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58th Brazilian Ceramic Conference, CBC 2014

作者： Delbrücke, Tiago Gouvêa, Rogério A. Raubach, Cristiane W. Longo, Elson Sousa, Vânia C. M.tebcheranic, Sergio Kubaski, Evaldo T. Moreira, Mário L. Jurado, Jose R. Cava, Sergio Graduate Program in Science and Materials Engineering Technology Development Center Federal University of Pelotas RS Pelotas96010-900 Brazil Laboratory of Biomaterials & Advanced Ceramics Federal University of Rio Grande do Sul RS Porto Alegre91509-900 Brazil Interdisciplinary Laboratory of Ceramic Materials Ponta Grossa State University PR Ponta Grossa84030-900 Brazil National Institute of Science and Technology of Materials in Nanotechnology Paulista State University SP Araraquara14801-907 Brazil Glass Department Institute of Glass and Ceramic Madrid28049 Spain Institute of Physics and Mathematics Federal University of Pelotas RS Pelotas96010-900 Brazil

The improvement on the development of porous ceramic materials has leaded to new technologies in thermal insulation, for example, composite materials for better performance of pressure vessels in rocket engines. Within this context, the present work aims to evaluate the ability of a refractory ceramic base alumina/zirconia through the processes of co-precipitation and replica method in an organic fiber template. The green body was burnt-out and sintered at 1200-1600°C to obtain the continuous porous ceramic fibers. In the FEG-SEM analysis, an interconnected porous structure with small grains was observed. The crystalline phases were determined by X-ray diffraction and compared to micro-Raman results regarding the crystalline structure confirms that there present in the material zirconia is composed of more than one phase. Porosity was calculated through a mercury porosimeter as 77.9%, and the Laser Flash method gave a thermal conductivity value of 1.61 K W.m−1 .K−1 for the Al2 O3-ZrO2 fibers. © 2015 Trans Tech Publications Ltd, Switzerland.

关键词： Porosity

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Chemical changes in polyetherimide (PEI) joined by friction-based injection clinching joining (F-ICJ) technique

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AIP Conference Proceedings 2016年第1期1779卷

作者： M. Sônego A. B. Abibe J. F. dos Santos L. B. Canto S. T. Amancio-Filho 1Graduate Program in Materials Science and Engineering (PPG-CEM) Federal University of São Carlos (UFSCar) São Carlos SP Brazil 2Helmholtz-Zentrum Geesthacht Centre for Materials and Coastal Research Institute of Materials Research Materials Mechanics Solid State Joining Processes Geesthacht Germany 3Hamburg University of Technology Institute of Polymer Composites Hamburg Germany

The study of new joining technologies for multimaterial structures is motivated by the environmental friendly policy of weight reduction in the automotive industry. Friction-based Injection Clinching Joining (F-ICJ) (European Patent Application EP 14182938.2) is a new staking-based joining technique, which uses frictional heating to produce joints in an energy-efficient and fast manner. In F-ICJ a non-consumable tool applies friction and force to soften or melt and deform a polymeric stud fitted in a through hole of a joining partner. After consolidation, the deformed stud (stake) mechanically joins the partners by creating a staked joint. The thermomechanical process exposes the polymer to high temperatures (250 - 290°C) and deformation rates resulting from the combination of tool rotational speeds of 8000-12000 rpm and short joining cycles (5-10 seconds). Resulting changes in material properties can affect the global performance of the joints. This study aims to investigate the chemical changes occurred in the polymeric partner of hybrid joints on polyetherimide (PEI) and aluminum 6082-T6. Molecular weight distribution (Size-Exclusion Chromatography - SEC) and chemical structure (Fourier transform infrared spectroscopy – FTIR) analyses were performed on the base material and PEI extracted from a joint to evidence any possible chemical changes caused by frictional heating. The polymeric sample from the joint showed number-average molecular weight (Mn) 23% smaller and weight-average molecular weight (Mw) 15% smaller than the PEI base material. FTIR spectra show reduction in the intensity of phthalimide bands owing to the F-ICJ process. Therefore, these analyses identified the extension of chain scission in the PEI caused by shear and heat imposed by F-ICJ process, which are fundamental for process optimization.

