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151.
Intermetallic growth and ball shear behavior of annealed Cu wire bonds on Al have been studied. The shear strength of Cu ball
bonds decreased with time, and ductile fracture was the dominant failure mode from 125°C to 150°C. Al pad peel-off occurred
as the aging temperature was increased above 150°C. The overall Cu/Al intermetallic thickness exhibited parabolic behavior
as a function of time. A linear correlation was established between ball shear strength, metal peel-off occurrence, and intermetallic
growth. The Cu/Al intermetallic growth activation energy was 0.23 eV, and the intermetallics identified in the experiment
were CuAl2 and CuAl. 相似文献
152.
153.
Omar S. Ahmed Charles Tardif Caroline Rouger Vessela Atanasova Florence Richard-Forget Pierre Waffo-Téguo 《Comprehensive Reviews in Food Science and Food Safety》2022,21(2):1161-1197
Mycotoxins are metabolites produced by molds that contaminate food commodities, are harmful to both humans and animals, as well as cause economic losses. Many countries have set regulatory limits and strict thresholds to control the level of mycotoxins in food and feedstuffs. New technologies and strategies have been developed to inhibit toxigenic fungal invasion and to decontaminate mycotoxins. However, many of these strategies do not sufficiently detoxify mycotoxins and leave residual toxic by-products. This review focuses on the use of phenolic compounds obtained from botanical extracts as promising bioagents to inhibit fungal growth and/or to limit mycotoxin yields. The mechanism of these botanicals, legislation concerning their use, and their safety are also discussed. In addition, recent strategies to overcome stability and solubility constraints of phenolic compounds to be used in food and feed stuffs are also mentioned. 相似文献
154.
Wheat gluten: high molecular weight glutenin subunits--structure, genetics, and relation to dough elasticity 总被引:2,自引:0,他引:2
ABSTRACT: Gluten proteins, representing the major protein fraction of the starchy endosperm, are predominantly responsible for the unique position of wheat amongst cereals. These form a continuous proteinaceous matrix in the cells of the mature dry grain and form a continuous viscoelastic network during the mixing process of dough development. These viscoelastic properties underline the utilization of wheat to prepare bread and other wheat flour based foodstuffs. One group of gluten proteins is glutenin, which consists of high molecular weight (HMW) and low molecular weight (LMW) subunits. The HMW glutenin subunits (HMW-GS) are particularly important for determining dough elasticity. The common wheat possesses 3 to 5 HMW subunits encoded at the Glu-1 loci on the long arms of group 1 chromosomes (1A, 1B, and 1D). The presence of certain HMW subunits is positively correlated with good bread-making quality. Glutamine-rich repetitive sequences that comprise the central part of the HMW subunits are actually responsible for the elastic properties due to extensive arrays of interchain hydrogen bonds. Genetic engineering can be used to manipulate the amount and composition of the HMW subunits, leading to either increased dough strength or more drastic changes in gluten structure and properties. 相似文献
155.
Khaled Daqrouq Ibrahim N. Abu-Isbeih Omar Daoud Emad Khalaf 《International Journal of Speech Technology》2010,13(2):101-115
This paper investigates the utilization of wavelet filters via multistage convolution by Reverse Biorthogonal Wavelets (RBW)
in high and low pass band frequency parts of speech signal. Speech signal is decomposed into two pass bands of frequency;
high and low, and then the noise is removed in each band individually in different stages via wavelet filters. This approach
provides better outcomes because it does not cut the speech information, which occurs when utilizing conventional thresholding.
We tested the proposed method via several noise probability distribution functions. Subjective evaluation is engaged in conjunction
with objective evaluation to accomplish optimal investigation method. The method is simple but has surprise high quality results.
The method shows superiority over Donoho and Johnstone thresholding method and Birge-Massart thresholding strategy method. 相似文献
156.
A fluidized bed crystallization technology was found to be a feasible method for the reduction of scaling tendency of seawater. Seeded crystallization experiments in a pilot plant fluidized bed crystallizer were conducted. The obtained results for seawater, with initial salinity of 55.75 g/kg and initial pH of 8.23 at a constant temperature of 50 °C, have proven that the Ryznar Stability Index of seawater has been changed dramatically from its initial value of 4.77 (in the range of high scaling potential) to the value of 5.10 (in the range of middle to small scaling potential) over a time period of 180 min. 相似文献
157.
