1,751 research outputs found
Synthesis, crystal structure and thermochromism of benzimidazolium tetrachlorocuprate: (C7H7N2)2[CuCl4]
No full textThe synthesis and crystal structure of thermochromic, yellow benzimidazolium tetrachlorocuprate(II), (C7H7N2)(2)CuCl4 (1), have been reported. The compoundcrystallizes in the C2/c space group and contains discrete tetrahedral CUCl42- species. It absorbs one molecule of water from humid atmosphere at room temperature to produce a hydrated green form, (C7H7N2)(2)CuCl4.H2O, which upon heating loses the water molecule in two steps to form the anhydrous yellow compound 1. The role of the water molecule on the solid state, yellowreversible arrowgreen thermochromic transformation is discusse
Arbitration and Dispute Settlement in Foreign Indirect Investment. The increasing significance and use of arbitration in international loan agreements, syndicated loans and international bond issues
No full textThis dissertation examines the suitability of arbitration for the resolution of securities regulatory claims and it adoption globally, which has resulted in international arbitration becoming the favoured dispute resolution mechanism in the securities industry. The author explains that disputes arising out of international bilateral and syndicated loan agreements are generally considered to be arbitrable, while international bond disputes are often derived from the controversies over the application of mandatory national laws and the compliance with securities regulation provisions - so the arbitrability of international bond disputes depends on the acceptance of the arbitrability of securities regulatory claims
A monolithically integrated power JFET and Junction Barrier Schottky diode in 4H silicon carbide
No full textEfficiency of power management circuits depends significantly on their constituent switches and rectifiers. The demands of technology are increasingly running up against the intrinsic properties of Si based power devices. 4H-Silicon Carbide (SiC) has superior properties that make it attractive for high power applications. SiC rectifiers are already a competitive choice and SiC switches have also been commercialized recently. Junction Barrier Schottky (JBS) diodes, which combine the advantages of PN and Schottky, have higher Figure of Merit (FOM) as rectifiers. Among switches, a robust and mature process has been developed for Silicon Carbide Vertical Junction Field Effect Transistors (VJFETs), which currently gives it the highest unipolar FOM. Switches are frequently combined with anti-parallel diodes in power circuits. This thesis describes the development of a SiC-based monolithically integrated power switch and diode. Monolithic integration increases reliability and efficiency, and reduces cost. Because of their superior properties and similarities in fabrication, we chose the SiC VJFET and JBS diode as the switch and rectifier. Detailed design, fabrication and characterization of the integrated switch to block above 800 V and conduct current beyond 100 A/cm2 is explained. In this process, the first physics-based 2-D compact model is developed for reverse leakage in a JBS diode as a function of design parameters. Since the gate-channel junctions of SiC VJFETs cannot be assumed to be abrupt, an existing analytical model for Si VJFETs is extended to account for graded gate-channel junctions. Using these analytical models, design rules are developed for the VJFET and JBS diode. Finite element simulations are used to find the best anode layout of the JBS diode and optimize electric field termination in the integrated device to ensure their capability to operate at high voltage. Finally, a spin-on glass based process is developed for filling the gate trenches of the VJFET to improve long-term robustness in extreme environments. The integrated power switch developed in this thesis points to the attractions of monolithic integration in SiC power circuits. Analytical compact design equations derived here will facilitate faster and easier design of switches and rectifiers for desired circuit operation.Ph. D.Includes bibliographical referencesIncludes vitaby Rahul Radhakrishna
Clinical and electroencephalogram correlation of self-limited epilepsy with autonomic seizures
No full textIndocyanine green fluorescent cholangiography: The new standard practice to perform laparoscopic cholecystectomy in pediatric patients. A comparative study with conventional laparoscopic technique
