bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling of anisotropic surfaces within a covariant contact description
Authors: Konyukhov Alexander , Schweizerhof Karl
Published: December 2005

Within covariant contact descriptions all necessary characteristics, such as kinematics of deformation and the weak form, as well as all necessary operations, such as linearization and derivation of the finite difference scheme, are described in the specially defined local surface coordinate system, which is related to the closest point projection procedure. This description allows to generalize all contact characteristics into an anisotropic domain for both adhesion and sliding behavior in a straightforward form. The model can be used to describe the average behavior of machined surfaces. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimal Shape Design for Metal Forming Problems by the Finite Element Method
Authors: Lotfi Abdelhakim
Published: December 2005

In this work, a method for calculation of the optimal shapes of axisymmetrical converging dies by the finite element method is presented. The shape optimization problem considered in this paper is to find the best shape of the die such that the flow rate will be uniform at the die exit.The optimization problem is to minimize an objective function by varying a part of boundary (ie: the shape of die) subject to constraints imposed by the metal forming problem. In this method, the B‐spline functions allow us to determine the shape of the die, using its control points as design variables. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Contact Interaction of Faces of the Plane Crack under Harmonic Loading
Authors: Menshykov Oleksandr V.
Published: December 2005

The present work is devoted to the solution of the three‐dimensional fracture mechanics problem for a linear elastic, homogeneous and isotropic solid with a stationary plane crack under normal time‐harmonic loading. The problem has been solved by the method of boundary integral equations with the allowance for the contact interaction of the opposite faces of the crack. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Implementation of Thermomechanical Coupling for Shape Memory Alloys into the Finite Element Method
Authors: Pietryga Michael , Christ Daniel , Reese Stefanie
Published: December 2005

NiTi alloys open up new fields of application on the basis of their distinctive thermomechanical properties. Many options of practical application of shape memory alloys are imaginable. For example catheters or stents made of NiTi play an important role in medical technology. Thus the further development and optimisation of simulation tools for shape memory alloys (SMA) structures will play an important role in the future. Based on the powerful material model of Helm [1] the present contribution focuses on the coupling between mechanical and thermal fields. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulation of forming processes by using a new large deformation solidshell concept
Authors: Schwarze Marco , Reese Stefanie
Published: December 2005

This contribution deals with a new finite element formulation for the efficient simulation of forming processes, in particular for sheet metal forming. For that goal an isoparametric eight‐node solid‐shell formulation with linear ansatz functions is developed in which the undesirable effect of locking is completely eliminated. So only one element over the thickness is necessary which increases noticeably the numerical efficiency. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical solution of steady and unsteady flow over a vibrating airfoil in a channel
Authors: Honzátko Radek , Kozel Karel , Horáček Jaromír
Published: December 2005

The work deals with a numerical solution of 2D steady and unsteady inviscid incompressible flow over the profile NACA 0012 in a channel. The finite volume method (FVM) in a form of cell‐centered explicit schemes at quadrilateral C‐mesh is used. Governing system of equations is the system of incompressible Euler equations. The method of artificial compressibility and time dependent method is applied to steady computations. The small disturbance theory (SDT) applied to a numerical solution of flow over a rotated profile by a small angle only is mentioned. Brief introduction is given to the Arbitrary (Semi) Lagrangian‐Eulerian (ALE) method used for unsteady computations. Some numerical results of unsteady flow over a vibrating profile achieved by both SDT and ALE method are presented. Unsteady flow is caused by prescribed oscillations of the profile (one degree of freedom) fixed in an elastic axis. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
RANS‐simulation of premixed turbulent combustion using the level set approach
Authors: Kurenkov A. , Oberlack M.
Published: December 2005

A model for premixed turbulent combustion is investigated using a RANS‐approach. The evolution of the flame front is described with the help of the level set approach [1] which is used for tracking of propagating interfaces in free‐surface flows, geodesics, grid generation and combustion. The fluid properties are conditioned on the flame front position using a burntunburnt probability function across the flame front. Computations are performed using the code FASTEST‐3D which is a flow solver for a non‐orthogonal, block‐structured grid. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Kritik an gebräuchlichen dynamischen Messungen zur Bestimmungeffektiver elastischer Moduln
Authors: Besdo Silke , Besdo D.
Published: December 2005

Bei numerischen Simulationen von Knochengewebe oder strukturierten Medien werden elastische Konstanten benötigt. Um diese mit Hilfe dynamischer Verfahren, z.B. durch die Laufzeitenbestimmung von Ultraschallwellen, zu bestimmen, kann es, besonders bei den Schermoduln, zu beträchtlichen Fehlern kommen. Der Grund hierfür ist, dass zum einen bei der Aufbringung einer Schub‐Belastung stets auch Biegung auftritt und auerdem Biegewellen entstehen, die durch die einzelnen Bälckchen der Struktur laufen. Somit liegen die ermittelten Schubmoduln zu dicht an den Elastizitätsmoduln. Daher kann es vorkommen, dass eine negative Querkontraktionszahl ermittelt wird und einem Material ein auxetisches Verhalten zugesprochen wird, welches es gar nicht hat. Anhand von Balkentheorien und dynamisch‐numerischen Simulationen desWellendurchlaufs für 2D‐ und 3D‐Modelle kann gezeigt werden, dass tatsächlich Biegewellen und Longitudinalwellen vorweglaufen, die sich am Ende wieder zu einer Scherverformung umlagern. Diese wird dann als Ankunft der Scherwelle gemessen, obwohl die eigentliche Scherwelle erst wesentlich später angekommt. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Aerodynamic Interaction of Systems of Bodies in a Supersonic Flow
Authors: Stulov V. P. , Stulov P. V. , Zhdan I. A.
Published: December 2005

