PENGARUH MODEL PEMBELAJARAN COOPERATIF GIVING QUESTION AND GETTING ANSWER TERHADAP HASIL BELAJAR SISWA PADA MATERI DINAMIKA ATMOSFER DI MA DARUL HIKMAH PEKANBARU

AYU STIPANI (2022) : PENGARUH MODEL PEMBELAJARAN COOPERATIF GIVING QUESTION AND GETTING ANSWER TERHADAP HASIL BELAJAR SISWA PADA MATERI DINAMIKA ATMOSFER DI MA DARUL HIKMAH PEKANBARU Penelitian ini dilakukan untuk mengetahui hasil belajar siswa di Madrasah Aliyah Darul Hikmah Pekanbaru pada Materi Atmosfer dengan menggunakan Model Pembelajaran Cooperatif Giving Question And Getting Answer. Tujuan dari penelitian ini adalah untuk melihat Pengaruh ModelPembelajaran Cooperatif Giving Question And GettingAnswer Terhadap Hasil Belajar Siswa. Desain penelitian yang dilakukan dalam penelitian yaitu quasi eksperimen dengan pola Nonequivalent Control Group Design atau pre-test-post-test. Populasi dan sampel dalam penelitian ini adalah siswa kelas X Sosial yang berjumlah 34 siswa. Teknik pengambilan sampel pada penelitian ini menggunakan teknik lempar koin, sehingga yang menjadi sampel pada penelitian ini adalah siswa kelas X Sosial 1 sebagai kelas eksperimen yang berjumlah 20 siswa dan X Sosial 2 sebagai kelas kontrol yang berjumlah 14 siswa. Pengumpulan data dilakukan dengan menggunakan tes soal dan dokumentasi. Berdasarkan hasil penelitian dapat disimpulkan bahwa Pengaruh Model Pembelajaran Cooperatif Giving Question And GettingAnswerdiperoleh kategori lebih baik dibandingkan kelas kontrol, pada kelas eksprimen sebesar 79.75, sedangkan pada kelas kontrol sebesar 68.21. Berdasarkan analisis uji-t antara kelas eksperimen dan kontrol diperoleh nilai t hitung > t tabel yaitu (0,000>0,05)yang berarti Ha diterima dan Ho ditolak. Kata kunci: CGQGA (Giving Question And Getting Answer) – Hasil Belaja

Neutron diffraction reveals sequence-specific membrane insertion of pre-fibrillar islet amyloid polypeptide and inhibition by rifampicin

AbstractHuman islet amyloid polypeptide (hIAPP) forms amyloid deposits in non-insulin-dependent diabetes mellitus (NIDDM). Pre-fibrillar hIAPP oligomers (in contrast to monomeric IAPP or mature fibrils) increase membrane permeability, suggesting an important role in the disease. In the first structural study of membrane-associated hIAPP, lamellar neutron diffraction shows that oligomeric hIAPP inserts into phospholipid bilayers, and extends across the membrane. Rifampicin, which inhibits hIAPP-induced membrane permeabilisation in functional studies, prevents membrane insertion. In contrast, rat IAPP (84% identical to hIAPP, but non-amyloidogenic) does not insert into bilayers. Our findings are consistent with the hypothesis that membrane-active pre-fibrillar hIAPP oligomers insert into beta cell membranes in NIDDM

Overview of the TCV tokamak experimental programme

The tokamak a configuration variable (TCV) continues to leverage its unique shaping capabilities, flexible heating systems and modern control system to address critical issues in preparation for ITER and a fusion power plant. For the 2019-20 campaign its configurational flexibility has been enhanced with the installation of removable divertor gas baffles, its diagnostic capabilities with an extensive set of upgrades and its heating systems with new dual frequency gyrotrons. The gas baffles reduce coupling between the divertor and the main chamber and allow for detailed investigations on the role of fuelling in general and, together with upgraded boundary diagnostics, test divertor and edge models in particular. The increased heating capabilities broaden the operational regime to include T (e)/T (i) similar to 1 and have stimulated refocussing studies from L-mode to H-mode across a range of research topics. ITER baseline parameters were reached in type-I ELMy H-modes and alternative regimes with \u27small\u27 (or no) ELMs explored. Most prominently, negative triangularity was investigated in detail and confirmed as an attractive scenario with H-mode level core confinement but an L-mode edge. Emphasis was also placed on control, where an increased number of observers, actuators and control solutions became available and are now integrated into a generic control framework as will be needed in future devices. The quantity and quality of results of the 2019-20 TCV campaign are a testament to its successful integration within the European research effort alongside a vibrant domestic programme and international collaborations

Physics research on the TCV tokamak facility: from conventional to alternative scenarios and beyond

The research program of the TCV tokamak ranges from conventional to advanced-tokamak scenarios and alternative divertor configurations, to exploratory plasmas driven by theoretical insight, exploiting the device’s unique shaping capabilities. Disruption avoidance by real-time locked mode prevention or unlocking with electron-cyclotron resonance heating (ECRH) was thoroughly documented, using magnetic and radiation triggers. Runaway generation with high-Z noble-gas injection and runaway dissipation by subsequent Ne or Ar injection were studied for model validation. The new 1 MW neutral beam injector has expanded the parameter range, now encompassing ELMy H-modes in an ITER-like shape and nearly non-inductive H-mode discharges sustained by electron cyclotron and neutral beam current drive. In the H-mode, the pedestal pressure increases modestly with nitrogen seeding while fueling moves the density pedestal outwards, but the plasma stored energy is largely uncorrelated to either seeding or fueling. High fueling at high triangularity is key to accessing the attractive small edge-localized mode (type-II) regime. Turbulence is reduced in the core at negative triangularity, consistent with increased confinement and in accord with global gyrokinetic simulations. The geodesic acoustic mode, possibly coupled with avalanche events, has been linked with particle flow to the wall in diverted plasmas. Detachment, scrape-off layer transport, and turbulence were studied in L- and H-modes in both standard and alternative configurations (snowflake, super-X, and beyond). The detachment process is caused by power ‘starvation’ reducing the ionization source, with volume recombination playing only a minor role. Partial detachment in the H-mode is obtained with impurity seeding and has shown little dependence on flux expansion in standard single-null geometry. In the attached L-mode phase, increasing the outer connection length reduces the in–out heat-flow asymmetry. A doublet plasma, featuring an internal X-point, was achieved successfully, and a transport barrier was observed in the mantle just outside the internal separatrix. In the near future variable-configuration baffles and possibly divertor pumping will be introduced to investigate the effect of divertor closure on exhaust and performance, and 3.5 MW ECRH and 1 MW neutral beam injection heating will be added

