Fatigue Assessment of Mooring Chain Considering the Effects Of Mean Load and Corrosion

2021 ◽  
Author(s):  
Erling N. Lone ◽  
Thomas Sauder ◽  
Kjell Larsen ◽  
Bernt J. Leira
Keyword(s):  
Negative Impact ◽  
Fatigue Tests ◽  
Design Practice ◽  
Extended Formulation ◽  
Considerable Influence ◽  
Corrosion Condition ◽  
Capacity Model ◽  
Significant Negative Impact ◽  
The Mean ◽  
Mooring Chain

Abstract Results from full scale fatigue tests of offshore mooring chains performed in recent years have revealed considerable influence of both mean load and corrosion condition on the fatigue capacity. It has been shown that a reduction of the mean load gives an increase in fatigue life, whereas the corrosion experienced by used chains have a significant negative impact. Neither of these effects are properly addressed by current S-N design curves or design practice. This paper suggests an extended S-N curve formulation, that includes the effects of mean load and corrosion condition. The parameters of the extended formulation are estimated empirically from mooring chain test data that includes new and used chains, with various mean loads and with different degrees of corrosion. The fitted capacity model is then used for fatigue calculation for the mooring system of a semi-submersible, showing the importance of using realistic mean loads and mooring chain corrosion in fatigue assessments.

scholarly journals RADIOGRAPHIC IMPLICATIONS OF THE SURGICAL WAITING LIST FOR THE TREATMENT OF SPINAL DEFORMITY

2018 ◽  
Vol 17 (1) ◽  
pp. 19-22
Author(s):  
LEONARDO YUKIO JORGE ASANO ◽  
MARINA ROSA FILÉZIO ◽  
MATEUS PIPPA DEFINO ◽  
VINÍCIUS ALVES DE ANDRADE ◽  
ANDRÉ EVARISTO MARCONDES CESAR ◽  
...  
Keyword(s):  
Surgical Planning ◽  
Negative Impact ◽  
Waiting Times ◽  
Waiting List ◽  
Surgical Morbidity ◽  
Level Of Evidence ◽  
Mean Waiting Time ◽  
Significant Negative Impact ◽  
Double Approach ◽  
The Mean

ABSTRACT Objective: The aim of this study was to evaluate the implications of long waiting times on surgery lists for the treatment of patients with scoliosis. Methods: Radiographs of 87 patients with scoliosis who had been on the waiting list for surgery for more than six months were selected. Two surgeons answered questionnaires analyzing the radiographs when entering the waiting list and the current images of each patient. Results: Data from 87 patients were analyzed. The mean waiting time for surgery was 21.7 months (ranging from seven to 32 months). The average progression of the Cobb angle in the curvature was 21.1 degrees. Delayed surgery implied changes in surgical planning, such as greater need of instrumentation, osteotomies, and double approach. Conclusions: Long waiting lists have a significant negative impact on surgical morbidity of patients with scoliosis, since they increase the complexity of the surgery. Level of evidence: IV. Type of study: Descriptive study.

Abstract WP431: Comparing EMS and Emergency Department Last Known Well Times in Ohio

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Mussa Zatreh ◽  
Melissa Richardson
Keyword(s):  
Emergency Department ◽  
Negative Impact ◽  
Improve Patient Care ◽  
Accurate Information ◽  
Hospital Size ◽  
Patient Demographics ◽  
Significant Negative Impact ◽  
The Mean ◽  
The Difference ◽  
Revascularization Therapy