Use of numerical experiment methods gives broad opportunities for studying complex flows by rather simple and inexpensive means. This work is devoted to researches on aerodynamic interference of bodies in supersonic flows. Interest to similar problems is shown in a number of areas of modern mechanics: meteoritics, movement of multiphase media, applied fields. The head shock wave before a configuration of spheres with growth of distance h monotonously breaks up to individual shock waves before spheres of forward lines. The basic conclusion of this research is the following: distortion of supersonic stream around systems of bodies as though is transferred downstream, i.e. the influence of back bodies on the flow nearby forward bodies is small. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Kinetic model for chemical reactions in hypersonic non‐equilibrium flows
Authors: Zus Florian , Olivier Herbert
Published: December 2005

The interaction between vibrational relaxation and chemical processes is significant in many gas dynamic environments such as high‐enthalpy air flows. Extending a work of Marrone and Treanor [1] the influence of the vibrational excitation is examined not only on dissociation reactions, but also on exchange reactions. A synthetic cross section is chosen which allows to obtain a relatively simple form of a coupling factor between experimentally measured rates, valid only in thermal equilibrium, and theoretically derived rates, valid also in strong thermal‐nonequilibrium. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Implication for Lie group symmetries for RANS modeling
Authors: Guenther Silke , Oberlack Martin
Published: December 2005

Since the symmetries of fluid motion are admitted by all statistical quantities of turbulent flows as can be taken from the multipoint equations, we can derive conditions for turbulence models so that they capture the proper flow physics. Concerning these constraints we will exemplary investigate the k – ϵ – model for its capability to reproduce new scaling laws derived from symmetry methods. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preparation and EMI shielding properties of nickel‐coated PET fiber filled epoxy composites
Authors: Zeng W. , Tan S.T.
Published: December 2005

Electrically conductive composites were prepared using epoxy resin (EP) as matrix and nickel‐coated polyethylene teraphthalate (PET) fibers as filler. The fibers were coated with nickel by plating and ultrasonic electroless deposition techniques. The coaxial transmission line method was used to measure the electromagnetic interference (EMI) shielding effectiveness of the nickel‐coated PET fiber/EP composites. The contents of nickel and phosphorus in the coating were determined by X‐ray photoelectron spectroscopy (XPS). As a result, the ultrasonic electroless nickel‐coated PET fiber/EP composites showed excellent electrical conductive capability and better EMI shielding effectiveness due to higher content of nickel and lower content of phosphorus in the coating than conventional plated nickel‐coated PET fiber/EP composites. POLYM. COMPOS., 27:24–29, 2006. © 2005 Society of Plastics Engineers
Proteome analysis identifies novel protein candidates involved in regeneration of the cerebellum of teleost fish
Authors: Zupanc Marianne M. , Wellbrock Ursula M. , Zupanc Günther K. H.
Published: December 2005

In contrast to mammals, adult teleost fish exhibit an enormous potential to regenerate neuronal tissue after injuries to the CNS. By combining a well‐defined cerebellar lesion paradigm with differential proteome analysis at a post‐lesion survival time of 3 days, we screened for protein candidates involved in repair of the fish brain. Out of nearly 900 protein spots detected on 2‐D gels, spot intensity was significantly increased at least twofold in 30 spots and decreased to at least half the intensity of control tissue in 23 spots. The proteins associated with 24 of the spots were identified by PMF and MS/MS fragmentation. The cellular localization and the spatiotemporal patterns of two of these proteins, beta‐actin and beta‐tubulin, were further characterized through immunohistochemistry. Comparison of the observed changes in protein abundance with the previously characterized events underlying regeneration of the cerebellum suggests that the proteins identified are especially involved in cellular proliferation and survival, as well as axonal sprouting.
Expressed proteome analysis of human hepatocellular carcinoma in nude mice (LCI‐D20) with high metastasis potential
Authors: Shen Huali , Cheng Gang , Fan Huizhi , Zhang Jie , Zhang Xiangmin , Lu Haojie , Liu Chunli , Sun Fengxia , Jin Hong , Xu Xuejiao , Xu Guobin , Wang Sheng , Fang Caiyun , Bao Huimin , Wang Yan , Wang Jing , Zhong Hua , Yu Ziniu , Liu Yinkun , Tang Zhaoyou , Yang Pengyuan
Published: December 2005

