bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lubricants condition monitoring by using a global performance passport
Authors: Radulescu I , Radulescu A V 
Published: January 2020

Abstract
Lubricants degradation processes are characterized by the physical and chemical indicators changes for oils composition, caused by internal and external factors and the operating conditions severity. Lubricants condition monitoring involves experimental methods to study their behaviour, for developing a lubricants life cycle assessment methodology. The paper proposes the lubricants behaviour complete characterization by using a global performance passport, to study the rheological, tribological and microscopic properties, for various wear stages. The global rheological lubricant feature is expressed by the maximum film pressure, by using the original rheological experimental module. The reference rheological lubricant feature is obtained by using the viscometer validation module, based on the variation of viscosity by the temperature. The tribological lubricant feature is given by the tribological experimental module, based on friction coefficient variation according to the normal pressing force and sliding speed. The structural microscopic lubricant feature is shown by the wear particles analysis module, analysing the solid particles type identified in the fresh and worn lubricant. The global performance lubricants passport assess the lifetime reserve, function the specific use conditions, to reduce operating costs. To do the initial investment for the preliminary experimental tests conduct it is recommended to determine the economic profitability threshold for the user investment.
A simple analytical model for an elastohydrostatic thrust bearing
Authors: Cicone T , Marinescu A A , Sorohan S 
Published: January 2020

Abstract
A new design of an elastohydrostatic bearing with a structurally elastic pad is theoretically analyzed. A single recess circular thrust bearing has the upper pad provided with a large cavity, covered with an elastic metallic membrane. The latter deflects under the pressure distribution in the bearing, creating a radial convergent gap. A simplified axi-symmetric analytical model based on two assumptions is proposed: (i) parabolic approximation for the elastic component of the film thickness and (ii) the maximum elastic deformation of the membrane is calculated analytically using a simplified linear pressure variation in radial direction on the land. Thus, the coupled equations for fluid film and elastic deformation can be solved successively and the bearing performance characteristics can be easily calculated. A parametric analysis, function of a complex elastic parameter and relative recess radius was performed, showing higher load capacity and lower friction similarly to what was previously obtained using rubber-based compliant bearings. A first stage of validation of the analytical model consisted in using a structural finite element model. For the sake of simplicity, the pressure distribution was written in an APDL code using the ANSYS program. The comparison showed small differences for typical values of the recess radius.
Evaluation of inertia effects in planar squeeze flow inside soft, porous layers
Authors: Lupu G , Turtoi P , Cicone T 
Published: January 2020

Abstract
The resistance to flow of a fluid squeezed out from a soft and porous structure under compression, generates high load capacity. The process is dependent on permeability, which is variable during compression of the porous layer. This mechanism (named Ex-Poro-Hydrodynamic Lubrication – XPHD) plays an important role in a wide range of tribological applications (biolubrication, shock absorbers, etc.). A literature search reveals that Darcy’s law is intensively used for modeling flow through porous media. However, for high porosity materials and relatively high velocity flows that may occur during impact, the inertia effects could be significant. The full squeeze solution of high velocity flow inside deformable porous materials including inertia effects and permeability variation with the level of compression could not be found in the literature. A numerical study for planar squeeze flow of a Newtonian liquid inside a soft porous layer, based on the Darcy flow model including Forchheimer correction, is presented in this paper. The porous material is compressed at high speed between two perfectly rigid, parallel and impermeable discs. Finite differences technique is used to solve the system of equations. Pressure distribution, load and Reynolds pore based number variation during compression are obtained and compared with similar values predicted by simple analytical models based on Darcy law. The results define the limits of Darcy approach in XPHD lubrication.
Some considerations about the effect of grooves on the viscous coupling performances
Authors: Stoicescu A I , Predescu A , Gâtu V 
Published: January 2020

