Inner Diameter
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2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Zibo Jin ◽  
Jin Zhou ◽  
Daochun Li

The shear pin structure is widely used in aeronautics and astronautics structures to deal with emergency structure separation problems. The shear pin design has a strict restriction on the precise failure load and definite failure mode. Previous research has conducted shear fracture tests and simulations of solid shear pins while there is a lack of detailed research on the shear fracture of hollow shear pins with large diameters. In this research, a 3-dimensional finite element model was built based on the actual shear pin installed on the aircraft engine pylon and the model was validated by the experiment. The influences of the inner diameter of hollow shear pins on the shear fracture process were investigated by conducting finite element simulations. The structural deformation, energy dissipation in the fracture process, and failure load of shear pins were evaluated. It is found that as the inner diameter increases, the failure mode of shear pins changed and would result in difficulties on the structure separation. To solve this problem, a new configuration of hollow shear pin was proposed for the purpose of obtaining both desired failure load and failure mode. The new configuration was verified by the fracture simulation and it is found that the new configuration is effective and can be used to improve the shear fracture performance.


Author(s):  
KRISHNAPHANISRI PONNEKANTI ◽  
K. SUNITHA

Objective: Azelnidipine (AZEL) and Telmisartan (TELM) combination is referred to the sufferers of hypertension. No analytical process has yet been mentioned for the TELM and AZEL combination analysis. We, therefore, have designed for its first time stability demonstrating methodology based on HPLC for analysing TELM and AZEL in the tablets and bulk. Methods: The assay of TELM and AZEL was get done on a 250 mm length C18 column (Supelco, 4.6 mm inner diameter, 5.0 μm particle size), and utilized 0.1M Na2SO4 (pH 3.6) and acetonitrile (55% volume:  45% volume) as the mobile solvents phase, at a stream rate 1.0 ml/min. HPLC recognition of TELM and AZEL was taken by a photodiode array sensor set at 258 nm. For validation of the stability demonstrating methodology proposed in terms of sensitivity, precision, specificity, linearity, device adequacy, robustness and accuracy, ICH directives were followed. Results: Calibration curves of TELM and AZEL were generated in the array of 20-60 µg/ml and 4-12 µg/ml with recovery percentage ranges of 99.62%-101.05% and 97.76%-100.17%, and detection limits of 0.020 µg/ml and 0.009 µg/ml, respectively. TELM and AZEL stability was inspected in the existence of acid, base, light, heat, and oxidation and it was realised to be more stable under oxidation degradation testing conditions employed when compared to acid, alkaline, photo, and heat degradation testing conditions applied. Conclusion: The observations demonstrated that the described HPLC stability demonstrating methodology was suitable for quantitating TELM and AZEL combination in tablets and bulk.


2021 ◽  
Vol 9 (3B) ◽  
Author(s):  
Bertan Beylergil ◽  

Fiber reinforced composites have been widely used in automotive industry since they offer significant weight reduction, low manufacturing and tooling cost, and better integration of parts compared to metal counterparts. In this study, design optimization of a hybrid aluminum/composite drive shaft subjected to torsion was carried out using ANSYS Workbench with ACP module. The numerical validation of finite element (FE) model was carried out by means of theoretical, experimental, and numerical studies in the literature. The ply material, lay-up orientations, and thickness of aluminum layer were considered as design variables. The geometric parameters in design were the length and inner diameter of the drive shaft. Two important design constraints, the minimum first mode natural frequency and design torque, were considered to satisfy the design requirements of a rear-wheel drive shaft used in automotive industry. The optimum design variables were determined by using screening method. The optimum design parameters (length, inner diameter, ply angle, and material) were presented in tabular form. Compared to nonoptimized scenario, the optimized solution reduced the cost of the hybrid composite drive shaft about 30% without ignoring the design requirements.


10.6036/9616 ◽  
2021 ◽  
Vol 96 (5) ◽  
pp. 468-472
Author(s):  
JOSE MARIA FRANQUET BERNIS ◽  
Francesc Xavier Grau Vidal

In this work, several studies of aging pipes have been compiled and, starting on the basis of circulating flow through a pipe of t years of age is based on the inner diameter and driving age, some design life tables have been made corresponding to the main materials and components of pipes specifically: iron, steel, concrete, fibre cement and plastics, determining the corresponding ageing by multiple linear regression equations, obtained for all these materials. Several proposals of analytical configuration of the mathematic functions of aging (flow-time) that can be useful for the study and prevention of this phenomenon are also made.


