Study of Effects of the Effective Edge Safety Factor on the Energy confinement Time in IR-T1 Tokamak

We present study of the effects of effective edge safety factor 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 is obtained from them. Therefore, the effective edge safety factor obtained. Also, energy confinement time is obtained using diamagnetic loop. Experimental results on IR-T1 show that the maximum energy confinement time relate to the low values of effective edge safety factor (2.5 < q _eff (a) < 2.8). This is agreement with theoretical approach.     

Suction-enhanced siphon valves for centrifugal microfluidic platforms

In traditional centrifugal microfluidic platforms pumping is restricted to outward fluid flow, resulting in potential real estate issues for embedding complex microsystems. To overcome the limitation, researchers utilize hydrophilic channels to force liquids short distances back toward the disk center. However, most polymers used for CD fabrication are natively hydrophobic, and creating hydrophilic conditions requires surface treatments/specialized materials that pose unique challenges to manufacturing and use. This work describes a novel technology that enjoys the advantages of hydrophilic fluidics on a hydrophobic disk device constructed from untreated polycarbonate plastic. The method, termed suction-enhanced siphoning, is based on exploiting the non-linear hydrostatic pressure profile and related pressure drop created along the length of a rotating microchannel. Theoretical analysis as well as experimental validation of the system is provided. In addition, we demonstrate the use of the hydrostatic pressure pump as a new method for priming hydrophobic-based siphon structures. The development of such techniques for hydrophobic fluidics advances the capabilities of the centrifugal microfluidic platform while remaining true to the goal of creating disposable polymer devices using feasible manufacturing schemes.     

Measurement of the Shafranov Parameter in Presence of the Toroidal Field Ripple in IR-T1 Tokamak

In this paper we present an investigation of the effects of Toroidal Field ripple (TF ripple) on the Shafranov parameter in IR-T1 Tokamak. For this purpose, a diamagnetic loop with its compensation coil were designed and installed on outer surface of the IR-T1 Tokamak. Amplitude of the TF ripple is obtained 0.01, and also the effect of TF ripple on the Shafranov parameter discussed. In presence of the TF ripple and in low field side of the IR-T1 Tokamak chamber (θ = 0), the local value of Shafranov parameter increased, whereas in the high field side (θ = 180) the Shafranov parameter decreased.     

Measurements of the Plasma Current Density and Q-Profiles in IR-T1 Tokamak

The purposes of this paper are determination of the current density and safety factor profiles, J(r) and q(r), in IR-T1 tokamak. For these purposes, a diamagnetic loop with its compensation coil, and also an array of magnetic probes were designed, constructed, and installed on outer surface of the IR-T1 tokamak chamber, and then the poloidal beta and poloidal and radial magnetic fields measured. Moreover, a few approximate values of the internal inductance for the different possible profiles of the plasma current density are also calculated. From the results, current density and q-profiles obtained.     

Efficient and Stable Inverted Wide-Bandgap Perovskite Solar Cells and Modules Enabled by Hybrid Evaporation-Solution Method

Wide-bandgap perovskite solar cells (WBG-PSCs), when partnered with Si bottom cells in tandem configuration, can provide efficiencies up to 44%; yet, the development of stable, efficient, and scalable WBG-PSCs is required. Here, the utility of the hybrid evaporation-solution method (HESM) is investigated to meet these demanding requirements via its unique advantages including ease of control and reproducibility. A PbI₂/CsBr layer is co-evaporated followed by coating of organic-halide solutions in a green solvent. Bandgaps between 1.55–1.67 eV are systematically screened by varying CsBr and MABr content. Champion efficiencies of 21.06% and 20.35% in cells and 19.83% and 18.73% in mini-modules (16 cm²) for perovskites with 1.64 and 1.67 eV bandgaps are achieved, respectively. Additionally, 18.51%-efficient semi-transparent WBG-PSCs are implemented in 4T perovskite/bifacial silicon configuration, reaching a projected power output of 30.61 mW cm⁻² based on PD IEC TS 60904-1-2 (BiFi200) protocol. Despite similar bandgaps achieved by incorporating Br via MABr solution and/or CsBr evaporation, PSCs having a perovskite layer without MABr addition show significantly higher thermal and moisture stability. This study proves scalable, high-performance, and stable WBG-PSCs are enabled by HESM, hence their use in tandems and in emerging applications such as indoor photovoltaics are now within reach.     

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.     

Investigation of Effects of Toroidal Field Ripple on Plasma Poloidal Beta in IR-T1 Tokamak

We present an investigation of effect of Toroidal Field (TF) ripple (due to finite number of the toroidal field coils) on the plasma poloidal Beta in IR-T1 Tokamak. For this purpose, array of magnetic probes and also a diamagnetic loop with its compensation coil were designed, constructed, and installed on the outer surface of IR-T1. Amplitude of the TF ripple is obtained 0.01, and also the effect of the TF ripple on the poloidal Beta discussed. In the high field side region of tokamak chamber, the TF ripple effect is decreasing of the poloidal Beta, whereas the low field side has inverse situation.     

A Simplified Technique for Determination of Plasma Displacement in the IR-T1 Tokamak

In this paper we presented a simplified technique for the determination of plasma displacement based on poloidal flux measurement in IR-T1 tokamak. This instrument consists of a two semicircle loops which installed toroidally on inner and outer sides of tokamak chamber and connected with each other. Really, this instrument detects the difference of poloidal flux on High Field Side (HFS) and Low Field Side (LFS), which we needed in calculating of the Shafranov shift. Main benefit of our proposed instrument is its simplicity. Based on this technique we measured the plasma position, and to compare the result obtained using this technique, array of four magnetic probes are also designed, constructed and installed on outer surface of the IR-T1 tokamak and plasma position obtained from them. Results are in good agreement with each other.     

Numerical Modeling of Heat Transfer for Gas-Solid Flow in Vertical Pipes

A two-fluid model (TFM) based on the kinetic theory was used to study the heat transfer of gas-solid flows in a vertical pneumatic conveyor. A 2-D, vertical pipe with 1.1 m length and 0.017 m internal diameter was chosen as the computation domain. Pipeline has 0.86 m heat transfer section after a 0.28 m developing section. It was found that the voidage has minimum and dimensionless velocities, and temperatures have maximum values in the centerline. A convective heat transfer coefficient decreases along the pipeline, and it was found that the heat transfer coefficient of gas-solid flow is greater than clean gas.