bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fatigue Life Prediction of Cold Rolled Rotary Shouldered Threaded Connections
Authors: Song Fei , Du Michael , Li Ke 
Published: January 2019

The bottom hole assembly (BHA) of a modern drill string for directional drilling mainly comprises a drill bit, a rotary steerable system, and a measurement while drilling tool. The tools and subs used on a BHA are screwed together through rotary shouldered threaded connections. Each connection is made up with a pin and a box. These connections are the weakest links when the BHA undergoes a large number of revolutions in a curved well section. When the fatigue life of a connection is consumed during a drilling job, a twist-off would occur, which could result in an enormous amount of non-productive time and possibly loss of the bottom BHA section in the hole. Cold rolling has proven to be able to improve fatigue resistance of a threaded connection by pressing a rolling wheel against the thread root and generating a layer of compressive residual stress at the root. Understanding how cold rolling improves fatigue resistance of a threaded connection is important for optimization of the rolling parameters and prediction of the BHA service life in a given drilling condition.
In this paper, a predictive method is presented for fatigue life of a cold rolled threaded connection. A finite element model was developed to simulate the cold rolling process. The resulting deformation and stress states at the root were carried over through makeup of the pin and the box as well as through cyclic bending of the connection. The fatigue life predictions were found to be in favorable agreement with the experimental measurements from full-scale fatigue tests at different bending moment levels applied.
A Finite Element Approach for Study of Wave Attenuation Characteristics of Epoxy Polymer Composite
Authors: Kulkarni Shank S. , Tabarraei Alireza , Ghag Pratik P. 
Published: January 2019

The properties of the inclusions, viz. size, shape, and distribution significantly affect macroscopic properties of a polymer composite. Finite element (FE) modeling provides a viable approach for investigating the effects of the inclusions on the macroscopic properties of the polymer composite. In this paper, finite element method is used to investigate ultrasonic wave propagation in polymer matrix composite with a dispersed phase of inclusions. The finite element models are made up of three phases; viz. the polymer matrix, inclusions (micro constituent), and interphase zones between the inclusions and the polymer matrix. The analysis is performed on a three dimensional finite element model and the attenuation characteristics of ultrasonic longitudinal waves in the matrix are evaluated. The attenuation in polymer composite is investigated by changing the size, volume fraction of inclusions, and addition of interphase layer. The effect of loading frequency of the wave on the attenuation characteristics is also studied by varying the frequency in the range of 1–4 MHz.
Results of the test revealed that higher volume fraction of inclusions gave higher attenuation in the polymer composite as compared to the lower volume fraction model. Smaller size of inclusions are preferred over larger size as they give higher wave attenuation. It was found that the attenuation characteristics of the polymer composite are better at higher frequencies as compared to lower frequencies. It is also concluded that the interphase later plays a significant role in the attenuation characteristics of the composite.
Engineering a Pool Ladder to Prevent Drownings in Above-Ground Pools
Authors: Pierce William H. , Ziernicki Richard M. 
Published: January 2019

In the United States, approximately 44 children under the age of five years old drown each year after gaining unauthorized access to above-ground pools via pool ladders. Approximately 704 additional children sustain submersion-related injuries after gaining unauthorized access to above-ground pools via pool ladders. In many cases, these events occurred during brief lapses of adult supervision. The societal cost associated with these deaths and injuries ranges from 134 to 342 million dollars per year. In addition to societal costs, there is also a significant loss in quality of life for near-drowning victims and their families.
Since the 1960’s, several medical studies have been published that discuss children under the age of five accessing above-ground pools and drowning. Several of these medical studies propose solutions to reduce the likelihood of drowning. Despite the proposed solutions in these studies, the rate of such drownings in above-ground pools has not decreased. However, the medical studies do not address how proper and safe engineering design of pool ladders can and should be used to prevent such occurrences.
This paper adds engineering science to these medical studies by including safety engineering principles that can be used to prevent young children from gaining unauthorized access to above-ground pools via pool ladders. Specifically, this paper addresses, hazard and risk assessment, passive safety systems that can be added to pool ladders to prevent drowning incidences, and the economic and technological feasibility of such passive safety systems. This paper shows that the benefits associated with the reduction in societal costs of drowning or near-drowning outweigh the cost of adding passive safety systems to pool ladders.
Preliminary Development of a Measurement Standard Using a Research Simplex Atomizer
Authors: Leask Scott B. , Li Alice K. , McDonell Vincent G. , Samuelsen Scott 
Published: January 2019

