An Improved Robust Optimization Approach for Scheduling Under Uncertainty

In practice, the uncertainty in processing time data frequently affects the feasibility of optimal solution of the nominal production scheduling problem. Using the unit-specific event-based continuous time model for scheduling, we develop a novel multi-stage robust approach with corrective action to ensure robust feasibility of the worst case solution while reducing the conservatism arising from traditional robust optimization approaches. We quantify the probability of constraint satisfaction by using a priori and a posteriori probabilistic bounds for known and unknown uncertainty distributions, consequently, improving the objective value for a given risk scenario. Computational experiments on several examples were carried out to measure the effectiveness of the proposed method. For a given constraint satisfaction probability, the proposed method improves the objective value compared to the traditional robust optimization approaches

Large reservoirs: are they the last Oasis for the survival of cities in India?

Urban water demand is rapidly growing in India due to high growth in urban population and rapid industrialization. Meeting this growing demand is a big challenge for the urban planners in India. Incidentally, urban areas in arid and semi arid regions of India are experiencing rapid growth. As a result, the supplies from local water resources including aquifers are far less than the high and concentrated water demands in most urban areas. Under such situations, the cities have to rely on large reservoirs. The paper argues that urban growth would be jeopardized in absence of water supplies from large reservoirs. The analysis of 302 urban centres shows that as population of cities grow, their reliance on surface water sources also grows. Also, greater the share of surface water in the city water supplies, better the level of water supply. A multiple regression analysis of 190 class I cities and 240 class II towns further supports this finding. In Class I cities, with every unit increase in population, there is a 1.12 unit increase in quantum of water supplies. Whereas in Class II towns, with every increase in population, there is only a 0.40 unit increase in quantum of water supply. This shows greater capacities of large cities to respond to the growing water demands, induced by population growth and urbanization. The future projections of population growth, economic development and future water demands clearly means that the role of large reservoirs in meeting the demand of urban water supply is going to be more critical.urban water supply; large reservoirs; urbanization; population growth; India.

Water, human development and economic growth: some international perspectives

Water resources developmentInvestmentWater storageEconomic aspectsSocial aspects

Groundwater pollution and contamination in India: the emerging challenge

Groundwater pollution / Pollution by agriculture / Water quality / Fluorides / Drinking water / India / Gujarat

Pedaling out of poverty: Social impact of a manual irrigation technology in South Asia.

Irrigation management / Treadle pump / Treadle pump technology / Technology transfer / Manual pumps / Water lifting / Low lift pumps / Aquifers / Poverty / Irrigated farming / Social impact / Income / Marketing / Pricing / South Asia / India / Bangladesh / Nepal

Development and validation of dissolution method for carvedilol compression-coated tablets

