Lyapunov Exponent and the Solid-Fluid Phase Transition

We study changes in the chaotic properties of a many-body system undergoing a solid-fluid phase transition. To do this, we compute the temperature dependence of the largest Lyapunov exponents $\lambda_{max}$ for both two- and three-dimensional periodic systems of $N$-particles for various densities. The particles interact through a soft-core potential. The two-dimensional system exhibits an apparent second-order phase transition as indicated by a $\lambda$-shaped peak in the specific heat. The first derivative of $\lambda_{max}$ with respect to the temperature shows a peak at the same temperature. The three-dimensional system shows jumps, in both system energy and $\lambda_{max}$, at the same temperature, suggesting a first-order phase transition. Relaxation phenomena in the phase-transition region are analyzed by using the local time averages.Comment: 16 pages, REVTeX, 10 eps figures, epsfig.st

Numerical simulation of reverse electrodialysis with ammonium bicarbonate

A closed-loop reverse electrodialysis (RED) system using thermolytic solution has drawn significant attention in a low-grade waste heat energy recovery. The closed-loop characteristic enable the system have merits such as no need of repetitive pretreatment cost and removal of locational constraint than open-loop RED with sea and river water. In this study, we presents the numerical simulation of RED using ammonium bicarbonate which is one of the promising solute. The permselectivity of ion exchange membrane was calculated from membrane potential with various concentration ratios. We found that the polarization and the power density curve using the computed permselectivity are similar to the experimental results. The RED performance with ammonium bicarbonate was validated according to various concentration combination and flow rate. The open circuit voltage (OCV) and power density fit well for a wide range of solution concentration and the various flow rate. Finally, the optimum value of net power density, which consider the pumping loss, was obtained in terms of the intermembrane distance and the concentration ratio by the net power density contour. Please click Additional Files below to see the full abstract

ANASYSIS OF ISOMETRICITY OF THE ANTERIOR CRUCIATE LIGAMENT DURING KNEE FLEXION-EXTENSION FOR OPTIMAL LIGAMENT RECONSTRUCTION

Anterior cruciate ligament (ACL) is liable to a major injury that often results in a functional impairment requiring surgical reconstruction. The success of reconstruction depends on such factors as attachment positions, initial tension of ligament and surgical methods of fixation. The purpose of this study is to find isometric area of the substitute during flexion/extension and to simulate successful ACL reconstruction position using MADYMO(MAthematical DYnamic MOdel) software

Power Generation with Thermolytic Reverse Electrodialysis for Low-Grade Waste Heat Recovery

Closed-loop reverse electrodialysis (RED) systems that use a thermolytic solution for low-grade waste heat recovery have attracted significant attention. They have several cost benefits, e.g., the absence of repetitive pretreatment and removal of locational constraints, when compared with open-loop RED systems using seawater and river water. This study presents a model of RED that uses ammonium bicarbonate, and this is a promising solution for closed-loop systems. The modified Planck-Henderson equation is used to calculate the ion exchange membrane potential. The calculation is based on the conductivity measurements as ionization carbonate electrochemical information has not been reported before this study. The solution resistance is experimentally determined. The experimentally obtained permselectivity is implemented into the model to predict the membrane potential more accurately. The results of the improved model are well matched with experimental results under results under various operating conditions of the RED system. In addition, in the model of this study, the net power density was characterized with the consideration of the pumping loss. The improved model predicts a maximum net power density of 0.84 W/m2 with an intermembrane distance of 0.1 mm, a flow rate of 3 mL/min, and a concentration ratio of 200 as optimum conditions. The results of the study are expected to improve our understanding of the ammonium bicarbonate-RED system and contribute to modeling studies using ammonium bicarbonate or certain other compounds for novel technologies of waste heat recovery

Analysis of Platforms and Functions of Mobile-Based Personal Health Record Systems

ObjectivesLittle is known about the platforms and functionalities of mobile-based personal health record (PHR) applications. The objective of this study was to investigate these two features of PHR systems.MethodsThe unit of analysis was general hospitals with more than 100 beds. This study was based on a PHR survey conducted from May 1 to June 30, 2020 and the National Health Insurance administrative data as of March 31, 2020. The study considered the platform, Android and iPhone operation system (iOS), and types of functionalities of PHR systems. Among the 316 target hospitals, 103 hospitals had adopted PHR systems. A logistic regression analysis was used.ResultsThis study found that 103 hospitals had adopted mobile-based PHR systems for their patients. Sixty-four hospitals (62.1%) were adopting both Android and iOS, but 36 (35.0%) and 3 (2.9%) hospitals were adopting Android only or iOS only, respectively. The PHR systems of hospitals adopting both platforms were more likely to have functions for viewing prescriptions, clinical diagnostic test results, and upcoming appointment status compared to those adopting a single platform (p \u3c 0.001). The number of beds (odds ratio [OR] = 1.004; confidence interval [CI], 1.001–1.007; p = 0.0029) and the number of computed tomography systems (CTs) per 100 beds (OR = 6.350; CI, 1.006–40.084; p = 0.0493) were significantly associated with the adoption of both platforms.ConclusionsMore than 60% of hospitals had adopted both Android and iOS platforms for their patients in Korea. Hospitals adopting both platforms had additional functionalities and significant association with the number of beds and CTs