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Pellet injection is currently the primary candidate for achieving efficient plasma fuelling, one of the key issues for steady-state operation in large fusion devices. In this paper, pellet injection experiments are performed for several magnetic configurations of the TJ-II stellarator. The aim of this study is to increase the understanding of the role played by rational surfaces in plasmoid drift and deposition profiles in stellarators. The analysis of experimentally observed plasmoid drifts is supported by simulations of such cases made with the HPI2 code. Plasmoid drift is found to be significantly reduced, as in tokamaks, in the vicinity of rational surfaces. This is attributed to the fact that plasmoid external charge reconnection lengths are shorter near rational surfaces, resulting in a more effective damping of the plasmoid drift. Although the effect of plasmoid external currents on the drift is expected to be negligible in stellarators, compared with those caused by plasmoid internal currents, the effect observed in TJ-II is clearly measurable. In addition, simulations show that enhanced drift reductions near rational surfaces lead to significantly different deposition profiles for the magnetic configurations included in this study. This implies that it should be possible to select the magnetic configurations to obtain more efficient pellet fuelling.

Experiments were conducted in deuterium plasma in the TJ-II stellarator by means of swept Langmuir probes mounted on reciprocating probes manipulators. The results were processed using the four-parameter fit, as well as the triple-probe and the first-derivative probe techniques. The parameters determined were the floating potential, the ion saturation current density, the electron temperature and density, and the plasma potential. The results were obtained for two plasma heating techniques – electron cyclotron resonance heating (ECRH) and neutral beam injection (NBI) heating. In the case of ECRH, employing the first-derivative probe technique resulted in finding that the electron-energy distribution function (EEDF) was not Maxwellian, but rather a bi-Maxwellian one with thermal (14-25 eV) and cold (4-5 eV) electrons. In comparison, during NBI heating we found a Maxwellian EEDF with the electron temperature being around 5 eV and slightly increasing in the confined plasma, but always remaining below 15 eV. We present a detailed analysis and discussion of the data for the plasma parameters as acquired by different techniques of using the reciprocating probe manipulator.

The operation of the Optimization of Liquid Metal Advanced Targets (OLMAT) facility began in April 2021 with the scientific objective of exposing liquid-metal plasma facing components (PFCs) to the particle and power fluxes provided by one of the hydrogen neutral beam injectors of the TJ-II stellarator. The system can deliver heat fluxes from 5 to 58 MW m −2 of high energy hydrogen neutral particles (≤ 33 keV) with fluxes up to 10 22  m 2  s −1 (containing an ion fraction ≤ 33% in some instances), pulsed operation of 30–150 ms duration and repetition rates up to 2 min −1 . These characteristics enable OLMAT as a high heat flux (HHF) facility for PFC evaluation in terms of power exhaust capabilities, thermal fatigue and resilience to material damage. Additionally, the facility is equipped with a wide range of diagnostics that includes tools for analyzing the thermal response of the targets as well as for monitoring atomic/plasma physics phenomena. These include spectroscopy, pyrometry, electrical probing and visualization (fast and IR cameras) units. Such particularities make OLMAT a unique installation that can combine pure technological PFC research with the investigation of physical phenomena such as vapor shielding, thermal sputtering, the formation/characterization of plasma plumes with significant content of evaporated metal and the detection of impurities in front of the studied targets. Additionally, a myriad of surface characterization techniques as SEM/EDX for material characterization of the exposed PFC prototypes are available at CIEMAT. In this article, first we provide an overview of the current facility upgrade in which a high-power CW laser, that can be operated in continuous and pulsed modes (0.2–10 ms), dump and electrical (single Langmuir) probe embedded on the target surface have been installed. This laser operation will allow simulating more relevant heat loading scenarios such as nominal steady-state divertor heat fluxes (10–20 MW m −2 in continuous mode) and transients including ELM loading and disruption-like events (ms time scales and power densities up to GW m −2 range). The work later focuses on the more recent experimentation (2022 fall campaign) where a 3D printed Tungsten (W) Capillary Porous System (CPS) target, with approximated 30 μm pore size and a 37% porosity and filled with liquid tin. This porous surface was a mock-up of the PFC investigated in the ASDEX Upgrade divertor manipulator. The target composed with this element was eventually exposed to a sequence of shots with the maximum heat flux that OLMAT provides (58 ± 14 MWm −2 ). Key questions as resilience to dry-out and particle ejection of the liquid metal layer, its refilling, the induced damage/modification of the porous W matrix and the global performance of the component are addressed, attempting to shed light on the issues encountered with the PFC at tokamak scale testing.

