Microprocessor-based thyristorized control system for speed controlof coiler motor

A microcomputer system developed for the real-time speed control of a coiler-motor in a wire rod mill at the Bhilai Steel Plant, India, is discussed. The software permits the dynamic control of the coiler motor speed and also controls the tensionless back-end problem of the wire rod, resulting in considerable reduction in metal loss and production delay. The net annual saving due to introduction of the system is Rs. 6.2 million (around $0.50 million), and since the cost of implementation of the system is Rs. 5.3 million, the pay-back period is only ten months     

Buttonhole ulceration and perforation of the rectum

Immune status was examined in 231 patients facing pneumoconiosis and coniotuberculosis so as to observe a dependence on pneumoconiosis type (silicosis, electric welder's pneumoconiosis), severity of the process, activity of tuberculosis. Markedly changed T and B immunity, having already appeared at initial stage of the disease, were revealed. Those changes due to the tuberculosis activity were characterized by lymphocytosis, marked functional immaturity of T lymphocytes, depressed B lymphocytes count, elevated serum Ig level.     

Performance of a 2-hole Y-Ba-Cu-O rf SQUID

A two-hole rf SQUID has been fabricated out of bulk YBCO by drilling two holes and careful erosion of the wall between the holes. Commercial SQUID electronics is inductively coupled to the SQUID through a copper coil glued in one of the holes. Periodic oscillations in V-B characteristic of the SQUID are observed at 77 K. The spectral density of the flux noise in the white noise region is 5·5 × 10⁻⁴Φ₀ / √Hz. The flux noise is frequency-dependent below 200 Hz.     

Transient and thermally stimulated depolarization currents in polyvinyl formal films

Transient currents in double-sided vacuum aluminized polyvinyl formal (PVF) film samples of thickness 40 μm were investigated in the charge and discharge modes at different temperatures and fileds. The results observed suggest that the transient currents are governed by charge injection processes leading to space charge effects. Comparative studies of the isochronal characteristics (i.e. current–temperature plots at fixed times) with the thermally stimulated discharge current (TSDC) indicated a strong resemblance between the two techniques. These studies suggest that the simultaneous mechanism of movement of charges through microscopic distances coupled with dipolar orientation may be responsible for the TSDC peak observed at 100°C.     

Outbreak of viral hepatitis B in a rural community in India linked to inadequately sterilized needles and syringes

BACKGROUND AND METHODS: Four hundred and eighty-four patients with inflammatory bowel disease underwent clinical examination, ultrasonography, and biochemical liver function tests, to estimate the prevalence of hepatobiliary alterations. The patient group included patients without a history of liver disease. Controls were recruited from patients with functional symptoms. RESULTS: More patients with ulcerative colitis than controls had liver steatosis and increased alkaline phosphatase levels. Factors increasing the probability of liver damage were long-standing disease, the presence of moderate/severe disease activity, and treatment with steroids and mesalazine. A significant association was found between biliary disease and long-standing colitis and also therapy with steroids and mesalazine. Alkaline phosphatase and aminotransferase levels were significantly higher in Crohn's disease patients than in controls. Hepatic and biliary damage was found more commonly in the 1st year after diagnosis. CONCLUSIONS: The monitoring of hepatobiliary function is suggested for patients with inflammatory bowel disease, even in the absence of symptoms and history.     

Synthesis of double-rocker mechanism with optimum transmission characteristicsSynthese du double mecanisme oscillant a bielle avec caracteristiques optima de transmission

A simple analytical procedure is presented for the synthesis of the planar 4-bar double-rocker mechanism for coordinating the prescribed extreme positions. For optimum transmission characteristics, the design criterion used is the equal deviation of the transmission angles from 90° at the two dead-centre positions. Numerical examples are provided to illustrate the method.     

