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Some recent advances in fluidized-bed polymerization technology

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Particuology 2010年第6期8卷 578-581页

作者： jan van Egmond Mike Tilston Union Carbide Corporation a subsidiary of The Dow Chemical CompanyFreeportTX 77541USA

The fluidized-bed polymerization process has been in use for decades. From the manufacturer＇s perspective it is desirable to improve technology without major modification of the reactor system. Therefore, in order to meet the demand for new products or more efficient reactor operation, manufacturers prefer to improve the catalyst system in the most cost effective manner. Using polypropylene production as an example, some recent advances in fluidized-bed polymerization technology are presented.

关键词： Fluidized bed Polymerization Polypropylene Catalyst Donor Kinetics

MRCKα is a novel regulator of prolactin-induced lactogenesis in bovine mammary epithelial cells

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Animal Nutrition 2022年第3期10卷 319-328页

作者： Fang Wang jürgen van Baal Lu Ma Xuejun Gao jan Dijkstra Dengpan Bu State Key Laboratory of Animal Nutrition Institute of Animal ScienceChinese Academy of Agricultural SciencesBeijing100193China Animal Nutrition Group Wageningen University and ResearchWageningen6708WDthe Netherlands College of Animal Science Yangtze UniversityJingzhou434020China joint Laboratory on Integrated Crop-Tree-Livestock Systems of the Chinese Academy of Agricultural Sciences(CAAS) Ethiopian Institute of Agricultural Research(EIAR)and World Agroforestry Center(ICRAF)Beijing100193China

Myotonic dystrophy-related Cdc42-binding kinase alpha(MRCKα)is an integral component of signaling pathways controlling vital cellular processes,including cytoskeletal reorganization,cell proliferation and cell *** this study,we investigated the physiological role of MRCKα in milk protein and fat production in dairy cows,which requires a dynamic and strict organization of the cytoskeletal network in bovine mammary epithelial cells(BMEC).Within a selection of 9 Holstein cows,we found that both mRNA and protein expression of MRCKα in the mammary gland were upregulated during lactation and correlated positively(r>0.89)with the mRNA and protein levels of *** positive correlations(r>0.79)were found in a primary culture of BMEC stimulated with prolactin for 24 *** these cells,silencing of MRCKα decreased basal b-casein,sterol-regulatory element binding protein(SREBP)-1 and cyclin D1 protein level,phosphorylation of mTOR,triglyceride secretion,cell number and viabilitydwhile overexpression of MRCKα displayed the reversed ***,silencing of MRCKα completely prevented the stimulatory action of prolactin on the same *** data demonstrate that MRCKα is a critical mediator of prolactin-induced lactogenesis via stimulation of the mTOR/SREBP1/cyclin D1 signaling pathway.

关键词： Myotonic dystrophy-related Cdc42-binding kinase alpha Bovine mammary gland Prolactin Mechanistic target of rapamycin Sterol regulatory element-binding protein-1 Cyclin D1

Investigation of operational parameters for an industrial CFB combustor of coal,biomass and sludge

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China Particuology 2007年第4期5卷 247-254页

作者： Manon van de Velden jan Baeyens Bill Dougan Alan McMurdo Department of Chemical Engineering University of Birmingham B15 2TT Birmingham United Kingdom UPM-Kymmene Caledonian Paper Ltd.AyrUnited Kingdom

The combustion of coal and/or biomass （sludge, wood waste, RDF, etc.） in a circulating fluidized bed has been a commercial topper for over 20 years, and references to principles and applications are numerous and widespread although few data are presented concerning the operation of large scale CFB-units. The authors studied the CFB-combustion at UPM-Kymmene （Ayr）, a major paper mill relying for its steam production upon the combustion of coal （80-85 %）, wood bark （5-10%） and wastewater treatment sludge （5-10%）. The maximum capacity of the CFB is 58 MWth. A complete diagnostic of the operation was made, and additional tests were performed to assess the operating mode. The plant schematics, relevant dimensions and process data are given. To assess the operation of the UPM-CFB, it is important to review essential design parameters and principles of CFB combustors, which will be discussed in detail to include required data, heat balance and flowrates, operating versus transport velocity, kinetics and conversion （including the possible effect of the Bouduard reaction if carbon is present）. Since the residence time in the riser and the cyclone efficiency determine the burnout of circulating fuel-particles, the UPM-CFB was subjected to a stimulus response technique using nickel oxide as tracer. Results illustrate the efficiency of the cyclone separation and the number of recycle loops for particles of a given size. Results will also be used to assess the cyclone operation and efficiency and to comment upon expected and measured carbon conversion.

