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Transport Method (transport + method)
Selected AbstractsChemInform Abstract: Stoichiometric Single Crystal Growth of AgGaS2 by Iodine Transport Method and Characterization.CHEMINFORM, Issue 7 2009P. Prabukanthan Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Improvements in the 2D TEP Neutral Particle Transport Calculation in Edge PlasmasCONTRIBUTIONS TO PLASMA PHYSICS, Issue 7-9 2006D. Zhang Abstract Extensions of the 2D Transmission and Escape Probability neutral particle transport method in treating the spatial non-uniformity of collision sources and neutral energy effects are presented. These extensions have been tested by benchmarks against Monte Carlo calculations for specially designed models and for realistic DIII-D discharges. The comparisons indicate these extensions improve accuracy of the TEP method. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Supplementary data confirming the relationship between critical Shields stress, grain size and bed slopeEARTH SURFACE PROCESSES AND LANDFORMS, Issue 11 2007Gareth Pender Abstract This article presents new experimental data on threshold conditions for motion of coarse uniform sediments. The experiments were conducted with 2·8 mm gravel in a 7·5 m long by 0·3 m wide flume and included measurements of hydraulic characteristics and rate of bed particle movement for a range of flows at different bed slopes. A reference transport method was used to define the beginning of sediment motion. Results from experiments with glass balls (diameters 6 and 9 mm) and coarse uniform gravels (17·5 and 38·6 mm) conducted by other researchers were used as an additional independent data set. The experimental data confirm the recent finding that the critical Shields stress for motion of coarse uniform sediment varies with both grain size and bed slope. Copyright © 2007 John Wiley & Sons, Ltd. [source] Self-Assembled In-Plane Growth of Mg2SiO4 Nanowires on Si Substrates Catalyzed by Au NanoparticlesADVANCED FUNCTIONAL MATERIALS, Issue 15 2010Zhou Zhang Abstract In-plane growth of Mg2SiO4 nanowires on Si substrates is achieved by using a vapor transport method with Au nanoparticles as catalyst. The self-assembly of the as-grown nanowires shows dependence on the substrate orientation, i.e., they are along one, two, and three particular directions on Si (110), (100), and (111) substrates, respectively. Detailed electron microscopy studies suggest that the Si substrates participate in the formation of Mg2SiO4, and the epitaxial growth of the nanowires is confined along the Si <110> directions. This synthesis route is quite reliable, and the dimensions of the Mg2SiO4 nanowires can be well controlled by the experiment parameters. Furthermore, using these nanowires, a lithography-free method is demonstrated to fabricate nanowalls on Si substrates by controlled chemical etching. The Au nanoparticle catalyzed in-plane epitaxial growth of the Mg2SiO4 nanowires hinges on the intimate interactions between substrates, nanoparticles, and nanowires, and our study may help to advance the developments of novel nanomaterials and functional nanodevices. [source] Liposome transport of hydrophobic drugs: Gel phase lipid bilayer permeability and partitioning of the lactone form of a hydrophobic camptothecin, DB-67JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 1 2008Vijay Joguparthi Abstract The design of liposomal delivery systems for hydrophobic drug molecules having improved encapsulation efficiency and enhanced drug retention would be highly desirable. Unfortunately, the poor aqueous solubility and high membrane binding affinity of hydrophobic drugs necessitates extensive validation of experimental methods to determine both liposome loading and permeability and thus the development of a quantitative understanding of the factors governing the encapsulation and retention/release of such compounds has been slow. This report describes an efflux transport method using dynamic dialysis to study the liposomal membrane permeability of hydrophobic compounds. A mathematical model has been developed to calculate liposomal membrane permeability coefficients of hydrophobic compounds from dynamic dialysis experiments and partitioning experiments using equilibrium dialysis. Also reported is a simple method to study the release kinetics of liposome encapsulated camptothecin lactone in plasma by comparing the hydrolysis kinetics of liposome entrapped versus free drug. DB-67, a novel hydrophobic camptothecin analogue has been used as a model permeant to validate these methods. Theoretical estimates of DB-67 permeability obtained from the bulk solubility diffusion model and the "barrier-domain" solubility diffusion model are compared to the experimentally observed value. The use of dynamic dialysis in drug release studies of liposome and other nanoparticle formulations is further discussed and experimental artifacts that can arise without adequate validation are illustrated through simulations. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:400,420, 2008 [source] Anterior versus posterior approach in reconstruction of infected nonunion of the tibia using the vascularized fibular graft: potentialities and limitationsMICROSURGERY, Issue 3 2002Sherif M. Amr M.D. The potentialities, limitations, and technical pitfalls of the vascularized fibular grafting in infected nonunions of the tibia are outlined on the basis of 14 patients approached anteriorly or posteriorly. An infected nonunion of the tibia together with a large exposed area over the shin of the tibia is better approached anteriorly. The anastomosis is placed in an end-to-end or end-to-side fashion onto the anterior tibial vessels. To locate the site of the nonunion, the tibialis anterior muscle should be retracted laterally and the proximal and distal ends of the site of the nonunion debrided up to healthy bleeding bone. All the scarred skin over the anterior tibia should be excised, because it becomes devitalized as a result of the exposure. To cover the exposed area, the fibula has to be harvested with a large skin paddle, incorporating the first septocutaneous branch originating from the peroneal vessels before they gain the upper end of the flexor hallucis longus muscle. A disadvantage of harvesting the free fibula together with a skin paddle is that its pedicle is short. The skin paddle lies at the antimesenteric border of the graft, the site of incising and stripping the periosteum. In addition, it has to be sutured to the skin at the recipient site, so the soft tissues (together with the peroneal vessels), cannot be stripped off the graft to prolong its pedicle. Vein grafts should be resorted to, if the pedicle does not reach a healthy segment of the anterior tibial vessels. Defects with limited exposed areas of skin, especially in questionable patency of the vessels of the leg, require primarily a fibula with a long pedicle that could easily reach the popliteal vessels and are thus better approached posteriorly. In this approach, the site of the nonunion is exposed medial to the flexor digitorum muscle and the proximal and distal ends of the site of the nonunion debrided up to healthy bleeding bone. No attempt should be made to strip the scarred skin off the anterior aspect of the bone lest it should become devitalized. Any exposed bone on the anterior aspect should be left to granulate alone. This occurs readily when stability has been regained at the fracture site after transfer of the free fibula. The popliteal and posterior tibial vessels are exposed, and the microvascular anastomosis placed in an end-to-side fashion onto either of them, depending on the length of the pedicle and the condition of the vessels themselves. To obtain the maximal length of the pedicle of the graft, the proximal osteotomy is placed at the neck of the fibula after decompressing the peroneal nerve. The distal osteotomy is placed as distally as possible. After detaching the fibula from the donor site, the proximal part of the graft is stripped subperiosteally, osteotomized, and discarded. Thus, a relatively long pedicle could be obtained. To facilitate subperiosteal stripping, the free fibula is harvested without a skin paddle. In this way, the use of a vein graft could be avoided. Patients presenting with infected nonunions of the tibia with extensive scarring of the lower extremity, excessively large areas of skin loss, and with questionable patency of the anterior and posterior tibial vessels are not suitable candidates for the free vascularized fibular graft. Although a vein graft could be used between the recipient popliteal and the donor peroneal vessels, its use decreases flow to the graft considerably. These patients are better candidates for the Ilizarov bone transport method with or without free latissimus dorsi transfer. © 2002 Wiley-Liss, Inc. MICROSURGERY 22:91,107 2002 [source] Cleaner process for synthesis of zeolite MCM-22 by vapor-phase transport methodASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 5 2009Xingsheng Liu Abstract A cleaner process for synthesis of zeolite MCM-22 by vapor-phase transport method was studied in this paper. Firstly, zeolite MCM-22 was synthesized at different hexamethyleneimine (HMI) dosages by vapor-phase transport (VPT) method. It was concluded that the aluminosilicate gel was not crystallized completely and the product crystallinity was low when the HMI/gel mass ratio was <0.3. Then, the as-synthesized product and the surplus liquid, which were obtained at mass ratio 0.3 HMI : 1.0 gel, were characterized by TG-DTA and FTIR, respectively. It was found that a part of HMI did not play the role of structure-directing and remained in the surplus liquid after synthesis of zeolite MCM-22. The surplus liquid chemical properties, which have not change after synthesis of zeolite MCM-22 by VPT method, still contained only HMI and H2O. Re-adding of HMI and deionized water, the surplus liquid was reused to synthesize zeolite MCM-22 by VPT method. Based on the experimental results of surplus liquid reuse, it was known that the surplus liquid can be reused via re-adding of HMI and deionized water. It could make the VPT method become a cleaner process. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] | ||||||||||