The correlation of microstructure and mechanical properties of in-situ Al-Mg2Si cast composite processed by equal channel angular pressing

In this paper, the effect of equal channel angular pressing (ECAP) on microstructure and mechanical properties of hypereutectic Al-20%Mg2Si and Al-15%Mg2Si, as well as hypoeutectic Al-10%Mg2Si composites has been investigated. After fabricating the composites by in-situ casting, the composites were processed using the ECAP process up to two passes at room temperature. Microstructural studies have been carried out using a field emission scanning electron microscopy equipped with an energy dispersive X-ray spectrometer. Mechanical properties were also documented using Vickers microhardness and shear punch tests. In the hypereutectic composites, a decrease in the average size of pro-eutectic Mg2Si (Mg2Sip) particles, breakages in eutectic networks, and lengthening of the Al (α) phase in direction of shear bands were observed after the ECAP process. For instance, the average size of Mg2Sip Particles in Al-20%Mg2Si composite reduced from 40 to 17 μm after 2 passes of ECAP. Furthermore, a uniform distribution of Mg2Sip particles was developed in the matrix. In hypoeutectic composite, the ECAP process caused a uniform distribution of eutectic Mg2Si (Mg2SiE) in the matrix that considered a favorable microstructure. Microhardness measurements and shear punch results showed an ascending trend after each pass of ECAP for all specimens. For example, microhardness and shear strength of Al-20%Mg2Si increased from 88 HV and 109 MPa to 119 HV and 249 MPa after two passes indicating 35% and 34% increments, respectively. Density and porosity calculations by Archimedes principle revealed that the density of the composites increased after two passes of ECAP due to the reduction of porosity

Interactive Visual Labelling versus Active Learning: An Experimental Comparison

Methods from supervised machine learning allow the classification of new data automatically and are tremendously helpful for data analysis. The quality of supervised maching learning depends not only on the type of algorithm used, but also on the quality of the labelled dataset used to train the classifier. Labelling instances in a training dataset is often done manually relying on selections and annotations by expert analysts, and is often a tedious and time-consuming process. Active learning algorithms can automatically determine a subset of data instances for which labels would provide useful input to the learning process. Interactive visual labelling techniques are a promising alternative, providing effective visual overviews from which an analyst can simultaneously explore data records and select items to a label. By putting the analyst in the loop, higher accuracy can be achieved in the resulting classifier. While initial results of interactive visual labelling techniques are promising in the sense that user labelling can improve supervised learning, many aspects of these techniques are still largely unexplored. This paper presents a study conducted using the mVis tool to compare three interactive visualisations, similarity map, scatterplot matrix (SPLOM), and parallel coordinates, with each other and with active learning for the purpose of labelling a multivariate dataset. The results show that all three interactive visual labelling techniques surpass active learning algorithms in terms of classifier accuracy, and that users subjectively prefer the similarity map over SPLOM and parallel coordinates for labelling. Users also employ different labelling strategies depending on the visualisation used

Complications of transcatheter closure in patent ductus arteriosus patients

Background: Published studies have shown excellent success rates and also low rates of life-threatening complications with trans-catheter closure of patent ductus arteriosus (PDA). However, most studies to date have been conducted in developed nations and reports from developing countries such as Iran are lacking. Objectives: To report our experience with trans-catheter closure of patent ductus arteriosus (PDA) and compare two devices and complications. Patients and Methods: From 2007 to 2011, 72 consecutive PDA cases were prospectively enrolled. For PDAs � 2 mm, the coiling method was employed whereas patients with PDA > 2 mm received Amplatzer duct occlusion (ADO). Success was defined as trivial residual shunt (< 1 mm) in the echocardiography performed 30 minutes after the procedure. After the procedure, the patients were admitted to the pediatric cardiology ward and observed for 72 hours during which the occurrence of major and minor complications was monitored. Major complications included cardiac arrest, displacement and/or embolization of the device and patient needing blood transfusion due to severe hemorrhage. Sampling was based on convenience method and the patients who had significant pulmonary artery hypertension were excluded from our study. Statistical analyses were done using SPSS software version 23 (IBM corp., New York, United States). Continuous variables are presented as mea

Evaluation of Hydroalcoholic Extract of Cinnamon Effect on Testicular Tissue and Fertility of Busulfan-Induced Oligo-Spermic Model Rats