The present study describes the development and validation of a dissolution method for carvedilol compression-coated tablets. Dissolution test was performed using a TDT-06T dissolution apparatus. Based on the physiological conditions of the body, 0.1N hydrochloric acid was used as dissolution medium and release was monitored for 2 hours to verify the immediate release pattern of the drug in acidic pH, followed by pH 6.8 in citric-phosphate buffer for 22 hours, to simulate a sustained release pattern in the intestine. Influences of rotation speed and surfactant concentration in medium were evaluated. Samples were analysed by validated UV visible spectrophotometric method at 286 nm. 1% sodium lauryl sulphate (SLS) was found to be optimum for improving carvedilol solubility in pH 6.8 citric-phosphate buffer. Analysis of variance showed no significant difference between the results obtained at 50 and 100 rpm. The discriminating dissolution method was successfully developed for carvedilol compression-coated tablets. The conditions that allowed dissolution determination were USP type I apparatus at 100 rpm, containing 1000 ml of 0.1N HCl for 2 hours, followed by pH 6.8 citric-phosphate buffer with 1% SLS for 22 hours at 37.0 ± 0.5 ºC. Samples were analysed by UV spectrophotometric method and validated as per ICH guidelines.O presente estudo descreve o desenvolvimento e a validação de método de dissolução para comprimidos revestidos de carvedilol. O teste de dissolução foi efetuado utilizando-se o aparelho para dissolução TDT-06T. Com base nas condições fisiológicas do organismo, utilizou-se ácido clorídrico 0,1 N como meio de dissolução e a liberação foi monitorada por 2 horas para se verificar o padrão de liberação imediata do fármaco em condições de pH baixo, seguidas por pH 6,8 em tampão cítrico-fosfato por 22 horas, para simular o padrão de liberação controlada no intestino. Avaliou-se a influência da velocidade de rotação e a concentração de tensoativo no meio. As amostras foram analisadas por método espectrofotométrico UV-visível validado, em 286 nm. O laurilsulfato sódico a 1% (SLS) mostrou-se ótimo para aumentar a solubilidade do carvedilol em pH 6,8 em tampão cítrico-fosfato. A análise da variância não mostrou diferença significativa entre os resultados obtidos a 50 e a 100 rpm. O método da dissolução discriminante foi desenvolvido com sucesso para os comprimidos revestidos de carvedilol. As condições que permitiram a determinação da dissolução foram: aparelho USP tipo I a 100 rpm, contendo 1000 mL de HCL 0,1 N por 2 horas, seguido de pH 6,8 com tampão cítrico-fosfato, com 1% de SLS por 22 horas a 37,0 ± 0,5 ºC. Amostras foram analisadas por método espectrofotométrico e validadas pelas normas ICH

Clinical Outcome of Infants Younger than Two Months in Children Ward of a Tertiary Care Hospital, Nepal

Introductions: Newborn and young infants are most vulnerable for preventable deaths, particularly in developing countries. This study was conducted to see the clinical profile and outcome of infants less than two months of age admitted in children ward of Patan Hospital.Methods: This descriptive retrospective study was conducted at Patan Hospital, over 12 months from April 2014 to March 2015. Hospital records of all admitted infant less than two were reviewed. The demographic characteristics, clinical profile and clinical outcome were descriptively analyzed.Results: Out of 2062 admissions in children ward, 614 (29.8%) were infants less than two months,out of which 482were neonate less than 28 days. Among these neonates. 114 were inborn. Out of 436 infection, blood culture was positive in 37 (8.9%). There were 4 (0.04%) deaths, 4 (0.04%) referral and 22 (0.25%) left against medical advice. Infection 436 (436) was the commonest cause of illness, of which neonatal sepsis 163 (37.4%), pneumonia 130 (30%) staphylococcal skin infection 39 (8.7%) and UTI 34 (7.8%). There were 71(11.6%) cases of neonatal hyperbilirubinemia. Blood culture was positive in 55(9%) with CONS being the commonest organism isolated; 19  (51.3%).Conclusions: Children ward contributes significantly to the care of sick infants less than two months of age, especially out born ones, requiring neonatal care facility in tertiary level hospital of Nepal. As most admissions are for infection, followed by hyperbilirubinemia, pediatrics wards need to be equipped and staffed accordingly to meet the need of sick young infants.Keywords: children ward, clinical profile, neonatal sepsi

An Improved Robust Optimization Approach for Scheduling Under Uncertainty

In practice, the uncertainty in processing time data frequently affects the feasibility of optimal solution of the nominal production scheduling problem. Using the unit-specific event-based continuous time model for scheduling, we develop a novel multi-stage robust approach with corrective action to ensure robust feasibility of the worst case solution while reducing the conservatism arising from traditional robust optimization approaches. We quantify the probability of constraint satisfaction by using a priori and a posteriori probabilistic bounds for known and unknown uncertainty distributions, consequently, improving the objective value for a given risk scenario. Computational experiments on several examples were carried out to measure the effectiveness of the proposed method. For a given constraint satisfaction probability, the proposed method improves the objective value compared to the traditional robust optimization approaches