bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recent developments in modelling of liquid phase electroepitaxy under applied magnetic field
Authors: Dost S. , Sheibani H. , Liu Y. C. , Lent B. 
Published: February 2005

AbstractGrowth of single crystals under magnetic field is of interest for suppressing the adverse effect of natural convection and for better mixing in the liquid solution, which are the favorable conditions for prolonged growth and high quality crystals. In this short review article, recent developments in the modelling of electroepitaxy under magnetic field are presented. An application is given for the liquid phase electroepitaxial growth of GaAs bulk single crystals under a static magnetic field. Experimental results, that have shown that the growth rate under an applied static magnetic field is proportional to the applied magnetic field, and increases with the field intensity level, are predicted from the present model. The model also predicts growth interface shapes accurately. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Behavior of oxygen bubbles during crystal growth of Ca12Al14O33 by floating method in magnetic field
Authors: Park J. K. , Shimomura T. , Yamanaka M. , Watauchi S. , Kishio K. , Tanaka I. 
Published: February 2005

AbstractMagnetic field generator using a helium‐free superconducting magnet was installed with an infrared light heating floating zone (FZ) apparatus. Single crystals of Ca12Al14O33, in which oxygen bubbles easily remain when it is grown by a conventional FZ, were grown in various magnetic conditions in order to investigate the behavior of oxygen bubbles in molten zone, and to research the magnetic effects on FZ growth. When the crystals were grown at the lower position than center of the magnet bore, where magnetic force to paramagnetic oxygen gas is upward, oxygen bubbles formed in the molten zone were inclined to go toward stronger field and the grown crystals were half transparent and half opaque. The distribution of remaining oxygen bubbles in crystals was rather lopsided than centered. These effects might be explained by the magnetic force effect and the magnetic convection effect driven by inhomogeneous heating of the melt.
3D global analysis of CZ‐Si growth in a transverse magnetic field with rotating crucible and crystal
Authors: Liu Lijun , Kakimoto Koichi 
Published: February 2005

AbstractThree‐dimensional global simulations were carried out for a small Czochralski furnace for silicon crystal growth with a recently developed global model. The furnace is placed in a transverse magnetic field with rotating crucible and crystal. The convective, conductive and radiative heat transfers in the entire furnace were solved in a three‐dimensionally conjugated way. Three‐dimensional distributions of temperature and velocity were analyzed. The melt‐crystal interface was found to have nearly rotational symmetry, and the azimuthal non‐uniformity of temperature is much weaker on the crystal and crucible sidewalls in the case of high rotation rates of crucible and crystal than in the case of non‐rotating crucible and crystal. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In situ interferometric investigation of hillock morphology of the {100} and {101} faces of KDP growing in TMS gels
Authors: Krasiński M. J. 
Published: February 2005

AbstractThe results of an in situ interferometric study of the surface morphology of {100} and {101} faces of potassium dihydrogen phosphate (KDP) crystals growing in the tetramethoxysilane gel are described and discussed. It was observed that: (a) in the case of crystal growth in gel both slopes of hillocks and surface kinetic coefficient are smaller than in solution growth, (b) for low supersaturations face growth rate linearly depends on bulk supersaturation and the structure of growth centers depends on the supersaturation and growth rate, and (c) for high supersaturations polyhedral instability appears. Supersaturation threshold for transition to polyhedral instability was estimated and formation of gel inclusions is discussed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Adsorption of 3d‐elements onto zinc oxalate dihydrate in aqueous oxalate solutions
Authors: Pencheva J. , Donkova B. , Djarova M. , Maksimova S. 
Published: February 2005

