ScienceCinema

...of global warming ? ...coal has created a global warming of temperatures ...that global warming is real and that we have changed the world ...the global warming possibly ten degrees that have ? ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

British Library Electronic Table of Contents (United Kingdom)

Dielectric and thermal characteristics of gel grown single crystals of ytterbium tartrate trihydrate have been carried out. The dielectric constant has been measured as a function of frequency in the range 2?kHz?1?MHz and temperature range 30?300??C. The dielectric constant increases with temperature, attains a peak near 215??C, and then decreases as the temperature exceeds 215??C. The dielectric anomaly at 215??C is suggested to be due to phase transition brought about in the material. The dielectric behaviour of the material is correlated with the results on thermal analysis. Thermogravimetric and differential thermal analysis have been used to study the thermal characteristics of the material. The experimental results show that the material is thermally stable up to 200??C. The decompos...

International Nuclear Information System (INIS)

BaTi_0_._9(Ni_1_/_2W_1_/_2)_0_._1O_3 ceramics were fabricated and their dielectric properties were investigated. With the sintering temperature increasing from 1250 to 1280 deg. C, the grain size abruptly increases from 1-2 to 20-40 #mu#m, accompanying significant changes in dielectric response. The samples with larger grains exhibit giant dielectric constant characteristics, which are considered to be mainly attributed to the domain boundary effect. The activation energies of the dielectric relaxation E_r_e_l_a_x=0.325 eV reveal the existence of microdomains in larger grains. The ac conductivity results also give the evidence of the domain boundary effect in the present ceramics.

Science.gov (United States)

The kinetics of electrical breakdown of thin (15-70 ?m) layers of polymers and ceramics in a constant-sign field at 77-480 K has been investigated. The temperature dependences of the longevity (breakdown waiting time) of both dielectrics have been found to be similar to each other. At elevated temperatures, the longevity of the dielectrics varies exponentially with increasing temperature, and at reduced temperatures, it is temperature-independent (there is an athermal plateau). The mechanisms of elementary events controlling the process of preparation of the dielectrics for breakdown at elevated and reduced temperatures are the thermal-fluctuation over-barrier electron transition from trap to trap and the tunneling (under-barrier) transition, respectively. The hopping electron transport in the field ...

ScienceCinema

...that global warming is cost ...just global warming ...global warming ...

Energy Technology Data Exchange (ETDEWEB)

The effect of warm rolling under various conditions on the microstructure and mechanical property was investigated using an AZ31 Mg alloy sheet. Several processing parameters such as initial thickness, thickness reduction by a single pass rolling, rolling temperature, roll speed, and roll temperature were varied to elicit an optimum condition for the warm rolling process of AZ31 Mg alloy. Microstructure and mechanical properties were measured for specimens subjected to rolling experiments of various conditions. Warm rolling of 30% thickness reduction per pass was possible without any side-crack at temperatures as low as 200 C under the roll speed of 30 m/min. The initial microstructure before rolling was the mixed one consisting of partially recrystallized and cast structures. Grain refinement was found to occur actively during the warm ...

British Library Electronic Table of Contents (United Kingdom)

Fine-grained BaTiO3-based X7R ceramic materials were prepared and the effects of milling process on the core-shell structures and dielectric properties were investigated using scanning electron microscope, transmission electron microscope, and energy dispersive spectroscopy (EDS). As the milling time extends, the dielectric constant of the ceramics increases, whereas the temperature coefficient of capacitance at 125degreeC drops quickly. The changes in dielectric properties are considered relevant to the microstructure evolution caused by the milling process. Defects on the surface of BaTiO3 particles increase because of the effects of milling process, which will make it easier for additives to diffuse into the interior grains. As the milling time increases, the shell region gets thicker a...

International Nuclear Information System (INIS)

Thermally stable materials with low dielectric constant (k<3.9) are being hotly pursued. They are essential as interlayer dielectrics/intermetal dielectrics in integrated circuit technology, which reduces parasitic capacitance and decreases the RC time constant. Most of the currently employed materials are based on silicon. Low k films based on organic polymers are supposed to be a viable alternative as they are easily processable and can be synthesized with simpler techniques. It is known that the employment of ac/rf plasma polymerization yields good quality organic thin films, which are homogenous, pinhole free and thermally stable. These polymer thin films are potential candidates for fabricating Schottky devices, storage batteries, LEDs, sensors, super capacitors and for EMI shielding. Recently, great efforts have been made in finding alternative methods to prepare low dielectric constant thin ...

Energy Technology Data Exchange (ETDEWEB)

The effective electron mobility was measured as a function of surface field in polysilicon thin film transistors having the following three types of gate dielectrics; silicon dioxide deposited by low temperature (350degC) plasma-enhanced chemical vapor deposition (PECVD), low temperature (400degC) nitrogen-rich PECVD silicon nitride and high temperature (1050degC) thermally grown silicon dioxide. At low surface fields, the maximum true effective electron mobility was 40[+-]3 cm[sup 2] V[sup -1] s[sup -1] in all devices independent of the type of gate dielectric, indicating that the quality of the interface is the same. However, at high surface fields a stronger degradation of the mobility was observed in devices having the thermally grown silicon dioxide as gate dielectric, indicating the presence of surface roughness within the interfacial region. The ...

British Library Electronic Table of Contents (United Kingdom)

In this work, we report the preparation of lead titanate (PT) nanoceramics (with an average grain size of ~200nm in diameter) by using hydrothermal PT nanoparticles as start materials and characterized the dielectric and ferroelectric properties. The dielectric constant of the ceramic was found to be ~180 (at 1kHz) at room temperature and reached a maximum value of 8330 at ~490^oC, suggesting that the Curie temperature of the nanoceramics is consistent with the known value of PT crystals. Ferroelectric domains and hysteresis loops were obtained through piezoelectric force microscopy measurements, which provide direct and clear evidence for the ferroelectricity in the nanoceramic samples.

International Nuclear Information System (INIS)

The results of dielectric measurements in a wide frequency range have been used to find that solid solution samples on the basis of PbSc_1_/_2Sb_1_/_2O_3 have blurred phase transitions. The Curie-Weiss law is performed for different compositions in the temperature range 10-150 K above Curie point. The change of value and sign of the difference between Curie and Curie-Weiss temperatures is connected with the change of phase transition blurring degree.

CERN Document Server

We study from a critical perspective several quantum-electrodynamic phenomena commonly related to vacuum electromagnetic (EM) fluctuations in complex media. We compute the resonance-shift, the spontaneous emission rate, the local density of states and the van-der-Waals-Casimir pressure in a dielectric medium using a microscopic diagrammatic approach. We find, in agreement with some recent works, that these effects cannot be attributed to variations on the energy of the EM vacuum but to variations of the dielectric self-energy. This energy is the result of the interaction of the bare polarizability of the dielectric constituents with the EM fluctuations of an actually polarized vacuum. We have found an exact expression for the spectrum of these fluctuations in a statistically homogeneous dielectric. Those fluctuations turn out to be different to the ones of normal radiative modes. It is the latter that ...

ScienceCinema

...contribution to global warming ...states i think impact of global warming ? and ...contributor to global warming ...

International Nuclear Information System (INIS)

The rapid progress of industrialization and urbanization due to economic growth and concentration of social function in the urban areas in Japan have had an adverse effect on the urban environment. In most cities, it has become evident that the increase in energy consumption is causing environmental problems, including a temperature rise in the urban atmosphere (urban heat island) and air pollution. This paper reports the results of field observations and three dimensional simulations of the urban heat island using a three-dimensional modelling vorticity-velocity vector potential formation, in the Tokyo metropolitan area. According to the simulation for urban warming in the study area for the year 2031, the maximum temperature of a summer evening (18:00) would exceed 43 degrees celsius, indicating that Tokyo would no longer be comfortable for its inhabitants. It is concluded that in the near future, the problem of the urban ...

ScienceCinema

...global warming um ? know he's been right into our our ...who was a little bit about global warming and cooling ...global warming ...america uh we can help ? global warming and reduce the demand for electricity and and ...now means that those who immediately combat global warming ? ...global warming ...global warming ...global warming by ...we ? in terms of the contribution to global warming is a small i mean anything else ...global warming and ...among scientists are speaking out about global warming the only thing they really talk about a year to ...the other factors that affect global warming and i i just feel that ...problem of global warming would have to ...global warming ...global ...

ScienceCinema

...great global warming ...global warming and and uh if something is known about ...

Science.gov (United States)

Description of how global warming could be disastrous for much of the earth's population....

International Nuclear Information System (INIS)

Measurements of the electrical conductivity, dielectric constant and magnetic susceptibility of pellets of erbium tungstate are reported for the temperature range 300 to 1000 K. The known phase transition near 600 K is in evidence in all these measurements. The conductivity data for T>600 K have been analysed in terms of an exponential relation sigma=sigmasub(0)exp(-Esub(g)/2kT), giving sigma_0=8.892x10"2ohm"-"1cm"-"1 and Esub(g)=1.52eV. There is a weak dispersion in the dielectric constant at around 10"4Hz and a rapid increase above 600 K. The high-temperature data for the susceptibility obey a Curie-Weiss law that gives a value of 9.50 Bohr magneton for Er"3"+ ions and a (ferromagnetic) Curie temperature of 160 K. (author).

Energy Technology Data Exchange (ETDEWEB)

The properties of capacitors are reviewed in general, including dielectrics, induced polarization, and permanent polarization. Then capacitance characteristics are discussed and modelled. These include temperature range, voltage, equivalent series resistance, capacitive reactance, impedance, dissipation factor, humidity and frequency effects, storage temperature and time, and lifetime. Applications of energy storage capacitors are then discussed. (LEW)

International Nuclear Information System (INIS)

The present situation of the researches that have been made for predicting the process and range of diffusion of warm drain is reviewed. This review is divided into eight sections. The first section deals with the present situation of warm drain from power plants. For the establishment of drainage standard, there are many difficult problems to be solved because water temperature differs in its nature from other regulation items. In the second section, the process of diffusion and cooling of warm drain is explained. The third section deals with the diffusion characteristics of warm drain in Japanese coastal sea due to water temperature. Two types of diffusion are known. One is dominant irregular current, and the other is periodical reciprocating stream. The fourth section deals with the methods of prediction of diffusion. Research methods and simulation models ...

Science.gov (United States)

The Global Warming International Center (GWIC) is the international body disseminating information on global warming science and policy, serving both governamental, non-governamental ... ...

International Nuclear Information System (INIS)

Diurnal and seasonal thermal constancy, a greatly delayed seasonal temperature maximum, and summer cool and winter warm conditions characterize the stream environment below a deep-release dam in Colorado. Low diversity index and equitability values and changes in macroinvertebrate species composition may result from failure of the temperature regime to provide the thermal stimuli essential for various life-cycle phenomena. It is hypothesized that the following sublethal effects, directly or indirectly resulting from the modified temperature regime, may further alter macroinvertebrate community structure: reduction of niche overlap and a shift toward an equilibrium community as a consequence of reduced environmental fluctuation; more intense competition associated with greater productivity; elimination of major invertebrate predators; and failure of the limited temperature range to ...

Science.gov (United States)

The brain hypothermia treatment is an attractive therapy for the neurologist because of its neuroprotection in hypoxic-ischemic encephalopathy patients. The present paper deals with the possibility of controlling the brain and other viscera in different temperatures from the viewpoint of system control. It is theoretically attempted to realize the special brain hypothermia treatment to cool only the head but to warm the body by using the simple apparatus such as the cooling cap, muffler and warming blanket. For this purpose, a biothermal system concerning the temperature difference between the brain and the other thoracico-abdominal viscus is synthesized from the biothermal model of hypothermic patient. The output controllability and the asymptotic stability of the system are examined on the basis of its structure. Then, the maximum temperature difference to be realized is shown ...

International Nuclear Information System (INIS)

Possibility for using a sodium iodide scintillator as a reference signal source is considered. Experimental data on studying the performance of a gamma thickness gage with an additional scintillator are given. Results of experimental investigations of a thickness gage dummy proved practical expediency of the principle being considered. It is established, in particular, that the device is ready to operate without warm-up with a constant sensitivity, the deviation not exceeding 0.5%, in the ambient temperature range of 15-25 deg C.

International Nuclear Information System (INIS)

Mn-modified Pb0.92La0.08(Zr0.65Ti0.35)O3 (PLZT) was prepared chemically by a coprecipitate method using their respective nitrate salts and isopropoxides. Differential thermal analysis (DTA) and X-ray analysis clearly show the formation of PLZT single rhombohedral phase for samples calcined beyond 750 C. Uniform grain distribution was observed from scanning electron microscopic (SEM) studies and grain size was found to increase with Mn doping up to x=0.08 and then decreased. Dielectric measurement shows the decrease in peak transition temperature (TC) with Mn doping up to x=0.12 and then increase along with a sharp rise in dielectric maxima. A diffuse dielectric dispersion is observed in all the compositions. A detailed dispersion study was carried out using the Vogel-Fulcher empirical relation, a universal relaxation law and the Havriliak-Negami function. The Vogel-Fulcher relation fitting parameters of ...

Science.gov (United States)

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ScienceCinema

...global warming and so ...

International Nuclear Information System (INIS)

At atmospheric pressure and room temperature, dielectric barrier discharge induced plasma oxidation for achieving supported TiO2 photocatalysts derived from TiCl4 adsorbed onto ?-Al2O3 pellets was studied. The supported TiO2/?-Al2O3photocatalysts prepared by a cyclic 'adsorption-discharge' approach, without requirement of heat treatment, exhibit high activity in the photocatalytic degradation reaction of formaldehyde. The mass spectra and optical emission spectra during O2/Ar discharge for oxidizing the adsorbed-state TiCl4 were measured. The mechanism for the TiO2 formation from adsorbed-state TiCl4 by plasma oxidation was discussed.

ScienceCinema

...global warming issues ...people stopping we put a big issue with global warming copenhagen going on at the moment it's a waste of money ...

Science.gov (United States)

... insight into the best way to communicate about global warming and it's impact on wildlife to the " ... ...

Science.gov (United States)

Archived Web resource. Information about the impacts of global warming on the environmental quality and recreation, such as ... ...

