Freezing Characteristics Along a Horizontal Cooled Tube Immersed in Aqueous Binary Solution With Main Flow

1993 ◽  
Vol 115 (1) ◽  
pp. 54-62 ◽  
Author(s):  
M. Yamada ◽  
S. Fukusako ◽  
M. Tago ◽  
A. Horibe
Keyword(s):  
Initial Temperature ◽  
Binary Solution ◽  
Considerable Effect ◽  
Test Solution ◽  
Temperature Ratio ◽  
Cross Sectional ◽  
Cooling Temperature ◽  
Cooling Tube ◽  
Glycol Solution ◽  
Flow Duct

An experimental study has been performed to investigate the freezing characteristics of an aqueous binary solution along a horizontal cooled tube. A copper coaxial cooling tube was set horizontally in a flow duct which has cross-sectional dimensions of 120 mm × 200 mm. Ethylene-glycol solution was utilized as a test solution. Observation of frozen layer, measurement of heat-transfer coefficient, and visualization of flow pattern were extensively carried out under a variety of concentration of the solution, initial temperature, cooling temperature, and flow velocity as parameters. It was found that the characteristics of the frozen layer could be well grouped using both the Reynolds number and the cooling temperature ratio, and that the flow field had a considerable effect on the characteristics of the frozen layer. The correlations of the averaged frozen-layer thickness at the steady state were determined.

scholarly journals A Cross-Sectional Study of the Relationships between Work-Related Affective Feelings Expressed by Workers in Turkey

2020 ◽  
Vol 17 (24) ◽  
pp. 9470
Author(s):  
Erman Çakıt ◽  
Waldemar Karwowski ◽  
Tadeusz Marek ◽  
Magdalena Jaworek ◽  
Grzegorz Wrobel
Keyword(s):  
Structural Equation ◽  
Work Performance ◽  
Critical Role ◽  
Cross Sectional Study ◽  
Considerable Effect ◽  
Equation Modeling ◽  
Cross Sectional ◽  
Work Related ◽  
Work Effectiveness ◽  
Main Components

Understanding employees’ feelings at work plays a significant role in developing practical and effective organizational and human resource management policies and practices. Furthermore, work-related emotions may have a considerable effect on workers’ health and wellbeing and affect work effectiveness and work performance. The objectives of the current study were to investigate the relationships among four work-related (WOR) affective feelings (WORAF) and to validate the WORAF questionnaire in a Turkish sample. A survey was performed including four constructs: (1) WOR feelings of happiness, (2) WOR feelings of anxiety, (3) WOR feelings of anger, and (4) WOR feelings of dejection. A total of 322 workers from various companies in Turkey completed a paper-based survey. A research model was developed, and its main components were estimated with partial least squares structural equation modeling (PLS-SEM). The results revealed that dejection and anger at work play a critical role in experienced anxiety in occupational settings. Similarly, dejection, anger, and anxiety at work play a crucial role in perceived happiness at work.

scholarly journals PREVALENCE AND RISK FACTORS FOR OCCURRENCE OF CONGENITAL ANOMALIES IN NEONATES AT HOSPITAL FOR CHILD AND MATERNITY IN MISAN PROVINCE

2020 ◽  
Vol 17 (36) ◽  
pp. 1176-1185
Author(s):  
Esraa Abd Almuhsen ALI ◽  
Hussein Fadhil ALJAWADI
Keyword(s):  
Risk Factors ◽  
Birth Defects ◽  
Health Care Systems ◽  
Action Plan ◽  
Central Nervous System Involvement ◽  
Cross Sectional Study ◽  
Considerable Effect ◽  
Cross Sectional ◽  
Care Systems ◽  
Congenital Disabilities

Congenital disabilities affect a remarkable proportion of neonates and have a significant role in hospital admission, morbidity, and pediatrics mortality. Besides, the long-term morbidity and disability caused by birth defects may have a considerable effect on the development of the child and family and health care systems. In Misan, congenital disabilities are considered a third common cause of neonatal mortality. This study aimed to estimate the prevalence, types, and risk factors of congenital disabilities to have an action plan toward preventing the occurrence of these defects. A cross-sectional study performed in the neonatal care unit in Misan Hospital for Child and Maternity during the period of two years (2018 and 2019). Misan province is located in the South East of Iraq. The information was collected from the files of patients and registration records. Any delivered a live neonate with birth defects was enrolled in this study. These cases were diagnosed depending on history, clinical examination supported by other investigations, and radiographic studies whenever needed. The prevalence rates of congenital disabilities were 7.1/1000 and 6.6/1000 live birth in 2018 and 2019, respectively. Central nervous system involvement was the most typical pattern. Congenital disabilities were more frequent in male, single, and term babies of maternal age 18-35 years living in an urban area with a consanguinity history. Thus, the prevalence rate of congenital disabilities was notably high in Misan. Efforts toward prevention, as well as improving the prenatal diagnosis, would be essential.