BACKGROUND AND OBJECTIVE: Busulfan is one of the cancer treatment drugs that cause infertility of the patient. In traditional medicine, one of the important properties of cinnamon is enhancement of fertility. The aim of this study was to investigate the effect of cinnamon on the physiological structure of testes and fertility rate of busulfan-treated rats. METHODS: In this experimental study, 24 adult male rats were divided into 3 groups of 8 subjects, Sham: healthy rats without intervention. Control group: Busulfan-sterilized rats (15 mg/kg) intraperitoneal injection, Cinnamon group: Busulfan-treated rats + cinnamon extract (200 mg/kg) for fourteen days. The testicles length, width and weight parameters as well as the formation of germinal cells were analyzed by H &#38; E staining and optical microscopy. FINDINGS: The number of spermatogonia cells, primary spermatocytes and spermatid in the cinnamon group was 72.25&#177;12.63, 61.71&#177;11.47, and 79.1&#177;10.02, and in the control group was 51.83&#177;23.37, 31.67&#177;5.27 and 38.67&#177;15.7 respectively, and the increase in cinnamon group was significant (p&#60;0.005). The testicles length, width and weight parameters in the cinnamon group were increased compared to the control group (busulfan). The thickness of germinal epithelium in the cinnamon and control group was 53.46 &#177; 16.44 and 30.4&#177;10.21 respectively, which was significantly higher in the cinnamon group (p&#60;0.001). CONCLUSION: According to the findings of this study, cinnamon extract has positive therapeutic and protective effects on testicular tissue and increases sperm production in busulfan-treated rats

Seamless integration of the coastal ocean in global marine carbon cycle modeling

We present the first global ocean-biogeochemistry model that uses a telescoping high resolution for an improved representation of coastal carbon dynamics: ICON-Coast. Based on the unstructured triangular grid topology of the model, we globally apply a grid refinement in the land-ocean transition zone to better resolve the complex circulation of shallow shelves and marginal seas as well as ocean-shelf exchange. Moreover, we incorporate tidal currents including bottom drag effects, and extend the parameterizations of the model's biogeochemistry component to account explicitly for key shelf-specific carbon transformation processes. These comprise sediment resuspension, temperature-dependent remineralization in the water column and sediment, riverine matter fluxes from land including terrestrial organic carbon, and variable sinking speed of aggregated particulate matter. The combination of regional grid refinement and enhanced process representation enables for the first time a seamless incorporation of the global coastal ocean in model-based Earth system research. In particular, ICON-Coast encompasses all coastal areas around the globe within a single, consistent ocean-biogeochemistry model, thus naturally accounting for two-way coupling of ocean-shelf feedback mechanisms at the global scale. The high quality of the model results as well as the efficiency in computational cost and storage requirements proves this strategy a pioneering approach for global high-resolution modeling. We conclude that ICON-Coast represents a new tool to deepen our mechanistic understanding of the role of the land-ocean transition zone in the global carbon cycle, and to narrow related uncertainties in global future projections

Interactive impacts of meteorological and hydrological conditions on the physical and biogeochemical structure of a coastal system

The German Bight was exposed to record high riverine discharges in June 2013, as a result of flooding of the Elbe and Weser rivers. Several anomalous observations suggested that the hydrodynamical and biogeochemical states of the system were impacted by this event. In this study, we developed a biogeochemical model and coupled it with a previously introduced high-resolution hydrodynamical model of the southern North Sea in order to better characterize these impacts and gain insight into the underlying processes. Performance of the model was assessed using an extensive set of in situ measurements for the period 2011–2014. We first improved the realism of the hydrodynamic model with regard to the representation of cross-shore gradients, mainly through inclusion of flow-dependent horizontal mixing. Among other characteristic features of the system, the coupled model system can reproduce the low salinities, high nutrient concentrations and low oxygen concentrations in the bottom layers observed within the German Bight following the flood event. Through a scenario analysis, we examined the sensitivity of the patterns observed during July 2013 to the hydrological and meteorological forcing in isolation. Within the region of freshwater influence (ROFI) of the Elbe–Weser rivers, the flood event clearly dominated the changes in salinity and nutrient concentrations, as expected. However, our findings point to the relevance of the peculiarities in the meteorological conditions in 2013 as well: a combination of low wind speeds, warm air temperatures and cold bottom-water temperatures resulted in a strong thermal stratification in the outer regions and limited vertical nutrient transport to the surface layers. Within the central region, the thermal and haline dynamics interactively resulted in an intense density stratification. This intense stratification, in turn, led to enhanced primary production within the central region enriched by nutrients due to the flood but led to reduction within the nutrient-limited outer region, and it caused a widespread oxygen depletion in bottom waters. Our results further point to the enhancement of the current velocities at the surface as a result of haline stratification and to intensification of the thermohaline estuarine-like circulation in the Wadden Sea, both driven by the flood event

