Search results for: psychrophilic conditions

Authors: Babak Safaei, Ahmad Ghanbari, Arash Rahmani

Abstract:

In the present study, the free vibration characteristics of double-walled carbon nanotubes (DWCNTs) are investigated. The small-scale effects are taken into account using the Eringen’s nonlocal elasticity theory. The nonlocal elasticity equations are implemented into the different classical beam theories namely as Euler-Bernoulli beam theory (EBT), Timoshenko beam theory (TBT), Reddy beam theory (RBT), and Levinson beam theory (LBT) to analyze the free vibrations of DWCNTs in which each wall of the nanotubes is considered as individual beam with van der Waals interaction forces. Generalized differential quadrature (GDQ) method is utilized to discretize the governing differential equations of each nonlocal beam model along with four commonly used boundary conditions. Then molecular dynamics (MD) simulation is performed for a series of armchair and zigzag DWCNTs with different aspect ratios and boundary conditions, the results of which are matched with those of nonlocal beam models to extract the appropriate values of the nonlocal parameter corresponding to each type of chirality, nonlocal beam model and boundary condition. It is found that the present nonlocal beam models with their proposed correct values of nonlocal parameter have good capability to predict the vibrational behavior of DWCNTs, especially for higher aspect ratios.

Keywords: double-walled carbon nanotubes, nonlocal continuum elasticity, free vibrations, molecular dynamics simulation, generalized differential quadrature method

Procedia PDF Downloads 283

Authors: Michael Zhang, Nicholas Marriage, Valerie Astle, Marie-Louise Ratican, Jonathan Ash, Haddijatou Hughes

Abstract:

Objective: Young infants are often brought to the Emergency Department (ED) with a variety of complaints, some of them are non-specific and present as a diagnostic challenge to the attending clinician. Whilst invasive investigations such as blood tests and lumbar puncture are necessary in some cases to exclude serious infections, some basic clinical tools in additional to thorough clinical history can be useful to assess the risks of serious conditions in these young infants. This study aimed to examine the utilization of one of clinical tools in this regard. Methods: This retrospective observational study examined the medical records of infants under 6 months presenting to a mixed urban ED between January 2013 and December 2014. The infants deemed to have non-specific complaints or diagnoses by the emergency clinicians were selected for analysis. The ones with clear systemic diagnoses were excluded. Among all relevant clinical information and investigation results, utilization of Standard Paediatric Observation Chart (SPOC) was particularly scrutinized in these medical records. This specific chart was developed by the expert clinicians in local health department. It categorizes important clinical signs into some color-coded zones as a visual cue for serious implication of some abnormalities. An infant is regarded as SPOC positive when fulfills 1 red zone or 2 yellow zones criteria, and the attending clinician would be prompted to investigate and treat for potential serious conditions accordingly. Results: Eight hundred and thirty-five infants met the inclusion criteria for this project. The ones admitted to the hospital for further management were more likely to have SPOC positive criteria than the discharged infants (Odds ratio: 12.26, 95% CI: 8.04 – 18.69). Similarly, Sepsis alert criteria on SPOC were positive in a higher percentage of patients with serious infections (56.52%) in comparison to those with mild conditions (15.89%) (p < 0.001). The SPOC sepsis criteria had a sensitivity of 56.5% (95% CI: 47.0% - 65.7%) and a moderate specificity of 84.1% (95% CI: 80.8% - 87.0%) to identify serious infections. Applying to this infant population, with a 17.4% prevalence of serious infection, the positive predictive value was only 42.8% (95% CI: 36.9% - 49.0%). However, the negative predictive value was high at 90.2% (95% CI: 88.1% - 91.9%). Conclusions: Standard Paediatric Observation Chart has been applied as a useful clinical tool in the clinical practice to help identify and manage young sick infants in ED effectively.

Keywords: clinical tool, infants, non-specific complaints, Standard Paediatric Observation Chart

Procedia PDF Downloads 237

Authors: Himanshu Dehra

Abstract:

An experimental study was conducted for ascertaining electrical and thermal characteristics of a pair of photovoltaic (PV) modules integrated with solar wall of an outdoor room. A pre-fabricated outdoor room was setup for conducting outdoor experiments on a PV solar wall with passive and active ventilation through the outdoor room. The selective operating conditions for glass coated PV modules were utilized for establishing their electrical and thermal characteristics. The PV solar wall was made up of glass coated PV modules, a ventilated air column, and an insulating layer of polystyrene filled plywood board. The measurements collected were currents, voltages, electric power, air velocities, temperatures, solar intensities, and thermal time constant. The results have demonstrated that: i) a PV solar wall installed on a wooden frame was of more heat generating capacity in comparison to a window glass or a standalone PV module; ii) generation of electric power was affected with operation of vertical PV solar wall; iii) electrical and thermal characteristics were not significantly affected by heat and thermal storage losses; and iv) combined heat and electricity generation were function of volume of thermal and electrical resistances developed across PV solar wall. Finally, a comparison of temperature plots of passive and active ventilation envisaged that fan pressure was necessary to avoid overheating of the PV solar wall. The active ventilation was necessary to avoid over-heating of the PV solar wall and to maintain adequate ventilation of room under mild climate conditions.

