bluuebunny/crossref_metadata_2025 huggingface dataset:
Input Power Determined From Temperatures in Simulated Skin Protected Against Thermal Radiation
Authors: Davies J. M.
Published: February 2012

With thermal protective systems, the power transferred from an opaque layer to the skin or a skin simulant determines the temperature of the skin and in turn the degree of burn. The power input was calculated from the measured temperature of the simulant by expressing the power as a series of functions, with unknown constants, whose Laplace transforms were of the proper form for comparison with the measured temperatures and thus determine the constants. The lag of temperature behind the power causes some uncertainty in the latter, but practically adequate precision is attainable.
Experiments on Turbulent Heat Transfer in an Asymmetrically Heated Rectangular Duct
Authors: Sparrow E. M. , Lloyd J. R. , Hixon C. W.
Published: February 2012

An experimental investigation of the effect of asymmetrical heating on fully developed turbulent heat transfer has been carried out. The test apparatus was a rectangular duct of aspect ratio 5:1. The duct was constructed so that the two long sides of the rectangular cross section could be heated at different preselected rates, while the two short sides were unheated. Two cases of asymmetrical heating were studied: (a) One of the two long sides was heated, while the second was unheated; (b) both of the long sides were heated, with the heating rate at one side being twice that of the other. For the first case, the heat transfer coefficients are lower than those for the symmetrically heated duct. For the second case, the coefficients for the more strongly heated wall are also below the values for symmetrical heating, while the coefficients for the lesser-heated wall are greater than the symmetric heating results. These findings are in qualitative agreement with analytical predictions for the parallel-plate channel. Furthermore, by applying an analytically motivated correlation procedure (reference [10]), it was shown that overall Nusselt number results for asymmetric heating could be brought into virtual coincidence with those for symmetric heating.
Nucleate Boiling Instability of Alkali Metals
Authors: Marto P. J. , Rohsenow W. M.
Published: February 2012

A simplified theoretical model for bubble nucleation stability has been proposed, and an approximate stability criterion has been developed. This criterion contains both fluid and surface properties, and it predicts that nucleation for sodium should be unstable. Commercial-grade sodium was boiled from a horizontal disk at pressures near 60 mm Hg absolute, with sodium temperatures near 1200 F. Heat fluxes as high as 236,000 Btu/hr ft2 were attained. Boiler surface finishes ranged from highly polished mirror finishes to coarse, porous coatings. The effects of surface material, chemical treatment, heat flux, and cavity geometry on nucleation stability were measured, and the experimental results agreed with the predictions of the proposed stability model.
Effects of Surface Conditions on Nucleate Pool Boiling of Sodium
Authors: Marto P. J. , Rohsenow W. M.
Published: February 2012

Commercial grade sodium was boiled from a horizontal disk at pressures of 65 mm, 200 mm, and 400 mm Hg absolute, with sodium temperatures ranging from 1200 F to 1500 deg F. Heat fluxes as high as 236,000 Btu/hr sq ft were attained. Boiler surface finishes ranged from highly polished mirror finishes to coarse, porous coatings. By following a prescribed cleaning and filling procedure, nucleate-boiling results were generally reproducible for a given-type surface. The effect of roughness as well as any aging and hysteresis effects were experimentally determined. Incipient nucleate boiling results are discussed as well as the effect of pressure and pool depth on the nucleate-boiling curve.
Off-Specular Peaks in the Directional Distribution of Reflected Thermal Radiation
Authors: Torrance K. E. , Sparrow E. M.
Published: February 2012

Experiments have been performed which demonstrate that the directional distribution of reflected thermal radiation for moderate to large angles of incidence is not intermediate to the specular and diffuse limits as commonly assumed. Indeed, for such angles of incidence on roughened surfaces, maxima in the reflected intensity distribution occur at polar angles larger than the specular angle. In some cases, the intensity of this off-specular maximum is three or four times the intensity in the specular-ray direction. The materials studied were aluminum, nickel, copper, a nickel-copper alloy, and magnesium-oxide ceramic, thereby encompassing both metals and nonmetals. Controlled surface roughnesses of 0.23 to 5.8 microns were employed over a wavelength range extending from 0.5 to 6 microns. The angle of incidence was varied from 10 to 75 deg, while reflected radiation was collected in the plane of incidence at polar angles ranging from 0 to 89 deg. The experimental results are arranged on the basis of a surface-roughness-to-wavelength ratio, σm/λ. Certain trends of the off-specular peak with incident angle and σm/λ are noted.
Nonuniform Cooling of a Heat-Generating Cylinder or Sphere
Authors: Fagan Walter , Leipziger Stuart
Published: February 2012

A heat-generating solid cylinder or sphere is cooled in steady state with a heat transfer coefficient which varies arbitrarily on the surface. A solution is obtained which permits exact calculation of the temperature distribution. Simple approximate solutions are also obtained for the two cases where (a) the heat transfer coefficient does not differ greatly from its average value, and (b) the coefficient differs greatly from its average value. Numerical studies are made, and the errors resulting from the approximate solutions are calculated.
Maximum Two-Phase Vessel Blowdown From Pipes
Authors: Moody F. J.
Published: February 2012

Existing flow models are applied to predict maximum two-phase flow from a constant area, adiabatic pipe with friction. Graphs are given for maximum steam/water flow rate in terms of pipe f(L/D) and entrance stagnation properties. Theoretical blow-downs are graphed for 1000 and 2000 psia saturated-water systems with f(L/D) ranging from 0.0 to 100. Estimated pipe flow rates and blowdown transients are compared with steam/water data. Reasonable agreement is shown.
An Interferometric Study of Mass Transfer From a Vertical Plate at Low Reynolds Numbers
Authors: El-Wakil M. M. , Myers G. E. , Schilling R. J.
Published: February 2012

