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71.
72.
B. Jarvis A. W. Holmes 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1982,32(1):224-232
Biotechnology has been defined in various ways but is essentially the application of biological systems to the manufacturing industries. By implication therefore food biotechnology is the application of plant, animal and microbial systems to the production and industrial processing of food, through the development of new cultivars and livestock strains, of microorganisms with particular characteristics, and thence of new and alternative food raw materials, additives, processing aids, etc. After the publication in 1980 of the report of a joint working party on biotechnology, an appraisal was made of the awareness, interest in and potential applications for biotechnology in the food manufacturing industries. This appraisal was done, firstly, by questionnaire to food-manufacturing companies, trade associations, etc., second, by follow-up discussions with appropriate academic, research institute and industrial experts in the area of biotechnology and, third, as part of a Delphi forecasting exercise. Biotechnology is not new. Indeed, the food and related industries provide potent examples of the traditional application of biotechnology in areas as diverse as the brewing of vinegar and alcoholic beverages, through to the production of cured meats, the application of enzymes to the tenderisation of meats and the production of isomerose from starch. Since foods are biological materials per se, any technological treatments of food are, by definition, applications of biotechnology. There are two primary aspects to food biotechnology. Firstly, the positive application of biological processes in the development of new or improved food products and, second, the application of what we refer to elsewhere as ‘negative biotechnology’. The latter is the application of technological skills to the prevention of undesirable biological change. Both are relevant to the modern food-manufacturing industry and must be considered in parallel. This paper is concerned specifically with the application of positive biotechnology to the food industry. The objective is to summarize some of the findings from our surveys and to indicate areas in which biotechnology developments may be applied in the food-manufacturing industries. 相似文献
73.
J. R. Thompson Jr. H. Ramm J. F. Jarvis Horst Meyer 《Journal of Low Temperature Physics》1970,2(5-6):521-537
An accurate study of the nuclear molar susceptibility of liquid He
3
has been made. Particularly emphasized was the comparison of in the liquid with that in solid He
3
. The experimental results of this work define a three-dimensional surface T/C versus temperatureT and molar volumeV between 0.35 and 2.2° K and between 26 and 37 cm
3
/mole. HereC is the molar Curie constant of solid He
3
, assumed to beN
A
µ
2
/k
B
T, where is the nuclear magnetic moment and N
A
Avogadro's number. The measurements were accomplished using a carefully designed pulsed NMR set, and sample-and-hold circuitry with a digital voltmeter for readout. Most of the measurements were made at fixed temperature relative to a sample of bcc solid He
3
, usually at a density of 22.50 cm
3
/mole. These data were complemented by measurement of versusT at fixed pressure. Except at the highest temperatures, the scatter in the values was about 0.3%, and the results are estimated to be accurate within ±0.5%. At sufficiently high temperatures, the susceptibility is found to tend asymptotically towards Curie's law by comparison with solid He
3
. The deviation from Curie's law, to temperatures near 0.5° K, could be empirically written as (1–T/C)=bT
d
whereb andd are density-dependent parameters. Comparison with theories and previous measurements of the nuclear susceptibility are made. Below 1° K, the present results are about midway between those of Beal and Hatton
9
and those of Thomson, Meyer, and Adams.
8
Research supported by a grant from the National Science Foundation and from the AROD. The results have been presented as an Abstract inBull. Am. Phys. Soc.
14, 601 (1969), submitted in partial fulfillment for the Ph.D. in physics by J. R. Thompson, May 1969. 相似文献
74.
75.
Discusses a federal proposal that would limit the amount of health insurance an employer could provide tax free to employees. This could lead to the elimination of cost-effective health benefits such as mental health coverage, drug and alcohol abuse programs, and other preventive care services. The proposal threatens health security and is unlikely to provide additional tax revenues for the government. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
76.
The spectrum and coherency are useful quantities for characterizing the temporal correlations and functional relations within and between point processes. This article begins with a review of these quantities, their interpretation, and how they may be estimated. A discussion of how to assess the statistical significance of features in these measures is included. In addition, new work is presented that builds on the framework established in the review section. This work investigates how the estimates and their error bars are modified by finite sample sizes. Finite sample corrections are derived based on a doubly stochastic inhomogeneous Poisson process model in which the rate functions are drawn from a low-variance gaussian process. It is found that in contrast to continuous processes, the variance of the estimators cannot be reduced by smoothing beyond a scale set by the number of point events in the interval. Alternatively, the degrees of freedom of the estimators can be thought of as bounded from above by the expected number of point events in the interval. Further new work describing and illustrating a method for detecting the presence of a line in a point process spectrum is also presented, corresponding to the detection of a periodic modulation of the underlying rate. This work demonstrates that a known statistical test, applicable to continuous processes, applies with little modification to point process spectra and is of utility in studying a point process driven by a continuous stimulus. Although the material discussed is of general applicability to point processes, attention will be confined to sequences of neuronal action potentials (spike trains), the motivation for this work. 相似文献
77.
