We study the high-energy emission of the Galactic black hole candidate GX 339-4 using INTEGRAL/SPI and simultaneous RXTE/PCA data. By the end of January 2007, when it reached its peak luminosity in hard X-rays, the source was in a bright hard state. The SPI data from this period show a good signal to noise ratio, allowing a detailed study of the spectral energy distribution up to several hundred keV. As a main result, we report on the detection of a variable hard spectral feature (>150 keV) which represents a significant excess with respect to the cutoff power law shape of the spectrum. The SPI data suggest that the intensity of this feature is positively correlated with the 25 - 50 keV luminosity of the source and the associated variability time scale is shorter than 7 hours. The simultaneous PCA data, however, show no significant change in the spectral shape, indicating that ...
The Westerbork Northern Sky Survey (WENSS) and the NRAO/VLA Sky Survey (NVSS) were used to determine an upper limit to the diffuse radio flux from the nearby cluster Abell 2199. For the entire cluster, this limit is <3.25 Jy at 327 MHz from WENSS; for the inner 15' radius, the limit is <168 mJy at 1.4 GHz. These limits are used to constrain the cluster magnetic field by requiring that the radio flux be consistent with the hard X-ray (HXR) flux observed by BeppoSAX, assuming that the observed HXR excess is due to inverse Compton (IC) scattering of cosmic microwave background photons by relativistic electrons in the intracluster gas. We find that the magnetic field must be very weak (<0.073 uG) in order to avoid producing an observable radio halo. We also consider the possibility that the HXR excess is due to nonthermal bremsstrahlung (NTB) by a population of suprathermal electrons which are being accelerated to ...
The major details of the inspection and replacement of the bearing journals on each of the four heat transport pumps (HTPs) at Wolsung nuclear generating station in Korea are presented in this paper. Investigation following fracture of one of the journals in 1985 revealed that it was excessivelyhard. The journal material (ASTM A296 CA 40) is considered to be prone to stress corrosion fatigue if the hardness exceeds Rc 40. In 1986 May, during a planned outage, the HTPs were disassembled, the journals were inspected, found to be excessivelyhard, and all were replaced. At the same time, the pump to motor couplings were all refurbished to ensure proper alignment.
An ex-employee's claims that inadequate enforcement of radiation safety regulations allowed excess radiation exposure thereby causing his deteriorating health was not substantiated by a thorough investigation.
High interelectrode voltage peaks have been observed simultaneously with the emission of hard X-ray bursts from a flash X-ray tube. The magnitude of the voltage peaks may exceed twice the initial charging voltage. It has also been observed that the discharge emits bursts of X-and P-band microwaves radiation which are coincident with the emission of the hard X-ray bursts. The results indicate that the microwaves and X-rays have a common origin in discharge plasma movements and an acceleration model for electrons in the plasma is presented as one possible explanation of the observed phenomena.
Context: The colliding-wind binary Eta Car exhibits soft X-ray thermal emission that varies strongly around periastron, and non-thermal emission seen in hard X-rays and gamma-rays. Aims: To definitively identify Eta Car as the source of the hard X-ray emission, to examine how changes in the 2-10 keV band influence changes in the hard X-ray band, and to understand more clearly the mechanisms producing the non-thermal emission using new INTEGRAL observations obtained close to periastron. Methods: A Chandra observation encompassing the ISGRI error circle was analysed, and all other soft X-ray sources (including the outer shell of Eta Car itself) were discarded as likely counter-parts. New hard X-ray images of Eta Car were studied close to periastron, and compared to previous observations far from periastron. Results: The ...
Molecular dynamics simulations have been carried out of the radial distribution function of the hard sphere fluid for a range of densities in the equilibrium fluid and just into the metastable region. The first derivative of the hard-sphere radial distribution function at contact was computed and its density dependence fitted to a simple analytic form. Comparisons were made with semi-empirical formulae from the literature, and of these the formula proposed by Tao et al (1992 Phys. Rev. A 46 8007) was found to be in best agreement with the simulation data, although it slightly underestimates the derivative at the higher packing fractions in excess of about 0.45. Close to contact, within a few per cent of the particle diameter, the radial distribution function can be represented well by a second order polynomial. An exponential function, which has some useful analytic features, can also be applied in this region.
In this paper, the control scheme of a liquefied petroleum gas (LPG)-diesel dual-fuel engine with electronic control is illustrated, the external characteristics and load characteristics of the LPG-diesel dual-fuel engine and the diesel engine are compared and analysed, and the results of automobile road tests are also given. The experimental results show that, compared with diesel, the output performance of dual fuel is not reduced, while smoke emission of dual fuel is significantly reduced, NO{sub x} emission of dual fuel is hardly changed, but HC emission and CO emission of dual fuel are increased and fuel consumption of dual fuel is reduced. (Author)
We examine the accretion properties in a sample of 42 hard (3-60keV) X-ray selected nearby broad-line AGNs. The energy range in the sample is harder than that usually used in the similar previous studies. These AGNs are mainly complied from the RXTE All Sky Survey (XSS), and complemented by the released INTEGRAL AGN catalog. The black hole masses, bolometric luminosities of AGN, and Eddington ratios are derived from their optical spectra in terms of the broad H$\\beta$ emission line. The tight correlation between the hard X-ray (3-20keV) and bolometric/line luminosity is well identified in our sample. Also identified is a strong inverse Baldwin relationship of the H$\\beta$ emission line. In addition, all these hard X-ray AGNs are biased toward luminous objects with high Eddington ratio (mostly between 0.01 to 0.1) and low column density ($<10^{22} \\mathrm{cm^{-2}}$), which is ...
The peak flux relationship between hard X-rays and microwaves from solar flares is studied using about 400 events simultaneously recorded with the hard X-ray burst spectrometer on the SMM satellite and the Nobeyama 17 GHz radiometer. The data indicate that the hard X-ray and microwave peak fluxes correlate best for X-ray energies of less than about 80 keV for impulsive flares and greater than about 360 keV for extended flares. By postulating that electrons responsible for microwave emission at 17 GHz are those emitting hard X-rays at these photon energies, it is concluded that: (1) in impulsive flares, microwaves at about 20 GHz are emitted mainly by electrons of less than about 200 keV from a layer through which the electrons stream down into the thick-target hard X-ray source; and (2) in extended flares, microwaves are emitted mainly by MeV electrons trapped ...
Combustion characteristics of Korean anthracite in a circulating fluidized bed and freeboard were investigated. A test coal was selected with heating value of 4,429kcal/kg and ash content of 38%. Characteristics of combustion, sorbent effect on desulphurisation and emission of SO{sub x} and NO{sub x} were monitored by varying process variables such as feed rate, (Ca+K)/S ratio, and excess air ratio at the given properties of coal. Optimum operating conditions were studied by analysing: axial profiles of temperature, effect of excess air ratio, characteristics of loopseal and bag filter ashes, and emission of toxic gases. 9 refs., 9 figs., 3 tabs.
The distributions of the effective numbers of 6q-fluctons in the energy, momentum and distance to the center of mass of nucleus are studied. Many characteristics of these distributions are shown to be universal, i.e. independent of the flucton size. The saturation of the flucton density in A > 80 nuclei and other peculiarities are found, which define different behavior of the effective numbers of fluctons and deuterons. This fact provides an explanation of the known underestimate by a factor of 1.5-6 of the cross sections of hard inclusive (p, p'd) process on nuclei calculated in the quasi-elastic approximation.
We aim to obtain a consistent description of non-thermal emissions from Abell 2256 and to give a prediction for a gamma-ray emission from this galaxy cluster. Assuming that a radio relic illuminates a localization of an ongoing merger, and that both radio and non-thermal part of hard X-ray emission are due to electron component of cosmic rays filling the relic, we derived from radio and hard X-ray properties of the relic in A2256 the magnetic field strength and number densities for relativistic electrons and protons. Due to the interpretation of the radio relic as a structure formed just where a shock front is, we discuss a gamma-ray emission at the cluster periphery. The estimated strength of the magnetic field in the relic is equal to 0.05 \\muG, while the amplitude of the electron number density varies from 3 x 10^{-4} to 3 x 10^{-5} cm^{-3} (respectively for ...
In a recent paper by Hooper and Goodenough, data from the Fermi Gamma Ray Telescope was analyzed and an excess of gamma rays was found in the emission spectrum from the Galactic Center Region. Hooper and Goodenough show that the excess can be well explained by 7-10 GeV annihilating dark matter with a power law density profile if the dark matter annihilates predominantly to tau pairs. In this paper we present such a dark matter model by extending the MSSM to include four Higgs doublets and one scalar singlet. A Z2 symmetry is imposed that enforces a Yukawa structure so that the up quarks, down quarks, and leptons each receive mass from a distinct doublet. This leads to an enhanced coupling of scalars to leptons and allows the model to naturally achieve the required phenomenology in order to explain the gamma ray excess. Our model yields the correct dark matter thermal relic density and avoids collider ...
The optical properties of divalent europium activated Ca-#alpha#-SiAlON were investigated and the excitation and emission processes were discussed. The emission wavelength is influenced by the activator concentration of Eu more than the codopant concentration of Ca, in case of the same matrix composition of #alpha#-SiAlON. The red-shift of emission increases when the concentration of Eu increases. In addition, it was revealed that the red-shift of emission would be caused by the construction of the package of optical device. The correlated color temperature becomes low by the red-shift for the white light-emitting diode (LED) lamp using Ca-#alpha#-SiAlON:Eu phosphor when the phosphor powder concentration increases in the transparent resin which coats the primary light source of a blue LED die. The additional red-shift can be observed when the excessive amount of phosphor coating is ...
Methodology, characteristics, features and results obtained for greenhouse gases within the recent Swiss LCA study 'Environmental Life-Cycle Inventories of Energy Systems' are presented. The focus of the study is on existing average Full Energy Chains (FENCHs) in the electricity generation mixes in Europe and in Switzerland. The systems, including coal (hard coal and lignite), oil, natural gas, nuclear and hydro, are discussed one by one as well as part of the electricity mixes. Photovoltaic systems are covered separately since they are not included in the electricity mixes. A sensitivity analysis on methane leakage during long-range transport via pipeline is shown. Whilst within the current study emissions are not attributed to specific countries, the main sectors contributing to the total GHGs emissions calculated for the various FENCHs are specified. (author). 10 refs, 10 figs, 9 tabs.
In order to establish the optimum fueling in a natural gas fueled dual fuel engine, tests were made for some operational parameters and their combination on the engine performances and the exhaust emissions. The results show that the gas oil quantity should be increased and gas oil injection timing should be advanced to suppress unburned hydrocarbon emission at middle and low output range, while the quantity should be reduced and the timing should be retarded to avoid onset of knock at high loads. The unburned hydrocarbon emission and the thermal efficiency are improved at the same load avoiding too lean natural gas premixture by restriction of intake charge air. However the improvement is limited because the ignition and initial combustion of pilot diesel fuel is deteriorated when the cylinder pressure is excessively lowered by throttling. The increase in pilot gas oil amount is effective for low-load ...
We present the X-ray properties of a sample of 17 radio sources observed with the Chandra X-ray Observatory as part of a project aimed at studying the X-ray emission from their radio jets. In this paper, we concentrate on the X-ray properties of the unresolved cores. The sample includes 16 quasars (11 core-dominated and 5 lobe-dominated) in the redshift range z=0.30--1.96, and one low-power radio-galaxy at z=0.064. No diffuse X-ray emission is present around the cores of the quasars, except for the nearby low-power galaxy that has diffuse emission on a scale and with a luminosity consistent with other FRIs. No high-amplitude, short-term variability is detected within the relatively short Chandra exposures. However, 1510-089 shows low-amplitude flux changes with a timescale of $\\sim$25 minutes. The X-ray spectra of the quasar cores are generally well described by a single power law model with Galactic absorption. However, ...
Rossi X-ray Timing Explorer (RXTE) observations of the bright supernova remnant Cas A have revealed a hard power law component above 10 keV in addition to two thermal components inferred from ASCA measurements of the many line centroids from low-Z elements. The power law can be shown to be consistent with synchrotron emission from radio to hard x-rays by electrons of up to 4 x 10"1"3 eV. Measurement of the 1157 keV line by CGRO from "4"4Sc in the chain of decay of "4"4Ti predicts that the two "4"4Ti lines at 68 and 78 keV should appear at the CGRO intensity. RXTE has placed upper limits on such lines that are marginally consistent with the CGRO measurement. Implications of these results on sites for cosmic ray acceleration and nucleosynthesis are discussed.
The energy, angular momentum, and distance (measured from the center of mass of the nucleus) distributions of the effective number of 6q-fluctons are investigated and it is shown that many of the characteristics of these distributions are universal, i.e., independent of the flucton size. ''Saturation'' of the flucton density in nuclei with mass A approx > 80 and certain other features that determine the difference between the behaviors of the effective numbers of fluctons and deuterons are reported. This is used to explain the well known underestimation (by a factor of 1.5--6) of the cross section for the hard inclusive (p, p'd) process on nuclei calculated in the quasielastic formalism. See S. G. Kadmenskii and V. I. Furman, Alpha decay and elated nuclear reactions (in Russian), Energoatomizdat, Moscow, 1985.
The energy, angular momentum, and distance (measured from the center of mass of the nucleus) distributions of the effective number of 6/ital q/-fluctons are investigated and it is shown that many of the characteristics of these distributions are universal, i.e., independent of the flucton size. ''Saturation'' of the flucton density in nuclei with mass /ital A//approx gt/80 and certain other features that determine the difference between the behaviors of the effective numbers of fluctons and deuterons are reported. This is used to explain the well known underestimation (by a factor of 1.5--6) of the cross section for the hard inclusive (/ital p/, /ital p/'/ital d/) process on nuclei calculated in the quasielastic formalism. See S. G. Kadmenskii and V. I. Furman, /ital Alpha/ /ital decay/ /ital and elated/ /ital nuclear/ /reactions/ (in Russian), Energoatomizdat, Moscow, 1985.
Excessive erosion of the labyrinth seal of a 100 MW geothermal turbine has been investigated. This study used computational fluid dynamics (CFD) and aims to identify one cause of erosion and a possible solution for substantially reducing it. The predictions were based upon a numerical calculation using a CFD model of the labyrinth seal with a water/steam flow containing hard solid particles and solved with a commercial CFD code: Fluent V5.0. The results confirmed the existence of flow conditions that play a major role in the rotor labyrinth seal erosion. Afterwards, the flow path was simulated with changes of rotor labyrinth seal geometry, which are indeed feasible of being implemented. The results confirmed that it is possible to reduce the erosion process by approximately 80% by incorporating a steam flow deflector in the fourth stage diaphragm, which changes the steam flow direction in the inlet zone to the rotor labyrinth seal channel, ...
Diffuse {gamma}-ray emission produced by the interaction of cosmic-ray particles with matter and radiation in the Galaxy can be used to probe the distribution of cosmic rays and their sources in different regions of the Galaxy. With its large field of view and long observation time, the Milagro Gamma Ray Observatory is an ideal instrument for surveying large regions of the Northern Hemisphere sky and for detecting diffuse {gamma}-ray emission at very high energies. Here, the spatial distribution and the flux of the diffuse {gamma}-ray emission in the TeV energy range with a median energy of 15 TeV for Galactic longitudes between 30{sup o} and 110{sup o} and between 136{sup o} and 216{sup o} and for Galactic latitudes between -10{sup o} and 10{sup o} are determined. The measured fluxes are consistent with predictions of the GALPROP model everywhere except for the Cygnus region (l {element_of} [65{sup o}, 85{sup o}]). For the ...
The failure took place on a welded elbow pipe which exhibited a catastrophic transverse rupture. The failure was located on the welding HAZ region, parallel to the welding path. Branching cracks were detected at the edge of the rupture area. Deposits of corrosion products were also spotted. The optical microscope analysis showed the presence of transgranular failures which were related to the stress corrosion cracking (SCC) and were predominantly caused by the welding residual stress. The significant difference in hardness between the welded area and the pipe confirmed the findings. Moreover, the failure was also caused by the low Mo content in the stainless steel pipe which was detected by means of spark emission spectrometer. (orig.)
"2H, "4He, "1"6O, "4"0Ca, "8"0Zr, "1"4"0Yb, "2"2"4112, "3"3"6168 nuclei are invesigated in terms of flucton model. Effective numbers of nuclear fluctons and deuterons are calculated. Values of complete effective numbers of low-radius deuterons and fluctons with S=1 spin and T=0 isospin are presented. Investigation results of inclusive reactions of quasi-elastic knock-out of deuterons by fast protons are discussed. 9 refs.; 1 fig.; 1 tab.
Aerosol and gas measurements were made with the University of Minnesota Mobile Laboratory (UMML) during the VISTTA programme near Page, Arizona. The UMML was stationed on Zilnez Mesa approx. 65 km east of the Navajo coal-fired power plant. Measurements were made both in and out of the power plant plume and were made during the day and night. Measured parameters included aerosol size distributions, Aitken nuclei count, ozone and sulphur dioxide concentrations, the aerosol light scattering coefficient, and meteorological parameters including ultraviolet radiation intensity. Concentrations of NO and NO/SUB/x were occasionally measured. Data show clear evidence of gas-to-particle conversion in the plume with aerosol volume being added in the 0.01 MUm - 0.32 MUm dia. range and new particles being formed. The observed excess aerosol volume depends strongly upon the SO/SUB/2 concentrations and the time of day with none observed in plume parcels which were not exposed to ...
The recently observed X-ray synchrotron emission from four supernova remnants (SNRs) has strengthened the evidence that cosmic-ray electrons are accelerated in SNRs. We show that if this is indeed the case, the local electron spectrum will be strongly time-dependent, at least above roughly 30 GeV. The time dependence stems from the Poisson fluctuations in the number of SNRs within a certain volume and within a certain time interval. As far as cosmic-ray electrons are concerned, the Galaxy looks like actively bubbling Swiss cheese rather than a steady, homogeneously filled system. Our finding has important consequences for studies of the Galactic diffuse gamma-ray emission, for which a strong excess over model predictions above 1 GeV has recently been reported. While these models relied on an electron injection spectrum with index 2.4 (chosen to fit the local electron flux up to 1 TeV), we show that an electron injection ...
Previous work has shown the Orion Bar to be an interface between ionized and molecular gas, viewed roughly edge on, which is excited by the light from the Trapezium cluster. Much of the emission from any star-forming region will originate from such interfaces, so the Bar serves as a foundation test of any emission model. Here we combine X-ray, optical, IR and radio data sets to derive emission spectra along the transition from H+ to H0 to H2 regions. We then reproduce the spectra of these layers with a simulation that simultaneously accounts for the detailed microphysics of the gas, the grains, and molecules, especially H2 and CO. The magnetic field, observed to be the dominant pressure in another region of the Orion Nebula, is treated as a free parameter, along with the density of cosmic rays. Our model successfully accounts for the optical, IR and radio observations across the Bar by including a significant magnetic ...
Ways of reducing the excessive energy consumption in the Polish sugar industry are examined. The three main areas where energy reduction measures might be taken are: reducing the process heat demand which arises from the need to evaporate excess water from the juice supplied to the crystallisers; improving the effectiveness of the thermal system by moving from the present four-effect evaporation to five-effect evaporation and using crystallisation vapours for juice heating; replacing old steam boilers with more efficient units. Most Polish sugar factories are relatively small, however, and the energy saving measures, all of which require the installation of more modern equipment, are not economically feasible in the short term. Moreover, the stringent limits on atmospheric emissions which come into effect in 1998 will require factories to use low-sulphur coal and install costly glue-gas cleaning equipment. With limited ...
This paper presents diffraction-limited 1-18 micron images of the young quadruple star system HD 98800 obtained with the W. M. Keck 10-m telescopes using speckle and adaptive optics imaging at near-IR wavelengths and direct imaging at mid-IR wavelengths. The two components of the visual binary, A and B, both themselves spectroscopic binaries, were separable at all wavelengths, allowing us to determine their stellar and circumstellar properties. Combining these observations with spectroscopic data from the literature, we derive an age of 10 Myr, masses of 0.93 and 0.64 M_sun and an inclination angle of 58 deg for the spectroscopic components of HD 98800 B, and an age of 10 Myr and a mass of 1.1 M_sun for HD 98800 Aa. Our data confirm that the large mid-IR excess is entirely associated with HD 98800 B. This excess exhibits a black body temperature of 150 K and a strong 10 micron silicate emission feature. The theoretical ...
Dysprosium #alpha#-sialon ceramic has been fabricated from #alpha#-Si_3N_4, AlN, Al_2O_3 and Dy_2O_3 starting powders, using gas pressure sintering at 1800 deg C or higher temperatures under a relatively low gas pressure of 0.9MPa N_2. The resultant #alpha#-sialon grains showed significantly different features, such as equiaxed, elongated, and even a few extraordinarily large with high aspect ratio grains in the fine matrix, which has rarely been observed in #alpha#' ceramics. It is suggested that the temperature strongly influences the grain morphologies of #alpha#-sialon, playing an important role particularly in the latter stage of the 'nucleation-growth' process. Such a microstructural morphology of mixed with equiaxed and elongated grains toughens the #alpha#-sialon ceramics and leaves them still hard. Overly high temperature treatment leads to the preferential growth of a few #alpha#' grains which become excessively large and long, but ...
Highly swollen nanoporous layers produced in material surfaces by He implantation are of special interest for applications such as catalysis. Here we investigate whether nanoporous layers can be produced in the covalently bonded insulating ceramic, SiAlON. The retention of highly swollen porous structures in thinned TEM sections prepared from such hard brittle materials is particularly challenging. We have successfully prepared such sections both parallel to, and perpendicular to, the implanted surface. At intermediate doses the bubble structures are very similar to those found in metals. At high helium doses local swellings at depths around the mean projected range of the He ions (#approx#360 nm) are estimated to be well in excess of 200%. Bubble structures are stable under heating to temperatures up to 1200 deg. C. It is found that the highly cavitated layer is buried below a crystalline overlayer of compact SiAlON. This overlayer is ...
Selective formation of ZnO nanodots was accomplished by metalorganic chemical vapor deposition on nanopatterned SiO_2/Si substrates. Self-organized ZnO nanodots were selectively formed in nanopatterned lines of Si created by etching of SiO_2 with focused ion beam (FIB), whereas any nanodots were hardly observed on the SiO_2 surface in the vicinity of the FIB-sputtered Si areas. The mechanism of the selective formation of ZnO nanodots on FIB-nanopatterned lines is mainly attributed to the effective migration of Zn adatoms diffusing on the SiO_2 surface into the Si lines followed by the nucleation at surface atomic steps and kinks created by Ga"+ ion sputtering. Cathodoluminescence measurements confirmed that the emission originated from the selectively grown ZnO nanodots.
Chromium nitride thin films were deposited on SA-304 stainless steel substrates by using direct-current reactive magnetron sputtering. The influence of process conditions such as nitrogen content in the fed gas, substrate temperature, and different sputtering gases on microstructural characteristics of the films was investigated. The films showed (200) preferred orientation at low nitrogen content (< 30%) in the fed gas. The formation of Cr_2N and CrN phases was observed when 30% and 40% N_2 were used, with a balance of Ar, respectively. Field emission scanning electron microscopy and atomic force microscopy were used to characterize the morphology and surface topography of the thin films, respectively. Microhardness tests showed a maximum hardness of 16.95 GPa for the 30% nitrogen content.
A new combustion system for a small direct injection diesel engine has been developed, with a spheroidal cavity and swirl nozzle characterized by weak spray penetration and wide spray angle. This system is intended to realize air-borne mixture formation and good combustion processes over wide operating ranges. In-cylinder observations of the system reveal that droplets are easily bent in the direction of air movement, ignition occurs near the spray tip, and the flame is hard to envelop the spray. In a single cylinder engine of 460 cm/sup 3/ swept volume, the system realizes active diffusion burning and mild premixed burning despite of long ignition delay, and provides low fuel consumption and low smoke emission, especially at low speeds.
The nature of the hard X-ray source XSSJ12270-4859 is still unclear though it was claimed to be a magnetic Cataclysmic Variable. We here present a broad-band X-ray and gamma ray study based on a recent XMM-Newton observation and archival INTEGRAL and RXTE data. From the Fermi/LAT 1-year point source catalogue, we tentatively associate XSSJ12270-4859 with 1FGLJ1227.9-4852, a source of high energy gamma rays with emission up to 10GeV. We complement the study with UV photometry from XMM-Newton and ground-based optical and near-IR photometry. The X-ray emission is highly variable showing flares and intensity dips. The X-ray flares consist of flare-dip pairs. Flares are also detected in the UV range but not the dips. Aperiodic dipping behaviour is also observed during X-ray quiescence but not in the UV. The 0.2-100keV spectrum is featureless and described by a power law model with Gamma=1.7. The 100MeV-10GeV spectrum is instead ...
... in the body. PTH is made by the parathyroid glands -- four small glands located in the neck behind ... is due to excess PTH release by the parathyroid glands. This excess occurs due to an enlargement of ...
The European Union Emissions Trading Scheme (EU ETS) has imposed a price on the allowances for CO2 emissions of electricity companies. Integrating this allowance price into the price of electricity earns a rent for companies who have received these allowances for free. During Phase I, 2005-2007, rents corresponding to the aggregate value of allocated allowances amounted to roughly Euro 13 billion per year. However, due to the specific price-setting mechanism in electricity markets true rents were considerably higher. This is due to the fact that companies also that have not received any allowances gain additional infra-marginal rents to the extent that their variable costs are below the new market price after inclusion of the allowance price. Producers with low carbon emissions and low marginal costs thus also benefit substantially from carbon pricing. This paper develops a methodology to determine the specific interaction ...
Moderate-resolution, near-infrared spectra between 0.8 and 5.2 #mu#m were obtained for 12 late-type (K0-M3) disk-bearing members of the #approx#5 Myr old Upper Scorpius OB association using SpeX on the NASA Infrared Telescope Facility. For most sources, continuum excessemission first becomes apparent between #approx#2.2 and 4.5 #mu#m and is consistent with that produced by single-temperature blackbodies having characteristic temperatures ranging from #approx#500 to 1300 K. The near-infrared spectra for 5 of 12 Upper Scorpius sources exhibit Pa#gamma#, Pa#beta#, and Br#gamma# emission, indicators of disk accretion. Using a correlation between Pa#beta# and Br#gamma# emission line luminosity and accretion luminosity, mass accretion rates ( M-dot ) are derived for these sources that range from M-dot = 3.5x10"-"1"0 to 1.5 x 10"-"8 M_s_u_n yr"-"1. Merging the SpeX observations with Spitzer Space Telescope ...
In the 80's, because of the oil crisis, the Natural Gas (NG) appeared as a fuel with a great potential for Diesel replacement in Heavy Duty Vehicles. At that time, PETROBRAS with other companies have developed partial conversion technologies from Diesel to NG, known as 'Dual Fuel'. Engine dynamometer and vehicle bus tests have been developed to verify its technical and economical viability. Because of several factors, the Dual Fuel Program did not advance and the experience was interrupted. At the same time, other experiences using NG Otto Cycle bus engines, manufactured in Brazil, have been conducted, mainly at Sao Paulo, nevertheless, without expansion. Currently, factors as increase of the NG converted light vehicles fleet; the NG excess in the National Market, which has contributed to the NG distribution net expansion; the Environmental Legislature in vigor, that continuously determine lower emission limits; the ...
The radioiodine-labeled amines currently available as brain-imaging agents, based on our previous work and that of others, are prepared either by exchange labeling or by direct iodination of a protected intermediate. The intrinsic slowness of these processes limits their potential for use with the positron-emitting 122I, as it has a half-life of only 3.6 min. This isotope has advantages of a low dose to the patient and availability from a generator containing the parent 20-h 122Xe. To develop a radiopharmaceutical in which 122I could be utilized, we prepared a number of secondary and tertiary amines (maintaining the 2,5-dimethoxy substitution pattern which allows direct iodination at the 4-position) with 131I. The organ distributions of these compounds were studied, and the best properties were found in the N,N-dimethyl homologue (2,5-dimethoxy-N,N-dimethyl-4-iodoamphetamine). This compound was successfully synthesized in a matter of seconds, with a chemical yield and radioactive ...
The radioiodine-labeled amines currently available as brain-imaging agents, based on our previous work and that of others, are prepared either by exchange labeling or by direct iodination of a protected intermediate. The intrinsic slowness of these processes limits their potential for use with the positron-emitting 122I, as it has a half-life of only 3.6 min. This isotope has advantages of a low dose to the patient and availability from a generator containing the parent 20-h 122Xe. To develop a radiopharmaceutical in which 122I could be utilized, we prepared a number of secondary and tertiary amines (maintaining the 2,5-dimethoxy substitution pattern which allows direct iodination at the 4-position) with 131I. The organ distributions of these compounds were studied, and the best properties were found in the N,N-dimethyl homologue (2,5-dimethoxy-N,N-dimethyl-4-iodoamphetamine). This compound was successfully synthesized in a matter of seconds, with a chemical yield and radioactive ...
In a recent study of a search for enhancements from the galactic center with muons at sea level using the TUPI muon telescope, we have found several ground level enhancements (GLEs) as very sharp peaks above the count rate background. This paper reports a consistent analysis of two GLEs observed in December 2003 and detected after an up-grade of the data acquisition system, which includes a noise filter and which allows us to verify that the GLEs are not mere background fluctuations. The main target of this study is a search for the origin of the GLEs. The results show that one of them has a strong correlation with a solar flare, while the other has an unknown origin, because there is neither a satellite report of a solar flare, nor prompt X-ray emission, and nor a excess of nuclei during the raster scan where the GLE was observed. Even so, two possibilities are analyzed: the solar flare hypothesis and the gamma ray burst (GRB) hypothesis. We ...
We have calculated the on-axis spectrum of spontaneous radiation emitted by an electron moving along a planar undulator that has a magnetic profile along the axis that approximates a square wave. (This could be obtained in practice by driving a ferromagnetic undulator into saturation by excessive current in the windings.) We find considerable enhancement of the harmonic radiation spectrum. We compare the harmonic power emitted by an electron moving through an undulator having a sine-wave field profile with the radiation emitted from an undulator having a square-wave profile; the latter is approximated by the first three Fourier components of the undulator magnetic field profile along the axial direction. Examples are computed for 40MeV electrons taking K < 1, for spontaneous radiation emitted along the axis of the system. The emission at harmonics f > 1 is greatly enhanced for the approximate square-wave magnetic profile: the ratio of the ...
HD 100453 has an IR spectral energy distribution (SED) which can be fit with a power-law plus a blackbody. Previous analysis of the SED suggests that the system is a young Herbig Ae star with a gas-rich, flared disk. We reexamine the evolutionary state of the HD 100453 system by refining its age (based on a candidate low-mass companion) and by examining limits on the disk extent, mass accretion rate, and gas content of the disk environment. We confirm that HD 100453B is a common proper motion companion to HD 100453A, with a spectral type of M4.0V - M4.5V, and derive an age of 10 +/- 2 Myr. We find no evidence of mass accretion onto the star. Chandra ACIS-S imagery shows that the Herbig Ae star has L_X/L_Bol and an X-ray spectrum similar to non-accreting Beta Pic Moving Group early F stars. Moreover, the disk lacks the conspicuous Fe II emission and excess FUV continuum seen in spectra of actively accreting Herbig Ae stars, and from the FUV ...