Experimental concentration profiles in steady-state, two-component boundary layers formed by the evaporation of a volatile liquid from a porous vertical flat plate into a heated airstream were obtained by an interferometric technique. Tests were conducted with benzene and n-heptane as the evaporating fluids with airstream temperatures ranging from 70 to 94 F and airstream velocities ranging from 90 to 120 fpm. The Reynolds number range, based on the distance from the leading edge of the plate, was from 75 to 1800. It was experimentally observed that transition from laminar flow occurred at Reynolds numbers between 300 and 600. These values, much lower than generally reported in the literature for heat transfer alone, are believed to be related to the relatively thick boundary layers induced by mass transfer of the heavier-than-air fluid from the plate and the associated free-convection effects. While the flow was primarily forced convection, the experimental data indicated a strong natural-convection effect when compared with analytical predictions based on forced convection alone. This was due primarily to the mass transfer into the boundary layer. An attempt was made to analytically account for the effects of mass transfer and natural convection on the Sherwood-Reynolds numbers relationship by utilizing perturbation solutions for the analogous heat transfer problem. The trends shown by this analysis agreed with the experimental data in the laminar portion of the boundary layer. The absolute magnitudes, however, still differed significantly, showing that first-order perturbation solutions of the mass transfer and free-convection effects are inadequate and pointing to the need for more theoretical work.
On the Solution of the Diffusion Equations by Numerical Methods
Authors: Barakat H. Z. , Clark J. A.
Published: February 2012

An explicit-finite difference approximation procedure which is unconditionally stable for the solution of the general multidimensional, nonhomogeneous diffusion equation is presented. This method possesses the advantages of the implicit methods, i.e., no severe limitation on the size of the time increment. Also it has the simplicity of the explicit methods and employs the same “marching” type technique of solution. Results obtained by this method for several different problems are compared with the exact solution and with those obtained by other finite-difference methods. For the examples solved the numerical results obtained by the present method are in closer agreement with the exact solution than are those obtained by the other methods.
How Actin Gets the PIP
Authors: Moss Stephen E.
Published: February 2012

The relative concentrations of different phosphoinositide species may dictate whether actin comets or membrane ruffles are formed.
For Whom the Clock Tolls
Authors: Foley John F.
Published: February 2012

Circadian control of the abundance of Toll-like receptor 9 regulates innate and adaptive immune responses.
Daptomycin versus Vancomycin in a Methicillin-Resistant Staphylococcus aureus Endophthalmitis Rabbit Model: Bactericidal Effect, Safety, and Ocular Pharmacokinetics
Authors: Lefèvre Sophie , Saleh Maher , Marcellin Luc , Subilia Audrey , Bourcier Tristan , Prévost Gilles , Jehl François
Published: February 2012

Staphylococcus aureus
is a frequent cause of acute endophthalmitis, and infection with this virulent bacterium is often associated with a poor visual outcome. In this study, we investigated the bactericidal efficacy and the safety of intravitreal daptomycin (DAP), a lipopeptide antibiotic with broad-spectrum activity against Gram-positive bacteria, compared with those of intravitreal vancomycin (VAN) in a methicillin-resistant
S. aureus
endophthalmitis rabbit model. The pharmacokinetics and pharmacodynamics of daptomycin in the infected eyes were also studied. Rabbits were randomly divided into three treatment groups (
n
= 8) and one untreated group (
n
= 4), to compare the effect of single intravitreal injections of 0.2 mg and 1 mg of daptomycin (DAP 0.2 and DAP 1 groups, respectively) with that of 1 mg of intravitreal vancomycin (VAN 1 group). Vitreal aspirates were regularly collected and grading of ocular inflammation was regularly performed until euthanasia on day 7. In the DAP 0.2 group, 62.5% of the eyes were sterilized and the mean bacterial count presented a reduction of 1 log unit. In the DAP 1 and VAN 1 groups, the infection was eradicated (100% and 87.5% of eyes sterilized, respectively), with a 4-log-unit reduction of the mean bacterial count. The bactericidal efficacy in the DAP 1 group was not inferior to that in the VAN 1 group and was superior to that of the other regimens in limiting the ocular inflammation and preserving the architecture of the ocular structures (
P
< 0.05). The elimination half-life (
t
1/2β
) of daptomycin was independent of the administered dose (38.8 ± 16.5 h and 40.9 ± 6.7 h, respectively, for the DAP 0.2 and DAP 1 groups) and was significantly longer than the
t
1/2β
of vancomycin (20.5 ± 2.0 h for the VAN 1 group) (
P
< 0.05). This antibiotic could therefore be considered for the treatment of intraocular infections caused by Gram-positive bacteria.
Genomewide Overexpression Screen for Fosfomycin Resistance in Escherichia coli: MurA Confers Clinical Resistance at Low Fitness Cost
Authors: Couce Alejandro , Briales Alejandra , Rodríguez-Rojas Alexandro , Costas Coloma , Pascual Álvaro , Blázquez Jesús
Published: February 2012