International Nuclear Information System (INIS)

Praseodymium-doped Bi_4Ti_3O_1_2 (BIT) with various compositions of dopant, Pr (x = 0.5, 0.6, 0.7, 0.8) in Bi_4_-_xPr_xTi_3O_1_2 (BPT) were synthesized using a low temperature wet chemical technique. Powders calcined at 800 deg. C exhibit a single phase polycrystalline perovskite bismuth-layered structure. Randomly oriented plate-like structures were observed under Scanning Electron Microscope (SEM). A small amount of Pr doping (x = 0.5) resulted in dramatically reduced of grain size from 2 #mu#m to less than 50 nm in which Pr plays the role as a grain growth inhibitor. However, by increasing the composition of Pr, bigger grain size of up to 1 #mu#m was observed for x = 0.8 that was caused by diffusion of Pr in the perovskite structure. Dielectric properties showed that dielectric permittivity decreased with the addition of x = 0.50, and increasing with further addition of Pr. Dissipation factor (tan #delta#) followed the ...

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

We have grown ferroelectric Pb{sub 0.92}La{sub 0.08}Zr{sub 0.52}Ti{sub 0.48}O{sub 3} (PLZT) films on platinized silicon and LaNiO{sub 3}-buffered nickel substrates by chemical solution deposition using a sol-gel process based on acetic acid chemistry. The following measurements were obtained under zero-bias field: relative permittivity of {approx}960 and dielectric loss of {approx}0.04 on the PLZT film grown on Pt/Si substrates, and relative permittivity of {approx}820 and dielectric loss of {approx}0.06 on the PLZT film grown on LNO-buffered Ni substrates. In addition, a relative permittivity of 125 and dielectric loss of 0.02 were measured at room temperature under a high bias field of 1 x 10{sup 6} V/cm on PLZT deposited on LNO-buffered nickel substrate. Furthermore, a steady-state leakage current density of {approx}8.1 x 10{sup -9} A/cm{sup 2} and mean breakdown field strength of 1.7 x 10{sup 6} ...

Science.gov (United States)

An experimental investigation of natural convection heat transfer from a commercially available semiconductor device package is presented. The package was centrally mounted on a ceramic substrate. The package-substrate assembly formed one surface of a dielectric-filled cubical enclosure of aspect ratio one. The top surface of the enclosure was maintained at prescribed temperature. Surface temperature measurements were made at various locations on the substrate, the package lid, as well as the chip center. These measurements are reported for three dielectric fluids and three enclosures top surface temperatures, both with the substrate oriented horizontally as well as vertically. The results indicate that the maximum input power without exceeding a chip junction temperature of 80 C is 2.58 watts with FC-75 as the cooling fluid and the upper boundary maintained at ...

Energy Technology Data Exchange (ETDEWEB)

The absence of high-temperature electronics is an obstacle to the development of untapped energy resources (deep oil, gas and geothermal). US natural gas consumption is projected to grow from 22 trillion cubic feet per year (tcf) in 1999 to 34 tcf in 2020. Cumulatively this is 607 tcf of consumption by 2020, while recoverable reserves using current technology are 177 tcf. A significant portion of this shortfall may be met by tapping deep gas reservoirs. Tapping these reservoirs represents a significant technical challenge. At these depths, temperatures and pressures are very high and may require penetrating very hard rock. Logistics of supporting 6.1 km (20,000 ft) drill strings and the drilling processes are complex and expensive. At these depths up to 50% of the total drilling cost may be in the last 10% of the well depth. Thus, as wells go deeper it is increasingly important that drillers are able to monitor conditions down-hole such as ...

British Library Electronic Table of Contents (United Kingdom)

For an ultrafine grain ferrite/cementite (UGF/C) steel, the Charpy impact energy was measured at temperatures from 373K to 4.2K, and tensile tests were carried out at temperatures between 323K and 77K. For the steel with annealed microstructure, the ductile-to-brittle transition appearance temperature (DBTT) was lower than the Charpy transition temperature (CTT). With increasing annealing time at 873K, the DBTT and the CTT increased, and the DBTT approached the CTT. The DBTT decreased with decreasing effective grain size. The effective grain size correlated to the grain size of the larger grain size peak in the distribution of grains with {100} planes. The annealed microstructures had higher yield strength for equivalent toughness (including upper shelf energy, DBTT and CTT) compared to th...

Energy Technology Data Exchange (ETDEWEB)

There are two major water currents off the coast of Peru in South America. The Humboldt or Peru current travels northwest across latitudes 35/sup 0/S to 6/sup 0/S. To the north, a branch of the equatorial current flows southward down to latitudes 6-7/sup 0/S in normal years. Its warm, less salty water is poor in nutrients and cannot support fishery. In some years, this warm current extends much more southward, down to 12/sup 0/S. This has a catastrophic effect leading to a mass mortality of the anchovies and, in turn, of the guano birds and less production of farm crops. This phenomenon occurs around Christmas (summer in the southern hemisphere) and is, therefore, called El Nino. The main feature of El Nino is to change the sea surface temperature. An abnormal rise in sea surface temperature can give rise to odd air movements which can change the monsoons pattern, even at distant places, profoundly. In ...

British Library Electronic Table of Contents (United Kingdom)

BaxSr1-xTiO3 (x=0.6, 0.75, 0.80, 0.85 and 0.9) compositions are prepared by solid-state reaction route using controlled heating and cooling. Density optimization by varying sintering temperature was achieved. X-ray diffraction (XRD) analysis shows the phase pure materials. The lattice constant decreases from 3.9868A (x=0.90) to 3.9449A (x=0.60) with increasing Sr2+; the tetragonal distortion also decreases. Dielectric constant show sharp peaks for samples having low strontium content (0.10, 0.15) and gets smeared out as the strontium content is increased (0.20, 0.25). For further higher Sr2+ composition (0.40), the dielectric peak could not be observed in the measured temperature range. The peak broadening in Sr2+ rich compositions indicates that diffused transitions and is attributed to t...

Energy Technology Data Exchange (ETDEWEB)

Diesel passenger car is superior to gasoline engine car in the fuel economy, but it has some defects to improve: noise, startability, particulate and transient performance, etc. Among these problems, this paper presents particularly transient performance in a diesel engine and clarifies the causes of its decline at lower temperature operation. As the results, it is found that the transient torque at the early stage of acceleration is only 50% at -20/sup 0/C, and that when coolant temperature went up to 20/sup 0/C, the transient torque approaches to that of the warmed up engine. The transient response become worse with retarding the injection timing and with decreasing the engine speed. On the other hand, since the normal response is not obtained despite using high cetane number fuel, main cause of the inferior transient torque is not the poor combustion, but the increase of friction or cooling loss.

Energy Technology Data Exchange (ETDEWEB)

A method for determining the mobility of hydrogen as a function of temperature in superconducting niobium cavities comprising: 1) heating a cavity under test to remove free hydrogen; 2) introducing hydrogen-3 gas into the cavity; 3) cooling the cavity to allow absorption of hydrogen-3; and 4) measuring the amount of hydrogen-3 by: a) cooling the cavity to about 4.degree. K while flowing a known and regulated amount of inert carrier gas such as argon or helium into the cavity; b) allowing the cavity to warm at a stable rate from 4.degree. K to room temperature as it leaves the chamber; and c) directing the exit gas to an ion chamber radiation detector.

Energy Technology Data Exchange (ETDEWEB)

The purpose of this study is fabrication and characterization of silver nanofluid by the submerged arc nanoparticle synthesis system (SANSS). The silver metal electrodes under the electrical discharge will melt and evaporate rapidly and condense to form the nanoparticles in the lower temperature dielectric liquid and produce the suspended nanoparticle. The results showed that the spherical nanosilver particle formed in the ethylene glycol and the mean particle size is about 12.5 nm. The prepared silver nanofluid was irradiated under the 410 nm visible light, electrons could be excited from the valence band to the conduction band. The silver nanofluid more closely resembles Newtonian fluids.

International Nuclear Information System (INIS)

Mo gate Mos capacitors exhibit a negative shift of their C-V characteristic by up to 240 mV, at 125 C, in response to 1000 ppm hydrogen, in controlled nitrogen atmospheres. The experimental methods for obtaining capacitance and conductance, as a function of polarisation voltage, as well as the relevant equivalent circuits are reviewed. The single-state interface state density, at the semiconductor-dielectric interface, decreases from 2.66 x 10"1"1 cm"-"2 e-v"-"1, in pure nitrogen, to 2.5 x 10"1"1 cm"-"2 e-v"-"1 in 1000 ppm hydrogen in nitrogen mixtures, at this temperature. (Author)

International Nuclear Information System (INIS)

Ferroelectric Pb_0_._9_8_2_-_zLa_0_._0_1_2#DELTA#_0_._0_0_6Ba_z(Zr_0_._5_5Ti_0_._4_5)O_3 (PLZT; z = 0-6 mol%) ceramic compositions were fabricated by a mixed-oxide method. X-ray diffraction studies of sintered ceramics indicate the coexistence of rhombohedral and tetragonal phases in the 5 mol% Ba-doped PLZT composition. Grain growth is inhibited with increasing Ba concentration in the PLZT system as evidenced by scanning electron micrographs. Dielectric constant and dielectric loss as a function of temperature suggest that #epsilon#_r_t and tan #delta# are increased up to compositions containing 4 and 5 mol% Ba, respectively. The dielectric maximum (#epsilon#_T_c) decreased to 4 mol% Ba and gradually increased to 6 mol% Ba, whereas, with increasing Ba concentration in the PLZT system, the Curie temperature (T_C) decreased from the composition with no Ba to that with 6 mol% Ba. ...

Science.gov (United States)

Information about the greenhouse effect, the role of greenhouse gases in global climate change, levels of greenhouse gases in the atmosphere, and references....

Science.gov (United States)

Is global warming contributing to amphibian declines and extinctions by promoting outbreaks of the chytrid fungus Batrachochytrium dendrobatidis? Analyzing patterns ... ...

International Nuclear Information System (INIS)

The static magnetization of solid "3He contained in sintered copper was measured. The results of the density on the melting curve show that below 5 mK, the magnetization M rises above the Curie-Weiss law extrapolated from high temperature. It reaches a maximum of twice as much as the Curie Weiss law value at temperature Tm, which would be somewhat below 1.25 mK if the system could be warmed up at infinitesimally slow rate. Below Tm, M decreases rapidly to 0.4 of its maximum, then appears to become independent of temperature. The previously reported decrease of specific heat below the Curie-Weiss law value in the range below 4 mK is apparently related to the increase of M in that range. At the low temperature end, apparent decrease of M is due to the fact that there is background magnetization which is out of equilibrium with the thermometer when there is solid "3He in the sample ...

Energy Technology Data Exchange (ETDEWEB)

Specimens of glassy Pd{sub 80}Si{sub 20} were irradiated at temperatures below 100K with 3.5 MeV krypton ions. After irradiation, changes in the sound velocity were measured at 80 K without warm-up by Brillouin scattering. The sound velocity decreased with increasing ion fluence and exponentially approached a saturation value of -4.7%. The change in the shear elastic modulus per unit concentration n of defects was estimated to be d(ln C)/dn = -9.4 to -4.7. The results of the present study are compared with changes in the elastic properties predicted recently by an interstitialcy model for glassy metals, and with the elastic properties of glassy metals after thermal treatment.

International Nuclear Information System (INIS)

GaAs1-xPx p-n junction structures were grown on the epi-ready n-type GaAs(100) substrate by solid source MBE system for different phosphor compositions. To obtain the lattice-match sample structure was applied graded growth procedure. The structural and optical properties of the sample structures with different P concentration were investigated by using X-ray diffraction (XRD), spectroscopic ellipsometry (SE). In addition, The range of lattice parameters in the graded epilayer and phosphorous composition were determined from the HRXRD rocking curve simulation. We analyse dielectric function spectra of disordered GaAs1-xPx junction structures measured using spectroscopic ellipsometry at room temperature in the 0.6-4.7 eV photon energy region. The critical energy points such as band gap energy and spin-orbit-split energy of these structures were determined using SE data. It is detected that E0, E1 ,E2 energies of the GaAs1-xPx p-n junction ...

British Library Electronic Table of Contents (United Kingdom)

Praseodymium-doped Bi4Ti3O12 (BIT) with various compositions of dopant, Pr (x=0.5, 0.6, 0.7, 0.8) in Bi4-xPrxTi3O12 (BPT) were synthesized using a low temperature wet chemical technique. Powders calcined at 800degreeC exhibit a single phase polycrystalline perovskite bismuth-layered structure. Randomly oriented plate-like structures were observed under Scanning Electron Microscope (SEM). A small amount of Pr doping (x=0.5) resulted in dramatically reduced of grain size from 2mm to less than 50nm in which Pr plays the role as a grain growth inhibitor. However, by increasing the composition of Pr, bigger grain size of up to 1mm was observed for x=0.8 that was caused by diffusion of Pr in the perovskite structure. Dielectric properties showed that dielectric permittivity decreased with the ad...

CERN Document Server

Using electron spin resonance, lattice position and dynamic properties of Mn2+ ions were studied in 0.5 and 2 % manganese doped SrTiO3 ceramics prepared by conventional mixed oxide method. The measurements showed that Mn2+ ions substitute preferably up to 97 % for Sr if the ceramics is prepared with a deficit of Sr ions. Motional narrowing of the Mn2+ ESR spectrum was observed when temperature increases from 120 K to 240-250 K that was explained as a manifestation of off-center position of this ion at the Sr site. From the analysis of the ESR spectra the activation energy Ea = 86 mV and frequency factor 1/?0 ? (2-10)x10^(-14) 1/s for jumping of the impurity between symmetrical off-center positions were determined. Both values are in agreement with those derived previously from dielectric relaxation. This proves the origin of dielectric anomalies in SrTiO3:Mn as those produced by the reorientation dynamics of Mn2+ dipoles.

International Nuclear Information System (INIS)

BaTiO_3 compacts, when fluxed with < 2 vol% of a complex borate glass phase, were sintered to near theoretical density at temperatures < 1175 degrees C in 2 h. Microstructural analysis showed a uniform grain size < 1.0 #mu#m with 0.75 wt% ZrO_2 added to the flux phase as a grain growth inhibitor. TEM analysis revealed a microcrystalline grain-boundary phase with the ZrO_2 resident along the grain boundaries. These samples displayed an essentially flat dielectric profile, low dissipation factors (< 2%) over the range 25 degrees to 125 degrees C, a near linear dependence (#approx# #+-# 15%) between 25 degrees and - 55 degrees C, and significantly increased voltage stability. X-ray diffraction analysis of these small-grained materials indicates a suppression of the tetragonal structure toward a more cubic modification.