Keywords: photovoltaic solar wall, solar energy, passive ventilation, active ventilation

Procedia PDF Downloads 386

Authors: S. M. Shahinul Islam, Israt Ara, Narendra Tuteja, Sreeramanan Subramaniam

Abstract:

Through anther and microspore culture methods, complete homozygous plants can be produced within a year as compared to the long inbreeding method. Isolated microspore culture is one of the most important techniques for rapid development of haploid plants. The efficiency of this method is influenced by several factors such as cultural conditions, growth regulators, plant media, pretreatments, physical and growth conditions of the donor plants, pollen isolation procedure, etc. The main purpose of this study was to improve the isolated microspore culture protocol in order to increase the efficiency of embryoids, its regeneration and reducing albinisms. Under this study we have tested mainly three different microspore isolation procedures by glass rod, homozeniger and by blending and found the efficiency on gametic embryogenesis. There are three types of media viz. washing, pre-culture and induction was used. The induction medium as AMC (modified MS) supplemented by 2, 4-D (2.5 mg/l), kinetin (0.5 mg/l) and higher amount of D-Manitol (90 g/l) instead of sucrose and two types of amino acids (L-glutamine and L-serine) were used. Out of three main microspore isolation procedure by homogenizer isolation (P4) showed best performance on ELS induction (177%) and green plantlets (104%) compared with other techniques. For all cases albinisims occurred but microspore isolation from excised anthers by glass rod and homogenizer showed lesser numbers of albino plants that was also one of the important findings in this study.

Keywords: androgenesis, pretreatment, microspore culture, regeneration, albino plants, Oryza sativa

Procedia PDF Downloads 346

Authors: Ya-Ting Liao, Chien-Chang Huang

Abstract:

Green diesel is a renewable biofuel obtained from plant oil or fatty acid deoxygenation. Because the molecular structure of green diesel is similar to that of fossil fuel, green diesel can be directly used in present vehicle engines without blending with fossil fuel. In this study, mesoporous carbon-based catalysts with doped metal ions, such as Mg, Ni, or Fe, were prepared using co-polymers and gallic acid as molecular templates and carbon sources, respectively. The prepared catalysts were then applied to carry out the deoxygenation of fatty acid and waste cooking oil. To obtain the highest net energy from the produced green diesel, the catalyzed deoxygenation reaction and catalyst preparation processes were carried out under ambient conditions, respectively, to avoid using H₂ as a reagent and reducing agent. XRD, BET, SEM, EDS, FT-IR, and pyridine-IR characterized the composition and configuration of the prepared catalyst. The results display that the doped metal ions were well-dispersed in the carbon-based catalyst and the surface of the catalysts was rich in Lewis acid sites after the catalysts were calcined at the proper temperature. The pore size present on the catalyst was 9-11 nm. To catalyze the deoxygenation of fatty acid by the prepared catalysts at 320℃ under H₂-free conditions, high fatty acid conversion (99%) and high selectivity for hydrocarbons (78%) were obtained when the ratio of doped Ni to doped Mg was optimized.

Keywords: ordered mesoporous carbon, catalysts, hydrocarbons, deoxygenation

Procedia PDF Downloads 66

Authors: Othman M. Hakami, Abdul Jabbar Al-Rajab

Abstract:

Occurrence of heavy metals in water resources increased in the recent years albeit at low concentrations. Lead (PbII) is among the most important inorganic pollutants in ground and surface water. However, removal of this toxic metal efficiently from water is of public and scientific concern. In this study, we developed a rapid and efficient removal method of lead from water using chitosan/magnetite nanoparticles. A simple and effective process has been used to prepare chitosan/magnetite nanoparticles (NPs) (CS/Mag NPs) with effect on saturation magnetization value; the particles were strongly responsive to an external magnetic field making separation from solution possible in less than 2 minutes using a permanent magnet and the total Fe in solution was below the detection limit of ICP-OES (<0.19 mg L-1). The hydrodynamic particle size distribution increased from an average diameter of ~60 nm for Fe3O4 NPs to ~75 nm after chitosan coating. The feasibility of the prepared NPs for the adsorption and desorption of Pb(II) from water were evaluated using Chitosan/Magnetite NPs which showed a high removal efficiency for Pb(II) uptake, with 90% of Pb(II) removed during the first 5 minutes and equilibrium in less than 10 minutes. Maximum adsorption capacities for Pb(II) occurred at pH 6.0 and under room temperature were as high as 85.5 mg g-1, according to Langmuir isotherm model. Desorption of adsorbed Pb on CS/Mag NPs was evaluated using deionized water at different pH values ranged from 1 to 7 which was an effective eluent and did not result the destruction of NPs, then, they could subsequently be reused without any loss of their activity in further adsorption tests. Overall, our results showed the high efficiency of chitosan/magnetite nanoparticles (NPs) in lead removal from water in controlled conditions, and further studies should be realized in real field conditions.

