Search results for: simple reaction time

Authors: Alexander E. Hramov, Vadim V. Grubov, Alexey A. Koronovskii, Maria K. Kurovskaуa, Anastasija E. Runnova

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The perception of visual signals in the brain was among the first issues discussed in terms of multistability which has been introduced to provide mechanisms for information processing in biological neural systems. In this work the influence of the cognitive noise on the visual perception of multistable pictures has been investigated. The study includes an experiment with the bistable Necker cube illusion and the theoretical background explaining the obtained experimental results. In our experiments Necker cubes with different wireframe contrast were demonstrated repeatedly to different people and the probability of the choice of one of the cubes projection was calculated for each picture. The Necker cube was placed at the middle of a computer screen as black lines on a white background. The contrast of the three middle lines centered in the left middle corner was used as one of the control parameter. Between two successive demonstrations of Necker cubes another picture was shown to distract attention and to make a perception of next Necker cube more independent from the previous one. Eleven subjects, male and female, of the ages 20 through 45 were studied. The choice of the Necker cube projection was detected with the Electroencephalograph-recorder Encephalan-EEGR-19/26, Medicom MTD. To treat the experimental results we carried out theoretical consideration using the simplest double-well potential model with the presence of noise that led to the Fokker-Planck equation for the probability density of the stochastic process. At the first time an analytical solution for the probability of the selection of one of the Necker cube projection for different values of wireframe contrast have been obtained. Furthermore, having used the results of the experimental measurements with the help of the method of least squares we have calculated the value of the parameter corresponding to the cognitive noise of the person being studied. The range of cognitive noise parameter values for studied subjects turned to be [0.08; 0.55]. It should be noted, that experimental results have a good reproducibility, the same person being studied repeatedly another day produces very similar data with very close levels of cognitive noise. We found an excellent agreement between analytically deduced probability and the results obtained in the experiment. A good qualitative agreement between theoretical and experimental results indicates that even such a simple model allows simulating brain cognitive dynamics and estimating important cognitive characteristic of the brain, such as brain noise.

Keywords: bistability, brain, noise, perception, stochastic processes

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Authors: Nadeem Qaiser, Sherjeel Munsif Khan, Muhammad Mustafa Hussian, Vincent Tung

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One of the emerging fields in the detection of chronic diseases is based on the point-of-care (POC) early monitoring of the symptoms and thus provides a state-of-the-art personalized healthcare system. Nowadays, wearable and flexible sensors are being used for analyzing sweat, glucose, blood pressure, and other skin conditions. However, localized jaw-bone swelling called parotid-swelling caused by some viruses has never been tracked before. To track physical motion or deformations, strain sensors, especially piezoresistive ones, are widely used. This work, for the first time, reports carbon nanotubes (CNTs)-based piezoresistive sensing patch that is highly flexible and stretchable and can record muscle deformations in real-time. The developed patch offers an excellent gauge factor for in-plane stretching and spatial expansion with low hysteresis. To calibrate the volumetric muscle expansion, we fabricated the pneumatic actuator that experienced volumetric expansion and thus redefined the gauge factor. Moreover, we employ a Bluetooth-low-energy system that can send information about muscle activity in real-time to a smartphone app. We utilized COMSOL calculations to reveal the mechanical robustness of the patch. The experiments showed the sensing patch's greater cyclability, making it a patch for personal healthcare and an excellent choice for monitoring the real-time POC monitoring of the human muscle swelling.

Keywords: piezoresistive strain sensor, FEM simulations, CNTs sensor, flexible

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Authors: D. Dorota

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This paper presents a method to generate and schedule task in the architecture of embedded systems based on the simulated annealing. This method takes into account the attribute of divisibility of tasks. A proposal represents the process in the form of trees. Despite the fact that the architecture of Network-on-Chip (NoC) is an interesting alternative to a bus architecture based on multi-processors systems, it requires a lot of work that ensures the optimization of communication. This paper proposes an effective approach to generate dedicated NoC topology solving communication problems. Network NoC is generated taking into account the energy consumption and resource issues. Ultimately generated is minimal, dedicated NoC topology. The proposed solution is assumed to be a simple router design and the minimum number of lines.

Keywords: Network-on-Chip, NoC-based embedded systems, scheduling task in embedded systems, simulated annealing

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Authors: Deokyeong Choe, Sung Hun Youn, Younggon Kim, Chul Soo Shin

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L-Cysteine, a sulfur-containing amino acid, has been often used in the pharmaceutical, cosmetic, food, and feed additive industries. This amino acid has been usually produced by acid-hydrolysis of human hair and poultry feathers. There are many problems, such as avoidance for use of animal hair, low yields, and formation of harmful waste material. As an alternative, the enzymatic conversion of D, L-2-amino-Δ2-thiazoline-4-carboxylic acid (ATC) to L-cysteine has been developed as an environmental-friendly method. However, the substrate solubility was too low to be used in industry. In this study, high concentrations of eutectic substrate solutions were prepared to solve the problem. Eutectic melting occurred at 39°C after mixing ATC and malonic acid at a molar ratio of 1:1. The characteristics of eutectic mixtures were analyzed by FE-SEM, EDS mapping, and XPS. However, since sorbitol, MnSO4, and NaOH should be added as supplements to the substrate mixture for the activation and stabilization of the enzyme, strategies for sequential addition of total five compounds, ATC, malonic acid, sorbitol, MnSO4, and NaOH were established. As a result, eutectic substrate mixtures of 670 mM ATC were successfully formulated. After 6 h of enzymatic reaction, 550 mM L-cysteine was made.

