46 research outputs found
Thermal conductance of interfaces between titanium nitride and group IV semiconductors at high temperatures
No full textThis article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Samreen Khan, Xinping Shi, Joseph Feser, Richard Wilson; Thermal conductance of interfaces between titanium nitride and group IV semiconductors at high temperatures. Appl. Phys. Lett. 22 July 2024; 125 (4): 041601. https://doi.org/10.1063/5.0220124 and may be found at https://doi.org/10.1063/5.0220124.
© 2024 Author(s). Published under an exclusive license by AIP Publishing.
This article will be embargoed until 07/22/2025.Measuring the temperature dependence of material properties is a standard method for better understanding the microscopic origins for that property. Surprisingly, only a few experimental studies of thermal boundary conductance at high temperatures exist. This lack of high temperature data makes it difficult to evaluate competing theories for how inelastic processes contribute to thermal conductance. To address this, we report time domain thermoreflectance measurements of the thermal boundary conductance for TiN on diamond, silicon-carbide, silicon, and germanium between 120 and 1000 K. In all systems, the interface conductance increases monotonically without stagnating at higher temperatures. For TiN/SiC interfaces, ranges from 330 to 1000 MW/m2-K, with a room temperature conductance of 750 MW/m2-K. The interface conductance for TiN/diamond ranges from 140 to 950 MW/m2-K. Notably, for all four interfacial systems, the conductance continues to increase with temperature even after all phonon modes in the vibrationally soft material are thermally excited. This observation suggests that inelastic processes are significant contributors to the thermal conductance in all four interfacial systems, regardless of whether the materials forming the interface are vibrationally similar or dissimilar. Our study fills a notable gap in the literature for how interfacial conductance evolves at high temperatures and tests burgeoning theories for the role of inelastic processes in interfacial thermal transport.This work was supported as part of ULTRA, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award No. DE-SC0021230
Anti-Ro Positivity in Systemic Lupus Erythematosus: Association with Clinical Phenotypes and Other Antibodies
No full textBackground: Anti-Ro antibody positivity (anti-Ro+) can have possible association with the clinical features and serology in patients with systemic lupus erythematosus (SLE). Methods: This retrospective observational study enrolled 158 SLE patients at the Rheumatology department, Fauji Foundation Hospital, from 1st May to 31st October 2023. Demographic and clinical data were collected. Patients were stratified by anti-Ro (positive vs negative), concomitant anti-La (anti-Ro+/ anti-La+; anti-Ro- / anti-La-; anti-Ro+/anti-La- and anti-Ro-/anti-La+), and ANA status (positive vs negative). Mann-Whitney U and Chi-square tests were employed for comparisons, with statistical significance set at p[Formula: see text]0.05 Results: Study population consisted mainly of females (98.7%), with median age of 30± 20 years. Anti-Ro antibodies were positive in 74(46.8%) patients. This group had significantly higher discoid rash (16.2% vs 6%, p-value 0.04), sicca symptoms (41.1% vs 31%, p-value 0.005), anemia (71.6% vs 56%, p-value 0.04) compared to anti-Ro negative group. No significant differences were observed in nephritis (29.7% vs 34.5%, p=0.52) or neurological disease (9.5% vs 11.9%, p=0.69) between the two groups. Anti-Ro+ /anti-La+ group had higher myositis (20.6%), sicca symptoms (55.9%) and fever (70.6%) compared to other groups. ANA+/anti-Ro+ group (48.6%) had significant association with sicca symptoms (50.7%) and fever (64.2%). Conclusion: Anti-Ro positivity in SLE is associated with muco-cutaneous manifestations and anemia. Concomitant anti-La positivity is linked to increased xerophthalmia, myositis, and fever. While anti-Ro status is independent of ANA, the combination of both autoantibodies is associated with increased sicca symptoms and fever in SLE patients
Flexural Behavior and Composite Action of Structural Concrete Insulated Panels as Floor Slabs: Effects of Reinforcement Placement and Spacing