We report for the first time an expressed proteome for human hepatocellular carcinoma (HCC) in nude mice model. Most cases of human liver cancer are HCC with highly metastatic ability. Therefore, the early prediction or diagnosis and effective treatment are the key points of research. We have previously successfully established a human HCC nude mice model (LCI‐D20) with high metastasis potential. To understand better the tumor biology of HCC it is worth to explore the relativity of all expressed protein profiles in the LCI‐D20 HCC nude mice model. With advanced proteomics technologies, we have carried out a proteomic analysis with following stages: protein sample preparation of cancer tissue, including total cellular extraction and sequential fractionation, 2‐DE and 2‐D LC separation, ESI/MALDI‐MS/MS identification, as well as data‐dependent bioinformatics. The identified proteins were classified bioinformatically respective to their function, biological process and intracellular localization. Some important proteins found in HCC, e.g. metabolism enzymes, proteins regulating cell motility, signaling proteins, and heat shock proteins, are discussed in terms of their metastasis.
Synthesis and characterization of polyimides derived from (3‐amino‐2,4,6‐trimethylphenyl)‐(3′‐aminophenyl)methanone and aromatic dianhydrides
Authors: Li Z. X. , Lin L. Q. , Zhang W. M. , Wu T. , Pu J. L.
Published: December 2005

A series of new polyimides were prepared via the polycondensation of (3‐amino‐2,4,6‐trimethylphenyl)‐(3′‐aminophenyl)methanone and aromatic dianhydrides, that is, 3,3′,4,4′‐biphenyltetracarboxylic dianhydride (BPDA), 4,4′‐oxydiphthalic anhydride, 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride, and 2,2′‐bis(3,4‐dicarboxyphenyl) hexafluoropropane dianhydride. The structures of the polyimides were characterized by Fourier transform infrared and NMR measurements. The properties were evaluated by solubility tests, ultraviolet–visible analysis, differential scanning calorimetry, and thermogravimetric analysis. The two different meta‐position‐located amino groups with respect to the carbonyl bridge in the diamine monomer provided it with an unsymmetrical structure. This led to a restriction on the close packing of the resulting polymer chains and reduced interchain interactions, which contributed to the solubility increase. All the polyimides except that derived from BPDA had good solubility in strong aprotic solvents, such as N‐methyl‐2‐pyrrolidinone, N,N′‐dimethylacetamide, N,N‐dimethylformamide, and dimethyl sulfone, and in common organic solvents, such as cyclohexanone and chloroform. In addition, these polyimides exhibited high glass‐transition values and excellent thermal properties, with an initial thermal decomposition temperature above 470 °C and glass‐transition temperatures in the range of 280–320 °C. The polyimide films also exhibited good transparency in the visible‐light region, with transmittance higher than 80% at 450 nm and a cutoff wavelength lower than 370 nm. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1291–1298, 2006
New combined polymer/chromium approach for investigating the phototransformations involved in hologram formation in dichromated poly(vinyl alcohol)
Authors: Djouani Fatma , Israëli Yaël , Frezet Lawrence , Rivaton Agnès , Lessard Roger A. , Bolte Michèle
Published: December 2005

The photochemical behavior of dichromated poly(vinyl alcohol) films has been analyzed upon exposure at 365 nm in relationship with the performances of holograms recorded in such photosensitive materials. The evolution of both involved species, poly(vinyl alcohol) and chromium, has been quantified by the implementation of an innovative approach. This approach combines the monitoring of the structural modification of the polymeric matrix and the fate of the various chromium species. For the first time, it has been established that chromium(V) not only is an indicator of the hologram quality, as previously assessed, but also appears to be responsible for the crosslinking implied in the hologram formation. Actually, the crosslinking has been proved to proceed through coordination bonds around chromium(V), which acts as a bridge between the polymeric chains. The role played by the ammonium cations in the hologram quality has also been elucidated. The improvement brought by ammonium dichromate with respect to potassium dichromate involves amide groups resulting from poly(vinyl alcohol) phototransformation. These groups provide additional chelating sites for chromium(V), leading to an increase in the matrix crosslinking. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1317–1325, 2006
Phonon dispersion in polycytidilic acid
Authors: Srivastava Seema , Panday Manish Kumar , Srivastava Shinoo , Gupta Vishwambhar Dayal , Khan I. A.
Published: December 2005

A study of the normal modes of vibration and their dispersion in polycytidilic acid based on the Urey–Bradley force field and Raman and Fourier transform infrared spectroscopy is reported. Characteristic features of dispersion curves such as regions of high density of states, repulsion, and character mixing of dispersive modes are discussed. The predictive value of the heat capacity as a function of temperature is reported. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 504–516, 2006
Modeling the Porosity Evolution of a Powder under Uniaxial Compression
Authors: Lamy Peggy , Brunet Luc , Thomas Gérard
Published: December 2005

The purpose of this work is to present a new model describing the evolution of powder porosity versus applied pressure during uniaxial compression. This model is based on quasi‐chemical treatments and population balances. It is generally admitted that compression is composed of four steps: a first reorganization of the initial particles, a fragmentation of some initial particles, a second rearrangement of the initial and secondary particle mixture and a plastic deformation stage. So the model is constructed around these four steps. Experimental results on eighteen different powders show a fair agreement with theoretical results and material physical constant values. The use of this model can allow classifying the reorganization, fragmentation and plastic deformation abilities of the products and it will be useful in order to optimize the elaboration process.
Surface Energy and Crystallization Phenomena of Ammonium Dinitramide
Authors: Teipel Ulrich , Heintz Thomas
Published: December 2005