Abstract
A viscous coupling transmits torque by viscous shearing of the oil film between one or multiple pairs of discs that are in relative motion one to the other. A viscous coupling uses a viscous fluid as a working medium and performs best in full film lubrication condition. A continuous film of oil must be present at all times between the two surfaces that are in relative motion. Only in this stage, when operating in full film lubrication condition, this coupling can achieve the maximum transmission of torque. This kind of study is of a great importance since this coupling is widely used all around the world in all sorts of applications. In this paper, the effect of grooves on the viscous coupling performances was carried out deeply using a Computational Fluid Dynamics Software. The flow of the fluid film and shear torque between the friction pair are complex and keep changing with the operating conditions, the geometry, the number of grooves, the properties of the working oil and the thickness of the oil film.
Standardization in testing ballistic protection systems
Authors: Ojoc G G , Pirvu C , Sandu S , Deleanu L 
Published: January 2020

Abstract
Even more than in other field of activities, standardization in ballistic protection is in trends of CEN/CENELEC declaration that “standards build trust”, promoting innovation and introduction of new, performant solutions based on test procedures and protocols that are able to point out quality and safety for such systems. Ballistic testing standards have particular specifications for ballistic materials, differentiation of tests being made especially on the purpose of the ballistic protection product. In the last decades, test methods have been refined and measurement devices have become more complex. The main set of standards is developed by military organizations (as NATO), highly industrialized countries, where the military and research in the field are priorities (USA, European Community, Asian countries, South Africa). Some states refer to American standards by using them as guides. Depending on the destination of the ballistic product, specifications in standards are different. The authors give examples of how standards requirements are implemented in testing ballistic protection systems, in order to point out the particularities of introducing and verifying new and classical products in this domain. Generally, the results of the ballistic tests are evaluated by acceptance or rejecting the tested product, based on specific criteria, included in standards.
A survey of Mechanical failure and design for Reliability of MEMS
Authors: Somà A 
Published: January 2020

Abstract
In this paper, several experimental mechanical investigation techniques are presented to evaluate the reliability of micro-electro-mechanical systems (MEMS). Microsystems in recent years have spread in many everyday devices. We find micro-scale sensors and actuators in automotive, biomedical and aerospace applications where are demanded very strict performance requirements. Electromechanical non-linear coupling is often a crucial problem both in design and also for the reliability of the system. Mechanism of failure and failure modes has to be taken into account in order to evaluate the reliability of the final system. Focusing on device failure, it emerges that mechanical damage is the most significant source. In this paper a survey of recent advance in mechanical testing of MEMS is presented including: mechanical fatigue, mechanical strength and plasticity, surface and contact failure and creep. Different design of testing specimens is discussed to identify the material properties and failure modes behavior in order to obtain design rules and strategies.
Validation of professional tooth brushing test device, test methodology and analysis
Authors: Achimescu B M , Ciortan S , Buciumeanu M 
Published: January 2020

Abstract
The present work is focused on developing a test apparatus to simulate the contact situation of the toothbrush used in professional toothbrushing (cleaning and polishing) and a dental biomaterial. Cylindrical samples (8×5 mm) were manufactured from a resin composite (frequently used in practice) in similar manner with the preparation of dental restorations in clinical conditions. The tests were carried by using two different toothpastes: a professional toothpaste and a home used toothpaste. All the experiments were carried out for 15 min, under 280 g normal load applied on the brush and the operating speed was around 5000 rev/min. The preliminary results on the dental restorative material selected for this study indicated that the proposed system is consistent and useful for the investigation of the microabrasion processes that arise at the surface of dental biomaterials.
Fretting manifestations in total hip prosthesis
Authors: Capitanu L , Badita L L , Florescu V , Tiganesteanu C , Isvoranu L F 
Published: January 2020

