bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of Single Flank Test Results Providing Topography Errors of Spiral Bevel Gears
Authors: Jerabek Filip , Szánti Gábor , Torvinen Seppo 
Published: December 2020

Abstract
A method for analyzing single flank test results is proposed. The analysis yields geometrical deviations of spiral bevel gears. It is based on extracting information on the meshing tooth surfaces from the transmission error curve and digital photograph of the contact pattern. A neural network is trained by a batch of computer simulated transmission error curves and respective contact patterns belonging to systematically varied geometrical deviations. Taking advantage of the generalization capability of the neural network, it can be used to yield tooth flank topography errors on the basis of single flank test measuring results. Giving similar results to coordinate measurement, the method extends the capabilities of single flank test significantly. It saves costly coordinate measuring time, which may be especially advantageous in case of large bevel gears. It takes only minor changes for the analysis to be applicable for any types of gears.
Load Distribution in Cylindrical Worm Gears
Authors: Simon Vilmos V. 
Published: December 2020

Abstract
A method for the determination of load sharing between the instantaneously engaged worm threads and gear teeth, for the calculation of load distribution along the teeth and transmission errors in different types of cylindrical worm gears is presented. The method covers both cases — that of the theoretical line and point contact. The bending and shearing deflections of worm thread and gear tooth, the local contact deformations of the mating surfaces, the axial deformations of worm body, gear body bending and torsion, deflections of the supporting shafts, and the manufacturing and alignment errors of worm and gear are included. Based on the real load distribution the tooth contact pressure is calculated, in the case of point contact in two different ways, and the obtained results are compared. Also, the total transmission error, consisting of the kinematical transmission error due to the mismatch of the worm gear drive and of the transmission error caused by the deflections of worm thread and gear teeth, is calculated. The method is implemented by a computer program. By using this program the influence of the type of worm gear drive and of design and manufacturing parameters on load distribution and transmission errors is investigated and discussed.
Steady Power Continuously Variable Speed Traction Drive
Authors: Cretu Ovidiu 
Published: December 2020

Abstract
An original continuously variable speed traction drive (variator) is presented. The device is capable of automatically adjusting the transmission ratio according to the value of torque delivered. The device is able to control and sustain a steady power transmitted. A study of the transmission ratio and of the power transmitted by the device is performed using the “Mathematica 4.0”.
The results of the study show that the device can be designed for a large range of power transmitted, making it suitable to be incorporated into the automobile’s power train. The complex geometric configuration generated by simple geometric shapes offers a great potential for optimization for different applications.
A Study on Jumping Characteristics in Synchronous Belt Drives
Authors: Koyama Tomio , Zhang Weiming , Kagotani Masanori 
Published: December 2020

Abstract
The jumping characteristics at the driven pulley of synchronous belt drives are experimentally discussed. The jumping of synchronous belt occurs when the elongation of free span of the belt is over than a certain value. In this paper, an empirical formula for the jumping torque of L type synchronous belt is presented. The following parameters are considered in the empirical formula: tensile stiffness of belt, height of belt tooth, coefficient of traction, belt installation tension, wrapping angle of belt, diameter of pulley pitch circle, bending stiffness of shaft.
Transmission Error Analysis of Helical Gears for Any Load Condition: Practical Calculation Program for Windows PC and Application
Authors: Saiki Kouhei , Watanabe Takeshi 
Published: December 2020

Abstract
Recently, the gear noise reduction of car transmission, especially for light load condition, is of increasing importance due to the unsparing needs of silence. Since the transmission error is the exciting source of gear noise, the purpose of this study, is to establish an effective method to analyze the transmission error of helical gears with any 3-D tooth surface cutting error for any load condition including light load. The shaft misalignment due to the assembly errors, and the variable shaft deflection caused by the transmitted torque, are also considered.
This paper introduces an exact transmission error analysis method of helical gears, in consideration of the nonlinear tooth separation phenomenon at light load condition. As a result, a practical program for Windows personal computer to calculate the transmission error, is also developed. By using this program, the gear designer can find the optimum shape of tooth surface, and the gear producer can evaluate the quality of his manufactured gears.
For confirming the proposed analysis method and the calculation program, the tooth contact pattern of several gear pairs are measured and compared with the calculated result. Especially, it is clarified that the transmission performance of the helicoid bias-in tooth surface modification is better than that of the helicoid bias-out tooth surface modification.
Development of an Analytical Model for the Static and Dynamic Transmission Error Calculation: Validation on a Single Vehicle Gear Vibration Test Bench
Authors: Cricenti Fabrizio , Lang Claus-Hermann , Paradiso Domenico 
Published: December 2020

