Properties of Reactive Oxygen Species by Quantum Monte Carlo

The electronic properties of the oxygen molecule, in its singlet and triplet states, and of many small oxygen-containing radicals and anions have important roles in different fields of Chemistry, Biology and Atmospheric Science. Nevertheless, the electronic structure of such species is a challenge for ab-initio computational approaches because of the difficulties to correctly describe the statical and dynamical correlation effects in presence of one or more unpaired electrons. Only the highest-level quantum chemical approaches can yield reliable characterizations of their molecular properties, such as binding energies, equilibrium structures, molecular vibrations, charge distribution and polarizabilities. In this work we use the variational Monte Carlo (VMC) and the lattice regularized Monte Carlo (LRDMC) methods to investigate the equilibrium geometries and molecular properties of oxygen and oxygen reactive species. Quantum Monte Carlo methods are used in combination with the Jastrow Antisymmetrized Geminal Power (JAGP) wave function ansatz, which has been recently shown to effectively describe the statical and dynamical correlation of different molecular systems. In particular we have studied the oxygen molecule, the superoxide anion, the nitric oxide radical and anion, the hydroxyl and hydroperoxyl radicals and their corresponding anions, and the hydrotrioxyl radical. Overall, the methodology was able to correctly describe the geometrical and electronic properties of these systems, through compact but fully-optimised basis sets and with a computational cost which scales as $N^3-N^4$, where $N$ is the number of electrons. This work is therefore opening the way to the accurate study of the energetics and of the reactivity of large and complex oxygen species by first principles

Observational tests for oscillating expansion rate of the Universe

We investigate the observational constraints on the oscillating scalar field model using data from type Ia supernovae, cosmic microwave background anisotropies, and baryon acoustic oscillations. According to a Fourier analysis, the galaxy number count $N$ from redshift $z$ data indicates that galaxies have preferred periodic redshift spacings. We fix the mass of the scalar field as $m_\phi=3.2\times 10^{-31}h$ ${\rm eV}$ such that the scalar field model can account for the redshift spacings, and we constrain the other basic parameters by comparing the model with accurate observational data. We obtain the following constraints: $\Omega_{m,0}=0.28\pm 0.03$ (95% C.L.), $\Omega_{\phi,0} -158$ (95% C.L.) (in the range $\xi \le 0$). The best fit values of the energy density parameter of the scalar field and the coupling constant are $\Omega_{\phi,0}= 0.01$ and $\xi= -25$, respectively. The value of $\Omega_{\phi,0}$ is close to but not equal to $0$. Hence, in the scalar field model, the amplitude of the galaxy number count cannot be large. However, because the best fit values of $\Omega_{\phi,0}$ and $\xi$ are not $0$, the scalar field model has the possibility of accounting for the periodic structure in the $N$--$z$ relation of galaxies. The variation of the effective gravitational constant in the scalar field model is not inconsistent with the bound from observation.Comment: 9 pages, 11 figures, 1 table, Accepted for publication in Physical Review

UJI DIAGNOSTIK FNAB (FINE NEEDLE ASPIRATION BIOPSY) DIBANDINGKAN DENGAN BIOPSI PATOLOGI ANATOMI DALAM MENDIAGNOSIS KARSINOMA TIROID