To determine whether the overexpression of chromosomal genes can confer fosfomycin resistance, genomewide screening of a complete set of 5,272 plasmid-expressed open reading frames of
Escherichia coli
(ASKA collection) was performed. Major results are that (i) no clinical level of resistance is achieved by overexpressing chromosomal genes, except
murA
; (ii) this level is reached at a low fitness cost; and (iii) this cost is much lower than that imposed by other mutations conferring fosfomycin resistance.
rplC
T460C Identified as a Dominant Mutation in Linezolid-Resistant Mycobacterium tuberculosis Strains
Authors: Beckert Patrick , Hillemann Doris , Kohl Thomas A. , Kalinowski Jörn , Richter Elvira , Niemann Stefan , Feuerriegel Silke
Published: February 2012

The ribosomal L3 protein was identified as a novel target in linezolid (LZD)-resistant
Mycobacterium tuberculosis
strains. Next-generation sequencing confirmed
rplC
T460C as the sole mutation in an LZD-resistant
M. tuberculosis
H37Rv strain selected
in vitro
. Sequencing analysis revealed the
rplC
T460C mutation in eight further LZD-resistant isolates (three
in vitro
-selected mutants and five patient isolates, including isolates from three different patients that developed LZD resistance during treatment) but in none of the susceptible control strains (
n
= 84).
Highly Resistant Salmonella enterica Serovar Typhi with a Novel
gyrA
Mutation Raises Questions about the Long-Term Efficacy of Older Fluoroquinolones for Treating Typhoid Fever
Authors: Koirala Kanika Deshpande , Thanh Duy Pham , Thapa Sudeep Dhoj , Arjyal Amit , Karkey Abhilasha , Dongol Sabina , Shrestha Upendra Man , Farrar Jeremy J. , Basnyat Buddha , Baker Stephen
Published: February 2012

As a consequence of multidrug resistance, clinicians are highly dependent on fluoroquinolones for treating the serious systemic infection typhoid fever. While reduced susceptibility to fluoroquinolones, which lessens clinical efficacy, is becoming ubiquitous, comprehensive resistance is exceptional. Here we report ofloxacin treatment failure in typhoidal patient infected with a novel, highly fluoroquinolone-resistant isolate of
Salmonella enterica
serovar Typhi. The isolation of this organism has serious implications for the long-term efficacy of ciprofloxacin and ofloxacin for typhoid treatment.
Afa/Dr Diffusely Adhering Escherichia coli Strain C1845 Induces Neutrophil Extracellular Traps That Kill Bacteria and Damage Human Enterocyte-Like Cells
Authors: Marin-Esteban Viviana , Turbica Isabelle , Dufour Guillaume , Semiramoth Nicolas , Gleizes Aude , Gorges Roseline , Beau Isabelle , Servin Alain L. , Lievin-Le Moal Vanessa , Sandré Catherine , Chollet-Martin Sylvie
Published: February 2012

We recently documented the neutrophil response to enterovirulent diffusely adherent
Escherichia coli
expressing Afa/Dr fimbriae (Afa/Dr DAEC), using the human myeloid cell line PLB-985 differentiated into fully mature neutrophils. Upon activation, particularly during infections, neutrophils release neutrophil extracellular traps (NETs), composed of a nuclear DNA backbone associated with antimicrobial peptides, histones, and proteases, which entrap and kill pathogens. Here, using fluorescence microscopy and field emission scanning electron microscopy, we observed NET production by PLB-985 cells infected with the Afa/Dr wild-type (WT)
E. coli
strain C1845. We found that these NETs were able to capture, immobilize, and kill WT C1845 bacteria. We also developed a coculture model of human enterocyte-like Caco-2/TC7 cells and PLB-985 cells previously treated with WT C1845 and found, for the first time, that the F-actin cytoskeleton of enterocyte-like cells is damaged in the presence of bacterium-induced NETs and that this deleterious effect is prevented by inhibition of protease release. These findings provide new insights into the neutrophil response to bacterial infection via the production of bactericidal NETs and suggest that NETs may damage the intestinal epithelium, particularly in situations such as inflammatory bowel diseases.
Whole-Genome Sequence of the Human Pathogen Legionella pneumophila Serogroup 12 Strain 570-CO-H
Authors: Amaro Francisco , Gilbert Jack A. , Owens Sarah , Trimble William , Shuman Howard A.
Published: February 2012

We present the genomic sequence of the human pathogen
Legionella pneumophila
serogroup 12 strain 570-CO-H (ATCC 43290), a clinical isolate from the Colorado Department of Health, Denver, CO. This is the first example of a genome sequence of
L. pneumophila
from a serogroup other than serogroup 1. We highlight the similarities and differences relative to six genome sequences that have been reported for serogroup 1 strains.
Complete Genome Sequence of Clinical Isolate Pantoea ananatis LMG 5342
Authors: De Maayer Pieter , Chan Wai Yin , Rezzonico Fabio , Bühlmann Andreas , Venter Stephanus N. , Blom Jochen , Goesmann Alexander , Frey Jürg E. , Smits Theo H. M. , Duffy Brion , Coutinho Teresa A.
Published: February 2012

The enterobacterium
Pantoea ananatis
is an ecologically versatile species. It has been found in the environment, as plant epiphyte and endophyte, as an emerging phytopathogen, and as a presumptive, opportunistic human pathogen. Here, we report the complete genome sequence of
P. ananatis
LMG 5342, isolated from a human wound.
Genome Sequences of Four Divergent Multidrug-Resistant Acinetobacter baumannii Strains Isolated from Patients with Sepsis or Osteomyelitis
Authors: Zurawski Daniel V. , Thompson Mitchell G. , McQueary Christin N. , Matalka Malcolm N. , Sahl Jason W. , Craft David W. , Rasko David A.
Published: February 2012