Abstract
Automotive companies are being challenged when they seek to guarantee very high quality and reliability levels for their products. Customers may complain about comfort and various other concerns such as noise generated by a certain component. Analytical, numerical simulation and testing are used to understand how certain modifications to the product can affect the excited noise level.
This paper presents an analytical approach used in order to predict noise levels coming from an engaged vehicle gear pair. This is done by evaluating the static and dynamic transmission error with load distribution on the teeth engaged for the different values of micro-geometric teeth modifications. Comparing the analytical and experimental results shows that both factors can be extremely linked with noise generated by two mating gears.
Study of Transient Response of a Gear Train Under Pulsating Torque
Authors: Zhang Q. John , Rescigno Jerry 
Published: December 2020

Abstract
This paper studied the transient response of a single reduction gear train under a pulsating torque. A 4-DOF model has been used to estimate the impact load on the gear teeth. The system equations are solved under different gear backlash, inertia, stiffness and gear ratio conditions. The sensitivities of impact load versus these parameters have been summarized. The nonlinear behavior of the impact force changing from period to random due to the torque drop is investigated. Angular velocity test verified the power input curve. Angular acceleration and lock-rotor tests show the agreement between the model simulation and experimental result.
The Effect of Gating and Material on Measured Transmission Error and Noise of Injection Molded Gears
Authors: Snow Chris , Houser Donald R. , Luscher Anthony F. 
Published: December 2020

Abstract
The use of plastic gears is expanding in many different markets. Their application is cost-effective when produced on a large scale using a net-shape process such as injection molding. However, variables in the molding process have a direct impact on final gear geometry. In this paper gears molded out of three different polymeric materials using three different gating configurations are used to show the effect of gating on runout, transmission error, and noise. The runout characteristics directly affect long-term transmission error and act to create side banding about the mesh harmonics in the frequency spectrum in both transmission error and noise signals. Additionally, load and speed effects on the gear noise are verified, and gear noise levels for different materials are compared.
Design and Testing of a Compliant Floating-Opposing-Arm (FOA) Centrifugal Clutch
Authors: Crane Nathan B. , Howell Larry L. , Weight Brent L. 
Published: December 2020

Abstract
A floating-opposing-arm (FOA) centrifugal clutch is presented that uses compliant segments to reduce the part count and increase manufacturability. The clutch performs all of the functions of a centrifugal clutch, but consists of only two pieces. Torque is increased by connecting aggressive and non-aggressive contact surfaces in connected pairs. This arrangement increases the torque output of the FOA clutch by over 100% relative to a commercial one-piece compliant centrifugal clutch design of the same size and material. Yet, since this design is compliant, it remains simple to manufacture. This clutch is presented and modeled using the pseudo-rigid-body-model (PRBM) technique. The model predictions are compared to test data from five prototypes. The FOA clutch is also demonstrated in a gasoline-powered string trimmer.
Shakedown Analysis of a Finite Plate With Single Edge Notch Under Uniaxial Tension
Authors: Attia M. S. , Abdel-Karim M. , Megahed M. M. 
Published: December 2020

Abstract
In this paper, the shakedown load factor for a finite rectangular plate with a single edge notch at its mid-length is evaluated by a number of numerical and analytical techniques. These techniques include full elasto-plastic finite element solution coupled with line search technique and an iterative elastic technique known as the elastic compensation method which relies on successive reduction of elastic modulus in regions where elastic stresses exceed yield strength. In addition, an analytical technique proposed recently in the literature, which relies on a gradient optimization technique is employed. The shakedown load factor values obtained through different solution techniques are compared. The comparison showed discrepancies between literature solutions and the solutions presented herein. The reasons behind this discrepancy are scrutinized and certain recommendations are made to ensure validity of shakedown solutions.
Effects of multisession transcranial direct current stimulation as an augmentation to cognitive tasks in patients with neurocognitive disorders in Japan: a study protocol for a randomised controlled trial
Authors: Inagawa Takuma , Yokoi Yuma , Yamada Yuji , Miyagawa Nozomi , Otsuka Takeshi , Yasuma Naonori , Omachi Yoshie , Tsukamoto Tadashi , Takano Harumasa , Sakata Masuhiro , Maruo Kazushi , Matsui Mie , Nakagome Kazuyuki 
Published: December 2020