Stability of particle flocs upon addition of natural organic matter under quiescent conditions 总被引:7,自引:0,他引:7
In this research, the influence of two natural organic polymers (polysaccharide and humic acid) on the stability of colloidal aggregates was examined. The primary objective of this research was to determine whether addition of organic matter to floc suspensions results in the fragmentation or stabilization of aggregates. A second objective was to determine how the size of aggregates and the composition of organic matter influence the floc breakup or stabilization process. It was found that the stability of aggregates depended on the type of organic material present as well as floc size. For example, humic acid increased the stability of aggregates more effectively than polysaccharides of larger size. It was also found that the addition of humic acid or polysaccharide generally decreased the rate of coagulation of small aggregates but had less influence on large aggregates. In no case did the addition of polysaccharide or humic acid result in the fragmentation of particle aggregates. The existence of strong interparticle forces within flocs prevented aggregate breakup upon adsorption of natural organic polymers. The results presented here provide important new information regarding the influence of NOM on the behavior of particles in aquatic systems. 相似文献
78.
Rapid oxidation and accretion of iron onto high surface area media has been investigated as a potential passive treatment option for ferruginous. net-alkaline minewaters. Two pilot-scale reactors were installed at a site in County Durham, UK. Each 2.0 m high cylinder contained different high surface area plastic trickling filter media. Ferruginous minewater was fed downwards over the media at various flow-rates with the objective of establishing the efficiency of iron removal at different loading rates. Residence time of water within the reactors was between 70 and 360 s depending on the flow-rate (1 and 12 l/min, respectively). Average influent total iron concentration for the duration of these experiments was 1.43 mg/l (range 1.08-1.84 mg/l; n = 16), whilst effluent iron concentrations averaged 0.41 mg/l (range 0.20-1.04 mg/l; n = 15) for Reactor A and 0.38 mg/l (range 0.11-0.93 mg/l; n = 16) for Reactor B. There is a strong correlation between influent iron load and iron removal rate. Even at the highest loading rates (approximately 31.6 g/day) 43% and 49% of the total iron load was removed in Reactors A and B, respectively. At low manganese loading rates (approximately 0.50-0.90 g/day) over 50% of the manganese was removed in Reactor B. Iron removal rate (g/m3/d) increases linearly with loading rate (g/day) up to 14 g/d and the slope of the line indicates that a mean of 85% of the iron is removed. In conclusion. it appears that the oxidation and accretion of ochre on high surface area media may be a promising alternative passive technology to constructed wetlands at certain sites. 相似文献
79.
Vera Hollink Maarte van Someren Bob J Wielinga 《User Modeling and User-Adapted Interaction》2007,17(1-2):183-214
Users of web sites often do not know exactly which information they are looking for nor what the site has to offer. The purpose
of their interaction is not only to fulfill but also to articulate their information needs. In these cases users need to pass
through a series of pages before they can use the information that will eventually answer their questions. Current systems
that support navigation predict which pages are interesting for the users on the basis of commonalities in the contents or
the usage of the pages. They do not take into account the order in which the pages must be visited. In this paper we propose
a method to automatically divide the pages of a web site on the basis of user logs into sets of pages that correspond to navigation
stages. The method searches for an optimal number of stages and assigns each page to a stage. The stages can be used in combination
with the pages’ topics to give better recommendations or to structure or adapt the site. The resulting navigation structures
guide the users step by step through the site providing pages that do not only match the topic of the user’s search, but also
the current stage of the navigation process. 相似文献
80.
Bob L. Sturm 《Journal of Intelligent Information Systems》2013,41(3):371-406
We argue that an evaluation of system behavior at the level of the music is required to usefully address the fundamental problems of music genre recognition (MGR), and indeed other tasks of music information retrieval, such as autotagging. A recent review of works in MGR since 1995 shows that most (82 %) measure the capacity of a system to recognize genre by its classification accuracy. After reviewing evaluation in MGR, we show that neither classification accuracy, nor recall and precision, nor confusion tables, necessarily reflect the capacity of a system to recognize genre in musical signals. Hence, such figures of merit cannot be used to reliably rank, promote or discount the genre recognition performance of MGR systems if genre recognition (rather than identification by irrelevant confounding factors) is the objective. This motivates the development of a richer experimental toolbox for evaluating any system designed to intelligently extract information from music signals. 相似文献