EXPERIMENTAL STUDY OF CHLORIDE-INDUCED STRESS CORROSION CRACKING (CISCC) FOR AUSTENITIC SUS 304L UNDER THERMAL INSULATION

Chloride-Induced Stress Corrosion Cracking (CISCC) has been frequently reported in the petrochemical industries where it usually causes failure to the austenitic stainless steel structures encased with thermal insulation in a chloride-containing environment. This study aims to analyze and evaluate the risk of chloride concentration and different types of insulation materials on CISCC of Austenitic SUS 304L. The experimental study was carried out for 14 days using U-bend specimens through the Drip Test apparatus, as per ASTM G30 and ASTM C692. U-Bend specimens were installed onto the test rig and shielded with different insulation materials. Sodium chloride (NaCl) salt solutions were periodically dripped onto the specimens, to simulate the wet and dry cycle. Insulation materials used were rockwool, calcium silicate and perlite, whereas the concentrations of NaCl solutions were set at 0.1, 1.0 and 3.5 wt.%. The specimens were inspected using dye penetration tests (DPT), stereo microscope and optical microscope throughout the study to determine the CISCC susceptibility. Results showed that cracking was observed on the specimen with rockwool insulation at 3.5 wt% NaCl and 90°C. Rockwool has a high water absorption capacity at which saltwater will evaporate when in contact with a hot metal surface, resulting in the build-up of salt deposits of high concentration over time. SCC was not observed on other specimens with different conditions, but salt deposits, general corrosion and pitting corrosion were found. From the study, the thermal insulation of rockwool was found to have the highest tendency to cause SCC, followed by calcium silicate and perlite

Perception Enhancements Using Visual Attributes in Sequence Motif Visualization

Human factor theories are always being neglected especially in the design of biological tools. This problem was found in sequence logo which is used to visualize the conservation characteristics of the biological sequence motifs. Previous studies have found some limitations in the graphical representation which cause biasness and misinterpretation of the results in sequence logo. Therefore, the aim of this study is to investigate on the visual attributes performance in helping viewers to perceive and interpret the information based the preattentive theories and Gestalt principles of perception. A survey was carried out to gather user’s opinion. The results showed some limitations in the use of colour, negative space, size and arrangement of the nucleotides and the lack of information and interactivity in the sequence logo. Therefore, improvements in standardizing the colour, graphical representation of the nucleotides and interactivity of the tool are needed to solve the problems of biasness and misinterpretation of the results in sequence logo visualization

Kalman Filter Models for the Prediction of Individualised Thermal Work Strain

It is important to monitor and assess the physiological strain of individuals working in hot environments to avoid heat illness and performance degradation. The body core temperature (Tc) is a reliable indicator of thermal work strain. However, measuring Tc is invasive and often inconvenient and impractical for real-time monitoring of workers in high heat strain environments. Seeking a better solution, the main aim of the present study was to investigate the Kalman filter method to enable the estimation of heat strain from non-invasive measurements (heart rate (HR) and chest skin temperature (ST)) obtained ‘online’ via wearable body sensors. In particular, we developed two Kalman filter models. First, an extended Kalman filter (EFK) was implemented in a cubic state space modelling framework (HR versus Tc) with a stage-wise, autoregressive exogenous model (incorporating HR and ST) as the time update model. Under the second model, the online Kalman filter (OFK) approach builds up the time update equation depending only on the initial value of Tc and the latest value of the exogenous variables. Both models were trained and validated using data from laboratory- and outfield-based heat strain profiling studies in which subjects performed a high intensity military foot march. While both the EKF and OKF models provided satisfactory estimates of Tc, the results showed an overall superior performance of the OKF model (overall root mean square error, RMSE = 0.31°C) compared to the EKF model (RMSE = 0.45°C)

Computational Model for Predicting the Location of Glass Solidification in Optic Fiber Drawing

ABSTRACT This paper presents a computational model for predicting the location at which the glass fiber solidifies during a highspeed drawing process. Although modeling of the optic fiber drawing process has been of interest for the past two decades, traditional fiber drawing process uses small diameter preforms and low draw speeds, where the glass usually solidifies and turns into fiber inside the furnace. Much larger preforms drawn at higher speeds have been used in the state-of-the-art fiber drawing systems to improve production efficiency and reduce cost. Insulated post-chambers are often added below the furnace to reduce the glass cooling rate so that the optical loss in the fiber is low. To provide a basis for design optimization of the post-chamber, we have solved the conjugate problem of the glass free surface flow and the air convection to determine the location where the glass solidifies. As radiation is the dominant mode of heat transfer in the glass, the radiative transfer equation (RTE) is solved directly by discrete ordinate method (DOM). The heat flux due to the mixed convection of the air is also numerically calculated along the glass free surface, which involves the boundary layer flow around a continuously moving fiber and the buoyancy driven flow through the open-ended channel. The calculated free shapes are compared against the experimentally measured data to verify the computational model