No full textStructural Concrete Insulated Panels (SCIPs) offer a precast, lightweight, and off-site option for several types of construction including residential, commercial, and industrial structures. This study addresses a critical gap in the existing literature by investigating the flexural behavior of Structural Concrete Insulated Panels (SCIPs) under pinned-ended conditions—unlike prior research that focused primarily on fixed-ended configurations. It further introduces original variations in reinforcement placement and spacing, offering a novel perspective on enhancing composite action and deflection performance in floor slab applications. By experimentally evaluating four distinct SCIP configurations using four-point bending tests, the research contributes new empirical data to inform optimized structural design. The findings reveal ultimate moment capacities ranging from 2.84 to 5.70 kN m, and degrees of composite action between 6.5% and 28.2%. Notably, SCIP-2 and SCIP-3 satisfied ACI 318-19 deflection criteria, demonstrating their viability for structural flooring systems. The findings emphasize the capacity of SCIPs to transform the building sector by providing practical and sustainable solutions for floor systems
Synthesis of Indoles via Intermolecular and Intramolecular Cyclization by Using Palladium-Based Catalysts
No full textAs part of natural products or biologically active compounds, the synthesis of nitrogen-containing heterocycles is becoming incredibly valuable. Palladium is a transition metal that is widely utilized as a catalyst to facilitate carbon-carbon and carbon-heteroatom coupling; it is used in the synthesis of various heterocycles. This review includes the twelve years of successful indole synthesis using various palladium catalysts to establish carbon-carbon or carbon-nitrogen coupling, as well as the conditions that have been optimized
Ultrasound Assisted Synthesis and In Silico Modelling of 1,2,4-Triazole Coupled Acetamide Derivatives of 2-(4-Isobutylphenyl)propanoic acid as Potential Anticancer Agents
No full textThe development of an economical method for the synthesis of biologically active compounds was the major goal of this research. In the present study, we have reported the ultrasound-radiation-assisted synthesis of a series of novel N-substituted 1,2,4-triazole-2-thiol derivatives. The target compounds 6a–f were efficiently synthesized in significant yields (75–89%) by coupling 1,2,4-triazole of 2-(4-isobutylphenyl) propanoic acid 1 with different electrophiles using ultrasound radiation under different temperatures. The sonication process accelerated the rate of the reaction as well as yielded all derivatives compared to conventional methods. All derivatives were confirmed by spectroscopic (FTIR, 1HNMR, 13CNMR, HRMS) and physiochemical methods. All derivatives were further screened for their anticancer effects against the HepG2 cell line. Compound 6d containing two electron-donating methyl moieties demonstrated the most significant anti-proliferative activity with an IC50 value of 13.004 µg/mL, while compound 6e showed the lowest potency with an IC50 value of 28.399 µg/mL. The order of anticancer activity was found to be: 6d > 6b > 6f > 6a > 6c > 6e, respectively. The in silico modelling of all derivatives was performed against five different protein targets and the results were consistent with the biological activities. Ligand 6d showed the best binding affinity with the Protein Kinase B (Akt) pocket with the lowest ∆G value of −176.152 kcal/mol. Compound 6d has been identified as a promising candidate for treatment of liver cancer
Update on the Reactivity of Saccharin: An Excellent Precursor for the Synthesis of Biologically Important Molecules
No full textAnti-Ro Positivity in Systemic Lupus Erythematosus: Association with Clinical Phenotypes and Serological Profile
No full textObjective: To determine the association of anti-Ro antibody with the clinical features and serology in systemic lupus erythematosus (SLE) patients. Methods: This retrospective observational study enrolled 158 SLE patients at the Rheumatology Department, Fauji Foundation Hospital, from May 1 to October 31, 2023. Demographic and clinical data were collected. Patients were stratified by anti-Ro (positive vs. negative), concomitant anti-La (anti-Ro[Formula: see text]/anti-La[Formula: see text], anti-Ro[Formula: see text]/anti-La[Formula: see text], anti-Ro[Formula: see text]/anti-La[Formula: see text], and anti-Ro[Formula: see text]/anti-La[Formula: see text]), and anti-nuclear antibody (ANA) status (positive vs. negative). Mann-Whitney