This paper reports on an experimental investigation of premixed methane/air combustion stabilized within a reticulated partially stabilized zirconia foam burner that was performed. A flame holder was used to extend the stability range to allow a stable flame to be maintained for a variety of flow rate and equivalence ratio combinations. The stability range, temperature distributions, and emissions were examined over a range of equivalence ratios and flow rates. The flame was found to be axisymmetric for all conditions in which the reactants were sufficiently well mixed and the flow distribution was sufficiently uniform. Burning speeds were measured that were well in excess of the laminar flame speed. The axial temperature distribution (measured around the burner annulus) in the postflame zone was found to be relatively insensitive to flow rate but dependent upon the burner core length. Very low concentrations of NO_x were found for fuel/air ...
The influence of the sulfur dioxide emissions from a large copper smelter in Tacoma, Washington, USA, was studied by measuring the chemical composition of rainwater collected upwind and downwind of the source, before and after permanent closure of the smelter in 1985. Data analysis was based on a statistical model that accounted for variability associated with location of 25 sampling sites within three geographic regions, smelter operation, ten individual rain events observed over 2 years, and measurement uncertainty. After smelter closure, the upwind-downwind differences in mean hydrogen ion and excess sulfate ion concentrations within a 600 km/sup 2/ region extending to 25 km downwind of the source had decreased significantly compared to the pre-closure value. No significant decreases in mean ion concentrations were observed farther downwind in the Seattle, urban area. During five events sampled prior to smelter closure, we estimate that an ...
A new atomistic approach to Si device process simulation is presented. It is based on a Monte Carlo diffusion code coupled to a binary collision program. Besides diffusion, the simulation includes recombination of vacancies and interstitials, clustering and re-emission from the clusters, and trapping of interstitials. We discuss the simulation of a typical room-temperature implant at 40 keV, 5{times}10{sup 13} cm{sup {minus}2} Si into (001)Si, followed by a high temperature (815{degree}C) anneal. The damage evolves into an excess of interstitials in the form of extended defects and with a total number close to the implanted dose. This result explains the success of the {open_quote}{open_quote}+1{close_quote}{close_quote} model, used to simulate transient diffusion of dopants after ion implantation. It is also in agreement with recent transmission electron microscopy observations of the number of interstitials stored in (311) defects. ...
A new atomistic approach to Si device process simulation is presented. It is based on a Monte Carlo diffusion code coupled to a binary collision program. Besides diffusion, the simulation includes recombination of vacancies and interstitials, clustering and re-emission from the clusters, and trapping of interstitials. We discuss the simulation of a typical room-temperature implant at 40 keV, 5x10"1"3 cm"-"2 Si into (001)Si, followed by a high temperature (815 degree C) anneal. The damage evolves into an excess of interstitials in the form of extended defects and with a total number close to the implanted dose. This result explains the success of the open-quote open-quote+1 close-quote close-quote model, used to simulate transient diffusion of dopants after ion implantation. It is also in agreement with recent transmission electron microscopy observations of the number of interstitials stored in (311) defects. copyright 1996 American Institute ...
A unified physically based ion implantation damage model has been developed which successfully predicts both the impurity profiles and the damage profiles for a wide range of implant conditions for arsenic, phosphorus, BF{sub 2}, and boron implants into single-crystal silicon. In addition, the amorphous layer thicknesses predicted by this new damage model are also in excellent agreement with experimental measurements. This damage model is based on the physics of point defects in silicon, and explicitly simulates the defect production, diffusion, and their interactions which include interstitial-vacancy recombination, clustering of same type of defects, defect-impurity complex formation, emission of mobile defects from clusters, and surface effects for the first time. New computationally efficient algorithms have been developed to overcome the barrier of the excessive computational requirements. In addition, the new model has been incorporated ...
A unified physically based ion implantation damage model has been developed which successfully predicts both the impurity profiles and the damage profiles for a wide range of implant conditions for arsenic, phosphorus, BF_2, and boron implants into single-crystal silicon. In addition, the amorphous layer thicknesses predicted by this new damage model are also in excellent agreement with experimental measurements. This damage model is based on the physics of point defects in silicon, and explicitly simulates the defect production, diffusion, and their interactions which include interstitial-vacancy recombination, clustering of same type of defects, defect-impurity complex formation, emission of mobile defects from clusters, and surface effects for the first time. New computationally efficient algorithms have been developed to overcome the barrier of the excessive computational requirements. In addition, the new model has been incorporated in the ...
Using the activitation method (n,2n) excitation-functions were measured for "5"4Fe, "7"0Ge, "7"4Se, "8"5Rb, sup(86,88)Sr, "8"9Y, "9"2Mo, and "2"0"4Hg in the neutron-energy region 13-18 MeV. The results are checked for consistency by means of a systematic of (n,2n) cross-sections as a function of the nuclear neutron excess (N-Z)/A. Furthermore the data are compared with results from the statistical nuclear reactions theory which were calculated using optical model absorption cross-sections and the Fermi-gas-model formula for the nuclear level density. In the case of "2"0"4Hg the influence of preequilibrium nucleon emission was taken into account. (orig.).
Hard Nano-Strutural Coatings Resistant to the Extreme Conditions of Chemical, Abrasive and High Energy Media for Thermonuclear Power, Oil and Gas and Chemical Industries
The fatigue and fracture behavior of hard tissues are topics of considerable interest today. This special group of organic materials comprises the highly mineralized and load-bearing tissues...Full Text Available
Superconducting rf cavities are increasingly used in accelerators. Gradient is a parameter of particular importance for the ILC. Much progress in gradient has been made over the past decade, overcoming problems of multipacting, field emission, and breakdown triggered by surface impurities. However, the quenching limit of the surface magnetic field for niobium remains a hard limitation on cavity fields sustainable with this technology. Further exploration of materials and preparation may offer a path to surpassing the current limit. For this purpose, we have designed a resonant test cavity. One wall of the cavity is formed by a flat sample of superconducting material; the rest of the cavity is copper or niobium. The H field on the sample wall is 75% higher than on any other surface. Multipacting is avoided by use of a mode with no surface electric field. The cavity will be resonated through a coupling iris with high-power rf at superconducting ...
This study presents a rapid and selective method for the recovery of lanthanides and yttrium, existing in economically interesting concentrations, from red mud, the byproduct of the alumina production. The leaching process is based on the extraction of these elements with diluted nitric acid from red mud under moderate conditions and without using any preliminary treatment. Several parameters such as leaching agents, contact time, temperature, pressure and solid to liquid ratio were investigated in order to achieve an optimum recovery. The process followed here was selected taking into account its efficiency for the selective recovery of yttrium and lanthanides, but also its suitability for the subsequent liquid-liquid extraction of the leaching solution for the separation of the individual lanthanides. The achieved recovery percentages were for Y about 90%, for the investigated heavy lanthanides (Dy, Er, Yb) up to 70%, for the middle ones (Nd, Sm, Eu, Gd) up to 50% and for the group ...
This study presents a rapid and selective method for the recovery of lanthanides and yttrium, existing in economically interesting concentrations, from red mud, the byproduct of the alumina production. The leaching process is based on the extraction of these elements with diluted nitric acid from red mud under moderate conditions and without using any preliminary treatment. Several parameters such as leaching agents, contact time, temperature, pressure and solid to liquid ratio were investigated in order to achieve an optimum recovery. The process followed here was selected taking into account its efficiency for the selective recovery of yttrium and lanthanides, but also its suitability for the subsequent liquid-liquid extraction of the leaching solution for the separation of the individual lanthanides. The achieved recovery percentages were for Y about 90%, for the investigated heavy lanthanides (Dy, Er, Yb) up to 70%, for the middle ones (Nd, Sm, Eu, Gd) up to 50% and for the group ...
The X-ray spectra of {approx}200 AGN collected from Swift-BAT were analyzed to test the Unified Model for AGN. Specifically, the photon indices, high energy cutoffs, and reflection components of Sy1 and Sy2 were compared. Under the Unified Model, the photon indices and reflection components for Sy1 should be larger than Sy2 and the high energy cutoffs should be the same. Fitting a simple power law model to the sample spectra proved to be insufficient. The PEXRAV model fit the spectra of the Sy1 and Sy2 significantly better, indicating that a reflection component and/or high energy cutoff exists as the Unified Model expects. Using both the simple power law and PEXRAV models it was concluded that in the population studied, Sy1 had a larger photon index than Sy2, as expected by the Unified Model. For Sy1 and Sy2, the reflection components were found to be compatible, but given the large errors, this finding cannot be said to be evidence against the Unified Model. However, it was concluded ...
Monodisperse europium-activated titania hollow phosphors had been synthesized by a facile one-pot hydrothermal method using carbon spheres as hard templates. Samples were characterized by X-ray powder diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, energy dispersive spectrometer and photoluminescence spectrum. The strongest emission intensity was observed with TiO2:Eu0.2 hollow spheres and TiO2:Eu0.2 hollow spheres calcining at 550^oC. Moreover, the strongest excitation of TiO2:Eu0.2 hollow spheres transferred from 400 to 500^oC and the effective nonradiative energy transfer from the TiO2 hollow spheres host matrix to Eu^3^+ ions crystal field states was realized due to changes of crystalline field in the environment around Eu^3^+ ions occupying Ti^4^+ site...
We report on the results of a simultaneous monitoring campaign employing eight Chandra X-ray (0.5-10 keV) and six VLA/EVLA (8.4 GHz) radio observations of NGC 4051 over seven months. Evidence for compact jets is observed in the 8.4 GHz radio band; This builds on mounting evidence that jet production may be prevalent even in radio-quiet Seyferts. Assuming comparatively negligible local diffuse emission in the nucleus, the results also demonstrate an inverse correlation of L_radio proportional to L_X-ray ^(-0.72+/-0.04) . Current research linking the mass of supermassive black holes and stellar-mass black holes in the "low/hard" state to X-ray luminosities and radio luminosities suggest a "fundamental plane of accretion onto black holes" that has a positive correlation of L_radio proportional to L_X-ray^(0.67+/-0.12) . Our simultaneous results differ from this relation by more than 11 sigma, indicating that a separate mode of accretion and ...
We construct models for gamma-ray bursts where the emission comes from internal shocks in a relativistic wind with a highly non uniform distribution of the Lorentz factor. We follow the evolution of the wind using a very simplified approach where a large number of layers interact by direct collisions but where all pressure waves have been suppressed. We suppose that the magnetic field and the electron Lorentz factor reach large equipartition values in the shocks. Synchrotron photons emitted by the relativistic electrons have a typical energy in the gamma-ray range in the observer frame. Synthetic bursts are constructed as the sum of the contributions from all the internal elementary shocks and their temporal and spectral properties are compared to the observations. We reproduce the diversity of burst profiles, the ``FRED'' shape of individual pulses and the short time scale variability. Synthetic bursts also satisfy the duration-hardness ...
Highly intelligent, confident, and successful, alpha males represent about 70% of all senior executives. Natural leaders, they willingly take on levels of responsibility most rational people would find overwhelming. But many of their quintessential strengths can also make alphas difficult to work with. Their self-confidence can appear domineering. Their high expectations can make them excessively critical. Their unemotional style can keep them from inspiring their teams. That's why alphas need coaching to broaden their interpersonal tool kits while preserving their strengths. Drawing from their experience coaching more than 1,000 senior executives, the authors outline an approach tailored specifically for the alpha. Coaches get the alpha's attention by inundating him with data from 360-degree feedback presented in ways he will find compelling--both hard-boiled metrics and vivid verbatim comments from colleagues about his strengths and ...
In 1978, China's coal mining industry achieved an output of 618,000,000 metric tons of raw hard coal, an increase of 128,000,000 tons compared with 1977. This has been achieved primarily by increased new mine development and the modernizaion and expansion of existing mines. While 96% of China's coal is currently produced from underground mines, only 33% of this output is from full mechanized operations, i.e., mechanized longwall retreat faces. Over 1% is produced by hydraulic mining. The current Ten-Year Plan (1975-1985) established that the major thrust of new development and activity should be made particularly in the Shandong, Anhui, Henan, Guizhou, and Yunnan provinces. China is presently concentrating on the construction/enlargement of eight major coal mining centers, mainly in the north and northeast of the country, each with a designed capacity in excess of 10,000,000 tons a year. China has elected to import large ...
Off-grid power generation is meant to supply remote or rural area, where grid connection is almost impossible in terms of cost and geography, such as island, aborigine's villages, and areas where nature preservation is concern. Harnessing an abundance renewable energy sources using versatile hybrid power systems can offer the best, least-cost alternative solution for extending modern energy services to remote and isolated communities. The conventional method for off-grid power generation is using diesel generator with a renewable energy (RE) technology utilizing solar photovoltaic, wind, biomass, biogas and/or mini/micro hydro. A hybrid technology is a combination of multiple source of energy; such as RE and diesel generator and may also include energy storage such as battery. In our design, the concept of solar hybrid system is a combination of solar with diesel genset and battery as an energy storage. The main objective of the system are to reduce the cost of operation and ...
As an explosion develops in the collapsed core of a massive star, neutrino emission drives convection in a hot bubble of radiation, nucleons, and pairs just outside a proto-neutron star. Shortly thereafter, neutrinos drive a wind-like outflow from the neutron star. In both the convective bubble and the early wind, weak interactions temporarily cause a proton excess (Y{sub e} {approx}> 0.50) to develop in the ejected matter. This situation lasts for at least the first second, and the approximately 0.05-0.1 M{sub {circle_dot}} that is ejected has an unusual composition that may be important for nucleosynthesis. Using tracer particles to follow the conditions in a two-dimensional model of a successful supernova explosion calculated by Janka, Buras, and Rampp (2003), they determine the composition of this material. most of it is helium and {sup 56}Ni. The rest is relatively rare species produced by the decay of proton-rich isotopes unstable ...
There is renewed interest in the development of natural gas vehicles in response to the challenge to reduce urban air pollution and consumption of petroleum. The natural gas/diesel dual fuel engine is one way to apply natural gas to the conventional diesel engine. Dual fuel engines operating on natural gas and diesel emit less nitrogen oxides, and less carbon soot to the air compared to conventional diesel engines. The problem is that at light loads, fuel efficiency is reduced and emissions of hydrocarbons and carbon monoxide are increased. This thesis focused on control methods for emissions of hydrocarbons and carbon monoxide in the dual fuel engine at light loads. This was done by developing a reverse flow catalytic converter to complement dual fuel engine exhaust characteristics. Experimental measurements and numerical simulations of reverse flow catalytic converters were conducted. Reverse flow creates a high reactor temperature even when ...
We present photoelectric BVRI photometry for 16 T Tau and related stars in the Rho Oph dark cloud, as well as vidicon spectroscopic observations for nine stars. The color excesses of these stars favor circumstellar dust shells as the source of the observed infrared excesses.
By a direct Archimedes' technique, volumetric data were obtained for liquid In, Mg, Pb, and Sb and mixtures of In-Sb, Mg-Sb, and Pb-Sb. In this paper the excess volumes for the alloys studied are presented and discussed.
Zinc is an essential trace metal ion for growth, but an excess of Zn is toxic and microorganisms express diverse resistance mechanisms. To understand global bacterial responses to excess Zn, we conducted...Full Text Available
BackgroundExcessive television (TV) viewing might play an important role in the development of cardiovascular disease (CVD). The aim of this study was to examine the independent...Full Text Available
BackgroundEffective prevention of excessive alcohol use has the potential to reduce the public burden of disease considerably. We investigated the cost-effectiveness of Screening...Full Text Available
Intensive work has long been going on to find out the unknown origin that sets off curious tribo-physicochemical phenomena and that causes various kinds of problems in oil-lubricated sliding contacts in mechanical and processing systems. The strange tribochemical reaction is one of the such curious chemical phenomena observed in the degradation of perfluoropolyether (PFPE) lubricating oil film in a hard disk drive. Plasma (triboplasma) (Nakayama and Mirza 2006 Tribol. Trans. 49 17) would be one of the most probable origins of the problems if it were generated sufficiently intensely in oil-lubricated sliding contacts, as it is in such a highly energetic state. The generation of plasma was predicted in both dry and oil-lubricated sliding (Nakayama 1997 Japan. J. Tribol. 42 1077, Nakayama 2004 Surf. Coat. Technol. 188-189 599). However, plasma generation in industrially important oil-lubricated contacts has not yet been proven, though it has been found in dry sliding ...
runs are necessary, provision shall be made for expansion joints, motion of the units, or similar compensation to ensure that no excessive strains are ...
The inner part of a fusion reactor will have to operate at very high neutron loads. In steady-state reactors the minimum fluence before the scheduled replacement of the reactor core should be at least l0-15 Mw.yr/m2. A more frequent replacement of the core is hardly compatible with economic constraints. A most recent summary of the discussions of these issues is presented in Ref. [l]. If and when times come to build a commercial fusion reactor, the availability of information on the behavior of materials and components at such fluences will become mandatory for making a final decision. This makes it necessary an early development and construction of a neutron source for fusion material and component testing. In this paper, we present information on one very attractive concept of such a source: a source based on a so called Gas Dynamic Trap. This neutron source was proposed in the mid 1980s (Ref. [2]; see also a survey [3] with discussion of ...
BackgroundThe hard clam, Mercenaria mercenaria, has been affected by severe mortality episodes associated with the protistan parasite QPX (Quahog Parasite Unknown)...Full Text Available
Sep 1, 2011 ... Title: Hardness, density, and shrinkage characteristics of silk-oak from Hawaii. Author: Youngs, R. L.. Date: 1964. Source: Research note FPL ...
The issue of beam-induced damage on diffractive hard X-ray optics is addressed. For this purpose a systematic study on the radiation damage induced by a high-power X-ray beam is carried out in both...Full Text Available
This report covers the test methods and equipment for testing aircraft armor both hard and soft. The hard armor are the typical ceramic type while the soft armor are various types of layered composite materials. 10 figs. (JEF)
The crystal structure, electronic structure, and photoluminescence properties of EuxSi6-zAlz-xOz+xN8-z-x (x=0-0.1, 0xMySi6-zAlz-x-yOz+x+yN8-z-x-y (M=2Li, Mg, Ca, Sr, Ba) have been studied. Single-phase EuxSi6-zAlz-xOz+xN8-z-x can be obtained in very narrow ranges of x?0.06 (z=0.15) and z2+ ions can be incorporated into nitrogen-rich Si6-zAlzOzN8-z. The Eu2+ ion is found to occupy the 2b site in a hexagonal unit cell (P63/m) and directly connected by six adjacent nitrogen/oxygen atoms ranging 2.4850-2.5089 A. The calculated host band gaps by the relativistic DV-X? method are about 5.55 and 5.45 eV (without Eu2+ 4f5d levels) for x=0 and 0.013 in EuxSi6-zAlz-xOz+xN8-z-x (z=0.15), in which the top of the 5d orbitals overlap with the Si-3s3p and N-2p orbitals within the bottom of the conduction band of the host. EuxSi6-zAlz-xOz+xN8-z-x shows a strong green emission with a broad Eu2+ band centered at about 530 nm under UV to near-UV excitation range. The excitation and ...
The world's 500 million road vehicles using internal combustion engines account for roughly half of global oil consumption and, in Italy, for about 50% of all nitrogen oxide and 90% of carbon monoxide emissions. In efforts to conserve petroleum reserves and reduce air pollution, research programs are being conducted to develop hydrogen fueled automotive engines. Hydrogen combustion products are carbon dioxide free, and when burned with a large excess of air, this fuel produces water vapour and only small amounts of nitrogen oxides. Hydrogen fueled vehicles can be made to operate in a dual fuel mode so as to allow the use of petrol or diesel fuel in travel over long distances. Currently, because technical and economic difficulties relevant to hydrogen fuel storage limit driving range and payload (there are bulk and weight problems in compressed gas and metal hydride storage systems, and cost problems in cryogenic storage), only limited research ...
This book summarizes the research that has been conducted in Canada over the past five years on the issue of climate change impacts on key sectors such as water resources, agriculture, forestry, fisheries, coastal zones, transportation, and human health and well-being. The book refers to the growing evidence that climate change is occurring. The Intergovernmental Panel on Climate Change (IPCC) believes that these changes have already contributed to increases in annual precipitation, cloud cover and extreme temperatures over the last 50 years. It suggests that it in order to develop an effective strategy for adaptation, it is necessary to understand the vulnerability of each sector to climate change in terms of the nature of climate change, the climatic sensitivity of the region being considered, and the capacity to adapt to the changes. Adaptation will require a reduction in greenhouse gas emissions in order to lower the rate of climate change. Problems associated ...
Sources of industrial emissions of 1,3-butadiene are discussed both by process (production, consumers) and type (equipment leaks, point sources). Quantification of the emissions are presented, as reported...Full Text Available
This paper deals with the combustion process of the turbocharged dual-fuel engine with regard to improvement to thermal efficiency and exhaust gas emissions. It describes the method of charge-air control used to achieve optimal operation in either a pure diesel engine or a gas engine using the pilot-ignition process (dual-fuel principle). The change-over from gas to diesel operation and vice versa can be made automatically even under full load, i. e. the engine can be changed over from one mode of operation to the other without interruption. The exhaust gas constituents emitted by the dual-fuel engine are less detrimental to the environment than those of other internal-combustion engines: CO is hardly present at all; NOx is no higher than that from good diesel engines, or even lower; SO/sub 2/ does not occur since the natural gas, which is used most frequently, and the pilot fuel are practically free of sulfur; CH (hydrocarbons) in this case ...
Uniform and transparent thin films of Zn_1_-_xCo_xO (0 #=# 0.035, CoO (cubic) was detected as the secondary phase. Influence of Co addition on the volume fraction of grain boundaries has been interpreted. Increase in Co content in the range 0 #<=# x #<=# 0.10 led to quenching of near-band edge and blue emissions, decrease in band gap energy (E_g) from 3.36 eV to 3.26 eV, decrease in film thickness and refractive index and an increase in extinction coefficient of Zn_1_-_xCo_xO thin films. The change in nature of stress from compressive to tensile with lower to higher doping of Co is corroborative with the angular peak shift of (002) plane of ZnO lattice. An overall increase in microhardness of Zn_1_-_xCo_xO thin films up to x = 0.05 is attributed to change in microstructure and evolution of secondary phase and as the secondary phase separates out the overall stress is released leading to lowering of hardness after this concentration. ...
Tritium occurs in nature in trace amounts, but its concentration is changing due to natural and artificial sources. Studies focusing on natural tritium have to take into account the effect of artificial sources. Also, the impact of tritium is an important issue in environmental protection, e.g. in connection with the emissions from nuclear power plants. The present work focuses on the rain washout of tritium emitted from the Paks nuclear power plant in Hungary. Rainwater collectors were placed around the plant and after a period of precipitation, rainwater was collected and analysed for tritium content. Samples were analysed using low-level liquid scintillation counting, with some also subject to the more accurate "3He ingrowth method. The results clearly show the trace of the tritium plume emitted from the plant; however, values are only about one order of magnitude higher than environmental background levels. A washout model was devised to estimate the ...
Biomass contains nitrogen that is converted to NOx on combustion. Conversion of biomass into producer gas by thermal gasification offers an opportunity to reduce NOx-emissions by NH3 removal from the producer gas with water. Waste water will have to be treated before it can be drained. Recovered NH3 may have value as base chemical, but usually will have to be disposed off as waste. Recycling within the gasification process is an option to dispose off NH3 waste, provided NH3 is broken down under gasification conditions. We present experimental data on NH3 destruction in a CFB gasifier at temperatures from 780C to 860C, when NH3 is injected into the gasification air. Within that temperature range, the fraction of NH3 that is broken down increases from less than 50% to nearly 100%. Clearly, the presence of O2 at the injection point leads to a much higher rate of NH3 destruction than observed for purely thermal cracking. Although measurement of the NOx concentration in ...
The Kyoto Protocol foresees emission trading but does not yet specify verification of (uncertain) emissions. This paper analyses a setting in which parties can meet their emission targets by reducing emissions, by investing in monitoring (reducing uncertainty of emissions) or by (bilaterally) trading permits. We derive the optimality conditions and carry out various numerical simulations. Our applications suggest that including uncertainty could increase compliance costs for the USA, Japan and the European Union. Central Europe and the Former Soviet Union might be able to gain from trading due to higher permit prices. Emissions trading could also lower aggregate uncertainty on emissions.
BACKGROUNDHirsutism is the presence of excess body or facial terminal (coarse) hair growth in females in a male-like pattern, affects 5–15% of women, and is an important...Full Text Available
SUMMARYHomeostatic synaptic plasticity is a negative feedback mechanism neurons use to offset excessive excitation or inhibition by adjusting their synaptic strengths. Recent...Full Text Available
Molar excess volumes, VE and molar excess enthalpies, HE of 1,3-dioxolane (D) (i) + propan-1-ol, 1,3-dioxolane (i) + butan-1-ol and 1,3-dioxolane (i) + butan-2-ol (j) binary mixtures have been measured as a function of composition at 308.15 K. The analysis of VE data by graph, theoretical approach reveals that while propan-1-ol, butan-1-ol exist as associated entities in the pure state; 1,3-dioxolane and butanol exist as monomers in their pure state. These (i+j) binary mixtures are characterized by interactions between ethereal oxygen atom of D(i) and hydrogen atom of alkanols. The IR studies lend additional support to the proposed structure of molecular entitles in these mixtures. The energetics of the mixtures have also been studied.
Molar excess enthalpies and molar excess volumes are reported for the systems H_2O + (C_2H_5)_3N and D_2O + (C_2H_5)_3N at temperatures below and above their lower critical solution temperatures. The molar excess enthalpies are slightly less exothermic for the D_2O system. The molar excess volumes of the H_2O and D_2O systems are within experimental error of one another. Compositions of conjugate solutions estimated from the calorimetric and volumetric measurements agree with those obtained from published liquid-liquid phase diagrams. (Auth.).
Obesity is characterized by the abnormal or excessive deposition of fat in the adipose tissue. Its consequences go far beyond adverse metabolic effects on health, causing an increase in oxidative stress,...Full Text Available
Molar excess volumes, V/sup E/, and molar excess enthalpies, H/sup E/, have been determined at 298.15 K by using dilatometer and an LKB flow microcalorimeter, respectively, for benzene (A), toluene (A), o-xylene (A), m-xylene (A), or rho-xylene (A) + o-chlorotoulene (B) mixtures. While both the V/sup E/ and the H/sup E/ values are positive for benzene (A) = o-chlorotoluene (B) mixtures, they are negative for the rest of the binary mixtures. The data have also been compared with the available literature values.
Numerous reports of chronic renal disease in patients who habitually use phenacetin-containing compounds to excess have aroused considerable controversy over the possible relationship between phenacetin,...Full Text Available
Vapor-liquid equilibria, by head-space gas-chromatographic analysis of the equilibrated vapor phase directly withdrawn from the equilibration apparatus, and molar excess volumes, V[sup E], by means of a vibrating-tube densimeter, of binary mixtures containing thiaalkanes or dithiaalkanes with n-alkanes or cyclohexane, were determined at 298.15 K. The excess molar Gibbs free energies, GE, of the examined mixtures were obtained by a least-squares treatment of the equilibrium data. The GE and V[sup E] values indicate that the steric effect exerted by the alkyl groups adjacent to the S group causes a regular decrease of the G[sup E] (or V[sup E]) with increasing the number of alkyl groups in the thiaalkane. A tentative approach, based on an additivity scheme of surface interactions combined with the scaled particle theory, is presented to estimate the energies of solvation in terms of group contributions.
Excessive dietary phosphorus may increase cardiovascular risk in healthy individuals as well as in patients with chronic kidney disease, but the mechanisms underlying this risk are not completely understood....Full Text Available
Government policies that encourage exploitation--in particular excessive logging and clearing for ranches and farms--are largely to blame for the accelerating destruction of tropical forests. This paper surveys the problem in detail and briefly recommends potential solutions.
Purpose: To remove excessive driving pressure applied to an unisolated control rod drive by returning excessive coolant to a condensed water storage tank or to the inlet side of a drive water pump using a coolant flow rate control pipe of a control rod driving hydraulic system. Constitution: Excessive water is returned to a condensed water tank while controlling the excessive coolant by a flow control valve in response to variations in the pressure difference between the reactor pressure and the driving water line when the control rods are isolated using a pipe from the outlet side of the drive water pump to the condensed water storage tank. Thus, the control rod to be isolated is prevented form being dropped. (Sekiya, K.).
... The thermostable Thermus aquaticus DNA polymerase, (Taq pol), in the presence of excess deoxynucleoside triphosphates (dNTPs), including deoxyadenosine ...
... the program manager plans to spend $23.2 million to procure 107 Hornets in excess of the 270 required by the 82nd Airborne Division for its basic ...
The theoretical hardness against total dose of the six-transistor SRAM cell is investigated in detail. An explicit analytical expression of the maximum tolerable threshold voltage shift is derived for two cross-coupled inverters. A numerical method is used to explore the hardness of the read and write operations. Both N- and P-channel access transistors designs are considered and their respective advantages are compared. The study points out that the radiation hardness mainly relies on the technology. Results obtained with the very robust Gate-All-Around process are finally presented.
Hardness of beta-sialon with four different composition index values of 0.25, 0.50, 0.75 and 1.0 in the system Ni/sub 3/N/sub 4/-AlN-Al/sub 2/O/sub 3/ with the addition of 6% Y/sub 2/O/sub 3/ as sintering aid has been reported. These composition were pressureless sintered for 90, 180 and 270 min in nitrogen atmospheres at temperatures ranging from 1650 to 1800 deg. C. Highest hardness was achieved when the composition index was 0.25 was sintered for 270 minutes at 1750 deg. C. (author).
CH Cygni is a symbiotic star consisting of an M giant and an accreting white dwarf, which is known to be a highly variable X-ray source with a complex, two-component, spectra. Here we report on two Suzaku observations of CH Cyg, taken in 2006 January and May, during which the system was seen to be in a soft X-ray bright, hard X-ray faint state. Based on the extraordinary strength of the 6.4 keV fluorescent Fe K-alpha line, we show that the hard X-rays observed with Suzaku are dominated by scattering.
The 8 papers in the report deal with the following areas: Introduction to diesel particulate emissions, alternative fuels, and the transit industry; Technical problems and policy issues associated with the 1991 bus emissions standards; Reducing transit bus emissions: comparative costs and benefits of methanol, particulate traps, and fuel modification; Effects of applying emissions averaging, trading, and banking to transit buses; Strategic review of heavy-duty engine emission regulations and alternate fuels; Meeting bus emissions standards--a perspective; Economic evaluation of bus maintenance contracting; Objectives for a transit-bus-fleet management data, information, and knowledge exchange.
