Simultaneous size and topology optimization of 3D outrigger‐braced tall buildings with inclined belt truss using genetic algorithm

To investigate the optimum location of the outrigger system, a metaheuristic‐based size and topology optimization of the outrigger‐braced tall buildings is carried out by various three‐dimensional structural frames with different shapes of belt trusses. By considering the elastic behavior, the whole elements of the structural models such as beams, columns, core, and trusses are optimized simultaneously in conjunction with the location of the outrigger. Furthermore, to reach more optimality, several novel types of belt truss are proposed having inclined and inverse‐inclined belt trusses with better structural and architectural features and optimum performance in comparison with the horizontal one. Different models with 25 to 40 stories having various span numbers are optimized using the genetic algorithm, and the results are compared with each other. In the modeling process, the exact wind load distribution is applied to the structure based on the ASCE7‐16 rather than the uniform or triangular ones. According to the results, the optimum cross‐sectional size and outrigger locations of different models are obtained, and it is indicated that the proposed novel belt trusses are optimal solution for the problem.     

Organic matter chlorination rates in different boreal soils: the role of soil organic matter content

Transformation of chloride (Cl(-)) to organic chlorine (Cl(org)) occurs naturally in soil but it is poorly understood how and why transformation rates vary among environments. There are still few measurements of chlorination rates in soils, even though formation of Cl(org) has been known for two decades. In the present study, we compare organic matter (OM) chlorination rates, measured by (36)Cl tracer experiments, in soils from eleven different locations (coniferous forest soils, pasture soils and agricultural soils) and discuss how various environmental factors effect chlorination. Chlorination rates were highest in the forest soils and strong correlations were seen with environmental variables such as soil OM content and Cl(-) concentration. Data presented support the hypothesis that OM levels give the framework for the soil chlorine cycling and that chlorination in more organic soils over time leads to a larger Cl(org) pool and in turn to a high internal supply of Cl(-) upon dechlorination. This provides unexpected indications that pore water Cl(-) levels may be controlled by supply from dechlorination processes and can explain why soil Cl(-) locally can be more closely related to soil OM content and the amount organically bound chlorine than to Cl(-) deposition.     

Plasma Magnetic Fluctuations Measurement on the Outer Surface of IR-T1 Tokamak

In this paper we present an experimental investigation of effects of external rotating helical field (RHF) on magnetic field fluctuations around the IR-T1 tokamak chamber. For this purpose, two magnetic pickup coils were designed, constructed, and installed on the outer surface of the IR-T1 tokamak chamber, and then from their output signals after compensation and integration, poloidal and normal components of the magnetic fields measured. Experimental results show that presence of RHF with L = 3 mode can improve the plasma confinement by flatting the plasma current and reducing the amplitude of magnetic field fluctuations.     

Experimental Study of Effects of the Internal Inductance on the Energy Confinement Time in IR-T1 Tokamak

In this paper we present an experimental study of effects of the internal inductance on the energy confinement time, in IR-T1 tokamak. For this purpose, four magnetic pickup coils were designed, constructed, and installed on the outer surface of the IR-T1, and Then Shafranov parameter (asymmetry factor) is obtained from them. On the other hand, also diamagnetic loop were constructed and installed on IR-T1, and poloidal Beta is determined from it. Therefore, the internal inductance obtained. Also, energy confinement time is obtained using diamagnetic loop. Experimental Results show that maximum energy confinement time (which correspond to minimum collisions, minimum microinstabilities, and minimum transport) in IR-T1, relate to the low values of internal inductance (\( 0.61 \, < \, li \, < \, 0.72 \)). This is agreement with theoretical approach.     

Low Dissipation with Normalized Flux Surfaces in 2-Dimensional Coordinate for IR-T1 Tokamak Using Grad–Shafranov Equation Solution

Together with the problem of confinement, plasma–wall interactions present the major constraints toward a magnetic fusion reactor. The solutions of Grad–Shafranov equation (GSE) analytically can be used for theoretical studies of plasma equilibrium, transport and magneto-hydrodynamic stability. Here we introduce specific choices for source functions, kinetic pressure and poloidal plasma current, to be quadratic in poloidal magnetic flux and derive an analytical solution for GS equation. With applying this solution to IR-T1 tokamak, we have calculated the poloidal magnetic flux, toroidal current density and normalized pressure profiles for this tokamak. Toroidal and poloidal flows can considerably change the equilibrium parameters of tokamak. These effects on the equilibrium of tokamak plasmas are numerically investigated using a code FLOW. As a comparative approach to equilibrium problem, the code is used to model equilibrium of IR-T1 tokamak for case pure toroidal flow.     

The Effects of Percent and Position of Nitrogen Atoms on Electronic and Thermoelectric Properties of Graphene Nanoribbons

Graphene-based nanostructures exhibit electronic properties that are not present in extended graphene. Graphene nanoribbons (GNRs) are expected to display extraordinary properties in the form of nanostructures. The effect of percent and position of nitrogen atoms on electronic and thermoelectric properties of a GNR is studied using Landauer approach and density functional theory. For this purpose the density of States, electronic current and thermal current have been calculated. Moreover, an analytical model for the thermo-conductance of the nanosized junction in two-dimensional graphene nanosystems developed. The results show that increasing of nitrogen atoms, increases the splitting of p-orbitals as well as band gap at Fermi level. Also the presence of nitrogen impurities is shown to yield resonant backscattering, whose features are strongly dependent on the position of the dopants. It is demonstrated that increasing N concentration decrease the thermal conductivity due to multi-scattering. In addition I–V characteristics exhibit robust nonlinear behaviors, which are strongly dependent on the position and theconcentration of the nitrogen atoms.     

Energieeffiziente Wärmebehandlung der Gusslegierungen AlSi7Mg0,3 und AlSi9Cu3(Fe)

In this research work, a modified energy efficient T6 heat treatment was performed on AlSi7Mg0.3 and AlSi9Cu3(Fe) castings produced on pilot scale, where a part of the heat from the casting process was used during solution annealing. Calculations of the possible energy savings showed that the novel energy saving heat treatment can gain up to 260 kJ of thermal energy per kilogram of casting compared to conventional methods. To produce samples of the energy efficient heat treatment, the castings were ejected from the squeeze casting machine at 300?°C and immediately transferred to the annealing furnace and subsequently water quenched and artificially aged.     

Efficient and Thermally Stable Wide Bandgap Perovskite Solar Cells by Dual-Source Vacuum Deposition

Wide bandgap perovskites are being widely studied in view of their potential applications in tandem devices and other semitransparent photovoltaics. Vacuum deposition of perovskite thin films is advantageous as it allows the fabrication of multilayer devices, fine control over thickness and purity, and it can be upscaled to meet production needs. However, the vacuum processing of multicomponent perovskites (typically used to achieve wide bandgaps) is not straightforward, because one needs to simultaneously control several thermal sources during the deposition. Here a simplified dual-source vacuum deposition method to obtain wide bandgap perovskite films is shown. The solar cells obtained with these materials have similar or even larger efficiency as those including multiple A-cations, but are much more thermally stable, up to 3500 h at 85 °C for a perovskite with a bandgap of 1.64 eV. With optimized thickness, record efficiency of >19% and semitransparent devices with stabilized power output in excess of 17% are achieved.