Acinetobacter baumannii
is a Gram-negative bacterium that causes nosocomial infections worldwide, with recent prevalence and higher frequency in wounded military personnel. Four
A. baumannii
strains from the Walter Reed Army Medical Center (WRAMC) isolated between 2008 and 2009 were sequenced, representing diverse, multidrug-resistant isolates from osteomyelitis or septic patients.
Genome Sequence of Weissella confusa LBAE C39-2, Isolated from a Wheat Sourdough
Authors: Amari Myriam , Laguerre Sandrine , Vuillemin Marlène , Robert Hervé , Loux Valentin , Klopp Christophe , Morel Sandrine , Gabriel Bruno , Remaud-Siméon Magali , Gabriel Valérie , Moulis Claire , Fontagné-Faucher Catherine
Published: February 2012

Weissella confusa
is a rod-shaped heterofermentative lactic acid bacterium from the family of
Leuconostocaceae
. Here we report the draft genome sequence of the strain
W. confusa
LBAE C39-2 isolated from a traditional French wheat sourdough.
Genome Sequences of Three Leuconostoc citreum Strains, LBAE C10, LBAE C11, and LBAE E16, Isolated from Wheat Sourdoughs
Authors: Laguerre Sandrine , Amari Myriam , Vuillemin Marlène , Robert Hervé , Loux Valentin , Klopp Christophe , Morel Sandrine , Gabriel Bruno , Remaud-Siméon Magali , Gabriel Valérie , Moulis Claire , Fontagné-Faucher Catherine
Published: February 2012

Leuconostoc citreum
is a key microorganism in fermented foods of plant origin. Here we report the draft genome sequence for three strains of
Leuconostoc citreum
, LBAE C10, LBAE C11, and LBAE E16, which have been isolated from traditional French wheat sourdoughs.
Genome Sequence of Comamonas testosteroni ATCC 11996, a Representative Strain Involved in Steroid Degradation
Authors: Gong Wenjie , Kisiela Michael , Schilhabel Markus B. , Xiong Guangming , Maser Edmund
Published: February 2012

Comamonas testosteroni
strains belong to the family of
Comamonadaceae
and are known for their ability to utilize steroid compounds as carbon source. Here, we present the draft genome sequence of strain ATCC 11996, with a G+C content of 61.48%.
Climatic determinants of white spruce cone crops in the boreal forest of southwestern Yukon
Authors: Krebs C.J. , LaMontagne J.M. , Kenney A.J. , Boutin S.
Published: February 2012

White spruce ( Picea glauca (Moench) Voss) cone crops were measured from 1986 to 2011 in the Kluane region of southwestern Yukon to test the hypothesis that the size of cone crops could be predicted from spring and summer temperature and rainfall of years t, t – 1, and t – 2. We counted cones in the top 3 m of an average of 700 white spruce trees each year spread over 3–14 sites along 210 km of the Alaska Highway and the Haines Highway. We tested the conventional explanation for white spruce cone crops that implicates summer temperatures and rainfall in years t and t – 1 and rejected it, since it explained very little of the variation in our 26 years of data. We used exploratory data analysis with robust multiple regressions coupled with Akaike’s information criterion corrected (AICc) analysis to determine the best statistical model to predict the size of cone crops. We could statistically explain 54% of the variation in cone crops from July and August temperatures of years t – 1 and t – 2 and May precipitation of year t – 2. There was no indication of a periodicity in cone crops, and years of large cone crops were synchronous over the Kluane region with few exceptions. This is the first quantitative model developed for the prediction of white spruce cone crops in the Canadian boreal forest and has the surprising result that weather conditions 2 years prior to the cone crop are the most significant predictors.
Fungal endophytes improve wheat seed germination under heat and drought stress
Authors: Hubbard Michelle , Germida James , Vujanovic Vladimir
Published: February 2012

Seed germination is a critical life stage for plants survival and timely seedling establishment especially in stressful environments. We hypothesized that fungal endophytes would improve wheat seed germination under heat and drought stress. The hydrothermal time (HTT) model of germination is a conceptual model useful for predicting the timing and energy of germination (EG) under a given set of conditions. The HTT and EG are applied, for the first time, to determine if one or more compatible endophytic fungi enhance heat or drought tolerance in wheat. Fungal endophytes tested dramatically increased the percent of germination, improved EG and HTT values, and diminished wheat susceptibility to heat and drought as measured by fresh weight of seedlings. When colonized by the most effective fungal endophyte, the values of the parameters tested in wheat seeds exposed to heat stress resembled those of unstressed seeds.
Phenology, leaf gas exchange, growth, and seed yield in contrasting Medicago truncatula and Medicago laciniata populations during prolonged water deficit and recovery
Authors: Yousfi Nasreddine , Slama Ines , Abdelly Chedly
Published: February 2012

The aims of this study were to investigate the effect of prolonged water stress and recovery on phenology, growth, and seed yield in Tunisian contrasting populations of Medicago truncatula and Medicago laciniata . After ample irrigation for 24 days, the plants of each population were divided into two lots: the first lot was irrigated at 100% field capacity (FC), and the second at only 45% FC. After 24 days of treatment, one lot of dehydrated plants was rewatered at 100% FC, while the other was maintained at 45% FC. Interspecific and intraspecific differences were found in phenological responses to water deficit. All growth parameters were more reduced in M. truncatula populations than in M. laciniata populations. The water shortage tolerance of M. laciniata populations was associated with a lower metabolic impairment of photosynthesis and maintenance of relatively higher leaf relative water content. Seed yield was also more reduced in M. truncatula populations compared with M. laciniata populations. In M. laciniata, seed mass was a compensation mechanism to sustain seed yield under drought conditions. Seed yield variation between populations under water deficit was explained mainly by variation in seed number per plant.
Vertical uplift capacity of a group of two coaxial anchors in a general c–ϕ soil
Authors: Kumar Jyant , Naskar Tarun
Published: February 2012

