We have continued to finish up our work on analyzing relationships between elastic properties and rock microstructure. We have worked on theoretical models for the effects of sorting and packing on elastic moduli and seismic velocities. After analyzing the scanning acoustic images of shales to quantify textures at different scales, we are now using theoretical inclusion models to quantify the elastic property variation with texture. In the closing phases of this project most of our efforts are now focused on writing up the results and preparing the final reports.
This book presents topics on: Density of rocks and minerals, includes histograms of density ranges; elastic constants of minerals, elastic moduli, thermal properties; inelastic properties, strength and rheology for rocks and minerals, rock mechanics and friction, and stress-strain relations; radioactivity, decay constants and heat production of isotope systems in geology; seismic attenuation, in rocks, minerals, and the earth, with application to oil exploration and terrestrial studies; and index.
We use X-ray scattering and molecular simulations to investigate the structural properties of complexes of multivalent cationic lipids and DNA molecules. At low mole fraction of neutral lipids (NLs), $\\Phi_{\\rm NL}$, the complexes show dramatic DNA compaction down to essentially close packed DNA arrays with a DNA interaxial spacing $d_{\\rm DNA}=25\\AA$. A gradual increase in $\\Phi_{\\rm NL}$ does not lead to a continuous increase in $d_{\\rm DNA}$ as observed for DNA complexes of monovalent cationic lipids (CLs). Instead, distinct spacing regimes exist, with sharp transitions between them. Three packing states have been identified: (i) close packed, (ii) condensed, but not close packed, with $d_{\\rm DNA}=27-28\\AA$, and (iii) an expanded state, where $d_{\\rm DNA}$ increases gradually with $\\Phi_{\\rm NL}$. Based on our experimental and computational results, we conclude that ...
The development of a twinned microstructure in hexagonal close-packed rolled magnesium compressed in the in-plane direction has been monitored in situ with neutron diffraction. The continuous conversion of the parent to daughter microstructure is tracked through the variation of diffraction peak intensities corresponding to each. Approximately 80% of the parent microstructure twins by 8% compression. Elastic lattice strain measurements indicate that the stress in the newly formed twins (daughters) is relaxed relative to the stress field in the surrounding matrix. However, since the daughters are in a plastically 'hard' deformation orientation, they quickly accumulate elastic strain as surrounding grains deform plastically. Polycrystal modeling of the deformation process provides insight about the crystallographic deformation mechanism involved.
The nucleation and propagation of hydrofractures by injection of over pressured fluids in an elastic and isotropic medium are studied experimentally. Non-Newtonian fluids are injected inside a gelatine whose mechanical properties are assumed isotropic at the experimental strain rates. Linear elastic theory predicts that plastic deformation associated to breakage of gelatin bonds is limited to a small zone ahead of the tip of the propagating fracture and that propagation will be maintained while the fluid pressure exceeds the normal stress to the fracture walls (Ch\\'avez-\\'Alvarez,2008) (i.e., the minimum compressive stress), resulting in a single mode I fracture geometry. However, we observed the propagation of fractures type II and III as well as nucleation of secondary fractures, with oblique to perpendicular trajectories with respect to the initial fracture. In the Video (http://hdl.handle.net/1813/14122) experimental ...
...furnished with commercial or military export packing. Military export packing, if offered, shall be in accordance with Mil-Std-2073-1 Level A or B as specified. If commercial export packing is offered, the offer or pricelist shall include...
A fast and simple flow-through optosensor was designed and characterized for the direct screening of four tetracycline (TCC) antibiotics (tetracycline, oxytetracycline, chlortetracycline and doxycycline) in water and bovine milk samples. The proposed optosensor provides rapid binary yes/no overall responses, being appropriate for the screening of this family of antibiotics above or below a pre-set concentration threshold. The experimental set-up is based on a flow-injection manifold coupled on-line to a phosphorescence detector. Aliquots of the samples are pretreated with Eu(III) to form room temperature phosphorescent metal chelates and injected in the flow manifold. Those chelates are then on-line retained on a conventional flow-cell (packed with polymeric Amberlite XAD-4 particles) which is placed inside the cell holder of the phosphorimeter. After the emission is registered, the antibiotic-metal complexes are eluted from the ...
Calculations in "7Li have been carried out for the differential coherent elastic scattering cross-section of thermal neutrons at a fixed scattering angle #theta#_0(148"o) and varying the energy of incident neutrons (or corresponding d-spacings). The results are reported, as variations of the ratio #SIGMA#_0"c"o"h (#theta#_0, d)/#SIGMA#_0"c"o"h (#theta#_0) with d-spacing, at atmospheric pressure and at two temperatures, 80 and 20 K. The calculations at 80 K correspond to BCC lithium whereas at 20 K all the possible crystallographic structures of polytype lithium (BCC, 9R, HCP and FCC) were considered. On comparing our results with the time-of-flight (TOF) measurements of Berliner et al. (Physical Review, B40, 12086, 1989) we find that up to 80 K lithium-7 does not undergo any martenistic transformation whereas the structural state at 20 K can be described by the co-existence of the original BCC phase with 9R, HCP and FCC closed packed ...
A laboratory differential simulation method is used for the design of carbonization columns at coal-tar processing in which phenols are regenerated from phenolate solution by carbon dioxide absorption. The design method is based on integration of local absorption rates of carbon dioxide along the column. The local absorption rates into industrial phenolate mixture are measured in a laboratory model contactor for various compositions of the gas and liquid phases under the conditions that ensure the absorption rates in the laboratory absorber simulate the local rates in the industrial column. On the bases of the calculations, two-step carbonization columns were designed for 30000 t/year of the phenolate solution treatment by carbon dioxide. The absorption proceeds at higher pressure of 500 kPa and temperatures from 50 to 65 C, pure carbon dioxide is used and toluene is added. These conditions have the following favourable effects: (I) significant size reduction of the columns, (ii) it is ...
Development of Scientific Foundations of the Technology of the Metal Matrix Packing of Leaky Unreprocessible Spent Nuclear Fuel of Different Purpose Reactors for a Long-term Environmentally Safe Storage.
Information is presented concerning solute concentration in a porous layer; solute concentration in a packed crevice; corrosion of a packed carbon steel crevice in NaCl-O"2 solutions; and effect of copper on corrosion in NaCl-O"2 solutions.
A 300 W fuel cell power pack has been developed for educational purposes in close collaboration with the Fachhochschule Solothurn Nordwestschweiz. The project was initiated and financed by the Swiss Federal Office of Energy. The outlay and the performance of the power pack are described. (author) 3 figs.
As the amount of urban and industrial wastes is increasing more and more, recycling is very necessary. Daily, there are many news about packing, even more since European Union is getting ready a Directive that will propose and will impose the reuse and recycling of the materials used to produce the packs. This Directive will be followed by different national laws of the countries members of EU. This paper describes the increasing use of aluminium for packing, and particularly its use for beverage cans, its characteristic and applications.
2.1.1 Levels of preservation and packaging and the levels of packing to be applied selectively are defined in MIL-STD-2073-1 and are mandatory for use or ...
The extraction and recovery of cesium from simulated Purex waste solutions was successfully demonstrated in the pilot plant pulse column. Stable volumetric capacities as high as 670 gph/ft/sup 2/ (sum of both phases) were obtained for alkaline supernate-type waste; however, for efficient operation (transfer unit height - HTU -of two feet or less), the maximum throughput rate was limited to about 500 gph/ft/sup 2/. This rate could be achieved with feeds diluted to densities within 0.08 g/cc of the solvent density. Stable feed was prepared from simulated current, denitrated waste by addition of citric acid to complex the iron before neutralization to the desired operating pH of 7 to 8. Capacities of 500 gph/ft/sup 2/ were readily achieved with this feed, together with HTU's of 1.0 to 1.3 feet. Sodium extracted with the cesium was satisfactorily scrubbed from the solvent with a dilute citric acid solution. Scrub section sodium decontamination factors ...
Several new complexes of isomeric schiff bases derived from salicylaldehyde and o-hydroxybenzylamine/o-aminobenzyl-alcohol with Pr(III), Nd(III), Sm(III), Gd(III), Tb(III), and Dy(III) have been synthesized and characterized by elemental analysis, molar conductance, IR, electronic spectra and magnetic susceptibility measurements. The schiff bases behave as monobasic tridentate ONO donor and dibasic tridentate ONO donor ligands and form complexes of the type Ln(LH)L. (author). 12 refs.
(I)Results are given for photoproduction of the D{sup *} at 103 GeV. Clean signals are seen for the decay D{sup *{+-}} {yields} {pi}{sup {+-}}D{sup 0} with the D{sup 0} decaying into both K{sup {-+}}{pi}{sup {+-}} and K{sup {-+}}{pi}{sup {+-}}{pi}{sup 0}. Analysis of the Dalitz plot for the K{pi}{pi} mode gives branching fractions (BFs) for K{sup {minus}}{rho}{sup +}, K{sup *{minus}}{pi}{sup +}, and {anti K}{sup *0}{pi}{sup 0} final states. The BF for D{sup 0} {yields} K{sup {minus}}{rho}{sup +}, much lower than a previous result, is in approximate agreement with the value expected for an l=1/2 final state. (II)Inelastic and elastic J/{psi} photoproduction on H is investigated at 103 GeV. The inelastic cross section with E{sub {psi}}/E{sub {gamma}} {lt} 0.9 is significantly lower than the corresponding result for muoproduction on Fe targets, but consistent with second-order perturbative QCD calculation. The mean p{sub +} of inelastic events is larger than that of ...
The characteristics of martensitic transformations in solids are largely determined by the elastic strain that develops as martensite particles grow and interact. To study the development of microstructure, a finite-element computer simulation model was constructed to mimic the transformation process. The transformation is athermal and simulated at each incremental step by transforming the cell which maximizes the decrease in the free energy. To determine the free energy change, the elastic energy developed during martensite growth is calculated from the theory of linear elasticity for elastically homogeneous media, and updated as the transformation proceeds.
The synapsin III gene, SYN3, which belongs to the family of synaptic vesicle-associated proteins, has been implicated in the modulation of neurotransmitter...Full Text Available
Study results on long-term thermal and corrosion resistance of packs with electro-insulation layer of aluminium nitride are presented. Structural changes of nitride ceramics and contact zones between metal and ceramics are considered. It is shown that multilayer metallo-ceramic packs, manufactured by gas-phase technology have high electro- and thermophysical properties, high thermal and corrosion resistance relative to cesium vapor, vacuum density as well as high thermo-resistance. 8 refs., 4 figs.
A nitrogen oxides decreasing combustion method comprising: mixing a fuel and air with each other; bringing the mixture obtained into contact with a packed catalyst; and adding a fresh supply of the fuel to the stream obtained to form a mixed gas and causing the mixed gas to undergo non-catalytic thermal combustion, characterized in that only a catalytic reaction or combustion occurs at the packed catalyst; the temperature of the packed catalyst is kept lower than the ignition temperature of the mixture; the adiabatic flame temperature which is reached by the non-catalytic thermal combustion of the mixed gas is lower than the temperature at which the nitrogen oxides occur. 39 figs.
Ribbon parachute fabrics were tested during development and production of a 24 ft parachute, and after 2.5 years ambient exposure at several storage sites. The effects of sewing, packing, and parachute deployment on material strength were obtained in the 1000 lb Kevlar ribbon after moisture exposure during packing, and when packed parachutes absorbed moisture or were thermal cycled. Individual yarn samples from the low strength ribbons exhibited little change in strength indicating that the material itself had not degraded. Factors leading to the change in ribbon strength are discussed. Considering all materials, there have been no indications to date of any uncontrollable changes in material strength that would limit the use of Kevlar in parachute applications.
D-11. The Contractor shall pack and mark all hardware deliverable under this ... Handling, and Transportation, and/or MIL-STD-2073-1 and MIL-STD 2073-2, ...
We investigate ordering properties of two-dimensional granular materials using several shapes created by welding ball bearings together. Ordered domains form much more easily in two than in three dimensions, even when configurations lack long-range order. The onset of ordered domains occurs near a packing density of 0.8, a phenomenon observed previously for disks. One of our shapes, the trapezoid, has packings that remain disordered and near the transition density even after annealing by shaking. Although random packings are unstable for disks and many other shapes in two dimensions, trapezoid packings provide an approach to studying two-dimensional randomness. We also find that the rotational symmetry of a shape is an excellent predictor of how easily it orders, and a potential guide to identifying two-dimensional shapes that remain random after annealing.
The oxygen production of a photosynthetic gas exchanger containing Chlorella pyrenoidosa (1% packed cell volume) was measured when various concentrations of carbon dioxide were present...Full Text Available
Purpose: The purpose of this study was to compare nutrient content and cost of home-packed lunches to nutrient standards and prices for reimbursable school lunches. Methods: Researchers observed food and beverage contents of 333 home packed lunches at four north Texas elementary schools. Nutritionist Pro was used to analyze lunches for calories, total fat, saturated fat, protein, fiber, vitamin A, vitamin C, calcium, iron, fiber, and sodium content. These values were then compared to National School Lunch Program (NSLP) standards and other nutrient standards. Cost of each home-packed lunch was estimated based on food prices at three local supermarkets. A one-sample t-test (p = 0.05) was used to compare nutrient values of home packed lunches to National School Lunch Program (NSLP) standards. A paired t-test was used to compare cost of home packed lunches to each school's full price ...
... Thus initiation will be from the shock generated from the front surface of the pellet after traversing the inert packing. Exploding bridgewire detonator ...
A new method for computing petroleum reserves which takes into account the volumetric elasticity of stratal petroleum and a porous medium of a collector is examined based on the example of developing petroleum beds of Cretaceous horizon of the Groznenskiy region.
Previous ultrasound elasticity imaging experiments supported a generally accepted concept that the hardness of deep venous thrombi increases with thrombus aging. Results also showed that this...Full Text Available
A study to define the effectiveness limits of sulfamic acid and to discover other better stabilizers for Pu(III) is described. Ascorbic and isoascorbic acids, used in conjunction with sulfamic acid reduced Pu(IV) to stable Pu(III) in nitric acid. Aminoguanidine sulfate also retarded the oxidation of Pu(III) but did not reduce Pu(IV). (J.R.D.)
A pre-stack migration algorithm for elastic waves in two-dimensional variable-velocity media is developed, implemented, and tested. The algorithm operates in the time-space domain and is based on reverse-time finite-difference extrapolation of elastic waves. The algorithm is explained and demonstrated in the context of imaging of elastic vertical seismic profile data, but is applicable to any source-recorder geometry. Synthetic test examples include a point diffractor, laterally homogeneous layers, and the flank of a salt dome.
Ab initio total-energy calculations, based on the exact muffin-tin orbital method, are used to determine the elastic properties of Pd1-xAgx random alloys in the face-centered-cubic crystallographic phase. The compositional disorder is treated within the coherent-potential approximation. The single crystal and polycrystalline elastic constants and the Debye temperature are calculated for the whole range of concentration, 0?x?1. It is shown that the variation in the elastic parameters of Pd-Ag alloys with chemical composition strongly deviates from a simple linear or parabolic trend. The complex electronic origin of these anomalies is demonstrated.
This paper examines the seismic signatures of discrete, finite-length fractures, and outlines an approach for elastic, prestack reverse-time imaging of discrete fractures. The results of this study highlight the importance of incorporating fracture-generated P-S converted waves into the imaging method, and presents an alternate imaging condition that can be used in elastic reverse-time imaging when a direct wave is recorded (e.g., for crosswell and VSP acquisition geometries).
The effective elastic constants of a superlattice composed of layers of orthorhombic symmetry (with principal axes along the superlattice axis) are derived. These results generalize previous determinations for elastically isotropic layers (Rytov, Akust. Zh. 2, 71 (1956) (Sov. Phys.: Acoust. 2, 68 (1956))), but a completely different approach is used.
A theoretical model is proposed for analyzing elastic scattering of 100-150 MeV #alpha#-particles on intermediate mass nuclei. It is shown that, within the scope of this model accounting for inhomogeneous target-nucleus density, an anomalous growth of differential cross section of elastic scattering in the region of average angles can be explained.
The purpose of the invention is to improve adaptability of a compression shield to irregularities of a face. This goal is achieved in that a compressible shield is made in the form of a lattice of elastic transverse plates with grooves, elastic vertical elements installed in the grooves, and an elastic plate which is concave toward the face. The plate is located vertically in the middle of the shield. The compressible shield is attached by hinges to a deflector. Telescopic cross pieces are attached by hinges to the covering section of reinforcement, offering the possibility of longitudinal movement at the point of attachment.
Using the example of perhydrophenanthrene, perhydroanthracene and cyclopentanodecalin isomers a possibility is shown to use packed capillary columns containing graphitized thermal carbon black for a complete separation of high-boiling mixtures of polycyclic saturated hydrocarbon isomers in accordance with the geometric structure of their molecules.
The concept of a multi-cavity volumetric solar receiver is very attractive for the profitability of certain of its characteristics such as high efficiency and economy. The absorber is based on a pack of small ceramic cavities which intercept and absorb the inherent high solar flux reflected from an array of mirrors. Atmospheric air acts as a coolant medium when it is drawn through the pack. A model for an overall heat transfer performance of the receiver is given and numerically solved.
The radiation polymerization of multifunctional unsaturated polyester-monomer mixtures in wood forms interpenetrating network system. The mechanical resistance (compression, abrasion, hardness, etc.) of these composite materials are generally well over the original wood, however the impact strength is almost the same or even reduced, in comparison to the wood itself. An attempt is made using elastic polyester resins to produced wood-polyester composite materials with improved modulus of elasticity and impact properties. For the impregnation of European beech wood two types of elastic unsaturated polyester resins were used. The exothermic effect of radiation copolymerization of these resins in wood has been measured and the dose rate effects as well as hardening dose was determined. Felxural strength and impact properties were examined. Elastic unsaturated polyester resins improved the impact strength of ...
We develop a large scale parallel viscous-elastic analysis program incorporating a mesoscopic self-consistent model developed by Laws. In the model, macroscopic elastic constants are treated as variables depending on the shape and statistical properties of pre-existing microscopic pores and change due to neutron irradiation. We apply this program to the visco-elastic analysis of nuclear graphite structures under neutron irradiation environment in High Temperature Gas-cooled Reactor (HTGR), as an example problem. Furthermore the calculated results by this parallel computational program are compared with those by one of commercial finite element analysis codes, FINAS, for validating elastic and thermal stress analysis function. (author)
This study reports on the physical-chemical behaviour of swelling di-octahedral clays (smectites) and their interaction with aqueous solutions and bacteria (Shewanella putrefaciens). Experimental results are presented for compacted clays, hydrated under confined volume conditions, using a new type of reaction-cell (the 'wet-cell' of Warr and Hoffman, 2004) that was designed for in situ X-ray diffraction (XRD) measurement. For comparison, dispersed clay systems were studied using standard batch solutions subjected to varying degrees of agitation. The combination of time-dependent in situ XRD measurements with gravimetric measurements and calculated diffraction patterns using the CALCMIX software (Plancon and Drits, 1999) allowed to successful quantification of the dynamics of water uptake and storage. This analytical procedure combined with published water vapour adsorption data enabled determination of the abundance of structured water layers, developed in the ...
The type III secretion system among Gram-negative bacteria is known to deliver effectors into host cell to interfere with host cellular processes. The type III secretion system in Yersina, Pseudomonas and Enterohemorrhagic Escherichia coli have been well documented to be involved in the bacterial pathogenicity. The existence of type III secretion system has been demonstrated in neuropathogenic E. coli K1 strains. Here, it is observed that the deletion mutant of type III secretion system in E. coli strain EC10 exhibited defects in the invasion and intracellular survival in Acanthamoeba castellanii (a keratitis isolate) compared to its parent strain. Next, it was determined whether type III secretion system plays a role in E. coli K1 survival inside Acanthamoeba during the encystment process...
The present study numerically investigates the enhancement of forced convective heat transfer from a single circular cylinder embedded in a packed bed of spherical particles confined by two impermeable parallel plates. The heat transfer results from the heated cylinder, with and without the presence of a porous medium, are compared. The results show that the presence of the porous particles enhances the heat transfer from the cylinder; however, the significant heat transfer augmentation is produced at high Re due to the effect of thermal dispersion. In addition, the effect of Re on Nut is much greater than that of kr and Bi in the porous channel. It is also found that the %?p is much higher than %HTE producing from packing the empty channel.
We aimed to investigate the effects of local anesthetics soaked in Merocel nasal packs on hemorrhage and pain after septoplasty. The methodology includes a prospective double-blind study that was conducted in patients undergoing septoplasty because of nasal septal deviation. The study included 143 patients. The patients were divided into four groups. Each group received 1% lidocaine?+?0.000625% adrenalin, 0.375% ropivacaine, 0.25% bupivacaine as study groups or 0.9% sodium chloride as a control group in their Merocel packs postoperatively. The local anesthetics or sodium chloride were reapplied at the eighth postoperative hour. Each patient was given a questionnaire where verbal analog score and amount of postoperative hemorrhage was noted. The statistical analysis was performed using two ...
Recently we have found that carbon nano-materials have ability to recognize softer actinides(III). In this presentation, separation of americium(III) from lanthanides(III) by chromatography with carbon nano-materials, such as carbon nano-tubes and graphite, has been investigated by batch adsorption experiments and chromatography. The separation factor (SF) between americium(III) and lanthanide(III) was about 2 in the range of pH from 1 to 4 by using carbon nano-tube, graphite and activated charcoal. The separation factor depended on the diameter of carbon nano-tubes. Smaller one, 3-20 nm diameter, showed the best selectivity for americium(III), which separation factor was about 2.0, although larger one, 40-70 nm, showed almost no selectivity. The same behavior has been observed by using graphite powder and activated charcoal although acid- or alkali pretreated ...
Bacteria expressing type III secretion systems (T3SS) have been responsible for the deaths of millions worldwide, acting as key virulence elements in diseases ranging from plague to typhoid...Full Text Available
ObjectivesThe updated Rome III criteria for pediatric functional gastrointestinal disorders (FGIDs) include new FGID categories and changes to the Rome II criteria...Full Text Available
It has been discovered that iron(III) chloride complexes supported on activated charcoal oxidize phosphine under normal conditions. The process accelerates as the concentration of the chloride ions and the proton acid increases.
Endosomal sorting complexes required for transport (ESCRTs) are heteromeric protein complexes required for multivesicular body (MVB) morphogenesis. ESCRTs I, II, III and III-associated are ubiquitous...Full Text Available
Mutations in SPTBN2, the gene encoding β-III spectrin, cause spinocerebellar ataxia type 5 in humans (SCA5), a neurodegenerative disorder resulting in loss of motor...Full Text Available
Electronic and structural properties of antiphase boundaries in group III-V semiconductor compounds have been receiving increased attention due to the potential to integration of optically-active III-V...Full Text Available
The evolution of the Doublet III neutral beam armor is followed from the initial design of a radiation cooled metallic tile to the present actively cooled graphite design. Results of the thermal and stress analyses that dictated the present design are reviewed.
Capsulation of terbium(III) chloride in porous glass in the amount of 1.5-150 #mu#mole g"-"1 was carried out by impregnation of the glass substrate with variable concentrations of the salt aqueous solutions. Maximum luminosity of terbium(III) chloride in porous glass is found at its concentration of 120 #mu#mole g"-"1, that is close to the corresponding monolayer surface filling. Concentration dependences of terbium(III) luminescence and its quenching by adsorbed water are in agreement with the ideas of molecular fragmentation and uniform distribution of capsulated salt on the substrate surface
... Abstract : The purpose of this study was to evaluate the tooling cost estimating equation of the DAPCA III model and determine if more accurate ...
The use of 2-pyridinealdoxime (paoH)/N,N′-donor ligand (L-L) “blend” in cobalt chemistry has afforded two cationic mononuclear cobalt(III) complexes of the general type [Co(pao)2(L-L)]+,...Full Text Available
Pseudomonas syringae is a gram-negative bacterial plant pathogen that is dependent on a type III protein secretion system (TTSS) and the effector proteins it translocates into plant...Full Text Available
We present an estimate of the Gamma Ray Bursts which should be expected from metal-free, elusive first generation of stars known as PopulationIII (PopIII). We derive the GRB rate from these stars from the Stellar Formation Rate obtained in several Reionization scenarios available in the literature. In all of the analyzed models we find that GRBs from PopIII are subdominant with respect to the ''standard'' (PopII) ones up to z {approx} 10.
During electrolysis of a "2"4"8Cm(III) solution in 2M K_2CO_3 at pH=13, partial oxidation of curium to a higher oxidation state, probably Cm(IV), was observed. The absorption spectra of Cm(III) and Cm(IV) in K_2CO_3 solution were recorded and the molar extinction coefficients of main absorption bands of curium were evaluated. (author).
A metamaterial that is composed of solid viscoelastic elements with controllable properties is proposed in this Letter. This enables an adaptable and general acoustic metamaterial to be practically realised. An array of masses with a single elastic connection to a supporting viscoelastic structure, such as one that is dynamically equivalent to an array of Helmholtz resonators, only provides a system with negative effective mass. A local active control scheme applied to each of these masses can emulate additional elastic connections to the supporting structure. An array of masses with a suitable local control scheme can provide both the negative effective stiffness and mass required for negative refraction. The tuneable feedback control parameters determine the characteristics of the region...
Based on the generalized gradient approximation (GGA) of density functional theory (DFT) and the full-potential linearized augmented plane wave (FLAPW) at the level including all electrons, the lattice parameters of graphite are calculated and optimized. Some elastic wave velocities transmitted in graphite are deduced. Using the methods of elastic wave velocity method and the atomic displacement method, the Debye frequency of graphite is obtained. The standard heat capacity, entropy, sublimation enthalpy of graphite is deduced at 289.5 k and 1 atm. The calculated results are discussed and compared with experimental data. (authors)
The effect of elastic and plastic strains on the magnetic properties of ferrite-pearlite steels has been studied. It has been shown that the sensitivity to elastic-tensile and bending strains is four to five times greater for remnant magnetization than for coercive force. In order to determine the degree of cold plastic deformation of high-carbon steels, a two-parametric testing technique based on the use of remnant magnetization and coercive force was suggested. An MMT-2 device was recommended for measurement of the required parameters.
This contribution analyzes elastic-backscatter lidar data and temperature and humidity profiles from radiosondes acquired in Barcelona in July 1992. Elastic-backscatter lidar data reveal the distribution of aerosols within the volume of atmosphere scanned. By comparing this information with temperature and humidity profiles of the atmosphere at a similar time, we are able to asses de relationship among aerosol distribution and atmospheric stability or water content, respectively. Comparisons have shown how lidar`s revealed layers of aerosols correspond to atmospheric layers with different stability condition and water content.
In a cross-over study, participants (n=59) were randomly assigned to receive either 100 kcal packs or standard size packages of snacks for 1-week. After a minimum of a 1-week washout period,...Full Text Available
Requirements for food packaging materials include whether there is any interaction between the food and the package during or after the irradiation, and whether as a result of the irradiation, volatile or leachable substances are released from the pack into the food. The performance of cellulose-based materials and plastic films under irradiation are discussed.
One of the important aspects in an absorption system is the effectiveness in which the gas and liquid phases come into contact with each other. An effective absorption process will provide sufficient contacting area for the gas and liquid phases to interact upon. With this in mind, work was conducted to evaluate carbon dioxide (CO{sub 2}) absorption into aqueous solutions of monoethanolamine (MEA) using two different types of contacting devices: gas absorption membrane (GAM) modules and traditional packed columns. The performance of these two absorption devices was compared to one another using the overall mass transfer coefficient (K{sub G}a{sub v}) as a basis. The GAM module contained microporous polypropylene hollow fibre membranes and the packed absorption column contained Sulzer DX structured packing. The results indicate that GAM modules tend to have slightly larger K{sub G}a{sub v} values, potentially opening the ...
In this article, a method of producing elastic ferromagnetic composite containing particles of chemical pure iron with sizes of 0.10-0.15 mm was described. The particles were dispersed in an elastic matrix of an elastic silicone rubber. The filling factor of composite by ferromagnetic particles and porous factors were changed in the range from 0.15 to 0.45. The samples of the obtained composite were placed in the magnetic field with induction of 0-8 T, produced by the Bitter-type magnet. The longitudinal magnetostriction of samples was measured by using a coaxial capacitor with a movable plate. It was found that the maximal relative elongation of samples was 4.81% and hysteresis of magnetostriction and also remanent magnetostriction amounted to 1.08%. A slow decay of remanent magnetostriction up to 0.14% in 10{sup 5} s was also observed.
AbstractMicrobial capsules are important for virulence, but their architecture and physical properties are poorly understood. The human pathogenic fungus Cryptococcus neoformans...Full Text Available
The structural stability, electronic and elastic properties of ScN under high pressure were investigated by using full-potential linearized augmented plane-wave (FP-LAPW) method. Our calculations indicate that there exists a pressure-induced structural phase transformation from the ambient rock-salt (B1) phase to CsCl-type (B2) phase above 335 GPa. The origin of moderate high bulk modulus, mechanical and high melting point was analyzed by electronic properties. The variations of elastic constants (C_i_j) with volume and pressure have been investigated. Moreover, the volume dependencies of Debye temperature, the longitudinal and transverse elastic wave velocities have been presented.
The authors consider the dynamics of interacting elastic disks in the plane. This is an experimentally realizable two-dimensional model of dry granular flow where the stresses can be visualized using the photoelastic effect. As the elastic disks move in a vacuum, they interact through collisions with each other and with the surrounding geometry. Because of the finite propagation speed of deformations inside each grain it can be difficult to capture computationally even simple experiments involving just a few interacting grains. The goal of this project is to improve our ability to simulate dense granular flow in complex geometry. They begin this process by reviewing some past work, how they can improve upon previous work. the focus of this project is on capturing the elastic dynamics of each grain in an approximate, computationally tractable, model that can be coupled to a molecular dynamics scheme.
The data base for the form factors of the nucleon obtained from elastic ep scattering is discussed, as well as some recent developments in their calculation.
... The measured elastic modulus was fairly close to the predicted value, but the ultimate compressive strength (UCS) was quite a bit below the MSC ...
Microbial population and moisture content of traditional herbal medicines contaminated with 3 kinds of aerobic microbes, packed in 5 kinds of plastic packaging materials, followed by irradiation at minimum dose of 5 kGy and stored for 6 months were investigated. The highest reduction of microbial counts during storage was observed on samples packed in polyethylene bags. All of packaging materials used were found to be impermeable to microbes and water vapour. Radiation and packaging materials used acted synergistically to inactivate microbes durind storage. The microbial counts decreased as much as 2 to 4 log cycles during storage. (author).
