pages, 23 figures. Submitted to the Journal of Fluid Mechanic

Multilevel Analysis of Effective Factor on Academic Resilience Among High School Students of Underdeveloped Regions of Mobarakeh

A this study aimed to determine the factors influencing resilience at individual, family and school level and surveyed on 250 female (n=192) and male students (n=58) of less developed regions in the Mobarekeh. Hierarchical liner regression (HLM) showed that individual (self-esteem and academic motivation) and the family-level variables (family social capital) have significant relationship with academic resilience and despite the school level variables associated with resilience in the second model, with the entrance of other variables in the final model, the relationship becomes insignificant. Finally, some suggestions provided for improving resilience in these areas

Evaluation of Different Best Management Practices for Erosion Control on Machine Operating Trails

Ground-based mechanized forest operations often lead to increased runoff and soil loss on unbound forest roads and machine operating trails, which in turn can impede the technical trafficability of machines and cause negative impacts on the environment. The aim of this study was to evaluate the effectiveness of three Best Management Practice (BMP) treatments used to control erosion occurring on machine operating trails. The treatments included water bar, water bar and hardwood brush (H-brush), and water bar and softwood brush (S-brush). For a more comprehensive assessment of both brush treatments, two levels of brush thickness were tested; 0.5 m and 1.0 m. Results indicate that the most effective BMP treatments were the water bar and softwood brush followed by the water bar and hardwood brush and finally the least effective was the water bar. The average runoff rates and soil loss from the machine operating trails with the water bar treatment (52.64 l per plot, 8.49 g m-2) were higher than runoff and soil loss at the trails protected with hardwood brush (23.75 l per plot, 4.5 g m-2), and the trails protected by the hardwood brush had higher runoff and soil loss compared to trails covered by softwood brush (15.83 l per plot, 2.98 g m-2). Furthermore, results of this study showed that regardless of the treatment, the amount of runoff and soil loss decreased consistently as the thickness of the brush mat increased. Overall, erosion control techniques similar to either H-brush or S-brush that provide direct soil coverage should be used for erosion control, and final selection should be based on costs, availability of material, or landowner objectives

Microstructure and Phase Formation in a Rapidly Solidified Laser-Deposited Ni-Cr-B-Si-C Hardfacing Alloy

In this study, microstructural evolutions and phase selection phenomena during laser deposition of a hardfacing Ni-Cr-B-Si-C alloy at different processing conditions are experimentally investigated. The results show that even minor variations in the thermal conditions during solidification can modify the type and morphology of the phases. Higher undercoolings obtained at faster cooling rates suppressed the primary borides and encouraged floret-shape mixtures of Ni and Cr5B3 via a metastable reaction. Variations in the boride phases are discussed in terms of nucleation-and growth-controlled phase selection mechanisms. These selection processes also influenced the nature and proportion of the Ni-B-Si eutectics by changing the amount of the boron available for the final eutectic reactions. The results of this work emphasize the importance of controlling the cooling rate during deposition of these industrially important alloys using laser beam or other rapid solidification techniques. (C) The Minerals, Metals & Materials Society and ASM International 201

Current Range in Lightning Return Strokes

In our investigation of breakdown waves, we use a one-dimensional, steady-state, constant velocity fluid model. This investigation involves breakdown waves for which the electric field force on electrons is in the opposite direction of wave propagation. The waves are considered to be shock fronted and the electron gas partial pressure is large enough to sustain the wave propagation. Our basic set of electron fluid-dynamical equations is composed of the equations for conservation of mass, momentum and energy, coupled with Poisson’s equation. This investigation involves breakdown waves for which a large current exists behind the shock front. The current behind the shock front alters the set of electron fluid-dynamical equations as well as the boundary conditions at the shock front. For the range of reported experimental current values (Wang et al. 1999), we have been able to solve the electron fluid dynamical equations within the dynamical transition region of the wave. Wave profile for electric field and electron velocity, number density and temperature within the dynamical transition region of the wave will be presente

Impact assessment of skidding extraction: Effects on physical and chemical properties of forest soils and on maple seedling growing along the skid trail

Several studies investigated soil disturbances caused on skid trails by forest logging. However, there is still a lack of knowledge about the severity and the distance of disturbances along both sides from the trails. The aims of this study were: i) to investigate the changes in physical and chemical properties of soil along the sides of skidding trails; ii) to measure the effects of soil compaction on of maple seedlings growth. Two levels of trail gradient ( < 20% and > 20 %), four levels of traffic frequency (3, 8, 15, and 30 passes) and four distance buffer strip zones (0.5 m intervals from 0 to 2 m in distance) on both sides of skid trail edges were analyzed. Each treatment included three replicate plots. In order to investigate the effect of compaction on seedlings emergence and growth, maple seeds were sown after logging. The results highlighted significant changes in physical and chemical properties of soil for each traffic frequency in the closest buffer strip (from 0 to 0.5 m from the skid trail edges). The largest changes in soil properties were identified at 0.5 m distance zones for a slope gradient > 20% after 3, 8, 15, and 30 skidding cycles. The highest changes were recorded on slope category > 20%. The higher the soil compaction the lower the germination rate, root length, and stem height of seedlings

The Temperature of the CMB at 10 GHz

We report the results of an effort to measure the low frequency portion of the spectrum of the Cosmic Microwave Background Radiation (CMB), using a balloon-borne instrument called ARCADE (Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission). These measurements are to search for deviations from a thermal spectrum that are expected to exist in the CMB due to various processes in the early universe. The radiometric temperature was measured at 10 and 30 GHz using a cryogenic open-aperture instrument with no emissive windows. An external blackbody calibrator provides an in situ reference. A linear model is used to compare the radiometer output to a set of thermometers on the instrument. The unmodeled residuals are less than 50 mK peak-to-peak with a weighted RMS of 6 mK. Small corrections are made for the residual emission from the flight train, atmosphere, and foreground Galactic emission. The measured radiometric temperature of the CMB is 2.721 +/- 0.010 K at 10 GHz and 2.694 +/- 0.032 K at 30 GHz.Comment: 8 pages including 5 figures. Submitted to The Astrophysical Journa