Simulation Research on Cross-Sectional Stability of Expanded Diameter Conductors Based on ANSYS

2012 ◽  
Vol 256-259 ◽  
pp. 2838-2843
Author(s):  
Jia Jun Si ◽  
Jian Cheng Wan ◽  
Bin Liu ◽  
Yao Ding
Keyword(s):  
Power Transmission ◽  
Element Model ◽  
Aluminum Wire ◽  
Key Factors ◽  
Cross Sectional ◽  
Simulation Research ◽  
Contact Points ◽  
Electricity Power ◽  
The Wire ◽  
Significant Factors

The expanded diameter conductors are widely used for high voltage electricity power transmission due to its superior ability to prevent electronic corona phenomenon. However an undesired stability problem of wire distribution configuration within the cross-section of the conductor often occurs during the power line stringing processes, especially for the not-well-designed conductor structures. This phenomenon is typically characterized by the appearance of outer wire/wires jumping out of the layer; therefore it is also referred as wire jump-out problem. Finite element model which can predict the wire jump-out phenomenon has been successfully developed in this research project. Series of stimulations have been carried out to investigate the key factors to cause the wire jump-out problem. The reduction of radial distances between the adjacent aluminum wire layers due to the obvious indentation deformation at the trellis contact points were identified to be one of the most significant factors to lead to the wire jump-out problem. Numerical results show that keeping sufficient initial gap between the adjacent outer layer wires in the initial design can be a simple effective way to relieve/avoid the wire jump-out problem.

scholarly journals Design of Large Connectors of Overhead Power Lines

2018 ◽  
Vol 61 (5) ◽  
pp. 432-439 ◽  
Author(s):  
M. A. Korotkevich ◽  
N. V. Prokofieva
Keyword(s):  
Power Transmission ◽  
Power Lines ◽  
Traditional Theory ◽  
Engineering Structures ◽  
Cross Sectional ◽  
Flexible Filament ◽  
Nominal Voltage ◽  
The Wire ◽  
The Difference ◽  
Overhead Power Lines

It is found that the voltage at the lowest points of the wire or cable sag and at the points of their suspension on the pillars in the same span, determined in accordance with the properties of a perfectly flexible filament (similar to which the wires and cables are located in the span), differ slightly, and taking the difference of the mentioned values into account is only of methodologycal importance. The article presents the results of the calculation of wire and cable sag of large spans of power transmission line of 500 m or more length using both the traditional theory of the catenary line and the theory of equal resistance, when the cross-sectional area of a wire or cable, proportional to their tension, is considered variable in the span length, which provides the same probability of breaking them at any point of the span. When calculating the wires and cables in normal and emergency conditions, the largest sags are determined, which take place either at a higher ambient temperature or at a load of the wire with ice. The wire must be mounted in such a way as to ensure the normalized permissible dimensions to crossed engineering structures, water barriers or land, that are determined depending on the nominal voltage of the line. It is noted that the values of the wire and cable sags determined using the theory of the catenary line for the transition spans are less (although slightly) as compared to the data obtained on the basis of the theory of the equal resistance circuit. This must be taken into account in the design process.

scholarly journals Perspectives of Healthcare Professionals Regarding Factors Associated with Antimicrobial Resistance (AMR) and Their Consequences: A Cross Sectional Study in Eastern Province of Saudi Arabia

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 878
Author(s):  
Mohamed A. Baraka ◽  
Amany Alboghdadly ◽  
Samar Alshawwa ◽  
Asim Ahmed Elnour ◽  
Hassan Alsultan ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Inappropriate Prescribing ◽  
Healthcare Providers ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Key Factors ◽  
Eastern Province ◽  
Cross Sectional ◽  
Factors Associated ◽  
Factors Influencing

