Pull-Out and Push-Out Tests for Rubber-to Metal Adhesion

1989 ◽  
Vol 62 (4) ◽  
pp. 757-766 ◽  
Author(s):  
A. N. Gent ◽  
S. Y. Kaang
Keyword(s):  
Large Fraction ◽  
Theoretical Treatment ◽  
Total Force ◽  
Compression Tests ◽  
Cross Sectional ◽  
Pull Out ◽  
Good Accord ◽  
Compressive Loads ◽  
And Control ◽  
Push Out

Abstract A study has been carried out of adhesive failure forces for a steel rod embedded in and bonded to a rubber block. Emphasis has been placed on comparing tension (pull-out) and compression (push-out) forces. A fractional contribution to the pull-out force appeared to be significant for rods having a diameter greater than about 0.5 mm in the present experiments. Indeed, it became a large fraction of the total force when the rod diameter was 1 mm or more. On the other hand, it was negligibly small in push-out experiments. They would therefore be preferred on this basis for measuring the strength of adhesion. But experimental difficulties in carrying out compression tests are considerable. Tall blocks become unstable under large compressive loads, and short ones are markedly stiffer than long ones, due to restraints on their lateral expansion, which are difficult to specify and control. Thus, although measurements of push-out force for a wide variety of samples have been shown to be in good accord with a simple theoretical treatment of debonding, ignoring friction, it is recommended that pull-out tests be retained for assessing the strength of adhesive bonds. Caution is necessary to minimize the effect of friction. The theoretical treatment indicates that the product aL of the rod radius a and the embedded length L should be held smaller than the cross-sectional area of the block in which the rod is embedded.

Elastic Stability of Rubber Compression Springs

1965 ◽  
Vol 38 (2) ◽  
pp. 415-430 ◽  
Author(s):  
A. N. Gent
Keyword(s):  
Classical Theory ◽  
Shear Stiffness ◽  
Elastic Stability ◽  
Buckling Load ◽  
Theoretical Treatment ◽  
Experimental Measurements ◽  
Loading Conditions ◽  
Good Accord ◽  
Compressive Loads ◽  
Compression Springs

Abstract Experimental measurements are described of the critical (buckling) compressive loads for columns of rubber springs under various loading conditions. They are shown to be in good accord with the theoretical treatment of Haringx, in which the classical theory of buckling is modified to take into account the shear deflection of column elements. Measurements are also described of the shape of the buckled column and of the shear stiffness of columns under compressive loads smaller than the buckling load. They are found to be satisfactorily described by the theory also.

X-Ray Replication of Submicrometer Linewidth Patterns

1977 ◽  
Vol 35 ◽  
pp. 136-137
Author(s):  
Henry I. Smith ◽  
D.C. Flanders
Keyword(s):  
Electron Beam Lithography ◽  
Cross Sectional ◽  
X Ray ◽  
Electron Backscattering ◽  
Spatial Frequencies ◽  
Cross Sectional Profile ◽  
Carbon Foils ◽  
Sectional Profile ◽  
And Control ◽  
Soft Radiation

Scanning electron beam lithography has been used for a number of years to write submicrometer linewidth patterns in radiation sensitive films (resist films) on substrates. On semi-infinite substrates, electron backscattering severely limits the exposure latitude and control of cross-sectional profile for patterns having fundamental spatial frequencies below about 4000 Å(l),Recently, STEM'S have been used to write patterns with linewidths below 100 Å. To avoid the detrimental effects of electron backscattering however, the substrates had to be carbon foils about 100 Å thick (2,3). X-ray lithography using the very soft radiation in the range 10 - 50 Å avoids the problem of backscattering and thus permits one to replicate on semi-infinite substrates patterns with linewidths of the order of 1000 Å and less, and in addition provides means for controlling cross-sectional profiles. X-radiation in the range 4-10 Å on the other hand is appropriate for replicating patterns in the linewidth range above about 3000 Å, and thus is most appropriate for microelectronic applications (4 - 6).

ROLE OF PHARMACIST INTERVENTION ON COPD PATIENTS OF SELECTED AREAS IN CHITRADURGA: A KAP STUDY

2019 ◽  
Vol 8 (2) ◽  
Author(s):  
Melvin K Mathews ◽  
Abubaker Siddiq ◽  
Bharathi D R
Keyword(s):  
Illness Perceptions ◽  
Pharmacist Intervention ◽  
Cross Sectional Study ◽  
Chronic Obstructive ◽  
Cross Sectional ◽  
Obstructive Pulmonary Disease ◽  
Copd Patients ◽  
Post Test ◽  
Knowledge Practice ◽  
And Control

