Manufacturing and testing of 3D-printed polymer isogrid lattice cylindrical shell structures

This article focuses on the use of fused deposition modeling (FDM) technology to manufacture and test polymer isogrid lattice cylindrical shell (LCS) structures with equilateral triangular unit-cells using non-professional and conventional 3D printing software and hardware. A parametric and automated 3D model for these structures is created in SolidWorks using the Visual Basic (VBA) programming language. Different configurations of the isogrid LCS structure are modeled, manufactured, and tested in order to determine the compressive structural strength and stiffness, as well as to investigate structural instability. The experimental results are used to deduce the inherent limitations of 3D printing, including the inhomogeneities, imperfections, and non-isotropic nature of FDM, as well as the effect of the configurations on local buckling behavior. The results suggest that coupling between local and global buckling has an impact on the compressive stiffness and strength of LCS structures, reducing the accuracy of structural designs neglecting these effects.F71E-503E-DE74 | AD?LIO MANUEL DE SOUSA CAVADASN/

Methane production and energy partition in sheep fed timothy silage- or hay-based diets

Methane is produced as a result of anaerobic fermentation of the soluble and structural carbohydrates by methanogens in the rumen of ruminant animals. Removal of methane from rumen represents a loss of approximately 7.22% of gross energy intake.  Four ruminally fistulated Cheviot wethers were used in a crossover design to determine methane production and energy partition in sheep fed timothy silage- or hay-based diets. The experimental diets consisted of either timothy silage or timothy hay and a commercial concentrate (85:15, on DM basis). Variables measured were nutrients digestibility, energy balance and methane production. Apparent digestibilities of DM, OM, CP, NDF, ADF, cellulose and hemicellulose were significantly higher (P0.05) on sheep fed silage-based diet than those fed hay-based diet. Sheep fed silage-based diet had greater (P0.01) urinary energy loss, methane and heat production, but lower (P0.05) fecal energy loss. Methane production, either expressed as g kg-1 dry matter intake or g day-1 was markedly lower (P0.05) in hay-based diet as compared to silage-based diet. There was a strong relationship between methane production (g day-1) and NDF digested (g day-1) (R2 = 88.4%, P0.001). Methane production expressed as g kg-1 NDF digested in silage-based diet was higher (P0.05) than in hay-based diet (66.44 vs 62.70). These results indicate that methane release by sheep increased with increasing NDF digested. Key Words : Methane, Silage, Hay, Neutral detergent fiber, Shee

Meningkatkan Hasil Belajar Siswa Pada Mata Pelajaran IPS Dengan Menggunakan Metode Diskusi Di Kelas IV SD Inpres Watunonju

Permasalahan utama dan mendasar pada penelitian ini adalah rendahnya hasil belajar siswa pada pelajaran IPS kelas IV SD Inpres Watunonju. Tujuan penelitian untuk meningkatan hasil belajar siswa pada mata pelajaran IPS di kelas IV SD Inpres Watunonju melalui penerapan metode diskusi. Rancangan penelitian tindakan kelas ini dilakukan dalam dua siklus dan setiap siklus terdiri dari empat tahap yaitu (1) perencanaan (2) Pelaksanaan (3) observasi (4) refleksi. Pengumpulan data melalui teknik pemberian tes, wawancara, observasi dan pencatatan lapangan. Analisis data dilakukan melalui reduksi, penyajian dan penarikan kesimpulan. Subjek penelitian ini adalah siswa kelas IV SD Inpres Watunonju yang berjumlah 20 orang siswa. Hasil penelitian menunjukan data awal siswa yang kategori tuntas 4 orang atau presentase ketuntasan klasikal 20%. Pada siklus 1 banyak siswa yang tuntas 10 orang presentase ketuntasan klasikal 50%. Sedangkan Siklus II banyaknya siswa yang tuntas 19 orang, presentase ketuntasan klasikal 95%. Dari hasil penelitian yang dilaksanakan, maka dapat ditarik kesimpulan yaitu penerapan metode diskusi dalam proses pembelajaran, dapat meningkatkan hasil belajar siswa pada mata pelajaran IPS dikelas IV SD Inpres Watunonju. Hal ini dapat ditunjukan dari perolehan peningkatan secara klasikal siklus I dan siklus II. Penerapan metode diskusi hanyalah satu dari sekian banyak metode pembelajaran yang dapat digunakan. Para guru dapat mencari metode. Media atau strategi pembelajaran yang lain yang unik untuk meningkatkan kompetensi sisw

