4,025 research outputs found
Techno-economic analysis of levoglucosan production via fast pyrolysis of cotton straw in China
No full textPyrolysis of cotton straw is a promising technology because of the large variety of chemical species that can be produced. A more promising chemical-levoglucosan, is the subject of this study. The techno-economic feasibility of producing levoglucosan via fast pyrolysis and extraction was evaluated by modeling a 200,000 dry ton cotton straw/year facility. Experimental and modeling data were gathered from recent publications and used for analysis. For the modeled feedstock handling capacity, the results indicated that levoglucosan production could reach around 18,000 ton/year. The estimated levoglucosan production cost, including byproduct credits, was $3.3 per kg. Additionally, sensitivity analysis was performed to determine the effect of variability in different system parameters on the levoglucosan production cost
Upgrading effluent from anaerobic digestion of dairy manure through hydrothermal carbonization
No full textThe coupling of hydrothermal carbonization (HTC) and anaerobic digestion (AD) is investigated in this paper. Effluent from AD of dairy manure was collected as feedstock for the HTC process. Three parameters, temperature, reaction time and pH, were investigated. Central composite design (CCD) and response surface methodology (RSM) were applied for the optimization of hydrochar production. Mass balance was performed for the HTC process. The results showed that temperature was the most significant parameter for hydrochar production. With the increase of temperature and time, the energy and mass yields of hydrochar decreased, while the high heating value (HHV) increased. Optimization models set up for hydrochar production showed that 260oC, 70 min with AD effluent of pH 6 was the best option. Hydrochar with HHV of about 20.18 MJ/kg could be achieved with mass and energy yields of 49.09% and 62.99%, respectively. Chemical oxygen demand (COD) of resulting HTC process water was analyzed. More than 30% COD remained in the liquid, which showed that HTC processed water could have a potential to be recirculated back to the AD system. HTC of the AD effluent could greatly reduce odor issues caused by AD processes, and the hydrochar had good dewatering and drying properties. Consequently, integrating HTC after AD promises to be a way to deal with various wastes in an environmental friendly way
sj-docx-1-cvd-10.1177_20480040211059374 - Supplemental material for Cardiovascular health and risk of hospitalization with COVID-19: A Mendelian Randomization study
No full textSupplemental material, sj-docx-1-cvd-10.1177_20480040211059374 for Cardiovascular health and risk of hospitalization with COVID-19: A Mendelian Randomization study by Marina Cecelja, Cathryn M. Lewis and
Ajay M. Shah, Phil Chowienczyk in JRSM Cardiovascular Disease</p
Exports, Foreign Direct Investments and Productivity: Are Services Firms different?
No full textThis paper contributes to the literature on international firm activities and firm performance by providing the first evidence on the link of productivity and both exports and foreign direct investment (fdi) in services firms from a highly developed country. It uses unique new data from Germany - one of the leading actors on the world market for services - that merge information from regular surveys and from a one-time special purpose survey performed by the Statistical Offices. Descriptive statistics, parametric and non-parametric statistical tests and regression analyses (with and without explicitly taking differences along the conditional productivity distribution and firms with extreme values, or outliers, into account) indicate that the productivity pecking order found in numerous studies using data for firms from manufacturing industries – where the firms with the highest productivity engage in fdi while the least productive firms serve the home market only and the productivity of exporting firms is in between – does not exist among firms from services industries. In line with the theoretical model and the empirical results for software firms from India provided by Bhattacharya, Patnaik and Shah (2010) there is evidence that firms with fdi are less productive than firms that export.Exports, foreign direct investments, productivity, services firms
Rain or shine? Forecasting search process performance in exploratory search tasks
No full textMost information retrieval (IR) systems consider relevance, usefulness, and quality of information objects (documents, queries) for evaluation, prediction, and recommendation, often ignoring the underlying search process of information seeking. This may leave out opportunities for making recommendations that analyze the search process and/or recommend alternative search process instead of objects. To overcome this limitation, we investigated whether by analyzing a searcher’s current processes we could forecast his likelihood of achieving a certain level of success with respect to search performance in the future. We propose a machine-learning-based method to dynamically evaluate and predict search performance several time-steps ahead at each given time point of the search process during an exploratory search task. Our prediction method uses a collection of features extracted from expression of information need and coverage of information. For testing, we used log data collected from 4 user studies that included 216 users (96 individuals and 60 pairs). Our results show 80–90% accuracy in prediction depending on the number of time-steps ahead. In effect, the work reported here provides a framework for evaluating search processes during exploratory search tasks and predicting search performance. Importantly, the proposed approach is based on user processes and is independent of any IR system.This is the peer reviewed version of the following article: Shah, C., Hendahewa, C. and González-Ibáñez, R. (2015), Rain or shine? Forecasting search process performance in exploratory search tasks. Journal of the Association for Information Science and Technology, which has been published in final form at https://dx.doi.org/10.1002/asi.23484. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.Peer reviewe
Fungal pretreatment of miscanthus for fermentable sugar production: experimental and techno-economic evaluation
No full textLignocellulosic biomass is an abundant, renewable feedstock for biorefineries, but pretreatment is usually required to overcome its high recalcitrance to biodegradation. Fungal pretreatment, an alternative process to traditional pretreatments, can enhance the enzymatic digestibility of the lignocellulosic biomass. Fungal pretreatment can be performed at low temperature, without added chemicals, and no wastewater generation. However, in comparison with traditional pretreatments, longer residence times, lower yields, and feedstock sterilization requirements make it challenging to implement. This work investigated the fungal pretreatment of the dedicated energy crop Miscanthus × giganteus with the white rot fungus Ceriporiopsis subvermispora. Fungal pretreatment of non-sterile miscanthus was performed in batch using miscanthus previously colonized with the fungus as inoculum. The process enhanced the enzymatic digestibility of miscanthus by 2-fold over that of untreated miscanthus, and was comparable to the pretreatment of sterilized miscanthus inoculated with a pure culture of the white rot fungus. The finished material from the unsterilized pretreatment was used as inoculum for two more generations in a sequential fungal pretreatment process, where no increase in enzymatic digestibility was observed. A propagation of indigenous fungi that out-colonized C. subvermispora was observed through the generations, showing that sterilization is a required step for the stability and reproducibility of fungal pretreatment. A techno-economic analysis of the production of fermentable sugars from miscanthus using fungal pretreatment showed that the process was not feasible at full biorefinery scale due to the high capital cost caused by long residence time, low feedstock bulk density, and low sugar yields
Response by Sag et al to Letter Regarding Article, “Distinct Regulatory Effects of Myeloid Cell and Endothelial Cell NAPDH Oxidase 2 on Blood Pressure”
No full textSupplemental Material, sj-pdf-1-ojs-10.1177_23259671231161293 - Assessment of 30 Years of Randomized Controlled Trials in <i>The American Journal of Sports Medicine:</i> 1990-2020
No full textSupplemental Material, sj-pdf-1-ojs-10.1177_23259671231161293 for Assessment of 30 Years of Randomized Controlled Trials in The American Journal of Sports Medicine: 1990-2020 by Ajay Shah, Graeme Hoit, Lucy Lan and Daniel B. Whelan in Orthopaedic Journal of Sports Medicine</p
Data for: Comparative study of changes in composition and structure during sequential fungal pretreatment of non-sterile lignocellulosic feedstocks
No full textAppendixComparative study of changes in composition and structure during sequential fungal pretreatment of non-sterile lignocellulosic feedstocks: supplementary materia
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