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Inside Cover: Nonplanar Butterfly-Shaped π-Expanded Pyrrolopyrroles (Chem. Eur. J. 46/2016)

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Chemistry – A European Journal 2016年第46期22卷 16326-16326页

作者： Maciej Krzeszewski Takuya Kodama Eli M. Espinoza Prof. Dr. Valentine I. Vullev Prof. Dr. Takashi Kubo Prof. Dr. Daniel T. Gryko Institute of Organic Chemistry Polish Academy of Sciences Kasprzaka 44–52 01-224 Warsaw Poland Department of Bioengineering Department of Biochemistry Department of Chemistry and Materials Science and Engineering Program University of California Riverside California 92521 USA Graduate School of Science Osaka University Toyonaka Osaka 560-0043 Japan

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Localized microjetting in the collapse of surface macrocavities

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Physical Review E 2015年第2期91卷 022405-022405页

作者： K. L. Olney P.-H. Chiu D. J. Benson A. Higgins M. Serge V. F. Nesterenko Department of Mechanical and Aerospace Engineering University of California San Diego La Jolla California 92093 Materials Science and Engineering Graduate Program University of California San Diego La Jolla California 92093 Department of Structural Engineering University of California San Diego La Jolla California 92093 Department of Mechanical Engineering McGill University Quebec H3A 0C3 Canada

This paper focuses on the multiscale mechanism of collapse of hemicylindrical annular surface macrocavities in steel caused by high-strain, high-strain rate plastic flow of copper. Experiments and simulations revealed that a two-stage process is responsible for the observed microjetting phenomena: the formation of lateral copper microjets from the localized shear flow in copper at the interface during the filling of the cavity, and their subsequent collision at the apex of the macrocavity generating two additional horizontal microjets. The lengths of these microjets were an order of magnitude smaller than the cavity size but linearly scaled with the cavity radius. This process of microjet development is sensitive to the cavity geometry and is unlike the previously observed jetting phenomena in cavitation, impact crater collapse, or shock-induced cavity collapse.

关键词： VERY light jets SURFACES (Physics) STRAIN rate (materials science) PLASTICITY COPPER METALS -- Mechanical properties

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Subnational mapping of HIV incidence and mortality among individuals aged 15–49 years in sub-Saharan Africa, 2000–18: a modelling study

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The Lancet HIV 2021年第6期8卷 e363-e375页