2021 ◽  
Author(s):  
Jingjing Hu ◽  
Zhaobin Cai

Abstract Objective: Mounting evidence links cirrhosis patients with left ventricular diastolic dysfunction(LVDD) has a poor prognosis. However, little is known about these particular individuals. Therefore, we conducted this cross-sectional study to assess the prevalence of LVDD and its associated risk factors.Methods: Consecutive cirrhosis patient who were attending Hangzhou Xixi hospital from January 2018 to December 2019 were included in this study. According to the American Society of Echocardiography 2016 criteria, cirrhosis patients were sorted into two group: the left ventricular diastolic dysfunction(LVDD) group and left ventricular diastolic function normal(LVDDn) group. Patients’ demographic data, clinical characteristics, laboratory data were recorded. Furthermore, we conducted a multi-factor analysis.Results: A total of 398cirrhosis patients were included in the study. The incidence of LVDD in this study was 49.7% (198 cases). In this study, the mean age and BMI of the patients were 52.9±8.2 years and 23.0±3.3kg/m2,respectively. Of 398 patients, 255(64.1%) of them were males. With regard to etiology, there were 296 patients (74.4%) with hepatitis B cirrhosis and 59 patients (14.8%) with alcoholic cirrhosis. The LVDD group had higher age, higher BMI, greater frequency of ascites and esophageal varices, prolonged prothrombin time, increased international normalized ratio, increased bilirubin, increased CK and AST, and longer QT interval than the LVDDn group(p<0.05, both). In terms of echocardiography, the LVDD group had larger aortic inner diameter, left atrial inner diameter and left ventricular wall diastolic thickness than LVDDn group(p<0.05, both). The multivariate analysis showed age>55 years, BMI>24kg/m2, hepatic decompensated, QTcB>440ms were independently associated with risk of LVDD.Conclusion: The prevalence of LVDD among cirrhosis patients was 49.8%. Cirrhosis patients with LVDD had worse liver function. Further, age>55 years, BMI>24kg/m2, hepatic decompensated, QTcB>440ms were independent predictors of LVDD.


Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1460
Author(s):  
Ruibang Sun ◽  
Xing Yang ◽  
Juncai Wang ◽  
Peng Chen ◽  
Liusuo Wu

With the widespread use of substations around the world, oil jet fire accidents from transformer oil-filled equipment in substations caused by faults have occurred from time to time. In this paper, a series of transformer oil jet fire experiments are carried out by changing the external heat source (30 cm and 40 cm) and the inner diameter of the container (5 cm, 8 cm and 10 cm) to study the axial centerline temperature distribution of the transformer oil jet fire plume of the transformer oil-filled equipment in the substation. The experiment uses K-type thermocouple, electronic balance and CCD to measure and assess the temperature distribution of the axial centerline of the fire plume of the transformer oil jet. The result demonstrates that the axial centerline temperature of the fire plume increases with the external heat release rate and the inner diameter of the container. In addition, a novel axial temperature distribution prediction model of the transformer oil jet fire plume is established. This model can effectively predict the oil jet fire plume temperature of transformer oil- filling equipment in substations, and provide help for substation fire control.


2021 ◽  
Author(s):  
Yusen Feng ◽  
Pengcheng Ma ◽  
Lijuan Wang ◽  
Guifang Sun ◽  
Bin Liu ◽  
...  

