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Comparative Analysis: Trays versus Packed Columns in Pressure-Swing Distillation for the Separation of Tetrahydrofuran, Water and Ethanol Azeotropic Mixture

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World Journal of Engineering and Technology 2024年第3期12卷 798-819页

作者： Samuel Oluwaseun Ogunrinde Tolulope daniel Adekoya Thomas A. Orhadahwe Department of Mechanical Engineering Faculty of Engineering Ajayi Crowther University Oyo Nigeria AstraZeneca Boston Massachusetts USA

This paper delves into the comparative study of tray and packed column pressure swing distillation systems, focusing on the separation of a ternary mixture containing ethanol, tetrahydrofuran (THF), and water. The study particularly emphasizes the production of 99.5 w/w% tetrahydrofuran from the downstream product of 1,4-butanediol synthesis via diethyl maleate. Pro/II simulation software is utilized to explore various system configurations, including sieve trays, valve trays, and packed columns. Material and energy balances are performed to ascertain stream compositions and energy demands. The investigation encompasses the effects of column operating pressure on condenser and reboiler temperatures, as well as the implications of utility streams. A rigorous distillation model is employed to compare valve tray, sieve tray, and random packing (utilizing Norton Super Intalox) column designs by varying the number of trays, reflux ratio, and second distillation column pressure. Heat exchangers are integrated into the model, and their areas and utility flow rates are computed and integrated into the economic assessment. Economic analysis, guided by Net Present Value (NPV) calculations over a 20-year span, drives the selection of the most cost-effective design. Results demonstrate that while all designs are energy-efficient, the packed column system emerges as the most economical choice, offering a comprehensive framework for the separation process. Furthermore, optimal design configurations and operating conditions for both tray and packed column systems are outlined, providing valuable insights for industrial applications.

关键词： Azetrope Tetrahydrofuran Ethanol Pressure-Swing Distillation Simulation

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基于小波分析的地磁甚低频脉动指数及其在高磁纬度地区甚低频脉动共轭对比研究中的应用

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极地研究 2024年第1期36卷 37-51页

作者：徐中华 CRobert Clauer Michael DHartinger Hyomin Kim daniel R Weimer 美国弗吉尼亚理工大学弗吉尼亚州黑堡24061 美国科罗拉多州博多尔市空间科学研究所科罗拉多州博多尔69122 美国新泽西理工学院日地研究中心新泽西州纽瓦克07102

地磁甚低频脉动是甚低频磁流体波在磁层中传播的地面表现,开发近实时空间天气产品来监测这些地磁脉动至关重要。本文基于小波分析提出一种地磁甚低频脉动指数,并将其应用于研究在南极洲及西格陵兰岛的磁共轭位置观测到的地磁甚低频脉动... 详细信息

地磁甚低频脉动是甚低频磁流体波在磁层中传播的地面表现,开发近实时空间天气产品来监测这些地磁脉动至关重要。本文基于小波分析提出一种地磁甚低频脉动指数,并将其应用于研究在南极洲及西格陵兰岛的磁共轭位置观测到的地磁甚低频脉动。研究结果表明,(1)该指数可有效识别Pc4—Pc5频率范围内的脉动事件(包括瞬态事件),并获得甚低频脉动在时域和频域的重要特征。(2)基于共轭位置地磁脉动的小波分析比较揭示了冬至日、夏至日条件下南北半球甚低频脉动的相似性和差异。本研究也表明,南北半球磁共轭位置观测到地磁脉动存在的差异受到行星际磁场条件、磁场拓扑、观测磁纬度和日照等条件影响,需要进一步研究案例中实际磁层和电离层配置以及驱动条件。

关键词：地磁扰动地磁甚低频脉动地磁共轭

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Sustaining forest biodiversity:Exploring the effect of long-term natural disturbance dynamics on contemporary lichen communities in primary forest ecosystems

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Forest Ecosystems 2024年第4期11卷 556-567页

