A Comprehensive Optimization Framework for Designing Sustainable Renewable Energy Production Systems

As the world has recognized the importance of diversifying its energy resource portfolio away from fossil resources and more towards renewable resources such as biomass, there arises a need for developing strategies which can design renewable sustainable value chains that can be scaled up efficiently and provide tangible net environmental benefits from energy utilization. The objective of this research is to develop and implement a novel decision-making framework for the optimal design of renewable energy systems. The proposed optimization framework is based on a distributed, systematic approach which is composed of different layers including systems-based strategic optimization, detailed mechanistic modeling and operational level optimization. In the strategic optimization the model is represented by equations which describe physical flows of materials across the system nodes and financial flows that result from the system design and material movements. Market uncertainty is also incorporated into the model through stochastic programming. The output of the model includes optimal design of production capacity of the plant for the planning horizon by maximizing the net present value (NPV). The second stage consists of three main steps including simulation of the process in the simulation software, identification of critical sources of uncertainties through global sensitivity analysis, and employing stochastic optimization methodologies to optimize the operating condition of the plant under uncertainty. To exemplify the efficacy of the proposed framework a hypothetical lignocellulosic biorefinery based on sugar conversion platform that converts biomass to value-added biofuels and biobased chemicals is utilized as a case study. Furthermore, alternative technology options and possible process integrations in each section of the plant are analysed by exploiting the advantages of process simulation and the novel hybrid optimization framework. In conjunction with the simulation and optimization studies, the proposed framework develops quantitative metrics to associate economic values with technical barriers. The outcome of this work is a new distributed decision support framework which is intended to help economic development agencies, as well as policy makers in the renewable energy enterprises

Modeling, Simulation and Analysis of Renewable Energy Production Systems: Application to Multi-Product Biorefineries

The primary purpose of this research is to investigate the design and modelling of fully integrated processes which utilize renewable feedstock as raw materials and evaluate the alternative technology and possible process integration options for biorefinery processes to select the optimal configuration based on the production yields and economical profit criteria. The case study considered in this work is a lignocellulosic biorefinery plant which has different technology choices for each section of the process and the ability to produce multi-products from lignocellulosic raw materials. We analyzed different scenarios by simulating the superstructures in Aspen Plus. To incorporate more non-linarites in the process and put more realism in simulations, complex kinetics of bio-reactions are modeled in Matlab based on the experimentally calculated kinetics from literature. To reduce the toxicity of hydrolysates generated from pretreatment, detoxification is necessary as the by-products can have negative impact on downstream process sections such as enzymatic hydrolysis and fermentation. Two technology options are considered for detoxification process in our study. Additionally, two alternative solid separation routes are proposed and evaluated. Sustainable biorefinery requires a portfolio of products to produce different bio-fuels and bio-chemicals. In this work, one of the proposed scenarios considers succinic acid as a co-product of the plant. Final results show the optimal biorefinery process by evaluating the alternative process configurations based on the product yields and economic parameters. Succinic acid production makes a huge increase in the profitability of the plant. Ammonia conditioning is selected as detoxification technology, and separating solids after the first distillation column is the preferable technology

The role of acidic amino acids in the hydration and stabilization of halophilic proteins

