New Aerodynamic Studies of an Adaptive Winglet Application on the Regional Jet CRJ700

This study aims to evaluates how an adaptive winglet during flight can improve aircraft aerodynamic characteristics of the CRJ700. The aircraft geometry was slightly modified to integrate a one-rotation axis adaptive winglet. Aerodynamic characteristics of the new adaptive design were computed using a validated high-fidelity aerodynamic model developed with the open-source code OpenFoam. The aerodynamic model successively uses the two solvers simpleFoam and rhoSimpleFoam based on Reynold Averaged Navier Stokes equations. Characteristics of the adaptive winglet design were studied for 16 flight conditions, representative of climb and cruise usually considered by the CRJ700. The adaptive winglet can increase the lift-to-drag ratio by up to 6.10% and reduce the drag coefficient by up to 2.65%. This study also compared the aerodynamic polar and pitching moment coefficients variations of the Bombardier CRJ700 equipped with an adaptive versus a fixed winglet

On Brane Inflation Potentials and Black Hole Attractors

We propose a new potential in brane inflation theory, which is given by the arctangent of the square of the scalar field. Then we perform an explicit computation for inflationary quantities. This potential has many nice features. In the small field approximation, it reproduces the chaotic and MSSM potentials. It allows one, in the large field approximation, to implement the attractor mechanism for bulk black holes where the geometry on the brane is de Sitter. In particular, we show, up to some assumptions, that the Friedman equation can be reinterpreted as a Schwarzschild black hole attractor equation for its mass parameter.Comment: 12 pages. Reference updated and minor changes added. Version to appear in Int. J. Mod. Phys.

Variable cavity volume tooling for high-performance resin infusion moulding

This article describes the research carried out by Warwick under the BAE Systems/EPSRC programme ‘Flapless Aerial Vehicles Integrated Interdisciplinary Research – FLAVIIR’. Warwick's aim in FLAVIIR was to develop low-cost innovative tooling technologies to enable the affordable manufacture of complex composite aerospace structures and to help realize the aim of the Grand Challenge of maintenance-free, low-cost unmanned aerial vehicle manufacture. This article focuses on the evaluation of a novel tooling process (variable cavity tooling) to enable the complete infusion of resin throughout non-crimp fabric within a mould cavity under low (0.1 MPa) injection pressure. The contribution of the primary processing parameters to the mechanical properties of a carbon composite component (bulk-head lug section), and the interactions between parameters, was determined. The initial mould gap (di) was identified as having the most significant effect on all measured mechanical properties, but complex interactions between di, n (number of fabric layers), and vc (mould closure rate) were observed. The process capability was low due to the manual processing, but was improved through process optimization, and delivered properties comparable to high-pressure resin transfer moulding

Research on the Friction Properties of DP600 Stainless Steel as a Function of Bending Angle and Pin Diameter

[EN] The rapid evolution of materials and manufacturing processes, driven by global competition and new safety and environmental regulations has had an impact on automotive structures (Body In White; BIW) manufacturing. The need for lighter vehicles, with more equipment, that are safer and eco-friendly at the same time, relates to the entire life cycle of the car. Car and steelmakers agree that weight reduction is possible, and the solution involves the use of new advanced high-strength steels. Thinner and stronger materials lead to higher demands on stamping, the most used manufacturing in BIW parts. The use of advanced high-strength steels raises new challenges, especially concerning the lubrication between the die and the sheet. To study the lubrication conditions of the stamping process, a sheet metal forming a simulator was developed. The simulator consists of two cylinders that pull the strip of steel and a pin in between. The angle between the cylinders can be adjusted from 0 to 90 degrees, which allows analysis of the effect of the stamping angle. The pull force and velocity can be set and measured, and the peripheric pin velocity, the strain, and the strain velocity can be measured as well. In this work, the tribological properties of Dual-Phase 600 stainless steel using different processing conditions have been analyzed. To this end, a factorial experiments design with twelve parameters that compare the behavior of different angles and diameters was run. The results showed that the friction coefficient increases by increasing the bending angle and decreases with pin diameter.Sanchez-Caballero, S.; Sellés, M.; Pla-Ferrando, R.; Segui Llinares, VJ.; Peydro, MA. (2021). Research on the Friction Properties of DP600 Stainless Steel as a Function of Bending Angle and Pin Diameter. Materials Proceedings. 3(1):1-7. https://doi.org/10.3390/IEC2M-09248173