An Experimental Study of the Effect of High Electric Field on Mass Transfer Enhancement

Applying corona wind as a novel technique can lead to a great level of heat and mass transfer augmentation by using a very small amount of energy. The enhancement of forced flow evaporation rate by applying electric field (corona wind) has been experimentally evaluated in this study. Corona wind produced by a fine wire electrode charged with positive high DC voltage impinges on water surface and leads to an evaporation enhancement by disturbing the saturated air layer over water surface. The study was focused on the effect of corona wind velocity, electrode spacing, and air flow velocity on the level of the evaporation enhancement. Two sets of experiments, i.e. with and without electric field, have been conducted. The data obtained from the first experiment were used as a reference for the evaluation of the evaporation enhancement in the presence of electric field. The applied voltages ranged from corona threshold voltage to spark over voltage with increments of 1 kV. The results shows that corona wind has a great enhancement effect on water evaporation rate, but its effectiveness gradually diminishes by increasing air flow velocity. The maximum enhancements are 7.3 and 3.6 times for air velocities of 0.125 and 1.75 m.s-1 respectively

Classification of coastal-marine habitats in Gwatr Bay using ecological standard classification (CMECS)

This research was conducted during 2007-2008 with the main aim of classifying marine coastal habitats in Gwatr Bay located in Iran-Pakistan border, south east of Sistan-Blaluchetan Province. We used Coastal-Marine Ecological Standard Classification (CMECS) with three data layers covering water column, benthic cover classifier and geomorphology. Layers and habitats information were analyzed in a GIS environment and the indicator species were determined. WCC classification was done based on temperature, salinity and clarity classifiers for Ichthyoplankton communities. The result showed that two main seasonal habitats including spring habitat (spring, summer and winter) and fall habitat, affected by the monsoon season is present in the area. Also we considered particle size and total organic matter in sediment as classifiers for benthic habitats which indicated two different habitats based on distances from shore. Habitats were divided into unmixed macro-benthos community (polychaete) and mixed macro-benthos community including: Polychaete, Amphipoda and Gastropoda. The habitats were shown on digital GIS maps with their specific codes

Ecological studies of Bisheh-palan Wetland (Broojerd)

Bisheh-Dalan wetland is located in southern of Broojerd city near the Tireh River with 914 hectares area.This survey was done in 2002-2003.Water temperature variation between 8 at 23/5 °C, the quantity pH between 6.5-7.4, Ec between 362-443 μm/cm, minimum-dissolved oxygen 5/5 mg/l in Bisheh-Dalan area. The phytoplankton comprised 4 families and 15 genus include (Microcystis Gloeotrehia Gloeocapsa, Merismopedia Ceratium, Glenodinium, Gymnodinium, Peridinium Closterium, Stauratrum, Treubaria, Cymbella, Cyclotella, Nitzchia, Navieula), the zooplanktons had 3 families and 10 genus, consist (Stmocephalus, Shnucephalus, Diaphanasoma, Simocephalus, Daphnia, Eueyclops, Attheylla, Cyclops, Trinema, Aeanthoeyclops) and the benthos have been had 10 orders and 15 families with names (Ecdyonuridae, Caenidae, Baetidae, Chiranomidae, Calicidae, Dytiscidae, Limmaeidae, Planorbiidae, Glossosomatidae , Tubificidae, Erpobdellidae, Planariidae, Gammaridae) in Bisheh-Dalan area. The fishes of Bisheh-Dalan wetland composed 2 family with names Cyprinidae and poeciliidae with 7 genus and 8 species. Maximum number of fishes located to Capoeta with 2 Species