247 research outputs found
STUDI META ANALISIS PENGARUH RETURN ON ASSETS (ROA), KEPEMILIKAN MANAJERIAL, UKURAN PERUSAHAAN, DEBT TO ASSET RATIO (DAR) TERHADAP MANAJEMEN LABA
Penelitian ini bertujuan untuk menguji apakah profitabilitas, leverage, kepemilikan manajerial dan ukuran perusahaan mempengaruhi laba manajemen di Indonesia dan untuk menganalisis apakah variasi temuan disebabkan oleh model pengukuran efek moderasi manajemen laba atau pengukuran variabel penjelas. Penelitian ini menggunakan pendekatan teknik meta-analisis dengan sampel sebanyak 54 dari jurnal periode tahun 2016-2022. Hasil penelitian memperkuat temuan meta-analisis dari penelitian sebelumnya dimana manajemen laba dilakukan untuk tujuan yang berbeda tujuan. Bukti empiris menunjukkan bahwa atribut profitabilitas dan leverage yaitu; Return on Asset dan Debt to Equity Ratio ditemukan sebagai mekanisme pemantauan yang kuat yang dapat menekan manajemen laba. Bukti empiris mendukung beberapameta-analisis sebelumnya dalam bidang akuntansi dimana variabel pengukuran moderator berpengaruh terhadap heterogenitas temuan penelitian. Penelitian di masa depan harus mencakup korelasi matriks, dan mempertimbangkan langkah-langkah terperinci dari manajemen laba dan lebih banyak atribut dewan direksi untuk memfasilitasi penelitian menggunakan metaanalisis. Hasilnya menunjukkan bahwa nilai ROA, LEV, kepemilikan manajerial dan ukuranperusahaan dapat meningkatkan kepercayaan investor dengan membatasi manajemen laba.
Divertor conditions relevant for fusion reactors achieved with linear plasma generator
Intense magnetized hydrogen and deuterium plasmas have been produced with electron densities up to 3.6¿×¿1020¿m-3 and electron temperatures up to 3.7¿eV with a linear plasma generator. Exposure of a W target has led to average heat and particle flux densities well in excess of 4¿MW m-2 and 1024¿m-2 s-1, respectively. We have shown that the plasma surface interactions are dominated by the incoming ions. The achieved conditions correspond very well to the projected conditions at the divertor strike zones of fusion reactors such as ITER. In addition, the machine has an unprecedented high gas efficiency
Plasma detachment study of high density helium plasmas in the Pilot-PSI device
We have investigated plasma detachment phenomena of high-density helium plasmas in the linear plasma device Pilot-PSI, which can realize a relevant ITER SOL/Divertor plasma condition. The experiment clearly indicated plasma detachment features such as drops in the plasma pressure and particle flux along the magnetic field lines that were observed under the condition of high neutral pressure; a feature of flux drop was parameterized using the degree of detachment (DOD) index. Fundamental plasma parameters such as electron temperature (T e) and electron density in the detached recombining plasmas were measured by different methods: reciprocating electrostatic probes, Thomson scattering (TS), and optical emission spectroscopy (OES). The T e measured using single and double probes corresponded to the TS measurement. No anomalies in the single probe I – V characteristics, observed in other linear plasma devices [16, 17, 36], appeared under the present condition in the Pilot-PSI device. A possible reason for this difference is discussed by comparing the different linear devices. The OES results are also compared with the simulation results of a collisional radiative (CR) model. Further, we demonstrated more than 90% of parallel particle and heat fluxes were dissipated in a short length of 0.5 m under the high neutral pressure condition in Pilot-PSI.</p
Progress in Impurity Transport Studies on TEXTOR Using New VUV Spectrometers with High Time Resolution
Soledge2D‐Eirene simulations of the Pilot‐PSI linear plasma device compared to experimental data
