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排序方式: 共有1427条查询结果,搜索用时 31 毫秒
181.
Claudio Baiocchi Martina Magni Francesco Romaniello Emanuele Forte Mauro Fontana 《Journal of the American Oil Chemists' Society》2020,97(10):1057-1069
Nominal sorbitan tristearate (E492) commercial samples are widely used generally as emulsifiers and particularly as anti-bloom agents in confectionery products. In spite of this generalized use, their qualitative and quantitative evaluation is poorly documented in literature and the relative works go back to the last decades of last century. In the present work, a deep study by HPLC-High Resolution Mass Spectrometry of qualitative composition of five E492 commercial samples was made up showing a very complex pattern of stearic and palmitic acid esters with the sorbitol anhydrides, sorbitan, and isosorbide. A clear distinction of sorbitan mono-, di-, tri-, and tetra-esters, of sorbitol penta- and hexa-esters and isosorbide mono- and di-esters was achieved. Contemporarily, difference in the qualitative pattern between E492 commercial samples coming from different suppliers was established. As a consequence, quantitative evaluation can be reliably obtained by using as calibration standard the same E492 present in real samples. The accuracy and recovery of the method were determined allowing in this way a reliable application to commercial confectionery products. The detailed knowledge of STS composition may be of great help to orient the synthesis conditions in order to modulate its properties as a function of various experimental necessities. 相似文献
182.
Composite films in coacervation condition offer an alternative to change properties of protein-based films, and they present potential applications such as inclusion, stabilization, and release of bioactive compounds in foods. Maximum interactions between soy protein isolate (SPI) (5%) and high methoxyl pectin (PEC) (0.5, 1, 1.5, and 2%), by zeta potential analysis, are found at a pH of 3. The transparency of the SPI films is lost at this pH. When PEC is added to SPI films, the elasticity, solubility, and permeability to water vapor are not significantly altered, but the tensile strength increases. Permeabilities to oxygen are higher for low PEC contents, but as PEC is added, their values are typical of SPI films produced at a pH of 11. A homogeneous structure is found at the higher PEC concentrations. The interactions of PEC–SPI can be useful to tailor films and coatings for applications such as to carry and protect substances of interest. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48732. 相似文献
183.
Alessandra Dellaquila Gabriele Greco Elisabetta Campodoni Mauro Mazzocchi Barbara Mazzolai Anna Tampieri Nicola M. Pugno Monica Sandri 《应用聚合物科学杂志》2020,137(22):48739
Silks have been widely used as biomaterials due to their biocompatibility, biodegradability, and excellent mechanical properties. In the present work, native spider silk was used as organic template for controlled nucleation of hydroxyapatite (HA) nano-coating that can act as biomimetic interface. Different bio-inspired neutralization methods and process parameters were evaluated to optimize the silk functionalization. The morphology and chemical composition were investigated by scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analysis and mechanical properties were studied through tensile tests. Results showed that the optimized protocol enabled a controlled and homogeneous nucleation of apatite nano-crystals while maintaining silk mechanical performances after mineralization. This study reports the optimization of a simple and effective bio-inspired nucleation process for precise nucleation of HA onto spider silk templates, suitable to develop high-performance hybrid interfaces for bone tissue engineering. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48739. 相似文献
184.
Federico Pallottino Alessio Cimini Corrado Costa Francesca Antonucci Paolo Menesatti Mauro Moresi 《Journal of the Institute of Brewing》2020,126(4):394-405
Over the last 80 years, malting and brewing has evolved through increased scientific understanding, driven by numerous factors including efficiency improvement, cost reduction, quality enhancement, risk minimisation, brand marketing and image enhancement. The aim of this work was to review the historical trends in global brewing research in order to identify current opportunities and emerging trends, as well as uncover future key drivers. A bibliometric analysis was performed with English language peer reviewed literature from the Scopus database together with mapping using the VOSviewer clustering software. The bibliometric results were structured to identify which affiliations, authors, and journals have been involved in brewing research, as well as the average number of citations per paper. The bibliometric mapping yielded ‘research term maps’, where the words occurring more frequently in the research papers were grouped in coloured clusters by area of interest, and their relationships indicated. The year maps revealed which average terms tended to emerge in chronological order. The estimated average citation number per paper was about nine. Countries, including Spain, Czech Republic, Italy and Belgium displayed higher average citation scores than the world average. In the period 1940-79, brewing publications were mainly process oriented whereas between 2008-18, there was a shift in focus to the consumer (health and social responsibility) and to environmental sustainability. © 2020 The Institute of Brewing & Distilling 相似文献
185.