With the help of self-assembly, thermal sintering, selective etching techniques and sol-gel process, the non-close packed (ncp) face-centered cubic (fcc) photonic crystals of titanium dioxide (TiO2) hollow spheres connected by TiO2 cylindrical tubes have been fabricated using silica template. The photonic bandgap calculations indicate that the ncp structure of TiO2 hollow spheres was easier to open the pseudogaps than close packed system at the lowest energy. PMID:17097102
This patent describes a nitrogen oxides decreasing combustion method which comprises: a first step of mixing a fuel and air with each other; a second step of bringing the mixture obtained in the first step into contact with a packed catalyst such that only catalytic combustion occurs; and a third step of adding a fresh supply of the fuel to a stream obtained from the second step to form a mixed gas and causing the mixed gas to undergo non-catalytic thermal combustion. The temperature of the packed catalyst is lower than the ignition temperature of the mixture and the adiabatic flame temperature of the mixed gas is lower than a temperature at which the nitrogen oxides occur.
Development of surface monitoring of the quality of round rubber packing rings for well instruments is discussed. A method is shown for testing the rings under conditions which simulate the operating conditions. A method is proposed for rapid monitoring of the conditions for vulcanization of the rings by the method of determining the ''ring modulus.''
The foils of various materials were irradiated with "6"0Co with an activity of 11,538 TBq. The minimum radiation dose was 25 kGy. Changes in chemico-physical properties were evaluated by infrared spectroscopy and were not detected after irradiation with 25 kGy. Packing foils were subjected to the following tests: mechanical tests, tests of weld strength, tests of impact resistance, free fall tests, permeability tests for water vapour and microbiological tests. The results of all tests were tabulated. The tests showed that the foils are impermeable for microorganisms and provided the welds are airtight the packed products remain sterile. (J.P.).
This user's guide describes BNW-III, a computer code developed by the Pacific Northwest Laboratory (PNL) as part of the Dry Cooling Enhancement Program sponsored by the US Department of Energy (DOE). The BNW-III code models a modular dry/wet cooling system for a nuclear or fossil fuel power plant. The purpose of this guide is to give the code user a brief description of what the BNW-III code is and how to use it. It describes the cooling system being modeled and the various models used. A detailed description of code input and code output is also included. The BNW-III code was developed to analyze a specific cooling system layout. However, there is a large degree of freedom in the type of cooling modules that can be selected and in the performance of those modules. The costs of the modules are input to the code, giving the user a great deal of flexibility.
ABSTRACT New observations from the Hubble Ultra Deep Field suggest that the star formation rate at Formula Not Shown drops off faster than previously thought. Using a newly determined star formation rate for the normal mode of Population II/I (PopII/I) stars, including this new constraint, we compute the Thomson scattering optical depth and find a result that is marginally consistent with Wilkinson Microwave Anisotropy Probe 5 results. We also reconsider the role of Population III (PopIII) stars in light of cosmological and stellar evolution constraints. While this input may be needed for reionization, we show that it is essential in order to account for cosmic chemical evolution in the early universe. We investigate the consequences of PopIII stars on the local metallicity distribution fu...
The electrochemical behavior of Sb(III) ions was investigated in LiCl-KCl molten salt at 673K. The reaction mechanism and transport parameters of electroactive species were determined by transient electrochemical techniques (such as cyclic voltammetry, square wave voltammetry, chronopotentiometry and chronoamperometry) at a molybdenum electrode. The results showed that electrochemical reduction of Sb(III) in LiCl-KCl melts occurred in a reaction step with an exchange of three electrons. A voltammogram with a different scan rate in LiCl-KCl containing 1.45x10^-^4molcm^-^3 SbCl3 showed that the deposition/dissolution reaction of Sb(III) ions was not completely reversible. The diffusion coefficient of Sb(III) ions was 1.65(+/-0.01)x10^-^5cm^-^2s^-^1 at 673K. The electroreduction of Sb(III) io...
The elastic scattering angular distributions of 25 MeV alpha particles scattered from "7"3Ge, "8"9Y, "9"0Zr, "9"1Zr"9"4Zr, "9"3Nb, "4"4Ca and "4"5Sc have been measured experimentally, and fitted using a conventional optical model. (author).
The results of measuring elastic ..pi../sup -/ d backward scattering, which emphasize the structure in the energy dependence of this cross section observed by us at slightly lower energies, are presented. Its possible theoretical interpretation is discussed.
We discuss the consequence of local duality for elastic scattering, and derive a model-independent equation between structure functions at x ? 1 and elastic electromagnetic form factors. Then the electromagnetic form factors of proton are discussed using the quark-hadron duality theory. We also debate the form factor of proton in a bound state. It may be an effective approach to study the form factor of proton in media.
Threshold pump intensity values leading to irreversible damage to colored laser elements based on elastic polymers were measured. The damage to colored elastomers is connected with absorbing microinclusions but is independent of molecular absorption. It is shown that damage to the elastomers has a pronounced threshold character in contrast to the microdamage accumulation effect in glassy polymers. The damage threshold for elastomers is 1.5 times higher, which is connected with the absence of microstresses (characteristics for organic glasses) in the specimens. 13 references.
Cross sections for elastic scattering of 12 GeV protons from /sup 40/Ca nuclei have been calculated using the flucton model. The influence of the collective flucton nucleon correlations on the calculated cross sections is examined. The calculated cross sections are in significant disagreement with the experimental data. This may be considered as an argument against the flucton model.
Cross sections for elastic scattering of 12 GeV protons from "4"0Ca nuclei have been calculated using the flucton model. The influence of the collective flucton nucleon correlations on the calculated cross sections is examined. The calculated cross sections are in significant disagreement with the experimental data. This may be considered as an argument against the flucton model. (orig.).
Migration-based methods have been recently proposed to improve the estimation of angle-dependent reflectivity in the presence of complex structures. An anisotropic prestack reverse-time migration is developed to estimate the reflectivity as function of the local illumination angle. This migration method generates four simultaneous images which corresponds to the in-depth (local) plane-wave response for PP, PS, SP and SS reflections, and can be used in a Zoeppritz-based elastic inversion scheme. (author)
On the basis of symmetry way of texture description a calculation method of elastic moduli of two-phase titanium alloys with rolling texture has been suggested. Efficiency of the calculation formulas is checked by comparing the calculation results of Young modulus anisotropy in the sheet plane of (#alpha#+#beta#)-titanium alloy VT23 with the experimental data.
Abstract in english This paper presents an HP-Adaptive Procedure with Hierarchical formulation for the Boundary Element Method in 2-D Elasticity problems. Firstly, H, P and HP formulations are defined. Then, the hierarchical concept, which allows a substantial reduction in the dimension of equation system, is introduced. The error estimator used is based on the residual computation over each node inside an element. Finally, the HP strategy is defined and applied to two examples.
Organic modification of aerogel chemical formulations is known to transfer desirable hydrophobicity to lightweight solids. However, the effects of chemical modification on other material constants such as elasticity, compliance, and sound dampening present a difficult optimization problem. Here a statistical treatment of a 9-variable optimization is accomplished with multiple regression and an artificial neural network (ANN). The ANN shows 95 percent prediction success for the entire data set of elasticity, compared to a multidimensional linear regression which shows a maximum correlation coefficient, R=0.782. In this case, using the Number of Categories Criterion for the standard multiple regression, traditional statistical methods can distinguish fewer than 1.83 categories (high and low elasticity) and cannot group or cluster the data to give more refined partitions. A non-linear surface requires at least 3 categories ...
The energy E(c/a) for a bcc element stretched along its [001] axis (the Bain path) has a minimum at c/a=1, a maximum at c/a=#sq root#(2), and an elastically unstable local minimum at c/a>#sq root#(2). An alternative path connecting the bcc and fcc structures is the rhombohedral lattice. The primitive lattice has R3m symmetry, with the angle #alpha# changing from 109.4 deg. (bcc), to 90 deg. (simple cubic), to 60 deg. (fcc). We study this path for the non-magnetic bcc transition metals (V, Nb, Mo, Ta, and W) using both all-electron linearized augmented plane wave and projector augmented wave VASP codes. Except for Ta, the energy E(#alpha#) has a local maximum at #alpha#=60 deg., with local minima near 55 deg. and 70 deg., the latter having lower energy, suggesting the possibility of a metastable rhombohedral state for these materials. We first examine the elastic stability of the 70 deg. minimum structure, and determine that only W is ...
LEDF (Large Equipment Dismantling Facility) will be constructed for the purpose of decontaminating the high level {alpha} solid waste generated in oarai engineering center of JNC. And, main processing process of LEDF is incineration and melting system. LEDF will be intended to reduce the secondary waste that occurs along with the operation of the off gas processing equipment of incineration and melting system. It assumed that we are able to eliminate the adsorption tower using silica gel, if the decontamination factor to volatile ruthenium is able to expect in the packed scrubber that is established to remove harmful gas. Thereupon, we carried out this tests that eliminates the adsorption tower and reduces the secondary waste. The decontamination factor (DF) to the volatile ruthenium by the water scrubber is confirmed in the established institution which is in Tokai Works. However, decontamination factor differs and depends on the ruthenium concentration, harmful ...
LEDF (Large Equipment Dismantling Facility) will be constructed for the purpose of decontaminating the high level #alpha# solid waste generated in oarai engineering center of JNC. And, main processing process of LEDF is incineration and melting system. LEDF will be intended to reduce the secondary waste that occurs along with the operation of the off gas processing equipment of incineration and melting system. It assumed that we are able to eliminate the adsorption tower using silica gel, if the decontamination factor to volatile ruthenium is able to expect in the packed scrubber that is established to remove harmful gas. Thereupon, we carried out this tests that eliminates the adsorption tower and reduces the secondary waste. The decontamination factor (DF) to the volatile ruthenium by the water scrubber is confirmed in the established institution which is in Tokai Works. However, decontamination factor differs and depends on the ruthenium concentration, harmful ...
Patients with acquired immunodeficiency syndrome (AIDS) are subject to a spectrum of central nervous system (CNS) disorders. Recent evidence implicates the human T-cell lymphotropic virus type III (HTLV-III) in the pathogenesis of some of these illnesses, although the cells infected by the virus have yet to be identified. Using in situ hybridization, the authors examined brain tissue from two patients with AIDS encephalopathy for the presence of HTLV-III RNA. In both cases, viral RNA was detected and concentrated in, though not limited to, the white matter. The CNS cells most frequently infected included macrophages, pleomorphic microglia, and multinucleated giant cells. Less frequently, cells morphologically consistent with astrocytes, oligodendroglia, and rarely neurons were also infected. The findings strengthen the association of HTLV-III with the pathogenesis of AIDS encephalopathy. In situ ...
The oxidation of Cr(III) hydroxides, mixed Fe(III)-Cr(III) hydroxides, and specimens of spinel phases NiCr2O4 and Fe(Cr,Fe)2O4 have been investigated in alkaline suspensions under the action of air and pure oxygen (1-3 atm). The rate of reaction increases with increasing alkali concentration, temperature, and oxygen pressure. Pu(IV) fixed on chromium hydroxides is not oxidized by oxygen under these conditions but is retained in the precipitate.
Three red giants (HD 49566 (G5III), HD 169370 (K0III) and HD 169751 (K2III)) have been observed in the CoRoT seismo field and additional ground-based spectra have been acquired. We present preliminary results of a detailed study of these stars using the observational constraints from the spectra and CoRoT data, and models from the YREC stellar evolution code.
Based on a recent investigation that modeled the elastic properties (ie, strength, stiffness and range) of multistranded wires made from linearly elastic materials, three-stranded (triple) and six-stranded coaxial (coax) stainless steel (SS) wires were compared to single-stranded (single) SS and conventional nickel titanium (NiTi) leveling wires. To measure Young's modulus of elasticity (E), flexural tests were performed with an Instron mechanical testing machine in a three-point bending arrangement having a span length of 8.9 mm or 12.5 mm. A strong correlation between wire stiffness and the area moment of inertia demonstrated that strand interaction was negligible at low activations and that E = 199 GPa was constant even for the heavily drawn coax strands. Using the Instron with an extensometer, the 0.1% yield strengths (sigma(YS)) of the single SS wires and the straight inner strands within the coax wires were tested. ...
The extraction of Am(III) and Eu(III) has been investigated using mixtures of synthesized aromatic dithiophosphinic acids (R_2PSSH) and tributylphosphate (TBP), trioctylphosphine oxide (TOPO) or tributylphosphine oxide (TBPO) in toluene from nitric acid (0.01-1.5 mol l"-"1). There was no detectable extraction when R_2PSSHs were used alone as extractants for either Am(III) or Eu(III) (D_A_m_,_E_u<10"-"4) under the experimental conditions used in this study. High separation factors (D_A_m/D_E_u>20) with D_A_m>1 were achieved in the nitric acid range 0.1-1 moll"-"1 by means of a synergistic mixture of bischlorodithiophosphinic acid with TBP, TOPO or TBPO. (orig.)
This paper presents the isothermal characteristics of methanol onto two specimens of activated carbons namely Maxsorb III and Tsurumi activated charcoal. Dubinin Raduskevich (D-R) equation is used to correlate the adsorption isotherms and to form the pressure-temperature-concentration diagram for both of the assorted pairs. Experimental results show that the maximum adsorption capacity of Maxsorb III/methanol pair is 1.76 times that of activated charcoal/methanol pair. Employing a time-independent mathematical model, the performance of adsorption cooling cycle using Maxsorb III/methanol and activated charcoal/methanol pairs has been studied and compared with that of three other types of carbon based adsorbent/methanol pairs. Theoretical calculations show the superiority of Maxsorb III/methanol pair for both of air-conditioning and ice-making applications. (author)
Studies on the separation of Ag(I) during the recovery of Pu from analytical waste generated during potentiometric determination of Pu using AgO as oxidant, by precipitation of Pu as ammonium plutonium (III) oxalate have shown that most of the Ag(I) is separated during the reduction of Pu to Pu(III) state by ascorbic acid. A decontamination factor of 54 was obtained. Additional a decontamination factor of 5.8 was obtained during the precipitation of Pu as ammonium plutonium (III) oxalate. The Ag content was determined by gamma spectrometry, using "1"1"1Ag as a tracer (T_1_/_2 7.45 d, #gamma# 342.1 keV) and HPGe as detector. The studies indicate that Ag is preferentially separated almost quantitatively during the recovery of plutonium, when acidity adjustment is done with NaOH instead of NH_3. (author)
Page 1. Software Vulnerabilities in Java Fred Long October 2005 CERT ... iii Abstract Java is essentially a safe language with good security features. ...
A process is described for making a compound selected from a crystalline spinel of the formula A/sup II/V/sub 2-x//sup III/C/sub x//sup III/O/sub 4/ formula (1) or a crystalline perovskite of the formula D/sup III/V/sub 1-y//sup III/C/sub y//sup III/O/sub 3/ formula (2) from a pentavalent vanadium compound, where A is one or more of Mg, Zn, Mn, Fe, Co, Ni, Cu and Cd; D is one ore more of Y, the rare earths and Bi; C is one or more of Al, Ga, Cr, Fe and Co, x is zero to <2, and y is zero to<1. The process comprises (1) reducing a pentavalent vanadium oxidic compound to substantially the V/sup III/ state by heating at 100/sup 0/C. or less an aqueous medium slurry or solution of the pentavalent compound containing a reducing agent selected from hydrazine and a hydrocarbylhydrazine, (2) providing in the aqueous medium either before, during or after the ...
This patent describes the vapor phase catalytic dehydrogenation of a C/sub 2/-C/sub 4/ paraffin by contacting the paraffin with a spinel of the formula A/sup III/V/sub 2-x//sup III/C/sub x//sup III/O/sub 4/, formula (1) or a crystalline perovskite of the formula D/sup III/V/sub 1-y//sup III/C/sub y//sup III/O/sub 3/, formula (2) where A is one or more of Mg, Zn, Mn, Fe, Co, Ni, Cu and Cd; D is oone of more of Y, the rare earths and Bi; C is one or more of Al, Ga, Cr, Fe and Co, x is zero to < 1.9, and y is zero to < 0.9, which spinel or perovskite is made by a process which comprises (1) reducing a pentavalent vanadium oxidic compound to substantially the V/sup 111/ state by heating at 100/sup 0/C or less an aqueous medium slurry of solution of the pentavalent compound containing a reducing agent selected from hydrazine and a hydrocarbylhydrazine, (2) ...
This paper studies the analytical application of europium (III)-morin complex which is formed in alkaline medium and has an intense color. The extent of europium extraction was determined by adding to the extract a morin solution in isoamyl alcohol in a 50-100-fold excess with respect to europium. The dependence of the optical density of the extracts on the ph in the system europium (III)-morin-water-organic solvent for different excesses of the reagent is shown: this indicates formation of two extractable complexes, one being dominant in the pH range 4-7, the other at pH greater than or equal to 8.5. The extraction of the europium (III)-morin complex from alkaline solution is used for direct extraction-photometric determination of europium(III) in compounds of elements having amphoteric properties or forming amines (Zns, Mo0/sub 3/).
Stage III and stage IV recovery have been investigated resistometrically following 6.1 MeV alpha-particle irradiation at 4.2 K. The activation energy associated with stage III shows a gradual increase from 0.35 +- 0.02 eV to 0.39 +- 0.02 eV. Stage IV (155 to 180 K) is associated with an activation energy of 0.46 +- 0.03 eV. The present results are compared with those obtained after electron and neutron irradiation. The stage III recovery kinetics are interpreted in terms of the Goesele-Seeger theory for interstitial migration in highly anisotropic hexagonal metals. Stage IV is ascribed to monovacancy migration. (author).
... learn more about the thermal stability of InNP2 Me, a sample contained in a previously evacuated tube was heated at 100°C for 13 days. Neither ...
Natural circulation experiments carried out in the REWET-III facility in 1985 have been used for RELAP5/MOD2 assessment. The REWET-III facility is a scaled-down model of VVER-440 type reactors. The facility consists of a pressure vessel in which the downcomer is simulated with an external pipe assembly, hot and cold legs with loop seals and a horizontal steam generator. The volume scaling factor compared to the reference reactor is 1:2333. The present paper summarizes the experiences gained in the RELAP5/MOD2 calculations of selected REWET-III single- and two-phase natural circulation experiments. The code's ability to represent the main phenomena of experiments in both cases was satisfactory.
Natural circulation experiments carried out in the REWET-III facility in 1985 have been used for RELAP5/MOD2 assessment. The REWET-III facility is a scaled-down model of VVER-440 type reactors. The facility consists of a pressure vessel in which the downcomer is simulated with an external pipe assembly, hot and cold legs with loop seals and a horizontal steam generator. The volume scaling factor compared to the reference reactor is 1:2333. The present paper summarizes the experiences gained in the RELAP5/MOD2 calculations of selected REWET-III single- and two-phase natural circulation experiments. The code`s ability to represent the main phenomena of experiments in both cases was satisfactory.
Natural circulation experiments carried out in the REWET-III facility in 1985 have been used for RELAP5/MOD2 assessment. The REWET-III facility is a scaled-down model of VVER-440 type reactors. The facility consists of a pressure vessel in which the downcomer is simulated with an external pipe assembly, hot and cold legs with loop seals and a horizontal steam generator. The volume scaling factor compared to the reference reactor is 1:2333. The present paper summarizes the experiences gained in the RELAP5/MOD2 calculations of selected REWET-III single- and two-phase natural circulation experiments. The code's ability to represent the main phenomena of experiments in both cases was satisfactory.
Theoretical assessment on the chromatographic {sup 99m}Tc generator preparation using (n, {gamma}) {sup 99}Mo produced ex-natural molybdenum was carried out. The relationship between the neutron flux for MoO{sub 3} target activation, Mo-content or Mo adsorption capacity of column packing material, {sup 99m}Tc pertechnetate concentration and/or {sup 99m}Tc radioactivity of eluate was established. The reasonably lower limit of neutron flux of reactor and Molybdenum content of column packing material were found out to estimate the production of portable chromatographic generators available for nuclear medicine application. The concentration of {sup 99m}Tc pertechnetate eluate of low {sup 99m}Tc concentration using the column elution technique was also evaluate theoretically and conducted successfully in practice. Three options of {sup 99m}Tc generator using Titanium-Molybdate, Zirconium-Molybdate and Zirconium Oxide as generator ...
Introduces three designs of development working protection recommended for immediate roof, basic roof and a coal seam of 1.5-2 m, 2.5-4 m and 0.7-1.1 m thickness respectively. The first design of roof control includes a dummy road with breaker props (cutting-off support) and pack, and reinforced concrete props. The second pattern comprises a breaking gate, two rows of cutting-off timber support, up to 10 m long pack and wood chocks. According to the third pattern a breaking road was executed 5.7-6 m away from the face end with breaker props at both its sides. Two rows of pack chocks were added to the dip. Advantages and drawbacks of the three patterns are pointed out. Stress distribution in rock is shown. Position of roof and support before and after roof settling is shown. The cost of the three methods is analyzed. Recommendations useful in application of the method are provided.
Cobalt-60 gamma radiation has been found to be an effective means of immobilizing stationary phases onto gas and liquid chromatographic supports. The ability of a phase to crosslink was determined to be highly dependent on its chemical structure. Gamma radiation was employed to immobilize Se-30, a methylsilicone, and 216 PS onto Chromosorb WHP for packed column chromatography. The resultant columns exhibited increased thermal stability and a high degree of efficiency. Several blended phases containing varying ratios of Se-30:216 PS were also immobilized onto chromatographic packings. This work was further extended to the immobilization of Se-30 and 216 PS onto fused silica capillaries via gamma radiation. Columns exhibited excellent efficiency and improved thermal stability. An investigation into the role of immobilization of polymeric phases for HPLC was undertaken. Results indicate that gamma radiation can immobilzied polyoctadecylsiloxane ...
Four materials, carbon felt cube (CFC), granular graphite (GG), granular activated carbon (GAC) and granular semicoke (GS) were tested as packed anodic materials to seek a potentially practical material for microbial fuel cells (MFCs). The microbial community and its correlation with the electricity generation performance of MFCs were explored. The maximum power density was found in GAC, followed by CFC, GG and GS. In GAC and CFC packed MFCs, Geobacter was the dominating genus, while Azospira was the most populous group in GG. Results further indicated that GAC was the most favorable for Geobacter adherence and growth, and the maximum power densities had positive correlation with the total biomass and the relative abundance of Geobacter, but without apparent correlation with the microbial diversity. Due to the low content of Geobacter in GS, power generated in this system may be attributed to other microorganisms such as Synergistes, ...
Maximum cross-correlation techniques have been used with satellite data to estimate winds and sea surface velocities for several years. Los Alamos National Laboratory (LANL) is currently using a variation of the basic maximum cross-correlation technique, coupled with a deterministic application of a vector median filter, to measure transverse winds as a function of range and altitude from incoherent elastic backscatter lidar data taken throughout large volumes within the atmospheric boundary layer. Hourly representations of three- dimensional wind fields, derived from elastic lidar data taken during an air-quality study performed in a region of complex terrain near Sunland Park, New Mexico, are presented and compared with results from an Environmental Protection Agency (EPA) approved laser doppler velocimeter. The wind fields showed persistent large scale eddies as well as general terrain following winds in the Rio Grande valley.
In previous work, on cooling from 300 K to 10 K the elastic moduli for both #alpha#- and #delta#-Pu dropped 30%. This large change may reflect effects of 5f-electron localization. In this work, the elastic moduli at ambient temperature of several Pu-Ga alloys were measured using resonant ultrasound spectroscopy (RUS). The strong temperature dependence of the bulk and shear modulus and the temperature independence of Poisson's ratio was confirmed and the upper temperature limit for #alpha#-Pu was extended to 360 K. Measurements of the time dependence of the shear moduli of Pu and Pu-2.36 at.% Ga were determined with high precision as a function of time and temperature. Using a model for time dependence of point defects, we determined the exponential time constant at ambient temperature for such variations. The low temperature results are consistent with Fluss .
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.
The literature regarding the free vibration analysis of Bernoulli?Euler and Timoshenko beams under various supporting conditions is plenty, but the free vibration analysis of Reddy?Bickford beams with variable cross-section on elastic soil with/without axial force effect using the Differential Transform Method (DTM) has not been investigated by any of the studies in open literature so far. In this study, the free vibration analysis of axially loaded and semi-rigid connected Reddy?Bickford beam with variable cross-section on elastic soil is carried out by using DTM. The model has six degrees of freedom at the two ends, one transverse displacement and two rotations, and the end forces are a shear force and two end moments in this study. The governing differential equations of motion of the r...
General expressions for the interlattice displacements of the A-15 structure compounds are obtained in terms of the strain components making use of the deformation theory. The nature of the interlattice displacements of all the 8 atoms in the unit cell is discussed. It is found that the interlattice displacements occur in such a way that the pair of atoms along any linear chain move in opposite directions with equal magnitudes. Expression for the strain energy of these compounds is developed using deformation theory and this is compared with the strain energy expression from continuum theory to obtain the elastic constants. The theoretical values of the elastic constants fairly agree with the experimental values for V_3Si, V_3Ge and Nb_3Sn. (author).
General expressions for the interlattice displacements of the A-15 structure compounds are obtained in terms of the strain components making use of the deformation theory. The nature of the interlattice displacements of all the 8 atoms in the unit cell is discussed. It is found that the interlattice displacements occur in such a way that the pair of atoms along any linear chain move in opposite directions with equal magnitudes. Expression for the strain energy of these compounds is developed using deformation theory and this is compared with the strain energy expression from continuum theory to obtain the elastic constants. The theoretical values of the elastic constants fairly agree with the experimental values for V3Si, V3Ge and Nb3Sn.
From the first principles total energy calculations based on full-potential linear augmented plane wave method (FPLAPW), the elastic properties of XPt_3 (X=V, Cr, Mn, Fe, Co, Ni) are reported here. Theoretical values of Young's modulus, shear modulus, Poisson's ratio and Debye temperature are estimated from the computed elastic constants. From the analysis of the ratio of shear to bulk modulus, it is found that these intermetallic compounds are ductile in nature except CrPt_3, which is brittle. The calculated results are compared with other reported values.
This study estimates the electricity demand function for the residential sector of South Korea with the aim of examining the effects of improved energy efficiency, structural factors and household lifestyles on electricity consumption. In the study, time series data for the period from 1973 to 2007 is used in a structural time series model to estimate the long-term price and income elasticities and annual growth of underlying energy demand trend (UEDT) at the end of the estimation period. The result shows a long-term income elasticity of 1.33 and a long-term price elasticity of -0.27% with -0.93% as the percentage growth of UEDT at the end of the estimation period. This result suggests that, in order to encourage energy efficiency in the residential sector, the government should complement the market based pricing policies with non-market policies such as minimum energy efficiency standards and public enlightenment.
This study estimates the electricity demand function for the residential sector of South Korea with the aim of examining the effects of improved energy efficiency, structural factors and household lifestyles on electricity consumption. In the study, time series data for the period from 1973 to 2007 is used in a structural time series model to estimate the long-term price and income elasticities and annual growth of underlying energy demand trend (UEDT) at the end of the estimation period. The result shows a long-term income elasticity of 1.33 and a long-term price elasticity of -0.27% with -0.93% as the percentage growth of UEDT at the end of the estimation period. This result suggests that, in order to encourage energy efficiency in the residential sector, the government should complement the market based pricing policies with non-market policies such as minimum energy efficiency standards and public enlightenment. ...
This study estimates the electricity demand function for the residential sector of South Korea with the aim of examining the effects of improved energy efficiency, structural factors and household lifestyles on electricity consumption. In the study, time series data for the period from 1973 to 2007 is used in a structural time series model to estimate the long-term price and income elasticities and annual growth of underlying energy demand trend (UEDT) at the end of the estimation period. The result shows a long-term income elasticity of 1.33 and a long-term price elasticity of -0.27% with -0.93% as the percentage growth of UEDT at the end of the estimation period. This result suggests that, in order to encourage energy efficiency in the residential sector, the government should complement...
The elastic and inelastic scattering of "1"4C at 51 MeV from targets of "4"0Ca, "5"6Fe, "6"0Ni, "6"6Zn and "8"8Sr has been measured using a Q3D spectrometer. The "1"4C-nucleus potentials have been derived by optical-model analysis of the observed elastic scattering; the inelastic scattering differential cross sections were interpreted in the distorted-wave Born approximation and also in the coupled-channels approach. The analysis yields "1"4C-nucleus potentials that closely resemble "1"2sup(,)"1"3C and "1"6O potentials. (orig.).
Available in abstract form only. Full text of publication follows: In this study. simulation of carbon dioxide absorption by Sodium Hydroxide solution in a packed bed has been investigated. At first, mass and energy balances were applied around a differential height of the bed. So, the governing equations were obtained. Surface renewal theory by Danckwerts was used to represent the mass transfer operation Finally, by changing the operating parameters like solvent temperature, inlet gas composition pressure and height of the bed, the effect of these parameters on the absorption and the composition of carbon dioxide in exit stream have been investigated. (authors)
The first part of the study contains a literature compilation of more than 50 original publications reporting the radiation induced effects in 17 different high polymer materials and glass which are relevant in the manufacturing of medical devices or packing materials. The results collected demonstrate that high energy radiation, i.e. gamma- or X-rays, causes various physical and chemical alterations in high polymer materials. A detailed summary and discussion of the results of the original publications is not included in the present report, it will be presented in the second part of the study. Furthermore, the second part of the study will refer to the aspect of wholesomeness of irradiated medical devices or packing materials in a more general manner of representation. (orig.).
Porous ?-SiAlON ceramics are synthesized by reaction bonded method using hollow alumina spheres (HASs) as both sintering aids and pore-forming agents. Both micropores and macropores, which are constructured by SiAlON grains with different morphologies, are formed in the final SiAlON samples. The micropores are three-dimentional, and are built by equiaxial grains. While the hollow macropores, which have the similar morphology to hollow alumina sphere, are packed by elongated grains. In the sintering process, the solid dissolution process takes place, giving rise to the different alumina concentration of liquid phase, and thus resulting in the formation of two kinds of grains, the equiaxial grain and the elongated grain.
