bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variation of GaAs surface charge under an electron beam: effect on cathodoluminescence signal
Authors: Nouiri A. , Elateche Z. , Aouati R. , Belabed N. 
Published: July 2007

AbstractThis work is a self‐consistent calculation model of the GaAs surface charge under electronic bombardment. The surface charge due to surface defects can be influenced by the electron–hole pair generated at the surface zone (in the depletion region). Numerical results show that the donor states charge decreases under the cathodic excitation, but when the surface states are of acceptor type, the surface charge increases with increasing excitation levels (increasing of beam current). In the case of donor states, the cathodoluminescence (CL) intensity increases when the energy level Et, associated with the surface density Nt, is near the conduction band Ec. In the case of acceptor states, the same behavior of CL intensity has been observed when Et is near the valance band Ev. In all cases, the CL intensity decreases when Et moves to the middle of the band gap. According to this calculation, it is clear that the variation of surface charge must be taken into account in all surface analysis techniques based on electron beams. Copyright © 2007 John Wiley & Sons, Ltd.
Development of drift design model for high‐rise buildings subjected to lateral and vertical loads
Authors: Park Hyo Seon , Seo Ji Hyun , Kwon Yun Han 
Published: July 2007

AbstractRecent developments of resizing algorithms based on displacement participation factor have had a significant impact on drift design of high‐rise buildings. However, most drift design methods based on resizing algorithms have considered only lateral load and overlooked the effect of the vertical load in the calculation of member displacement participation factors. Therefore, in this paper, the practical drift design method of high‐rise buildings is presented in the form of a resizing algorithm by developing product integral modules required for the calculation of displacement participation factors with the consideration of both lateral and vertical loads. The effect of vertical load on the drift design model based on member displacement participation factors is investigated in detail using the verifying example of a 20‐story building structure. The drift design method in combination with the strength design module is then applied to the drift design of a 60‐story high‐rise building structure. Copyright © 2007 John Wiley & Sons, Ltd.
Seismic response of semi‐active friction‐damped reinforced concrete structures with self‐variable stiffness
Authors: Iskhakov I. , Ribakov Y. 
Published: July 2007

AbstractThe influence of structural self‐variable stiffness and semi‐active friction dampers on the behavior of reinforced concrete (RC) buildings during strong earthquakes is discussed. A fully braced six‐story beamless RC frame is analyzed. The effect of concrete braces (with only constructive reinforcement) as a self‐variable mechanism is studied. It is shown that up to a certain limit the frame itself controls its behavior by adapting its dynamic characteristics in the real time of the earthquake. This self‐adaptation is achieved by autonomous disengagement of the braces under tension and their further nonlinear action under compression. The system has several levels of seismic adaptation, and it selects one of them for enhanced response to the given earthquake. However, when the limit is reached, further self‐adaptation of the frame becomes impossible. The occurrence of an earthquake of higher magnitude can then lead to disengagement of the concrete braces under compression, intensifying structural damage and even causing collapse. The use of semi‐active controlled friction dampers is proposed as a means of preventing the collapse of braces under compression, thereby enabling structures to withstand earthquakes. The forces in the friction dampers are regulated according to an optimal control algorithm. Modulation of the friction level in real time during the earthquake yields additional improvement of structural seismic behavior and obviates the need for retrofitting. Copyright © 2007 John Wiley & Sons, Ltd.
Computation of story drifts considering panel zone deformations for multistory steel moment frames with welded flange plate connections
Authors: Hsiao J. Kent , Schultz William , Petersen Troy , Vaicik Stephen 
Published: July 2007