AbstractA study of the sorption of 3d‐transition elements onto ZnC2O4.2H2O has been carried out.To reveal the mechanism of the process, the experiments were performed in two media of different oxalate ion concentrations – 1.10‐2 and 4.10‐4 mol/l, by the separate and by the joint presence of the microcomponents in the system. In the latter case, copper was also added, the sorption of which has been previously well studied. Different mechanisms of sorption in the different media were found, the determining role of the neutral oxalate complexes having been manifested. In the case of manganese and cobalt, in the medium with oxalate ions deficit, sorption by neutral complexes in the adsorption layer A is supplemented by ion‐exchange sorption in the first surface layer S. The sorption of nickel under oxalate ion excess is proved to be an irreversible process, and the concept of its sorption by a mixed complex with the participation of the macrocomponent, Zn[Ni(C2O4)2], is advanced. The experimental data show the occurrence of segregation of Mn and Ni by their sorption onto the growth steps, and the absence of segregation of Co by its sorption. An interesting result is the extension of the validity of the Paneth‐Fajans rule in the case of so‐called complex oxalates, growing by neutral oxalate complexes, such as the oxalates of the macro‐ and microcompoments, studied in the present work. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lattice parameter measurements of boron doped Si single crystals
Authors: Kucytowski J. , Wokulska K. 
Published: February 2005

AbstractThe influence of boron dopants and oxygen impurity on lattice parameters of Si single crystals is studied. Concentrations of boron and oxygen were determined by the Bond method. A linear contraction of the crystal lattice was observed due to high boron doping of Si single crystals. Lattice parameters of Si single crystals increased below the lower limit boron concentration NB = 2.1 × 1016 cm‐3. This proves the presence oxygen at low boron concentrations. In highly boron‐doped Si single crystals no oxygen influence on lattice parameter change was observed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Raman scattering study of (SrAl0.5Ta0.5O3)1‐x‐y: (LaAlO3)x : (CaAl0.5Ta0.5O3)y solid solution crystals
Authors: Runka T. , Aleksiyko R. , Berkowski M. , Drozdowski M. 
Published: February 2005

AbstractThe Raman studies of three‐component (SrAl0.5Ta0.5O3)1‐x‐y:(LaAlO3)x:(CaAl0.5Ta0.5O3)y solid solution crystals versus composition are reported. The assignment of vibrational modes in Raman spectra of investigated crystals is proposed. Structural changes of (SrAl0.5Ta0.5O3)1‐x‐y:(LaAlO3)x:(CaAl0.5Ta0.5O3)y crystal from cubic to tetragonal and from tetragonal to orthorhombic phase were observed by Raman spectroscopy, while the change of crystal composition. The most significant changes of Raman spectra manifesting about changes of crystal structure were observed predominantly in the range of lattice modes. Splitting of cubic F2g modes resulting from lowering of the symmetry was observed. Changes of the intensity of Raman bands indicate the increase of disorder of crystal structure with increase of LaAlO3 content. This disorder is connected with the arrangement of B ion sublattice. It was revealed that Raman results supply essential information on complex structure and changes of degree of order of three‐component solid solution crystals. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synchrotron X‐ray investigation of La0.3Sr0.7Al0.65Ta0.35O3 crystals
Authors: Wierzchowski W. , Wieteska K. , Graeff W. , Sakowska H. , Łukasiewicz T. , Pawłowska M. 
Published: February 2005

AbstractThe La0.3Sr0.7Al0.65Ta0.35O3 (LSAT) substrates were studied with a number of X‐ray diffraction methods exploring both synchrotron white and monochromatic beam. The observation of selective etching patterns was performed in neighbouring samples. White beam back‐reflection projection topographs revealed only the segregation fringes around the central core and a delicate grain‐like structure. The most important for verification of dislocation presence were the transmission projection and section topographs. These topographs also did not reveal any images of extended dislocation but only the growth bands and tiny grain‐like structure. The section topographs provided some details of paroboloidal growth surface inside the crystal. It may be concluded that the investigated crystal probably contains small coherent inclusions responsible for the etch pits and the mentioned grain‐like structure. The synchrotron rocking curves revealed a number of maxima, which might be attributed to the regions with different lattice parameter, connected with segregation fringes. The sequence of maxima was different for different regions of the sample. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spatial conditional discrimination learning in developing rats
Authors: Brown Kevin L. , Pagani Jerome H. , Stanton Mark E. 
Published: February 2005