Joint FAO/IAEA/WHO Expert Committee approved the use of radiation treatment of foods. Nowadays food packaging are mostly made of plastics, natural or synthetic, therefore effect of irradiation on these materials is crucial for packing engineering for food irradiation technology. By selecting the right polymer materials for food packaging it can be ensured that the critical elements of material and product performance are not compromised. When packaging materials are in contact with food at the time of irradiation that regulatory approvals sometimes apply. The review of the R-and-D and technical papers regarding material selection, testing and approval is presented in the report. The most information come from the USA where this subject is well elaborated, the International Atomic Energy Agency (IAEA) reports are reviewed as well. The report can be useful for scientists and food irradiation plants operators. (author)
The large amount of plastic products presently produced necessitates recycling and reuse of these non-biodegradable materials. However, the degradation in the mechanical properties of products made from recycled plastic is a major drawback that limits their use. This study aims to improve the mechanical properties of products made from recycled plastic by utilizing the Taguchi optimization method, instead of coupling the products with additives. By adopting L9 Taguchi OA, products made from various compositions of virgin and recycled plastic are produced by injection moulding. Four controllable factors (i.e., melt temperature, packing pressure, injection time, and packing time), each at three levels, are tested to determine the optimal combination of factors and levels in the manufacturing...
Herein, we demonstrate the structure of the PS colloidal crystals which were fabricated on the hydrophilic/hydrophobic Si wafers by a spin-coating technique. Monodisperse PS colloids are spin-coated onto self-assembled monolayers of 3-(aminopropyl)triethoxysilane and propyltrimethoxysilane coated Si wafers. PS spheres organized as ordered close-packed face-centered cubic structure with (111) planes on the hydrophilic surface while they gathered without the crystal structure on the hydrophobic surface. This paper also reports a simple and rapid method to fabricate the close-packed structure of hollow TiO2 spheres. The colloidal crystal of TiO2 hollow spheres was prepared using the PS sphere template on the hydrophobic surface. The mechanism for the growing multilayers of self-assembled PS p...
Continuing high rates of acidic deposition in the eastern United States may lead to long-term effects on stream communities, because sensitive catchments are continuing to lose anions and cations. A two-year study of the effects of pH and associated water chemistry variables on detrital processing in three streams with different bedrock geology in the Monongahela National Forest, West Virginia were investigated. Leaf pack processing rates and macroinvertebrate colonization and microbial biomass (ATP concentration) on the packs in the three stream were compared. It was found that macroinvertebrate and microbial communities differed both among streams that differed in their capacity to buffer the effects of acidic precipitation and among years in the same stream; these differences in biotic communities were not large enough to affect rates of leaf processing between the two years of the study, but they did significantly affect processing rates ...
Oxydes d'Uranium et de Plutonium. J. Nucl. Mat., vol. 33, no. 1, Oct. 1969, pp. 40-51. 21. Hall, A. R.: Elastic Moduli and Internal Friction of Some Uranium ...
The purpose of our research program is to understand the influence of elastic misfit strain and applied stress on the development of microstructure in two-phase coherent alloys. The long-term goal of our research is to identify those material parameters that promote microstructural stability in multiphase systems at elevated temperatures. Our efforts since the last progress report in February 1991 have been twofold. First, we have continued performing coarsening simulations of elastically and diffusionally interacting particles in an infinite matrix. In addition, we have been performing simulations of unstressed systems during coarsening. Secondly, we have begun to develop an experimental component to the research that would allow a careful comparison between theory, computer simulations and experiment. We have continued to focus our computer simulations of stressed systems on elastically homogeneous and isotropic systems ...
We use a novel normal mode analysis of an elastic network model drawn from configurations generated during microsecond all-atom molecular dynamics simulations to analyze the mechanism of auto-inhibition...Full Text Available
A new method is described for continuously measuring cell turgor pressure (P), hydraulic conductivity (Lp), and volumetric elastic modulus (ε) in higher plant cells, using a pressure...Full Text Available
Advanced aerospace vehicles and system components tend to be slim and elastic, ...... In the manufacturing sector, semiconductor manufacturing requires ... The energy generation and storage for modern-day sensor networks, ...... Current NASA roadmaps point towards development of new hydrocarbon fueled engines. ...
When a metallic alloy is quenched into a miscibility gap, a mixture of two phases develops, whose domain structure then coarsens because of the interfacial energy between the two phases. This spatial arrangement of the domains and the rate at which they evolve may be strongly influenced by elastic interactions. In a recent paper, the authors described a method for simulating the effect of anisotropic elastic interactions in a two-dimensional Ising model of a cubic alloy, using Kawasaki dynamics with the elastic interactions represented by a long-range two-body interaction potential. Here they present the results of such simulations at various temperatures, alloy compositions and misfits (by misfit they mean the difference in size between the two kinds of atom), exhibiting snapshots both of the microscopic configurations (corresponding to experimental measurements using transmission electron microscopy) and of their squared ...
Angular distributions of "6Li+"6Li elastic scattering were measured for E_l_a_b=5-40 MeV. An optical model analysis of these data together with older data of "7Li+"7Li elastic scattering taken at E_l_a_b = 8-17 MeV was performed with the aim to search for a ''global'' OM potential which describes elastic scattering in both Li-Li systems in a broad energy range. Both surface and volume absorbing potentials can be found which fulfill this requirement if a linear energy dependence is assumed of the depths of the real as well as the imaginary potential. These depths, if fitted to individual angular distributions, are found to vary in a correlated manner with the beam energy. This is taken as indication of strong coupling between elastic, inelastic, and reaction channels. This is corroborated by the existence of resonances in reaction channels at these energies where the potential depths are most ...
Background: Intramedullary fixation of midclavicular fractures may be a better option than non-operative treatment for high performance/professional athletes because of the potential reduction...Full Text Available
Elastic scattering of 27.2 MeV #alpha# particles on "4"0Ca has been investigated. Differential cross sections have been measured in the angular range from 10 deg to 175 deg in the lab. system. The theoretical analysis has proceeded from the proposition that the results of a calculation based on the optical model in the range of small angles (less than 20 deg for "4"0Ca) are independent of parameters and shape of the potential employed. Elastic scattering of #alpha# particles at angles up to 50 deg has been calculated using three sets of the optical potential parameters in the energy range 23.37-28.92 MeV. In the range of small angles a rather similar behaviour of the calculated curves can be observed whereas in the range of medium and large angles these curves behave very differently. The success in the reproduction of the angular distributions for the entire energy range is indicative of the weak energy dependence of the optical potential ...
Glasses in the system (1 - x) [29Na2O- 4Al2O3- 67B2O3]- xZnO (0 ? x ? 35 mol%), have been prepared by the melt quenching technique. Elastic properties, X-ray and FT-IR spectroscopic studies have been employed to study the role of ZnO on the structure of the investigated glass system. Elastic properties and Debye temperature have been investigated using sound wave velocity measurements at 4 MHz at room temperature. The results showed that the density increases and the molar volume decreases while both sound velocities and the determined glass transition temperatures decrease with increase in x. X-ray and infrared spectra of the glasses reveal that the borate network consists of diborate units and is affected by the increase in the concentration of ZnO content. These results are interpreted in terms of the decrease in the N4 values (fraction of tetrahedral coordinated boron atoms), and substitution of longer bond lengths of Zn-O in place of ...
As part of a larger elastic numerical modeling project, we have been investigating how energy reflected from steeply dipping interfaces is recorded using typical multicomponent acquisition geometries. Specifically, we have been interpreting how rcflection events from the flanks of salt dome structures are distributed on 3C and 4C phones for vertical seismic profiles (VSPs) and ocean bottom seismic (OBS) or land surface surveys. The ultimate goal of this investigation is to improve the structural imaging of steeply dipping interfaces and eventually to evaluate the usc of the recorded elastic wavefield for fluid description near these interfaces. In the current work, we focus on a common assumption used when processing converted wave reflection seismic data that most PP energy is recorded on the vertical geophone and/or the hydrophone and that most PS energy is recorded on the horizontal geophones. This is a useful assumption when it is valid, ...
The curvature elastic modulus (bending stiffness) of stearoyloleoyl phosphatidylcholine (SOPC) bilayer membrane is determined from membrane tether formation experiments. R. E. Waugh and R. M. Hochmuth...Full Text Available
Electron elastic and collisional excitation cross sections from the ground state of potassium are calculated using the noniterative integral-equation method of Henry, Rountree, and Smith [Comput. Phys. Commun. 23, 233 (1981)] in the electron energy range 4#<=#E#<=#200 eV. Configuration-interaction target wave functions that take account of correlation and polarization effects are used to represent the ground state and the six lowest excited states 4p "2P degree, 5s "2S, 3d "2D, 5p "2P degree, 4d "2D, and 6s "2S. Elastic and discrete excitation cross sections are obtained in a seven-state close-coupling (7CC) approximation. The 7CC elastic and excitation cross sections are compared and contrasted. Near threshold the elastic cross section dominates the resonance, 4s "2S#->#4p "2P degree, and the sum of the other remaining excitation cross sections. Comparison of our total cross sections with some ...
Failure of bone under monotonic and cyclic loading is related to the bone mineral density, the quality of the bone matrix and the evolution of microcracks. The theory of linear elastic fracture...Full Text Available
The extreme strength and elasticity of spider silks originate from the modular nature of their repetitive proteins. To exploit such materials and mimic spider silks, comprehensive strategies...Full Text Available
A comparative study by Eu-L/sub III/ X-ray absorption and /sup 151/Eu-Moessbauer spectroscopy is presented for the EuPd/sub 2-x/Au/sub x/ Si/sub 2/ series. Possible ways to distinguish between mixed-valent behaviour and final-state effects in the L/sub II /I-edge spectra are discussed.
Computer simulations and experiments indicate that we can shape the infrared picosecond pulses of the Mark III FEL in amplitude, frequency, and phase. Strongly modulated fundamental and second harmonic pulses have been generated by operating the Mark III FEL in the regime of strong sideband growth. In this paper, we present the results of simulations and experiments for second harmonic generation with fundamental inputs from 2 to 3 {mu}m.
The symposium had four areas in analytical methodology to study global environmental change: air; water, wastes and speciation, analytical methodology and environmental management. The symposium had 24 conferences and papers.
Experimental results are presented on the quasi-statistic polarization reversal and on the effect of high dc electric field on the behaviour of LiNH_4SO_4 and LiND_4SO_4 monocrystals, namely in the vicinity of the II-III phase transformation.
The Doublet III device is operating with an extensive system of plasma limiters and wall protective armor. Operations with up to 8MW of neutral beam power and 1.5MA plasma current are planned. Design and operational performance of the following systems are discussed: 1. Water-cooled graphite moveable limiter. 2. Water-cooled graphite fixed limiter and neutral beam wall armor. 3. Radiatively cooled Inconel divertor plates.
PurposeRTOG protocol 95-17 was a phase I/II trial to evaluate multi-catheter brachytherapy as the sole method of adjuvant breast radiotherapy for stage I/II breast...Full Text Available
This report presents the methodologies and results of the field/laboratory experiments and mathematical modeling defined for the phase III of the project. Results from test cases 2-6 are given in separate chapters of the report (which have been indexed separately), and the last chapter discusses the lessons learned from the three phases of the DECOVALEX project.
The bioenergetic capacity of skeletal muscle in a 17-year-old patient with a severe defect in complex III of the electron transport chain has been examined by 31P NMR measurements of the molar ratio...Full Text Available
The 1.04 GeV-proton elastic scattering from /sup 40/Ca is studied in the framework of the coherent density fluctuation model (CDFM). The calculations are carried out in the Glauber theoretical scheme with three different charge densities. It is shown that: i) the account of the flucton correlations leads to results considerably different from those obtained in the independent particle Glauber approach (IPGA); ii) in contrast to the case of IPGA the use of a more realistic density improves the agreement of CDPM-results with the experimental data.
The 1.04 GeV-proton elastic scattering from "4"0Ca is studied in the framework of the coherent density fluctuation model (CDFM). The calculations are carried out in the Glauber theoretical scheme with three different charge densities. It is shown that: i) the account of the flucton correlations leads to results considerably different from those obtained in the independent particle Glauber approach (IPGA); ii) in contrast to the case of IPGA the use of a more realistic density improves the agreement of CDPM-results with the experimental data. (orig.).
The effect of particle/matrix interface debonding on composites consisting of elastic particles and viscoelastic matrix is studied. The interface debonding is represented by a nonlinear cohesive law for the high explosive PBX 9501. The Mori-Tanaka method gives the constitutive relation of the composite in terms of the properties of elastic particles, viscoelastic matrix, and nonlinear cohesive law for interfaces. For the example of a composite with spherical particles subject to hydrostatic tension, simple analytical expressions of the composite stress-strain relation are obtained. The strain rate and temperature have strong effects on the composite behavior. High strain rate and low temperature give high strength of the composite. However, the rate and temperature effects decrease as the ...
Metallic multilayers offer a fantastic playground to investigate elastic stresses in films of nanometer thickness. We will present and discuss a few examples from our recent work on Au-Ni and Ag-Cu systems where we combined plate bending measurements and electron or X-ray diffraction to investigate stress buildup and interfacial mixing. Comparing these two cases we discuss the results with respect to basic parameters like the misfits in lattice parameters and in elastic moduli, the mixing enthalpies and the surface energies.
Nano-materials in which a large fraction of atoms resides within a few atomic layers near the surface can be designed to have novel properties by manipulating their surface parameters. We show that the effective elastic constants of nano-porous/cellular materials can be made to exceed those of the parent materials provided the pore surface elastic parameters satisfy certain conditions. These stiff nano-porous materials herald a radical breakthrough in sandwich-type construction.
Nano-materials in which a large fraction of atoms resides within a few atomic layers near the surface can be designed to have novel properties by manipulating their surface parameters. We show that the effective elastic constants of nano-porous/cellular materials can be made to exceed those of the parent materials provided the pore surface elastic parameters satisfy certain conditions. These stiff nano-porous materials herald a radical breakthrough in sandwich-type construction.
A simple model is outlined to describe the collision of cast phenol-formaldehyde resin spheres such as the balls used in the parlor game of pocket billiards, based in part on the famous analysis of elastic collisions developed by Heinrich Hertz over 100 years ago. The analysis treats the normal and tangential components of the initial sphere's velocity independently as it collides with a stationary identical second sphere. The collective effects of these and other parameters on the trajectory of the second sphere are provided in the conclusions.
Characterization of high temperature superconducting film and bulk samples has been carried out using 2 MeV [alpha]-particle Rutherford backscattering, 2.4 MeV proton elastic scattering, 2.4 MeV proton-induced x-ray emission, 9 MeV proton induced [gamma]-ray emission and 100 MeV iodine elastic recoil detection analysis techniques. The objective was to compare different ion beam based techniques for: (i) compositional analysis; and (ii) consistency of the results obtained for samples prepared using similar preparation methodology. (author).
We calculate the normalized factorial moments of multiplicity distributions through three models for elastic hadron scattering (Chou-Yang, Henzi-Valin and Menon-Pimentel). Connections between the moments and the inelastic overlap function and/or eikonal function are obtained by means of an impact parameter representation for the multiplicity distribution. The predictions are compared with experimental data on factorial moments from both inelastic and non-single-diffractive events. The model results present best agreement with the inelastic events and data favour the model by Henzi and Valin. (author)
We discuss elastic electron-deuteron (ed) scattering beyond the Born approximation. The reaction amplitude contains six generalized form factors, but only three linearly independent combinations of them (generalized charge, quadrupole, and magnetic form factors) contribute to the reaction cross section in second-order perturbation theory. We examine the two-photon exchange and find that it includes two types of diagrams, where two virtual photons are interacting with the same nucleon and where the photons are interacting with different nucleons. It is shown that the two-photon-exchange amplitude is strongly connected with the deuteron wave function at short distances.
We present results from ab-initio electronic-structure calculations of mechanical properties of the rhombohedral phase of vanadium reported in recent experiments (R Ia), and other predicted high-pressure phases (R Ib and bcc), focusing on properties relevant to dynamic experiments. We find that of the three transitions the largest volume collapse (1.3%) is for the R Ia to R Ib transition. Calculations of the single crystal and polycrystal elastic constants reveal a remarkably small discontinuity across the phase transitions even at zero temperature where the transitions are first order.
The development of a capability to infer wind velocities simultaneously at a number of ranges along one direction in real time is described. The elastic backscatter lidar data used was obtained using the XM94 lidar, developed by Los Alamos National Laboratory for the US Army Chemical and Biological Detection Command. In some respects this problem is simpler than measuring wind velocities on meso-meteorological scales. Other requirements, particularly high temporal fidelity, have driven the development of faster software algorithms and suggested opportunities for the evolution of the hardware.
Cross sections for the elastic and inelastic scattering of /sup 16/O on /sup 58/Ni, /sup 88/Sr, /sup 40/Ca, and /sup 48/Ca have been calculated in a coupled-channels treatment, including the low-lying 2/sup +/ and 3/sup /minus// states of both projectile and target. Real, energy-independent ion-ion potentials and form factors were used, and fusion was simulated by ingoing wave boundary conditions in all channels. The agreement with the measured scattering data is qualitatively as good as obtained in previous optical-model calculations.
Cross sections for the elastic and inelastic scattering of "1"6O on "5"8Ni, "8"8Sr, "4"0Ca, and "4"8Ca have been calculated in a coupled-channels treatment, including the low-lying 2"+ and 3"- states of both projectile and target. Real, energy-independent ion-ion potentials and form factors were used, and fusion was simulated by ingoing wave boundary conditions in all channels. The agreement with the measured scattering data is qualitatively as good as obtained in previous optical-model calculations.
The analyzing power has been measured for elastic scattering of vector-polarized deuterons from /sup 92,94,96/Zr and /sup 92/Mo at E/sub d/ = 12 MeV. Previous measurements on /sup 88/Sr and /sup 98/Mo have been extended. The present data combined with published measurements on /sup 90,91/Zr and /sup 76,78,80,82/Se show that these angular distributions can be explained only if one considers both collective and neutron structure-dependent effects.
We show that specially designed two-dimensional arrangements of full elastic cylinders embedded in a nonviscous fluid or gas define (in the homogenization limit) a new class of acoustic metamaterials characterized by a dynamical effective mass density that is anisotropic. Here, analytic expressions for the dynamical mass density and the effective sound velocity tensors are derived in the long wavelength limit. Both show an explicit dependence on the lattice filling fraction, the elastic properties of cylinders relative to the background, their positions in the unit cell, and their multiple scattering interactions. Several examples of these metamaterials are reported and discussed.
The manual was prepared for State and local government officials, local emergency planning committee (LEPCs), and other community groups that want to make Title III work. It is intended as a practical guide for those who have little or no previous experience in the field of communication, whose time must be snatched from home and office, and whose resources are limited. The manual has three major sections: Part I discusses planning, which is vital to the success of a communication program; Part II suggests ways to get and keep people involved, especially important because Title III affects so many different sectors of the community; Part III, a how-to-do-it section, talks about specific tasks, such as giving a speech or writing a press release. Appendices include a detailed explanation of the law, a glossary, a list of recent studies related to Title III communications, a list of educational materials, ...
In the MnIII complex of the title compound, [MnIII(C18H12N4O2)(H2O)2]ClO4, the MnIII atom is coordinated by four N atoms from the bpb2- [1,2-bis(pyridine-2-carboxamido)benzene] ligand located in the equatorial plane and two O atoms of water molecules at axial positions, yielding a distorted MnN4O2 octahedral coordination geometry. The bpb2- ligand is nearly planar, with a maximum deviation of 0.2311 (3) A from the mean plane. The MnIII complex cation and the perchlorate anion, both of which are located on twofold rotation axes, are connected by O-H...O and C-H...O hydrogen bonds into a three-dimensional supramolecular network structure.
The contribution is concerned from a legal point of view with the systematic recording, classification and assessment of specific problems concerning the post-operational phase of a nuclear power plant. As an introduction, present experience with decommissioning in the Federal Republic of Germany is dealt with. The first part treats the factual side of section 7 III AtG, explains the terms mentioned, the concrete extent of licensing and priority relations. In part 2 the preconditions for licensing pursuant to section 7 III AtG are dealt with, the stipulations of which are made difficult in particular on account of the reference in section 7 III sentence 2 AtG. The third part is concerned with the legal consequence of section III AtG, i.e. the extent of official discretionary powers, whereby aspects of radioactive waste management carry great weight. In part four administrative and procedural ...
A non-invasive diagnostic tool that could identify malignancy in situ and in real time would have a major impact on the detection and treatment of cancer. We have developed and are testing early prototypes of an optical biopsy system (OBS) for detection of cancer and other tissue pathologies. The OBS invokes a unique approach to optical diagnosis of tissue pathologies based on the elastic scattering properties, over a wide range of wavelengths, of the microscopic structure of the tissue. The use of elastic scattering as the key to optical tissue diagnostics in the OBS is based on the fact that many tissue pathologies, including a majority of cancer forms, manifest significant architectural changes at the cellular and sub-cellular level. Since the cellular components that cause elastic scattering have dimensions typically on the order of visible to near-IR wavelengths, the elastic (Mie) scattering ...
The average angle of repose and the packing density of random planar heaps of hard disks falling ballistically onto a sticky base line, where the first layer of disks is quenched in random positions, are computed for heaps with a small fixed number of gaps in the base layer. The results we find appear to be almost independent of the size of the heap and they agree with those obtained from computer simulations of large systems.
This book includes the latest developments and covers pump performance, selection and operations, materials, seals and packings, effective fluid characteristics, filtration, piping systems, economics, valves, instrumentation, automatic controls, power transmission equipment, pump and pipeline heating, and more. An extensive data section contains formulas, charts, symbols, nomographs, and standard specification documents.
The wavefunction of a positron in ReO is calculated using the augmented-plane-wave method. Due to the loosely-packed structure of ReO_3, the ground-state GAMMA_1 wavefunction exhibits a marked anisotropy particularly around the oxygen ions, and a large fraction of a positron is distributed in the interstitial region. Experimental results of the positron annihilation 2#gamma#-correlations and the positron annihilation rates in ReO_3 are discussed based on the positron wavefunction. (orig.).
Phthalate esters (PE's) are plasticizers used to soften PVC-based medical devices. PE's are the most abundant man-made pollutants and increase the risk of developing an allergic respiratory disease...Full Text Available
New standardization techniques of samples in multielement instrumental neutron-activation analysis (INAA) of biological materials (BM) are considered. New methodical developments of sample preparation techniques, BM tableting, creation of comparison standards and standardization of packing material are suggested. Correlated data on concentration of different elements in standard specimens-comparison standards are presented for mass INAA, that is: for phenol-formaldehyde resin-base and human blood-base synthetic standards. 7 refs.; 3 tabs.
...Butley river and Ore estuary, Boyton Marshes attracts breeding wading birds in spring and ducks, geese and swans in winter. It's also ...The spectacular cliffs at Fowlsheugh are packed with 130,000 breeding seabirds in the spring and summer, including guillemots, razorbills and kittiwakes. Freiston ...for its breeding avocets and terns, which can be seen throughout the spring and summer. Access is by boat only and the trip ... During spring and autumn, it is an ideal place to see migrant wading birds, gulls and terns. Leighton Moss Leighton ...
The electric power industry can use the carbon dioxide absorption process to capture carbon from high-volume flue gas. However, the current cost of the process is too high due to the approximation method used in process design. The absorption column is typically designed with parameters that are assumed to be constant over the whole length of the column, resulting in an oversized unit. This approximation method is no longer valid given new environmental and economic concerns. In order to develop an accurate column design for high-efficiency carbon dioxide (CO{sub 2}) capture, it is necessary to understand the phenomena taking place in the system. A mechanistic model is presented for a robust absorber design that takes into account mass-transfer and hydrodynamic behaviour within the CO{sub 2} absorption columns. The capture performance of a packed column under a wide range of design and operating conditions was determined using a model based on the kinetics and ...
In studying the absorption of carbon dioxide by absorbents impregnated with alkanol amines, researchers used a laboratory-scale packed column to determine the overall gas-phase mass-transfer coefficients and enhancement factors. A model derived for the mechanism of the chemical reaction taking place in the interfacial layer accounts for the effect of the reaction upon the absorption rate better than other models.
The hard-sphere radial distribution functions, g_H_S(r/d,#eta#), for the face-centered cubic and hexagonal close-packed phases have been computed by the Monte Carlo method at nine values of the packing fraction, #eta#[=(#pi#/6)#rho#d"3], ranging from 4% below the melting density to 99% of the close-packed density. The Monte Carlo data are used to improve available analytic expressions for g_H_S(r/d,#eta#). By utilizing the new g_H_S(r/d,#eta#) in the Henderson and Grundke method [J. Chem. Phys. 63, 601 (1975)], we next derive an expression for y_H_S(r/d,#eta#) [=g_H_S(r/d)exp#left brace##beta#V_H_S(r)#right brace#] inside the hard-sphere diameter, d. These expressions are employed in a solid-state perturbation theory [J. Chem. Phys. 84, 4547 (1986)] to compute solid-state and melting properties of the Lennard-Jones and inverse-power potentials. Results are in close agreement with Monte Carlo and lattice-dynamics ...
The use of aqueous methyldiethanolamine (MDEA) for selective removal of hydrogen sulfide from acid gas streams has been studied in a 2 inch column packed with 1/4 inch ceramic Intalox saddles. The column was operated in a counter-current, steady state fashion. The feed gas composition varied between 1 and 5 mole % hydrogen sulfide and between 0 and 50 mole % carbon dioxide. In order to assist the development of packed column absorption models, the rate at which pure carbon dioxide absorbs into 2 M MDEA was measured as a function of pressure, liquid flow rate and packed bed length. The importance of end effects was carefully evaluated. In addition, draining and tracer methods were used to estimate the amount of static holdup present in the column. Using classical draining methods, as much as 50 % of the total holdup was found to be static. However, according to the step decrease in tracer method, less than 5 % of the total ...
In this paper, we evaluate the performance of the 1- and 5-site models of methane on the description of adsorption on graphite surfaces and in graphitic slit pores. These models have been known to perform well in the description of the fluid-phase behavior and vapor-liquid equilibria. Their performance in adsorption is evaluated in this work for nonporous graphitized thermal carbon black, and simulation results are compared with the experimental data of Avgul and Kiselev (Chemistry and Physics of Carbon; Dekker: New York, 1970; Vol. 6, p 1). On this nonporous surface, it is found that these models perform as well on isotherms at various temperatures as they do on the experimental isosteric heat for adsorption on a graphite surface. They are then tested for their performance in predicting the adsorption isotherms in graphitic slit pores, in which we would like to explore the effect of confinement on the molecule packing. Pore widths of 10 and 20 A are chosen in this ...
The purpose of this research was to investigate the de-entrainment of boron for evaporators used in nuclear power plants. The forced circulation and semi-continuous type evaporator was used in the experiment. Cyclone and glass-wool packed column which is supposed to provide good decontamination factor as well as easy maintenance, were selected as de-entrainment device to be used in the evaporation of radioactive liquid wastes. The de-entrainment device combined with cyclone and glass-wool column has shown overall DF more than 1000 for boron.
The first analysis of inelastic J/{psi} meson production in photoproduction (Q{sup 2}<2.5 GeV{sup 2}) of the H1 experiment for the second phase of HERA (HERA II) is presented. The analysis is carried out at low and medium elasticities. The production of heavy quarks (charm, or bottom) is of special interest since the mass of the quarks provides a hard scale for the application of perturbative QCD. The muonic decay channel is used to select the J/{psi} mesons. The data was collected by the H1 detector during the period 2003-2005, and corresponds to an integrated luminosity of 133 pb{sup -1}. However only a subset of this data could be analysed. At the start of HERA II the trigger system was affected by a sizeable background. Then a fault was introduced in the trigger software during the summer 2004 and was only discovered and solved in April 2006. This means that approximately 80 % of the triggered events at medium elasticities and 65 % ...
Simple, one-zone models for inhomogeneous chemical evolution of the Galactic halo are used to predict the number fraction of zero-metallicity, Population III stars, which currently is empirically estimated at < 4e-4. These analytic models minimize the number of free parameters, highlighting the most fundamental constraints on halo evolution. There are disagreements of at least an order of magnitude between observations and predictions in limiting cases for both homogeneous Simple Model and Simple Inhomogeneous Model (SIM). Hence, this demonstrates a quantitative, unambiguous discrepancy in the observed and expected fraction of Population III stars. We explore how the metallicity distribution of the parent enrichment events f(z_0) drives the SIM and predictions for the Population III fraction. The SIM shows that the previously-identified "high halo" and "low halo" populations are consistent with a continuous evolutionary ...
The temperature dependences of the Grueneisen parameter, heat capacity, bulk modulus and linear thermal expansion coefficient of sixteen III-V zincblende compounds are studied by first-principles response-function calculations. The fundamental relationships among these physical parameters are explored. Negative thermal expansions at lower temperature are found in most of these III-V phases except for the nitrides and boron compounds. By analyzing the cell-volume dependences of the phonon spectrum, it is found that the phases with a negative thermal expansion show a significant acoustic phonon weakening at the X-point in their phonon dispersion, while slight weakening is only seen around the L-point for those boron phases. There is no sign of phonon weakening in the nitrides. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
Phosphate/chromate and accelerated chromate coatings were produced on commercially available aluminium. The Cr, P and Fe components of the conversion coatings were determined by radioactive tracer technique. The tracer technique was combined with ion-exchange and film-sectioning methods to determine the chromium(III)/total chromium ratio in the accelerated chromate coating. It was found that during the acidic dissolution of the conversion coating the chromium(III)/total chromium ratio may suffer changes. The film-forming components in the metal/bath interface are supersaturated and deposited onto the aluminium. The identified components of the accelerated chromate coatings are Cr(OH)sub(3), Cr(OH)CrOsub(4) and Crsub(4)(Fe(CN)sub(6))sub(3) and the chromium(III)/total chromium ratio was found to be cca. 2/3. (author). 11 refs.; 5 figs.
Raman and infrared spectroscopy of para-H{sub 2} to pressures in excess of 200GPa and to 8K using new ultrapure synthetic diamond anvils reveals numerous new vibrational excitations in the three high-pressure phases. Highly resolved Raman-active librons indicate differences in orientational ordering between phasesII and III, including evidence for changes within phaseII. The librons in phaseIII are strongly pressure dependent and reflect a substantial increase in ordering with pressure. Multiple vibrons in all three phases (I, II, and III) are observed. The results place new bounds on predicted crystal structures and dynamics of the dense molecular solid. {copyright} {ital 1997} {ital The American Physical Society}
The EXAFS spectra of the platinum(III) complexes Pt/sub 4/(OAc)/sub 10/(OH)/sub 2/ (I) and Pt/sub 4/ (OAc)/sub 4/(OH)/sub 8/(H/sub 2/O)/sub 2/ (II) have been investigated. It has been found by a curve-fitting method and with the aid of Fourier transformations that the shortest Pt-Pt distances are 2.61 A in complex I and 2.36 and 2.6 A in II. The values of the bond lengths obtained are consistent with the molecular structures proposed for complexes I and II, which contain skeletons of four platinum atoms in the form of a square or a rectangle, as well as with the known literature data on the lengths of Pt-Pt bonds in Pt(III) complexes.
