1,793 research outputs found
Simplified Analytical Method for Optimized Initial Shape Analysis of Self-Anchored Suspension Bridges and Its Verification
A simplified analytical method providing accurate unstrained lengths of all structural elements is proposed to find the optimized initial state of self-anchored suspension bridges under dead loads. For this, equilibrium equations of the main girder and the main cable system are derived and solved by evaluating the self-weights of cable members using unstrained cable lengths and iteratively updating both the horizontal tension component and the vertical profile of the main cable. Furthermore, to demonstrate the validity of the simplified analytical method, the unstrained element length method (ULM) is applied to suspension bridge models based on the unstressed lengths of both cable and frame members calculated from the analytical method. Through numerical examples, it is demonstrated that the proposed analytical method can indeed provide an optimized initial solution by showing that both the simplified method and the nonlinear FE procedure lead to practically identical initial configurations with only localized small bending moment distributions
Nonflammable Lithium Metal Full Cells with Ultra-high Energy Density Based on Coordinated Carbonate Electrolytes
Coupling thin Li metal anodes with high-capacity/high-voltage cathodes such as LiNi0.8Co0.1Mn0.1O2 (NCM811) is a promising way to increase lithium battery energy density. Yet, the realization of high-performance full cells remains a formidable challenge. Here, we demonstrate a new class of highly coordinated, nonflammable carbonate electrolytes based on lithium bis(fluorosulfonyl)imide (UFSI) in propylene carbonate/fluoroethylene carbonate mixtures. Utilizing an optimal salt concentr ation (4 M LiFSI) of the electrolyte results in a unique coordination structure of Li+-FSI-solvent cluster, which is critical for enabling the formation of stable interfaces on both the thin Li metal anode and high-voltage NCM811 cathode. Under highly demanding cell configuration and operating conditions (Li metal anode = 35 mu m, areal capacity/charge voltage of NCM811 cathode = 4.8 mAh cm(-2)/4 .6 V, and anode excess capacity [relative to the cathode] = 0.83), the Li metal-based full cell provides exceptional electrochemical performance (energy densities = 679 Wh kg(cell)(-1)/1,024 Wh L-cell(-1)) coupled with nonflammability
Identification of protein functions using a machine-learning approach based on sequence-derived properties
<p>Abstract</p> <p>Background</p> <p>Predicting the function of an unknown protein is an essential goal in bioinformatics. Sequence similarity-based approaches are widely used for function prediction; however, they are often inadequate in the absence of similar sequences or when the sequence similarity among known protein sequences is statistically weak. This study aimed to develop an accurate prediction method for identifying protein function, irrespective of sequence and structural similarities.</p> <p>Results</p> <p>A highly accurate prediction method capable of identifying protein function, based solely on protein sequence properties, is described. This method analyses and identifies specific features of the protein sequence that are highly correlated with certain protein functions and determines the combination of protein sequence features that best characterises protein function. Thirty-three features that represent subtle differences in local regions and full regions of the protein sequences were introduced. On the basis of 484 features extracted solely from the protein sequence, models were built to predict the functions of 11 different proteins from a broad range of cellular components, molecular functions, and biological processes. The accuracy of protein function prediction using random forests with feature selection ranged from 94.23% to 100%. The local sequence information was found to have a broad range of applicability in predicting protein function.</p> <p>Conclusion</p> <p>We present an accurate prediction method using a machine-learning approach based solely on protein sequence properties. The primary contribution of this paper is to propose new <it>PNPRD </it>features representing global and/or local differences in sequences, based on positively and/or negatively charged residues, to assist in predicting protein function. In addition, we identified a compact and useful feature subset for predicting the function of various proteins. Our results indicate that sequence-based classifiers can provide good results among a broad range of proteins, that the proposed features are useful in predicting several functions, and that the combination of our and traditional features may support the creation of a discriminative feature set for specific protein functions.</p
A Study of Solids and Gas Mixing in a Partitioned Fluidized Bed
A partitioned fluidized bed gasifier has been developed for improving coal gasification performance. The basic concept is to divide a fluidized bed into two parts, a gasifier and a combustor, by a partition. Char is burnt in the combustor and generated heat is supplied to the gasifier by solid mixing. Therefore, solid mixing should be maximized whereas gas mixing between syngas and the combusted gas should be minimized. In this study, gas and solid mixing behaviors were verified in cold model acrylic beds. For monitoring solid mixing behavior, transient temperature trends in the beds were analyzed. A heat source and a heat sink were installed in each bed. Dozens of thermocouples were used to monitor temperature distribution
Effect of blood pressure and glycemic control on the plasma cell-free DNA in hemodialysis patients
AbstractBackgroundThe plasma levels of cell-free DNA (cfDNA) are known to be elevated under inflammatory or apoptotic conditions. Increased cfDNA levels have been reported in hemodialysis (HD) patients. The aim of this study was to investigate the clinical significance of cfDNA in HD patients.MethodsA total of 95 patients on HD were enrolled. We measured their predialysis cfDNA levels using real-time EIF2C1 gene sequence amplification and analyzed its association with certain clinical parameters.ResultsThe mean plasma cfDNA level in the HD patients was 3,884 ± 407 GE/mL, and the mean plasma cfDNA level in the control group was 1,420 ± 121 GE/mL (P < 0.05). Diabetic patients showed higher plasma cfDNA levels compared with nondiabetic patients (P < 0.01). Patients with cardiovascular complications also showed higher plasma cfDNA levels compared with those without cardiovascular complication (P < 0.05). In univariable analysis, the cfDNA level was associated with 3-month mean systolic blood pressure (SBP), white blood cell, serum albumin, creatinine (Cr), normalized protein catabolic rate in HD patients. In diabetic patients, it was significantly correlated with SBP, hemoglobin A1c, and serum albumin. In multivariate analysis, SBP was the independent determinant for the cfDNA level. In diabetic patients, cfDNA level was independently associated with hemoglobin A1c and SBP.ConclusionsIn patients with HD, cfDNA is elevated in diabetic patients and patients with cardiovascular diseases. Uncontrolled hypertension and poor glycemic control are independent determinants for the elevated cfDNA. Our data suggest that cfDNA might be a marker of vascular injury rather than proinflammatory condition in HD patients