Keywords: chitosan, magnetite, water, treatment

Procedia PDF Downloads 392

Authors: Lev Chernyshev, Ekaterina Lieshout, Natalia Kabaliuk

Abstract:

Sit-skis enable individuals with limited lower limb or core movement to ski unassisted confidently. The rise in popularity of the Winter Paralympics has seen an influx of engineering innovation, especially for the Downhill and Super-Giant Slalom events, where the athletes achieve speeds as high as 160km/h. The growth in the sport has inspired recent research into sit-ski aerodynamics. Crosswinds are expected in mountain climates and, therefore, can greatly impact a skier's maneuverability and aerodynamics. This research investigates the impact of crosswinds on the drag force of a Paralympic sit-ski using Computational Fluid Dynamics (CFD). A Paralympic sit-ski with a model of a skier, a leg cover, a bucket seat, and a simplified suspension system was used for CFD analysis in ANSYS Fluent. The hybrid initialisation tool and the SST k–ω turbulence model were used with two tetrahedral mesh bodies of influence. The crosswinds (10, 30, and 50 km/h) acting perpendicular to the sit-ski's direction of travel were simulated, corresponding to the straight-line skiing speeds of 60, 80, and 100km/h. Following the initialisation, 150 iterations for both first and second order steady-state solvers were used, before switching to a transient solver with a computational time of 1.5s and a time step of 0.02s, to allow the solution to converge. CFD results were validated against wind tunnel data. The results suggested that for all crosswind and sit-ski speeds, on average, 64% of the total drag on the ski was due to the athlete's torso. The suspension was associated with the second largest overall sit-ski drag force contribution, averaging at 27%, followed by the leg cover at 10%. While the seat contributed a negligible 0.5% of the total drag force, averaging at 1.2N across the conditions studied. The effect of the crosswind increased the total drag force across all skiing speed studies, with the drag on the athlete's torso and suspension being the most sensitive to the changes in the crosswind magnitude. The effect of the crosswind on the ski drag reduced as the simulated skiing speed increased: for skiing at 60km/h, the drag force on the torso increased by 154% with the increase of the crosswind from 10km/h to 50km/h; whereas, at 100km/h the corresponding drag force increase was halved (75%). The analysis of the flow and pressure field characteristics for a sit-ski in crosswind conditions indicated the flow separation localisation and wake size correlated with the magnitude and directionality of the crosswind relative to straight-line skiing. The findings can inform aerodynamic improvements in sit-ski design and increase skiers' medalling chances.

Keywords: sit-ski, aerodynamics, CFD, crosswind effects

Procedia PDF Downloads 60

Authors: Tobias Schramm, Günther Prokop

Abstract:

Degraded vehicle shock absorbers represent a risk for road safety. The exact effect of degraded vehicle dampers on road safety is still the subject of research. This work is intended to contribute to estimating the effect of degraded twin-tube dampers of passenger cars on road safety. An axle model was built using a damper model to simulate different degradation levels. To parameterize the model, a realistic parameter space was estimated based on test rig measurements and database analyses, which is intended to represent the vehicle field in Germany. Within the parameter space, simulations of the axle model were carried out, which calculated the transmittable lateral forces of the various axle configurations as a function of vehicle speed, road surface, damper conditions and axle parameters. A degraded damper has the greatest effect on the transmittable lateral forces at high speeds and in poor road conditions. If a vehicle is traveling at a speed of 100 kph on a Class D road, a degraded damper reduces the transmissible lateral forces of an axle by 20 % on average. For individual parameter configurations, this value can rise to 50 %. The axle parameters that most influence the effect of a degraded damper are the vertical stiffness of the tire, the unsprung mass and the stabilizer stiffness of the axle.