IntroductionTranscranial direct current stimulation (tDCS) is a potentially novel strategy for cognitive enhancement in patients with disorders. We present a study protocol for a randomised controlled trial designed to evaluate the safety and efficacy of tDCS combined with cognitive tasks on cognition in such patients.Method and analysisThis is a two-arm, parallel-design, randomised, sham-controlled trial, in which participants and raters will be blinded at a single centre. Stratified randomisation will be conducted, and a randomisation sequence will be generated through the Electronic Data Capture system. Patients who met the Diagnostic and Statistical Manual of Mental Disorders-5 criteria for neurocognitive disorders will be recruited and randomised to receive either active (2 mA for 20 min) or sham (stimulation ramped up and down for 1 min) stimulation in 10 sessions over five consecutive days. A direct current will be transferred by a 35 cm2 saline-soaked sponge electrode. An anode will be placed over the left dorsolateral prefrontal cortex, and a cathode will be placed over the right supraorbital cortex. Calculation tasks will be conducted in both arms as a cognitive task for 20 min during the stimulation. This task consists of basic arithmetic questions, such as single-digit addition, subtraction, multiplication and division. The primary outcome will be the mean change in the Alzheimer Disease Assessment Scale–cognition at Day 5 after baseline. Depressive symptoms, as measured by the geriatric depression scale, and quality of life, as measured by the Medical Outcomes Study 36-item Short-Form Health Survey, will also be assessed. Data will be collected at baseline, within 3 days following the final stimulation and 1 month thereafter. The estimated sample size is 46 per group based on the assumptions that an estimated mean difference is −1.61 and SD is 2.7. Mixed models for repeated measures will be used for the statistical analysis.Ethics and disseminationThe National Center of Neurology and the Psychiatry Clinical Research Review Board (CRB3180006) approved this study. The results of this study will be published in a scientific peer-reviewed journal.Trial registration detailsJapan Registry of Clinical Trials jRCTs032180016.
Role of contextual and compositional characteristics of schools for health inequalities in childhood and adolescence: protocol for a scoping review
Authors: Herke Max , Moor Irene , Winter Kristina , Hoffmann Stephanie , Spallek Jacob , Hilger-Kolb Jennifer , Pischke Claudia , Dragano Nico , Novelli Anna , Richter Matthias 
Published: December 2020

IntroductionChildhood and adolescence are crucial life stages for health trajectories and the development of health inequalities in later life. The relevance of schools for health and well-being of children and adolescents has long been recognised, and there is some research regarding the association of contextual and compositional characteristics of schools and classes with health, health behaviour and well-being in this population. Little is known about the role of meso-level characteristics in relation to health inequalities. The aim of this scoping review is to retrieve and synthesise evidence about the mediating or moderating role of compositional or contextual characteristics of schools for the association between students’ socioeconomic position and health in primary and secondary education.Methods and analysisWe will conduct a systematic search of electronic databases in PubMed/Medline, Web of Science and Education Resources Information Center. Studies must meet the following inclusion criteria: (1) The population must be students attending primary or secondary schools in developed economies. (2) The outcomes must include at least one indicator for individual health, health behaviour or well-being. (3) The study must include at least one contextual or compositional characteristic of the school context and one individual determinant of socioeconomic position. (4) The study must also examine the mediating or moderating role of the contextual or compositional characteristic of the school context for the associations between socioeconomic position and health, health behaviour or well-being. (5) The study must be published since 1 January 2000 in English or German language. We will provide a narrative synthesis of findings.Ethics and disseminationWe will not collect primary data and only include secondary data derived from previously published studies. Therefore, ethical approval is not required. We intend to publish our findings in an international peer-reviewed journal and to present them at national and international conferences.
Whole exome HBV DNA integration is independent of the intrahepatic HBV reservoir in HBeAg-negative chronic hepatitis B
Authors: Svicher Valentina , Salpini Romina , Piermatteo Lorenzo , Carioti Luca , Battisti Arianna , Colagrossi Luna , Scutari Rossana , Surdo Matteo , Cacciafesta Valeria , Nuccitelli Andrea , Hansi Navjyot , Ceccherini Silberstein Francesca , Perno Carlo Federico , Gill Upkar S , Kennedy Patrick T F 
Published: December 2020