Keywords: D, L-2-amino-Δ2-thiazoline-4-carboxylicacid, enzymatic conversion, eutectic solution, l-cysteine

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Authors: Mohammed R. Elkobaisi, Abdelsalam Maatuk

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The search engines are the large scale information retrieval tools from the Web that are currently freely available to all. This paper explains how to convert the raw resulted number of search engines into useful information. This represents a new method for data gathering comparing with traditional methods. When a query is submitted for a multiple numbers of keywords, this take a long time and effort, hence we develop a user interface program to automatic search by taking multi-keywords at the same time and leave this program to collect wanted data automatically. The collected raw data is processed using mathematical and statistical theories to eliminate unwanted data and converting it to usable data.

Keywords: search engines, information extraction, agent system

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Authors: Qiao Fan, Xiaobo Guo, Junxian Zhu, Xiaohu Ding, Ching-Yu Cheng, Tien-Yin Wong, Mingguang He, Heping Zhang, Xueqin Wang

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A systematic, simultaneous analysis of multiple phenotypes in genome-wide association studies (GWASs) draws a great attention to integrate the signals from single phenotypes with increased power. However, lacking an interpretable and efficient multivariate GWAS analysis impede the application of such approach. In this study, we propose to decompose the multivariate model into a series of simple univariate models. This transformation illuminates what exactly the individual trait contributes to the significant signals from the multivariate analyses. By employing our approach in the analysis of three myopia-related endophenotypes from the Singapore Malay Eye Study (SIMES), we identify novel candidate loci which were successfully validated in an independent Guangzhou Twin Eye Study (GTES).

Keywords: GWAS multivariate, multiple traits, myopia, association

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Authors: Saeed Delara, Kendra MacKay

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Varying methodologies are considered for pile design for both Russian and Western approaches. Although both approaches rely on toe and side frictional resistances, different calculation methods are proposed to estimate pile capacity. The Western approach relies on compactness (internal friction angle) of soil for cohesionless soils and undrained shear strength for cohesive soils. The Russian approach relies on grain size for cohesionless soils and liquidity index for cohesive soils. Though most recommended methods in the Western approaches are relatively simple methods to predict pile settlement, the Russian approach provides a detailed method to estimate single pile and pile group settlement. Details to calculate pile axial capacity and settlement using the Russian and Western approaches are discussed and compared against field test results.

Keywords: pile capacity, pile settlement, Russian approach, western approach

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Authors: Kalu Uka Orji, Nasiman Sapari, Khamaruzaman W. Yusof

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Exposure of galena (PbS), tealite (PbSnS2), and other associated minerals during mining activities release lead (Pb) and other heavy metals into the mining water through oxidation and dissolution. Heavy metal pollution has become an environmental challenge. Lead, for instance, can cause toxic effects to human health, including brain damage. Ex-mining pond water was reported to contain lead as high as 69.46 mg/L. Conventional treatment does not easily remove lead from water. A promising and emerging treatment technology for lead removal is the application of the electrocoagulation (EC) process. However, some of the problems associated with EC are systematic reactor design, selection of maximum EC operating parameters, scale-up, among others. This study investigated an EC process for the removal of lead from synthetic ex-mining pond water using a batch reactor and Fe electrodes. The effects of various operating parameters on lead removal efficiency were examined. The results obtained indicated that the maximum removal efficiency of 98.6% was achieved at an initial PH of 9, the current density of 15mA/cm2, electrode spacing of 0.3cm, treatment time of 60 minutes, Liquid Motion of Magnetic Stirring (LM-MS), and electrode arrangement = BP-S. The above experimental data were further modeled and optimized using a 2-Level 4-Factor Full Factorial design, a Response Surface Methodology (RSM). The four factors optimized were the current density, electrode spacing, electrode arrangements, and Liquid Motion Driving Mode (LM). Based on the regression model and the analysis of variance (ANOVA) at 0.01%, the results showed that an increase in current density and LM-MS increased the removal efficiency while the reverse was the case for electrode spacing. The model predicted the optimal lead removal efficiency of 99.962% with an electrode spacing of 0.38 cm alongside others. Applying the predicted parameters, the lead removal efficiency of 100% was actualized. The electrode and energy consumptions were 0.192kg/m3 and 2.56 kWh/m3 respectively. Meanwhile, the adsorption kinetic studies indicated that the overall lead adsorption system belongs to the pseudo-second-order kinetic model. The adsorption dynamics were also random, spontaneous, and endothermic. The higher temperature of the process enhances adsorption capacity. Furthermore, the adsorption isotherm fitted the Freundlish model more than the Langmuir model; describing the adsorption on a heterogeneous surface and showed good adsorption efficiency by the Fe electrodes. Adsorption of Pb2+ onto the Fe electrodes was a complex reaction, involving more than one mechanism. The overall results proved that EC is an efficient technique for lead removal from synthetic mining pond water. The findings of this study would have application in the scale-up of EC reactor and in the design of water treatment plants for feed-water sources that contain lead using the electrocoagulation method.