Modeling of Convective Heat and Mass Transfer Characteristics of Anode-Supported Planar Solid Oxide Fuel Cells

2006 ◽  
Vol 4 (2) ◽  
pp. 185-193 ◽  
Author(s):  
Y. N. Magar ◽  
R. M. Manglik
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Convective Heat ◽  
Porous Layer ◽  
Reaction Rate ◽  
Electrochemical Reaction ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Cross Sectional ◽  
Flow Duct

Convective heat and mass transfer in a planar, trilayer, solid oxide fuel cell (SOFC) module is considered for a uniform supply of volatile species (80%H2+20%H2O vapor) and oxidant (20%O2+80%N2) to the electrolyte surface with a uniform electrochemical reaction rate. The coupled heat and mass transfer is modeled by steady incompressible fully developed laminar flow in the interconnect ducts of rectangular cross sections for both the anode-side fuel and cathode-side oxidant flows. The governing three-dimensional mass, momentum, energy, species transfer, and electrochemical kinetics equations are solved computationally. The homogeneous porous-layer flow, which is in thermal equilibrium with the solid matrix, is coupled with the electrochemical reaction rate to properly account for the flow-duct and anode/cathode interface heat/mass transfer. Parametric effects of the rectangular flow-duct cross-sectional aspect ratio and anode porous-layer thickness on the variations in temperature and mass/species distributions, flow friction factor, and convective heat transfer coefficient are presented. The thermal and hydrodynamic behavior is characterized for effective convective cooling performance, and interconnect channels of cross-sectional aspect ratio of ∼2-3 along with relative anode porous-layer thickness of ∼0.5-1.5 are seen to provide optimal thermal management and species mass transport benefits in the SOFC module.

scholarly journals Prevalence of Upper Extremity Musculoskeletal Disorders in Dentists: Symptoms and Risk Factors

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Forouzan Rafie ◽  
Azadeh Zamani Jam ◽  
Arash Shahravan ◽  
Maryam Raoof ◽  
Ali Eskandarizadeh
Keyword(s):  
Musculoskeletal Disorders ◽  
Cross Sectional Study ◽  
Considerable Effect ◽  
Cross Sectional ◽  
Daily Work ◽  
Significant Relationships ◽  
Experienced Pain ◽  
Number Of Patients ◽  
Upper Extremity Musculoskeletal Disorders ◽  
Nordic Musculoskeletal Questionnaire

Aim. The purpose of the present research was to examine the factors that lead to musculoskeletal disorders in dentists by assessing their posture using RULA method.Materials and Methods. In this cross-sectional study, 130 dentists (84 male and 46 female) participated. The posture of the subjects during their normal workload was recorded by using the RULA method, and the range of musculoskeletal pains by using the Nordic Musculoskeletal Questionnaire (NMQ), and individual and professional data was assessed by a demographics questionnaire. All tests were performed at theP<0.05level.Results. Assessment of the physical status of the subjects showed that 82.8% of subjects were at high risk of musculoskeletal disorders. The majority of musculoskeletal pains were in the neck (55.9%) and the shoulder (43.8%). Moreover, 68.9% of the subjects had experienced pain at least once over the last year. Significant relationships were observed between musculoskeletal pain and daily work hoursP=0.07and number of patientsP=0.02, but the pain was not significantly associated with BMI and experience.Conclusion. The present findings showed that unsuitable posture of dentists during work has a considerable effect on musculoskeletal disorders. Therefore, further investigation is required to avoid the detrimental effects of wrong posture.

scholarly journals Quantitative Phase Imaging to Study the Effect of Sodium Dodecyl Surfactant on Adherent L929 Fibroblasts on Tissue Culture Plates

Photonics ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 508
Author(s):  
Sonthikan Sitthisang ◽  
Jeeranan Boonruangkan ◽  
Meng Fatt Leong ◽  
Kerm Sin Chian ◽  
Young-Jin Kim
Keyword(s):  
Sodium Dodecyl ◽  
Cellular Membrane ◽  
Test Solution ◽  
Phase Imaging ◽  
Quantitative Phase Imaging ◽  
Control Solution ◽  
Cross Sectional ◽  
Organ Regeneration ◽  
Cellular Components ◽  
Phosphate Buffered Saline