Abstract Objective: This study is designed to explore the dual-source computed tomography (DSCT) imaging manifestations of the origin of three rare pulmonary artery abnormalities, and to improve the understanding and diagnosis of the disease.Methods: Collected 30 cases of patients diagnosed by DSCT with pulmonary artery abnormal origins, and retrospectively analyzed their imaging data and postoperative pathological data.Results: Among the 30 patients with abnormal pulmonary artery origin, 16 patients were with unilateral pulmonary artery absence (UAPA), 8 patients were with anomalous origin of unilateral pulmonary artery (AOPA), and 6 patients were left pulmonary artery suspension (LPAS). The diagnosis rate of DSCT is significantly higher than that of echocardiography. The results of DSCT imaging showed that the inner diameter of the ascending aorta, the aortic arch and the descending aorta of UAPA patients were significantly larger than those of LPAS patients (P<0.05). Compared with AOPA patients, the left pulmonary artery diameter, the ratio of the left main pulmonary artery diameter to the main pulmonary artery diameter, and ratio of the left main pulmonary artery diameter to the right main pulmonary artery diameter were significantly increased in UAPA patients (P<0.05). There was no significant difference in the ratio of the inner diameter of the ascending aorta to the descending aorta in patients with UAPA, AOPA and LPAS. Compared with UAPA patients, AOPA patients had no significant changes in the inner diameter of the main pulmonary artery, the inner diameter of the right main pulmonary artery, and the ratio of the inner diameter of the right main pulmonary artery to the main pulmonary artery.Conclusion: DSCT can be used to diagnose the origin of pulmonary artery abnormalities and distinguish its types.


Author(s):  
K. P. Artykov ◽  
B. Sadulloev ◽  
O. F. Soliev ◽  
N. M. Mirzoev

Aim. To evaluate the results of treatment of renal hypertension in varicocele after the formation of the proximal intervenous anastomosis.Material and methods. A survey was conducted among 167 patients with varicocele aged 16 to 39 years. The evaluation of the Varicocele degree was made by the classification of the Amerla Cubin, which is used in the WHO Classification (1997). All patients had clinical signs of varicocele. Ipsilateral testicle hypotrophy was detected in 21 (12.6%) and hydrocele 6 (3.6%) patients. All patients before and after the operation went through the analysis of ejaculate.Results and discussion. The renotesticular hemodynamic type of varicocele was found in 115 (68.9%) of 167 surveyed patients. Varicocele of 1 degree was detected in 17 (14.8%) cases, 2 degrees in 31 (26.9%) and 3 degrees in 67 (58.3%) patients. With doppler ultrasonography of the veins of the spermatic cord, the inner diameter varied from 3 to 6 mm. On average, this value was 4.3±1.1 mm. All these patients received subinguinal varicocelectomy by Marmar. Therefore, the vein drainage operations to reduce renal hypertension was carried out for 65 (56.5%) patients.Conclusion. The formation of intervenous anastomoses is a pathogenetically justified method of treating regional venous renal hypertension in varicocele.


BMC Neurology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Qingjing Tan ◽  
Chao Qin ◽  
Junwei Yang ◽  
Tianbao Wang ◽  
Haohai Lin ◽  
...  

Abstract Purpose To obtain normal ranges for the inner diameters of the carotid arteries. Methods This retrospective analysis included consecutive patients with disease-free carotid arteries who had undergone 3D-DSA at two hospitals in Nanning, Guangxi, between March 2013 and March 2018. Demographic and clinical characteristics, including Essen Stroke Risk Score (ESRS), were extracted from the medical records. The 3D-DSA data were used to calculate the inner diameters of the carotid arteries. Results The analysis included 1182 patients (837 males) aged 58.81 ± 11.02 years. The inner diameters of the proximal carotid sinus (CS), CS bulge, distal CS, and common carotid artery (CCA) were larger on the right than on the left (P < 0.05). The inner diameters of the proximal CS, CS bulge, distal CS, and CCA on both sides were larger for males than females (P < 0.05). The inner diameters of the proximal CS, CS bulge, and distal CS on both sides were smaller for patients aged > 65 years than for patients aged ≤ 55 years (P < 0.05). Right CCA inner diameter did not vary with age, whereas left CCA inner diameter was larger for patients aged > 55 years than for patients aged ≤ 45 years (P < 0.05). The inner diameters of the proximal CS, CS bulge, and distal CS on both sides were smaller for patients with ESRS ≥ 3 than those with ESRS < 3 (P < 0.05). Conclusion This study provides reference values for the internal diameters of normal carotid arteries. Carotid artery diameters varied with side, sex, and age.


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