Factors reported in the literature associated with inappropriate prescribing of antimicrobials include physicians with less experience, uncertain diagnosis, and patient caregiver influences on physicians’ decisions. Monitoring antimicrobial resistance is critical for identifying emerging resistance patterns, developing, and assessing the effectiveness of mitigation strategies. Improvement in prescribing antimicrobials would minimize the risk of resistance and, consequently, improve patients’ clinical and health outcomes. The purpose of the study is to delineate factors associated with antimicrobial resistance, describe the factors influencing prescriber’s choice during prescribing of antimicrobial, and examine factors related to consequences of inappropriate prescribing of antimicrobial. A cross-sectional study was conducted among healthcare providers (190) in six tertiary hospitals in the Eastern province of Saudi Arabia. The research panel has developed, validated, and piloted survey specific with closed-ended questions. A value of p < 0.05 was considered to be statistically significant. All data analysis was performed using the Statistical Package for Social Sciences (IBM SPSS version 23.0). 72.7% of the respondents have agreed that poor skills and knowledge are key factors that contribute to the inappropriate prescribing of antimicrobials. All of the respondents acknowledged effectiveness, previous experience with the antimicrobial, and reading scientific materials (such as books, articles, and the internet) as being key factors influencing physicians’ choice during antimicrobial prescribing. The current study has identified comprehensive education and training needs for healthcare providers about antimicrobial resistance. Using antimicrobials unnecessarily, insufficient duration of antimicrobial use, and using broad spectrum antimicrobials were reported to be common practices. Furthermore, poor skills and knowledge were a key factor that contributed to the inappropriate use and overuse of antimicrobials, and the use of antimicrobials without a physician’s prescription (i.e., self-medication) represent key factors which contribute to AMR from participants’ perspectives. Furthermore, internal policy and guidelines are needed to ensure that the antimicrobials are prescribed in accordance with standard protocols and clinical guidelines.

scholarly journals Prevalence of suicidal ideation and associated factors among HIV positive perinatal women on follow-up at Gondar town health institutions, Northwest Ethiopia: a cross-sectional study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Leul Belachew Zewdu ◽  
Mebratu Mitiku Reta ◽  
Niguse Yigzaw ◽  
Koku Sisay Tamirat
Keyword(s):  
Suicidal Ideation ◽  
Unplanned Pregnancy ◽  
Cross Sectional Study ◽  
Hiv Positive ◽  
Hiv Status ◽  
Cross Sectional ◽  
Factors Associated ◽  
Gondar Town ◽  
Perinatal Women ◽  
Significant Factors

Abstract Background Suicidal behaviors cover a range or continuum of acts from suicidal ideations to a series of actions, commonly known as suicidal attempts or deliberate self-harms. Though different mental disorders related studies were conducted among HIV/AIDS patients, there is a scarcity of information about the magnitude and determinants of suicidal thoughts among perinatal women. Therefore, this study aimed to determine the prevalence of suicidal ideation and associated factors among HIV positive perinatal women in the study setting. Methods An institution-based cross-sectional study was conducted among perinatal women on treatment to the prevention of mother to child transmission of HIV/AIDS at Gondar town health facilities. A total of 422 HIV-positive perinatal women were selected systematically and the data collected through medical record review and interview using a Composite International Diagnostic Interview (CIDI) toolkit. A binary and multivariable logistic regression model was employed to identify factors associated with suicidal ideation. An Adjusted Odds Ratio (AOR) with 95% Confidence Interval (CI) was computed to see the strength of association between outcome and independent variables. Characteristics having less than 0.05 p-value had been taken as significant factors associated with the outcome of interest. Result The prevalence of suicidal ideation was found to be 8.2% (95% CI; 5.7 to 11.3) and with a standard error of 0.013. Perinatal depression (AOR=4.40, 95%CI: 1.63 11.85), not disclosed HIV status (AOR=3.73, 95%CI: 1.44 9.65), and unplanned pregnancy (AOR=2.75, 95%CI: 1.21 6.21) were significant factors associated with suicidal ideation. Conclusion The magnitude of suicidal ideation among HIV positive perinatal women was found to be low. Perinatal depression, non-disclosed HIV status, and unplanned pregnancy were factors significantly associated with suicidal ideation. This finding suggests the integration of mental health services with maternal and HIV support programs.