The data taken at the Tevatron experiments have been analyzed to search for Higgs bosons. For the Standard Model Higgs searches, no excess is observed, the data are in good agreement with the expectations, so that limits are set on the production rates. For various theoretical models beyond the Standard Model, there is no excess either, which allows to derive constraints in their respective parameter spaces.
... of Hanoi or Missionaries and Cannibals, It is not immediately obvious what constitutes a "move"--that is, what actual manipulations of the physical ...
Monolithic SiAlON ceramics are hard and brittle with little possibility for property design, but multi-phase SiAlON ceramics offer great scope for controlling microstructural development and desired properties. The ceramics can also be reinforced by separate additions of other hard, refractory compounds. The toughness in all these SiAlON composites can be increased by several mechanisms, and the best effect is reached if they are combined. When glassy phase is present, crack paths are affected by the strains caused by different thermal expansion of the glassy phase and the crystals and also by the interface properties. The crystal shape influence toughness, especially pronounced is the effect of the elongated #beta#- grains. Different toughening mechanisms are achieved by separately added reinforcement phases. The hardness is raised by the presence of #alpha# SiAlON and other hard constituents, such as ...
Counter-current regeneration of 2-stage sodium zeolite softeners has been employed in reducing hardness leakage level of steamflooding water to less than 1 ppm when raw water contains as much as 5,000 ppm of the total dissolved solids. Hardness leakage is caused by sodium displacement of calcium and magnesium from the bottom of the exchanger bed. This study presents nomographs providing for rapid calculations to be made, for which a convenient operational mode does not already exist. The nomographs relate the hardness leakage as a function of salt quality and influent water quality and present solutions for predicting the leakage level, salt quality requirement or the treatability of raw water required for steamflooding projects.
... interacting systems in which common-envelope evolutionary effects make it hard to generalize the results to single-star evolution, although they ...
BackgroundThe ongoing epidemiological transition in Mexico minimizes the relative impact of neurocysticercosis (NC) on public health. However, hard data on the disease frequency...Full Text Available
Necrotizing sialometaplasia, is a benign inflammatory lesion primarily involving the minor salivary glands of the hard palate. The lesion often presents itself as a deep-seated palatal ulcer with clinical...Full Text Available
Oct 30, 2009... of Belgian sheepherding dogs that are popular with the police and military. ... "She was a hard-working K-9 and she will be missed." ...
Interest in optics for hard X-ray broad-band application is growing. In this paper, we compare the hard X-ray (20-100 keV) reflectivity obtained with an energy-dispersive reflectometer, of a standard commercial gold thin-film with that of a 600 bilayer W/Si X-ray supermirror. The reflectivity of the multilayer is found to agree extraordinarily well with theory (assuming an interface roughness of 4.5 Angstrom), while the agreement for the gold film is less, The overall performance of the supermirror is superior to that of gold, extending the band of reflection at least a factor of 2.8 beyond that of the gold, Various other design options are discussed, and we conclude that continued interest in the X-ray supermirror for broad-band hard X-ray applications is warranted.
Interest to thin film of metals' silicides first of all is conditioned intrinsic al them unique physical properties. On their basis of it is possible to produce extremely sophisticated devices of solid-state electronics, production which needs the controlled change of physics, chemical and electrical properties with high-level of accuracy. On the present time most are in detail investigated composition, structure and properties of three-dimensional samples of metals' silicides. In the last years the intensive are led to researches in the direction of creation and study of physical-chemical properties thin (500-1000 Angstroms) and ultrafine (100-120 Angstroms) films silicides. It has information about composition, morphology of surface and emission of properties of thin film of silicides of barium, of cobalt and of palladium, was obtained in conditions of ultra-high vacuum. Low energy ion implantation and further annealing on composition, electronic and crystalline ...
BackgroundPolicies on waste disposal in Europe are heterogeneous and rapidly changing, with potential health implications that are largely unknown. We conducted a health impact assessment of landfilling and incineration in three European countries: Italy, Slovakia and England.MethodsA total of 49 (Italy), 2 (Slovakia), and 11 (England) incinerators were operating in 2001 while for landfills the figures were 619, 121 and 232, respectively. The study population consisted of residents living within 3 km of an incinerator and 2 km of a landfill. Excess risk estimates from epidemiological studies were used, combined with air pollution dispersion modelling for particulate matter (PM10) and nitrogen dioxide (NO2). For incinerators, we estimated attributable cancer incidence and years of life lost (YoLL), while for landfills we estimated attributable cases of congenital anomalies and low birth weight infants.ResultsAbout 1,000,000, 16,000, and 1,200,000 subjects lived ...
Mercury has had various uses in nuclear fuel reprocessing and other nuclear processes, and so is often present in radioactive and mixed (both radioactive and hazardous according to the Resource Conservation and Recovery Act) wastes. Depending on regulatory requirements, the mercury in the off-gas must be controlled with sometimes very high efficiencies. Compliance to the Hazardous Waste Combustor (HWC) Maximum Achievable Control Technology (MACT) standards can require off-gas mercury removal efficiencies up to 99.999% for thermally treating some mixed waste streams. Several test programs have demonstrated this level of off-gas mercury control using fixed beds of granular sulfur-impregnated activated carbon. Other results of these tests include: (a) The depth of the mercury control mass transfer zone was less than 15-30 cm for the operating conditions of these tests, (b) MERSORB(reg_sign) carbon can sorb Hg up to 19 wt% of the carbon mass, and (c) the spent carbon retained almost all ...
The resulting emissions of the firing of ceramic products of all type are described, the factors are enumerated to diminish the emissions in the kilns and the technologies applied in the kilns to reduce these emissions while carrying out energy saving are described briefly. (author)
Full text: As one of the Top 5 utilities in Europe, Rheinisch-Westfaelisches Elektrizitaetswerk AG, FWB: RW, RWE, operates a diversified generating capacity of about 45 GW; RWE Power alone generates over 30 GW. Besides a share of approximately 20% nuclear power, a large proportion of the generating base is in lignite and hard coal. RWE has an ambitious, Euro10 bn newbuild program of about 10 GW modern fossil fired plants and further expansion plans across Europe. By 2012, RWE intends to invest between Euro 15 and 20 bn outside Germany.The European Union has a challenging policy to increase the share of renewables, improve energy efficiency, and reduce greenhouse gases by 2020. At the same time, ageing power plants need to be replaced. This requires an enormous investment program across Europe. Nuclear power therefore, as a proven technology with low lifecycle carbon emissions and reasonable lifecycle cost, is a crucial contributor to achieve ...
The average angle of repose and the packing density of random planar heaps of hard disks falling ballistically onto a sticky base line, where the first layer of disks is quenched in random positions, are computed for heaps with a small fixed number of gaps in the base layer. The results we find appear to be almost independent of the size of the heap and they agree with those obtained from computer simulations of large systems.
The structure and properties of composite powder coatings on the base of titanium carbide are studied. It is shown the electron-beam welding deposition of powders on the base of nickel and titanium carbide allows to produce of high-quality wear-resistant coatings which superior in density and hardness compared with sputtered ones. Changes of hardening phase volume percentage as well as composition of metal matrix make possible to control coatings hardness
This paper summarizes the current scientific and technological knowledge about greenhouse gas emissions from various agricultural practices and the manufacturing of food. The study also provides estimates that compare agriculture-related alternatives for reducing greenhouse gas emissions.
This study resumes the discovery of an excess of actinium 227 found around by EL4 nuclear reactor actually in dismantling. The search for the origin of this excess revealed a real inquiry of investigation during three years. Because a nuclear reactor existed in this area a particular attention will have concerned this region. The doubt became the line of conduct to find the answer to the human or natural origin of this excess. Finally and against any evidence, it appears that the origin of this phenomenon was natural, consequence of the particular local geology. The detail of the different investigations is given: search of a possible correlation with the composition of elevations constituent of lanes, search (and underlining) of new sites in the surroundings of the Rusquec pond and the Plouenez station, study of the atmospheric deposits under winds of the nuclear power plant and in the east direction, search of a possible ...
In this study, a regional dynamical model (WRF) is used to drive biogenic emission models to calculate high resolution (10 x 10 km) biogenic emissions of isoprene (C_5H_8), monoterpenes (C_1H_1_6), and nitric oxide (NO) in China. This high resolution biogenic inventory will be available for the community to study the effect of biogenic emissions on photochemical oxidants in China. The biogenic emissions are compared to anthropogenic emissions to gain insight on the potential impact of the biogenic emissions on tropospheric chemistry, especially ozone production in this region. The results show that the biogenic emissions in China exhibit strongly diurnal, seasonal, and spatial variations. The isoprenoid (including both isoprene and monoterpenes) emissions are closely correlated to tree density and strongly vary with ...
We explore the relationship between the hard X-ray photon index $\\Gamma$ and the Eddington ratio (\\xi=L_{X}(0.5-25 keV)/L_{Edd}) in six XRBs. We find that different XRBs follow different anti-correlations between $\\Gamma$ and $\\xi$ when $\\xi$ is less than a critical value, while they follow the same positive correlation when $\\xi$ is larger than the critical value. This anti-correlation and positive correlation are also found in LLAGNs and QSOs respectively, and the anti-correlation and positive correlation of different XRBs roughly converge to the same point ($\\log \\xi=-2.1, \\Gamma=1.5$), which may correspond to the accretion mode transition, since that the anti-correlation and positive correlation are consistent with the prediction of ADAFs and standard disk/corona system respectively. The traditional low/hard state are divided into two parts by the cross point $\\log \\xi\\sim-2.1$, i.e., faint-hard state in the ...
Micro-Vickers hardness measurement has been used to determine the composition of functionally graded materials (FGMs). Materials used in the present study are Al-SiC, Al-Shirasu and Al-Al{sub 3}Ni FGMs, which are fabricated by a centrifugal method. The micro-hardness of the aluminum matrix for Al-SiC FGM markedly increases as the volume fraction of SiC particles increases. However, the tendency is not so clear in the cases of Al-Shirasu and Al-Al{sub 3}Ni FGMs. Plastic strain energy due to thermal misfits between the matrix and dipersed particles is calculated based on an elasto-plastic analysis by applying a shell theory after Lee et al. The hardness is correlated theoretically with the composition gradient through the mean plastic strain energy (responsible for dislocation density). It is concluded that the composition gradient of metal-based FGMs can be determined from micro-hardness measurements. ...
A flow microcalorimeter of the Picker design has been used to measure molar excess enthalpies at 298.15 K of the seven binary liquid mixtures 1-chloronaphthalene + n-hexane, + n-heptane, + n-octane, + n-decane, + n-dodecane, + n-pentadecane, and + n-hexadecane. Experiments were performed in the discontinuous mode, covering essentially the whole composition range. The overall imprecision of the measurements is characterized by standard deviations from Redlich-Kister type smoothing equations of generally less than +- 1 per cent of the maximum value Hsub(max)sup(E) of the excess enthalpy (with respect to mole fraction). The most striking feature is that for 6 <= n <= 16 (n denotes the number of C-atoms of the n-alkane) Hsub(max)sup(E) decreases with increasing n, the correlation being approximately linear. - For the mixtures 1-chloronaphthalene + n-hexane, + n-heptane, + n-octane, + n-dodecane, + n-pentadecane, and + n-hexadecane molar ...
A specific application of single photon emission tomography to the relative quantitation of the pituitary region is described together with the results obtained in 19 patients with pituitary adenoma...Full Text Available
activities, including the combustion of diesel fuel in heavy-duty vehicles and jet fuel in aircrafts. Current details on emissions from the transportation and other...
Secondary energy can be described as a surplus of electrical energy in a hydropower because the lower demand of energy in some period of the day and the excess of water in the reservoir during the rainy periods. This study proposes the using of the excess of energy at Itaipu Bi nacional for electrolytically hydrogen production and ammonia for nitrogenous fertilizers. Ammonia is a raw material for nitrogenous fertilizers synthesis and produced using hydrogen and nitrogen from the atmosphere. This paper determines the minimal cost of hydrogen production and the capacity of hydrogen production, with this data and according the ammonia market for nitrogenous fertilizers in the Centre/South region was estimated the better capacity of ammonia production for one plant near Itaipu. The process of ammonia production using energy excess is the most environmental acceptable. (author)
Molar excess volumes have been determined by means of a vibrating-tube densimeter for binary liquid mixtures of cycloalkanones (cyclopentanone and cyclohexanone) + cyclohexane, + benzene, and + tetrachloromethane. The V/sup E/ data are reported over the complete mole fraction range at 288.15, 298.15, and 308.15{Kappa}. The obtained excess volumes are positive for mixtures of cyclopentanone with cyclohexane and are negative for mixtures of the cycloalkanones with benzene and tetrachloromethane; for the system cyclohexanone-cyclohexane the V/sup E/ values are positive for a wide range of mole fraction, but at very low cyclohexane mole fraction an inversion of the sign of V/sup E/ is observed. The data show that in the considered range of temperature the values of the temperature coefficient ({partial derivative}V/sup E//{partial derivative}T) are negative for mixtures of the cycloalkanones with benzene and are almost zero for mixtures with ...
To measure electron reactions on a picosecond timescale the investigators developed a picosecond pulse-conductivity technique, which makes use of the electron fine-structure pulses of our LINAC (pulse width 25 vs FWHM) to produce excess electrons and now detects changes in sample conductance under optimum conditions with an instrumental response of 18 ps. This resolution is in agreement with a theoretical estimate. This technique has been successfully applied to study excess electron reactions in solvents covering a mobility range from 0.24 to 100 cm/sup 2/V/sup -1/s/sup -1/; extension to lower mobility liquids seem possible.
Dark Matter annihilation (DMA) may yield an excess of gamma rays and antimatter particles, like antiprotons and positrons, above the background from cosmic ray interactions. The excess of diffuse Galactic Gamma Rays from EGRET shows all the features expected from DMA. The new precise measurements of the antiproton and positron fractions from PAMELA are compared with the EGRET excess. It is shown that the charged particles are strongly dependent on the propagation model used. The usual propagation models with isotropic propagation models are incompatible with the recently observed convection in our Galaxy. Convection leads to an order of magnitude uncertainty in the yield of charged particles from DMA, since even a rather small convection will let drift the charged particles in the halo to outer space. It is shown that such anisotropic propagation models including convection prefer a contribution from DMA for the ...
Dark Matter annihilation (DMA) may yield an excess of gamma rays and antimatter particles, like antiprotons and positrons, above the background from cosmic ray interactions. Several signatures, ranging from the positron excess, as observed by HEAT, AMS-01 and PAMELA, the gamma ray excess, as observed by the EGRET spectrometer, the WMAP-haze, and constraints from antiprotons, as observed by CAPRICE, BESS and PAMELA, have been discussed in the literature. Unfortunately, the different signatures all lead to different WIMP masses, indicating that at least some of these interpretations are likely to be incorrect. Here we review them and discuss their relative merits and uncertainties. New x-ray data from ROSAT suggests non-negligible convection in our Galaxy, which leads to an order of magnitude uncertainty in the yield of charged particles from DMA, since even a rather small convection will let drift the charged particles in ...
A model is presented to account for the effects of ion-induced defects during implantation processing of Si. It will be shown that processing is quite generally affected by the presence of defect excesses rather than the total number of defects. a defect is considered excess if it represents a surplus locally of one defect type over its compliment. Processing spanning a wide range of implantation conditions will be presented to demonstrate that the majority of the total defects played little or no role in the process. This is a direct result of the ease with which the spatially correlated Frenkel pairs recombine either dynamically or during a post-implantation annealing. Based upon this model, a method will be demonstrated for manipulating or engineering the excess defects to modify their effects. In particular high-energy, self-ions are shown to inject vacancies into a boron implanted region resulting in suppression of ...
Experimental data on density, viscosity, and refractive index at T = (298.15, 303.15, and 308.15) K, while speed of sound values at T = 298.15 K are presented for the binary mixtures of (methylcyclohexane + benzene), methylbenzene (toluene), 1,4-dimethylbenzene (p-xylene), 1,3,5-trimethylbenzene (mesitylene), and methoxybenzene (anisole). From these data of density, viscosity, and refractive index, the excess molar volume, the deviations in viscosity, molar refraction, speed of sound, and isentropic compressibility have been calculated. The computed values have been fitted to Redlich-Kister polynomial equation to derive the coefficients and estimate the standard errors. Variations in the calculated excess quantities for these mixtures have been studied in terms of molecular interactions between the component liquids and the effects of methyl and methoxy group substitution on benzene ring.
This report describes the results from acoustic emission (AE) and ultrasonic monitoring of the Aespoe Pillar Stability Experiment (APSE) at SKB's Hard Rock Laboratory (HRL), Sweden. The APSE is being undertaken to demonstrate the current capability to predict spalling in a fractured rock mass using numerical modelling techniques, and to demonstrate the effect of backfill and confining pressure on the propagation of micro-cracks in rock adjacent to deposition holes within a repository. An ultrasonic acquisition system has provided acoustic emission and ultrasonic survey monitoring throughout the various phases of the experiment. Results from the entire data set are provided with this document so that they can be effectively compared to several numerical modelling studies, and to mechanical and thermal measurements conducted around the pillar volume, in an 'integrated analysis' performed by SKB ...
Molar excess volumes, V{sup E} and molar excess enthalpies, H{sup E} of 1,3-dioxolane (D) (i) + propan-1-ol, 1,3-dioxolane (i) + butan-1-ol and 1,3-dioxolane (i) + butan-2-ol (j) binary mixtures have been measured as a function of composition at 308.15 K. The analysis of V{sup E} data by graph, theoretical approach reveals that while propan-1-ol, butan-1-ol exist as associated entities in the pure state; 1,3-dioxolane and butanol exist as monomers in their pure state. These (i+j) binary mixtures are characterized by interactions between ethereal oxygen atom of D(i) and hydrogen atom of alkanols. The IR studies lend additional support to the proposed structure of molecular entitles in these mixtures. The energetics of the mixtures have also been studied.
Molar excess volumes, V{sup E}, molar excess enthalpies, H{sup E}, and speeds of sound, u, of o-toluidine (i) + cyclohexane or n-hexane or n-heptane (j) binary mixtures have been determined over entire range of composition at 308.15 K. Speeds of sound data have been utilized to predict isentropic compressibility changes of mixing, {kappa}{sub S}{sup E} of (i + j) mixtures. The observed V{sup E}, H{sup E} and {kappa}{sub S}{sup E} data have been analyzed in terms of Graph theory. The analysis of V{sup E} data by Graph theory reveals that o-toluidine exists as an associated molecular entity and (i + j) mixtures contain 1:1 molecular complex. It has been observed that V{sup E}, H{sup E} and {kappa}{sub S}{sup E} values calculated by Graph theory compare well with their corresponding experimental values. The observed data have also been analyzed in term of Flory theory.
Molar excess volumes, VE, molar excess enthalpies, HE, and speeds of sound, u, of o-toluidine (i) + cyclohexane or n-hexane or n-heptane (j) binary mixtures have been determined over entire range of composition at 308.15 K. Speeds of sound data have been utilized to predict isentropic compressibility changes of mixing, ?SE of (i + j) mixtures. The observed VE, HE and ?SE data have been analyzed in terms of Graph theory. The analysis of VE data by Graph theory reveals that o-toluidine exists as an associated molecular entity and (i + j) mixtures contain 1:1 molecular complex. It has been observed that VE, HE and ?SE values calculated by Graph theory compare well with their corresponding experimental values. The observed data have also been analyzed in term of Flory theory.
Damaging inflammation arising from autoimmune pathology and septic responses results in severe cases of disease. In both instances, anti-inflammatory compounds are used to limit the excessive...Full Text Available
Excessive weight loss due to protein calorie malnutrition (PCM) is a significant problem in Nigerian children. This syndrome may be difficult to differentiate from the wasting disease caused by human...Full Text Available
The effect of the water-chemical regime (WCR) on damage sustained by heating surfaces of steam generators at NPP is analyzed. It is indicated that phosphate treatment with minimal excesses of phosphates in the steamgenerator water is the most optimal method of managing the WCR regime of horizontal steam generators.
The inflammatory process has direct effects on normal and abnormal wound healing. Hypertrophic scar formation is an aberrant form of wound healing and is an indication of an exaggerated function of...Full Text Available
AIMS OF THE STUDY: Type-2 diabetic patients have excessive cardiovascular mortality, primarily related to diabetic nephropathy. The extent of the morbidity due to nephropathy in type-2 diabetes mellitus...Full Text Available
Obesity and metabolic syndrome result from excess calorie intake and genetic predisposition and are mechanistically linked to type II diabetes and accelerated body aging; abnormal nutrient and insulin...Full Text Available
Disorders of the adrenal gland are rare and complex, with many potential pitfalls in their management. An understanding of embryology, anatomy, physiology and biochemistry is crucial. Surgical treatment may be required for syndromes of hormonal excess and/or suspicion of neoplasia.
Many genetic processes depend on proteins interacting with specific sequences on DNA. Despite the large excess of nonspecific DNA in the cell, proteins can locate their targets rapidly. After initial...Full Text Available
BackgroundSince 1954, there have been in excess of 800 cases of rabies as a result of European Bat Lyssaviruses types 1 and 2 (EBLV-1, EBLV-2) infection, mainly...Full Text Available
Patients experiencing several cancers can be a challenge, as optimal treatment options for the different cancers might interfere with each other. In this case report, we present a woman diagnosed with...Full Text Available
The dissimilatory iron-reducing bacterium Geobacter metallireducens was found to require iron at a concentration in excess of 50 μM for continuous cultivation on nitrate. Growth...Full Text Available
Obesity is a risk factor for stroke and neurodegenerative disease. Excess body fat has been linked to impaired glucose metabolism, insulin resistance, and impulsivity and may be a precursor to decline...Full Text Available
Both deficiency and excess of growth hormone (GH) are associated with increased mortality and morbidity. GH replacement in otherwise healthy subjects leads to complications, whereas individuals with...Full Text Available
Most Vega-like stars have far-infrared excess (60micron or longward in IRAS, ISO, or Spitzer MIPS bands) and contain cold dust (~ 4% of the stars in nearby young stellar associations.
Details of ion transporting abnormalities in cystic fibrosis airway epithelium are now known. The central hypothesis, that excessive drying of the airway surfaces is a primary event that leads to all...Full Text Available
Shilajit has been used traditionally in folk medicine for treatment of a variety of disorders, including syndromes involving excessive complement activation. Extracts of Shilajit contain significant...Full Text Available
Excess caveolin-1 has been reported to play a role in age-dependent hyporesponsiveness to growth factors in vitro. Therefore, we hypothesized that caveolin-1–dependent hyporesponsiveness...Full Text Available
OBJECTIVE--To determine whether the seeming excess of childhood leukaemia and lymphoma identified in Seascale, Cumbria, UK, remains unusual when put into a wider context. DESIGN--Analysis of cancer...Full Text Available
ObjectiveThe purpose of the study was to assess the risk of CHD associated with excess weight measured by BMI and waist circumference (WC) in two large cohorts of...Full Text Available
Signatures of natural selection occur throughout the human genome and can be detected at the sequence level. We have re-sequenced ABCE1, a host candidate gene essential for...Full Text Available
In order to investigate the systematics of the loop expansion in high temperature gauge theories beyond the leading order hard thermal loop (HTL) approximation, we calculate the two-loop electron proper self-energy #SIGMA# in high temperature QED. The two-loop bubble diagram of #SIGMA# contains a linear infrared divergence. Even if regulated with a nonzero photon mass M of order of the Debye mass, this infrared sensitivity implies that the two-loop self-energy contributes terms to the fermion dispersion relation that are comparable to or even larger than the next-to-leading order (NLO) contributions of the one-loop #SIGMA#. Additional evidence for the necessity of a systematic restructuring of the loop expansion comes from the explicit gauge-parameter dependence of the fermion damping rate at both one and two loops. The leading terms in the high temperature expansion of the two-loop self-energy for all topologies arise from an explicit ...
Densities were measured with a vibrating-tube densimeter for binary mixtures of dimethyl sulfoxide + thiophene at temperatures from 293.15 to 313.15 K as a function of composition. Molar excess volumes V[sup E] for the mixtures, determined from the density data, are negative and become more negative with an increase in temperature. The coefficients of thermal expansion were also evaluated from the temperature dependence of the density.
The solar powered electric vehicle race began in Arlington, Texas on June 20, 1993 and finished 7 days later in Minneapolis, Minnesota. Thirty four teams from Universities across the United States and Puerto Rico completed the race out of thirty six entries. The race demonstrated the viability of sunlight powered vehicles as the better average daily speeds were in excess of 50 miles an hour. Even in the rain, most average speeds were in excess of 15 miles an hour. Analyzed results, photographs, and project details are included. (GHH)
The transformation of Pd/Si to Pd{sub 2}Si/Si is investigated using depth-resolved positron annihilation, x-ray diffraction and Auger electron spectroscopy studies. The observed defect-sensitive positron S-parameter value of 1.022-1.054 indicates the existence of divacancies across the silicide/silicon interface and Si substrate region. Our experimental observation of vacancy defects is consistent with the model proposed for excess vacancy generation across the interface consequent to Si diffusion. (letter to the editor)
Al, Ga and In complexing with methylthymol blue (H_6R) purified by gel filtration is studied. in the case of metal excess complexes with the ratio of components M:H_6R=2:1 with #lambda#=587(Al), 590(Ga) and 593 nm(In) appear. In the case of reacting agent excess complexes with the ratio of component 1:1 with #lambda#_m_a_x=480-490 (Al) and 480 nm(Ga, In) appear. The mechanism of complexing reactions is studied. Molar extinction coefficients and stability constants are calculated.
An overview of emissive display technologies is presented. Display types briefly described include: cathode ray tubes (CRTs), field emission displays (FEDs), electroluminescent displays (ELDs), and plasma display panels (PDPs). The critical role of phosphors in further development of the latter three flat panel emissive display technologies is outlined. The need for stable, efficient red, green, and blue phosphors for RGB fall color displays is emphasized.
In this report is described the sources to nitrogen emission and how the emission have changed over time. The cost and effect of the proposals given by the Swedish Environmental Protection Agency to cope with the emission of nitrogen to the sea is also treated. A separate chapter describes what we know today about phosphorus and eutrophication Basic document to report SNV--4735. 25 figs, 11 tabs
Proper estimation of shipping emissions is essential for an impact assessment of shipping on air quality and health in port cities and coastal regions. In the Netherlands shipping is an important source of particulate matter. This report provides an internationally accessible and transparent summary and description of the methodologies used in the Netherlands Pollutant Release and Transfer Register (PRTR) to estimate PM emissions from shipping, including recently implemented updates.
This article analyses the role of energy intensity and the relationship between CO{sub 2} emissions and primary energy in order to explain the evolution of CO{sub 2} emissions by unit of real GDP. It also distinguishes two different meanings of CO{sub 2} emissions Kuznets curve hypothesis: the weak and the strong sense. It considers the case of Spain in the period 1972-1997 as an example in which there is not any evidence supporting this hypothesis in either sense. (author)
This paper reviews emission standards, technologies to control emissions, and the cost of these controls. It is concluded that international bodies will increasingly set minimum emissions, these standards will continue to be reduced, and in addition new substances will be controlled. The cost of this control will likely not exceed 0.5 cents per kWe-hr. 4 refs., 3 tabs.
The CO{sub 2} emissions can be reduced by using economic instruments, like carbon tax. This project included two specific questions related to CO{sub 2} taxation. First one was the economic effects of increasing CO{sub 2} tax and decreasing other taxes. Second was the economic adjustment costs of reducing net emissions instead of gross emissions. A computable general equilibrium (CGE) model was used in this analysis. The study was taken place in Helsinki School of Economics
Pollutant emissions due to fossil fuel and biomass energy utilization in Turkey have been estimated. Standard emission factors were used for estimating the levels of particulate matter, sulfur oxides, nitrogen oxides, carbon monoxide, volatile organic compounds, and aldehydes. The results are presented for different fuels and energy-consuming sectors for the reference year 1987. Total Turkish emissions vs energy consumption are presented for every fifth year since. 1960. (author).
Amorphization and a dual implant technique have been used to manipulate residual defects that persist following implantation and post-implant thermal treatments. Residual defects can often be attributed to ion-induced defect excesses. A defect is considered to be excess when it occurs in a localized region at a concentration greater than its complement. Sources of excess defects include spatially separated Frenkel pairs, excess interstitials resulting from the implanted atoms, and sputtering. Preamorphizing prior to dopant implantation has been proposed to eliminate dopant broadening due to ion channeling as well as dopant diffusion during subsequent annealing. However, transient-enhanced diffusion (TED) of implanted boron has been observed in pre-amorphized Si. The defects driving this enhanced boron diffusion are thought to be the extended interstitial-type defects that form below the ...
Amorphization and a dual implant technique have been used to manipulate residual defects that persist following implantation and post-implant thermal treatments. Residual defects can often be attributed to ion-induced defect excesses. A defect is considered to be excess when it occurs in a localized region at a concentration greater than its complement. Sources of excess defects include spatially separated Frenkel pairs, excess interstitials resulting from the implanted atoms, and sputtering. Preamorphizing prior to dopant implantation has been proposed to eliminate dopant broadening due to ion channeling as well as dopant diffusion during subsequent annealing. However, transient-enhanced diffusion (TED) of implanted boron has been observed in pre-amorphized Si. The defects driving this enhanced boron diffusion are thought to be the extended interstitial-type defects that form below the ...
In the paper, the effect of Ni content, WC grain size and Mo2C addition on WC-6.25wt%TiC-9.3wt%Ni cemented carbide were investigated to improve the properties of Ni-bonded cemented carbides. The results show that the decrease of Ni content will result in the decrease of transverse rupture strength and increase of hardness; with the decrease of WC particle size, hardness increases due to the refinement of WC grains, however, the transverse rupture strength decrease due to the decrease of Ni binder thickness; Mo2C proves to be an effective grain growth inhibitor. With the increase of Mo2C content, the WC grains are refined and the hardness and transverse rupture strength are improved. Generally, when the Ni content is decreased to 8.4wt%, 13.45mm WC is used and 1.2wt% Mo2C is added, a higher...
Microprocessor based ''smart'' pressure, level, and flow transmitters were tested to determine the radiation hardness of this class of electronic instrumentation for use in reactor building applications. Commercial grade Complementary Metal Oxide Semiconductor (CMOS) integrated circuits used in these transmitters were found to fail at total gamma dose levels between 2500 and 10,000 rad. This results in an unacceptably short lifetime in many reactor building radiation environments. Radiation hardened integrated circuits can, in general, provide satisfactory service life for normal reactor operations when not restricted to the extremely low power budget imposed by standard 4--20 mA two-wire instrument loops. The design of these circuits will require attention to vendor radiation hardness specifications, dose rates, process control with respect to radiation hardness factors, and non-volatile programmable memory technology. 3 ...