Keywords: vehicle dynamics, vehicle simulation, vehicle component degradation, shock absorber model, shock absorber degradation

Procedia PDF Downloads 97

Authors: Pierre Mintom, Armel Assiene Agamou, Leslie Toukem, William Dakam, Christine Fernande Nyangono Biyegue

Abstract:

Context: Hyperuricemia, the presence of high levels of uric acid in the blood, is a known precursor to the development of gout. Recent studies have suggested a strong association between hyperuricemia and disorders of lipoprotein metabolism, specifically hypercholesterolemia. Understanding the factors associated with these conditions in gout patients is essential for effective treatment and management. Research Aim: The objective of this study was to determine the prevalence of hyperuricemia, hypercholesterolemia, and the double burden of hyperuricemia-hypercholesterolemia in the gouty population. Additionally, the study aimed to identify the factors associated with these conditions. Methodology: The study utilized a database from a survey of 150 gouty patients recruited at the Laquintinie Hospital in Douala between August 2017 and February 2018. The database contained information on anthropometric parameters, biochemical markers, and the food and drugs consumed by the patients. Hyperuricemia and hypercholesterolemia were defined based on specific serum uric acid and total cholesterol thresholds, and the double burden was defined as the co-occurrence of hyperuricemia and hypercholesterolemia. Findings: The study found that the prevalence rates for hyperuricemia, hypercholesterolemia, and the double burden were 61.3%, 76%, and 50.7% respectively. Factors associated with these conditions included hypertriglyceridemia, atherogenicity index TC/HDL ratio, atherogenicity index LDL/HDL ratio, family history, and the consumption of specific foods and drinks. Theoretical Importance: The study highlights the strong association between hyperuricemia and dyslipidemia, providing important insights for guiding treatment strategies in gout patients. Additionally, it emphasizes the significance of nutritional education in managing these metabolic disorders, suggesting the need to address eating habits in gout patients. Data Collection and Analysis Procedures: Data was collected through surveys and medical records of gouty patients. Information on anthropometric parameters, biochemical markers, and dietary habits was recorded. Prevalence rates and associated factors were determined through statistical analysis, employing odds ratios to assess the risks. Question Addressed: The study aimed to address the prevalence rates and associated factors of hyperuricemia, hypercholesterolemia, and the double burden in gouty patients. It sought to understand the relationships between these conditions and determine their implications for treatment and nutritional education. Conclusion: Findings show that it’s exists an association between hyperuricemia and hypercholesterolemia in gout patients, thus creating a double burden. The findings underscore the importance of considering family history and eating habits in addressing the double burden of hyperuricemia-hypercholesterolemia. This study provides valuable insights for guiding treatment approaches and emphasizes the need for nutritional education in gout patients. This study specifically focussed on the sick population. A case–control study between gouty and non-gouty populations would be interesting to better compare and explain the results observed.

Keywords: gout, hyperuricemia, hypercholesterolemia, double burden

Procedia PDF Downloads 44

Authors: Vibha Sinha, Sumedha Chakma

Abstract:

Arsenic (As) contamination in drinking water is a serious concern worldwide resulting in severe health maladies. To tackle this problem, several hydrogel based matrix which selectively uptake toxic metals from contaminated water has increasingly been examined as a potential practical method for metal removal. The major concern in hydrogels is low stability of matrix, resulting in poor performance. In this study, the potential of hybrid hydrogel-biochar matrix synthesized from natural plant polymers, specific for As removal was explored. Various compositional and functional group changes of the elements contained in the matrix due to the adsorption of As were identified. Moreover, to resolve the stability issue in hydrogel matrix, optimum and effective mixing of hydrogel with biochar was studied. Mixing varied proportions of matrix components at the time of digestion process was tested. Preliminary results suggest that partial premixing methods may increase the stability and reduce cost. Addition of nanoparticles and specific catalysts with different concentrations of As(III) and As(V) under batch conditions was performed to study their role in performance enhancement of the hydrogel matrix. Further, effect of process parameters, optimal uptake conditions and detailed mechanism derived from experimental studies were suitably conducted. This study provides an efficient, specific and a low-cost As removal method that offers excellent regeneration abilities which can be reused for value.

Keywords: arsenic, catalysts, hybrid hydrogel-biochar, water purification

Procedia PDF Downloads 175

Authors: S. Chuenchooklin

Abstract:

This research was conducted in the Lower Ping River Basin downstream of the Bhumibol Dam and the Lower Wang River Basin in Tak Province, Thailand. Most of the tributary streams of the Ping can be considered as ungauged catchments. There are 10- pumping station installation at both river banks of the Ping in Tak Province. Recently, most of them could not fully operate due to the water amount in the river below the level that would be pumping, even though included water from the natural river and released flow from the Bhumibol Dam. The aim of this research was to increase the performance of those pumping stations using weir projects in the Ping. Therefore, the river analysis system model (HEC-RAS) was applied to study the hydraulic behavior of water surface profiles in the Ping River with both cases of existing conditions and proposed weirs during the violent flood in 2011 and severe drought in 2013. Moreover, the hydrologic modeling system (HMS) was applied to simulate lateral streamflow hydrograph from ungauged catchments of the Ping. The results of HEC-RAS model calibration with existing conditions in 2011 showed best trial roughness coefficient for the main channel of 0.026. The simulated water surface levels fitted to observation data with R2 of 0.8175. The model was applied to 3 proposed cascade weirs with 2.35 m in height and found surcharge water level only 0.27 m higher than the existing condition in 2011. Moreover, those weirs could maintain river water levels and increase of those pumping performances during less river flow in 2013.