作者： Rhiannon Gloor Marek Svitok Martin Mikolas Jenyk Hofmeister Josef Halda Pavel Janda Francesco Maria Sabatini Lucie Zemanova Arne Buechling daniel Kozak Matej Ferencik Michal Frankovic Martin Dusatko Miroslav Svoboda Department of Forest Ecology Faculty of Forestry and Wood SciencesCzech University of Life Sciences PragueKamycka 129Praha 6–Suchdol16500Czech Republic Faculty of Ecology and Environmental Sciences Technical University in ZvolenT.G.Masaryka 2496001ZvolenSlovakia Institute of Botany Plant Science and Biodiversity CenterSlovak Academy of SciencesDúbravska cesta 984523BratislavaSlovakia PRALES Odtrnovie 56301322RosinaSlovakia Faculty of Science University of Hradec KraloveHradecka 1285Hradec KraloveⅢ50003Czech Republic BIOME–Biogeography and Macroecology Department of BiologicalGeological and Environmental Sciences(BIGEA)Alma Mater Studiorum-University of Bolognavia Irnerio 42BolognaItaly

In this era of biodiversity loss and climate change,quantifying the impacts of natural disturbance on forest communities is imperative to improve biodiversity conservation *** and epixylic lichens are effective forest quality bioindicators,as they are generally long-lived organisms supported by continuity of specific forest structures and their associated microclimatic ***,how lichen communities respond to the effects of fluctuating historical disturbances remains *** a dendrochronological approach,this study investigates how natural disturbance dynamics indirectly influence various lichen community metrics in some of Europe's best-preserved primary mixed-beech *** modelling revealed that natural historical disturbance processes have decades-long effects on forest structural attributes,which had both congruent and divergent impacts on lichen community richness and *** species richness indirectly benefited from both historical and recent higher-severity disturbances via increased standing dead tree basal area and canopy openness respectively-likely through the presence of both pioneer and late-successional species associated with these ***-listed species richness showed a dependence on habitat continuity(old trees),and increased with disturbance-related structures(standing dead trees)whilst simultaneously benefiting from periods without severe disturbance events(old trees and reduced deadwood volume).However,if the disturbance occurred over a century in the past,no substantial effect on forest structure was ***,while disturbance-mediated forest structures can promote overall richness,threatened species appear vulnerable to more severe disturbance events-a concern,as disturbances are predicted to intensify with climate ***,the high number of threatened species found reinforce the critical role of primary forest structural attributes for biodiversity ***

关键词： Mixed-beech forests Species richness Old-growth forests Carpathian mountains Biodiversity conservation Dendroecology Fagus sylvatica

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Complement-dependent neuroinflammation in spinal cord injury:from pathology to therapeutic implications

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Neural Regeneration Research 2025年第5期20卷 1324-1335页

作者： Hassan Saad Bachar El Baba Ali Tfaily Firas Kobeissy Juanmarco Gutierrez Gonzalez daniel Refai Gerald R.Rodts Christian Mustroph David Gimbel Jonathan Grossberg daniel L.Barrow Matthew F.Gary Ali M.Alawieh Department of Neurosurgery Emory University School of MedicineAtlantaGAUSA Department of Neurology Yale UniversityNew HavenCTUSA Center for Neurotrauma Multiomics&Biomarkers(CNMB)Morehouse School of MedicineAtlantaGAUSA

Spinal cord injury remains a major cause of disability in young adults,and beyond acute decompression and rehabilitation,there are no pharmacological treatments to limit the progression of injury and optimize recovery in this *** the thorough investigation of the complement system in triggering and propagating cerebral neuroinflammation,a similar role for complement in spinal neuroinflammation is a focus of ongoing *** this work,we survey the current literature investigating the role of complement in spinal cord injury including the sources of complement proteins,triggers of complement activation,and role of effector functions in the *** study relevant data demonstrating the different triggers of complement activation after spinal cord injury including direct binding to cellular debris,and or activation via antibody binding to damage-associated molecular *** effector functions of complement have been implicated in spinal cord injury,and we critically evaluate recent studies on the dual role of complement anaphylatoxins in spinal cord injury while emphasizing the lack of pathophysiological understanding of the role of opsonins in spinal cord *** this pathophysiological review,we systematically review the different translational approaches used in preclinical models of spinal cord injury and discuss the challenges for future translation into human *** review emphasizes the need for future studies to dissect the roles of different complement pathways in the pathology of spinal cord injury,to evaluate the phases of involvement of opsonins and anaphylatoxins,and to study the role of complement in white matter degeneration and regeneration using translational strategies to supplement genetic models.