Latar Belakang : Diperkirakan terdapat 0,5-10 kasus per 100.000 penduduk yang menderita nodul tiroid pada populasi dunia. Nodul tiroid yang bersifat ganas memerlukan terapi secepatnya, sedangkan yang jinak dapat diterapi secara medikamentosa. FNAB merupakan langkah diagnostik awal pengelolaan nodul tiroid. Tehnik FNAB aman, murah, dapat dipercaya dan resiko komplikasi kecil. Tujuan : Menjelaskan nilai diagnostik FNAB dibandingkan dengan biopsi patologi anatomi dalam mendiagnosis karsinoma tiroid pada pasien di RSUP Dr. Kariadi Semarang Metode: Subyek penelitian adalah pasien RSUP Dr. Kariadi Semarang yang memiliki nodul tiroid yang telah diperiksa menggunakan FNAB dan Biopsi Patologi Anatomi. Data hasil pemeriksaan FNAB dan biopsi Patologi Anatomi dari setiap sampel kemudian dikumpulkan untuk dianalisis sesuai rumus untuk mencari sensitifitas, spesifitas, nilai ramal positif, dan nilai ramal negatif. Hasil : Total sampel yang didapatkan adalah 34 sampel. Pada penelitian ini didapatkan nilai sensitifitas FNAB 100%, spesifitas 84%, nilai ramal positif 69%, dan nilai ramal negatif 100%. Kesimpulan : FNAB mempunyai nilai diagnostik yang baik untuk mendiagnosis karsinoma tiroid. Kata kunci : Uji diagnostik, FNAB, karsinoma tiroi

Karakteristik Biografis dan Pengaruhnya terhadap Kinerja Individual yang Dimediasi oleh Kepuasan Kerja

Tujuan Penelitian – Penelitian ini bertujuan untuk mengetahui apakah terdapat pengaruh dari karakteristik biografis terhadap kepuasan kerja dan kinerja individual serta apakah kepuasan kerja mampu menjadi variabel mediasi antara karakteristik biografis dengan kinerja individual.Desain/Metodologi/Pendekatan – Penelitian ini merupakan penelitian kausalitas dan data yang digunakan adalah data kuantitatif. Data dikumpulkan dengan menggunakan kuesioner dengan jumlah sampel 220 orang. Data dianalisis menggunakan analisis jalur.Temuan – 1) Tidak ada pengaruh karakteristik biografis terhadap kinerja individual, 2) Ada pengaruh karakteristik biografis dan kepuasan kerja secara bersama-sama terhadap kinerja individual, dan 3) Kepuasan kerja mampu menjadi variabel mediasi (intervening) antara karakteristik biografis dan kinerja individual dosen.Keterbatasan Penelitian – Untuk penelitian selanjutnya dapat ditambahkan variabel lainnya seperti karakteristik pekerjaan dan karakteristik organisasi

VLSI Implementation of Discrete Cosine Transform Based on the Shared-Multiplier Algorithm

In this paper a new algorithm for discrete cosine transform (DCT) is proposed. This algorithm is especially efficient for VLSI implementation because each multiplier in @e 1-D DCT is shared by two constants rather than one. This greatly reduces the chip area, and the high speed characteristics are still retained. Based on this algorithm, we have developed the corresponding bit-parallel, fully-pipelined architecture for the size-8 DCT. The core area of the chip is only 8.6mm x 8.5mm, using 1.2um double-metal single-poly CMOS technology. This chip is simulated for operation at the maximum speed of 100 MHz which far exceeds the speed requirement of the HDTV system (70 MHz)

Microcracks, spall and fracture in glass : A study using short pulsed laser shock waves

Copyright 1998 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Journal of Applied Physics, 83(7), 3583-3594, 1998 and may be found at http://dx.doi.org/10.1063/1.36657

Evaluation of Avifauna Species Found in the Area of PT Arutmin Indonesia-NPLCT, Kota Baru, South Kalimantan

Avifauna is a biological aspect, which is easy to use as a decision making to arrange the development of the mining-product port area on postmining. The objective of the research was to evaluate composition of avifauna species in the area of PT Arutmin Indonesia – NPLCT based on the presence or the residence, the preference to the habitat type, the dominant diet, and the propagation indicator. Evaluation was conducted through grouping the field data or published databased on such four parameters and comparing to the references. Among 57 avifauna species in the area, 39 are resident, because they were always found in all observations. A single species is an endemic to Kalimantan. Five other species may be migrants originating relatively far from the research area. Avifauna was likely to prefer secondary forest to other habitat types. Based on dominant diet, there were frugivore, granivore, insectivore, carnivore, nectarivore, omnivore, and piscivore. Various nests were found and those reflected opportunity the birds to propagate in the are