Keywords: HEC-RAS, HMS, pumping stations, cascade weirs

Procedia PDF Downloads 378

Authors: Piyakajornkul T., Noppiboon S., Hochareon L., Kitsubun P.

Abstract:

Nowadays, DNA vaccines become an interesting subject in the third vaccine generation. The platform of DNA vaccines production has been developed and its downstream process becomes challenging due to the quality of the products in terms of purity and percentage of supercoiled DNA. To overcome these challenges, tangential flow filtration (TFF), which is involved in the purification process, could be used since it provides effective separation of impurity prior to performing further purification steps. However, operating conditions of TFF is varied based on several factors such as sizes of target particle and impurities, a concentration of solution as well as a concentration polarization on the membrane surface. In this study, pVAX1/lacZ was used as a model of TFF optimization in order to prevent a concentration polarization that can lead to the membrane fouling and also minimize a diafiltration volume while maintaining the maximum permeate flux resulting in proper operating times and buffer volume. By using trans membrane pressure (TMP) excursion method, feed flow rates and TMP were varied. The results showed a correlation of permeate flux with TMP where the maximum volume concentration factor reached 2.5 times of the initial volume when feed flow rate and TMP were 7 liters/m²/min and 1 bar, respectively. It was optimal operating conditions before TFF system undergone pressure independent regime. In addition, the diafiltration volume was 14 times of the concentrated volume prior to performing a further anion chromatography process.

Keywords: concentration polarization, DNA vaccines, optimization, permeate flux, pressure dependent, tangential flow filtration (TFF), trans membrane pressure (TMP)

Procedia PDF Downloads 145

Authors: Rita Greco, Giuseppe Carlo Marano

Abstract:

Chloride induced reinforcement corrosion is widely accepted to be the most frequent mechanism causing premature degradation of reinforced concrete members, whose economic and social consequences are growing up continuously. Prevention of these phenomena has a great importance in structural design, and modern Codes and Standard impose prescriptions concerning design details and concrete mix proportion for structures exposed to different external aggressive conditions, grouped in environmental classes. This paper focuses on reinforced concrete columns load carrying capacity degradation over time due to chloride induced steel pitting corrosion. The structural element is considered to be exposed to marine environment and the effects of corrosion are described by the time degradation of the axial-bending interaction diagram. Because chlorides ingress and consequent pitting corrosion propagation are both time-dependent mechanisms, the study adopts a time-variant predictive approach to evaluate the residual strength of corroded reinforced concrete columns at different lifetimes. Corrosion initiation and propagation process is modelled by taking into account all the parameters, such as external environmental conditions, concrete mix proportion, concrete cover and so on, which influence the time evolution of the corrosion phenomenon and its effects on the residual strength of RC columns.

Keywords: pitting corrosion, strength deterioration, diffusion coefficient, surface chloride concentration, concrete structures, marine environment

Procedia PDF Downloads 306

Authors: Abhinay Puvvala, Veerendra Kumar Rai

Abstract:

A bottleneck situation arises when the outflow is lesser than the inflow in a pipe-like setup. A more practical interpretation of bottlenecks emphasizes on the realization of Service Level Objectives (SLOs) at given workloads. Our approach detects two key aspects of bottlenecks – when and where. To identify ‘when’ we continuously poll on certain key metrics such as resource utilization, processing time, request backlog and throughput at a system level. Further, when the slope of the expected sojourn time at a workload is greater than ‘K’ times the slope of expected sojourn time at the previous step of the workload while the workload is being gradually increased in discrete steps, a bottleneck situation arises. ‘K’ defines the threshold condition and is computed based on the system’s service level objectives. The second aspect of our approach is to identify the location of the bottleneck. In multi-tier systems with a complex network of layers, it is a challenging problem to locate bottleneck that affects the overall system performance. We stage the system by varying workload incrementally to draw a correlation between load increase and system performance to the point where Service Level Objectives are violated. During the staging process, multiple metrics are monitored at hardware and application levels. The correlations are drawn between metrics and the overall system performance. These correlations along with the Service Level Objectives are used to arrive at the threshold conditions for each of these metrics. Subsequently, the same method used to identify when a bottleneck occurs is used on metrics data with threshold conditions to locate bottlenecks.

