Chemical vapour deposition synthetic diamond: materials, technology and applications

Substantial developments have been achieved in the synthesis of chemical vapour deposition (CVD) diamond in recent years, providing engineers and designers with access to a large range of new diamond materials. CVD diamond has a number of outstanding material properties that can enable exceptional performance in applications as diverse as medical diagnostics, water treatment, radiation detection, high power electronics, consumer audio, magnetometry and novel lasers. Often the material is synthesized in planar form, however non-planar geometries are also possible and enable a number of key applications. This article reviews the material properties and characteristics of single crystal and polycrystalline CVD diamond, and how these can be utilized, focusing particularly on optics, electronics and electrochemistry. It also summarizes how CVD diamond can be tailored for specific applications, based on the ability to synthesize a consistent and engineered high performance product.Comment: 51 pages, 16 figure

Removal of dissolved organics from produced water by forward osmosis

This study investigated the performance of the forward osmosis (FO) process for treating produced water. Water permeate flux and reverse salt flux (RSF) were examined at different feed pH values and operating configurations (i.e. FO, pressure retarded osmosis (PRO), and reverse osmosis (RO) modes). Acetic acid was selected as a model organic acid to present the dissolved organic fraction in produced water. Results reported here indicate that only membranes specifically designed for FO applications can be used in the FO and PRO modes. Due to the internal concentration polarization phenomenon, the PRO mode resulted in a higher water permeate flux and RSF than those in the FO mode. Acetate rejection was pH dependent in both the FO and RO modes. Furthermore, in the RO mode, acetate rejections by the FO membranes were higher than their nanofiltration counterparts. Results reported here suggest that FO can be a viable treatment option for the removal of dissolved organics from produced water

Aprotinin prevents proteolytic epithelial sodium channel (ENaC) activation and volume retention in nephrotic syndrome.

Volume retention in nephrotic syndrome has been linked to activation of the epithelial sodium channel (ENaC) by proteolysis of its γ-subunit following urinary excretion of serine proteases such as plasmin. Here we tested whether pharmacological inhibition of urinary serine protease activity might protect from ENaC activation and volume retention in nephrotic syndrome. Urine from both nephrotic mice (induced by doxorubicin injection) and nephrotic patients exhibited high aprotinin-sensitive serine protease activity. Treatment of nephrotic mice with the serine protease inhibitor aprotinin by means of subcutaneous sustained-release pellets normalized urinary serine protease activity and prevented sodium retention, as did treatment with the ENaC inhibitor amiloride. In the kidney cortex from nephrotic mice, immunofluorescence revealed increased apical γ-ENaC staining, normalized by aprotinin treatment. In Xenopus laevis oocytes heterologously expressing murine ENaC, aprotinin had no direct inhibitory effect on channel activity but prevented proteolytic channel activation. Thus, our study shows that volume retention in experimental nephrotic syndrome is related to proteolytic ENaC activation by proteasuria and can be prevented by treatment with aprotinin. Hence, inhibition of urinary serine protease activity might become a therapeutic approach to treat patients with nephrotic-range proteinuria

A non-recycle flow still for the experimental determination of vapor-liquid equilibria in reactive systems

Experiments for the determination of vapor-liquid equilibrium (VLE) data with a Non-Recycle Flow Still (NFS) are described. Due to short residence times, the NFS is especially suited for systems with thermally unstable components and for reactive mixtures. VLE data of the latter are necessary for modeling reactive distillation processes. With the NFS isobaric data both at atmospheric and at reduced pressure can be gained. The potential of this technique is demonstrated and validated with the well-known, non-reactive systems methanol-ethanol and ethanol-water. The other (mainly reactive) binary mixtures investigated stem from two esterification systems (methyl formate and ethyl acetate production) and one etherification system (tert-amyl methyl ether production). The NRTL equation is used for modeling of the VLE data. The data acquired with the NFS are compared with literature data (whenever possible) or with results of group contribution methods. (orig.)Special print from: Fluid Phase Equilibria 153(1998), p. 113-134Available from TIB Hannover: RR 8872(1998,8) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Equilibrium adsorption measurements of pure Nitrogen, Carbon Dioxide, and Methane on a Carbon molecular sieve at cryogenic temperatures and high pressures†

A detailed experimental study of the adsorption behavior at equilibrium of pure nitrogen, methane, and carbon dioxide gases on a commercial carbon molecular sieve (Shirasagi MSC 3K-161) is reported at temperatures between 115 K to 323 K and pressures up to 5 MPa. A volumetric-type apparatus was used to obtain over 200 excess (Gibbs) adsorption capacity data over this range of pressure and temperature with an estimated uncertainty of 4 %. The absolute adsorption isotherms were type I in the IUPAC classification with the adsorption capacity at constant pressure increasing significantly with decreasing temperature. For each gas, the adsorption data were regressed to a four parameter Toth equation to represent the temperature and pressure dependence of the data with a relative standard uncertainty of 4 %. The optimized parameters from the Toth equation included the isosteric enthalpies of adsorption that were 17 kJ·mol−1, 27 kJ·mol−1, and 18 kJ·mol−1 for N2, CO2, and CH4, respectively