Friction, Contact Pressure, and Nonlinear Behavior of Steel Tubes in Subsea Umbilicals

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Farzan Parsinejad ◽  
Chris Kassner ◽  
Mark Kurtz ◽  
Naiquan Ye
Keyword(s):  
Contact Pressure ◽  
Fatigue Damage ◽  
Cross Sections ◽  
Contact Stiffness ◽  
Global Analysis ◽  
Nonlinear Behavior ◽  
Steel Tubes ◽  
Cross Sectional ◽  
Cross Sectional Design ◽  
The Impact

This paper focuses on evaluating the impact of friction and contact pressure on helical steel tubes. The initial gaps between steel tubes and adjacent layers, friction coefficients and the contact stiffness are the main factors that affect such investigation. A novel methodology by using UFLEX2D (a MARINTEK product) has been applied for modeling complex umbilical cross sections and for the study of these parameters. Two cross sections for the same subsea application but with different designs have been investigated in the study. It has been shown how fatigue damage can be significantly impacted by different cross-sectional design. For this study, nonlinear moment/curvature relationship has been included in the analyses. Based on the findings of this study, more realistic results can be achieved by including the nonlinear behavior in global analysis for fatigue damage calculations instead of using nominal bending stiffness supplied by umbilical manufacturer.

Friction, Contact Pressure and Non-Linear Behavior of Steel Tubes in Subsea Umbilicals

2013 ◽  
Author(s):  
Farzan Parsinejad ◽  
Chris Kassner ◽  
Mark Kurtz ◽  
Naiquan Ye
Keyword(s):  
Contact Pressure ◽  
Fatigue Damage ◽  
Cross Sections ◽  
Friction Stress ◽  
Stress Range ◽  
Steel Tubes ◽  
Load Variation ◽  
Linear Behavior ◽  
Non Linear ◽  
The Impact

Steel tube umbilical risers in deep water applications are subject to significant variable environmental loads during operation. These tubes are designed to carry high pressure fluids, up to 15,000 psi. The stresses accumulated in the walls consist of contribution from movement of the floating platform on which the umbilical is connected, axial tension due to the weight of umbilical and ancillaries, and internal pressure due to end cap effect. The helically wound steel tubes in umbilicals are un-bonded and can slip against adjacent layers. Therefore the stresses in these tubes experience a hysterical feature when the slip changes directions. It is known that in addition to bending stress, friction stress range has a major contribution in fatigue damage. If there is full slip, the friction stress range will be a constant value regardless of the load variation. However in many cycles the full slip is not reached and the stress range is proportional to load variation. This paper focuses on evaluating the impact of friction and contact pressure on helical steel tubes. The initial gaps between steel tubes and adjacent layers, friction coefficients and the contact stiffness are the main factors that affect such investigation. A novel methodology by using UFLEX2D (a MARINTEK product) has been applied for modeling complex umbilical cross sections and for the study of these parameters. Two cross sections for the same subsea application but with different designs have been investigated in the study. It has been shown how fatigue damage can be significantly impacted by different cross sectional design. For this study, non-linear moment/curvature relationship has been included in the analyses. Based on the findings of this study, more realistic results can be achieved by including the non-linear behavior in global analysis for fatigue damage calculations instead of using nominal bending stiffness supplied by umbilical manufacturer.

Public Sector Employment, Quality of Government, and Well-Being: A Global Analysis

2021 ◽  
pp. 223386592110117
Author(s):  
Robert Davidson ◽  
Alexander Pacek ◽  
Benjamin Radcliff
Keyword(s):  
Public Sector ◽  
Global Analysis ◽  
Well Being ◽  
Subjective Well Being ◽  
Cross Sectional ◽  
Political Factors ◽  
The Public ◽  
Employment Quality ◽  
The Impact

While a growing literature within the study of subjective well-being demonstrates the impact of socio-political factors on subjective well-being, scholars have conspicuously failed to consider the role of the size and scope of government as determinants of well-being. Where such studies exist, the focus is largely on the advanced industrial democracies of the Organization for Economic Co-Operation and Development. In this study, we examine the size of the public sector as a determinant of cross-national variation in life satisfaction across a worldwide sample. Our findings strongly suggest that as the public sector grows, subjective well-being increases as well, conditional on the extent of quality of government. Using cross-sectional data on 84 countries, we show this relationship has an independent and separable impact from other economic and political factors.

scholarly journals CORRELATION BETWEEN SMOKE-FREE AREAS AND SMOKING BEHAVIOR IN INDONESIA