A 3D-printed continuously variable transmission for an electric vehicle prototype

This paper aims to present the design of a new 3D-printed continuously variable transmission (CVT) developed for an electric vehicle prototype competing in Shell Eco-marathon electric battery category, a world-wide energy efficiency competition sponsored by Shell. The proposed system is composed of a polymeric conic geared friction wheel assembled in the motor axle and directly coupled to the rear tire of the vehicle. The conical shape allows to implement a continuous variation of the geared friction wheel diameter in contact with the tire. The motor with the geared friction wheel was mounted over a board with linear bearings, allowing the speed ratio to change by moving the board laterally. A computational simulation model of a prototype electric vehicle with the proposed 3D-printed CVT was created in Matlab/Simulink environment to obtain the traction force in the geared friction wheel and also to analyze the vehicle performance. The simulation results demonstrated possibilities of increasing vehicle speed range output and available torque in the rear traction wheel. Also, it is shown with the simulated model that the designed CVT consumes 10.46% less energy than a fixed transmission ratio, demonstrating the CVT concept?s potential for battery consumption reduction. Lastly, a 3D-printing slicing software with an optimization algorithm plug-in was used to determine the best printing parameters for the conic geared friction wheel based on the tangential force, maximum displacement and safety factor. When compared to the original part with a 100% infill density, the optimized solution reduced the component mass by about 12% while maintaining safe mechanical resistance and stiffness.2314-4B69-C2B9 | C?sar Miguel de Almeida VasquesN/

Nanopositioning of a diamond nanocrystal containing a single NV defect center

Precise control over the position of a single quantum object is important for many experiments in quantum science and nanotechnology. We report on a technique for high-accuracy positioning of individual diamond nanocrystals. The positioning is done with a home-built nanomanipulator under real-time scanning electron imaging, yielding an accuracy of a few nanometers. This technique is applied to pick up, move and position a single NV defect center contained in a diamond nanocrystal. We verify that the unique optical and spin properties of the NV center are conserved by the positioning process.Comment: 3 pages, 3 figures; high-resolution version available at http://www.ns.tudelft.nl/q

Papel del Formato Comercial en la Lealtad al Establecimiento Minorista

En entornos altamente competitivos como los minoristas, caracterizados por una creciente heterogeneidad de la demanda y por la proliferaci¢n de nuevas formas comerciales, cada vez son m s comunes los comportamientos de compra cruzada entre establecimientos. Esto convierte la fidelizaci¢n de los clientes en un desaf¡o estrat‚gico clave para los operadores minoristas en la consolidaci¢n de su posici¢n en el mercado. Con el objeto de comprender mejor esta realidad, se establece un marco te¢rico explicativo de los distintos perfiles de lealtad al establecimiento minorista por parte de los consumidores. M s espec¡ficamente se analiza el papel de los formatos comerciales en la estructura de lealtad observable en el mercado. Mediante un an lisis emp¡rico sobre los patrones de gasto en alimentaci¢n de una muestra de 580 hogares espa¤oles se evidencia que, aunque los consumidores regularmente simultanean compras en distintos formatos comerciales, concretamente el supermercado, el descuento y el hipermercado, exhiben una alta lealtad comportamental hacia una £nica ense¤a dentro de cada tipo de formato seleccionado. El patr¢n observado pone de manifiesto que los formatos comerciales definen perfiles diferenciados de establecimiento afines a los beneficios buscados en distintas situaciones de compra.Lealtad al establecimiento, compra cruzada, formato comercial, comercio minorista de alimentaci¢n.

