During rheological tests, STF shows instantaneous spike in viscosity above a critical shear rate. Fabrication of STF-Kevlar composites requires preparation of STF, dilution with ethanol, and then impregnation with Kevlar. In the current approach, nanoscale silica particles were dispersed directly into a mixture of PEG and ethanol through a sonic cavitation process. Two types of silica nanoparticles were used in the investigation: 30 nm crystalline silica and 7 nm amorphous silica. The admixture was then reinforced with Kevlar fabric to produce flexible armor composites. In the next step, silica particles

are functionalized with a silane coupling agent to enhance bonding between silica and PEG. The PF-02341066 mouse performance of the resulting armor composites improved significantly. As evidenced by National Institute of Justice spike tests, the energy required for zero-layer penetration (i.e., no penetration) jumped twofold: from 12 to 25 J cm(2)/g. The source of this improvement has been traced to the formation of siloxane (Si-O-Si) bonds between silica and PEG and superior coating of Kevlar filaments with particles. Fourier transform infrared, x-ray photoemission spectroscopy, and scanning electron microscopy studies were performed to examine chemical bonds, elemental composition, and particle dispersion

responsible for such improvement. In summary, our experiments have demonstrated that functionalization of silica particles followed by GW786034 solubility dmso direct dispersion into PEG resulted in superior Kevlar composites having much higher spike resistance.”
“Antiulcerogenic activity

of crude ethanolic extract of Celtis iguanaea leaves (CEE) was observed with experimental models such as ethanol, indomethacin, stress and pyloric ligation-induced gastric ulcers. Results obtained from indomethacin-induced ulcer showed the hexane fraction (HF) as the active fraction of CEE. This fraction inhibits the gastric acid secretion, increasing the gastric pH, decreasing the gastric acidity and total gastric contents. Neither the CEE nor the HF alters intestinal motility, thereby excluding a cholinergic antagonist mechanism. Further studies need to be conducted with HF in order to elucidate the active principle and the PLX4032 solubility dmso pharmacological mechanism involved.”
“This work presents a procedure for calculating field emission from conducting nanofibers based on an electrostatic continuum model. A perfectly conducting nanofiber with finite length in the presence of a static electric field is considered. An analytic expression is obtained for the resultant electrostatic potential by employing the slender body approximation. The total external potential is used in conjunction with the one-dimensional WKB approximation to estimate the tunneling probability of the electrons in the fiber due the total external field.