Decellularization is the process of removing cellular components from native tissues or organs to obtain an acellular, collagenous scaffold for use in tissue engineering and organ regeneration. Surfactants are widely used to produce acellular scaffolds for clinical applications. However, cell–surfactants interactions have not been studied in depth. Cell-surfactant interaction was studied in a time-lapsed manner using sodium dodecyl sulfate (SDS) solution (surfactant) on adherent L929 fibroblasts as a test solution, phosphate-buffered saline (PBS) solution as control solution (isotonic), and deionized water as positive test solution (hypotonic), respectively. The QPI results show changes in the relative height and cross-sectional area of the cells, with various test solutions and exposure times. In particular, it was observed that the removal of the cell with SDS involved the disruption of the cellular membrane and detachment of the cell contents from the adhering surface. This study demonstrated the feasibility of using the QPI technique to understand the decellularization process.

scholarly journals Analysis of Psychosocial Adjustment in the Family During Confinement: Problems and Habits of Children and Youth and Parental Stress and Resilience

2021 ◽  
Vol 12 ◽  
Author(s):  
Magdalena P. Andrés-Romero ◽  
Juan M. Flujas-Contreras ◽  
Mercedes Fernández-Torres ◽  
Inmaculada Gómez-Becerra ◽  
Pilar Sánchez-López
Keyword(s):  
Psychological Adjustment ◽  
Psychosocial Adjustment ◽  
Parental Stress ◽  
Cross Sectional Study ◽  
Considerable Effect ◽  
Cross Sectional ◽  
Health Crisis ◽  
Psychological Difficulties ◽  
High Level ◽  
The Relationship

The COVID-19 health crisis has led to a dramatic change in dynamics and habits of families, which may be a factor involved in the development and maintenance of problems and difficulties in children. The present study is a cross-sectional study that aims to describe and analyze the relationship between the difficulties in psychological adjustment and the change of habits of the infant-juvenile population as perceived by their parents and their stress and resilience during the total confinement of the first wave of the COVID-19 pandemic in Spain, as well as analyzing the course of the changes and the relationships between weeks 3 to 6, that is, the score of different participants in each week of the confinement. The sample is comprised of 883 parents of children and adolescents between 3 and 18 years of age. Children’s psychological adjustment, children’s habits, parental stress, and parental resilience were assessed by parents. The results show that parents perceive a change in the habits and psychological difficulties in their children. At the same time, our results describe parents with a high level of stress and resilience, with differences depending on the children’s ages. The time of confinement accentuates the perception of parents about the psychological difficulties of their children and parental stress, as well as a decrease in resilience. These difficulties are reduced when the parent has resilience competencies. These results show that the resilience of parents mediate the relationship between parental stress and psychological problems of their children. These results shows that COVID-19 lockdown had a considerable effect on families, both on children and parents. Some practical implications based on results are provided.

Medical Informatics: Once More Towards Systematization

1996 ◽  
Vol 35 (03) ◽  
pp. 189-192
Author(s):  
R. Haux
Keyword(s):  
Health Care ◽  
Medical Informatics ◽  
Strong Relationship ◽  
Health Sciences ◽  
Considerable Effect ◽  
Cross Sectional ◽  
Systematic Processing ◽  
Medical Discipline ◽  
Research And Education

Abstract:Commenting on a paper by Van Bemmel (Medical Informatics, Art or Science? [1]), the following questions are raised: What is the meaning of medical informatics?, How to systematize medical informatics?, Is medical informatics an art, a science or a technology?. It is argued that medical informatics is concerned with the systematic processing of data, information and knowledge in medicine and health care, and that medical informatics is not just the application of computers in these fields. Three classifications for medical informatics research and education are presented. It is concluded that medical informatics is a scientific medical discipline, similar to surgery, internal medicine, epidemiology, or microbiology; and that medical informatics has a strong relationship with the health sciences concerning its field of application, and to informatics concerning its methods and tools. It is a cross-sectional discipline, with relevance for virtually all other specialties of medicine and the health sciences. This is the reason for its impact on research and education in these specialties. It also causes that the quality of the processing of data, information and knowledge has a direct and considerable effect upon the quality of health care in practically all these specialties.

The Effect of the Liquid Upflow Velocity and the Substrate Concentration on the Start-Up and Steady-State Periods of Lab-Scale UASB Reactors

1992 ◽  
Vol 25 (7) ◽  
pp. 41-50 ◽  
Author(s):  
C. M. M. Campos ◽  
G. K. Anderson
Keyword(s):  
Steady State ◽  
Kinetic Parameters ◽  
Loading Rate ◽  
Liquid Velocity ◽  
Considerable Effect ◽  
Cross Sectional ◽  
Start Up ◽  
Kinetic Coefficients ◽  
Volumetric Loading ◽  
Uasb Reactors