The vertical uplift resistance of a group of two horizontal coaxial strip anchors, embedded in a general c–[Formula: see text] soil (where c is the unit cohesion and [Formula: see text] is the soil friction angle), has been determined by using the lower bound finite element limit analysis. The variation of uplift factors Fc and Fγ, due to the components of soil cohesion and unit weight, respectively, with changes in depth (H) / width (B) has been established for different values of vertical spacing (S) /B. As compared to a single isolated anchor, the group of two anchors provides a significantly greater magnitude of Fc for [Formula: see text] ≤ 20° and with H/B ≥ 3. The magnitude of Fc becomes almost maximum when S/B is kept closer to 0.5H/B. On the other hand, with the same H/B, as compared to a single anchor, hardly any increase in Fγ occurs for a group of two anchors.
Seismic deformation analysis of Tuttle Creek Dam
Authors: Stark Timothy D. , Beaty Michael H. , Byrne Peter M. , Castro Gonzalo , Walberg Francke C. , Perlea Vlad G. , Axtell Paul J. , Dillon John C. , Empson William B. , Mathews David L.
Published: February 2012

To facilitate the design of seismic remediation for Tuttle Creek Dam in east central Kansas, a seismic finite difference analysis of the dam was performed using the software FLAC and the UBCSAND and UBCTOT soil constitutive models. The FLAC software has a key advantage because it can use calibrated site-specific constitutive models. Earlier deformation analyses using a hyperbolic constitutive model for the foundation fine-grained materials did not properly represent the modulus and strength reduction and predicted extremely large permanent deformations. Cyclic triaxial laboratory tests using high-quality samples and in situ vane shear tests were used to calibrate the FLAC constitutive model herein. The resulting FLAC analysis of the unremediated dam predicted an upstream slope toe deformation of about 0.6 m, a crest settlement of about 0.6 m, and a downstream slope toe deformation of about 1.5 m using the design ground motion. Based on the estimated permanent deformations and other factors, it was decided that the anticipated upstream slope and crest deformations were tolerable and only the downstream slope had to be remediated to protect the downstream seepage control system.
EVALUATION OF WMN-GA FOR DIFFERENT MUTATION AND CROSSOVER RATES CONSIDERING GIANT COMPONENT PARAMETER
Authors: BAROLLI ADMIR , ODA TETSUYA , XHAFA FATOS , BAROLLI LEONARD , TAKIZAWA MAKOTO , UCHIDA KAZUNORI
Published: February 2012

Wireless Mesh Networks (WMNs) are currently attracting a lot of attention from wireless research and technology community due to their importance as means for providing cost-efficient broadband wireless connectivity. WMNs are based on mesh topology, in which every node is connected to one or more nodes, enabling thus the information transmission in more than one path. In this paper, we deal with the effects of mutation and crossover operators in GA for node placement problem. We evaluate the performance of the proposed system using different genetic operators and different distributions of router nodes considering giant component parameter. The simulation results show that for Exponential and Linear Ranking methods, the system has a good performance.
MATHEMATICS IN ECONOMICS: REDUCIBILITY AND/OR APPLICABILITY?
Authors: SARUKKAI SUNDAR
Published: February 2012

The use of mathematics in physics is not restricted to non-formal use with emphasis on approximation and computability. There is also a domain of creative use of symbolic manipulation as well as of metaphoric imagination that makes applicability in the sciences so effective. The challenge to mathematical use in economics is to find ways to use it in these creative ways, including finding new discursive and writing strategies. For this to be possible, the nature of realism in economics has to be delineated since the way in which mathematics is used in economics seems to be in the "reductive" mode instead of the "applied" mode.
A NOTE ON THE CONCEPT OF APPROXIMATE EQUILIBRIUM IN ECONOMIC THEORY
Authors: FOLEY DUNCAN K.
Published: February 2012

The problem of the computability of Walrasian competitive equilibrium is considered from the point of view of concepts of approximate equilibrium. Neither the market-clearing nor Negishi approaches to the proof of existence of Walrasian competitive equilibrium give rise to adequately robust notions of approximate equilibrium. This explains the non-computability of Walrasian competitive equilibrium. The problem lies in the economic conception of markets, in particular the inconsistent treatment of information underlying the Walrasian definition. When trade takes place at disequilibrium prices decentralized market exchange redistributes income and economic welfare, and its equilibrium is path-dependent. The set of such equilibrium outcomes, however, in contrast to the Walrasian competitive equilibrium, is constructive and computable.
DISLOCATION MECHANISM OF TWINNING IN Ni–Mn–Ga
Authors: ZÁRUBOVÁ N. , GE Y. , GEMPERLOVÁ J. , GEMPERLE A. , HANNULA S.-P.
Published: February 2012