Keywords: bottleneck, workload, service level objectives (SLOs), throughput, system performance

Procedia PDF Downloads 220

Authors: Anny Lucrece Nlend Nkott, Ludovic Temple

Abstract:

The appearance in 2012 of the CRISPR-CaS9 genome editing technique marks a turning point in the field of genetics. This technique would make it possible to create new varieties quickly and cheaply. Although some consider CRISPR-CaS9 to be revolutionary, others consider it a potential societal threat. To document the controversy, we explain the socioeconomic conditions under which this technique could be accepted for the creation of a rainfed rice variety in Madagascar. The methodological framework is based on 38 individual and semistructured interviews, a multistakeholder forum with 27 participants, and a survey of 148 rice producers. Results reveal that the acceptability of genome editing requires (i) strengthening the seed system through the operationalization of regulatory structures and the upgrading of stakeholders' knowledge of genetically modified organisms, (ii) assessing the effects of the edited variety on biodiversity and soil nitrogen dynamics, and (iii) strengthening the technical and human capacities of the biosafety body. Structural mechanisms for regulating the seed system are necessary to ensure safe experimentation of genome editing techniques. Organizational innovation also appears to be necessary. The study documents how collective learning between communities of scientists and nonscientists is a component of systemic processes of varietal innovation. This study was carried out with the financial support of the GENERICE project (Generation and Deployment of Genome-Edited, Nitrogen-use-Efficient Rice Varieties), funded by the Agropolis Foundation.

Keywords: CRISPR-CaS9, varietal innovation, seed system, innovation system

Procedia PDF Downloads 139

Authors: Mohammad Bagher Heidari, Hefzollah Mohammadian

Abstract:

TETRA (Terrestrial Trunked Radio) is a digital radio communication standard, which has been implemented in several different parts of the gas refinery ninth (phase 12th) by South Pars Gas Complex. Studies on possible impacts on the users' health considering different exposure conditions are missing. Objectives: To investigate possible acute effects of electromagnetic fields (EMF) of two different levels of TETRA hand-held transmitter signals on cognitive function and well-being in healthy young males. Methods: In the present double-blind cross-over study possible effects of short-term (2.5 h) EMF exposure of handset-like signals of TETRA (450 - 470 MHz) were studied in 30 healthy male participants (mean ± SD: 25.4 ±2.6 years). Individuals were tested on nine study days, on which they were exposed to three different exposure conditions (Sham, TETRA 1.5 W/kg and TETRA 10.0 W/kg) in a randomly assigned and balanced order. Participants were tested in the afternoon at a fixed timeframe. Results: Attention remained unchanged in two out of three tasks. In the working memory, significant changes were observed in two out of four subtasks. Significant results were found in 5 out of 35 tested parameters, four of them led to an improvement in performance. Mood, well-being and subjective somatic complaints were not affected by TETRA exposure. Conclusions: The results of the present study do not indicate a negative impact of a short-term EMF- effect of TETRA on cognitive function and well-being in healthy young men.

Keywords: TETRA (terrestrial trunked radio), electromagnetic fields (EMF), mobile telecommunication health research (MTHR), antenna

Procedia PDF Downloads 289

Authors: X. Li, Y. Liu, H. Wong, B. Pardoen, A. Fabbri, F. McGregor, E. Liu

Abstract:

The target of this paper is to investigate how saturated poroelastic soils subject to freezing temperatures behave and how different boundary conditions can intervene and affect the thermo-hydro-mechanical (THM) responses, based on a particular but classical configuration of a finite homogeneous soil layer studied by Terzaghi. The essential relations on the constitutive behavior of a freezing soil are firstly recalled: ice crystal - liquid water thermodynamic equilibrium, hydromechanical constitutive equations, momentum balance, water mass balance, and the thermal diffusion equation, in general, non-linear case where material parameters are state-dependent. The system of equations is firstly linearized, assuming all material parameters to be constants, particularly the permeability of liquid water, which should depend on the ice content. Two analytical solutions solved by the classic Laplace transform are then developed, accounting for two different sets of boundary conditions. Afterward, the general non-linear equations with state-dependent parameters are solved using a commercial code COMSOL based on finite elements method to obtain numerical results. The validity of this numerical modeling is partially verified using the analytical solution in the limiting case of state-independent parameters. Comparison between the results given by the linearized analytical solutions and the non-linear numerical model reveals that the above-mentioned linear computation will always underestimate the liquid pore pressure and displacement, whatever the hydraulic boundary conditions are. In the nonlinear model, the faster growth of ice crystals, accompanying the subsequent reduction of permeability of freezing soil layer, makes a longer duration for the depressurization of water liquid and slower settlement in the case where the ground surface is swiftly covered by a thin layer of ice, as well as a bigger global liquid pressure and swelling in the case of the impermeable ground surface. Nonetheless, the analytical solutions based on linearized equations give a correct order-of-magnitude estimate, especially at moderate temperature variations, and remain a useful tool for preliminary design checks.

