Improved AdS/QCD Model with Matter

We study an improved AdS/QCD model at finite temperature and chemical potential. An Ansatz for the beta-function for the boundary theory allows for the derivation of a charged dilatonic black hole in bulk. The solution is asymptotically RN-AdS in the UV and AdS2 * R3 in the IR. We discuss the thermodynamical aspects of the solution. The fermionic susceptibilities are shown to deviate from the free fermionic limits at asymptotic temperatures despite the asymptotically free nature of the gauge coupling at the boundary. The Polyakov line, the temporal and spatial string tensions dependence on both temperature and chemical potential are also discussed

Beats of the Magnetocapacitance Oscillations in Lateral Semiconductor Superlattices

We present calculations on the magnetocapacitance of the two-dimensional electron gas in a lateral semiconductor superlattice under two-dimensional weak periodic potential modulation in the presence of a perpendicular magnetic field. Adopting a Gaussian broadening of magnetic-field-dependent width in the density of states, we present explicit and simple expressions for the magnetocapacitance, valid for the relevant weak magnetic fields and modulation strengths. As the modulation strength in both directions increase, beats of the magnetocapacitance oscillations are observed, in the low magnetic field range (Weiss-oscillations regime), which are absent in the one-dimensional weak modulation case.Comment: 11 pages, 7 figures, accepted by Mod. Phys. Lett. B (March 2007

Higgs Properties in the Fourth Generation MSSM: Boosted Signals Over the 3G Plan

The generalization of the MSSM to the case of four chiral fermion generations (4GMSSM) can lead to significant changes in the phenomenology of the otherwise familiar Higgs sector. In most of the 3GMSSM parameter space, the lighter CP-even $h$ is $\sim 115-125$ GeV and mostly Standard Model-like while $H,A,H^\pm$ are all relatively heavy. Furthermore, the ratio of Higgs vevs, $\tan \beta$, is relatively unconstrained. In contrast to this, in the 4GMSSM, heavy fourth generation fermion loops drive the masses of $h,H,H^\pm$ to large values while the CP-odd boson, $A$, can remain relatively light and $\tan \beta$ is restricted to the range 1/2 \lsim \tan \beta \lsim 2 due to perturbativity requirements on Yukawa couplings. We explore this scenario in some detail, concentrating on the collider signatures of the light CP-odd Higgs at both the Tevatron and LHC. We find that while $gg \to A$ may lead to a potential signal in the $\tau^+\tau^-$ channel at the LHC, $A$ may first be observed in the $\gamma \gamma$ channel due to a highly loop-enhanced cross section that can be more than an order of magnitude greater than that of a SM Higgs for $A$ masses of $\sim 115-120$ and $\tan\beta<1$. We find that the CP-even states $h,H$ are highly mixed and can have atypical branching fractions. Precision electroweak constraints, particularly for the light $A$ parameter space region, are examined in detail.Comment: 20 pages, 7 figures; typos fixed, refs adde

Manajemen Sumber Daya Teknologi Informasi Laboratorium Komputer Menggunakan Balanced Scorecard (BSC) Dan COBIT 5

Laboratorium komputer merupakan salah satu sarana pembelajaran yang berbasis Teknologi Informasi (TI) yang terdiri dari tiga sumber daya TI, yaitu software, hardware, dan brainware. Tidak adanya kesesuaian antara kemampuan hardware dengan spesifikasi hardware yang digunakan dapat menghambat pengguna (brainware) dalam melakukan praktikum dan pembelajaran di laboratorium. Selain itu, ketidaksesuaian tersebut juga mengakibatkan software berjalan lambat dan computer sering error sehingga praktikum menjadi terganggu dan berjalan tidak lancar. Untuk mengetahui kesesuaian antar sumber daya TI yang ada di laboratorium dibutuhkan proses pengukuran manajemen sumber daya TI yang ada saat ini. Skala likert menjadi salah satu metode untuk mengukur kinerja software, hardware, dan tata kelola laboratorium saat ini. Hasil pengukuran kemudian dievaluasi menggunakan framework Balance Scorecard (BSC) dengan melalui beberapa tahapan dan penyelarasan strategi TI. Setelah mengetahui hasil evaluasi dan kendala-kendala apa saka yang ada dalam melakukan pengelolaan maka langkah berikutnya adalah menentukan bagaimana cara memperbaiki dan melakukan peningkatan tata kelola TI. COBIT 5 akan menjadi framework pelengkap untuk memperbaiki sekaligus memprediksi pengembangan manajemen sumber daya TI. Hasil penelitian ini menunjukkan bahwa integrase antara COBIT 5 dengan Balance Scorecard (BSC) memberikan kemampuan dalam melakukan pengukuran tata kelola laboratorium serta memberikan kemampuan untuk meningkatkan pelayanan secara kontinyu