Energy Technology Data Exchange (ETDEWEB)

Space heating/cooling systems account for approximately 30% of the global energy consumption. Such systems contribute to global warming by emitting 0.39.1011 MWh of heat and 2.9.1010 tons of CO{sub 2}. There is a general understanding that the way to reduce global warming is a more efficient use of energy and increased use of renewable energy in all fields of the society. The poultry industry in the Mid East is an important business. There are e.g. 13000 chicken farms in Syria producing 172,000 ton of meat. This industry employs directly almost 150,000 people. The total investment in chicken farming is 130 BSP. Even though, the annual mean temperature in Syria is {approx}15-18 C the winter temperatures are close to freezing for two months. Since the chickens need a temperature of 21-35 C, depending on age, approximately 168.103 tons of coal (1170 GWh) is consumed for heating these ...

Energy Technology Data Exchange (ETDEWEB)

Magnesium is known to have poor formability at room temperature, mainly attributed to its hexagonal lattice structure. This paper presents the findings generated from development of warm forming to produce thin-walled magnesium components. Finite element analysis was conducted to evaluate the formability of the material and the simulated results were compared to the tensile results and product formability. Tensile tests were used to verify the formability of the sheet metal at difference temperatures. The process parameters considered in the feasibility study were forming temperature, in the range of 28 C to 300 C and magnesium sheet (AZ31B-H24) thickness, in the range of 0.4 mm to 1 mm. Magnesium hand phone covers of a thickness down to 0.4 mm have been successfully produced. The feasible forming temperature was found to be between 200 C and 250 C. Metallographic examination shows ...

ScienceCinema

...energy back into space model global warming the ? is the energy that ...

Science.gov (United States)

This fact sheet summarizes the potential impact of climate change as it relates to California's electricity supply. ...

ScienceCinema

...you know global warming and all that but that's a very small ...

Energy Technology Data Exchange (ETDEWEB)

The use of WPC as an important insulating material is studied by determining its dielectric constant. The variation of dielectric constant with moisture content is also investigated. Preliminary results show that all untreated woods studied have a higher dielectric constant than their polymer composites with the exception of Kapur and Keruing. It is therefore postulated that the presence of polymers has led to a decrease in the number of polarizable units. Such a material may be useful commercially.

KoreaScience (Korea)

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The primary objective of this project is to investigate the effects of global change on the biodiversity of aphid communities in Western Europe. Biodiversity has been examined at 3 levels: total number of species, phenology and reproductive strategy. Data were provided by EXAMINE, the European suction traps network which has been now operating for 35 years. 392 different species have been identified. At each location, total number of species has been regularly increasing, one additional species being caught every 1 or 2 years depending on location. This is due to introduced species but also to warming which favours rare species. No general trend of increasing density has been detected, but phenological earliness of almost all species (annual date of first appearance in suction traps) is strongly correlated with temperature and especially with mean daily temperature (during more or less long periods of time lying principally ...

International Nuclear Information System (INIS)

The Moessbauer emission spectrum of "2"4"1Am metal was investigated for influences of radiation self damage. Samples were kept continuously for 230 h at 4.2 K and spectra were taken each 10 to 20 h. No change in f-factor was observed, while the linewidth increased monotonically and reached saturation after approximately 180 h. The original width could be reproduced by a brief warming to room temperature. The increase in width reflects the change in quadrupole interaction due to the creation of lattice defects. The constancy of the f-factor indicates that the basic crystalline structure is retained.

Energy Technology Data Exchange (ETDEWEB)

The mechanisms involved in the glacial inception are still poorly constrained due to a lack of high resolution and cross-dated climate records at various locations. Using air isotopic measurements in the recently drilled NorthGRIP ice core, we show that no evidence exists for stratigraphic disturbance of the climate record of the last glacial inception ({proportional_to}123-100 kyears BP) encompassing Dansgaard-Oeschger events (DO) 25, 24 and 23, even if we lack sufficient resolution to completely rule out disturbance over DO 25. We quantify the rapid surface temperature variability over DO 23 and 24 with associated warmings of 10{+-}2.5 and 16{+-}2.5 C, amplitudes which mimic those observed in full glacial conditions. We use records of {delta}{sup 18}O of O{sub 2} to propose a common timescale for the NorthGRIP and the Antarctic Vostok ice cores, with a maximum uncertainty of 2,500 years, and to examine the interhemispheric sequence of events ...

Energy Technology Data Exchange (ETDEWEB)

In the present study, element interdiffusions at the cofired interface of 9/1 Ag/Pd electrode and lead magnesium niobate (PMN)-based ferroelectrics were investigated using Auger Electron Spectroscopy (AES). Intense interdiffusions at the interface were observed while Ag and Pd could penetrate into the ceramics for about 1 {mu}m. Ag-doping experiments were carried out to further study the effects of Ag diffusion on electrical properties of the ceramics. The results showed that Ag could be incorporated into solid solution of the ceramics as Ag{sup +}. As a whole, the Curie temperature (Tc) and dielectric constant of the ceramics decreased with Ag addition. However, Ag addition had no obvious effect on the insulation resistivity. The results inferred that Ag{sup +} could substitute for Pb{sup 2+} at A site of ABO{sub 3} lattice, thereby oxygen vacancies were generated.

Energy Technology Data Exchange (ETDEWEB)

A 150 Watt thermophotovoltaic (TPV) power generator is being developed. The technical approach taken in the design focused on optimizing the integrated performance of the primary subsystems in order to yield high energy conversion efficiency and cost effectiveness. An important aspect of the approach is the use of a selective emitter radiating to a bandgap matched photovoltaic array to minimize thermal and optical recuperation requirements, as well as the non-recoverable heat losses. For the initial prototype system, fibrous ytterbia emitters radiating in a band centered at 980 nm are matched with high efficiency silicon photoconverters. The integrated system includes a dielectric stack filter for optical energy recovery and a ceramic recuperator for thermal energy recovery. The system has been operated with air preheat temperatures up to 1350K. The design of the system and development status are presented. {copyright} {ital 1997 American ...

Energy Technology Data Exchange (ETDEWEB)

Basic properties and battery performances of the novel high temperature stable lithium salt (Li{sub 2}B{sub 12}F{sub 12}, Dilithium Dodecafluorododecaborate; Li{sub 2}DFB) were studied using a Mn-based cathode and anode composed of a hard carbon and graphite mixture. The effect of co-solvents (mainly linear carbonate in electrolyte formulation of PC/EC/co-solvent (5/30/65 vol% mixture)) on conductivity, viscosity, charge-discharge capacities, rate performance, temperature performance, cycle life and storage life at 60 C was investigated. Conductivity of Li{sub 2}DFB electrolyte increased with reducing its viscosity by changing co-solvent and increasing the volume of the higher dielectric solvent. Li{sub 2}DFB electrolytes showed comparable discharge capacity and columbic efficiency against LiPF{sub 6} electrolyte. Li{sub 2}DFB electrolytes improved the storage life and cycle life of a Mn-based cell at 60 C. (author)

International Nuclear Information System (INIS)

The purpose of this work was to investigate the optical properties of several high T/sub c/ compounds in the form of sputtered films. The measurements are used toward this end: optical absorptance (using a calorimetric technique near 4.2K), which yields (after Kramers-Kronig analysis) the complex dielectric function, and thermoreflectance (which measures the change in reflectance in the optical range when a 1 to 10_0K temperature wave is applied), performed at two ambient temperatures (80 and 300_0K), yielding the differential dielectric function. The sputtered films included Nb"3Ge, Nb"3Al, V"3Ga and Nb"3Ir. It is noted that Nb"3Ir is not a high T/sub c/ superconductor. The thermoreflectance on the bulk samples V"3Si, V"3Ge and single crystal Cr"3Si were not performed because the samples were not in the form of thin films. The thermomodulation studies are correlated with the absorptance measurements in ...

Science.gov (United States)

Lead-free piezoelectric ceramics (1-x)K0.5Na0.5NbO3-xAgSbO3+0.75 mol % MnO2 were prepared by a conventional solid-state sintering technique, and the piezoelectric and dielectric properties of the ceramics were studied. The results of x-ray diffraction suggest that AgSbO3 diffuses into the K0.5Na0.5NbO3 lattices to form a new solid solution with a single-phase orthorhombic perovskite structure. After the addition of AgSbO3, the paraelectric cubic-ferroelectric tetragonal phase transition temperature (TC) and the ferroelectric tetragonal-ferroelectric orthorhombic phase transition temperature (TO-T) decrease, and the ceramics become ``softened,'' resulting in significant improvements in the ferroelectric and piezoelectric properties. The ceramics with x=0.03-0.10 exhibit excellent piezoelectric properties: d33=130-216 pC/N, kp=0.44-0.51, and kt=0.40-0.52. The ceramics also exhibit a good thermal stability up to high TO-T, ...

ScienceCinema

...same sort of handle ? religious that we have on global warming or energy policy or ...other words my claim is that we need to study religion the way we study global warming and all the other really serious phenomena on this planet ...

International Nuclear Information System (INIS)

Crystalline and non-crystalline iron oxide (#alpha#-Fe_2O_3) thin films were obtained by spray pyrolysis onto glass substrate at different temperatures. The results of X-ray diffraction showed that with increasing the deposition time, the film structure changed from non-crystalline to crystalline at the same substrate temperature. At different substrate temperatures and low deposition times (5 min), iron oxide appears almost in non-crystalline form. With rising the substrate temperature and deposition time, the crystallinity was improved. The effect of substrate temperature as well as deposition time on the optical features (absorption coefficient and bandgap) and optical constants of these films has been investigated. Optical constants of the films were determined from spectrophotometric measurement of reflectance and transmittance. Analysis of the results showed that, for ...

Science.gov (United States)

We have grown crack-free antiferroelectric (AFE) Pb{sub 0.92}La{sub 0.08}Zr{sub 0.95}Ti{sub 0.05}O{sub 3} (PLZT) films on nickel foils by chemical solution deposition. To eliminate the parasitic effect caused by the formation of a low-permittivity interfacial oxide, we applied a conductive buffer layer of lanthanum nickel oxide (LNO) on the nickel foil by chemical solution deposition prior to the PLZT deposition. Use of the LNO buffer allowed high-quality film-on-foil capacitors to be prepared at high temperatures in air. With the AFE PLZT deposited on LNO-buffered Ni foils, we observed field-induced phase transformations of AFE to ferroelectric (FE). The AFE-to-FE phase transition field, E{sub AF} = 260 kV cm{sup -1}, and the reverse phase transition field, E{sub FA} = 220 kV cm{sup -1}, were measured at room temperature on a {approx}1.15 {micro}m thick PLZT film grown on LNO-buffered Ni foils. The relative permittivities of the AFE and FE ...

ScienceCinema

...changes consistent with global warming ? uh how to regional scale within ...

Scientific Electronic Library Online (English)

Abstract in english We present a detailed derivation of the effective dielectric constant to be used in the dispersion relation for electrostatic waves in the case of a plasma immersed in a inhomogeneous magnetic field, with inhomogeneity perpendicular to the direction of the magnetic field.

Energy Technology Data Exchange (ETDEWEB)

In order to design the microstructure of ceramics with desired dielectric property, an estimation method of dielectric constant of ceramics taking into account the characteristics of microstructure of the ceramics is proposed. In the estimation model, the microstructure of ceramics is represented by the assembly of unit cells comprising of grain, pore and grain boundary. The sizes of grain and pore and the thickness of grain boundary in each unit cell were determined exactly according to their size and thickness distributions in a real ceramic. The dielectric constant of the assembly can be calculated on the basis of equivalent circuit theory. The estimated values of dielectric constant of ceramic BaTiO{sub 3} using the proposed estimation method agree well with experimental ones. The dependence of characteristics of microstructure on the dielectric constant was clarified by the ...

Energy Technology Data Exchange (ETDEWEB)

The effect of longer ice-free periods on the seasonal variation and total annual values of phytoplankton primary production was considered along with the efficiency and productivity of the phytoplankton communities at different water temperatures by constant light. The studied pond, Vasikkalampi, is located in the town Jvyaskyla in central Finland. The pond is slightly eutrophic and its water is used for cooling purposes by a 35 MW thermal powerplant. The cooling water is taken in the middle of the pond and it returns as heated effluent to the northern part, near the surface, about 100 m from the intake pipe. This circulation and warming of the water keeps the pond open throughout the year except during the coldest weeks in the winter when some parts freeze over. The increase of the water temperature was not sufficient to be optimal for photosynthesis in the spring. The phytoplankton biomass starts to increase early in the ...

Science.gov (United States)

Demand for compact instrumentation, portable field equipment, and new electromagnetic weapons is

Science.gov (United States)

... 1 ..... 14 High Dielectric Constant Ceramics for Use in Blumlein Transmission Lines ..... 14 ...

Energy Technology Data Exchange (ETDEWEB)

We present device results from polysilicon thin film transistors (TFTs) fabricated at a maximum temperature of 100&hthinsp;{degree}C on polyester substrates. Critical to our success has been the development of a processing cluster tool containing chambers dedicated to laser crystallization, dopant deposition, and gate oxidation. Our TFT fabrication process integrates multiple steps in this tool, and uses the laser to crystallize deposited amorphous silicon as well as create heavily doped TFT source/drain regions. By combining laser crystallization and doping, a plasma enhanced chemical vapor deposition SiO{sub 2} layer for the gate dielectric, and postfabrication annealing at 150&hthinsp;{degree}C, we have succeeded in fabricating TFTs with I{sub ON}/I{sub OFF} ratios {gt}5{times}10{sup 5} and electron mobilities {gt}40 cm{sup 2}/V&hthinsp;s on polyester substrates. {copyright} {ital 1999 American Vacuum Society.}

CERN Document Server

This work investigates the impingement of a liquid microdroplet onto a glass substrate at different temperatures. A finite-element model is applied to simulate the transient fluid dynamics and heat transfer during the process. Results for impingement under both isothermal and non-isothermal conditions are presented for four liquids: isopropanol, water, dielectric fluid (FC-72) and eutectic tin-lead solder (63Sn-37Pb). The objective of the work is to select liquids for a combined numerical and experimental study involving a high resolution, laser-based interfacial temperature measurement to measure interfacial heat transfer during microdroplet deposition. Applications include spray cooling, micro-manufacturing and coating processes, and electronics packaging. The initial droplet diameter and impact velocity are 80 {\\mu}m and 5 m/s, respectively. For isothermal impact, our simulations with water and isopropanol show very ...

