The use of aluminum-based hybrid metal matrix composite (HMMC) materials, especially in engine components like pistons, is intended to improve wear resistance and overall performance. Crucial tribological indicators, such as wear and friction coefficients, underscore the significance of these materials. However, present aluminum alloys have limited wear because of clustered reinforced particles and relatively high coefficients of thermal expansion (CTE), resulting in inadequate anti-seizure properties during dry sliding conditions. This research introduces a novel “Hybrid Metal Matrix Composite of Al7068 Reinforced with Fly Ash-SiC-Al2O3”. Al7068 is employed for its superior strength-to-weight ratio and specific modulus, which is ideal for components exposed to cyclic loads and varying temperatures. The integration of fly Ash (FA), silicon carbide (SiC), and alumina (Al2O3) as reinforcements enhances wear resistance, diminishes particle clustering, improves stiffness, mitigates CTE discrepancies, and fortifies the composite against strain and corrosion, thereby enhancing its overall performance. The Stir-casting method was used with optimized reinforcement percentages (10 % total), and comprehensive evaluations through wear tests and mechanical property analyses determined the composite's optimal composition. The proposed HMMC variant with the most suitable reinforcement percentage exhibited enhanced engine piston functionality, reduced wear, low deformation of 0.20 mm, and a comparatively higher ultimate tensile strength of 190 megapascals (Mpa).

We investigated three fan-shaped jets observed above sunspot light bridges or nearby sunspot regions. The study aimed to explore the dynamics and physical properties of jets’ features that appear as blob-like structures at the tips of the jets, which we call ‘dark blobs’. A transparent region is observed beneath the dark blobs, creating a visible gap between the dark blobs and the trailing body of the jets. These phenomena were studied in chromospheric and transition region imaging and spectral high-resolution co-observations from the Visible Imaging Spectrometer of the Goode Solar Telescope at the Big Bear Solar Observatory and the Interface Region Imaging Spectrograph (IRIS), together with data from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory. We analyzed the jets’ morphology and fine structure. We obtained the spatial scale and the dynamics of the dark blobs that are seen mostly in the wings of the Hα line and have a cross-section of about 0.2′′–0.3′′. The dark blobs and the transparent regions are seen bright (in emission) in the IRIS slit-jaw 1330 Å, 1400 Å, and AIA 304 Å images. The IRIS Si iv 1394 Å spectrum of the brightenings showed blue-shifted emission of about 16 km s−1 with non-thermal velocities of up to 40 km s−1. We also estimated the electron density of the blue-shifted brightenings to be 1012.1±0.2 cm−3. Our findings likely suggest that we detect the observational signatures of shock waves that generate and/or contribute to the evolution of fan-shaped jets.

The Challan instrument is a solar full-disk imaging spectroscopic telescope planned to be installed at three sites with a 120-degree longitudinal difference, enabling continuous 24-hour observations of the Sun. It will take data every 2.5 min with a spatial resolution of 2–3′′ and a spectral resolving power (R) of >43,000 in Hα and Ca ii 8542 Å bands simultaneously. Challan is composed of two modules, each dedicated to a specific waveband. This modular design is beneficial in minimizing the scattered light and simplifying the structure and engineering. The primary scientific goal of Challan is to investigate solar flares and filament eruptions. It is also expected to detect small-scale events in the solar chromosphere. In 2025, Challan will be installed at the Big Bear Solar Observatory for test observational runs, followed by scientific runs in 2026.

