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81.
Shahrzad Ghaffari Mosanenzadeh Hani E. Naguib Chul B. Park Noureddine Atalla 《Journal of Polymer Science.Polymer Physics》2014,52(15):1002-1013
Bio‐based foams are the solution to environmental concerns raised by petrochemical‐based open cell foams used in various industries for sound absorption. While conventional petrochemical‐based polymers take centuries to degrade or may not degrade at all, bio‐based polymers decompose to biomass, water, and carbon dioxide in a matter of months when exposed to proper environment. To increase the potential of replacing current petrochemical foams, mechanical as well as acoustic characteristics of bio‐based foams need to be improved. This article studies the effect of blending two bio‐based polymers and physics of the blends on acoustic and mechanical properties of resulting polymer composite foams. Different blends of polylactide with three grades of polyhydroxyalkanoates were foamed and characterized based on acoustic and mechanical performance. Rheological properties of pure polymers as well as their blends were studied and effect of polymer blends on acoustic absorption of the resulting foams was investigated. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 1002–1013 相似文献
82.
This article reports on the fabrication of oriented composite fibers between polylactide (PLA) and multiwall carbon nanotube (MWNT). The fibers were fabricated using a custom‐built melt fiber‐drawing setup. The influence of processing parameters on the final fiber diameter and on the orientation were characterized and optimized. Composite fibers were fabricated at various MWNT contents. Addition of low amounts of MWNT (0.25–1 wt %) to PLA did not have a significant effect on the diameters of the fibers. Observations of the composite morphology under STEM indicated preferential orientation of the MWNTs along the draw direction of the fibers. Increasing amounts of MWNTs was found to increase crystallization kinetics and content. The crystalline content had a direct and profound implication on the mechanical properties with 0.5‐wt % MWNT fibers having the highest crystalline content and also the highest Young's modulus. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 477–484 相似文献
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Mohammad M. Al-Arab Khaled R. Barqawi Hani D. Tabba' 《Monatshefte für Chemie / Chemical Monthly》1987,118(10):1143-1146
Using cyclic voltammetry, the anodic oxidation potentials for a series of 15 substituted aromatic cyanoesters have been measured and analyzed. Irreversible anodic oxidations were observed, in addition to a cathodic reduction wave. The different aromatic species exhibited different potential values, in accordance with the type of the substituent and nature of the aromatic nucleus.
Anodische Oxidationspotentiale aromatischer Cyanoester (Kurze Mitteilung)
Zusammenfassung Unter Verwendung von cyclischer Voltametrie wurden die anodischen Oxidationspotentiale einer Serie von 15 substituierten aromatischen Cyanoestern gemessen und analysiert. Zusätzlich zu einer kathodischen Reduktionswelle wurden irreversible anodische Oxidationen beobachtet. Dabei zeigten die verschiedenen Verbindungen je nach dem Substitutionstyp und der Natur des aromatischen Kerns unterschiedliche Potentialwerte.相似文献
85.
Salim S. Sabri Mustafa M. El-Abadelah Hani A. Yasin 《Journal of heterocyclic chemistry》1987,24(1):165-169
A series of new N-(2-benzimidazol)(S)-α-aminoesters and the respective N-oxides have been prepared, and their spectral data discussed. The CD spectra of the aliphatic and aromatic amino ester derivatives of either series show sign reversal for the observed Cotton effect (CE) band. This chiroptical behaviour was rationalized as due to differences in conformational isomerism. 相似文献
86.
O. Ayed Nassef Hani E. Elsayed-Ali 《Spectrochimica Acta Part B: Atomic Spectroscopy》2005,60(12):1564-1572
Laser induced breakdown spectroscopy is combined with a spark discharge to operate in a laser triggered spark discharge mode. This spark discharge laser induced breakdown spectroscopy (SD-LIBS) is evaluated for Al and Cu targets in air under atmospheric pressure. Significant enhancement in the measured line intensities and the signal-to-background ratios, which depend on the spark discharge voltage and the laser fluence, is observed in spark discharge laser induced breakdown spectroscopy when compared to laser induced breakdown spectroscopy alone for similar laser conditions. The measured line intensities increase with the applied voltage for both targets, and the ratio of the measured line intensity using spark discharge laser induced breakdown spectroscopy to that using laser induced breakdown spectroscopy is found to increase as the laser fluence is decreased. For Al II 358.56, such intensity enhancement ratio increases from 50 to 400 as the laser fluence is decreased from 48 to 4 J/cm2 at an applied voltage of 3.5 kV. Thus, spark discharge laser induced breakdown spectroscopy allows for using laser pulses with relatively low energy to ablate the studied material, causing less ablation, and hence less damage to its surface. Moreover, applying spark discharge laser induced breakdown spectroscopy gives up to 6-fold enhancement in the S / B ratio, compared to those obtained with laser induced breakdown spectroscopy for the investigated spectral emission lines. 相似文献
87.
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88.
Mahboubeh Rabbani Rahmatollah Rahimi Hani Farajnejad Ghadi 《Journal of Sol-Gel Science and Technology》2018,85(2):340-348
Bismuth ferrite (BiFeO3) nanopowder have been successfully synthesized for the first time via a microwave-assisted sol-gel combustion method by using citric acid as fuel. The resulting nanopowder was characterized using FT-IR, TG-DTA, XRD, EDX, VSM, SEM, and UV-Vis DRS. A ferromagnetic hysteresis loop with a saturation magnetization (MS) of 0.66?emu?g?1 has been observed at room temperature in the sample. The optical properties of the nanosized BiFeO3 showed its small band gap (=2.08?eV) indicates a possibility of utilizing much visible light for photocatalysis. 相似文献
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90.