Ammonium dinitramide (ADN) was characterized during recrystallization from the melt. The surface tension of molten ADN at 97 °C was measured to be 89 mN/m. The wetting angles between molten ADN and different solid surfaces (polytetrafluoroethylene, glass, steel, and aluminum) were determined. The wettability depends on the surface tension of molten ADN, the free surface energy of the solid surfaces and the interfacial tension between the solid and liquid. Observations of the recrystallization behavior of molten ADN showed that nucleation does not occur, even at super cooling rates of 70 K. Crystallization can be initiated by the application of seed crystals.
High Pressure Raman Spectroscopic Study of the Effects of n‐Ethylamines and Water on the 2‐Nitropropane/Nitric Acid System
Authors: Gobin Cedric , Petitet Jean Pierre
Published: December 2005

High pressure Raman spectroscopy measurements in a diamond anvil cell (0–10 GPa) on 2‐nitropropane/nitric acid/X (X=triethylamine, diethylamine, and water) ternary systems and 2‐nitropropane/nitric acid/water/Y (Y=triethylamine and diethylamine) quaternary systems are reported. The modifications of the chemical behavior of the 2‐nitropropane/nitric acid model system, induced by the presence of triethylamine, diethylamine, and/or water, were studied at ambient and high pressure. At ambient pressure, the ionization of the nitric acid has been observed with each of the additives. Moreover, in the case of ethylamines, new peaks have been observed and the hypothesis of a 2‐nitropropane/ethylamine complex is advanced. At high pressure, the decomposition of the 2‐nitropropane/nitric acid system, with an oxygen balance near zero, has been observed only in presence of triethylamine. The role of each additive to the 2‐nitropropane/nitric acid system in the modification of the respective reducing and oxidizing character of the components, and in the reactivity of the system, is discussed. Several hypotheses are advanced concerning the sensitizing effect of the additives on the 2‐nitropropane/nitric acid system.
Preparation and Characterization of Reticular Nano‐HMX
Authors: Yongxu Zhang , Dabin Liu , Chunxu Lv
Published: December 2005

Reticularly structured HMX (octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine) of nano‐size particles was simply prepared by reprecipitation at room temperature. The sample prepared by reprecipitation was characterized by SEM, TEM, XRD, DSC, and drop weight impact. The results of SEM and TEM indicated that spherical HMX particles of about 50 nm in diameter aggregated into reticularly structured conglomerates. There are two phases (γ‐ and β‐HMX) existing in the reticularly structured HMX as shown in the XRD pattern. It was also proved by DSC that the maximum energy release during decomposition of the reticularly structured HMX is at lower temperature. In addition, the testing result of drop weight impact showed that the reticularly structured HMX is less sensitive to impact.
A Novel Synthetic Route to Hexanitrohexaazaisowurtzitane
Authors: Pang Si‐Ping , Yu Yong‐Zhong , Zhao Xin‐Qi
Published: December 2005

A new, non‐hydrogenolytic synthesis of hexanitrohexaazaisowurtzitane (HNIW, 1) has been investigated. The treatment of hexabenzylhexaazaisowurtzitane (HBIW, 2) with potassium permanganate in acetic anhydride resulted in oxidative debenzylation and acetylation to give tetraacetyldibenzylhexaazaisowurtzitane (TADB, 3a) and other intermediates from the oxidation. Subsequent nitrosolysis and nitrolysis of these intermediates with 65% HNO3/NaNO2 and 70% HNO3/AN produced HNIW in fair yield.
Superoxide dismutase in the prostate lobes of aging brown Norway rats
Authors: Pechenino Angela S. , Brown Terry R.
Published: December 2005

BACKGROUND

Spontaneous age‐dependent epithelial cell hyperplasia occurs in the lateral and dorsal, but not the ventral, lobes of aging Brown Norway (BN) rats. Diminished antioxidant enzyme activities and increased formation of reactive oxygen species (ROS) promote the pathology of many aging disorders. We investigated the hypothesis that prostatic epithelial cell hyperplasia in the BN rat was related to age‐dependent and/or lobe‐specific changes in superoxide dismutase (SOD).

MATERIALS AND METHODS

Using Western blots, immunohistochemistry and enzyme activity assays we determined the levels of protein expression, subcellular localization, and activities, respectively, of the three SOD isoforms, cytoplasmic SOD1, mitochondrial SOD2, and extracellular SOD3 in the ventral, lateral, and dorsal prostate lobes of 4‐month‐old rats with normal prostate morphology, in 24‐month‐old rats with lobe‐specific hyperplasia and in older 30‐month‐old rats.

RESULTS

We observed little change in SOD activities as a function of age, although expression of SOD3 increased in the prostatic lobes of older rats. SOD2 levels were higher in the lateral lobe of 4‐ and 24‐month‐old rats, but declined by 30 months of age to levels in the ventral and dorsal lobes. SOD1 was localized by immunohistochemistry to the nuclei of epithelial cells in all lobes, but the number of immunopositive nuclei increased in the lateral and dorsal lobes of 24‐month‐old animals. The concentration of zinc was highest in the prostate lobes of 24‐month‐old animals.