U and Chi-square tests were employed for comparisons, with statistical significance set at p<0.05. Results: The study population consisted mainly of females (98.7%), with a median age of 30 years. Anti-Ro[Formula: see text] patients (46.8%) exhibited higher discoid rash (16.2% vs. 6%, p [Formula: see text] 0.04), sicca symptoms (52.7% vs. 31%, p [Formula: see text] 0.005), and anemia (71.6% vs. 56%, p [Formula: see text] 0.04). No significant differences were observed in nephritis (29.7% vs. 34.5%, p [Formula: see text] 0.52) or neurological disease (9.5% vs. 11.9%, p [Formula: see text] 0.69) between the two groups. The anti-Ro[Formula: see text]/anti-La[Formula: see text] group had higher myositis (20.6%), sicca symptoms (55.9%), and fever (70.6%) compared to other groups. The ANA[Formula: see text]/anti-Ro[Formula: see text] group (48.6%) had significant association with sicca symptoms (50.7%) and fever (64.2%). Conclusion: Anti-Ro[Formula: see text] SLE in South Asians is associated with sicca symptoms, anemia, fever, and myositis—findings critical for tailored management. Co-positivity with anti-La amplifies risks, warranting vigilant monitoring
Medical Students & e-Learning during COVID-19 Crisis: A Structural Equation Modeling Based Study
No full textBackground: COVID-19 crisis affected the medical education throughout the world. During the infectious outbreak, closure of universities was the only solution to prevent the spread of virus. However, adoption of e-Learning helped in sustaining the medical educational activities.
Objective: The current study focus on e-Learning acceptance among medical students during the COVID-19 crisis in Pakistan.
Study type, settings & duration: This cross-sectional study was conducted at the four different medical institutes of Punjab from January 2021 to March 2021.
Methodology: The random sample technique was used to include 314 medical students by using the sample section criteria suggested by Krejcie and Morgan. We also proposed a self-proposed conceptual model supported by Media System Dependency Theory.
Results: Findings indicated that despite e-Learning has some limitations for the medical students, still we found a strong significant relationship between students' positive perceptions towards e-Learning during the Covid-19. i.e., the significance for H1, e-Learning and its Impact was (β =0.266, p <0.011), for H2, e-Learning as a Substitute, (β= 0.144, p<0.00), and the H3, the Perceptions of students towards e-Learning was (β =0.2121, p <0.000).
Conclusion: We concluded that, e-Learning is a potential solution to sustain the educational activities and balance the cessation of ward rotations during the lockdown. Using e-Learning during the COVID-19 not only depicted the role of internet-based learning, it also highlighted the greater dependence on new media technology
Sustainable Dyeing of Microwave Treated Polyester Fabric using Disperse Yellow 211 Dye
No full textThe aim of current work is to evaluate the dyeing performance of newly introduced disperse dye to improve its dyeing behavior onto polyester fabric using microwave radiation. Microwave heating has promisingly improved the disperse dyeing of polyester fabrics. Disperse Yellow 211 (DY 211) has been used to dye the polyester fabric under the influence of microwave treatment. Both the fabric and dye solution, were treated with the microwaves for 1- 6 min. Different dyeing parameters such as temperature, time, dispersant and dye bath volume were also optimized and ISO standard methods for colorfastness were employed to rate the influence of microwave and ultraviolet treatment on disperse dyeing. It is found that microwave treated polyester (RP, 6 min), has given good color strength and darker shades upon dyeing at 90°C for 40 min. in the presence of 2 g/100ml of dispersant using 70 mL of irradiated dye solution (RS, 6 min) of pH 8. Similarly using dye bath of pH 11, microwave treated polyester (RP, 6 min.) has given good color strength and darker shades upon dyeing at 70°C for 35 min.in the presence of 1 g/100ml of dispersant. using 50 mL of irradiated dye solution (RS). ISO standards for fastness to light, washing and rubbing revealed that good to excellent ratings have been obtained from different shades dyed at optimal condition. It is inferred that Microwave treatment has not only reduced the dyeing conditions but also improved the color characteristics of dyed polyester fabric.</jats:p