Proteins of halophilic organisms that accumulate molar concentrations of KCl in their cytoplasm have much higher content in acidic amino acids than proteins of mesophilic organisms. It has been proposed that this excess is necessary to maintain proteins hydrated in an environment with low water activity: either via direct interactions between water and the carboxylate groups of acidic amino acids or via cooperative interactions between acidic amino acids and hydrated cations, which would stabilize the folded protein. In the course of this Ph.D. study, we investigated these possibilities using atomistic molecular dynamics simulations and classical force fields. High quality parameters describing the interaction between K+ and carboxylate groups present in acidic amino acids are indispensable for this study. We first evaluated the quality of the default parameters for these ions within the widely used AMBER ff14SB force field for proteins and found that they perform poorly. We propose new parameters, which reproduce solution activity derivatives of potassium acetate solutions up to 2 mol/kg and the distances between potassium ions and carboxylate groups observed in x-ray structures of proteins. To understand the role of acidic amino acids in protein hydration, we investigated this aspect for 5 halophilic proteins in comparison with 5 mesophilic ones. Our results do not support the necessity of acidic amino acids to keep folded proteins hydrated. Proteins with a larger fraction of acidic amino acids indeed have higher hydration levels. However, the hydration level of each protein is identical at low (b_KCl = 0.15 mol/kg) and high (b_KCl = 2 mol/kg) KCl concentration. It has also been proposed that cooperative interactions between acidic amino acids with nearby hydrated cations stabilize the folded protein and slow down its solvation shell; according to this theory, the cations would be preferentially excluded from the unfolded structure. We investigate this possibility through extensive free energy calculation simulations. We find that cooperative interactions between neighboring acidic amino acids exist and are mediated by the ions in solution but are present in both folded and unfolded structures of halophilic proteins. The translational dynamics of the solvation shell is barely distinguishable between halophilic and mesophilic proteins; therefore, such a cooperative effect does not result in unusually slow solvent dynamics as has been suggested

Proteins maintain hydration at high [KCl] concentration regardless of content in acidic amino acids

Proteins of halophilic organisms, which accumulate molar concentrations of KCl in their cytoplasm, have a much higher content in acidic amino acids than proteins of mesophilic organisms. It has been proposed that this excess is necessary to maintain proteins hydrated in an environment with low water activity, either via direct interactions between water and the carboxylate groups of acidic amino acids or via cooperative interactions between acidic amino acids and hydrated cations. Our simulation study of five halophilic proteins and five mesophilic counterparts does not support either possibility. The simulations use the AMBER ff14SB force field with newly optimized Lennard-Jones parameters for the interactions between carboxylate groups and potassium ions. We find that proteins with a larger fraction of acidic amino acids indeed have higher hydration levels, as measured by the concentration of water in their hydration shell and the number of water/protein hydrogen bonds. However, the hydration level of each protein is identical at low (bKCl = 0.15 mol/kg) and high (bKCl = 2 mol/kg) KCl concentrations; excess acidic amino acids are clearly not necessary to maintain proteins hydrated at high salt concentration. It has also been proposed that cooperative interactions between acidic amino acids in halophilic proteins and hydrated cations stabilize the folded protein structure and would lead to slower dynamics of the solvation shell. We find that the translational dynamics of the solvation shell is barely distinguishable between halophilic and mesophilic proteins; if such a cooperative effect exists, it does not have that entropic signature

High-throughput Fabrication of Drug-loaded Core-shell Tablets with Adjustable Release Profiles from Surface-erodible and Photocrosslinkable Polyanhydrides

Controlled-release tablets enhance the effectiveness of therapies for various clinical conditions. Photocrosslinkable polyanhydrides that undergo surface erosion were recently introduced as suitable materials for manufacturing tablets with tunable release profiles. However, their erosion behavior has not been comprehensively studied. In this thesis, the erosion kinetics of photocrosslinkable polyanhydrides was studied by exploring the impact of different parameters (the polymer composition and geometry, as well as the temperature, pH, and shaking rate of the solution during the in vitro experiments) on their mass loss profiles, followed by a release kinetic model fitting. The results indicate that the temperature was the only parameter that could affect the induction period (the lag time) substantially. Moreover, polymers with the same surface area to volume ratios showed similar mass loss percentage despite their dissimilar volumes and surface areas. Although tablets with adjustable release profiles have been studied before, lack of a fast and large-scale production technique is a significant limitation that holds back their widespread application. A high-throughput fabrication platform was developed that was then utilized to manufacture controlled-release polyanhydride tablets. Tunable release profiles with the high-throughput fabricated tablets were achieved

General health, economic status, and marriage duration as predictors of marital commitment during reproductive age among Iranian married women