본 논문은 인도 영어극에서 가장 중요한 목소리 중 하나인 아시프 쿠림 보이의 선택된 희곡들에 나타난 식민주의의 주제와 재현 방식을 고찰한다. 쿠림보이의 희곡들은 식민주의의 개념과 그 다양한 양상을 드러내며, 자본주의가 독립 이후 인도 사회 전반에 미친 영향을 바탕으로 식민주의의 비인간화 행위를 지적한다. 그의 희곡들은 학문적 연구의 대상으로 다루어졌으며, 일부는 지역어로 번역되기도 하였다. 쿠 림보이의 작품은 역사와 정치 등 폭넓은 주제를 포괄하고 있으며, 인종, 계급, 젠더와 같은 문제들이 많은 작품에서 부각되지만 이에 대한 심층적인 논의는 아직 부족하다. 그는 시대의 중대한 문제들에 대한 지속적인 관심을 통해 삶에 대한 독자적인 시각을 형성하며, 동시대적 주제에 대한 뚜렷한 입장을 가진 독특한 극작가로 평가된다. 또한 그는 현대 사회의 비참한 현실을 가감 없이 드러내는 데 주력한다.

인도 연극의 선구자인 비제이 텐둘카르는 인도 연극을 전통적 뿌리에서 현대적이고 혼종적인 형태로 탈바꿈시키는 데 중추적인 역할을 하였다. 본 논문은 텐 둘카르의 작품이 어떻게 토착 문화 요소와 서구 모더니즘의 영향을 결합하며 인도 연 극의 진화를 반영하는지를 탐구한다. 산스크리트 희곡과 마하바라타, 라마야나와 같은 서사에 뿌리를 둔 전통 인도 연극은 도덕적 이분법과 사회 규범에 중점을 두었다. 그 러나 탈식민 시대의 인도 영어 연극, 특히 텐둘카르의 작품은 도시 중산층이 직면한 현대 사회 정치적 문제들을 다루는 방향으로 전환되었다. 텐둘카르의 􋺷정숙! 재판이 진행 중이다􋺸는 가부장제, 성 역할, 사회적 위선과 같은 주제를 조명하며 그 전환을 대표하는 사례 연구로 제시된다. 이 희곡은 모의 재판이라는 개념을 통해 사회적 불의 와 여성 억압을 비판하며, 현대 인도 사회의 보다 넓은 투쟁을 상징한다. 텐둘카르의 인도주의적 접근은 기존의 규범에 도전하며 진정성, 성실성, 새로운 도덕 질서를 옹호 한다. 그의 심리적, 실존적, 여성주의적 문제에 대한 집중은 현대 삶의 분열성을 부각 시킨다. 본 논문은 텐둘카르만의 독특한 시각을 분석함으로써, 인도 연극이 사회 비판 과 문화적 혼종성의 장으로 진화한 과정을 보여준다.

Galaxy evolution studies require the measurement of the physical properties of galaxies at different redshifts. In this work, we build supervised machine learning models to predict the redshift and physical properties (gas-phase metallicity, stellar mass, and star formation rate) of star-forming galaxies from the broad-band and medium-band photometry covering optical to near-infrared wavelengths, and present an evaluation of the model performance. Using 55 magnitudes and colors as input features, the optimized model can predict the galaxy redshift with an accuracy of σ(Δz/1+z) = 0.008 for a redshift range of z < 0.4. The gas-phase metallicity [12 + log(O/H)], stellar mass [log(Mstar)], and star formation rate [log(SFR)] can be predicted with the accuracies of σNMAD = 0.081, 0.068, and 0.19 dex, respectively. When magnitude errors are included, the scatter in the predicted values increases, and the range of predicted values decreases, leading to biased predictions. Near-infrared magnitudes and colors (H, K, and H −K), along with optical colors in the blue wavelengths (m425–m450), are found to play important roles in the parameter prediction. Additionally, the number of input features is critical for ensuring good performance of the machine learning model. These results align with the underlying scaling relations between physical parameters for star-forming galaxies, demonstrating the potential of using medium-band surveys to study galaxy scaling relations with large sample of galaxies.

