Synthesis and morphology of nanosized zeolite L

AFM is a powerful tool for imaging nanoscale surface features; it provides two and three dimensional crystal structure images and other information about actual surface of zeolite crystallites. In this paper, nanosized zeolite L is synthesized in different crystallization times and a study of crystal growth of zeolite L is reported using atomic force microscopy (AFM). X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) techniques are used for characterization of the as synthesized samples. TEM and two‐dimensional AFM images indicate that the zeolite particles are in a nano‐range and they have hexagonal structure. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

On the multi-phase M/G/1 queueing system with random feedback

In this paper we consider an M/G/1 queue with k phases of heterogeneous services and random feedback, where the arrival is Poisson and service times has general distribution. After the completion of the i-th phase, with probability θ _i the (i + 1)-th phase starts, with probability p _i the customer feedback to the tail of the queue and with probability 1 − θ _i − p _i  = q _i departs the system if service be successful, for i = 1, 2 , . . . , k. Finally in kth phase with probability p _k feedback to the tail of the queue and with probability 1 − p _k departs the system. We derive the steady-state equations, and PGF’s of the system is obtained. By using them the mean queue size at departure epoch is obtained.     

Properties of Modified Hexagonal Boron Nitride as Stable Nanofluids for Thermal Management Applications

Russian Journal of Applied Chemistry - In this report, hexadecylamine (HDA) as a Lewis base was used to prepare exfoliated layers of modified hexagonal boron nitride h-BN (mh-BN) via two distinct...     

Effect of synthesis method on physicochemical and catalytic properties of Cu–Zn-based mesoporous nanocatalysts for water-gas shift reaction

Two new mesoporous nanocatalysts based on CuO–ZnO/MgO were synthesized by using a modified liquid-phase method. Due to use of this method, the nanocatalysts contained an efficient ZnO/MgO phase in which MgO is incorporated into ZnO phase. The structural and catalytic properties of the nanocatalysts in the water-gas shift reaction were investigated compared with samples prepared by conventional sol–gel and liquid-phase methods as references, as well as a commercial catalyst. The results reveal that the new nanocatalysts exhibited higher surface area, lower degree of agglomeration, and higher activity than the reference samples, indicating the influence of both the synthesis method and phase composition.