A Novel Approach to Railway Track Faults Detection Using Acoustic Analysis.

Regular inspection of railway track health is crucial for maintaining safe and reliable train operations. Factors, such as cracks, ballast issues, rail discontinuity, loose nuts and bolts, burnt wheels, superelevation, and misalignment developed on the rails due to non-maintenance, pre-emptive investigations and delayed detection, pose a grave danger and threats to the safe operation of rail transport. The traditional procedure of manually inspecting the rail track using a railway cart is both inefficient and prone to human error and biases. In a country like Pakistan where train accidents have taken many lives, it is not unusual to automate such approaches to avoid such accidents and save countless lives. This study aims at enhancing the traditional railway cart system to address these issues by introducing an automatic railway track fault detection system using acoustic analysis. In this regard, this study makes two important contributions: data collection on Pakistan railway tracks using acoustic signals and the application of various classification techniques to the collected data. Initially, three types of tracks are considered, including normal track, wheel burnt and superelevation, due to their common occurrence. Several well-known machine learning algorithms are applied such as support vector machines, logistic regression, random forest and decision tree classifier, in addition to deep learning models like multilayer perceptron and convolutional neural networks. Results suggest that acoustic data can help determine the track faults successfully. Results indicate that the best results are obtained by RF and DT with an accuracy of 97%

Infection of hepatitis C virus genotypes in hepatocellular carcinoma patients from rural areas of Faisalabad region, Pakistan

The aim of this retrospective study was to investigate the infection of hepatitis C virus (HCV) genotypes in hepatocellular carcinoma (HCC) patients from rural areas of Faisalabad region. Among 179 HCC subjects, men and women were 51 and 49%, respectively. All samples positive for HCV RNA by qualitative PCR were genotyped, applying genotype-specific PCR. They were confirmed using HCV 5’ non-coding region sequence analytical data. Major risk factor for HCC development and progression was identified to be chronic HCV. It was found among 56.5 ± 2.1 years of age. All these HCC cases were HCV-related and no case was linked with other types of viruses. Using genotype specific primers, HCV genotype 3a (55.3%) was significantly (P<0.0001) higher, followed by 3b (15.8%), 1 (9.24%), 4 (8.05%) and 2 (7.15%). Other genotypes, namely 5a and 6a were only 1.19 and 1.05% among the HCC patients. About 1.05% remained un-typed because of minute viral load. HCV genotype 3a was strongly linked with HCC, followed by 3b. Moreover, HCC was linked with liver cirrhosis (81%). It is suggested that genotyping may be recommended before starting interferon therapy.Key words: Etiology, genotyping, hepatitis C virus, hepatocellular carcinoma, prevalence, α-fetoprotein

Risk factors for wound infection in surgery for spinal metastasis

Wound infection rates are generally higher in patients undergoing surgery for spinal metastasis. Risk factors of wound infection in these patients are poorly understood. Purpose To identify demographic and clinical variables that may be associated with patients experiencing a higher wound infection rate. Study design Retrospective study with prospectively collected data of spinal metastasis patients operated consecutively at a University Teaching Hospital, adult spine division which is a tertiary referral centre for complex spinal surgery. Patient sample Ninety-eight patients were all surgically treated, consecutively from January 2009 to September 2011. Three patients had to be excluded due to inadequate data. Outcome measures Physiological measures, with presence or absence of microbiologically proven infection. Methods Various demographic and clinical data were recorded, including age, serum albumin level, blood total lymphocyte count, corticosteroid intake, Malnutrition Universal Screening Tool (MUST) score, neurological disability, skin closure material used, levels of surgery and administration of peri-operative corticosteroids. No funding was received from any sources for this study and as far as we are aware, there are no potential conflict of interest-associated biases in this study. Results Higher probabilities of infection were associated with low albumin level, seven or more levels of surgery, use of delayed/non-absorbable skin closure material and presence of neurological disability. Of these factors, levels of surgery were found to be statistically significant at the 5 % significance level. Conclusion Risk of infection is high (17.9 %) in patients undergoing surgery for spinal metastasis. Seven or more vertebral levels of surgery increase the risk of infection significantly (p < 0.05). Low albumin level and presence of neurological disability appear to show a trend towards increased risk of infection. Use of absorbable skin closure material, age, low lymphocyte count, peri-operative administration of corticosteroids and MUST score do not appear to influence the risk of infection

Developmental, cellular, and biochemical basis of transparency in the glasswing butterfly Greta oto

Numerous species of Lepidoptera have transparent wings, which often possess scales of altered morphology and reduced size, and the presence of membrane surface nanostructures that dramatically reduce reflection. Optical properties and anti-reflective nanostructures have been characterized for several ‘clearwing’ Lepidoptera, but the developmental basis of wing transparency is unknown. We apply confocal and electron microscopy to create a developmental time-series in the glasswing butterfly, Greta oto, comparing transparent and non-transparent wing regions. We find that scale precursor cell density is reduced in transparent regions, and cytoskeletal organization differs between flat scales in opaque regions, and thin, bristle-like scales in transparent regions. We also reveal that sub-wavelength nanopillars on the wing membrane are wax-based, derive from wing epithelial cells and their associated microvillar projections, and demonstrate their role in enhancing-anti-reflective properties. These findings provide insight into morphogenesis of naturally organized micro- and nanostructures and may provide bioinspiration for new anti-reflective materials