AbstractThe present study established an effective procedure for studying spatial conditional discrimination learning in juvenile rats using a T‐maze. Wire mesh located on the floor of the maze as well as a second, identical T‐maze apparatus served as conditional cues which signaled whether a left or a right response would be rewarded. In Experiment 1, conditional discrimination was evident on Postnatal Day (PND) 30 when mesh + maze or maze‐alone were the conditional cues, but not when mesh‐alone was the cue. Experiment 2 confirmed that mesh‐alone was sufficiently salient to support learning of a simple (nonconditional) discrimination. Its failure to serve as a conditional cue in Experiment 1 does not reflect its general ineffectiveness as a stimulus. Experiment 3 confirmed that the learning shown in Experiment 1 was indeed conditional in nature by comparing performance on conditional versus nonconditional versions of the task. Experiment 4 showed that PND19 and PND23 pups also were capable of performing the task when maze + mesh was the cue; however, the findings indicate that PND19 subjects do not use a conditional strategy to learn this task. The findings suggest postnatal ontogeny of conditional discrimination learning and underscore the importance of conditional cue salience, and of identifying task strategies, in developmental studies of conditional discrimination learning. © 2005 Wiley Periodicals, Inc. Dev Psychobiol 46: 97–110, 2005.
The cost management edge for financial services
Authors: Garg Ashish 
Published: February 2005

AbstractHolding down costs has long been a corporate objective, yet companies continue to struggle to find ways to generate better‐quality information—either with the help of, or sometimes in spite of, the cost management tools already in place. But as a best‐practices survey shows, cost management—when executed effectively—can be a key contributor to strategic goals. © 2005 Wiley Periodicals, Inc.
Evaluating the “keep‐or‐drop” decision
Authors: Sopariwala Parvez R. 
Published: February 2005

AbstractDetermining the relevant costs for short‐term decision‐making is an important part of every cost/managerial accounting textbook. One of the decisions is the “keep or drop” decision—i.e., should a company keep or drop an existing product line or department in the short term? This article points out that keep‐or‐drop decisions are usually long‐term decisions. As a result, it suggests that only a segmented activity‐based costing (ABC) income statement should be used for determining if a product line or department should be kept or dropped. © 2005 Wiley Periodicals, Inc.
Photographic print defects attributable to point source enlargers
Authors: Mollenhauer Hilton H. , Droleskey Robert E. 
Published: February 2005

AbstractPoint source enlargers may cause unusual types of printing defects. One type is a large spot in the center of the enlarged picture field that sometimes appears when the edges of negatives are not adequately masked during printing. Another type is a blurry image caused by a defect in the polycontrast filter. The defect appears in the filter as a small spot of about 1/8‐inch diameter, formed, presumably, by heat from the focused beam of the point source light. A spot defect of this type is difficult to see by a cursory visual examination of the filter and may develop unnoticed and persist for months before it is finally recognized.
Acetylcholine receptor at neuromuscular junctions by EM autoradiography using mask analysis and linear sources
Authors: Salpeter Miriam M. , Smith Chari D. , Matthews‐Bellinger Julia A. 
Published: February 2005

AbstractSeveral methods of analyzing EM autoradiograms are now available. Two such procedures, the grain density distribution (or histogram) method and the mask method use the resolution of the EM autoradiographic technique to generate grain distributions expected from postulated sources, and compare these with the observed grains in the autoradiograms. These two methods are here compared in the analysis of label on linear sources: the distribution of labeled acetylcholine receptor (AChR) down the postjunctional folds of lizard and frog neuromuscular junctions. The receptors were labeled with I‐25‐α‐bungarotoxin and the autoradiograms coated with the high resolution Kodak emulsion 129–01. We found that both methods gave similar results in confirming that the bulk of the AChR is concentrated on the thickened region of the membrane at the top ∼2000 A of the junctional folds, and that there may be a gradient of receptor concentration down the folds. The grain density distribution method is simpler, but does not lend itself easily to quantifying the extent of deviation from simple models. Although computer graphics is not necessary for either method, its use allows the expected grains from linear sources to be generated quickly, making the mask analysis a feasible routine method for assigning the extent of label in different membrane regions.
A quantitative evaluation of the glomerular capillary endothelium in rat and human kidneys: Utilization of vascular perfusion, freeze‐cracking of tissue, and scanning electron microscopy
Authors: Dobyan Dennis C. , Eknoyan Garabed , Magill Linda S. , Sarrafian Myrna , Bulger Ruth Ellen 
Published: February 2005

