检索结果-南通市图书馆

Mechanical and natural ventilation systems in a greenhouse designed using computational fluid dynamics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2014年第1期7卷 1-16页

作者： Jorge flores-Velazquez Juan I.Montero Esteban J.Baeza Juan C.Lopez Mexican Institute of Water Technology.Paseo Cuauhnáhuac 8532 Col.ProgresoC.P.62550JiutepecMor.Mexico Institut de Recerca i Tecnologia Agroalimentàries 08348Cabrils(Barcelona)Spain IFAPA Centro La Mojonera(Junta de Andalucía) Camino San Nicolás 104745 La MojoneraAlmeríaSpain Fundación Cajamar.Estación Experimental“Las Palmerillas”Autovía del Mediterráneo Km 416 704710El EjidoAlmeríaSpain

The aim of this study was to analyse air exchange and temperature distribution in a greenhouse with combined mechanical and natural ventilation and to design more efficient mechanical ventilation *** this purpose,a computational fluid dynamics(CFD)model of the greenhouse was *** configurations were considered:Configuration 1(mechanical ventilation and closed roof ventilators),Configurations 2 and 3(mechanical ventilation and roof ventilators open 30%and 100%,respectively).After validation,the CFD model was used to improve the design of the greenhouse mechanical ventilation system in each of the three configurations *** greenhouse lengths,28 m,50 m,75 m and 100 m,were used in the *** to fan ventilation only,roof ventilation improved the climate of fan-ventilated greenhouses in terms of the air exchange rate(22%)and climate uniformity because the internal air was mixed better than with mechanical ventilation *** the greenhouse length increased,more advantages were achieved with natural ventilation compared to mechanical *** most configurations,there was a strong linear correlation between temperature gradient and greenhouse *** greenhouse whose regression line had the steepest slope was the one with closed roof *** the fan capacity produced a general reduction in temperature,but the effect was less intense for the greenhouses with open roof *** to box inlet ventilators,an enlarged continuous inlet in the wall opposite the fans increased overall system performance because it eliminated backflow recirculation zones,which are prone to produce high temperatures.

关键词： greenhouse cooling fan ventilation roof ventilators combined ventilation

Comparative study on simultaneous removal of calcium and sulfate ions from flotation recycling water by aluminum hydroxide

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2022年第7期32卷 2379-2390页

作者： Ángel Daniel GUERRERO-flores Martha Araceli ELIZONDO-ÁLVAREZ JoséManuel flores-ÁLVAREZ Alejandro URIBE-SALAS Department of Metallurgical Engineering CINVESTAV-IPNUnidad Saltillo25900Ramos ArizpeCoahuilaMéxico Department of Materials Unidad Académica de Ingeniería IUniversidad Autónoma de Zacatecas“Francisco García Salinas”ZacatecasZacatecasMéxico Facultad de Ciencias Químicas Universidad de ColimaCoquimatlánColimaMéxico

Due to the environmental policies and economic reasons,the water used in some flotation operations of complex sulfide ores is recirculated,causing the ion concentration of some species to increase over time,affecting the flotation of the minerals of *** this work,an experimental and thermodynamic analysis of the synthetic solutions was presented with a high content of calcium and sulfate *** study focused on evaluating the use of two aluminum compounds for the precipitation of Ca^(2+)and SO_(4)^(2−)in the form of *** amorphous aluminum hydroxide was found to be more efficient than the crystalline one,giving rise to 83%calcium and 91%sulfate *** XRD analysis of the solids showed the main reaction product of ettringite,accompanied by small amounts of calcite,due to the absorption of atmospheric carbon *** final solution after the chemical treatment showed residual calcium and sulfate concentrations below 200 mg/***,the kinetics of calcium removal appeared to correspond to a second order reaction with respect to calcium concentration,with an apparent activation energy of 53.48 kJ/mol,which may suggest that the ettringite precipitation process is governed by the chemical reaction.