Predictions for the operation of tokamak divertors are reliant on edge plasma simulations typically utilizing a fluid plasma code in combination with a Monte Carlo code for neutral species. Pilot‐PSI is a linear device operating with a cascaded arc plasma source that produces plasmas comparable to those expected in the ITER divertor (Te ∼ 1 eV, ne ∼ 1021 m−3). In this study, plasma discharges in Pilot‐PSI are modelled using the Soledge2D fluid plasma code coupled to the Eirene neutral Monte Carlo code. The plasma is generated using an external source of plasma density and power. These input parameters are tuned in order to match Thomson scattering (TS) measurements close to the cascaded arc source nozzle. The sensitivity of the simulations to different atomic physics models is explored. It is found that elastic collisions between ions and hydrogen molecules have a strong influence on calculated profiles. Without their inclusion, supersonic flow regimes are obtained with M ∼ 2 close to the target plate. Simulation results are compared with experimental findings using TS close to the target and, in the case of Pilot‐PSI, a Langmuir probe embedded in the target. Comparison between experimental trends observed in a background pressure scan and the simulations show that the inclusion of the elastic collision is mandatory for the trends to be reproduced.</p
Divertor conditions relevant for fusion reactors achieved with linear plasma generator
LiMeS-Lab:An Integrated Laboratory for the Development of Liquid–Metal Shield Technologies for Fusion Reactors
The liquid metal shield laboratory (LiMeS-Lab) will provide the infrastructure to develop, test, and compare liquid metal divertor designs for future fusion reactors. The main research topics of LiMeS-lab will be liquid metal interactions with the substrate material of the divertor, the continuous circulation and capillary refilling of the liquid metal during intense plasma heat loading and the retention of plasma particles in the liquid metal. To facilitate the research, four new devices are in development at the Dutch Institute for Fundamental Energy Research and the Eindhoven University of Technology: LiMeS-AM: a custom metal 3D printer based on powder bed fusion; LiMeS-Wetting, a plasma device to study the wetting of liquid metals on various substrates with different surface treatments; LiMeS-PSI, a linear plasma generator specifically adapted to operate continuous liquid metal loops. Special diagnostic protection will also be implemented to perform measurements in long duration shots without being affected by the liquid metal vapor; LiMeS-TDS, a thermal desorption spectroscopy system to characterize deuterium retention in a metal vapor environment. Each of these devices has specific challenges due to the presence and deposition of metal vapors that need to be addressed in order to function. In this paper, an overview of LiMeS-Lab will be given and the conceptual designs of the last three devices will be presented.</p
Collective Thomson scattering system for determination of ion properties in a high flux plasma beam
A collective Thomson scattering system has been developed for measuring ion temperature, plasma velocity and impurity concentration in the high density magnetized Magnum-PSI plasma beam, allowing for measurements at low temperature (4 x 10 20m3,while avoiding laser plasma heating caused by inverse Bremsstrahlung. The collective Thomson scattering system is based on the fundamental mode of a seeded Nd:YAG laser and equipped with an LIVAR M506 camera (EBABS technology). The first collective Thomson scattering measurements are taken at the linear plasma generator Pilot-PSI, 40 mm downstream of the cascaded arc source. At this location, the ion temperature is about equal to the electron temperature in the bulk of the plasma beam
High heat flux capabilities of the Magnum-PSI linear plasma device
Magnum-PSI is an advanced linear plasma device uniquely capable of producing plasma conditions similar to those expected in the divertor of ITER both steady-state and transients. The machine is designed both for fundamental studies of plasma-surface interactions under high heat and particle fluxes, and as a high-heat flux facility for the tests of plasma-facing components under realistic plasma conditions. To study the effects of transient heat loads on a plasma-facing surface, a novel pulsed plasma source system as well as a high power laser is available. In this article, we will describe the capabilities of Magnum-PSI for high-heat flux tests of plasma-facing material
Investigation of internal transport barrier in OH mode with sawtooth oscillation and in discharges where sawtooth are suppressed by off-axis ECRH
- …