No full textBackground: This study aimed to compare outcomes of standard laparoscopic cholecystectomy and indocyanine green fluorescent cholangiography laparoscopic cholecystectomy over a 10-year period. Methods: From 2013 to 2023, 173 laparoscopic cholecystectomies were performed in 2 pediatric surgery units: 83 using standard technique (G1) and 90 using indocyanine green fluorescent cholangiography (G2). Patients included 96 girls and 77 boys, with a median age of 12.3 years (range 4-17) and a median weight of 51 kg (range 19-114). The 2 groups were compared regarding the following: (1) perioperative complications rate; (2) overall length of surgery (T1); (3) length of cystic duct isolation, clipping, and sectioning (T2); (4) time of gallbladder removal (T3); (5) degree of visualization of biliary tree; (6) safety and feasibility of indocyanine green fluorescent cholangiography; (7) incidence of anatomical anomalies detected intraoperatively. Results: All laparoscopic cholecystectomies were accomplished without conversion to open. The perioperative complications rate was significantly higher in G1 compared with G2 (12% vs 0%; P = .0007). Median T1, T2, and T3 were significantly longer in G1 (90, 37, 35 minutes) compared with G2 (55, 17, 19 minutes) (P = .0001), respectively. The visualization rate of the complete biliary tree was significantly higher in G2 (98.8%) than in G1 (80.7%) (P = .0001). No adverse reactions to indocyanine green were recorded. The incidence of biliary anomalies detected intraoperatively was significantly higher in G2 (7.8%) than in G1 (1.2%) (P = .03). Conclusion: Indocyanine green fluorescent cholangiography can be considered the new standard practice to perform laparoscopic cholecystectomy in pediatrics. Indocyanine green fluorescence provided superior visualization of biliary anatomy, increased detection of anatomic variants, faster procedure, and fewer complications compared with conventional technique. Indocyanine green fluorescent cholangiography was safe, feasible, simple, inexpensive, and a timesaving tool
Resetting disturbance observers with application in compensation of bounded nonlinearities like hysteresis in piezo-actuators
No full textThis paper presents a novel nonlinear (reset) disturbance observer for dynamic compensation of bounded nonlinearities like hysteresis in piezoelectric actuators. Proposed Resetting Disturbance Observer (RDOB) utilizes a novel Constant-gain Lead-phase (CgLp) element based on the concept of reset control. The fundamental limitations of linear DOB which results in contradictory requirements and in a dependent design between DOB and feedback controller are analysed. Two different configurations of RDOB which attempt to alleviate these problems from different perspectives are presented and an example plant is used to highlight the improvement. Stability criteria are presented for both configurations. Performance improvement seen with both RDOB configurations compared to linear DOB is also verified on a practical piezoelectric setup for hysteresis compensation and results analysed.Accepted Author ManuscriptMechatronic Systems Desig
Molecular Phylogeny of OVOL Genes Illustrates a Conserved C2H2 Zinc Finger Domain Coupled by Hypervariable Unstructured Regions
Full text linkOVO-like proteins (OVOL) are members of the zinc finger protein family and serve as transcription factors to regulate gene expression in various differentiation processes. Recent studies have shown that OVOL genes are involved in epithelial development and differentiation in a wide variety of organisms; yet there is a lack of comprehensive studies that describe OVOL proteins from an evolutionary perspective. Using comparative genomic analysis, we traced three different OVOL genes (OVOL1-3) in vertebrates. One gene, OVOL3, was duplicated during a whole-genome-duplication event in fish, but only the copy (OVOL3b) was retained. From early-branching metazoa to humans, we found that a core domain, comprising a tetrad of C2H2 zinc fingers, is conserved. By domain comparison of the OVOL proteins, we found that they evolved in different metazoan lineages by attaching intrinsically-disordered (ID) segments of N/C-terminal extensions of 100 to 1000 amino acids to this conserved core. These ID regions originated independently across different animal lineages giving rise to different types of OVOL genes over the course of metazoan evolution. We illustrated the molecular evolution of metazoan OVOL genes over a period of 700 million years (MY). This study both extends our current understanding of the structure/function relationship of metazoan OVOL genes, and assembles a good platform for further characterization of OVOL genes from diverged organisms
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