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Validity of Amontons's law for run-in short-cut aramid fiber reinforced elastomers:The effect of epoxy coated fibers

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Friction 2020年第3期8卷 613-625页

作者： M.KHAFIdH d.J.schipper M.A.MASEN N.VLEUGELS W.K.dIERKES J.W.M.NOORdERMEER Faculty of Engineering Technology University of TwenteEnschede 7500AEThe Netherlands dutch Polymer Institute Eindhoven 5600AXThe Netherlands department of Mechanical Engineering Universitas Islam IndonesiaYogyakarta 55584Indonesia department of Mechanical Engineering Imperial College LondonLondon SW72AZUnited Kingdom

Friction between two contacting surfaces is studied *** of the k n o w n friction theories is Amontons,law which states that the friction force is proportional to the normal ***,Amontons7 law has been found to be invalid for *** the present study,the validity of Amontons7 law for short-cut aramid fiber reinforced elastomers is *** types of fillers are used to reinforce the elastomers,namely highly dispersible silica and short-cut aramid ***-cut aramid fibers with two different surface treatments are used,namely non-reactive fibers with standard oily finish(SF-fibers)and fibers treated with an epoxy coating(EF-fibers).A pin-on-disc tribometer is used to investigate the frictional behavior of the composites in sliding contact with a granite counter *** results show that,after the run-in phase,Amontons,law is valid for those composites that are reinforced by short-cut aramid fibers(without reinforcing filler,i.e.,silica)if the contact pressure is below a threshold ***,once the contact pressure exceeds this threshold value,Amontons'law will be *** threshold contact pressure of the composites containing EF-fibers is higher than of the composites containing *** composites that are reinforced by silica and short-cut aramid fibers do not follow Amontons7 law.

关键词： Amontons's law elastomer epoxy coated fiber short-cut aramid fiber

Production of liquid bio-fuel from catalytic de-oxygenation:Pyrolysis of beech wood and flax shives

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燃料化学学报 2019年第2期47卷 153-166页

作者： Chetna Mohabeer Luis Reyes Lokmane Abdelouahed Stéphane Marcotte Jean-Christophe Buvat lucette Tidahy Edmond Abi-Aad Bechara Taouk Normandie Univ INSA Rouen NormandieUNIROUENLaboratoire de Sécurité des Procédés Chimiques Normandie Univ INSA Rouen NormandieUNIROUEN Université du Littoral Cte d'Opale Unité de Chimie Environnementale et Interactions sur le Vivant

This study presents a detailed analysis of the catalytic de-oxygenation of the liquid and gaseous pyrolytic products of two biomasses (beech wood and flax shives) using different catalysts (commercial HZSM-5 and H-Y,and lab-synthesised Fe-HZSM-5,Fe-H-Y,Pt/Al2O3 and CoMo/Al2O3). The experiments were all conducted in a semi-batch reactor under the same operating conditions for all feed materials. BET specific surface area,BJH pore size distribution and FT-IR technologies have been used to characterise the catalysts,while gas chromatography-mass spectrometry (GC-MS),flame ionisation detection (GC-FId) and thermal conductivity detection (GC-TCd) were used to examine the liquid and gaseous pyrolytic products. It was firstly seen that at higher catalyst-to-biomass ratios of 4∶1,de-oxygenation efficiency did not experience any further significant improvement. FeHZSM-5 was deemed to be the most efficient of the catalysts utilised as it helped reach the lowest oxygen contents in the bio-oils samples and the second best was HZSM-5. It was also found that HZSM-5 and H-Y tended to privilege the decarbonylation route(production of CO),whilst their iron-modified counterparts favoured the decarboxylation one (production of CO2) for both biomasses studied. It was then seen that the major bio-oil components (carboxylic acids) underwent almost complete conversion under catalytic treatment to produce mostly unoxygenated aromatic compounds,phenols and gases like CO and CO2. Finally,phenols were seen to be the family most significantly formed from the actions of all catalysts.

关键词： pyrolysis biomass catalytic treatment de-oxygenation bio-oil upgrading

Activity and Selectivity of Bimetallic Catalysts Based on SBA-15 for Nitrate Reduction in Water

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Materials Sciences and Applications 2023年第2期14卷 78-93页

作者： Mouhamad Rachini Mira Jaafar Nabil Tabaja Sami Tlais Rasha Hamdan Fatima Al Ali Ola Haidar Ali Jaber Mohammad Kassem Eugene Bychkov lucette Tidahy Renaud Cousin dorothée dewaele Tayssir Hamieh Joumana Toufaily Laboratory of Materials Catalysis Environment and Analytical Methods (MCEMA) EDST FS Lebanese University Hariri Campus Hadath Lebanon Université du Littoral Cô te d’Opale (ULCO) LPCA EA 4493 F-59140 Dunkerque France Laboratory of Applied Studies for Sustainable development and Renewable Energy (LEAddER) EDST Lebanese University Hariri Campus Hadath Lebanon College of Engineering and Technology American University of the Middle East Kuwait Kuwait department of Chemistry American University of Beirut Riad El-Solh Beirut Lebanon Laboratoire de Recherche et développement des Médicaments et des Produits Naturels RdMPN Faculty of Pharmacy Lebanese University Hariri Campus Hadath Lebanon Université du Littoral Cô te d’Opale UCEIV Unité de Chimie Environnementale et Interactions sur le Vivant EA 4492 SFR Condorcet FR CNRS 3417 Dunkerque France Centre Commun de Mesures Université du Littoral C&ocircte d’Opale Dunkerque France Faculty of Science and Engineering Maastricht University Maastricht The Netherlands

