Biomedical subjects

S A Abbasi

Publications and source records attributed to S A Abbasi.

26 records · Page 2Linked to original sources

PubMed2001

Assessment of sustainable vermiconversion of water hyacinth at different reactor efficiencies employing Eudrilus eugeniae kinberg.

The viability of vermireactors fed with different proportions of water hyacinth (WH) and cowdung (CD) was assessed over six-month trials. All reactors performed sustainably with a steadily rising vermicast output, worm zoomass, and number of offspring. There was no mortality in any of the reactors. A change in the WH:CD ratios from 4:1 to 6:1 had no discernable impact on the reactor performances. Attempts were also made to improve the efficiency of the reactors in terms of vermicast production per unit time and per unit digester volume. These attempts led to the 'high-rate' vermireactor in which 5.6 times greater vermicast was produced per litre of digester volume per day than in the 'low-rate' reactors. The high-rate vermireactors also performed sustainably, with steady vermicast output, animal growth, and reproduction.

Animal Feed↗

PubMed2001

Identification and classification of key variables and their role in environmental impact assessment: methodology and software package INTRA.

There is, as yet, no proven methodology to enable, objectively, the identification of key parameters out of a large number one normally encounters during any EIA. As EIA is a costly and time-consuming exercise, it is necessary to separate the man from the boys--so to speak--in order to optimize costs and efforts. In this paper a methodology for distinguishing the more important parameters from the less important ones, developed by us, is described. The methodology aims at identifying and shortlisting the key parameters which ought to be studied in a given EIA situation, thereby helping in reducing time, effort, and cost of EIA. With this methodology a system structure is developed which gives hierarchical pattern of inter-parameter interaction, and reveals several distinguishing features of each parameter. A software package INTRA (INTer-parameter Relationship Analysis) based on this methodology, has been developed. The paper also describes a case study in which INTRA has been used to study the environmental impacts of urbanization of a typical third world town (Roorkee).

Developing Countries↗

PubMed2001

Screening of four species of detritivorous (humus-former) earthworms for sustainable vermicomposting of paper waste.

Four specices of detritivorous (humus-former) earthworms were tested for their ability to vermicompost paper waste blended with cowdung in 6:1 (w/w) ratio. The anecic Lampito mauritii, Kinberg and the epigeic Eudrilus eugeniae, Kinberg were the most effective of the four species employed; 20 animals of each of these species generated castings amounting to about 52% of the feed mass (75 g) per fortnight. The performance of these two species was followed by the anecic Drawida willsi, Michaelsen and the epigeic Perionyx excavatus, Perrier; they achieved approximately 46% vermiconversion in comparable settings. The vermireactors were sustainable as the animals have remained consistently healthy and reproductive over a period of six months, and are continuing to remain so, turning in a steadily rising vermicast output. During this period E. eugeniae have grown to 2.3 times their original weight while the other three species have more than trebled their weights. The studies establish the feasibility of vermicomposting as a viable process for the gainful utilization of paper waste in an environmentally clean manner. They also indicate that all the four species of the worms screened by us are suitable for the process, with L. mauritii and E. eugeniae a shade more efficient than the other two species.

Animals↗

PubMed2001

Enhancement in the treatment efficiency and conversion to energy of dairy wastewaters by augmenting CST reactors with simple biofilm support systems.

Dairy wastewaters are rich in organic carbon and nutrients. When disposed without proper treatment they cause severe pollution of water and land. But if treated by anaerobic fermentation such wastewaters can yield useful clean energy in the form of methane. The systems commonly used for such fermentation throughout the world are Continuously Stirred Tank Reactors (CSTRs). We describe attempts to upgrade CSTR performance by incorporating biofilm support systems (BSSs) within the existing reactors. The focus of the work has been to find inexpensive and easy-to-install BSS which could significantly enhance the rate of waste treatment as well as quantum of energy recovery (as methane). Our experiments with various BSS options have revealed that rolls of nylon mesh (-1 mm openings), of 5 cm height and 2 cm dia, when incorporated in CSTRs at the biofilm-surface: digester-volume ratio of 0.3 cm2 cm-3, enabled the CSTRs to perform better with up to 25% improvement in methane yield. The studies, thus, reveal that simple devices of the type used by us as BSS can significantly improve the performance of CST anaerobic digesters treating dairy wastes. The enhancement is evidently due to the development of active biofilms on the BSS which not only enhance the contact of the water with micro-organisms but also reduce microbial washout. Further, such devices are inexpensive and very easy to incorporate--the gains are thus achieved with very little cost and effort. BSSs were also found by us to enhance conversion of volatile fatty acids--derived earlier by us from aquatic weed water hyacinth--into methane-rich biogas.