Introduction: During the hyperacute phase of acute stroke management, time the patient was last known well (LKW) is a critical data element. Hospital Emergency Department (ED) personnel rely on accurate information reported by Emergency Medical Services (EMS) prior to arrival, which triggers the intensity of resources organized to determine patient eligibility for revascularization therapy. Over-triage can cause “alarm fatigue”, provider burnout, and/or overutilization of valuable resources. Conversely, under triage may cause a delay in, or lack of, revascularization therapy, which can have significant negative impact on the patient’s outcome. A review of the literature revealed contradictory data about the accuracy of LKW as reported by EMS. Purpose: The purpose of this project is to determine frequency and magnitude of discrepancies between LKW as reported by EMS and ED. The data was analyzed for trends that may influence discrepancies, such as hospital size, location, and patient demographics. Methods: Data on 2,092 patients from 49 hospitals was analyzed from Get With The Guidelines®-Stroke. The difference in the LKW (ΔLKW) was calculated based on source of documentation from EMS or ED. Three datasets were created based on the magnitude of the ΔLKW. For each dataset, the mean, median and patient demographics such as mean age, race, and stroke type were calculated. Results: Of 2,092 patients, 951 (45%) showed an exact match between LKW as reported by EMS and ED (ΔLKW=0), whereas 1,141 patients (55%) showed a discrepancy in the LKW (ΔLKW>0). Discrepancies were not influenced by hospital location or size. Of the overall population, 54% were male, 18% were black, and 73% were diagnosed with an ischemic stroke. The mean age was 72 years. Further collaboration is needed between EMS and ED personnel to improve the accuracy of LKW, and thereby improve patient care and provider efficiency.

scholarly journals The Impacts of Emergency Vehicle Signal Preemption on Urban Traffic Speed

2012 ◽  
Vol 49 (1) ◽  
Author(s):  
Hualiang (Harry) Teng ◽  
Valerian Kwigizile ◽  
Gang Xie ◽  
Mohamed Kaseko ◽  
A. Reed Gibby
Keyword(s):  
Opposite Direction ◽  
Negative Impact ◽  
Urban Traffic ◽  
Transition Time ◽  
Gps Data ◽  
Emergency Vehicle ◽  
Emergency Vehicles ◽  
Significant Negative Impact ◽  
The Mean ◽  
The Impact

We used GPS data from paratransit vehicles to evaluate the impact of emergency vehicles on urban traffic speeds. The results indicate that speed variance is significantly higher during emergency preemption and the mean speeds of traffic flowing in the same direction as the emergency vehicle and on crossing streets are lower during preemption than during normal conditions. Regression results indicate that traffic on major arterials and traffic in the opposite direction of the emergency vehicle tend to have higher speed during signal preemption. Signal preemption during peak periods and duration of preemption had a significant negative impact on traffic speeds. Also, the transition time has a negative impact on traffic speeds. The authors recommend further research on how to optimize (minimize) the preemption duration as well as transition time. Also, the impact of median type and number of lanes should be evaluated.

Mean Load Impact on Mooring Chain Fatigue Capacity: Lessons Learned From Full Scale Fatigue Testing of Used Chains

2019 ◽  
Author(s):  
Øystein Gabrielsen ◽  
Kjell Larsen ◽  
Oddgeir Dalane ◽  
Hans B. Lie ◽  
Svein-Arne Reinholdtsen
Keyword(s):  
Fatigue Test ◽  
Limit State ◽  
Fatigue Tests ◽  
Load Level ◽  
Full Scale ◽  
General Corrosion ◽  
Test Results ◽  
Original Design ◽  
The Mean ◽  
Mooring Chain

Abstract Fatigue of mooring chain is for many floating offshore installations a limiting factor in design. With aging installations and the need for field life extension beyond the original design life, questions on mooring chain endurance are raised. Current SN curves utilized in fatigue limit state (FLS) calculation are based on full scale testing of new chain, performed at a high mean load level (20% of the chains minimum breaking load (MBL)). The high mean load level in the tests do not correspond to the conditions for many chains in operation, as mean load in fatigue relevant seastates are often significantly less than mean load used in the new chain fatigue tests. Mooring chains in operation also experience different degree of corrosion, both general corrosion and pitting. Surface roughness and corrosion pits contribute to crack initiations, and thus reduce fatigue capacity. Fatigue tests with new chain condition cannot be assumed representative for corroded chains. As part of mooring integrity programs, Equinor has been replacing mooring chains since year 2000. To assess actual fatigue capacity, many chain segments have been full scale fatigue tested. First tests started in 2011, and the tests cover different degrees of corrosion. The tests have been performed at typical mean load levels relevant for operation of the installations, which for most cases are less than 20%MBL. From these tests it is observed that fatigue capacity in some cases are better than expected for new chain, even for chain segments with significant corrosion. Fatigue test results show a large effect of the mean load. For test cases with significant corrosion and high mean load (20%MBL), a significant reduction in fatigue capacity compared to new chains is found. This paper presents some of the fatigue test results on used chain, highlighting the effect of the mean load for the given chain conditions. Effect of corrosion at mean load of 20%MBL is also included. The paper discusses some of the underlaying causes for the mean load dependency.