Tensile tests were performed in situ in a transmission electron microscope to investigate the twinning mechanism in non-modulated Ni–Mn–Ga martensite. The reorientation of the twin variants occurs via twinning dislocations. Their generation and movement were followed; the glide plane and Burgers vector were verified. Individual twinning dislocations were visualized.
SMA (Cu-BASED, NiTi) FOR USE IN DAMPING: THE IMPLICATIONS OF RELIABILITY FOR LONG TIME APPLICATIONS AND AGING BEHAVIOR
Authors: ISALGUE ANTONIO , AUGUET CARLOTA , CARRERAS GUILLEM , TORRA VICENÇ
Published: February 2012

Guaranteed behavior of SMA in damping needs deep study of the alloy behavior according to the requirements. Pseudoelastic window, evolution of properties, self-heating and fatigue are the major concerns. The analysis shows that selected alloys can do the work. The application to portico and to cable oscillations in realistic systems shows an excellent damping effect. Useful simulation requires a good phenomenological model. A cubic model is built with improved results at low deformation.
LARGE-SIZED DYE-SENSITIZED SOLAR CELLS WITH TiO2 CEMENTED AND PROTECTED SILVER GRIDS
Authors: LAN ZHANG , WU JIHUAI , LIN JIANMING , MIAOLIANG
Published: February 2012

Large-sized dye-sensitized solar cells were prepared with TiO2 cemented and protected Ag grids in the photo and counter electrodes. The addition of high conductive TiO2 cemented Ag grids can maintain high performance with the enlargement of the cells. The preparation of the compact TiO2 layer on the Ag grids can prevent the corrosion of the electrolyte, moreover, when it is prepared on the whole area of the photo electrode, it also can play as the blocking layer for further enhancing the performance of cells. The presented method shows a simple and efficient way to prepare high performance large single cells.
ASSESSMENT OF THE INFLUENCE OF R-PHASE FORMATION ON THE MATERIAL BEHAVIOR OF NiTi USING A MICROMECHANICAL MODEL
Authors: HEINEN RAINER , MIRO SHORASH
Published: February 2012

Shape memory alloys (SMA) show several interesting features in their material behavior which are due to martensitic phase transformation. In NiTi , this transformation covers the three crystallographic phases of austenite, martensite, and R-phase. This publication analyzes the influence of the R-phase formation on the overall material behavior by means of a micromechanical model. The model is based on energy minimization with the assumption of a certain energy dissipation when martensite is formed. To simplify the formulation, the dissipation associated with the transformation between austenite and R-phase is neglected, since the geometrical change in unit cell geometry is relatively small in this case. Numerical simulations show that especially the slope reduction in the stress–strain curve, which is known from experiments, can be explained by R-phase formation.
RELAXOR FERROELECTRIC MATERIALS FOR MICROWAVE TUNABLE APPLICATIONS
Authors: ZHANG QIWEI , ZHAI JIWEI , KONG LING BING
Published: February 2012

With strong dependences of dielectric constant on external applied electric fields, relaxor barium zirconium titanate ( BaZr x Ti 1-x O 3 or BZT) and barium stannate titanate ( BaSn x Ti 1-x O 3 or BTS), in both bulk ceramic and thin film forms, are increasingly being recognized as potential candidates of microwave tunable materials for device applications. This paper is aimed to review the recent progress in understanding the dielectric properties (such as tunability, dielectric loss and dielectric constant) of these relaxor materials. However, due to their relatively high dielectric constant and loss tangent, pure Ba(Zr,Ti)O3 and Ba(Sn,Ti)O3 do not fully satisfy the requirements of practical device applications. Therefore, various strategies have been developed to improve the dielectric properties of these two groups of relaxor materials. In this paper, we first discussed the dielectric tunability characteristics of pure Ba(Zr,Ti)O3 and Ba(Sn,Ti)O3 and then summarized the strategies that have been used, including (i) small amount acceptor or donor doping (such as rare-earth ions and transition metal ions) and (ii) forming composites with low loss and low dielectric constant microwave dielectric materials (such as MgO , MgTiO3 and so on). At the same time, the relationship between relaxor behavior and dielectric tunability was also discussed.
IMPEDANCE AND MODULUS SPECTROSCOPY CHARACTERIZATION OF SODIUM-BISMUTH TITANATE-BASED LEAD-FREE FERROELECTRIC MATERIALS
Authors: SHARMA DHANANJAY K. , KUMAR RAJU , RAI RADHESHYAM , SHARMA SEEMA , KHOLKIN ANDREI L.
Published: February 2012

In this paper, we present impedance spectroscopy of Sodium Bismuth Titanate-based materials belonging to (1-x) Na 1/2 Bi 1/2 TiO 3-x BaTiO 3(x = 0.04) (NBT–BT) system. NBT–BT ceramics are prepared by high temperature solid-state reaction method. X-ray diffraction technique showed single-phase polycrystalline sample with an ABO3 perovskite structure. Dielectric behavior and the impedance relaxation were investigated in a wide range of temperature (room temperature (RT) –500°C) and frequency (1 kHz–1 MHz). A broad dielectric constant peak was observed over a wide temperature range around the phase transition temperature. The complex impedance plot exhibited one impedance semicircle identified over the frequency range of 1 kHz–1 MHz, which is explained by the grain effect of the bulk. The centers of the impedance semicircles lie below the real axis, which indicates that the impedance response is a Cole–Cole type relaxation.
DIELECTRIC PROPERTIES OF ULTRAFINE Zn-DOPED CaCu3Ti4O12 CERAMIC
Authors: SINGH LAXMAN , RAI U. S. , MANDAL K. D. , YASHPAL MADHU
Published: February 2012