Cold-flow spray researchers have an array of diagnostic tools to extract meaningful information on spray characteristics. The efficacy of many of these tools, however, depends heavily on calibration, alignment, and human operation. This can lead to large discrepancies in data values for seemingly identical setups between workers. The application of experimental data to numerical models is thereby hindered due to inconsistencies in results caused by experimental error. Previously, an attempt was made to produce a “standard spray” through the use of a research simplex atomizer (RSA). As manufacturing processes and diagnostic tools have improved, the research simplex atomizer is being revisited.
Here, a new research simplex atomizer has been investigated. Fundamental datasets captured from detailed test conditions are presented to provide benchmark data with the intention of other workers testing the reproducibility of the results. Preliminary findings between laboratories show good agreement in droplet size measurements.
Further, emphasis is placed on the sensitivity of laser diagnostics used and the effect their operation can incur. To satisfy the requirements of a measurement standard, it is paramount that all workers adhere to similar diagnostic configurations and detail their operating parameters.
Aerodynamics Analysis for Optimization the Design of a Baja SAE Chassis
Authors: Maradey Lázaro Jessica Gissella , Ardila Gómez Sergio Andrés , Esteban Villegas Helio Sneyder 
Published: January 2019

The aerodynamic analysis of vehicles using Computational Fluid Dynamics (CFD) is a powerful tool that is used to explore and investigate how air flow behaves around the vehicle, gives a qualitative idea of aerodynamic behavior and provides engineers with the information necessary to design the pieces that will be tested in the wind tunnel. This technique allows to find the values of forces and moments to get an idea of the drag resistance and lift forces on the vehicle. It is also possible to determine the position of the center of pressure that exerts a vital importance in the definition of the directional stability of the vehicle in its lateral dynamics. On the other hand, it offers the advantage of being able to see many variables of the problem that are very difficult to access in reality, for example to see current lines, vortex shedding, fields of pressures around the vehicle. Although the use of CFD has become a common practice in the automotive industry in recent decades, it is still not considered as a single technique, since one of the limitations is related to the dynamics of a turbulent flow is quite complex so which analytical and computational study depends on what is called Turbulence Models.
This article aims to show the aerodynamic design process by CFD simulation of a Baja SAE vehicle chassis using Ansys software, widely used for simulation of static charges, thermodynamics, fluid mechanics, multiphysics systems and vibrations and to provide information that can be validated experimentally in the future.
A Study of Water Transport of Hollow Fiber Membranes Over Various Operating Conditions
Authors: Chae Jongmin , Yu Sangseok 
Published: January 2019

A membrane humidifier is a device to provide water vapor into the proton exchange membrane fuel cell stack that is used for transportation application due to global warming. Since inadequate humidification severely affects the performance and durability of a fuel cell stack, it is necessary to equip the humidifier for delivery humidification into the fuel cell vehicle.
In this study, the performance of humidification in hollow fiber membrane is investigated. While the test section is exposed to external humidity condition, dry air is provided through hollow fiber membrane so that the water transport is facilitated. Since various parameters can change the performance, the performance investigation has to be carried out with parameters. In this study the water transport of hollow fiber membrane is investigated in terms of principle operating conditions such as temperature, pressure, and flow rate.
Neck Loading Model of a Child in a Car Seat
Authors: Bohn Gregory , Valerio Veronica , Hall Caitlin , Coronado Kathia , Saboori Parisa 
Published: January 2019

It has been shown that children are susceptible to many dangers in child safety seats that do not involve a car accident. One issue involves the hyperextension of the neck muscles when the child falls asleep in a slumped position. Another issue is positional asphyxia, which is a form of asphyxia where the child’s position prevents them from breathing adequately.
The present study designed a realistic model of the cervical spine and conducted a finite element analysis to observe if and where stress and strain concentrations existed. This analysis simulated the effects of a moving vehicle on the child while their head was slumped forward.
A car seat redesign was also undertaken to overcome the afore mentioned issues. This involved employing a motor and control system.
Parametric Study and Improvement of Phase Separation in Intermediate Headers of Microchannel Condensers
Authors: Li Jun , Hrnjak Pega 
Published: January 2019

Phase separation has been proven to be beneficial to air-cooled parallel flow microchannel condensers for air conditioning systems. The inlet to the condenser with phase separation is located at the middle of the condenser height. After the first pass, in the vertical second header of the condenser, vapor phase separates from liquid phase mainly due to gravitational effects. In ideal case vapor should go to the top exit and liquid to the bottom exit, resulting in increased heat transfer. Due to interaction between vapor and liquid, separation is not perfect, expressed through the separation efficiency.
This paper presents a parametric study of phase separation efficiency in the intermediate headers, with the target to improve separation efficiency. Header prototypes which have two exits are made with transparent PVC to simulate the real header and provide visual access. Using R-134a as a baseline, the measurement of separation efficiency and its general trend will be shown first. The results are compared to those of a mechanistic model based on flow regime and force balance analysis. Inlet mass flux in simulation is controlled at 87 kg·m−2·s−1 – 311 kg·m−2·s−1 and inlet quality at 0.05–0.25. The observed flow patterns in header are compared with the modeling results as well. Then, the header diameter is increased, which effectively improves the separation efficiency due to reduction of vapor velocity in header. Finally, R245fa and R32 are modeled in comparison with R-134a to discuss the effect of fluid properties on separation efficiency.
Development of a New Course on Microgrids and Distributed Energy Resources
Authors: Haghani Sasan 
Published: January 2019

