Effect of a nitric oxide synthase inhibitor and a glucocorticosteroid on exhaled nitric oxide

Nitric oxide (NO) is produced by a variety of cells within the respiratory tract, including inflammatory epithelial cells. NO has been detected in the exhaled air of normal human subjects, and its concentration is raised in asthmatic patients. To study whether exhaled NO arises from the respiratory tract, we administered a NO synthase (NOS) inhibitor, NG-monomethyl-L-arginine (L-NMMA), by inhalation (490 mg) in a double-blind randomized manner in nine normal and six asthmatic subjects. Because exhaled NO may arise from an inducible isoform of NO synthase that may be inhibited by glucocorticosteroids, we also studied the effects of oral prednisolone (30 mg orally for 3 d) in seven normal and six asthmatic subjects in a separate double-blind crossover study with matched placebo. After nebulized L-NMMA, there was a significant fall in peak exhaled NO compared with saline control values, with a mean fall of 43.6 +/- 5.6% in normal subjects (p < 0.01) and of 39.7 +/- 6.5% (p < 0.01) in asthmatic subjects, which persisted for 4 h. There were no effects of L-NMMA inhalation on heart rate, blood pressure, or FEV1 in either normal or asthmatic patients. Administration of oral prednisolone (30 mg) resulted in a fall in exhaled NO concentrations in asthmatic subjects by 21.6 +/- 5.0% at 48 h (p < 0.01) but no significant change in normal subjects. These data suggest that NOS inhibitors may be safely given in normal and asthmatic patients and that the increased exhaled NO seen in asthmatic patients is likely to be caused by induction of inducible NOS.     

Steep front impulse flashover tests on a solid-state relay

A protective relay system, subjected to a high-voltage, steep-front impulse, has been shown to fail in the laboratory via flashover-induced current follow through on the DC power supply. Laboratory experiments were performed to characterize the response of a protective relay to steep-front impulses. These impulses may be the result of a nuclear-induced, high-altitude electromagnetic pulse. Tests were also conducted to quantify the protection offered by a surge protection package on the DC circuits of a relay system. Results from these tests were used to assess the vulnerability of a protective relay     

Regulating the disposal of cigarette butts as toxic hazardous waste

The trillions of cigarette butts generated each year throughout the world pose a significant challenge for disposal regulations, primarily because there are millions of points of disposal, along with the necessity to segregate, collect and dispose of the butts in a safe manner, and cigarette butts are toxic, hazardous waste. There are some hazardous waste laws, such as those covering used tyres and automobile batteries, in which the retailer is responsible for the proper disposal of the waste, but most post-consumer waste disposal is the responsibility of the consumer. Concepts such as extended producer responsibility (EPR) are being used for some post-consumer waste to pass the responsibility and cost for recycling or disposal to the manufacturer of the product. In total, 32 states in the US have passed EPR laws covering auto switches, batteries, carpet, cell phones, electronics, fluorescent lighting, mercury thermostats, paint and pesticide containers, and these could be models for cigarette waste legislation. A broader concept of producer stewardship includes EPR, but adds the consumer and the retailer into the regulation. The State of Maine considered a comprehensive product stewardship law in 2010 that is a much better model than EPR. By using either EPR or the Maine model, the tobacco industry will be required to cover the cost of collecting and disposing of cigarette butt waste. Additional requirements included in the Maine model are needed for consumers and businesses to complete the network that will be necessary to maximise the segregation and collection of cigarette butts to protect the environment.     

Electrical and Optical Characterization of Melt-Grown Bulk InAs<Subscript>1−<Emphasis Type="Italic">y</Emphasis></Subscript>P<Subscript><Emphasis Type="Italic">y</Emphasis></Subscript> Crystals

Bulk ternary InAs_1−y P _y polycrystals with diameters up to 50 mm were grown from a pseudobinary InP-InAs melt using the vertical Bridgman technique. Electrical and optical properties were investigated as functions of alloy composition and sample temperature. As-grown undoped crystals have been found to exhibit n-type conductivity irrespective of alloy composition. Though the bulk InAs_1−y P _y substrates show high optical transmission out to long wavelengths as well as high carrier mobility, they exhibit random compositional fluctuations across the substrate area.     