Microanalytical methods suitable for the determination of Fe, Cu in HT-29 (human colon adenocarcinoma) cells treated with different iron compounds (Fe(II) sulfate, Fe(III) chloride, Fe(III) citrate and Fe(III) transferrin) and cultured in medium supplemented or not with 10% (v/v) fetal calf serum (FCS) by total reflection X-ray fluorescence spectrometry (TXRF) and simultaneous graphite furnace atomic absorption spectrometry (GF-AAS) were developed. The developed TXRF method was also suitable for Zn determination in the samples. The main advantage of the proposed methods is the execution of all sample preparation steps following incubation and prior to the elemental analysis in the same Eppendorf tubes. Sample preparation was performed at microscale (115mL sample volume) with 65% nitric aci...
Ruthenium(II) and Iridium(III) polypyridyl complexes have been intensively investigated due to their use in energy conversion and light-emitting devices and materials for non-linear optics. Quantum mechanical computer simulations of molecules and materials have become increasingly popular in the scientific community. Along with experimental investigations, such computational analyses can provide complementary information on the electronic and optical properties of transition metal compounds of interest for optoelectronic applications. Here, we provide a unified review of recent work carried out on computational investigations of a large series of Ruthenium(II) and Iridium(III) polypyridyl complexes, discussing the relations between their electronic structure and optical properties and thei...
VSP data are usually acquired in order to obtain high-resolution images of complex structures in reservoirs and near boreholes. The authors present an elastic iterative migration scheme which has few limitations regarding the complexity of the geology, and where the macromodel for both P- and S-wave velocities is automatically improved and updated at each iteration. They avoid wavefield separation (up/down and P/S) and the simplifying assumptions of small dips underlying most such methods. The migration scheme is based on elastic inversion theory. The wavefield extrapolation is based on a high-order, coarse-grid, finite-difference solution to the elastic two-way wave equation. At each iteration, the macromodel is updated using a gradient method, in which the gradient is computed by correlation of forward-modelled fields with back-propagated residual fields. The first iteration of the migration scheme is equivalent to ...
The choice of treatment in adult skeletal Class III occlusions often poses a particularly tricky problem for the orthodontist. Faced with the option of either orthodontic camouflage or orthognathic surgery, the clinician's clinical experience is of paramount importance, especially in borderline cases. The aim of our study was to uncover a guide model enabling the practitioner to distinguish between skeletal Class III cases which can be suitably treated with orthodontics and those requiring orthognathic surgery. The lateral headfilms of 47 adult patients exhibiting skeletal Class III occlusions were analyzed. The orthodontic group comprised 22 patients and the surgical group 25. Twenty-seven linear, proportional and angular measurements were scrutinized. Stepwise discriminant analysis was used to identify the dentoskeletal and esthetic variables which most distinguished the two groups. The Holdaway angle was chosen to ...
We present H-alpha and [O III] (5007 Angstroms) images of the nebula powered by the jet of the black hole candidate and microquasar Cygnus X-1, observed with the 2.5m Isaac Newton Telescope (INT). The ring-like structure is luminous in [O III] and there exists a thin outer shell with a high [O III] / H-alpha flux ratio. This outer shell probably originates in the collisionally excited atoms close to the front of the bow shock. Its presence indicates that the gas is shock excited as opposed to photoionised, supporting the jet-powered scenario. The shock velocity was previously constrained at 20 = 100 km/s (1 sigma confidence) based on a comparison of the observed [O III] / H-alpha ratio in the bow shock with a number of radiative shock models. From this we further constrain the time-averaged power of the jet: P_Jet = (4 - 14)*10^36 erg/s. The H-alpha flux behind the shock front is typically 4*10^-15 ...
Related to other research on the effectiveness of flow boiling heat transfer augmentation using various types of turbulators this investigation comprises a definitive study of the effect of large discrete roughness elements on heat transfer over the entir...
One membrane oxygen enricher (Oxygen Enrichment Company OE-4E) and four molecular sieve (MS) concentrators (Mountain Medical Econo2, De Vilbiss MINI DeVO2, Cryogenic Roomate III, and Mountain Medical...Full Text Available
Aim:Report of 125 pediatric patients of empyema thoracis treated by open decortication, highlighting the presentation, delay in referral, operative findings, the response...Full Text Available
A rapid and sensitive method for the separation and determination of titanium and iron in thiocyanate system has been developed. The extractability of Ti(II) by high molecular weight (HMWA) in organic solvent (HCl/sub 3/) and its separation from Fe(III) was examined. The yellow coloured complex of Ti(II)-SCN in quantitatively extracted into the organic phase containing tribenzyl tribenzylamine (TBA) - a high molecular weight amine, whereas the blood red coloured complex of Fe(III)-SCN formed under the same conditions get separated in the aqueous phase. On the basis of the selective extractability, a method has been developed for the separation as well as simultaneous determination of Ti(II) and Fe(III) in presence of many other elements. The molar extinction coefficients were found to be 1.9 x 10/sup 5/ l mol/sup -1/ cm/sup -1/ and 1.11 x 10/sup 5/ l mol/sup -1/ cm/sup -1/ respectively for Ti(II) and ...
We studied the sorption of As(III) and As(V) onto ferrihydrite as affected by pH, nature and concentration of organic [oxalic (OX), malic (MAL), tartaric (TAR), and citric (CIT) acid] and inorganic [phosphate (PO4), sulphate (SO4), selenate (SeO4) and selenite (SeO3)] ligands, and the sequence of anion addition. The sorption capacity of As(III) was greater than that of As(V) in the range of pH 4.0-11.0. The capability of organic and inorganic ligands in preventing As sorption follows the sequence: SeO4~SO43 PO4. The efficiency of most of the competing ligands in preventing As(III) and As(V) sorption increased by decreasing pH, but PO4 whose efficiency increased by increasing pH. In acidic systems all the competing ligands inhibited the sorption of As(III) more than As(V), but in alkaline e...
Abstract The present work, regarding the determination of ultratrace Os(VIII), Ru(III) and Ir(III) in superficial waters is an interesting example of the possibility to simultaneously, or better sequentially determine each single element in real samples by voltammetry. The method is based on the catalytic current of the Os(VIII)- and Ru(III)-bromate systems by square wave voltammetry and on the Ir(III) determination by square wave catalytic adsorptive stripping voltammetry. 0.5-mol-L-1 acetate buffer pH-4.9+7.710-2-mol-L-1 NaBrO3 and 0.5-mol-L-1 acetate buffer pH-4.9+7.710-2-mol-L-1 NaBrO3+2.310-5-mol-L-1 cetyltrimethylammonium bromide (CTAB) +0.2-mol-L-1 KCl were employed as the supporting electrolytes. The analytical procedure was verified by the analysis of the standard reference materi...
Functional gastrointestinal disorders (FGIDs) represent a common and important class of disorders within gastroenterology. RomeI, the first edition was published in 1994, with symptom-based diagnostic...Full Text Available
Lupus anticoagulant, concentrations of anticardiolipin antibodies, antithrombin III, plasminogen, (free) protein S, protein C, prothrombin, platelet counts, and bleeding times were determined in 74...Full Text Available
Resonance Raman spectra are reported for the organometallic phenyl-FeIII complexes of horse heart myoglobin. We observed the resonance enhancement of the ring vibrational modes of the bound phenyl group....Full Text Available
The efficiency of the synthesized zeolite NaY from rice husk ash (RHA) in the removal of Cr(III) from aqueous solution was studied. Zeolite NaY was synthesized from RHA via seeding technique and the identification of its structure was done by X-ray Diffraction (XRD) technique and the elemental analysis was carried out by X-ray Fluorescence (XRF). The physicochemical properties which were related to the use of the zeolite NaY as a sorbent was also investigated. The synthesized zeolite NaY has higher cation exchange capacity (CEC) than the commercial zeolite NaY due to the higher amount of sodium content in the synthesized as well as the lower ratio of silica to alumina. The synthesized zeolite NaY together with the commercial one as comparison was used in the sorption of the Cr(III) in aqueous solution by batch sorption experiments. The kinetic study showed that the Cr(III) uptake by both zeolites were based on the pseudo ...
Background and objectives: Chronic kidney disease (CKD) is associated with impaired physical activity. However, it is unclear whether the associations of physical activity with mortality are modified...Full Text Available
The developing Integrated Academic Information System (IAIMS) at Columbia-Presbyterian Medical Center provides data sharing links between two separate corporate entities, namely Columbia University...Full Text Available
Naturally occurring, double-stranded RNA (ds-RNA)) was immunogenic when injected into mice, rats, guinea-pigs, rabbits, dogs and baboons. The response to native material administered intravenously (i.v.)...Full Text Available
Some common decay organisms of vegetables and ripened fruits are Alternaria species. Even fruits and vegetables kept under refrigeration can be spoiled by Alternaria species because the mold grows at...Full Text Available
The primary aim of this study was to develop a model system that uses epidermal cells (keratinocytes and accessory pigmented cells) cultured on a reconstituted basement membrane biomatrix for use in...Full Text Available
The major activities of the various Institute's departments are highlighted. The following departments are included: (i) Tokamak; (ii) Pulse plasma systems; (iii) Thermal plasma; (iv) Materials engineering; (v) Laser plasma; and (vi) Optical diagnosis. (P.A.)
If the first (PopIII) stars were very massive, their final fate is to collapse into very massive black holes. Once a proto-black hole has formed into the stellar core, accretion continues through a disk. It is widely accepted, although not confirmed, that magnetic fields drive an energetic jet which produces a burst of TeV neutrinos by photon-meson interaction, and eventually breaks out of the stellar envelope appearing as a Gamma Ray Burst (GRB). Based on recent numerical simulations and neutrino emission models, we predict the expected neutrino diffuse flux from these PopIII GRBs and compare it with the capabilities of present and planned detectors as AMANDA and IceCube. If beamed into 1% of the sky, we find that the rate of PopIII GRBs is $\\le 4 \\times 10^6$ yr$^{-1}$. High energy neutrinos from PopIII GRBs could dominate the overall flux in two energy bands [$10^4 - 10^5$] GeV and [$10^5 - 10^6$] ...
The results of an experimental study of axial and crossflow velocity in a 7-pin wire wrapped bundle similar for FFTF fuel bundles are reported. The results are compared with the forced crossflow model of the COBRA-III C computer program. (JWR)
The programming of cellular networks to achieve new biological functions depends on the development of genetic tools that link the presence of a molecular signal to gene-regulatory activity. Recently,...Full Text Available
This study examines the results of bacterial culture from 159 endometrial biopsy samples from 97 commercial dairy cows and correlations between bacteriological and histological findings. Bacteria were...Full Text Available
This is the second of two papers which critically examine the relationship between the 1918/19 influenza pandemic and encephalitis lethargica (EL). The role of influenza in the etiology of EL...Full Text Available
This work was made with the purpose to complete information about the hydrolysis constants of Europium (III) in high ion strength media. So it was determined at a ion forces media 4, 5 and 6 M of sodium perchlorate at 303 K. The method used was the potentiometric with the aid of the Super quad computer program. In high ion strength media, the measurements of p H do not correspond directly to negative logarithm of the concentration of hydrogen ions, by this it is necessary to calibrate the electrode in these conditions. The Europium was hydrolized at pC{sub H} values greater 6 in all cases. The potentiometric method used under the described experimental conditions is adequate to determine the hydrolysis constants of Europium (III). According to the results and diagrams of chemical species of Europium obtained we can conclude that the hydrolysis constants, differ by its distribution but not in its identity. (Author)
Objective:To estimate the prevalence of insulin resistant syndrome (IRS) among newly diagnosed patients with type 2 diabetes and to test their validity against two indices...Full Text Available
The reserves and the mine are described. Planned capacity is 27.5 million tonnes per year of coal for the Sasol II and Sasol III liquefaction plants. There will be 7 longwall faces, 15 entry workings with shotfiring, and 19 entries with continuous miners.
In most insect species, juvenile hormones regulate critical physiological processes such as metamorphosis and reproduction. In insects, these sesquiterpenoids are synthesized by retrocerebral endocrine...Full Text Available
BackgroundIn 1988, the SPILI project was established in order to evaluate the cardiovascular disease (CVD) risk profile of the inhabitants of Spili, in rural Crete, Greece. The first...Full Text Available
The level of total extracellular neuraminidase produced by 74 clinical isolates of group B streptococci isolated from diseased or asymptomatically colonized infants was assayed. Extracellular neuraminidase...Full Text Available
The realization theory linear dynamical systems, previously developed over a field, are extended to a large class of commutative rings. The principal result is that the existence criterion for a finite...Full Text Available
The nuo-6 and isp-1 genes of C. elegans encode, respectively, subunits of complex I and III of the mitochondrial respiratory chain. Partial loss-of-function...Full Text Available
...capacity, and ownership of all planned and existing onshore pipelines, storage facilities, refineries, petrochemical...will be served by the port, including: (i) Onshore pipelines; (ii) Storage facilities; (iii)...
ii) Flammability: (iii) A capacity to oxidise: (iv) Corrosiveness: (v) Toxicity (including chronic ...an explosion or fire: (d) For substances with corrosive properties: (i) To reduce the ...likelihood of any unintended corrosion:(ii) To control the adverse effects of any corrosion:
The thermodynamics of protonation and europium(III) complex formation with substituted methane diphosphonic acids have been reported recently. These ligands form strong complexes with europium in moderately acidic solutions ((H{sup +}) {ge} 0.1 M), conditions not conducive to complexation by most carboxylate and aminopolycarboxylate ligands. A correlation of log {beta} vs pK{sub a} values for phosphonate and carboxylate ligands is used to explore the effect of ligand structure on complex stability. 5 refs., 1 fig.
A few metal complexes of isatin-isonicotinoylhydrazone with Ni(II), Cr(III), Co(II), Cu(II), Zn(II) and Cd(II) have been prepared and characterized on the basis of elemental analyses, infrared and electronic spectra as well as "1H NMR spectra, conductivity and magnetic measurements. In view of the results obtained, it has been found that two molecules of isatin-isonicotinoylhydrazone are chelated to the central metal ion as bis-uninegative ONO tridentate ligand forming non-electrolytic octahedral metal complexes. (author)
The solvent extraction of europium(III) into solutions of thenoyltrifluoroacetone and benzoic acid in cyclohexane, carbon tetrachloride, benzene, chloroform, pentachloroethane, and tetrachloroethane has been measured at 25/sup 0/ C. It has been found that the extracted species involve two types of adducts, EuA/sub 3/HB and EuA/sub 3/ . 2HB where A denotes the TTA anion and HB the benzoic acid monomer. The magnitude of the adduct formation constants in different solvents has been correlated with the dimerization constants of benzoic acid in the solvents. 2 figures, 2 tables.
Separations of metal ions on the basis of Donnan dialysis across anion-exchange membranes should be possible if the receiver electrolyte composition favors the formation of selected anionic complexes of the sample metal ions. Moreover, such a separation has the possibility of being better suited from some applications than batch or column experiments with anion-exchange resins. The above hypothesis are tested on the platinum-group metal ions, Pt(IV), Rh(III), Pd(II), Ir(III), and Ir(IV). 13 references, 4 tables.
The symposium, Polycrystalline Thin Films - Structure, Texture, Properties, and Applications III, was held at the 1997 Materials Research Society Spring Meeting on March 31--April 4 in San Francisco, California. The topics and investigations were interdisciplinary in nature, and ranged from fundamental to technological. Specifically, the work presented in this volume includes film growth, texture and structural evolution, phase transformation, characterization of grain boundaries and interfaces, stress analysis, and works on polycrystalline Si and SiGe films and devices. Fifty four papers were processed separately for inclusion on the data base.
The symposium, Polycrystalline Thin Films - Structure, Texture, Properties, and Applications III, was held at the 1997 Materials Research Society Spring Meeting on March 31--April 4 in San Francisco, California. The topics and investigations were interdisciplinary in nature, and ranged from fundamental to technological. Specifically, the work presented in this volume includes film growth, texture and structural evolution, phase transformation, characterization of grain boundaries and interfaces, stress analysis, and works on polycrystalline Si and SiGe films and devices. Fifty four papers were processed separately for inclusion on the data base.
It has been predicted for several years that light is focused (optically guided) as well as amplified by the electron beam in a free electron laser (FEL). The degree of focusing depends strongly on both electron beam and optical beam characteristics. In an FEL oscillator the degree of focusing varies with intracavity optical power during the macropulse. We report the first direct measurements of the evolution of transverse optical model size and shape between small signal and saturation in a short wavelength (Compton regime) FEL oscillator. The mode measurements on the Mark III FEL oscillator are shown to be consistent with theory, requiring both refractive and gain contributions to guiding. (orig.).
The effect of variations of the fundamental constants on the thermonuclear rate of the triple alpha reaction, "4He(#alpha##alpha#, #gamma#)"1"2C, that bridges the gap between "4He and "1"2C is investigated. We have followed the evolution of 15 and 60 M#centre dot# zero metallicity stellar models, up to the end of core helium burning. They are assumed to be representative of the first (Population III) stars. The calculated oxygen carbon abundances resulting from helium burning can then be used to constrain the variation of the fundamental constants.
This executive summary presents the motivation, structure, objectives, methodologies and results of the first stage of the international DECOVALEX project - DECOVALEX I (1992-1995). The acronym stands for Development of Coupled Models and their Validation against Experiment in Nuclear Waste Isolation, and the project is an international effort to develop mathematical models, numerical methods and computer codes for coupled thermo-hydro-mechanical processes in fractured rocks and buffer materials for geological isolation of spent nuclear fuel and other radioactive wastes, and validate them against laboratory and field experiments. 24 refs.
Completion of the Phase III evaluation and comparison of salt disposition alternatives was supported with enhanced computer models and analysis for each case on the ''short list'' of four options. SPEEDUP(TM) models and special purpose models describing mass and energy balances and flow rates were developed and used to predict performance and production characteristics for each of the options. Results from the computational analysis were a key part of the input used to select a primary and an alternate salt disposition alternative.
This handbook breaks down the complex field of nuclear reactor calculations into major steps. Each step presents a detailed analysis of the problems to be solved, the parameters involved, and the elaborate computer programs developed to perform the calculations. This book bridges the gap between nuclear reactor theory and the implementation of that theory, including the problems to be encountered and the level of confidence that should be given to the methods described. Volume III: Control Rods and Burnable Absorber Calculations. Perturbation Theory for Nuclear Reactor Analysis. Thermal Reactors Calculations. Fast Reactor Calculations. Seed-Blanket Reactors. Index.
Viscoelasticity of gel films prepared from solvent-soluble constituents without ash of coal using the mixed solvent of carbon disulfide and N-methyl-2-pyrrolidinone (CS2-NMP) was measured to study the network structure of the constituents. In experiment, Upper Freeport coal and Zao Zhuang coal were used as specimens. Viscoelasticity of various gels with different weight fractions of solvent was measured by creep measurement under a fixed load and stress-strain analysis under variable loads. In the 2nd and 3rd creep measurements, although no large changes in elastic strain and viscoelastic strain were found, viscous strain gradually decreased with an increase in viscosity. In the case of small weight fraction of solvent, small viscous strain and viscoelastic strain were found, while slightly large elastic strain was found. It was thus suggested that this elastic strain is derived from not only physical cross-linked networks ...
In this letter a method to estimate the visco-elastic response of monolithic ceramics to cyclic loading conditions at high temperatures is proposed. A relation is observed between the visco-elastic energy dissipation measured for two silicon nitride materials, and the structural characteristics of their respective intergranular phases. Some consequences for the fatigue resistance of the tested materials, and of non-transforming monolithic ceramics in general, are discussed. Two batches (G for glassy and C for crystalline) of SiAlON have been studied. The G-batch is obtained by pressureless sintering of silicon nitride powder with Y_2O_3 (6 wt%) and 6AlN-SiO_2 (5 wt%) as sintering additives. The main phase after sintering is #beta#-sialon. Upon cooling from the sintering temperature the amorphous intergranular residues of the sintering additives and of SiO_2, which is unavoidably present as a thin layer on the silicon nitride powder, crystallize ...
Recently, the development of shape memory alloy (SMA) actuators, in the forms of wire, thin film and stent have been found increasingly in the fields of materials science and smart structures and engineering. The increase in attraction for using these materials is due to their many unique materials, mechanical, thermal and thermal-mechanical properties, which in turn, evolve their subsequent shape memory, pseudo-elasticity and super-elasticity properties. In this paper, a common type of SMA actuator, Nitinol wires, were embedded into advanced composite structures to modulate the structural dynamic responses, in terms of natural frequency and damping ratio by using its shape memory and pseudo-elastic properties. A simple theoretical model is introduced to estimate the natural frequency of the structures before and after actuating the embedded SMA wires. The damping ratios of different SMA composite beams were measured ...
Glasses in the system (95-x) [0.25 Na2O-0.75 B2O3]-x P2O5-5 Fe2O3 (0?x?15 mol%), have been prepared by the melt quenching technique. Elastic properties and FT-IR spectroscopic studies have been employed to study the role of P2O5 on the structure of the glass system. Elastic properties Poisson's ratio, micro-hardness and Debye temperature have been investigated using sound wave velocity measurements at 4 MHz (both longitudinal and shear) at room temperature. The results showed that the density and the molar volume increase as both sound velocities and the determined glass transition temperatures decrease with increasing the contents of P2O5. Infrared spectra of the glasses reveal that the borate network consists of diborate units and is affected by the increase in the concentration of P2O5 content as a second network former. These results are interpreted in terms of the replacement of the diborate units with B-O-B bridges by phosphate units with ...
The ultimate compressive strength and modulus of elasticity of femoral cortical bone from adult geese (Anser anser), were determined by sex and by quadrant by compressing small right circular cylinders which were 2.4 mm in height and 0.8 mm in diameter. The average ultimate compressive strength was 183 +/- 29 MPa. The average modulus of elasticity was 13.2 +/- 3.4 GPa. The bending strength and bending modulus of elasticity were determined by a three point bend test on rectangular prisms which had the approximate dimensions 0.75 mm X 0.75 mm X 25 mm. The average bending strength was 263 +/- 44 MPa while the average bending modulus was 19.6 +/- 3.1 GPa. The calcium content was determined by atomic absorption spectrophotometry and no correlation was found with the mechanical properties. The histology of the cortical bone was examined both quantitatively and qualitatively. A unique type of Haversian bone is described. Goose ...
With regard to the elastic wave exploration, discussions have been given on the relationship between frequency and resolution in P-wave velocity tomography using the initial travel time. The discussions were carried out by using a new analysis method which incorporates the concept of Fresnel volume into tomography analysis. The following two arrangements were used in the calculation: a cross hole arrangement, in which seismic source and vibration receiving points were arranged so as to surround the three directions of a region extending 250 m in the horizontal direction and 500 m in the vertical direction, and observation is performed between two wells, and a permeation VSP arrangement in which the seismic source is installed on the ground surface and receiving points installed in wells. Restructuring was performed on the velocity structure by using a total of 819 observation travel times. This method has derived results of the restructuring according to ...
The differential recoil cross sections of H have been determined for 1.5-3.0 MeV He"+ incidence. In order to obtain precise data, we have performed simultaneous detection and spectrum simulation of recoiled H and backscattered He. In addition, a careful cross check has been made by secondary ion mass spectrometry (SIMS). The present results have revealed a pronounced contribution from a nuclear short-range interaction. The He"+ energy and recoil angle dependence of the H recoil cross sections are well reproduced by adding the nuclear term, which is simply derived from effective range theory. Our computer simulation program of elastic recoil combined with Rutherford backscattering spectra makes it possible to determine the depth distributions of H together with other elements absolutely, without any ambiguities. The present elastic recoil analysis is employed to determine the H composition of amorphous Si(H) films deposited on Si wafers. An ...
A model describes the effect of changes to the pore structure on the mechanical properties of semi-coke during coking. The gap tensile experiment makes it possible to determine the mechanical properties of the coke and semi-coke; a theoretical analysis is valid for the deformation of samples in the gap tensile test, by which the gap tensile strength of the coke can be determined, and by which a method for the simultaneous determination of the effective modulus of elasticity was developed. The effect of the pore structure on the mechanical properties is given in semi-empirical equations. The main point here is to check whether a pore in the coke can be regarded as a Griffith crack, and whether the interaction of pores can be neglected. A model which takes the pore distribution into account was also developed and tested. A model for the change of pore structure during coking, which includes the contraction of the semi-coke, and which presupposes a difference in ...
Kevlar 49/epoxy laminates often exhibit substantial material nonlinearity when subjected to bending. This is a consequence of the yeild-like behavior of a Kevlar 49/epoxy lamina in fiber-directed compression. In this paper, analyses that utilize a simple idealization of compressive yielding are described and calculated results for Kevlar 49 reinforced beams and rings are compared with available data. First, results of a finite element analysis of a thin, unidirectionally reinforced ring subjected to diametral compression are presented. This analysis uses beam elements that incorporate linear tensile and elastic-perfectly plastic compressive behavior. Then a method used to analyze quasi-isotropic beams tested in four-point bending is discussed. This finite element analysis uses a layered shell element with a lamina constitutive model that permits elastic-perfectly plastic response to fiber-directed compression, but otherwise assumes linear ...
Precise measurements of the single spin asymmetry AN, and the double spin asymmetry ANN, in proton-proton (pp) elastic scattering in the region of four-momentum transfer squared 0.0012 have been performed using a polarized atomic hydrogen gas jet target and the Relativistic Heavy Ion Collider (RHIC) polarized proton beam. We present measurements of AN and ANN at center-of-mass energies ?(s)=6.8 and 13.7 GeV. These spin-dependent observables are sensitive to the poorly known hadronic spin-dependent amplitudes. Comparing AN at different energies, a ?(s) dependence of the hadronic single spin-flip amplitude is suggested. A hadronic double spin-flip amplitude from the ANN data is consistent with zero within a 2-? level. We also present ??T, estimated from the measured ANN data. The results for ??T are consistent with zero. Our results provide significant constraints toward a comprehensive understanding of the reaction mechanism for pp elastic ...
In this Letter, we study the structural, elastic and electronic properties of perovskite semiconductor SrTiO_3 using two different methods: the full-potential linearized augmented plane wave (FP-LAPW) method and the pseudo-potential plane wave (PP-PW) scheme in the frame of generalized gradient approximation (GGA). We have evaluated the ground state quantities such as lattice parameter, bulk modulus and its pressure derivative as well as the elastic constants. Also, we have presented the results of the band structure, densities of states and charge densities. These results were in favourable agreement with previous theoretical works and the existing experimental data. To complete the fundamental characteristics of this compound we have analyzed the thermodynamic properties such as thermal expansion coefficient, and specific heats in the whole pressure range from 0 to 20 GPa and temperature range from 0 to 1200 K.
First-principles plane-wave pseudopotential and full-potential linearized-augmented plane-wave methods have been used to study the elastic and electronic properties of several potential superhard RuO_2 phases. The structures, relative stabilities, and the elastic constants and bulk moduli of these phases have been calculated within local-density approximation (LDA) and generalized gradient approximation (GGA). In RuO_2, the LDA and GGA approximations yield smaller and larger lattice constants, respectively, for the Pa3-bar-RuO_2 structure. The internal structural parameter for oxygen atoms in the Pa3-bar structure has a volume dependence that differs from the experimental result and therefore implies a significantly different compression mechanism. The calculated bulk moduli are very similar for the fluorite and Pa3-bar structures and therefore apparently independent of the internal structural parameter. The structure and stability of a ...
This research involves the development of an analysis which yielded recommendations regarding the plate thickness at which the effects of transverse shear become significant enough to be taken into consideration during vibration testing of composite plates. The specimens designed using this analysis are to be used for the {open_quotes}inverse{close_quotes} problem of determining through-the-thickness elastic constants as well as in-plane elastic constants from modal vibration response data. The effects of transverse shear were studied over the range of practical plate aspect ratios (length to thickness ratios) and mode numbers. Behavior of composite plates ranging from isotropic to highly orthotropic was studied in order to investigate the effects of transverse shear. Orthotropic plates having in-plane dimensions of 254 x 254 mm and thicknesses varying from 10 mm to 80 mm, with free-free edge boundary conditions, were considered. A methodology ...
We have measured the K-shell ionization probability Psub(K) across the isobaric analog resonances in the elastic channel of the reactions /sup 88/Sr(p, p/sub 0/)/sup 88/Sr at 5.06 MeV and /sup 86/Sr(p, p/sub 0/)/sup 86/Sr at 6.02 MeV. The dependence of Psub(K) on the beam energy for two scattering angles 90/sup 0/ and 155/sup 0/ is analysed in the framework of the theory developed by Anholt et al. taking into account the effect of compound-nucleus scattering. A compound elastic cross section (dsigma/d..cap omega..)sub(CE)=40+-10 mb/se at the peak of the resonance is deduced in the reaction /sup 88/Sr+p at 5.06 MeV, while the experimental results agree with a negligible value of (dsigma/d..cap omega..)sub(CE) for the resonance in /sup 86/Sr+p at 6.02 MeV.
We have measured the K-shell ionization probability Psub(K) across the isobaric analog resonances in the elastic channel of the reactions "8"8Sr(p, p_0)"8"8Sr at 5.06 MeV and "8"6Sr(p, p_0)"8"6Sr at 6.02 MeV. The dependence of Psub(K) on the beam energy for two scattering angles 90"0 and 155"0 is analysed in the framework of the theory developed by Anholt et al. taking into account the effect of compound-nucleus scattering. A compound elastic cross section (dsigma/d#OMEGA#)sub(CE)=40+-10 mb/se at the peak of the resonance is deduced in the reaction "8"8Sr+p at 5.06 MeV, while the experimental results agree with a negligible value of (dsigma/d#OMEGA#)sub(CE) for the resonance in "8"6Sr+p at 6.02 MeV. (orig.).