AbstractThe 2003 International Building Code (IBC) requires that the contribution of panel zone deformations to overall story drifts be included in the mathematical model of the physical steel moment‐resisting frame systems. A finite‐element model can accurately take the panel zone deformations into consideration for the computation of story drifts, yet the preparation of the model is usually very time consuming. A line‐element model significantly simplifies the frame analysis, yet it cannot address the issue of panel zone deformations. These two types of models are statistically evaluated in this paper for steel moment frames with welded flange plate (WFP) connections. A total of 16 beam–column combinations are evaluated for each type of model. The elastic story drift of each beam–column combination is then obtained from each type of model. Finally, adjustment factors are developed to correct the story drifts that are computed using the line‐element models for the frames with WFP connections. Copyright © 2007 John Wiley & Sons, Ltd.
Drift design model for high‐rise buildings based on resizing algorithm with a weight control factor
Authors: Seo Ji Hyun , Song Weon‐Keun , Kwon Yun Han , Hong Kappyo , Park Hyo Seon 
Published: July 2007

AbstractIt is well known that the weight of the structural system for a high‐rise building to resist lateral loads increases in nonlinear fashion with increase in building height and slenderness ratio. For a given building height or slenderness ratio, the weight of the structural system for a high‐rise building subjected to lateral loads depends on the degree of stiffness of the building structure. Therefore, at the final stage of the structural design process, it has been a challenge to structural engineers to improve the efficiency of a structural system by either minimizing the weight of a structure for a given limit on lateral displacement or maximizing the degree of stiffness for a given weight of a structure. In this paper, a resizing design method that can minimize the magnitudes of lateral displacement and inter‐story drift of a high‐rise building with respect to structural weights is presented. Based on the proposed design method, the relation between the structural weight and the magnitude of lateral displacement is investigated using two examples, including a 60‐story high‐rise building. Copyright © 2007 John Wiley & Sons, Ltd.
Slit‐connected coupling beams for tunnel‐form building structures
Authors: Yuksel S. Bahadir 
Published: July 2007

AbstractOpenings to provide functional use in shear walls of tunnel‐form buildings result in coupled shear walls and coupling beams. These beams are deep compared to their clear span above the door openings; however, their thickness is less than 250mm. Moreover, they are subjected to high shear forces under lateral loads. Dimensional constraints make their design against high shear forces difficult when code‐specified reinforcement configurations are applied. In this paper, slits at each end of coupling beams are proposed to decrease the shear stiffness and shear forces of these deep coupling beams. The structural behavior of coupled shear walls with slit‐connected coupling beams (SCCBs) is investigated by performing two‐dimensional static and dynamic analyses. Stiffness terms of SCCBs are obtained as a result of extensive finite element simulations. Based on the parametric study conducted, an equivalent prismatic beam model representing SCCBs is proposed. Thereby, coupled shear walls having SCCBs can be analyzed by the equivalent frame method using the equivalent prismatic beam model. Copyright © 2007 John Wiley & Sons, Ltd.
Integrated aerodynamic load determination and stiffness design optimization of tall buildings
Authors: Chan C. M. , Chui J. K. L. , Huang M. F. 
Published: July 2007

AbstractModern tall steel buildings are wind sensitive and are prone to dynamic serviceability problems. Although wind tunnel techniques have emerged as valuable tools in providing reliable prediction of the wind‐induced loads and effects on tall buildings, current design practice normally considers the wind tunnel‐derived loads as constant static design loads. Such practice does not take into account the change in wind‐induced structural loads while the dynamic properties of a building are modified during the design synthesis process. This paper presents a computer‐based technique that couples together an aerodynamic wind tunnel load analysis routine and an element stiffness optimization method to minimize the cost of tall steel buildings subject to the lateral drift design criteria, while allowing for instantaneous prediction and updating of wind loads during the design synthesis process. Results of a full‐scale steel building framework with the same geometric shape of the Commonwealth Advisory Aeronautical Research Council (CAARC) standard building indicate that not only is the proposed technique able to produce the cost‐effective element stiffness distribution of the structure satisfying the serviceability wind drift design criteria, but a potential benefit of reducing the design wind loads can also be achieved by the stiffness optimization method. Copyright © 2007 John Wiley & Sons, Ltd.
Characterization of osteoporotic bone structures by bidimensional images through x‐ray microfluorescence with synchrotron radiation
Authors: Lima Inayá , Anjos Marcelino J. , Fleiuss Maria Lucia F. , Rosenthal Doris , Lopes Ricardo T. 
Published: July 2007