Abstract
This paper analyses the fretting and fretting wear phenomena to the classical and modular hip prostheses. Theoretical and experimental manifestations are studied, at the interface of the femoral stem with the bone cement mantle, at the taper junction between the femoral stem and the femoral head of the prosthesis, as well as at the tapering of the femoral neck adapter’s connections with the stem and the femoral head. The aim of the paper is to highlight the modularization implications of the femoral component of the Total Hip Prosthesis, especially its tribological implications (fretting wear of modular junctions, fatigue and corrosion by fretting) which can contribute to wear and increasing ion concentrations of the metal in the blood, and the possibility of the femoral shaft fracture at the femoral head junction. Theoretical approach described, allows the “Archard” law implementation to predict the fretting wear. Experimental laboratory studies focused on the analysis of the tribological phenomena occurring at the taper junctions between the femoral head and neck, as well as the neck and femoral stem, highlighting the relevant qualitative tribological aspects. For this purpose, experimental junctions were fabricated and tested on a universal MTS mechanical machine, equipped with a fatigue testing device.
Dynamic and tribological contact study for human fingertips at very low speeds
Authors: Călin A , Tudor A , Stoica M , Stoica N , Subhi K 
Published: January 2020

Abstract
Nonlinear elastic models have been widely used to describe the mechanical behaviour of complex materials such as skin. The subject of skin modelling is fairly new and of great importance to fields such as robotics and the development of skin-like materials to orthopaedics and prosthetics. The present article serves to add to the findings of previous authors and present experimental values gathered using the “Stick-Slip Experimental Stand” within the Machine Elements and Tribology Department on the tribological aspects regarding friction at very low speeds. The scope of this article is to evaluate the static and kinetic friction coefficients of the human skin in contact with different materials. A total of 5 different materials were tested to find the static and kinetic friction coefficient. The tested materials were steel, bronze, and 3 types of materials found on the inside of working gloves in direct contact with human skin: leather (bovine origin) and 2 types of textiles (cotton and nylon). All tests were performed at 1.8 mm/min, with an initial load of 7.5 Newton and a test time of 1000 seconds. The total distance evaluated was 9.25 mm.
Effect of microstructure on wear behaviour of aluminium 2014 (Al2014)
Authors: Bhaumik S , Paleu V , Chowdhury D , Cîrlan Paleu C , Datta S 
Published: January 2020

Abstract
The paper investigates the effect of ageing on the hardness and wearing of Al2014. Precipitation hardening and ageing were carried out on the samples. The samples were solution treated at 550°C and were naturally aged. Quenching was carried out using ice-brine solution. Vickers Hardness were taken at regular intervals till 900 hours. The peak hardness value of the natural aged sample was found to be 86HV (93 hours) as compared to the untreated sample (32.4HV) The wear tests were conducted at 10N, 500rpm for 30 minutes. After the tribo test it was observed that the coefficient of friction increased by 7.06% in the naturally aged sample, but the wear rate in case of as-received samples was 46% higher than that of the naturally aged sample. The change in the microstructure of Al2014 is the primary reason for the difference in wear rate of the samples. The present work will help to understand the influence of heat treatment of aluminium alloy on wear properties.
Temperature influence on mechanical properties of chromium nitride thin films
Authors: şerdean F M , Merie V V , Negrea G , Bîrleanu C , Mărieş I 
Published: January 2020

Abstract
Thin films present interest for researchers due to their applicability in areas such as developing microelecromechanical devices, hard coatings, cutting tools and diffusion barriers. This paper is focused on studying the influence of the testing temperature on the mechanical properties of chromium nitride (CrN) thin films. For this purpose, CrN thin films were deposited by direct current magnetron sputtering on silicon substrate using a chromium target of high purity. All the films were obtained by keeping almost all deposition parameters constant, while the nitrogen flow rate was varied. Hence, three types of samples of CrN thin films were obtained using different nitrogen flow rates namely 2 cm3/min, 4 cm3/min and 6 cm3/min. The mechanical properties of these thin films such as the hardness and Young’s modulus were investigated by performing nanoindentation using an atomic force microscope. All experimental investigations were conducted by varying the testing temperature between 20 oC and 100 oC. The purpose was to find the dependency between the testing temperature and the mechanical properties of CrN films deposited at different nitrogen flow rates. The obtained experimental results indicate a significant influence of the testing temperature on the properties of the studied CrN thin films.
Patient Engagement With an Automated Telephone Symptom Management Intervention: Predictors and Outcomes
Authors: Sikorskii Alla , Given Charles W , Given Barbara A , Banik Asish , Krauss John C 
Published: January 2020

Abstract

Background
Self-management of symptoms related to cancer and its treatment is important for maintaining treatment regimens and improving outcomes.