scholarly journals Discontinuation of the Bleeding Time Test without Detectable Adverse Clinical Impact

2001 ◽  
Vol 47 (7) ◽  
pp. 1204-1211 ◽  
Author(s):  
Christopher M Lehman ◽  
Robert C Blaylock ◽  
Donald P Alexander ◽  
George M Rodgers
Keyword(s):  
Platelet Aggregation ◽  
Bleeding Time ◽  
Negative Impact ◽  
Invasive Procedure ◽  
Bleeding Complications ◽  
Major Surgery ◽  
Populations At Risk ◽  
Before And After ◽  
Significant Negative Impact ◽  
The Mean

Abstract Background: The bleeding time (BT) test predicts a higher bleeding complication rate in populations at risk for inherited or acquired platelet dysfunction, but it is of limited assistance in evaluating individual patients. There are no reports of clinical outcomes after discontinuation of the BT test. Methods: Interviews with a subset of the physicians who had ordered the BT test before discontinuation of the test were conducted. The total number of platelet-aggregation tests, the mean number of monthly, unmodified platelet units transfused, the incidence of kidney biopsy complications, and the number of doses of 1-deamino-8-d-arginine vasopressin (DDAVP) administered 5 months before and after discontinuation of the BT test were compared. We recorded the rates of bleeding complications in the Major Surgery Risk Pool during the 12 months before and the 5 months after the discontinuation of the BT test. Results: Clinicians reported they did not significantly change their preprocedural work-ups, postpone an invasive procedure, experience an increase in bleeding complications, or increase their use of blood products after discontinuation of the BT test. Platelet-aggregation tests (n = 9, before and after), platelet transfusions (P = 0.958), and DDAVP administration (before = 24; after = 10) did not increase after discontinuation of the BT test. The rate of postprocedural bleeding complications did not increase significantly in either Major Surgery Risk Pool cases (<3ς deviation from the mean rate) or in patients undergoing renal biopsies (P = 0.225 for decrease in hematocrit; P = 1.000 for the percentage of patients transfused) after discontinuation of the BT test. Conclusions: Our study failed to identify a clinically significant, negative impact of discontinuing the BT test.

Comparison of Time spent between an electronic and a paper-based laboratory information system by laboratorians at a polyclinic in Greater Accra, Ghana: A time-motion study

2020 ◽  
Author(s):  
Philip Boakye
Keyword(s):  
Information System ◽  
Negative Impact ◽  
Laboratory Information System ◽  
Time Motion ◽  
Accessible Information ◽  
Motion Study ◽  
Significant Difference ◽  
Significant Negative Impact ◽  
Key Issues ◽  
Motion Studies

The acceptance of electronic laboratory information system (LIS) is gradually increasing in developing countries. However, the issue of time effectiveness due to computerization is less clear as there is fewer accessible information. One of the key issues for laboratorians is their indecision with LISs’ would-be effect of time on their work. A polyclinic in Ghana was in the process of implementing electronic LIS. Several of the laboratorians did not have knowledge and skill in computing and there were disagreeing views on the time effectiveness of the LIS after implementation. The management of the polyclinic laboratory was concerned to assess time advantageousness of recording data when using the electronic LIS compared with paper-based LIS. <div><br></div><div>Five randomly selected laboratorians were provided two sheets of paper with tables to document the time they spent for both paper-based and electronic LIS. Data were collected for a total of 230 records,115 electronic LIS and 115 paper-based LIS. The t-test (mean-comparison test) was computed to compare the means of both electronic and paperbased LIS times. </div><div><br></div><div>There was a statistical significant difference in the time spent between electronic and paper-based LIS. The time spent between paper-based and electronic LIS was 0.41 minutes (95% CI 0.15 to 0.66) longer than in electronic LIS. </div><div><br></div><div>LIS can be adopted in polyclinics without having significant negative impact on time spent between electronic and paper-based LIS. More time–motion studies that include laboratorians are however necessary in order to get a more complete picture of time spent between electronic and paper-based LIS. </div>