Nitrate from the application of nitrogen-based fertilizers in intensive agriculture is a notorious waste product, though it lacks cost-effective solutions for its removal from potential drinking water resources. Catalytic reduction appears to be a promising technique for converting nitrates to benign nitrogen gas. Mesoporous silica SBA-15 is a frequently used catalyst support that has large surface areas and highly ordered nanopores. In this work, mesoporous silica SBA-15 bimetallic catalysts for nitrate reduction were investigated. The catalyst was optimized for the selection of promoter metal (Sn and Cu), noble metal (Pd and Pt) and loading ratios of these metals at different temperatures and reduction conditions. The catalysts prepared were characterized by FT-IR, N2 physisorption, XRd, SEM, and ICP. All catalysts showed the presence of cylindrical mesoporous channels and uniform pore structures that remained even after metals loading. In the presence of a CO2 buffer, the catalysts 4Pd-1Cu/SBA-15 and 1Pt-1Cu/SBA-15 reduced at 100?C under H2 and 1Pd-1Cu/SBA-15 reduced at 200°C under H2 demonstrated very high nitrate conversion. Furthermore, the forementioned Pd catalysts had higher N2 selectivity (88% - 87%) compared to Pt catalyst (80%). Nitrate conversion by the 4Pd-1Cu/SBA-15 catalyst was significantly decreased to 81% in the absence of CO2.

关键词： Bimetallic Catalyst Heterogeneous Catalyst Nitrate Reduction SBA-15 XRd BET SEM FTIR ICP

Laparoscopic hepatectomy reduces postoperative complications and hospital stay in overweight and obese patients

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World Journal of Gastrointestinal Surgery 2021年第1期13卷 19-29页

作者： daniel Heise Jan Bednarsch Andreas Kroh Sandra schipper Roman Eickhoff Marielle Coolsen Ronald Van dam Sven Lang Ulf Neumann Florian Ulmer department of Surgery and Transplantation University Hospital RWTH AachenAachen 52074Germany department of Surgery Maastricht University Medical CenterMaastricht 6229 HXNetherlands

BACKGROUNd Laparoscopic liver surgery is currently considered the standard of care for various liver ***,studies focusing on perioperative outcome after laparoscopic hepatectomy(LH)in overweight patients are still sparse and its benefit compared to open hepatectomy(OH)is a matter of *** To analyze postoperative outcomes in overweight[body mass index(BMI)over 25 kg/m²]and obese(BMI over 30 kg/m²)patients undergoing LH and compare postoperative outcome with patients undergoing *** Perioperative data of 68 overweight(BMI over 25 kg/m²)including a subcohort of obese(BMI over 30 kg/m²)patients(n=27)who underwent LH at our institution between 2015 and 2019 were retrospectively analyzed regarding surgical outcome and compared to an equal number of patients undergoing *** The mean BMI was 29.8±4.9 kg/m2 in the LH group and 29.7±3.6 kg/m2 in the OH group with major resections performed in 20.6%(LH)and 26.5%(OH)of cases,*** time(194±88 min vs 275±131 min;Pd vs 1.1±0.8 d;P=0.031)and hospital stay(7.3±3.6 d vs 15.7±13.5 d;Pd major complications(1.5%vs 14.7%,P=0.002)were observed less frequently after *** additional investigation analyzing the subgroup of obese patients who underwent LH(n=27)and OH(n=29)showed a shorter operative time(194±81 min vs 260±137 min;P=0.009)and a reduced length of hospitalization(7.7±4.3 d vs 17.2±17 d;Pdifference in postoperative complications or overall *** LH is safe and cost-effective in overweight and obese ***,LH is significantly associated with fewer postoperative complications and reduced hospital stay compared to OH in these patients.

关键词： Laparoscopic hepatectomy Obesity Overweight Morbidity Postoperative outcome Cost

Semi-Automatic Fracture Mapping Using Cellular Neural Networks Applied to ALOS PALSAR 2 Images of the Western Highlands of Cameroon

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International Journal of Geosciences 2021年第11期12卷 1055-1069页

作者： Valère-Carin Jofack Sokeng Benjamin N’gounou Ngatcha Fernand Koffi Kouame Jean Homian danumah lucette Akpa You Unité de Recherche et d’Expertise Numérique Université Virtuelle de C&#244 te d’Ivoire Abidjan C&#244 te d’Ivoire Centre Universitaire de Recherche et d’Application en Télédétection Abidjan C&#244 te d’Ivoire Laboratoire Mixte International en Sciences de l’Eau (LAMISE) Université de Ngaoundéré Ngaoundéré Cameroun

In Cameroon in general and in the Highlands of Cameroon in particular, there is no fracture map since its realization is not easy. The region’s harsh accessibility and climatic conditions make it difficult to carry out geological prospecting field missions that require large investments. This study proposes a semi-automatic lineament mapping approach to facilitate the elaboration of the fracture map in the West Cameroon Highlands. It uses neural networks in tandem with PCI Geomatica’s LINE algorithm to extract lineaments semi-automatically from an ALOS PALSAR 2 radar image. The cellular neural network algorithm of Lepage et al (2000) is implemented to enhance the pre-processed radar image. Then, the LINE module of Geomatica is applied to the enhanced image for the automatic extraction of lineaments. Finally, a control and a validation of the expert by spatial analysis allows elaborating the fracture map. The results obtained show that neural networks enhance and facilitate the identification of lineaments on the image. The resulting map contains more than 1800 fractures with major directions N20° - 30°, NS, N10° - 20°, N50° - 60°, N70° - 80°, N80° - 90°, N100° - 110°, N110° - 120&#

关键词： Fracture Map Lineament Mapping Cellular Neural Networks Highlands of Cameroon ALOS PALSAR Image

First Study on Laser Bone Ablation System at the Skull Base for Micro Surgery Based on Vision Navigation

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First Study on Laser Bone Ablation System at the Skull Base ...