2020 ◽  
Vol 8 (2) ◽  
pp. 117
Author(s):  
Mohamad Anis Fahmi
Keyword(s):  
Public Awareness ◽  
Smoking Behavior ◽  
Secondary Data ◽  
Computer Application ◽  
P Value ◽  
Cross Sectional ◽  
Positive Correlation ◽  
The Government ◽  
Cross Sectional Design ◽  
The Impact

Background: Low public awareness of the impact of smoking makes the implementation of smoke-free areas (KTR) difficult. Smoke-free areas aim to protect the public from the direct and indirect effects of smoking. Purpose: This study aimed to analyze the correlation between the application of smoke-free areas and the prevalence of active and ex-smokers in Indonesia. Method: This study implemented a cross-sectional design, using secondary data from the Riskesdas 2018 on active and ex-smokers. KTR application data were obtained from the Profile of Non-Communicable Diseases in 2016. A Pearson product-moment test was conducted by a computer application to determine the correlation coefficient (r). This coefficient was used to describe the level of correlation between the two variables; significance was determined as a p value of 5%. Results: This study showed that the average application of KTR throughout Indonesia was 50.83%, active smokers comprised 23.49% of the population, and ex-smokers comprised 4.94%. Most active smokers were in Java and Sumatra, while the majority of ex-smokers were in Java and Sulawesi and the majority of KTR was in Java. This study shows that there is a positive correlation between KTR application and the percentage of ex-smokers (r = 0.46; p value = 0.01). Conclusion: There is a positive correlation between the application of KTR and an increase in ex-smokers. The government needs to increase the application of KTR policies.

scholarly journals DAMPAK OVERCAPACITY TERHADAP TINGKAT STATUS GIZI NARAPIDANA

2020 ◽  
Vol 15 (1) ◽  
pp. 60-66
Author(s):  
Faiz Fakhri Isjwara
Keyword(s):  
Body Weight ◽  
Nutritional Status ◽  
Negative Impact ◽  
Sampling Technique ◽  
Ideal Body Weight ◽  
Correctional Institution ◽  
Cross Sectional ◽  
Cross Sectional Design ◽  
Unbalanced Diet ◽  
The Impact

The principle of the organization of prisons (Lembaga Pemasyarakatan/ LAPAS) must prioritize a humane approach so that prisoners and prisoners receive their rights. If the implementation is good, the objective of LAPAS is to carry out social reintegration, namely the restoration of the unity of life, life and livelihood of prisoners and correctional students both prisoners as individuals, social beings and God's creatures with society can be achieved. However, this organization faces obstacles, namely the problem of overcapacity. This can have implications for suboptimal and can even lead to failure to function as a correctional institution. The problem of over capacity will also have an impact on the health conditions of prisoners. Sleep conditions, eating patterns, health services that are less than the maximum due to over capacity will certainly have a negative impact on the nutritional status of prisoners. This study aims to determine the impact of Overcapacity Impacts on the Nutritional Status Level of Prisoners in Class II A Penitentiary, Sidoarjo. This type of research is a quantitative correlational analytic survey with a cross-sectional design. The number of samples was 91 inmates. The sampling technique is by random sampling. Data is collected by weighing body weight and height and comparing with ideal body weight. The results showed that the more overcapacity, the nutritional status of prisoners decreased. Room conditions can affect the provision of an unbalanced diet. Thus, that this causes the prisoners to experience malnutrition.

scholarly journals Effect of Core Mass and Alloy on Cyclic Fatigue Resistance of Different Nickel-Titanium Endodontic Instruments in Matching Artificial Canals

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5734
Author(s):  
Sebastian Bürklein ◽  
Lennart Zupanc ◽  
David Donnermeyer ◽  
Karsten Tegtmeyer ◽  
Edgar Schäfer
Keyword(s):  
Fatigue Resistance ◽  
Cyclic Fatigue ◽  
Nickel Titanium ◽  
The Other ◽  
Design Parameters ◽  
Core Mass ◽  
Cross Sectional ◽  
Significance Level ◽  
Cross Sectional Design ◽  
The Impact