Study and modification of the reactivity of carbon fibers

The reactivity to air of polyactylonitrile-based carbon fiber cloth was enhanced by the addition of metals to the cloth. The cloth was oxidized in 54 wt% nitric acid in order to increase the surface area of the cloth and to add carbonyl groups to the surface. Metal addition was then achieved by soaking the cloth in metal acetate solution to effect exchange between the metal carbon and hydrogen on the carbonyl groups. The addition of potassium, sodium, calcium and barium enhanced fiber cloth reactivity to air at 573 K. Extended studies using potassium addition showed that success in enhancing fiber cloth reactivity to air depends on: extent of cloth oxidation in nitric acid, time of exchange in potassium acetate solution and the thoroughness of removing metal acetate from the fiber pore structure following exchange. Cloth reactivity increases essentially linearly with increase in potassium addition via exchange

A Perturbative Approach to the Relativistic Harmonic Oscillator

A quantum realization of the Relativistic Harmonic Oscillator is realized in terms of the spatial variable $x$ and {\d\over \d x} (the minimal canonical representation). The eigenstates of the Hamiltonian operator are found (at lower order) by using a perturbation expansion in the constant $c^{-1}$. Unlike the Foldy-Wouthuysen transformed version of the relativistic hydrogen atom, conventional perturbation theory cannot be applied and a perturbation of the scalar product itself is required.Comment: 9 pages, latex, no figure

Modelling and design smart controller of magneto rheological using bouc-wen and sim model for motorcycle suspension system

Suspension system is a type of structural equipment attached to the wheels of a vehicle for the purpose of reducing the effects of irregularities on road surfaces. This paper investigates the Magneto rheological (MR) suspension system in motorcycle and compares its advantages with the passive suspension system. Passive suspension element can only store and dissipate energy associated with local relative motion. Moreover its energy cannot be controlled as the suspension properties remain fixed at all time, unlike MR suspension which has the ability to overcome these drawbacks. The characteristic of the latter is related to micron-sized particles, typically iron, that forms particle chains, when appropriate electric field is applied. Two modelling approaches which are the Bouc-Wen model and Sim models, were used in this research. By comparing these two MR models and passive suspension system, it can be concluded that the Bouc-Wen model gives the best result. It is also shown that MR suspension systems reduce the displacement amplitude around 30% whereas the time settling is reduced from 10 to 3 seconds, compared to the passive suspension system

Root uptake of lipophilic zinc-rhamnolipid complexes

This study investigated the formation and plant uptake of lipophilic metal-rhamnolipid complexes. Monorhamnosyl and dirhamnosyl rhamnolipids formed lipophilic complexes with copper (Cu), manganese (Mn), and zinc (Zn). Rhamnolipids significantly increased Zn absorption by Brassica napus var. Pinnacle roots in 65Zn-spiked ice-cold solutions, compared with ZnSO4 alone. Therefore, rhamnolipid appeared to facilitate Zn absorption via a nonmetabolically mediated pathway. Synchrotron XRF and XAS showed that Zn was present in roots as Zn-phytate-like compounds when roots were treated with Zn-free solutions, ZnSO4, or Zn-EDTA. With rhamnolipid application, Zn was predominantly found in roots as the Zn-rhamnolipid complex. When applied to a calcareous soil, rhamnolipids increased dry matter production and Zn concentrations in durum (Triticum durum L. cv. Balcali-2000) and bread wheat (Triticum aestivum L. cv. BDME-10) shoots. Rhamnolipids either increased total plant uptake of Zn from the soil or increased Zn translocation by reducing the prevalence of insoluble Zn-phytate-like compounds in roots

Zeroing in on Supersymmetric Radiation Amplitude Zeros

Radiation amplitude zeros have long been used to test the Standard Model. Here, we consider the supersymmetric radiation amplitude zero in chargino-neutralino associated production, which can be observed at the luminosity upgraded LHC. Such an amplitude zero only occurs if the neutralino has a large wino fraction and hence this observable can be used to determine the neutralino eigenstate content. We find that this observable can be measured by comparing the p_T spectrum of the softest lepton in the trilepton $\chi_1^\pm \chi_2^0$ decay channel to that of a control process such as $\chi_1^+ \chi_1^-$ or $\chi_2^0 \chi_2^0$. We test this technique on a previously generated model sample of the 19 dimensional parameter space of the phenomenological MSSM, and find that it is effective in determining the wino content of the neutralino.Comment: 19 pages, 7 figure

Uniqueness of nontrivially complete monotonicity for a class of functions involving polygamma functions

For $m,n\in\mathbb{N}$, let $f_{m,n}(x)=\bigr[\psi^{(m)}(x)\bigl]^2+\psi^{(n)}(x)$ on $(0,\infty)$. In the present paper, we prove using two methods that, among all $f_{m,n}(x)$ for $m,n\in\mathbb{N}$, only $f_{1,2}(x)$ is nontrivially completely monotonic on $(0,\infty)$. Accurately, the functions $f_{1,2}(x)$ and $f_{m,2n-1}(x)$ are completely monotonic on $(0,\infty)$, but the functions $f_{m,2n}(x)$ for $(m,n)\ne(1,1)$ are not monotonic and does not keep the same sign on $(0,\infty)$.Comment: 9 page