Energy Technology Data Exchange (ETDEWEB)

The Gulf of California represents one of the most productive and unique marginal seas in the world. The mouth of the Gulf captures warm equatorial water while annual wind patterns assure major upwelling of nutrient-rich water leading to a rich marine biota. These conditions have created a wide array of tropical through warm temperate carbonate environments. The most unusual of these environments is located in the La Paz region of Baja California Sur where tropical-subtropical water temperatures and low rainfall have allowed growth of corals, calcareous red algae, and other shelled invertebrates to form a carbonate bank environment. Sampling and mapping transacts in shallow bays north of La Paz and on the adjacent Espiritu Santo island have revealed a full spectrum of subenvironments including mangrove bordered, terrigenous mud dominated coastal zones, which grade into carbonate tidal flats. In addition, single coral heads ...

Science.gov (United States)

Aluminum, due to its low density and low cost, is a key material for future lightweight applications. However, like other structural materials, aluminum is subject to various forms of corrosion damage that annually costs the United States approximately 5% of its GNP [1]. The main goal is to investigate the effects of various solution anions on aluminum surfaces, and specifically probe pit initiation and inhibition. Using surface analysis techniques including X-ray photoelectron spectroscopy, Auger electron spectroscopy, and scanning electron microscopy, results have been correlated with those obtained from electrochemical methods and a radiolabeling technique developed in the Wieckowski laboratory. Analysis of data has indicated that important variables include type of anion, solution pH, and applied electrode potential. While aggressive anions such as chloride are usually studied to elucidate corrosion processes to work ultimately toward inhibition, its corrosive properties can be ...

Energy Technology Data Exchange (ETDEWEB)

Today, as a result of increase in oil prices, limited fossil fuel resources, environmental consideration and global warming, the methyl ester fuels have been focused on alternative fuels. Methyl ester fuels can be used more efficiently in low heat rejection engines (LHR), in which the temperature of combustion chamber is increased by creating a thermal barrier. In this study, the piston, cylinder head, exhaust and inlet valves of a diesel engine were coated with the ceramic material Al{sub 2}O{sub 3}-TiO{sub 2} by the plasma spray method. Thus, a thermal barrier was provided for the parts of the combustion chamber with these coatings. The effects of corn oil methyl ester that produced by the transesterification method, and No. D2 fuels' performance and exhaust emissions' rate were studied by using equal in every respect coated and uncoated engines. Tests were performed on the uncoated engine, and then repeated on the coated ...

International Nuclear Information System (INIS)

The thermal regime immediately downstream from bottom release reservoirs is often characterized by reduced diel and seasonal (winter warm/summer cool) conditions. These unusual thermal patterns have often been implicated as a primary factor underlying observed downstream changes in the species composition of aquatic macroinvertebrate communities. The potential mechanisms for selective elimination of benthic species by unusual thermal regimes has been reviewed. Although the effects of temperature on the rate and magnitude of larval growth and development has been included in the list of potential mechanisms, only recently have field studies below dams focused on this interrelationship. This study investigates the overall community structure as well as the seasonal pattern of larval growth and development for several univoltine species of insects in the Delaware River below or near the hypolimnetic discharge of the Cannonsville and Pepeacton ...

Energy Technology Data Exchange (ETDEWEB)

The need for a hydrogen economy is driven by increasing fuel prices, depleting oil reserves and uncertainty over supplies, and concerns about global warming and environmental pollution. Alternative methods to portable energy sources such as fossil fuels are being developed that are more efficient and carbon-emission-neutral. A prospective method is to produce hydrogen as an energy carrier. This paper presented a study on the degradation of materials under conditions of the sulphur-iodine (SI) thermochemical cycle. The paper provided background information on the study and presented a schematic of the SI cycle. A literature review was presented along with materials selected, such as refractory metals, reactive metals, superalloys, glassy metals, ceramics, cermets, polymers, composites, and coatings. The experimental method was then described. A capsule method was developed to rapidly quantify the decomposition rate of the candidate materials under the target ...

Energy Technology Data Exchange (ETDEWEB)

For the removal and recycle of CO2, a global warming gas, utilization of photosynthesis by micro algae is investigated. Formed micro algae are decomposed into CO2, H2O and CH4 again, which does not result in the permanent fixation. For the effective utilization of these micro algae, creation of petroleum alternate energy was tried through the co-liquefaction of micro algae with coal. Were investigated influences of the reaction temperature during the co-liquefaction and influences of catalysts, such as Fe(CO)5-S, Ru(CO)12, and Mo(CO)6-S, which are effective for the coal liquefaction. Micro algae, such as chlorella, spirulina, and littorale, and Yallourn brown coal were tested. It was found that co-liquefaction of micro algae with coal can be successfully proceeded under the same conditions as the liquefaction of coal. The oil yield obtained from the co-liquefaction in the presence of Fe(CO)5-S, an effective catalyst for coal liquefaction, ...

Energy Technology Data Exchange (ETDEWEB)

The further optimisation and improvement of the efficiency of internal combustion engines require the realisation of new technologies leading to a distinctively faster warm-up behaviour of the coolant and lubricants as well as of the engine components after a cold start. In order to achieve reduced fuel consumption and exhaust gas emissions with the help of heat management, the design criteria of innovative cooling systems need to be reflected and adapted to future requirements. The use of intelligent components within the cooling system, such as the 'Stand Alone Rotary Valve' as a thermostat's substitute or the use of coolant pumps with a rotary valve integrated into the pump's inlet chamber, offer new ways to realise in a decisively quicker and more flexible way the appropriate heating up and cooling down procedures at varying driving conditions. A description of both of the intelligent components for the cooling system is ...

Energy Technology Data Exchange (ETDEWEB)

''S-220'' white oil is used currently to impregnate and fill high voltage cables for 110-500 kilovolts; it has high electrical characteristics and meets production and use standards. High pressure and cooling problems, however, require filling cables with lower viscosity oils, while insulation needs still demand high viscosity. The authors developed a new white oil similar to S-220 using a neutral oil made in producing sulfonate additives. The process involved vacuum distillation, low-temperature paraffination, sulfation with oleum, neutralizing with ammonium hydroxide and simultaneous extraction of sulfo-salts and contact purification. The lowest content of aromatic hydrocarbons was sought. Dielectric qualities varied with viscosity. Satisfactory thermooxidational capability was found at 50/sup 0/C with an oil of no less than 50 mm/sup 2//sec viscosity. The final white oil had no more than 2% aromatic ...

CERN Document Server

We have performed multicanonical Monte Carlo simulations of C-peptide of ribonuclease A. It is known by CD and NMR experiments that this peptide has high alpha-helix content in aqueous solution and that the side-chain charges of residues Glu-2$^-$ and His-12$^+$ play an important role in the stability of the alpha-helix. In order to confirm these experimental implications, we have used two analogues of the peptide with charged and neutral side chains of Glu-2 and His-12. Two dielectric functions, distance-dependent and constant, are considered to study the effects of solvent contributions. All the simulations were started from random initial conformations. Various thermodynamic quantities such as average helicity as a function of residue number and average distance between two side chains as a function of temperature are calculated. The results are found to be in accord with the implications of CD and NMR experiments. The lowest-energy ...

International Nuclear Information System (INIS)

Highly conductive biaxially textured RuO_2 thin films were deposited on technically important SiO_2/Si substrates by pulsed laser deposition, where yttria-stabilized zirconia (YSZ) produced by ion-beam-assisted-deposition (IBAD) was used as a template to enhance the biaxial texture of RuO_2 on SiO_2/Si. The biaxially oriented RuO_2 had a room-temperature resistivity of 37 #mu##OMEGA#-cm and residual resistivity ratio above 2. We then deposited Ba_0_._5Sr_0_._5TiO_3 thin films on RuO_2/IBAD-YSZ/SiO_2/Si. The Ba_0_._5Sr_0_._5TiO_3 had a pure (111) orientation normal to the substrate surface and a dielectric constant above 360 at 100 kHz. copyright 1998 Materials Research Society.

CERN Document Server

We analyze the impact of trap states in the oxide layer of a superconducting tunnel junctions, on the fluctuation of the Josephson critical current, thus on coherence in superconducting qubits. Two mechanisms are usually considered: the current blockage due to repulsion at the occupied trap states, and the noise from electrons hopping across a trap. We extend previous studies of noninteracting traps to the case where the traps have on-site electron repulsion inside one ballistic channel. The repulsion not only allows the appropriate temperature dependence of 1/f noise, but also is a control to the coupling between the computational qubit and the spurious two-level systems inside the oxide dielectric. We use second order perturbation theory which allows to obtain analytical formulae for the interacting bound states and spectral weights, limited to small and intermediate repulsions. Remarkably, it still reproduces the main features of the model ...

Energy Technology Data Exchange (ETDEWEB)

A multi-faceted research program has been performed to investigate in detail several aspects of free and forced convective cooling of underground electric cable systems. There were two main areas of investigation. The first one, reported in Volume 1, dealt with the fluid dynamic and thermal aspects of various components of the cable system. In particular, friction factors for laminar flow in the cable pipes with various configurations were determined using a finite element technique; the temperature distributions and heat transfer in splices were examined using a combined analytical numerical technique; the pressure drop and heat transfer characteristics of cable pipes in the transitional and turbulent flow regime were determined experimentally in a model study; and full-scale model experimental work was carried out to determine the fluid dynamic and thermal characteristics of entrance and exit chambers for the cooling oil. The second major area of activity, ...

International Nuclear Information System (INIS)

The detailed energy-band structure of hexagonal-close-packed technetium, corresponding to the atomic configuration 4d"55s"2 of its seven outermost valence electrons, has been obtained throughout the Brillouin zone using the composite-wave variational version of the augmented-plane-wave (APW) method in conjunction with the X#alpha# (#alpha# = 0.702 99) exchange approximation for obtaining the potentials. From the band-structure data the electronic density of states (DOS) and the angular-momentum--decomposed DOS were calculated by the accurate Gilat-Raubenheimer method. These quantities were used to calculate the electron-phonon coupling constant and the transition temperature (T/sub c/) using the theories of Gaspari and Gyorffy and of McMillan. Also studied were the Fermi surface and the optical properties of Tc via the imaginary part of the interband dielectric constant for bound electrons, the latter being the first of such a study on Tc to ...

Energy Technology Data Exchange (ETDEWEB)

The aim of this paper is offering a critical review of Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS), the approach of multi-elemental quantitative analysis of LIBS spectra, based on the measurement of line intensities and plasma properties (plasma electron density and temperature) and on the assumption of a Boltzmann population of excited levels, which does not require the use of calibration curves or matrix-matched standards. The first part of this review focuses on the applications of the CF-LIBS method. Quantitative results reported in the literature, obtained in the analysis of various materials and in a wide range of experimental conditions, are summarized, with a special emphasis on the departure from nominal composition values. The second part is a discussion of the simplifying assumptions which lie at the basis of the CF-LIBS algorithm (stoichiometric ablation and complete atomization, thermal equilibrium, homogeneous plasma, thin ...

Energy Technology Data Exchange (ETDEWEB)

Transmission terminations available today are very reliable, but they need to be. In the field, they are continually exposed to pollution and extremes of ambient temperature. In many cases, they are in the rifle sights of vandals. In contrast, cable joints - often cited as the weakest links from an electrical viewpoint - are generally protected from physical damage underground and many of the short cable systems being installed in the US today can be built without joints. All cable systems need terminations - mostly to air-insulated equipment. At 69 through 138 kV, there is intense competition among manufacturers to supply terminations for solid-dielectric cable that are low in cost, reliable, and require a minimum of skill to install. Some utilities are looking also for terminations that fit a range of cable sizes; terminations that do not contain liquid that can leak out; and terminations that are shatter-proof. All of these improvements are ...

International Nuclear Information System (INIS)

The n=4 Aurivillius phase, Bi5Ti3CrO15, was synthesised by solid state reaction. Rietveld analysis of high resolution neutron diffraction data demonstrated this material to adopt the polar space group A21am at room temperature, transforming to the aristotype I4/mmm structure above 650 oC. This phase transition is coincident with an anomaly in DSC signal and relative permittivity, which are characteristic of a ferroelectric-paraelectric phase transition. Bi5Ti3CrO15 exhibits paramagnetic behaviour at low temperature, with short range antiferromagnetic interactions, but no evidence for long range magnetic ordering. This is considered a consequence of significant disorder of Ti and Cr over the available octahedral sites, as demonstrated by analysis of neutron diffraction data. -- Graphical abstract: We report here the synthesis, structure and characterisation of the n=4 Aurivillius phase Bi5Ti3CrO15. Analysis of neutron powder diffraction and ...

Energy Technology Data Exchange (ETDEWEB)

The influences of compressive stress on the dielectric properties of (1 - x)Pb(In{sub 1/2}Nb{sub 1/2})O{sub 3}-xPbTiO{sub 3} (x = 0.1-0.5) ceramics was investigated in this study. The dielectric properties were measured under compressive stress applied parallel and perpendicular to electric field. The results clearly showed that the superimposed compression stress had pronounced effects on the dielectric properties of PIN-PT ceramics. In general, with increasing compressive stress the dielectric constant of the ceramics increased and decreased when the stress was applied parallel and perpendicular, respectively, to the electric field direction. The dielectric loss tangent, however, decreased in both stress cases. The observations were mainly interpreted in terms of competing influences of the domain switching through non-180 deg. domain walls, clamping of domain walls, de-ageing and ...

Science.gov (United States)

Jan 5, 2004 ... Even if dinosaurs were cold-blooded, in the Mesozoic Era (when dinosaurs roamed the Earth), Antarctica was warm enough to have them. ...

Science.gov (United States)

Analysis of ENSO Dynamics and ThermoDynamics in the Western Pacific Warm Pool - An Application of Multi-Sensor Satellite Observations. ...