Factors influencing the ignition of flames from air-fired swirl pf burners retrofitted to oxy-fuel

Combustion tests were undertaken in a vertical pilot-scale furnace (1.2 MWt) at the IHI test facility in Aioi, Japan, to compare the performance of an air fired swirl burner retrofitted to oxy fired pf coal combustion with the oxy fired feed conditions established to match the furnace heat transfer for the air fired case. A turn down test at a reduced load was also conducted to study the impact on flame stability and furnace performance.Experimental results include gas temperature measurements using pyrometry to infer the ignition location of the flames, flue gas composition analysis, and residence time and carbon burnout. Theoretical computational fluid dynamics (CFD) modelling studies using the Fluent 6.2 code were made to infer mechanisms for flame ignition changes.Previous research has identified that differences in the gas compositions of air and oxy systems increase particle ignition times and reduce flame propagation velocity in laminar systems. The current study also suggests changes in jet aerodynamics, due to burner primary and secondary velocity differences (and hence the momentum flux ratio of the flows) also influence flame shape and type.For the oxy fuel retrofit considered, the higher momentum flux of the primary stream of the oxy-fuel burner causes the predicted ignition to be delayed and occur further distant from the burner nozzle, with the difference being accentuated at low load. However, the study was limited to experimental flames being all Type-0 (low swirl with no internal recirculation), and therefore future work consider higher swirl flames (with internal recirculation) more common in industry.     

Development of nanofibrous morphology in LDPE/LLDPE/PP blends and its effect on mechanical properties of blend films

Nanofibrous morphology has been observed in ternary blends of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and isotactic polypropylene (PP) when these were melt‐extruded via slit die followed by hot stretching. The morphology was dependent on the concentration of the component polymers in ternary blend LDPE/LLDPE/PP. The films were characterized by wide angle X‐ray diffraction (XRD), scanning electron microscopy (SEM), and testing of mechanical properties. The XRD patterns reveal that the β phase of PP is obtained in the as‐stretched nanofibrillar composites, whose concentration decreases with the increase of LLDPE concentration. The presence of PP nanofibrils shows significant nucleation ability for crystallization of LDPE/LLDPE blend. The SEM observations of etched samples show an isotropic blend of LDPE and LLDPE reinforced with more or less randomly distributed and well‐defined nanofibrils of PP, which were generated in situ. The tensile modulus and strength of LDPE/LLDPE/PP blends were significantly enhanced in the machine direction than in the transverse direction with increasing LLDPE concentration. The ultimate elongation increased with increasing LLDPE concentration, and there was a critical LLDPE concentration above which it increased considerably. There was a dramatic increase in the falling dart impact strength for films obtained by blow extrusion of these blends. These impressive mechanical properties of extruded samples can be explained on the basis of the formation of PP nanofibrils with high aspect ratio (at least 10), which imparted reinforcement to the LDPE/LLDPE blend. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Lector with Footed-Diode Inverter: A Technique for Leakage Reduction in Domino Circuits

Leakage power consumption is a major technical problem faced in nanometer or deep submicron CMOS circuit technology. A new circuit technique based on “lector stacking” is proposed in this paper for reducing the subthreshold and gate oxide leakage currents in the idle and non-idle modes of operation for domino circuits. In this technique a p-type and an n-type leakage control transistor (LCT) are introduced between the pull-up and pull-down network, and the gate of one is controlled by the source of the other. For any combination of inputs, one of the LCTs will operate near its cut-off region and will increase the resistance between supply voltage and ground, resulting in reduced leakage current. Lector stacking retains the logic state during the idle mode as in the conventional footerless domino logic. Furthermore, the leakage current is suppressed at the output inverter circuit by adding a diode-footed transistor below the n-type transistor of the inverter, offering a more resistive path between supply voltage and ground.The proposed circuit technique for AND2, OR2, OR4, and OR8 circuits reduces the active power consumption by 13.66 % to 44.45 % and by 12 % to 33 % at the low and high die temperatures, respectively, compared to the standard footerless domino logic circuits. During idle mode for the same logic gates, 1.64 % to 79.39 % and 1.2 % to 35.19 % reduction of leakage current is observed with low and high inputs at 25 °C and 110 °C respectively. Similarly, during non-idle mode 0.94 % to 99.3 % and 1.57 % to 98.58 % is observed with low and high inputs at 25 to 110 °C, respectively, when compared to standard footerless domino logic circuits.