Microgrids are an essential element of smart grids and are identified as a key component for improving power reliability and quality, increasing system energy efficiency, and providing the possibility of grid-independence to individual end-user sites. Microgrids support a flexible and efficient electric grid by enabling the integration of growing deployments of distributed energy resources such as solar and wind power. According to a recent Navigant report, spending on microgrid enabling technologies will reach 112 billion dollars by 2026. While the development of microgrids and distributed energy technologies are underway, a recent Department of Energy jobs report indicates that the U.S. does not have enough skilled workers to fill 1.5 million new energy jobs by 2030. Furthermore, even the most experienced workers often lack the updated skills and training needed to successfully support the advanced systems, tools and devices that make up microgrids. Hence it is important to develop new courses that can equip our students with the necessary technical skills to enter the microgrids job market.
This paper presents the development of a new course on microgrids and distributed energy resources. This course is a follow up to a previously developed course on Smart Grids. The paper will discuss the course content, the pedagogical approach used to deliver the course, and some of the students’ projects and presentations.
Informal and formal care preferences and expected willingness of providing elderly care in Germany: protocol for a mixed-methods study
Authors: de Jong Lea , Plöthner Marika , Stahmeyer Jona Theodor , Eberhard Sveja , Zeidler Jan , Damm Kathrin 
Published: January 2019

IntroductionIn Germany, the number of elderly people in need of care is expected to increase from 2.4 million in 2015 to 3.2 million in 2030. The subsequent rise in demand for long-term care facilities is unlikely to be met by the current care structures and available staff. Additionally, many Germans still prefer to be cared for at home for as long as possible. In light of recent changes, such as increasing employment rates of women and growing geographical distances of family members, informal caregiving becomes more challenging in the future. The aim of this study is to explore preferences for informal and formal care services in the German general population, as well as the expected willingness of providing elderly care.Methods and analysisA mixed-methods approach will be used to explore care preferences and expected willingness of providing elderly care in the German general population. A systematic literature review will be performed to provide an overview of the current academic literature on the topic. Qualitative interviews will be conducted with informal caregivers, care consultants and people with no prior caregiving experiences. A labelled discrete choice experiment will be designed and conducted to quantitatively measure the preferences for informal and formal care in the German general population. People between 18 and 65 years of age will be recruited in cooperation with a (regional) statutory health insurance (AOK Lower Saxony). A mixed multinomial logit regression model and a latent class finite mixture model will be used to analyse the data and test for subgroup differences in care preferences.Ethics and disseminationThe study has been approved by the Committee for Clinical Ethics of the Medical School in Hannover. Data will be treated confidential to ensure the participants' anonymity. The results will be discussed and disseminated to relevant stakeholders in the field.Trial registration numberDRKS00012266.
Association between the concurrence of pre-existing chronic liver disease and worse prognosis in patients with an herb-Polygonum multiflorumthunb. induced liver injury: a case-control study from a specialised liver disease center in China
Authors: Jing Jing , Wang Rui-lin , Zhao Xin-yan , Zhu Yun , Niu Ming , Wang Li-fu , Song Xue-ai , He Ting-ting , Sun Yong-qiang , Xu Wen-tao , Yu Si-miao , Wang Li-ping , Guo Yu-ming , Bai Zhao-fang , Xiao Xiao-he , Wang Jia-bo 
Published: January 2019

