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131.
Andres Castellanos-Gomez Menno Poot Gary A Steele Herre SJ van der Zant Nicolás Agra?t Gabino Rubio-Bollinger 《Nanoscale research letters》2012,7(1):233
We fabricate freely suspended nanosheets of molybdenum disulphide (MoS2) which are characterized by quantitative optical microscopy and high-resolution friction force microscopy. We study the elastic deformation of freely suspended nanosheets of MoS2 using an atomic force microscope. The Young''s modulus and the initial pre-tension of the nanosheets are determined by performing a nanoscopic version of a bending test experiment. MoS2 sheets show high elasticity and an extremely high Young''s modulus (0.30 TPa, 50% larger than steel). These results make them a potential alternative to graphene in applications requiring flexible semiconductor materials.PACS, 73.61.Le, other inorganic semiconductors, 68.65.Ac, multilayers, 62.20.de, elastic moduli, 81.40.Jj, elasticity and anelasticity, stress-strain relations. 相似文献
132.
Ana M. Díez-Pascual Mohammed Naffakh Carlos Marco Gary Ellis Marián A. Gómez-Fatou 《Progress in Materials Science》2012,57(7):1106-1190
Polyetherketones, PEKs, are an important family of high-performance thermoplastic materials that display a unique combination of toughness, stiffness, thermooxidative stability, chemical and solvent resistance, flame retardancy, and retention of physical properties at high temperatures. A relevant step forward in the development of these materials has been the recent incorporation of nanofillers to extend their utility in advanced technological applications. This review provides an extensive overview of the research on PEK-based nanocomposites with a special emphasis on both carbon-based nanofillers, such as nanotubes or nanofibers, and inorganic nanoparticles. Nanocomposites can be fabricated by simple, low-cost conventional techniques such as extrusion and compression molding, generally combined with pre-processing stages involving mechanochemical treatments in organic solvents. Different strategies employed to efficiently incorporate carbon nanofillers into these matrices, including polymer functionalization, covalent grafting and nanofiller wrapping in compatibilizing systems are described. The analysis of the influence of the preparation and processing conditions as well as the nanofiller type, attributes and loading on the structure and properties of the resulting materials is also considered. Composites incorporating carbon nanofillers display remarkably improved thermal stability, electrical and thermal conductivity as well as mechanical property enhancements compared to the neat polymers. On the other hand, the incorporation of inorganic nanoparticles such as WS2, SiO2 or Al2O3 significantly enhances the tribological properties of the matrix, mainly the coefficient of friction and wear resistance. Finally, current and potential applications of these multifunctional nanocomposite materials in fields such as medicine, telecommunications, electronics, aerospace, automobile and chemical industries are described. 相似文献
133.
Spray drying of a phenolic‐rich membrane filtration fraction of olive mill wastewater: optimisation and dried product quality
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Ivana Sedej Rebecca Milczarek Selina C. Wang Runqi Sheng Roberto de Jesús Avena‐Bustillos Lan Dao Gary Takeoka 《International Journal of Food Science & Technology》2016,51(8):1900-1909
Olive mill wastewater (OMWW) from 3‐ and 2‐phase mills was subjected to a two‐step membrane filtration process. The obtained reverse osmosis retentate (RO‐R) is a phenolic‐rich coproduct stream, and the reverse osmosis permeate is a near‐pure water stream. A pilot‐scale spray dryer was used for the production of RO‐R powder. The optimum temperature/feed pump conditions were obtained for 3‐phase (150°C/4.4 Hz) and for 2‐phase RO‐R (175°C/3.8 Hz). The powders obtained by spray drying under these conditions were analysed for physicochemical properties, including identification and quantification of phenolic compounds. Protocatechuic acid, 3‐hydroxytyrosol, tyrosol, vanillic acid and p‐coumaric acid were quantified in both RO‐R powders, which show the possibility to obtain a phenolic‐rich powder from an OMWW filtration fraction. This will lead towards better usage of by‐products from olive oil production. 相似文献
134.
135.