Keywords: ex-mining water, electrocoagulation, lead, adsorption kinetics

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Authors: C. J. Tien, C. S. Chen, S. F. Huang, Z. X. Wang

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Algae in soil ecosystems can produce organic matters and oxygen by photosynthesis. Heterocyst-forming cyanobacteria can fix nitrogen to increase soil nitrogen contents. Secretion of mucilage by some algae increases the soil water content and soil aggregation. These actions will improve soil quality and fertility, and further increase abundance and diversity of soil microorganisms. In addition, some mixotrophic and heterotrophic algae are able to degrade petroleum hydrocarbons. Therefore, the objectives of this study were to analyze the effects of algal addition on the degradation of total petroleum hydrocarbons (TPH), diversity and activity of bacteria and algae in the diesel-contaminated soil under different nutrient contents and frequency of plowing and irrigation in order to assess the potential bioremediation technique using edaphic algae. The known amount of diesel was added into the farmland soil. This diesel-contaminated soil was subject to five settings, experiment-1 with algal addition by plowing and irrigation every two weeks, experiment-2 with algal addition by plowing and irrigation every four weeks, experiment-3 with algal and nutrient addition by plowing and irrigation every two weeks, experiment-4 with algal and nutrient addition by plowing and irrigation every four weeks, and the control without algal addition. Soil samples were taken every two weeks to analyze TPH concentrations, diversity of bacteria and algae, and catabolic genes encoding functional degrading enzymes. The results show that the TPH removal rates of five settings after the two-month experimental period were in the order: experiment-2 > expermient-4 > experiment-3 > experiment-1 > control. It indicated that algal addition enhanced the degradation of TPH in the diesel-contaminated soil, but not for nutrient addition. Plowing and irrigation every four weeks resulted in more TPH removal than that every two weeks. The banding patterns of denaturing gradient gel electrophoresis (DGGE) revealed an increase in diversity of bacteria and algae after algal addition. Three petroleum hydrocarbon-degrading algae (Anabaena sp., Oscillatoria sp. and Nostoc sp.) and two added algal strains (Leptolyngbya sp. and Synechococcus sp.) were sequenced from DGGE prominent bands. The four hydrocarbon-degrading bacteria Gordonia sp., Mycobacterium sp., Rodococcus sp. and Alcanivorax sp. were abundant in the treated soils. These results suggested that growth of indigenous bacteria and algae were improved after adding edaphic algae. Real-time polymerase chain reaction results showed that relative amounts of four catabolic genes encoding catechol 2, 3-dioxygenase, toluene monooxygenase, xylene monooxygenase and phenol monooxygenase were appeared and expressed in the treated soil. The addition of algae increased the expression of these genes at the end of experiments to biodegrade petroleum hydrocarbons. This study demonstrated that edaphic algae were suitable biomaterials for bioremediating diesel-contaminated soils with plowing and irrigation every four weeks.

Keywords: catabolic gene, diesel, diversity, edaphic algae

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Authors: U.B Mahadevswamy UBM, Siraj Ahmed Siraj

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As the title of the paper indicates about brainwaves and its uses for various applications based on their frequencies and different parameters which can be implemented as real time application with the title a smart brain wave sensor system for paralyzed patients. Brain wave sensing is to detect a person's mental status. The purpose of brain wave sensing is to give exact treatment to paralyzed patients. The data or signal is obtained from the brainwaves sensing band. This data are converted as object files using Visual Basics. The processed data is further sent to Arduino which has the human's behavioral aspects like emotions, sensations, feelings, and desires. The proposed device can sense human brainwaves and detect the percentage of paralysis that the person is suffering. The advantage of this paper is to give a real-time smart sensor device for paralyzed patients with paralysis percentage for their exact treatment. Keywords:-Brainwave sensor, BMI, Brain scan, EEG, MCH.

Keywords: Keywords:-Brainwave sensor , BMI, Brain scan, EEG, MCH

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Authors: I. K. Sharma

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Over the years world over system are being developed by research labs continuously monitor under water parameters in the coastal waters of sea such as conductivity, salinity, pressure, temperature, chlorophyll and biological blooms at different levels of water column. The research institutions have developed profilers which are launched by ship connected through cable, glider type profilers following underwater trajectory, buoy any driven profilers, wire guided profilers etc. In all these years, the effect was to design autonomous profilers with no cable quality connection, simple operation and on line date transfer in terms accuracy, repeatability, reliability and consistency. Hence for the Ministry of Communication and Information Technology, India sponsored research project to National Institute of Oceanography, GOA, India to design and develop autonomous vertical profilers, it has taken system and AVP has been successfully developed and tested.