Background: Chronic obstructive pulmonary disease (COPD) is preventable and treatable disease state characterized by air flow limitation that is not fully reversible. Severity of the symptoms is increased during exacerbations. Objectives: The purpose of the study is to assess and improve the knowledge regarding COPD among study subjects. Materials and Methods: A Cross-sectional interventional study was carried out among the peoples in selected areas of the Chitradurga city for a period of six months. Result: A total 207 subjects enrolled in the study in that 155 male and 52 females. In our study mean score of post test was more (5.87±1.68) when compare to pre-test (2.63±1.46) which show significant increase in their knowledge after educating them (p=0.000). A total of 207 subjects were enrolled into the study. SPSS Software was used to calculate the statistical estimation. Paired t-test was used to detect the association status of different variables. Conclusion: The relatively good level of COPD awareness needs to be maintained to facilitate future prevention and control of the disease. This study had identified that negative illness perceptions should be targeted, so that they will not avoid patients from seeking for COPD treatment and adhere to it. Key words: Cross sectional study, Knowledge, practice, COPD.

A positive psychology study and intervention on the well-being of French PhD students in biology

2017 ◽  
Author(s):  
Gabriel Marais ◽  
Rebecca Shankland ◽  
Pascale Haag ◽  
Robin Fiault ◽  
Bridget Juniper
Keyword(s):  
Mental Health ◽  
Positive Psychology ◽  
Large Fraction ◽  
Reference Sample ◽  
Well Being ◽  
Attrition Rates ◽  
Human Costs ◽  
The Uk ◽  
And Control ◽  
Health And Well Being

In France, little data are available on mental health and well-being in academia, and nothing has been published about PhD students. From studies abroad, we know that doing a PhD is a difficult experience resulting in high attrition rates with significant financial and human costs. Here we focused on PhD students in biology at university Lyon 1. A first study aimed at measuring the mental health and well-being of PhD students using several generalist and PhD-specific tools. Our results on 136 participants showed that a large fraction of the PhD students experience abnormal levels of stress, depression and anxiety, and their mean well-being score is significantly lower than that of a British reference sample. French PhD student well-being is specifically affected by career uncertainty, perceived lack of progress in the PhD and perceived lack of competence, which points towards possible cultural differences of experiencing a PhD in France and the UK. In a second study, we carried out a positive psychology intervention. Comparing the scores of the test and control groups showed a clear effect of the intervention on reducing anxiety. We discuss our results and the possible future steps to improve French PhD students’ well-being.

Cut off value of plasma 25-hydroxyvitamin D concentration for predicting metabolic syndrome

2019 ◽  
pp. 68-73
Author(s):  
Trong Nghia Nguyen ◽  
Thi Nhan Nguyen ◽  
Thi Dua Dao
Keyword(s):  
Metabolic Syndrome ◽  
Medical Center ◽  
Cross Sectional Study ◽  
Control Group ◽  
Cross Sectional ◽  
Hydroxyvitamin D ◽  
The Metabolic Syndrome ◽  
25 Hydroxyvitamin D ◽  
Key Words Metabolic Syndrome ◽  
And Control

Background: The metabolic syndrome is a constellation of cardiometabolic risk factors that tend to cluster together in affected individuals more often than predicted by chance. The presence of the metabolic syndrome substantially increases the risk of developing type 2 diabetes and cardiovascular disease, and is associated with a range of adverse clinical outcomes, many of which are closely associated with aging. Current estimates suggest that approximately 20 - 25% of the world’s population is affected by the metabolic syndrome. The prevalence of the metabolic syndrome rises with age and more than 45% of people aged over 60 years have the metabolic syndrome. Recent studies show that low vitamin D status is very common in the world and this is a risk factor of metabolic syndrome. Objective: (1) Plasma 25-hydroxyvitamin D concentration in subjects with metabolic syndrome. (2) Cut off value of plasma 25-hydroxyvitamin D concentration for predicting metabolic syndrome. Material and method: A cross-sectional study with control group on 318 adult subjects for health examinations at International Medical Center at Hue Central Hospital, including 139 subjects with metabolic syndrome and control group of 179 healthy subjects. Metabolic syndrome was defined according to the IDF, NHLBI, AHA, WHF, IAS, IASO (2009). Plasma hydroxyvitamin D concentration was measured using chemiluminescent microparticle immunoassay. Reciever operating characteristic (ROC) curve were generated to assess sensitivity and specificity for different cut off value of 25-hydroxyvitamin D concentration for predicting metabolic syndrome. Results: Plasma 25-hydroxyvitamin D concentration in subjects with metabolic syndrome was 26.4 ng/ml, incidence of plasma 25-hydroxyvitamin D deficiency (59.7%) was significantly higher than in control group (23.5%) (p < 0.001). The optimal cut off point for 25-OH-D concentration for predictor of metabolic syndrome as 26.4 ng/ml (AUC=0.657, sensitivity=53.4%, specificity=71.6%). Conclusion: In 139 subjects with metabolic syndrome, the plasma 25-hydroxyvitamin D concentration was 26.4 ng/ml and the incidence of 25-hydroxyvitamin D deficiency in the metabolic syndrome group was 59.7%. The optimal cut off point for plasma 25-hydroxyvitamin D concentration for predictor of metabolic syndrome as 26.4 ng/ml. Key words: Metabolic syndrome, 25-hydroxyvitamin D

