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91.
Acrylonitrile–butadiene–styrene (ABS)–clay composite and intercalated nanocomposites were prepared by melt processing, using Na‐montmorillonite (MMT), several chemically different organically modified MMT (OMMT) and Na‐laponite clays. The polymer–clay hybrids were characterized by WAXD, TEM, DSC, TGA, tensile, and impact tests. Intercalated nanocomposites are formed with organoclays, a composite is obtained with unmodified MMT, and the nanocomposite based on synthetic laponite is almost exfoliated. An unintercalated nanocomposite is formed by one of the organically modified clays, with similar overall stack dispersion as compared to the intercalated nanocomposites. Tg of ABS is unaffected by incorporation of the silicate filler in its matrix upto 4 wt % loading for different aspect ratios and organic modifications. A significant improvement in the onset of thermal decomposition (40–44°C at 4 wt % organoclay) is seen. The Young's modulus shows improvement, the elongation‐at‐break shows reduction, and the tensile strength shows improvement. Notched and unnotched impact strength of the intercalated MMT nanocomposites is lower as compared to that of ABS matrix. However, laponite and overexchanged organomontmorillonite clay lead to improvement in ductility. For the MMT clays, the Young's modulus (E) correlates with the intercalation change in organoclay interlayer separation (Δd001) as influenced by the chemistry of the modifier. Although ABS‐laponite composites are exfoliated, the intercalated OMMT‐based nanocomposites show greater improvement in modulus. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
92.
In this article a thermal model has been developed to determine the convective mass transfer for different Grashof Number range in solar distillatiOn process. The model is based on simple regression analysis. Based on the experimental data obtained from the rigorous outdoor experimentation on passive and active distillation systems for summer climatic conditions, the values of C and n have been calculated. The modified values of C and n for Nu=C(GrPr)n, are proposed as C=0.0322; N=0.4114 for 1.794 × 1066 in a passive solar still and C=0.0538; N=0.383 for 5.498 × 1066 in an active solar still. The percentage deviation between experimental and theoretical results are found within an accuracy of 12%. 相似文献
93.
Oil/Water Separation: Table Salt as a Template to Prepare Reusable Porous PVDF–MWCNT Foam for Separation of Immiscible Oils/Organic Solvents and Corrosive Aqueous Solutions (Adv. Funct. Mater. 41/2017)
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96.
The continued development of ferroelectric materials into more and more consumer led applications has been at the forefront
of recent ferroelectric material research. It is, however, possible to view a ferroelectric as a wide band gap semi-conductor
that can sustain a surface charge density. This charge density arises from the movement of ions in the crystal lattice and
the need to compensate for this charge. When viewing ferroelectrics as polarisable semi-conductors a large number of new interactions
are possible. One such is the use of super band gap illumination to generate electron–hole pairs. These photogenerated carriers
can then perform local electrochemistry. What is most interesting for ferroelectric materials is that the REDOX chemistry
can be chosen by selectively modifying the domain structure of the ferroelectric—we can perform oxidation and reduction on
the surface of the same material at spatially separate locations, or use the material to drive photoexcited carriers apart.
This means we can separate the REDOX products or produce patterns of photogenerated material in places we have predetermined.
This review aims to introduce the background research that has led to the current understanding as well a highlight some of
the current areas that require further development. 相似文献
97.
Sushant K. Manwatkar A. Bahrudheen Shashi Bhushan Tiwari S. V. S. Narayana Murty P. Ramesh Narayanan 《Journal of Failure Analysis and Prevention》2017,17(3):505-512
In view of its excellent wear and corrosion resistance, AISI 440C steel is the material of choice for the fabrication of ball screws used in actuator systems of satellite launch vehicles. During the routine acceptance test of a ball screw, longitudinal cracks were observed at the shaft location of the ball screw. The optical microstructure of the ball screw material (AISI 440C) revealed the presence of aligned carbides (carbide banding). Fractographic observations revealed the cracking to be along the carbide bands. Based on detailed optical and scanning electron microscopic observations, the cracking of the ball screws was attributed to the carbide bands. 相似文献
98.
In this paper, an attempt is made to estimate the internal heat transfer coefficients of a deep basin hybrid (PV/T) active solar still. The estimation is based on outdoor experimental observation of hybrid (PV/T) solar still for composite climate of New Delhi (latitude 28°35′N and longitude 77°12′E). The internal heat transfer coefficients are evaluated by using thermal models proposed by various researchers. The comparison of hourly yield predicted using various thermal models to the experimental has also been carried out by evaluating the correlation coefficient and percentage deviation. It is observed that, Kumar and Tiwari model (KTM) better validate the results than the others model. The average annual values of convective heat transfer coefficient for the passive and hybrid (PV/T) active solar still are observed as 0.78 and 2.41 W m−2 K−1, respectively at 0.05 m water depth. 相似文献
99.
100.
In this paper, we present and evaluate a parallel algorithm for parameter tuning of parallel applications. We discuss the impact of performance variability on the accuracy and efficiency of the optimization algorithm and propose a strategy to minimize the impact of this variability. We evaluate our algorithm within the Active Harmony system, an automated online/offline tuning framework. We study its performance on three benchmark codes: PSTSWM, HPL and POP. Compared to the Nelder–Mead algorithm, our algorithm finds better configurations up to seven times faster. For POP, we were able to improve the performance of a production sized run by 59%. 相似文献