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31.
The aim of this study was to evaluate the combined effect of salt (sodium chloride, 0–8% w/v), sorbate (potassium sorbate, 0–4.5% w/v), nisin (0–500 ppm) and lysozyme (0–500 ppm) on the survival of Clostridium sporogenes as a non‐toxigenic surrogate of Clostridium botulinum in terms of the probability of growth by using a central composite rotatable design. The results indicated that salt and sorbate were the most effective factors in preventing the growth of Cl. sporogenes in high‐moisture (>95%) and low‐acid conditions. The probability of growth of Cl. sporogenes in broth was reduced by combinations of salt and sorbate. Nisin and lysozyme had insignificant effects on the probability of growth of Cl. sporogenes (P > 0.05). Lysozyme individually and in combination with nisin had no inhibitory effect on Cl. sporogenes. Overall, the addition of sorbate and lysozyme may allow the salt concentration to be reduced while preventing growth.  相似文献   
32.
Cellulose is a fascinating biopolymer of almost inexhaustible quantity. While being a lightweight material, it shows outstanding values of strength and stiffness when present in its native form. Unsurprisingly, cellulose fibre has been rigorously investigated as a reinforcing component in biocomposites. In recent years, however, a new class of monocomponent composites based on cellulosic materials, so-called all-cellulose composites (ACCs) have emerged. These new materials promise to overcome the critical problem of fibre–matrix adhesion in biocomposites by using chemically similar or identical cellulosic materials for both matrix and reinforcement. A number of papers scattered throughout the polymer, composites and biomolecular science literature have been published describing non-derivatized and derivatized ACCs. Exceptional mechanical properties of ACCs have been reported that easily exceed those of traditional biocomposites. Several different processing routes have been applied to the manufacture of ACCs using a broad range of different solvent systems and raw materials. This article aims to provide a comprehensive review of the background chemistry and various cellulosic sources investigated, various synthesis routes, phase transformations of the cellulose, and mechanical, viscoelastic and optical properties of ACCs. The current difficulties and challenges of ACCs are clearly outlined, pointing the way forward for further exploration of this interesting subcategory of biocomposites.  相似文献   
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34.
This article is a discussion of how to measure urban inequality using the results of large household samples. It has two aims. The first is to de-mystify the methods of measuring earnings inequality by discussing their logic and their results in plain language that is suitable for a non-specialist audience. The second is to persuade the reader that such surveys can be suitable for measuring income derived from all kinds of livelihood strategies, including informal sector activities. The results show persistently high levels of inequality over time among income earners on the Copperbelt. Disaggregation of the employed workforce by major occupational groups reveals increasingly more elementary and middle-income workers than higher income managers, professionals, and technicians. This pattern differs by gender, however, with only women experiencing a marked increase in low-skill, low-wage employment.  相似文献   
35.
Multimedia Tools and Applications - Microsoft has recently released a mixed reality headset called HoloLens. This semi-transparent visor headset allows the user who wears it to view the projection...  相似文献   
36.
Protein–polysaccharide complexes are used to improve protein stability and encapsulate high‐value ingredients, yet the influence of different salts on their formation has not been investigated. Using light scattering and turbidimetry, effects of chloride, sulphate and thiocyanate salts on β‐lactoglobulin and pectin complexes (protein/pectin ratio = 2:1 and 4:1) were determined in relation to effects of pH and ionic strength. Effects of anions on complex formation were significant at 25 mmol kg?1 added ionic strength. Cation effects were not significant. At 100 mmol kg?1 ionic strength, pH of complex formation increased with sulphate salts (pH 5.1) relative to chloride and thiocyanate salts (pH 4.9), while pH of coacervation increased with sulphate salts (pH 4.7) and decreased with thiocyanate salts (pH 4.4) relative to chloride salts (pH 4.6). Pure β‐lactoglobulin stability was otherwise reduced with thiocyanate salts below pH 5, implying a significant effect of pectin interactions.  相似文献   
37.
Informal settlements have become dominant forms and processes of urban development in many cities, yet the task of helping students engage with design issues in such contexts is fraught with difficulties of access, safety, and complexity. Drawing on detailed fieldwork, this article explores ways in which informal settlement formation can be taught in design studio through the use of games that simulate incremental practices of room-by-room accretion and prospects for transformation. The pedagogical goals are to effect a blurring of authorship and authority, to undermine top-down thinking, and to nourish forms of design imagination that unite process and form.  相似文献   
38.
Primary Li-air cell development   总被引:1,自引:0,他引:1  
In the present communication, we report on recent researches for optimizing the performance of a primary organic-based Li-air cell. These researches focus on new processing technologies for a high capacity and high rate capable carbon cathode, and the development of oxygen selective membranes based on polysiloxane and methacrylate-polysiloxane copolymers. These membranes, generally classified as silicone rubbers exhibit high permeability for oxygen and impede water transport from the atmosphere into the Li-air cell and solvent loss from the cell into the atmosphere.  相似文献   
39.
The paper introduces and supports the contention that an idiographic methodology is appropriate to the post- hoc study and interpretation of individual construction project cash flows. A cash flow model based on the logit transformation is proposed to be consistent with this methodology. The model is based on historical data, and yields two parameters to describe each individual project. The model is tested using two samples totalling 72 projects. Goodness of fit for the model, using a measure of standard deviation from 1.0% to 4.6%, with a median of 2.5%, is found for individual projects.

The experimental hypothesis (that there is substantial variation between projects) is supported by the graphical and statistical evidence of deviation, which is argued to be the result of the individual ontology of each project - systematic error - rather than random error from an ideal. The paper concludes that forecasts of individual cash flows are invalid when derived from analysis of grouped data.  相似文献   
40.
Abstract

The grey squirrel Sciurus carolinensis is thought to have contributed to the decline of red squirrel S. vulgaris populations in the UK through resource competition and disease spread. This study used mtDNA sequencing to assess patterns of grey squirrel dispersal in the UK. Patterns of genetic variation within the dloop sequence were characterised for seven grey squirrel populations. Infiltration directions and potential barriers to dispersal are identified and discussed, with a focus on Cumbria, a county at the forefront of grey squirrel expansion. Understanding the dynamics of grey squirrel dispersal will aid their management at a landscape scale and enhance the conservation of red squirrels.  相似文献   
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