作者： Sartorius, Benn VanderHeide, John D. Yang, Mingyou Goosmann, Erik A. Hon, Julia Haeuser, Emily Cork, Michael A. Perkins, Samantha Jahagirdar, Deepa Schaeffer, Lauren E. Serfes, Audrey L. LeGrand, Kate E. Abbastabar, Hedayat Abebo, Zeleke Hailemariam Abosetugn, Akine Eshete Abu-Gharbieh, Eman Accrombessi, Manfred Mario Kokou Adebayo, Oladimeji M. Adegbosin, Adeyinka Emmanuel Adekanmbi, Victor Adetokunboh, Olatunji O. Adeyinka, Daniel Adedayo Ahinkorah, Bright Opoku Ahmadi, Keivan Ahmed, Muktar Beshir Akalu, Yonas Akinyemi, Oluwaseun Oladapo Akinyemi, Rufus Olusola Aklilu, Addis Akunna, Chisom Joyqueenet Alahdab, Fares Al-Aly, Ziyad Alam, Noore Alamneh, Alehegn Aderaw Alanzi, Turki M. Alemu, Biresaw Wassihun Alhassan, Robert Kaba Ali, Tilahun Alipour, Vahid Amini, Saeed Ancuceanu, Robert Ansari, Fereshteh Anteneh, Zelalem Alamrew Anvari, Davood Anwer, Razique Appiah, Seth Christopher Yaw Arabloo, Jalal Asemahagn, Mulusew A. Asghari Jafarabadi, Mohammad Asmare, Wondwossen Niguse Atnafu, Desta Debalkie Atout, Maha Moh'd Wahbi Atreya, Alok Ausloos, Marcel Awedew, Atalel Fentahun Ayala Quintanilla, Beatriz Paulina Ayanore, Martin Amogre Aynalem, Yared Asmare Ayza, Muluken Altaye Azari, Samad Azene, Zelalem Nigussie Babar, Zaheer-Ud-Din Baig, Atif Amin Balakrishnan, Senthilkumar Banach, Maciej Bärnighausen, Till Winfried Basu, Sanjay Bayati, Mohsen Bedi, Neeraj Bekuma, Tariku Tesfaye Bezabhe, Woldesellassie M. Mequanint Bhagavathula, Akshaya Srikanth Bhardwaj, Pankaj Bhattacharyya, Krittika Bhutta, Zulfiqar A. Bibi, Sadia Bikbov, Boris Birhan, Tsegaye Adane Bitew, Zebenay Workneh Bockarie, Moses John Boloor, Archith Brady, Oliver J. Bragazzi, Nicola Luigi Briko, Andrey Nikolaevich Briko, Nikolay Ivanovich Burugina Nagaraja, Sharath Butt, Zahid A. Cárdenas, Rosario Carvalho, Felix Charan, Jaykaran Chatterjee, Souranshu Chattu, Soosanna Kumary Chattu, Vijay Kumar Chowdhury, Mohiuddin Ahsanul Kabir Chu, Dinh-Toi Cook, Aubrey J. Cormier, Natalie Maria Cowden, Richard G. Culquichicon, Carlos Dagnew, Baye Dahlawi, Saad M.A. D Centre for Tropical Medicine and Global Health Nuffield Department of Medicine University of Oxford Oxford United Kingdom Malaria Atlas Project University of Oxford Oxford United Kingdom The George Institute for Global Health University of Oxford Oxford United Kingdom Department of Health Metrics Sciences School of Medicine University of Washington Seattle WA United States Institute for Health Metrics and Evaluation University of Washington Seattle WA United States Department of Global Health University of Washington Seattle WA United States Department of Medicine University of Washington Seattle WA United States Insights Program Bill and Melinda Gates Foundation Seattle WA United States Global Programs Medical Teams International Seattle WA United States Department of Pediatric Newborn Medicine Brigham and Women's Hospital Boston MA United States Advanced Diagnostic and Interventional Radiology Research Center Tehran University of Medical Sciences Tehran Iran Multiple Sclerosis Research Center Tehran University of Medical Sciences Tehran Iran Department of Epidemiology and Biostatistics Tehran University of Medical Sciences Tehran Iran Pediatric Chronic Kidney Disease Research Center Tehran University of Medical Sciences Tehran Iran Department of Environmental Health Engineering Tehran University of Medical Sciences Tehran Iran Metabolomics and Genomics Research Center Tehran University of Medical Sciences Tehran Iran Research Center for Immunodeficiencies Tehran University of Medical Sciences Tehran Iran Department of Public Health Arba Minch University Arba Minch Ethiopia Department of Medical Laboratory Sciences Arba Minch University Arba Minch Ethiopia College of Medicine and Health Science Arba Minch University Arba Minch Ethiopia Department of Nursing Arba Minch University Arba Minch Ethiopia Department of Biomedical Sciences Arba Minch University Arba Minch Ethiopia Department of Public Health Debre Berhan University Debre Brehan

Background: High-resolution estimates of HIV burden across space and time provide an important tool for tracking and monitoring the progress of prevention and control efforts and assist with improving the precision and efficiency of targeting efforts. We aimed to assess HIV incidence and HIV mortality for all second-level administrative units across sub-Saharan Africa. Methods: In this modelling study, we developed a framework that used the geographically specific HIV prevalence data collected in seroprevalence surveys and antenatal care clinics to train a model that estimates HIV incidence and mortality among individuals aged 15–49 years. We used a model-based geostatistical framework to estimate HIV prevalence at the second administrative level in 44 countries in sub-Saharan Africa for 2000–18 and sought data on the number of individuals on antiretroviral therapy (ART) by second-level administrative unit. We then modified the Estimation and Projection Package (EPP) to use these HIV prevalence and treatment estimates to estimate HIV incidence and mortality by second-level administrative unit. Findings: The estimates suggest substantial variation in HIV incidence and mortality rates both between and within countries in sub-Saharan Africa, with 15 countries having a ten-times or greater difference in estimated HIV incidence between the second-level administrative units with the lowest and highest estimated incidence levels. Across all 44 countries in 2018, HIV incidence ranged from 2·8 (95% uncertainty interval 2·1–3·8) in Mauritania to 1585·9 (1369·4–1824·8) cases per 100 000 people in Lesotho and HIV mortality ranged from 0·8 (0·7–0·9) in Mauritania to 676·5 (513·6–888·0) deaths per 100 000 people in Lesotho. Variation in both incidence and mortality was substantially greater at the subnational level than at the national level and the highest estimated rates were accordingly higher. Among second-level administrative units, Guijá District, Gaza Province, Mozambique,

