金子みすゞの「死の理解」とスピリチュアリティの一考察 : 作品『雪』を中心にして

A two dimensional Computational Fluid Dynamics (CFD) model was developed to simulate the fluid flow and heat transfer of the molten steel in a ladle during the holding time, with gas purging from the bottom. Transient analysis of the temperature and the velocity distribution of the liquid steel during ladle standing and subsequent gas stirring was conducted, by employing a pressure-based fully-implicit finite volume approach. Stratification, which can adversely affect the quality of steel products, was seen to develop due to natural convection. Therefore, particular attention was paid to study the effect of bottom gas stirring in minimizing the thermal stratification. This was accomplished by introducing a novel approach of coupling the effects of natural convection and axisymmetric bottom gas injection. Various parametric studies was undertaken to examine the effects of standing time, gas flow rate and geometry of the ladle on the resultant thermal field. It was observed that bottom purging situation induces a strong recirculatory flow in the molten steel bath, with an increase in the order of turbulence giving rise to thermal homogenization. The results indicate that the thermal stratification can be effectively eliminated by a relatively gentle agitation. Homogenization takes place at a faster rate with an increase in the amount of bottom gas flow. The effect of ladle size was found to be inconsequential, in comparison to other parameters

Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks

A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons (H) in proton-proton collisions collected by the CMS experiment at the LHC at root s = 8 TeV. The data correspond to an integrated luminosity of 19.7 fb(-1). The search considers HH resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and t (t) over bar events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95 confidence level for the product of the production cross section and branching fraction sigma(gg -> X) B(X -> HH -> b (b) over barb (b) over bar) range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with amass scale Lambda(R) = 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV

Search for supersymmetry in events with one lepton and multiple jets in proton-proton collisions at root s=13 TeV

Peer reviewe

Measurement of the top quark mass using charged particles in pp collisions at root s=8 TeV

Peer reviewe

Search for anomalous couplings in boosted WW/WZ -> l nu q(q)over-bar production in proton-proton collisions at root s=8TeV

Peer reviewe

Scaling estimations of thermal and flow field in gas-stirred ladles

To obtain a better understanding of the physical process involved in gas stirring of a steelmaking vessel, a scaling analysis approach is developed that accounts for the effects of natural convection and axisymmetric bottom gas injection in the vessel. The orders of magnitude of some important quantities such as the transient velocity scale, thermal boundary layer thickness, and the critical flow rate to homogenize the thermal stratification in the molten steel are predicted successfully

A generalized formulation of latent heat functions in enthalpy-based mathematical models for multicomponent alloy solidification systems

A systematic and generalized procedure for mathematical formulation of latent heat functions, as applicable for enthalpy-based solidification modeling of multicomponent alloy systems, is developed. The method uses a metallurgically appropriate thermo-solutal coupling strategy, in conjunction with updating of respective phase fractions, in order to obtain solutions of field variables that are consistent with the pertinent phase-change morphology. The present approach can model the solidification of multicomponent alloys for a wide range of local scale diffusion behavior of the constituent species

A generalized enthalpy-based macro model for ternary alloy solidification simulations

In this article, a generalized macroscopic mathematical model is developed to simulate the transport phenomena occurring during the solidification of ternary alloy systems. The model is essentially based on a fixed-grid, enthalpy-based control-volume approach. Microscopic features pertaining to complex thermosolutal transport mechanisms are incorporated through a novel formulation of latent enthalpy evolution, consistent with the phase-change morphology of general multicomponent alloy systems. Numerical simulations are performed for two different ternary steel alloys of apparently contrasting thermosolutal transport characteristics, and the resulting convection and macrosegregation patterns are analyzed in detail. The mathematical model is also tested by comparing the present numerical results with benchmark analytical solutions and experimental data reported in the literature for ternary alloy solidification systems, and excellent agreement is found in this regard

Effective viscosity of nanoscale colloidal suspensions

A comprehensive model for predicting the effective viscosity of dilute suspensions of nanoscale colloidal particles is presented in this work. The physics of complex interparticle interaction mechanisms is considered in details to characterize the rheological features of the suspension (nanofluid), expressed in terms of the effective viscosity variations as functions of the particle fraction. This is accomplished by addressing the details of the agglomeration-deagglomeration kinetics in a spatio-temporally evolving manner, in tune with the pertinent variations in the effective particulate dimensions, volume fractions, as well as the aggregate structure of the particulate system. Detailed analysis of the results reveals a profound influence of the combined particle agglomeration and breakup features as well as the interparticle interaction potentials on the rheological characteristics of the nanofluid. Predictions from the model agree well with the experimental results reported in the literature