49 research outputs found
A Phase Change Material Technology Review Paper in Solar Energy Uses and Storage
The rapidly rising issue of declining the non-renewable resources available has focused the world attention on how renewable resources can be better used and harvested. Solar energy is one of the essential sources of renewable energy. Solar energy is a source of renewable energy for various applications in the world today. The present study is regarded as a summary of early studies on utilizing phase-change material in the use and storage of solar power. Due to its high thermal density, the isothermal nature and the easy power, the late thermosetting with the material is an advantageous way to store thermal energy. This paper summarizes how thermal energy can be efficiently stored via PCM in thermal energy storage systems of solar collectors. PCMs are isothermal, have higher density energy storage and are capable of operating in varying temperature environments. Therefore, an attempt was made in this paper to summarize an analysis of the various applications of phase change material (PCM), even solar collection device integrating PCMs
The behaviour of different design of flexible force sensor based velostat during implementation of static load with different contact area
Great attention has been given to flexible force sensors and the materials that have been used as a sensing material by studying their properties and evaluate their behaviours with different types of loads. Velostat is one of the most promising sensing materials that has been widely studied and evaluated for different applications due to their distinct traits of flexibility, suitable cost as well as their ability to cover the wearable applications. This work makes focus on the behaviour of Velostat flexible force sensor by measuring the resistivity of the sensor while applying loads with different contact area. Two different designs of sensor have been studied, which are the single output flexible force sensor and multioutput matrix flexible force sensor, by applying loads starting from 0.98 (N) to 9.8 (N) with four compression disc having different diameters. It has been found that the two design behave in opposite manner. The resistance of the single output design decreased as the contact area increased, while the matrix design showed an increasing in the resistance as the contact area increased
Using a Laboratory Model Test to Evaluate Collapsibility of Gypseous Soils Improved by Sludge
Collapsibility of gypseous soils may cause excessive settlement and severe damage to engineering structures. Many improvement methods have been employed to reduce the collapsibility of these soils, such as by using physical methods or chemical additives. The collapsibility of the improved gypseous soils has conventionally been evaluated by using the odometer test, which may not accurately replicate the field conditions because of the small size of the test specimens. In this research, a laboratory model test of 600x600x600 mm with a model footing of 100x100mm was developed to measure the collapse characteristics of sandy soil with a gypsum content of 37%. The test was first conducted on specimens in the model at three different relative densities. The test was then performed after compacting the top layer of the test specimens [thickness from 50 to 100 mm] to the maximum dry density, as obtained from the Standard Compaction Test. Water treatment sludge was also used to further improve the top compacted layer. The results indicated that the collapsibility settlement reduction factor was 75% when the top layer of 50 mm thickness was compacted to the maximum dry density. Additionally, when the sludge was used with the top layer, the collapsibility settlement reduction factor was 86%
Novel variants in COL4A4 and COL4A5 are rare causes of FSGS in two unrelated families
We report two female patients with focal segmental glomerulosclerosis and chronic kidney disease. The first patient was found to have a heterozygous, de novo, pathogenic variant in COL4A5 (c.141+1G>A, IVS2+1G>A), which is associated with Alport syndrome. The second patient was found to have a heterozygous, likely pathogenic variant in COL4A4 (c.2842G>T). Both these variants in COL4A5 and COL4A4 are novel, and they were detected using whole exome sequencing and gene panel testing, respectively. Additionally, we discuss the complexities of diagnosis in such cases and the benefits of using the abovementioned diagnostic approaches
Correction: Novel variants in COL4A4 and COL4A5 are rare causes of FSGS in two unrelated families
No abstract available
Emergence and Variability of Broad Absorption Line Quasar Outflows
We isolate a set of quasars that exhibit emergent C iv broad absorption lines
(BALs) in their spectra by comparing spectra in the SDSS Data Release 7 and the
SDSS/BOSS Data Releases 9 and 10. After visually defining a set of emergent
BALs, follow-up observations were obtained with the Gemini Observatory for 105
quasars. We find an emergence rate consistent with the previously reported
disappearance rate of BAL quasars given the relative numbers of non-BAL and BAL
quasars in the SDSS. We find candidate newly emerged BALs are preferentially
drawn from among BALs with smaller balnicity indices, shallower depths, larger
velocities, and smaller widths. Within two rest-frame years (average) after a
BAL has emerged, we find it equally likely to continue increasing in equivalent
width in an observation six months later (average) as it is to start
decreasing. From the time separations between our observations, we conclude the
coherence time-scale of BALs is less than 100 rest-frame days. We observe
coordinated variability among pairs of troughs in the same quasar, likely due
to clouds at different velocities responding to the same changes in ionizing
flux; and the coordination is stronger if the velocity separation between the
two troughs is smaller. We speculate the latter effect may be due to clouds
having on average lower densities at higher velocities due to mass conservation
in an accelerating flow, causing the absorbing gas in those clouds to respond
on different timescales to the same ionizing flux variations.Comment: 37 pages, 25 figure
Intra-Abdominal Candidiasis