Investigation on the free vibration behavior of sandwich conical shells with reinforced cores

2021 ◽  
pp. 109963622110204
Author(s):  
Mehdi Zarei ◽  
Gholamhossien Rahimi ◽  
Davoud Shahgholian-Ghahfarokhi
Keyword(s):  
Free Vibration ◽  
Orientation Angle ◽  
Element Model ◽  
Filament Winding ◽  
Vertex Angle ◽  
Sandwich Shell ◽  
Cross Sectional ◽  
Conical Shells ◽  
Vibration Behavior ◽  
Axial Forces

The free vibration behavior of sandwich conical shells with reinforced cores is investigated in the present study using experimental, analytical, and numerical methods. A new effective smeared method is employed to superimpose the stiffness contribution of skins with those of the stiffener in order to achieve equivalent stiffness of the whole structure. The stiffeners are also considered as a beam to support shear forces and bending moments in addition to the axial forces. Using Donnell’s shell theory and Galerkin method, the natural frequencies of the sandwich shell are subsequently derived. To validate analytical results, experimental modal analysis (EMA) is further conducted on the conical sandwich shell. For this purpose, a method is designed for manufacturing specimens through the filament winding process. For more validation, a finite element model (FEM) is built. The results revealed that all the validations were in good agreement with each other. Based on these analyses, the influence of the cross-sectional area of the stiffeners, the semi-vertex angle of the cone, stiffener orientation angle, and the number of stiffeners are investigated as well. The results achieved are novel and can be thus employed as a benchmark for further studies.

scholarly journals Current status of periodontitis and its association with tobacco use amongst adult population of Sunsari district, in Nepal

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
K. Goel ◽  
S. Sharma ◽  
D. D. Baral ◽  
S. K. Agrawal
Keyword(s):  
Tobacco Use ◽  
Smokeless Tobacco ◽  
Periodontal Diseases ◽  
Adult Population ◽  
Multivariate Logistic Regression Analysis ◽  
Case Definition ◽  
Current Status ◽  
Cross Sectional ◽  
Factors Associated ◽  
Significant Factors

Abstract Background Tobacco products are considered significant, but preventable factors related to initiation and progression of periodontal diseases. We assessed the prevalence of periodontitis and evaluated its association with tobacco use and other factors amongst the adult population of Sunsari district in eastern Nepal. Methods A community-based, cross-sectional study was conducted in rural municipalities in the province one of eastern Nepal. A total of 440 adults were interviewed with a set of a pre-tested semi-structured questionnaire. Data on social demographics, adverse oral habits followed by periodontal clinical examination were recorded. Prevalence of periodontitis was assessed by a case definition provided by CDC-AAP. Univariate and multivariate logistic regression analysis was done to measure the association between tobacco use and other factors with periodontitis. Results The overall prevalence of periodontitis was found to be 71.6%. Majority (85.4%) of tobacco users had periodontitis and they were significantly associated with the disease and its severity. The study identified age groups, 45–65 years (AOR = 7.58, 95% CI 3.93–14.61), plaque accumulation (AOR = 1.01, 95% CI 1.00–1.02), smoking (AOR = 3.14, 95% CI 1.36–7.27), khaini users (smokeless tobacco, AOR = 2.27, 95% CI 1.12–4.61) and teeth loss (AOR = 2.02, 95% CI 1.21–3.38) as the significant factors associated with periodontitis. Conclusion The prevalence of periodontitis is high in the surveyed rural adult population. Cigarette smoking along with the use of smokeless tobacco in the form of khaini were identified as significant factors associated with periodontitis.