The simultaneous biosorption of Cr(VI) and Cu(II) on free Rhizopus arrhizus in a packed column operated in the continuous mode was investigated and compared to the single metal ion situation. The breakthrough curves were measured as a function of feed flow rate, feed pH, and different combinations of metal ion concentrations in the feed solutions. Column competitive biosorption data were evaluated in terms of the maximum (equilibrium) capacity in the column, the amount of metal loading on the R. arrhizus surface, the adsorption yield, and the total adsorption yield. In the single-ion situation the adsorption isotherms were developed for optimum conditions, and it was seen that the adsorption equilibrium data fit the noncompetitive Freundlich model. For the multicomponent adsorption equilibrium the competitive adsorption isotherms were also developed. The competitive Freundlich model for binary metal mixtures represented most the column adsorption equilibrium data ...
This paper describes the effects of SiC coating on the oxidation resistance of C/C composites in combusting fields, which are expected to be applied to high temperature structural materials at over 1770K. The coating methods employed were CVD and pack cementation. The time changes in weight loss of the specimens were measured at temperatures of 1770K and 1900K under the equivalence ratio of 0.9 generated by methane-air combustion, and the surface of the specimens before and after the experiment was observed by SEM. Although the weight loss of the specimens coated by the CVD method was minimal, the coating layer was easily peeled off from the substrate. On the other hand, the layer of the specimens coated by the pack cementation method was stable and adhered to the substrate, but the substrate was degraded because of penetration of oxygen through the pores in the layer. To cover the pores, the specimens were additionally coated with glass ...
The Energy crisis happens to be one of the greatest challenges we are facing today. In this view, much effort has been made in developing new, cost effective, environmentally friendly energy conversion and storage devices. The performance of such devices is fundamentally related to material properties. Hence, innovative materials engineering is important in solving the energy crisis problem. One such innovation in materials engineering is porous materials for energy storage. Porous electrode materials for lithium-ion batteries (LIBs) offer a high degree of electrolyte-electrode wettability, thus enhancing the electrochemical activity within the material. Among the porous materials, mesoporous materials draw special attention, owing to shorter diffusion lengths for Li+ and electronic movement. Nanostructured mesoporous materials also offer better packing density compared to their nanostructured counterparts such as nanopowders, nanowires, nanotubes etc., thus ...
Power plants generate a great amount of ash during coal combustion. From this process two different kinds of ashes are extracted: fly ash (FA) and bottom ash (BA). In this work possible use of both fly and bottom ash as raw material for the ceramic industry is analyzed. The samples were formed by mechanical mixing of both kinds of ashes, and density evolution during conformation as structural ceramic (packing, pressing and sintering) was studied. It was verified that powders with larger fly ash content exhibited higher packing density resulting in compacts with improved green and sintered densities. Preheating treatments at temperatures above 600{sup o}C also increased the green and sintered densities. Dilatometric curves on compacts formed from FA and BA powders were run at constant heating rate and at isothermal cycles. From the analysis of these data it can be established that liquid-phase sintering is the densification mechanism present at ...
This paper reports that the co-deposition of chromium and silicon into a 2.25Cr-1.0Mo-0.15C steel, alloy 800, and type 304 stainless steel has been achieved using the pack cementation process. The ferritic coating produced on the 2.25 Cr-1.0Mo steel was approximately 225 {mu}m (9 mils) thick, whereas the inward diffusion of chromium and silicon produced a two-phase structure of ferrite and austenite for type 304. Chromium and silicon were incorporated into the austenitic solid solution upon diffusion into alloy 800. All coatings had approximately 25 to 35 wt% Cr and 2 to 3% Si at the surface. Cyclic oxidation testing in air of the coated 2.25Cr-1.0Mo steel (T = 700{degrees} C) and type 304 (T = 1035{degrees} C) showed a dramatic decrease in the oxidation kinetics compared to the original uncoated alloys. The cyclic oxidation of alloy 800 was also improved.
The objective of this report was to evaluate four possible alternative methods of preparing and packaging spent fuel assemblies for geologic disposal against the Reference Process of unmodified spent fuel. The four alternative processes were: (1) End fitting removal, (2) Fission gas venting and resealing, (3) Fuel bundle disassembly and close packing of fuel pins, and (4) Fuel shearing and immobilization. Systems analysis was used to develop a basis of comparison of the alternatives. Conceptual processes and facility layouts were devised for each of the alternatives, based on technology deemed feasible for the purpose. Assessments were made of 15 principal attributes from the technical, operational, safety/risk, and economic considerations related to each of the alternatives, including both the surface packaging and underground repository operations. Specific attributes of the alternative processes were evaluated by assigning a number for each that expressed its ...
In this paper we consider the adsorption of argon on the surface of graphitized thermal carbon black and in slit pores at temperatures ranging from subcritical to supercritical conditions by the method of grand canonical Monte Carlo simulation. Attention is paid to the variation of the adsorbed density when the temperature crosses the critical point. The behavior of the adsorbed density versus pressure (bulk density) shows interesting behavior at temperatures in the vicinity of and those above the critical point and also at extremely high pressures. Isotherms at temperatures greater than the critical temperature exhibit a clear maximum, and near the critical temperature this maximum is a very sharp spike. Under the supercritical conditions and very high pressure the excess of adsorbed density decreases towards zero value for a graphite surface, while for slit pores negative excess density is possible at extremely high pressures. For imperfect pores (defined as pores that cannot ...
Using a noneikonal expression for the two-body scattering amplitude, consistent with the proton-nucleon scattering data, the cross-section of the 1.04 GeV-proton elastic scattering on {sup 40}Ca is calculated by the Glauber-Sitenko theoretical scheme in the framework of the coherent density fluctuation model (CDFM) as well as of the independent-particle model (IPM). It is shown that the use of the noneikonal amplitude in the CDFM calculations improves the agreement with the experimental data especially at larger scattering angles in contrast to the case of the independent-particle model. To that end a decisive role play the zero-motion flucton correlations taken into account in the CDFM. (orig.).
Using a noneikonal expression for the two-body scattering amplitude, consistent with the proton-nucleon scattering data, the cross-section of the 1.04 GeV-proton elastic scattering on "4"0Ca is calculated by the Glauber-Sitenko theoretical scheme in the framework of the coherent density fluctuation model (CDFM) as well as of the independent-particle model (IPM). It is shown that the use of the noneikonal amplitude in the CDFM calculations improves the agreement with the experimental data especially at larger scattering angles in contrast to the case of the independent-particle model. To that end a decisive role play the zero-motion flucton correlations taken into account in the CDFM. (orig.).
We develop the formalism of a unified semi-microscopic description of low-energy proton and {alpha}-particle interaction with nuclei. We analyze elastic and inelastic proton scattering at the energy 25.05 MeV and {alpha}-particle scattering at the energy 104 MeV by the {sup 90}Zr nucleus. Information is obtained on differences in the deformation of the proton and neutron distributions. We study the energy dependence of the semi-microscopic {alpha}-particle potential including the energy dependence of the potential geometry.'' We analyze the change in angular distributions of elastically scattered {alpha} particles with increase of energy and the contribution to the scattering cross section from nucleon-nucleon correlations.
This paper is concerned with the fracture analysis of thin cylindrical shells subject to secondary bending stresses with some degree of elastic follow-up. A P.Y.F.M. failure assessment route is utilised for an initial investigation. Results are presented graphically and indicate the differences obtained by considering the stresses as primary or secondary in nature. The Jsup(*) contour integral is computed from the results of a non-linear finite element analysis of a thermally loaded cracked cylinder. Comparison is made between Jsup(*) and the P.Y.F.M. failure criteria demonstrating the degree of conservatism in the latter. It is observed that LEFM may be appropriate for moderate load levels but that the elastic follow-up of the structure causes enhancement of Jsup(*) for higher loads, at which stage LEFM becomes non-conservative. (orig.).
We demonstrate a novel cross-sectional deformation, called the radial corrugation, of multi-walled carbon nanotubes (MWNTs) under hydrostatic pressure. Theoretical analyses based on the continuum elastic approximation have revealed that MWNTs consisting of more than ten concentric walls undergo elastic deformations at critical pressure Formula Not Shown , above which the circular shape of the cross-section becomes radially corrugated. Various corrugation modes have been observed by tuning the innermost tube diameter and the number of constituent walls, which is a direct consequence of the core-shell structure of MWNTs. Cross-sectional views of MWNT under high hydrostatic pressure: elliptic deformation with the mode index n = 2 (left), and radial corrugations with n = 5 (center), and n = 6 ...
Elastic scattering cross sections of keV protons in solids (Z=3-82) are calculated using the partial wave expansion technique and the ''muffin-tin'' bound-atom potential. The differential cross sections for small scattering angles of less than 10deg are smaller than those with the Ziegler-Biersack-Littmark potential at all energies and for all solids, although, for larger angles, the two cross sections agree with each other. The mean free paths of the protons in the solids, obtained from the total cross sections, decrease very slowly with decreasing energy. Furthermore, at low energies they approach half the nearest-neighbor distance, which is taken as the radius of the augmented plane wave sphere in the muffin-tin model of crystalline solids. (orig.).
A macroscopic realization of the strange virtual particles is presented. The classical Helmholtz and the quantum mechanical Schr\\"odinger equations are analogous differential equations. Their imaginary solutions are called evanescent modes in the case of elastic and electromagnetic fields. In the case of non-relativistic quantum mechanical fields they are called tunneling solutions. The imaginary solutions of this differential equation point to strange consequences: They are non local, they are not observable, and they described as virtual particles. During the last two decades QED calculations of the imaginary solutions have been experimentally confirmed for phonons, photons, and for electrons. The experimental proofs of the predictions of the non-relativistic quantum mechanics and of the Wigner phase time approach for the elastic, the electromagnetic and the Schr\\"odinger fields will be presented in this article. The results are zero ...
Numerical simulations are used to test the kinetic theory constitutive relations of inertial granular shear flow. These predictions are shown to be accurate in the dilute regime, where only binary collisions are relevant, but underestimate the measured value in the dense regime, where force networks of size $\\xi$ are present. The discrepancy in the dense regime is due to non-collisional forces that we measure directly in our simulations and arise from elastic deformations of the force networks. We model the non-collisional stress by summing over all paths that elastic waves travel through force networks. This results in an analytical theory that successfully predicts the stress tensor over the entire inertial regime without any adjustable parameters.
This work describes the ability of ion beam analysis techniques IBA to simultaneously determine the concentration and the possible depth profile of some light elements, such as carbon, oxygen and nitrogen, in matrices of high atomic number Z, such as stainless steel materials. In fact, the nitriding process of some materials has the potential to improve their tribological and mechanical properties and to offer various advantages as compared with other methods used in the modification of surfaces. Gas and Plasma nitriding were applied to certain types of steel, such as AISI-304 and H-13 which are commonly used in the industry, in order to improve their hardness and their surface corrosion resistance. The improvement was correlated with the depth profile of N and the consequent structure variations. More specifically, non-Rutherford elastic backscattering (alpha, alpha) at 5 MeV was performed on different samples, before and after nitriding, in order to determine the ...
A series of SiAlON materials with a cordierite-based matrix were annealed for different lengths of time to cause crystallization of the glass phase. Their fracture toughness, hardness, and elastic modulus were measured from room temperature up to 1100"0C. The fracture toughness generally decreased with temperature. Short time annealing raised toughness at lower temperatures, while further annealing lowered it back to the value for as-hot pressed materials. At higher test temperatures annealing had no effect on toughness. This annealing behavior is significantly different from that previously reported in the system SaAlON-YAG. Hardness decreased monotonically with temperature for all samples. Both hardness and the elastic modulus were not affected by the annealing treatment. At elevated temperatures appreciable scatter of modulus results allowed only a rough trend of decrease with temperature to be observed.
Glass fiber-reinforced polymer (GFRP) reinforcing bars were used recently as main reinforcement for concrete structures. The noncorrodible GFRP material exhibits linear-elastic stress-strain characteristics up to failure with relatively low modulus of elasticity compared to steel. This raises concerns on GFRP performance in structures where energy dissipation, through plastic behavior, is required. The objective of this research project is to assess the seismic behavior of concrete beam-column joints reinforced with GFRP bars and stirrups. Two full-scale exterior T-shaped beam-column joint prototypes are constructed and tested under simulated seismic load conditions. One prototype is totally reinforced with GFRP bars and stirrups, while the other one is reinforced with steel. The experimen...
Dense samples of #beta#-sialons (with z from 1 to 4) were pressuressly sintered for different time (15-240 minutes) and at relatively low temperature of 1600 C using single-phase #beta#-sialon powders synthesized by combustion nitridation. The samples were characterized using ultrasonic method for determination of elastic properties (E,G,#mu#). Also, hardness by Knoop and fracture toughness by Vickers indentation microfracture method was estimated. With increasing z number Young's modulus decreases from 293 to 179 GPa. Simultaneously Poisson ratio increases by about 30%. The highest values of hardness and fracture toughness were obtained for sialon with z equal to 1. (orig.).
This paper presents the results of the dynamic response analysis of the pipe-restraints system by the general purpose finite element program ADINA. The analysis was carried out for the pipe whip tests performed under the PWR-LOCA conditions using 4-in. test pipe. In the analysis, the test pipe was modeled by an assemblage of the beam elements with the isotropic elastic-plastic material properties and the restraints were represented by the truss elements with the nonlinear elastic material properties including gap effect. The following results are obtained through the analysis. (1) Pipe can be modeled with the beam elements, when the overhang length is short and, therefore, the flattening of a cross-section of pipe is small. (2) The steady state restraint force can be predicted by modeling the restraints with the truss elements.
Stoichiometric MgAl{sub 2}O{sub 4} spinel specimens irradiated in FFTF-MOTA at temperatures between 385 and 750C to fluences ranging from 2.2 to 24.9 {times} 10{sup 22}n cm{sup {minus}2} (E>0.1 MeV) darken significantly, but do not develop any significant loss in weight or change in dimensions. Similar behavior was observed in both single crystal and fully dense polycrystalline specimens. Measurements of elastic constants by an ultrasonic technique show that no measurable changes occur as a result of the irradiation. These and other results confirm the stability of this material for fusion application as an electrical insulator.
The simultaneous hydrogen and silicon atom densities in amorphous silicon, a-Si, films prepared by the glow discharge technique have been measured by 25 MeV #alpha#-particle elastic scattering. Integrated band intensities for the silicon-hydrogen stretching modes, #omega#_1sup(s) and #omega#_2sup(s) in the region 1800 to 2200 cm"-"1 were determined for the same freely supported films. A similar analysis has been carried out for the bands observed at 890, 840 and 640 cm"-_1. Effective oscillator strengths for the #omega#_1sup(s) and #omega#_2sup(s) modes in a-Si films have been estimated and compared with the current theories on the effect of the silicon matrix on the infrared absorption characteristics. (author).
The contribution of exchange processes (heavy stripping and substitution) into the amplitude of the 25-30 MeV #alpha#-particle elastic scattering by "1"2C and "4"0Ca nuclei is examined taking into account the distortion of plane waves of initial and finite particles. The eikonal approximation is used for accounting for distortions. The matrix elements of exchange processes are calculated. The results of calculations show that the Wronskian cutoff radii are close to those which have been obtained for calculation of exchange processes in the plane-wave approximation. The moduli of the values defining the contribution of exchange processes to the total S matrix are plotted. Also presented are Argand diagrams and angular distributions for both reactions. It has been established that the account for exchange processes improves the agreement of theoretical curves with the experiment in the whole range of angles, as compared with the optical model.
In this study, the authors evaluated how much price changes in food and energy - two basic living expenditures competing for consumers' budgets - would affect consumer welfare. We first estimated a US complete demand system to quantify the interdependent demand relationships among 11 categories of consumption expenditures. Among the estimates, the own price elasticities of both food and energy are relatively inelastic, a finding that explains the dynamics of the recent soaring food and energy prices. The estimated demand elasticities were then incorporated into the measurement of Hicksian compensating variation to analyse the consumer welfare effects of price changes in food and energy. The results indicated that an increase in food and energy prices would increase compensated expenditures...
We have colocalized elastin and fibrillin-1 with perlecan in extracellular matrix of tensional and weight-bearing connective tissues. Elastin and fibrillin-1 were identified as prominent components of paraspinal blood vessels, and posterior longitudinal ligament in the human fetal spine and outer annulus fibrosus of the fetal intervertebral disc. We also colocalized perlecan with a synovial elastic basal lamina, where the attached synovial cells were observed to produce perlecan. Elastin, fibrillin-1 and perlecan were co-localized in the intima and media of small blood vessels in the synovium and in human fetal paraspinal blood vessels. Elastic fibers were observed at the insertion point of the anterior cruciate ligament to bone in the ovine stifle joint where they colocalized with perleca...
Elastic scattering of 22 MeV alpha particles by "2"3Na, sup(24-25-26)Mg, "2"7Al and "2"8Si has been measured between 24"0 and 174"0 lab. Partial angular distributions, from 120"0 to 174"0, were also measured at incident energies of 18.4 and 20.7 MeV for "2"4Mg, and 18.9 and 20.5 MeV for "2"8Si. The most striking feature of the data is the large angle behaviour: spin-zero nuclei display more pronounced backward oscillations and the cross section rises more steeply towards 180"0 for 4n nuclei than for the others. (Z.M.).
It has been shown that two-dimensional arrays of rigid or fluidlike cylinders in a fluid or a gas define, in the limit of large wavelengths, a class of acoustic metamaterials whose effective parameters (sound velocity and density) can be tailored up to a certain limit. This work goes a step further by considering arrays of solid cylinders in which the elastic properties of cylinders are taken into account. We have also treated mixtures of two different elastic cylinders. It is shown that both effects broaden the range of acoustic parameters available for designing metamaterials. For example, it is predicted that metamaterials with perfect matching of impedance with air are now possible by using aerogel and rigid cylinders equally distributed in a square lattice. As a potential application of the proposed metamaterial, we present a gradient index lens for airborne sound (i.e. a sonic Wood lens) whose functionality is demonstrated by multiple ...
It has been shown by recent experiments that bulk immiscible metals (e.g. Ag/Cu, Ag/Co and Au/Ni) can form binary alloys on certain surfaces where the substrate mediates the elastic misfits between the two components, thus relieving the elastic strain in the overlayer. These novel surface alloys exhibit a rich phase structure. We formulate a two-component Frenkel-Kontorova model in one dimension to study surface alloy formation. This model can naturally incorporate dislocation formation that plays a crucial role in determining the actual structure of the system. Using energy minimization calculations we provide a phase diagram in terms of average alloy composition and the energy of mixing. Monte Carlo simulations were also performed to study the structure and interaction of the emerging dislocations.
The survival of acetabular components depends on several factors: wear, osteolysis and septic or aseptic loosening. Osteolysis seems to be the main cause for concern in cementless arthroplasties. Acetabular osteolysis results from particle debris and segmental unloading of acetabular bone by rigid sockets. We investigated a cementless elastic monoblock socket with regard to acetabular osteolysis and aseptic loosening in a cohort of young patients. We evaluated 158 hip arthroplasties with a minimum follow-up of ten?years (ten to 18) and a mean age of 42?years (18?50). The overall revision rate at 14?years was 80% with a 98% survival rate for aseptic loosening. The mean polyethylene wear rate was 0.11?mm/year. Progressive acetabular osteolysis was seen in 3% of patients evaluated. In conclus...
The authors have presented results of an investigation of wettability of SiC particulates by liquid alloys of the Al-Si-Mg system. The evaluation of wetting has been carried out through the determination of the threshold pressure for infiltration of packed SiC particulates by the liquid alloy. The results indicate that whereas Si and Mg additions do not affect wetting, in the case of the ternary alloys the contact angle decreases in an amount proportional to the content of Mg[sub 2]Si.
A study of two forest areas in India investigated how much energy is wasted when high stumps are left after trees are cut to produce wooden boxes for packing the apple harvest. Measurements of the stumps determined the total wood pulp wasted, which was 1191 tons during 1981. The calorific value of the stumps would supply a year's cooking and heating fuels for 747 families of five. Additional fuel is wasted by abandoning the branches and tree tops which are unsuitable for box construction. 5 references, 4 tables.
The authors report a novel configuration for a zinc-particle, packed-bed anode in which an open structure of high hydraulic permeability is maintained indefinitely in a cell with closely spaced walls by the formation of particle bridges and associated gaps. The configuration minimizes electrolyte pumping costs, allows rapid refueling and partial recharge, and provides for 100% zinc consumption. This approach benefits zinc/air fuel batteries by allowing nearly continuous operation and fuel recycle without commercial infrastructure; it benefits Zn/[Fe(CN){sub 6}]{sup {minus}3} batteries by eliminating shape-change and polarization problems found with planar anodes.
New technologies make multi-megajoule glass lasers economically feasible. Laser architectures using harmonic switchout, target plane holographic injection, phase conjugation, continuous apodization and higher amplifier efficiencies have been devised. A plan for a multi-megajoule laser which can be built for an acceptable cost relies on manufacturing economies of scale and the demonstration of the new technologies presented here. These include continuous pour glass production, rapid harmonic crystal growth, switching of large blocks of power using larger capcaitors packed more economically and by using large identical parts counts.
The marine ram-type blowout preventer deployed from an offshore drilling rig has one serious disadvantage, its inaccessibility. A development to promote reliability of the subsea ram-type preventer and reduce the excess running and pulling to charge out rams, is the variable bare ram (VBR). Unlike the standard ram, the VBR has the ability to pack off a range of pipe sizes. Interest in VBR's has been revived and research and development in this equipment goes on at each of three manufacturer's facilities in Houston.
Microporous membranes are suitable for the CO{sub 2}-MEA (monoethanolamine) system because the overall mass transfer coefficient K of the membrane is approximately 10 times larger than that of composite membranes consisting of microporous membranes and homogeneous membranes. The overall volumetric mass transfer coefficient K{center_dot} of the hollow-fiber contact is more than 5 times larger than that of a conventional packed bed, which suggests that adorption using the present method has the advantage of making the absorption more compact. 8 refs., 7 figs., 4 tabs.
The author describes feasibility study on the scheme of disposing spent guide tubes at Daya Bay nuclear power plant, including scheme selection, packing cask design, disposal operation and technological process, budget estimation and safety evaluation. The research results show that the new scheme is feasible on technology, and reasonable on budget. If the scheme is adopted to dispose the spent guide tubes at Daya Bay nuclear power station, it can not only save large funds, but also accumulate experience on disposing non-compressible low and intermediate level solid radioactive wastes produced at nuclear power station for the country
As a counter measure to protect against global warming, the development of CO{sub 2} recovery technology from fossil fuel power plant flue gas has continued. MEA processes are widely used for CO{sub 2} recovery from combustion flue gas in average use etc. However, if we consider power plant scale CO{sub 2} recovery, the biggest theme is the reduction of energy needed to recover CO{sub 2}. The paper focuses on sterically hindered amines and a new absorber packing. Also optimum steam system analysis results are indicated. 1 ref., 16 figs., 3 tabs.
A packed column was used for investigating the desorption rate of CO{sub 2} from aqueous methyldiethanolamine (MDEA) and activated MDEA solutions. Experiments were conducted within the temperature range 30--70 C, the concentration of MDEA was 4.28 kmol/m{sup 3}, and the concentration of piperazine (PZ) was 0.10 kmol/m{sup 3} for aqueous activated MDEA solutions. Experimental data confirmed that the kinetics model of absorption CO{sub 2} into aqueous MDEA and activated MDEA solutions can be applicable to the situations in which desorption occurs, and the desorption rate of model predictions agree well with that of experimental determination.
The performance of a solar chemical heat pipe was studied using CO{sub 2}reforming of methane as the endothermic reaction. A directly heated vertical reactor, packed with a rhodium catalyst was used. The solar tests were carried out in the Schaeffer solar furnace of the Weizmann Institute of Science. The power absorbed was up to 6.3 KW, the maximal flow rates of the gases reached 11,000 1/h, and the methane conversions reached 85%. A computer model was developed to simulate the process. Agreement of the calculations with the experimental results was quite satisfactory.
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Electric and hybrid-electric vehicles are being developed and commercialized around the world at a rate never before seen. These efforts are driven by the prospect of vehicles with lower emissions and higher fuel efficiencies. The widespread adaptation of such vehicles promises a cleaner environment and a reduction in the rate of accumulation of greenhouse gases, Critical to the success of this technology is the use of electrochemical power sources such as batteries and fuel cells, which can convert chemical energy to electrical energy more efficiently and quietly than internal combustion engines. This overview will concentrate on the work being conducted in the US to develop advanced propulsion systems for the electric and hybrid vehicles, This work is spearheaded by the US Advanced Battery Consortium (USABC) for electric vehicles and the Partnership for a New Generation of Vehicle (PNGV) for hybrid-electric vehicles, both of which can be read about on the world wide web ...
Modern high-resolution electron microscopy (HREM) instruments, which are capable of a point-to-point resolution of better than 0.2 nm, have allowed atomic-scale observations of a variety of internal interfaces. The application of the HREM technique to fcc model systems for the purpose of addressing a number of interface issues will be examined in this paper. Atomic structure observations for heterophase interfaces of metal/metal and metal/metal-oxide systems as well as HREM studies of grain boundaries in NiO and Au will be discussed with emphasis on generic structural features and the role of the interface plane. Comparisons between observed interface structures and atomistic computer modeling results have shown agreements for some interfaces, as well as certain differences in others. A number of structural features are common to both metal and oxide grain boundaries, as well as certain heterophase boundaries. Of particular importance in close-packed solids appears ...
Cassava is cultivated almost all over the world and it is considered one of the most important nutritious sources of calories in the human diet. Cassava is a viable food against starvation in several poor areas of the world because it is an extremely resistant culture and may reach satisfactory economical yield. We utilized vacuum packed industrialized cassava irradiated with 0,1 kGy, 3kGy and 5kGy and stored under refrigeration for 1, 21, 30 and 50 days. Our objective was to analyse the synergistic effect of vacuum packing, irradiation and refrigeration on the preservation of minimally processed cassava. The samples were analyzed for pH, acidity, weight, humidity, texture and color. The irradiation did not affect the chemical characteristics of the cassava. Neither the pH nor the acidity, the most relevant variables to verify deterioration in cassava, presented significant alterations during the period of storage. Comparing the irradiated ...
While tritium exposure to the site-workers in Wolsung NPP is upto about 40 % of the total personnel exposure, Korea Institute of Nuclear Safety has asked tritium removal facility, as one of the requirements for post reactor construction, after operation of four CANDU reactors in Wolsung site. For the purpose of essential removal of tritium from the heavy water system of the heavy water reactors, an experiment of Ar-N{sub 2} cryogenic distillation tower was carried out as a preliminary study for development of liquid-phase catalytic exchange - cryogenic hydrogen distillation process. The steady-state reached after 50 minutes under 90 K in the Ar-N{sub 2} distillation column (inner diameter 20 mm, height 500 mm) packed with Dixon ring ({phi} 3 mm x H 3 mm), and the ratios of Ar-concentration at the top and at the bottom measured by gas chromatography within {+-}1 % relative error was approximately 93 : 3. This value was distillation performances quite higher than ...
CeO{sub 2}-TiO{sub 2} catalysts are prepared by coprecipitation method, and the activity and stability in the catalytic wet air oxidation (CWAO) of phenol are investigated in a batch reactor and packed-bed reactor. CeO{sub 2}-TiO{sub 2} mixed oxides show the higher activity than pure CeO{sub 2} and TiO{sub 2}, and CeO{sub 2}-TiO{sub 2} 1/1 catalyst displays the highest activity in the CWAO of phenol. In a batch reactor, COD and TOC removals are about 100% and 77% after 120 min in the CWAO of phenol over CeO{sub 2}-TiO{sub 2} 1/1 catalyst at reaction temperature of 150 {sup o}C, the total pressure of 3 MPa, phenol concentration of 1000 mg/L, and catalyst dosage of 4 g/L. In a packed-bed reactor using CeO{sub 2}-TiO{sub 2} 1/1 particle catalyst, over 91% COD and 80% TOC removals are obtained at the reaction temperature of 140 {sup o}C, the air total pressure of 3.5 MPa, the phenol concentration of 1000 mg/L for 100 h continue reaction. Leaching ...
The following paragraphs summarize the progress of each research project funded under the WVU Cooperative Agreement during the third quarter of 1997 (July - September 1997). The projects are arranged according to their 1997 WVU task number. WVU Focus Area 1.0: Subsurface Contaminants, Containment and Remediation Task No. 1.1: Project discontinued. Task No. 1.2: Development of Standard Test Protocols and Barrier Design Models for Desiccation Barriers (K. Amininan & S. Ameri): A number of experiments were preformed this period to evaluate the ability of the dried sand-packs to act as a barrier to liquids. Water infiltration tests were done with a constant head, dispersing 80 ml of water, and by adding water in small increments. Results indicate that when the water is spilled over the sand-pack, it has the tendency to channel through the sand-pack, significantly reducing the capacity of the dried zone to retain liquid ...
This article describes acoustic methods used in the in-service inspection of the dams and peripheral concrete structures of the Toktogul, Kurpsai, and Bratsk hydroelectric and pumped storage plants. The tests were conducted to assess the compression strength, elasticity, and tensile strength of the concretes. Comparative evaluations against drill core studies proved the acoustic methods to be sufficiently accurate in predicting aging behavior and loss of mechanical and physical integrity in the concretes.
The effects of gamma irradiation at 0.2#approx#0.4 Mrad and condition for processing of buckwheat noodles on sensory quality and physical properties were investigated. The results were as follows: (1) Sensory evaluation of buckwheat noodles, prepared with the 70 % ratio of buckwheat flour, was decreased according to an increase of irradiation dose of buckwheat flour. Hardness and adhesiveness of buckwheat noodles caused by irradiation should be given large effect to the texture. Elasticity of buckwheat noodles was linearly decreased with increasing of irradiation dose of buckwheat flour, and elasticity of buckwheat noodles was decreased about 15 % by an increase of irradiation dose at 0.3 Mrad. (2) Maximum torque in Farinograph test was linearly decreased with increasing of irradiation dose of buckwheat flour, and maximum torque was decreased about 3 % by increasing of irradiation dose with 0.1 Mrad. (3) Sensory evaluation was also decreased by ...
ATP is synthesized by ATP synthase (FOF1-ATPase). Its rotary electromotor (FO) translocates protons (in some organisms sodium cations) and generates torque to drive...Full Text Available
A method is presented for calculating the thermal stability of blast furnace coke over a wide range of sizes, based on a study of the coke behaviour pattern in the blast furnace and the change in its thermo-elastic properties during reheating. Using as an example a Novolipetsk metallurgical plant, the possibility was demonstrated of using the thermal stability index calculated by the proposed method for an unambiguous assessment of the quality of blast furnace coke.