ASSESSMENT OF THE SPATIOTEMPORAL DYNAMICS OF THE MACROPHYTE THICKET ECOSYSTEMS IN THE NEVA BAY AND THE ADJACENT WATERS OF THE EASTERN GULF OF FINLAND

2017 ◽  
Author(s):  
Ekaterina Maksimova ◽  
Ekaterina Maksimova ◽  
Vladimir Zhigulsky ◽  
Vladimir Zhigulsky ◽  
Vladimir Shuisky ◽  
...  
Keyword(s):  
Aquatic Vegetation ◽  
Temporal Dynamics ◽  
Negative Impact ◽  
Spatiotemporal Dynamics ◽  
Gulf Of Finland ◽  
Active Growth ◽  
Nesting Sites ◽  
Significant Negative Impact ◽  
And Migration ◽  
Neva Bay

The macrophyte thicket ecosystems of higher aquatic vegetation in the Neva Bay (NB) and Eastern Gulf of Finland (EGoF) perform many important roles, including acting as the habitats, nesting sites and migration sites for aquatic and semi-aquatic birds, creating the specific conditions necessary for the spawning and growth of many species of fish, and taking part in the self-purification of the aquatic ecosystems. Many anthropogenic disturbances, hydraulic works in particular, have a significant negative impact on these macrophyte thicket ecosystems. In recent years, the active growth of a new type of macrophyte thicket has been observed in the NB. This is due to the aftereffects of the construction of the Saint Petersburg Flood Prevention Facility Complex (FPFC). It is quite likely that the total macrophyte thicket area in these waters is currently increasing. In the future, it will be necessary to assess the environmental impacts of the hydraulic works on the macrophyte thicket of the NB and EGoF, taking into account the background processes of the spatiotemporal dynamics of the reed beds in the waters in question. To do this, it will be necessary to carry out a comprehensive study of these ecosystems and identify patterns in their spatial and temporal dynamics. The program of the study has been developed and is currently being implemented by Eco-Express-Service, a St. Petersburg eco-design company.

On the Major Differences between the Banking Systems of the EAEU States

2020 ◽  
Vol 26 (4) ◽  
pp. 397-406
Author(s):  
T. E. Chekanova
Keyword(s):  
Financial Stability ◽  
Systems Approach ◽  
Negative Impact ◽  
Banking Regulation ◽  
Member States ◽  
Banking Systems ◽  
Significant Negative Impact ◽  
The Difference ◽  
The Government ◽  
Major Factors

The presented study examines the problems of integration of the national banking systems of the member states of the Eurasian Economic Union (EAEU).Aim. The study aims to examine the major differences in various aspects of functioning of banking systems in the EAEU member states in terms of their impact on integration processes.Tasks. The author identifies the most prominent features of the banking systems of the EAEU states; reveals the depth of the existing differences through a comparative analysis of various indicators of national banking systems; outlines ways of overcoming integration problems associated with differences in the banking sectors of the Union states.Methods. This study is based on universal general scientific methods and elements of comparative, functional, and economic analysis within the framework of a systems approach. The author uses regulatory documents and banking reports of the EAEU states, statistical and analytical materials of the Eurasian Economic Commission (EEC), and data of Moody’s international rating agency.Results. The study identifies a number of aspects that contain the major differences in the functioning of banking systems in the EAEU member states; highlights the disproportions in the scale, level of development, financial stability, and risks of the banking spheres of the Union states; comparatively analyzes the proportion of banking and non-banking structures in the system and the share of the government and non-resident companies in the capital of banks; marks the difference in the pricing of banking services; determines differences in the existing approaches to banking regulation and the established standards; analyzes the major differences in the legislative acts of the central banks and governments of the EAEU member states and in the terms and definitions used. According to the results of the study, the major factors hindering the development of integration processes between the banking systems of the EAEU states are identified.Conclusions. The existing differences between the banking systems of the EAEU countries are diverse and multifaceted. The author states that the aspects addressed in this study have a significant negative impact on the further development of integration processes, describing the major directions and actions of the member states aimed at minimizing the exiting differences, which are required to facilitate the convergence of the states and the transition towards a common financial market.