CONCLUSION

Based upon our data, superoxide dismutase is not significantly altered in the rat prostate during aging and thus is unlikely to be an important factor in the evolution of epithelial cell hyperplasia. Prostate © 2005 Wiley‐Liss, Inc.
E‐cadherin polymorphisms and haplotypes influence risk for prostate cancer
Authors: Bonilla Carolina , Mason Tshela , Long Layron , Ahaghotu Chiledum , Chen Weidong , Zhao Aiqiu , Coulibaly Aoua , Bennett Frankly , Aiken William , Tullock Trevor , Coard Kathleen , Freeman Vincent , Kittles Rick A.
Published: December 2005

BACKGROUND

The E‐cadherin (CDH1) gene has been implicated in prostate cancer (PCA) risk, however, the exact mechanism is unknown. Several polymorphisms, such as the C/A variant −160 base pairs from the transcription start site, in the CDH1 gene promoter region have been associated with cancer risk, mainly in European descent populations.

METHODS

We screened the entire coding region and 3.0 kilobases of the CDH1 promoter for polymorphisms in 48 African Americans using dHPLC. Twenty‐one (21) polymorphisms were observed. Four polymorphisms, including −160C/A, were genotyped in a genetic association study using incident PCA cases (N = 427) and unaffected controls (N = 337) of similar age from three different ethnic groups consisting of African Americans, Jamaicans, and European Americans.

RESULTS

We observed a significantly higher frequency of the −160A allele among European American PCA patients (27.5%) compared to the control group (19.7%) (P = 0.04). More importantly, among men of European ancestry under the age of 65 who possess the −160 A allele there was over three times increased risk for prostate cancer (P = 0.05). Also, the AACT haplotype bearing the −160A allele was significantly associated with PCA in European Americans (P = 0.04).

CONCLUSIONS

Our data indicate that CDH1 likely is a low‐penetrant PCA susceptibility gene, however, population differences in linkage disequilibrium within the CDH1 gene region may influence the effect of susceptibility alleles such as −160A. © 2005 Wiley‐Liss, Inc.
Spatial correlations of most mobile or immobile particles in supercooled Al2O3
Authors: Van Hoang Vo
Published: December 2005

Spatial correlations of most mobile and immobile particles in supercooled Al2O3 model at the temperatures of 2100 K have been investigated by using molecular dynamics (MD) method. Simulations were done in the basic cube under periodic boundary conditions containing 3000 ions with Born–Mayer type pair potentials. We evaluate the non‐Gaussian parameter for the self‐part of the van Hove correlation function, atomic displacement distribution (ADD) and cluster‐size distributions of most mobile and immobile particles in the model. We compare the partial radial distribution functions (PRDFs) for the 5% most mobile or immobile Al, O particles with the corresponding mean ones. We have found that mean cluster size grows with decreasing temperature. The composition evolution in subset of most mobile or immobile particles upon cooling and annealing was obtained and presented. The relation between local structure and dynamics in the system has been studied and discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical transition properties of the Nd3+ ions in Ca3(BO3)2 crystal
Authors: Lu Xiuai , You Zhenyu , Li Jianfu , Zhu Zhaojie , Jia Guohua , Wu Baichang , Tu Chaoyang
Published: December 2005

Ca3(BO3)2 single crystals have been grown by the Czochraski technique. The absorption and emission spectra have been measured at room temperature. From the Judd–Ofelt theory analysis, the intensity parameters were determined to be Ω2 = 4.63 × 10–20 cm2, Ω4 = 2.40 × 10–20 cm2, and Ω6 = 10.4 × 10–20 cm2. The calculated radiative probabilities, radiative lifetimes, and the branching ratios have been evaluated for the 4F3/2 excited state using the calculated intensity parameters. The stimulated emission cross‐section was also measured at 1060 nm. The results indicate that this crystal can be considered as a promising material for solid‐state laser application. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Incidence and Impact of Risk Factors in Critically Ill Trauma Patients
Authors: Bochicchio Grant V. , Joshi Manjari , Bochicchio Kelly , Shih Diane , Meyer W. , Scalea Thomas M.
Published: December 2005

There is a paucity of data describing the incidence of pre‐existing diseases or risk factors and their effects in trauma patients. We conducted a prospective study to determine the incidence of such factors in critically ill trauma patients and to evaluate their impact on outcome. The study, performed over a 2‐year period, examined the hospital course of all trauma patients admitted to the ICU. Multiple risk factors were evaluated and analyzed via multivariate regression analysis. Outcome was evaluated by infection rate, hospital length of stay, ventilator days, and mortality matched for age and Injury Severity Score (ISS). A total of 1172 patients (73% blunt injury) were enrolled over the study period. Of these, 873 (74.5%) were male. The mean age was 42.5 years with an ISS of 19.8. Tobacco use (24%) was the most common risk factor identified, followed by hypertension (HTN, 17%), coronary artery disease (9%), chronic obstructive pulmonary disease (COPD)/reactive airway disease (4%), non‐insulin‐dependent diabetes (NIDDM) (4%), insulin‐dependent diabetes (IDDM) (3.2%), cancer (3%), liver disease (2%), and HIV/AIDS (1.4%). Of these risk factors, IDDM was found to be an independent risk factor for infection (0.004) and ventilator days (0.047), increasing age was found to be an independent risk factor for hospital length of stay (0.023) and mortality (<0.001), and HTN was found to be an independent risk factor for increased ventilator days (0.04). In addition, COPD/reactive airway disease was found to be an independent predictor of ventilator days, infection, and ICU days (P < 0.05). Thus, increased age, IDDM, COPD, and HTN are most predictive of outcome in critically ill trauma patients. With our aging population it is becoming increasingly important to identify pre‐existing risk factors on admission in order to minimize their effects on outcome.
Biomechanical Evaluation of a New Composite Bioresorbable Screw
Authors: BAILEY C. A. , KUIPER J. H. , KELLY C. P.
Published: December 2005