Keywords: oceanography, water column, autonomous profiler, buoyancy

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Authors: Gyo Woo Lee, Man Young Kim

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A mathematical heat transfer model for the prediction of transient heating of the slab in a direct-fired walking beam type reheating furnace has been developed by considering the nongray thermal radiation with given furnace environments. The furnace is modeled as radiating nongray medium with carbon dioxide and water with five-zoned gas temperature and the furnace wall is considered as a constant temperature lower than furnace gas one. The slabs are moving with constant velocity depending on the residence time through the non-firing, charging, preheating, heating, and final soaking zones. Radiative heat flux obtained by considering the radiative heat exchange inside the furnace as well as convective one from the surrounding hot gases are introduced as boundary condition of the transient heat conduction within the slab. After validating thermal radiation model adopted in this work, thermal fields in both model and real reheating furnace are investigated in terms of radiative heat flux in the furnace and temperature inside the slab. The results show that the slab in the furnace can be more heated with higher slab emissivity and residence time.

Keywords: reheating furnace, steel slab, radiative heat transfer, WSGGM, emissivity, residence time

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Authors: Zhiyong Li, Hiroshi Katayama

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Since 1990s, e-commerce and internet business have been grown gradually over the word and customers tend to express their demand attributes in terms of specification requirement on parts, component, product structure etc. This paper deals with designing effective decoupling points for build to order systems under e-commerce environment, which can be realized through tradeoff relation analysis between two major criteria, customer order lead time and value of work in progress. These KPIs are critical for successful BTO business, namely time-based service effectiveness on coping with customer requirements for the first issue and cost effective ness with risk aversive operations for the second issue. Approach of this paper consists of investigation of successful business standing for BTO scheme, manufacturing model development of this scheme, quantitative evaluation of proposed models by calculation of two KPI values under various decoupling point distributions and discussion of the results brought by pattern of decoupling point distribution, where some cases provide the pareto optimum performances. To extract the relevant trade-off relation between considered KPIs among 2-dimensional resultant performance, useful logic developed by former research work, i.e. Katayama and Fonseca, is applied. Obtained characteristics are evaluated as effective information for managing BTO manufacturing businesses.

Keywords: build-to-order (BTO), decoupling point, e-commerce, order-to-delivery lead time (ODLT), work in progress (WIP)

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Authors: Nouredine Benouzza, Ahmed Hamida Boudinar, Azeddine Bendiabdellah

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An algorithm for Eccentricity Fault Detection (EFD) applied to a squirrel cage induction machine is proposed in this paper. This algorithm employs the behavior of the stator current spectral analysis and the localization of the Rotor Slot Harmonic (RSH) frequency to detect eccentricity faults in three phase induction machine. The RHS frequency once obtained is used as a key parameter into a simple developed expression to directly compute the eccentricity fault frequencies in the induction machine. Experimental tests performed for both a healthy motor and a faulty motor with different eccentricity fault severities illustrate the effectiveness and merits of the proposed EFD algorithm.

Keywords: squirrel cage motor, diagnosis, eccentricity faults, current spectral analysis, rotor slot harmonic

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Authors: Bintao Wu, Xiangfang Xu, Yugang Miao，Duanfeng Han

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Joining of 1 mm thick aluminum 6061 to titanium TC4 was conducted using Bypass-current MIG welding-brazed, and stable welding process and good bead appearance were obtained. The Joint profile and microstructure of Ti/Al joints were observed by optical microscopy and SEM and then the structure of the interfacial reaction layers were analyzed in details. It was found that the intermetallic compound layer at the interfacial top is in the form of columnar crystal, which is in short and dense state. A mount of AlTi were observed at the interfacial layer near the Ti base metal while intermetallic compound like Al3Ti、TiSi3 were formed near the Al base metal, and the Al11Ti5 transition phase was found in the center of the interface layer due to the uneven distribution inside the weld pool during the welding process. Tensile test results show that the average tensile strength of joints is up to 182.6 MPa, which reaches about 97.6% of aluminum base metal. Fracture is prone to occur in the base metal with a certain amount of necking.

Keywords: bypass-current MIG welding-brazed, Al alloy, Ti alloy, joint characteristics, mechanical properties

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Authors: Sorore Benabid

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The Q-enhanced LC filters are the most used architecture in the Bandpass (BP) Continuous-Time (CT) Delta-Sigma (ΣΔ) modulators, due to their: high frequencies operation, high linearity than the active filters and a high quality factor obtained by Q-enhanced technique. This technique consists of the use of a negative resistance that compensate the ohmic losses in the on-chip inductor. However, this technique introduces a zero in the filter transfer function which will affect the modulator performances in term of Dynamic Range (DR), stability and in-band noise (Signal-to-Noise Ratio (SNR)). In this paper, we study the effect of this zero and we demonstrate that a calibration of the excess loop delay (ELD) is required to ensure the best performances of the modulator. System level simulations are done for a 2ndorder BP CT (ΣΔ) modulator at a center frequency of 300MHz. Simulation results indicate that the optimal ELD should be reduced by 13% to achieve the maximum SNR and DR compared to the ideal LC-based ΣΔ modulator.