关键词： Circulating fluidized bed Combustion Coal Biomass Operation Cyclone

Impact of black cherry on pedunculate oak vitality in mixed forests:Balancing benefits and concerns

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Forest Ecosystems 2023年第6期10卷 690-699页

作者： Ellen Desie Bart Muys jan den Ouden Bart Nyssen Rita Sousa-Silva Leon van den Berg Arnold van den Burg Gert-jan van Duinen Koenraad van Meerbeek Maaike Weijters Karen vancampenhout Division Forest Nature and LandscapeKU Leuven Campus GeelKleinhoefstraat 4B-2240 GeelBelgium Division Forest Nature and LandscapeKU LeuvenCelestijnenlaan 200EBox 2411B-3001 LeuvenBelgium KU Leuven Plant Institute B-3001 LeuvenBelgium Forest Ecology and Management Group Wageningen UniversityP.O.Box 47Wageningenthe Netherlands Bosgroep Zuid-Nederland Huisvenseweg 145591 VD Heezethe Netherlands Young Academy for Sustainability Research University of Freiburg79104 Freiburg im BreisgauGermany Aquatic Ecology&Environmental Biology Radboud University NijmegenHeyendaalseweg 1356525 AJ Nijmegenthe Netherlands Biosphere/Zoological Museum Netherlands Onderlangs 176731 BK Otterlothe Netherlands Stichting Bargerveen Toernooiveld 16525 ED Nijmegenthe Netherlands B-WARE Research Centre/Radboud University Nijmegen Toernooiveld 16525 ED Nijmegenthe Netherlands

The vitality of European forests continues to decline due to new pests and diseases,climate-change related disturbances and high loads of atmospheric nitrogen *** soil health is a major factor underpinning the low vitality of West-European *** tree species with soil ameliorative traits is proposed as an avenue to counteract soil acidification and improve overall forest *** we evaluate the impact of black cherry(Prunus serotina Ehrh.),a known rich litter species,on the vitality of neighboring pedunculate oak(Quercus robur L.)in ten mixed forests on sand in Germany,Belgium and the *** found that black cherry admixture increases foliar N and P to a surplus whereas it causes deficiencies in foliar Mg,thereby resulting in an overall negative effect on oak foliar nutrient ***,defoliation of oak leaves by herbivory decreases with the proximity of black *** structural equation modelling(SEM),we tested the hypothesized‘improved soil health’*** analyses showed that black cherry admixture leads to lower accumulation in the humus layer,resulting in higher soil base saturation which has a positive effect on foliar Ca yet a negative effect on total ***,the SEM illustrated that herbivory of oak leaves decreases when black cherry is admixed,both via dilution and improved soil *** effects of black cherry on oak vitality via“improved soil health”in our SEM are however small in comparison to direct ***,our study showed that the combined positive and negative impacts of black cherry on oak vitality are limited,which tempers the potential benefits of using the rich litter species to counteract oak decline via improved soil health–yet,the concern of black cherry as an invasive alien species negatively affecting the vitality of mature pedunculate oak trees may also be exaggerated.