The effect of type of water supply on water quality in a developing community in South Africa

1997 ◽  
Vol 35 (11-12) ◽  
pp. 35-40 ◽  
Author(s):  
B. Genthe ◽  
N. Strauss ◽  
J. Seager ◽  
C. Vundule ◽  
F. Maforah ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Supply ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
E Coli ◽  
Guideline Values ◽  
Developing Communities ◽  
Quality Guideline ◽  
And Control ◽  
The Relationship

Efforts to provide water to developing communities in South Africa have resulted in various types of water supplies being used. This study examined the relationship between the type of water supply and the quality of water used. Source (communal taps, private outdoor and indoor taps) and point-of-use water samples were examined for heterotrophic plate counts (HPC), total and faecal coliforms, E. coli, and coliphages. Ten percent of samples were also analysed for enteric viruses, Giardia and Cryptosporidium. Approximately 320 households were included in a case-control study. In addition, a cross-sectional study was conducted. Both studies examined the relationship between different types of water facilities and diarrhoea among pre-school children. The source water was of good microbial quality, but water quality was found to have deteriorated significantly after handling and storage in both case and control households, exceeding drinking water quality guideline values by 1-6 orders of magnitude. Coliphage counts were low for all water samples tested. Enteric viruses and Cryptosporidium oocysts were not detected. Giardia cysts were detected on one occasion in case and control in-house samples. Comparisons of whether in-house water, after handling and storage, complied with water quality guideline values demonstrated households using communal taps to have significantly poorer quality than households using private outdoor or indoor taps for HPC and E. coli (χ2 = 14.9, P = 0.001; χ2 = 6.6, P = 0.04 respectively). A similar trend (although not statistically significant) was observed for the other microbial indicators. The cross-sectional study demonstrated an apparent decrease in health risk associated with private outdoor taps in comparison to communal taps. This study suggests that a private outdoor tap is the minimum level of water supply in order to ensure the supply of safe water to developing communities.

Investigation on emotion and behavior of children aged 1-11 during the pandemic of COVID-19: A Cross-sectional study in Guizhou, China (Preprint)

2020 ◽  
Author(s):  
Yushi Mo ◽  
Yan Luo ◽  
Hong Li ◽  
Dewei Xiao ◽  
Shuqing Liu ◽  
...  
Keyword(s):  
Behavioral Problems ◽  
Prevention And Control ◽  
Online Survey ◽  
Sleep Problems ◽  
Emotional Problems ◽  
Control Measures ◽  
Emotional And Behavioral Problems ◽  
Guizhou Province ◽  
Cross Sectional ◽  
And Control

BACKGROUND In face of the sudden epidemic of COVID-19, strict prevention and control measures had been urgently carried out all over China. Because of the long-term home quarantine, all kinds of people were affected by it. OBJECTIVE In order to understand the mental health of children during the pandemic of COVID-19, this study investigated the prevalence and characteristics of emotional and behavioral problems of children aged 1-11 in Guizhou. METHODS Based on the online survey platform, the survey link was pushed through Wechat in April 2020. Electronic questionnaires were used to investigate children's demographic characteristics, emotional or behavioral problems. RESULTS A total of 3505 valid questionnaires were received from 9 prefectures and cities in Guizhou Province. 39.67% of the children in the 1-2-year-old group had emotional problems. 17.63% of the children agd 3-5 years had behavioral or emotional problems. And 23.57% of the children agd 6-11 years havd behavioral problems. CONCLUSIONS During the home quarantine period of prevention and control of COVID-19, even young children were adversely affected. The prevalence of emotional and behavioral problems in children was high, which was mainly manifested as anxiety, difficulty in concentration and sleep problems.

scholarly journals Infection control practices and challenges in Pakistan during the COVID-19 pandemic: a multicentre cross-sectional study

2021 ◽  
pp. 175717742110127
Author(s):  
Salma Abbas ◽  
Faisal Sultan
Keyword(s):  
Personal Protective Equipment ◽  
Prevention And Control ◽  
Infection Prevention ◽  
Hospital Staff ◽  
Cross Sectional Study ◽  
Infection Prevention And Control ◽  
Protective Equipment ◽  
Cross Sectional ◽  
Healthcare Facilities ◽  
And Control