Keywords: continuous-time bandpass delta-sigma modulators, excess loop delay, on-chip inductor, Q-enhanced LC filter

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Authors: Ali Anwar, Hu Qinglei, Li Bo, Muhammad Taha Ali

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In this paper a generic model of perturbed nonlinear systems is considered which is affected by hard backlash nonlinearity at the input. The nonlinearity is modelled by a dynamic differential equation which presents a more precise shape as compared to the existing linear models and is compatible with nonlinear design technique such as backstepping. Moreover, a novel backstepping based nonlinear control law is designed which explicitly incorporates a continuous-time adaptive backlash inverse model. It provides a significant flexibility to control engineers, whereby they can use the estimated backlash spacing value specified on actuators such as gears etc. in the adaptive Backlash Inverse model during the control design. It ensures not only global stability but also stringent transient performance with desired precision. It is also robust to external disturbances upon which the bounds are taken as unknown and traverses the backlash spacing efficiently with underestimated information about the actual value. The continuous-time backlash inverse model is distinguished in the sense that other models are either discrete-time or involve complex computations. Furthermore, numerical simulations are presented which not only illustrate the effectiveness of proposed control law but also its comparison with PID and other backstepping controllers.

Keywords: adaptive control, hysteresis, backlash inverse, nonlinear system, robust control, backstepping

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Authors: Anca Dinischiotu, Sorina Nicoleta Voicu

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Silica nanoparticles (SiO2-NPs) are widely used in consumer products such as paints, plastics, insulation materials, tires, concrete production, as well as in gene delivery systems and imaging procedures. Environmental human exposure to them occurs during utilization of these products, in a time-dependent manner, the uptake being by topic and inhalation route especially. SiO2-NPs enter cells and induce membrane damage, oxidative stress and inflammatory reactions in a concentration-dependent manner. In this study, MRC-5 cells (human fetal lung fibroblasts) were exposed to amorphous SiO2-NPs at a dose of 62.5 μg/ml for 24, 48 and 72 hours. The size distribution of NPs was a lognormal function, in the range 3-14 nm. A time-dependent decrease of total reduced glutathione concentration by 36%, 50%, and 78% and an increase of NO level by 62%, 32%, respectively 24% compared to control were noticed. An up-regulation of NF-kB expression by 20%, 50% respectively 10% and of Nrf-2 by 139%, 58%, and 16% compared to control after 24, 48 and 72 hours was noticed also. The expression of IL-1β, IL-6, IL-8, and COX-2 was up-regulated in a time-dependent manner. Also, the expression of MMP-2 and MMP-9 were down-regulated after 48 and 72 hours, whereas their activities raised in a time-dependent manner. Exposure of cells to NPs up-regulated the expression of inducible NO synthase, as previously was shown, and probably this is the reason for the increased level of NO, that can react with the thiol groups of reduced glutathione molecules, diminishing its concentration Nrf2 is a transcription factor translocated in nucleus, under oxidative stress, where downstream gene expression activates in order to modulate the adaptive intracellular response against oxidative stress. The cross-talk between Nrf2 and NF-kB activities regulates the inflammatory processes. The activation of NF-kB could activate up-regulation of IL-1β, IL-6, and IL-8. The increase of COX-2 expression could be correlated with IL-1β one. Also, probably in response to the pro-inflammatory cytokines, MMP-2 and MMP-9 were induced and activated. In conclusion, the exposure of MRC-5 cells to SiO2-NPs generated inflammation in a time-dependent manner.

Keywords: inflammation, MRC-5 cells, oxidative stress, silica nanoparticles

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Authors: Meriam Khelifa

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In recent years, many studies have focused on the harvesting of the vibrations energy to produce electrical energy using contact separation (CS) triboelectric nanogenerators (TENG). The simplest design for a TENG consists of a capacitor comprising a single moving electrode. The conversion efficiency of vibration energy into electrical energy can, in principle, reach 100%. But to actually achieve this objective, it is necessary to optimize the parameters of the TENG, such as the dielectric constant and the thickness of the insulator, the load resistance, etc. In particular, the use of a switch which is actioned at optimal times within the TENG cycle is essential. Using numerical modeling and experimental design, we applied a methodology to find the TENG parameters which optimize the energy transfer efficiency (ETE) to almost 100% for any vibration frequency and amplitude. The rather simple design of a TENG is promising as an environment friendly device. It opens the doors for harvesting acoustic vibrations from the environment and to design effective protection against environmental noise.

Keywords: vibrations, CS TENG, efficiency, design of experiments

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Authors: Jong Kook Lee, Sangcheol Eum, Jaehong Kim

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Wollastonite/hydroxyapatite composite coatings on zirconia were obtained by room temperature spray process. Wollastonite powder was synthesized by solid-state reaction between calcite and silica powder. Hydroxyapatite powder was prepared from bovine bone by the calcination at 1200oC 1h. From two starting raw powders, three kinds of powder mixture were obtained by the ball milling for 24h. By using these powders, wollastonite/hydroxyapatite coatings were fabricated on zirconia substrates by a room temperature spray process, and their microstructure and biological behavior were investigated and compared with pure wollastonite and hydroxyapatite coatings. Wollastonite/hydroxyapatite coatings on zirconia substrates were homogeneously formed in microstructure and had a nanoscaled grain size. The phase composition of the resultant wollastonite/hydroxyapatite coatings was similar to that of the starting powders, however, the grain size of the wollastonite or hydroxyapatite particles was reduced to about 100 nm due to their formation by particle impaction and fracture. The wollastonite/hydroxyapatite coating layer exhibited bioactivity in a stimulated body fluid and forming ability of new hydroxyapatite precipitates of 25 nm during in vitro test in SBF solution, which was enhanced by the increasing wollastonite content.