Contribution of Lamb wave modes in the formation of higher order modes cluster (HOMC) guided waves

2021 ◽  
pp. 095440622110424
Author(s):  
Z Abbasi ◽  
F Honarvar
Keyword(s):  
Finite Element ◽  
Wave Packet ◽  
Lamb Wave ◽  
Guided Waves ◽  
Element Model ◽  
Higher Order ◽  
Guided Wave ◽  
Cross Sectional ◽  
Higher Order Modes ◽  
Wave Modes

In recent years, Higher Order Modes Cluster (HOMC) guided waves have been considered for ultrasonic testing of plates and pipes. HOMC guided waves consist of higher order Lamb wave modes that travel together as a single nondispersive wave packet. The objective of this paper is to investigate the effect of frequency-thickness value on the contribution of Lamb wave modes in an HOMC guided wave. This is an important issue that has not been thoroughly investigated before. The contribution of each Lamb wave mode in an HOMC guided wave is studied by using a two-dimensional finite element model. The level of contribution of various Lamb wave modes to the wave cluster is verified by using a 2D FFT analysis. The results show that by increasing the frequency-thickness value, the order of contributing modes in the HOMC wave packet increases. The number of modes that comprise a cluster also increases up to a specific frequency-thickness value and then it starts to decrease. Plotting of the cross-sectional displacement patterns along the HOMC guided wave paths confirms the shifting of dominant modes from lower to higher order modes with increase of frequency-thickness value. Experimental measurements conducted on a mild steel plate are used to verify the finite element simulations. The experimental results are found to be in good agreement with simulations and confirm the changes observed in the level of contribution of Lamb wave modes in a wave cluster by changing the frequency-thickness value.

Uncertain crisis time affects psychosocial dimensions in beta-thalassemia patients during Covid-19 pandemic: A cross-sectional study

2021 ◽  
pp. 135910532110499
Author(s):  
Chiara Cerami ◽  
Gaia Chiara Santi ◽  
Irene Sammartano ◽  
Zelia Borsellino ◽  
Liana Cuccia ◽  
...  
Keyword(s):  
Well Being ◽  
Cross Sectional Study ◽  
Beta Thalassemia ◽  
Sectional Study ◽  
Key Factors ◽  
Chronic Patients ◽  
Cross Sectional ◽  
Life Habits ◽  
Anxiety Levels ◽  
Anxiety Depression

Psychosocial variables are key factors influencing the delicate equilibrium of chronic patients during crisis time. In this study, we explored distress, anxiety, depression, loneliness, coping strategies, and changes in life habits in 43 beta-thalassemia patients and 86 controls during Covid-19 pandemic. Patients showed higher anxiety levels and a predominant transcendent coping profile compared to controls. Patients significantly differed from controls in outdoor habits. Social isolation and habits changes in uncertain life-threaten situations as Covid-19 pandemic are particularly detrimental in fragile beta-thalassemia patients. Structured support interventions are needed to promote well-being in the Covid-19 era.

scholarly journals A novel strain sensor using a microchannel embedded in PDMS

2018 ◽  
Vol 4 (2) ◽  
pp. 1 ◽  
Author(s):  
Angelica Campigotto ◽  
Stephane Leahy ◽  
Ayan Choudhury ◽  
Guowei Zhao ◽  
Yongjun Lai
Keyword(s):  
Finite Element ◽  
Rotation Angle ◽  
Strain Sensor ◽  
Element Model ◽  
Strain Sensors ◽  
Gauge Factor ◽  
Sectional Area ◽  
Cross Sectional ◽  
Higher Sensitivity

A novel, inexpensive, and easy-to-use strain sensor using polydimethylsiloxane (PDMS)  was developed. The sensor consists of a microchannel that is partially filled with a coloured liquid and embedded in a piece of PDMS. A finite element model was developed to optimize the geometry of the microchannel to achieve higher sensitivity. The highest gauge factor that was measured experimentally was 41. The gauge factor was affected by the microchannel’s square cross-sectional area, the number of basic units in the microchannel, and the inlet and outlet configuration. As a case study, the developed strain sensors were used to measure the rotation angle of the wrist and finger joints.