Energy Technology Data Exchange (ETDEWEB)

In this letter we present a derivation, from the D0-brane picture, of the background monopole field and in general of the full dynamics of the Yang-Mills theory on the dielectric D2-brane of Myers. To do this we study the large N limit of the fuzzy sphere relevant to the dielectric solution. In contrast to the usual interpretation where the commutative D2-brane picture arises directly from the large N limit of the D0-brane picture, we find that a residual non-commutativity must be preserved in order to make the connection by means of the Seiberg-Witten map.

Energy Technology Data Exchange (ETDEWEB)

Vehicle heating requires a substantial amount of energy. Engines in conventional cars produce enough waste heat to provide comfort heating and defogging/defrosting, even under very extreme conditions. Electric vehicles (EVs), however, generate little waste heat. Using battery energy for heating may consume a substantial fraction of the energy storage capacity, reducing the vehicle range, which is one of the most important parameters in determining EV acceptability. Water vapor generated by the vehicle passengers is in large part responsible for the high heating loads existing in vehicles. In cold climates, the generation of water vapor inside the car may result in water condensation on the windows, diminishing visibility. Two strategies are commonly used to avoid condensation on windows: windows are kept warm, and a large amount of ambient air is introduced in the vehicle. Either strategy results in a substantial heating load. These strategies are often used in ...

CERN Document Server

Monopolar charge disorder effects are studied in the context of fluctuation-induced interactions between neutral dielectric slabs. It is shown that quenched bulk charge disorder gives rise to an additive contribution to the net interaction force which decays as the inverse distance between dielectric surfaces. This effect may thus completely mask the standard Casimir--van der Waals effect. By contrast, annealed (bulk or surface) charge disorder leads to a net interaction force whose large-distance behavior coincides with the universal Casimir force between perfect conductors, which scales as inverse cubic distance, and the dielectric properties enter only in subleading corrections.

British Library Electronic Table of Contents (United Kingdom)

This paper presents the results of the degree of irreversible changes of dielectric properties of vacuum circuit breakers with CuCr and CuBi contacts before and after short-circuit breaking operations. Tests of dielectric properties were performed on four different types of switching vacuum chamber with RMF electrodes in the form of a spiral disk with slots. The paper describes the configuration of measuring system for determining the dielectric properties of circuit breakers with DC, AC and pulse voltage. It also describes the measuring procedure. The results were analyzed and the experimentally obtained random variable breakdown voltage is found to belong to Weibull distribution in all cases. Based on these results it was found that for the vacuum circuit breakers with CuCr contacts and ...

Energy Technology Data Exchange (ETDEWEB)

The article surveys studies into the global warming which have found that the OECD countries are responsible for less than half of the total registered warming. Calculation and analysis methods for estimating the global contributions from the blocks of OECD, Africa/America/Middle East, Asia and former Soviet Union/Eastern Europe are presented. The results and some pollution abatement measures are discussed.

British Library Electronic Table of Contents (United Kingdom)

Ultrafine grained steels with different carbon contents were produced through warm caliber rolling and evaluated for their stress-strain behavior along with the reduction in area. It was found that the reduction in area-tensile strength balance is far better than the conventional ferrite+pearlite steels and even superior to bainitic steels for all materials tested in the present study.

Energy Technology Data Exchange (ETDEWEB)

T. D. Lee's method for developing the Feynman rules for gauge fields in a cavity is reformulated in terms of path integral. His work is then extended by deriving these rules, in the Feynman gauge, for a spherical cavity. In any gauge only the gauge particle propagator is altered, while all the Feynman rules for gauge field couplings are left unaltered by the presence of a dielectric medium.

Science.gov (United States)

Results from scanning electron microscopy, Fourier transform infrared spectroscopy and the measurement of thermally stimulated current show that a high density of the physical defects and the chemical defects are introduced into the surface of the silicone rubber plates after they are treated by corona discharge plasma. These defects behave electrically as shallow electron traps, leading to the formation of a uniform discharge in air at higher pressure when the corona-modified silicone rubber is used in dielectric barrier discharge.

Energy Technology Data Exchange (ETDEWEB)

The aim of this research project, funded jointly by SILMU and by the Agricultural Research Centre of Finland, was to evaluate the possible effects of changes in climate and carbon dioxide concentration on the growth, development and yield of field crops and on crop pests and diseases in Finland. The study focused on two cereal crops (spring wheat and spring barley), a grass species (meadow fescue), some common pathogens of cereals and potato, insect pests of small fruits and nematode risk of potato and sugar beet. The results of this study indicate the following effects on crop production of the `best guess` climate change anticipated for Finland by 2050: A lengthening of the potential growing season of 3-5 weeks. A northward expansion of about 250-500 km in suitability for cereal production. Increased yields of adapted spring cereals. New, longer-season cultivars would benefit from both higher temperatures and elevated CO{sub 2}. Improved potential for the ...

International Nuclear Information System (INIS)

We present sensitive high angular resolution (0.''57-0.''78) SO, SO_2, CO, C_2H_5OH, HC_3N, and HCOCH_2OH line observations at millimeter and submillimeter wavelengths of the young O-type protostar W51 North made with the Submillimeter Array. We report the presence of a large (about 8000 AU) and hot molecular circumstellar disk around this object, which connects the inner dusty disk with the molecular ring or toroid reported recently and confirms the existence of a single bipolar outflow emanating from this object. The molecular emission from the large disk is observed in layers with the transitions characterized by high excitation temperatures in their lower energy states (up to 1512 K) being concentrated closer to the central massive protostar. The molecular emission from those transitions with low or moderate excitation temperatures is found in the outermost parts of the disk and exhibits an inner cavity with an angular size of around 0.''7. ...

Energy Technology Data Exchange (ETDEWEB)

A new formulation of the theory of tachyons using the same two postulates as in special relativity is applied to the electrodynamics of material media. A discussion of Lagrange`s equations and Hamilton`s equations for `classical` charged tachyons shows that such a formalism is a viable approach. An essay is included on why tachyons can be considered to be localised particles for the purpose of calculations. Tachyonic transformations of the electromagnetic fields D, P, H and M are shown to be the same as for bradyonic transformations. Examples discussed include the electric dipole moment of a tachyonic current loop, constitutive equations, polarisation in tachyonic dielectric materials and the velocity of light in tachyonic dielectric media. This is followed by discussions of the collision energy loss for charged tachyons interacting with a material medium and a mathematical proof that tachyons cannot emit Cherenkov radiation when passing ...

International Nuclear Information System (INIS)

The structural, electronic and optical properties of ZnX and CdX (X = Se, Te and S) are studied using density functional theory by the Wien2k package. The energy band gap, real and imaginary parts of the dielectric function, energy loss function, optical absorption coefficient and reflectivity spectra of these compounds are calculated. The Engel-Vosko approach improves the energy band gaps of ZnX and CdX compounds. The calculated optical parameters are in good agreement with available experimental results, particularly in the Engel-Vosko approach. Furthermore the effect of hydrostatic pressure on the energy band gap, the real and imaginary parts of the dielectric function of these compounds is studied. The first and second order pressure coefficient for the energy band gaps, the static dielectric function and the static reflectivity spectra are calculated.

International Nuclear Information System (INIS)

In this paper, 0.75Pb(Fe2/3W1/3)O3-0.25PbTiO3-0.15 wt% MnO (0.75PFW-0.25PT-0.15 wt% MnO) ceramics are synthesized by two different methods, the conventional direct oxide synthesized (DS) method and two-step indirect synthesized (IS) method. The low-field dielectric responses are investigated by using the empirical law, the Curie-Weiss law, the modified-Landau theory and the spin-glass model. Due to the IS method, the lattice structure and the grain structure of the samples are changed. Furthermore, the dielectric properties are evidently modified. It is suggested that the ordering degree of B-site cations is enhanced by using the IS synthesized method.

Energy Technology Data Exchange (ETDEWEB)

A dielectric-wall linear accelerator is improved by a high-voltage, fast rise-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface.

Energy Technology Data Exchange (ETDEWEB)

The paper reports the results of the studies performed at the Electric Research Center of ENEL (Italian National Electricity Board) in the field of compacting high voltage transmission lines, from the point of view of dielectric and corona noise constraints. The results of switching impulse withstand voltage tests, performed on typical compact line insulation configurations, are given and optimization criteria of such insulation configurations in relation to switching impulse are outlined. The constraints regarding surface withstand voltage in polluted conditions of the above insulations are analyzed and the possibility of reducing their dimensions by using unconventional insulation materials is considered. Finally, evaluations of corona noise in the case of optimization of the line encumbrance from the point of view of dielectric constraints are given.

Energy Technology Data Exchange (ETDEWEB)

A decade ago, Lovelock and Whitfield raised the question of how much longer the biosphere can survive on Earth. They pointed out that, despite the current fossil-fuel induced increase in the atmospheric CO[sub 2] concentration, the long-term trend should be in the opposite direction: as increased solar luminosity warms the Earth, silicate rocks should weather more readily, causing atmospheric CO[sub 2] to decrease. In their model, atmospheric CO[sub 2] falls below the critical level for C3 photosynthesis, 150 parts per million (p.p.m.), in only 100 Myr, and this is assumed to mark the demise of the biosphere as a whole. Here, this problem is re-examined using a more elaborate model that includes a more accurate treatment of the greenhouse effect of CO[sub 2] a biologically mediated weathering parameterization, and the realization that C4 photosynthesis can persist to much lower concentrations of atmospheric CO[sub 2] ([lt]10 p.p.m.). It was found that a ...

International Nuclear Information System (INIS)

An experimental approach has been performed to ascertain the effectiveness of semi-solid strip casting using a horizontal twin roll caster. The demand for light-weight products with high strength has grown recently due to the rapid development of automobile and aircraft technology. One key to such development has been utilization of magnesium alloys, which can potentially reduce the total product weight. However, the problems of utilizing magnesium alloys are still mainly related to high manufacturing cost. One of the solutions to this problem is to develop magnesium casting-rolling technology in order to produce magnesium sheet products at competitive cost for commercial applications. In this experiment, magnesium alloy AZ31B was used to ascertain the effectiveness of semi-solid roll strip casting for producing magnesium alloy sheets. The temperature of the molten magnesium, and the roll speeds of the upper and lower rolls, (which could be changed independently), ...

CERN Document Server

IRAM 30m observations reveal that the deeply obscured IR-luminous galaxy NGC4418 has a rich molecular chemistry - including unusually luminous HC3N line emission. We furthermore detect: ortho-H2CO 2-1, 3-2; CN 1-0, 2-1; HCO+, 1-0. 3-2, HCN 3-2, HNC 1-0, 3-2 (and tentatively OCS 12-11). The HCN, HCO+, H2CO and CN line emission can be fitted to densities of n=5 x 10E4 - 10E5 cm-3 and gas temperatures Tk=80-150 K. Both HNC and HC3N are, however, significantly more excited than the other species which requires higher gas densities - or radiative excitation through e.g. mid-IR pumping. The HCN line intensity is fainter than that of HCO+ and HNC for the 3-2 transition, in contrast to previous findings for the 1-0 lines where the HCN emission is the most luminous. We tentatively suggest that the observed molecular line emission is consistent with a young starburst, where the emission can be understood as emerging from dense, warm gas with an ...

Science.gov (United States)

Outgoing longwave radiation (OLR) and low-level wind fields in the Atlantic and Pacific Intertropical Convergence Zone (ITCZ) are dominated by variability on synoptic time scales primarily associated with convectively coupled easterly waves during boreal summer and fall. This study uses spectral filtering of observed OLR data to capture the convective variability coupled to Pacific easterly waves. Filtered OLR is then used to isolate easterly waves in winds, temperature and humidity fields from TAO/TRITON and TAO/EPIC buoys, radiosondes, and gridded reanalysis products. Our analysis shows that while some of the Pacific easterly waves originate in the Atlantic, most of the waves appear to form and strengthen within the Pacific. Pacific easterly waves have wavelengths of 3300-5500 km and phase speeds of 9-13 m s-1. A warm, moist boundary layer is observed ahead of the convective wave, with moisture lofted quickly through the troposphere by deep ...

Energy Technology Data Exchange (ETDEWEB)

It has been understood that production of hydrogen from fossil and carbonaceous fuels with reduced CO{sub 2} emission to the atmosphere is key to the production of hydrogen-rich fuels for mitigating the CO{sub 2} greenhouse gas climate change problem. The conventional methods of hydrogen production from fossil fuels (coal, oil, gas and biomass) include steam reforming and water gas shift mainly of natural gas (SRM). In order to suppress CO{sub 2} emission from the steam reforming process, CO{sub 2} must be concentrated and sequestered either in or under the ocean or underground (in aquifers, or depleted oil or gas wells). Up to about 40% of the energy is lost in this process. An alternative process is the pyrolysis or the thermal decomposition of methane, natural gas (TDM) to hydrogen and carbon. The carbon can either be sequestered or sold on the market as a materials commodity or used as a fuel at a later date under less severe CO{sub 2} restraints. The energy sequestered in the ...

Science.gov (United States)

We previously reported that the peroxisome proliferator-activated receptor gamma coactivator-1 (PGC-1) mRNA in rat epitrochlearis muscle was increased after swimming exercise training. In the present study, we demonstrated further that PGC-1 mRNA expression in the epitrochlearis muscle of 4-5-week-old male Sprague-Dawley rats was increased after a 6-h acute bout of low-intensity swimming exercise. With this increase, the expression level was approximately 8-fold of control and immersion group rats that stayed for 6-h in warm water, maintained at the identical temperature of the swimming barrel (35 degrees C) (p<0.01). Second, PGC-1 mRNA expression in the muscle was found to have increased 6-h after 30 10-s tetani contractions were induced by in vitro electrical stimulation. Finally, PGC-1 mRNA expression in the muscle incubated for 18-h with 0.5mM 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR: a 5' AMP-activated protein kinase (AMPK) ...

Energy Technology Data Exchange (ETDEWEB)

Rhodium (Rh) is a critical component of current automotive three-way catalysts (TWCs), particularly with regard to NO{sub x} and CO conversion at rich and stoichiometric air-fuel ratios (A/F). Rh supported on CeO{sub 2} was active for NO{sub x} and CO conversions but could be deactivated easily by high temperature aging. The cause of the deactivation is ascribed to the sintering of CeO{sub 2}. ZrO{sub 2} incorporation into CeO{sub 2} is reported to have high thermal durability in terms of oxygen storage capacity (OSC). There has been no report showing direct experimental evidence that Rh-loaded on CeO{sub 2}-ZrO{sub 2} mixed oxides induced effects on TWC performance improvement in the actual automotive exhaust. In the present paper, the Rh-CeO{sub 2} interaction contributing to NO{sub x} reduction and the catalytic behavior of Rh-loaded CeO{sub 2}-ZrO{sub 2} mixed oxide is addressed. Incorporating CeO{sub 2}-ZrO{sub 2} into a catalyst offered significant ...