Keywords: wollastonite, hydroxyapatite composite coatings, room temperature spay process, zirconia

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Authors: Caroline Alice Rouget-Virbel, F. Dean Toste

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Heterobimetallic systems have been precedented in a wide array of bioinorganic and heterogeneous catalytic settings, in which cooperative bond-breaking and bond-forming events mediated by neighboring metal sites have been proposed but are challenging to study and characterize. Heterodinuclear transition-metal catalysis has recently emerged as a promising strategy to tackle challenging chemical transformations, including C−C and C−X couplings as well as small molecule activation. It has been shown that these reactions can traverse nontraditional mechanisms, reactivities, and selectivities when homo- and heterobimetallic systems are employed. Moreover, stoichiometric studies of transmetallation from gold complexes have demonstrated that R transfer from PPh3–Au(I)R to Cp- and Cp*-ligated group 8/9 complexes is a viable elementary step. With these considerations in mind, we hypothesized that heterobimetallic Au–M complexes could serve as a viable and tunable catalyst platform to explore mechanisms and reactivity. In this work, heterobimetallic complexes containing Au(I) centers tethered to Ir(III) and Rh(III) piano stool moieties were synthesized and characterized. Preliminary application of these complexes to a catalytic allylic arylation reaction demonstrates bimetallic cooperativity relative to their monomeric metal components.

Keywords: heterobimetallic, catalysis, gold, rhodium

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Authors: Lal Hussain, Wajid Aziz, Imtiaz Ahmed Awan, Sharjeel Saeed

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Multiscale entropy analysis (MSE) is a useful technique recently developed to quantify the dynamics of physiological signals at different time scales. This study is aimed at investigating the electroencephalogram (EEG) signals to analyze the background activity of alcoholic and control subjects by inspecting various coarse-grained sequences formed at different time scales. EEG recordings of alcoholic and control subjects were taken from the publically available machine learning repository of University of California (UCI) acquired using 64 electrodes. The MSE analysis was performed on the EEG data acquired from all the electrodes of alcoholic and control subjects. Mann-Whitney rank test was used to find significant differences between the groups and result were considered statistically significant for p-values<0.05. The area under receiver operator curve was computed to find the degree separation between the groups. The mean ranks of MSE values at all the times scales for all electrodes were higher control subject as compared to alcoholic subjects. Higher mean ranks represent higher complexity and vice versa. The finding indicated that EEG signals acquired through electrodes C3, C4, F3, F7, F8, O1, O2, P3, T7 showed significant differences between alcoholic and control subjects at time scales 1 to 5. Moreover, all electrodes exhibit significance level at different time scales. Likewise, the highest accuracy and separation was obtained at the central region (C3 and C4), front polar regions (P3, O1, F3, F7, F8 and T8) while other electrodes such asFp1, Fp2, P4 and F4 shows no significant results.

Keywords: electroencephalogram (EEG), multiscale sample entropy (MSE), Mann-Whitney test (MMT), Receiver Operator Curve (ROC), complexity analysis

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Authors: H. Benaldjia, N. Habib, F. Djefaflia, A. Nait-Merzoug, A. Harat, J. El-Haskouri, O. Guellati

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Currently, the technology has attracted knowledge of energy storage sources similar to batteries, capacitors and super-capacitors because of its very different applications in many fields with major social and economic challenges. Moreover, hydroxides have attracted much attention as a promising and active material choice in large-scale applications such as molecular adsorption/storage and separation for the environment, ion exchange, nanotechnology, supercapacitor for energy storage and conversion, electro-biosensing, and catalysts, due to their unique properties which are strongly influenced by their composition, microstructure, and synthesis method. In this context, we report in this study the synthesis of hydroxide-based nanomaterials precisely based on Ni and Fe using a simple hydrothermal method with mono and bi precursors at optimized growth conditions (6h-120°C). The obtained products were characterized using different techniques, such as XRD, FTIR, FESEM and BET, as well as electrochemical measurements.

Keywords: energy storage, Supercapacitors, nanocomposites, nanohybride, electro-active materials.