First experiments are reported of the simultaneous exposure of a number of Sn-wetted W CPSs and a reference W CPS to 100 ms NBI pulses (divertor steady-state loading conditions) and 2 ms long high-energy laser pulses (divertor ELM like loading conditions) at the High-Heat Flux OLMAT facility. The use of a fast-frame imaging camera allows monitoring the onset of particle ejection from the targets during laser pulses and obtaining the corresponding laser heat fluxes as a measure of the resilience of these targets. Fast camera images are used also to determine ejected particle numbers and to estimate their maximum velocities as laser power is increased in order to compare the influence of W CPS structure on these parameters. In addition, the craters resulting from particle ejection are studied for each target with an optical microscope and a scanning electron microscope. Moreover, in-situ W and Sn particle ejection is followed using visible emission spectroscopy and post-exposure W melting after particle ejection is observed using the energy dispersive X-ray method EDX for all the studied targets. This shows that Sn is unable to protect the underlying W substrate from high-energy laser damage, albeit a subsequent refilling of the formed craters with Sn is visible during NBI-only pulses after laser damage. Thus, it is considered that optimization of surface refilling/replenishment with Sn is needed to improve the W substrate protection. From this work, it is also found that the W CPS reference material has a higher laser heat flux threshold for particle ejection than the Sn-wetted targets. Nevertheless, it is important to take into account that in these experiments with laser pulses, the possible beneficial effects of vapor shielding that can take place during particle irradiation at ELMs or disruptions are not present, thus these experiments represent a worst-case scenario.

The temporal and spatial deposition of extracellular matrix proteins is critical for nephrogenesis and glomerular maturation. We previously characterized leprecan as a novel chondroitin sulfate proteoglycan which has been recently shown to have prolyl hydroxylase activity. In this study, we examine the distribution of leprecan during nephrogenesis and after a hypertrophic stimulus to the adult kidney. During development, leprecan was localized to mesenchymal aggregates, early comma- and S-phase structures as determined by immunohistochemistry and in situ hybridization. Leprecan mRNA was increased in cells around the vascular cleft of the S- and comma-phase glomeruli. Expression was found in podocytes, mesangial cells, and parietal epithelial cells of loop-phase glomeruli. Leprecan mRNA was substantially decreased in the glomeruli of the adult kidney compared to the developing kidney with a uniform distribution between the glomeruli and the tubules. Within adult glomeruli, leprecan was found in the mesangium mesangial matrix, podocytes, and in Bowman's capsule. In response to glomerular hypertrophy, produced by unilateral nephrectomy, leprecan synthesis was increased in the adult kidney. We suggest that the regulated expression of leprecan during glomerular development or hypertrophy coupled with its reported prolyl hydroxylase activity plays a role during basement membrane assembly.

Two neutral-beam based diagnostic techniques are numerically evaluated for the stellarator TJ-II. The evaluation considers the beam from a dedicated diagnostic neutral beam injector that provides a 5 ms pulse of hydrogen accelerated to 30 keV as well as the light throughput of a dual purpose optical system that views the beam as it traverses the microwave, or neutral beam, heated plasmas of this magnetic confinement device. In the first instance, in which the implementation of the beam emission spectroscopy technique is considered for characterizing medium to long wavelength plasma turbulence, detailed estimates are made to determine the Balmer Hα light intensity reaching avalanche photodiode modules. In the second instance, similar detailed estimates are made for the spectrograph-based experimental set-up used for the Motional Stark Emission technique that has been successfully employed to determine the magnitude and direction of the internal magnetic field in TJ-II plasmas. In addition, optical measurements made to evaluate beam energy and composition are described. Finally, estimates and measurements are compared and discussed in order to complete this work.

Alkaline copper quat (ACQ) is an established wood preservative that is formulated with solubilized copper in amine solvent. This article describes three separate trials in Australia that investigated whether substituting soluble copper with micronized copper affects performance. ACQ and micronized copper quat (MCQ) performed similarly in Pinus radiata against four brown-rot fungi in a soil-block bioassay, while MCQ performed slightly better against two white-rot fungi in Eucalyptus delegatensis . A 2.3-year in-ground stake trial in the wet tropics at Innisfail also found that ACQ and MCQ performed comparably in P. radiata and Corymbia maculata . This was a severe test site with attack caused by soft-rot fungi, white-rot fungi, and termites. An H3 (outside, aboveground) field test against termites in Darwin showed that ACQ- or MCQ-treated P. radiata and C. maculata performed similarly against Coptotermes acinaciformis and Mastotermes darwiniensis . These trials demonstrated that MCQ performs comparably to ACQ under the test conditions used.