AbstractModern morphological investigation requires the use of a variety of technological approaches and the employment of rigorous morphometric analysis for an adequate evaluation of the structural and ultrastructural features of a tissue or organ. The introduction of the technique of freeze‐cracking of tissue to expose new surfaces has made it possible to quantitate the normal surface characteristics of the glomerular capillaries of the mammalian kidney. This report describes the techniques used for the preparation and quantitative assessment of normal glomerular endothelial morphology. The techniques of in vivo and in vitro vascular perfusion of kidneys as a method of fixation and the freeze‐cracking of tissue are outlined in detail. In addition, a morphometric analysis of the endothelial surface characteristics are described and values are reported for the control rat and human kidneys from transplant donors.
Polyethylene glycol (PEG) embedding and subsequent de‐embedding as a method for the structural and immunocytochemical examination of biological specimens by electron microscopy
Authors: Kondo Hisatake 
Published: February 2005

AbstractA simple and reliable method to make resinless sections for electron microscopy was recently developed by using polyethylene glycol (PEG) as a transient embedding media. In this paper the practical procedure of this PEG method is described in detail. Normal ultrastructure of several types of in‐situ cells in resinless sections is demonstrated. The cytoplasmic matrix of all in‐situ cells examined is revealed to consist of the microtrabecular lattice. A result from application of this technique to immuno‐electron microscopy is also illustrated. This method is shown to have potential in overcoming the problem of intracellular penetration of macromolecular antibodies. Several artifacts caused by failures in specimen preparations are displayed. The real or artifactual nature of the microtrabecula is briefly discussed.
Zone‐axis diffraction patterns by the “Tanaka” method
Authors: Eades J. A. 
Published: February 2005

AbstractThe “Tanaka” method is one of several techniques that make it possible to obtain zone‐axis electron diffraction patterns in a transmission electron microscope without the restriction in the field of view that limits normal convergent‐beam diffraction patterns.The method employs a convergent‐beam of electrons focused to a probe in a plane that does not coincide with the specimen. The selected area aperture can then be used to eliminate all but one of the diffracted beams to obtain the desired pattern. Practical details of operation and values of operating parameters are discussed.The Tanaka method is a useful addition to the techniques available to the electron microscopist, especially since no instrumental modification is required.
An iodized mounting medium for coal particles
Authors: Gomez C. O. , Strickler D. W. , Austin L. G. 
Published: February 2005

AbstractA high electron‐density embedding medium was developed for SEM observation of inorganic constituents of organic or carbonaceous particles. The components used are a common epoxy resin in which iodoform is dissolved before the addition of the hardener. An iodoform content of 10% by weight proved satisfactory for obtaining excellent contrast between the matrix and embedded carbonaceous particles in the SEM. The system has been successfully applied in the preparation of polished specimens of coal particles. There is no interference between the iodine and any of the most abundant or most important coal mineral components, but it was found that the epoxy resin contained chlorine as a contaminant.
Parallax measurements on stereomicrographs of hydrated single molecules: Their accuracy and precision at high magnification
Authors: Ruben George C. , Marx Kenneth A. 
Published: February 2005

AbstractStereoimaging of hydrated single complex macromolecules requires thin freeze‐etch platinum‐carbon replicas (⩽200 Å) and that the transmission electron microscope (TEM) be equipped with a tilt‐rotation eucentric goniometer stage. The original parallax equation is an accurate approximation for high‐magnification work, micrographs (105 ×) being less than 0.3% in error. In addition, we have derived formulas for high‐magnification work to measure heights, lateral distances, and the object tilt angle for an object not lying flat on the film surface. The accuracy of the height measurements is evaluated on spermidine‐condensed DNA toruses. By using the maximum error equation derived from the original parallax equation, we discuss methods to improve the height measurement precision (95% fractile) to the 5–10 Å range.
A microcomputer program in “BASIC” for the accurate determination of the height of small particles
Authors: Lea P. J. 
Published: February 2005