A study of the influence of the concentration of secondary addition, high concentrations of primary dopant, diffusion enhancer and stabilizer on radiation hardness is presented. It is concluded that the diffusion enhancing technique is the most powerful method for improving radiation hardness. A new polystyrene scintillator which contains 2% pT, 0.02% POPOP, 20% diffusion enhancer and 0.02% stabilizer gave 91% of initial light output immediately after 3 Mrad irradiation in air. Data are presented that show that scintillator prepared from commercial polymer is more radiation-hard and has greater light output than scintillator prepared from monomer. It is assumed that this difference is due to different molecular weight distributions. Some protocols for acceleration of aging (yellowing and crazing) are presented. It is shown that one of the main reasons for aging of plastic scintillators is residual monomer. 10 refs., 18 ...
A series of SiAlON materials with a cordierite-based matrix were annealed for different lengths of time to cause crystallization of the glass phase. Their fracture toughness, hardness, and elastic modulus were measured from room temperature up to 1100"0C. The fracture toughness generally decreased with temperature. Short time annealing raised toughness at lower temperatures, while further annealing lowered it back to the value for as-hot pressed materials. At higher test temperatures annealing had no effect on toughness. This annealing behavior is significantly different from that previously reported in the system SaAlON-YAG. Hardness decreased monotonically with temperature for all samples. Both hardness and the elastic modulus were not affected by the annealing treatment. At elevated temperatures appreciable scatter of modulus results allowed only a rough trend of decrease with temperature to be observed.
PurposeThe purpose of this study was to determine the relationship between the changes of soft and hard tissues after modified anterior segmental osteotomy on the maxilla and mandible and to evaluate unintended facial changes using cephalometric and photometric analyses.Materials and MethodsThe subjects included 29 women and 1 man (22 to 50 years of age) who were diagnosed as bialveolar or bimaxillary protrusion and underwent modified anterior segmental osteotomy on the maxilla and mandible. Lateral cephalograms and lateral and frontal photographs taken preoperatively and postoperatively were analyzed.ResultsThere was a significant change in all soft and hard tissue parameters except the labiomental angle. The ratio of upper lip to maxillary incisor retraction was 0.67:1 and the ratio of l...
The introduction of tolerance to radiation (''radiation-hardness'') into large electronic systems is one of the major tasks to which this Handbook will be put. The practices recommended here for inculcating radiation-tolerance in equipment require advanced physical modeling techniques, precise engineering procedures, and firm assurance procedures. The degree to which these procedures should be used in an equipment project can be measured by the severity of the raw radiation environment, the desired reliability of the system, and the requirement of that project for radiation-sensitive technologies. The balance of device/circuit design versus shielding will depend on whether the radiation is highly penetrating -- as in isotope handling or military environments -- or readily attenuated, as in space. In this chapter the authors have attempted to summarize the essential features of the radiation hardening of large assemblies of equipment and how effective control of ...
Dense samples of #beta#-sialons (with z from 1 to 4) were pressuressly sintered for different time (15-240 minutes) and at relatively low temperature of 1600 C using single-phase #beta#-sialon powders synthesized by combustion nitridation. The samples were characterized using ultrasonic method for determination of elastic properties (E,G,#mu#). Also, hardness by Knoop and fracture toughness by Vickers indentation microfracture method was estimated. With increasing z number Young's modulus decreases from 293 to 179 GPa. Simultaneously Poisson ratio increases by about 30%. The highest values of hardness and fracture toughness were obtained for sialon with z equal to 1. (orig.).
Leptonic pair production on nuclei ad EMC-effect are discussed within the frames of the flucton model with scaling distortion. Cumulative production of direct photons and leptonic pairs as a test of the model of hard collisions is considered. The results of calculations of massive leptonic pair production cross sections on nucleus fluctons, caculations of the ratio of deuterium and iron structural functions, cross sections of direct photon production on sup(181)Ta nuclei at Esub(p)=400 GeV and cross section of #pi#-meson production in the model of hard collisions are presented. Experimental discovery of direct cumulative photons is concluded to be important for understanding the mechanism of parton hard scattering from nucleus fluctons.
Ceramic ball bearings of silicon nitride are used for hard disk drive (HDD) spindle motors, to increase seed, reliability and memory capacity of the HDDs. Silicon nitride ceramics have advantages of lightweight, high strength and hardness over the conventional steel for bearings, but is expensive. A new process of high cost performance has been developed for mass production of the small-size ceramic balls. The company plans to apply these bearings to higher devices, e.g., servers, for the time being, and to expand the applicable areas, e.g., common devices and other small-size motors. The ceramic bearings have been developed jointly with Koyo Seiko Co. Ltd. (translated by NEDO)
The costs of greenhouse gas emission-reductions vary among countries depending on emission levels, technologies used, past emission-reduction achievements, path of economic development, fuel mix, and initial endowment of hydrocarbon resources. The criterion of cost-effectiveness therefore suggests that the ways should be found to encourage emission reductions in the countries where the required costs of reduction of additional unit of emissions are the lowest. These countries usually face crucial capital constraints and have other development priorities than investing in reduction of greenhouse gas emissions. Developed countries could invest their resources in the former Soviet Union and the east European countries to achieve the same level of reduction of greenhouse gases with lower costs than they could in their own countries.
Proposed features of the competitive electricity market in Ontario were reviewed. The speaker predicted that demand for renewable energy in Ontario`s competitive electricity market will be affected by green power, emissions trading, labelling, and renewables portfolio standard. Under current regulations retailers can charge customers a premium for purchasing electricity generated by `green` sources. The existing limits on emissions of sulphur dioxide, nitrogen oxides and carbon dioxides will remain in place, but an emissions cap and trading program for all Ontario-based generation is an option to consider. Ontario`s Market Design Committee (MDC) has recommended the implementation of emissions trading for electricity-related air pollutants for all generators located in Ontario. The complex mechanics of emission trading are explained. The MDC recommendation of the use of standard ...
This report focuses on air quality at the Nevada Test Site (NTS) for 1994. A general description of the effluent sources are presented. Each potential source of NTS emissions was characterized by one of the following: (1) by monitoring methods and procedures previously developed at NTS; (2) by a yearly radionuclide inventory of the source, assuming that volatile radionuclides are released to the environment; (3) by the measurement of tritiated water concentration in liquid effluents discharged to containment ponds and assuming all the effluent evaporates over the course of the year to become an air emission; or (4) by using a combination of environmental measurements and CAP88-PC to calculate emissions. Appendices A through J describe the methods used to determine the emissions from the sources. These National Emission Standards for Hazardous Air Pollutants (NESHAP) ...
This study investigates the carbon dioxide (CO2) emissions patterns in coordination with the economic development of Taiwan. The resulting quadratic relationship between emissions and income are partly due to the structural change of energy supply in Taiwan, with the introduction of nuclear energy in 1980 to 1986. This relationship is quite unique and different from the N-shaped relationships in some developed countries (de Bruyn and Opschoor, 1997; Friedl and Getzner, 2003). The CO2 emissions in Taiwan increase with the increasing imports of raw materials for economic activities and the increasing use of electricity. There is no evidence that the substantial increase of Taiwan's service sector contributed to slowing its CO2 emissions.
Method for determining the concentration of atomic species in gases and solids. Measurement of at least two emission intensities from a species in a plasma containing the species after a sufficient time period has elapsed after the generation of the plasma and during a second time period, permits an instantaneous temperature to be established within the sample. The concentration of the atomic species to be determined is then derived from the known emission intensity of a predetermined concentration of that species in the sample at the measured temperature, a quantity which is measured prior to the determination of the unknown concentration, and the actual measured emission from the unknown species, or by this latter emission and the emission intensity of a species having known concentration within the sample.
There is a need to reduce air pollutant emissions in some U.S. urban regions to meet federal and state air quality guidelines. Opportunities exist for reducing pollutant emissions from natural gas appliances in the residential sector. A cost-benefit analysis on various pollutant-reducing strategies is needed to evaluate these opportunities. The effectiveness of these pollutant-reducing strategies (e.g., low-emission burners, energy conservation) can then be ranked among themselves and compared with other pollutant-reducing strategies available for the region. A key step towards conducting a cost-benefit analysis is to collect information on pollutant emissions from existing residential natural gas appliances. An extensive literature search was conducted to collect data on residential natural-gas-appliance pollutant emission factors. The literature primarily describes laboratory ...
A stiff skin forms on surface areas of a flat polydimethylsiloxane (PDMS) upon exposure to focused ion beam (FIB) leading to ordered surface wrinkles. By controlling the FIB fluence and area of exposure...Full Text Available
Investigations of superdense compression touch on such problems as ultrahigh-frequency oscillations of matter in the generation of gravitational waves, the powerful pumping of hard coherent radiation, and the laboratory simulation of stellar interiors. This paper reviews the theory of supercompression and discusses some experiments involving multifoil collision supercompression.
These sky images are scanned for point sources above a specified ... The threshold criteria are: a) Gold: >4 sigma in both the Soft AND Hard bands. b) Silver: ... Filtering: Currently, there is no plan for filtering within the GCN based ...
ObjectiveTo implement a role-reversal exercise to increase first-year pharmacy students' awareness of communication barriers in the health care setting, especially for deaf and hard-of-hearing...Full Text Available
ObjectivesPericardial tamponade after cardiac surgery is difficult to diagnose, thereby rendering timing of rethoracotomy hard. We aimed at identifying factors predicting the outcome...Full Text Available
ASTROSAT, India's first dedicated astronomy satellite is slated for launch in 2007. The primary science objective of ASTROSAT is to explore the Universe using broad-band instruments covering optical, UV, soft X-ray and hard X-ray studies
Plasma nitriding in glow discharge is a process of modifying surface properties of a material by which surface hardness, corrosion resistance, fatigue strength etc. of a material can be improved
BackgroundIn Trinidad and Tobago, the law on the mandatory use of seat belts was passed in 1995, but this law is hardly enforced. The objective of this study was to determine the...Full Text Available
This report discusses the following topics on superconductivity: nonlinearities in hard superconductors such as surface impedance of a type II superconductimg half space and harmonic generation and intermodulation due to alternating transport currents; and nonlinearities in superconducting weak links such as harmonic generation by a long Josephson Junction in a superconducting slab.
Ultra fine tungsten carbide and cobalt powders were milled by high energy planetary ball mill at different ball to powder weight ratios (BPR) to produce particles of WC-10wt%Co hard metal in nanometer scale size. Microstructural characterizations by TEM show that the particle size of tungsten carbide was achieved to 32nm after milling at 15 BPR during 10h. In order to reduce the WC grain growth during the sintering process, tantalum carbide was added to the hard metal as a WC grain growth inhibitor. The nano hard metal powders were compacted at 200MPa pressure and sintered at 1370-1450degreeC temperatures in a high purity hydrogen atmosphere. The results show that the addition of 0.6wt% of TaC improves the hardness and fracture toughness from 1493 HV30 and 11.8MPam (for TaC free sample) to...
Excimer laser processing enables both thermally-driven transformations and the incorporation of solutes into the surface of materials through melting and diffusional mixing. We have examined the effect of excimer laser processing on the microstructure and surface mechanical properties of titanium alloys. Changes in the surface hardness due to laser processing were studied using a Nanoindenter [trademark]. Alloying experiments using both mixing of evaporated surface layers of boron and laser gas alloying in air and in nitrogen all result in changes in the surface hardness of the material. Alloying with boron results in an amorphous surface which is somewhat harder than the as polished surface. Laser processing in air and pure nitrogen results in incorporation of oxygen and nitrogen and the development of fine ([approximately] 50 nm) precipitates of TiO and TiN respectively. Substantial increases in surface hardness result ...
Constraint-based lexical models of language processing assume that readers resolve temporary ambiguities by relying on a variety of cues, including particular knowledge of how verbs combine...Full Text Available
The October 2000 terrorist attack on the guided-missile destroyer USS Cole (DDG 67) in the port of Aden, Yemen, is commonly viewed in the larger context of al-Qa'ida's September 11th campaign. Beyond the initial official investigations, the military force...
The methods of surface modification of Ti-Zr alloy by laser treatment are considered. Characteristics of laser modification without- and with surface melting and with melting in different gaseous environments and with nickel microalloying are presented. Maximum depth, hardness and corrosion resistance are observed under nickel laser alloying.
Pressureless-sintered AlN and hot-pressed, pressureless-sintered and reaction-bonded SiC were neutron irradiated at temperatures between 100 and 785degC up to a fluence of 5.2 x 10"2"4 n/m"2. The hardness was increased by up to 51% in AlN and 84% in SiC. The hardness decreased after annealing at temperatures around the irradiation temperature. At the same temperatures, the macroscopic length, which was increased by irradiation, also began to decrease. The hardness and length were almost recovered after 1,200 #approx# 1,400degC annealing. Thus, hardening in irradiated AlN and SiC is controlled by the number of point defects, or, more precisely, by the strain caused by small point defect clusters which pin down dislocation movement. Dislocation loops were still observed in some samples after 1,400degC annealing while the hardness was almost recovered to that in the unirradiated state. Thus, the existence ...
BackgroundA goal of human genetics is to discover genetic factors that influence individuals' susceptibility to common diseases. Most common diseases are thought to result from the...Full Text Available
Plant surfaces covered with crystalline epicuticular waxes are known to be anti-adhesive, hardly wettable and preventing insect attachment. But there are insects that are capable of gluing their eggs...Full Text Available
68 replaced carbon steel piping in secondary system of pressurized water reactor (PWR) has been investigated by visual examination for checking thinning conditions. It is well known that the flow-accelerated corrosion (FAC) was inhibited by traces of Cr in steel. Therefore, the chemical compositions of those steels have been measured. In addition, the micro structure and hardness of those steels have been investigated. And the relationship between those material variables and FAC rate was considered. As the results, (1) The Cr contents in those steels were below 0.1 wt% except one sample. Minute quantities of chromium increase the resistance against FAC. But the water velocity was thought to be the dominant factor rather than chemical composition in steel, at least such as below 0.1%Cr. (2) Hardness of all piping has been satisfied the specifications of each materials. The hardness of steels was not correlated with wall ...
Previous ultrasound elasticity imaging experiments supported a generally accepted concept that the hardness of deep venous thrombi increases with thrombus aging. Results also showed that this...Full Text Available
The adhesive proteins secreted by marine mussels form a natural glue that cures rapidly to form strong and durable bonds in aqueous environments. These mussel adhesive proteins contain an unusual...Full Text Available
Deposition of hard coatings may influence the mechanical properties of the bulk material and its corrosion resistance. In this work we study the hardness of the coated and the back side of 100Cr6 steel plates. Electrochemical corrosion tests were performed in O{sub 2}-saturated acetate buffer of pH 5.6 at 25degC. Chromium nitride and titanium nitride coatings prepared by different physical vapour deposition processes, such as arc, thermionic arc evaporation, magnetron sputtering and ion-beam-assisted deposition (IBAD) were compared. The results show that, for sufficient corrosion protection, chromium nitride layers have to be thicker than 500 nm. An increased nitrogen partial pressure in the evaporation chamber of the IBAD process improves the corrosion resistance significantly. The hardness of the substrates was reduced in the case of thermoionic arc evaporation only, indicating a deposition temperature of more than ...
Laser surface alloying with gaseous nitrogen was utilized to improve the wear resistance of a Ti-6Al-4V alloy. Wear-resistant composite coatings reinforced by hard TiN dendrites were produced 'in-situ' on a substrate of a Ti-6Al-4V alloy. The hardness and wear resistance of the laser alloyed coating under two-body abrasive and block-on-ring full-sliding wear conditions were significantly enhanced. (orig.)
We report on measurements of radiation hardness of the plastic scintillating fiber SCSF-81. Fibers were irradiated with "6"0Co #gamma#-rays and fast neutrons up to 105 Gy and up to 5 x 1013 n/cm"2, respectively. Deterioration of the attenuation length of the scintillating fiber was studied. Some significant deterioration was observed at the integrated dose of about 1 x 103 Gy and at the integrated neutron flux (neutron fluence) of about 1 x 1012 n/cm"2 for #gamma#-ray and neutron irradiation, respectively. (author).
A flow field and particle trajectory in a HDD (Hard Disk Drive) between two rotating disks in axisymmetric enclosures is investigated using CFD code FLUENT/UNS. The RNG k-{epsilon} model is used as a turbulent model. In this study, the flow field between two disks are symmetric, and the flow field near the enclosure is very complex. Cross stream vectors are shown both for blowing and no blowing from the hub. The larger a particle, the more fast the particle deposits at the walls. In the case of blowing from the hub, the more fast the particle deposits at the walls. (author). 9 refs., 12 figs., 1 tab.
Wood-plastic combination (WPC) was produced by {gamma}-irradiation of persimmon impregnated with acrylonitrile and styrene. The hardness and strength of WPC obtained were higher than those of an unmodified wood. Thus, it was found that the WPC is suited for a head of golf club, because the Shore hardness value of WPC is 36% greater than that of unmodified wood. An impregnation method of monomers with some pigments could produce colored WPC without diminishing natural grain. Head of golf club could be manufactured from colored WPC in practice. (auhtor).
Wood-plastic combination (WPC) was produced by #gamma#-irradiation of persimmon impregnated with acrylonitrile and styrene. The hardness and strength of WPC obtained were higher than those of an unmodified wood. Thus, it was found that the WPC is suited for a head of golf club, because the Shore hardness value of WPC is 36% greater than that of unmodified wood. An impregnation method of monomers with some pigments could produce colored WPC without diminishing natural grain. Head of golf club could be manufactured from colored WPC in practice. (auhtor).
An interferometric technique for hard X-rays is presented. It is based on two transmission gratings and a phase-stepping technique, and it provides separate radiographs of the phase and absorption profiles of bulk samples. Tomographic reconstruction yields quantitative three-dimensional maps of the X-ray refractive index and of the attenuation coefficient, with a spatial resolution down to a few microns. The method is mechanically robust, it requires little monochromaticity, and can be scaled up to large fields of view. These are important prerequisites for use with laboratory X-ray sources. Numerous applications ranging from wave front sensing to medical radiography are presently under investigation.
Glow discharge plasma nitriding of AISI 304 austenitic stainless steel has been carried out for different processing time under optimum discharge conditions established by spectroscopic analysis. The treated samples were analysed by X-ray diffraction (XRD) to explore the changes induced in the crystallographic structure. The XRD pattern confirmed the formation of an expanded austenite phase (#gamma#_N) owing to incorporation of nitrogen as an interstitial solid solution in the iron lattice. A Vickers microhardness tester was used to evaluate the surface hardness as a function of indentation depth (#mu#m). The results showed clear evidence of surface changes with substantial increase in surface hardness.
The effects of variable hardness, pH, alkalinity, humics, and suspended clay on the chemical speciation of copper and its toxicity to fathead minnow larvae in Lake Superior water were investigated. Two proposed methods (toxicity factors and chemical speciation) for predicting LC50 values in specific natural waters from laboratory toxicity data and the average site specific values of general water quality parameters were evaluated. The accuracy of the cupric ion-selective electrode in determining CU/sup +2/ activities in ambient and chemically altered Lake Superior water was also determined.
The world steel industry and market and the current status and prospects for the Japanese steel industry are discussed with particular reference to China, Europe, and the US. Trends in coking coal supply from Australia, Canada, and Mongolia and changes in demand for hard and semi-soft coking coals are considered. Canadian coal plays a significant role in the hard coking coal and PCI coal markets. This is expected to continue. Emerging concerns include the strong Canadian dollar and increases in fuel and materials costs. Canadian suppliers are asked to improve efficiencies, be competitive in the overall coal chain, and diversify their PCI coal reserves. 14 figs.
The efficiency of NbC on WC grain coarsening in a WC-10wt.%Co hardmetal alloy was demonstrated by hardness measurement and WC granulation observation. The heterogeneous and overall grain growth were controlled. A low temperature experimentally produced NbC was used and compared to the inhibition potential of a commercial NbC powder. The results were the same in terms of structural fineness and hardness. The dispersion of the experimental NbC was not a problem, in spite of its size. The experimental NbC has very large particles, formed by agglomerates of small crystallites. During milling these agglomerates could be broken down. (orig.)
We have implemented a virtual Young's double slit experiment for hard X-ray photons with micro-fabricated bi-prisms. We observe fringe patterns with a scintillator, and quantify interferograms by detecting X-ray fluorescence from a scanned 30nm Cr metal film. The observed intensities are best modeled with a near-field, Fresnel analysis. The maximum fringe number in the overlap region is proportional to the ratio of real to imaginary parts refractive index of the prism material. The horizontal and vertical transverse coherence lengths at beamline APS 8-ID are measured.
The effect of severe plastic deformation by cold high pressure torsion (HPT) on radio frequency (RF) plasma nitriding of pure iron, as well as St2K50 and X5CrNi1810 steels was investigated. Nitriding was carried out for 3 h in a nitrogen atmosphere at a pressure of 10"-"5 bar and temperatures of 350 and 400 deg. C. Nitrided specimens were analysed by scanning electron microscopy (SEM), X-ray diffraction and micro hardness measurements. It was found that HPT enhances the effect of nitriding leading almost to doubling of the thickness of the nitrided layer for pure iron and the high alloyed steel. The largest increase in hardness was observed when HPT was combined with RF plasma nitriding at 350 deg. C. In the case of pure iron, the X-ray diffraction spectra showed the formation of #epsilon# and #gamma#' nitrides in the compound layer, with a preferential formation of #gamma#' at the expense of the #alpha#-phase at the higher nitriding ...
Ion Beam Induced Luminescence (IBIL) and Ion Beam Induced Charge Collection (IBICC) have been applied in the study of the luminescence emission efficiency and investigation of the homogeneity of the luminescence emission in phosphors. The IBIL imaging was performed by using sharply focused ion beams or broad/partially-focused ion beams. The luminescence emission homogeneity in samples was examined to reveal possible distributed crystal-defects that may lead to the inhomogeneity of the luminescence emission in samples.The purpose of the study is to search for suitable luminescent thin films that have high homogeneity of luminescence emission, large IBIL efficiency under heavy ion excitation, and can be placed as a thin layer on the top of microelectronic devices to be analyzed with Ion Photon Emission Microscopy (IPEM). The emission yield was ...
The objectives of this study were to characterize the changes of VOC material emission profiles over time and develop a method to account for such changes in order to enhance a source identification technique that is based on the measurements of mixed air samples and the emission signatures of individual building materials determined by PTRMS. Source models, including powerlaw model, doubleexponential decay model and mechanistic diffusion model, were employed to track the change of individual material emission signatures by PTRMS over a ninemonth period. Samples of nine typical building materials were tested individually for nine months and later in combination to obtain actual mixture emissions. VOC emissions from each material were measured in a 50liter smallscale chamber. Chamber air was sampled by PTRMS over a 28day period to determine their emission rate ...
To predict air quality properly at a given location, it is necessary to identify all emission sources that will have significant impact at that location. Furthermore, the atmospheric pollutants that are emitted by these sources must be identified and quantitatively characterized. Once the air-quality predictions have been made, it is desirable to have some historical air-quality data for comparison. An efficient means of obtaining this information is through the use of detailed emission inventories and an inventory of air-quality-monitoring stations. Therefore, as part of the Alberta Government/Industry Acid Deposition Research Program (ADRP), three comprehensive inventories have been developed, namely: a sulfur dioxide (SO/sub 2/) emission inventory, a nitrogen oxides (NOx) emission inventory, and an inventory of air-quality-monitoring stations. Volume 2, Design of the Emission ...
This publication describes the modification of the road traffic exhaust emission calculation model LIISA and presents the new calculation results. The model has already established its position as the most important inventory tool for regional road traffic emissions in Finland. The LIISA model calculates road traffic emissions as a whole. The system comprises of three separate models: 1. a model for calculating automobile emissions for the years 2001-2021, 2. a model for calculating emissions backwards for the years 1980-2000, 3. a model for calculating the emissions of motorcycles and mopeds. All three parts have been modified. The LIISA model is one of the submodels of the comprehensive LIPASTO calculation system developed at VTT Building and Transport. The LIPASTO model is an inventory tool for emissions regarding all traffic modes in ...
The main pollutants from marine diesel engines are oxides of nitrogen (NOx), sulfur oxides (SOx) and particulates (soot). However, the proposed marine diesel engine emission regulations will primarily focus on the levels of NOx and SOx. In the future, once the proposed regulations are met, the limits and levels of other emissions will come under increasing scrutiny, such as particulates, hydrocarbons and carbon monoxide. Regardless of the type of pollutant, there are generally two classes of emission control: (1) techniques that reduce the amount of pollutant formed in the combustion process, or (2) prevent the pollutants from reaching the atmosphere. Unfortunately, some of these control techniques will not be able to meet the incoming regulations. Therefore, this paper identifies the diesel engine emissions of concern, the impending regulations, and the merits of current and future ...
Air toxics from the industrial wastewater treatment plants (IWTPs) impose serious health concerns on its surrounding residential neighborhoods. To address such health concerns, one of the key challenges is to quantify the air emissions from the IWTPs. The objective here is to characterize the air emissions from the IWTPs and quantify its associated uncertainty. An IWTP receiving the wastewaters from an airplane maintenance facility is used for illustration with focus on the quantification of air emissions for benzyl alcohol, phenol, methylene chloride, 2-butanone, and acetone. Two general fate models, i.e., WATER9 and TOXCHEM+V3.0 were used to model the IWTP and quantify the air emissions. Monte Carlo and Bootstrap simulation were used for uncertainty analysis. On average, air emissions fr...
For Stage II of the European Dioxin Project the following objectives were set: - Amendment of existing emission data collected for most relevant emission sources in order to reduce uncertainties of emission estimates. Collecting first emission data from countries not yet performing dioxin emission measurement programs. Extending the inventory of dioxin emissions to ambient air produced in Stage I by a complementary study on emissions to land and water. Extending the regional scope of data collection to countries in Central Europe. The report of Stage II of the European Dioxin Project is presented in 3 Volumes. Volume 1 contains an overview on the background and approach of different activities carried out and on the results obtained. These results are put into a broader view regarding the dioxin reduction measures in Europe leading to ...
Research reported here reveals that the reduction of CO{sub 2} emissions into the atmosphere, is mainly dependent on the decrease of the use of fossil fuels, but also on the development of environment-friendly technology and greening of the environment. 2 refs.
An improved method of counting acoustic emission (AE) events from water-stressed stems of cedar (Thuja occidentalis L.) is presented. Amplified AEs are analyzed on a real time basis...Full Text Available
Measurements are reported of ultrasonic acoustic emissions (AEs) measured from sapwood samples of Thuja occidentalis L. and Tsuga canadensis (L.) Carr. during air dehydration....Full Text Available
An ASTER (advanced spaceborne thermal emission and reflection radiometer) is one of the image sensors. It is to be installed in an earth survey polar orbit platform satellite, EOS-AM1, which is to be launched in 1998, and it is going to start its operation. Data observed by the thermal infrared remote sensing of ASTER include the spectral emissivity, and the spectral emission reflectivity which is expressed by the function of temperature. It is required to overcome technical problems how to extract the spectral emissivity from the observed data. The spectral emissivity extracted from the remote sensing data by the MMD method, measured for samples collected in Cuprite area, Nevada, and/or measured at sampled points were compared to each other and discussed. The hemisphere spectral reflectivity, which is indirect spectral emissivity, agreed well with the direct ...
In order to investigate the effects ethanol-diesel blends and altitude on the performance and emissions of diesel engine, the comparative experiments were carried out on the bench of turbo-charged diesel...Full Text Available
A historical prospective mortality study was conducted on a cohort of 34 156 male members of a heavy construction equipment operators union with potential exposure to diesel exhaust emissions. This...Full Text Available
The Natural Gas Vehicle Challenge `92, organized by Argonne National Laboratory and sponsored by the US Department of Energy, the Energy, Mines, and Resources - Canada, the Society of Automotive Engineers, and many others, resulted in 20 varied approaches to the conversion of a gasoline-fueled, spark-ignited, internal combustion engine to dedicated natural gas use. Starting with a GMC Sierra 2500 pickup truck, donated by General Motors, teams of college and university student engineers strived to optimize Chevrolet V-8 engines operating on natural gas for improved emissions, fuel economy, performance, and advanced design features. This paper focuses on the results of the emission event, and compares engine mechanical configurations, engine management systems, catalyst configurations and locations, and approaches to fuel control and the relationship of these parameters to engine-out and tailpipe emissions of regulated ...
In VHTGR (Very High Temperature Gas-cooled Reactor), the radiation plays an important role in heat transfer through the cavity in RCCS (Reactor Cavity Cooling System). We performed the series of experiments to measure the emissivity using the infrared thermometer with wavelength range of 8#approx#14 #mu#m. As the first step, the transmittance of Zinc Selenide (ZnSe) window was measured to estimate the emissivity that can compensate the attenuation effect of window. The kind of gas with various concentrations in the cavity will be released during postulated accidents to the coolant type, so it is essential to estimate the effects of gas on the measurement of emissivity. In this manner we measured the emissivity with the air, the helium and the steam inside chamber. The results represent that the concentration of the air and the helium do not affect the emissivity significantly while ...
Spontaneous radiation by an atom in a Rydberg state is inhibited by use of parallel conducting planes to eliminate the vacuum modes at the transition frequency. Spontaneous radiation emission is observed to turn off abruptly at the cutoff frequency of the waveguidelike structure, and the natural lifetime is measured to increase by a factor of at least 20.
Simulations with a regional chemical transport model show that anthropogenic emissions of volatile organic compounds and nitrogen oxides (NOx = NO + NO2) lead to a dramatic diurnal...Full Text Available
Emissions of sulphur and nitrogen oxides are continuing to fall in Europe but rise in Asia, according to calculations based on individual countries' predictions of economic development. The upward trend is slower than in previous predictions. 2 refs., 2 figs., 2 tabs.
Proper assessment of the hypothesis which correlates polycyclic aromatic hydrocarbons (PAHs) with the unidentified infrared emission bands requires additional experimental laboratory data. In order to address this need, thermal infrared emission studies were performed on a subset of PAHs suggested to be of astrophysical importance. It was proposed that infrared emission from interstellar PAHs occurs following absorption of an ultraviolet photon. Since energy transfer to the ground electronic state can be rapid for a species in which intersystem crossing is negligible, the emission spectrum may be viewed as resulting from an equilibrium vibrational temperature (Leger and d'Hendecourt, 1987). This has been the basis for using infrared absorption spectra to calculate the corresponding emission spectra at various temperatures. These calculations were made using room temperature infrared ...
Air pollution abatement measures are not an end in themselves, and undesirable side effects should be taken into account. The proposed emission index takes into account the total emissions caused by a technical project as well as the effects of the individual pollutants.