关键词： ettringite ion removal aluminum hydroxide calcium sulfate

Synthesis of surface controlled nickel/palladium hydride nanodendrites with high performance in benzyl alcohol oxidation

在线全文

学校读者我要写书评

暂无评论

Nano Research 2019年第6期12卷 1467-1472页

作者： Zipeng Zhao Michelle M.flores Espinosa Jihan Zhou Wang Xue Xiangfeng Duan Jianwei Miao Yu Huang Department of Materials Science and Engineering University of CaliforniaLos AngelesCA 90095USA Department of Physics and Astronomy University of CaliforniaLos AngelesCA 90095USA Department of Chemistry and Biochemistry University of CaliforniaLos AngelesCA 90095USA California Nanosystems Institute University of CaliforniaLos AngelesCA 90095USA

Benzaldehyde byproduct is an imperative intermediate in the production of fine chemicals and *** selectivity to benzaldehyde is therefore critical in alcohol oxidation reactions at the industrial ***,we report a simple but innovative method for the synthesis of palladium hydride and nickel palladium hydride nanodendrites with controllable morphology,high stability,and excellent catalytic *** synthesized dendrites can maintain the palladium hydride phase even after their use in the chosen catalytic ***,the high surface area morphology and unique interaction between nickel-rich surface and palladium hydride (β-phase) of these nanodendrites are translated in an enhanced catalytic activity for benzyl alcohol oxidation *** Ni/PdH0.43 nanodendrites demonstrated a high selectivity towards benzaldehyde of about 92.0% with a conversion rate of 95.4%,showing higher catalytic selectivity than their PdH0.43 counterparts and commercial Pd/*** present study opens the door for further exploration of metal/metal-hydride nanostructures as next-generation catalytic materials.

关键词： benzyl alcohol selectivity benzaldehyde palladium hydride oxidation nanodendrites

Role of vitamin B_(12) on methylmalonyl-CoA mutase activity

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2012年第6期13卷 423-437页

作者： Tóshiko TAKAHASHI-IIGUEZ Enrique GARCíA-HERNANDEZ Roberto ARREGUíN-ESPINOSA María Elena flores Department of Molecular Biology and Biotechnology Institute of Biomedical ResearchNational Autonomous University of MexicoD.F.04510Mexico Department of Chemistry of Biomacromolecules Institute of ChemistryNational Autonomous University of MexicoD.F.04510Mexico

Vitamin B 12 is an organometallic compound with important metabolic derivatives that act as cofactors of certain enzymes,which have been grouped into three subfamilies depending on their *** them,methylmalonyl-CoA mutase (MCM) has been extensively *** enzyme catalyzes the reversible isomerization of L-methylmalonyl-CoA to succinyl-CoA using adenosylcobalamin (AdoCbl) as a cofactor participating in the generation of radicals that allow isomerization of the *** crystal structure of MCM determined in Propionibacterium freudenreichii *** has helped to elucidate the role of this cofactor AdoCbl in the reaction to specify the mechanism by which radicals are generated from the coenzyme and to clarify the interactions between the enzyme,coenzyme,and *** existence of human methylmalonic acidemia (MMA) due to the presence of mutations in MCM shows the importance of its role in *** recent crystallization of the human MCM has shown that despite being similar to the bacterial protein,there are significant differences in the structural organization of the two *** studies have identified the involvement of an accessory protein called MMAA,which interacts with MCM to prevent MCM's inactivation or acts as a chaperone to promote regeneration of inactivated *** interdisciplinary studies using this protein as a model in different organisms have helped to elucidate the mechanism of action of this isomerase,the impact of mutations at a functional level and their repercussion in the development and progression of MMA in *** is still necessary to study the mechanisms involved in more detail using new methods.

关键词： Vitamin B 12 Methylmalonyl-CoA mutase (MCM) MMAA MeaB Methylmalonic academia (MMA) Protectase Reactivase

road to stemness in hepatocellular carcinoma

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2017年第37期23卷 6750-6776页

作者： Teresita NJ flores-Téllez Saúl Villa-Trevino Carolina Pina-Vázquez Departam ento de Biología Celular Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional(CINVESTAV-IPN) Av.IPN No.2508 Col