Purpose
To determine factors associated with engagement in a symptom self-management intervention among patients initiating oral anticancer treatment.

Methods
This secondary analysis included 127 patients randomized to the medication adherence reminder and symptom management intervention in a recently completed trial. Patients were recruited from six Comprehensive Cancer Centers, interviewed at intake, and mailed a Symptom Management Toolkit (Toolkit) with self-care management strategies for 18 symptoms. During eight automated telephone weekly calls, patients were asked to use the Toolkit to manage elevated symptoms. Toolkit use and symptoms were tracked weekly, and generalized linear mixed-effects models were used to determine factors predictive of Toolkit use. General linear modeling was used to relate the Toolkit use during intervention to postintervention symptom severity.

Results
Better cognitive function at intake into the trial and higher symptom burden were predictive of the patients’ initial decision to try the Toolkit during Week 1. In subsequent weeks, Toolkit use in the previous week and worsening of symptoms were associated with greater odds of Toolkit use. The extent of Toolkit use modified the relationship between intake and 8 week symptom severity: among patients with higher levels of severity at intake, use of the Toolkit conferred greater benefit at 8 weeks.

Conclusions
Patients make realistic decisions regarding when to use a self-directed approach to self-management and are likely to use strategies when their symptoms are higher and to forego use once symptoms subside.

Clinical Trial Registration
NCT02043184.
Adolescents’ Depressive Symptom Experience Mediates the Impact of Long-Term Exposure to Maternal Depression Symptoms on Adolescents’ Body Mass Index
Authors: Cordola Hsu Amber R , Niu Zhongzheng , Lei Xiaomeng , Kiresich Emily , Li Yawen , Hwang Wei-Chin , Xie Bin 
Published: January 2020

Abstract

Background
Obesity is a cardiovascular disease risk factor and affects approximately 13.7 million U.S. children and adolescents between the ages 2 and 19 years old in 2015–2016.

Purpose
To determine the relationship between children’s average long-term exposure to maternal depressive symptoms age 1 month to Grade 6 and adolescents’ body mass index (BMI) z-score at age 15 mediated by the adolescents’ depressive symptom experience.

Methods
A total of 1,364 infants and their families from the Eunice Kennedy Shriver National Institute of Child Health and Human Development Study of Early Child Care and Youth Development were recruited.

Results
Mediation analyses revealed a significant relationship between children’s average long-term exposure to maternal depressive symptoms from age 1 month to Grade 6 and adolescents’ BMI z-score at age 15 (total effect = 0.015, p = .013, 95% confidence interval (CI): 0.0032, 0.027). The adolescents’ experience of depressive symptoms significantly mediated this relationship (indirect effect = 0.0021, bias-corrected bootstrapped 95% CI: 0.0004, 0.0044), with this mediated relationship more pronounced in girls.

Conclusions
Findings indicate the possible existence of a mediating role of adolescents’ depressive symptoms experience in the pathway from average long-term exposure to maternal depressive symptoms during children’s early life to adolescents’ elevated BMI.
Simulating trees with millions of species
Authors: Louca Stilianos 
Published: January 2020

Abstract

Motivation
The birth-death (BD) model constitutes the theoretical backbone of most phylogenetic tools for reconstructing speciation/extinction dynamics over time. Performing simulations of reconstructed trees (linking extant taxa) under the BD model in backward time, conditioned on the number of species sampled at present day and, in some cases, a specific time interval since the most recent common ancestor (MRCA), is needed for assessing the performance of reconstruction tools, for parametric bootstrapping and for detecting data outliers. The few simulation tools that exist scale poorly to large modern phylogenies, which can comprise thousands or even millions of tips (and rising).