Ultrafine powder of CaCu2.80Zn0.20Ti4O12 ceramic was prepared using a novel semi-wet method. DTA/TG analysis of dry powder gives pre-information about formation of final product around 800°C. The formation of single phase was confirmed by X-ray diffraction analysis. The average particle size of sintered powder of the ceramic obtained from XRD and Transmission electron microscopy was found 59 nm and 102 nm, respectively. Energy Dispersive X-ray studies confirm the stoichiometry of the synthesized ceramic. Dielectric constant of the ceramic was found to be 2617 at room temperature at 1 kHz.
PHASE-FIELD SIMULATION FOR MICROSTRUCTURAL DEVELOPMENT OF TEXTURED CERAMICS PREPARED BY REACTION TEMPLATED GRAIN GROWTH
Authors: LIU LIANGLIANG , GAO FENG , HU GUOXIN , LIU JIANGNAN
Published: February 2012

A modified model using phase-field method in order to describe the microstructural development for the reaction templated grain growth process was developed. The current model well expressed anisotropic enlargement of the template particles. The initial parameters such as the matrix particles size, the template particles size, fraction, aspect ratio of the template particles and porosity were examined. The simulation results show that the fraction of oriented grains increases with decreasing the matrix particles size and porosity, and increasing the fraction of the initial template particles. An increase for the aspect ratio of template particles gives rise to the anisotropic microstructure development. The study suggests that the simulation results would give a guiding principle in terms of the initial preparation conditions for the textured ceramics having both a large fraction of oriented grains and anisotropic microstructure.
NONVOLATILE MEMORY TECHNOLOGY: A DRIVER TO FUTURE NANOELECTRONICS
Authors: LU CHIH-YUAN
Published: February 2012

Flash memory has served as an important technology driver due to its many new applications. Despite the fact that NAND flash has out run lithography and other scaling barriers and thus is facing steep challenges, several innovative solutions are being developed to carry its momentum, and it continues to serve as a technology driver in the nanoelectronics era. New devices that are not based on charge storage, on the other hand, are promising to further boost system performance by offering low-power, high-density, and fast latency storage. These new developments should provide the next generation memory and storage solutions that will elevate system performance to a new level.
Military aspects of hydrogeology: an introduction and overview
Authors: Mather John D. , Rose Edward P. F.
Published: February 2012

The military aspects of hydrogeology can be categorized into five main fields: the use of groundwater to provide a water supply for combatants and to sustain the infrastructure and defence establishments supporting them; the influence of near-surface water as a hazard affecting mobility, tunnelling and the placing and detection of mines; contamination arising from the testing, use and disposal of munitions and hazardous chemicals; training, research and technology transfer; and groundwater use as a potential source of conflict. In both World Wars, US and German forces were able to deploy trained hydrogeologists to address such problems, but the prevailing attitude to applied geology in Britain led to the use of only a few, talented individuals, who gained relevant experience as their military service progressed. Prior to World War II, existing techniques were generally adapted for military use. Significant advances were made in some fields, notably in the use of Norton tube wells (widely known as Abyssinian wells after their successful use in the Abyssinian War of 1867/1868) and in the development of groundwater prospect maps. Since 1945, the need for advice in specific military sectors, including vehicle mobility, explosive threat detection and hydrological forecasting, has resulted in the growth of a group of individuals who can rightly regard themselves as military hydrogeologists.
Basement hydrogeology and fortification of the Channel Islands: legacies of British and German military engineering
Authors: Robins N. S. , Rose E. P. F. , Cheney C. S.
Published: February 2012

The islands of Jersey, Guernsey, Alderney and Sark lie close to the Normandy coast of France. They expose a largely Precambrian crystalline basement of metamorphic and igneous rocks – Jersey and Alderney also expose some early Palaeozoic clastic sediments – and all have a thin but widespread Quaternary sedimentary cover. The three largest islands were progressively fortified by the British between the early 13th and mid-19th centuries, and by German forces during occupation in World War II, a legacy illustrated by the castles, forts and numerous German coastal fortifications that still adorn them. A German military geologist based on Jersey from mid-1941 to mid-1944, and a military geological team on Guernsey and Alderney during 1942, generated hydrogeological maps and reports that were then in advance of understanding of crystalline basement aquifers elsewhere in the British Isles. All the major documents have now been found in Germany, the USA and UK, although none survived on the islands themselves. Geological mapping and hydrogeological studies postwar under the auspices of the British Geological Survey were completed without access to German data. However, German and British data together now facilitate an appraisal of the heavily stressed aquifers on these small, hard-rock islands over an unusually long (65 year) timespan.
Hydrogeology and the
Bundeswehr
: water supply to German armed forces in Somalia, Kosovo and Afghanistan between 1993 and 2010
Authors: Willig Dierk
Published: February 2012

An army, the
Bundeswehr
, was created in the Federal Republic of Germany in 1956, from the 1960s supported by full-time geologists employed as civilians but with reserve army military ranks. A peak geologist strength (about 20) was achieved in the 1980s, to provide expertise that included hydrogeology. Roles in these Cold War years were confined to Germany, but included guidance to ensure that potable water would be available both to the civilian population and armed forces during a state of emergency, and the optimum siting of boreholes to supply water to military installations. In 1993,
Bundeswehr
troops deployed overseas, to support United Nations (UN) peace-keeping operations in Somalia. Military geological expertise was used to site wells that enhanced secure water supplies for German and other UN personnel, and the civilian population. In 1999,
Bundeswehr
troops were among those of the North Atlantic Treaty Organisation (NATO) deployed to Kosovo. Wells to supply water to German troops in Albania and Yugoslavian Macedonia prior to deployment, and in Kosovo itself, were drilled under civilian contract but military geologist guidance. From 2002,
Bundeswehr
troops joined coalition forces in Afghanistan. Well drilling was again guided by military geologist expertise, but contract drilling proved inadequate, so was supplemented by rigs operated by military engineers. These operations have proved the value to the
Bundeswehr
of retaining military expertise in both hydrogeology and well drilling.
Using computer simulation to explore the importance of hydrogeology in remote sensing for explosive threat detection
Authors: Howington S. E. , Peters J. F. , Ballard J. R. , Eslinger O. J. , Fairley J. R. , Kala R. V. , Goodson R. A. , Price S. J. , Hines A. M. , Wakeley L. D.
Published: February 2012