Troglitazone halts diabetic glomerulosclerosis by blockade of mesangial expansion. Renal complications of long-term, poorly controlled type 2 diabetes mellitus include glomerulosclerosis and interstitial fibrosis. The onset and progression of these complications are influenced by underlying pathophysiologies such as hyperglycemia, hypertriglyceridemia, and hypercholesterolemia. Troglitazone, a thiazolidinedione, has been shown to ameliorate these metabolic defects. However, it was not known whether therapeutic intervention with troglitazone would prevent the onset and progression of glomerulosclerosis. Sixty male ZDF/Gmi™ rats and 30 age-matched Zucker lean rats were in the study. The ZDF/Gmi™ rats were divided into two groups, one in which blood glucose levels were uncontrolled (30 animals) and another (30) in which blood glucose was controlled via dietary administration of troglitazone. Ten animals from each group were sacrificed at one, three, and six months into the study. The kidneys were harvested and processed for immunostaining with BM-CSPG, a marker for mesangial matrix. Images of 200 glomeruli per animal were captured using digital imaging microscopy, and the index of mesangial expansion (total area mesangium/total area of tuft) per glomerular section was measured. The administration of troglitazone ameliorated the metabolic defects associated with type 2 diabetes mellitus. Moreover, the glomeruli from tissue sections of animals given troglitazone showed no mesangial expansion when compared with normoglycemic control animals, whereas the uncontrolled diabetic animals showed significant mesangial expansion at all time intervals. Therapeutic intervention with the thiazolidinedione troglitazone halts the early onset and progression of mesangial expansion in the ZDF/Gmi™ rat, preventing the development of glomerulosclerosis in this animal model of type 2 diabetes mellitus.

We describe the design, construction, and performance of an efficient new flexure-compensated Cassegrain échelle spectrograph for the 2.1-m (82-in.) Struve reflector at McDonald Observatory. The instrument has a resolving power R = λ/∆λ of 60,000 for two CCD pixels (for a reciprocal velocity dispersion of 2.5 km s⁻ⁱ per pixel) and provides continuous wavelength coverage for λ < 8000 A using a thinned backside-illuminated Reticon 1200x400 CCD detector. Total wavelength coverage in a single exposure varies from roughly 500 Å at λ = 4400 Å (range 4200-4700 Å) to 2500 Å at λ = 7500 Å (range 6500-9000 Å), and the total system efficiency at λ = 6000 Å from the top of the atmosphere through the telescope, spectrograph, and CCD detector is 10% or more. The mechanical design of the Cassegrain-mounted spectrograph incorporates a unique cantilevered counterweight system designed to drastically reduce the effects of gravitational flexure. In spite of the large physical size of the Cassegrain instrument, worst-case flexure shifts over 60° (4 hr) of telescope motion are less than ½ pixel and are typically on the order of 0.2 pixels or less from all sources. A subsequent paper will describe the CCD and associated electronics in detail.

The call for educational reform by the Carnegie Foundation for the Advancement of Teaching marked a pivotal juncture in the trajectory of medical education in the United States. The call underscored the imperative for educational restructuring to equip forthcoming physicians with the requisite skills to engage in lifelong learning. Among the several active teaching methods is the Peer Instruction (PI), a brainchild of Eric Mazur, empowering students to steer their own education and wield knowledge adeptly into real-world scenarios. In this review paper, we delve into the core elements of PI which involves the combination of four dynamic pedagogical approaches which are: Just-in-Time Teaching, ConcepTest, Audience Response System, and Think-Pair-Share technique. PIs effectiveness notwithstanding, it is not exempt from limitations such as its flexible implementation, lengthy time, the level of expertise required for instructional design, among others. While Peer Instruction has become increasingly popular among educators across other disciplines, with proven educational benefits with positive outcomes, PIs footprint in gradate and postgraduate medical education remains inchoate, evidenced by a paucity of scholarly references. This underscores a crucial gap - despite its proven potency in fueling engagement and learning, PI still lacks formal recognition and acknowledgement as a distinct instructional method in medical education. Within these boundaries, the promise of heightened education and amplified engagement beckons further exploration of PI as a medical educational model, warranting more consideration and research.