关键词： Rich litter species Black cherry Nutrient cycling Insect herbivory Dilution effect Humus type Pedunculate oak Plant-soil interaction

Dietary Fibres and Whole Grain Products for Improving Health and Reducing Disease Risks

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食品科学 2004年第10期25卷 421-422页

作者： jan Willem van der Kamp TNO Nutrition and Food Research P.O.Box 360 3700 AJ Zeist The Netherlands and ICC International Associa-tion for Cereal Science and Technology

In recent years the occurrence of civilisation related diseases such as diabetes and obesity is increasing at a dramatic rate. This results in a growing consumer awareness of relationships between diet and health. Industry is respond ing to this trend by introducing products with a healthy image, including products with dietary fibre. Every year about 500 products are being launched globally with statements regarding their fibre content. Dietary fibre is usually defined as "the edible parts of plants or analogous carbohydrates that are resistant to digestion and absorption in the human small intestine with complete or partial fermentation in the large intestine. Dietary fibre includes polysaccharides, oligosaccharides, lignin, and associated substances. Dietary fibres promote beneficial physiological effects including laxation, and/or blood cholesterol attenuation, and/or blood glucose attenuation" (AACC, 2001).

关键词：食物纤维谷类产品保健营养

Colour-ring wear and loss effects in citizen science mark-resighting studies

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Avian Research 2019年第2期10卷 148-162页

作者： Andrew M.Allen Bruno j.Ens Martijn van de Pol Henk van der jeugd Magali Frauendorf Henk-jan van der Kolk Kees Oosterbeek jeroen Nienhuis Eelke jongejans Department of Animal Ecology and Physiology Radboud University6500 GL NijmegenThe Netherlands Sovon Dutch Centre for Field Ornithology 6503 GANijmegen and Sovon-Texel1790 AB Den BurgThe Netherlands Department of Animal Ecology Netherlands Institute of Ecology NIOOKNAW6708 PB WageningenThe Netherlands Dutch Centre for Avian Migration and Demography 6700 AB WageningenThe Netherlands Centre for Avian Population Studies WageningenThe Netherlands

Background: Ring wear and loss may have important consequences for mark-recapture studies that aim to estimate survival trends. Our study quantifies the rates of wear and loss from a long-running colour-ringing project of the Eurasian Oystercatcher (Haematopus ostralegus) in the Netherlands. Methods: Our analysis included 8909 colour-ringed oystercatchers with 118,071 resightings, predominantly ringed and observed by citizen scientists. We quantified how ring wear and loss may vary with ring colour and age, and how this may impact resighting probabilities. We then determined how ring loss may impact survival estimates and resighting probabilities of mark-recapture models by simulating four scenarios of how citizen scientists may resight and report birds with lost colour rings. Results: Annual rates of colour ring loss averaged 2.5% compared with 1% for ring wear, but lost rings also had a higher reporting probability (31.2%) than worn rings (10.3%). Lost rings may not directly impact survival estimates since 50% of oystercatchers with lost rings could still be uniquely identified. Ring wear and loss rapidly increased between 10 and 15 years after ringing. Rates of ring loss were comparable amongst ring colours, but the wear rate appeared higher for red and white rings compared to other colours. Rates of ring wear and loss varied significantly amongst different regions in our study, which were characterised as having different habitat features. Differential rates of ring wear may have important implications for studies conducted over large geographical scales or of multiple species. Conclusions: Based on simulations of ring loss in our population, estimates of apparent survival may be 0.3–1.2% lower whilst the impact of ring wear was deemed even lower. We developed a table of recommendations containing advice for ring fitting, data collection, study design, and mark-recapture analyses, so that future colour-ringing studies can benefit from our experiences in collecti

关键词： Bias Bird migration Citizen science Colour-ring Mark-recapture Shorebirds Survival

Implementing a DIKW model on a deep mine cooling system

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International journal of Mining Science and Technology 2019年第2期29卷 319-326页

作者： jan Gabriel Pretorius Marc john Mathews Philip Maré Marius Kleingeld johann van Rensburg Centre for Research and Continued Engineering Development North-West University Pretoria 0081 South Africa TEMM International (Pty) Ltd

The South African mining industry has been experiencing increasing economic pressure. Deep mines also suffer from very hot workplaces, which leads to safety risks. These factors place stress on managers to reach their production targets while providing safe workplace conditions. The data information knowledge wisdom(DIKW) model, also known as the wisdom hierarchy, was implemented on a deep mine cooling system. This study aims to show that a simple model such as the DIKW model can assist managers in improving their deep mine cooling system's performance. The study found that the DIKW approach is a suitable approach for use on mine cooling systems to facilitate operational *** the DIKW approach to a case study on a mine cooling system created substantial awareness and facilitated a cooling duty improvement of 55% which relates to an increase of 5.3 MW of refrigeration. The results of this study indicate that the DIKW approach may be a suitable approach to optimise management on deep mines using their existing infrastructure.

