Effects of oxide and water on friction of rail steel – new test method and friction mapping

A novel tribo-testing method using a pin-on-plate tribometer was developed to test and visualise the coefficient of friction over surfaces with oxides present to examine low adhesion issues. Tribo-test data was recorded each pass over test surfaces showing how friction changes with mechanical action. Trackside environmental monitoring and railhead swabbing was performed to investigate the physical and chemical environment of the railhead. Iron oxides were both synthesised on and deposited on rail steel substrates to simulate “wet-rail” conditions. Powdered oxide layers of magnetite, haematite, goethite and lepidocrocite were deposited on rail steel substrates to investigate individual oxides. Composition was analysed using x-ray diffraction and scanning electron microscopy before testing. Magnetite, Haematite and Lepidocrocite were formed when water alone was applied to the surfaces. Low friction was observed on oxidised sample surfaces only outside high roughness, oxide pitted, areas, but these conditions were shown to be difficult to achieve and transient

Interpolation in variable exponent spaces

In this paper we study both real and complex interpolation in the recently introduced scales of variable exponent Besov and Triebel–Lizorkin spaces. We also take advantage of some interpolation results to study a trace property and some pseudodifferential operators acting in the variable index Besov scale

Iron oxide and water paste rheology and its effect on low adhesion in the wheel/rail interface

The “wet-rail” phenomenon results in low adhesion between wheel and rail throughout the year, occurring transiently on a slightly wet, or drying railhead. It has been previously proposed that it is caused by a mixture of iron oxides and small amounts of water (from dew or precipitation) on the railhead that form a friction reducing paste. This paper outlines a novel combination of rheology, modelling and experimental work using a twin disc test rig to determine how the rheology of this iron oxide paste affects adhesion. The yield strength of different types of iron oxides, along with solid oxide fraction of the friction reducing paste, was assessed and used as an input into an “adhesion model” for assessing water and oxide suspensions. The rheological and modelling results were compared against very low adhesion recorded in twin disc experimental validation when simulating the wet-rail phenomenon

Magnetic moments of short-lived nuclei with part-per-million accuracy: Towards novel applications of β\beta-detected NMR in physics, chemistry and biology

We determine for the first time the magnetic dipole moment of a short-lived nucleus with part-per-million (ppm) accuracy. To achieve this two orders of magnitude improvement over previous studies, we implement a number of innovations into our $\beta$-detected Nuclear Magnetic Resonance ($\beta$-NMR) setup at ISOLDE/CERN. Using liquid samples as hosts we obtain narrow, sub-kHz linewidth, resonances, while a simultaneous in-situ $^1$H NMR measurement allows us to calibrate and stabilize the magnetic field to ppm precision, thus eliminating the need for additional $\beta$-NMR reference measurements. Furthermore, we use ab initio calculations of NMR shielding constants to improve the accuracy of the reference magnetic moment, thus removing a large systematic error. We demonstrate the potential of this combined approach with the 1.1 s half-life radioactive nucleus $^{26}$Na, which is relevant for biochemical studies. Our technique can be readily extended to other isotopic chains, providing accurate magnetic moments for many short-lived nuclei. Furthermore, we discuss how our approach can open the path towards a wide range of applications of the ultra-sensitive $\beta$-NMR in physics, chemistry, and biology.Comment: re-submitte

An analysis of the quality of experimental design and reliability of results in tribology research

In recent years several high profile projects have questioned the repeatability and validity of scientific research in the fields of psychology and medicine. In general, these studies have shown or estimated that less than 50% of published research findings are true or replicable even when no breaches of ethics are made. This high percentage stems from widespread poor study design; either through the use of underpowered studies or designs that allow the introduction of bias into the results. In this work, we have aimed to assess, for the first time, the prevalence of good study design in the field of tribology. A set of simple criteria for factors such as randomisation, blinding, use of control and repeated tests has been made. These criteria have been used in a mass review of the output of five highly regarded tribology journals for the year 2017. In total 379 papers were reviewed by 26 reviewers, 28% of the total output of the journals selected for 2017. Our results show that the prevalence of these simple aspects of study design is poor. Out of 290 experimental studies, 2.2% used any form of blinding, 3.2% used randomisation of either the tests or the test samples, while none randomised both. 30% repeated experiments 3 or more times and 86% of those who repeated tests used single batches of test materials. 4.4% completed statistical tests on their data. Due to the low prevalence of repeated tests and statistical analysis it is impossible to give a realistic indication of the percentage of the published works that are likely to be false positives, however these results compare poorly to other more well studied fields. Finally, recommendations for improved study design for researchers and group design for research group leaders are given

Evaluation of enzymatic extract with lipase activity of yarrowia lipolytica. an application of data mining for the food industry wastewater treatment