Instrument failure during root canal preparation is still a concern among endodontists. However, it remains unclear whether the use of more martensitic alloys or the cross-sectional design parameters (i.e., core mass) significantly improve fracture resistance. The aim of the study was to evaluate the impact of core mass and alloy on dynamic cyclic fatigue resistance of nickel-titanium endodontic instruments in matching artificial canals at body temperature. Two groups were tested. (A) taper 0.04: F360 (Komet, Lemgo, Germany), Twisted file (Sybron Endo, Glendora, CA, USA) (=TF), JIZAI (Mani, Tochigi, Japan) (=J_04) (all size #25) and the variable tapered TruNatomy (Dentsply, Ballaigues, Switzerland) (size #26) (=TN). (B) size #25; taper 0.06: (Mtwo (VDW, Munich, Germany), JIZAI (Mani) (=J_06), and variable tapered Hyflex EDM OneFile (Coltene Whaledent, Altstätten, Switzerland) (=HF). Time, number of cycles to fracture (NCF), and number and length of fractured fragments were recorded and statistically analysed using ANOVA Student-Newman-Keuls, Kruskal–Wallis or Chi-square test (significance level = 0.05). (A) TN showed the significantly shortest time until fracture, followed by TF, F360 and J_04 which also differed significantly, while NCF showed the following order: F360 < TN < TF < J_04 (p < 0.05). Only one J_04 but all instruments of the other groups fractured within the test-limit of 10 min. (B) Mtwo was significantly inferior concerning time until fracture and NCF, compared to J_06 and HF (p < 0.05), which did not differ significantly (p > 0.05). While all Mtwo instruments fractured, only four instruments failed in the other groups (p < 0.05). Within the limitations of this study, alloy and cross-sectional design (i.e., core mass) were critical factors regarding instrument failure, but none of these factors could be determined as a main parameter for increased or decreased time, and cycles to fracture. Rather, it seemed to be the interaction of multiple factors (e.g., longitudinal and cross-sectional design, alloy, and rotational speed) that was responsible for differences in the time and cycles to fracture. Nonetheless, all instruments had lifetimes that allow safe clinical use. However, the superiority or inferiority of an instrument with regard to cyclic fatigue based on laboratory results—even when identical trajectories are guaranteed—may be considered questionable, as the characteristics and design parameters of the instruments vary considerably, and the experimental setups lack additional clinical parameters and thus clinical relevance.

Impact of nurses' emotional intelligence on the implementation of a professional practice model in cancer care

2021 ◽  
Vol 30 (19) ◽  
pp. 1110-1116
Author(s):  
Majeda A Al-Ruzzieh ◽  
Omar Ayaad
Keyword(s):  
Emotional Intelligence ◽  
Professional Practice ◽  
Sampling Technique ◽  
Mean Value ◽  
Cancer Center ◽  
Practice Model ◽  
Cross Sectional ◽  
Effective Implementation ◽  
Cross Sectional Design ◽  
The Impact

Aim: To examine the impact of emotional intelligence on the effective implementation of a professional practice model in a specialised cancer centre. Methods: The study used a cross-sectional design with 580 frontline nurses at King Hussein Cancer Center, Jordan. The sample was selected using a convenience sampling technique. Data were collected using two self-administered questionnaires to measure emotional intelligence and professional practice. Results: The overall mean value of emotional intelligence was 5.60 out of 6 (SD=0.78), while the overall mean value for the implementation of the professional practice model was 4.76/5 (SD=0.59). The results showed that the overall mean value of emotional intelligence had a significant positive correlation with the effective implementation of the professional practice model (r=0.580, P<0.001), even after adjusting for the participants' demographics (P<0.001). Conclusion: Emotional intelligence can be considered a predictor for the effective implementation of a professional practice model.

Water Entry of a Wedge by Hydroelastic Orthotropic Plate Theory

1999 ◽  
Vol 43 (03) ◽  
pp. 180-193 ◽  
Author(s):  
Odd M. Faltinsen
Keyword(s):  
Impact Velocity ◽  
Cross Sections ◽  
Orthotropic Plate ◽  
Plate Theory ◽  
Three Dimensional ◽  
Water Entry ◽  
Natural Period ◽  
Cross Sectional ◽  
Flow Effects ◽  
The Impact

Water entry of a hull with wedge-shaped cross sections is analyzed. The stiffened platings between two transverse girders on each side of the keel are separately modeled. Orthotropic plate theory is used. The effect of structural vibrations on the fluid flow is incorporated by solving the two-dimensional Laplace equation in the cross-sectional fluid domain by a generalized Wagner's theory. The coupling with the plate theory provides three-dimensional flow effects. The theory is validated by comparison with full-scale experiments and drop tests. The importance of global ship accelerations is pointed out. Hydrodynamic and structural error sources are discussed. Systematic studies on the importance of hydroelasticity as a function of deadrise angle and impact velocity are presented. This can be related to the ratio between the wetting time of the structure and the greatest wet natural period of the stiffened plating. This ratio is proportional to the deadrise angle and inversely proportional to the impact velocity. A small ratio-means that hydroelasticity is important and a large ratio means that hydroelasticity is not important.