Carcinogenic process has been proposed to relay on the capacity to induce local tissue damage and proliferative repair. Liver has a great regeneration capacity and currently, most studies point towards the dominant role of hepatocytes in regeneration at all levels of liver damage. The most frequent liver cancer is hepatocellular carcinoma(HCC). Historical findings originally led to the idea that the cell of origin of HCC might be a progenitor cell. However, current linage tracing studies put the progenitor hypothesis of HCC origin into question. In agreement with their dominant role in liver regeneration, mature hepatocytes are emerging as the cell of origin of HCC, although, the specific hepatocyte subpopulation of origin is yet to be determined. The relationship between the cancer cell of origin(CCO) and cancer-propagating cells, known as hepatic cancer stem cell(HCSC) is unknown. It has been challenging to identify the definitive phenotypic marker of HCSC, probably due to the existence of different cancer stem cells(CSC) subpopulations with different functions within HCC. There is a dynamic interconversion among different CSCs, and between CSC and non-CSCs. Because of that, CSC-state is currently defined as a description of a highly adaptable and dynamic intrinsic property of tumor cells, instead of a static subpopulation of a tumor. Altered conditions could trigger the gain of stemness, some of them include: EMT-MET, epigenetics, microenvironment and selective stimulus such as chemotherapy. This CSC heterogeneity and dynamism makes them out reach from therapeutic protocols directed to a single target. A further avenue of research in this line will be to uncover mechanisms that trigger this interconversion of cell populations within tumors and target it.

关键词： Cancer stem cell Liver progenitor cell Liver stem progenitor cell Stemness Plasticity Cancer cell of origin Cancer stem cells subpopulations

Influence of Data Clouds Fusion From 3D RealTime Vision System on Robotic Group Dead Reckoning in Unknown Terrain

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2020年第2期7卷 368-385页

作者： Mykhailo Ivanov Oleg Sergyienko Vera Tyrsa Lars Lindner Wendy flores-Fuentes Julio Cesar Rodriguez-Quinonez Wilmar Hernandez Paolo Mercorelli Universidad Autónoma de Baja California MexicaliB.C.21100Mexico Universidad de Las Américas Quito 170125Equador Leuphana University of Lueneburg Lüneburg 21335Germany

This paper proposes the solution of tasks set required for autonomous robotic group behavior optimization during the mission on a distributed area in a cluttered hazardous *** navigation scheme uses the benefits of the original real-time technical vision system(TVS)based on a dynamic triangulation *** method uses TVS output data with fuzzy logic rules processing for resolution *** on previous researches,the dynamic communication network model is modified to implement the propagation of information with a feedback method for more stable data exchange inside the robotic *** to the comparative analysis of approximation methods,in this paper authors are proposing to use two-steps post-processing path planning aiming to get a smooth and energy-saving *** article provides a wide range of studies and computational experiment results for different scenarios for evaluation of common cloud point influence on robotic motion planning.

关键词： Data transfer group behavior machine vision navigation robotic group(RG) vision system

Growth retardation and severe anemia in children with Trichuris dysenteric syndrome

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Biomedicine 2015年第7期5卷 581-586页

作者： Rina Girard Kaminsky Renato Valenzuela Castillo Coralia Abrego flores Pediatric Department School of Medicine National Autonomous University of Honduras and Service of Parasitology University Hospital Honduras.P.O.Box 1547Tegucigalpa Honduras Pediatric Department School of Medicine National Autonomous University of Honduras Pediatric Psychology Unit University HospitalHonduras

Objective: To document epidemiologic data, clinical manifestations and treatment in hospitalized children with Trichuris dysenteric syndrome from Honduras during 2010-2012. Methods: Severe trichuriasis cases were identified by routine stool examinations from hospitalized patients(12 years old or less). Relevant epidemiologic, clinical and management data were obtained from review of clinical histories in the ward. Results: Of 122 Trichuris infections diagnosed in 11 528(1.0%) stool samples for all ages, 81(66.4%) were identified in the age group 2-12 years old, 21(25.9%) of which were severe(≥ 100 eggs in 2 mg of feces). Thirteen of those 21 patients collaborated in this study. Patients(9 males and 4 females) were of rural precedence, from large poor or very poor families, chronically parasitized, and between 2 and 12 years old. Dysentery of months duration, severe anemia and stunting were common complaints; clinical characteristics associated with heavy Trichuris infections included egg counts from 232-3 520 eggs per direct smear, hemoglobin from 3.4-10.8 g/d L, eosinophilia up to 43%, severe malnutrition and growth stunting. Orally administered drugs mebendazole, albendazole, metronidazole, nitaxozanide, and piperazine were prescribed at different dosages and duration other than recommended; no cure or egg excretion control was exercised before patient release. A range of 340 to about 10 000 worms were recovered after treatment from 8 patients. Conclusions: This report underlines the need for detailed community studies in trichuriasis morbidity, effective treatment assessment and clinical response in severely malnourished parasitized children.