关键词： complement neuroinflammation neuroplasticity regeneration spinal cord injury targeted therapy

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Measuring Causal Effect with ARDL-BART: A Macroeconomic Application

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Applied Mathematics 2024年第4期15卷 292-312页

作者： Pegah Mahdavi Mohammad Ali Ehsani daniel Felix Ahelegbey Mehrnaz Mohammadpour Department of Economic and Administrative Sciences University of Mazandaran Babolsar Iran Department of Economics and Management Sciences University of Pavia Pavia Italy Department of Mathematical Sciences University of Mazandaran Babolsar Iran

Modeling dynamic systems with linear parametric models usually suffer limitation which affects forecasting performance and policy implications. This paper advances a non-parametric autoregressive distributed lag model that employs a Bayesian additive regression tree (BART). The performance of the BART model is compared with selection models like Lasso, Elastic Net, and Bayesian networks in simulation experiments with linear and non-linear data generating processes (DGP), and on US macroeconomic time series data. The results show that the BART model is quite competitive against the linear parametric methods when the DGP is linear, and outperforms the competing methods when the DGP is non-linear. The empirical results suggest that the BART estimators are generally more efficient than the traditional linear methods when modeling and forecasting macroeconomic time series.

关键词： BART Model Non Parametric Modeling Machine Learning Regression Trees Bayesian Network VAR

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Assessment of Dose and Lifetime Risk of Exposure Induced Cancer in Adult Common Computed Tomography Scans in Douala-Cameroon

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Open Journal of Radiology 2024年第3期14卷 135-146页

作者： Celestin Mpeke Mokubangele Alexandre Ngwa Ebongue daniel Bongue Boniface Moifo Centre for Atomic Molecular Physics and Quantum Optics (CEPAMOQ) University of Douala Douala Cameroon Department of Physics Faculty of Science University of Douala Douala Cameroon Department of Radiology and Radiation Oncology Faculty of Medicine and Biomedical Sciences University of Yaounde 1 Yaounde Cameroon Radiology Department Yaounde Gynaeco-Obstetric and Pediatric Hospital Yaounde Cameroon

Background: Among medical technologies that use ionizing radiation, CT is currently the radio diagnostic technic that can deliver the highest radiation to the Patient compared with other conventional procedures. In developing countries, the uses and risks of CT have not been well characterized. Objective: To estimate the lifetime attributable risk (LAR) incidence and mortality for cancer for each procedure for adult’s patients who had Computed Tomography examinations in 10 imaging centers in the city of Douala-Cameroon so as to provide a reference data. Materials and Methods: We conducted a cross-sectional study describing radiation dose associated with the 8 most common types of diagnostic CT studies performed on 1287 consecutive adult patients at 10 Douala radiology department. We estimated lifetime attributable risks of cancer by study type from these measured doses. Estimation of LAR for cancer incidence and mortality was based on the effective dose, patient’s sex and age at exposure using the BIER VII preferred models. Results: Mean effective dose from CT scans examinations varied from: 0.30 and 8.81 mSv. The highest doses were observed for lumbar spine CT (8.81 mSv), followed by abdomen-pelvis procedure (6.46 mSv), chest-abdomen-pelvic CT (6.61 mSv), chest CT (3.90 mSv), cervical Spine CT (3.05 mSv), head CT (1.7 mSv) and lower for sinus CT (0.30 mSv). The LAR values of all cancer from patients’ CT scans obtained vary from 67.13 excess per 100,000 (about 1 in 1489) and 0.45 excess per 100,000 (about 1 in 222,222). All cancer risk was high for lumbar spine CT in women 20 years old (67.13 excess deaths in 100,000 scans) followed by chest-abdomen-pelvic CT (50.36 excess deaths in 100,000 scans) and abdomen-pelvic CT (49.22 excess deaths in 100,000 scans) for the same age group. The LAR of incidence and mortality values were higher from female’s patients than males and higher for younger than older patients. Conclusion: This study was set out to estimate the LAR v