International Nuclear Information System (INIS)

Ti-10V-2Fe-3Al is high strength, metastable beta titanium alloy developed by the Timet Division, Titanium Metals Corporation of America for enhanced forgeability and excellent mechanical property combinations, including deep hardening characteristics. Ti-10-2-3 has been the subject of intense thermomechanical processing (TMP) development and reduction to commercial practice for the full range of open die, closed-die and precision forged products utilized in aerospace and other applications. With commercially proven TMP, Ti-10-2-3 forgings provide a range of strength-fracture toughness combinations from 180 Ksi (1,240 MPa) minimum U.T.S. to 140 Ksi (965 MPa) minimum U.T.S with commensurate fracture toughness. With optimal TMP and these strength-toughness combinations, Ti-10-2-3 forgings are found provide superior smooth and notched fatigue properties critical to aerospace applications over incumbent alpha-beta alloys. The alloy retains 80 percent of its room ...

UK PubMed Central (United Kingdom)

Verapamil administered before treatment, but not after treatment, had a beneficial effect on a 90-minute warm ischemia-reperfusion rat liver injury model. The possible activation of proteases converting...Full Text Available

Science.gov (United States)

There is general consensus that climate change has contributed to the observed decline, and extinction, of many amphibian species throughout the world. ... ...

CERN Document Server

The 12 GeV upgrade at Jefferson Lab has identified two new large spectrometers as Physics detectors for the project. The first is a 7.5 Gev/c 35 m-sr. spectrometer that requires a pair of identical Combined Function Superconducting Magnets (CFSM) that can simultaneously produce 1.5 T dipole fields and 4.5 T/m quadrupole fields inside a warm bore of 120cm. The second is an 11 GeV/c 2 m-sr. spectrometer that requires a CFSM that simultaneously produces a dipole field of 4.0 T and a quadruple field of 3.0 T/m in a 60 cm warm bore. Magnetic designs using TOSCA 3D have been performed to realize the magnetic requirements, provide 3d fields for optics analysis and produce field and force information for the engineering feasibility of the magnets. A two-sector cos( theta )/cos(2 theta ) design with a low nominal current density, warm bore and warm iron design has been selected and analyzed. These low current ...

UK PubMed Central (United Kingdom)

BackgroundBlood sampling through heel lancing is the most common invasive painful procedure performed on newborn infants.Case PresentationWe report...Full Text Available

Science.gov (United States)

tact materials ate Ti-Pd-Ag and the back surface reflector is formed from evaporated .... Ti-Pd-Ag, Dielectric Wraparound. BSR. Evaporated Aluminum ...

Energy Technology Data Exchange (ETDEWEB)

A detailed examination of the aging processes that may take place in solid-dielectric extruded-type high voltage transmission cables under dry conditions is presented. Particular emphasis is placed on the aging process as affected by the separate and simultaneous action of four main aging factors, namely the electrical, mechanical and thermal stresses, and the physical and chemical environment. A number of pertinent aging models are considered and their validity and applicability to accelerated aging tests on solid-type transmission cables are discussed.

DEFF Research Database (Denmark)

Axially symmetric waveguides, resonators, and scatterers of arbitrary cross section and anisotropy in the cross section can be modeled rigorously with use of 2-D Cartesian-grid based codes by means of mere redefinition of material permittivity and permeability profiles. The method is illustrated by the frequencydomain simulations of resonant modes in a circular-cylinder cavity with perfectly conducting walls, a shielded uniaxial anisotropic dielectric cylinder, and an open dielectric sphere for which, after proper implementation of the perfectly matched layer boundary conditions, the radiation quality factor is also determined.

Energy Technology Data Exchange (ETDEWEB)

For years, the writing has been on the wall about the impact of climate change on the people, plants, animals, and habitats of Latin America and the Caribbean. Now, day-to-day experiences and eye-witness accounts from leading environmental and development groups are proving predictions to be correct. In the late 1990s, the world's pre-eminent group of climate scientists gathered under the Intergovernmental Panel on Climate Change (IPCC) and predicted a devastating range of impacts, including an increase in the intensity and number of extreme weather events exacerbating natural disasters, forest die-off, melting glaciers, and the drying out of temperate grasslands. The region's huge geographical diversity means that patterns of vulnerability to climate change are extremely varied. It also makes modelling difficult, although this is constantly improving. To avoid misunderstanding, it is important to point out that with or without global warming, ...

Energy Technology Data Exchange (ETDEWEB)

A study was undertaken of the effect of monovalent cations (Li/sup +/, Na/sup +/, K/sup +/) on the dielectric constant (epsilon) of the water-lipid interface of unilamellar phosphatidylcholine (PC) vesicles, i.e., the ester carbonyl oxygen region of the PC molecules or the neighborhood of the oxygen atoms of the phosphorylcholine moiety. epsilon was determined by reacting the free radical 1,1-diphenyl-2-picrylhydrazyl with ..cap alpha..-tocopherol incorporated in the lipid vesicles. The results are consistent with a decrease of epsilon (LiCl: 35.5 to 29.5; NaCl: 34 to 29; KCl: 33 to 29) as the concentration of the salts in the solvent media increases from 0.025 to 0.5 M. These effects can be rationalized in terms of dielectric saturation at the water-lipid interface brought about by ion-induced local electric fields. In the unilamellar PC vesicles the effect of the ions on epsilon follows the sequence K/sup +/ > Na/sup +/ > Li/sup +/ ...

Energy Technology Data Exchange (ETDEWEB)

This work has been undertaken with a view to study the effect of lanthanum content on properties of PLZT ceramics. The polycrystalline complex compounds of PLZT with Pb{sub 1-x}La{sub x}(Zr{sub 0.40}Ti{sub 0.60}){sub 1-x/4}O{sub 3}, +10% PbO formula were prepared from the nano-size individual oxides powders by hot-pressed process. Transparent PLZT (x/40/60) bulk ceramics with pure tetragonal phase was obtained. The studies of the microstructures, dielectric and ferroelectric properties of the ceramics were carried out. The experiment results showed that when La content increased from 7 to 13 mol.%, the grain size increased from 2 to 7 {mu}m. La content also effects the dielectric property obviously, the dielectric constant increased with La content increasing. Moreover, the ferroelectric properties are sensitive to the variation of La content.

Energy Technology Data Exchange (ETDEWEB)

Compact dielectric wall (DWA) accelerator technology is being developed at the Lawrence Livermore National Laboratory. The DWA accelerator uses fast switched high voltage transmission lines to generate pulsed electric fields on the inside of a high gradient insulating (HGI) acceleration tube. Its high electric field gradients are achieved by the use of alternating insulators and conductors and short pulse times. The DWA concept can be applied to accelerate charge particle beams with any charge to mass ratio and energy. Based on the DWA system, a novel compact proton therapy accelerator is being developed. This proton therapy system will produce individual pulses that can be varied in intensity, energy and spot width. The system will be capable of being sited in a conventional linac vault and provide intensity modulated rotational therapy. The status of the developmental new technologies that make the compact system possible will be reviewed. These include, high ...

International Nuclear Information System (INIS)

The spectre of major climate change caused by the greenhouse effect has generated intensive research, heated scientific debate and a concerted international effort to draft agreements for the reduction of greenhouse gas emissions. This report of Scientific Perspectives on the greenhouse problem explains the technical issues in the debate in language readily understandable to the non-specialist. The inherent complexities of attempts to simulate the earth's climate are explained, particularly with regard to the effects of clouds and the circulation of the oceans, which together represent the largest factors of uncertainty in current global warming forecasts. Results of the search for the 'greenhouse signal' in existing climate records aredescribed in chapter 3 (part two). Chapter 5 (part two) develops a projection of 21st-century warming based on relatively firm evidence of the earth's actual response to known increases in greenhouse gas ...

British Library Electronic Table of Contents (United Kingdom)

An ultrafine-grained ferrite/cementite (UGF/C) steel with a local high density of cementite particles was fabricated through caliber-warm-rolling followed by annealing and resulted in a bimodal-sized microstructure. The characteristic bimodal-sized microstructure was attributed to the original ferrite-pearlite structure and cementite spacing, and reflected the original ferrite-pearlite structure. The smaller-sized clusters corresponded to the former pearlite regions and the larger-sized clusters to the proeutectoid ferrite regions. The cementite particles naturally localized within the former pearlite region. Most of the ferrite coarsening did not occur until the cementite particle spacing reached a critical value. The UGF/C microstructure with a bimodal grain size showed a yield strength ...

International Nuclear Information System (INIS)

An attempt has been made to grow L-tartaric acid nicotinamide (LTN); a complex of tartaric acid, by employing a modified unidirectional method. The crystalline structure and quality are investigated by single crystal XRD and rocking curve studies. The linear and nonlinear optical properties are studied by UV-vis-NIR spectral analysis, SHG test, phase matching and laser induced damage threshold measurement. For comparison, parallel growth of the crystal was carried out by conventional method and the properties of the LTN samples grown by the conventional and unidirectional methods are investigated. The mechanical, photoconductivity and dielectric behavior of LTN crystals are also investigated.

Energy Technology Data Exchange (ETDEWEB)

This paper describes the measurement and computation of the resonant frequencies and the associated Q factors of dielectric parallelepipeds made of high-permittivity, low-loss ceramic materials. Each resonance peak is measured separately with a fine frequency step. A curve-fitting method is used to accurately estimate the resonant frequency and 3 dB bandwidth from the somewhat noisy measured data. The finite-difference time-domain method is used to compute the initial portion of the backscattered field due to a Gaussian pulse plane wave. The time response is then extended to zero value by Prony`s method. The measured and computed data is compared for a parallelepiped resonator of permittivity 37.84.

British Library Electronic Table of Contents (United Kingdom)

Cfiber/Si3N4 composites were prepared by hot-pressed sintering using a-Si3N4 powders, short carbon fibers and sintering additives as starting materials. The mechanical and dielectric properties of these composites were studied. When the short carbon fiber content of the composites increases from 0 to 1wt.%, the fracture toughness increases from 3.456 to 4.203MPam1/2, and both the real and imaginary part of permittivity increase greatly over the frequency range 8.2-12.4GHz. These effects were due to the anisotropy of short carbon fibers.

Energy Technology Data Exchange (ETDEWEB)

This paper describes the development of cellulose paper/plastic film/cellulose paper laminate insulated Self-Contained 500 kV Oil-Filled (OF) Cable and its accessories. Dielectric loss of this new cable was confirmed to be about one third that of conventional kraft paper cable. Moreover, by employing the reduced insulation thickness of 25 mm rather than that of 33 mm, as is usual with conventional cables, the new cable could be made very compact, due to the high dielectric strengths of laminated paper. As a result, the shipping reel length of the new cable, which is about 10% lighter in total weight and 10% smaller in overall diameter than conventional cables, could be dramatically increased. The reliability and the stability of the new cable have been demonstrated by the successful completion of a one and a half year field test.

Energy Technology Data Exchange (ETDEWEB)

This paper describes the specifications, conceptual design, prototype testing and operating experience of an oil-filled high voltage pulse transmission cable adapted from commercially available air-dielectric RF components. Lawrence Livermore National Laboratory's Advanced Test Accelerator (ATA) requires a method of transmitting 250kV, 70 nanosecond pulses from the power conditioning equipment to the accelerator. The oil-filled cable approach was chosen over alternative concepts because of its high voltage holding capacity, long life and flexibility. The criteria for cable and connector design are discussed. The results of prototype testing and performance of the final design are presented.

Energy Technology Data Exchange (ETDEWEB)

Wetlands can potentially sequester vast amounts of carbon. However, over 50% of wetlands globally have been degraded or lost. Restoration of wetland systems may therefore result in increased sequestration of carbon. Preliminary results of our investigations into atmospheric carbon sequestration by restored coastal wetlands indicate that carbon can be sequestered in substantial quantities in the first 2-50 years after restoration of natural hydrology and sediment accretion processes.

Energy Technology Data Exchange (ETDEWEB)

S-120 white oils are used to impregnate insulation and fill high voltage wires. Cooling oil flows of specified viscosities can increase the load capacity of wires. White oils are studied for viscosities and dielectric properties. To meet requirements, S-220 type oils of different medium or low viscosities are tested. Capacity can be increased by viscosity adjustment. Tests were also made to select optimum stabilizing additives to keep low-viscosity.

Energy Technology Data Exchange (ETDEWEB)

The bibliography contains citations concerning the properties of tantalum and tantalum compound films formed by sputtering techniques. Topics include processes, and electrical, magnetic, and dielectric properties of the sputtered films. Tantalum compounds studied include nitrates, oxides, and aluminides. The structural properties of sputtered films are also discussed. (Contains a minimum of 105 citations and includes a subject term index and title list.)

International Nuclear Information System (INIS)

In the present work, range and energy loss rate of "2"8Si in four dielectric track detectors viz: Makrofol-KG (MFKG), Makrofol-G (MFG), Triafol-BN (TBN) and LR-115 (cellulose nitrate) have been measured. To calculate these parameters, a curve fitting method was proved to be very useful and easier with more accuracy. (author)

International Nuclear Information System (INIS)

For a system of noninteracting electrons scattered by resonant levels of neutral impurities, we show that virial and quasiparticle corrections have nearly equal magnitudes. We propose a modification of the Boltzmann equation that includes quasiparticle and virial corrections and discuss their interplay on a dielectric function. copyright 1997 The American Physical Society.

Energy Technology Data Exchange (ETDEWEB)

The invention relates to a pulsed laser ablation method of metals and/or dielectric films from the surface of a wafer, printed circuit board or a hybrid substrate. By utilizing a high-energy ultra-short pulses of laser light, such a method can be used to manufacture electronic circuits and/or electro-mechanical assemblies without affecting the material adjacent to the ablation zone.

