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排序方式: 共有177条查询结果,搜索用时 46 毫秒
71.
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73.
Gas Sensors: Platinum Nanoparticle Loading of Boron Nitride Aerogel and Its Use as a Novel Material for Low‐Power Catalytic Gas Sensing (Adv. Funct. Mater. 3/2016)
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74.
Based on an offline and online survey of 967 people of Turkish origin living in these countries, we test how legacy and social media have influenced the participation of the members of the Turkish diaspora in Belgium, Germany and the Netherlands in the mid-2013 protests in Turkey’s social movement referred to as Gezi Park. This study also investigates how living in Europe can influence the behavior and attitudes of the sampled individuals from the Turkish Diaspora of Germany, Belgium and Netherlands during the period when the Gezi Park demonstration took place. Our results make it clear that social media were used by those who supported the protest movement, while those who opposed the protest movement primarily used or followed traditional sources of media, including Turkish and European television. Furthermore, supporters amongst the diaspora for the Gezi-protests were primarily active in accruing social capital through bonding and social networking among those who belong to the Turkish diaspora under the guise of the Gezi Park protests. Finally, a significant number of the supporters of the protests in the three countries took part in several different means of supporting the movement, including: disseminating awareness about the Gezi protests through social media, engaging in meetings, and in some cases, even severing contact with friends and acquaintances who did not share their support for the protest movement. 相似文献
75.
Composite scale of amorphous silica and calcium oxalate is very intractable; it imposes a significant fraction of scale management cost in sugar mill evaporators. This work evaluates silica and calcium oxalate composite fouling using dynamic fouling-loop experiments under different operating conditions with and without sugar. A novel closed-loop setup simulating in a single run the effect of feed concentration in successive stages of evaporation cycle was used. Experiments under constant composition and varying thermal hydraulic effect were conducted. Results indicated synergistic effects for initial silica and calcium oxalate supersaturation values of 2.6 and 1.7. Sugar effects became significant for concentrations in the third effect and above. The fouling mechanism was particulate deposition of silica and calcium oxalate colloidal species strengthened by consolidation; fouling rate increased with decreasing interfacial energy barrier between the surface and foulant, assessed by zeta-potential analysis. Deposit characteristics and deposition rates were concentration and thermal hydraulics dependent. Results confirmed the need that the 5 × 5 (types × stages of fouling) matrix of Epstein needs to be expanded to a 6 × 6 matrix to include composite fouling as a type of fouling. In this study the composite fouling was a surface-controlled process for which the activation energy was similar to typical chemical bond strengths, explaining the role of consolidation in composite fouling. The results contribute to advancement of fundamental understanding of heat exchanger fouling and to development of scale control strategies for composite fouling minimization in sugar mill evaporators. 相似文献
76.
Roya Derakhshan Mauro Mancini John Rodney Turner 《International Journal of Project Management》2019,37(1):73-86
With the aim of delving into the legitimacy formation mechanisms used by communities to make judgements about project organizations, this research studied the local community and surrounding environment of four oil extraction projects located in three developing countries. The results of the cross-case analysis suggest that communities' negative perceptions from government and media can influence their judgement of organizational behaviour. Additionally, this research proposes that local communities' anticipation of the consequences of protesting against the organization can make them decide not to take any action. According to institutional theory, when community individuals arrive at a legitimacy verdict about an organization, their future perceptions will mainly be influenced by this decision rather than conscious consideration of the conditions. Accordingly, this research recommends that organizations aiming to recover their reputation need to adopt compensation activities with a substantial influence on the improvement of conditions. It is only in such conditions that communities will consciously evaluate organizational legitimacy. Trivial changes in organizational behaviour will only result in adding new evidences in support of the illegitimacy of organizations. 相似文献
77.