Calculation of the octane number for aromatic hydrocarbons expected to be present in the gasoline range (40-200° C) was carried out by developing a new method using H-nmr spectroscopy and multiparametric regressional analysis. The additivity parameters suggested in the muliparametric regressional analysis are relevant to the chemical formula for mono, di, and poly alkyl substituted benzenes.
Two sets of relevant parameters in two different attempts were suggested to suit the calculation of the octane number of all the possible present aromatic in the gasoline range. The first attempt, gives rise to parametric equation (1) suitable to calculate the octane number for all mono substituted alkyl benzenes. However, application of the developed equation to di, tri, and poly substituted alkyl benzenes gives calculated octane number values, do not agree with the observed values. In the second attempt additional parameters were included in the regression analysis; they are resonance (R), steric (S), and inductive (I) effects. The new developed equation (2) gives calculated octane number values comparable to the observed ones for all the possible and hypothetical aromatics in gasoline. 相似文献
Two sets of relevant parameters in two different attempts were suggested to suit the calculation of the octane number of all the possible present aromatic in the gasoline range. The first attempt, gives rise to parametric equation (1) suitable to calculate the octane number for all mono substituted alkyl benzenes. However, application of the developed equation to di, tri, and poly substituted alkyl benzenes gives calculated octane number values, do not agree with the observed values. In the second attempt additional parameters were included in the regression analysis; they are resonance (R), steric (S), and inductive (I) effects. The new developed equation (2) gives calculated octane number values comparable to the observed ones for all the possible and hypothetical aromatics in gasoline. 相似文献
158.
Diana Villanueva Alma-Delia Cuevas-Rasgado Omar Juárez Adolfo Guzmán-Arenas 《Expert systems with applications》2013,40(2):598-610
In natural language processing (NLP), disambiguation is the procedure used to solve name conflicts of polysemic concepts (different meanings); in fact, phrase disambiguation is a problem not totally solved in NLP. Several disambiguation types exist; for instance, noun disambiguation (bank is a word with several meanings) or when a word is both used as a noun and as a preposition. Work herein reported describes an algorithm and its implementation to disambiguate prepositions in Spanish phrases; some of them are: a {to} (Translation to English are in bold for explanation purposes; they give only one of the senses of the Spanish word, which usually have multiple meanings.), ante {before}, bajo {under}, cabe {fits}, desde {from}, contra {against}, en {in}, por {by}, según {according to}, sin {without}, entre {between}, so {under}, con {with}, hacia {towards}, sobre {about}, hasta {until}, de {of}, tras {after}, para {for}. This tool will be used in a text analyzer (being built) that converts a text document to its corresponding ontology representation, with the goal of allowing another program to use the information to answer non trivial questions (**). 相似文献
159.
In this study, pure rhodium was fabricated and mechanically investigated at the nanoscale for the first time. The nanopillars approach was employed to study the effects of size on the yield point. Nanopillars with different diameters were fabricated using electroplating followed by uniaxial compression tests. Scanning electron microscopy (SEM) was used as a quality control technique by imaging the pillars before and after compression to ensure the absence of cracks, buckling, barrelling or any other problems. Transmission electron microscopy and SEM were used as microstructural characterization techniques. Due to substrate-induced effects, only the plastic region of the stress–strain curves were investigated, and it was revealed that the yield point increases with size reduction up to certain limit, then decreases with further reduction of the nanopillar size (diameter). The later weakening effect is consistent with the literature, which demonstrates the reversed size effect (the failure of the plasticity theory) in nanocrystalline metals, i.e. smaller is weaker. In this study, however, the effect of size reduction is not only weakening, but is strengthening-then-weakening, which the authors believe is the true behavior of nanocrystalline materials. 相似文献
160.
Omar Hussain Tharam Dillon Farookh Khadeer Hussain Elizabeth Chang 《Simulation Modelling Practice and Theory》2011,19(2):704-717
Business activities are a result of carefully formed associations between different users in order to achieve certain pre-decided outcomes. Decision-making in such associations is an important step and transactional risk analysis is one of the integral processes that facilitates this step. This paper presents an approach that determines the negative consequences (termed as financial risk) of forming e-business associations. Unlike other approaches, our model captures the different types of events and their uncertainties to determine the financial risk by using the convolution operator and expressing it as a probabilistic measure rather than as a crisp financial value. Such representation makes sense as the financial risk may be determined at a point of time in future where nothing is certain. Depending upon the complexity of the problem, we explain the different ways of using the convolution operator to determine the financial risk. The simulation result shows a better representation and understanding of the financial risk that will provide important inputs to the transactional risk analysis and the decision-making process. 相似文献