The work reported here concerns the evolution of the shape of a coherent, cubic precipitate as it grows by coarsening. The work was motivated by the need to explain recent experimental observations that show that cuboidal ..gamma.. Ni/sub 3/Al precipitates in Ni-Al alloys resist coarsening and decompose into doublets of parallel rectangular plates and octets of small cubes. The theoretical model assumes a precipitate of cubic phase with negative elastic anisotropy, and neglects any difference between the elastic constants of the precipitate and the matrix. The elastic energy of the precipitate is then calculated as a function of its morphology, including the possibility of decomposition into doublets or octets of discrete particles. The results show that a cuboidal precipitate with (100) faces and edge length, 2a, is metastable with respect to transition to a doublet of discrete plates, with dimensions a x 2a x 2a, that are ...
It is shown that elastic scattering data for protons of 100-200 MeV are consistent with an absorptive potential that is stronger in the nuclear interior and of the slightly shorter range than is usually assumend, which is more in agreement with microscopically calcuated potentials. Consequences for certain (p,p') and (e,e'p) reactions are shown. (orig.).
Correlations of the Woods-Saxon four-parameter optical potential of scattering of 38 MeV #alpha# particles on sup(68)Zn have been analyzed. A search for discrete sets of potential parameters and functional ratios between different parameters is carried out.
The correlation between superconductivity and structural transformation in the A-15 compounds are examined in a unified way on the basis of the Gor'kov three-dimensional model and the anisotropic pairing interaction. The temperature dependence of the elastic modulus, the strain order parameter and the energy gaps of superconductivity are obtained and compared with the experimental data. (auth.).
Structural instabilities are now being found in many high-temperature superconductors. Compounds with the A-15 (#beta#-W) structure comprise the most important group of these materials, and their properties have been extensively studied for over 15 years. A review is given of some of these results, particularly those relating to the elastic behavior. The empirical relation of the structural instability and the anharmonicity to the high superconducting transition temperature is discussed.
The Rayleigh scattering of Moessbauer radiation has been measured on highly oriented fibres of Na-hyaluronate at different hydration levels. The elastic- and-inelastic-scattering intensities, measured as a function of the scattering vector Q, have provided information on the dynamic structuring of the water molecules to the polysaccharidic chains.
This volume of the monograph covers the following topics: activation analysis, non-activation interaction analysis (elastic scattering of charged particles, absorption and backscattering of beta radiation and photons, radionuclide X-ray fluorescence analysis, thermalization, scattering and absorption of neutrons, use of ionization caused by nuclear radiation, use of ionization by alpha or beta radiation for the measurement of pressure, density and flow rate of gases), and automation in radioanalytical chemistry. (P.A.).
We discuss the origin of Bloom-Gilman duality and the relationship between resonances and scaling in deep-inelastic scattering. We present a simple quantum mechanical model which reproduces the essential features of Bloom-Gilman duality at low Q{sup 2}, and describe applications of local duality relating structure functions at x{approximately}1 and elastic electromagnetic form factors.
It is shown that elastic scattering data for protons of 100-200 MeV are consistent with an absorptive potential that is stronger in the nuclear interior and of the slightly shorter range than is usually assumend, which is more in agreement with microscopically calcuated potentials. Consequences for certain (p,p') and (e,e'p) reactions are shown.
It is suggested that the large reduction of the superconducting transition temperature Tc due to defects observed experimentally in some A-15 compounds is caused by smearing of a high peak in the density of states at the Fermi level. The influence of defects on other physical properties (the magnetic susceptibility ?, the elastic modulus Cs, the structural transformation temperature Tm and the electrical resistivity ?) is also discussed from the same point of view. We expect the anomalous temperature dependence of ?, Cs and ? will be suppressed by defects.
In this study, a probabilistic seismic risk analysis of the Wolsung NPP containment building was performed by a seismic hazard analysis and a seismic fragility analysis based on the nonlinear dynamic time-history analyses. The conventional seismic fragility analysis of the safety related structures in a NPP have been performed by using the linear elastic analysis results. The probabilistic seismic risk of the containment building was 5.19e-8.
In this study, a probabilistic seismic risk analysis of the Wolsung NPP containment building was performed by a seismic hazard analysis and a seismic fragility analysis based on the nonlinear dynamic time-history analyses. The conventional seismic fragility analysis of the safety related structures in a NPP have been performed by using the linear elastic analysis results. The probabilistic seismic risk of the containment building was 5.19e-8.
The lepton flavor-violating coherent ( /sup -/, e/sup -/) conversion is investigated. Photonic and nonphotonic contributions arising in various gauge models are considered. The dependence of the conversion rate on the structure of the nucleus is given by the elastic form factors. These are obtained in the context of shell model taking into account finite-size effects or extracted from the electron scattering data whenever possible. The relevant branching ratios are studied throughout the periodic table.
It is shown that low-frequency elastic vibrations of near-surface planar defects cause high-frequency ultrasonic radiation in surrounding air. The frequency conversion mechanism is concerned with contact nonlinearity of the defect vibrations and provides efficient generation of air-coupled higher-order ultraharmonics, ultrasubharmonics, and combination frequencies. The nonlinear air-coupled ultrasonic emission is applied for location and high-resolution imaging of damage-induced defects in a variety of solid materials.
This report discusses the following topics: Prompt fission neutron energy spectra for {sup 235}U and {sup 239}Pu; Two-parameter measurement of nuclear lifetimes; ``Black`` neutron detector; Data reduction techniques for neutron scattering experiments; Inelastic neutron scattering studies in {sup 197}Au; Elastic and inelastic scattering studies in {sup 239}Pu; and neutron induced defects in silicon dioxide MOS structures.
Nanocrystalline materials can exhibit properties which are considerably different from their coarse-grained counterparts, making them unique for basic or applied research and also very promising for potential applications. The topics which are addressed in the present paper are magnetic properties and magnetic correlations on the nanometer scale, mechanical properties, in particular the influence of grain boundaries on the elastic and plastic behaviour, and vibration models of grain boundary atoms in nanostructured materials. (author)
Elastic depth imaging of both P-wave and S-wave prestack seismic reflection data is formulated as a degraded form of Kirchhoff migration known as Wavepath Migration (WM). Applications to the SEG/EAGE salt model show that the method is sufficiently versatile anti relaitively inexpensive. It handles S-wave data with at least the same accuracy as Pwave data when local mode conversions are removed. WM also provides an understanding of multi-mode illumination.
Molecular dynamics computer simulations of a dense nanocrystalline Nickel sample are performed on the parallel Cray T3 (EPFL-Lausanne). The sample contains 50 grains with an average size of 3 nm. By perturbing the relaxed configuration elastic and plastic properties are studied. (author) 1 fig., 1 ref.
The macroscopic behavior of magnetostrictive materials results from domain evolutions occurring at a microscopic scale. The author shows how to compute magnetization and magnetostriction curves by appraising the behavior of the underlying microstructures. The method hinges on an averaging device (Young measures), which allows one to pass from the microscopic to the macroscopic scale. He takes into account the kinematical constraints on the accommodation of elastic effects, and he highlights the role of material symmetry in the selection of energetically optimal microstructures.
The cross sections for proton-proton elastic scattering at Fermilab and ISR energies are investigated in the framework of the multiple constituent scattering formalism, including the contributions of the inelastic intermediate states. We find that the higher-order multiple scattering amplitudes are strongly suppressed due to the presence of the inelastic intermediate states. The calculated cross sections reproduce the high energy experimental data fairly well. (author).
The Grueneisen parameter and lattice thermal expansion of the A-15 compounds V_3Si and V_3Ge at room temperature are evaluated on the basis of the method due to Brugger and Fritz from the third order elastic constants reported earlier. The calculated values are compared with available experimental values and are found to fit satisfactorily. (author).
Experimental and evaluated integral parameters derived from nuclear plus interference differential elastic scattering cross sections are presented for all projectile/target combinations of the particles p, d, t, /sup 3/He, and ..cap alpha... The data include reaction rates, average fractional energy losses per collision and per unit path length, and average laboratory scattering cosines. The resulting parameters are of potential use in analysis of charged-particle transport.
Phased array provides many advantages over conventional ultrasonic testing method, but phased array has also limitations. This paper describes typical results of the experimental sound field analysis generated from the array probe. A photo-elastic ultrasonic visualization technique was applied in this study. The sound fields of shear wave generated from the array probe was equivalent to that from the fixed angle probe. (author)
It is shown that the section of the energy surface corresponding to the longitudinal mode by the principal xy-plane for the A-15 compounds will degenerate into four points at the corners of a square at very low temperatures in the cubic phase. When the quasi-shear mode propagating along the (110) direction becomes soft, simultaneously the longitudinal mode will exhibit unusually high phonon focussing. (author).
The strength, stiffness, and range of single-stranded stainless steel (SS) and superelastic nickel-titanium (NiTi) archwires were compared with those of alternative leveling products, including nylon-coated and multistranded wires. Wire cross-sections were photographed after being potted in polymer, ground, and polished. Because the rectangular wires had rounded or beveled corners, gravimetric measurements and specific gravity calculations quantified the actual polygonal cross-sectional areas versus the ideal rectangular cross-sectional areas. Beveling reduced the cross-sectional areas by 7% to 8%; this decreased the wire stiffnesses by 15% to 19%. Using a testing machine, we measured the yield strengths, the elastic limits, and the ultimate tensile strengths in tension, and wire stiffnesses in 3-point bending. From cyclic loading tests, the elastic limits of the superelastic NiTi wires were approximately 90% and 45% of their ultimate tensile ...
Glasses in the system (1 - x) [29Na{sub 2}O- 4Al{sub 2}O{sub 3}- 67B{sub 2}O{sub 3}]- xZnO (0 {<=} x {<=} 35 mol%), have been prepared by the melt quenching technique. Elastic properties, X-ray and FT-IR spectroscopic studies have been employed to study the role of ZnO on the structure of the investigated glass system. Elastic properties and Debye temperature have been investigated using sound wave velocity measurements at 4 MHz at room temperature. The results showed that the density increases and the molar volume decreases while both sound velocities and the determined glass transition temperatures decrease with increase in x. X-ray and infrared spectra of the glasses reveal that the borate network consists of diborate units and is affected by the increase in the concentration of ZnO content. These results are interpreted in terms of the decrease in the N{sub 4} values (fraction of tetrahedral coordinated boron atoms), and ...
The report consist of the following appendices: A. Cost annualization model; B. Facility level analysis; C. Market model methodology; D. Summary of Demand and Supply Elasticity Literature; E. Sensitivity analysis; and F. Cost effectiveness analysis.
With the help of the symmetry at the P point, we have determined the relations between the force constants and the moduli of elasticity for A-15 compounds. Based on these relations, a semi-experimental method for the study of the lattice dynamic behaviors of A-15 compounds is developed. Numerical calculations of the phonon spectrum of Nb/sub 3/Sn and its temperature dependence have been made, and they are in good agreement with the experimental data.
The paper contains a numerical evaluation of the expressions for the absorptive potential in heavy ion reactions given earlier. With a standard folding expression for the real part of the ion-ion potential general good agreement is found with experimental data for the angular distributions of elastic and inelastic scattering. Special interest is attached to the case of /sup 16/O + /sup 28/Si where the calculated imaginary potential is very small at low bombarding energies.
The paper contains a numerical evaluation of the expressions for the absorptive potential in heavy ion reactions given earlier. With a standard folding expression for the real part of the ion-ion potential general good agreement is found with experimental data for the angular distributions of elastic and inelastic scattering. Special interest is attached to the case of "1"6O + "2"8Si where the calculated imaginary potential is very small at low bombarding energies. (orig.).
A string sieve is proposed which includes a frame, a sifting surface made of string, a device for attaching the strings made in the form of rollers installed in staggered order and a tensing device attached to traverses. To improve the effectiveness of sifting by self cleaning of the sifting surface during operation, the rollers are installed on the traverses by means of a unit of hinges, whose elastic elements are made with varying rigidity.
The nano-structured Fe(III)-doped TiO{sub 2} photocatalysts with anatase phase have been developed for the oxidation of non-biodegradable different organic dyes like methyl orange (MO), rhodamine B (RB), thymol blue (TB) and bromocresol green (BG) using UV-Hg-lamp. The different compositions of Fe{sub x}Ti{sub 1-x}O{sub 2} (x = 0.005, 0.01, 0.05, and 0.1) nanocatalysts synthesized by chemical method (CM), have been characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectra, specific surface area (BET), transmission electronic microscopy (TEM) analysis, XPS, ESR and zeta potential. From XRD analysis, the results indicate that all the compositions of Fe(III) doped in TiO{sub 2} catalysts gives only anatase phase not rutile phase. For complete degradation of all the solutions of the dyes (MO, RB, TB, and BG), the composition with x = 0.005 is more photoactive compared all other compositions of Fe{sub x}Ti{sub 1-x}O{sub 2}, and ...
A patient with a totally edentulous maxilla and a seVere Class III intermaxillary relationship in the anterior region was treated by implants. In the mandible, there were 10 teeth between the second premolars. The inclination and width of the maxillary anterior residual bone were measured on cephalometric X-ray film obtained before treatment. The results of cephalometric analysis did not support clockwise rotation of the mandible or lingual angling of the maxillary anterior teeth by use of prosthesis to improve the Class III relationship. Ten implants were simultaneously placed in the maxilla. Then, a maxillary temporary full bridge was seated after reduction of the crown lengths of the mandibular anterior teeth. An apically positioned flap operation was performed to eliminate periodontal pockets and to obtain clinically suitable crown lengths of the mandibular anterior teeth. A noncemented, screw-retained maxillary full bridge and a ...
III-V semiconductors, GaAs and in particular InGaP, are used in many different electronic applications, such as high power and high frequency devices, laser diodes and high brightness LED. Their direct bandgap and high reliability make them ideal candidates for the realisation of high efficiency solar cells: in the past years they have been successfully used as power sources for satellites in space, where they are able to produce electricity from sunlight with an overall efficiency of around 30%. Nowadays, the use of arsenides and phosphides as photovoltaic (PV) devices is confined only to space applications since their price is much higher than conventional Si flat panel modules, the leading PV market technology. But with the introduction of multijunction solar cells capable of operating in high concentration solar light, the area and, therefore, the cost of these cells can be reduced and will eventually find an application and market also on Earth. This article ...
The paper briefly describes the nuclear reactor facilities at Sandia Laboratories which are used for simulating nuclear weapon produced neutron environments. These reactor facilities are used principally in support of continuing R and D programs for the Department of Energy/Office of Military Application (DOE/OMA) in studying the effects of radiation on nuclear weapon systems and components. As such, the reactors are available to DOE and DOD agencies and their contractors responsible for the radiation hardening of advanced nuclear weapon systems. Emphasis is placed upon two new reactor simulation sources; the Sandia Pulse Reactor-III (SPR-III) Facility which enhances the neutron exposure volume capabilities over those presently available with the existing SPR-II Facility, and the Upgraded Annular Core Pulse Reactor (ACPR) Facility which enhances the neutron exposure capabilities over those of the former ACPR Facility.
The iron(III) molar extinction coefficient in H/sub 2/O-0.4 M H/sub 2/SO/ sub 4/ solution at maximum absorption and 25 deg C, epsilon /sub s/, was determined to be 2220 plus or minus 20 liters mole/sup -1/ cm/sup -1/. The ratio of the iron(III) molar extinction coefficient in D/sub 2/O-0.4 M H/sub 2/SO/ sub 4/ solution at maximum absorption and 25 deg C to epsilon /sub s/ was found to be 1.068 P 0.004. The acidity effect is presented graphically, since the effect is nonlinear. The temperature coefficients were determined to be +(0.63 plus or minus 0.02)% per de gree centigrade for light water solutions and +(0.36 plus or minus 0.02)% per degree centigrade for heavy water solutions. (auth)
The biosorption of phosphate from aqueous solutions using Fe(III)-treated Staphylococus xylosus cells was investigated. Langmuir and Freundlich isotherm models were applied to describe the adsorption equilibrium and found that Langmuir isotherm model fitted the equilibrium data better than Freundlich isotherm model. The biosorption capacity of Fe(III)-treated biomass for phosphate was found to be 70.92mg/g at optimum conditions of pH 3.0, biomass concentration 0.5g/L and equilibrium phosphate-biomass time 60min respectively. The sorption efficiency at initial phosphate concentration of 50mg/L was not influenced upon addition of SO4^2^-, Cl^-, CO3^2^-, NO3^-, Mg^2^+ and Ca^2^+ ions from 0 to 800mg/L, whereas under the same conditions, phosphate sorption was increased with increase in concen...
An extremely sensitive stripping voltammetric procedure for ultra-trace determination of iridium(III) is reported. The method is based on the interfacial accumulation of the iridium(III)-CTAB complex onto the glassy carbon electrode, followed by the catalytic reduction of the adsorbed complex in the presence of bromate. 0.3molL^-^1 acetate buffer pH 4.7+6.9x10^-^2molL^-^1 NaBrO3+2.7x10^-^5molL^-^1 cetyltrimethylammonium bromide (CTAB)+0.2molL^-^1 KCl was employed as the supporting electrolyte. The analytical procedure was verified by the analysis of the standard reference materials: Sea Water BCR-CRM 403 and Fresh Water NIST-SRM 1643d. The accuracy, expressed as relative error e%, was satisfactory, being lower than 6%, while precision as repeatability, expressed as relative standard deviat...
The concepts of ''fast'' and ''slow'' time scale valence measurements are emphasized by a comparison of L/sub III/ absorption and Mossbauer effect measurements on the temperature induced valence change in EuPd/sub 2/Si/sub 2/. Further the authors show how synchrotron radiation based L/sub III/ measurements of the Ce-valence state can be used to demonstrate electronic structure trends under wide changes in chemical environment. The purpose of this paper is to provide an introduction to researchers in the People's Republic of China to the field of mixed valent rate earth compounds. They hope to illustrate some of the basic concepts in this field, how the field is contributing to the overall insight into the chemical physics of solids and finally how synchrotron radiation measurements in particular are playing a key role in this field.
Volume III of the documentation for the Phase I Data Analysis Task performed in support of the current Regional Flow Model, Transport Model, and Risk Assessment for the Nevada Test Site Underground Test Area Subproject contains the data covering groundwater recharge and discharge. Because of the size and complexity of the model area, a considerable quantity of data was collected and analyzed in support of the modeling efforts. The data analysis task was consequently broken into eight subtasks, and descriptions of each subtask's activities are contained in one of the eight volumes that comprise the Phase I Data Analysis Documentation.
We provide a brief review of our recent results from optically detected magnetic resonance studies of grown-in non-radiative defects in two most important dilute nitride systems-Ga(In)NAs grown on GaAs substrates and Ga(Al,In)NP grown on Si and GaP substrates. These results have led to the identification of defect complexes in the alloys, involving intrinsic defects such as As_G_a antisites and Ga_i self-interstitials. They have also shed light on formation mechanisms of the defects and on their role in non-radiative carrier recombination that is harmful to the performance of potential optoelectronic and photonic devices based on these dilute nitrides.
Moessbauer spectra of the Fe(III) compounds (C[sub 2]H[sub 5])[sub 4]NFeX[sub 4] (X = Cl, Br) exhibit the following anomalies above [approx] 260 K: (i) the f-factor drops with respect to normal thermal behavior, (ii) the second-order Doppler shift drops similarly, (iii) the single-line spectrum broadens, becoming asymmetric at room temperature. These phenomena are discussed in relation to possible phase transitions in these systems. (orig.)
This report describes progress during the first year of a three-year project. The objective of the research is to examine new design approaches for achieving very high conversion efficiencies. The program is divided into two areas. The first centers on exploring new thin-film approaches specifically designed for III-V semiconductors. The second area centers on exploring design approaches for achieving high conversion efficiencies without requiring extremely high quality material. Research activities consisted of an experimental study of minority carrier recombination in n-type, metal-organic chemical vapor deposition (MOCVD)-deposited GaAs, an assessment of the minority carrier lifetimes in n-GaAs grown by molecular beam epitaxy, and developing a high-efficiency cell fabrication process.
This report describes progress during the first year of a three-year project. The objective of the research is to examine new design approaches for achieving very high conversion efficiencies. The program is divided into two areas. The first centers on exploring new thin-film approaches specifically designed for III-V semiconductors. The second area centers on exploring design approaches for achieving high conversion efficiencies without requiring extremely high quality material. Research activities consisted of an experimental study of minority carrier recombination in n-type, metal-organic chemical vapor deposition (MOCVD)-deposited GaAs, an assessment of the minority carrier lifetimes in n-GaAs grown by molecular beam epitaxy, and developing a high-efficiency cell fabrication process.
We report electronic and magnetic structure of arsenic-doped manganese clusters from density-functional theory using generalized gradient approximation for the exchange-correlation energy. We find that arsenic stabilizes manganese clusters, though the ferromagnetic coupling between Mn atoms are found only in Mn$_2$As and Mn$_4$As clusters with magnetic moments 9 $\\mu_B$ and 17 $\\mu_B$, respectively. For all other sizes, $x=$ 3, 5-10, Mn$_x$As clusters show ferrimagnetic coupling. It is suggested that, if grown during the low temperature MBE, the giant magnetic moments due to ferromagnetic coupling in Mn$_2$As and Mn$_4$As clusters could play a role on the ferromagnetism and on the variation observed in the Curie temperature of Mn-doped III-V semiconductors.
The purpose of this work is the elucidation of the f"n electronic structure of neutral mono base adducts derived from tris(#eta#"5-cyclopentadienyl)-lanthanide(III) (Cp_2Ln). The available data on related compounds like bis adducts and anionic mono adducts of the same moiety was also analyzed. The first aim was to derive the experimental crystal field splitting pattern from optical, magnetooptical and magnetochemical measurements and to reproduce it using an empirical Hamiltonian operator. The eigenvalues and eigenvectors obtained in this manner were used for a quantitative interpretation of the magnetochemical, EPR- and NMR-spectroscopic properties. For the latter subject it was necessary to develop an own procedure for the NMR analysis of paramagnetic compounds. This method is based on factor analysis and as demonstrated in the second part of this work, is clearly superior to all previous procedures. (orig.).
Luminescent transition metal complexes are enjoying a growing interest because of their ubiquitous applications in, e.g., the fields of material science, sensors and (biomedical) diagnostics, and iridium(III) and ruthenium(II) complexes are among the best studied. Due to their long-living excited states, these complexes can have a strong interaction with dioxygen, resulting in luminescence quenching. This oxygen quenching might be regarded as an unwanted effect in luminescence imaging, but, on the other hand, it can be exploited for diagnostic and therapeutic applications as well. After a theoretical introduction concerning the dioxygen quenching mechanism and the parameters involved, in the second part of this review we focus on the possibility of tailoring this quenching by modifying sel...
An 80 keV, 3.6 MW neutral beam injection system has recently been installed on Doublet III, and the installation of a second system is scheduled within several months. Armor plate consisting of /approximately equals/100 graphite tiles (10 cm x 10 cm) coated with TiC has been plated over portions of the inner vacuum wall lying in the line of sight of the ion sources. In order to monitor the condition of the armor plate an infrared camera and a set of optical pyrometers have been installed alongside the beamline and view the armor plate through a CaF/sub 2/ window. The pyrometers measure the temperature of the armor plate associated with the maximum of the intensity distribution of each ion source.
Antibodies to human native and denatured types I, II, III, IV, and V collagens were measured using 125I-radioimmunoassay. Mean levels of binding by sera from 30 rheumatoid arthritis patients were significantly higher than those from 20 normal subjects against all of the collagens tested. The relative antibody concentration was higher in synovial fluid than in simultaneously obtained serum. Many patients with gout or various other rheumatic diseases also had detectable anticollagen antibodies. With a few notable exceptions, the majority of the reactivity detected in all patient groups was directed against covalent structural determinants present on all of the denatured collagens, suggesting a secondary reaction to tissue injury.
New Schiff base chelating ligands were synthesized by reacting equimolar quantities of 2,3-dimethyl-4-formyl-1-phenyl-3-pyrazoline-5-one and o-anisidine, p-anisidine, m-anisidine, o-toluidine, p-toluidine, m-toluidine, 2,6-xylidine or 2,4-xylidine in ethanol medium. Their subsequent reaction with gadolinium (III) nitrate hexahydrate in 2:1 molar ratio gave complexes that were characterized by elemental analyses, molar conductances, magnetic measurements, electronic and I.R. spectral studies. All the chelates were found to be non-electrolytic in nature. (author). 15 refs., 1 fig., 1 tab.
The present work focuses on investigations of a highly selective ligand for Am(III)/Ln(III) separation: bis-triazinyl-pyridine (BTP). By means of nano-electro-spray mass spectrometry, complex formation of BTP with selected elements of the lanthanide series is investigated. We show that the diluent drastically influences complex speciation. Measurements obtained in the extraction-relevant diluent 1-octanol show the occurrence of Ln(BTP){sub i} (i 1-3) species in different relative abundances, depending on the lanthanide used. Here, the relative abundances of the Ln(BTP){sub 3} complexes correlate with the distribution ratios for extraction to the organic phase of the respective lanthanide. (authors)
The intensity of superstructure reflections and associated diffuse scattering from In_0_._5Ga_0_._5P and In_0_._5Al_0_._5P epitaxic layers grown on (001) GaAs substrates was mapped in reciprocal space. The Warren-Cowley short-range-order parameters were obtained through the usual process for evaluating Fourier coefficients. Varying values for the correlation length in different directions indicate how group III atoms stack up in ordered states. The resultant structure with long-range order confirms the hypothesis made on the basis of electron diffraction and high-resolution transmission electron microscopy studies. (orig.).
We evaluated the relation between the lipiodol accumulative pattern on CT 1 month after 1st Lp-TAE and the effect of Lp-TAE and recurrence of hepatocellular carcinoma (HCC) in 70 cases undergoing Lp-TAE twice. The lipiodol accumulative pattern on CT can be classified into four types (I: homogeneous, II: defect, III: inhomogeneous, IV: no or slight). In the type I, recurrence of the main tumor was 26.7%, daughter was 73.7%, suggesting a good effect of Lp-TAE. In the types II, III and IV, recurrence of the main tumor was seen in 66.7%, 83.3% and 83.3%, respectively, suggesting that the effect of Lp-TAE was worse according to the lipiodol accumulative pattern on CT. The lipiodol accumulative pattern on CT is useful for the detection of recurrence and assessment of the effect of Lp-TAE. (author).
Phage display is effective in screening peptides that mimic venom's neutralizing epitopes. A phage display cyclized heptapeptide library (C7C library) was panned with purified divalent antivenin IgG, which neutralizes Naja naja atra venom (NAV) and Bungarus multicinctus venom (BMV). The selected heptapeptide sequences were aligned with known protein sequences of NAV and BMV in GenBank. One of the four consensus sequences, L/PKSSLL, mimicked the crucial epitope on Loop III of Taiwan cobra cardiotoxin that is associated with the venom's lethal potency. In dot blot analysis, several clones showed varying reactivities for NAV monovalent antivenin and lesser cross-reactions with BMV monovalent antivenin. The KSSLLRN-carrying phage occurred four times in selected clones and showed the strongest ...
2,6-Diacetyl pyridine based ligand was synthesized by the reaction of 2,6-diacetyl pyridine with thiocarbohydrazide in presence of acetic acid. The coordination compounds with Cr(III) and Ni(II) metal ions having [Cr(L)X]X2 and [Ni(L)X]X compositions (where L=ligand and X=NO3^-, Cl^- and CH3COO^-) were synthesized and characterized by physicochemical and spectral studies. The studies like elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, UV-Vis, NMR, mass and EPR reveal that the complexes are octahedral. The compounds were examined against the pathogenic fungal and bacterial strains like Alternaria brassicae, Aspergillus niger, Fusarium oxysporum, Xanthomonas compestris and Pseudomonas aeruginosa. A. niger causes the diseases Apergillosis and Oto...
The synapsin III gene, SYN3, which belongs to the family of synaptic vesicle-associated proteins, has been implicated in the modulation of neurotransmitter release and in synaptogenesis, suggesting a potential role in several neuropsychiatric diseases. The human SYN3 gene is located on chromosome 22q12-13, a candidate region implicated in previous linkage studies of schizophrenia. However, association studies of SYN3 and schizophrenia have produced inconsistent results. In this study, four SYN3 SNPs (rs133945 (-631 C>G), rs133946 (-196 G>A), rs9862 and rs1056484) were tested in three sets of totally 3759 samples that comprise 655 affected subjects and 626 controls in the Irish Case-Control Study of Schizophrenia (ICCSS), 1350 samples incorporating 273 pedigrees in the Irish Study of High D...
In this review, we demonstrate the developmental appearance, structural features, and reorganization of transient cerebral zones and structures in the human fetal brain using a correlative histological and MRI analysis. The analysis of postmortem aldehyde-fixed specimens (age range: 10 postovulatory weeks to term) revealed that, at 10 postovulatory weeks, the cerebral wall already has a trilaminar appearance and consists of: (1) a ventricular zone of high cell-packing density; (2) an intermediate zone; (3) the cortical plate (in a stage of primary consolidation) with high MRI signal intensity. The anlage of the hippocampus is present as a prominent bulging in the thin limbic telencephalon. The early fetal telencephalon impar also contains the first commissural fibers and fornix bundles in the septal area. The ganglionic eminence is clearly visible as an expanded continuation of the proliferative ventricular zone. The basal ganglia showed an initial aggregation of ...
The objective of this work is to improve the process for CO{sub 2} capture by alkanolamine absorption/stripping by developing an alternative solvent, aqueous K{sub 2}CO3 promoted by piperazine (PZ). Pilot plant testing was performed in a 16.8-inch ID absorber and stripper with recirculation of air and CO{sub 2}. Three solvents (7 m MEA, 5 m K{sup +}/2.5 m PZ, and 6.4 m K{sup +}/1.6 m PZ) were tested in four campaigns with three different absorber packings. Pilot plant testing established that 5 m K{sup +}/2.5 m PZ requires two times less packing than 7 m MEA and three times less packing than 6.4 m K{sup +}/1.6 m PZ. A rigorous model of the thermodynamics and mass transfer was developed in the RateSep{trademark} block of AspenPlus{reg_sign}. The double matrix stripper reduces energy consumption by 5 to 15%. The best K{sup +}/PZ solvent, 4 m K{sup +}/4 m PZ, and the best process configuration, double matrix stripper with a ...