Intra-abdominal candidiasis (IAC) is the second most common form of invasive candidiasis after candidaemia. IAC is a broad term and can be classified on the basis of anatomical site (Candida peritonitis, pancreatic candidiasis, biliary tract candidiasis, gastrointestinal candidiasis, and hepatosplenic candidiasis) as well as clinical setting (community acquired versus nosocomial). The risk factors linked with IAC are candida colonisation, anastomotic leak, multiple instrumentation, long-term broad spectrum antibiotic use, total parenteral nutrition, and immunocompromised state. Clinically, IAC is not different from intraabdominal bacterial infection. Patients generally present with signs and symptoms of intra-abdominal sepsis after not responding to antibiotic therapy and with a background history of multiple surgical interventions or history of delayed source control. Radiological investigations, like ultrasonography and computed tomography scan, not only aid in diagnosis but also assist in differentiating medical from surgical cases. Microbiological diagnosis requires isolation of candida from an intra-abdominal specimen. Differentiation between colonisation and infection is difficult. Generally, progressive and persistent colonisation is associated with high risk of infection. Blood cultures have poor sensitivity for IAC. Non-culture based techniques used for diagnosis are mannan/anti-mannan assay, beta-D glucan assay, and validated polymerase chain reaction. Four types of antifungal strategies described in the literature are prophylaxis (risk factor driven), pre-emptive (colonisation or biomarker driven), empirical (fever driven), and targeted therapy (microbiology driven). Over recent years, global epidemiology has shown a shift from Candida albicans to non-albicans. Local epidemiology plays an important role in selection of the appropriate empirical therapy. The purpose of this review is to discuss different types of IAC based on their classification, risk factors, and management
From model-driven to data-driven : a review of hysteresis modeling in structural and mechanical systems
Hysteresis is a natural phenomenon that widely exists in structural and mechanical systems. The characteristics of structural hysteretic behaviors are complicated. Therefore, numerous methods have been developed to describe hysteresis. In this paper, a review of the available hysteretic modeling methods is carried out. Such methods are divided into: a) model-driven and b) datadriven methods. The model-driven method uses parameter identification to determine parameters. Three types of parametric models are introduced including polynomial models, differential based models, and operator based models. Four algorithms as least mean square error algorithm, Kalman filter algorithm, metaheuristic algorithms, and Bayesian estimation are presented to realize parameter identification. The data-driven method utilizes universal mathematical models to describe hysteretic behavior. Regression model, artificial neural network, least square support vector machine, and deep learning are introduced in turn as the classical data-driven methods. Model-data driven hybrid methods are also discussed to make up for the shortcomings of the two methods. Based on a multi-dimensional evaluation, the existing problems and open challenges of different hysteresis modeling methods are discussed. Some possible research directions about hysteresis description are given in the final section
Cyber-Security Incidents: A Review Cases In Cyber-Physical Systems
Cyber-Physical Systems refer to systems that have an interaction between computers, communication channels and physical devices to solve a real-world problem. Towards industry 4.0 revolution, Cyber-Physical Systems currently become one of the main targets of hackers and any damage to them lead to high losses to a nation. According to valid resources, several cases reported involved security breaches on Cyber-Physical Systems. Understanding fundamental and theoretical concept of security in the digital world was discussed worldwide. Yet, security cases in regard to the cyber-physical system are still remaining less explored. In addition, limited tools were introduced to overcome security problems in Cyber-Physical System. To improve understanding and introduce a lot more security solutions for the cyber-physical system, the study on this matter is highly on demand. In this paper, we investigate the current threats on Cyber-Physical Systems and propose a classification and matrix for these threats, and conduct a simple statistical analysis of the collected data using a quantitative approach. We confirmed four components i.e., (the type of attack, impact, intention and incident categories) main contributor to threat taxonomy of Cyber-Physical System
Carbimazole-Induced Jaundice in Thyrotoxicosis: A Case Report.
Carbimazole is a commonly used antithyroid drug in thyrotoxicosis. It is generally well tolerated, and its side effects include allergic skin reactions, gastrointestinal upset, agranulocytosis, and hepatotoxicity. Hepatitis is a rare but serious side effect. Here we report a case of carbimazole-induced hepatitis with severe cholestasis that was managed by switching to propylthiouracil. Most of the literature recommends radioiodine or surgery as the definitive treatment for hyperthyroidism in thionamide-induced hepatitis rather than switching to other thionamide. However, substitution of one thionamide for another can be tried as we did in this case, without any increased risk of hepatotoxicity as the mechanism of liver injury differs in both groups. A previously healthy 30-year-old lady who was diagnosed with thyrotoxicosis one month earlier that was treated with carbimazole 60 mg daily was admitted to the medical ward with yellowish discoloration of sclera, urine, and pruritus of one-week duration. Systemic examination was unremarkable except for icterus. Investigation showed hyperbilirubinemia and elevated liver enzymes. A probable diagnosis of carbimazole-induced cholestatic hepatitis was made and the drug was discontinued. Other causes of hepatitis and cholestasis were excluded. Attempts to arrange radioiodine or treat the patient surgically were not successful. She was continued on propranolol and later started on steroids and propylthiouracil. The patient's liver function tests (LFTs) started improving gradually. On follow-up, LFTs normalized at four weeks and thyroid function tests (TFTs) showed signs of improvement. The patient was followed up for six months after discharge and was doing well clinically on follow-up; her repeat TFT and LFT were completely normal. Carbimazole-induced hepatitis is exceedingly rare; however, it should be considered in patients with jaundice and thyrotoxicosis. Despite reports of cross-reactivity of the two available antithyroid drugs, switching from carbimazole to propylthiouracil and steroid therapy may be an option if other options of definitive therapy could not be arranged or are contraindicated