Cristina Dai Prá Martens Franklin Jean Machado Mauro Luiz Martens Filipe Quevedo Pires de Oliveira e Silva Henrique Mello Rodrigues de Freitas 《International Journal of Project Management》2018,36(2):255-266
Entrepreneurial orientation (EO) is a strategic posture of an organization, and it is related to basic policies and practices for the development of entrepreneurial actions looking for creating competitive advantages. This study develops and tests a model of the relationship between entrepreneurial orientation and project success in Brazilian context. As quantitative research, a survey was used to collect data. A sample of 100 valid answers from project practitioners was treated through the structural equation modeling method. As research implications, the main result points out the positive correlation between the entrepreneurial orientation and the project success, contributing to the development of this research subject and helping to minimize the gap in the literature that addresses the relationship between project success and EO. In practical terms, understanding that innovativeness, risk taking, proactiveness, autonomy and competitive aggressiveness (the dimensions of the EO) can contribute to project success and can also indirectly impact on organizational performance, could help organizations get competitive advantage when developing correlate factors. Finally, the results suggest that practices of project management can be aligned to the firm's entrepreneurial orientation to enable firms to attain better results in their projects and generate a competitive advantage. On other hand, given the proportion of the impact of EO on project success (20.3%) identified in this study, it is critical that project management professionals expand their horizon to recognize other factors that affect project success. 相似文献
186.
187.
Rodella LF Favero G Boninsegna R Buffoli B Labanca M Scarì G Sacco L Batani T Rezzani R 《Microscopy research and technique》2011,74(8):772-777
An interesting clinical option for optimizing healing tissue is the use of platelet concentrate. Platelets contain high quantities of growth factors, among these TGF-β1 and VEGF, which are known to be implicated in tissue regeneration. CGF is produced by processing blood samples with a special centrifuge device; three layers are formed: top acellular plasma (PPP), middle CGF and bottom red blood cells (RBC) layers. Given that to date there are no data concerning the biological characteristic of CGF, the aim of this study was to evaluate the presence of TGF-β1 and VEGF in CGF and also in PPP and RBC layers. In addition, since circulating stem cells are recruited from blood to injured tissue for healing we also evaluated the presence of CD34 positive cells. Our data show the presence of TGF-β1 and VEGF in CGF and RBC layers. In addition, we show CD34 positive cells in CGF. 相似文献
188.
Design and control of an AS/RS 总被引:2,自引:0,他引:2
Riccardo Manzini Mauro Gamberi Alberto Regattieri 《The International Journal of Advanced Manufacturing Technology》2006,28(7-8):766-774
Automated storage/retrieval systems (AS/RSs) are a combination of equipment and controls which automatically handle, store
and retrieve materials (components, tools, raw material and subassemblies) with great speed and accuracy. Consequently, they
are widely used in industrial companies to manage products with cost-effective utilization of time, space and equipment. This
paper presents a multi-parametric dynamic model of a product-to-picker storage system with class based storage allocation
of products. Thousands of what-if scenarios are simulated in order to measure the impact of alternative design and operating
configurations on the expected system performance and to identify the most critical factors and combinations of factors affecting
the response of the system. Class based storage proves to be a very effective way of both reducing the picking cycle time
and maximizing the throughput of the system. The rapid effectiveness of visual interactive simulation (VIS) in supporting
the design (redesign) and control of new (existing) warehouses emerges, responding to the need for flexibility which modern
companies need in order to adapt to strongly changing operating conditions quickly. 相似文献
189.
Temporal planning is a research discipline that addresses the problem of generating a totally or a partially ordered sequence of actions that transform the environment from some initial state to a desired goal state, while taking into account time constraints and actions' duration. For its ability to describe and address temporal constraints, temporal planning is of critical importance for a wide range of real‐world applications. Predicting the performance of temporal planners can lead to significant improvements in the area, as planners can then be combined in order to boost the performance on a given set of problem instances. This paper investigates the predictability of the state‐of‐the‐art temporal planners by introducing a new set of temporal‐specific features and exploiting them for generating classification and regression empirical performance models (EPMs) of considered planners. EPMs are also tested with regard to their ability to select the most promising planner for efficiently solving a given temporal planning problem. Our extensive empirical analysis indicates that the introduced set of features allows to generate EPMs that can effectively perform algorithm selection, and the use of EPMs is therefore a promising direction for improving the state of the art of temporal planning, hence fostering the use of planning in real‐world applications. 相似文献
190.