The pharmacokinetic concepts of bioavailability and biotransformation are introduced into the assessment of public health risk from experimental data concerning the emissions of potentially mutagenic...Full Text Available
This study was undertaken to collect emissions performance data for Canadian and comparable American refineries. The objective was to examine parameters that affect refinery air emissions performance and develop methods or correlations to normalize emissions performance. Another objective was to correlate and compare the performance of Canadian refineries to comparable American refineries. For the purpose of this study, benchmarking involved the determination of levels of emission performance that are being achieved for generic groups of facilities. A total of 20 facilities were included in the benchmarking analysis, and 74 American refinery emission correlations were developed. The recommended benchmarks, and the application of those correlations for comparison between Canadian and American refinery performance, were discussed. The benchmarks were: sulfur oxides, nitrogen oxides, ...
The Flory model is applied to predict the isobaric expansion coefficients, {alpha}{sub P}, isentropic, {kappa}{sub S}, and isothermal, {kappa}{sub T}, compressibilities and speeds of sound, u, of the highly complex mixtures: hydroxyether + alkane, + dibutylether, + 1-butanol or + 2-methoxyethanol, 1-alkanol + alkane, and 1-alkanol + dibutylether. Predictions were obtained using the energetic parameter, {chi}{sub 12}, determined from values of excess enthalpies, H{sup E}, and from values of the excess isochoric internal energies, U{sub V}{sup E}, at equimolar composition. No meaningful differences exist between such predictions. Deviations between experimental and calculated values are lower than 2% for mixtures containing alkoxyethanols. Poorer results are obtained for 1-alkanol + dibutylether mixtures with deviations up to 5%. It is shown that predictions on {alpha}{sub P}, {kappa}{sub S}, {kappa}{sub T}, and u essentially depend on structural ...
The Flory model is applied to predict the isobaric expansion coefficients, ?P, isentropic, ?S, and isothermal, ?T, compressibilities and speeds of sound, u, of the highly complex mixtures: hydroxyether + alkane, + dibutylether, + 1-butanol or + 2-methoxyethanol, 1-alkanol + alkane, and 1-alkanol + dibutylether. Predictions were obtained using the energetic parameter, ?12, determined from values of excess enthalpies, HE, and from values of the excess isochoric internal energies, UVE, at equimolar composition. No meaningful differences exist between such predictions. Deviations between experimental and calculated values are lower than 2% for mixtures containing alkoxyethanols. Poorer results are obtained for 1-alkanol + dibutylether mixtures with deviations up to 5%. It is shown that predictions on ?P, ?S, ?T, and u essentially depend on structural effects and not on the orientational effects present in the studied mixtures. Results are improved ...
We demonstrate that the excess vacancies induced by a 1 MeV Si implant reduce the excess interstitials generated by a 40 keV Si implant during thermal annealing when these two implants are superimposed in silicon. It is shown that this previously observed reduction is dominated by vacancy annihilation and not by gettering to deeper interstitial-type extended defects. Interstitial supersaturations were measured using B doping superlattices (DSL) grown on a silicon-on-insulator (SOI) substrate. Implanting MeV and keV Si ions into the B DSL/SOI structure eliminated the B transient enhanced diffusion normally associated with the keV implant. The buried SiO{sub 2} layer in the SOI substrate isolates the deep interstitials-type extended defects of the MeV implant, thereby eliminating the possibility that these defects getter the interstitial excess induced by the keV Si implant. {copyright} {ital 1999 American Institute of ...
We demonstrate that the excess vacancies induced by a 1 MeV Si implant reduce the excess interstitials generated by a 40 keV Si implant during thermal annealing when these two implants are superimposed in silicon. It is shown that this previously observed reduction is dominated by vacancy annihilation and not by gettering to deeper interstitial-type extended defects. Interstitial supersaturations were measured using B doping superlattices (DSL) grown on a silicon-on-insulator (SOI) substrate. Implanting MeV and keV Si ions into the B DSL/SOI structure eliminated the B transient enhanced diffusion normally associated with the keV implant. The buried SiO_2 layer in the SOI substrate isolates the deep interstitials-type extended defects of the MeV implant, thereby eliminating the possibility that these defects getter the interstitial excess induced by the keV Si implant. copyright 1999 American Institute of Physics.
Ion implantation of Si (60 keV, 1{times}10{sup 14}/cm{sup 2}) has been used to introduce excess interstitials into silicon predoped with high background concentrations of B, which were varied between 1{times}10{sup 18} and 1{times}10{sup 19}/cm{sup 3}. Following post-implantation annealing at 740{degree}C for 15 min to allow agglomeration of the available interstitials into elongated {l_brace}311{r_brace} defects, the density of the agglomerated interstitials was determined by plan-view transmission electron microscopy observation of the defects. We report a significant reduction in the fraction of excess interstitials trapped in {l_brace}311{r_brace} defects as a function of boron concentration, up to nearly complete disappearance of the {l_brace}311{r_brace} defects at boron concentrations of 1{times}10{sup 19}/cm{sup 3}. The reduction of the excess interstitial concentration is interpreted in terms of boron-interstitial ...
Ion implantation of Si (60 keV, 1x10"1"4/cm"2) has been used to introduce excess interstitials into silicon predoped with high background concentrations of B, which were varied between 1x10"1"8 and 1x10"1"9/cm"3. Following post-implantation annealing at 740 degree C for 15 min to allow agglomeration of the available interstitials into elongated #left brace#311#right brace# defects, the density of the agglomerated interstitials was determined by plan-view transmission electron microscopy observation of the defects. We report a significant reduction in the fraction of excess interstitials trapped in #left brace#311#right brace# defects as a function of boron concentration, up to nearly complete disappearance of the #left brace#311#right brace# defects at boron concentrations of 1x10"1"9/cm"3. The reduction of the excess interstitial concentration is interpreted in terms of boron-interstitial clustering, and implications for ...
A prototype electron applicator system providing circular and rectangular fields for use in intraoperative electron beam therapy with a Varian Clinac 18 linear accelerator has been fabricated. The dosimetric properties of this system for a variety of electron-beam energies, applicator sizes, and x-ray collimator settings was documented. Significant findings include: (a) surface dose values are in excess of 90% for electron energies of 12 MeV and above; (b) for the 18-MeV beam, the deepest depth where the central axis dose is 90% of its maximum value is in excess of 50 mm for circular applicators whose diameters are in excess of 5 cm; and (c) the treatment time to deliver 1000 rads ''given dose'' (at a given dose rate of 300 MU/min) is on the order of 3--4 min. Cross-field behavior is acceptable for the intended application and x-ray contamination is less than 4% for any applicator/electron energy combination. A system for ...
Transient-enhanced diffusion (TED) during thermal annealing of ion-implanted B in Si is well established and attributed to the ion-induced, excess interstitials. On the other hand, the mechanism to account for TED of B in preamorphized (PA) Si remains unclear. Enhanced diffusion of the B persists in regrown layers even though the ion-induced interstitial defects responsible for TED in B{sup +}-only implanted Si are eliminated following regrowth. To test the hypothesis that TED in PA Si results from the {open_quotes}excess{close_quotes} interstitial-type defects below the amorphous-crystalline (a-c) interface, a buried PA layer has been recrystallized from the surface inward to the SiO{sub 2} interface of silicon-on-insulator material to eliminate all possible sources of excess interstitials. The effect on B diffusion and the role of the residual interstitial-type defects will be discussed. {copyright} {ital 1999 American ...
An analysis of the mortality of workers employed at the Commissariat a l'Energie Atomique (CEA) between 1946 and 1994 is presented. Standardized Mortality Ratios (SMR) are computed with reference to the French national population for the period 1968-1994. 51 286 workers are included in the study. 3 784 deaths occurred between 1968 and 1994. A healthy worker effect is observed for men (SMR=0.53 Cl{sub 90%}=[0.52; 0.55]) and for women (SMR=0.70 Cl{sub 90%}=[0.64; 0.76]). An excess is observed for male pleural cancers (SMR=1.54, Cl{sub 90%}=[1.03; 2.21]). An excess of breast cancer is observed among women, statistically significant for the 1980-1994 period (SMR=1.30, Cl{sub 90%}=[1.04; 1.61]). An excess is observed for malignant melanoma for both sexes (SMR=1.38, Cl{sub 90%}=[0.95; 1.96]), stronger for the 1990-1994 period (SMR=2.11, Cl{sub 90%}=[1.25; 3.34]). It diminishes with age. (orig.)
In this paper we consider the adsorption of argon on the surface of graphitized thermal carbon black and in slit pores at temperatures ranging from subcritical to supercritical conditions by the method of grand canonical Monte Carlo simulation. Attention is paid to the variation of the adsorbed density when the temperature crosses the critical point. The behavior of the adsorbed density versus pressure (bulk density) shows interesting behavior at temperatures in the vicinity of and those above the critical point and also at extremely high pressures. Isotherms at temperatures greater than the critical temperature exhibit a clear maximum, and near the critical temperature this maximum is a very sharp spike. Under the supercritical conditions and very high pressure the excess of adsorbed density decreases towards zero value for a graphite surface, while for slit pores negative excess density is possible at extremely high pressures. For imperfect ...
A survey of various mechanisms for particle emission in hydrodynamics is presented. First, in the case of sudden freeze out, the problem of negative contributions in the Cooper-Frye formula and ways out are presented. Then the separate chemical and thermal freeze out scenario is described and the necessity of its inclusion in a hydrodynamical code is discussed. Finally, we show how to formulate continuous particle emission in hydrodynamics and discuss extensively its consistency with data. We point out in various cases that the interpretation of data is quite influenced by the choice of the particle emission mechanism.
The production of and emission factors for the air-polluting matters sulfur dioxide, nitrogen oxides, carbon monoxide, hydrocarbons (esp. benz(a)pyrene), aldehyde and soot with regard to natural gas, excluding process furnaces, are dealt with. The comparison with other fuels indicates that only as to nitrogen oxides and carbon monoxide are emission factors equal in order of magnitude. As a summary measure of all air-polluting matters the emission index as proposed already in 1972 is applied. It shows emissions with single-room furnaces for heating oil EL to be six times as high as with natural gas; with black-coal briquettes the factor is at least 33, with wood chimneys about 200.
The Federal Republic of German (FRG) had uniquely strict emission legislation for particulates SO_2 and NO_X from fossil-fired power plants. The 13th Regulation to the Federal Emission Control Act required that by 1 July 1988 all large furnaces fired with solid or liquid fuels that would not be decommissioned by 1993 be retrofitted with SO_2 control technology. The emission limits are 15 per cent of the sulphur introduced with the fuel (400 mg/m"3 maximum) at thermal capacities above 300 MW. 1 ref., 9 figs, 15 bibliographies.
The emission of light charged particles from heavy fragments of uranium fission induced by 153-MeV protons is studied. The probability of their emission is 2.7 x 10{sup - 2} per fission event. It is found that these particles affect the distribution of angles of fragment divergence and the angular distribution of heavy fragments with respect to the primary-proton beam. Experimental results suggest that the preequilibrium emission of particles is correlated with fission. Two mechanisms of interaction between 153-MeV protons and uranium nuclei are considered. 13 refs., 10 figs., 1 tab.
The effect of atmospheric radioactive emissions from United Kingdom nuclear installations on acid deposition is assessed. Nitrogen oxide and ozone production resulting from and associated with discharges of airborne radioactivity, comparison with conventional emissions, and the direct effects of radioactive emissions on trees, are all discussed. (UK).
One requirement of a thermophotovoltaic (TPV) radiator is to efficiently emit photons at high temperatures to TPV cells for conversion to electric power. Because many candidate radiator materials with adequate structural properties display low emissivity, coatings or other surface modifications are required for enhancement of emissivity. Six plasma sprayed coatings and one textured surface demonstrated adequate thermal stability and emittance values of 0.8 or greater. Promising attributes of modified surfaces are identified.
This article, with 25 references, reviews the soil sources and sinks of carbon dioxide, methane, and nitrous oxide. The mitigation of greenhouse gas releases is discussed covering reduction of carbon dioxide emissions by a change in land use, the use of alternative waste disposal methods such as composting or recycling to reduce methane emissions, and management of nitrogen fertiliser applications to reduce nitrous oxide emissions. (Author)
Designing efficient policies for curbing greenhouse gas (GHG) emissions is of particular interest for todays policy makers, in view of global climate change threats. This paper analyses the options Switzerland has for curbing its CO{sub 2} emissions. Using MARKAL and MARKAL-NACRO models, it investigates, in particular effects of national and international carbon taxes. (author) 3 figs., 1 tab., 6 refs.
The report summarizes the results of a dioxin/furan emissions test of a secondary copper recovery cupola furnace equipped with an afterburner for hydrocarbon emissions control and two baghouses for particulate emissions control. The cupola furnace is used...
Greenhouse gas emissions from international maritime transport are exempt from liabilities under the Kyoto Protocol. Research into quantifying these emissions is ongoing, and influences policy proposals to reduce emissions. This paper presents a cargo-based analysis of fuel consumption and greenhouse gas emissions from New Zealand's international maritime transport of goods. Maritime transport moves 99.5% (by mass) of New Zealand's internationally traded products. It is estimated that 73% of visiting vessels' activity can be directly attributed to the movement of goods in and out of New Zealand. A cargo-based methodology was used to estimate that the international maritime transport of New Zealand's imports and exports consumed 2.5 million tonnes (Mt; 2.6 billion litres) of fuel during the year 2007, which generated 7.7 Mt of carbon dioxide (CO_2) emissions. Double-counting of ...
The method of life-cycle assessment (LCA) has been applied to cars with different power trains. As an example, the results for greenhouse gas (GHG) emissions are presented. They show possibilities and limits for the reduction of these emissions in the transportation sector by means of advanced technology. (author) 2 figs., 4 refs.
The method for calculating emissions to air has been revised, which has led to adjustments. Because of this, emissions in 1999 cannot yet be compared with previous years. Emissions in 1990 - 1998 are being recalculated now using the new method and are expected to be ready during 2001. Emissions to air of carbon dioxide (CO_2) in Sweden was 56.58 million tonnes in 1999, not including emissions from biofuels and international bunkers. The major sources of CO_2 emissions are the combustion of fossil fuels and the use of fuels for mobile sources. Total emissions to air of sulphur dioxide (SO_2) and nitrogen oxides (NO_x, counted as NO_2) in Sweden was 66 000 and 263 000 tonnes respectively in 1999. International bunkers are not included. The major source of SO_2 emissions is combustion of fossil fuels. Road traffic is the ...
The Baldwin Effect, a negative correlation between emission-line equivalent width and luminosity in active galactic nuclei, is still of interest as a diagnostic of accretion physics nearly thirty years after its discovery. This review examines recent developments in the study of correlations between line and continuum emission in AGNs, as measured both in ensembles and in individual sources.
In this letter, the effect of vacancies generated by preirradiated laser on dopant diffusion and activation in preamorphized silicon substrate has been studied. Laser-induced melting in silicon was used to generate excess vacancies near the maximum melt depth before silicon substrate amorphization and subsequent boron implantation. We demonstrate that by matching the preirradiated laser melt depth with the implant amorphize depth, it can effectively reduce the silicon self-interstitials released from the end-of-range defect band. The results show great suppression in boron transient enhanced diffusion and significant removal of end-of-range defects. This is attributed to the recombination of laser-generated excess vacancies with preamorphizing induced free silicon interstitials at the end-of-range region.
Abstract We present a study of the impact of different model groups in the detection of circumstellar debris discs. Almost all previous studies in this field have used kurucz (atlas9) model spectra to predict the stellar contribution to the flux at the wavelength of observation, thus determining the existence of a disc excess. Only recently have other model groups or families like marcs and nextgen (phoenix) become available to the same extent as atlas9. This study aims to determine whether the predicted stellar flux of a disc target can change with the choice of model family can a disc excess be present in the use of one model family whilst being absent from another. A simple comparison of kurucz model spectra with marcs and nextgen model spectra of identical stellar parameters was conduc...
Associated production of a baryonic Z' boson with the W boson can account for the excess in Wjj production observed by the CDF collaboration at the Tevatron. We analyze other possible channels of this Z' at the Tevatron and at the LHC, including \\gamma Z' and Z Z' with the Z' -> jj. We show that the chances of confirming this baryonic Z' is better at the Tevatron than at the LHC because of the faster growing backgrounds at the LHC. Unfortunately the current systematic uncertainties of the order of 10% cannot yield any significant excess in both \\gamma Z' and Z Z' channels at the Tevatron and also at the LHC. Nevertheless the search using the b\\bar b decay mode of Z' is much more feasible at the LHC, provided that the branching ratio B(Z' -> b\\bar b) > 0.1. In particular, the W Z' -> l \
Using gasoline as an example of additives for cold start improvement, fuel vapor composition of methanol-gasoline mixtures, fuel evaporation rate in consideration of temperature drop due to heat of fuel evaporation, air fuel ratio, stoichiometric air fuel ratio and excess air ratio of fuel vapor were calculated. The mixture formation of methanol-gasoline mixtures at low temperature in otto cycle engines was studied. Van Laar's empirical formula was used to estimate the partial pressure of high-percentage methanol blends. It was found that the most part of fuel vapor is occupied by gasoline, even when a small amount of gasoline is added to methanol resulting to an extremely small excess air ratio. It is obvious that this vapor pressure adjustment using gasoline is the dominant factor for improvement in cold startability. (10 figs, 1 tab, 10 refs)
This paper studies the analytical application of europium (III)-morin complex which is formed in alkaline medium and has an intense color. The extent of europium extraction was determined by adding to the extract a morin solution in isoamyl alcohol in a 50-100-fold excess with respect to europium. The dependence of the optical density of the extracts on the ph in the system europium (III)-morin-water-organic solvent for different excesses of the reagent is shown: this indicates formation of two extractable complexes, one being dominant in the pH range 4-7, the other at pH greater than or equal to 8.5. The extraction of the europium (III)-morin complex from alkaline solution is used for direct extraction-photometric determination of europium(III) in compounds of elements having amphoteric properties or forming amines (Zns, Mo0/sub 3/).
Several experimental runs have been carried out to study nucleate boiling of binary mixtures consisting of Freon-11 and lube oils such as SUNISO 3GS and 4GS in oil concentrations ranging from 0 to 24% by volume. The effect of the heating source temperature on the rate of boiling at various pressures has been studied and the boiling curves at different oil concentrations and pressures have been investigated at an excess temperature of up to 80/sup 0/C. The experimental data have been used to find the effect of pressure, oil concentration and excess temperature on the boiling heat transfer coefficient. The P-T relations for both kinds of mixtures have been measured at different oil concentrations. The heat lost to the atmosphere have also been studied as a function of oil concentration for both kinds of mixtures.
Low-porosity #alpha#- and #beta#-SiAlON composite material was prepared when the powder mixture intended for preparation of yttrium #alpha#-SiAlON, with the formula Y_0_._4Si_1_2_-_m_+_nAl_m_+_nO_nN_1_6_- _n, was attritor milled in isopropyl alcohol or contained excess oxygen (n > 0.6). The region of stability of single-phase yttrium #alpha#-SiAlON was smaller at lower temperatures. Wet milling (in isopropyl alcohol) of AlN powder was found to introduce excess oxygen into the milled powder.
Purpose: To stably control the reactor water level so as not to cause excess water feeding in a BWR type reactor. Constitution: A flow control valve is disposed to the exit of a feedwater pump for a nuclear reactor and the valve is controlled by a flow regulator to maintain the water level constant in the reactor. A signal from a water level controller is inputted to the flow regulator to thereby control the flow rate control valve. In this case, the flow regulator remains in a saturated state just after the starting of the feedwater pump, in which the pump flowrate is at 100% to result in an excess water feeding condition. In view of the above, a feedback circuit is provided to the flow regulator so that the saturated state is eliminated and the water feeding can be controlled directly from the water level controller. (Kamimura, M.).
The production of the {lambda}- and {sigma}{sup 0}-hyperons has been measured via the pp{yields}pK{sup +}{lambda}/{sigma}{sup 0} reaction at the internal COSY-11 facility in the excess energy range between 14 and 60 MeV. The transition of the {lambda}/{sigma}{sup 0} cross-section ratio from about 28 at Q{<=}13 MeV to the high-energy level of about 2.5 is covered by the data showing a strong decrease of the ratio between 10 and 20 MeV excess energy. Effects from the final-state interactions in the p-{sigma}{sup 0} channel seem to be much smaller than in the p-{lambda} channel. Estimates of the effective range parameters are given for the N{lambda} and the N{sigma} systems. (orig.)
The thermal stability and deformability of Mn-Al-C alloys containing 0.6 pct C are investigated experimentally as a function of excess phase content. It is shown that an increase in Mn content from 68.9 to 73.5 pct leads to increased stability of the high-temperature epsilon phase. The enrichment of the system Mn-Al-Cu in Mn and Al above the optimum composition leads to the formation of nonmagnetic excess phases, eta and beta, which reduce the magnetization of the alloy. In addition, a decrease in thermal stability is observed in the alloy with 73.5 pct Mn due to the decomposition of the ferromagnetic phase. 7 references.
This paper examines cupric chloride solid conversion during hydrolysis in a thermochemical copper-chlorine (Cu-Cl) cycle for hydrogen production. The hydrolysis reaction is a challenging step, in terms of the excess steam requirement and the decomposition of cupric chloride (CuCl_2) into cuprous chloride (CuCl) and chlorine (Cl_2). The hydrolysis and decomposition reactions are analyzed with respect to the chemical equilibrium constant. The effects of operating parameters are examined, including the temperature, pressure, excess steam and equilibrium conversion. A maximization of yield and selectivity are very important. Rate constants for the simultaneous reaction steps are determined using a uniform reaction model. A shrinking core model is used to determine the rate coefficients and predict the solid conversion time, with diffusional and reaction control. These new results are useful for scale-up of the engineering equipment in the ...
Excessive physical activity plays an important role in the progression of anorexia nervosa (AN) by accelerating weight loss during dietary restriction. To search for mechanisms underlying this trait, a panel of mouse chromosome substitution strains derived from C57BL/6J and A/J strains was exposed to a scheduled feeding paradigm and to voluntary running wheel (RW) access. Here, we showed that A/J chromosomes 4, 12 and 13 contribute to the development of a disrupted RW activity in response to daily restricted feeding. This pattern is characterized by intense RW activity during the habitual rest phase and leads to accelerated body weight loss. Regions on mouse chromosomes 4, 12 and 13 display homology with regions on human chromosomes linked with anxiety and obsessionality in AN cohorts. The...
Deep level effects in GaAs MOSFET have been characterised in the ohmic channel using DLTS, low frequency excess noise and dispersion technique. An isothermal multi exponential curve fitting method has been devised and implanted into the DLTS system. Multi exponential curve fitting method used to decompose a multi exponential transient into its constituents so that the peak signature can be better characterised for the case whereas several peaks are closely spaced. Low frequency excess noise and dispersion techniques also confirm the trap in signature of the same traps observed in the DLTS measurements. (author)
We have investigated the effect of plasma nitriding and plasma nitrocarburizing on the microstructure and properties of electroplated chromium. Plasma nitriding and plasma nitrocarburizing are applied to 15-100 [mu]m thick electroplated hard chromium coatings to increase both the wear and the corrosion resistance. The properties of the plasma-modified hard chromium layers are characterized by measuring the wear resistance with a Taber wear tester and the corrosion resistance with a salt spray fog test. Cyclic voltammetry is performed in a standard electrochemical cell using a 0.5 M H[sub 2]SO[sub 4] solution acidified to pH 0.3. The compound layer after plasma nitriding consists of CrN and Cr[sub 2]N with a maximum hardness of about 1100 HK[sub 0.01]. After plasma nitrocarburizing, Cr[sub 3]C[sub 2] and Cr[sub 7]C[sub 3] are formed. After plasma nitrocarburizing, the maximum hardness is increased up to ...
In the present thesis I discuss the hard spectator interaction amplitude in B {yields} {pi}{pi} at NLO i.e. at O({alpha}{sup 2}{sub s}). This special part of the amplitude, whose LO starts at O({alpha}{sub s}), is defined in the framework of QCD factorization. QCD factorization allows to separate the short- and the long-distance physics in leading power in an expansion in {lambda}{sub QCD}/m{sub b}, where the short-distance physics can be calculated in a perturbative expansion in {alpha}{sub s}. Compared to other parts of the amplitude hard spectator interactions are formally enhanced by the hard collinear scale {radical}({lambda}{sub QCD}m{sub b}), which occurs next to the mb-scale and leads to an enhancement of {alpha}{sub s}. From a technical point of view the main challenges of this calculation are due to the fact that we have to deal with Feynman integrals that come with up to five external legs and with three ...
Diamond-like carbon thin films for tribological applications were deposited by d.c.-magnetron sputtering of a graphite target in a pure argon atmosphere or in a reactive hydrogen or methane atmosphere at pressures between 0.1 and 1 Pa in a graded constitution to improve adhesion and reduce residual stress. The temperature of the metallic, carbon- and ceramic-like substrates was below 100 C. The mechanical, thermal, electronic and optical properties of the carbon thin films show a significant dependence on the ion energy. Below 220 eV, strongly adherent black conductive films with hardness values up to 2000 HV0.05 were obtained. Hard and superhard diamond-like carbon thin films were deposited in an energy range between 220 and 370 eV with hardness values up to 4000 HV0.05. They are insulating, optically transparent and show a high degree of hardness combined with high compressive stress in the order of 4 ...
Over the past 40 years, cavern storage of LPG's, petrochemicals, such as ethylene and propylene, and other petroleum products has increased dramatically. In 1991, the Gas Processors Association (GPA) lists the total U.S. underground storage capacity for LPG's and related products of approximately 519 million barrels (82.5 million cubic meters) in 1,122 separate caverns. Of this total, 70 are hard rock caverns and the remaining 1,052 are caverns in salt deposits. However, along the eastern seaboard of the U.S. and the Pacific northwest, salt deposits are not available and therefore, storage in hard rocks is required. Limited demand and high cost has prevented the construction of hard rock caverns in this country for a number of years. The storage of natural gas in mined caverns may prove technically feasible if the geology of the targeted market area is suitable; and economically feasible if the cost and ...
This report presents estimates of the annual anthropogenic UK emissions of greenhouse gases for the years 1990-93 for submission under the Framework Convention on Climate Change. The gases considered are carbon dioxide, methane, nitrous oxide, nitrogen oxides, carbon monoxide and non-methane volatile organic compounds. Emissions of all the gases have declined since 1990. In particular, those of carbon dioxide have fallen by 4%; those of methane by 8% and those of nitrous oxide by 28%. Emission estimates are reported in the IPCC Standard Tables format disaggregated by source category and fuel. The methodology used for the estimates and how they relate to the UK National Atmospheric Emissions Inventory is discussed in an appendix. (author)
Fugitive dust emissions from stockpiles in the open storage yards of industrial zones and the subsequent atmospheric dust dispersion have brought about many ecological and economical problems. This paper introduces a new approach to reduce pollutant emissions by simply changing pile configuration and without affecting the operational activity on these parks. Flow around piles of different geometries and for various wind conditions was studied using previously validated Computational Fluid Dynamic (CFD) simulations. Different pile height scenarios were investigated corresponding to a constant material volume and a fixed angle of repose under various wind magnitudes. The results obtained were integrated in order to evaluate the rate of dust emissions for the various configurations considered. It was found that, for the range of wind conditions and pile dimensions tested, an optimal geometry exists which corresponds to the ...
The document presents an overview on atmospheric pollution in Lebanon, with an analysis of sources of pollution, their impact on local and global environment and their control.Local causes of pollution are mainly: -Thermal power plants of electric power production which produce 75% SO_2 emission and 60% dust - Industries, especially cement industry - Land transportation which produces 70% NOX emission and 50% CO_2 A description of air pollution caused by these three sectors is revealed. Pollutants derived from fuel combustion are analyzed. It is estimated that in 2010, Co_2 emission will reach 5204450 tons, SO_2 emission will be 136470 tons, NOX emissions 96870 and dust estimated to 4130 tons. CFC consumption and measures of control according to Montreal Protocol are described. Recommendations for control of air pollution in Lebanon within a national policy are presented.
The production of atmospheric pollutants in combustion processes depends on plant characteristic, combustion conditions and fuel quality. The influence of fuel quality on the emission of sulphur oxides, nitrogen oxides, carbon monoxide, dust and carbon dioxide and on the emission of some toxic pollutants, such as heavy metals and polycyclic aromatic hydrocarbons, is analysed. The comparison between the emission limits, fixed by the Italian legislation, and the uncontrolled pollutant emissions, produced by fossil fuel combustion in power plants and industrial use, shows that, in order to comply with the limits, a reduction of pollutant emissions is required through the use of abatement systems and cleaner fuels where natural gas has a primary role. The use of cleaner fuels is particularly required in heating plants and appliances for the residential sector, where the development of ...
This patent describes a low emission duel fuel engine system. It comprises: a dual fuel engine having a combustion chamber; a fuel oil supply connected to the engine; a fuel gas supply connected to the engine; and means connected between the fuel oil supply and the engine for injecting fuel oil into the engine. The means connected between the engine and fuel oil supply limiting the injection of fuel oil to the combustion chamber to pilot ignition quantities only, wherein the limiting means includes means for limiting the injection of fuel oil such that the exhaust emission of NO{sub x} is at an emission rate of less than 1 GM/PH-HR, whereby the exhaust emission performance of the dual fuel engine is enhanced.
The formaldehyde surface emission monitor (FSEM) has been developed for passive non-destructive measurement of formaldehyde (CH/sub 2/O) emission rates from CH/sub 2/O resin-containing materials. It is envisaged as a potential quality control and in-situ monitoring technique. For quality control applications to pressed-wood products, strong correlations between the results of the FSEM and environmentally controlled (small scale) chamber tests were observed. The FSEM is used to measure the cumulative CH/sub 2/O emission from a finite area of pressed-wood product during a fixed test period. The final result is reported as an average CH/sub 2/O emission rate (mg CH/sub 2/O/m/sup 2/h).
Investigations were conducted on the range of emission rates of NO, NO[sub 2], CO and hydrocarbons, and the thermal efficiencies produced by each burner on three production cookers, supplied by different Australian manufacturers. It was found that the emissions and efficiencies were markedly affected by (1) the thermal input, both with and without a load on the burner, and (2) the load-height to flame-length ratio, with a load on the burner. The effect of hydrocarbon leakage into the secondary/dilution air was investigated, to explain the observed correlation of hydrocarbon emission rate with dilution air flow. The hydrocarbons were found to arise from two sources: -leakage from the stabilisation ports at the base of the burner, which was found to be significant at the higher thermal input; -incomplete combustion of the fuel in the premix, which was the dominant source of hydrocarbons emissions at the ...