关键词： Anemia Honduras Stunting Trichuris dysentery syndrome

Polyoxidovanadates a new therapeutic alternative for neurodegenerative and aging diseases

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第3期19卷 571-577页

作者： Sonia Irais Gonzalez-Cano Gonzalo flores Jorge Guevara Julio Cesar Morales-Medina Samuel Treviño Alfonso Diaz Faculty of Chemical Sciences Benemerita Autonomous University of PueblaPueblaMexico Institute of Physiology Benemerita Autonomous University of PueblaPueblaMexico Department of Biochemistry Faculty of MedicineNational Autonomous University of MexicoMexico CityMexico Animal Reproduction Research Center CINVESTAV-Autonomous University of TlaxcalaTlaxcalaMexico

Aging is a natural phenomenon characterized by a progressive decline in physiological integrity,leading to a deterioration of cognitive function and increasing the risk of suffering from chronic-degenerative diseases,including cardiovascular diseases,osteoporosis,cancer,diabetes,and *** is considered the major risk factor for Parkinson’s and Alzheimer’s disease ***,diabetes and insulin resistance constitute additional risk factors for developing neurodegenerative ***,no treatment can effectively reverse these neurodegenerative ***,some antidiabetic drugs have opened the possibility of being used against neurodegenerative *** the previous framework,Vanadium species have demonstrated a notable antidiabetic *** research group evaluated polyoxidovanadates such as decavanadate and metforminium-decavanadate with preventive and corrective activity on neurodegeneration in brain-specific areas from rats with metabolic *** results suggest that these polyoxidovanadates induce neuronal and cognitive restoration *** review aims to describe the therapeutic potential of polyoxidovanadates as insulin-enhancer agents in the brain,constituting a therapeutic alternative for aging and neurodegenerative diseases.

关键词： Alzheimer’s disease antidiabetic brain cognition diabetes insulin neurodegeneration neuroinflammation oxidative stress Vanadium species

Segmentation of thermal infrared images of cucumber leaves using K-means clustering for estimating leaf wetness duration

在线全文

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2020年第3期13卷 161-167页

作者： Dongmei Wen Aixin Ren Tao Ji Isabel Maria flores-Parra Xinting Yang Ming Li Beijing Research Center for Information Technology in Agriculture/National Engineering Research Center for Information Technology in Agriculture/National Engineering Laboratory for Agri-product Quality Traceability/National Meteorological Service Center of Urban Agriculture Beijing 100097China College of Plant Protection China Agricultural UniversityBeijing 100193China Department of Sustainable Crop Production UniversitàCattolica del Sacro Cuore29122 PiacenzaItaly Department of Informatics University of AlmeriaAlmeriaCP04120Spain

Leaf wetness duration(LWD)is a critical parameter used to predict plant disease,but its determination under actual field conditions is a major *** this study,a method for determining LWD using thermal infrared imaging was developed and applied to cucumber plants grown in a solar *** images of the plant leaves were captured using an infrared scanning camera,and a leaf wetness area segmentation method consisting of two procedures was ***,a color space conversion was performed automatically by an image-processing ***,the K-means clustering algorithm was applied to enable the segmentation of the wetness area on the thermal ***,to enable overall thermal image analysis,an initial leaf wetness threshold(LWT)of 5%was defined(where wetness values higher than 5%indicated that the leaf was in a wet state).The results of comparative experiments conducted using thermal images of plant leaves captured using an infrared scanning camera and human visual observation indicated that the estimated LWD values were generally higher than the observed LWD values,because slight leaf wetness condensations were overlooked by the human eye but detected by the infrared scanning *** these differences were not found to be statistically significant in this study,the proposed method for determining LWD using thermal infrared imaging may provide a new LWD detection method for cucumber and other plants grown in solar greenhouses.

关键词： thermal imaging K-means clustering algorithm leaf wetness duration cucumber