This research was carried out in order to study the effect of the upflow liquid velocity (ULV), the COD concentration, the volumetric loading rate (VLR) and the hydraulic loading rate (HLR) on the start-up and steady-state performance of UASB reactors treating soluble substrate with 3,000 mgCOD/l at mesophyllic temperature (35°C). Three lab-reactors (UASB) were constructed with different liquid volumes, and also with different cross-sectional areas. The three UASB reactors were started up with the same biological loading rate (BLR), but the start-up procedures were based on different criteria. After the start-up had been carried out successfully with the formation of the granules, all the three UASB reactors were operated under steady-state conditions for up to eight different HRT(s), namely: 16, 14, 12, 10, 8, 6, 4 and 2 hours. For each of the three reactors the kinetic parameters were determined using the Monod model. Analysis of the influence of the operational factors and reactor design on the kinetic coefficients is described. The results indicate that the liquid upflow velocity has considerable effect on the sludge in this type of system, thereby acting as a selective process in the cultivation of the biomass. Analysis of sensitivity on the kinetic parameters indicated which was the most sensitive kinetic parameter for these reactors.

scholarly journals Analisa Pipa Heat Exchanger (Cooling Tube) Bervariasi Pada Turbine Guide Bearing Pembangkit Listrik Tenaga Air Siguragura

2021 ◽  
Vol 2 (2) ◽  
pp. 49-62
Author(s):  
Tambos Sianturi
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Power Plants ◽  
Paper Industry ◽  
Temperature Drop ◽  
Maximum Temperature ◽  
Cross Sectional ◽  
Overall Heat Transfer Coefficient ◽  
Cooling Tube ◽  
Rotary Type

A heat exchanger is a medium used to produce heat transfer from one fluid to another. Heat Exchanger can be used to raise the temperature or as a heater (regenerator) or lower the temperature or as a coolant (recuperator) depending on the view of heat transfer that occurs. Heat exchangers have been widely used in industries such as the chemical industry, paper industry, power plants, and other industries. In the example, each machine unit uses a heat exchanger media (especially rotary type machines) to keep the bearing temperature in normal temperature even though the unit is operated continuously or continuously. This study will analyze the temperature drop that occurs when the length of the heat exchanger pipe is added to the turbine guide bearing of PLTA Siguragura. From the research results, the maximum temperature on the guide bearing cooling tube reaches 47.3 [° C], the overall heat transfer coefficient on the guide bearing cooling tube is 98.87 [W / m²ºC], ∆Tmin on the guide bearing cooling tube installed (with 2 layers) is 14.1 [° C] and ∆Tmin which can be achieved with a cross-sectional area of ​​5.73 [m²] is 6.63 [° C]

scholarly journals Assessment of Need for Recovery and Its Relationship With Work Characteristics and Health in a Sample of Chinese Doctors: A Cross-Sectional Survey

2021 ◽  
Vol 9 ◽  
Author(s):  
Tao Sun ◽  
Yu Shi ◽  
Dong Yin ◽  
Shu'e Zhang ◽  
Xiaohe Wang
Keyword(s):  
Health Outcomes ◽  
Online Survey ◽  
Well Being ◽  
Considerable Effect ◽  
Targeted Prevention ◽  
System Reform ◽  
Work Characteristics ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Need For Recovery

Background: China is launching an unprecedented health care system reform. However, the long-term interests of doctors seem to have been ignored during this process especially considering that the work environment and work-life balance for doctors have severely deteriorated over the past decade.Their well-being and health are facing substantial threats due to heavy workloads and inadequate recovery opportunities. This study aimed to investigate the extent of need for recovery (NFR) among Chinese doctors and to examine their work-related fatigue. The study also examines the relationship of NFR with workplace satisfaction and health outcomes among Chinese doctors.Methods: A total of 2,617 doctors from 30 administrative regions in China participated in this study to assess the need for recovery and its relationship with work characteristics and health. A cross-sectional survey was conducted using the Chinese version of the Need for Recovery Scale (NFRS). Participants were invited to complete an anonymous online survey during May 2016. Data were analyzed using descriptive statistics, one-way ANOVA, reliability analysis, Pearson correlations, and hierarchical multiple regression analysis.Results: Significant differences in NFR scores were found across demographic characteristics such as age, service years, hospital levels, educational attainment, professional positions, work shifts, and working time. Regardless of any illnesses they might be experiencing, about 70.0% of participants remained at their job even though many doctors (22.1%) must continue working under the policies of the organization, which led to more pronounced NFR (P &lt; 0.001). Further, a higher NFR was negatively related to workplace well-being and self-reported health outcomes of participants.Conclusions: Work-induced fatigue is a growing threat to doctors in China and their recovery opportunities are extremely limited in the workplace. High NFR exerts a considerable effect on their workplace well-being and health. China's hospital managers should pay close attention to the fact that doctors have little chance of recovery, and should offer doctors' positive encouragement and support to enhance well-being. To improve doctors' working conditions, targeted prevention policies must be introduced by policymakers to control this spreading crisis.

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