A new bioresorbable composite cannulated screw has been developed for small bone fracture fixation. The LG (“Little Grafter”) screw is manufactured from Biosteon™, which is a composite of poly l-lactic acid and hydroxyapatite. This study aimed to compare interfragmentary compression generated by this new screw with conventional metal screws commonly used in scaphoid fracture fixation. Four small metallic screws were compared with the LG screw, using a bone model produced from rigid polyurethane foam. The screws included the Acutrak, Asnis III, Herbert and Herbert–Whipple screws. The mean maximum compression forces for the LG screw, the Asnis and the Acutrak were comparable (LG 32.3 N, Asnis 32.8 N, Acutrak 38.3 N), whereas those using the Herbert and the Herbert–Whipple screw were significantly lower (Herbert 21.8 N, Herbert–Whipple 19.9 N). The bioresorbable LG screw has been shown to have good compressive properties compared to commonly used small bone fragment compression screws.
Electromyography Monitoring of Patients With Salivary Gland Diseases
Authors: Vaiman Michael , Nahlieli Oded , Segal Samuel , Eviatar Ephraim
Published: December 2005

OBJECTIVE

To provide a description of surface electromyography (sEMG) of spontaneous saliva swallowing (SSS) and monitoring of swallow rate in patients with salivary gland diseases.

STUDY DESIGN

Numbers of SSS obtained during 2 hours of sEMG monitoring were compared with sialometry data for healthy volunteers (n = 100), patients with Sjögren syndrome (n = 10), and patients after parotid gland (n = 15) and submandibular gland (n = 16) surgery.

RESULTS

Normative: 1 SSS every 2 minutes and 15 seconds; Sjögren: 1 SSS every 13 minutes (P < 0.001); parotid gland surgery: 1 SSS every 3 minutes and 24 seconds (P = 0.26); submandibular gland surgery: 1 SSS every 5 minutes and 04 seconds (P < 0.05). Sjögren patients and patients after submandibular surgery had hyposalivation correlated with less SSS.

CONCLUSION

The established normal rate of SSS makes this modality applicable for evaluating salivary flow for potentially identifying and ruling out abnormalities. Parotid gland surgery does not significantly affect salivary flow rate. Sialometry combined with sEMG monitoring give a clinician more reliable data to evaluate salivary gland disorders than sialometry alone.

EBM RATING

B‐2
Effect of Topical Mitomycin C on the Healing of Surgical and Laser Wounds: A Hint on Clinical Application
Authors: Roh Jong‐Lyel , Koo Bon Seok , Yoon Yeo‐Hoon , Rha Ki Sang , Park Chan IL
Published: December 2005

OBJECTIVES

Mitomycin C (MMC) is used in otolaryngological surgery to reduce complications from postoperative scarring. However, the effects of MMC on wound healing at different doses and on different wound types have not been fully described. The aim of this study was to evaluate the effects of topical MMC at 2 different doses on the healing of surgical and laser wounds.

STUDY DESIGN AND SETTING

This was a randomized study using 20 rabbits. Six full‐thickness wounds were made by excision or laser vaporization on the flank skin. The wounds were randomly treated by topical MMC of 0.4 or 1.0 mg/mL or saline for 5 minutes.

RESULTS

Re‐epithelialization and contraction of the original wounds were significantly delayed by the use of MMC (P < 0.01). The delayed healing effect of MMC was more prominent in the laser wounds than in the excision wounds. MMC inhibited collagen deposition and fibroblast proliferation of wounds on histological analysis. The 2 different concentrations of MMC showed no difference in gross or histological wound healing characteristics.

CONCLUSION

Our results showed that MMC delays the healing of wounds as a result of the inhibition of fibrosis, especially for laser wounds.
Interspecific relationships between two species of sympatric Afrotropical water snake in relation to a seasonally fluctuating food resource
Authors: Luiselli Luca
Published: December 2005

In this paper, the ecological relationships and the resource partitioning patterns in a two-species system of sympatric aquatic snakes (Grayia smythii and Afronatrix anoscopus) from a riverine forest area in southern Nigeria, West Africa, were tested. The monthly availability of their food resources in the field, and the monthly variation in the feeding relationships between these snakes and their preys, were also studied. Food items of 1245 snakes, i.e. 554 Grayia smythii, and 691 Afronatrix anoscopus, were examined. The mean body length of Grayia smythii was significantly larger than that of Afronatrix anoscopus in any interspecific comparison, i.e. males versus males, females versus females, and females versus males; however, in both species the females attained significantly larger body sizes than the males. 676 prey items were obtained from the stomachs of Afronatrix anoscopus, and 390 from those of Grayia smythii. Both species of snake exhibited an increased activity in the open during the wet months, and this increased activity was positively correlated to the higher abundance of prey during the wet season. In both species the diet consisted of a great variety of different amphibian and fish species. Direct interference competition was not observed. The month-by-month dietary patterns exhibited by the two snake species were similar. Mean prey size was significantly larger in the larger species, and the difference in prey size between the two snake species increased during the dry season, i.e. during the period of reduced prey availability. The monthly availability of the three main food types for these snakes varied, and were significantly more abundant during the wet season (April–September). A positive relationship between prey availability and prey use by snakes strongly suggests that the two snake species are predatory generalists, utilizing prey in relation to their abundance in the field.
Biogeochemistry of an afrotropical montane rain forest on Mt. Kilimanjaro, Tanzania
Authors: Schrumpf Marion , Zech Wolfgang , Axmacher Jan C. , Lyaruu Herbert V. M.
Published: December 2005