AbstractA formula is derived to enable the calculation of the true height of an object, such as a shadowed latex bead, from electron micrographs. Knowing only the angle of shadowing and the length of the evaporated shadow, and by substituting these values in the derived formula, a microcomputer may be programmed to carry out the necessary computations. An example of such a microcomputer program is given. The correct determination of the height of particles by electron microscopy using the shadowing technique is one of the most accurate methods available for the determination of small particle height.
A study of living plant specimens by low‐temperature scanning electron microscopy
Authors: Kaneko Yasuko , Matsushima Hisashi , Wada Masao , Yamada Mitsuhiko 
Published: February 2005

AbstractYoung fresh Tradescantia reflexa stamen hair cells were used to clarify the optimal conditions for direct viewing and taking photographs with a scanning electron microscope (SEM) equipped with a cryo‐system. The rate of protoplasmic streaming in the cells was measured under an optical microscope after examining and photographing them in the SEM over a period of a few minutes. Almost the same rate of streaming (5.5 μm/second, 20°C) was observed in nonirradiated control cells and irradiated cells photographed in the SEM using an accelerating voltage of 10 kV with the cryo‐stage at a temperature of – 15°C. (The specimen holder and specimen were not at this temperature, but, rather, probably somewhat higher.) Fresh plant organs, tissues, and cells were also tested under the same conditions. The fine structure was well preserved in detail. The procedures were as follows: (1) prompt attachment of fresh plant materials on an aluminum specimen holder with double‐faced adhesive Scotch tape or a small amount of plastic adhesive for woodcraft; (2) setting the holder on the cryo‐stage cooled to –15°C in advance and rapid evacuation; and (3) quick SEM examination and photography (within several minutes). The advantages of this method are summarized as follows: (1) high possibility of viewing living materials; (2) minimal artifacts: freedom from chemical fixation and additional procedures utilized in ordinary SEM specimen preparation; and (3) simplicity, speediness, and economy in preparation for viewing. Since the specimens were not likely to be frozen during quick examination and photography, this method might well be called “low‐temperature SEM” (LT‐SEM) as distinguished from “cryo‐SEM”.
Sectioning spherical aluminum oxide particles for transmission electron microscopy
Authors: Tucker Dennis S. , Jenkins Elijah J. , Hren John J. 
Published: February 2005

AbstractA technique was developed to aid in the interpretation of nucleation and growth characteristics of otherwise electron‐opaque Al2O3 particles. The technique involved embedding a dense collection of particles in an Epon mixture and sectioning with a diamond knife on an ultramicrotome. Serial sections were utilized to obtain three‐dimensional information. It was found that ultramicrotomy does not introduce artifacts in ceramics which would otherwise affect measurements of the crystallite size or phase fraction, nor does it affect the crystallographic data significantly.It was observed that α‐Al2O3 nucleated at the surface of isolated particles and in the neck region of sintered particles. Other data, obtained from diffraction and in situ hot‐stage studies, indicated that each polycrystalline α‐Al2O3 particle transformed to a nearly single crystal of γ‐Al2O3, which extended into adjacent particles under favorable circumstances.
The fatty acid monolayer technique for preparing frozen‐hydrated specimens
Authors: Chang Chung‐Fu , Ohno Tamotsu , Glaeser Robert M. 
Published: February 2005

AbstractA major difficulty in preparing frozen‐hydrated specimens from solutions is to control an optimal thickness of water remaining on the EM grid just before it is immersed in liquid nitrogen. In this report, we describe a modification of the fatty acid monolayer technique for preparing frozen‐hydrated specimens. With the use of this technique, all excess solvent is removed when a behenic acid (a fatty acid) monolayer film is picked up over the surface of the electron microscope grid. Low‐dose electron diffraction patterns and optical diffraction patterns of low‐dose micrographs of bacteriorhodopsin (bR) of Halobacterium halobium thus prepared show strong reflection orders at a resolution of ∽4 Å and ∽10 Å, respectively. Because the preparation of thin, hydrated specimens by the behenic acid monolayer technique does not depend upon evaporation of water, a dramatic change of ion concentration and pH is not expected to occur. The method should be applicable to specimens which need to be kept in a specific buffer and/or at a specific ionic strength.