Gold nanoparticles (Au NPs) decorated carbon nanofibers (CNFs) have been prepared by an electrospinning approach and then carbonized. The prepared Au-CNFs were employed to modifying a screen printed electrode (SPE) for simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA). Au NPs are uniformly dispersed on carbon nanofibers were confirmed by the structure and morphological studies. The modified electrodes were tested in cyclic voltammetry (CV), differential pulse voltammetry (DPV) and chronoamperometry (CA) to characterize their electrochemical responses. Compared to bare SPE, the Au-CNFs/SPE had a better sensing response to AA, DA, and UA. The electrochemical oxidation signal of AA, DA and UA are well separated into three distinct peaks with peak potential separation of 280 mV, 159 mV and 439 mV between AA-DA, DA-UA and AA-UA respectively in CV studies and the corresponding peak potential separation in DPV studies are 290 mV, 166 mV and 456 mV. The Au-CNFs/SPE has a wide linear response of AA, DA and UA in DPV analysis over the range of 5–40 μM ( R2 = 0.9984), 2–16 μM ( R2 = 0.9962) and 2–16 μM ( R2 = 0.9983) with corresponding detection limits of 0.9 μM, 0.4 μM and 0.3 μM at S/N = 3, respectively. The developed modified SPE based sensor exhibits excellent reproducibility, stability, and repeatability. The excellent sensing response of Au-CNFs could reveal to a promising approach in electrochemical sensor.

In recent years, the search on fabrication of highly efficient, stable, and cost-effective alternative to Pt for the hydrogen evolution reaction (HER) has led to the development of new catalysts. In this study, we investigated the electrocatalytic HER activity of the Toray carbon substrate by creating defect sites in its graphitic layer through ultrasonication and anodization process. A series of Toray carbon substrates with active sites are prepared by modifying its surface through ultrasonication, anodization, and ultrasonication followed by anodization procedures at different time periods. The anodization process significantly enhances the surface wettability, consequently resulting in a substantial increase in proton flux at the reaction sites. As an implication, the overpotential for HER is notably reduced for the Toray carbon (TC-3U-10A), subjected to 3 min of ultrasonification followed by 10 min of anodization, which exhibits a significantly lower Tafel slope value of 60 mV/dec. Furthermore, the reactivity of the anodized surface for HER is significantly elevated, especially at higher concentrations of sulfuric acid, owing to the enhanced wettability of the substrate. The lowest Tafel slope value recorded in this study stands at 60 mV/dec underscoring the substantial improvements achieved in catalytic efficiency of the defect-rich carbon materials. These findings hold promise for the advancement of electrocatalytic applications of carbon materials and may have significant implications for various technological and industrial processes.

Complex structure constituting of several layers of heteroatom-doped N-CDs are used as a main sensing film along with aluminum electrodes in conductometric gas sensing system for sensitive and selective monitoring of CO2 and CO gases diluted with normal air, which are extensively prevalent in the atmosphere primarily due to the industrial revolution, locomotives, and numerous natural phenomena’s and the limit of detection (LOD) turned out to be 400 ppm and 30 ppm, respectively, with 20% relative humidity at 30 °C and pressure 1 (atm) which are good for healthy air quality checks. The sensor performance was satisfactory and bidirectional at ambient room temperature (30 °C) and pressure (1 atm) conditions but the relative humidity (50%) at 30 °C had a detrimental impact on the sensing responses, therefore intermittent heating at 80 °C for several minutes between the sensing responses was provided to the sensing chip or one should use gas filter membranes to block humidity, thereby maintaining its constant performance with great ease and accuracy. The cyclic voltammetry revealed well-defined oxidation and reduction peaks, with excellent stability and reversibility. In a nutshell, heteroatom-doped N-CDs’ nanocomposite material can revolutionize in a better environmental pollution monitoring by sensing gases in an extensively lesser response and recovery times.

Under Trump and Biden, the US trade policy has veered away from its traditional approach, developed since World War II, from multilateralism to focusing primarily on national and unilateral concerns. At the center of this approach have been tensions with China. This includes a renewal of industrial policies, protectionism and, most importantly, reliance on national security, manifested by newer and unexpected geopolitical developments. The discussion of trade policy today has become very toxic, especially during this presidential campaign season, with its renewed focus on tariffs. The trade debate in the US is now entering a new stage with the nomination of Kamala Harris and J.D. Vance. I believe the US drift away from the postwar policies of promoting global trade and investment will continue. Nationalist and protectionist policies will continue as part of a new economic and industrial policy, fused with national security concerns and rhetoric, no matter who wins.