scholarly journals Numerical and Experimental Study of Cross-Sectional Effects on the Mixing Performance of the Spiral Microfluidics

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1470
Author(s):  
Omid Rouhi ◽  
Sajad Razavi Bazaz ◽  
Hamid Niazmand ◽  
Fateme Mirakhorli ◽  
Sima Mas-hafi ◽  
...  
Keyword(s):  
Cross Sections ◽  
Numerical Study ◽  
Large Angle ◽  
Element Model ◽  
Channel Length ◽  
Cross Sectional ◽  
Flow Rates ◽  
Lab On Chip ◽  
Mixing Performance ◽  
Dean Flow

Mixing at the microscale is of great importance for various applications ranging from biological and chemical synthesis to drug delivery. Among the numerous types of micromixers that have been developed, planar passive spiral micromixers have gained considerable interest due to their ease of fabrication and integration into complex miniaturized systems. However, less attention has been paid to non-planar spiral micromixers with various cross-sections and the effects of these cross-sections on the total performance of the micromixer. Here, mixing performance in a spiral micromixer with different channel cross-sections is evaluated experimentally and numerically in the Re range of 0.001 to 50. The accuracy of the 3D-finite element model was first verified at different flow rates by tracking the mixing index across the loops, which were directly proportional to the spiral radius and were hence also proportional to the Dean flow. It is shown that higher flow rates induce stronger vortices compared to lower flow rates; thus, fewer loops are required for efficient mixing. The numerical study revealed that a large-angle outward trapezoidal cross-section provides the highest mixing performance, reaching efficiencies of up to 95%. Moreover, the velocity/vorticity along the channel length was analyzed and discussed to evaluate channel mixing performance. A relatively low pressure drop (<130 kPa) makes these passive spiral micromixers ideal candidates for various lab-on-chip applications.

scholarly journals Views on Unassisted Childbirth among Mothers at a Teaching Hospital in Kuala Lumpur, Malaysia

2021 ◽  
Vol 50 (5) ◽  
pp. 1357-1365
Author(s):  
Aniza Ismail ◽  
Nur Farahani Anas ◽  
Shun Qin Neo ◽  
Najwa Hayati Ab Ghani ◽  
Muhammad Amir Ridzwan Mahadi ◽  
...  
Keyword(s):  
Teaching Hospital ◽  
Working Mothers ◽  
Healthcare Services ◽  
Income Group ◽  
Antenatal Clinic ◽  
Bivariate Analysis ◽  
Cross Sectional ◽  
Middle Income ◽  
Significant Factors

A cross-sectional study was conducted among mothers visiting antenatal clinic in UKMMC from 1st to 19th August 2016 to acquire opinions on unassisted childbirth and the determinant factors among mothers at a teaching hospital. Structured questionnaires were used in assessing their opinions on unassisted childbirth. A total of 259 respondents were recruited, 229 of them who met the inclusion criteria were included for analysis. Majority (87.3%) was Malay and 98.7% of respondents were more than 25 years old. The prevalence for mothers who agreed with unassisted childbirth was 6.6%. Bivariate analysis showed Malay (p=0.013) and non-working mothers (p=0.000) are the significant factors. There was no significant association between opinions on unassisted childbirth and quality of government healthcare services. Multivariate analysis showed middle income and non-working mothers were the significant factors contributing to opinions on unassisted childbirth. The outcome showed minority of mothers agreed with unassisted childbirth, middle income group and non-working mothers agreed on unassisted childbirth. Dissatisfaction to the quality of care at government healthcare services was not found to be the reason for unassisted childbirth. However, there could be other factors contributing to opinions on unassisted childbirth delivery which were not studied. Community-based study should be conducted to determine the other factors.

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