Yield response of wetland rice to band placement of urea solution in various soils in the tropics

Alternative N-fertilizer management practices are needed to increase productivity and the N-use efficiency of flooded rice (Oryza sativa L.). Seven field experiments were conducted at various sites in Bangladesh and Indonesia to evaluate the effect of time and method of fertilizer-N application on grain yield in transplanted rice. Conventional fertilizer application was compared with band placement of liquid urea using a mechanical push-type injector and point placement of urea supergranules. With band placement, grain yields were up to 38 and 55% higher than with researchers' and farmers' practices, respectively, and similar to those with point placement of urea supergranules.     

A novel technique for isolation of pure sperm heads from disintegrated mammalian spermatozoa

The phenomenon of differential charge distribution on sperm surface membrane has been utilised here in a low e.m.f. (electro motive force) capillary electrophoresis system to effect separation of sperm heads from disintegrated mixed spermatozoal subfractions. Washed caudal sperm of goat (Black Bengal variety) and ejaculated washed human sperm were fractionated by sonication into head, mid-piece and tail portions. Routine techniques of density gradient centrifugation on Percoll and/or sucrose were performed with sonicated spermatozoa for separation into their respective subfractions. The products obtained were not free of contamination in either case. Mixed sperm fractions when subjected to the afore mentioned modified capillary electrophoresis technique only the head pieces exhibited high affinity for migration towards the cathode terminal. With this method around 50% of the total sperm heads were separated and collected in absolutely pure form at the cathode side within 2 hrs. at 150 volts (V) and 1.5 milliampere (mA) current at 37.5 degrees C. A 4 cm. long capillary tube with a bore size 1.2 mm. was used for this purpose.     

Lactic acid: recent advances in products,processes and technologies — a review

Lactic acid, the most widely occurring hydroxycarboxylic acid, is an enigmatic chemical. It was discovered a long time ago and its use in food preservation and processing and as a specialty chemical has grown over the years with current production of about 120 000 t yr^?1. Its potential as a major chemical feedstock, derived from renewable carbohydrates by sustainable technologies, to make plastics, fibers, solvents and oxygenated chemicals, had also been recognized. Recently, new technologies have emerged that can overcome major barriers in separations and purification and processing. Advances in electrodialysis (ED) and bipolar membranes and one particular process configuration termed the ‘double ED’ process, a specific combination of desalting ED followed by ‘water‐splitting’ ED with bipolar membranes, has given very promising results, showing a strong potential for an efficient and economic process for recovery and purification of lactic acid without generating a salt waste. For the production of polymers, several advances in catalysts and process improvements have occurred in the technology to produce dilactide and its polymerization to produce plastics and fibers by Natureworks LLC, which is the leader in lactic polymer technology and markets. Other advances in esterification technology with pervaporation and development of biosolvent blends also have a high potential for ‘green’ solvents in many applications. Recently, a considerable amount of pioneering effort in technology, product development and commercialization has been expended by several companies. To overcome the barriers to replace long‐established petroleum‐derived products, further real support from consumer, regulatory and government organizations is also needed. Copyright © 2006 Society of Chemical Industry     

Wavelet based robust sub-band features for phoneme recognition

Wavelet transform has been found to be an effective tool for the time-frequency analysis of non-stationary and quasi-stationary signals. Recent years have seen wavelet transform being used for feature extraction in speech recognition applications. In the paper a sub-band feature extraction technique based on an admissible wavelet transform is proposed and the features are modified to make them robust to additive white Gaussian noise. The performance of this system is compared with the conventional mel frequency cepstral coefficients (MFCC) under various signal to noise ratios. The recognition performance based on the eight sub-band features is found to be superior under the noisy conditions compared with MFCC features.     

Heating effects of clock drivers in bulk, SOI, and 3-D CMOS

Steady-state and transient thermal behavior of the highest power density element in systems and chips-the clock driver-in bulk, silicon-on-insulator (SOI), and three-dimensional (3-D) CMOS is examined. Despite significant metal wiring, a majority of the heat conducts through the buried oxide (BOX) in SOI and the buried interconnect layer in 3-D CMOS. 3-D CMOS has the potential to improve substantially over SOI CMOS in thermal behavior by increasing the wiring density directly beneath the clock driver. Temperature mismatch (important for analog applications) between device planes in 3-D CMOS occurs within a characteristic length, which is as large as 13 /spl mu/m for clock drivers. These results suggest advantages and architectural options for the design of high-power devices in 3-D integration.     

The effect of temperature on the flow field in a continuous rotating annular electrophoresis column

The effect of a non-uniform temperature profile on the flow field in a continuous rotating annular electrophoresis column is investigated. The momentum balance equation is solved for packed as well as unpacked columns using a centered-difference finite difference technique with a known temperature profile. The packed column analysis utilizes a parallel annular channel model similar to the capillary channel model used in packed bed columns. Results indicate that the changes in density and viscosity as result of the temperature variation have a significant effect on the flow field. Effects of voltage gradient and column geometry are also discussed.     

Effect of air leak on long term performance of air heater

In this paper, the effect of an air leak on the air heater performance is investigated. “Air leaking in” and “air leaking out” systems are examined. The effect of various parameters like leakage rate, mass flow rate, solar insolation, plate length and ambient temperature has been studied. The possibility that air leakage can take place from any where along the length of the collector has been incorporated in the model. It is found that, for “air leaking in” systems, efficiency goes up, while for “air leaking out” systems, efficiency decreases from the no-leak situation, and it depends on the position of the leak.     

Adaptive neural net (ANN) models for desulphurization of hot metal and steel

Neural nets can be adapted to complex patterns of interrelated input and output variables in a process even if the data sets contain a lot of noise. In this work two specific examples for the application of adaptive neural nets (ANN) in steel Industry are described. First, the sulphur content of hot-metal, obtained at the end of calcium carbide powder injection into 4001 torpedo ladles is predicted as a function of hot-metal weight, treatment time, initial sulphur content, gas flow rate and powder injection rate. The values predicted by the trained ANN model for a completely new set of input test data compare well with the actual values obtained on the shop floor. In the second example, the sulphur content of steel, obtained at the end of blow is predicted as a function of liquid-metal weight, total amount of oxygen injected, amount of iron ore added, and the temperature, contents of carbon, manganese, phosphorus and sulphur determined by in-blow sampling in a 300 t converter. The ANN predicted values of sulphur content of steel at tap (without reblow) also agree well with the values obtained on the shop floor.