In contrast to their well-studied counterparts in the Neotropics and in Asia, East African montane rain forests are surrounded by semi-arid savanna plains. These plains have a high erosion potential for salt crusts accumulated at the soil surface. Hence it may be hypothesized that East African montane forest ecosystems experience strongly enhanced nutrient inputs via dry deposition, which alters their overall biogeochemistry. The aim of our study was to test this hypothesis by investigating K, Mg, Ca, Na and N-forms in rainfall, throughfall, fine litter, litter percolate and soil solution of a montane rain forest at Mt. Kilimanjaro. Four forest plots situated at elevations between 2250 and 2350 m asl on the south-western slopes of Mt. Kilimanjaro were studied for 2 y. In contradiction to our hypothesis, inputs of K, Mg, Ca and Na via rainfall (7.5, 0.9, 2.3 and 6.2kg ha−1y−1) and throughfall (35, 2.0, 3.5 and 11kg ha−1−1) were low on Mt. Kilimanjaro. Fluxes of NH4-N and NO3-N were within the range observed at other montane rain forests, with NO3-N being the only nutrient partly absorbed in the forest canopies (2.9kg ha−1y−1 in rainfall, 0.9kg ha−1y−1 in throughfall). The highest overall nutrient concentrations in water samples occurred in litter percolate (1.4mg l−1 K, 0.3mg l−1 Mg, 0.8mg l−1 Ca, 0.3mg l−1 NH4-N, 0.9mg l−1 NO3-N), with values still being low compared to other sites. Nutrient concentrations in seepage water strongly declined with increasing soil depth. Thus, both inputs and losses of base cations from the forest by water pathways are assumed to be low. N or P limitation of growth is not expected since high fluxes of N and P in fine litter (119 and 5.9kg ha−1y−1 for N and P respectively) indicate low within-stand efficiency.
Gleaning bats as underestimated predators of herbivorous insects: diet of Micronycteris microtis (Phyllostomidae) in Panama
Authors: Kalka Margareta , Kalko Elisabeth K. V.
Published: December 2005

Predators of herbivorous insects play important roles in tropical ecosystems as herbivory may affect structure and diversity of plant populations. Although insectivorous bats are particularly abundant and diverse in the tropics, their impact on herbivorous insects is little understood. To assess prey consumption, we observed the gleaning bat Micronycteris microtis (Phyllostomidae) continuously for 3 mo including 16 full nights at a nightly feeding roost on Barro Colorado Island in Panama using infrared videotaping combined with collection of prey remains. Individual bats consumed about 61–84% of their body mass in arthropods per night. Diet analysis revealed a high percentage of herbivorous insects, constituting more than half (51%) of all prey and over 70% of prey biomass. Dominant prey were caterpillars (33% of prey biomass), and other herbivores including crickets, katydids, scarab beetles and phasmids. Furthermore, a novel feeding behaviour was observed as M. microtis selectively discarded parts of intestines of phytophagous insects before consumption, probably to avoid intake of plant material either for ballast reduction and/or for protection from secondary plant compounds. Combined with estimated feeding rates of insects in sympatric bat species, our data suggest that gleaning bats are important predators of herbivorous insects and might be under-estimated reducers of herbivory in the tropics.
He diffusion in monazite: Implications for (U‐Th)/He thermochronometry
Authors: Boyce J. W. , Hodges K. V. , Olszewski W. J. , Jercinovic M. J.
Published: December 2005

The light rare earth phosphate mineral monazite contains high concentrations of Th and U and thus should have potential as a (U‐Th)/He thermochronometer. New 4He diffusion experiments confirm this potential but suggest that the bulk closure temperature may be so strongly compositionally dependent that successful applications will require careful sample characterization prior to (U‐Th)/He dating. Three experiments were performed on single crystals of Monazite 554, a material that has been used as a standard for Th‐Pb ion microprobe geochronology. The data from each experiment yielded a linear array on an Arrhenius diagram, consistent with simple diffusion behavior. However, the diffusion parameters indicated for each grain were statistically different, indicating closure temperatures (assuming a cooling rate of 10°C/Myr) of 206 ± 24°C, 230 ± 4°C, and 286 ± 13°C. X‐ray compositional maps of Monazite 554 illustrate a possible cause of this discrepancy: strong and geometrically complex chemical zoning that varies from grain to grain and likely corresponds to several episodes of growth and dissolution. If He diffusivity in monazite is compositionally controlled, individual crystals with such inconsistent zoning (which is typical of naturally occurring monazites) should have different bulk closure temperatures.
Large‐scale atmospheric dynamics and local intense precipitation episodes
Authors: SanchezGomez E. , Terray L.
Published: December 2005