De Broglie Wavelength of a Nonlocal Four-Photon

Superposition is one of the most distinct features of quantum theory and has been demonstrated in numerous realizations of Young's classical double-slit interference experiment and its analogues. However, quantum entanglement - a significant coherent superposition in multiparticle systems - yields phenomena that are much richer and more interesting than anything that can be seen in a one-particle system. Among them, one important type of multi-particle experiments uses path-entangled number-states, which exhibit pure higher-order interference and allow novel applications in metrology and imaging such as quantum interferometry and spectroscopy with phase sensitivity at the Heisenberg limit or quantum lithography beyond the classical diffraction limit. Up to now, in optical implementations of such schemes lower-order interference effects would always decrease the overall performance at higher particle numbers. They have thus been limited to two photons. We overcome this limitation and demonstrate a linear-optics-based four-photon interferometer. Observation of a four-particle mode-entangled state is confirmed by interference fringes with a periodicity of one quarter of the single-photon wavelength. This scheme can readily be extended to arbitrary photon numbers and thus represents an important step towards realizable applications with entanglement-enhanced performance.Comment: 19 pages, 4 figures, submitted on November 18, 200

Synergy study on charge transport dynamics in hybrid organic solar cell: photocurrent mapping and performance analysis under local spectrum

Charge transport dynamics in ZnO based inverted organic solar cell (IOSC) has been characterized with transient photocurrent spectroscopy and localised photocurrent mapping-atomic force microscopy. The value of maximum exciton generation rate was found to vary from 2.6 × 1027 m−3s−1 (Jsat = 79.7 A m−2) to 2.9 × 1027 m−3s−1 (Jsat = 90.8 A m−2) for devices with power conversion efficiency ranging from 2.03 to 2.51%. These results suggest that nanorods served as an excellent electron transporting layer that provides efficient charge transport and enhances IOSC device performance. The photovoltaic performance of OSCs with various growth times of ZnO nanorods have been analysed for a comparison between AM1.5G spectrum and local solar spectrum. The simulated PCE of all devices operating under local spectrum exhibited extensive improvement with the gain of 13.3–13.7% in which the ZnO nanorods grown at 15 min possess the highest PCE under local solar with the value of 2.82%

Structural insights into RNA processing by the human RISC-loading complex.

Targeted gene silencing by RNA interference (RNAi) requires loading of a short guide RNA (small interfering RNA (siRNA) or microRNA (miRNA)) onto an Argonaute protein to form the functional center of an RNA-induced silencing complex (RISC). In humans, Argonaute2 (AGO2) assembles with the guide RNA-generating enzyme Dicer and the RNA-binding protein TRBP to form a RISC-loading complex (RLC), which is necessary for efficient transfer of nascent siRNAs and miRNAs from Dicer to AGO2. Here, using single-particle EM analysis, we show that human Dicer has an L-shaped structure. The RLC Dicer's N-terminal DExH/D domain, located in a short 'base branch', interacts with TRBP, whereas its C-terminal catalytic domains in the main body are proximal to AGO2. A model generated by docking the available atomic structures of Dicer and Argonaute homologs into the RLC reconstruction suggests a mechanism for siRNA transfer from Dicer to AGO2

Association of maternal Vitamin D status with glucose tolerance and caesarean section in a multi-ethnic Asian cohort: the growing up in Singapore towards healthy outcomes study

10.1371/journal.pone.0142239PLoS ONE10111-16GUSTO (Growing up towards Healthy Outcomes

Whole-Genome Cartography of Estrogen Receptor α Binding Sites

Using a chromatin immunoprecipitation-paired end diTag cloning and sequencing strategy, we mapped estrogen receptor α (ERα) binding sites in MCF-7 breast cancer cells. We identified 1,234 high confidence binding clusters of which 94% are projected to be bona fide ERα binding regions. Only 5% of the mapped estrogen receptor binding sites are located within 5 kb upstream of the transcriptional start sites of adjacent genes, regions containing the proximal promoters, whereas vast majority of the sites are mapped to intronic or distal locations (>5 kb from 5′ and 3′ ends of adjacent transcript), suggesting transcriptional regulatory mechanisms over significant physical distances. Of all the identified sites, 71% harbored putative full estrogen response elements (EREs), 25% bore ERE half sites, and only 4% had no recognizable ERE sequences. Genes in the vicinity of ERα binding sites were enriched for regulation by estradiol in MCF-7 cells, and their expression profiles in patient samples segregate ERα-positive from ERα-negative breast tumors. The expression dynamics of the genes adjacent to ERα binding sites suggest a direct induction of gene expression through binding to ERE-like sequences, whereas transcriptional repression by ERα appears to be through indirect mechanisms. Our analysis also indicates a number of candidate transcription factor binding sites adjacent to occupied EREs at frequencies much greater than by chance, including the previously reported FOXA1 sites, and demonstrate the potential involvement of one such putative adjacent factor, Sp1, in the global regulation of ERα target genes. Unexpectedly, we found that only 22%–24% of the bona fide human ERα binding sites were overlapping conserved regions in whole genome vertebrate alignments, which suggest limited conservation of functional binding sites. Taken together, this genome-scale analysis suggests complex but definable rules governing ERα binding and gene regulation