Agriculture↗

PubMed2000

Modelling and simulation of heavy gas dispersion on the basis of modifications in plume path theory.

An analytical model for heavy gas dispersion based on the modifications in plume path theory has been developed. The model takes into account the variations in temperature, density, and specific heat during the movement of heavy gas plume. The model has been tested for three hazardous gases - chlorine, natural gas and liquefied petroleum gas. The results have been compared with the recently generated experimental data as also with the outputs of other models. A good agreement is observed qualitatively as well as quantitatively. A study has also been carried out to simulate the effect of the wind speed, density of the gas, and venting speed on dispersion. Based on the simulation study a set of empirical equations has been developed. The equations are validated by theoretical as well as experimental studies.

Air Movements↗

PubMed2000

Analytical simulation and PROFAT II: a new methodology and a computer automated tool for fault tree analysis in chemical process industries.

Fault tree analysis (FTA) is based on constructing a hypothetical tree of base events (initiating events) branching into numerous other sub-events, propagating the fault and eventually leading to the top event (accident). It has been a powerful technique used traditionally in identifying hazards in nuclear installations and power industries. As the systematic articulation of the fault tree is associated with assigning probabilities to each fault, the exercise is also sometimes called probabilistic risk assessment. But powerful as this technique is, it is also very cumbersome and costly, limiting its area of application. We have developed a new algorithm based on analytical simulation (named as AS-II), which makes the application of FTA simpler, quicker, and cheaper; thus opening up the possibility of its wider use in risk assessment in chemical process industries. Based on the methodology we have developed a computer-automated tool. The details are presented in this paper.

Chemical Industry↗

PubMed1999

Drug resistance in Mycobacterium tuberculosis: a four years experience.

OBJECTIVE: To assess the prevalence of drug resistance amongst the clinical isolates of M. tuberculosis. SETTING: Armed Forces Institute of Pathology, Rawalpindi. METHOD: Four first line anti-tuberculosis drugs, isoniazid (INH), rifampicin (RIF), ethambutol (ETH) and streptomycin (STR) were tested on 300 isolates from clinical samples, by agar dilution method on Lowenstein Jensen medium. The sensitivities were interpreted by the resistance ratio method. RESULTS: One hundred and fifty eight (52.66%) isolates were found resistant to one drug at least. Among the resistant isolates, 79 (26.33%) were resistant to INH, 72 (24.0%) to RIF, 84 (28.0%) to STR and 70 (23.33%) to ETH with or without resistance to other drugs. Multi-drug resistance (MDR) was found in 41 isolates (13.66%). CONCLUSION: To overcome this problem there is a need to establish centres at a number of places all over the country with professionals trained to handle the emerging problem of MDR. Each centre must be equipped with adequate facilities for susceptibility testing so that the resistance pattern can be ascertained and treatment regimens tailored accordingly.

Drug Resistance, Microbial↗

PubMed1981

Toxicity of molybdenum and its trace analysis in animal tissues and plants.

A sensitive, selective, rapid and reproducible method is presented for the analysis of submicrogram levels of molybdenum in animal tissues (Liver) and plants. The method is based on solvent extraction of Molybdenum (VI) using isoamyl alcohol solution of N-o-tolyl-o-methoxy-benzohydroxamic acid at pH 1.5-2.5, and subsequent spectrophotometric determination of the yellow extract at 350 nm.

Animals↗