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Abstract

A release of radioactive material into the environment can lead to hazardous exposure of the population and serious future concerns about health issues such as an increased incidence of cancer. In this context, a practical methodology capable of providing useful basic information from the scenario can be valuable for immediate decisions and future risk assessment. For this work, the simulation of a radiological dispersal device (RDD) filled with americium-241 was considered. The radiation dose simulated by the HotSpot code was used as an input to the epidemiological equations from BEIR V producing the data used to assess the risk of lung cancer development. The methodology could be useful in providing training for responders aimed to the initial support addressed to decision-making for emergency response at the early phase of an RDD scenario. The results from the simulation allow estimating (a) the size of the potentially affected population, (b) the type of protection action considering gender and location of the individuals, (c) the absorbed doses, (d) the matrix of lung cancer incidence predictions over a period of 5 years, and (e) the cost-effectiveness in the initial decision environment.

Abstract

Every firm today is facing significant problems which are a consequence of the influence of external and internal factors. This necessitates strategic changes in its activities, which focus on the development of the basic elements of intangible assets - people, knowledge and system, whose effective combination allows building competitive advantage and company growth. The main, specific intangible resource of the company is the business model itself, which is the economic basis of the strategic behavior of the company. From this point of view the purpose of the study is: 1) developing a sustainable business model for the construction firm, 2) analyzing the mechanism by which the manager creates and/or develops his own sustainable business model, taking into account the specifics of the construction market.

Abstract

The dynamic changes in the external (and often inside) environment place every firm in front of serious new and unknown challenges and make it more difficult to adapt to them. Under these conditions known traditional short-term models of corporate behavior have an increasingly limited role and a chance for success. The main problem and goal of the company should be a clearly defined long-term strategy that allows building competitive advantages and performance. Therefore, the purpose of the study is to analyze the impact of a dynamic external environment (market) on strategic behavior by developing a conceptual model: “Dynamics of the external environment (market) - Strategic behavior - Competitive advantages” to be applied and tested in the activity of the construction firm.

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Abstract

This paper deals with effect of number and position of friction dampers on seismic response of 2D steel frame. For the present study four structures with six storeys are subjected to a time history analysis. For each story are using two, four and six friction dampers with different positions keeping slip load and stiffness constant. To study the effect of number and position of dampers in structures, are analysed the time period, top roof displacement, maximum base shear and percentage energy dissipated in accordance with energy induced in the frame. The results indicate that number and placement of damper affects the structural response. A large number of dampers do not always lead to best benefit in terms of energy dissipation.

Abstract

We have explored the effectiveness of Geant4 by using it to simulate phonon conduction in Sn Host with Si Nanowire Interface. Our Monte Carlo Simulation shows that the effectiveness of the phonon conduction Geant4 simulation increases when the system attained a steady state of 100 time steps. We have simulated phonon conduction in Sn host with Si nanowire interface using a Geant4Condensed Matter Physics Monte Carlo simulation toolkit in a low cost and less powerful processing computer machine. In the simulation, phonons were displaced inside a computation domain from their initial positions with the velocities and direction vectors assigned to them. A time step was selected so that a phonon can move at most the length of one sub-cell in one time step. Our phonon conduction analysis of SiSn based alloy using Geant4 showed performance enhancement and reasonable predicted thermal values. Numerical predictions of the thermal profile simulations of the values of the temperature in each cell were all within ten percent of the average temperature of Silicon – Tin.

Abstract

As a crucial core physics parameter, the control rod reactivity has to be predicted for the control and safety of the reactor. This paper studies the control rod reactivity calculation of the pebble-bed reactor with three scenarios of UO2, (Th,U)O2, and PuO2 fuel type without any modifications in the configuration of the reactor core. The reactor geometry of HTR-10 was selected for the reactor model. The entire calculation of control rod reactivity was done using the MCNP6 code with ENDF/B-VII library. The calculation results show that the total reactivity worth of control rods in UO2-, (U,Th)O2-, and PuO2-fueled cores is 15.87, 15.25, and 14.33%Δk/k, respectively. These results prove that the effectiveness of total control rod in thorium and uranium cores is almost similar to but higher than that in plutonium cores. The highest reactivity worth of individual control rod in uranium, thorium and plutonium cores is 1.64, 1.44, and 1.53%Δk/k corresponding to CR8, CR1, and CR5, respectively. The other results demonstrate that the reactor can be safely shutdown with the control rods combination of CR3+CR5+CR8+CR10, CR2+CR3+CR7+CR8, and CR1+CR3+CR6+CR8 in UO2-, (U,Th)O2-, and PuO2-fueled cores, respectively. It can be concluded that, even though the calculation results are not so much different, however, the selection of control rods should be considered in the pebble-bed core design with different scenarios of fuel type.

Abstract

In this paper, we performed a first principle study for new half-Heusler LiSrX(X= N, P, and As) working with WIEN2k code in the frame work of the density functional theory, and the Boltzmann theory. We estimated the exchange-correlation potential by the generalized gradient approximation (GGA). Energetically, the three compounds show a high stability in structure type2, we notice that the lattice constant increased while bulk modulus decreased in replacing the ions of size increasing. Based on our calculations, LiSrN, LiSrP, and LiSrAs compounds are mechanically stable, and show semiconductor nature with indirect band gaps of 1.21, 1.75 for LiSrN and LiSrAs, and direct band gap of 1.94 eV for LiSrP. The thermoelectric properties are calculated for LiSrX (X=N, P, and As) and they found a high power factor for the p-type doping concentration.