Shock behaviour of a phenolic resin

Phenolic resins are used in many aspects of everyday life, e.g. as the matrix material for carbon fibre laminates used in the aerospace industry. Consequently, detailed knowledge of this material, especially while under shock loading, is extremely useful for the design of components that could be subjected to impact during their lifespan. The shock Hugoniot equations of state for phenolic resin (Durite SC-1008), with initial density of 1.18 g cm⁻³ have been determined using the plate-impact technique with in situ manganin stress gauges. The Hugoniot equation in the shock velocity–particle velocity plane was found to be non-linear in nature with the following equation: U _S = 2.14 + 3.79u _p − 1.68u _p². Further, the Hugoniot in the pressure–volume plane was observed to largely follow the hydrostatic curve. Lateral gauge measurements were also obtained. An ANSYS Autodyn^TM 2D model was used to investigate the lateral stress behaviour of the SC-1008. A comparison of the Hugoniot elastic limit calculated from the shear strength and measured sound speeds gave reasonable agreement with a value of 0.66 ± 0.35 GPa obtained.     

通透幕墙引光线:坦帕美术馆

一眼望去,你甚至看不出它和普通小展馆的区别。这正是建筑师希望达到的效果:设计一个最适宜观赏艺术品的空间,而不是一个独立的空间雕塑。在这里你看不到任何花哨的形式处理。     

Simulation of Terahertz Generation from Lateral Diffusion Currents in Semiconductor Devices

In this paper we model the carrier dynamics and resulting THz emission from lateral diffusion currents within a semiconductor device which has been partially masked by a metallic mask. We present a numerical 1D model and a 1D Monte Carlo simulation which both demonstrate that regardless of the excitation laser spot shape we do not expect to see measurable THz emission in the direction of the optical pump propagation from lateral diffusion currents. Experimentally such devices do produce strong THz emission. We analytically investigate the role of the metal mask and we found that it suppresses the emission of dipoles that are in a region that is less than a wavelength away from the interface. The results from the numerical model are also included in a finite element analysis model of the geometry which predicts THz emission if and only if the metal mask is present.     

Human Performance Issues and User Interface Design for Teleoperated Robots

In the future, it will become more common for humans to team up with robotic systems to perform tasks that humans cannot realistically accomplish alone. Even for autonomous and semiautonomous systems, teleoperation will be an important default mode. However, teleoperation can be a challenging task because the operator is remotely located. As a result, the operator's situation awareness of the remote environment can be compromised and the mission effectiveness can suffer. This paper presents a detailed examination of more than 150 papers covering human performance issues and suggested mitigation solutions. The paper summarizes the performance decrements caused by video images bandwidth, time lags, frame rates, lack of proprioception, frame of reference, two-dimensional views, attention switches, and motion effects. Suggested solutions and their limitations include stereoscopic displays, synthetic overlay, multimodal interfaces, and various predicative and decision support systems.     

Yield Strengths of Biaxially Textured Metallic Substrates (Ni and its Alloys) Determined Using a Simplified Test Method

A simple testing method is used to compare the yield strengths (YS) of biaxially textured metallic substrates (Ni and its alloys) presently under development for YBa₂Cu₃O_7−x coated conductors. This method is based on a retired ASTM D3379 tensile test standard method that was originally recommended for single filament materials. Several common textured substrates, such as Ni, Ni-3at.%W, and Ni-5at.%W, procured from different manufacturers, were tested using this method, and the data were compared with the values reported in the literature. A new alloy substrate (constantan (Cu55-Ni44-Mn1wt.%)) that is biaxially textured in-house was also tested using this method, and the YS data were compared with those of other substrates. For the substrates used in this study, the data obtained using this method indicated that Ni substrates have YS of ∼52 MPa, Ni-3at.%W substrates have YS of ∼106 MPa, Ni-5at.%W substrates have YS 163 MPa, and Cu55-Ni44-Mn1 wt.% substrates have YS of 74 MPa.