Ocean-atmosphere interaction and synoptic weather conditions in association with the two contrasting phases of monsoon during BOBMEX-1999

Surface meteorological parameters acquired during the field phase experiment, BOBMEX-99, for the stationary periods (SP I and II) of the ship ORV Sagar Kanya over Bay of Bengal have been analysed. Active and weak monsoon conditions were observed during the first and the second phase of the experiment respectively over India as well as over the stationary ship location. The phase mean sea surface temperature (SST) is found to be the same in both the phases, however large differences have been observed in the phase mean values of wind speed, mean sea level pressure, latent heat and momentum fluxes at air-sea interface. Synoptic scale monsoon disturbances formed only during the period of strong north-south pressure gradient over the Bay region. Events of prominent fall in SST and in the upper 15 m ocean layer mean temperature and salinity values during typical rainfall events are cited. The impact of monsoon disturbances on ocean-atmosphere interface transfer processes has been investigated

Hydrologic modelling

Advances in computational tools and modeling techniques combined with enhanced process knowledge have, in recent decades, facilitated a rapid progress in hydrologic modeling. From the use of traditional lumped models, the hydrologic science has moved to the much more complex, fully distributed models that exude an enhanced knowledge of hydrologic processes. Despite this progress, uncertainties in hydrologic predictions remain. The Indian contribution to hydrologic science literature in the recent years has been significant, covering areas of surface water, groundwater, climate change impacts and quantification of uncertainties. Future scientific efforts in hydrologic science in India are expected to involve better, more robust observation techniques and datasets, deeper process-knowledge at a range of spatio-temporal scales, understanding links between hydrologic and other natural and human systems and integrated solutions using multidisciplinary approaches

Kidney injury molecule-1: a urinary biomarker for contrast induced acute kidney injury.

Back ground: Urinary kidney injury molecule 1 (KIM-1) is early biomarker for renal damage. A few studies have been published analyzing the potential use of urinary kidney injury molecule-1 (KIM-1) as a biomarker for acute kidney injury. However no study has been done related to Acute Kidney Injury associated with contrast administration. Aim: To search for new markers to identify Acute Kidney Injury (ARF) associated with contrast administration earlier than serum creatinine. Material and Methods: We studied 100 consecutive patients with normal serum creatinine undergoing angiographic procedure. We assessed urine KIM-1, at 4h, 8h, and 24 hours after the angiographic procedure. Serum creatinine was measured at basal, 24h and 48 hours after the procedure. Results: There was a significant rise in urinary KIM-1 levels at 24 hours after the angiographic procedure. The presence of contrast induced nephropathy associated with acute Kidney Injury was 12%. Conclusion: The present study highlighted the importance of urinary KIM-1 in detecting Acute Kidney Injury associated with contrast administration earlier than Serum creatinine. Key words: Neutrophil-gelatinase-associated lipocalin. Contrast-induced nephropathy. Cystatin C. Glomerular Filtration Rate (GFR), Kidney injury molecule -1 (KIM-1)

A fuzzy risk approach for performance evaluation of an irrigation reservoir system

Abstract In this paper, a model for fuzzy risk of low yield of a crop is developed to study the implications of a reservoir operating policy model. When an optimal operating policy is derived based on a known objective, the policy itself does not, in general, indicate a measure of the system performance unless a criterion to this effect is embedded in the objective function. While a systems analyst is interested in the nature of the objective function used in arriving at a policy, the irrigation decision maker would look for the implications of using the policy through answers to the questions such as, how often the system will fail and how quickly it will recover from a failure. It is, therefore, important that the implications of reservoir operation with a given policy be studied keeping in view the interests of the decision makers. Some earlier studies on reservoir operation models for irrigation have considered reliability, resiliency and productivity index, as the performance indicators of the operating policy. In this paper, fuzzy risk of low yield of a crop is considered as another performance indicator to address uncertainties due to both randomness and fuzziness. Uncertainty due to randomness arises primarily because of the random variations of hydrologic variables such as reservoir inflows and rainfall in the command area. Uncertainty due to imprecision or fuzziness arises because of uncertain crop yield response to various factors (such as farm practices and climatic variables) other than to the applied water. Two important concepts are introduced in this paper with respect to irrigation reservoir system. The first one is related to viewing the low yield of a crop, as a fuzzy event. The second concept is related to the definition of fuzzy risk of low yield of a crop. The fuzzy risk of low yield is derived using the concept of probability of a fuzzy event. G(k, i, l, M, p, t) system performance measure corresponding to storage class interval k in period t and l in period t + 1, inflow class i, rainfall class p and soil moisture vector M in period t i class interval to which the inflow in period t belongs j class interval to which the inflow in period t + 1 belongs k class interval to which storage at the beginning of period t belongs l class interval to which storage at the beginning of period t + 1 belongs l * optimal value of l l * (k, i, p, M, t) optimal end of period storage, for a given initial storage class interval k, inflow class interval i, rainfall class interval p, and initial soil moisture vector of demand from crop c in period t ER t effective rainfall in period t ET t ac actual evapotranspiration of crop c in period t ET t pc potential evapotranspiration of a crop c in period t F c farm practices for crop c FETDM fuzzy evapotranspiration deficit model crisp set of low relative yield of a crop c m c class interval to which soil moisture of crop c at the beginning of period t belongs M soil moisture vector in period t, m 1 , . . . , m NC , representing the initial soil moisture class intervals of crops in period t M = {m 1 , . . . , m NC } soil moisture vector representing the soil moisture class intervals of crops in period t nk class interval to which the relative yield of a crop belongs NC number of crops NC t number of crops in time period t p class interval to which the rainfall in period t belongs P probability of a fuzzy event P t ij probability that the inflow Q t+1 in time period t + 1 is in class interval j, given the inflow Q t in time period t is in class interval i K.R. Suresh, P.P. Mujumdar / Agricultural Water Management 69 (2004