Finding explosive threats in complex environments is a challenge. Benign objects (e.g. rocks, plants and rubbish), ground surface variation, heterogeneous soil properties and even shadows can create anomalies in remotely sensed imagery, often triggering false alarms. The overarching goal is to dissect these complex sensor images to extract clues for reducing false alarms and improve threat detection. Of particular interest is the effect of soil properties, particularly hydrogeological properties, on physical temperatures at the ground surface and the signatures they produce in infrared imagery. Hydrogeological variability must be considered at the scale of the sensor's image pixels, which may be only a few centimetres. To facilitate a deeper understanding of the components of the energy distribution, a computational testbed was developed to produce realistic, process-correct, synthetic imagery from remote sensors operating in the visible and infrared portions of the electromagnetic spectrum. This tool is being used to explore near-surface process interaction at a fine scale to isolate and quantify the phenomena behind the detection physics. The computational tools have confirmed the importance of hydrogeology in the exploitation of sensor imagery for threat detection. However, before this tool's potential becomes a reality, several technical and organizational problems must be overcome.
Effect of near-surface hydrology on soil strength and mobility
Authors: Priddy Jody D. , Berney Ernest S. , Peters John F.
Published: February 2012

History has repeatedly demonstrated the potentially negative influence of near-surface hydrology on military mobility. Increased moisture and saturation in soil results in a transition from solid to somewhat liquid states. As soil approaches the liquid state, the shear strength available for supporting traffic of ground vehicles or aircraft diminishes. Historical engagements elucidate the importance for armies to recognize soil conditions that could compromise manoeuvre. Since World War II, the US Army has pursued research aimed at equipping soldiers with the tools and knowledge needed to account for the impact of near-surface hydrology on mobility. Significant portions of the research have been focused on characterizing soil trafficability as a controlling factor in ground vehicle mobility and on developing methods for rapidly assessing soil conditions to ensure adequate bearing capacity for expediently constructed roads and airfields. In contrast, hydrological conditions can also produce extremely dry soil with potential for surface layers to break down under ground vehicle and aircraft traffic loadings, resulting in a propensity for extreme dust generation, an entirely different problem for military mobility that the research has also been addressing. Mobility problems associated with these adverse soil conditions have not been eliminated, but the research has produced significant advancements.
Development of cleanup technologies for the management of US military installations
Authors: Miller Jerry , Foran Christy
Published: February 2012

In 1989 the environmental restoration programmes conducted independently by the US Army, Navy and Air Force were rationalized to jointly support research and technology transfer in this important field. By 1994 cleanup efforts were concentrated in four main areas: site investigation, groundwater modelling, treatment technologies and the fate/impact of potential contaminants. Since 1994, technology development has moved forward rapidly. Groundwater monitoring wells have served as the conventional method of collecting groundwater samples, although direct pushed technologies are now providing a faster and cheaper alternative. A range of groundwater models has been supported and a model is being developed for the Army to forecast the fate and risk of constituents derived from munitions. Cleanup technologies are increasingly moving away from processes that remove sediment or groundwater to
in situ
solutions. These include range management using lime, the establishment of biologically active zones for indigenous microbes, and phytoremediation. The environmental fate of contaminants has been predicted using flexible models. Examples are given from a number of sites including the US Military Academy at West Point and Langley Air Force Base. Investment continues to support studies to provide safer, faster and better remediation of contaminants related to past military use.
Crouching enemy, hidden ally: the decisive role of groundwater discharge features in two major British battles, Flodden 1513 and Prestonpans 1745
Authors: Younger Paul L.
Published: February 2012

Geomorphological features associated with groundwater discharge zones can affect ground conditions so greatly that they determine the outcomes of battles. Two cases in point are found in Scottish history: (i) despite outnumbering their English foes, the Scots lost the Battle of Flodden Field (9 September 1513), largely due to failing to identify the presence of marshy ground associated with an area of groundwater discharge; (ii) on 21 September 1745, the Jacobites defeated the Hanoverian army at Prestonpans by finding a way around marshland corresponding to a regional groundwater discharge zone, upon which the Hanoverian commander had been relying as a natural defensive feature. Analysis of both battlefields drawing upon present-day understanding of local stratigraphy and hydrogeological conditions allows identification of the specific groundwater discharge patterns that largely determined the outcomes of these two emblematic battles. At Flodden, the proximal source of groundwater discharge is Quaternary outwash gravels, distally fed from sedimentary strata (Cementstones) of lowermost Dinantian age. In the case of Prestonpans, the groundwater emerges from particularly arenaceous coal-bearing strata of Namurian age. Both case studies suggest that military commanders selecting advantageous terrain could benefit from consulting hydrogeologists who are familiar with the intricacies of groundwater geomorphology.