Abusive supervisors and employees who cyberloaf

2020 ◽  
Vol 30 (3) ◽  
pp. 789-809 ◽  
Author(s):  
Upasnaa A. Agarwal ◽  
James B. Avey
Keyword(s):  
Psychological Contract ◽  
Abusive Supervision ◽  
Psychological Contract Breach ◽  
Full Time ◽  
Cross Sectional ◽  
Contract Breach ◽  
Content Type ◽  
Mediating Role ◽  
Cross Sectional Design ◽  
The Impact

PurposeThe purpose of this study is to examine the effects of abusive supervision on cyberloafing behavior, to test the mediating role of PsyCap in this relationship and the extent to which these relationships are moderated by psychological contract breach.Design/methodology/approachA total of 394 full-time managers across different Indian organizations served as the sample for this study.FindingsThe results revealed that the abusive supervision and PsyCap are significantly correlated with cyberloafing, the relationship between abusive supervision and cyberloafing is partially mediated by PsyCap and the impact of abusive supervision and PsyCap on cyberloafing is moderated by psychological contract breach such that the effects of abusive supervision and PsyCap on cyberloafing are stronger when employees perceive high psychological contract breach.Research limitations/implicationsA cross-sectional design and use of self-reported questionnaires are a few limitations of this study.Originality/valueThis is one of the first studies examining cyberloafing in response to abusive supervision and one of the few attempts to examine the effects of abusive supervision on individual resources (PsyCap) in response to workplace mistreatment. This study is also the first to examine these phenomena in the Indian context.

The impact of teaching-research conflict on job burnout among university teachers

2019 ◽  
Vol 31 (1) ◽  
pp. 76-90
Author(s):  
Yongzhan Li ◽  
Yongxin Li ◽  
Gloria Castaño
Keyword(s):  
Small Sample ◽  
Job Burnout ◽  
Personal Accomplishment ◽  
Cross Sectional ◽  
Content Type ◽  
University Teachers ◽  
Teaching Research ◽  
Cross Sectional Design ◽  
The Impact ◽  
The Relationship

Purpose To fill the previous research gap, focusing on two constructs, i.e. perceived supervisor support (PSS) and psychological capital (PsyCap), this study aims to explore the mechanism underlying the relationship between teaching–research conflict (TRC) and job burnout among university teachers using the lens of job demands–resources (JD-R) model. Design/methodology/approach First, theoretically grounded hypotheses linking teaching–research conflict, PSS and PsyCap to job burnout were formulated. Then, a cross-sectional design was used to test the theoretical model presented in this study. Findings The results showed that TRC was positively linked to emotional exhaustion (EE) and depersonalization (DP), but negatively linked to personal accomplishment; PSS moderated the effect of TRC on both EE and DP but did not act as a moderator in the relationship between TRC and personal accomplishment; and PsyCap moderated the effect of TRC on all the three dimensions of job burnout. Research limitations/implications Given that the data were collected from single-source, the study was vulnerable to the common method variance. Besides, the relative small sample size limits the representativeness of the sample. Moreover, the cross-sectional design cannot confirm causal relationship between variables. Despite these limitations, the findings of this research can potentially inform effective interventions aimed at reducing the effect of TRC on job burnout among university teachers. Originality/value Based on the JD-R model, PSS and PsyCap are used to explore the effect of TRC on job burnout for the first time.

The impact of supervisor humor on newcomer adjustment

2016 ◽  
Vol 37 (4) ◽  
pp. 540-554 ◽  
Author(s):  
Panagiotis Gkorezis ◽  
Eugenia Petridou ◽  
Katerina Lioliou
Keyword(s):  
Design Methodology ◽  
Self Report ◽  
Hierarchical Regression ◽  
Cross Sectional ◽  
Content Type ◽  
Relational Identification ◽  
Cross Sectional Design ◽  
The Impact ◽  
The Relationship

Purpose – Substantial research has examined the pivotal role of supervisor positive humor in generating employee outcomes. To date, though, little is known about the relationship between supervisor humor and newcomers’ adjustment. The purpose of this paper is to contribute to this gap by examining the effect of supervisor positive humor on newcomers’ adjustment. In doing so, the authors highlighted relational identification with the supervisor as a mediating mechanism that explains the aforementioned association. Design/methodology/approach – Data were drawn from 117 newcomers. In order to collect the data the authors used the snowball method. Also, hierarchical regression analysis was conducted. Findings – The results demonstrated that supervisor positive humor affects employees’ relational identification with the supervisor which, in turn, positively relates to newcomers’ adjustment. Research limitations/implications – Data were collected using a cross-sectional design and, therefore, the authors cannot directly assess causality. Moreover, the authors used self-report measures which may strengthen the causal relationships. Originality/value – To the best of the knowledge, this is the first study that illustrates the role of supervisor humor in enhancing both newcomers’ relational identification and adjustment.

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