Optimum harvesting policy for an age-structured forest

In this paper, an attempt has been made to develop a model for determining the optimal policy for felling and planting trees of a particular species in a forest, in order to maximize the total yield over a specified period of time. The model takes into account not only the time at which trees should be felled but also how many trees and of what age.     

Design optimization of first wall and breeder unit module size for the Indian HCCB blanket module

The Indian test blanket module(TBM) program in ITER is one of the major steps in the Indian fusion reactor program for carrying out the RD activities in the critical areas like design of tritium breeding blankets relevant to future Indian fusion devices(ITER relevant and DEMO).The Indian Lead–Lithium Cooled Ceramic Breeder(LLCB) blanket concept is one of the Indian DEMO relevant TBM,to be tested in ITER as a part of the TBM program.Helium-Cooled Ceramic Breeder(HCCB) is an alternative blanket concept that consists of lithium titanate(Li_2TiO_3) as ceramic breeder(CB) material in the form of packed pebble beds and beryllium as the neutron multiplier.Specifically,attentions are given to the optimization of first wall coolant channel design and size of breeder unit module considering coolant pressure and thermal loads for the proposed Indian HCCB blanket based on ITER relevant TBM and loading conditions.These analyses will help proceeding further in designing blankets for loads relevant to the future fusion device.     

A multi-stage production inventory system,including service time

The basic objective in this paper is to bring down inventory carrying cost, in a multistage production inventory system, by incorporating the idea of service time in the model. The paper considers models with two types of information flow: the serial information flow, in which the inventories at each stage are measured against, orders placed by the following stage, and the parallel information flow, in which they are measured against customer orders materializing at the finished goods stage.

The optimization involved, considering the service times, smoothing of the production rate, etc., would serve to specify which points in the manufacturing process should be inventory points and which points should not. Also, it determines how big should the in-process inventories be for maximum operating efficiency.     

The integrated multiscale modeling of diamond chemical vapor deposition

The fundamental mechanisms of diamond growth occur on the atomic scale; however, the geometry of the deposition reactor and the other operating parameters directly affect the chemical composition of the gas and the temperature at the growth surface. The properties are, in turn, controlled by both atomic- and microstructural-scale features. By developing diamond-growth models at each length scale and coupling the output of one model into the next, a comprehensive simulation scheme for diamond deposition is realized. This approach provides the missing link between chemical vapor deposition reactor design/operating conditions and the material structure/properties.     

Optimum Control of a Certain Class of Servomechanism†

Linear control systems governed by the vector matrix differential equation x = A x + B u have been considered. It has been shown how to find the optimum control u so that the system, starting from an initial position x(0), is steered to a state specifying the first p coordinates of the system in time t _o fixed in advance, the values attained by the (n—p) coordinates being immaterial, where n is the dimension of the system. The optimization considered here is with regard to the norm of u supposed to belong to L _m E _r space.     

X-ray characterization of annealed Cu/Ni multilayers

A detailed study has been made of the X-ray characterization of Cu/Ni multilayers. Different mathematical models have been used to calculate the X-ray diffraction intensity and theoretical and experimental profiles were compared. An extended step model, which incorporates repeat-period fluctuations, and a model for interdiffusion were used. By varying the repeat-period fluctuation, the theoretical X-ray profile obtained from the extended step model was compared with the experimental curve. A best fit was obtained for a 1.6% fluctuation in the repeat period. For the second model, Cu/Ni samples annealed for different times (i.e. 2, 6, 14 and 20 h) were considered. The experimental values of the amplitudes of the first and second harmonics of the interplanar spacing were compared with the theoretical values. A coherent interface is predicted for the un-annealed sample. It is observed that the longer the annealing time, the higher is the interdiffusion. The interplanar spacing of the multilayers approaches the average interplanar spacing of the homogeneous Cu/Ni mixture with the longer annealing time (i.e. 20 h). This revised version was published online in November 2006 with corrections to the Cover Date.     

Die Bedeutung geringer Arsengehalte im Ferronickel für die zukünftige Nickelversorgung der Stahlindustrie

Erläuterung der Nickelversorgung in der Stahlindustrie. Folgerungen für die Stahlherstellung beim Übergang auf arsenhaltiges Nickeloxiderz. Verhalten von Arsen bei der Herstellung von nichtrostendem Chrom-Nickel-Stahl mit rd. 18% Cr, 9% Ni und mit 0,009, 0,046 und 0,061% As. Prüfen der mechanischen Eigenschaften, der Schweißbarkeit und der chemischen Beständigkeit dieser Stähle in Abhängigkeit vom Arsengehalt. Abschätzen des Einflusses vorgegebener Arsengehalte auf die Neigung zur Anlaßsprödigkeit von Baustahl mit Gehalten bis zu 4% Ni. Überlegungen zur Gefährdung der Umwelt durch Arsen in den hier vorkommenden Gehalten.     

Optimization of Cropping Pattern in a Canal Command Area Using Fuzzy Programming Approach

Water Resources Management - Optimal cropping pattern depends on water availability and other constraints like crop area, soil properties, use of fertilizer, and local socio-economic conditions....     

Facile synthesis of asymmetric patchy Janus Ag/Cu particles and study of their antifungal activity

Asymmetric patchy Ag/Cu Janus nanoparticles (NPs) were synthesized via a “seed-mediated” approach. This is the first report of synthesis of nanometer sized metal-based Janus NPs without using complicated methods. Selective adsorption of the surfactant onto the seed NPs leads to the formation of Janus type structure. Subsequently the reduction potential of Ag⁺/Ag⁰ and Cu²⁺/Cu⁰ systems directs the formation of the “patch”. The patchy Janus NPs show significant antifungal activity towards a potent rice pathogen thus offering the prospect of future application in crop protection.