Analisis Prinsip Energi Pada Metode Elemen Hingga Tinjauan Pemodelan Elemen Uniaksial Kuadratik Terhadap Elemen Uniaksial Kubik

Kekakuan elemen adalah dengan menggunakan prinsip energi potensial minimum (the principle ofminimum potential energy). Cara ini sangat tepat digunakan untuk memperoleh persamaankeseimbangan sebuah elemen yang kompleks yang memiliki derajat kebebasan yang tinggi. Prinsipenergi potensial minimum hanya berlaku untuk bahan yang bersifat elastis maupun plastis. Namundemikian kedua prinsip tersebut akan memberikan persamaan keseimbangan elemen yang sama untukkondisi material yang bersifat elastis. Energi potensial total benda elastik terdiri dari energi reganganyang timbul pada saat terjadinya distorsi dan energi potensial beban yang bekerja di dalam ataudipermukaan benda elastik tersebut. Rumusan dari energi potensial sebuah benda elastik dapatdigunakan untuk memformulasi matriks kekakuan elemen dan vektor beban. Jika sebuah batanguniaksial yang dibebani beban aksial merata dan beban terpusat yang berada ditengah bentangan,dengan menggunakan prinsip energi potensial stasioner, maka dapat ditentukan gaya yang timbul danbesarnya arah perpindahan yang terjadi. Hasil analisis yang diperoleh menggunakan metode elemenhingga menyatakan bahwa dengan menggunakan Elemen Kubik lebih baik dalam mendiskripsikanarah perpindahan yang terjadi dibandingkan Elemen Kuadratik. Berbeda dengan hasil gaya yangterjadi, dimana hasil yang diperoleh elemen kuadratik lebih besar dibandingkan Elemen Kubik

Efeito do óleo essencial de citronela sobre a mortalidade e oviposição do caruncho do feijão-caupi.

Resumo 0626

Enraizamento in vitro de Inhame da Costa (Dioscorea rotundata).

Com o objetivo de otimizar o meio de cultura para promover o enraizamento de plantas de inhame in vitro, microestacas de plantas de Inhame da Costa (Dioscorea rotundata) pré-estabelecidas in vitro foram utilizadas como fonte de explantes iniciais e cultivadas em meios de cultura com diferentes concentrações de sais e vitaminas do MS e doses de carvão ativado. Aos 30 dias, avaliaram-se as seguintes variáveis: altura de planta, número de folhas e de raízes. A utilização do meio ½ MS com 1,0 g de carvão ativado promoveu um melhor desenvolvimento (maior altura e maior número de folhas) das plantas de inhame. Quando se comparou os diferentes tipos de meio, o meio ½ MS também foi o mais adequado para promover o enraizamento das plantas de inhame in vitro utilizando 0,5 ou 1g L-1 de carvão ativado

Influence of realistic parameters on state-of-the-art LWFA experiments

We examine the influence of non-ideal plasma-density and non-Gaussian transverse laser-intensity profiles in the laser wakefield accelerator analytically and numerically. We find that the characteristic amplitude and scale length of longitudinal density fluctuations impacts on the final energies achieved by electron bunches. Conditions that minimize the role of the longitudinal plasma density fluctuations are found. The influence of higher order Laguerre-Gaussian laser pulses is also investigated. We find that higher order laser modes typically lead to lower energy gains. Certain combinations of higher order modes may, however, lead to higher electron energy gains.Comment: 16 pages, 6 figures; Accepted for publication in Plasma Physics and Controlled Fusio

Micropropagação de inhame da costa (Dioscorea rotundata) em diferentes intensidades luminosa.

Microestacas de plantas de inhame da costa (Dioscorea rotundata) pré-estabelecidas in vitro foram utilizadas como fonte de explantes iniciais e cultivadas em meio MS, contendo 100 mg L-1 de inositol, 20 mg L-1 de cisteina, 0,20 mg L-1 de ANA, 0,15 mg L-1 de BAP e 0,08 mg L-1 de GA3 testando diferentes intensidade luminosa. Aos 30 dias, avaliaram-se as seguintes variáveis: número de brotos e de folhas e altura de planta. As melhores respostas para os números de brotos formados ocorreram com os explantes cultivados em sala de crescimento 100% iluminada. Contudo verificou-se que a maior média para a altura de planta e a maior número de folhas foi encontrada com 30 % de iluminação

Very High Mach Number Electrostatic Shocks in Collisionless Plasmas

The kinetic theory of collisionless electrostatic shocks resulting from the collision of plasma slabs with different temperatures and densities is presented. The theoretical results are confirmed by self-consistent particle-in-cell simulations, revealing the formation and stable propagation of electrostatic shocks with very high Mach numbers ($M \gg 10$), well above the predictions of the classical theories for electrostatic shocks.Comment: 6 pages, submitted to Phys. Rev. Let

Successful Yukawa structures in Warped Extra Dimensions

For a RS model, with SM fields in the bulk and the Higgs boson on the TeV-brane, we suggest two specific structures for the Yukawa couplings, one based on a permutation symmetry and the other on the Universal Strength of Yukawa couplings hypothesis (USY). In USY, all Yukawa couplings have equal strength and the difference in the Yukawa structure lies in some complex phase. In both scenarios, all Yukawa couplings are of the same order of magnitude. Thus, the main features of the fermion hierarchies are explained through the RS geometrical mechanism, and not because some Yukawa coupling is extremely small. We find that the RS model is particularly appropriate to incorporate the suggested Yukawa configurations. Indeed, the RS geometrical mechanism of fermion locations along the extra dimension, combined with the two Yukawa scenarios, reproduces all the present experimental data on fermion masses and mixing angles. It is quite remarkable that in the USY case, only two complex phases of definite value +-Pi/2 are sufficient to generate the known neutrino mass differences, while at same time, permitting large leptonic mixing in agreement with experiment.Comment: 11 page