Sintered glass-ceramics were produced from coal fly ashes, red mud from aluminum production and silica fume. The capabilities of Tuncbilek fly ash and a mixture of Orhaneli fly ash, red mud and silica fume to be vitrified and devitrified by sintering process were investigated by means of scanning electron microscopy and X-ray diffraction analysis. To determine the effect of binder in the sintering technique, glass powders were pressed without or with the addition of polyvinyl alcohol. Owing to microstructural observations, density and hardness measurements, it can be said that physical properties and the hardness of the produced samples strongly depended on the crystallization degree of the samples. Toxicity characteristic leaching procedure test results showed that glass-ceramic samples produced by using sintering technique could be considered as nonhazardous materials. Chemical durability of the sintered glass-ceramic samples was also good. ...
Hard X-ray/gamma-ray spectrometers aboard two interplanetary spacecraft, Ulysses and Pioneer Venus Orbiter (PVO), and two near-Earth spacecraft, Yohkoh and Compton Gamma Ray Observatory (GRO/BATSE), are currently in operation. A unique set of circumstances have permitted the observation of the 15 November 1991 (2238 UT) flare by all the four instruments. This intense flare (GOES class X 1.5) was associated with the bright (3B) H-alpha flare located on the disk (S13, W19) in the active region 6919. At the time of the flare, the Ulysses and PVO spacecraft were located respectively 101[degree] and 52[degree] west of the Sun-Earth line. Thus the view angles for the PVO and Ulysses instruments were quite different from those of the near-Earth instruments on GRO and Yohkoh. The preliminary photon energy spectra observed by the four instruments at different times during the flare will be presented and their implications regarding the directivity of ...
Total-dose irradiation seriously damages MOS devices and their circuit performance. Threshold voltage shifts, transconductance degradation and increase in off-state leakage current are generally observed for irradiated devices. These instabilities are essentially due to positive and/or negative charge trapping in SiO_2 and interface trap generation at the SiO_2/Si interface. Radiation hardening of CMOS VLSIs is to eliminate these trapping effects, and for this purpose, special considerations for fabrication processes and layout design are necessary. In this paper, basic mechanisms for radiation-induced charge trapping and related effects on MOS devices are reviewed. Also discussed are radiation-hardening technologies from both fabrication-process and layout-design viewpoints. Using these technologies, 1 #mu#m radiation-hard CMOS gate arrays have been successfully developed. Experimental data taken for 2k-gate test chips indicate that radiation ...
A systematic study was made on MoSi{sub 2}-based nanolayer coatings. Alternating layers with thickness 1-20 nm were prepared by sputtering. Nitrided MoSi{sub 2} has a very high crystallization temperature, >1000 C, and MoSi{sub 2}Nx (x=3-4) can be used as a stable second phase reinforcement or diffusion barrier coatings. Mechanical properties depend strongly on phase and morphology of the layers: hardness and modulus is significantly increased in the crystallization. The nanolayers have much higher hardness but lower modulus (which project higher toughness in the nanolayers). Wear resistance is improved with decreasing layer thickness. Single phase MoSi{sub 2}Nx (x=0-4.2) has a wide range of hardness and modulus with varying N content and annealing, suggesting the possibility of engineering MoSi{sub 2}Nx to produce different material properties for different mechanical applications. Most of this paper is made up of ...
Direct current (DC) glow discharge plasma nitriding was carried out on three selected surface-roughened AISI 304 stainless steel samples at 833 K under 4 mbar pressures for 24 h in the presence of N{sub 2}:H{sub 2} gas mixtures of 50 : 50 ratios. After plasma nitriding, the phase formation, case depth, surface roughness, and microhardness of a plasma-nitrided layer were evaluated by glancing angle x-ray diffractogram, optical microscope, stylus profilometer, and Vickers microhardness tester techniques. The case depth, surface hardness, and phase formation variations were observed with a variation in initial surface roughness. The diffraction patterns of the plasma-nitrided samples showed the modified intensities of the {alpha} and {gamma} phases along with those of the CrN, Fe{sub 4}N, and Fe{sub 3}N phases. Hardness and case depth variations were observed with a variation in surface roughness. A maximum hardness of 1058 Hv ...
An experimental evaluation of the Fano factor F in silicon at hard X-ray energies (5.9-136.5 keV) has been performed by means of a low-noise, high charge collection efficiency silicon drift detector with on-chip electronics. A dependence of F from the detector temperature as well as from the energy of the X-ray photons has been found. Assuming a pair creation energy equal to 3.64 eV, at +20 deg. C the F factor was observed to vary from 0.124{+-}0.006 at 5.9 keV up to 0.159{+-}0.002 at 122 keV. At -35 deg. C, the change of F with respect to the photon energy was less remarkable but nevertheless statistically significant, from 0.123{+-}0.002 at 5.9 keV up to 0.134{+-}0.001 at 122 keV. To our knowledge, the present results represent the first experimental evidence of an energy dependence of the Fano factor in silicon at hard X-ray energies.
This paper presents the first results on formation and study of structure and properties of micro- and nanocomposite combined coatings. By means of modeling the deposition processes (deposition conditions, current density-discharge, plasma composition and density, voltage) we formed the three-layer nanocomposite coatings of Ti-Al-N/Ti-N/Al_2O_3. The coating composition, structure and properties were studied using physical and nuclear-physical methods. The Rutherford proton and helium ion backscattering, scanning electron microscopy with microanalysis, grazing incidence X-ray diffraction, as well as nanohardness tests (hardness) were used. Measurements of wear resistance and corrosion resistance in NaCl, HCl and H_2SO_4 solutions were also performed. For testing mechanical properties such characteristics of layered structures as hardness H, elastic modulus E: H"3/E"2 etc. were measured. It is demonstrated that the formed three-layer ...
The plastic displacements around Knoop indentations made in hard titanium/aluminum multilayered films on soft aluminum alloy substrates have been studied. Indentations were cross-sectioned and imaged using the focused-ion-beam (FIB) milling and high-resolution scanning electron microscopy (SEM), respectively. The FIB milling method has the advantage of removing material in a localized region without producing mechanical damage to the specimen. The micrographs of the cross-sectioned indentations indicate that most of the plastic deformation around the indentation is dominated by the soft aluminum substrate. There is a very small change in the multilayered film thickness around the indentation{emdash}less than 10{percent}. The plastic deformation of the thin film resembles a membrane being deflected by a localized pressure gradient across the membrane. Stress-induced voids are also observed in the multilayered film, especially in the area around the indentation apex. ...
Al{sub x}Ga{sub 1{minus}x}P layers (0 {le} x {le} 0.7), with thicknesses of {ge}1 {micro}m were grown on Si (100) wafers by metal-organic molecular beam epitaxy (MOMBE) at 450 C. Transmission electron micrographs of the single crystal films revealed that the microstructure contains stacking faults and microtwins especially near the interface as well as both threading and misfit dislocations. Hardness and elastic modulus were measured using a Nanotest 500 indenter, which can probe the film properties without influence from the substrate. The hardness H varies linearly according to (11.8 {minus} 2.3x) GPa. The absence of alloy hardening is due to the fact that there is no difference in atomic size of Al and Ga. The indentation modulus E/(1{minus}v{sup 2}) decreases monotonically from 136 GPa for GaP to 129 GPa for Al{sub 0.7}Ga{sub 0.3}P and bows only slightly (about 2%) below the straight line of linear interpolation.
The effects of key metallurgical variables on the low fluence hardening in a set of A533B model steels were evaluated over a wide range of irradiation temperatures. Above about 163 degrees C hardening increased with higher copper and nickel contents, as is typical of the pressure vessel operating regime around 290 degrees C. However, at 121 degrees C the hardening was generally lower and unaffected by copper and nickel variations. This observation of decreased hardening with lower temperature (e.g. an open-quotes invertedclose quotes temperature dependence) is tentatively attributed to a reduced contribution of copper precipitation. Tensile data for a set of commercial steels with a range of (uncontrolled) compositions also showed minimal sensitivity to copper variations at 121 degrees C. Unlike the hardness data no systematic reductions in the yield stress increases were observed between 163 and 121 degrees C. However, the ultimate tensile strength did decrease at ...
A wear-resistant nitrided layer was formed on a 304L austenitic stainless steel substrate by DC plasma nitriding. Effects of DC plasma nitriding parameters on the structural phases, micro-hardness and dry-sliding wear behavior of the nitrided layer were investigated by optical microscopy, X-ray diffraction, scanning electron microscopy, micro-hardness testing and ring-on-block wear testing. The results show that the highest surface hardness over a case depth of about 10 #mu#m is obtained after nitriding at 460 deg. C. XRD indicated a single expanded austenite phase and a single CrN nitride phase were formed at 350 deg. C and 480 deg. C, respectively. In addition, the S-phase layers formed on the samples provided the best dry-sliding wear resistance under the ring-on-block contact configuration test.
In this work, an attempt was made to develop a novel type of wear-resistant composite employing a TiNi alloy matrix reinforced by hard particles. Titanium carbide was chosen as the reinforcing phase because of its high hardness and TiNi alloy as the matrix due to its pseudoelasticity and good toughness. TiC particles may sustain external load, while the TiNi matrix may accommodate deformation, absorb impact energy and retain the hard particles. Such a combination is expected to lead to an enhanced wear resistance, compared to TiNi alloy. As a matter of fact, some efforts were previously made to develop TiNi-matrix composite reinforced by ceramic particles. However, the emphasis of those studies was put on effects of the reinforcing particles on the phase transformation behavior, shape memory effect and some mechanical properties of the composite; no attempt was made to explore the potential benefit of the material for wear ...
TNF-doped Mylar is a new radiation-hard dielectric that has recently been qualified as a viable substitute for Mylar in capacitors. The advantage of TNF-doped Mylar is that it satisfies both the nuclear safety and radiation hardness requirements of weapons. Mylar is not radiation-hard. Aging and compatibility studies were carried out to insure that (1) TNF does not diffuse from the film during fabrication of the capacitor or during storage; and (2) there are no compatibility problems with aluminum foil (the conductor) or Fluorinert (the secondary dielectric). Losses of TNF were barely detectable during the vacuum bakes used in fabricating capacitors or during accelerated aging tests carried out below T{sub g} (70C) over a two year period in air. In other accelerated tests, no compatibility problems were detected with aluminum or Fluorinert. TNF-doped Mylar is now being used in the MC-4109 capacitor that was called out for ...
This report documents radionuclide air emission from the Hanford Site in 1997, and the resulting effective dose equivalent to the maximally exposed member of the public, referred to as the MEI. The report has been prepared in accordance with reporting requirements in the Code of Federal Regulations, Title 40, Protection of the Environment, Part 61, National Emissions Standards for Hazardous Air Pollutants, Subpart H, National Emission Standards for Emissions of Radionuclides Other than Radon from Department of Energy Facilities. This report has also been prepared in accordance with the reporting requirements of the Washington Administrative Code Chapter 246-247, Radiation Protection-Air Emissions. The effective dose equivalent to the MEI from the Hanford Site`s 1997 point source emissions was 1.2 E-03 mrem (1.2 E-05 mSv), which is well below the 40 CFR 61 ...
Using a sample of 30,000 quasars from SDSS-DR7, we explore the range of properties exhibited by high-ionization, broad emission lines, such as CIV 1549. Specifically we investigate the anti-correlation between L_UV and emission line EQW (the Baldwin Effect) and the "blueshifting" of high-ionization emission lines. The blueshift of the CIV emission line is nearly ubiquitous, with a mean shift of 810 km/s for radio-quiet (RQ) quasars and 360 km/s for radio-loud (RL) quasars, and the Baldwin Effect is present in both RQ and RL samples. Composite spectra are constructed as a function of CIV emission line properties in attempt to reveal empirical relationships between different line species and the SED. Within a two-component disk+wind model of the broad emission line region (BELR), where the wind filters the continuum seen by the disk component, we find that RL ...
Activities of the Referenzlaboratorium Reinhaltung der Luft at Magdeburg as well as existing air pollution standards in the German Democratic Republic are reviewed. The laboratroy coordinates research and standardization in the field of industrial air pollution for the Ministry of Health. The standards provide orientation for emission control by state district health inspectorates. Emission limits (in g/m/sup 3/) which are international standards for 15 selected industries are listed. Emission limits (in g/m/sup 3/) of GDR standards, issued between 1971 and 1984 are also provided. They concern emission of brown coal dust from coal preparation plants, dust and chemical compound emission from metallurgical plants, dust emission from plants of the limestone and cement industry as well as from cupola furnace plants, boiler plants, plants of the wood industry and ...
Magnetically driven non-stationary acceleration of jets in active galactic nuclei results in the leading parts of the flow being accelerated to much higher Lorentz factors than in the case of steady-state acceleration with the same parameters. The higher Doppler-boosted parts of the flow may dominate the high-energy emission of blazar jets. We suggest that highly variable GeV and TeV emission in blazars is produced by the faster moving leading edges of highly magnetized non-stationary ejection blobs, while the radio data trace the slower-moving bulk flow. Thus, the radio and gamma-ray emission regions have different, but correlated, Doppler factors. High-energy emission is generated, typically within the optically thick core, in the outer parts of the broad-line emission region, avoiding the radiative drag on the faster parts of the flow. The radio emission ...
This guide explained the requirements for Off-Road Compression Ignition Engine Emission Regulations established under the Canadian Environmental Protection Act. The regulations are enforced by Environment Canada, which authorizes and monitors the use of the national emissions mark. The regulations prescribe standards for off-road engines that operate as reciprocating, internal combustion engines, other than those that operate under characteristics similar to the Otto combustion cycle and that use a spark plug or other sparking device. The regulations apply to engines that are typically diesel-fuelled and found in construction, mining, farming and forestry machines such as tractors, excavators and log skidders. Four different types of persons are potentially affected by the regulations: Canadian engine manufacturers; distributors of Canadian engines or machines containing Canadian engines; importers of engines or machines for the purpose of ...
This guide explained the requirements for Off-Road Compression Ignition Engine Emission Regulations established under the Canadian Environmental Protection Act. The regulations are enforced by Environment Canada, which authorizes and monitors the use of the national emissions mark. The regulations prescribe standards for off-road engines that operate as reciprocating, internal combustion engines, other than those that operate under characteristics similar to the Otto combustion cycle and that use a spark plug or other sparking device. The regulations apply to engines that are typically diesel-fuelled and found in construction, mining, farming and forestry machines such as tractors, excavators and log skidders. Four different types of persons are potentially affected by the regulations: Canadian engine manufacturers; distributors of Canadian engines or machines containing Canadian engines; importers of engines or machines for the purpose of ...
This paper describes the development and a detailed analysis carried out on the luminescence characteristics of Pr"3"+ doped ZrF_4-BaF_2-LaF_3-YF_3-AlF_3-NaF glasses. In the present work our objectives are to elucidate the possible mechanisms that are responsible for NIR to red upconversion process and yellow to blue upconversion emission in terms of energy level schemes from the praseodymium containing fibre optical glass composition. We have studied their different physical and optical properties. Besides our investigation on the upconversion emission of these glasses, normal fluorescence studies have also been undertaken in explaining the mechanisms in demonstrating bright red and blue emissions upon excitations at visible and UV wavelengths. Besides these measurements works, a bright blue colour emission was observed under an UV source (202 nm) and upconverted prominent red ...
Measurements of ion-induced electron emission have been performed with helium and argon ions with energies between 300 and 900 eV on W, W with 10% Ti, Al, Al with 1% Cu, Al with 1% Si, Si, and Be. This article describes many of the important surface characteristics that influence the ion-induced electron emission. For low-energy ions, the substrate material was found to be less important as the velocity of the incident ion decreased. In the case of incident Ar"+ the substrate material had a negligible effect on the emission for this energy range. The presence of an adsorbed layer enhanced emission in all cases. Heating the substrates resulted in oxidation of the surfaces and a subsequent increase in emission. The electron emission from aluminum samples with smaller grain sizes was higher than samples of identical composition with larger grains. This effect is ...
With regard to polybrominated diphenyl ether (PBDE), there is few scientific knowledge on the emission patterns into the environment and exposure pathways to humans, and basic information is insufficient to consider what measures effective are. For the purpose of promoting risk reduction of target substances more effectively and efficiently, it is desirable to comprehend accurately the causal chain from the target substances utilization to the risk intake, and to evaluate the measures covering the whole applications of target substances. As the existing researches on the PBDE emission inventory, there are EU risk assessment report (European Chemical Bureau 2000, 2002, 2003), Danish EPA (1999), Palm et al.(2002) and Alcock et al. (2003). In addition, emissions of DecaBDE are published in TRI (Toxic Release Inventory) of US EPA. However, the primary information of the previous inventories is often the same and estimations ...
The increasing diffusion of small-scale energy systems within the distributed generation (DG) paradigm is raising the need for studying the environmental impact due to the different DG solutions in order to assess their sustainability. Addressing the environmental impact calls for building specific models for studying both local and global emissions. In this framework, the adoption of natural gas-fueled DG cogeneration technologies may provide, as a consequence of cogeneration enhanced overall energy efficiency and of natural gas relatively low carbon content, a significant reduction of global impact in terms of CO2 emissions with respect to the separate production of electricity and heat. However, a comprehensive evaluation of the DG alternatives should take into account as well the impact due to the presence of plants spread over the territory that could increase the local pollution, in particular due to CO and NOx, and thus could worsen the ...
This study tried to reduce NO{sub x} and particulate emissions simultaneously in a high speed direct-injection diesel engine. Fuel-rich combustion was used to reduce NO{sub x} emission at initial combustion stage and high turbulence combustion was used to reduce particulate emission at diffusion combustion stage. Experiments were carried out to investigate the effects of high squish combustion chambers with small throat on combustion process and exhaust emissions. Results showed that in the high squish combustion chamber, both NO{sub x} and particulate emissions reduced with retarded injection timing. Endoscopic high speed photography was employed to analyze experimental results. In the original combustion chamber at the early combustion stage, the high luminosity flame tended to spread out of the cavity. Fuel-rich mixture burned slowly over the piston crown. In the high squish ...
Heavy-duty trucks and buses are substantial contributors to the atmospheric oxides of nitrogen (NO_x) inventory, but prediction of their emissions in real use remains inchoate. Continuous emissions of NO_x were recorded from Chassis dynamometer testing of eight vehicles using a variety of transient cycles, including the Central Business District schedule. NO_x data were treated to account for sampling time lag and presented against instantaneous vehicle axle power. Data were repeatable from run to run and test schedule, but vehicle type and test cycle both influenced the instantaneous emissions rates. However, the resulting correlations may be used for mobile source NO_x contribution estimation when combined with vehicle activity data. The emissions data were also presented as NO_x/CO_2, which are valuable for comparison with remote sensing emissions data. The overall average ratio ...
The effect of severe plastic deformation by cold high pressure torsion (HPT) on radio frequency (RF) plasma nitriding of pure iron, as well as St2K50 and X5CrNi1810 steels was investigated. Nitriding was carried out for 3 h in a nitrogen atmosphere at a pressure of 10{sup -5} bar and temperatures of 350 and 400 deg. C. Nitrided specimens were analysed by scanning electron microscopy (SEM), X-ray diffraction and micro hardness measurements. It was found that HPT enhances the effect of nitriding leading almost to doubling of the thickness of the nitrided layer for pure iron and the high alloyed steel. The largest increase in hardness was observed when HPT was combined with RF plasma nitriding at 350 deg. C. In the case of pure iron, the X-ray diffraction spectra showed the formation of {epsilon} and {gamma}' nitrides in the compound layer, with a preferential formation of {gamma}' at the expense of the {alpha}-phase at the ...
Thin films of new metastable materials from the system Ti-B-C-N were deposited on metallic substrates by d.c. magnetron sputtering in different Ar+N{sub 2} atmospheres. The multiphase compound targets used were based on various compositions on the TiC-TiB{sub 2} and TiB{sub 2}-C tie lines of the Ti-B-C phase diagram. The structure and chemical composition of the films were characterized by electron microprobe analysis, depth profiling Auger electron spectroscopy, X-ray diffraction and transmission electron microscopy. The hardness, critical load of failure and the tribological behavior of the coatings were investigated. Superhard single-phase crystalline metastable Ti-B-C-N layers with hardness values exceeding 5000 HV{sub 0.05} and extremely low sliding wear against 100Cr6 and Al{sub 2}O{sub 3} counterparts could be produced by reactive sputtering of various TiC-TiB{sub 2} targets in Ar+N{sub 2} atmospheres with low nitrogen flows. In the case ...
The influences of temperature and duration of tempering on hardness and microstructure were investigated at high-temperature martensitic and low-carbon steels with 9% chrome and the further alloying elements molybdenium, vanadium, niobium and partially tungsten. After austenitizing and subsequent air cooling the steels were tempered at temperatures below, at and above Ac{sub 1b} for different times and finally a hardness test was performed. Making use of the temperature dependence of the hardness tempering diagrams were constructed and the Hollomon-Jaffe-Parameter on the three steels was determined within its application limits. Micrographs of the structure shows the formation of the carbides and the martensite. At tempering temperatures below Ac{sub 1b} a decrease of hardness occurs, above Ac{sub 1b}, a hardness rise due to the partial austenitizing was obtained. While hardening ...
Full text of publication follows: Radiation hardening and embrittlement due to high-energy neutron radiation around 623 K are the important issues on reduced-activation ferritic/martensitic (RAF/M) steels. It is expected that the improvement of radiation hardening might be one of effective ways to control the mechanical properties of RAF/M after irradiation. It has been reported that the weld joint has less hardening than the base metal from the tensile test results of TIG weldments irradiated in HFIR. This report indicated that radiation hardening can be reduced by the optimization of heat treatment condition for F82H. The purposes of this study are to establish the condition of heat treatment for minimum of radiation hardening in F82H steel using Neutron/Ion-irradiation and to examine a correlation between tensile property and micro-hardness before/after irradiation. The materials used in this study were F82H IEA heat and F82H heat treatment variants. Neutron ...
Using the Relativistic Mean Field Theory (RMF) it is shown that different proton fraction which is directly connected with the neutron excess and with the asymmetry of the system affects proto-neutron stars parameters and changes their composition. The obtained form of the equation of state allows to construct the mass-radius relations and shows that the increasing asymmetry creates more compact stars. The inclusion of {delta} meson together with nonlinear vector meson interaction terms and magnetic field make this effect even stronger.
The behaviour of an elastomeric seal for vehicle brake Tandem master cylinder is measured and analyzed in temperature and brake fluids changed. Working conditions are simulated for different piston rod velocity and cylinder supply pressure, in temperature rising, brakefluid boundary and Nanoaluminum oxide brakefluid oxide brakefluid lubrication. The result shows that Nanoaluminum oxide brakefluid with its ball shape can highly reduce friction coefficient to avoid seal excessive wear and reduce slick slip in brake applications.
The optimum conditions of complex formation of rhenium(IV) with acetylacetone in water-ethanol medium were found, and a spectrophotometric method for determining rhenium with limit of detection 0.1 ..mu..g/ml was proposed. Rhenium can be determined in the presence of a 1000-fold excess of molybdenum. The procedure was tested on model solutions and used for the determination of rhenium in alloys.
Stability concerns of the Par Pond Dam, an embankment structure in the Savannah River Site complex, resulted in a comprehensive evaluation of the state of its integrity. Specifically, excessive seepage through the embankment, slope failure due to an earthquake event as well as liquefaction potential of the embankment and the foundation are addressed and the potential of failure is evaluated. Lastly, remedial benefits of the addition of a berm structure are also assessed.
Events detected in a shielded plastic scintillation counter occurring in the 26 microsec preceding the arrival of an extensive air shower at ground level with local electron density or = 20 m to the -2 power and the 240 microsec after its arrival have been studied. No significant excess of events (tachyons) arriving in the early time domain have been observed in a sample of 11,585 air shower triggers.
The seawater in the intake structure flows into the large pump to with draw excess heat from the turbine steam condenser. In the intake structure of a nuclear power plant, undesirable pump operating characteristics such as vortices, impeller damages and non-uniform pump-approach flow around the pump bells take place frequently due to poorly-arranged intake geometry. In this study, physical modeling test was performed to predict the hydraulic phenomenon, and proposed flow control devices.
Implanted B and P dopants in Si exhibit transient enhanced diffusion (TED) during annealing which arises from the excess interstitials generated by the implant. In order to study the mechanisms of TED, transmission electron microscopy measurements of implantation damage were combined with B diffusion experiments using doping marker structures grown by molecular-beam epitaxy (MBE). Damage from nonamorphizing Si implants at doses ranging from 5{times}10{sup 12} to 1{times}10{sup 14}/cm{sup 2} evolves into a distribution of {l_brace}311{r_brace} interstitial agglomerates during the initial annealing stages at 670{endash}815{degree}C. The excess interstitial concentration contained in these defects roughly equals the implanted ion dose, an observation that is corroborated by atomistic Monte Carlo simulations of implantation and annealing processes. The injection of interstitials from the damage region involves the dissolution of ...
Implanted B and P dopants in Si exhibit transient enhanced diffusion (TED) during annealing which arises from the excess interstitials generated by the implant. In order to study the mechanisms of TED, transmission electron microscopy measurements of implantation damage were combined with B diffusion experiments using doping marker structures grown by molecular-beam epitaxy (MBE). Damage from nonamorphizing Si implants at doses ranging from 5x10"1"2 to 1x10"1"4/cm"2 evolves into a distribution of #left brace#311#right brace# interstitial agglomerates during the initial annealing stages at 670 endash 815 degree C. The excess interstitial concentration contained in these defects roughly equals the implanted ion dose, an observation that is corroborated by atomistic Monte Carlo simulations of implantation and annealing processes. The injection of interstitials from the damage region involves the dissolution of #left brace#311#right brace# defects ...
The initiation and progression of several forms of retinal degenerations involve excessive, repetitive, and/or sustained oxidative stress that, in turn, mediate photoreceptor cell damage and...Full Text Available
DescriptionThe switch from production-linked to environmental payments has focussed attention on the environmental impacts of farming. There is a growing awareness of the need to reduce the contamination of air with carbon dioxide, methane, ammonia and nitrogen gases (which contribute to the greenhouse effect) and to prevent the contamination of soil and water with excessive amounts of nitrogen, phosphorus and potassium. As beef production moves to become more sustainable and fully integrated with the wide [continued...
The basic design of a system installed in the Columbus, Ohio Zoo is described. The distribution system is described in detail. The control system is microprocessor controlled, with about 50 monitoring points. Preliminary evaluations have indicated that the system can operate with an overall coefficient of performance in excess of 3.5. 1 figure.
The first successful observation of double analog states in "8"8Zr and "9"0Mo has been made by means of the (#pi#"+,#pi#"-) pion double charge exchange (DCX) reaction. The systematics of the (N - Z) and the A dependence of analog DCX, made possible by these observations, is discussed. (orig.).
This 'Issues in Ecology' article from the Ecological Society of America provides information about the consequences of nutrient enrichment along the US coast. It describes problems such as harmful algal blooms (HABs), anoxia, hypoxia, and dead zones. It explains which nutrients are involved and describes implications of excess nutrients in regions such as the Gulf of Mexico/Mississippi River basin. The article features several color photographs, maps, and diagrams.
Volumetric properties of liquid mixtures of neon and hydrogen have been calculated using path integral hybrid Monte Carlo simulations. Realistic potentials have been used for the three interactions involved. Molar volumes and excess volumes of these mixtures have been evaluated for various compositions at 29 and 31.14 K, and 30 atm. Significant quantum effects are observed in molar volumes. Quantum simulations agree well with experimental molar volumes. Calculated excess volumes agree qualitatively with experimental values. However, contrary to the existing understanding that large positive deviations from ideal mixtures are caused due to quantum effects in Ne{endash}H{sub 2} mixtures, both classical as well as quantum simulations predict the large positive deviations from ideal mixtures. Further investigations using two other Ne{endash}H{sub 2} potentials of Lennard{endash}Jones (LJ) type show that excess volumes are very ...
Volumetric properties of liquid mixtures of neon and hydrogen have been calculated using path integral hybrid Monte Carlo simulations. Realistic potentials have been used for the three interactions involved. Molar volumes and excess volumes of these mixtures have been evaluated for various compositions at 29 and 31.14 K, and 30 atm. Significant quantum effects are observed in molar volumes. Quantum simulations agree well with experimental molar volumes. Calculated excess volumes agree qualitatively with experimental values. However, contrary to the existing understanding that large positive deviations from ideal mixtures are caused due to quantum effects in Ne - H_2 mixtures, both classical as well as quantum simulations predict the large positive deviations from ideal mixtures. Further investigations using two other Ne - H_2 potentials of Lennard - Jones (LJ) type show that excess volumes are very sensitive to the ...
The precipitation of excess silicon interstitials into dislocation loops is modeled. This situation occurs when an amorphous layer is created at the surface in order to avoid boron channeling and form shallow p junctions. The modeling of the nucleation of these extended defects is included into the process simulator IMPACT-4. Their density and mean radius are calculated for several annealing times and temperatures and they are compared with experimental characterizations. This is the first step towards a full modeling of the complex processes involved in the transient enhanced diffusion of boron.
Populations living close to high-voltage transmission lines often have residential magnetic field exposures in excess of 1 microT, and sometimes over 2 microT. Yet, populations studied in most epidemiologic...Full Text Available
Transit time, the time from bridgewire burst until breakout of detonation from the output pellet of an exploding bridgewire detonator, was measured as a function of burst current. From this data, in conjunction with known equations for run distance versus pressure, unreacted explosive Hugoniots, and detonation properties of the initial pressing pellet, the run distance in the initial pressing explosive pellet and shock pressure from the exploding bridgewire were determined, both as a function of burst current.
Besides industrial agglomerations suffering from excessive pollution of water, air, and soil, there are areas in the German Democratic Republic where beautiful scenery at first glance seems to be intact owing to the absence of large industries. That environmental problems exist also in the coastal regions of the German Democratic Republic is shown in this report. Some of the environmental sins mentioned, which are due to human failure, would seem to the editor to be not just GDR specific. (orig.).
DescriptionThis application is a request for Bridge Link funds to support studies in order to develop a full proposal under the Link Sustainable Livestock Scheme in collaboration with Dr Nigel Scollan of IGER. The hypothesis being examined is that the poor performance of some ruminants is due to poor nutrition at strategic time points during the animal's development. The initial hypothesis will be tested in sheep and the results from this will be used to develop the full proposal. Excessive fat in ruminan [continued...
Neutrophils from people with poorly controlled diabetes present a primed phenotype and secrete excessive superoxide. Phospholipase A2 (PLA2)-derived arachidonic acid (AA)...Full Text Available
The temperature and concentration dependence of the densities of binary CaBr_2-(Li, Na, K, Rb, Cs)Br, NaBr-(Sr, Ba)Br_2 and KBr-SrBr_2 mixtures have been measured using the method of hydrostatic weighing. With exception of the systems LiBr-CaBr_2 and NaBr-(Sr, Ba)Br_2 the calculated molar excess volumes are positiv in the investigated mixtures. (author).
We have developed a novel insulator concept that involves the use of alternating layers of conductors and insulators with periods less than 1 mm. We have demonstrated that these structures perform 2 to 5 times better than conventional insulators in long pulse, short pulse, and alternating polarity applications. We present new testing results showing exceptional behavior at DC, with gradients in excess of 110kV/cm in vacuum.
