A Shortcut Method for Estimating the HETP of Structured Packed Distillation Columns at Elevated Pressure

A shortcut model is developed for predicting the HETP of a structured packed distillation column operating at elevated pressure. The proposed model incorporates the geometrical parameters of the packing, physical properties of the vapor and liquid phases, and the hydrodynamics of the two‐phase flow. The proposed model is tested and validated by comparing the predicted results with the present experimental data and some published HETP data. The results show that the proposed model can predict the experimental data with a deviation smaller than 20 %.     

Self-reinforced materials based on aluminum nitride

Powder Metallurgy and Metal Ceramics -     

Nucleotide sequence and genome structure of mink enteritis virus

Diabetes mellitus is a common disease. It affects multiple organ systems. Adverse effects of hyperglycemia on infection, fracture healing, and bone remodeling have been recently reported. This study was conducted to evaluate the clinical and radiographic results of 93 total hip arthroplasties in 78 consecutive patients with diabetes. All femoral components were cemented using contemporary cementing techniques. Prophylactic antibiotics were given in each case. The mean follow-up period was 4.1 years (range, 2-6.5 years). Ninety-six percent of the hips were rated excellent or good. Radiolucencies were observed in only 3.7% of the stems, while 22.2% of the cups showed radiolucencies. There was a 4% revision incidence. There was no postoperative infection in this series--a distinct improvement from previously reported series. However, complications remained high at 24.3%. The most frequent complication was urinary tract infection (14.2%). The most serious complication was myocardial infarction. The authors believe total hip arthroplasty can be safely performed in patients with diabetes, provided that adequate medical and follow-up evaluations are performed. The medium-term clinical and radiographic follow-up evaluations are not inferior to reported series in patients without diabetes.     

Biofilm adaptation to sulfate reduction in anaerobic immobilized biomass reactors sujected to different COD/sulfate ratios.

Various aspects of biofilm adaptation to sulfate reduction in horizontal-flow anaerobic immobilized biomass (HAIB) reactors subjected to increasing sulfate concentrations and different COD/sulfate ratios are presented and discussed. Four bench-scale HAIB reactors filled with vegetal carbon (R1 and R2) and polyurethane foam matrices (R3 and R4) were utilized. Influent sulfate concentrations ranging from 500 to 3000 mg/L were applied at COD/sulfate ratios ranging from 5.0 to 1.7. Reactors R1 and R4 were operated with higher sulfate loads than those applied to R2 and R3. For the same COD/sulfate ratio, the highest sulfate reduction efficiency (approximately 80%) was displayed by the vegetal carbon reactor (R2) subjected to low sulfate loads. According to the results of our molecular biology analyses, the different support materials provided different biomass colonization conditions. The lowest diversity of sulfate-reducing bacteria was found in the HAIB filled with polyurethane foam matrices operating with high sulfate loads.     

Nonequilibrium nonstoichiometry in ionic compounds

Ionic substances under normal conditions are stoichiometric compounds with phase diagrams featuring no homogeneity regions. Crystals grown under nonequilibrium conditions, in particular, under significant centrifugal acceleration, are characterized by nonstoichiometric compositions (e.g., K_2−x Br_1.07). In this way, it is possible to obtain nonequilibrium nonstoichiometric ionic compounds possessing certain homogeneity regions. Nonstoichiometric crystals of KCl, KBr, and KI grown under various accelerations ranging within (1.3–100.0)×10³ g exhibit insignificant variations in the lattice constants and a significant increase in micro-hardness with acceleration.     

Growth and Characterization of YbBCO Films on Textured Gd2O3 Buffer-Layered Ni Tapes: All Sol–Gel Process

YbBa₂Cu₃O_7?x (YbBCO) thick films were grown on buffered, cube-textured Nickel tapes by sol–gel dip-coating method. Yb-123 films were prepared using solutions of Yb, Ba, and Cu organometallic compounds. A solution-based Gd₂O₃ buffer layer was deposited by dip-coating process with excellent texture and uniformity. The texture development and surface morphology of the buffer-layer films were examined by X-ray diffraction, pole figures, and ESEM analysis. Microstructure and characterization of Yb-123 films were done by ESEM, EDS, and XRD analysis. T _c and J _c were conducted by four-wire measurement method     

The making of the MCM/70 microcomputer

MCM/70, manufactured by Micro Computer Machines (MCM), was a small desktop microcomputer designed to provide the APL programming language environment for business, scientific, and educational use. MCM was among the first companies to fully recognize and act upon microprocessor technology's immense potential for developing a new generation of cost-effective computing systems. This article discusses the pioneering work on personal microcomputers conducted at MCM in the early 1970s and, in particular, the making of the MCM/70 microcomputer.