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Lignocellulosic feedstock is one of the potential renewable sources for producing ethanol for transportation. The process steps viz., acid pretreatment and enzymatic hydrolysis in bio-chemical process route are intended to produce fermentable sugars, which can be readily fermented for producing ethanol. However, the dilute acid pre-treatment and enzymatic hydrolysis process steps are found to be economically inefficient. The present work aims at optimizing these process steps for improving the process performance. Such optimization is expected to increase conversion, reduce energy or material requirement, thereby improving the economics. The kinetic models of acid pretreatment and enzymatic hydrolysis for lignocellulosic feedstock processing are adapted from literature. Subsequently, these kinetic models are augmented by associated mass and energy balances, to develop a batch reactor model and fed-batch reactor model for dilute acid pretreatment and enzymatic hydrolysis processes, respectively. Optimal control with Pontryagin's maximum principle has been implemented to determine the optimal time dependent profiles of heating and cooling fluid flow rates and operating temperatures for acid pretreatment and substrate feed rate profile for enzymatic hydrolysis to optimize the respective processes performance. Different objective functions such as maximizing concentration of desired product, minimizing the batch time, and maximizing profit have been considered. The simulation results yielded an increase of 6.7% and 8.8% in final concentration of desired product; 43% and 42.5% reduction in batch processing time for pretreatment and enzymatic hydrolysis processes, respectively. Finally, the simulation results have also provided optimal operating policies which have increased the profit of pretreatment by 124% and enzymatic hydrolysis by 150%, thereby improving the techno-economic feasibility for processing lignocellulosic feedstock. (C) 2017 Elsevier Ltd. All rights reserved.

Introduction: Idiopathic Pulmonary Fibrosis (IPF) is a chronic and progressive, condition that is due to aberrant wound healing response following repetitive alveolar injury. Though traditionally viruses have played a key role in altering the wound healing cascade, the role played by bacteria in the pathogenesis of IPF is unclear. If there is a recurrent bacterial isolate in sputum or bronchial wash, an appropriate antibiotic both prophylactically and therapeutically can help prevent the decline in lung function and morbidity. This is particularly relevant in the treatment since it involves immunosuppressives during exacerbations. Aim: This study analyses the sputum for bacterial isolates in patients with acute exacerbation of IPF and aims to find the significance of such association. Materials and Methods: Sputum samples of 60 patients who came with acute exacerbation of IPF to a Tertiary Medical College and Hospital between February 2015 to March 2016 were analysed. Patients who were unable to produce sputum and who had received antibiotics for the present exacerbation prior to admission were excluded. Expectorated sputum samples were collected in wide mouth sterile containers and were subjected to gram staining and culture using blood agar after assessing the sputum quality. Chi-Square tests were used to find the significant association between the bacterial isolates in the sputum samples. Results: Among the 60 patients, there were isolates in 78.3% (n=47) and rest had no isolates. Streptococcus pneumoniae was isolated in 12 patients and Escherichia Coli in 13 patients and these were found to have significant association statistically in patients presenting with acute exacerbation of IPF. Whereas the rest of the isolates like Klebsiella (n=9), Haemophillus influenza (n=8), Enterococcus (n=2) and Moraxella catarrhalis (n=3) were found to have insignificant association. Conclusion: Preserving the lung functions in patients with IPF is the basis of treatment. Whether infectious causes play a role in attenuating lung function and treating these with prophylactic antibiotics needs to be seen with larger studies in different geographic areas.

Lignocellulosic(LC) feedstock is one of the potential renewable sources for producing ethanol (second generation biofuel). However, technological bottlenecks and economic viability are of prime concern in producing ethanol from the LC feedstocks. In this context, to improve the process economics; one of the economically impacting process step in biochemical process route viz. enzymatic hydrolysis is optimized. In general fed-batch reactor is preferable option for enzymatic hydrolysis due to high productivities. The optimization of fed-batch operation generally involves finding the optimal substrate feeding profiles, with a view to optimize the performance index/ objective functional. With this scope, the kinetic model of enzymatic hydrolysis for LC feedstocks processing is considered from literature. Subsequently, the kinetic model parameters are used to develop a fed-batch reactor model for enzymatic hydrolysis process by associated mass balances. Optimal control has been implemented to determine the optimal time dependent profiles of substrate feed rate for fed-batch reactor to optimize the process performance. In this work, different objective functions such as maximizing concentration of glucose and, minimizing the batch time have been considered. The simulation results have provided the optimal operating policies to improve techno-economic feasibility of enzymatic hydrolysis operation for processing LC feedstock.