Development of Batch and Continuous Processes on Biodiesel Production in a Packed-Bed Reactor by a Mixture of Immobilized Candida rugosa and Rhizopus oryzae Lipases

In this study, transesterification and esterification were investigated in batch and continuous process using immobilized Candida rugosa and Rhizopus oryzae lipases. In the case of batch process, stepwise reaction method was investigated to prevent the lipase deactivation. Reaction conditions were as follows: temperature, 45 °C; agitation speed, 250 rpm; enzyme concentration, 20%; and water contents 10%. And then, conversion yield was 98.33% at 4 h. In the case of continuous process, circulation and long-term continuous system were investigated for development of efficient mass transfer system. Optimal reaction conditions were as follows: temperature, 45 °C; flow rate, 0.8 mL/min; and water contents, 10%. And then, conversion yield of biodiesel was 97.98% at 3 h. Especially, the maximum conversion yield using a mixture of immobilized lipases exceeded over 90% for 108 h in long-term continuous system under optimal reaction conditions (45 °C; flow rate, 0.8 mL/min; and water contents, 10%). These results should help in determining the best method for the biodiesel production and improving the design and operation of large scale by enzymatic systems.     

Constraining WIMP magnetic moment from CDMS II experiment

We consider a degenerate or a nearly degenerate dark matter sector where a sizable magnetic moment of a (almost) Dirac type neutral dark matter candidate N is anticipated. Then, due to soft photon exchange, the cross-section in direct detection of N   can be enhanced at low Q²$Q^2$ region. We discuss the implication of this type of models in view of the recent CDMS II report.     

Primordial curvature perturbation during and at the end of multi-field inflation

We study the generation of the primordial curvature perturbation in multi-field inflation. Considering both the evolution of the perturbation during inflation and the effects generated at the end of inflation, we present a general formula for the curvature perturbation. We provide the analytic expressions of the power spectrum, spectral tilt and non-Gaussianity for the separable potentials of two inflaton scalars, and apply them to some specific models.     

Biodiesel Production from Various Oils Under Supercritical Fluid Conditions by Candida antartica Lipase B Using a Stepwise Reaction Method

In this study, we evaluate the effects of various reaction factors, including pressure, temperature, agitation speed, enzyme concentration, and water content to increase biodiesel production. In addition, biodiesel was produced from various oils to establish the optimal enzymatic process of biodiesel production. Optimal conditions were determined to be as follows: pressure 130 bar, temperature 45 °C, agitation speed 200 rpm, enzyme concentration 20%, and water contents 10%. Among the various oils used for production, olive oil showed the highest yield (65.18%) upon transesterification. However, when biodiesel was produced using a batch system, biodiesel conversion yield was not increased over 65%; therefore, a stepwise reaction was conducted to increase biodiesel production. When a reaction medium with an initial concentration of methanol of 60 mmol was used and adjusted to maintain this concentration of methanol every 1.5 h during biodiesel production, the conversion yield of biodiesel was 98.92% at 6 h. Finally, reusability was evaluated using immobilized lipase to determine if this method was applicable for industrial biodiesel production. When biodiesel was produced repeatedly, the conversion rate was maintained at over 85% after eight reuses.     

Spectral index and non-Gaussianity in supersymmetric hybrid inflation

We consider a supersymmetric hybrid inflation model with two inflaton fields. The superpotential during inflation is dominated by W=(κS+κ′S′)M ², where S, S′ are inflatons carrying the same U(1) _R charge, κ, κ′ are dimensionless couplings, and M (∼10¹⁵⁻¹⁶ GeV) is a dimensionful parameter associated with a symmetry breaking scale. One light mass eigenstate drives inflation, while the other heavier mass eigenstate is stuck to the origin. The smallness of the lighter inflaton mass for the scalar spectral index n _s ≈0.96, which is the center value of WMAP7, can be controlled by the ratio κ′/κ through the supergravity corrections. We also discuss the possibility of the two field inflation and large non-Gaussianity in this setup.     

Randall-Sundrum model for self-tuning the cosmological constant

The vanishing cosmological constant in the four-dimensional space-time is obtained in a 5D Randall-Sundrum model with a brane (B1) located at y = 0. The matter fields can be located at the brane. For settling any vacuum energy generated at the brane to zero, we need a three-index antisymmetric tensor field A(MNP) with a specific form for the Lagrangian. For the self-tuning mechanism, the bulk cosmological constant should be negative.     

Effective supersymmetric theory and muon anomalous magnetic moment with R parity violation

The effective supersymmetric theory (ESUSY) with R parity conservation cannot give a large anomalous magnetic moment of μ. It is pointed out that the flavor conservation and a large (g−2)_μ within the experimental limits are achievable in the ESUSY with R parity violating couplings involving the third generation superparticles.     

The μ and soft masses from the intermediate scale brane with non-factorizable geometry

The proton decay problem and the negative brane tension problem in the original Randall–Sundrum model can be resolved by interpreting the Planck scale brane as the visible sector brane. The hierarchy problem is resolved with supersymmetry, and the TeV scales for soft masses and μ in supersymmetric models are generated by the physics at the intermediate scale (10^11–13 GeV) brane.