The object of this research was to obtain the Crude Enzymatic Extract (CEE) of Yarrowia lipolytica ATCC 9773, in the medium of 30% Water of Sales (SW) applying a biologically treatment to three different concentrations yeast inoculum food wastewater, collected from cheese and whey production. It was evaluated the behavior of the inoculum in a suitable medium that stimulates lipids biodegradation. The standard liquid-liquid partition method SM 5520 B was used to quantify fat and oil removal for each concentration of yeast, before treatment and post treatment. The Industrial Fat effluent was characterized by physical chemical patterns, and two treatments were evaluated; Treatment 1 consisted of pH 5.0 and treatment 2 with a pH of 6.5, both with the following characteristics; Concentration of inoculum 8% 12% and 16% at 27Â °C temperature and evaluation time 32Â h. The best results (2.702Â mg/L fat and 83% degradation oil) were found to be pH 5.0, 16% concentration and 27Â °C, BOD5, and COD decreased by 43.07% and 44.35%, respectively during the 32Â h; For pH 6.5, 8% concentration at 32Â h and at room temperature, degraded 2.177Â mg/L fat and oil (67% degradation); The BOD5, and COD decreased by 37.93% and 39.19%, in the same time span. The treatment at pH 5.0 inoculum concentration of 16% was effective in removing 83% of the volume of fats and oil in the effluent, representing a useful tool for the wastewater treatment

Experimental simulations of methane-oriented underground coal gasification using hydrogen - The effect of coal rank and gasification pressure on the hydrogasification process

This paper presents a series of surface experimental simulations of methane-oriented underground coal gasification using hydrogen as gasification medium. The main aim of the experiments conducted was to evaluate the feasibility of methane-rich gas production through the in situ coal hydrogasification process. Two multi-day trials were carried out using large scale gasification facilities designed for ex situ experimental simulations of the underground coal gasification (UCG) process. Two different coals were investigated: the “Six Feet” semi-anthracite (Wales) and the “Wesoła" hard coal (Poland). The coal samples were extracted directly from the respective coal seams in the form of large blocks. The gasification tests were conducted in the artificial coal seams (0.41 × 0.41 × 3.05 m) under two distinct pressure regimes - 20 and 40 bar. The series of experiments conducted demonstrated that the physicochemical properties of coal (coal rank) considerably affect the hydrogasification process. For both gasification pressures applied, gas from “Six Feet” semi-anthracite was characterized by a higher content of methane. The average CH4 concentration for “Six Feet” experiment during the H2 stage was 24.12% at 20 bar and 27.03% at 40 bar. During the hydrogasification of “Wesoła" coal, CH4 concentration was 19.28% and 21.71% at 20 and 40 bar, respectively. The process was characterized by high stability and reproducibility of conditions favorable for methane formation in the whole sequence of gasification cycles. Although the feasibility of methane-rich gas production by underground hydrogasification was initially demonstrated, further techno-economic studies are necessary to assess the economic feasibility of methane production using this process

Hydromechanical modelling of shaft sealing for CO2 storage

The geological sequestration of CO2 in abandoned coal mines is a promising option to mitigate climate changes while providing sustainable use of the underground cavities. In order to certify the efficiency of the storage, it is essential to understand the behaviour of the shaft sealing system. The paper presents a numerical analysis of CO2 transfer mechanisms through a mine shaft and its sealing system. Different mechanisms for CO2 leakage are considered, namely multiphase flow through the different materials and flow along the interfaces between the lining and the host rock. The study focuses on the abandoned coal mine of Anderlues, Belgium, which was used for seasonal storage of natural gas. A two-dimensional hydromechanical modelling of the storage site is performed and CO2 injection into the coal mine is simulated. Model predictions for a period of 500 years are presented and discussed with attention. The role and influence of the interface between the host rock and the concrete lining are examined. In addition the impact of some uncertain model parameters on the overall performance of the sealing system is analysed through a sensitivity analysis

Computational Methods for Protein Identification from Mass Spectrometry Data

Protein identification using mass spectrometry is an indispensable computational tool in the life sciences. A dramatic increase in the use of proteomic strategies to understand the biology of living systems generates an ongoing need for more effective, efficient, and accurate computational methods for protein identification. A wide range of computational methods, each with various implementations, are available to complement different proteomic approaches. A solid knowledge of the range of algorithms available and, more critically, the accuracy and effectiveness of these techniques is essential to ensure as many of the proteins as possible, within any particular experiment, are correctly identified. Here, we undertake a systematic review of the currently available methods and algorithms for interpreting, managing, and analyzing biological data associated with protein identification. We summarize the advances in computational solutions as they have responded to corresponding advances in mass spectrometry hardware. The evolution of scoring algorithms and metrics for automated protein identification are also discussed with a focus on the relative performance of different techniques. We also consider the relative advantages and limitations of different techniques in particular biological contexts. Finally, we present our perspective on future developments in the area of computational protein identification by considering the most recent literature on new and promising approaches to the problem as well as identifying areas yet to be explored and the potential application of methods from other areas of computational biology