Nenad L. Ignjatovi? Petar Ninkov Roya Sabetrasekh Dragan P. Uskokovi? 《Journal of materials science. Materials in medicine》2010,21(1):231-239
The purpose of the study presented in this paper has been to examine the possibility of the synthesis of a new nanoparticulate
system for controlled and systemic drug delivery with double effect. In the first step, a drug is released from bioresorbable
polymer; in the second stage, after resorption of the polymer, non-bioresorbable calcium phosphate remains the chief part
of the particle and takes the role of a filler, filling a bone defect. The obtained tigecycline-loaded calcium-phosphate(CP)/poly(dl-lactide-co-glycolide)(PLGA) nanoparticles contain calcium phosphate coated with bioresorbable polymer. The composite was
analyzed by FT-IR, XRD and AFM methods. The average particle size of the nanocomposite ranges between 65 and 95 nm. Release
profiles of tigecycline were obtained by UV–VIS spectroscopy in physiological solution at 37°C. Experimental results were
analyzed using Peppas and Weibull mathematical models. Based on kinetic parameters, tigecycline release was defined as non-Fickian
transport. The cytotoxicity of the nanocomposite was examined on standard cell lines of MC3T3-E1, in vitro. The obtained low
values of lactate dehydrogenase (LDH) activity (under 37%) indicate low cytotoxicity level. The behaviour of the composite
under real-life conditions was analyzed through implantation of the nanocomposite into living organisms, in vivo. The system
with the lowest tigecycline content proved to be an adequate system for local and controlled release. Having in mind the registered
antibiotics concentration in other tissues, delivery systems with a higher tigecycline content show both local and systemic
effects. 相似文献
78.
Shahram Shoeibi Maryam Amirahmadi Hossein Rastegar Roya Khosrokhavar Amin Mousavi Khaneghah 《Journal of food science》2013,78(5):T792-T796
It is important to have a reliable method to analyze pesticides in tea, a beverage commonly consumed in Iran. A validated method was developed for the determination of 20 pesticides in tea based on QuEChERS sample preparation and capillary gas chromatography‐quadrupole mass spectrometry in selective ion monitoring mode (GC‐MS/SIM) using triphenyl methane (TPM) solution as an internal standard. We used fortified, extracted, and cleaned‐up tea samples instead of calibration standards for quantitation, which substantially reduced adverse matrix‐related effects and negative recovery affected by graphite carbon black (GCB) on pesticide analysis. The recovery of pesticides at 3 concentration (40, 60, and 240 ng/g) ranged from 79.5% to 111.4% (n = 3). The method had acceptable repeatability with RSDr < 20%. The limits of quantification (LOQ) for all pesticides were ≤20 ng/g. The analytical results of the proposed method were in good agreement with proficiency test results (FAPAS, 19116). The recoveries and repeatabilities were in accordance with the criteria set by SANCO Guideline. The validated method was suitable for the analysis of pesticides in tea. 相似文献
79.
Abolfazl Yazdanpanah Reza Kamalian Fathollah Moztarzadeh Masoud Mozafari Roya Ravarian Lobat Tayebi 《Ceramics International》2012,38(6):5007-5014
In this research, the replacement effects of bioactive glass (BG) by nanocrystalline forsterite (NF) on the biomineralization, microstructural and mechanical properties of BG-based nanocomposites were investigated. The hybrid nanocomposites with different NF contents (0, 10, 20, and 30 wt%) were prepared from the nanopowders by means of conventional cold pressing method. Surprisingly, the addition of NF provided redundant mechanisms to improve the toughness of the BG matrix without deteriorating its biomineralization properties. In addition, the resulting enhancement in the fracture toughness, observed for the first time in highly bioactive BG/NF nanocomposites, indicated the potential of the prepared nanocomposites as advanced biomaterials for load-bearing bone tissue engineering applications. 相似文献
80.
Investigating the production and properties of Ag/TiO2/PP antibacterial nanocomposite filament yarns
In this research, investigating the possibility of producing, processing and also characterization of antibacterial organic/inorganic nanocomposite polypropylene fiber has been presented. For this purpose, PP powder and inorganic nanocomposite filler were mixed using a twin screw extruder and modified granule was produced. After producing as-spun filament yarns by a pilot plant melt spinning machine at the take-up speed of 2000 m/min, samples were drawn, textured and finally weft knitted. Physical and structural properties of as-spun and drawn yarns with constant and variable draw ratios were investigated. The experimental results revealed that the crystallinity reduction of modified as-spun yarns could be compensated by drawing process. Tensile properties of modified drawn yarns with the variable draw ratio were higher than the pure PP, whereas the inverse observation was noticed in the case of constant draw ratio. The investigation of antimicrobial activity showed a high percentage of biostatic efficiency on the modified samples. 相似文献