Plasma Controls (United States)

Placental chorionic surface vascular networks (PCSVNs) are essential high-capacitance, low-resistance distribution and drainage networks, and are hence important to placental function and to fetal and newborn health. It was hypothesized that variations in the PCSVN structure may reflect both the overall effects of genetic and environmentally regulated variations in branching morphogenesis within the conceptus and the fetus’s vital organs. A critical step in PCSVN analysis is the extraction of blood vessel structure, which has only been done manually through a laborious process, making studies in large cohorts and applications in clinical settings nearly impossible. The large variation in the shape, color, and texture of the placenta presents significant challenges to both machine and human to accurately extract PCSVNs. To increase the visibility of the vessels, colored paint can be injected into the vascular networks of placentas, allowing PCSVNs to be manually traced with a high level of accuracy.This paper provides a proof-of-concept study to explain the geometric differences between manual tracings of paint-injected and un-manipulated PCSVNs under the framework of a shape-context model. Under this framework, paint-injected and un-manipulated tracings of PCSVNs can be matched with nearly 100% accuracy. The implication of our results is that the manual tracing protocol yields faithful PCSVN representations modulo a set of affine transformations, making manual tracing a reliable method for studying PCSVNs. Our work provides assurance to a new pre-processing approach for studying vascular networks by ways of dye-injection in medical imaging problems.

Multilayers (MLs) of 31 bi-layers and a 10-nm layer thickness each of Si/SiC were deposited on silicon, quartz and mullite substrates using a high-speed, ion-beam sputter deposition process. The samples deposited on the silicon substrates were used for imaging purposes and structural verification as they did not allow for accurate electrical measurement of the material. The Seebeck coefficient and the electrical resistivity on the mullite and the quartz substrates were reported as a function of temperature and used to compare the film performance. The thermal conductivity measurement was performed for ML samples grown on Si, and an average value of the thermal conductivity was used to find the figure of merit, zT, for all samples tested. X-ray diffraction (XRD) spectra showed an amorphous nature of the thin films. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to study the film morphology and verify the nature of the crystallinity. The mobility of the multilayer films was measured to be only 0.039 to 1.0 cm2/Vs at room temperature. The samples were tested three times in the temperature range of 300 K to 900 K to document the changes in the films with temperature cycling. The highest Seebeck coefficient is measured for a Si/SiC multilayer system on quartz and mullite substrates and were observed at 870 K to be roughly −2600 μV/K due to a strain-induced redistribution of the states’ effect. The highest figure of merit, zT, calculated for the multilayers in this study was 0.08 at 870 K.

The size and morphology of particulate matter emitted from a light-duty gasoline-direct-injection (GDI) vehicle, over the FTP-75 and US06 transient drive cycles, have been characterized by transmission-electron-microscope (TEM) image analysis. To investigate the impact of gasoline particulate filters on particulate-matter emission, the results for the stock-GDI vehicle, that is, the vehicle in its original configuration, have been compared to the results for the same vehicle equipped with a catalyzed gasoline particulate filter (GPF). The stock-GDI vehicle emits graphitized fractal-like aggregates over all driving conditions. The mean projected area-equivalent diameter of these aggregates is in the 78.4-88.4 nm range and the mean diameter of primary particles varies between 24.6 and 26.6 nm. Post-GPF particles emitted over the US06 cycle appear to have an amorphous structure, and a large number of nucleation-mode particles, depicted as low-contrast ultrafine droplets, are observed in TEM images. This indicates the emission of a substantial amount of semivolatile material during the US06 cycle, most likely generated by the incomplete combustion of accumulated soot in the GPF during regeneration. The size of primary particles and soot aggregates does not vary significantly by implementing the GPF over the FTP-75 cycle; however, particles emitted by the GPF-equipped vehicle over the US06 cycle are about 20% larger than those emitted by the stock-GDI vehicle. This may be attributed to condensation of large amounts of organic material on soot aggregates. High-contrast spots, most likely solid nonvolatile cores, are observed within many of the nucleation-mode particles emitted over the US06 cycle by the GPF-equipped vehicle. These cores are either generated inside the engine or depict incipient soot particles which are partially carbonized in the exhaust line. The effect of drive cycle and the GPF on the fractal parameters of particles, such as fractal dimension and fractal prefactor, is insignificant.