Energy Technology Data Exchange (ETDEWEB)

A complete theory for waveguide laser modes for oversized metallic and dielectric waveguides with circular cross section has been developed for the submillimeter wavelength region. The experimental investigations have been done by a submillimeter heterodyne technique for the first stage using a Schottky barrier diode in an open structure mixer.

International Nuclear Information System (INIS)

Lead lanthanum zirconate titanate (PLZT) nanopowders with chemical compositions x/65/35 PLZT (x = 6 - 10 mol%) were prepared by sol-gel method. PLZT ceramics was obtained by the conventional sintering method and utilizing the hot pressing method. The investigations of dielectric and ferroelectric measurements of as obtained PLZT ceramics have revealed the influence of lanthanum concentration on the properties of PLZT electroceramics. (author)

British Library Electronic Table of Contents (United Kingdom)

The effect of the moisture content in amorphous polymers (PS, PVC, PMMA) on their electro-physical properties is considered. Analytical relationships describing the inflence of the external-field frequency and environmental relative humidity on the conductivity of the polymers are given. For the use of these polymers as active elements of moisture sensors, the moisture-resistive effect is estimated.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared

Environmental Research Database

ObjectivesThe overall scientific aim of this project is, through development of an appropriate numerical modelling tool, to identify and investigate the mechanisms that control the current observed rapid thinning and acceleration of Greenland outlet glaciers and to investigate their likely future behaviour in the context of climate warming. This aim is addressed through the four major specific objectives below. These objectives build on each and therefore the order of priority is driven by the order in wh [continued...]DescriptionCurrently, the Greenland ice sheet is undergoing rapid changes in the coastal regions which have been attributed to a general warming trend to the regions climate over the last decade. Several of the narrow and fast flowing outlet glaciers that drain the ice sheet into the sea are observed to have accelerated their flow and thinned. For instance, Jakobshavn Isbrae on the West coast of Greenland has almost doubled its ...

Energy Technology Data Exchange (ETDEWEB)

In this study, the exhaust gas from a common-rail direct injection diesel engine was investigated both upstream and downstream warm-up catalytic converters (WCC). Three different types of ultra-low sulfur fuels (ethanol-diesel blend, ethanol-diesel blend with cetane improver and pure diesel) were tested in this study. The objective of the work was to study the engine performance and the formation of THC (total hydro carbon), CO (carbon monoxide), NO{sub x} (nitrogen oxides), smoke and PM (particulate matters) when using these fuels. THC and CO emissions of the ethanol-diesel blend fuels were slightly increased, and about 50-80% mean conversion efficiencies of THC and CO on catalysts were achieved in the ECE R49 13-mode cycle. Smoke was decreased by more than 42% in the entire ECE 13-mode cycles. From the measurement of scanning mobility particle sizer (SMPS) for the particle size range of 10-385 nm, the total number and total mass of the PM of the ethanol-diesel ...

Energy Technology Data Exchange (ETDEWEB)

In response to the decisions adopted at the Third Session of the Conference of the Parties to the United Nations Framework Convention on Climate Change (Kyoto conference for the prevention of global warming) of 1997, hybrid vehicles, electric vehicles, and the like are being announced of their completion or placed on the market one after another as low pollution vehicles with CO2 emission to cause global warming reduced. Fuji Electric Co., Ltd., is engaged in the development of a DC-DC converter for hybrid vehicles in cooperation with Nissan Motor Co., Ltd. The product is characterized in (1) that it is small in size and light in weight because a step-down converter and an emergency step-up converter are integrated; (2) that it enjoys a high efficiency rate of 89%; (3) that its service life is long thanks to its design free of aluminum electrolytic capacitors; and (4) that it is provided with various reliability improving features, such as ...

Energy Technology Data Exchange (ETDEWEB)

In 1990, 176 million tonnes (mt) of air-traffic fuel was burned, which produced about 550 mt CO{sub 2}, 220 mt water, 3.5 mt NO{sub x} amd 0.18 mt SO{sub 2}. NO{sub x} emissions from air traffic may, by increasing ozone concentrations, be responsible for about 8% of global greenhouse warming. In the stratosphere NO{sub x} from aircraft is partly responsible for ozone depletion. With present technology 500 aircraft in the stratosphere would cause global ozone losses of 20%. Water vapour added by aircraft also contributes to global warming. In the form of ice crystals between 8 to 13 km above sea level, it acts as cirrus clouds. Probably the least damaging cruising altitude for aircraft is 9 km above sea level. Fuel consumption by aircraft is increasing. Air pollution abatement measures include substituting hydrogen fuel for kerosene, developing engines that emit less NO{sub x} and the introduction of internationally negotiated taxes on kerosene. ...

Energy Technology Data Exchange (ETDEWEB)

This article discusses the proper use of sandy land in China from the viewpoint of ecology. The many low-yield fields in every locality across China include sandy land that is unsuited to the cultivation of grains such as paddy rice, corn and wheat. Separate investigations of the northern plain and the southern coast between 1980 and 1982 demonstrated that sandy land in a warm climatic zone (e.g. Huang He) is suited to peanuts, soybeans and other oil-bearing crops; that forestation can be carried out on sandy land in Inner Mongolia and Xinjiang; and that coastal sandy land has much salinity and is best suited to growing horsetail beefwood. Moreover, the creation of windbreaks along the coasts of southern China has lessened the threat of wind-blown sand which had made rice not worth cultivating on sandy land. It is concluded that different crops can be grown on the sandy soil of China's temperate, warm, semitropical and tropical zones.

International Nuclear Information System (INIS)

During spring and autumn, the total number of amoebae and the number of acanthamoeba species able to grow at 37 degrees C were determined in six thermally polluted factory discharges and the surrounding surface waters. The isolated Acanthamoeba strains were studied for growth in axenic medium, cytopathic effect in Vito cell cultures, and virulence in mice. Although more amoebae were isolated in autumn, the number of Acanthamoeba species was lower than in spring, when the percent of pathogenic strains among the isolates was highest. Higher concentrations of amoebae were found in warm discharges, and more virulent strains occurred in thermal discharges than in surface waters.

Wastenet

... (restricted)] 251-260 Revisiting new variant famine: the case of Swaziland by Scott Naysmith & Alex Waal & Alan Whiteside [Downloadable! (restricted)] 261-269 Food prices and the HIV response: findings from rapid regional assessments in eastern and southern Africa in 2008[InlineMediaObject not available: see fulltext.][InlineMediaObject not available: see fulltext.] by Stuart Gillespie & Paul Jere & John Msuya & Scott Drimie [Downloadable! (restricted)] 271-289 Declining global per capita agricultural production and warming oceans ...

International Nuclear Information System (INIS)

The justification, strategies, and technology options for implementing advanced district heating and cooling systems in the United States are presented. The need for such systems is discussed in terms of global warming, ozone depletion, and the need for a sustainable energy policy. Strategies for implementation are presented in the context of the Public Utilities Regulatory Policies Act and proposed new institutional arrangements. Technology opportunities are highlighted in the areas of advanced block-scale cogeneration, CFC-free chiller technologies, and renewable sources of heating and cooling that are particularly applicable to district systems.

International Nuclear Information System (INIS)

Non-destructive methods of diagnosis for detecting cable degradation by aging are being studied recently for improvement of electric wires and cables. This study examines degradation behaviors of cable sheath and insulation by combined accelerated aging tests applying thermal and radiation stresses simultaneously using a typical low voltage cable. According to experiments, elongation of cross-linked polyethylene insulation deteriorated at a faster rate than PVC sheath did under low doses below 50 Gy/h. Therefore, measurements using a time domain dielectric spectrometer (TDS) were carried out for the purpose of developing a method of degradation diagnosis of insulation. It was found that values of tan#delta# measured at very low frequencies below 0.1 Hz increase in pace with degradation of insulation reflecting the level of degradation more effectively than those measured at frequencies around the commercial frequency. In order to consider causes of the increases of ...

International Nuclear Information System (INIS)

The millimeter microwave source of gyrotron-traveling-wave amplifier (gyro-TWT) is capable of generating high power coherent radiation in a broad bandwidth, while its performance is severely deteriorated by the stability problems. This paper focuses on modeling and the stability analysis of the Naval Research Laboratory (NRL) Ka-band TE01 mode gyro-TWT based on an interaction circuit alternately loaded with lossy ceramic shells and metal rings. The propagation characteristics of the interaction circuit is analyzed first, based on which the boundary impedance method is employed to build an equivalent uniform lossy circuit. Then the stability of the interaction system is studied using linear and nonlinear theories. The analysis reveals that, due to the special waveguide structure and the dielectric loss, the propagation characteristics of the complex waveguide are similar to that of a uniform lossy circuit. The analysis of the absolute instabilities characterizes the ...

Science.gov (United States)

Inductively coupled fluorocarbon (CF4/Ar and C4F8/Ar) plasmas were used to etch HfO2, which is a promising high-dielectric-constant material for the gate of complementary metal-oxide-semiconductor devices. The etch rates of HfO2 in CF4/Ar plasmas exceeded those in C4F8/Ar plasmas. The tendency for etch rates to become higher in fluorine-rich (high F/C ratio) conditions indicates that HfO2 can be chemically etched by fluorine-containing species. In C4F8/Ar plasmas with a high Ar dilution ratio, the etch rate of HfO2 increased with increasing bias power. The etch rate of Si, however, decreasd with bias power, suggesting that the deposition of carbon-containing species increased with increasing the power and inhibited the etching of Si. The HfO2/Si selectivity monotonically increased with increasing power, then became more than 5 at the highest tested bias power. The carbon-containing species to inhibit etching of Si play an important role in enhancing the HfO2/Si ...

Energy Technology Data Exchange (ETDEWEB)

Organic electronic devices using a pentacene have improved importantly in the last several years. We fabricated pentacene organic thin-film transistors (OTFTs) with dielectric SiO{sub 2} and ferroelectric Pb(Zr{sub 0.3},Ti{sub 0.7})O{sub 3} (PZT) gate insulators. The organic devices using SiO{sub 2} and PZT films had the field-effect mobility of approximately 0.1 and 0.004 cm{sup 2}/V s, respectively. The drain current in the transfer curve of pentacene/PZT transistors showed a hysteresis behavior originated in a ferroelectric polarization switching. In order to investigate the polarization effect of PZT gate dielectrics in a logic circuit, the simple voltage inverter using SiO{sub 2} and PZT films was fabricated and measured by an output-input measurement. The gain of inverter at the poling-down state was approximately 7.2 and it was three times larger than the value measured at the poling-up state.

International Nuclear Information System (INIS)

M-type hexagonal ferrite composition, Ba(1-x)SrxFe12O19 (x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0), was prepared by a two route ceramic method. Complex permittivity (?'-j?'') and complex permeability (?'-j?'') have been measured using a network analyzer from 8.2 to 12.4 GHz X-ray diffraction confirmed the M-type hexagonal structure and a scanned electron micrograph was used to analyze the grain size distribution of ferrite. Substitution of Sr2+ ions causes an increase in porosity that deteriorates the electromagnetic and microstructural properties in the doped samples. Both dielectric constant and dielectric loss are enhanced in comparison to the permeability and magnetic loss over the entire frequency region. This is due to a resistivity variation and the formation of Fe2+ ions, which increases the hopping mechanism between Fe2+ and Fe3+ ions.

International Nuclear Information System (INIS)

Atomic oxygen is measured in a pulsed dielectric barrier discharge (DBD) using two-photon absorption laser-induced fluorescence (TALIF). The ground-level atomic oxygen is excited to the 3p "3P state by two-photon absorption at 226 nm. Negative (-40 kV) or positive (+30 kV) pulsed DBD occurs in an O_2-N_2 mixture at atmospheric pressure. The pulse width of the DBD current is approximately 50 ns. The TALIF experiment shows that the decay rate of atomic oxygen increases linearly with O_2 concentration. This result proves that atomic oxygen decays mainly by the third-body reaction, O + O_2 + M #-># O_3 + M. The rate coefficient of the third-body reaction is estimated to be 2.2 x 10"-"3"4 cm"6 s"-"1 in the negative DBD and 0.89 x 10"-"3"4 cm"6 s"-"1 in the positive DBD. It is shown that the decay rate of atomic oxygen increases linearly with humidity. This can explain the well-known fact that ozone production in DBD is suppressed by increasing humidity.

Energy Technology Data Exchange (ETDEWEB)

Repeated exposure to cold air reduces the metabolic response to cold air exposure in man. The purpose of this investigation was to measure the change in resting metabolic rate (RMR) with exposure to 22C air and 4C air during a 12 day period. Four women sat in 22C air for 45 min followed by 45 min in 4C air each day for ten days. The authors measured RMR during a 45 min period in 22C air followed by 45 min in 4C air on four days. All subjects began their morning exposures on a Monday within 2 days of the onset of menses completing the study on a Friday, 12 days later. Subjects dressed in a T-shirt, shorts and cotton socks. During 45 min of exposure to warm air, RMR remained steady at 10% of VO{sub 2peak} on Day 1 and 10% on Day 5. RMR during exposure to warm air significantly increased to 13% of VO{sub 2peak} on Day 8 and remained elevated at 13% on Day 12. During exposure to cold air RMR peaked at 31% of CO{sub 2peak} by the 5th min on Day 1. ...

International Nuclear Information System (INIS)

This report is devoted to the investigation of the influence of electron collisions and radial non-uniformity of plasma density on phase characteristics, spatial attenuation and wave field structure of slow symmetric electromagnetic waves that propagate along cylindrical waveguide structure. It has been shown that collision rate and radial non-uniformity of plasma density for various parameters of waveguide structure and dielectric affect essentially on the wave characteristics and consequently, on the parameters of gas discharge that is sustained by this wave. The results obtained are of large importance for the construction of the theory of gas discharges that are sustained by the surface electromagnetic waves.

Energy Technology Data Exchange (ETDEWEB)

Probability distributions of partial discharge (PD) and dielectric breakdown voltage were investigated for the typical components of oil-filled transformer insulation. The equi-probabilistic PD and BD V-t characteristics were obtained from experimental results in the time range from several ..mu..sec to 10 hours. The authors point out that there is a close relationship between the scattering of PD voltage and the inclination of V-t characteristics in a long term region for ac voltage.