Associa??o de diclofenaco e code?na versus dexametasona para analgesia preemptiva em cirurgias de terceiros molares retidos: um ensaio cl?nico randomizado, controlado, triplo cego, boca dividida

A remo??o de terceiros molares inferiores retidos ? um procedimento invasivo com extenso trauma tecidual e resposta inflamat?ria p?s-operat?ria consider?vel. O objetivo deste estudo foi comparar o efeito da dexametasona 8mg (grupo controle) com o diclofenaco s?dico 50mg associados com fosfato de code?na 50mg (grupo experimental) para o controle da dor, edema e trismo, ap?s a exodontia dos terceiros molares inferiores impactados. Trinta terceiros molares inferiores de quinze pacientes saud?veis, com idade m?dia de 22,8 anos (desvio padr?o 12,62) receberam dose oral e ?nica de um dos f?rmacos uma hora antes de cada procedimento cir?rgico (dentes do lado esquerdo ou direito). Ap?s a cirurgia o edema foi aferido em 24, 48, 72 horas e 7 dias, sendo determinado por medidas lineares sobre o rosto, o trismo foi determinado pela abertura m?xima de boca. A dor p?s-operat?ria foi determinada pelo paciente atrav?s de uma escala visual de anal?gica, em intervalos de 24 horas, dentro de um per?odo total de 72 horas. A an?lise dos dados envolveu estat?stica descritiva, teste de Shapiro-Wilk, Wilcoxon, e teste T emparelhado (P<0,05). A dexametasona obteve melhores resultados nas an?lises de dor (p = 0,016) e edema (p = 0,08) no per?odo de 48 horas. N?o houve diferen?as estatisticamente significativas entre as drogas em rela??o ao trismo e ao n?mero de analg?sicos consumidos. Em conclus?o, a administra??o preventiva da dexametasona 8mg apresentou melhor controle da dor e edema nas exodontias bilaterais de terceiros molares inferiores impactados.Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Odontologia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016.Removing third retained molars is an invasive procedure with extensive tissue trauma and considerable postoperative inflammatory response. The aim of this study was to compare the effect of dexamethasone 8mg (control group) with diclofenac sodium 50mg associated with codeine phosphate 50 mg (experimental group) to control pain, swelling and trismus after extraction of third molars impacted. Thirty third molars fifteen healthy subjects with a mean age of 22.8 years (standard deviation 12.62) and received oral single dose of one of the drugs an hour before each surgery (teeth on the left or right). After surgery the edema was measured at 24, 48, 72 hours and 7 days, being determined by linear measurements on the face, trismus was determined by the maximum mouth opening. Postoperative pain was determined by the patient using a visual analogue scale at intervals of 24 hours, within a total period of 72 hours. The data analysis involved descriptive statistics, Shapiro-Wilk test, Wilcoxon test, and paired t-test (P <0.05). Dexamethasone better results in pain analysis (p = 0.016) and edema (p = 0.08) within 48 hours. There were no statistically significant differences between the drug relative to trismus, and the number of analgesics consumed. In conclusion, the preventive administration of dexamethasone 8mg showed better control of pain and edema in bilateral extractions of third molars impacted

As qualidades e benef?cios do poliestireno expandido (EPS) em compara??o a alvenaria convencional, viabilizando o conforto t?rmico

56 f. : il.Com o aumento da constru??o civil nas ?ltimas d?cadas, os pesquisadores atualmente se empenham em obter mais informa??es para melhorar a qualidade, desempenho, e produtividade no desenvolvimento das cidades sem afetar diretamente o meio ambiente. O Brasil por ser um pa?s tropical, em muitas ?pocas do ano o clima ? bem quente, consequentemente para atender o conforto t?rmico, o consumo de energia aumenta. Uma poss?vel solu??o para minimizar esse problema seria o uso de Poliestireno Expandido (EPS), entre dois blocos cer?micos proporcionando um isolamento interno e externo da edifica??o sem qualquer deforma??o, diminuindo assim o consumo de energia. O EPS vem ganhando espa?o na constru??o residencial e comercial. Por ser um material composto de ar e apenas 2% de poliestireno, tem se tornado excelente para economia e agilidade em uma obra. O que mais se destaca no EPS ? o isolamento t?rmico. Afinal, depois da obra finalizada o EPS ser? um otimo aliado contra o calor. Al?m disso, o isolamento t?rmico tem grande impacto na qualidade, durabilidade e economia de uma constru??o. Quando utilizado como veda??o interna o EPS atua na preven??o de mofo e umidade, j? que n?o absorve ?gua e n?o prolifera fungos e bact?rias. Dessa forma, conclui ? se com esse trabalho, que a utiliza??o do EPS em rela??o aos m?todos convencionais, demonstrou de fato proporcionar um maior conforto t?rmico