Weather extreme events have important consequences in the environmental, social and economic sectors. Numerous efforts have been devoted to identify the large‐scale (LSC) climate dynamics connected to them. In this paper we show that the LSC circulation patterns associated with intense precipitation episodes (IPE) over a specific domain can be identified from clustering algorithms. For an extended winter season (from 16th October to 15th April), using daily maps of geopotential height at 500 hPa selected on the basis of precipitation threshold exceedence, we found that over western France, the LSC pattern linked to IPE occurrence displays a strong negative anomaly over Great Britain. This pattern corresponds to the structure observed during the transition from Zonal to Greenland Anticyclone standard weather regimes. It is the least likely transition from the Zonal regime, suggesting potential links between atmospheric dynamics and the occurrence of IPE.
Constraining the boundary between the Sunda and Andaman subduction systems: Evidence from the 2002 Mw 7.3 Northern Sumatra earthquake and aftershock relocations of the 2004 and 2005 great earthquakes
Authors: DeShon Heather R. , Engdahl E. Robert , Thurber Clifford H. , Brudzinski Michael
Published: December 2005

The 2004 Mw 9.0 Sumatra‐Andaman earthquake initiated along the Andaman subduction zone, north of the last great Sumatra earthquake along the Sunda Trench in 1861. During the 2005 Mw 8.7 Banyak Islands earthquake, a portion of the 1861 rupture subsequently failed. The boundary between the 2004 and 2005 ruptures broadly coincides with local trench rotation and the southern edge of the Andaman microplate, which suggests structural control on fault segmentation. Aftershock relocations of the 2004 and 2005 earthquakes show little overlap, and the sharp boundary between the series locates near the 2002 Mw 7.3 Northern Sumatra earthquake. We posit that these features represent the southern extent of the stable Andaman microplate, ∼50–100 km northwest of what was previously reported. Broadband analyses of the 2002 earthquake yield a bilateral rupture pattern that is used to model Coulomb stress changes near the 2004 hypocenter to assess stress interactions along adjacent fault segments.
Westward shift of the Yellow Sea warm salty tongue
Authors: Huang Daji , Fan Xiaopeng , Xu Dongfeng , Tong Yuanzheng , Su Jilan
Published: December 2005

The accumulated in situ hydrographic survey as well as the satellite observed sea surface temperature (SST) show consistent westward shifting of the Yellow Sea Warm Salty Tongue (YSWST) in winter. A 2‐D thermal model is used to show the westward shifting of the YSWST due to cooling and advection. The MITgcm is applied to simulate the circulation in the Yellow and East China Seas. Under the northern monsoon wind in winter, the sea surface height (SSH) is adjusted to have a ridge in the channel and a trough in the 50–70 m iso‐bath in the Yellow Sea. The barotropic transport of SSH and baroclinic transport of horizontal density gradient play the major role for the shifting of the YSWST, while the Ekman wind drift plays a minor role.
FEMSECT: An inverse section model based on the finite element method
Authors: Losch M. , Sidorenko D. , Beszczynska‐Möller A.
Published: December 2005

A new inverse model is presented for the analysis of hydrographic section data in conjunction with velocity measurements. The model offers advantages over commonly applied interpolation techniques because it combines data and physical assumptions such as geostrophic balance in the framework of a finite element discretization. Specifically, a quadratic objective function of model‐data misfits is minimized to give estimates of transports together with formal error estimates. The finite element method allows the accurate representation of highly irregular bottom topography and ensures consistent interpolation of model variables to measurement points. The model is called Finite Element Method Section model (FEMSECT). FEMSECT also gives improved flexibility and performance over standard box models by allowing dynamic adjustment of the model variables temperature and salinity. Idealized test cases illustrate that the finite element methods solve the thermal wind equations far more accurately than standard finite difference methods, especially in the presence of steep topography. For a more realistic test, FEMSECT is applied to hydrographic conductivity‐temperature‐depth section data and moored instrument current meter measurements from an array in the Fram Strait. Transport estimates by FEMSECT prove to be more robust and less sensitive to the spatial data resolution than estimates by a conventional interpolation method that only uses information from moored instruments. FEMSECT is available as a highly portable Matlab code and can be run on an ordinary desktop computer.
High‐resolution numerical simulations of resuspending gravity currents: Conditions for self‐sustainment
Authors: Blanchette F. , Strauss M. , Meiburg E. , Kneller B. , Glinsky M. E.
Published: December 2005

We introduce a computational model for high‐resolution simulations of particle‐laden gravity currents. The features of the computational model are described in detail, and validation data are discussed. Physical results are presented that focus on the influence of particle entrainment from the underlying bed. As turbulent motions detach particles from the bottom surface, resuspended particles entrained over the entire length of the current are transferred to the current's head, causing it to become denser and potentially accelerating the front of the current. The conditions under which turbidity currents may become self‐sustaining through particle entrainment are investigated as a function of slope angle, current and particle size, and particle concentration. The effect of computational domain size and initial aspect ratio of the current on the evolution of the current are also considered. Applications to flows traveling over a surface of varying slope angle, such as turbidity currents spreading down the continental slope, are modeled via a spatially varying gravity vector. Particular attention is given to the resulting particle deposits and erosion patterns.