Non-relativistic Lee Model on two Dimensional Riemannian Manifolds

This work is a continuation of our previous work (JMP, Vol. 48, 12, pp. 122103-1-122103-20, 2007), where we constructed the non-relativistic Lee model in three dimensional Riemannian manifolds. Here we renormalize the two dimensional version by using the same methods and the results are shortly given since the calculations are basically the same as in the three dimensional model. We also show that the ground state energy is bounded from below due to the upper bound of the heat kernel for compact and Cartan-Hadamard manifolds. In contrast to the construction of the model and the proof of the lower bound of the ground state energy, the mean field approximation to the two dimensional model is not similar to the one in three dimensions and it requires a deeper analysis, which is the main result of this paper.Comment: 18 pages, no figure

Business Development in Renewable Energy (Case Study: Independent Power Plant (IPP) of Marine Current Turbine PT T-Files Indonesia

— Indonesia is experience a surplus in generating capacity of up to 27TWh by 2014 and makes this country struggling to provide electricity for its currents needs that sometimes give delays in capacity development (including with Independent Power Producer (IPP) projects). There are around 20 million households, or 80 million people, who currently have no access to public electricity. This study intends to find out what renewable energy in Indonesia in accordance with the potential that exists with case studies ocean current turbine power plant owned by PT T-Files Indonesia. This plant uses Gorlov turbine with a permanent magnet generator. Specifically this study aims to determine the feasibility of ocean current turbine power plants can be private power plants that sell electricity to PT PLN (Persero) to meet the electricity demand in Indonesia. Calculation of the cost of electricity per kilowatt-hour sales done in the conventional way with the ABCD method is the removal of the component C fuel component. Eligibility is done by searching IRR, NPV and PP from the power plant. Thus obtained if the power plant is feasible or not. Feasibility of the calculation found that the power plant is feasible electricity sales. Plan implementation is done by making 1-year period and electricity sales contracts for 15 years. It can be concluded that the development of electricity generation from renewable energy is feasible for IRR, NPV and PP meet

Glassy Dynamics of Protein Folding

A coarse grained model of a random polypeptide chain, with only discrete torsional degrees of freedom and Hookean springs connecting pairs of hydrophobic residues is shown to display stretched exponential relaxation under Metropolis dynamics at low temperatures with the exponent $\beta\simeq 1/4$, in agreement with the best experimental results. The time dependent correlation functions for fluctuations about the native state, computed in the Gaussian approximation for real proteins, have also been found to have the same functional form. Our results indicate that the energy landscape exhibits universal features over a very large range of energies and is relatively independent of the specific dynamics.Comment: RevTeX, 4 pages, multicolumn, including 5 figures; larger computations performed, error bars improve

Nonlinear kinetics of spinodal decomposition, and dissolution of inhomogeneities formed by spinodal decomposition in polymer blends

Nonlinear kinetics of both spinodal decomposition at early stages, and the dissolution of homogeneities formed during spinodal decomposition, is studied. Variation of the scattering intensity during a complete cycle consisting of a step temperature change from T1 in the one‐phase region to T2 in the two‐phase region, a period of spinodal decomposition followed by a temperature drop from T2 back to T1, and the subsequent relaxation to the original equilibrium state, is investigated at various wavenumbers. Step temperature changes within one‐phase region are also investigated.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113684/1/19920620107_ftp.pd

A Multicanonical Molecular Dynamics Study on a Simple Bead-Spring Model for Protein Folding

We have performed a multicanonical molecular dynamics simulation on a simple model protein.We have studied a model protein composed of charged, hydrophobic, and neutral spherical bead monomers.Since the hydrophobic interaction is considered to significantly affect protein folding, we particularly focus on the competition between effects of the Coulomb interaction and the hydrophobic interaction. We found that the transition which occurs upon decreasing the temperature is markedly affected by the change in both parameters and forms of the hydrophobic potential function, and the transition changes from first order to second order, when the Coulomb interaction becomes weaker.Comment: 7 pages, 6 postscript figures, To appear in J.Phys.Soc.Jpn. Vol.70 No.

A Many-body Problem with Point Interactions on Two Dimensional Manifolds

A non-perturbative renormalization of a many-body problem, where non-relativistic bosons living on a two dimensional Riemannian manifold interact with each other via the two-body Dirac delta potential, is given by the help of the heat kernel defined on the manifold. After this renormalization procedure, the resolvent becomes a well-defined operator expressed in terms of an operator (called principal operator) which includes all the information about the spectrum. Then, the ground state energy is found in the mean field approximation and we prove that it grows exponentially with the number of bosons. The renormalization group equation (or Callan-Symanzik equation) for the principal operator of the model is derived and the $\beta$ function is exactly calculated for the general case, which includes all particle numbers.Comment: 28 pages; typos are corrected, three figures are adde

Architects and the architectural profession in the Turkish context

This article explores the social construction of the architectural profession in the Turkish context from a historical perspective. It investigates architects' views regarding their roles in society and their positions vis-à-vis their clients and users. The data from in-depth interviews conducted with twenty-four practicing architects demonstrate that both traces of elitism and the tendency to define their professional roles to affect people's lives through their designs have prevailed in architects' beliefs and actions to varying degrees. © 2004 Tahire Erman, Burçak Altay, and Can Altay

pH dependence of cyanide and imidazole binding to the heme domains of \u3cem\u3eSinorhizobium meliloti\u3c/em\u3e and \u3cem\u3eBradyrhizobium japonicum\u3c/em\u3e FixL

Equilibrium and kinetic properties of cyanide and imidazole binding to the heme domains of Sinorhizobium meliloti and Bradyrhizobium japonicum FixL (SmFixLH and BjFixLH) have been investigated between pH 5 and 11. KD determinations were made at integral pH values, with the strongest binding at pH 9 for both ligands. KD for the cyanide complexes of BjFixLH and SmFixLH is 0.15 ± 0.09 and 0.50 ± 0.20 μM, respectively, and 0.70 ± 0.01 mM for imido-BjFixLH. The association rate constants are pH dependent with maximum values of 443 ± 8 and 252 ± 61 M−1 s−1 for cyano complexes of BjFixLH and SmFixLH and (5.0 ± 0.3) × 104 and (7.0±1.4) × 104M−1 s−1 for the imidazole complexes. The dissociation rate constants are essentially independent of pH above pH 5; (1.2 ± 0.3) × 10−4 and (1.7 ± 0.3) × 10−4 s−1 for the cyano complexes of BjFixLH and SmFixLH, and (73±19) and (77±14) s−1 for the imidazole complexes. Two ionizable groups in FixLH affect the rate of ligand binding. The more acidic group, identified as the heme 6 propionic acid, has a pKa of 7.6 ± 0.2 in BjFixLH and 6.8 ± 0.2 in SmFixLH. The second ionization is due to formation of hydroxy-FixLH with pKa values of 9.64± 0.05 for BjFixLH and 9.61 ± 0.05 for SmFixLH. Imidazole binding is limited by the rate of heme pocket opening with maximum observed values of 680 and 1270 s−1 for BjFixLH and SmFixLH, respectively