关键词： Patient Dose CT Scan BEIIR VII Report Cancer Risk Assessment

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Non-Darcy Flow in Molding Sands

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Open Journal of Applied Sciences 2024年第4期14卷 976-982页

作者： Miguel A. Barron-Meza Joan Reyes-Miranda daniel Flores-Sanchez Departamento de Materiales Universidad Autonoma Metropolitana Azcapotzalco Ciudad de Mexico Mexico

Darcy’s law is widely used to describe the flow in porous media in which there is a linear relationship between fluid velocity and pressure gradient. However, it has been found that for high numbers of Reynolds this law ceases to be valid. In this work, the Ergun equation is employed to consider the non-linearity of air velocity with the pressure gradient in casting sands. The contribution of non-linearity to the total flow in terms of a variable defined as a non-Darcy flow fraction is numerically quantified. In addition, the influence of the shape factor of the sand grains on the non-linear flow fraction is analyzed. It is found that for values of the Reynolds number less or equal than 1, the contribution of non-linearity for spherical particles is around 1.15%.

关键词： Darcy’s Law Molding Sands Non-Darcy Flow Reynolds Number Shape Factor

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Neurotoxicity of tetramethylammonium ion on larval and juvenile zebrafish:Effects on neurobehaviors and multiple biomarkers

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Journal of Environmental Sciences 2024年第9期143卷 138-147页

作者： Ruixin Zhang Rui Wang Jiajun Chang Gdaniel Sheng Daqiang Yin Key Laboratory of Yangtze River Water Environment Ministry of EducationCollege of Environmental Science and EngineeringTongji UniversityShanghai 200092China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China

Tetramethylammonium hydroxide(TMAH)is an important compound that utilized and released by the rapidly expanding semiconductor industry,which could hardly be removed by the conventional wastewater treatment *** a cholinergic agonist,the tetramethylammonium ion(TMA^(+))has been reported to induce toxicity to muscular and respiratory systems of mammals and human,however the toxicity on aquatic biota remains poorly *** investigated the neurotoxic effects of TMA^(+)exposure on zebrafish,based on neurobehavior tests and a series of *** inhibitions on the swimming distance of zebrafish larvae were observed when the exposure level exceeded 50 mg/L,and significant alterations on swimming path angles(straight and deflective movements)occurred even at 10 mg/*** tested neurobehavioral endpoints of zebrafish larvae were significantly positively correlated with reactive oxygen species(ROS)and malondialdehyde(MDA),significantly negatively related with the activities of antioxidant enzymes,but not significantly correlated with the level of acetylcholinesterase(AChE).Such relationship indicates that the observed neurotoxic effects on swimming behavior of zebrafish larvae is mainly driven by oxidative stress,rather than the alterations of *** the highest exposure concentration(200 mg/L),TMA^(+)evoked more severe toxicity on zebrafish juveniles,showing significantly stronger elevation on the MDA activity,and greater inhibitions on the activities of antioxidant enzymes and ACh E,suggesting juveniles were more susceptible to TMA^(+)exposure than larval zebrafish.

关键词： Tetramethylammonium Zebrafish Oxidative stress Acetylcholinesterase Neurobehavior

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Study of the Management and Disposal Practices of Unused or Out-of-Date Medicines by Households in the Municipality of Ouagadougou, Burkina Faso

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Journal of Biosciences and Medicines 2024年第3期12卷 291-302页

