Energy utilization in sugarcane production in North India

Average physical and monetary data on sugarcane crops, planted or ratooned, from 128 farms covering 122 ha in North India were transformed into energy equivalents and assessed for energy balance. Farm manure and irrigation consumed major shares. Energy inputs and yields were greatly reduced but energy utilization doubled in ratooned sugarcane. Average energy output-input ratios were about 0.8 and 2.3 for sugar and total biomass, respectively.     

Efficient management of critically important systems

Maintainability of goods producing systems is undertaken on the principles of minimum cost whereas the maintenance of service producing systems is done on the principles of operational reliability. In this paper, theoretical reliability of a service producing system is developed and its application is demonstrated through an actual case history.     

An analysis of the distributions of electronic states associated with hydrogenated amorphous silicon

We study the distributions of conduction band and valence band electronic states associated with hydrogenated amorphous silicon. We find that there are substantial deviations from square-root distributions of electronic states, particularly deep within the bands and within the gap region. We clearly identify where these distributions of electronic states exhibit square-root functional dependencies by fitting square-root functional forms to some experimental data. The corresponding DOS effective masses are determined, and are found to be about 2 to 4 times greater than the crystalline silicon case.     

Einfluß von Legierungselementen auf die Keimbildung von Perlit

Anwendung quantitativer metallographischer Messungen in Verbindung mit statistischen Auswerteverfahren zur Ermittlung der Keimbildungsgeschwindigkeit des Perlits in Legierungen des Eisens mit rd. 0,8 bis 0,9 % C ohne und mit Legierungsanteilen an 2,0% Si, 2,15% Co, 1,15% Cr oder 0,35% Mo. Folgerungen besonders über den Einfluß der Legierungselemente auf die Keimbildungsgeschwindigkeit des Perlits unter Berücksichtigung des Abstandes der Umwandlungstemperatur vom A₁-Punkt.     

Polarographic studies on the coupled product of β-diketones with aryl diazonium chloride

Polarographic reduction of some coupled product of acetyl acetone with aryl diazonium chloride takes place in a single 4-electron transfer, giving a diffusion controlled irreversible waves in B.R. buffers of pH range 2–11.8. The reduction in these compounds takes place at the ---NH---N=C bond. Effect of various cations, anions, surfactant and solvent percentage on the reduction has been discussed.     

FILM CONDENSATION ON A HORIZONTAL ISOTHERMAL SURFACE

This paper concerns an analytical study of laminar film condensation on horizontal isothermal surfaces. The flow that arises on a surface of finite length is studied to determine the temperature field and the local heat transfer to the surface. The study considers both transient and steady laminar flow. The governing nonlinear equations are also considered for the circumstance when the surface tension effects are included. The profiles in the condensate film, for steady laminar flow, are found to be strongly dependent on the edge conditions and on the length of the horizontal condensing surface. The dependence on vapor properties and on the surface temperature is also determined. The surface tension effects are found to be negligible, even for quite small values of the Bond number, for a surface terminated by a round fall. The results for transient, laminar, flow show that the transient effects are large for highly viscous condensing fluids and for low gravity fields. An expression for the local Nusselt number is also obtained.     

A load frequency control algorithm based on a generalized approach

A generalized approach to load frequency control that combines discontinuous control and dual-mode control and uses variable-structure-systems concepts is developed. Using this approach, a novel load-frequency control algorithm is proposed. Studies on a multi-area power system, including generation rate constraint and governor dead-band, demonstrate the effectiveness of the control scheme     

Enhanced Terahertz Receiver Using a Distributed Bragg Reflector Coupled to a Photoconductive Antenna

We report the use of a terahertz (THz) receiver fabricated using a photoconductive antenna mounted upon a distributed Bragg reflector (DBR). It is shown that the relative performance of the device is in accordance with the reflectivity curves of the DBR. At maximum reflectivity the device improved upon the reference THz signal by up to 30%. In addition, we characterize the saturation of the device with laser pump power and it is shown that the device exhibits an improved optical efficiency when compared to the reference receiver.     

Ethanol steam reforming study over ZSM-5 supported cobalt versus nickel catalyst for renewable hydrogen generation

The renewable hydrogen generation through ethanol steam reforming is one of the anticipated areas for sustainable hydrogen generation. To elucidate the role of Ni and Co with ZSM-5 support, catalysts were prepared by wet impregnation method and ethanol steam reforming(ESR) was performed. The catalysts were characterized by HR-XRD, ATR–FTIR, HR-SEM, TEM with SAED, EDAX, surface area analyzer and TPR. It had shown complete ethanol conversion at 773 K, but the selectivity in hydrogen generation was found higher for 10% Ni/ZSM-5 catalyst as compared to 10% Co/ZSM-5. The 10% Ni/ZSM-5 catalyst has about 72% hydrogen selectivity at temperature 873 K. It indicates that Ni is a more sustainable catalyst as compared to Co with ZSM-5 support for ESR. The C_2H_4 was found major undesirable products up to 823 K temperature. Nevertheless, the 10% Ni/ZSM-5 catalyst had shown its stability for high temperature(873 K) ESR performance.