AbstractThe objective of this study was to characterize the bone structures of the femoral head and the cortical and trabecular regions, using two‐dimensional images produced by x‐ray microfluorescence, which supplies information about the superficial distribution of minerals. The measurements were performed in the standard geometry with 45 incidence, and excitation with a white beam and an optical capillary with 20 µm diameter collimation in the x‐ray fluorescence (XRF) beam line at the Synchrotron Light National Laboratory (Campinas, Brazil). The results show that both the concentration and the distribution of the minerals vary significantly among the groups, mostly in relation to the element calcium, depending on the location and bone site. Copyright © 2007 John Wiley & Sons, Ltd.
Phenotypic variation in fruit and seed characteristics of buffalo gourd
Authors: Scheerens J. C. , Bemis W. P. , Dreher M. L. , Berry J. W. 
Published: July 2007

AbstractEighty‐five accessions of Buffalo gourd,Cucurbita foetidissima HBK., were assayed for variation in seven fruit and seed characteristics: fruit diameter (−x = 65 mm); seed weight per 100 seeds (−x = 3.8 g); seed weight per fruit (−x = 8.4 g); seed number per fruit (−x = 225); percentage embryo in seed (−x = 67.3%); percent crude fat of whole seed (−x = 32.9%); and percent crude protein of defatted embryo (−x = 69.5%). The variation in amino acid distribution (12) accessions) and in oil composition (15 accessions) was obtained. Relationships among traits were explored. Agronomic improvement through breeding was also discussed.
Reactions of lipids in corn with ammonia
Authors: Black L. T. , Spencer G. F. , Brekke O. L. 
Published: July 2007

AbstractAmmonia has recently been employed in experimental tests for the treatment of corn to inactivate aflatoxin, to control molds, and as a preservative during ambient‐air drying of freshly harvested high‐moisture corn. When these various ammonia treatments are properly applied, no adverse effects have been found on any of the constituents of whole corn. However, in the work being reported when 0.1% or more ammonia was in contact with corn in the presence of air for more than a few days, irreversible changes occurred in the polyunsaturated lipids that were proportionate to the ammonia concentrations. The extent of the changes were dependent upon: (a) air‐to‐corn ratio, (b) ammonia concentration, (c) temperature, (d) corn moisture, and (e) time. The changes were characterized by a reduction in unsaturation of the lipid, by incorporation of nitrogen into the lipids, and by a consequent increase in lipid polarity. The change in polarity of these altered lipids rendered them unextractable with the usual fat solvents. Air (oxygen) and an initiating mechanism that occurs naturally in corn were required for the lipid‐ammonia interaction to occur. This interaction involved only the polyunsaturated fatty acid moieties and formed a class of nitrogenous derivatives. Corn may be treated with ammonia for purposes of detoxification or preservation for long periods with no detectable adverse effects on the lipid composition, as long as headspace air is kept low during ammoniation. This may be accomplished in any of the following ways: (a) by ammonia ting the corn with a very limited headspace, (b) by ammoniating corn in a sealed bin and displacing the air in the headspace with ammonia gas, and (c) by replacing the headspace air with an inexpensive, inert gas such as nitrogen.
An investigation of the basic conditions for tocopherol determination in vegetable oils and fats by differential pulse polarography
Authors: Podlaha O. , Eriksson Å. , Toregård B. 
Published: July 2007

AbstractThe polarographic behavior of α‐, γ‐, and δ‐tocopherols was studied according to the proposed official IUPAC method for tocopherol determination in vegetable oils and fats. Each of the tocopherols had a different polarographic response; however, the tocotrienols had the same half‐wave potentials and probably also the same polarographic response as the corresponding tocopherols. Additives previously investigated plus several others were examined for possible interference. The results by polarography and a new high performance liquid chromatography (HPLC) method were compared. The analysis by t‐test at 99% significance level showed no differences for the determinations of α‐tocopherol, but the results for three of the γ‐tocopherol results were less consistent under the same conditions. The results for the determination of δ‐tocopherol were below the detection limit for polarography and could not be statistically evaluated. The polarographic method investigated was found to be uncomplicated and therefore suitable for routine work. However, when using the method, one has to take into account possible interference by additives and the limitations due to the lack of separation of β‐ from γ‐tocopherol and/or the interference of tocotrienols with the corresponding tocopherol peaks. From this aspect the HPLC method gives better resolution.
Preparation and selective hydrolysis of acetal esters
Authors: Adlof R. O. , Neff W. E. , Emken E. A. , Pryde E. H. 
Published: July 2007