International Nuclear Information System (INIS)

The plasma cladding waveguide, which is a cylindrical dielectric core surrounded by a plasma cladding, is developed, and the guided modes and their characteristics of this waveguide are displayed through the present detailed theoretical research. The conditions of the single mode existing in the plasma cladding waveguide have been given, and the defined forbidden gap of frequency is discussed. It is found that the usage characteristics of the plasma cladding waveguide vary strongly with plasma frequency, and changing the plasma parameters can control the propagation mode. This paper focuses on exhibiting the basic characteristics and the potential applications of this new type of waveguide.

International Nuclear Information System (INIS)

We have used scale models to measure the predicted coupling of electromagnetic fields simulating the effects of high-altitude nuclear electromagnetic pulses (HEMP) on the interior surfaces of electronic components. Predictive tools for exterior coupling are adequate. For interior coupling, however, such tools are in their infancy. Our methodological approach combines analytical, computational, and laboratory techniques in a complementary way to take advantage of their separate strengths. Computer models are a promising tool, as they can be used to treat complex objects with arbitrary shapes, dielectrics, and cables, and multiple apertures. Laboratory tests can expand the domain of investigation even further.

Energy Technology Data Exchange (ETDEWEB)

A solid electrolytic capacitor having a solid electrolyte comprising manganese dioxide dispersed in an aromatic polyamide capable of further cure to form polyimide linkages, the solid electrolyte being disposed between a first electrode made of valve metal covered by an anodic oxide film and a second electrode opposite the first electrode. The electrolyte autogenously produces water, oxygen, and hydroxyl groups which act as healing substances and is not itself produced pyrolytically. Reduction of the manganese dioxide and the water molecules released by formation of imide linkages result in substantially improved self-healing of anodic dielectric layer defects.

Energy Technology Data Exchange (ETDEWEB)

An overview of the understanding of correlation between valence electron and the optical properties of binary (A{sup N}B{sup 8-N}) and ternary (A{sup N}B{sup 2+N}C{sub 2}{sup 7-N}) tetrahedral semiconductors is presented here. We have presented two expressions relating the dielectric constant and electronic polarizability for the transition metal chalcogenides and pnictides (A{sup II}B{sup VI} and A{sup III}B{sup V}) and chalcopyrites (A{sup I}B{sup III}C{sub 2}{sup VI} and A{sup II}B{sup IV}C{sub 2}{sup V}) with the product of valence electrons and nearest neighbour distance d (A). The dielectric constant and electronic polarizability of these solids exhibit a linear relationship when plotted on a log-log scale against the nearest neighbour distance d (A), but fall on different straight lines according to the valence electron product of the compounds. We have applied the proposed relation on these solids and found a better agreement with the ...

CERN Document Server

The Influence Of Plasma Temperature On Wake Wave Generation

International Science & Technology Center (ISTC)

Development of a Plant for Neon Isotopes Separation by Low-Temperature Rectification Method

ScienceCinema

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Energy Technology Data Exchange (ETDEWEB)

The application of multi-objective genetic algorithms for green building design in two phases were presented in order to better help designers in the decision-making process. The purpose is to minimize two conflicting criteria: the life-cycle cost and the life-cycle environmental impact. Environmental impact criteria examined include energy and non-energy natural resources, global warming, and acidification. Variables focus on building envelope-related parameters. The application of multi-objective genetic algorithms is divided into two phases. The first phase intends to help designers in understanding the trade-off relationship between the two conflicting criteria. The second phase intends to refine the performance region that is of the designer's interest. The results after the two-phase application of the multi objective genetic algorithm were then presented. 13 refs., 4 tabs., 3 figs.

Energy Technology Data Exchange (ETDEWEB)

The thin windows for the Muon Ionization Cooling Experiment (MICE) liquid Absorber will be fabricated from 6061-T6-aluminum. The absorber and vacuum vessel thin windows are 300-mm in diameter and are 180 mm thick at the center. The windows are designed for an internal burst pressure of 0.68 MPa (100 psig) when warm. The MICE experiment design calls for changeable windows on the absorber, so a bolted window design was adopted. Welded windows offer some potential advantages over bolted windows when they are on the absorber itself. This report describes the bolted window and its seal. This report also describes an alternate window that is welded directly to the absorber body. The welded window design presented permits the weld to be ground off and re-welded. This report presents a thermal FEA analysis of the window seal-weld, while the window is being welded. Finally, the results of a test of a welded-window are presented.

International Nuclear Information System (INIS)

High energy consumption and the world population increase will lead to a shrinking use of fossil fuels. The combustion of Fossil fuel leads to the increase of carbon dioxide concentration in the atmosphere which leads to the probable increase of global warming. Therefore, concerns about carbon dioxide emissions may discourage widespread dependence on fossil fuels and encourage the development and use of renewable energy systems employing a variety of technologies Renewable energy systems have themselves an environmental impact. Land use and material employed are two areas that may have an adverse impact to the positive environmental picture of the renewable energy systems. The objective of this paper is to analyze these impacts with the use of a very powerful tool, the Life Cycle Assessment. (author)

British Library Electronic Table of Contents (United Kingdom)

Summary Reference to an ancient Hindu picture of a snarling dog may be a convincing enough proof to consider the fact that rabies has been known in the world for the past 50 centuries. Prior to the monumental observation about rabies of Fracastoro in the 16th century, facts and fantasies were intermingled in the study of rabies. In the realm of fantasy, consider the statement of Aristotle (otherwise a great philosopher) that only animals and not humans die of rabies. It took 19 centuries before Fracastoro finally established that infection with rabies is lethal for all warm-blooded beings including humans. The new era of rabies dates from the time of Galtier who isolated the virus and Pasteur who was able to create a somewhat attenuated strain of virus fixe which became the tool of laborat...

International Nuclear Information System (INIS)

This study serves to investigate the uptake of POPs in the different trophic levels (scrapers, collectors, predators, shredders) of macroinvertebrate communities sampled from a glacial and a non-glacial stream in the Italian Alps. The presented results show that the contaminant concentrations in glacial communities are generally higher compared to those from non-glacial catchments, highlighting the importance of glaciers as temporary sinks of atmospherically transported pollutants. Moreover, the data also suggests that in mountain systems snow plays an important role in influencing macroinvertebrate contamination. The main chemical uptake process to the macroinvertebrates is considered to be bioconcentration from water, as similar contaminant profiles were observed between the different trophic levels. The role of biomagnification/bioaccumulation is thought to be absent or negligible. The enrichment of chemicals observed in the predators is likely to be related to their greater lipid ...

Energy Technology Data Exchange (ETDEWEB)

Plastic formability of cast magnesium alloy that were hot rolled after roll strip casting was investigated to ascertain the feasibility of semi-solid strip casting process of AZ31B magnesium alloy. Hot rolling and heat treatment conditions were changed to examine which conditions were appropriate for producing AZ31B wrought magnesium alloys after strip casting process. Microscopic observation of the crystals of the manufactured wrought magnesium alloys was performed. It has been found that a limiting drawing ratio of 2.7 was possible in a warm deep drawing test of the cast magnesium alloy sheets after being hot rolled. (orig.)

British Library Electronic Table of Contents (United Kingdom)

Through their grazing activities limpets have an important role in controlling macroalgal abundance and as a result the structure and dynamics of rocky shore assemblages. Using two congeneric limpet species, with different biogeographic distributions, and whose ranges are expected to alter with climatic warming, we separated the magnitude of their grazing activity over time and the subsequent consequence for macroalgal growth.The northern/boreal limpet, Patella vulgata (L.), consistently grazed more than the southern/lusitanian limpet, P. depressa (Pennant), particularly during spring and summer when P. depressa was reproductively active. Individuals of Fucus vesiculosus (L.) that settled during this time were able to grow to a size where they escaped the grazing activities of P. depressa,...

British Library Electronic Table of Contents (United Kingdom)

We tested two approaches to forecast species distributions while balancing the impact of climate change against the inertia promoted by other influential factors that have been forecast as not changing. Given that mountain species are presumed to be more at risk due to climate warming, we selected an amphibian, a reptile, a bird, and a mammal species present in the Spanish mountains, to model their distributional response to climate change during this century. The climatic forecasts were made according to the general circulation models CGCM2 and ECHAM4 and to the A2 and B2 emission scenarios. We modelled the response of the species to spatial, topographic, human, and climatic variables separately. In our first approach, we compared each of these single-factor models using the Akaike Inform...

British Library Electronic Table of Contents (United Kingdom)

Forest gap models have been used widely in the study of forest dynamics, including predicting long-term succession patterns and assessing the potential impacts of climate change on forest structure and composition. However, little effort is devoted to predict forest dynamics in the high elevation areas, although they have the sensitive response to global climate change. In the present study, based on a modified height-diameter function, we developed a new version (FAREAST-GFSM) of the forest patch model, FAREAST for simulating the changes of subalpine forests. The observed data from the Gongga Mt. Alpine Station were also used to test model precision. With the improved performance of FAREAST-GFSM, we explored the impact of three warming scenarios on subalpine forest on the eastern Tibetan ...

British Library Electronic Table of Contents (United Kingdom)

Highly dispersed silver nanoparticles embedded in mesoporous thin films (MTFs) have been synthesized by modification of the interior surface of mesoporous silica with ethylenediamine moieties, which provided the coordination sites for the Ag ions, and subsequent reduction under hydrogen atmosphere. TEM observations show the mesoporous parent films have effectively controlled the growth of the synthesized silver nanoparticles. The composite films had an ultrafast nonlinear response time, as fast as 200 fs, and a third-order nonlinear optical susceptibility of 0.94??10?10 esu, which was enhanced by the local field enhancement effect that was present when the silver nanoparticles were embedded in the surrounding dielectric matrix. The origin of the ultrafast nonlinear response and the enhanc...

International Nuclear Information System (INIS)

Strong coupled organic-inorganic microcavities device has been realized and studied. One of the two cavities contains an organic thin film of tetrakis(4-methoxyphenyl)porphyrin, whereas the other microcavity is a dielectric structure coupled to the organic one by means of a LiF/ZnS Bragg mirror. Reflectivity spectra show the presence of two well defined cavity dips. We observe an energy splitting of the two cavity-modes. Despite only one cavity contains the active layer, the photoluminescence spectra display two peaks at the same energy of the reflectivity dips. These observations indicate the strong coupling of the two cavities. The comparison of the diagonalized effective Hamiltonian with the observed resonances further confirms the strong coupling.

Energy Technology Data Exchange (ETDEWEB)

For a solar cell, in order to minimize the loss of incident light, transparent glass or plastic material is used at the incident part. When a solar cell is watched from the light incident part, a silicon base material is directly observed with either block or brown color only. This invention enables a solar cell to give brighter color on the incident surface by placing a reflective film which reflects only the light of specific wavelength, without reducing the efficiency of the solar cell. This reflective film consists of multi-layered dielectric with 12 layers and alternative combination of highly refractive and less refractive substances. Highly refractive layer is Y/sub 2/O/sub 3/ with refractive index 1.74 and the less refractive layer is SiO/sub 2/ with refractive index 1.45. (5 figs)

CERN Document Server

A new particle swarm optimization (PSO) technique for electromagnetic applications is proposed. The method is based on quantum mechanics rather than the Newtonian rules assumed in all previous versions of PSO, which we refer to as classical PSO. A general procedure is suggested to derive many different versions of the quantum PSO algorithm (QPSO). The QPSO is applied first to linear array antenna synthesis, which is one of the standard problems used by antenna engineers. The performance of the QPSO is compared against an improved version of the classical PSO. The new algorithm outperforms the classical one most of the time in convergence speed and achieves better levels for the cost function. As another application, the algorithm is used to find a set of infinitesimal dipoles that produces the same near and far fields of a circular dielectric resonator antenna (DRA). In addition, the QPSO method is employed to find an equivalent circuit model for the DRA that can ...

International Nuclear Information System (INIS)

Nonrelativistic band calculations of Mattheiss for Nb and Petroff and Viswanathan for Mo are used to calculate the imaginary part epsilon_2 of the dielectric function for these metals. The structure resulting from interband transitions in the frequency range 0.1--0.5 Ry is found to give fairly good agreement with experiment. The calculation indicates that structure in epsilon_2 can arise from transitions away from symmetry points and lines in the Brillouin zone. The difficulty in distinguishing between the direct and indirect transition models for epsilon_2 is shown to arise from a lack of strong optical critical points. Predictions of the rigid-band model for the optical properties of Nb-Mo alloys are presented.

British Library Electronic Table of Contents (United Kingdom)

Abstract The air-water interface presents several interesting features, namely a) a molecularly flat environment, b) a boundary region between two phases with different dielectric constants, c) permits or promotes dynamic interactions within the interface region, and d) a point of interaction between hydrophobic compounds and aqueous molecules. Accordingly, Langmuir monolayers at the air-water interface have several unique characteristics and properties, which require investigation. In this review-type personal account, typical examples of molecular recognition and molecular patterning at air-water interfaces are first introduced, followed by descriptions of specific and unusual properties of monolayers on water. In addition, two examples of our own results concerning Langmuir monolayers a...

International Nuclear Information System (INIS)

In this paper, a Kramers-Kronig (KK) analysis of infrared (IR) reflectance spectrum of quaternary In_0_._0_1Al_0_._0_6Ga_0_._9_3N film grown by molecular beam epitaxy (MBE) is reported. The infrared measurement is performed in the reflection mode at an incident angle of 15 degree sign by Fourier transform infrared (FTIR) spectroscopy at T = 300 K. The Kramers-Kronig analysis of the reflectivity data has been used to obtain the real and imaginary parts of the index of refraction (n and k), and the real and imaginary parts of the dielectric response function (#epsilon#' and #epsilon#') of the materials. Finally, the transverse optical and longitudinal optical phonons for quaternary In_xAl_yGa_1_-_x_-_yN were obtained.

International Nuclear Information System (INIS)

The electronic structures of the set of molecular clusters of dielectric oxide crystals AWO4 (A = Pb, Cd, Zn), the sizes of which increase sequentially are ab-initio calculated by the Restricted Hartree-Fock (RHF) method. The results of calculations of molecular orbitals and energy dependences of partial densities of electronic states of different clusters are compared each to other and to experimental data. It is found that calculated electronic structures of the tungstate groups and cations which are surrounded in cluster by certain number of the nearest neighbor atoms of the crystals quite well represent the experimentally obtained value of the forbidden gap of corresponding AWO4 crystal. (authors)