Modelling Li+ Ion Battery Electrode Properties

We formulated two detailed models for an electrolytic cell with particulate electrodes based on a lithium atom concentration dependent Butler-Volmer condition at the interface between electrode particles and the electrolyte. The first was based on a dilute-ion assumption for the electrolyte, while the second assumed that Li ions are present in excess. For the first, we used the method of multiple scales to homogenize this model over the microstructure, formed by the small lithium particles in the electrodes. For the second, we gave rigorous bounds for the effective electrochemical conductivity for a linearized case. We expect similar results and bounds for the "full nonlinear problem" because variational results are generally not adversely affected by a sinh term. Finally we used the asymptotic methods, based on parameters estimated from the literature, to attain a greatly simplified one-dimensional version of the original homogenized model. This simplified model accounts for the fact that diffusion of lithium atoms within individual electrode particles is relatively much faster than that of lithium ions across the whole cell so that lithium ion diffusion is what limits the performance of the battery. However, since most of the potential drop occurs across the Debye layers surrounding each electrode particle, lithium ion diffusion only significantly affects cell performance if there is more or less complete depletion of lithium ions in some region of the electrolyte which causes a break in the current flowing across the cell. This causes catastrophic failure. Providing such failure does not occur the potential drop across the cell is determined by the concentration of lithium atoms in the electrode particles. Within each electrode lithium atom concentration is, to leading order, a function of time only and not of position within the electrode. The depletion of electrode lithium atom concentration is directly proportional to the current being drawn off the cell. This leads one to expect that the potential of the cell gradually drops as current is drawn of it. We would like to emphasize that all the homogenization methods employed in this work give a systematic approach for investigating the effect that changes in the microstructure have on the behaviour of the battery. However, due to lack of time, we have not used this method to investigate particular particle geometries

Enabling model-predictive design : rapid development of a PBM for an anti-solvent and cooling crystallisation in two different reactor geometries

The study aimed to develop a rapid model using gProms Formulated Products for a proprietary single polymorph active pharmaceutical ingredient (API) crystallisation at small scale for early process understanding. The model outcomes are then later used to inform the experimental design of continuous crystallisation for multi-addition antisolvent and cooling crystallization in both continuous oscillatory baffled reactor (COBC) and mixed-suspension and mixed- product removal (MSMPR) crystallise

Embryo rescue and plant regeneration in vitro of selfed chickpea (Cicer arietinum L.) and its wild annual relatives

The main constraint to the transfer of desired traits into cultivated chickpea from wild Cicer relatives is the presence of post-zygotic barriers which result in abortion of the immature embryo following interspecific hybridisation. Rescue of hybrid embryos in vitro and regeneration of hybrid plantlets could allow chickpea breeders to transfer desirable traits from wild relatives of chickpea. The development of embryo rescue techniques using selfed chickpea and selfed wild relatives is being used as a first step to protocols for wide hybrids. Optical microscopy studies of embryogenesis, in both selfs and hybrids, identified deleterious changes in the fertilised hybrid seed as early as 2–4 days after pollination in some crosses. These observations suggest that the appropriate time to rescue chickpea × C. bijugum hybrids is at the early globular stage of embryogenesis (2–7 days old), which requires the development of a complex tissue culture medium. In contrast hybrids between chickpea × C. pinnatifidum abort later (up to 15–20 days old) at the heart-shaped or torpedo stages, and are easier to rescue in vitro. Genotype also plays a significant role in the ability of immature selfed ovules to germinate in vitro. In this paper we report on the optimisation of␣protocols for rescueing immature embryos using selfed chickpea and its wild relatives in ovule, and subsequently to regenerate plantlets

Investigation of wet milling and indirect ultrasound as means for controlling nucleation in the continuous crystallization of an active pharmaceutical ingredient

This study compares the use of wet milling and indirect ultrasound for promoting nucleation and controlling the particle size during the continuous crystallization of a hard-to-nucleate active pharmaceutical ingredient (API). Both an immersion and an external wet mill installed on a recirculation loop were investigated. It was found that all methodologies significantly improved the nucleation kinetics, and the effects of key process parameters (e.g., mill speed, temperature, and ultrasound intensity) on particle size were experimentally investigated. A minimum d50 of 27 and 36.8 μm was achieved when using the wet mill and ultrasound, respectively. The effectiveness of wet milling was demonstrated in a three-stage mixed suspension mixed product removal continuous crystallization of the API that was operated continuously for 12 h (eight residence times), achieving a steady state with minimal fouling. Strategies for improving the overall robustness of the setup in routine manufacturing are discussed

Interstellar Dust Inside and Outside the Heliosphere

In the early 1990s, after its Jupiter flyby, the Ulysses spacecraft identified interstellar dust in the solar system. Since then the in-situ dust detector on board Ulysses continuously monitored interstellar grains with masses up to 10e-13 kg, penetrating deep into the solar system. While Ulysses measured the interstellar dust stream at high ecliptic latitudes between 3 and 5 AU, interstellar impactors were also measured with the in-situ dust detectors on board Cassini, Galileo and Helios, covering a heliocentric distance range between 0.3 and 3 AU in the ecliptic plane. The interstellar dust stream in the inner solar system is altered by the solar radiation pressure force, gravitational focussing and interaction of charged grains with the time varying interplanetary magnetic field. The grains act as tracers of the physical conditions in the local interstellar cloud (LIC). Our in-situ measurements imply the existence of a population of 'big' interstellar grains (up to 10e-13 kg) and a gas-to-dust-mass ratio in the LIC which is a factor of > 2 larger than the one derived from astronomical observations, indicating a concentration of interstellar dust in the very local interstellar medium. Until 2004, the interstellar dust flow direction measured by Ulysses was close to the mean apex of the Sun's motion through the LIC, while in 2005, the data showed a 30 deg shift, the reason of which is presently unknown. We review the results from spacecraft-based in-situ interstellar dust measurements in the solar system and their implications for the physical and chemical state of the LIC.Comment: 10 pages, 2 b/w figures, 1 colour figure; submitted to Space Science Review