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Authors: Mostafa Rezaee Saraji, Ali Keshavarz Panahi

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In this work, the processing steps for producing alumina parts using powder injection molding (PIM) technique and nano-powder were investigated and the thermal conductivity and flexural strength of samples were determined as a function of sintering temperature and holding time. In the first step, the feedstock with 58 vol. % of alumina nano-powder with average particle size of 100nm was prepared using Extrumixing method to obtain appropriate homogeneity. This feedstock was injection molded into the two cavity mold with rectangular shape. After injection molding step, thermal and solvent debinding methods were used for debinding of molded samples and then these debinded samples were sintered in different sintering temperatures and holding times. From the results, it was found that the flexural strength and thermal conductivity of samples increased by increasing sintering temperature and holding time; in sintering temperature of 1600ºC and holding time of 5h, the flexural strength and thermal conductivity of sintered samples reached to maximum values of 488MPa and 40.8 W/mK, respectively.

Keywords: alumina nano-powder, thermal conductivity, flexural strength, powder injection molding

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Authors: Hilal Karakuş, Berrin Akman

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Preschool years are considered as critical years because of shaping the future lives of individuals. All of the knowledge, skills, and concepts are acquired during this period. Also, basis of academic skills is based on this period. As all of the developmental areas are the fastest in that period, the basis of mathematics education should be given in this period, too. Mathematics is seen as a difficult and abstract course by the most people. Therefore, the enjoyable side of mathematics should be presented in a concrete way in this period to avoid any bias of children for mathematics. This study is conducted to examine mathematics concept acquisition of children in terms of different variables. Screening model is used in this study which is carried out in a quantity way. The study group of this research consists of total 300 children, selected from each class randomly in groups of five, who are from public and private preschools in Çankaya, which is district of Ankara, in 2014-2015 academic year and attending children in the nursery classes and preschool institutions are connected to the Ministry of National Education. The study group of the research was determined by stage sampling method. The schools, which formed study group, are chosen by easy sampling method and the children are chosen by simple random method. Research data were collected with Bracken Basic Concept Scale–Revised Form and Child’s Personal Information Form generated by the researcher in order to get information about children and their families. Bracken Basic Concept Scale-Revised Form consists of 11 sub-dimensions (color, letter, number, size, shape, comparison, direction-location, and quantity, individual and social awareness, building- material) and 307 items. Subtests related to the mathematics were used in this research. In the “Child Individual Information Form” there are items containing demographic information as followings: age of children, gender of children, attending preschools educational intuitions for children, school attendance, mother’s and father’s education levels. At the result of the study, while it was found that children’s mathematics skills differ from age, state of attending any preschool educational intuitions , time of attending any preschool educational intuitions, level of education of their mothers and their fathers; it was found that it does not differ by the gender and type of school they attend.

Keywords: preschool education, preschool period children, mathematics education, mathematics concept acquisitions

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Authors: Mingmei Zhang, Xinyong Li

Abstract:

Novel AgInS2/SnS2/RGO (AISR) heterojunctions photocatalysts were synthesized by simple hydrothermal method. The morphology and composition of the fabricated AISR nanocomposites were investigated by field-emission scanning electron microscopy (SEM), X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS). Moreover, the as-prepared AISR photocatalysts exhibited excellent photocatalytic activities for the degradation of Norfloxacin (NOR), mainly due to its high optical absorption and separation efficiency of photogenerated electron-hole pairs, as evidenced by UV–vis diffusion reflection spectra (DRS) and Surface photovoltage (SPV) spectra. Furthermore, laser flash photolysis technique was conducted to test the lifetime of charge carriers of the fabricated nanocomposites. The interfacial charges transfer mechanism was also discussed.

Keywords: AISR heterojunctions, electron-hole pairs, SPV spectra, charges transfer mechanism

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Authors: E. Steen, B. Dewulf, N. Müller, C. Vandycke, Y. Vandekerckhove

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Introduction: The care for a ST-elevation myocardial infarction (STEMI) patient is time-critical. Reperfusion therapy within 90 minutes of initial medical contact is mandatory in the improvement of the outcome. Primary percutaneous coronary intervention (PCI) without previous fibrinolytic treatment, is the preferred reperfusion strategy in patients with STEMI, provided it can be performed within guideline-mandated times. Aim of the study: During a one year period (January 2013 to December 2013) the files of all consecutive STEMI patients with urgent referral from non-PCI facilities for primary PCI were reviewed. Special attention was given to a subgroup of patients with prior out-of-hospital medical contact generated by the 112-system. In an effort to reduce out-of-hospital system delay to definitive care a change in pre-hospital 112 dispatch strategies is proposed for these time-critical patients. Actual time recordings were compared with travel time simulations for two suggested scenarios. A first scenario (SC1) involves the decision by the on scene ground EMS (GEMS) team to transport the out-of-hospital diagnosed STEMI patient straight forward to a PCI centre bypassing the nearest non-PCI hospital. Another strategy (SC2) explored the potential role of helicopter EMS (HEMS) where the on scene GEMS team requests a PCI-centre based HEMS team for immediate medical transfer to the PCI centre. Methods and Results: 49 (29,1% of all) STEMI patients were referred to our hospital for emergency PCI by a non-PCI facility. 1 file was excluded because of insufficient data collection. Within this analysed group of 48 secondary referrals 21 patients had an out-of-hospital medical contact generated by the 112-system. The other 27 patients presented at the referring emergency department without prior contact with the 112-system. The table below shows the actual time data from first medical contact to definitive care as well as the simulated possible gain of time for both suggested strategies. The PCI-team was always alarmed upon departure from the referring centre excluding further in-hospital delay. Time simulation tools were similar to those used by the 112-dispatch centre. Conclusion: Our data analysis confirms prolonged reperfusion times in case of secondary emergency referrals for STEMI patients even with the use of HEMS. In our setting there was no statistical difference in gain of time between the two suggested strategies, both reducing the secondary referral generated delay with about one hour and by this offering all patients PCI within the guidelines mandated time. However, immediate HEMS activation by the on scene ground EMS team for transport purposes is preferred. This ensures a faster availability of the local GEMS-team for its community. In case these options are not available and the guideline-mandated times for primary PCI are expected to be exceeded, primary fibrinolysis should be considered in a non-PCI centre.