Abstract and SummaryMedium chain length aldehydic acids and esters (C8‐C13) were synthesized by ozonolysis of readily available cyclic and straight chain alkenoate esters followed by rearrangement or reduction of the ozonide. The acetal esters, prepared by reaction of the aldehydic acids with CH3OH‐HC1, were characterized by gas liquid chromatography, proton magnetic resonance, carbon magnetic resonance, thin layer chromatography, and infrared analysis. Selective hydrolysis of the acetal esters to aldehyde esters was conveniently accomplished with H2O‐HC1‐CH3CN to give 95% or higher yields in less than 30 min. Development of this simple and effective hydrolysis procedure allows these medium chain length esters to be safely stored as their acetal esters, which retards their oxidation, trimerization, and decomposition.
Specific gravities of rapeseed and canbra oils
Authors: Ackman R. G. , Eaton C. A. 
Published: July 2007

Abstract and SummaryNew varieties of rapeseed oils grown in Canada have bess than 1% erucic (cis‐13‐docosenoic) acid and also a reduction in cis‐11‐eicosenoic acid. The replacement of these acids with C18 acids increased the specific gravity (25 C/25 C) from 0.9123 for an oil with 23.1% erucic acid to 0.9171 for an oil with 0.7% erucic acid. Soybean oil data are presented for comparison.
A quality control procedure for the gas liquid chromatographic evaluation of the flavor quality of vegetable oils
Authors: Waltking Arthur E. , Zmachinski Helen 
Published: July 2007

Abstract and SummaryAn objective procedure which is relatively simple and rapid is under study for the determination of the flavor quality of vegetable oils. This procedure utilizes the direct injection of an oil sample to which has been added an internal standard, into a packed precolumn of a gas Chromatograph. The volatiles are swept from the precolumn through a 10% SE‐30 column under operating parameters which permit complete elution of all volatiles and internal standard within 20 min. Some 1 5 to 20 samples can be evaluated in one day before it is necessary to replace any part of the foot‐long precolumn. Evaluations have been made by the gas liquid Chromatographic (GLC) procedure and by a flavor panel of oil samples subjected to a variety of storage conditions. Generally, differences in the GLC pattern are reflected in the flavor panel results.
Lipid‐Derived flavors of legume protein products
Authors: Sessa David J. , Rackis Joseph J. 
Published: July 2007

Abstract and SummaryLegumes contain unsaturated lipids that are susceptible to oxidative deterioration. Enzymic and non‐enzymic deterioration of these lipids results in the development of off‐flavors. The primary objective of this review is to summarize what is currently known about lipid‐derived flavors of soybeans and underblanched pea seeds(Pisum sativum). Identifying the numerous volatile compounds arising from breakdown of lipid hydroperoxides coupled with organoleptic evaluation defines the flavor problem. Major contributors to the green‐beaniness of soybeans were found to be 3‐cis‐hexenal, 2‐pentyl furan, and ethyl vinyl ketone. Oxidized phosphatidylchohnes cause some of the bitter taste. The interaction of lipid breakdown products with proteins, carbohydrates, and other constituents can affect flavor characteristics and also increase the problems of their removal from soy protein products. To prepare bland products, it will be necessary to develop processes that effectively remove bound flavor components and prevent formation of derived flavors. Solvent systems based on alcohol have been used to extract flavor principles from soybeans; aqueous alcohol treatment of the intact seed or blanching with hot water or steam inhibits formation of off‐flavors in peas and soybeans. A new approach involving infusion of antioxidants into the intact seed to control lipid deterioration during processing and storage is proposed to minimize flavor formation without subsequent undesirable changes in protein which occur with alcohol treatments.
Application of tracer techniques to studies on autoxidation reactions
Authors: Khan N. A. 
Published: July 2007