The available measurements on the cosmic-ray antiproton/proton ratio show an excess of antiprotons above predictions derived in the framework of the standard picture of cosmic-ray origin and propagation. Calculations are performed of the production from collisions of cosmic rays with the interstellar gas under the condition of distributed reacceleration. It could be shown that the calculated antiproton/proton ratio is enhanced compared to that derived from the leaky box model, but it remains difficult to bring it into agreement with the data by reasonable astrophysical assumptions. 15 references.
A simple and continuous model for the on-state current of polysilicon thin-film transistors, suitable for implementation in circuit simulators, is presented. The model includes the potential barrier at the grain boundaries, the channel length modulation and the excess current due to impact ionization. Comparison between measured output characteristics and the model shows excellent agreement over wide range of bias voltages and for devices with different gate lengths.
Using histopathologic diagnoses made on necropsy material from 3,024 military working dogs (MWDs) who died from 1968 to 1973, we analyzed the effect of military service in the Republic of Vietnam on testicular pathology. Among 1,048 MWDs that died in Vietnam and had no reported developmental risk factors for testicular disease, significant excesses of testicular hemorrhage, epididymitis/orchitis, sperm granuloma, testicular degeneration, and seminoma were evident. Among 126 MWDs with prior Vietnam service who died at other duty stations outside Vietnam from 1968 to 1973, significant excesses of testicular degeneration and seminoma were likewise evident. Among 136 MWDs with prior Vietnam service that later died from 1974 to 1980, seminoma continued to be diagnosed in significant excess. In each instance, the odds ratio for the association between Vietnam service and seminoma was 2.0 or greater. Analysis of ever service by ...
The MiniBooNE Collaboration reports first results of a search for {upsilon}{sub e} appearance in a {upsilon}{sub {mu}} beam. With two largely independent analyses, we observe no significant excess of events above background for reconstructed neutrino energies above 475 MeV. The data are consistent with no oscillations within a two neutrino appearance-only oscillation model.
Radiation induced polymerization of methylmethacrylate and copolymerization of styrene-acrylonitrile mixture in mamrase Carpinus betulus was carried out by means of #gamma#-ray, under different moisture levels and additives. Under all conditions the degree of polymerization was as high as 60%. No pronounced differences were observed in the kinetics of the polymerization of MMA either with moisture content of wood nor with kind and amount of additives. At high moisture (80% RH) content the dimensional stability of wood-PMMA was increased four fold as compared with untreated wood. The hardness increased about 100% for a weight conversion of monomer of about 30 to 40%. Hardness of this wood-polymer composite is comparable to that of the best noble woods in the world. (author).
In a forthcoming paper we describe a new approach to rapidity gap survival (RGS) in the production of high-mass systems (H = dijet, Higgs, etc.) in exclusive double-gap diffractive pp scattering, pp -> p + H + p. It is based on the idea that hard and soft interactions are approximately independent (QCD factorization), and allows us to calculate the RGS probability in a model-independent way in terms of the gluon generalized parton distributions (GPDs) in the colliding protons and the pp elastic scattering amplitude. Here we focus on the transverse momentum dependence of the cross section. By measuring the ''diffraction pattern'', one can perform detailed tests of the interplay of hard and soft interactions, and even extract information about the gluon GPD in the proton from the data.
The NACE MR-01-75 standard imposes a restriction of 22HRC maximum for regions of a pipeline girth weld that are not in direct contact with H[sub 2]S containing environments. TWI have demonstrated in an earlier project for the Pipeline Research Committee (PRC) that it may be permissible to relax this maximum hardness requirement. Such a relaxation, which already exists in the BS4515: 1984 standard, offers potential benefits when applied to the capping pass and heat affected zone of a pipeline girth weld. This report presents additional data to supplement that obtained in a previous PRC project conducted at TWI. Further pipe materials with differing pipe wall thicknesses have been welded, exposed to an internal H[sub 2]S containing environment and examined for sulphide stress corrosion cracking.
A series of nine model ferritic alloys were ion irradiated at #propor to#300 C using 2.5 MeV He ions to a dose of 1.4 x 10"2"1 ion/m"2, which corresponds to #propor to#0.1 dpa at a depth of 2 #mu#m and #propor to#3.5 dpa at the peak damage region which occurs at about 4 #mu#m deep. The resultant changes in hardness as a function of depth were measured using a Nanoindenter "t"r"a"d"e"m"a"r"k. TEM was used to investigate the defect distributions. The effect of various solutes, Cu and N in particular, but Mn and Ti as well, on the change of hardness and the defect distribution due to the ion irradiation are discussed. (orig.).
The corrosion behavior of hard metals with VC and Cr3C2 grain growth inhibitors was investigated in alkaline solutions by electrochemical methods. The two inhibitors have opposite effects on the corrosion behavior: Cr3C2 significantly improves the corrosion behavior, whereas VC-containing alloys show a poor resistance. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) and analytical transmission electron microscopy (TEM) analyses of the distributions of Cr and V in the composite material, as well as in the surface layers formed during corrosion were employed to clarify the influence of these elements on the corrosion behavior. The measurements showed that VC is precipitated mostly along the WC/binder interface after the liquid-phase sintering process, while Cr3C2 is almost homogene...
The X-ray storage phosphor CsBr:Eu2+ in form of needle image plates is believed to be a promising alternative to the granular BaFBr:Eu2+ with regard to PSL yield and spatial resolution. Unfortunately, CsBr:Eu2+ exhibits poor radiation hardness, which is caused by a migration of europium ions initiated by naturally existing defect centers like (Eu2+-VCs)-centers and X-ray generated MEu-centers. It will be shown that the formation of (Eu2+-O2?)-dipoles at the expense of (Eu2+-VCs)-dipoles, incorporated by thermal annealing in O2-containing and humid atmosphere, does not improve the radiation stability. There is, however, a strong improvement in the radiation hardness by codoping of CsBr:Eu2+ with lithium ions, which is accompanied by a complete suppression of the previously observed MEu-cent...
To clarify the mechanism of plasma nitriding, the authors examined the optical microstructure, the hardness, the precipitation, and the concentration of dissolved nitrogen in Fe-18Cr-9Ni nitrided using plasma in the range of 723-823 K. Compared with ammonia-gas nitriding, the features of plasma nitriding are the formation of small chromium-nitride precipitates (CrN), the absence of an externally nitrided layer, the high concentration of dissolved nitrogen, and the high hardness (HV = 1,200). The diffusion coefficient of nitrogen in the present alloy was determined using the growth rate of the internally nitrided layer, based on calculations used in internal oxidation. Plasma- and gas-nitriding were also compared with respect to the growth rate of the nitrided layer.
In the present investigation, the properties of plasma nitrided AISI 304 steel were studied by changing the presence of nitrogen in the gas mixture. The plasma nitriding was performed at temperature -560 deg C, pressure -4 mbar and duration 24 hours. The nitrided samples were characterized by evaluating the phase composition, micro hardness, and diffusion layer thickness. The phase analysis indicates the mixed phases of CrN and Fe_3N, Fe_3N and Fe_4N which has the highest intensity. The results show the glow discharge plasma nitriding in presence of N_2 (80 vol. %) and H_2 (rest) produced higher hardness as well as higher case depth. (author)
A polymer-based additive that permanently reduces hardness in wood electrical transmission poles treated with a chromated copper arsenate (CCA) preservative, has been developed by a team of IREQ researchers. A three-phase project is being funded by Hydro-Quebec to evaluate the additive's effect on full-size hydro poles subjected to actual climatic conditions. The evaluation project is designed to test the CCA and the additive's degree of retention by analyzing the hardness measurements against climbing tests, and the washing resistance of the chromium, copper and arsenate in the CCA/polymer-additive treatment. CCA-treated poles will be used for reference. Accelerated aging tests to characterize the polymer's resistance to UV rays will also be part of the validation program.
With the aim of optimizing the nitriding process, experimental studies of the plasma nitriding of four selected steels were carried out, using a d.c. glow discharge. The process parameters were varied systematically. By means of transmission and scanning electron microscopy and X-ray diffraction, the microstructures, including the thicknesses of the compound zones and the diffusion zones of the nitrided steels, were obtained. Using cross-sectional samples and a micro-Vickers indenter, hardness depth profiles were also obtained. From the time and temperature dependences of the hardness profiles, effective diffusion constants and corresponding activation enthalpies were obtained. Furthermore, in an attempt to shed some light on the atomistic nitriding mechanisms, the glow discharges were studied by measuring energy spectra of the energetic ions hitting the cathode (the steel test specimens). It was shown that an increase of the mean energy of the ...
Modifications of the structure and mechanical properties in LiF crystals irradiated with MeV-energy Au ions have been studied using nanoindentation, atomic force microscopy and optical spectroscopy. The nanostructuring of crystals under a high-fluence irradiation (above 1013 ions/cm2)?was?observed. Nanoindentation tests show a strong ion-induced increase of hardness (up?to 150?200%), which is related to the high volume concentration of complex color centers, defect aggregates, dislocation loops and grain boundaries acting as strong barriers for dislocations. From the?depth profiling of the hardness and energy loss it follows that both nuclear and electronic stopping mechanisms of MeV Au ions contribute to the creation of damage and hardening. Whereas the electronic stopping is dominating i...
Given the important role of parent-youth communication in adolescent well-being and quality of life, we sought to examine the relationship between specific communication variables and youth perceived quality of life in general and as a deaf or hard-of-hearing (DHH) individual. A convenience sample of 230 youth (mean age = 14.1, standard deviation = 2.2; 24% used sign only, 40% speech only, and 36% sign + speech) was surveyed on communication-related issues, generic and DHH-specific quality of life, and depression symptoms. Higher youth perception of their ability to understand parents' communication was significantly correlated with perceived quality of life as well as lower reported depressive symptoms and lower perceived stigma. Youth who use speech as their single mode of communication ...
A Y-Mg-Si-Al-O-N glass was submitted to swift heavy-ion bombardment at GANIL (Caen, France) and the influence of irradiation on the mechanical properties was studied. The mechanical properties of the glass were characterized both before and after irradiation. Changes in hardness, elastic modulus and fracture toughness of the near-surface irradiated layer were determined using indentation techniques. SRIM calculations allowed to estimate the ions penetration range and the energy deposition relative to electronic and nuclear interactions, which can be correlated to the experimental damaged depth. Meyer's hardness and Young's modulus decrease by about 30 %, while fracture toughness is increased by more than 40 %. (authors)
Magnetic properties of Fe-Co-Mo-Cu-B alloy system with Co up to 26at.% were investigated. After proper thermal treatment, the nanocrystalline grain remains tiny, the density hardly increases, but the room-temperature saturation attains 1.5T mainly due to a high enough Curie temperature. The generally observed slant hysteresis loops point to ribbon surfaces, which stress the ribbon interior and induce a specific magnetoelastic contribution to hard-ribbon-axis magnetic anisotropy even after vacuum annealing. The effect does not come from cobalt but rather from the lack of silicon. Partial removal of the surfaces resulted in a decrease of the loop tilt.
The effect of various hydrogen concentrations on the crystal lattice period and the hardness of titanium alloy was examined, the alloy containing about 16 at.% Mo (27.5 wt. % Mo) and having #beta# structure. The peculiar features of the mechanism of plastic deformation of the alloy were studied after adding hydrogen to it. A dependence of the crystal lattice period on the concentration of hydrogen was obtained for TixMoxH_2 alloy. It has been established that the hardness of the Ti-Mo alloy does not change when hydrogen is added to it. The presence of hydrogen introduces changes into the mechanism of deformation of #beta#-titanium alloy. The configuration of the inverse pole figures after rolling proves that the transverse slip process in an alloy with hydrogen is hampered, and that the coplanar slip process is developing in it.
A test bench was designed and assembled to carry out impact tests on samples and components. The system allows simple and rapid adjustment of the test parameters, such as the shot size and air pressure, with good repeatability of the results. Tests on steel and light alloys were carried out under both as-produced condition and on thin hard-coated samples. Significant reductions in dimple dimensions were seen after coating. FE models simulating the experiments overestimated the dimple depths, although the parameter trend was satisfactorily captured. The residual stresses from coating and shot peening determined numerically are believed to have been proven effective against fatigue.
Ochratoxin A (OTA) was analyzed from 44 liquorice confectionery samples using immunoaffinity cleanup and liquid chromatography coupled with fluorescence detection. The presence of OTA was confirmed by methyl-ester derivatization. Liquorice confectionery samples were purchased from different retail outlets and supermarkets in Spain during 2007-2008, 16 of hard candies and 28 of soft candies. The incidence of OTA varied between 75% and 39% and mean ranged from 2.96 to 0.34mg/kg for hard and soft candies, respectively. Assuming a total mean value of 1.29mgOTA/kg sweet and a consumption of about 1.2g liquorice sweets per day, an OTA weekly uptake of 11ng was obtained, or, based on a total body weight of 30kg for a child consuming these sweets regularly, a weekly intake of 0.37ng/kg body weight...
Effect of oil palm empty fruit bunch (OPEFB) fiber and poly(methyl acrylate) grafted OPEFB on several mechanical properties of poly(vinyl chloride)/epoxidized natural rubber (PVC/ENR) blends were studied. The composites were prepared by mixing the fiber and the PVC/ENR blends using HAKEE Rheomixer at the rotor speed of 50 rpm, mixing temperature 150degreeC, and mixing period of 20 min. The fiber loadings were varied from 0 to 30% and the effect of fiber content in the composites on their ultimate tensile strength (UTS), Youngs modulus, elongation at break, flexural modulus, hardness, and impact strength were determined. An increasing trend was observed in the Youngs modulus, flexural modulus, and hardness with the addition of grafted and ungrafted fiber to the PVC/ENR blends. However the i...
AISI 5140 steel was plasma nitrided at various gas mixtures of nitrogen, hydrogen, and argon to investigate the actions of hydrogen and argon on plasma nitriding. The structural and mechanical properties of ion-nitrided AISI 5140 steel have been assessed by evaluating composition of phases, surface hardness, compound layer thickness, and case depth by using X-ray diffraction (XRD), microhardness tests, and scanning electron microscopy (SEM). It was found that the growth of compound layer can be controlled and the diffusion improved when the gas mixture includes H_2 gas. Additionally, it was determined that the amount of Ar in dual gas mixture must be at 20% minimum to obtain distinctive surface hardness and compound layer thickness.
In this work AISI 1045 steel were duplex treated via plasma nitriding of chromized layer. Samples were pack chromized by using a powder mixture consisting of ferrochromium, ammonium chloride and alumina at 1273K for 5h. The samples were then plasma-nitrided for 5h at 803K and 823K, in a gas mixture of 75%N2+25%H2. The treated specimens were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis and Vickers micro-hardness test. The thickness of chromized layer before nitriding was about 8mm and it was increased after plasma nitriding. According to XRD analysis, the chromized layer was composed of chromium and iron carbides. Plasma nitriding of chromized layer resulted in the formation of chromium and iron nitrides and carbides. The hardness of the duplex layer...
Microstructural observations of damage around indentations in Ti{sub 3}SiC{sub 2} are presented. The Vickers hardness decreased with increasing load and asymptotically approached 4 GPa at the highest loads. No indentation cracks were observed even at loads as high as 300 N. Preliminary strength versus indentation plots indicate that, at least for the large-grained material ({approx}100 {micro}m) studied here, Ti{sub 3}SiC{sub 2} is a damage-tolerant material able to contain the extent of microdamage to a small area around the indent. The following multiple energy-absorbing mechanisms have been identified from scanning electron micrographs of areas in the vicinity of the indentation: diffuse microcracking, delamination, crack deflection, grain push-out, grain pull-out, and the buckling of individual grains.
Silicon sensors have about ten times improved radiation hardness around 130 K temperature, compared with the state-of-art sensors close to room temperature. This is based on the Lazarus effect studied by the RD39 Collaboration of CERN. Other benefits of low temperatures will also be discussed. We shall describe the conceptual design of low-mass detector modules cooled using two-phase flow of argon in miniature cooling pipes integrated in the module structure between the sensors and the readout hybrid circuit. The main engineering features of the cooling system and mechanical support structures are discussed, as well as the benefits arising from the operation of the tracker under cryogenic vacuum. 4 Refs.
The combined processes of plasma nitriding and cathodic arc deposition of (Ti,Cr,Nb)CN coatings were applied to HSS substrates. The nitrided layers, obtained in a mixture of H2 (70%) and N2 (30%) at two different temperatures (480^oC and 510^oC), were examined for the microhardness depth profiles. Characterization of the duplex coatings was performed by investigating elemental and phase composition, texture, hardness, friction and wear. XRD and XPS analyses revealed the formation of a mixture of a carbonitride fcc solid solution, in a dominant proportion, and metallic chromium. The film hardness was measured to be ~34GPa. The duplex (Ti,Cr,Nb)CN coatings exhibited superior tribological behavior as compared to both nitrided layers and non-duplex coatings.
A link is made in this paper between proposed low energy scenarios for different Western European countries and the amount of pollutants that may result from these scenarios. Air pollutant emissions are calculated for the ten countries for which low energy scenarios are available. These scenarios emphasize stringent energy efficiency, maximizing the use of renewable (other than nuclear) energy, and minimizing the use of fossil fuels. Under these low energy scenarios, the average per capita energy use (year 2030) in the ten countries is estimated as 97 GJ/person, which is a decrease of 38% relative to 1980. Using the energy consumption figures from the low energy scenarios, together with sector- and fuel-specific emission factors from Europe, the resulting emissions of SO_2 , NO_x , and CO_2 were computed. These estimates do not take into account any add-on pollution controls over and above what was in place in 1980, or ...
This paper deals with estimating aircraft landing and take-off (LTO) emissions (HC, CO, NO_x, SO_2) at 40 Turkish airports including the biggest airports, i.e. Ataturk International Airport (AIA) in Istanbul, Antalya Airport in Antalya and Esenboga Airport in Ankara in 2001. The calculation model is based on flight data recorded by the State Airports Authority. The flight data include the type and number of aircraft, number of passengers, amount of cargo etc., which depend on day-time and date. For the emission calculations the International Civil Aviation Organization (ICAO)-Engine emission data bank, which includes minimum and maximum values for both fuel flow rates and emissions factors, is used. By using first the minimum and then the maximum values from the data bank, two estimations of aircraft LTO emissions at Turkish airports are calculated: i.e. minimum and maximum ...
Conventional plasma carburizing or nitriding for austenitic stainless steels results in a degradation of corrosion resistance. However, a low temperature plasma surface treatment can improve surface hardness without deteriorating the corrosion resistance. The 2-step low temperature plasma processes (the combined carburizing and post nitriding) offers the increase of both surface hardness and thickness of hardened layer and corrosion resistance than the individually processed low temperature nitriding and low temperature carburizing techniques. In the present paper, attempts have been made to investigate the influence of the introduction of Ar gas (0#approx#20%) in nitriding atmosphere during low temperature plasma nitriding at 370 .deg. C after low temperature plasma carburizing at 470 .deg. C. All treated specimens exhibited the increase of the surface hardness with increasing Ar level in the atmosphere and the surface ...
The influence of additionally injected short-wavelength photobleaching light on the radiation hardness of Ge-doped graded index fibers working at 1,300 nm wavelength is investigated. Predictions are complicated by the fact that more efficient shortwave bleaching light experiences higher radiation-induced loss. Promising results are found for low fiber temperatures (approx-lt -50 C) and bleaching light of about 835 nm wavelength.
A program was undertaken to radiation harden an existing power integrated circuit technology (BCDMOS) to total dose, gamma dot, SEU, and neutrons. Efforts have centered around hardening and optimizing our CMOS, DMOS, and NPN devices. Initial results indicate a substantial improvement in hardness over our existing commercial technology.
The quantitative imaging of a phase object using 16 keV x-rays is reported. The theoretical basis of the techniques is presented along with its implementation using a synchrotron x-ray source. It is found that the phase image is in quantitative agreement with independent measurements of the object. 13 refs., 5 figs.
Olive oil mill wastewaters (OMW) cause disposal problems because they contain powerful pollutants such as phenolic compounds. Complete biodegradation or removal of these compounds is hardly achieved by a single treatment method. In this work, we investigated 2 integrated technologies for the treatment of the recalcitrant contaminants of OMW, allowing water recovery and reuse for agricultural purposes. (Author)
In order to investigate interactions of (Ti,W)(C,N) and (Ti,Mo)(C,N) with binder metals solid/solid diffusion couples were annealed. These two-dimensional arrangements provide good access to phase reactions occurring upon sintering already in the solid state. It was found in (Ti,W)(C,N)/Co- and (Ti,W)(C,N)/Ni-based couples that the reaction zone is thinner in contact with Co than with Ni. It was also observed that the reaction rate with both Co and Ni is lower if nitrogen is added to the hard phases. Beside a thickness variation of the diffusion zones a change in the microstructure was found. At the interface of nitrogen-free hard phases in contact with Co elongated microstructural constituents are formed with the main axis perpendicular to the interface, while at the interface of nitrogen-containing hard phases these elongated microstructural constituents were found in contact with Ni. Also phase reactions and the ...
All over the world the implementation of energy efficient and clean technologies can be hardly considered without opening the way to competition and the involvement of private investment. If such terms are valid for reach countries there are even more adequate for economies in transition like Romania's, which inherited and obsolete productive equipment, can mobilize insufficient resources for development-modernization and exhibits a quasi-unanimous option of adhering at European Union. (author). 3 tabs., 11 refs.
MPFDs are a new class of detectors that utilize properties from existing radiation detector designs. A majority of these characteristics come from fission chamber designs. These include radiation hardness, gamma-ray background insensitivity, and large signal output.
In the year 2008, the high pressure partial turbine and two low pressure partial turbines in the hard coal power station Bergkamen (Federal Republic of Germany) were modernized. A three-dimensional blade design and innovative seals were used. This resulted into a distinct increase in efficiency among other things.
This study by CTES, L.C. meets two main objectives. First, evaluate the feasibility of using coiled tubing (CT) to drill 1.0 inches-2.5 inches diameter directional holes in hard rocks. Second, develop a conceptual design for a micro borehole drilling platform (MBDP) meeting specific size, weight, and performance requirements. The Statement of Work (SOW) in Appendix A contains detailed specifications for the feasibility study and conceptual design.
This statement summarizes Lawrence Livermore National Laboratory`s committment to making important scientific, technological, and business contributions to global sustainability. The quest has many aspects, some socio-political or economic and some technological, and some in which the soft and hard sciences become indistinguishable, as in visionary national strategies, like Holland`s, and futuristic regional and city development plans, like those of Kagoshima and Chattanooga.
The loosening equipment consists of a base machine and four-link suspension mechanism which is a cross frame with loosening gear connected to the base machine by universal hinges. In order to improve the reliability of the machine, the drive of transverse shifting in the cross frame is made of symmetrically arranged, shock-absorbing, hydraulic cylinders which are connected by additional universal hinges to the base machine and the lower pull rods. The design of the loosening machine guarantees its reliable operation on soil with significant quantity of hard inclusions.
With the frequent load changes to which a hard coal power station is subjected in the middle and peak load range, great demands are linked with the transient behaviour of the steam generator. Due to the serial connection of the crusher and boiler, the strongly delaying transient behaviour of the crusher compounds entirely with the transient behaviour of the steam generator. Therefore, a suggestion is to be made here as to the improvement of the dynamics of the crusher.
The influence of RTA (Rapid Thermal Anneal) treatment on MOS radiation hardness is demonstrated and compared with classical furnace treatment. In the case of the RTA, the oxide trapped charge is found to depend on: (i) the anneal temperature as expected, data are in good agreement with a recently developed model of oxygen out-diffusion; (ii) the location across the wafer with a radial dependence, results could be related to stress induced by thermal gradient.
The competitiveness of a new nuclear plant vs. a new oil or gas fired combined cycle plant or a coal fired plant in East-Asia, is reviewed in the paper. Both the nuclear and the fossil fired plants are evaluated as either utility financed or independent power producer (IPP) financed. Two types of advanced light water reactors (ALWRs) are considered in this paper, namely evolutionary ALWRs (1200 MWe size) and passive ALWRs (600 MWe class). A range of capital and total generation costs for each plant type is reported here. The comparison centers on three elements of overall competitiveness: generation costs, hard currency requirements, and employment requirements. Each of these aspects is considered perspective. Year-by-Year generation cost history over the plant lifetime is shown in some cases. It is found here that a utility financed evolutionary and passive ALWRs are broadly competitive with an IPP financed gas fired combined cycle plant and are more economic than ...
Geological, geophysical, and engineering-geological research conducted at the 'Yeniseisky' site obtained data on climatic, geomorphologic, geological conditions, structure and properties of composing rock, and conditions of underground water recharge and discharge. These results provide sufficient information to make an estimate of the suitability of locating a radioactive waste (R W) underground isolation facility at the Nizhnekansky granitoid massif
The removal of tritiated water vapour was tested by use of a small burning apparatus and a clinoptilolite filter. It was found that decontamination factor of about 10"4 could be obtained by a clinoptilolite filter. The adsorption of HTO in the clinoptilolite is caused by the diffusion, so it is necessary that filtration velocity is maintained below 0.01 m/sec. Decontamination factor was not influence by the moisture content of a clinoptilolite and tritiated water vapour once adsorbed on a filter was hardly removed. (auth.).
A systematic study of structure-mechanical properties relation is reported for MoSi{sub 2}-SiC nanolayer composites. Alternating layers of MoSi{sub 2} and SiC were synthesized by DC magnetron and rf-diode sputtering, respectively. Cross-sectional transmission electron microscopy was used to examine three distinct reactions in the specimens when exposed to different annealing conditions: Crystallization and phase transformation of MoSi{sub 2}, crystallization of SiC, and spheroidization of the layer structures. Nanoindentation was employed to characterize the mechanical response as a function of structural changes. As-sputtered material exhibits amorphous structures in both types of layers and has a hardness of 11 GPa and a modulus of 217GPa. Subsequent heat treatment induces crystallization of MoSi{sub 2} to form the C40 structure at 500C and SiC to form the a structure at 700C. The crystallization process is directly responsible for hardness ...
The mechanisms underlying life machinery are still not completely understood. Something is known, something is ?probably? known, other things are still unknown. Scientists all over the world are working very hard to clarify the processes regulating the cell life cycle and bioinformaticians try to support them by developing specialized automated tools. Within the plethora of applications devoted to the study of life mechanisms, tools for the analysis and comparison of biological networks are catching the attention of many researchers. It is interesting to investigate why.
Platelet-rich plasma (PRP) is a platelet concentrate that has widely been used to accelerate the healing of soft and hard tissues. The preparation of PRP has been described by several authors. Preparation protocols vary from system to system, depending on the concentration of different integrating proteins. The objective of this article is to describe the principal use of PRP mixed with fat grafts in aesthetic plastic surgery.
This Statistical Report presents results from the physical Swedish Environmental and Economic Accounts for the years 1993 and 1995 according to the classification NACE. The Environmental Economic Accounts constitute an integrated and comprehensive system for environmental and economic statistics. Environmental data are systematically presented together with economic data in a common framework. The system can be used for analyses of various relationships between economy and environment. Data on emissions to air of carbon dioxide, sulphur dioxide, nitrogen oxides, carbon monoxide, methane, nitrous oxide and ammonia are presented for 39 industries, government services and private consumption. The use of energy commodities in monetary and physical terms are also presented for the same sectors. Economic, energy and emission data are also presented in environmental and economic profiles and indicators. Environmental and economic profiles provide an ...
To aid in the study of lower hybrid current drive as a means of current profile control, the radial profile and velocity distribution of the fast current-carrying electrons and their time evolution must be known. As part of the recent effort to understand this fast electron transport, a diagnostic has been installed on PBX-M to measure the electron cyclotron emission from the fast electrons. An oblique horizontal view of upshifted cyclotron emission in the midplane can give radial as well as velocity space information about the fast electrons. Emission in X mode frequencies refracted by the right-hand cutoff is radially localized. The observed emission at a specific frequency comes only from the radial region r_t_u_r_n=#0. Emission measured by this new diagnostic has been found to be radially localized as predicted. It is also expected that localized moments of the distribution ...
This presentation gives the results of a research programme aimed at evaluating exhaust emissions from ships moving within confined coastal zones, as in Piraeus harbour. The level of various exhaust emissions were estimated on the basis of a mathematical model applied for each sea traffic element (ship). Hourly and daily records of all ships` movements in different parts of the harbour were compiled, covering extended periods of time and associated with different shipping operational characteristics (peaks, lows, etc). In order to correlate the exhaust emissions from shipping with the quality of the air in the area of interest, land-based measurements for the same pollutants were carried out in selected locations, near the port and in the greater Athens area. This enabled the investigation of time and spatial diffusion of exhaust emissions from shipping within the area of interest, taking into account ...
The report gives results of a project conducted to create a file containing comprehensive data on all electric utilities in the US. The National Acid Precipitation Assessment Program's (NAPAP's) emissions inventory activities focus on the estimation of emissions from pollutants that contribute to acid deposition. Electric utilities, which emit a large share of total acid deposition precursor emissions, are important for modeling analyses. Data reported by states to the National Emissions Data System (NEDS) for the 1985 NAPAP Emissions Inventory and data reported to the U.S. Department of Energy (DOE) on EIA Form 759, EIA Form 767, FERC Form 423, and the Integrated Data Base System (IDBS) were matched and combined. The resulting 1985 National Utility Reference File (NURF) contains detailed unit level data for nearly 10,000 electricity generating plants.
This report is an assessment of emission-control costs for municipal-waste combustors (MWCs). The details of the cost estimates, including their development, components, and cost premises, are addressed. A model-plant approach was used in the sizing and costing of the emission control systems. Due to differences in the feed-waste characteristics, combustion parameters, and emissions, separate cost estimates were required for mass burning (MB), modular (MOD), refuse-derived fuel (RDF), and fluid-bed combustion (FBC) type furnaces. Cost estimates were developed for control of particulate matter (PM) emissions only and for control of both acid gas and PM emissions from the MWC model plants. Controlled PM emission levels of 0.03, 0.02, and 0.01 gr/dscf, corrected to 12% CO/sub 2/, and 90 and 70% reductions of HC1 and SO2, respectively, were used to develop the ...
We present the results of a study on the 1.4 GHz kpc-scale radio emission in the complete flux density limited MOJAVE sample, comprising 135 radio-loud AGNs. While extended emission is detected in the majority of the sources, about 7% of the sources exhibit only radio core emission. Many BL Lacs exhibit extended radio power and kpc-scale morphology typical of powerful FRII jets, while a substantial number of quasars possess radio powers intermediate between FRIs and FRIIs. This poses challenges to the simple radio-loud unified scheme, which links BL Lacs to FRIs and quasars to FRIIs. We find a significant correlation between extended radio emission and pc-scale jet speeds: the more radio powerful sources possess faster jets. This indicates that the 1.4 GHz (or low frequency) radio emission is indeed related to jet kinetic power. Various properties such as extended radio power and ...
