Time-Lag Models for Continuous Stirred Tank and Plug Flow Digesters for Biogas Production

This work presents time-lag models for biogas production from anaerobic digestion of organic wastes in continuous stirred tank and plug flow digesters. The models have the ability of predicting the sigmoid nature of the volumetric rate of production of biogas with process time that is observed experimentally. The models are calibrated against experimental data on biogas production by anaerobic digestion of mixed vegetable wastes in a compartmental digester. The quality of fit of the models to these data is satisfactory (average root-mean-square error = 9.2%). However, the PFR time-lag model is a better representative of the compartmental digester than the CSTR lag model. The time-lag models have a simple mathematical form whose parameters can be estimated easily and they should be useful for correlating biogas yield with process time, and hence in formulating control schemes for an existing anaerobic digester

Bimolecular Photoinduced Electron Transfer in Static Quenching Regime: Illustration of Marcus Inversion in Micelle

Ultrafast bimolecular photoinduced electron transfer (PET) between six coumarin dyes and four viologen molecules in the stern layer of sodium dodecyl sulfate micelle have been studied using femtosecond broadband transient absorption spectroscopy and femtosecond fluorescence up-conversion spectroscopy over a broad reaction exergonicity (Δ<i>G</i>⁰). Emanating the formation of radical cation intermediates of viologen molecules using the transient absorption and the fast decay component of coumarins using the fluorescence up-conversion studies the forward bimolecular electron transfer rate (<i>k</i>_et) have been measured with high accuracy. The relationship of <i>k</i>_et with Δ<i>G</i>⁰ found to follow a Marcus type bell-shaped dependence with an inversion at −1.10 eV. In this report, we have studied PET reaction using ultrafast spectroscopy at the quencher concentration where static quenching regime prevails. Moreover, the incompetency of Stern–Volmer experiments in studying ultrafast PET has been revealed. In contrary to previous claims, here we found that the <i>k</i>_et is lower for lower lifetime coumarins, indicating that static, nonstationary and stationary regime of quenching have the minimal role to play to in the bimolecular electron transfer process. By far, this report is believed to be the most efficient and immaculate way of approaching Marcus inverted region problem in the case of bimolecular PET and settles the long-lasting debate of whether the same can be observed in micellar systems

Association of Frontline Worker-Provided Services with Change in Block-Level Complementary Feeding Indicators: An Ecological Analysis from Bihar, India

<div><p>Background</p><p>Insufficiencies in complementary feeding put infants and young children at increased risk of undernutrition. Till now, most Indian studies have looked at the individual level determinants of complementary feeding practices. We aimed to evaluate the association of frontline worker (FLW) provided nutritional counselling services, with change in community level indicators of complementary feeding practices among 9–11 month old children over time.</p><p>Methods</p><p>The study data was obtained from five rounds of ‘Lot Quality Assurance Sampling’ survey in eight districts of Bihar, an impoverished Indian state. The surveys were conducted as evaluation exercises for the ‘Integrated Family Health Initiative (IFHI)’–a multi-faceted program aimed at improving the maternal and child health outcomes in Bihar. The main outcome indicators were—current breastfeeding, age-appropriate minimum frequency of semi-solid food, age-appropriate minimum quantity of semi-solid food, initiation of complementary feeding at the right age, and dietary diversity. Repeated measures analysis was performed to determine the association of changes in the outcome indicators with coverage of FLW-provided counselling services.</p><p>Results</p><p>Visits by FLW, advices on age-appropriate frequency and handwashing were significant predictors of receiving age-appropriate frequency of feeding. The determinants of receiving age-appropriate quantity were—advices on age appropriate frequency and advices on handwashing. Receiving food support from AWC and FLW visits were significantly associated with initiating complementary feeding at the right age.</p><p>Conclusions</p><p>The present study identified the critical elements among the different types of FLW-provided services. The study findings, from an economically and socially underdeveloped region of India, would inform the relevant programs about the nutritional counselling services that need to be emphasized upon for reducing the burden of childhood malnutrition.</p></div

Socio-demographic and breast feeding related characteristics of children aged 0 to 8 completed months from 8 districts of Bihar.

<p>LQAS Survey: Rounds 2 to 5.</p

Proportions of 0–5 completed months old children who received only breastmilk during the previous 24 hours, stratified by age and exposure to counselling on exclusive breastfeeding.

<p>Proportions of 0–5 completed months old children who received only breastmilk during the previous 24 hours, stratified by age and exposure to counselling on exclusive breastfeeding.</p

Proportions of 6–8 completed months old children who were exclusively breastfed for 6 months, stratified by ‘season of nursing’.

<p>Proportions of 6–8 completed months old children who were exclusively breastfed for 6 months, stratified by ‘season of nursing’.</p

Proportion of children aged between 0–5 completed months who were breastfed exclusively during past 24 hours, according to age group.

<p>LQAS Survey: Rounds 2 to 5. (n = 20793).</p

Crude and adjusted associations of exclusive breastfeeding with seasonal variations among children aged 0–5 and 6–8 completed months.

<p>LQAS Survey: Rounds 2 to 5.</p

Season-wise trend in the proportions of 0–5 completed months old children who received only breastmilk during the previous 24 hours, stratified by age.

<p>Season-wise trend in the proportions of 0–5 completed months old children who received only breastmilk during the previous 24 hours, stratified by age.</p

Categorization of blocks in the state of Bihar as per socio-demographic characteristics and complementary feeding related service coverage.Bihar, 2011–13 (N = 137)¹.

<p>Categorization of blocks in the state of Bihar as per socio-demographic characteristics and complementary feeding related service coverage.Bihar, 2011–13 (N = 137)<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0166511#t001fn001" target="_blank">¹</a>.</p