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Transistors: Layer‐by‐Layer Assembled 2D Montmorillonite Dielectrics for Solution‐Processed Electronics (Adv. Mater. 1/2016)

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Advanced materials 2016年第1期28卷

作者： Jian Zhu Xiaolong Liu Michael L. Geier Julian J. McMorrow Deep Jariwala Megan E. Beck Wei Huang Tobin J. Marks Mark C. Hersam Department of Materials Science and Engineering Northwestern University 2220 Campus Drive Evanston IL 60208 USA Graduate Program in Applied Physics Northwestern University Evanston IL 60208 USA Department of Chemistry Northwestern University Evanston IL 60208 USA Department of Medicine Northwestern University Evanston IL 60208 USA

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On-Demand Guided Bone Regeneration with Microbial Protection of Ornamented SPU Scaffold with Bismuth-Doped Single Crystalline Hydroxyapatite: Augmentation and Cartilage Formation

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ACS applied materials & interfaces 2016年第6期8卷 4086-100页

作者： M Selvakumar Priyanka Srivastava Harpreet Singh Pawar Nimmy K Francis Bodhisatwa Das G Sathishkumar Bhuvaneshwaran Subramanian Saravana Kumar Jaganathan Gibin George S Anandhan Santanu Dhara Golok B Nando Santanu Chattopadhyay Indian Institute of Technology Rubber Technology Centre Kharagpur 721302 India. Sanjay Gandhi Post Graduate Institute of Medical Science Department of Medical Genetics Lucknow 226014 Uttar Pradesh India. Indian Institute of Technology School of Medical Science and Technology Kharagpur 721302 India. Bharathidasan University Department of Biotechnology and Genetic Engineering Tiruchirappalli 620024 Tamilnadu India. Indian Institute of Technology RISUG® and Allied Science Laboratories School of Medical Science and Technology Kharagpur 721302 India. Universiti Teknologi Malaysia Faculty of Bioscience and Medical Engineering IJN-UTM Cardiovascular Engineering Centre Johor Bahru 81310 Malaysia. National Institute of Technology Karnataka Department of Metallurgical and Materials Engineering Mangalore 575025 Karnataka India.

Guided bone regeneration (GBR) scaffolds are futile in many clinical applications due to infection problems. In this work, we fabricated GBR with an anti-infective scaffold by ornamenting 2D single crystalline bismuth-doped nanohydroxyapatite (Bi-nHA) rods onto segmented polyurethane (SPU). Bi-nHA with high aspect ratio was prepared without any templates. Subsequently, it was introduced into an unprecedented synthesized SPU matrix based on dual soft segments (PCL-b-PDMS) of poly(ε-caprolactone) (PCL) and poly(dimethylsiloxane) (PDMS), by an in situ technique followed by electrospinning to fabricate scaffolds. For comparison, undoped pristine nHA rods were also ornamented into it. The enzymatic ring-opening polymerization technique was adapted to synthesize soft segments of PCL-b-PDMS copolymers of SPU. Structure elucidation of the synthesized polymers is done by nuclear magnetic resonance spectroscopy. Sparingly, Bi-nHA ornamented scaffolds exhibit tremendous improvement (155%) in the mechanical properties with excellent antimicrobial activity against various human pathogens. After confirmation of high osteoconductivity, improved biodegradation, and excellent biocompatibility against osteoblast cells (in vitro), the scaffolds were implanted in rabbits by subcutaneous and intraosseous (tibial) sites. Various histological sections reveal the signatures of early cartilage formation, endochondral ossification, and rapid bone healing at 4 weeks of the critical defects filled with ornamented scaffold compared to SPU scaffold. This implies osteogenic potential and ability to provide an adequate biomimetic microenvironment for mineralization for GBR of the scaffolds. Organ toxicity studies further confirm that no tissue architecture abnormalities were observed in hepatic, cardiac, and renal tissue sections. This finding manifests the feasibility of fabricating a mechanically adequate nanofibrous SPU scaffold by a biomimetic strategy and the advantages of Bi-nHA ornamentatio

关键词： electrospun scaffold guided bone regeneration histology nanohydroxyapatite segmented polyurethane