DETC2005-84974 STRESS ANALYSIS AND LIFE ASSESSMENT OF ROTOR AND RETAINING RING OF GENERATOR FOR FOSSIL POWER PLANT
Increased rating of the generator capacity can be achieved by either increasing length or diameter of generator rotor body. Increasing the length of the rotor diameter should ensure the dynamic stability. On the other hand, increasing rotor diameter should satisfy the strength limit of current rotor material. ABSTRACT In addition to the higher centrifugal forces during normal operation in 3600 rpm, a generator rotor body is subjected to the contact pressures from shrink-fit between generator rotor and retaining ring. To obtain the structural reliability and life assessment of the generator, the finite element models were developed and structural analyses were carried out. The stress distributions and the critical locations of the rotor body were identified. Further, the fatigue life is performed to estimate the remaining life of generator. The critical crack size and probability of failure are also evaluated based on the analysis results. The critical sizes of a crack of generator are predicted using linear elastic fracture mechanics. These results will be applied to the development of a larger 1000MW capacity generator. This paper presents both stress analysis and life assessment results of the new 1000MW generator rotor assembly. The baseline design of the 800MW generator rotor was also evaluated for verifying the reliability of the analysis results. Two load cases, the contact pressures from shrink-fit between rotor and retaining ring and the centrifugal forces during normal operation in 3600 rpm, were considered. To obtain the structural reliability and life assessment of the generator, the finite element models were developed and structural analyses were carried out. The stress distributions and the critical locations of the rotor body were identified. Further, the fatigue life is performed to estimate the remaining life of generator. The critical crack size and probability of failure are also evaluated based on the analysis results INTRODUCTION In rapid technology advancement of the fossil power plant, it is inevitable that the output of a given turbine generator frame size will be increased from time to time. This has required redesign of the generator to keep pace with the increased rating. For turbine generators, increased rating presents challenges for designer. The designers to ensure that the new design can be satisfied the performance capabilities and electrical rating requirements, while maintaining mechanical, thermal and magnetic limits. These challenges come out largely as a result of increasing stresses, vibrational instability, fatigue and stress corrosion crack. To obtain the structural reliability and life assessment of the new generator, stress analyses, fatigue life assessment, and critical crack evaluation are required and the finite element analysis for the generator rotor assembly is used for this purpose
Thyroid function in obese Korean children and adolescents: Korea National Health and Nutrition Examination Survey 2013–2015
Purpose In recent years, there has been an increasing focus on thyroid function in pediatric obese patients, but no nationwide study evaluating the relationship between thyroid function and obesity has yet been conducted in Korea. We aimed to evaluate thyroid dysfunction in obese Korean children. Methods We analyzed the associations between obesity and thyroid hormone levels among 975 Korean boys and girls aged 10–18 years and who participated in the Korean National Health and Nutrition Examination Survey VI (2013–2015). Results Average serum thyrotropin (TSH) and serum free thyroxine (fT4) levels in the nonobese group were 2.7±0.1 μIU/mL and 1.3±0.0 ng/dL, respectively, and those in the overweight group were 3.1±0.2 μIU/mL and 1.2±0.0 ng/dL. Serum TSH level was significantly higher in the abdominal obesity group than in the normal group (P=0.023). fT4 level was significantly lower in both the overweight and abdominal obesity groups than in the normal group (P<0.001, P=0.014). Serum TSH level was associated positively with abdominal obesity and levels of high-density lipoprotein cholesterol and triglyceride. Serum fT4 level was negatively correlated with abdominal obesity (P=0.014). Conclusions Korean children with abdominal obesity showed increased TSH and decreased fT4 levels compared to normal children
Effect of rapid influenza diagnostic tests on patient management in an emergency department
Objective We evaluated the effect of rapid influenza diagnostic tests (RIDTs) on patient management in an emergency department for 3 years after 2009, and also identified factors associated with the choice of treatment for patients with influenza-like illnesses. Methods The study period consisted of three influenza epidemic seasons. Patients older than 15 years who underwent RIDTs in the emergency department and were then discharged without admission were included. Results A total of 453 patients were enrolled, 114 of whom had positive RIDT results and 339 had negative results. Antiviral medication was prescribed to 103 patients (90.4%) who had positive RIDT results, while 1 patient (0.3%) who tested negative was treated with antivirals (P<0.001). Conservative care was administered to 11 RIDT-positive patients (9.6%) and 244 RIDT-negative patients (72.0%) (P<0.001). Symptom onset in less than 48 hours, being older than 65 years, and the presence of comorbidities were not associated with the administration of antiviral therapy. Conclusion RIDT results had a critical effect on physician decision-making regarding antiviral treatment for patients with influenza-like illnesses in the emergency department. However, symptom onset in less than 48 hours, old age, and comorbidities, which are all indications for antiviral therapy, were not found to influence the administration of antiviral treatment
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