Aluminum-based composites are in high demand in industrial fields due to their light weight, high electrical conductivity, and corrosion resistance. Due to its unique advantages for composite fabrication, powder metallurgy is a crucial player in meeting this demand. However, the size and weight fraction of the reinforcement significantly influence the components' quality and performance. Understanding the correlation of these variables is crucial for building high-quality components. This study, therefore, investigated the correlations among various parameters—namely, milling time, reinforcement ratio, and size—that affect the composite’s physical and mechanical properties. An artificial neural network model was developed and showed the ability to correlate the processing parameters with the density, hardness, and tensile strength of Al2024-B4C composites. The predicted index of relative importance suggests that the milling time has the most substantial effect on fabricated components. This practical insight can be directly applied in the fabrication of high-quality Al2024-B4C composites.

We investigate the evolution of initial fractal clusters at 3 kpc from the Galactic Center (GC) of the MilkyWay and show how red supergiant clusters (RSGCs)-like objects, which are considered to be the result of active star formation in the Scutum complex, can form by 16 Myr. We find that initial tidal filling and tidal over-filling fractals are shredded by the tidal force, but some substructures can survive as individual subclusters, especially when the initial virial ratio is ≤0.5. These surviving subclusters are weakly mass segregated and show a top-heavy mass function. This implies the possibility that a single substructured star cluster can evolve into multiple ‘star clusters’.

In the present study, a novel pH-sensitive hydrogel composite of pectin-grafted-poly (acrylic acid-co-itaconic acid)/MWCNTs- COOH was prepared by using graft copolymerization of acrylic acid and itaconic acid on pectin backbone with incorporation of MWCNTS- COOH. The prepared hydrogel composite has been employed for the adsorption and controlled release of the diclofenac sodium (DS) drug. The hydrogel composite was characterized by the analysis methods: FTIR, XRD, SEM, and TGA to analyze structural characteristics before and after DS drug adsorption. The swelling ratio of the hydrogel composite was investigated at different pH values from pH 1.2 to 10. According to the results, the swelling ratio of the hydrogel composite was found 4195% at pH 7.4. Adsorption process parameters such as pH, contact time, adsorbent dose, and temperature were investigated and found to have a significant influence on DS drug adsorption. The maximum DS drug loading through adsorption of 91% was obtained at pH 3, adsorbent dose of 0.05 g, contact time of 150 min, and temperature of 15 °C. The adsorption isotherm and kinetic results were well-fitted to Freundlich and second-order models. Thermodynamic parameters including changes in Gibb’s free energy, enthalpy, and entropy suggested that the adsorption of DS drug onto hydrogel composite was a spontaneous and exothermic process. The in vitro drug release experiment showed that the cumulative release of DS drug from hydrogel composite after 35 h was significantly higher in simulated intestinal fluid at pH 7.4 than in simulated gastric fluid at pH 1.2.

Geopolitical risk is now among the most important factors in the formulation of multinational corporate strategy and the US trade policy. The US has aggressively enacted national-security-based trade sanctions, which recently include export controls on semiconductor chips and restrictions on outbound and inbound investment. The US has also adopted major legislation providing historical subsidies and tax breaks. Congress and the courts have upheld the president’s use of national security as a basis of trade actions and generally supported his protectionist policies. Trade should not be restricted or weaponized. Global and national rules need to be strengthened and, perhaps, a bit updated, but protectionism in the name of national security is a losing argument. The growing movement by the US to rely more on national security and protectionism in formulating trade policy is a very worrisome development. No one in Washington is proposing a return to pre-Trump policies. The real question is how far US trade policy will continue to change in the near future. Geopolitics will give us the answer.