A Fast Ion Loss Detector for the TCV Tokamak

A Fast Ion Loss Detector (FILD) was designed, assembled, installed and commissioned for TCV. This is a radially positionable, scintillator based detector that provides information on the 2D fast-ion velocity space lost at the probe's location. The collected particles are collimated inside the probe head and impinge upon a plate coated with a scintillator material that emits light. The photon flux is relayed to two acquisition systems: a sCMOS camera for high spatial resolution measurements of the emission locations in the scintillator, and fast photo-multipliers that allow time-correlation studies of fast-ion losses with high-frequency electromagnetic fluctuations. From its position with respect to the confined plasma and the fast-ion sources on TCV, FILD probes a small portion of the lost fast-ion phase space with high velocity-space and temporal resolution. Therefore, it naturally complements other available diagnostics such as neutral particle analysers, spectroscopy techniques for light emission from energetic particles following CX reactions, or neutron counters, which feature a broader, but less resolved, spatial coverage of fast-ion dynamics. The TCV-FILD design introduces some novelties for exploring new ranges of operation that may be adopted in similar systems for other Tokamaks, such as ITER. Two entrance slits can collect particles that circulate in co- and cntr-plasma current directions. This will be particularly useful when the second NBH system, injecting in the opposite toroidal direction, with particle energies that can excite strong Alfvénic modes, will be operated on TCV. A controlled pneumatic linear actuator radially positions the detector to expose the slits to the particle flux up to 9mm inward of the vessel wall. A plug-in design was conceived to facilitate diagnostic installation. The diagnostic was installed and commissioned during TCV experiments in 2020. The sensitivity of the detector to the local magnetic field line direction was investigated. The direction of the plasma current was found to select which of the two slits may be traversed by lost particles. The operational limits in discharges with NBH with total delivered energies up to 1MJ were assessed with the help of sensors monitoring the temperature of the probe head and cameras detecting visible light emissions resulting from the graphite shield heating by particle fluxes. Using FILD, fast-ion losses were detected for the first time on TCV in plasma discharges exhibiting strong MHD modes. Ejections of energetic ions were found correlated in time with Sawtooth crashes, as a sequence of individual events, and in strong phase coherence, as a continuous loss in time, with magnetic perturbations of a saturated and toroidally rotating magnetic island of a NTM. These observations, in addition to providing initial results on the relevant physics phenomena, stimulating further experiments and comparisons with theory, demonstrate the ability of TCV-FILD to provide valuable information in plasma discharges of interest for fast-ion studies. These measurements and additional information from other TCV diagnostics may now be combined to reconstruct, with tomographic inversion techniques, more of the fast-ion phase space. This will be used to identify the conditions for the excitation/suppression of magnetic instabilities, develop methods for their real-time control with heating and/or shaping actuators and investigate their dependencies on plasma parameters

Phase mixing flow in a drift-kinetic collisionless plasma. The case of a kinetic passive scalar.

Magnetised plasmas are found to be turbulent in a large variety of scenarios, from astrophysics to nuclear fusion. In solar wind, a collisionless environment, at scales much larger than the ion Larmor radius, the so called inertial range, turbulence is mainly due to the low frequency and strongly anisotropic Alfvènic fluctuations. Observations confirm the turbulent nature of solar wind by showing the existence of power law energy spectra for both Alfvènic fluctuating fields and the related compressive fluctuations. The latter result to be passively mixed by the Alfvènic cascade although affected by collisionless damping such as Landau damping. Indeed, it is not clear how the energy-cascade occurs in the phase space since the phase mixing consists in a transfer of energy towards smaller velocity space scales and this should prevent the observed fluid-like spectrum. In this work we investigate how the competition between phase mixing and nonlinear advection, depending on a stochastic $E \wedge B$-drift velocity, works in the Hermite-Fourier phase space. On a theoretical ground it turns out that the advection is responsible for coupling the phase mixing flow and an un-phase mixing flow coming back from smaller to larger velocity space scales. Because of this echo effect we expect to have a suppression on average of the Landau damping in some regions of the phase space. Therefore a fluid behaviour is restored. We adopted a Kinetic Reduced MHD framework: the reduced MHD model well describes, taking the critical balance conjecture by Goldreich and Sridhar as an ordering assumption, strongly anisotropic Alfvènic fluctuations whereas a drift-kinetic equation governs the distribution function for the magnetised ions (electrons are considered as isothermal). In particular we have focused on the Batchelor limit for a passive scalar, the ion distribution function, and the obtained equation has been solved numerically by means of a Monte Carlo code. We observed the suppression effect, along with power law spectra, in the anisotropic regime. Moreover a partitioning of the phase space is now possible in order to find analytical solutions for the regions dominated by the suppression or the phase mixing