Distributed AEC databases for collaborative design

The Architecture, Engineering and Construction (AEC) design process for a facility involves participation of many design specialists. These participants are architects, engineers (structural, mechanical and electrical) and contractors, who may be independent design professionals or design teams within an organization. From the viewpoint of information processing, two characteristic features distinguish the AEC design process from many other design domains. Firstly, there is a massive volume of design data involved in the design of each of its component specialties. Secondly, the specialization of the disciplines themselves warrant substantial autonomy. For design automation, this autonomy should be realized without sacrificing the collaborative nature of the multidisciplinary AEC design process. We propose autonomous AEC databases to deal with the first issue, and a global constraint maintenance mechanism for the second. Autonomous design databases can support the existing local applications in architectural, structural and mechanical engineering, and construction domains. However, a set of inter-disciplinary constraints needs to be enforced to ensure spatial and functional consistency of the design. A global constraint checking mechanism frees designers from the burden of keeping track of various design changes that may result in cross-functional conflicts. In this paper, we discuss the relevant issues for constraint management on distributed AEC databases. Although specific AEC examples will be used, the presentation is general enough to be applicable to other design domains, such as VLSI and manufacturing.     

Potential applications of polymeric microsphere suspension as subcutaneous depot for insulin

The objective of this investigation was to develop an injectable, depot-forming drug delivery system for insulin based on microparticle technology to maintain constant plasma drug concentrations over prolonged period of time for the effective control blood sugar levels. Formulations were optimized with two well-characterized biodegradable polymers namely, poly(DL-lactide-co-glycolide) and poly-epsilon-caprolactone and evaluated in vitro for physicochemical characteristics, drug release in phosphate buffered saline (pH 7.4), and evaluated in vivo in streptozotocin-induced hypoglycemic rats. With a large volume of internal aqueous phase during w/o/w double emulsion solvent evaporation process and high molecular weight of the polymers used, we could not achieve high drug capture and precise control over subsequent release within the study period of 60 days. However, this investigation revealed that upon subcutaneous injection, the biodegradable depot-forming polymeric microspheres controlled the drug release and plasma sugar levels more efficiently than plain insulin injection. Preliminary pharmacokinetic evaluation exhibited steady plasma insulin concentration during the study period. These formulations, with their reduced frequency of administration and better control over drug disposition, may provide an economic benefit to the user compared with products currently available for diabetes control.     

Studies of KVIC biogas system coupled with flat plate collector

a simple straightforward transient analysis of the Khadi Village Industrial Commission (KVIC) biogas plant coupled with a flat plate collector through a spiral/coil type heat exchanger is presented. To avoid night heast losses through the collectors, the plant is disassociated from the collectors during off-sunshine hours. The effects of various system parameters, viz. heat capacity of slurry, area of collectros, length of heat exchanger placed in slurry, flow rate, etc. on the variation of slurry temperature have been studied in detail. The results obtained from the proposed system have also been compared with the results of a conventional KVIC biogas plant. It is observed that the drop of slurry temperature in the harsh winter climatic condition can significantly be reduced by the present system, for higher production of biogas.     

Hydrologic modelling for runoff determination

The quantitative assessment of runoff from a catchment is necessitated when a structure in the vicinity of a watercourse has to be designed. In the present study the USDA Soil Conservation Service runoff curve numbers, modified for Indian conditions, are established for the Kaliaghai river basin from a digitized land‐use or land‐cover map derived from IRS‐IA LISS‐II data. The software ‘HYDMOD’ was developed to translate the curve number into volume of runoff. The linear regression model was developed to correlate the observed and estimated runoff. Average percentage deviation between the observed and estimated runoff was found to be in the order of 5.9.     

Metal wave-guide to dielectric image guide transition using exponential taper

A unique metal wave guide to dielectric image guide transition has been developed using exponential taper in dielectric wave guide. The propagation characteristics have been computed theoretically and taper impedance for the different cross-sections have been evaluated, so as to match it with the metal wave guide for efficient mode conversion. Transmission loss and return loss for triangular and exponentail taper with frequency for same dimensional parameters have been measured.     

Relative effectiveness of iron pyrites and gypsum as sulfur fertilizer for different cultivars of mustard (Brassica juncea)

Summary A field experiment was conducted during 1982–83 on the Gangetic alluvial soil (Typic Ustochrept) of Pura, Kanpur to study the effectiveness of iron pyrites and of gypsum as a sulfur fertilizer for three cultivars of mustard (Brassica juncea). Increasing the supply of sulfur through either pyrites or gypsum significantly increased the grain and straw yields and the concentration and uptake of sulfur in the three cultivars of mustard. The effectiveness of pyrites was very similar to that of gypsum.     

Performance of hot water systems with tanks in series

It is usual to extract hot water from a storage tank, using displacement by cold water from the mains; this causes the temperature of the outgoing hot water to decrease with time. In order to alleviate this undesirable feature a number of tanks in series may be employed. In this communication the effect of number of tanks on the outlet temperature of hot water, has been analytically investigated; it has been assumed that the only heat exchange, taking place in the tanks is on account of flow of water. The considerations in this analysis are similar to those made by Rabinovich and Fert [1] and Rabinovich [2], for a system of tanks in a solar collector loop without any outflow of water. Thus the analysis is best applicable when hot water is extracted at a fast rate, so that the gain or loss of heat by other mechanisms is negligible, compared to that due to the flow of water. The analysis should also be applicable to shallow solar ponds, Sodha et al. [3], and built in storage water heaters, Sodha et al. [4].