The Authenticated Tracking and Monitoring System (ATMS) has been designed to address the need for global monitoring of the status and location of proliferation-sensitive items. Conceived to utilize the proposed Global Verification and Location System (GVLS) satellite link, ATMS could use the existing International Maritime Satellite commercial communication system until GVLS is operational. The ATMS concept uses sensor packs to monitor items and environmental conditions, collects a variety of events data through a sensor processing unit, and transmits the data to a satellite, which then sends data to ground stations. Authentication and encryption algorithms will be used to secure the data. A typical ATMS application would be to track and monitor the safety and security of a number of items in transit along a scheduled shipping route. This paper also discusses a possible proof-of-concept system demonstration.
In this work, a mixed cationic--anionic [i.e. cetyltrimethylammonium bromide-sodium octyl sulphate] surfactant system was used to synthesize the magnetite particles. The loading content of iron ions (Fe{sup 3+} and Fe{sup 2+}) into the surfactant system was varied to study its effect on the formation of magnetite, magnetic and morphological properties of the magnetite particles encapsulated by the surfactant vesicles. It has been verified that the vesicle-encapsulated magnetite particles with sizes from 100 to 200 nm were formed, which were almost independent of the loading content of iron ions. However, the morphological structure of the magnetite particles was dependent on the loading content of iron ions and there existed an optimal loading content for a full packing of the surfactant vesicles with the magnetite particles.
In this work, a mixed cationic--anionic [i.e. cetyltrimethylammonium bromide-sodium octyl sulphate] surfactant system was used to synthesize the magnetite particles. The loading content of iron ions (Fe"3"+ and Fe"2"+) into the surfactant system was varied to study its effect on the formation of magnetite, magnetic and morphological properties of the magnetite particles encapsulated by the surfactant vesicles. It has been verified that the vesicle-encapsulated magnetite particles with sizes from 100 to 200 nm were formed, which were almost independent of the loading content of iron ions. However, the morphological structure of the magnetite particles was dependent on the loading content of iron ions and there existed an optimal loading content for a full packing of the surfactant vesicles with the magnetite particles.
Medicinal plants i.e. dried seeds of myristica argentea, myristica fragrans, coriandrum sativum and foeniculum vulgare were stored for 0 and 6 months, with and without gamma irradiation at 5 kGy. No detectable changes were seen in infrared and UV spectra, GLC chromatograms and refraction indices of steam distilled, essential oils from the irradiated medicinal plants. The same results were also obtained from irradiated samples stored for 6 months at ambient conditions. Storage for 6 months caused significant changes in the gas liquid chromatograms and UV spectra of all samples compared to non-stored samples. The moisture content of all samples packed in polyethylene bags seems to be constant after 6 months of storage. No measurable changes were found in the amount of essential oil content caused by irradiation.
Summary 1. In the Greater Yellowstone Ecosystem, bison Bison bison and elk Cervus canadensis nelsoni act as hosts for Brucella abortus. The presence of B. abortus within wildlife populations is an important conservation issue because of the risk of brucellosis transmission from wildlife to cattle. 2. We investigated conditions facilitating contact between bison (40-60% seroprevalence) and elk on a shared winter range in the Madison headwaters area of Yellowstone National Park. We evaluated the effects of snow pack, season, elk and bison population sizes, and wolf Canis lupus predation risk on the degree of spatial overlap between bison and elk from 1991 to 2006. 3. Sixty-eight per cent of 10 093 independent elk observations occurred within the known bison wintering range, 29% occurred with...
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As thin films become increasingly popular (for solar cells, LEDs, microelectronics, batteries), quantitative morphological information is needed to predict and optimize the film's electronic, optical and mechanical properties. This quantification can be obtained quickly and easily with X-ray diffraction using an area detector and synchrotron radiation in two simple geometries. In this paper, we describe a methodology for constructing complete pole figures for thin films with fiber texture (isotropic in-plane orientation). We demonstrate this technique on semicrystalline polymer films, self-assembled nanoparticle semiconductor films, and randomly-packed metallic nanoparticle films. This method can be immediately implemented to help understand the relationship between film processing and microstructure, enabling the development of better and less expensive electronic and optoelectronic devices.
Improved radionuclide generator include a substantially insoluble salt of a radioactive parent which may be directly packed in column for subsequent elution of the daughter radionuclide. An improved 188Re generator was prepared by reacting a radioactive tungsten (188W) as parent radionuclide incorporated with aluminum chloride to obtain an insoluble radioactive aluminum tungstate matrix. The investigated matrix was characterized on the basis of the chemical composition, IR, thermal analysis and mechanical stabilities. The factors affecting the elution performance were studied such as influence of pH, molar ratio and drying temperature. From the obtained data, the molar ratio W:Al was 1.5:1 at pH?=?4, the matrix dried at 105??C for 2 h. Chromatographic and multichannel analysis has been cur...
A detergent-containing radioactive liquid waste originating from atomic power plants is concentrated to have about 10 wt. % detergent concentration, then dried in a thin film evaporator, and converted into powder. Powdered activated carbon is added to the radioactive waste in advance to prevent the liquid waste from foaming in the evaporator by the action of surface active agents contained in the detergent. The activated carbon is added in accordance with the COD concentration of the radioactive liquid waste to be treated, and usually at a concentration 2-4 times as large as the COD concentration of the liquid waste to be treated. A powdery product having a moisture content of not more than 15 wt. % is obtained from the evaporator, and pelletized and then packed into drums to be stored for a predetermined period.
A detergent-containing radioactive liquid waste originating from atomic power plants is concentrated to have about 10 wt. % detergent concentration, then dried in a thin film evaporator, and converted into powder. Powdered activated carbon is added to the radioactive waste in advance to prevent the liquid waste from foaming in the evaporator by the action of surface active agents contained in the detergent. The activated carbon is added in accordance with the COD concentration of the radioactive liquid waste to be treated, and usually at a concentration 2-4 times as large as the COD concentration of the liquid waste to be treated. A powdery product having a moisture content of not more than 15 wt. % is obtained from the evaporator, and pelletized and then packed into drums to be stored for a predetermined period.
The relaxations of the Ti(0001) and Zr(0001) surfaces are studied using the plane-wave-basis pseudopotential method within the local-density approximation. We find that the first interlayer spacings of Ti(0001) and Zr(0001) are contracted with respect to the bulk spacings by 6.8% and 6.1%, respectively. Such large relaxations for the close-packed surfaces of Ti and Zr are in good agreement with recent linear-augmented-plane-wave calculations. In addition, we predict a weak vibrational effect on the surface relaxation of Zr(0001) by considering the free energy in the quasiharmonic approximation. This result can be attributed to a very strong bonding between the first- and second-layer Zr atoms as a consequence of the bond-order endash bond-length correlation. copyright 1997 The American Physical Society.
Photodestruction has received much attention in recent years. In particular, titanium dioxide (TiO{sub 2}) and ozonolysis have attained a position of prominence. These technologies hold promise for the destruction of trace amounts of aqueous high explosives that are generated by load and pack operations, as well as demilitarization activities. Currently this water is treated by passing through a bed of activated carbon. The carbon is then steam regenerated and reused, thus creating a second waste stream which must be disposed of, or the carbon is burned directly. Recent trends in environmental regulation have shown that this may not be a viable option for process water remediation in the future. This talk will discuss efforts to employ alternate aqueous treatment techniques that not only remove the explosives compounds but are able to transform the parent compound into carbon dioxide and water. Titanium dioxide photocatalysis as well as UV-ozone photolysis will be ...
The development of central receiver technology for the production of electricity is reasonably well established. One possible direction for future research and development efforts funded by the Department of Energy is high-temperature, high-performance systems. In this paper, the performance of central receiver systems is investigated for a range of heliostat sizes, field configurations, plant sizes, and receiver temperatures. The maximum plant efficiency achievable in a central receiver system that uses simple cavity geometry is shown for a range of receiver temperatures. The impact of changes in heliostat size, field packing density, and canting and focusing strategies on system efficiency are investigated over a range of plant sizes. The results of the study underscore the importance of accommodating high absorber plane fluxes in order to efficiently produce working temperatures at or above 1200/sup 0/C.
A dense Pd-Ag membrane reactor (MR) with 100% hydrogen selectivity packed with either Rh/La2O3 or Rh/La2O3-SiO2 as catalysts was used to carry out the dry reforming of methane. The membrane reactor simulation was performed using a well-known reactor model. For this purpose, we employed the equations derived from complete kinetic studies of the dry reforming of methane reaction in connection with both catalysts. In addition, we developed the kinetic equation for the reverse water gas shift reaction (RWGS). The combination of detailed kinetic studies with the measured permeation flux for the Pd-Ag membrane allowed a complete comparison between experimental and simulated operation variables. The variables studied for both catalysts were methane conversion and hydrogen permeation as a function...
Application of an optimization technique to extract the non-ideal parameters of gas absorption with chemical reactions process was described. The gas absorption was modeled using mass transfer theory to represent the realistic behaviors of an absorber. The model was a highly non-linear iterative model which correlated the overall rate of absorption as the function of unknown non-ideal parameters, including the physical liquid mass transfer coefficient and the wetted interfacial area of of packings. The optimization program was developed to minimize the sum of squares of relative errors between the model predictions and the experimental data. Four sets of experimental data (case studies) with different operating conditions were used for extracting parameters. Comparisons between predicted and experimental measured overall absorption rate were in good agreement, average absolute value of relative errors not exceeding 5.4 %. 18 refs., 3 tabs., 4 figs.
In 1934, Reinhardt asked for the centrally symmetric convex domain in the plane whose best lattice packing has the lowest density. He conjectured that the unique solution up to an affine transformation is the smoothed octagon (an octagon rounded at corners by arcs of hyperbolas). This article offers a detailed strategy of proof. In particular, we show that the problem is an instance of the classical problem of Bolza in the calculus of variations. A minimizing solution is known to exist. The boundary of every minimizer is a differentiable curve with Lipschitz continuous derivative. If a minimizer is piecewise analytic, then it is a smoothed polygon (a polygon rounded at corners by arcs of hyperbolas). To complete the proof of the Reinhardt conjecture, the assumption of piecewise analyticity must be removed, and the conclusion of smoothed polygon must be strengthened to smoothed octagon.
A mathematical model of multichannel radiometric inspection system was developed, in which the measurement results are reproduced in the form of a half-tone image equivalent to the radiation image of the irradiated object. The model makes the following assumptions: the beam of radiation is fan-shaped; the object of inspection is scanned discretely; the focal spot of the source is rectangular; the apertures of the detector are round, and the detectors themselves are equidistant from the sources, aimed at it, and form a close-packed array; the signals from the detectors are processed according to a time scheme; and the measurement results are corrected in a computer for normalizing the gains of the channels of the system. The mathematical model can serve as the basis for developing a method of calculating the optimal parameters of a multichannel radiometric system with visualization of the radiation images. 14 refs., 2 figs.
On efficient glass capillary columns packed with graphitized thermal carbon black (GTCB) the stereoisomers of aromatic and saturated tricyclic hydrocarbons are completely separated and identified. The Henry's adsorption constants of the individual isomers were determined from mixture at different temperatures. Five isomers of perhydroanthracene, five isomers of perhydrofluorene, two isomers of perhydrophenalene, four isomers of perhydroacenaphthene, as well as phenalene, dihydrophenalene, acenaphthene and acenaphthylene were investigated. The increase of the hydrogenization degree of unsaturated tricyclic hydrocarbons reduces the retention. Among the saturated tricyclic isomers the retention becomes shorter with the larger bending of the molecules, i.e. from the molecule having more equatorial bonds to the molecules having more axial connections. The experimentally determined Henry's constants were qualitatively compared with the structure of the ...
The microstructure and tensile properties of Ti-44Al-6V-3Nb-0.3Y (at.%) alloy after canned forging were investigated. SEM results showed that the TiAl pancake exhibits inhomogeneous microstructure, which can be ascribed to the temperature drop and friction between billet and outer pack during forging, as well as the intrinsic anisotropy of lamellar colony. By means of TEM observation and EBSD analysis, the microstructure in the dominant area of the pancake was further characterized. This deformation area consists of 87.7% content of g grains plus some refined lamellar colonies and the rest of B2 grains. The grain size ranges between 1mm and 8.5mm. High-angle boundaries dominate the deformation microstructure, several substructures and twins are observed as well. Additionally, current forge...
The separation and the mechanism of retention of ion associates of #alpha#-isomers of molybdic and tungstic heteropoly acids (HPA) of phosphorus(5), silicon(4), and germanium(4) with trioctylamine (TOA) on a column (80x3 mm) packed with Diasorb-130-CN (8 #mu#m) were studied in a flow of chloroform-tetrahydrofuran (THF) and chloroform-n-butanol-TOA mixtures with spectrophotometric detection at 320 nm. It is demonstrated that the adsorption of all the studied ion associates proceeds through the displacement THF molecule from the surface of the stationary phase and without the displacement of TOA molecules. Conditions for the separation of phospho- and silicomolybdic HPA and also phospho- and germanolybdic HPA were found. The chromatographic system using silica gel modified with nitrile groups as the stationary phase is of higher selective than that using ummodified silica gel.
Large-scale three dimensional molecular dynamics simulations of hopper flow are presented. The flow rate of the system is controlled by the width of the aperture at the bottom. As the steady-state flow rate is reduced, the force distribution P(f) changes only slightly, while there is a large change in the impulse distribution P(i). In both cases, the distributions show an increase in small forces or impulses as the systems approach jamming, the opposite of that seen in previous Lennard-Jones simulations. This occurs dynamically as well for a hopper that transitions from a flowing to a jammed state over time. The final jammed P(f) is quite distinct from a poured packing P(f) in the same geometry. The change in P(i) is a much stronger indicator of the approach to jamming. The formation of a peak or plateau in P(f) at the average force is not a general feature of the approach to jamming.
The losses of Hg from phenol formaldehyde resin - bound standards and hair samples in neutron activation analysis in case of their irradiation in the water filled nuclear reactor channel is studied. The mean losses of Hg during 20-30 hrs irradiation at (2-3)x10"1"8 n/cm"2 are 15-20% with their stopping at double Al-covers. The mean losses of Hg from standards at 200, 250 and 300 deg C are 30, 61 and 86% respectively and do not occur at 150 deg C after their 5 hour heating. The losses of Hg from hair samples packed in polyethylene tubes through the package walls in experimental conditions are not observed.
Soybean is one of the most economical and nutritious food packed with basic nutrients that combat diseases stemming from mal- and under-nutrition. Despite its rich nutritional profile, use of soybean in food has been limited because soybean proteins are often associated with compounds, which could exert a negative impact on the nutritional quality of the protein. Trypsin inhibitor (TI) is one of the important anti-nutritional factors that exert negative effect by causing growth inhibition. Soybean cultivar VLS-2 was irradiated with 250 Gy gamma rays in a gamma cell (200) with 60Co source installed at BARC to induce mutations for low trypsin inhibitor content. Three mutants with lower levels of TI content were identified and can be utilized for developing elite varieties of soybean. (author)
A qualitative method, involving supported liquid?liquid extraction (SLE) and ultra high pressure liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS?MS), was developed for the rapid tentative identification of various drugs of abuse in urine. In this study, 28 drugs and metabolites were covered by the screening procedure. Before analysis, urine samples were extracted by SLE and good extraction recoveries were obtained for most investigated compounds. The UHPLC strategy was then selected for the rapid separation of amphetamines, cocaine, opiates and related compounds in urine. Using columns packed with sub-2??m particles, analysis time was reduced down to 2?min, while maintaining acceptable performance. Finally, the detection was by tandem MS operating in the single reaction...
Presented in this report are the quantitative and qualitative aspects of the more than 5,800 applications of Grafoil on-plant. The subject all-graphite product was originally made by the Union Carbide Corporation. Its utilization in the forms of valve packing, gasketing and sealant tapes for leak repair and prevention on-plant since March 1970 is marked with typical zero-leak results. For all practical purposes, the successful results with Grafoil implementation indicate an unqualified control of leakage problems that began in 1967 with the V-11 and V-12 valves in the primary system of N Reactor. Meaningfully, the accruals of savings with existing and future applications shall continue to be incalculable in personnel exposure, maintenance, and capital. Inherent in the savings are the devised methodology and innovative developments coordinately employed in resolving the leak repair problems.
The possibility of employing a number of adsorbents (polyphenylquinoxaline, Tenax GC, Carbopak C, graphitized thermal carbon black, silica gels modified with pyrocarbon or hexamethyldisilazane) for the trapping of organic traces from air has been investigated. Adsorption capacities of these adsorbents with respect to a number of volatiles released from certain plastics used as building material (polyvinylchloride, Relin, Acronal, etc.) have been measured. A number of the volatiles were identified by gas chromatography - mass-spectrometry after trapping on the adsorbents investigated. Chromatographic separation after trapping on the adsorbents was carried out on wall-coated open-tubular capillary columns as well as in capillary columns packed with graphitized thermal carbon black.
We demonstrate experimentally that the route to a jammed state for a set of bi-dispersed frictional disks, subjected to uni-axial compression from a random initial unjammed state, consists of a consolidation state, a fragile jammed state, and finally a rigid jammed state. In the consolidation regime, the pressure on the sides increases very slowly with the packing fraction {phi} and there are no detectable stress chains. In the fragile jammed state, stress chains are visible, the pressure increases exponentially with {phi}, and the fraction of moving disks drops exponentially. Eventually, a final regime where particle displacements are below our resolution and the pressure varies approximately linearly with {phi} is reached. We argue that this scenario is generic for ather mal frictional compressed particles.
Molecular dynamics simulations have been carried out of the radial distribution function of the hard sphere fluid for a range of densities in the equilibrium fluid and just into the metastable region. The first derivative of the hard-sphere radial distribution function at contact was computed and its density dependence fitted to a simple analytic form. Comparisons were made with semi-empirical formulae from the literature, and of these the formula proposed by Tao et al (1992 Phys. Rev. A 46 8007) was found to be in best agreement with the simulation data, although it slightly underestimates the derivative at the higher packing fractions in excess of about 0.45. Close to contact, within a few per cent of the particle diameter, the radial distribution function can be represented well by a second order polynomial. An exponential function, which has some useful analytic features, can also be applied in this region.
Abstract A series of studies performed at our center demonstrates that gaseous microemboli (GME) remain a challenge in cardiac surgical procedures. Evaluation of novel oxygenators must address hemodynamic parameters and microemboli capture capability. The objective of this study is to compare two neonatal membrane oxygenators, the Quadrox i (MAQUET Cardiopulmonary AG, Hirrlingen, Germany) and the Capiox RX05 (Terumo Corporation, Tokyo, Japan), with respect to GME capture and hemodynamic energy delivery. The experimental circuit included a Maquet HL 20 heart lung machine, a Heater Cooler Unit HCU 30 (MAQUET Cardiopulmonary AG), a membrane oxygenator (Quadrox i Neonatal or Capiox RX05), and inch tubing from the COBE Heart/Lung Perfusion Pack (COBE Cardiovascular, Inc., Arvada, CO, USA). A Ca...
We investigate the limiting behavior of random tree growth in preferential attachment models. The tree stems from a root, and we add vertices to the system one-by-one at random, according to a rule which depends on the degree distribution of the already existing tree. The so-called weight function, in terms of which the rule of attachment is formulated, is such that each vertex in the tree can have at most K children. We define the concept of a certain random measure mu on the leaves of the limiting tree, which captures a global property of the tree growth in a natural way. We prove that the Hausdorff and the packing dimension of this limiting measure is equal and constant with probability one. Moreover, the local dimension of mu equals the Hausdorff dimension at mu-almost every point. We give an explicit formula for the dimension, given the rule of attachment.
This paper is concerned with the study of the Electrorheological RayleighTaylor instability (ERTI) at the interface between a densely packed saturated poorly conducting couple stress porous layer accelerated by a lighter poorly conducting couple stress fluid in a thin shell in the presence of a transverse electric field and laser radiation. A simple theory based on fully developed flow approximations is used to derive the dispersion relation for the growth rate of ERTI. The cutoff and the maximum wave numbers and the corresponding maximum frequencies are obtained. It is shown that the effects of couple stress parameter and the electric field reduce the growth rate considerably compared to a non-conducting fluid in the absence of an electric field. These are favorable to control the surface...
A systematic study of the effects of environmental factors on nylon 66 and Kevlar 29 strength degradation in parachute components is being conducted at Sandia National Laboratories. It includes: (1) accelerated aging studies in air, inert environments, humidity, ozone, and smog; (2) a 25-year surveillance program of parachutes in a variety of natural climatic environments; (3) moisture absorption as a function of humidity; (4) effects of surface coatings normally applied to parachutes; and (5) development of nondestructive evaluation techniques which can be used to map mechanical properties over the entire parachute surface. The accelerated aging and moisture absorption studies show that air, humidity, and smog contribute to degradation. Chemiluminescence, gas chromatographic pyrograms, and uv spectroscopy show promise as nondestructive evaluation techniques.
A study was undertaken to assess the effect of different storage temperatures on senescence and postharvest performance of isolated flowers of Ranunculus asiaticus L.. The main aim of the work was to develop a cost-effective storage protocol to reduce the postharvest losses and to bring out the transportation of cut flowers of R. Asiaticus. The flowers were subjected to two different storage treatments, dry storage and wet storage, and their postharvest performance was compared under laboratory conditions. For this purpose, the buds were harvested at 8:00 AM at loose bud stage (Stage II of flower development). The harvested buds were cut to a uniform size of 15 cm and processed for dry or wet storage. For dry storage, the buds were packed after wrapping them in moistened filter papers and ...
Tricking filters are a very promising alternative for the post treatment of effluents from UASB reactors treating domestic sewage,especially in developing countries. Although a fair amount of information is already available regarding organic mater removal in this combined system, very little is known in relation to nitrogen and surfactant removal in trickling filters post-UASB reactors. Therefore, the purpose of this study was to evaluate and compare the effect evaluate and compare the effect of different application rates and packing media types on trickling filters applied to the post-treatment of effluents from UASB reactors, regarding the removal of ammonia nitrogen and surfactants. (Author)
The phase transformations and properties of a precipitation-hardened Ni-Cr-based alloy are investigated as a function of C, B, Nb, and Cr contents. It is found that the primary role of Nb consists in the formation of an independent phase, delta-Ni3Nb, a part of a gamma/gamma-prime-delta eutectoid (for high C and B concentrations) and in stimulating the gamma-sigma reaction consecutively with the gamma double prime-delta reaction (for low C and B concentrations). In both cases, the long-term strength characteristics of the Nb-alloyed system are relatively low. The substitution of boron for carbon contributes to a reduction in the number of nucleation sites for topologically close-packed phases and to the formation of more stable (with respect to excess compounds) M3B2 and MB2 borides. The high-boron material exhibits better properties and phase stability under mechanical and thermal loading. 13 references.
In this work AISI 1045 steel were duplex treated via plasma nitriding of chromized layer. Samples were pack chromized by using a powder mixture consisting of ferrochromium, ammonium chloride and alumina at 1273K for 5h. The samples were then plasma-nitrided for 5h at 803K and 823K, in a gas mixture of 75%N2+25%H2. The treated specimens were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis and Vickers micro-hardness test. The thickness of chromized layer before nitriding was about 8mm and it was increased after plasma nitriding. According to XRD analysis, the chromized layer was composed of chromium and iron carbides. Plasma nitriding of chromized layer resulted in the formation of chromium and iron nitrides and carbides. The hardness of the duplex layer...
Injections of fuel-grade ethanol (95% v/v ethanol, 5% v/v hydrocarbon mixture as a denaturant) near the water table were conducted in two-dimensional physical models tightly packed with fine sands under varying water-table conditions. As the fuel migrated in the porous media following injection, the denaturant phase separated leaving a residual Light Non-Aqueous Phase Liquid (LNAPL) phase that occupied a region with a volume similar to that of an equal-sized spill of 100% LNAPL without ethanol. When the water table was raised, as may be expected following a catastrophic release that reaches groundwater, most of the ethanol-fuel mixture was mobilized and the vertical distribution of the generated LNAPL was increased. The lower boundary of the residual LNAPL was established during the initia...
A parachute system was designed and prototypes built to deploy a telemetry package behind an earth-penetrating weapon just before impact. The parachute was designed to slow the 10 lb. telemetry package and wire connecting it to the penetrator to 50 fps before impact occurred. The parachute system was designed to utilize a 1.3-ft-dia cross pilot parachute and a 10.8-ft-dia main parachute. A computer code normally used to model the deployment of suspension lines from a packed parachute system was modified to model the deployment of wire from the weapon forebody. Results of the design calculations are presented. Two flight tests of the WBS were conducted, but initiation of parachute deployment did not occur in either of the tests due to difficulties with other components. Thus, the trajectory calculations could not be verified with data. Draft drawings of the major components of the parachute system are presented.
In the new system presented in this paper, the cement clinker is sintered, not in a rotary kiln, but in two different furnaces: a spouted bed kiln and a fluidized bed kiln. The heat generated in the process of cooling the cement clinker is recovered by a fluidized bed cooler and a packed bed cooler, which are more efficient than the conventional coolers. Compared with the rotary kiln system, the new technology significantly reduces NO{sub x} emissions, appreciably cuts energy consumption, and reduces CO{sub 2} emissions as well. Thus, the new system is an efficient cement sintering system that is friendly to the global environment. In this paper, we describe this new technology as one of the applied technologies at an industrial level that is being developed in the Clean Coal Technology Project, and we present the results from test operations at our pilot plant.
A distillation column with an adjustable slope horizontal rectification section was constructed. A rotating screw brush was inserted into the section, which could be rotated from 0 to 600 rpm with an external motor. Distillation experiments were carried out using the system cyclohexane-heptane at total reflux at slopes of 0(horizontal), 5 and 10 degrees. Separation efficiency for the horizontal column was the highest of the three orientations, and was obtained as HETP from 0.04 to 0.16 m at F-factor of 0.05 to 0.4 m/s(kg/m{sup 3}){sup 1/2} in the range of 100 to 600 rpm. The HETP for each slope was roughly constant at a rotation speed of more than 300 rpm. The values of the pressure drop were found to be equivalent to those of one seventh to one fifth of conventional packed columns. (author)
This paper presents a general high level estimation model of communication throughput for the implementation of a given communication protocol. The model, which is part of a larger model that includes component price, software driver object code size and hardware driver area, is intended to be general enough to be able to capture the characteristics of a wide range of communication protocols and yet to be sufficiently detailed as to allow the designer or design tool to efficiently explore tradeoffs between throughput, bus widths, burst/non-burst transfers and data packing strategies. Thus it provides a basis for decision making with respect to communication protocols/components and communication driver design in the initial design space exploration phase of a co-synthesis process where a large number of possibilities must be examined and where fast estimators are therefore necessary. The fill model allows for additional (money) cost, software code size and hardware ...
Recently, foods are often exposed to radiation under packed states with various wrapping materials. In this study, the effects of #gamma#-ray radiation were investigated on the additives in wrapping materials on the market. 10 - 50 kGy #gamma# radiation was irradiated to samples under sealed condition in a glass-ware. Polyethylene bag and wrapping film, polypropylene wrapping film, cup and sheet, and polystyrene cup were used as samples. And the additives in these materials were analyzed by GC/MS to evaluate the radiation effects on them. The irradiation was found to induce rapid degradation of antioxidants, especially, Irgafos 168. Some fatty acid amides used as a lubricant and a plasticizer, DBP were also reduced, but not aliphatic hydrocarbons. However, all polystyrene products used in this study included no additives. The contents of styrene dimer and trimer in those wrapping materials were not changed by #gamma#-irradiation. (M.N.)
This paper describes the development and testing of a system to provide isolated power to the cathode-subsystem electronics of an x-ray tube. These components are located at the cathode potential of several hundred kilovolts, requiring a supply of power isolated from this high voltage. In this design a fiber-optically connected photonic power system (PPS) is used to recharge a lithium-ion battery pack, which will subsequently supply power to the cathode-subsystem electronics. The suitability of the commercially available JDSU PPS for this application is evaluated. The output of the ppe converter is characterized. The technical aspects of its use for charging a variety of Li-Ion batteries are discussed. Battery charge protection requirements and safety concerns are also addressed.
The effect of air addition on biomass tar conversion in catalytic packed bed crackers was studied using both an isothermal micro reactor and a fluidised bed bench scale biomass gasification set up with down stream tar crackers. The micro reactor was applied for experiments with artificial biomass producer gas containing naphthalene as a model tar compound. Experiments were carried out with inert silica and catalytically active calcined dolomite bed material both with and without air addition. Experimental results with real tar from the fluidised bed bench scale gasification set up were in qualitative agreement with results from the micro reactor experiments. (author)
The total amount of uranium dissolved in seawater at a uniform concentration of 3 mg U/m{sup 3} in the world's oceans is 4.5 billion tons. An adsorption method using polymeric adsorbents capable of specifically recovering uranium from seawater is reported to be economically feasible. A uranium-specific nonwoven fabric was used as the adsorbent packed in an adsorption cage 16 m{sup 2} in cross-sectional area and 16 cm in height. We submerged three adsorption cages in the Pacific Ocean at a depth of 20 m at 7 km offshore of Japan. The three adsorption cages consisted of stacks of 52 000 sheets of the uranium-specific non-woven fabric with a total mass of 350 kg. The total amount of uranium recovered by the nonwoven fabric was >1 kg in terms of yellow cake during a total submersion time of 240 days in the ocean.
The total amount of uranium dissolved in seawater at a uniform concentration of 3 mg U/m3 in the world's oceans is 4.5 billion tons. An adsorption method using polymeric adsorbents capable of specifically recovering uranium from seawater is reported to be economically feasible. A uranium-specific nonwoven fabric was used as the adsorbent packed in an adsorption cage 16 m2 in cross-sectional area and 16 cm in height. We submerged three adsorption cages in the Pacific Ocean at a depth of 20 m at 7 km offshore of Japan. The three adsorption cages consisted of stacks of 52 000 sheets of the uranium-specific non-woven fabric with a total mass of 350 kg. The total amount of uranium recovered by the nonwoven fabric was >1 kg in terms of yellow cake during a total submersion time of 240 days in the ocean.
This study investigated the optimum polyphenol extraction conditions for two Nigerian green leafy vegetables, Vernonia amygdalina (VA) and Gongronema latifolium (GL) that are widely used for food and medicinal purposes. Seven different solvents were used to extract the total phenolic contents of the leaves; 100% acetone, 80% acetone, 50% acetone, 100% ethanol, 70% ethanol, 100% methanol and 70% methanol and their total phenolic contents were determined. The results showed that the 80% acetone was significantly (p<0.05) the most effective for polyphenol extraction from the leaves and generally the acetone-containing solvents were more effective than alcohol-containing solvents. The 80% acetone extract was fractionated on a silicic acid-packed column to give two main fractions: acetone elute...