Abdulrahman Alharthi Madini O. Alassafi Robert J. Walters Gary B. Wills 《Telematics and Informatics》2017,34(2):664-678
Saudi universities have at their disposal a huge number of low cost IT resources to aid in teaching, research and learning. By migrating to cloud services, Saudi universities will be moving data and programs from local servers to the internet, thereby providing users with the ability to access and share information at any time from multiple devices. The migration to cloud-based IT resources is not yet widespread in Saudi universities due to several challenges including security, legal policies and implementation. At present, there is lack of research and guidance for Saudi universities on how to overcome these challenges and how contextual factors can influence the successful migration to the educational clouds.This research presents a framework for the successful migration to cloud technology in the Saudi Arabian universities. In this research, a set of key critical success factors (CSFs) were identified by synthesizing components from studies concerned with the migration of cloud for higher education and factors identified from the successful implementation of WBL (Web Based Learning) and ERP (Enterprise Resource Planning) on higher education in Saudi Arabia. Based on this knowledge, the proposed framework was evaluated via expert review and a survey by IT specialists from the Saudi universities. The initial CSFs were updated based on the expert reviews and the results were analysed. Based on the findings at this stage, additional CSFs were added to the framework as suggested by the experts. Subsequently, in order to confirm the reviewed CSFs, additional investigation via a structured online questionnaire was conducted and the outcome was analysed via one-sample t-test with the data integrity analysed via Cronbach’s alpha. The outcome indicated the majority of CSFs to be statistically significant except the Physical Location CSF. Potential future study and contributions are discussed. 相似文献
136.
Paul M. Young Rania O. Salama Bing Zhu Gary Phillips John Crapper Hak-Kim Chan 《Drug development and industrial pharmacy》2015,41(5):859-865
A series of co-engineered macrolide–mannitol particles were successfully prepared using azithromycin (AZ) as a model drug. The formulation was designed to target local inflammation and bacterial colonization, via the macrolide component, while the mannitol acted as mucolytic and taste-masking agent. The engineered particles were evaluated in terms of their physico-chemical properties and aerosol performance when delivered via a novel high-payload dry powder Orbital? inhaler device that operates via multiple inhalation manoeuvres. All formulations prepared were of suitable size for inhalation drug delivery and contained a mixture of amorphous AZ with crystalline mannitol. A co-spray dried formulation containing 200?mg of 50:50?w/w AZ: mannitol had 57.6%?±?7.6% delivery efficiency with a fine particle fraction (≤6.8?µm) of the emitted aerosol cloud being 80.4%?±?1.1%, with minimal throat deposition (5.3?±?0.9%). Subsequently, it can be concluded that the use of this device in combination with the co-engineered macrolide–mannitol therapy may provide a means of treating bronchiectasis. 相似文献
137.
138.
Jingming Ning Gary G. Hou Jingjing Sun Zhengzhu Zhang Xaiochun Wan 《International Journal of Food Science & Technology》2019,54(2):576-582
The effects of green tea powder (GTP) on the properties of hard red winter (HRW) flour and Chinese steamed bread were investigated. GTP was blended with HRW flour at levels of 0.00, 1.00, 2.00, 3.00 and 4.00 g GTP/100 g wheat flour. With the addition of GTP, the maximum torque of flour became stronger. The resilience and degree of green colour of steamed bread increased, while hardness and chewiness decreased, with the addition of GTP. The addition of 1.00% GTP did not significantly affect the specific volume, but remarkably influenced the hardness and resilience of steamed bread. In steamed bread formulated with GTP, the antioxidant activity was 0.84 mm TE per g at 1.00% of GTP and increased with GTP levels. The steamed bread had a pleasant flavour, and the degree of overall liking of steamed bread increased with GTP levels to the maximum used in this work. 相似文献
139.
Lithium‐sulfur batteries have attracted much research interest because of their high theoretical energy density and low‐cost raw materials. While the electrodes are composed of readily available materials, the processes that occur within the cell are complex, and the electrochemical performance of these batteries is very sensitive to a number of cell processing parameters. Herein, a simple electrochemical model will be used to predict, with quantitative agreement, the electrochemical properties of lithium‐sulfur cathodes with varying carbon to sulfur ratios. The discharge capacity and the polarization were very similar for the lowest sulfur loadings, while above 23.2 wt% sulfur the gravimetric capacity dropped significantly, and there was an increase in the cell polarization. In addition, a transition in the electrode morphology, from well dispersed to aggregated sulfur at the surface, will be reflected in the change in a critical model parameter demonstrating the sensitivity and functionality of even this simple model in predicting complex behavior in the lithium‐sulfur cells. 相似文献
140.
The monitoring of production line availability on a day-to-day basis and for continuous improvement is approached from a control charting point of view. Control limits are developed along with the length of time between monitoring periods to control accuracy. This provides a convenient way to monitor the availability measure at any desired level of accuracy. 相似文献