SummaryThe tracers containing deuterium, carbon isotopes, and heavy oxygen that may be applied to the studies on autoxidation reactions are described. The autoxidation of the deuterated compounds formed by replacing hydrogen atoms on the double bond has given concrete experimental evidence for the following phenomena of autoxidation reaction: a) initial attack of oxygen at the double bond and the inherent induction period, b) the propagation of autoxidation by attack on the methylenic group, alpha to the double bond during the steady state, c) the presence of resonance in the free radicals formed and consequent shifting of the double bond, and d) the location of the hydrogen atoms contributing to the formation of the major portion of the water.These investigations have led to the elucidation of some aspects of the mechanism of decomposition of peroxides and consequent formation of hydroxyl radicals, which attack the substrates at certain preferential points giving rise to water. They also provide the mechanisms of cleavage and formation of the volatile products.Our experiments have also established four different and distinct stages of autoxidation. Water formation in autoxidation is shown to be the outcome of the primary decomposition of peroxides, mainly hydroperoxides, and the formation of the organic volatile products to be that of the secondary decomposition at a later stage. These processes have been correlated to the bond strengths of the different atoms in the substrates and the resulting products. The advantages and disadvantages of the application of these tracer techniques to autoxidation reactions in general are also discussed.
The glyceride structure of natural fats. I. A technique for the quantitative determination of glyceride types in natural fats
Authors: Kartha A. R. S. 
Published: July 2007

SummaryThe acetone‐permanganate oxidation method for determination of GS3 has been shown to be unreliable because some hydrolysis of the azelaoglycerides occurs, the products of which are determined as GS3. The presence of excess acetic acid throughout the oxidation corrects this defect. GS2A can be precipitated quantitatively as the magnesium salt. Although it is contaminated with GSA2, its proportion can be calculated and from this the proportion of GS2U in the sample can be found.The remainder of the precipitate is GSA2; its weight, when added to that found in the filtrates, gives the total GSA2. From this, the percentage of GSU2 in the sample can be derived. The GS3 is determined separately, and the content of GU3 can be estimated by difference.
Pancreatic and Duodenal Invasion in Distal Bile Duct Cancer: Paradox in the Tumor Classification of the American Joint Committee on Cancer
Authors: Ebata Tomoki , Nagino Masato , Nishio Hideki , Igami Tsuyoshi , Yokoyama Yukihiro , Nimura Yuji 
Published: July 2007

AbstractBackgroundDistal bile duct cancer often invades the pancreas and/or duodenum. Invasion of the pancreas is defined as a T3 and that of the duodenum as a T4 tumor in the T classification of the American Joint Committee on Cancer (AJCC). The aim of this study was to assess whether this T classification is rational from the viewpoint of prognostic power.MethodNinety‐five patients with distal bile duct cancer were retrospectively analyzed according to the current T classification of the AJCC.ResultsThe main determinant of pT3 (n = 32) and pT4 (n = 30) was pancreatic and duodenal invasion, respectively, and the survival rates for patients with pT3 and pT4 are similar (p = 0.595). Duodenal invasion was present in 39% of the patients with pancreatic invasion, whereas pancreatic invasion was observed in 86% of those with duodenal invasion. The survival for patients with pancreatic invasion was not significantly different (p = 0.283) whether or not there was concomitant duodenal invasion (n = 19 and n = 37, respectively). Multivariate analysis identified venous invasion, distant metastasis, histologic grade, and pancreatic invasion as independent prognostic factors.ConclusionAlthough duodenal invasion usually occurs after pancreatic invasion, it is not a significant prognostic factor while pancreatic invasion is. The current T classification should be revised since it expresses tumor extension but does not reflect a survival in distal bile duct cancer.