INDUÇÃO AO ESTRO EM BOVINOS DE CORTE

O anestro puerperal em novilhas de 1º cria, é um dos principais fatores para diminuição dos índices de fertilidade no rebanho bovino de corte do Brasil. Atualmente são apresentadas diversas metodologias que buscam a reversão desse anestro, algumas relacionadas às ações de manejo. O presente trabalho objetivou testar um protocolo empregando, manejo de mamada interrompida e suplementação com mistura múltipla, comparando-se ao sistema tradicional da vaca com o bezerro-ao-pé. Os animais foram divididos em dois grupos. O Grupo 1 (N=160 - tratado), formado por animais que foram trabalhados com alteração de manejo ou seja mamada interrompida (aparte de 48 horas dos bezerros, quinzenalmente) e suplementados com um sal energético, disponibilizado para consumo de 300 g/dia, e o Grupo 2 de animais (testemunha - N= 160), sem o regime de mamada interrompida e sem o sal mineral energético. Os animais iniciaram o período de monta de 41 a 90 dias pós-parto, permanecendo com touros por período de 60 dias. Sessenta dias após a retirada dos touros foi feito o diagnóstico de gestação por palpação retal, atingido-se o seguinte resultado: O Grupo 1 de animais (tratado), demostrou eficiencia ao reverter o anestro, resultando em 60,6% de prenhez, ao passo que o grupo testemunha atingiu somente 36,9% dentro do mesmo período de serviço. Estrus induction in beef cattle Abstract The absence of puerperal heat postpartum anestrus in first offspring heifers is one of the major factors for the reduction of fertility in the Brazilian beef cattle herd. Nowadays, there are various methods to revert the anestrus, some related to management. Our aim was to test one protocol with calf milk restriction and energetic diet supplementation, comparing to a traditional method in reverting post partum anestrus. Animals were randomized in 2 groups. In group 1 (treatment) calves had milk restriction (48 hours, every 15 days) (N=160) and had been supplemented with white salt, minerals, soy and corn, calibrated to a daily consumption of 300g/day, and it had been compared to the group B (control group) (N=160). Animals were exposed to mating 41 to 90 days after parturition, staying with bulls for a 60 days period. After 60 days the females had been separated from bulls and gestation diagnostic performed by rectal palpation. The following results were obtained: Group 1 60,6% pregnancy, showing efficacy in reverting anestrus in first off spring heifers. Control group had only 36,9% pregnancy

Interference in the plasmon field excited by a diatomic molecule on metallic cylindrical nanostructures

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Palma de Majorque, la ville, le tourisme et le territoire

« Palma de Majorque, la ville, le tourisme et le territoire », Philippe Duhamel, Rémy Knafou et Miguel Seguí-Llinàs, in Vallat C. (dir.) Petites et grandes villes du Bassin Méditerranéen. Études autour de l’œuvre d’Étienne Dalmasso, École Française de Rome, p. 171-193

A SOMATOTROPINA RECOMBINANTE BOVINA (bST) E A DINÂMICA FOLICULAR EM BOVINOS LEITEIROS

The aim of the present research was to determine the influence of the recombinant bovine somatotropin (bST) on the reproduction of Black and White Holstein bovine females being evaluated along a complete estrous cycle. The follicular dynamics has been observed in regard to the diameter of the ovaries, number of follicular waves during the estrous cycle, duration of each follicular wave, number and diameter of the recruited follicles. Twelve females were used for the experiment, being six of the control group and six of the treated group, chosen at random. The treatment was carried out by administration of a dose of bovine recombinant somatotropin in the sixtieth day post partum (pp). The ovaries follicular dynamics was followed by daily ultrasound exams starting from the day of the first estrus base (visible estrus, considered the 0 day) post partum, until the animals manifested new estrous. In the 60th day the animals of the treated group received an injection of bST (500 mg, SC) and the animals of the group control, 1,4 ml of physiologic solution (SC), as placebo. For the ovarian monitoring of the animals, ultrasound apparel was used with transducer of 5 MHz. It has been observed that the bovine recombinant somatotropin administered in the 2nd month pp, did not display significant influence on the ovarian activity of the animals, the rate of daily milk production being increased only in 3,5%. The studies on the follicular dynamics and the bovine recombinant somatotropin didnt alter the length of the estrous cycle, the diameter of the ovaries, the number of waves follicular, the length of each wave, the number and the diameter of the recruited follicles.O trabalho objetivou determinar a influência da somatotropina recombinante bovina (bST) sobre a reprodução de vacas da raça Holandesa Preta e Branca. Durante um ciclo estral, verificou-se via ultrassonografia, a dinâmica folicular acompanhando-se particularmente o diâmetro dos ovários, o número de ondas foliculares durante o ciclo estral, a duração de cada onda folicular, o número e diâmetro dos folículos recrutados. Foram utilizadas doze fêmeas, sendo seis do grupo controle e seis do grupo tratado, escolhidas ao acaso. O tratamento foi executado mediante administração de uma dose de somatotropina recombinante bovina no sexagésimo dia post partum (pp). A dinâmica folicular dos ovários foi acompanhada por exames ultrassonográficos diários a partir do dia o (estro base e visível) após o parto, até que os animais manifestassem novo cio. No 60º dia os animais do grupo tratado receberam uma injeção de bST (500 mg, SC) e os animais do grupo controle, 1,4 ml de solução fisiológica estéril (SC), como placebo. Para o monitoramento ovariano dos animais, foi utilizado aparelho de ultrassonografia com transdutor de 5 MHz. Concluiu-se que a somatotropina recombinante bovina administrada no 2º mês pp, não exerceu significativa influência sobre a atividade ovariana dos animais, muito embora tenha havido aumento da produção leiteira diária em 3,5% durante o período pesquisado. Os estudos da dinâmica folicular e a somatotropina recombinante bovina não alteraram, o comprimento do ciclo estral, o diâmetro dos ovários, o número de ondas foliculares, o comprimento de cada onda, o número e o diâmetro dos folículos recrutados