Novel and unprecedented ion exchange resin cleaning system, for use in BWR plants and featuring a vibration separator and basic design factors of Radiological Solutions, Inc., had been delivered to Tokai No. 2 Power Station, Japan Atomic Power Company, in October 2005. This compactly-designed system effectively separates crud and resin fines from ion exchange resins, with no clogging of separation screens. It generates minimized waste liquid and has a specially designed over-pack cleaning tank. The system has been in operation for about 2 years and half now and favorable operational data, such as crud and sulfate concentration decrease in feed water and reactor water respectively, and evaluation results have been reported from Japan Atomic Power Company and so on. (author)
In this study, sulfured orange peel (MOP) was used as adsorbent to investigate its adsorption behaviors of Pb^2^+ and Zn^2^+ from aqueous solutions. The effects of solution pH, adsorption time and metal ion concentration on adsorption were studied in batch experiments. Both adsorption kinetics of Pb^2^+ and Zn^2^+ proceeded rapidly and could be well described by pesudo-second-order equation. The maximum Langmuir adsorption capacities for Pb^2^+ and Zn^2^+ removal by MOP were evaluated as 164 and 80mg/g, respectively. A binary mixture of Pb^2^+ and Zn^2^+ was studied by using a packed column, suggesting that effective mutual separation and pre-concentration of Pb^2^+ away from Zn^2^+ using MOP could be satisfactory achieved. The results indicate that MOP could be employed as an effective lo...
Hydrogen molecule adsorption on the (0001) surface of double hexagonal closed packed americium has been studied in detail within the framework of density functional theory. Weak molecular hydrogen adsorptions were observed. The most stable configuration corresponded to a Hor2 approach molecular adsorption at the one-fold top site where the molecule's approach is perpendicular to a lattice vector. Adsorption energies and adsorption geometries for different adsorption sites will be discussed. The change in work functions, magnetic moments, partial charges inside muffin-tins, difference charge density distributions and density of states for the bare Am slab and the Am slab after adsorption of the hydrogen molecule will be discussed. Reaction barrier for the dissociation of hydrogen molecule will be presented. The implications of adsorption on Am 5f electron localization-delocalization will be summarized.
The authors describe a small doubly reflecting research furnace. Its optical components, a heliostat and a concentrating array of hexagonal-in-plan-form mirrors, focus sunlight at the aperture of a cavity receiver. A perfect paraboloid of revolution would have given higher concentration ratios. But large paraboloids are difficult to make and manipulate. Small hexagons are convenient and can be close packed. Spherical mirrors centered on a sphere simplified construction and were economical. In this note they use a simple model to describe the radial distribution of the normal flux at the focus of such an array. A schematic representation of a cross section of the concentrator mirror array in a plane which includes its axis is shown.
Highly water-repellent surfaces have been prepared from arrayed nanowires of zinc oxide (ZnO) by a treatment with stearic acid. The layers are electrochemically deposited on a nanocrystalline seed layer from an oxygenated aqueous zinc chloride solution. An advancing contact angle (CA) as high as 176{sup 0} is obtained with a very small hysteresis {approx}1{sup 0}. These results, supplemented by infrared spectroscopy, show that the stearic acid forms a very well-packed self-assembled monolayer. The CA measurements show a very good stability of the treated surface even when exposed to harsh conditions or long-term ambient illumination.
A characteristic of filled elastomers is their ability to undergo very large deformations without damaging their internal structure. The material behaviour is mainly elastic, however, elastomers show hysteresis effects leading to damping properties, which are quite important as regards their applications in various fields of mechanical engineering.A series of experiments (tension, torsion and combinations of both) was carried out on cylindrical bars made of a carbon-black filled rubber mixture. In addition to a pronounced nonlinear rate-dependence, relaxation and viscosity properties are observed as being influenced by the process histories.The behaviour of elastomeric materials is modelled on the basis of a free energy function and evolution equations for additional internal variables. Incorporating or disregarding the very small rate-independent hysteresis, the constitutive modelling may be classified under viscoplasticity or viscoelasticity. The constitutive ...
Ammonia borane (AB) and sodium borohydride (SBH) are candidate materials for on-board hydrogen storage that can be dehydrogenated upon demand. The rheological properties of the dehydrogenated by-products are important to quantify their removal and transportability from the hydrogen storage system. This paper presents visco-elastic property (elastic stiffness and viscous damping) measurements of the spent fuels obtained from AB hydrolysis, hydrothermolysis and thermolysis; and SBH hydrolysis. Smaller stiffness and larger mobility (or smaller viscous damping) indicate better transportability of the spent fuel. In addition, flow property (dynamic angle of repose and avalanching time) measurements for the hydrolysis spent fuels of AB and SBH are also presented. Comparing with the SBH hydrolysis spent fuel, the AB hydrolysis spent fuel had a lower stiffness and larger mobility, as well as lower angles of dynamic repose and avalanche power peaks, ...
Control of thermal expansion is often necessary in the design and selection of electronic packages. In some instances, it is desirable to have a coefficient of thermal expansion intermediate between values readily attainable with single or two phase materials. The addition of a third phase in the form of fillers, whiskers, or fibers can be used to attain intermediate expansions. To help design the thermal expansion of multiphase materials for specific applications, a closed form model has been developed that accurately predicts the effective elastic properties of isotropic filled materials and transversely isotropic lamina. Properties of filled matrix materials are used as inputs to the lamina model to obtain the composite elastic properties as a function of the volume fraction of each phase. Hybrid composites with two or more fiber types are easily handled with this model. This paper reports that results for glass, quartz, and Kevlar fibers ...
Household demand for better environmental quality is the key factor in the long-term global applicability of the Environmental Kuznets Curve (EKC) hypothesis. We argue that, for given consumer preferences, the threshold income level at which the EKC turns downwards or the equilibrium income elasticity changes sign from positive to negative depends on the ability to spatially separate production and consumption. We test our hypothesis by estimating the equilibrium income elasticities of five pollutants, using 1990 data for the United States. We find that the change in sign occurs at lower income levels for pollutants for which spatial separation is relatively easy as compared to pollutants for which spatial separation is difficult. Our results suggest that even high-income households in the United States have not yet reached the income level at which their demand for better environmental quality is high enough to cause the income-pollution ...
Method is proposed for expanding the pile foundation elastic analysis method (displacement method) to cover a larger displacement region, and its appropriateness is verified by a field test. In this report, stability calculation is discussed in which the present displacement method is expanded by assuming an equivalent plastic hinge on the pile head and by replacing the soil spring in the large displacement region with an equivalent linear elastic spring. A static horizontal loading test is conducted for a foundation using a real pile, which is an application of this method. On the assumption that a hinge is generated on the pile head, the pile spring constant of the current displacement method is replaced with a value that takes into consideration the plastic hinge region, and this enables the analysis of pile behavior even after breakdown. This method is applied to the result of a loading test using a real foundation, and it is found that it ...
As the surroundings of objects of oil exploration grow more complicated, seismic survey methods have turned 3-dimensional and, in this report, several models are examined using the 3-dimensional simulation technology. The result obtained by the conventional wave tracking method is different from actual wavefields, and is unrealistic. The difference method among the fullwave modelling methods demands an exorbitantly long computation time and high cost. A pseudospectral method has been developed which is superior to the difference method, and has been put to practical use thanks to the advent of parallel computers. It is found that a 3-dimensional survey is mandatory in describing faults. After examining the SEG/EAGE Salt model, it is learned that the salt is well-developed and that 3-dimensional depth migration is required for sub-salt exploration. It is also found through simulation of the EAGE/S Overthrust model, which is an elastic model, that no quality records ...
The ratio of the proton's electric to magnetic form factor, G{sub E}/G{sub M}, can be extracted in elastic electron-proton scattering by measuring cross sections, beam-target asymmetry, or recoil polarization. Separate determinations of G{sub E}/G{sub M} by cross sections and recoil polarization observables disagree for Q{sup 2}>1 (GeV/c){sup 2}. Measurement by a third technique might uncover an unknown systematic error in either of the previous measurements. The beam-target asymmetry has been measured for elastic electron-proton scattering at Q{sup 2} = 1.51 (GeV/c){sup 2} for target spin orientation aligned perpendicular to the beam momentum direction. This is the largest Q{sup 2} at which G{sub E}/G{sub M} has been determined by a beam-target asymmetry experiment. The result, {mu}G{sub E}/G{sub M}=0.884{+-}0.027{+-}0.029, is compared to previous world data.
In this experiment, a beam incident from an oblique direction is reflected by a spherical lens toward the direction of incidence. When the surface of a matter is vibrated by elastic waves, the spherical lens comes into a translation motion that accompanies the vibration. It follows accordingly that the vibration on the surface of the matter may be detected by sensing the spherical lens travelling speed. Three components of the vibration may be determined if beams are focused at one spot from three directions. Detection of the S-wave component by LDV (laser Doppler vibrometer) discloses the complicated wave field in a heterogeneous material, and this physical model experiment may be utilized in various fields of study. For instance, information about problems that may surface in the field work may be collected beforehand in a physical model experiment for developing an S-wave-aided probing method. For the study of seismic wave propagation in a complicated ...
Differential elastic and inelastic neutron-scattering cross sections of elemental iron are measured from 4.5 to 10 MeV in increments of {approx}0.5 MeV. The measurements are made at >or{approx}40 scattering angles distributed between {approx}17 and 160 , with emphasis on elastic scattering and inelastic scattering due to the excitation of the yrast 2{sup +} state. The measured data is combined with earlier lower-energy results from this laboratory, with recent high-precision {approx}9.5-15 MeV results from the Physikalisch. Technische Bundesanstalt and with selected values from the literature to provide a detailed neutron-scattering data base extending from {approx}1.5 to 26 MeV. This data is interpreted in the context of spherical-optical and coupled-channels (vibrational and rotational) models, and the physical implications are discussed. Deformation, coupling, asymmetry and dispersive effects are explored. A good description of the ...
We analyze cross sections for quasielastic inclusive scattering of electrons on nuclei and show that the observed isolated peaks for relatively low Q{sup 2} are unique for the lightest targets. Focusing, in particular, on D and {sup 4}He, we investigate in two ways to what measure the above peaks can be allocated to nucleon-elastic processes. We first compute approximate upper limits for the nucleon-inelastic background in the quasielastic region due to inclusive {delta} excitation, and find those to be small. Far more precise is a semiphenomenological approach, where the dominance of nucleon-elastic processes is translated into a set of stringent requirements. We show that those are very well fulfilled for recent D data, and to a somewhat lesser extent for older D and {sup 4}He data. With knowledge of G{sub E,M}{sup p} and information on G{sub E}{sup n}, we then extract G{sub M}{sup n} and find agreement with values obtained by alternative ...
We analyze cross sections for quasielastic inclusive scattering of electrons on nuclei and show that the observed isolated peaks for relatively low Q"2 are unique for the lightest targets. Focusing, in particular, on D and "4He, we investigate in two ways to what measure the above peaks can be allocated to nucleon-elastic processes. We first compute approximate upper limits for the nucleon-inelastic background in the quasielastic region due to inclusive #DELTA# excitation, and find those to be small. Far more precise is a semiphenomenological approach, where the dominance of nucleon-elastic processes is translated into a set of stringent requirements. We show that those are very well fulfilled for recent D data, and to a somewhat lesser extent for older D and "4He data. With knowledge of G_E_,_M"p and information on G_E"n, we then extract G_M"n and find agreement with values obtained by alternative methods. We discuss the sensitivity of the ...
This paper presents the first results on formation and study of structure and properties of micro- and nanocomposite combined coatings. By means of modeling the deposition processes (deposition conditions, current density-discharge, plasma composition and density, voltage) we formed the three-layer nanocomposite coatings of Ti-Al-N/Ti-N/Al_2O_3. The coating composition, structure and properties were studied using physical and nuclear-physical methods. The Rutherford proton and helium ion backscattering, scanning electron microscopy with microanalysis, grazing incidence X-ray diffraction, as well as nanohardness tests (hardness) were used. Measurements of wear resistance and corrosion resistance in NaCl, HCl and H_2SO_4 solutions were also performed. For testing mechanical properties such characteristics of layered structures as hardness H, elastic modulus E: H"3/E"2 etc. were measured. It is demonstrated that the formed three-layer nanocomposite coatings have ...
It is well known that composite armors, consisting of glass elements confined with metallic tampers, are extraordinarily effective against shaped charge attack. Early experiments showed that jets fired against glass targets appeared to be bombarded by tiny fragments that destroyed alignment and reduced residual jet penetration. This result was attributed to an elastic rebound effect in which the outward radial motion of the target around the jet periphery was supposed to be arrested by tensile hoop stresses which developed behind the divergent shock front. Glass fragments were then accelerated radially inward and these destabilized the jet. To sustain the large tensile hoop stresses required, the glass must not have been fractured by the initial shock, behind which the stress state is typically well above the Hugoniot elastic limit. Modeling the penetration of a jet into glass requires not only determining the spall strength, i.e., the tensile ...
Recent advances in elastic-plastic fracture mechanics have made it possible to assess the stability of cracks in ductile piping systems. These technological developments have been used by Ontario Hydro as the nucleus of an approach for demonstrating that CANDU primary heat transport piping systems will not break catastrophically; at worst they would leak at a detectable rate. This leak-before-break approach has been taken on the Darlington nuclear generating station as a design stage alternative to the provision of pipe whip restraints on large diameter, primary heat transport system piping. Positive conclusions reached via this approach are considered sufficient to exclude the requirement to provide protective devices, such as pipe whip restraints. In arriving at the proposed leak-before-break approach a review of current and proposed leak-before-break licensing positions of other jurisdictions (particularly those in the United States and the Federal Republic of ...
Kinetic Monte Carlo (KMC) computer simulations are performed to determine the kinetics of SIA cluster 'clouds' in the vicinity of edge dislocations. The simulations include elastic interactions amongst SIA clusters, and between clusters and dislocations. Results of KMC simulations that describe the formation of 'SIA clouds' during neutron irradiation of bcc Fe and the corresponding evolution kinetics are presented, and the size and spatial distribution of SIA clusters in the cloud region are studied for a variety of neutron displacement damage dose levels. We then investigate the collective spatio-temporal dynamics of SIA clusters in the presence of internal elastic fields generated by static and mobile dislocations. The main features of the investigations are: (1) determination of the kinetics and spatial extent of defect clouds near static dislocations; (2) assessment of the influence of localized patches of SIA clouds on the ...
This work describes the ability of ion beam analysis techniques IBA to simultaneously determine the concentration and the possible depth profile of some light elements, such as carbon, oxygen and nitrogen, in matrices of high atomic number Z, such as stainless steel materials. In fact, the nitriding process of some materials has the potential to improve their tribological and mechanical properties and to offer various advantages as compared with other methods used in the modification of surfaces. Gas and Plasma nitriding were applied to certain types of steel, such as AISI-304 and H-13 which are commonly used in the industry, in order to improve their hardness and their surface corrosion resistance. The improvement was correlated with the depth profile of N and the consequent structure variations. More specifically, non-Rutherford elastic backscattering (alpha, alpha) at 5 MeV was performed on different samples, before and after nitriding, in order to determine the ...
Using a Q3D magnetic spectrometer the elastic and inelastic scattering of /sup 12/C on /sup 88/Sr and the neutron pick-up (/sup 12/C, /sup 13/C) has been studied. The spin alignment of the inelastically excited 2/sup +/ state of /sup 12/C (4.43 MeV) has been deduced from the line shapes broadened by the ..gamma..-decay in flight. Thus for each m-substate a full angular distribution was obtained. The m = 1 substate shows a shifted interference minimum, which is explained by the different strength of the Coulomb and nuclear amplitudes in the m-substates. The analysis of the data on elastic scattering, inelastic scattering, alignment and the neutron transfer can be described consistently with one choice of the optical model parameters.
Formulation is introduced for discretizing a boundary integral equation into an indirect boundary element method for the solution of 3-dimensional topographic problems. Yokoi and Takenaka propose an analytical solution-capable reference solution (solution for the half space elastic body with flat free surface) to problems of topographic response to seismic motion in a 2-dimensional in-plane field. That is to say, they propose a boundary integral equation capable of effectively suppressing the non-physical waves that emerge in the result of computation in the wake of the truncation of the discretized ground surface making use of the wave field in a semi-infinite elastic body with flat free surface. They apply the proposed boundary integral equation discretized into the indirect boundary element method to solve some examples, and succeed in proving its validity. In this report, the equation is expanded to deal with 3-dimensional topographic ...
This paper describes the test results on high-temperature strength properties of fire resistant steel(FR steel) for building, the formulation, and the examples of application to member tests and actual buildings. Because of its components and manufacturing method, FR steel excels in strength at elevated temperature due to precipitation and dispersion strengthening. Tests on high temperature properties of FR steel showed that every property such as strength, stress-strain curve, elastic modulus, and creep performance at high temperature was superior to those of conventional steels. Then, it was confirmed in the tensile tests at room temperature and high temperature after heat history that FR steel could be reused after fire. It was also found in the member tests that columns and beams of FR steel could support loadings equivalent to long-term allowable unit stress until the temperature rose up to 600 centigrade. Moreover, test results could be simulated by the ...
When the foundations of the building are designed and worked, the prediction calculation of immediate settlement of the building exercised practically is to calculate assuming the earth is a linear elastic body, but the actual stress-strain relationship of the earth is nonlinear and rigidity of the earth becomes lower as strain (or stress) increases. Hence in order to grasp the actual settling behavior of the earth, it is necessary to elucidate the nonlinear relationship between stress and strain. In this article, a prediction method of building settlement is introduced which uses an analytical technique of the multi-layered earth by the linear elasticity theory and takes into consideration strain dependency of rigidity of the earth. Part of the conclusion is as follows which has been obtained by studying the settling behaviors observed in examples of vertical loading tests of the pile foundations and the elasto-plastic settlement analytical ...
In culture migrating and interacting amoeboid cells can form nematic liquid crystal phases. A polar nematic liquid crystal is formed if the interaction has a polar symmetry. One type of white blood cells (granulocytes) form clusters where the cells are oriented towards the center. The core of such an orientational defect (disclination) is either a granulocyte forced to be in an isotropic state or another cell type like a monocyte. An apolar nematic liquid crystal is formed if the interaction has an apolar symmetry. Different cell types like human melanocytes (=pigment cells of the skin), human fibroblasts (=connective tissue cells), human osteoblasts (=bone cells), human adipocytes (= fat cells) etc., form an apolar nematic liquid crystal. The orientational elastic energy is derived and the orientational defects (disclination) of nematic liquid crystals are investigated. The existence of half-numbered disclinations show that the nematic phase has an apolar ...
Neutron diffraction was used to monitor elastic strains during in situ tension testing of a directionally solidified (DS) superalloy at 900 deg. C. Changes in misfit and thermal expansion coefficients of individual phases were obtained. In the {gamma} phase, it is demonstrated that elastic strains saturate at 350 MPa, which is well below the yield strength of the alloy. This is interpreted as the onset of dislocation glide through less stressed vertical channels. The critical resolved shear stress (CRSS) of {gamma} is found to be 143 {+-} 11 MPa, in agreement with a calculated CRSS that is dominated by Orowan bowing of dislocations through nanoscale-wide {gamma} channels. This provides confirmation of Orowan bowing in plasticity/creep of the {gamma} phase. Implications of CRSS and misfit in a 'threshold stress' for creep and rafting are discussed. The CRSS of {gamma}' is found to be consistent with pairwise ...
A multi-stage, multi-disk type seismic source was developed as a downhole seismic source. The seismic source is an improved version of the downhole seismic source of a system in which an elastic wave is generated by a weight accelerated by restitutive force of a spring striking the upper part of a laminated structure consisted of metal disks and elastic bodies installed in water in a well. Enhancing the vibration exciting efficiency requires impedance radiated from the disks to be increased. The multi-disk structure was adopted because of restrictions on the disk area under the limiting condition of being inside the well. Further limitation has still existed, which led to finally structuring the multi-disk type to a multi-stage construction to increase the radiated impedance. In order to increase average velocity on the radiation surface, mass relationship between the hammer and the anvil was sought so that the maximum velocity is achieved at ...
Youngkwang Unit 3,4 and Ulchin Unit 3 and 4 have had problem of the KSNP Steam Generator due to a severe fretting wear on the tube. In particular, the wears were localized and concentrated in the upper part of U-bend of the Central Cavity region. At the upper tube bundle Central Cavity, the fluid flow velocities and void fraction are very high, because the steam is made by high heat transfer at secondary region. Also, this region is affected easily by fretting wear due to it's unsupported span is longer than another regions. The fretting wear is assumed to be result of Flow-Induced Vibration (F. I. V), which can occur by many mechanisms. EFDP was added to UCN 5,6 for prevent fretting wear by the SEC LCC and DSHIC, a company of design and manufacture of the steam generator, respectively. In order to evaluate the efficacy of EFDP, ANSYS and ATHOS-3 Code were used. From sensitivity analysis and calculation results, Density and Velocity into the Central Cavity are reduced after ...
Youngkwang Unit 3,4 and Ulchin Unit 3 and 4 have had problem of the KSNP Steam Generator due to a severe fretting wear on the tube. In particular, the wears were localized and concentrated in the upper part of U-bend of the Central Cavity region. At the upper tube bundle Central Cavity, the fluid flow velocities and void fraction are very high, because the steam is made by high heat transfer at secondary region. Also, this region is affected easily by fretting wear due to it's unsupported span is longer than another regions. The fretting wear is assumed to be result of Flow-Induced Vibration (F. I. V), which can occur by many mechanisms. EFDP was added to UCN 5,6 for prevent fretting wear by the SEC LCC and DSHIC, a company of design and manufacture of the steam generator, respectively. In order to evaluate the efficacy of EFDP, ANSYS and ATHOS-3 Code were used. From sensitivity analysis and calculation results, Density and Velocity into the Central Cavity are reduced after the EFDPs ...
Purpose: The lifelong persistence of foreign bodies within the arteries may contribute to restenosis. Thus,biodegradable devices might decrease recurrence rates. Methods: Eleven polyhydroxybutyrate biodegradable stents and 13 tantalum stents were implanted into the iliac arteries of New Zealand white rabbits for up to 30 weeks. After killing the animals,the specimens were harvested, fixed in formalin, processed in paraffin,and stained. Results: Polyhydroxybutyrate instigated intense inflammatory and proliferative reactions with an increase in collagen (2.4- to 8-fold vs native segments), thrombosis and in-stentlumen narrowing (375.5-606.6 mm vs 655.6 #+-# 268.8 mm in native segments). The elastic membranes were destroyed in all specimens. The tantalum stents increased the in-stent lumen progressively (769.7 #+-# 366.6 mm vs 1309.9 #+-# 695.3 mm),penetrated the external elastic membrane, and increased mural collagen content (6- to 8.6-fold vs ...
This paper describes the derivation of a new equation that can be used to model the permeability behavior of a fractured, sorptive-elastic media, such as coal, under variable stress conditions commonly used during measurement of permeability data in the laboratory. The model is derived for cubic geometry under biaxial or hydrostatic confining pressures. The model is also designed to handle changes in permeability caused by adsorption and desorption of gases from the matrix blocks. The model equations can be used to calculate permeability changes caused by the production of methane from coal as well as the injection of gases, such as carbon dioxide, for sequestration in coal. Sensitivity analysis of the model found that each of the input variables can have a significant impact on the outcome of the permeability forecast as a function of changing pore pressure; thus, accurate input data are essential. The permeability model can also be used as a tool to determine ...
The possible role of space-like objects in elementary particle physics (and in quantum mechanics) is reviewed and discussed, mainly by exploiting the explicit consequences of the peculiar relativistic mechanics of Tachyons. Particular attention is paid: (i) to tachyons as the possible carriers of interactions; (ii) to the possibility of ''vacuum decays'' at the classical level; (iii) to a Lorentz-invariant bootstrap model; (iv) to the apparent shape of the tachyonic elementary particles and its possible connection with the de Broglie wave-particle dualism. (author).
An interest in electronic materials has led me to investigate new synthetic approaches to III-V' type semiconducting (13-15, current IUPAC designation for B and N groups in the Periodic Table) and magnetic (3-15) compounds. It is now possible to prepare binary (GaAs and GdP) and ternary mixed-metal (Al[sub x]Ga[sub 1-x]As) and mixed-pnictide (GaP[sub x]As[sub 1-x]) compounds in seconds from rapid, low-temperature-initiated metathesis reactions between a metal (III) trihalide and a trisodium pnictide, exemplified by MX[sub 3] + Na[sub 3]Pn [yields] MPn + 3 NaX, where M is Al, Ga, In, (Al,Ga), or a lanthanide; X is F, Cl, or I; and Pn is P, As, Sb, or (P,As). The precursors are mixed together in a dry box and ignited by light grinding with a mortar and pestle, or by brief, local heating from a hot filament. These reactions are very exothermic (calculated [Delta]H[sub rxn] (GaAs) = 138 kcal/mol) and typically reach temperatures in excess ...
Version III of the Salix Maskiner ``Bender`` coppice harvester was used to successfully harvest 11.2 hectares of short rotation poplar and willow coppice in February 1997. On a wide range of typical UK crop and site conditions, the Swedish harvester was shown to have productivity rates ranging from 4.28 to 7.97 odt/smh. Based on a total system cost of Pound 81.26 per scheduled machine hour, the Bender III is able to produce wood chip for between Pound 10.20 and pound 18.97 per dry tonne. The variation in machine productivity is dependent on crop productivity and working method, emphasising the importance of site design in optimising system efficiency. In willow crops the wood chip produced by the Bender III contained a significant amount of material greater than 75mm in length. The bulk of the chips however, fell into the 5-45mm category with only a very limited amount of fine materials less than 5mm in length. The chips ...
A detailed definitive cost estimate is given for an ethanol/gasohol storage and blending terminal serving a planned distillery at a Louisiana sugar factory. Included are an analysis of the accuracy of the estimate, labor rates efficiency, materials and labor escalation, as well as detailed calculations for each account of the project. (LEW)
A method has been developed for the adsorption of Sc"I"I"I employing inorganic ion exchanger zirconium phosphosilicate by batch method. Effects of various parameters have been evaluated on the percentage adsorption of Sc"I"I"I. Separation of Sc"I"I"I from various other elements is standardized. (author)
A retrospective epidemiological study (n = 7,875) of neurologically expressed disorders (NED) in ruminants before the onset of the bovine spongiform encephalopathy epidemic...Full Text Available
1. We studied the effects of flash photolysis on the novel enantiomeric cardiac inotropes EMD 57033 (a calcium sensitizer) and EMD 57439 (a phosphodiesterase III inhibitor) in rat isolated ventricular...Full Text Available
BackgroundWith 2.5 million new HIV infections per year, effective preventive methods against HIV are urgently needed, especially in sub-Saharan Africa. MDP301 is an ongoing trial...Full Text Available
We report on solid solution CePd[sub 2-x]Mn[sub x]Si[sub 2] which shows an interesting transition of the Ce-ion from magnetism in a Kondo regime to an intermediate valence state coupled with a strongly magnetic 3d sublattice. ((orig.))
This thesis dealt with the metal-organic gas phase epitaxy with nitrogen as carrier gas. For this first by means of three-dimensional modelings of the epitaxy process the influence of the carrier gas on the processes was explained. The optimization of the growth parameter for the whole light-emitting-diode structure in double-hetero arrangement resulted that an a temperature of 770 C and a V/ III-ratio of 150 layers with a high crystal quality could be reached.
kodali, mr (iii b.tech.) anil neerukonda inst. of science and chandrashekaran ramachandra reddy shekhar c mande lang="en-gb">kandavelmani, reg. cancer cen., trivandrum panda panda lang="en-gb">dr anand imtech, chandigarh lang="en-gb">ravichandran, reg. cancer cen., trivandrum reg. cancer cen., trivandrum chandrasekar, dr (lecturer) psg college of arts & science, imtech, chandigarh ...
C14, C15, and C16 alkyl nitriles, and C16 and C18 alkyl acetylenes at 10 to 105 micromolar concentrations promote the growth of stem sections from...Full Text Available
Previous studies demonstrated that perinatal exposure to polybrominated diphenyl ethers (PBDEs), a major class of brominated flame retardants, may affect thyroid hormone (TH) concentrations by inducing...Full Text Available
DescriptionThis project continues DEFRA's commitment to the International Programme on Chemical Safety, a joint WHO/ILO/UNEP programme. DEFRA's contribution involves preparing Environmental Health Criteira Documents (EHCs), Concise International Chemical Assessments Documents (CICADS) and input to the OECD test Guidelines Programme and gneral risk assessment guidance. Peer reviews of documents prepared through other research in the IPCS network have also been carried out,as well as attending and hosting ta [continued...
Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) remains an enigmatic medical condition. Creation of the (NIH) Chronic Prostatitis Collaborative Research Network (CPCRN) funded by...Full Text Available
This paper studies on the modelling of a butterfly-type control valve actuating by an on-off pneumatic solenoid valve. The mathematical model is composed of nonlinear differential equations three parts: (i) a solenoid valve, (ii) a pneumatic cylinder, (iii) a rotary-type butterfly valve. The flow characteristics of the butterfly control valve is analysed by a computer simulator, then its simple transfer function is identified from the step responses.
The nature of binding of Ru(phen) 2+ (I), Ru(bipy) 2+ (II), Ru(terpy) 2+ (III) (phen = 1,10-phenanthroline, bipy 3 = 2,2'-bipyridyl, 3 terpy = 2,2'2," - 2 terpyridyl) to DNA, poly[d(G-C)] and poly[d(A-T)]...Full Text Available
Radiotherapy has been reported to be of benefit in prolonging the survival of patients with cholangiocarcinoma. This study examined whether radiotherapy in addition to endoscopic stenting improved survival. The survival advantage of radiotherapy in those with a type II/III stricture is seen only in the first 10 months after diagnosis. The costs of radiotherapy and significantly increased time spent in hospital, however, raise doubts over its routine use in the management of non-resectable cholangiocarcinoma. (Author).
Suicide substrate β, γ-bidentate Rh(III)ATP (RhATP) was used to map the metal ion-binding site in yeast phosphoglycerate kinase (PGK). Cleavage of the RhATP-inactivated enzyme with...Full Text Available