ObjectivesThe present study aimed to evaluate the association between the concurrence of pre-existing chronic liver diseases (CLD) and worse prognosis in patients with HILI.DesignA case–control study.SettingTertiary hospital specialising in liver diseases in China.Participants145 hospitalised HILI patients were assessed with respect to prognosis by comparing HILI with or without pre-existing CLD from February 2007 to January 2017. Twenty-five HILI cases with pre-existing alcoholic liver disease (ALD) or non-alcoholic fatty liver disease (NAFLD) and 200 ALD or NAFLD controls matched 1:8 for sex, age (±4 years old), body mass index (±2 kg/m2), the type of CLD, alcohol intake (±5 g/d) and the presence or absence of cirrhosis.Primary outcome measuresMortality and chronicity in HILI patients with or without pre-existing CLD, and matched CLD patients.ResultsOf the 193 714 hospitalised patients with liver diseases, 5703 patients met the diagnostic criteria for drug-induced liver injury (DILI), which was attributed toPolygonum multiflorumThunb. (PMT) in 145 patients. Among these HILI patients, 22.8% (33 of 145) had pre-existing CLD, including 17 (51.5%) with ALD, 8 (24.2%) with NAFLD, 5 (15.2%) with chronic viral hepatitis and 3 (9.1%) with autoimmune liver disease. Compared with HILI patients without CLD, HILI patients with pre-existing CLD showed higher mortality (0.9% vs 9.1%, p=0.037) and higher chronicity (12.5% vs 30.3%, p=0.016). Compared with matched ALD (136 patients) or NAFLD (64 patients) patients, HILI patients with pre-existing ALD showed higher chronicity (35.3% vs 11.8%, p=0.019). Multivariate logistic regression analysis found that concurrence of pre-existing CLD was an independent risk factor for both of chronicity and mortality (OR 3.966, 95% CI 1.501 to 10.477, p=0.005), especially the chronicity (OR 3.035, 95% CI 1.115 to 8.259, p=0.030).ConclusionsConcurrence of pre-existing CLD could be an independent risk factor for worse prognosis, especially chronicity, in PMT-related HILI.
Finnish National Esophago-Gastric Cancer Cohort (FINEGO) for studying outcomes after oesophageal and gastric cancer surgery: a protocol for a retrospective, population-based, nationwide cohort study in Finland
Authors: Kauppila Joonas H , Ohtonen Pasi , Karttunen Tuomo J , Kokkola Arto , Laine Simo , Rantanen Tuomo , Ristimäki Ari , Räsänen Jari V , Saarnio Juha , Sihvo Eero , Toikkanen Vesa , Tyrväinen Tuula 
Published: January 2019

IntroductionSurgery for oesophageal and gastric cancers is associated with high morbidity, mortality and poor quality of life postoperatively. The Finnish National Esophago-Gastric Cancer Cohort has been established with the aim of identifying factors that could contribute to improved outcomes in oesophago-gastric cancer.Methods and analysisAll patients with oesophageal and gastric cancer diagnosed in Finland between 1987 and 2015 will be identified from the Finnish national registries. The Finnish Cancer Registry and Finnish Patient Registry will be used to identify patients that fulfil the inclusion criteria for the study: (1) diagnosis of oesophageal, gastro-oesophageal junction, or gastric cancer, (2) any surgical treatment for the diagnosed cancer and (3) age of 18 or over at the time of diagnosis. Clinical variables and complication information will be retrieved in extensive data collection from the medical records of the relevant Finnish hospitals and complete follow-up for vital status from Statistics Finland. Primary endpoint is overall all-cause mortality and secondary endpoints include complications, reoperations, medication use and sick leaves. Sub-studies will be implemented within the cohort to investigate specific populations undergoing oesophageal and gastric cancer surgery. The initial estimated sample size is 1800 patients with surgically treated oesophageal cancer and 7500 patients with surgically treated gastric cancer.Ethics and disseminationThe study has been approved by the Ethical Committee in Northern Ostrobothnia, Finland and The National Institute for Health and Welfare, Finland. Study findings will be disseminated via presentations at conferences and publications in peer-reviewed journals.
Outcomes reported in randomised clinical trials of major depressive disorder treatments in adolescents: a systematic scoping review protocol
Authors: Monsour Andrea , Mew Emma J , Szatmari Peter , Patel Sagar , Saeed Leena , Offringa Martin , Butcher Nancy J 
Published: January 2019

IntroductionMajor depressive disorder (MDD) is a common mental health condition in adolescents. Randomised clinical trials (RCTs) are the gold standard for assessing the safety and efficacy of interventions in this population. Heterogeneity in the outcomes measured and reported between RCTs limits the ability to compare, contrast, and combine trial results in a clinically meaningful way. There is currently no core outcome set (COS) available for use in RCTs evaluating interventions in adolescents with MDD. We will conduct a systematic scoping review of outcomes reported in adolescent depression RCTs to assess the variability of trial outcomes and to inform the development of a COS for adolescent MDD.Methods and analysisWe will apply methods based on the Joanna Briggs Institute scoping review methods manual. RCTs evaluating any treatment intervention for adolescent MDD published in the last 10 years will be located using an electronic bibliographic database search (MEDLINE, PsycINFO and Cochrane Central Register of Controlled Trials). Title and abstract screening, full-text screening, and data charting of eligible studies will be performed in duplicate. Outcomes identified will be mapped to an outcome-domain framework. Data analysis will include summary statistics of the characteristics of the included trials and outcomes.Ethics and disseminationThe results of this review will inform the development of a COS for adolescent MDD. The development and implementation of a COS for RCTs evaluating interventions in adolescents with MDD promise to help reduce variability in trial outcome selection, definition, measurement and reporting, ultimately facilitating evidence synthesis that will help to identify the best treatment practices for adolescents with MDD.