The exhaust emissions of a Diesel direct injection Perkins engine fueled with waste olive oil methyl ester were studied at several steady-state operating conditions. Emissions were characterized with neat biodiesel from used olive oil and conventional Diesel fuel. Results revealed that the use of biodiesel resulted in lower emissions of CO (up to 58.9%), CO{sub 2} (up to 8.6%, excepting a case which presented a 7.4% increase), NO (up to 37.5%), and SO{sub 2} (up to 57.7%), with increase in emissions of NO{sub 2} (up to 81%, excepting a case which presented a slight reduction). Biodiesel also presented a slight increase in brake-specific fuel consumption (lower than 8.5%) that may be tolerated due to the exhaust emission benefits. Combustion efficiency remained constant using either biodiesel or Diesel fuel. The proposed alternative for Diesel fuel could significantly decrease the ...
The document gives statistics on the pollutive emissions from Danish power plants during the period 1987-1996, the main pollutants being sulphur dioxide, nitrogen oxides and carbon dioxide. Data on efficiency levels relative to the production of electricity and heating and on the power plants` contribution to the total emission of CO{sub 2}, NO{sub x}, and SO{sub 2} from energy consumption in Denmark, are presented, and also as corrected for the net import of electricity. Other data on the emission of each of these chemicals by power plants are presented as factual, and corrected in accordance with the net import of electricity, and as factual per consumed and produced energy unit at the power plants. Short notes on related Danish legislation are found in addition to information on sources, methods and definitions used as a basis for the production of this document. Emission from power stations is ...
Historically, the bulk production of electricity has been achieved by burning fossil fuels, with unavoidable gaseous emissions, including large quantities of carbon dioxide: an average-sized modern coal-burning power station is responsible for more than 10 Mt of CO{sub 2} each year. This paper details typical emissions from present-day power stations and discusses the options for their reduction. Acknowledging that the cuts achieved in the past decade in the UK CO{sub 2} emissions have been achieved largely by fuel switching, the remaining possibilities offered by this method are discussed. Switching to less-polluting fossil fuels will achieve some measure of reduction, but the basic problem of CO{sub 2} emissions continues. Of the alternatives to fossil fuels, only nuclear power represents a zero-carbon large-scale energy source. Unfortunately, public concerns over safety and radioactive waste have ...
This paper investigates the relationship between economic growth and pollutant emissions for a small and open developing country, Tunisia, during the period 1961-2004. The investigation is made on the basis of the environmental Kuznets curve hypothesis, using time series data and cointegration analysis. Carbon dioxide (CO{sub 2}) and sulfur dioxide (SO{sub 2}) are used as the environmental indicators, and GDP as the economic indicator. Our results show that there is a long-run cointegrating relationship between the per capita emissions of two pollutants and the per capita GDP. An inverted U relationship between SO{sub 2} emissions and GDP has been found, with income turning point approximately equals to $1200 (constant 2000 prices) or to $3700 (in PPP, constant 2000 prices). However, a monotonically increasing relationship with GDP is found more appropriate for CO{sub 2} emissions. Furthermore, the ...
This paper investigates the relationship between economic growth and pollutant emissions for a small and open developing country, Tunisia, during the period 1961-2004. The investigation is made on the basis of the environmental Kuznets curve hypothesis, using time series data and cointegration analysis. Carbon dioxide (CO2) and sulfur dioxide (SO2) are used as the environmental indicators, and GDP as the economic indicator. Our results show that there is a long-run cointegrating relationship between the per capita emissions of two pollutants and the per capita GDP. An inverted U relationship between SO2 emissions and GDP has been found, with income turning point approximately equals to $1200 (constant 2000 prices) or to $3700 (in PPP, constant 2000 prices). However, a monotonically increasing relationship with GDP is found more appropriate for CO2 emissions. Furthermore, the causality results show that ...
This paper investigates the relationship between economic growth and pollutant emissions for a small and open developing country, Tunisia, during the period 1961-2004. The investigation is made on the basis of the environmental Kuznets curve hypothesis, using time series data and cointegration analysis. Carbon dioxide (CO{sub 2}) and sulfur dioxide (SO{sub 2}) are used as the environmental indicators, and GDP as the economic indicator. Our results show that there is a long-run cointegrating relationship between the per capita emissions of two pollutants and the per capita GDP. An inverted U relationship between SO{sub 2} emissions and GDP has been found, with income turning point approximately equals to 1200 (constant 2000 prices) or to 3700 (in PPP, constant 2000 prices). However, a monotonically increasing relationship with GDP is found more appropriate for CO{sub 2} emissions. Furthermore, the ...
We study the emission zone in a single-layer polymer light-emitting diode. The emission zone is found by studying the angular distribution of the electroluminescence. The emission is modeled by accounting for optical interference. We account for birefringence of the anode layer in our model. The active polymer was, however, found to be isotropic. The anode consists of a single-layer of the conducting polymer complex poly(3,4-ethylenedioxythiophene) and poly(styrene sulfonate) (PEDOT-PSS), with enhanced conductivity. As a cathode we use plain aluminum. By using only PEDOT-PSS we avoid having a thin metal layer or indium-tin-oxide as the anode in the path of the escaping light. The active material is a substituted polythiophene with excellent film forming properties. A comparison between the experimental and calculated angular distribution of light emission from a single-layered polymer light-emitting ...
A method was developed in which the potential of various measures is assessed systematically with a view to meeting the future EU5 emission specifications. Varied boundary conditions are taken into account, and their influence on the PM-NOx tradeoff was investigated. The relative cost is compared to an existing EU4 injection system. It was attempted to apply these measures to the impending US regulations (Tier2 Bin5) and to offer an outlook to EU6. The result shows that it is possible in principle for a car of the 1600 kg class to reduce NOx emissions while maintaining the EU4-PM emission standards.In the case of envisaged serial application subject to emission standards like US Tier 2 and EU6, much work is still required in terms of system robustness and life. In higher-class vehicles, the NOx reduction potential is lower, and it will be more difficult to make do without NOx treatment, especially with ...
Deregulation of the electric power industry in Alberta holds the prospect of providing greater choice for customers. One such option will be `green power` which is provided by renewable energy technologies. The energy produced would be without environmental impacts such as air emissions, water pollution, flooding, thermal emissions or waste by-products. Wind power, small scale hydro power, photovoltaics and biomass technologies have been termed as `green power`. The choices that customers make will not be focused on price alone. Market forces are emerging to demand reduction in emissions which will result in a market for `green energy` products and facilitate achieving goals for a sustainable future.
Divergence between aircraft engine emission regulations proposed by EPA and ICAO is discussed. Every engine, upon entering service, requires a certificate as to its compliance with emission standards. It is shown that despite the large variability in the measurements, it is possible to devise a certification procedure requiring the testing of one engine only. Statistical modeling of such a test at the 5% significance level is described. Values of the parameter standard deviation/mean recommended as certification standards for various pollutants are given. Features of a rational certification scheme to be formulated are outlined.
The problem of spectra formation in hydrodynamic approach to A+A collisions is discussed. It is analyzed in terms of the two different objects: distribution and emission functions. We show that though the process of particle liberation, described by the emission function, is, usually, continuous in time, the observable spectra can be also expressed by means of the Landau/Cooper-Frye prescription. We argue that such an approximate duality results from some symmetry properties that systems in A+A collisions reach to the end of hydrodynamic evolution and reduction of the collision rate at post hydrodynamic stage
An important aspect, which has to be considered in terms of municipal solid waste (MSW) management, is the stage of collection. The emissions generated from these systems can arrive to values that are of the same order of magnitude of emissions from combustion of waste in waste-to-energy plants. The present work faces the problem of transport, from intermediate station to the center of final combustion, placing attention to the emissions from scenarios that has been selected between real systems of management. This analysis can lead to highlight some important elements that can be useful to minimize the impacts.
The focus of this study is on the preparatory detection of uncertain net greenhouse gas (GHG) emission changes (also termed emission signals) under the Kyoto Protocol. The crucial question to be addressed is: How well do we need to know net emissions if we want to detect a specified emission signal after a given time? No restrictions exist as to what concerns the net emitter, which may be any GHG source or sink. Annex I countries are chosen as net emitters, simply for reasons of data availability and because of the excellent possibility of comparing net emitters (inter-country comparison). The countries' emissions - in an increasing number of cases even their uncertainties - are available permitting the application of preparatory signal detection techniques, which are suited to address the aforementioned question. We currently discuss four hierarchically-ordered detection ...
Hydrogen piston engines can be simultaneously optimized for improved thermal efficiency and for extremely low emissions. Using these engines in constant-speed, constant-load systems such as series hybrid-electric automobiles or home cogeneration systems can result in significantly improved energy efficiency. For the same electrical energy produced, the emissions from such engines can be comparable to those from natural gas-fired steam power plants. These hydrogen-fueled high-efficiency, low-emission (HELE) engines are a mechanical equivalent of hydrogen fuel cells. HELE engines could facilitate the transition to a hydrogen fuel cell economy using near-term technology.
A finite three-dimensional layer-by-layer photonic crystal with planar defects in a layer is shown to drastically modify the spontaneous emission rate of an embedded dipole. Finite-difference time-domain calculations with one quarter symmetric boundary condition and perfectly matched layer demonstrate the strong enhancement effects induced by the cavity resonance of defect modes and band-edge resonant modes. Simulation shows that the emission spectra are quite different when the position or polarization of the dipole is changed. Moreover, the extraction efficiency is calculated to observe the percentage of light leakage through a substrate.
Emission spectra obtained for three irradiated granular quartz samples under 1.43 eV excitation exhibited the 2.2 and 3.1 eV emission bands characteristic of feldspars. Excitation spectra of these same samples and several others show the 1.44 eV resonance typical of feldspars. This provides convincing evidence that the 2.2 and 3.1 eV infrared stimulated luminescence observed in these granular quartz samples arises from feldspar inclusions.
As part of a project to complete a comprehensive catalogue of astrophysically relevant emission lines in support of new-generation X-ray observatories using the Lawrence Livermore electron beam ion traps EBIT-I and EBIT-II, we studied emission lines of argon and sulfur in the soft X-ray and extreme ultraviolet region. Here we present observations of Ar IX through Ar XVI and S VII through S XIV between 20 and 75 {angstrom} to illustrate our work.
This paper presents an analysis of the performance of a selective emitter using small particles of rare earth compounds stable at high temperatures in a low emittance inert gas stream. An expression for the spectral emissive power excluding radiation scattering was derived to include the radiation in the emission band, produced by electronic transitions of the rare earth ion, and the continuum radiation outside the emission band produced by the rare earth host. Preliminary results suggest that a selective emitter based on suspended rare earth oxide particles will have high efficiency and merits further experimental investigation. {copyright} {ital 1996 American Institute of Physics.}
The possibilities of using both selective heavy ion induced X-ray emission and secondary ion mass spectroscopy (SIMS), for the identification of impurities present at low concentrations in cadmium telluride are examined. The relative concentrations of the impurities along CdTe crystals have been determined by exciting the X-ray emission of the elements in several slices with Ar and Kr ions and by comparing the relative characteristic X-ray emission yields. As a consequence of the quasimolecular inner shell ionization mechanism in heavy ion-atom collisions, Ar and Kr ions allow a strong excitation of the main impurities seen by SIMS namely Si, Cl and Ge, As, with only a minor contribution of Cd and Te. From the changes of the concentrations of the various impurities along the crystal, informations about segregation coefficients and compensation can be obtained.
This perspective view of Venus, generated by computer from NASA's Magellan data and color-coded with emissivity, shows part of the lowlands to the north of ...
The Toxicological Evaluation of Realistic Emissions of Source Aerosols (TERESA) study involved withdrawal, aging, and atmospheric transformation of emissions of three coal-fired power plants. Toxicological evaluations were carried out in rats exposed to different emission scenarios with extensive exposure characterization. Data generated had multiple levels of resolution: exposure, scenario, and constituent chemical composition. Here, we outline a multilayered approach to analyze the associations between exposure and health effects beginning with standard ANOVA models that treat exposure as a categorical variable. The model assessed differences in exposure effects across scenarios (by plant). To assess unadjusted associations between pollutant concentrations and health, univariate analyses...
The introduction of oxygen in the vicinity of a metallic target surface, bombarded with positive argon ions of twenty kiloelectron-volts, increases the number of sputtered atoms in the excited state. This phenomenon of exaltation, very sensitive in the case of nickel and aluminium, is much less marked in the case of molybdenum. Moreover, the emission of excited particles coming from the beam's ions is not modified. A quantum-mechanical model of a kinetic emission process, which permits the interpretation of the clean metallic target's emission phenomena, seems insufficient to explain all of the results obtained in the presence of oxygen. In this last case one can therfore use a thermodynamic model in which excited metallic particles can be formed directly by chemical surface reactions of neutralization or reduction. (orig.).
Gas separation membranes with polydimethylsiloxane(PDMS)/polystyrene(PS) were prepared by using the sequential interpenetrating polymer network (IPN) method with various PS contents (10?70wt%). These gas separation membranes can be applied to reduce the smoke density in the emission gas of diesel engines. PS content has a pronounced effect on the membrane performance. It was found that the optimized PS contents in the final membrane were 50wt%. The emission capacities of diesel engines used in this study were 632 cc and 11,149 cc. When the oxygen separation membrane was used in the diesel engines, the smoke density of both diesel engines was remarkably reduced (35?73%). The oxygen concentration in the inlet air affects the composition of the emission gases. Especially, hydrocarbon (HC) dec...
The purpose of this statement of work (SOW) is to establish laboratory analytical criteria and requirements for radioactive airborne emissions measurement sample and/or analysis activities.
Performance and emissions data were gathered on a normally aspirated single cylinder DI engine with various combinations of ceramic coatings installed. Thin ceramic thermal barrier coatings were applied to the piston crown and bowl, the head and valves, and the cylinder liner. The coated piston and head were run singly and in combination with the cylinder liner to investigate the effects of these different coated surfaces on emissions and performance. Coating the piston crown alone results in generally lower cylinder pressure, lower brake specific fuel consumption and lower NO(x) emission compared to the baseline engine. Soot emission is typically increased below 2000 RPM and decreased above 2000 RPM. Coating the head alone reduces cylinder pressure, but generally increases specific fuel consumption and NO(x) and soot emission. The KIVA-II code was used to model the Hydra engine ...
Corrosion of steam generator heat transfer tubes (SGHTT) is one of the important problems which affect safety operation of nuclear power plants (NPP), and the hazard of pitting corrosion of heat transfer tubes is the most serious. With an acoustic emission device, the signals during a corrosion test on SGHTT were collected and analyzed, and the corrosion points in the tubes were located accurately. The results show that pitting corrosion of heat transfer tubes has passed through three periods in its development: expansion phase, stationary phase and rapid developing phase. The corrosion damage of HTT can be found earlier with acoustic emission than any other non-destructive testing methods. Acoustic emission can be used for on-line and real-time monitoring of the safety and operation of the steam generator and has therefore a great significance. (orig.)
Global climate policy initiatives are now being proposed to compensate tropical forest nations for reducing carbon emissions from deforestation and forest degradation (REDD). These proposals have the potential to include developing countries more actively in international greenhouse gas mitigation and to address a substantial share of the world's emissions which come from tropical deforestation. For such a policy to be viable it must have a credible benchmark against which emissions reduction can be calculated. This benchmark, sometimes termed a baseline or reference emissions scenario, can be based directly on historical emissions or can use historical emissions as input for business as usual projections. Here, we review existing data and methods that could be used to measure historical deforestation and forest degradation reference scenarios including ...
Global climate policy initiatives are now being proposed to compensate tropical forest nations for reducing carbon emissions from deforestation and forest degradation (REDD). These proposals have the potential to include developing countries more actively in international greenhouse gas mitigation and to address a substantial share of the world's emissions which come from tropical deforestation. For such a policy to be viable it must have a credible benchmark against which emissions reduction can be calculated. This benchmark, sometimes termed a baseline or reference emissions scenario, can be based directly on historical emissions or can use historical emissions as input for business as usual projections. Here, we review existing data and methods that could be used to measure historical deforestation and forest degradation reference scenarios including FAO ...
This paper summarizes the main features of four current REDD proposals: Compensated Reduction, Papua New Guinea et al; Joint Research Center; and Brazil. ... ...
The influence of engine operating variables on the performance, emissions and heat release in a compression ignition engine operating in normal diesel and dual-fuel modes (with natural gas fuelling) was investigated. Substantial reductions in NO{sub x} emissions were obtained with dual-fuel engine operation. There was a corresponding increase in unburned hydrocarbon emissions as the substitution of natural gas was increased. Brake specific energy consumption decreased with natural gas substitution at high loads but increased at low loads. Experimental results at fixed pilot injection timing have also established the importance of intake manifold pressure and temperature in improving dual-fuel performance and emissions at part load. (Author)
The factors influencing premixed burning and the importance of premixed burning on the exhaust emissions from a small high-speed direct-injection diesel engine were investigated. The characteristics of premixed and diffusion burning were examined using a single-zone heat-release analysis. The mass of fuel burned in premixed combustion was found to be linearly related to the product of engine speed and ignition-delay time and to be essentially independent of the total amount of fuel injected. Accordingly, the premixed-burned fraction increased with increasing engine speed, with decreasing fuel-air ratio and with retarding injection timing. The hydrocarbon emissions did not correlate well with the premixed-burned fraction. In contrast, the oxides of nitrogen emissions were found to increase with decreasing premixed-burned fraction, indicating that diffusion burning, and not premixed burning, is the primary source of oxides of ...
NEWTON's first law prohibits the coupling of free tachyons to ordinary matter, if it is interpreted as selection rule interdicting emission without change of the rest-mass of the emitting system.
This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The authors investigated the evolution and radiation characteristics of individual neutron stars and stellar systems. The work concentrated on phenomena where new techniques and observations are dramatically enlarging the understanding of stellar phenomena. Part of this project was a study of x-ray and gamma-ray emission from neutron stars and other compact objects. This effort included calculating the thermal x-ray emission from young neutron stars, deriving the radio and gamma-ray emission from active pulsars and modeling intense gamma-ray bursts in distant galaxies. They also measured periodic optical and infrared fluctuations from rotating neutron stars and search for high-energy TeV gamma rays from discrete celestial sources.
(e.g. enclosed cooktop with built in emissions capture and treatment) . " Test hardware in laboratory, reduced pressure and analog habitat. " Objective 1. ...
Divergence betyveen aircraft engine emission regulations pro- posed by EPA and ICAO is discussed Every engine, upon entering service, requires a certificate ...
We have studied the nature of continuum emitted in the visible spectral range from a noncontracted positive column of discharge in a cesium vapor-xenon mixture at a pressure of 45 Torr and at a degree of ionization below 3 ? 10?6. The main contribution to the continuous emission under such conditions is due to electron-xenon atom bremsstrahlung. The intensity of emission has been experimentally and theoretically studied as a function of the electric field strength and electron density in the positive column. It is established that an increase in the visible emission intensity with the electric field strength is related to an increase in the number of hot electrons in plasma.
This paper reports extensive new optical and radio observations of NGC 5728, emphasizing the central regions. Deep photographs revealing detail in the faint spiral arms are briefly discussed. Broad-band UBV CCD images obtained to examine the colors of the stellar populations that comprise the bar and central ring are presented. The velocity field and emission maps obtained from imaging spectroscopic measurements in the H-alpha emission line are discussed. Conventional long-slit spectra covering the ionized gas in the nuclear region are described. Detailed maps of the radio emission in the central regions of NGC 5728 are presented. These combined data provide considerable evidence for the inflow of gas into the nuclear region, in response to the nonaxisymmetric gravitational potential of the bar. The possible relation of this phenomenon to the Seyfert nature of NGC 5728 is also considered. 48 references.
We report novel, high-angular resolution interferometric measurements that imply the near-infrared nuclear emission in NGC 4151 is unexpectedly compact. We have observed the nucleus of NGC 4151 at 2.2 microns using the two 10-meter Keck telescopes as an interferometer and find a marginally resolved source ~0.1 pc in diameter. Our measurements rule out models in which a majority of the K band nuclear emission is produced on scales larger than this size. The interpretation of our measurement most consistent with other observations is that the emission mainly originates directly in the central accretion disk. This implies that AGN unification models invoking hot, optically thick dust may not be applicable to NGC 4151.
The performance of the gaseous fuel supply and its influence on hydrocarbon (HC) emissions of dual-fuel engines have been investigated. A new design of manifold respirators with mixers is also presented in the paper. The design of the gaseous fuel supply system has a great influence on HC emissions in the dual-fuel engine at light load. The problem of scavenging is discussed and solved by using the manifold respirators in the dual-fuel engine. It performs the function of retarding the gaseous fuel entry timing from the moment of intake valve opening, and its delaying effects have been measured and tested. Experimental results show that the manifold respirator gives the best performance in reducing HC emissions compared with a common pipe mixer and a respirator with bo miser. In addition, the mixing effects are sensitive to the mixer configuration. (Author)
Ceramic coatings with high emission were fabricated on Ti6Al4V alloy by microarc oxidation (MAO) with additive FeSO4 into the electrolyte. The microstructure, chemical composition and chemical state of the coatings were determined by SEM, XRD, EDS and XPS, respectively. The bonding strength between the coating and substrate was studied by tensile strength test, together with the thermal shock resistance of the coating. The results showed that Fe content in the coating layer significantly affect its thermal emissivity. The relative content of Fe in the coatings surface increased at first and then decreased with increasing the concentration of FeSO4 in electrolytes, so does the emissivity of the coatings. The bonding strength became weaker with increasing the concentration of FeSO4. In addit...
The Kyoto Protocol attempts through political negotiations to guide participating industrialized countries' greenhouse gas (GHG) emissions from a positive growing trend, to reach a peak point (or turning point), and then be reduced to a negative growth. That means the relationship between decreasing GHG emissions and economic growth may be described by an inverted-U curve (or called a bell-shaped curve), which is consistent with the concept of the Environmental Kuznets Curve (EKC) hypothesis.This research observed that the economic development and GHG emissions in Economies in Transition (EITs) exhibit a hockey-stick curve trend (or called quasi-L-shape curve), that also generates a lot of "hot air" which is significant to the implementation of the Kyoto Protocol. In addition, through the ...
... non- emissive guidance and collision alert, automated transport in dynamic environments, and assembly and inspection. Foveal Vision, Autonomous Agents, ...
Biomass combustion is an important part in a sustainable energy system, but as well a source of submicron (particles < 1 #mu#m) particles in the air. Consequently, to obtain a good air quality together with increased biomass combustion there is a need for a better understanding of particle formation. This work is a part of a larger project about formation and emissions of particles from biofuel combustion. The report includes the work performed in the project during the year 2004. The aim of the project is to describe the release of inorganic components, which cause particle emissions, during combustion of single fuel particles of biofuel, e.g. wood pellets. The work is carried out by emission measurements, systematic combustion experiments and modelling work. The results are expected to contribute to the understanding of which parameters that influence the formation of fine particles and thus gain a better insight into ...
The report contains general information on aluminium and aluminium compounds concerning the existing standards, emissions, exposure levels and effect levels. The document is to be considered as a first evaluation to be used for the national discussion dur...
The iron foundry industry is considered to be a potential source of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). This study investigated the emission factors and total emission amounts of PCDD/Fs and dioxin-like polychlorinated biphenyls (DL-PCBs) from iron foundries in China. The concentrations and the World Health Organization toxicity equivalents (WHO-TEQs) are presented and the congener profiles are discussed in this paper. In the present work, 26 fly ash samples were collected and tested to quantify the PCDD/Fs and DL-PCBs generated by 14 plants of different scales, and five stack gas samples were collected from two (named as EFG and LFG) of those plants. The emission levels of PCDD/Fs and DL-PCBs indicated that hot-air cupolas had lower emissions than cold-air cupol...
The paper discusses a number of recent studies investigating into the energy conservation and environmental impacts of electric heating systems (off-peak storage systems). In future, i.e. in and after 1993, off-peak storage systems will be evaluated through comparative analyses of oil-fired heating systems, pollutant emission analyses, the eventual success of pollution abatement measures designed for power plant emissions to keep within the legal limiting values, and the possible abandonment of pollution abatement measures abroad. Opposing the electric heating studies submitted by the electric power industry the author refutes their favourable results referring to the palliative selection of inadequate or vague parameters. Assuming average power plant pollutant emissions of 180 mg/standard/sup 3/ the nitrogen oxide emissions of oil-fired heating systems (134.1 kg/Tj) are found to be below those of ...
Before the 1997 Kyoto Protocol on Climate Protection, the fluorinated greenhouse gases HFCs, PFCs, and SF6 (F-gases) aroused little public attention. Since then, the standards on surveying and reporting on national emissions have been rising constantly. Amongst others, the annual reporting to the UNFCCC secretariat makes detailed declarations on use and emissions of F-gases necessary, which have to be filled in specified formats for submission (Common Reporting Format = CRF). The scientific basis has been set out by the UNFCCC guidelines on reporting, in accordance with the instructions laid down in IPCC good practice guidance. Additionally, in Germany the Centralised System of Emissions (ZSE) shall provide a suitable tool to satisfy any quality needs of both activity data and emission factors. From 1995 onwards, activity data and emissions of each individual application sector ...
Los Alamos National Laboratory (the Laboratory) is subject to emissions reporting requirements for regulated air contaminants under Title 20 of the New Mexico Administrative Code, Chapter 2, Part 73 (20 NMAC 2.73), Notice of Intent and Emissions Inventory Requirements. The Laboratory has the potential to emit 100 tons per year of suspended particulate matter, nitrogen oxides, carbon monoxide, sulfur oxides, and volatile organic compounds. For 1998, combustion products from the industrial sources contributed the greatest amount of criteria air pollutants from the Laboratory. Research and development activities contributed the greatest amount of volatile organic compounds. Emissions of beryllium and aluminum were reported for activities permitted under 20 NMAC 2.72 Construction Permits.
Although various legislation and regulations have been adopted to promote the use of alternative-fuel vehicles for curbing urban air pollution problems, there is a lack of systematic comparisons of emission control cost-effectiveness among various alternative-fuel vehicle types. In this paper, life-cycle emission reductions and life-cycle costs were estimated for passenger cars fueled with methanol, ethanol, liquefied petroleum gas, compressed natural gas, and electricity. Vehicle emission estimates included both exhaust and evaporative emissions for air pollutants of hydrocarbon, carbon monoxide, nitrogen oxides, and air-toxic pollutants of benzene, formaldehyde, 1,3-butadiene, and acetaldehyde. Vehicle life-cycle cost estimates accounted for vehicle purchase prices, vehicle life, fuel costs, and vehicle maintenance costs. Emission control cost-effectiveness presented in dollars ...
The properties of negative-ion beams are very important for designing negative-ion apparatus and applications of negative-ion beams, especially, electron detachment cross-sections at the interaction between negative-ion beams and gas particles in the transport system, and secondary-electron emission factors when negative ions are incident on solid surfaces. These properties of negative-ion beams were investigated experimentally as a function of the ion energy under 50 keV. The single electron detachment cross-sections are almost constant in the other of 10[sup -15] cm[sup 2] in this energy range, but double electron detachment cross-sections increase in proportion to the ion velocity and much smaller than the single one. As for the secondary-electron emission factor, the emission factors for negative-ion beam are found to be larger by 1 than those for positive-ion beams. (author).
The properties of negative-ion beams are very important for designing negative-ion apparatus and applications of negative-ion beams, especially, electron detachment cross-sections at the interaction between negative-ion beams and gas particles in the transport system, and secondary-electron emission factors when negative ions are incident on solid surfaces. These properties of negative-ion beams were investigated experimentally as a function of the ion energy under 50 keV. The single electron detachment cross-sections are almost constant in the other of 10"-"1"5 cm"2 in this energy range, but double electron detachment cross-sections increase in proportion to the ion velocity and much smaller than the single one. As for the secondary-electron emission factor, the emission factors for negative-ion beam are found to be larger by 1 than those for positive-ion beams. (author).
Experiments have been conducted to study the effect of injection pressure on the combustion process and exhaust emissions of a direct injection diesel engine fueled with Orange Skin Powder Diesel Solution (OSPDS). Earlier investigation by the authors revealed that 30% OSPDS was optimum for better performance and emissions. In the present investigation the injection pressure was varied with 30% OSPDS and the combustion, performance and emissions characteristics were compared with those of diesel fuel. The different injection pressures studied were 215bar, 235bar and 255bar. The results showed that the cylinder pressure with 30% OSPDS at 235bar fuel injection pressure, was higher than that of diesel fuel as well as at other injection pressures. Similarly, the ignition delay was longer and wi...
This standard specifies requirements for the flameproofing and the limiting of surface temperature and exhaust emission control of diesel engine systems for use in underground coal mines.
The work described in the following is a portion of the MEET project (Methodologies for Estimation Air Pollutant Emissions from Transport). The overall goal of the MEET project is to consolidate and present methodologies which can be used to estimate air pollutant emissions from various types of traffic sources. One of the goals of MEET is to provide methodologies to be used in the COMMUTE project also funded by DG VII. COMMUTE is developing computer software which can be used to provide emissions inventories on the European scale. Although COMMUTE is viewed as a prime user of the information generated in MEET, the MEET results are intended to be used in a broader area, and on both smaller and larger spatial scales. The methodologies and data presented will be useful for planners on a more local scale than a national or continental basis. While most attention in previous years has been concentrated on ...
... 1-sigma ZOHF pixel-to-plxel statistical fluctuations ... Spatial frequency filtering shows distinct bands, but miss ... LOS emissivity at the point of closest ...
Fire-driven deforestation is the major source of carbon emissions from Amazonia. Recent expansion of mechanized agriculture in forested regions of Amazonia ...
on the range of available deforestation, forest degradation, ... Results: Deforestation estimates showed good agreement for multi-year trends of increasing ...
The molar heat capacities (Cp,m) of a series of synthetic forsterite (Fo)-fayalite (Fa), (Mg2SiO4+Fe2SiO4), olivines have been measured between 5K and 300K on milligram-sized samples with the Physical Properties Measurement System (Quantum Design(R)). Sharp, ?-type heat capacity anomalies are observed in the Fe-rich compositions fayalite, Fo10Fa90, Fo20Fa80, Fo30Fa70, and Fo40Fa60. The corresponding Neel temperatures TN decrease linearly from 64.5K in fayalite to 32.8K in Fo40Fa60 following the relationship TN=79.02.xFa-14.07. Fo50Fa50 and Mg-richer olivines show weak broad features in the heat capacity data around 15K to 20K that decrease in magnitude with increasing forsterite content. In order to derive and separate molar electronic, magnetic and vibrational heat capacity contributions, Cel,m, Cmag,m, and Cvib,m from the experimental heat capacities (Ctot,m), we used a single-parametric phonon dispersion model to calculate Cvib,m for the solid-solution members and fayalite. The ...