Keywords: STEMI, system delay, HEMS, emergency medicine

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Authors: Jummai Aliyu Mohammed

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The Sapir-Whorfian hypothesis postulates that the structure of a language determines the way in which species of that language view the world. It also states that the culture of a people finds reflection in their language. Consequently language becomes a vehicle of thought; a channel through which negative stereotypes of women is created and also one through which such images are dispelled. Women are generally portrayed as weaker vessels and inferior to men; a position which draws a counter reaction from women through their writings. In their writings, they attempt to reinvent womanhood and liberate the woman from the hitherto negative light they were portrayed. This position best describes the term feminism which argues that women be given equal rights in all spheres of life as men. This paper attempts to evaluate Ba’s ‘So Long a Letter’ and Alkali’s ‘The Stillborn’ with the view to identify the relationship between language and feminism. In evaluating this relationship, the paper concludes that there are several factors responsible for the variation in the speech pattern of male and female. All of these factors favour the male gender and further condemns the woman to oppression. Although the writers come from two different cultural backgrounds, the works amplify feminism and captured them as apostles of feminism.

Keywords: feminism, language, politics, Sapir-Whorfian hypothesis

Procedia PDF Downloads 171

Authors: Zafar Iqbal

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This study involved students of 6th semester enrolled in a Bachelor of Computer Science Program at university level. In this era of science and technology, e-learning can be helpful for grassroots in providing them access to education tenant in less developed areas. It is a potential substitute of face-to-face teaching being used in different countries. The purpose of the study was to explore the views of students about e-learning (Facebook) as an instructional tool. By using purposive sampling technique an intact class of 30 students included both male and female were selected where e-learning was used as an instructional tool. The views of students were explored through qualitative approach by using focus group interviews. The approach was helpful to develop comprehensive understanding of students’ views towards e- learning. In addition, probing questions were also asked and recorded. Data was transcribed, generated nodes and then coded text against these nodes. For this purpose and further analysis, NVivo 10 software was used. Themes were generated and tangibly presented through cluster analysis. Findings were interesting and provide sufficient evidence that face book is a subsequent e-learning source for students of higher education. Students acknowledged it as best source of learning and it was aligned with their academic and social behavior. It was not time specific and therefore, feasible for students who work day time and can get on line access to the material when they got free time. There were some distracters (time wasters) reported by the students but can be minimized by little effort. In short, e-learning is need of the day and potential learning source for every individual who have access to internet living at any part of the globe.

Keywords: e-learning, facebook, instructional tool, higher education

Procedia PDF Downloads 375

Authors: Harley Stephens

Abstract:

Although fiducial marker insertion is regarded as the ‘gold standard’ in terms of image guided radiotherapy (IGRT), its application must be considered carefully as the procedure can be invasive, time-consuming, and reliant on consultant expertise. Precision of the fiducials is dependent on these markers remaining in the same location and on the prostate not changing shape during the course treatment. To facilitate the acquirement of non-ionising IGRT and intra-fractional prostate tracking, Clarity TPUS was developed as an alternative imaging system. The main benefits of Clarity TPUS are that it is non-invasive, non-ionising and cost-effective. Other studies have compared fiducials to transabdominal ultrasound, which has since been proven to not be as accurate as trans-perineal imaging, as included in this study. CBCT fiducial translations and Clarity TPUS translations for 120 images as part of the PACE-C prostate SABR trial were retrospectively evaluated by three imaging specialists. Differences were analysed using correlation and Bland-Altman plots. Inter-observer matches agreed within 3mm 88.3 % of the time in left/right direction, 86.7 % of the time in in superior/inferior direction, and 91.7% of the time in ant/post direction. They agreed within 5mm more than 98.3 % of the time in all directions. The intra-class correlation co-efficient was calculated for each direction to show agreement between imaging specialist for inter-observer variability. Each was 0.95 or above, with 1 indicating perfect reliability. Agreement between observers was slightly higher for CBCT and fiducials at 98.7% agreement within 5 mm, compared to clarity TPUS where 96.7% agreement was seen within 5mm. Clarity TPUS has the benefit of no additional dose and intra-fractional monitoring, and results show a good correlation between the different modalities. Inter-observer variability is to be considered, and further research with a larger population would be of benefit.

Keywords: oncology, prostate radiotherapy, image guided radiotherapy, IGRT

Procedia PDF Downloads 108