ObjectiveThe involvement of HBV DNA integration in promoting hepatocarcinogenesis and the extent to which the intrahepatic HBV reservoir modulates liver disease progression remains poorly understood. We examined the intrahepatic HBV reservoir, the occurrence of HBV DNA integration and its impact on the hepatocyte transcriptome in hepatitis B ‘e’ antigen (HBeAg)-negative chronic hepatitis B (CHB).DesignLiver tissue from 84 HBeAg-negative patients with CHB with low (n=12), moderate (n=25) and high (n=47) serum HBV DNA was analysed. Covalently closed circular DNA (cccDNA), pregenomic RNA (pgRNA) were evaluated by quantitative PCR, whole exome and transcriptome sequencing was performed by Illumina, and the burden of HBV DNA integrations was evaluated by digital droplet PCR.ResultsPatients with low and moderate serum HBV DNA displayed comparable intrahepatic cccDNA and pgRNA, significantly lower than in patients with high HBV DNA, while hepatitis B core-related antigen correlated strongly with the intrahepatic HBV reservoir, reflecting cccDNA quantity. Whole exome integration was detected in a significant number of patients (55.6%, 14.3% and 25% in high, moderate and low viraemic patients, respectively), at a frequency ranging from 0.5 to 157 integrations/1000 hepatocytes. Hepatitis B surface antigen >5000 IU/mL predicted integration within the exome and these integrations localised in genes involved in hepatocarcinogenesis, regulation of lipid/drug metabolism and antiviral/inflammatory responses. Transcript levels of specific genes, including the proto-oncogene hRAS, were higher in patients with HBV DNA integration, supporting an underlying oncogenic risk in patients with low-level to moderate-level viraemia.ConclusionsHBV DNA integration occurs across all HBeAg-negative patients with CHB, including those with a limited HBV reservoir; localising in genes involved in carcinogenesis and altering the hepatocyte transcriptome.
Frequent police stops, parental incarceration and mental health: results among US non-Hispanic Black and White adolescent girls and boys
Authors: Jahn Jaquelyn L , Agenor Madina , Chen Jarvis T , Krieger Nancy 
Published: December 2020

BackgroundNational monitoring of police–public contact does not extend below age 16 and few studies have examined associations with adolescent mental health.MethodsWe describe the distribution of police stops in a nationally representative cross-sectional sample of adolescents ages 12 to 18 years in the Panel Study of Income Dynamics Child Development Supplement 2002 and 2007 (n=2557). We used survey-weighted race/ethnicity-stratified and gender-stratified regression models to examine associations between the frequency of police stops and both depressive symptoms and subjective well-being (emotional, psychological and social). We adjusted for several socioeconomic covariates and evaluated effect modification by parental incarceration.ResultsWe estimated that 9.58% of adolescents were stopped two or more times. Despite fewer police stops compared with boys, Black and White girls who were stopped at least two times in the last 6 months had higher average depression scores relative to girls who were not stopped (Black: 2.13 (95% CI: 0.73 to 3.53), White: 2.17 (95% CI: 1.07 to 3.27)) and these associations were stronger among girls whose parents had been incarcerated. Police stops were significantly associated with higher depressive scores for White, but not Black, boys (2+ vs 0 stops: White: 1.33 (95% CI: 0.31 to 2.36, Black: 0.53 (95% CI: –0.28 to 1.34)). Associations between subjective well-being and police stops were stronger among non-Hispanic Black relative to White girls, whereas for boys, associations varied across subjective well-being subscales.ConclusionNational monitoring data and public health research should examine adolescent police contact at younger ages stratified by both race/ethnicity and gender in order to better understand its relationship with adolescent mental health.
HPV16 and HPV18 seropositivity and DNA detection among men who have sex with men: a cross-sectional study conducted in a sexual health clinic in London
Authors: King Eleanor M , Mesher David , Sonnenberg Pam , Linley Ezra , Panwar Kavita , Beddows Simon , Soldan Kate , Borrow Ray , Jit Mark , Gilson Richard 
Published: December 2020

ObjectivesMen who have sex with men (MSM) have an increased risk of human papillomavirus (HPV) infection and related diseases compared with men who have sex exclusively with women. From April 2018, there has been a phased roll-out of HPV vaccination offered to MSM aged up to 45 years old who are attending sexual health clinics and HIV clinics in England. The vaccine is most effective if delivered prior to HPV infection. We estimated the proportion of MSM with no current vaccine-type infection and no serological evidence of prior infection, in a study undertaken prior to vaccine introduction.MethodsWe conducted a cross-sectional study among 484 MSM aged 18–40 years old who attended a sexual health clinic in London between 2010 and 2012. We estimated the prevalence of current and past infection by testing for HPV DNA in anogenital samples and for serum antibodies to HPV16 and HPV18.ResultsThe median age was 30 years (IQR 25–35). The prevalence of HPV16 and HPV18 DNA was 13.2% and 6.2%, respectively. Seropositivity for HPV16 and HPV18 was 28.5% and 17.1%, respectively, with 11.4% seropositive for both types. Seropositivity for the same HPV type was strongly associated with anogenital DNA detection. 279 MSM (57.6%) tested negative for both HPV16 and HPV18 serology and were DNA negative for these two types; only 5 MSM (1.0%) were seropositive and DNA positive for both HPV types.ConclusionsThis is the first study to determine both the prevalence of HPV DNA in anogenital samples and HPV seroprevalence among MSM attending a sexual health clinic in the UK. Over half of MSM in this study had no evidence of a previous or current infection with either of the high-risk HPV types included in the quadrivalent vaccine, which supports the rationale for opportunistic HPV vaccination of MSM attending sexual health clinics.