关键词： DIKW Cooling system Mining Reporting

Fluid-rock interaction in retrograde granulites of the Southern Marginal Zone,Limpopo high grade terrain,South Africa

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Geoscience Frontiers 2014年第5期5卷 673-682页

作者： jan Marten Huizenga Dirk van Reenen jacques L.R.Touret Unit of Environmental Sciences and Management North-West UniversityPrivate Bag X60012520South Africa Economic Geology Research Institute(EGRU) School of Earth and Environmental SciencesJames Cook UniversityTownsvilleQLD 4811Australia Department of Geology University of JohannesburgJohannesburgSouth Africa Institut de Mineralogie.de Physique des Materiaux et de Cosmochimie(IMPMC) Sorbonne Universites UPMC Univ Paris 06UMR CNRS 7590 Museum National d'Histoire Naturelle.IRD UMR 206.4 Place jussieu.F-75005

Fluid infiltration into retrograde granulites of the Southern Marginal Zone （Limpopo high grade terrain） is exemplified by hydration reactions, shear zone hosted metasomatism, and lode gold mineralisation. Hydration reactions include the breakdown of cordierite and orthopyroxene to gedrite ＋ kyanite, and anthophyllite, respectively. Metamorphic petrology, fluid inclusions, and field data indicate that a low H2O-activity carbon-saturated CO2-rich and a saline aqueous fluid infiltrated the Southern Marginal Zone during exhumation. The formation of anthophyllite after orthopyroxene established a regional retrograde anthophyllite-in isograd and occurred at P-Tconditions of -6 kbar and 610 ℃, which fixes the minimum mole fraction of H20 in the CO2-rich fluid phase at ~ 0.1. The maximum H20 mole fraction is fixed by the lower temperature limit （~800 ℃） for partial melting at -0.3. C-O-H fluid calculations show that the CO2-rich fluid had an oxygen fugacity that was 0.6 log10 units higher than that of the fayalite-magnetite- quartz buffer and that the CO2/（CO2＋CH4） mole ratio of this fluid was 1. The presence of dominantly relatively low density CO2-rich fluid inclusions in the hydrated granulites indicates that the fluid pressure was less than the lithostatic pressure. This can be explained by strike slip faulting and/or an increase of the rock permeability caused by hydration reactions.

关键词： GranuliteFluidLimpopoRetrogradeSouthern Marginal Zone

Liver failure caused by prolonged state of malnutrition following bariatric surgery

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World journal of Hepatology 2018年第3期10卷 396-399页

作者： Willem j Lammers Antonie jP van Tilburg jan A Apers janneke Wiebolt Department of Gastroenterology and Hepatology Erasmus Medical Center Department of Gastroenterology and Hepatology Franciscus Gasthuis and Vlietland Department of Surgery Franciscus Gasthuis and Vlietland Department of Internal Medicine Franciscus Gasthuis and Vlietland

Bariatric surgery is an effective tool in the treatment of patients with morbid obesity. In these case reports we describe 2 patients who developed liver failure after currently-practiced types of bariatric surgery, caused by a prolonged state of malnutrition provoked by psychiatric problems. Despite intensive guidance of a psychologist and dieticians after surgery, our patients deteriorated psychologically, resulting in a prolonged state of severe malnutrition and anorexia. Finally, a state of starvation was reached, passing a critical level of the liver capacity. Patients who present with signs of severe protein malnutrition after bariatric surgery should be closely monitored and checked for nutritional status. Specific attention should be given to patients who develop psychiatric problems post-bariatric surgery. If refeeding does not result in clinical improvement, reversal surgery should be considered in a timely manner.

关键词： Protein deficiency Hyperbilirubinemia Hyperammonemia Liver failure Urea cycle