Background: One of the important factors involved in a successful marriage during reproductive age is marital commitment. The aim of this study was to find which factors predict marital commitment during reproductive age in Iranian married women. Methods: This cross-sectional, population-based study was performed on married women. Adams and Jones' Dimensions of Commitment Inventory (DCI) were used to assess marital commitment. In addition, their current mental health was assessed using General Health Questionnaire (GHQ). The socioeconomic status of the participants was calculated based on household income, employment status, and education level. A total of 160 married women, who were between 15-49 years of age and were from six districts of Babol, were selected using a systematic random sampling method. Stepwise multiple regressions were used to determine the effect of independent variables on marital commitment. Results: The results of multiple regression showed that general health, the duration of marriage, and the economic status with standard beta coefficients of (-0.324), (-0.259), and (0.173) had the highest regression effect on marital commitment, respectively. These variables accounted for a total of 33% of the distribution of marital commitment. Conclusion: These findings suggest that general health, economic status, and the duration of marriage are predicable variables for marital commitment. It is necessary to emphasize the benefit of improving general health and economic status in increasing the degree of marital commitment, especially among women with longer duration of marriage

Prevalence of Sick Building Syndrome (SBS) among Students and Teachers of Guidance Schools in Babol, Winter 2018

Background: It is important to determine the prevalence of Sick Building Syndrome (SBS) symptoms in school students and teachers, which is relevant to the physical environment of the building. The aim of this study was to determine the prevalence of sick building syndrome in students and teachers of guidance schools in Babol. Methods: This descriptive and analytical cross-sectional study was carried out in 15 guidance schools in Babol in the winter of 2018, among 150 students and 95 teachers. The MM040EA (Miljomedicine040) questionnaire was used to collect data and was completed by interview. Data were analyzed using Chi-square test. Results: Among the 12 symptoms of SBS, 50.7% of students had fatigue, and 44.7% had headaches. There was a significant correlation between heavy headedness (p = 0.42) and headache (p = 0.029) with students’ gender. There was a significant correlation between the teachers’ gender with the redness or dryness of facial skin (p = 0.015), redness or itching of hands (p = 0.009) and also fatigue (p = 0.003). There was a significant correlation between the symptoms of the SBS with very high temperature in the students (p = 0.050), and with the noises (p = 0.40) in the teachers. Conclusion: The present study showed that more than half of the students and teachers had symptoms of SBS. Since the symptoms of SBS are associated with some physical conditions of the classroom and school environment, the health condition of the schools should be annually checked for all aspects

Cytomegalovirus infection and risk of preeclampsia: A meta-analysis of observational studies

Background: Cytomegalovirus (CMV) infection is one of the most common infectious diseases in pregnant women in terms of global impact and is related with many adverse health consequences during pregnancy. For the first time, we performed a systematic review and meta-analysis study to evaluate the possible association between CMV infection and preeclampsia (PE). Methods: A comprehensive literature search to identify the relevant papers published earlier than February 2018 was performed in PubMed, ISI (Web of Science), Google Scholar and SCOPUS databases. We followed the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines for design, analysis and interpretation of results. Pooled odds ratio (OR) and 95% confidence intervals (CI) were estimated using a random-effects meta-analysis model. Heterogeneity was assessed with Q-test and I2 statistics. Results: A total of 13 studies including 6158 pregnant women (2734 women with PE and 3424 healthy controls) met the eligibility criteria. The results of meta-analyses based on PCR (OR: 3.09; 95% CI:0.72–13.24; I2=57.3%), IgG-ELISA (OR: 1.24; 95% CI:0.83–1.85; I2=71%) and IgM-ELISA (OR: 1.04; 95% CI:0.66–1.65; I2=0.0%) demonstrated that CMV infection could not be a potential risk factor for PE. Conclusions: In conclusion, results of the present study demonstrated that CMV infection could not be a potential risk for developing PE. More epidemiological and experimental studies are needed to investigate the impact of CMV infection on the development of PE