作者： daniel Dori Adama Guembré Kampadilemba Ouoba Nicolas Méda Rasmané Semdé Drug Development Laboratory African Center of Excellence for Training Research and Expertise in Pharmaceutical Sciences (CEA-CFOREM) Sciences and Health Doctoral School Training and Research Unit in Health Sciences Joseph KI-ZERBO University Ouagadougou Burkina Faso Charles De Gaulle University Children's Hospital (CHUP-CDG) Ouagadougou Burkina Faso National Agency for Pharmaceutical Regulation (ANRP) Ministry of Health Ouagadougou Burkina Faso Public Health Laboratory Sciences and Health Doctoral School Joseph KI-ZERBO University Ouagadougou Burkina Faso

Introduction: Not all medicines that pass-through consumers’ hands are used, and some often expire in households. These health products can be sources of accidental risks and pollution when they are not properly disposed of. In Burkina Faso, there are as yet no guidelines for the disposal of unused medicines in households. The aim of this study was to estimate the extent of household possession of unused or expired medicines, and to describe attitudes and disposal practices. Methods: This was a descriptive cross-sectional study covering households in the Ouagadougou commune conducted from June to August 2021. Two-stage stratified sampling was used: selection of Enumeration Zones (EZs) and selection of households, with each EZ comprising several households. Data collection was based on direct interviews using a structured questionnaire. Data were processed using Epi Info software version 7.***.4.0. Results: In total, 417 household residents were surveyed out of the planned 423 households, corresponding to a completion rate of 98.58% compared with the initial sample. Among the respondents, 79.62% had unused and/or expired medicines in their household. A total of 2562 drug packaging units were counted, for a total weight of 121.90 kg. Nearly 75% were aware that improper disposal was a danger to the environment. Some respondents kept their unused medicines at home until they expired (43.41%), and disposed of them mainly by throwing them in the household garbage (75.58%). The majority (79%) were in favor of the government setting up a take-back program for these medicines. Conclusion: The introduction of a take-back program for unused or out-of-date medicines will ensure safer disposal of medicines, and better protection for households and the environment.

关键词： Unused Medicines Expired Medicines Disposal Household Risk

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Liver transplantation as an alternative for the treatment of perihilar cholangiocarcinoma: A critical review

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Hepatobiliary & Pancreatic Diseases International 2024年第2期23卷 139-145页

作者： Wellington Andraus Francisco Tustumi Alexandre Chagas Santana Rafael Soares Nunes Pinheiro daniel Reis Waisberg Liliana Ducatti Lopes Rubens Macedo Arantes Vinicius Rocha Santos Rodrigo Bronze de Martino Luiz Augusto Carneiro D’Albuquerque Department of Gastroenterology Transplantation UnitUniversidade de São PauloSão PauloBrazil

Background:Perihilar cholangiocarcinoma(phCCC)is a dismal *** is no consensus regard-ing the best treatment for patients with unresectable *** present review aimed to gather the current pieces of evidence for liver transplantation and liver resection as a treatment for phCCC and to build better guidance for clinical *** sources:The search was conducted in PubMed,Embase,Cochrane,and *** related references were searched *** criteria were:reports in English or Portuguese literature that a)patients with confirmed diagnosis of phCCC;b)patients treated with a curative intent;c)patients with the outcomes of liver resection and liver *** reports,reviews,letters,editorials,conference abstracts and papers with full-text unavailability were excluded from the ***:Most of the current literature is based on observational retrospective studies with low grades of *** resection has better long-term outcomes than systemic chemotherapy or palliation ther-apy and liver transplantation is a good alternative for selected patients with unresectable *** candidates for resection or transplantation should be medically fit and free of intrahepatic or extrahep-atic *** a general rule,patients presenting with a tumor having a longitudinal size>3 cm or extending below the cystic duct,lymph node disease,confirmed extrahepatic dissemination;intraoper-atively diagnosed metastatic disease;a history of other malignancies within the last five years,and did not complete chemoradiation regimen and were medically unfit should not be considered for *** of these criteria should be individually *** transplantation or resection should only be considered in highly experienced hepatobiliary centers,and any decision-making must be based on a multidisciplinary ***:phCCC is a complex condition with high *** therapies,including hepatec-tomy and liv

关键词： Liver transplantation Cholangiocarcinoma Liver neoplasms

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