Mahanadi streamflow: climate change impact assessment and adaptive strategies

Impacts of climate change on hydrology are assessed by downscaling large scale General Circulation Model (GCM) outputs of climate variables to local scale hydrologic variables. This modeling approach is characterized by uncertainties resulting from the use of different models, different scenarios, etc. Modeling uncertainty in climate change impact assessment includes assigning weights to GCMs and scenarios, based on their performances and providing weighted mean projection for the future. This projection is further used for water resources planning and adaptation to combat the adverse impacts of climate change. The present article summarizes the recent published work of the authors on uncertainty modeling and development of adaptation strategies to climate change for the Mahanadi river in India

Numerical Investigation of Heat Transfer Performance of Various Coiled Square Tubes for Heat Exchanger Application

AbstractIn heat exchanger application, working fluid inside the tubes is subjected to considerable temperature changes. In order to improve heat transfer performance, various strategies are proposed and evaluated; one of them is the application of coiled tubes. Coiled tubes have been used widely in heat exchanger application mainly due to the presence of secondary flow which enhances heat transfer considerably. This study addresses heat transfer performance of three configurations of coiled tubes with square cross-section, i.e. in-plane, helical and conical coiled tubes, subjected to large temperature difference. Their heat transfer performance is numerically evaluated and compared with that of a straight tube with identical cross-section and length. A concept of Figure of Merit (FoM) is introduced and utilized to fairly asses the heat transfer performance of the coiled tube configurations. The results indicate that FoM increase as the wall temperature increase. In addition, combination of temperature-induced buoyancy flow and curvature-induced secondary flow considerably affect the flow behavior and heat transfer performance inside the tubes

Electro-kinetic technology as a low-cost method for dewatering food by-product

Increasing volumes of food waste, intense environmental awareness, and stringent legislation have imposed increased demands upon conventional food waste management. Food byproducts that were once considered to be without value are now being utilized as reusable materials, fuels, and energy in order to reduce waste. One major barrier to the valorization of food by-products is their high moisture content. This has brought about the necessity of dewatering food waste for any potential re-use for certain disposal options. A laboratory system for experimentally characterizing electro-kinetic dewatering of food by-products was evaluated. The bench scale system, which is an augmented filter press, was used to investigate the dewatering at constant voltage. Five food by-products (brewer’s spent grain, cauliflower trimmings, mango peel, orange peel, and melon peel) were studied. The results indicated that electro-kinetic dewatering combined with mechanical dewatering can reduce the percentage of moisture from 78% to 71% for brewer’s spent grain, from 77% to 68% for orange peel, from 80% to 73% for mango peel, from 91% to 74% for melon peel, and from 92% to 80% for cauliflower trimmings. The total moisture reduction showed a correlation with electrical conductivity (R2¼0.89). The energy consumption of every sample was evaluated and was found to be up to 60 times more economical compared to thermal processing

Quantitative analysis of several random lasers

We prescribe the minimal set of experimental data and parameters that should be reported for random-laser experiments and models. This prescript allows for a quantitative comparison between different experiments, and for a criterion whether a model predicts the outcome of an experiment correctly. In none of more than 150 papers on random lasers that we found these requirements were fulfilled. We have nevertheless been able to analyze a number of published experimental results and recent experiments of our own. Using our method we determined that the most intriguing property of the random laser (spikes) is in fact remarkably similar for different random lasers.Comment: 3 pages, 1 figur