Efficiency of artificial insemination with sexed semen in cattle: reproductive viability

A técnica de citometria de fluxo tem sido utilizada com sucesso visando a sexagem de espermatozóides, gerando bezerros ou bezerras, de acordo com a preferência do produtor. O objetivo do presente experimento foi avaliar a taxa de nascimento ao utilizar um sêmen comercial sexado e comparar a eficiência com sêmen não sexado, bem como analisar o custo-benefício do sêmen sexado. Foram utilizadas 342 novilhas da raça Nelore localizada no município de Guaraniaçu-PR. O experimento foi realizado em outubro e novembro de 2006. Todos os animais pertenciam à mesma categoria animal com idade de 24 meses. Os animais eram criados a pasto (Brachiaria decumbens) em sistema de rotação de pastagem, com suplementação de sal mineral nos cochos. Foram formados dois grupos de animais: Grupo I (controle) formado por 155 novilhas e Grupo II (sêmen sexado) por 187 novilhas. Os animais estavam com o escore da condição corporal entre 2,5 e 3,0 (variação de 1 a 5). Em ambos os grupos de novilhas foi realizada a IA com observação de estro (manhã e tarde), inseminando-se 12 horas após a observação. No grupo I foi utilizado um sêmen comercial não sexado de um touro Nelore, proveniente de uma Central de coleta e congelamento. No grupo II foi utilizado um sêmen sexado para gerar fêmea, proveniente da mesma Central de IA. Os resultados demonstraram uma diferença significativa entre as taxas de nascimento (P<0,05), de 23% para o sêmen sexado e 46,45% para o convencional, gerando um aumento no custo do bezerro produzido com o sêmen sexado. Apesar da reduzida taxa de prenhez do sêmen sexado, a acurácia da sexagem, observada no nascimento foi de 93,02%.The insemination with sorted sperm by flow-cytometry technique has been used successfully to produce male or female calves, according to the choice of the producer. The aim of this experiment was to evaluate the rate of birth of a commercial sorted sperm and compare its efficiency with non sexed semen and analyse the economic viability of the sexed semen. The experiment was conducted in October and November 2006, at Guaraniaçu-PR, where 342 Nellore heifers were used. All animals belonged to the same category and age (24 months). The animals were managed in a system of rotation of pasture (Brachiaria decumbens), with mineral supplementation. They were separated in two groups: Group I (control) formed by 155 heifers and Group II (sexed sperm) formed by 187 heifers. The animals body condition scores were between 2.5 and 3.0 (range from 1 to 5). Artificial insemination was carried out in both groups followed by the observation of estrus system (morning and afternoon), the insemination being occurred 12 hours after the estrus. In group I was used a commercial not sexed semen of a Nellore bull, from a company of collection and freezing semen. In group II was used sexed female semen, from the same company of IA. The results showed a significant difference in the rates of birth (P<0.05), 23% in the sexed semen and 46.45% for conventional, generating an increase in the cost of calf produced with sexed semen. The accuracy of sexed semen was 93,02%

Finite elements analysis and multiobjective optimization: A way to reduce material and manufacturing cost

The aim of this paper is to introduce a method to reduce the weight in structures which are subjected to multiple restrictions like deformation, max allowable stress, natural frequency, etc.. The method is shown through the analysis of an aluminum bracket, whose maximum stress and deformation is well defined. The analysis is done using the Structural and Design of Experiments modules of Ansys Workbench v12.1. As result of the method a weight reduction of 50,2% is achieved.Sanchez-Caballero, S.; Sellés Cantó, MÁ.; Pla-Ferrando, R.; Segui Llinares, VJ. (2012). Finite elements analysis and multiobjective optimization: A way to reduce material and manufacturing cost. AIP Conference Proceedings. 1431:719-724. doi:10.1063/1.4707628S719724143