Results
Here I present efficient software for simulating reconstructed phylogenies under time-dependent BD models in backward time, conditioned on the number of sampled species and (optionally) on the time since the MRCA. On large trees, my software is 1000–10 000 times faster than existing tools.

Availability and implementation
The presented software is incorporated into the R package ‘castor’, which is available on The Comprehensive R Archive Network (CRAN).

Supplementary information
Supplementary data are available at Bioinformatics online.
Monotherapy efficacy of blood–brain barrier permeable small molecule reactivators of protein phosphatase 2A in glioblastoma
Authors: Merisaari Joni , Denisova Oxana V , Doroszko Milena , Le Joncour Vadim , Johansson Patrik , Leenders William P J , Kastrinsky David B , Zaware Nilesh , Narla Goutham , Laakkonen Pirjo , Nelander Sven , Ohlmeyer Michael , Westermarck Jukka 
Published: January 2020

Abstract
Glioblastoma is a fatal disease in which most targeted therapies have clinically failed. However, pharmacological reactivation of tumour suppressors has not been thoroughly studied as yet as a glioblastoma therapeutic strategy. Tumour suppressor protein phosphatase 2A is inhibited by non-genetic mechanisms in glioblastoma, and thus, it would be potentially amendable for therapeutic reactivation. Here, we demonstrate that small molecule activators of protein phosphatase 2A, NZ-8-061 and DBK-1154, effectively cross the in vitro model of blood–brain barrier, and in vivo partition to mouse brain tissue after oral dosing. In vitro, small molecule activators of protein phosphatase 2A exhibit robust cell-killing activity against five established glioblastoma cell lines, and nine patient-derived primary glioma cell lines. Collectively, these cell lines have heterogeneous genetic background, kinase inhibitor resistance profile and stemness properties; and they represent different clinical glioblastoma subtypes. Moreover, small molecule activators of protein phosphatase 2A were found to be superior to a range of kinase inhibitors in their capacity to kill patient-derived primary glioma cells. Oral dosing of either of the small molecule activators of protein phosphatase 2A significantly reduced growth of infiltrative intracranial glioblastoma tumours. DBK-1154, with both higher degree of brain/blood distribution, and more potent in vitro activity against all tested glioblastoma cell lines, also significantly increased survival of mice bearing orthotopic glioblastoma xenografts. In summary, this report presents a proof-of-principle data for blood–brain barrier—permeable tumour suppressor reactivation therapy for glioblastoma cells of heterogenous molecular background. These results also provide the first indications that protein phosphatase 2A reactivation might be able to challenge the current paradigm in glioblastoma therapies which has been strongly focused on targeting specific genetically altered cancer drivers with highly specific inhibitors. Based on demonstrated role for protein phosphatase 2A inhibition in glioblastoma cell drug resistance, small molecule activators of protein phosphatase 2A may prove to be beneficial in future glioblastoma combination therapies.
Treatment of Latent Tuberculosis Infection Based on the Interferon-γ Release Assay in Allogeneic Stem Cell Transplant Recipients
Authors: Park Joung Ha , Choi Eun-Ji , Park Han-Seung , Choi Sang-Ho , Lee Sang-Oh , Kim Yang Soo , Woo Jun Hee , Lee Jung-Hee , Lee Je-Hwan , Lee Kyoo-Hyung , Shim Tae Sun , Kim Sung-Han 
Published: January 2020

Abstract
In hematopoietic stem cell transplant recipients, the incidence of tuberculosis in positive interferon-γ release assay (IGRA) without isoniazid prophylaxis (3.58/100 person-years) was higher than in negative or indeterminate IGRA (1.15/100 person-years; P = .01) and in positive IGRA with isoniazid prophylaxis (0/100 person-years; P = .09). The number needed to treat was 22 (95% confidence interval, 12–99) with positive IGRA results.