Thermal Performance of Naturally Ventilated Classroom in the Faculty of Engineering Hasanuddin University, Gowa Campus

This study aims to identify the thermal performance of naturally ventilated classrooms of the new campus of Faculty of Engineering, Hasanuddin University in Gowa. The natural ventilation system has three main functions that are to provide healthy air for occupants, to provide thermal comfort to the occupants, and to cool the fabrics in the building interior. Thermal comfort perceived by the user is determined by many factors, including physical, psychological, etc. This research was conducted by using the experimental method with research analysis using CFD (Computational Fluid Dynamics) simulation method. The input parameters in the simulation were obtained through field measurement in the form of room dimension, ventilation open area, and microclimate parameter. The simulation is carried out at maximum open conditions in existing ventilation system with open and closed class door treatment. The simulation treatment of airflow input speeds were 0.25, 0.5, 0.75, and 1 m/s. The results showed that the existing ventilation system of Classroom at Faculty of Engineering (FoE) Hasanuddin University (Unhas) with an opening ratio of 16.59 to 22.76% of the floor area is good enough to flow and distribute comfortable air movement inside the classroom, especially at airflow speeds above 0.5 m/s

Modeling GRB 050904: Autopsy of a Massive Stellar Explosion at z=6.29

GRB 050904 at redshift z=6.29, discovered and observed by Swift and with spectroscopic redshift from the Subaru telescope, is the first gamma-ray burst to be identified from beyond the epoch of reionization. Since the progenitors of long gamma-ray bursts have been identified as massive stars, this event offers a unique opportunity to investigate star formation environments at this epoch. Apart from its record redshift, the burst is remarkable in two respects: first, it exhibits fast-evolving X-ray and optical flares that peak simultaneously at t~470 s in the observer frame, and may thus originate in the same emission region; and second, its afterglow exhibits an accelerated decay in the near-infrared (NIR) from t~10^4 s to t~3 10^4 s after the burst, coincident with repeated and energetic X-ray flaring activity. We make a complete analysis of available X-ray, NIR, and radio observations, utilizing afterglow models that incorporate a range of physical effects not previously considered for this or any other GRB afterglow, and quantifying our model uncertainties in detail via Markov Chain Monte Carlo analysis. In the process, we explore the possibility that the early optical and X-ray flare is due to synchrotron and inverse Compton emission from the reverse shock regions of the outflow. We suggest that the period of accelerated decay in the NIR may be due to suppression of synchrotron radiation by inverse Compton interaction of X-ray flare photons with electrons in the forward shock; a subsequent interval of slow decay would then be due to a progressive decline in this suppression. The range of acceptable models demonstrates that the kinetic energy and circumburst density of GRB 050904 are well above the typical values found for low-redshift GRBs.Comment: 45 pages, 7 figures, and ApJ accepted. Revised version, minor modifications and 1 extra figur

On the magnetic and energy characteristics of recurrent homologous jets from an emerging flux

In this paper, we present the detailed analysis of recurrent homologous jets originating from an emerging negative magnetic flux at the edge of an Active Region. The observed jets show multi-thermal features. Their evolution shows high consistence with the characteristic parameters of the emerging flux, suggesting that with more free magnetic energy, the eruptions tend to be more violent, frequent and blowout-like. The average temperature, average electron number density and axial speed are found to be similar for different jets, indicating that they should have been formed by plasmas from similar origins. Statistical analysis of the jets and their footpoint region conditions reveals a strong positive relationship between the footpoint-region total 131 {\AA} intensity enhancement and jets' length/width. Stronger linearly positive relationships also exist between the total intensity enhancement/thermal energy of the footpoint regions and jets' mass/kinetic/thermal energy, with higher cross-correlation coefficients. All the above results, together, confirm the direct relationship between the magnetic reconnection and the jets, and validate the important role of magnetic reconnection in transporting large amount of free magnetic energy into jets. It is also suggested that there should be more free energy released during the magnetic reconnection of blowout than of standard jet events

Remdesivir for COVID-19 and acute kidney injury: disproportionality analysis of data from the U.S. Food and Drug Administration Adverse Event Reporting System

Background: Evidence about remdesivir-associated acute kidney injury (AKI) among patients with novel coronavirus disease 2019 (COVID-19) was controversial. Aim: To investigate the signal of disproportionate reporting of remdesivir-related AKI in COVID-19 patients over time with data from US Food and Drug Administration Adverse Event Reporting System. Method: Adverse events in COVID-19 patients reported between April 2020 and September 2022 were included. Reporting odds ratios (RORs) of AKI and renal disorders (a more sensitive definition for AKI) were estimated to compare remdesivir with other medications prescribed in comparable situations of COVID-19. Results: During the entire study period, significant signals were identified for remdesivir-related AKI (ROR 2.00, 95% CI: 1.83–2.18) and renal disorder (ROR 2.35, 95% CI: 2.17–2.54) when compared to all comparable drugs. However, in the third quarter of 2022 (the most recent quarter) signals disappeared as the ROR of AKI was 1.50 (95% CI 0.91–2.45) and ROR of renal disorder was 1.69 (95% CI 1.06–2.70). Number of signals in sensitivity analyses and the proportion of AKI in remdesivir-associated events decreased over time. Conclusion: In COVID-19 patients, we observed diminishing signals of remdesivir-associated AKI over time and no significant signal in the most recent quarter, suggesting remdesivir might not be nephrotoxic. © 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG

Cosmopolitan Risk Community and China's Climate Governance

Ulrich Beck asserts that global risks, such as climate change, generate a form of ‘compulsory cosmopolitanism’, which ‘glues’ various actors into collective action. Through an analysis of emerging ‘cosmopolitan risk communities’ in Chinese climate governance, this paper points out a ‘blind spot’ in the theorisation of cosmopolitan belonging and an associated inadequacy in explaining shifting power-relations. The paper addresses this problem by engaging with the intersectionality of the cosmopolitan space. It is argued that cosmopolitan belonging is a form of performative identity. Its key characteristic lies in a ‘liberating prerogative’, which enables individuals to participate in the solution of common problems creatively. It is this liberating prerogative that coerces the state out of political monopoly and marks the cosmopolitan moment

Spatial Symmetry of Superconducting Gap in YBa2Cu3O7-\delta Obtained from Femtosecond Spectroscopy

The polarized femtosecond spectroscopies obtained from well characterized (100) and (110) YBa2Cu3O7-\delta thin films are reported. This bulk-sensitive spectroscopy, combining with the well-textured samples, serves as an effective probe to quasiparticle relaxation dynamics in different crystalline orientations. The significant anisotropy in both the magnitude of the photoinduced transient reflectivity change and the characteristic relaxation time indicates that the nature of the relaxation channel is intrinsically different in various axes and planes. By the orientation-dependent analysis, d-wave symmetry of the bulk-superconducting gap in cuprate superconductors emerges naturally.Comment: 8 pages, 4 figures. To be published in Physical Review B, Rapid Communication