scholarly journals Reserved Bed Program Reduces Neurosciences Intensive Care Unit Capacity Strain: An Implementation Study

Neurosurgery ◽  
2019 ◽  
Vol 86 (1) ◽  
pp. 132-138
Author(s):  
Christopher D Shank ◽  
Nicholas J Erickson ◽  
David W Miller ◽  
Brittany F Lindsey ◽  
Beverly C Walters
Keyword(s):  
Intensive Care ◽  
Economies Of Scale ◽  
Negative Impact ◽  
The United States ◽  
Fiscal Year ◽  
Implementation Study ◽  
Service Line ◽  
Hospital Units ◽  
Significant Negative Impact ◽  
Operational Issues

Abstract BACKGROUND Neurosciences intensive care units (NICUs) provide institutional centers for specialized care. Despite a demonstrable reduction in morbidity and mortality, NICUs may experience significant capacity strain with resulting supraoptimal utilization and diseconomies of scale. We present an implementation study in the recognition and management of capacity strain within a large NICU in the United States. Excessive resource demand in an NICU creates significant operational issues. OBJECTIVE To evaluate the efficacy of a Reserved Bed Pilot Program (RBPP), implemented to maximize economies of scale, to reduce transfer declines due to lack of capacity, and to increase transfer volume for the neurosciences service-line. METHODS Key performance indicators (KPIs) were created to evaluate RBPP efficacy with respect to primary (strategic) objectives. Operational KPIs were established to evaluate changes in operational throughput for the neurosciences and other service-lines. For each KPI, pilot-period data were compared to the previous fiscal year. RESULTS RBPP implementation resulted in a significant increase in accepted transfer volume to the neurosciences service-line (P = .02). Transfer declines due to capacity decreased significantly (P = .01). Unit utilization significantly improved across service-line units relative to theoretical optima (P &lt; .03). Care regionalization was achieved through a significant reduction in “off-service” patient placement (P = .01). Negative externalities were minimized, with no significant negative impact in the operational KPIs of other evaluated service-lines (P = .11). CONCLUSION Capacity strain is a significant issue for hospital units. Reducing capacity strain can increase unit efficiency, improve resource utilization, and augment service-line throughput. RBPP implementation resulted in a significant improvement in service-line operations, regional access to care, and resource efficiency, with minimal externalities at the institutional level.

scholarly journals The Influence of Urban Sprawl on Air Pollution and the Mediating Effect of Vehicle Ownership

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1261
Author(s):  
Aiping Tao ◽  
Qun Liang ◽  
Peng Kuai ◽  
Tao Ding
Keyword(s):  
Air Pollution ◽  
Urban Sprawl ◽  
Negative Impact ◽  
Empirical Support ◽  
Mediating Effect ◽  
Vehicle Ownership ◽  
Mediating Role ◽  
Effect Model ◽  
Significant Negative Impact ◽  
The Impact

Based on the panel data of 224 prefecture-level and above cities in China from 2003 to 2016, this paper empirically studies the impact of urban sprawl on air pollution and introduces a mediating effect model to test the mediating role of vehicle ownership concerning the impact of urban sprawl on air pollution. The research in this paper arrives at three conclusions. First, urban sprawl has a significant positive effect on air pollution, and this conclusion is still valid after solving the endogeneity problem and conducting a robustness test. Second, the results of mediating effect test show that urban sprawl indirectly affects air pollution through the partial mediating effect of vehicle ownership. By removing the mediating effect, urban sprawl has a significant negative impact on air pollution, indicating that the mediating effect of vehicle ownership is higher concerning the impact of urban sprawl on air pollution. Third, further panel quantile regression results show that the higher the level of air pollution, the weaker the mediating effect of vehicle ownership and the stronger the direct effect of urban sprawl on air pollution. These conclusions can provide some empirical support for solving the air pollution problems caused by urban sprawl in China.

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