Infrared waveguide fabrications with an E-beam evaporated chalcogenide glass film

Chalcogenide glasses have a variety of unique optical properties due to the intrinsic structural flexibility and bonds metastability. They are desirable materials for many applications, such as infrared communication sensors, holographic grating, optical imaging, and ultrafast nonlinear optic devices. Here, we introduce a novel electron-beam evaporation process to deposit the good quality arsenic trisulfide (As₂S₃) films and then the As₂S₃ films were used to fabricate the As₂S₃ waveguides with three approaches. The first method is photoresist lift-off. Because of the restriction of thermal budget of photoresist, the As₂S₃ film must be deposited at the room temperature. The second one is the silicon dioxide lift-off process on sapphire substrates, in which the As₂S₃ film could be evaporated at a high temperature (>180 °C) for better film quality. The third one is the plasma etching process with a metal protective thin layer in the pattern development process.     

A new approach to the cell formation problem with alternative processing routes and operation sequence

Cellular manufacturing (CM) is an important application of group technology in manufacturing systems. One of the crucial steps in the design of CM is the identification of part families and manufacturing cells. This problem is referred to as cell formation problem (CFP) in the literature. In this article, a solution approach is proposed for CFP, which considers many parameters such as machine requirement, sequence of operations, alternative processing routes, processing time, production volume, budget limitation, cost of machines, etc. Due to the NP-hardness of CFP, it cannot be efficiently solved for medium- to large-sized problems. Thus, a genetic algorithm (GA) is proposed to solve the formulated model. Comparison of the results obtained from the proposed GA to the globally optimum solutions obtained by Lingo Software and those reported in the literature reveals the effectiveness and efficiency of the proposed approach.     

Relationship between pore coarsening and mass loss during supersolidus liquid phase sintering of alpha brass

ABSTRACT

The effect of sintering variables on the zinc loss during sintering of brass was investigated. Zinc loss, evident through mass change, starts during heating of the powder at approximately 700°C. By supersolidus liquid phase sintering of the cold-pressed brass powder, the maximum amount of zinc loss occurred at lower temperatures and prolonged sintering times. At higher temperatures, especially near the zinc boiling point, the rate of zinc loss from the surface is surprisingly moderate since closing of the pores causes zinc to be trapped in the samples. At lower temperatures, in contrast, when the pores in the surface are open and there is also a lower volume fraction of liquid phase, zinc can easily escape from the samples. Generally, it was thus concluded that during sintering, zinc loss depends more strongly on the pore connectivity and the specific surface than just on the nominal vapour pressure.     

Development and optimization of self-nanoemulsifying drug delivery systems (SNEDDS) for curcumin transdermal delivery: an anti-inflammatory exposure

The purpose of this work is to develop novel lipid-based self-nanoemulsifying drug delivery systems (SNEDDS) as carriers for transdermal delivery of curcumin. SNEDDS containing black seed oil, medium chain mono- and diglycerides and surfactants, were prepared as curcumin delivery vehicles. Their formation spontaneity, morphology, droplet size, and drug loading were evaluated. Gel preparation containing two of the SNEDDS formulations were used in the carrageenan induced paw edema to evaluate the anti-inflammatory effect. Results showed droplet size as low as 71?nm. The highest drug loading was observed with SNEDDS-F6 of ～45?mg/g. In in-vivo investigation, SNEDDS-F6 exhibited significant anti-inflammatory activities in terms of 80% reduction in paw edema when compared with positive control. The prepared SNEDDS with the elevated entrapment efficiency, good transdermal penetration ability could be a suitable candidate for effective transdermal curcumin skin delivery.     

Basil Oil is a Promising Skin Penetration Enhancer for Transdermal Delivery of Labetolol Hydrochloride

Thepresent work investigates effectiveness of basil oil, a volatile oil containing alcoholic terpenes, as a potential penetration enhancer for improved skin permeation of labetolol hydrochloride (LHCl) with reference to camphor, geraniol, thymol, and clove oil. Saturation solubilities of LHCl were determined in water, vehicle (ethanol:water, 60:40 v/v) and vehicle containing 5% w/v terpenes. Comparable (P > 0.05) saturation solubilities were found suggesting an insignificant increase in LHCl flux across rat skin on account of thermodynamic activity. Permeation of LHCl in vehicle per se and in presence of 5% w/v enhancer was investigated by performing in vitro rat abdominal skin permeation studies using a side-by-side glass diffusion cell. Various parameters viz. steady state flux, permeability coefficient, lag time, partition coefficient, diffusion coefficient, and enhancement ratios (ER) were calculated from the permeation data. Basil oil produced the maximum enhancement (ER?=?46.52) over neat vehicle, among all enhancers. Activation energies for LHCl permeation in water, vehicle per se and in presence of 5% w/v basil oil were found to be 23.16, 18.71, and 10.98 kcal/mole, respectively. Lowering of activation energy in presence of basil oil suggests creation of new polar pathways in the skin for enhanced permeation of LHCl. Basil oil is proposed as a promising penetration enhancer for improved transdermal drug delivery of labetolol.     

Platinum(VI) dihydroxo tetramesitylporphyrin; characterization and chemical reactivity

Tetramesitylporphyrin platinum(VI) dihydroxo complex, TMPPt(OH)₂ · 2 benzoate was synthesized by addition of two equivalent of meta-chloroperbenzoic acid molecules to the tetramesitylporphyrin platinum(II). This complex was characterized by X-ray diffraction and spectroscopic methods, and is capable to convert two molecules of triphenylphosphine to triphenylphosphine oxide.     

Characterization of Ag(I), Co(II) and Cu(II) removal process from aqueous solutions using dolomite powder

Dolomite, a natural adsorbent, was used for removal of Ag(I), Cu(II) and Co(II) from aqueous solutions. Adsorption parameters including pH, temperature and contact time have been investigated to obtain adsorption mechanism. The results of experiments showed that adsorption of the metal ions increased by increasing pH values up to 5.5. The adsorption process was initially fast. Equilibrium isotherm data were analyzed using Langmuir, Freundlich and Dubinin-Radushkevich isotherm models. Maximum adsorption capacity of Ag(I), Cu(II) and Co(II) was 1.34, 1.63 and 2.84 mg/g at 20 oC, respectively. Kinetic models including Lagergren first-order and pseudo-second-order were used to test kinetic data. The results showed that pseudo-second-order has good agreement with experimental data. Thermodynamic parameters of the process were also investigated at different temperatures. The negative values of Gibbs free energy and enthalpy changes for Ag(I), Cu(II) and Co(II) indicated the spontaneous and exothermic nature of the adsorption process.     

Cynicism, hostility, and suicidal ideation in depressed outpatients

Differences between depressed patients with and without suicidal ideation were examined, focusing on anger, aggression, and hostility. The Adult Suicide Ideation Questionnaire was used to compare 42 outpatients with major depression in relationship to measures of anger, aggression, hostility, cynicism, life events, and depression. There were no differences on measures of anger, aggression, hostility, and on most measures of severity of depression, but the suicidal group demonstrated more evidence of cynicism. Suicidal ideation is associated with cynicism but is unrelated to measures of hostility, anger, or aggression or to severity of depression in outpatients.