Background: Patient and staff safety at healthcare facilities during outbreaks hinges on a prompt infection prevention and control response. Physicians leading these programmes have encountered numerous obstacles during the pandemic. Aim/objective: The aim of this study was to evaluate infection prevention and control practices and explore the challenges in Pakistan during the coronavirus disease 2019 pandemic. Methods: We conducted a cross-sectional study and administered a survey to physicians leading infection prevention and control programmes at 18 hospitals in Pakistan. Results: All participants implemented universal masking, limited the intake of patients and designated separate triage areas, wards and intensive care units for coronavirus disease 2019 patients at their hospitals. Eleven (61%) physicians reported personal protective equipment shortages. Staff at three (17%) hospitals worked without the appropriate personal protective equipment due to limited supplies. All participants felt overworked and 17 (94%) reported stress. Physicians identified the lack of negative pressure rooms, fear and anxiety among hospital staff, rapidly evolving guidelines, personal protective equipment shortages and opposition from hospital staff regarding the choice of recommended personal protective equipment as major challenges during the pandemic. Discussion: The results of this study highlight the challenges faced by physicians leading infection prevention and control programmes in Pakistan. It is essential to support infection prevention and control personnel and bridge the identified gaps to ensure patient and staff safety at healthcare facilities.

scholarly journals Mealtime Environment and Control of Food Intake in Healthy Children and in Children with Gastrointestinal Diseases

Children ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 77
Author(s):  
Katerina Sdravou ◽  
Elpida Emmanouilidou-Fotoulaki ◽  
Athanasia Printza ◽  
Elias Andreoulakis ◽  
Athanasios Evangeliou ◽  
...  
Keyword(s):  
Food Intake ◽  
Gastrointestinal Disease ◽  
Significant Proportion ◽  
Gastrointestinal Diseases ◽  
Healthy Children ◽  
Cross Sectional ◽  
Frequent Use ◽  
Child Autonomy ◽  
And Control ◽  
Mealtime Environment

Parental feeding practices and mealtime routine significantly influence a child’s eating behavior. The aim of this study was to investigate the mealtime environment in healthy children and children with gastrointestinal diseases. We conducted a cross-sectional case–control study among 787 healthy, typically developing children and 141 children with gastrointestinal diseases, aged two to seven years. Parents were asked to provide data on demographics and describe their mealtime environment by answering to 24 closed-ended questions. It was found that the majority of the children had the same number of meals every day and at the same hour. Parents of both groups exerted considerable control on the child’s food intake by deciding both when and what their child eats. Almost one third of the parents also decided how much their child eats. The two groups differed significantly in nine of the 24 questions. The study showed that both groups provided structured and consistent mealtime environments. However, a significant proportion of children did not control how much they eat which might impede their ability to self-regulate eating. The presence of a gastrointestinal disease was found to be associated with reduced child autonomy, hampered hunger cues and frequent use of distractions during meals.

scholarly journals Ten-year trends of hypertension treatment and control rate in Korea

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kwang-il Kim ◽  
Eunjeong Ji ◽  
Jung-yeon Choi ◽  
Sun-wook Kim ◽  
Soyeon Ahn ◽  
...  
Keyword(s):  
Age Groups ◽  
Favorable Effect ◽  
Age Group ◽  
Hypertension Treatment ◽  
Treatment Rate ◽  
Cross Sectional ◽  
The Past ◽  
Nationally Representative ◽  
Multistage Sampling ◽  
And Control

AbstractWe analyzed the Korean National Health and Nutrition Examination Survey (KNHANES) database to determine the trends of hypertension treatment and control rate in Korea over the past 10 years. In addition, we tried to investigate the effect of chronic medical conditions on hypertension management. We investigated the hypertension prevalence, awareness, treatment, and control rate from 2008 to 2017. KNHANES, which uses a stratified multistage sampling design, is a cross-sectional, nationally representative survey conducted by the Korean government. A total of 59,282 adults (≥ 20 years) were included, which was representative of the total population of around 40 million Koreans per year. The mean age was 50.7 ± 16.4 years and 42.6% were male. The prevalence of hypertension, hypercholesterolemia, diabetes mellitus, and obesity significantly increased over the 10 years. During this period, the hypertension treatment and control rate significantly improved. Hypertension treatment rate was significantly lower in the younger age group compared to the older age group, but the control rate among the treated patients was not significantly different between age groups. The treatment and control rates of hypertension were higher in patients with multimorbidity, which implies that it has a favorable effect on the treatment and control of hypertension. Hypertension treatment and control rate have improved over the past 10 years. The higher treatment and control rate in patients with multimorbidity suggest that the more aggressive surveillance might be associated with the improvement of hypertension treatment and control rate in Korea.

Sign in / Sign up

Export Citation Format

Share Document