Specific scopeThis standard is intended for use in association with EPPO Standards of set PP 1 Standards for the efficacy evaluation of plant protection products and provides detailed advice on the design and analysis of efficacy evaluation trials.Specific approval and amendmentFirst approved in 1989–09.First revision approved in 1998–09.Second revision approved in 2006–09.Revision mainly to reflect zonal assessment approved in 2012–09.

Mobile satellite antennas are gimbal-mounted with an active control system to keep the antenna pointed at the target satellite. Short time-scale antenna stabilization is achieved with gyroscope feedback. Long time-scale tracking of the satellite is maintained by scanning the antenna: The beam is intentionally nutated and the resulting change in signal strength is used to estimate how well the antenna is aligned to the satellite. We review the basic architectures for tracking with an outer control loop, assuming that the system is built upon a fast inner stabilization loop. The problem is formulated in a generic mathematical way, not specific to RF satellite communication. Approaches and nomenclature from other fields faced with the same problem of peak-seeking control are discussed. One common and simple technique for tracking is analyzed in detail to reveal the shortcomings that lead to degraded performance. An improvement is suggested and subjected to the same transient analysis to show the improvement. Implications to the overall closed-loop tracking systems are discussed.

This paper describes the development of a mathematical model for predicting the aerodynamic torque characteristics of dampers. The model relates position, velocity, and aerodynamic torque so that one of the three can be estimated if the other two are known. The model is based on the theory of free streamlines. The accuracy of the model was tested experimentally. A wind tunnel equipped with a five-point pitot tube array was used to test the torque characteristics of a damper with an offset-blade construction. The model was calibrated with one data set and tested with a second. The experimental results demonstrate that the model accurately predicts torque characteristics over a wide range of operating conditions.

ABSTRACT Although a long established practice throughout Europe initially covered by the individual standards of what is now the European community and now harmonised under Cenelec (Comite Europeen de Normalisation Electrotechnique) under standards EN 50-014-039 the EEx'e' concept for hazardous atmospheres is little known, little understood and, because of differing standards, little used on the North American Continent. This is a pity because the application of the concept can make the engineering design of an oil or petrochemical plant, oil-rig etc. simpler and more cost effective in that zone classification can be significantly less onerous, cheaper and virtually maintenance free apparatus can be used. This means, particularly on offshore oil and gas platforms Chat substantial savings in cost can be effected by means of the possible top-side weight reduction achieved by its use. These factors which are to the benefit of all should no longer be ignored by the major oil producing companies and the many competent engineers, consultants and contractors who serve them. References, figures and bibliography appear at the end of the paper. WHAT IS THE EEX'e' CONCEPT First of all it may be advantageous to compare our supposedly 'widely different' standards. 1. Definitions: IEC/Cenelec recognise three zones which are compared with an abbreviation of the NEC definitions as follows: ZONE 'O' - IEC/CENELEC An explosive gas or mixture is continuously present - or present for long periods. ZONE 1 - IEC/CENELEC An explosive gas or mixture is likely to occur in normal operation. CLASS I DIVISION 1 - USA/NEC In which ignitable concentrations of flammable gases or vapours exist under normal operating conditions or in which ignitable quantities of such gases or vapours may exist frequently because of repair or maintenance operations or leakage. ZONE 2 - IEC/CENELEC An explosive gas or mixture is not likely to occur and if it occurs will only exist for a short time. CLASS I DIVISION 2 - USA/NEC In which volatile flammable liquids or gases are handled, processed or used but in which the liquids, vapours or gases will normally be confined within closed containers or systems from which they can escape only in case of accidental puncture or breakdown. Now, if we exclude European zone 'O' which is exclusively for mining applications, we can see that Cenelec zone 1 equates very closely to NEC Class I Division 1 and that Cenelec zone 2 equates to Class I Division 2 so our classifications are broadly similar. What apparatus are we allowed to use in our respective zones/divisions? What now follows is a brief resum6 of the standards - for a more comprehensive study please refer to the standards. IEC79-10/CENELEC ZONE 1 . Flame-proof EEx'd', increased safety EEx'e' which houses non-incendive components and apparatus, intrinsically safe EEx'ia' and 'ib' pressurised EEx'p', oil immersed EEx'O', powder filled EEx'q' special protection EEx'S', encapsulated EEx'm' and any equipment suitable for zone 'O'. NEC CLASS I DIVISION 1 Flame-proof (explosion proof) intrinsically safe, purged and oil immersion.