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2-[(Hydroxymethyl)amino]ethanol in water as a preservative: Study of formaldehyde released by Taguchi's method

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IOP Conference Series: Earth and Environmental science 2016年第1期36卷

作者： W Wisessirikul S Loykulnant S Montha T Fhulua P Prapainainar Interdisciplinary Graduate Program in Advanced and Sustainable Environmental Engineering Thailand Advanced Institute of Science and Technology and Tokyo Institute of Technology Kasetsart University Bangkok 10900 Thailand Natural Rubber Focus Unit National Metal and Materials Technology Center NSTDA 111 Paholyothin Rd. Klong 1 Klong Luang Pathumthani 12120 Thailand Environment Research Unit National Metal and Materials Technology Center NSTDA 111 Paholyothin Rd. Klong 1 Klong Luang Pathumthani 12120 Thailand National Center of Excellence for Petroleum Petrochemicals and Advance Materials Department of Chemical Engineering Faculty of Engineering Kasetsart University Thailand Center of Excellence of Nanotechnology Kasetsart University Thailand

This research studied the quantity of free formaldehyde released from 2- [(hydroxymethyl)amino]ethanol (HAE) in DI water and natural rubber latex mixture using high-performance liquid chromatography (HPLC) technique. The quantity of formaldehyde retained in the solution was cross-checked by using titration technique. The investigated factors were the concentration of preservative (HAE), pH, and temperature. Taguchi's method was used to design the experiments. The number of experiments was reduced to 16 experiments from all possible experiments by orthogonal arrays (3 factors and 4 levels in each factor). Minitab program was used as a tool for statistical calculation and for finding the suitable condition for the preservative system. HPLC studies showed that higher temperature and higher concentration of the preservative influence the amount of formaldehyde released. It was found that conditions at which formaldehyde was released in the lowest amount were 1.6%w/v HAE, 4 to 40 °C, and the original pH. Nevertheless, the pH value of NR latex should be more than 10 (the suitable pH value was found to be 13). This preservative can be used to replace current preservative systems and can maintain the quality of latex for long-term storage. Use of the proposed preservative system was also shown to have reduced impact on the toxicity of the environment.

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Surface modification of yttria-stabilized tetragonal zirconia with different glass based liners

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Dental materials 2016年 32卷 e95-e96页

作者： D. Silva-Herzog Rivera D. Masuoka-Ito L.O. Sanchez-Vargas J.L. Menchaca-Arredondo A. Aragón-Piña B.I. Cerda-Cristerna Institutional Doctoral Program of Engineering and Materials Science Universidad Autónoma De San Luis Potosí México Mexico Dentistry Department Universidad Autónoma De Aguascalientes México Mexico Faculty of Physics and Mathematics Universidad Autónoma De Nuevo León México Mexico Research Center and Post-Graduate Studies Universidad Autónoma De San Luis Potosí México Mexico Faculty of Dentistry Río Blanco Universidad Veracruzana-Región Córdoba-Orizaba México Mexico

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A problem-based learning case study for teaching voice over internet protocol - VoIP: Using asterisk as a tool for teaching VoIP for information technology classes

A problem-based learning case study for teaching voice over ...

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6th International Conference on Computer Supported Education, CSEDU 2014

作者： Dias, M.C. Gabi, C.F. Rodrigues, E.P. Souza, V.R. Perkusich, A. Coordination of Electrical Engineering Federal Institute of Education Science and Technology of Paraíba - IFPB João Pessoa Brazil Post-Graduate Program in Electrical Engineering - PpgEE - COPELE Electrical Engineering Department Federal University of Campina Grande - UFCG Campina Grande Brazil

ISBN: (纸本)9789897580215

This paper shows the use of PBL (Problem-Based Learning) technique as a key to learning VoIP in courses like Electrical engineering and Computer Networks in conjunction with open source and the public domain software called Asterisk which was used to create the scenario of the experiment and the problems presented to the students. In order to make the validation, the experiment was applied to students of Bachelor in Electrical engineering and in Communication Technology System, undergraduate courses at the Federal Institute of Education, science and Technology of Paraíba - IFPB, in the Telephony subject, with promising results. The Asterisk software was presented as a useful and flexible tool for constructing scenarios and problems for the teaching of VoIP technologies and the used approach resulted as effective for improving the attainment of the defined learning objectives.

关键词： Teaching

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