Keywords: chemical potential, cryosuction, Laplace transform, multiphysics coupling, phase transformation, thermodynamic equilibrium

Procedia PDF Downloads 70

Authors: A. Khodabakhshi, A. Mortazavi

Abstract:

Accurate determination of rock mass deformation modulus, as an important design parameter, is one of the most controversial issues in most engineering projects. A 3D numerical model of standard plate load test (PLT) using the FLAC3D code was carried to investigate the mechanism governing the test process. Five objectives were the focus of this study. The first goal was to employ 3D modeling in the interpretation of PLT conducted at the Bazoft dam site, Iran. The second objective was to investigate the effect of displacements measuring depth from the loading plates on the calculated moduli. The magnitude of rock mass deformation modulus calculated from PLT depends on anchor depth, and in practice, this may be a cause of error in the selection of realistic deformation modulus for the rock mass. The third goal of the study was to investigate the effect of testing plate diameter on the calculated modulus. Moreover, a comparison of the calculated modulus from ISRM formula, numerical modeling and calculated modulus from the actual PLT carried out at right abutment of the Bazoft dam site was another objective of the study. Finally, the effect of plastic strains on the calculated moduli in each of the loading-unloading cycles for three loading plates was investigated. The geometry, material properties, and boundary conditions on the constructed 3D model were selected based on the in-situ conditions of PLT at Bazoft dam site. A good agreement was achieved between numerical model results and the field tests results.

Keywords: deformation modulus, numerical model, plate loading test, rock mass

Procedia PDF Downloads 159

Authors: Mariia Zhuldybina, Ahmed Moulay, Mirko Torres, Mike Rozel, Ngoc-Duc Trinh, Chloé Bois

Abstract:

To reduce the global waste of perishable goods, a solution for monitoring and traceability of their environmental conditions is needed. Temperature is the most controllable environmental parameter determining the kinetics of physical, chemical, and microbial spoilage in food products. To store the time-temperature information, time-temperature indicator (TTI) is a promising solution. Printed electronics (PE) has shown a great potential to produce customized electronic devices using flexible substrates and inks with different functionalities. We propose to fabricate a hybrid printed TTI using environmentally friendly materials. The real-time TTI profile can be stored and transmitted to the smartphone via Near Field Communication (NFC). To ensure environmental performance, Canadian Green Electronics NSERC Network is developing green materials for the ink formulation with different functionalities. In terms of substrate, paper-based electronics has gained the great interest for utilization in a wide area of electronic systems because of their low costs in setup and methodology, as well as their eco-friendly fabrication technologies. The main objective is to deliver a prototype of TTI using small-scale printed techniques under typical printing conditions. All sub-components of the smart labels, including a memristor, a battery, an antenna compatible with NFC protocol, and a circuit compatible with integration performed by an offsite supplier will be fully printed with flexography or flat-bed screen printing.

Keywords: NFC, printed electronics, time-temperature indicator, hybrid electronics

Procedia PDF Downloads 147

Authors: Monika Šípová, Daniela Marušáková, Claudia Aparicio

Abstract:

New sources and ways of producing energy are still seeking, and one of the sustainable ways is Generation IV nuclear reactors. The supercritical water-cooled reactor is one of the six nuclear reactors of Generation IV, and as a consequence of the development of light water, reactors seem to be the most perspective. Thus, materials usually used in light water reactors are also tested under the expected operating conditions of the supercritical water-cooled reactor. Austenitic stainless steel 08Cr18Ni10Ti is widely used in the eastern types of light water nuclear power plants. Therefore, specimens of 08Cr18Ni10Ti were exposed to conditions close to the pseudo-critical point of water and high-temperature supercritical water. The description and evaluation of the corrosion behaviour of austenitic stainless steel have been done based on the results of X-ray diffraction in combination with energy dispersive spectroscopy and electron backscatter diffraction. Thus, significant differences have been found in the structure and composition of oxides formed depending on the temperature of exposure. The high temperature of supercritical water resulted in localised form of corrosion in contrast to the thin oxide layer of 1 µm present on the surface of specimens exposed close to the pseudo-critical point of water. The obtained results are important for further research as the supercritical water can be successfully used as a coolant for small modular reactors, which are currently of interest.

Keywords: localised corrosion, supercritical water, stainless steel, electron backscatter diffraction

Procedia PDF Downloads 67

Authors: David Martinez-Pernia, Alvaro Rivera-Rei, Alejandro Troncoso, Gonzalo Forno, Andrea Slachevsky, David Huepe, Victoria Silva-Mack, Jorge Calderon, Mayte Vergara, Valentina Carrera

Abstract:

Background: Recent theories in the field of emotions have taken the relevance of motor control beyond a system related to personal autonomy (walking, running, grooming), and integrate it into the emotional dimension. However, to our best knowledge, there are no studies that specifically investigate how emotional stimuli related to motor control modify emotional states in terms of postural control and phenomenological experience. Objective: The main aim of this work is to investigate the emotions produced by stimuli of bodily imbalance (neutral, pleasant and unpleasant) in the postural control and the phenomenological experience of young, healthy adults. Methodology: 46 healthy young people are shown emotional videos (neutral, pleasant, motor unpleasant, and non-motor unpleasant) related to the body imbalance. During the period of stimulation of each of the videos (60 seconds) the participant is standing on a force platform to collect temporal and spatial data of postural control. In addition, the electrophysiological activity of the heart and electrodermal activity is recorded. In relation to the two unpleasant conditions (motor versus non-motor), a phenomenological interview is carried out to collect the subjective experience of emotion and body perception. Results: Pleasant and unpleasant emotional videos have significant changes with respect to the neutral condition in terms of greater area, higher mean velocity, and greater mean frequency power on the anterior-posterior axis. The results obtained with respect to the electrodermal response was that the pleasurable and unpleasant conditions produced a significant increase in the phasic component with respect to the neutral condition. Regarding the electrophysiology of the heart, no significant change was found in any condition. Phenomenological experiences in the two unpleasant conditions differ in body perception and the emotional meaning of the experience. Conclusion: Emotional stimuli related to bodily imbalance produce changes in postural control, electrodermal activity, and phenomenological experience. This experimental setting could be relevant to be implemented in people with motor disorders (Parkinson, Stroke, TBI) to know how emotions affect motor control.

Keywords: body imbalance stimuli, emotion, phenomenological experience, postural control

Procedia PDF Downloads 160

Authors: Hossein Ghadimi, Alireza Alizadeh, Oveis Abedinia, Noradin Ghadimi

Abstract:

This paper presents an enhanced Honey Bee Mating Optimization (HBMO) to solve the optimal design of multi machine power system stabilizer (PSSs) parameters, which is called the Interactive Honey Bee Mating Optimization (IHBMO). Power System Stabilizers (PSSs) are now routinely used in the industry to damp out power system oscillations. The design problem of the proposed controller is formulated as an optimization problem and IHBMO algorithm is employed to search for optimal controller parameters. The proposed method is applied to multi-machine power system (MPS). The method suggested in this paper can be used for designing robust power system stabilizers for guaranteeing the required closed loop performance over a prespecified range of operating and system conditions. The simplicity in design and implementation of the proposed stabilizers makes them better suited for practical applications in real plants. The non-linear simulation results are presented under wide range of operating conditions in comparison with the PSO and CPSS base tuned stabilizer one through FD and ITAE performance indices. The results evaluation shows that the proposed control strategy achieves good robust performance for a wide range of system parameters and load changes in the presence of system nonlinearities and is superior to the other controllers.

Keywords: power system stabilizer, IHBMO, multimachine, nonlinearities

Procedia PDF Downloads 490

Authors: Ayfer Kilicarslan, Kubra Onol, Sercan Basit, Muhlis Nezihi Saridede

Abstract:

Chalcopyrite (CuFeS2) is the most common primary mineral used for the commercial production of copper. The low dissolution efficiency of chalcopyrite in sulfate media has prevented an efficient industrial leaching of this mineral in sulfate media. Ferric ions, bacteria, oxygen and other oxidants have been used as oxidizing agents in the leaching of chalcopyrite in sulfate and chloride media under atmospheric or pressure leaching conditions. Two leaching methods were studied to evaluate chalcopyrite (CuFeS2) dissolution in acid media. First, the conventional oxidative acid leaching method was carried out using sulfuric acid (H2SO4) and potassium dichromate (K2Cr2O7) as oxidant at atmospheric pressure. Second, microwave-assisted acid leaching was performed using the microwave accelerated reaction system (MARS) for same reaction media. Parameters affecting the copper extraction such as leaching time, leaching temperature, concentration of H2SO4 and concentration of K2Cr2O7 were investigated. The results of conventional acid leaching experiments were compared to the microwave leaching method. It was found that the copper extraction obtained under high temperature and high concentrations of oxidant with microwave leaching is higher than those obtained conventionally. 81% copper extraction was obtained by the conventional oxidative acid leaching method in 180 min, with the concentration of 0.3 mol/L K2Cr2O7 in 0.5M H2SO4 at 50 ºC, while 93.5% copper extraction was obtained in 60 min with microwave leaching method under same conditions.

Keywords: extraction, copper, microwave-assisted leaching, chalcopyrite, potassium dichromate

Procedia PDF Downloads 354

Authors: Zehui Du, Chaiwat Prapainainar, Paisan Kongkachuichay, Paweena Prapainainar

Abstract:

The aim of this work was to obtain small crystalline size and high crystallinity of mordenites and analcimes, by modifying the aging time, agitation, water content, crystallization temperature and crystallization time. Two different hydrothermal methods were studied. Both methods used Na2SiO3 as the silica source, NaAlO2 as the aluminum source, and NaOH as the alkali source. The first method used HMI as the template while the second method did not use the template. Mordenite crystals with spherical shape and bimodal in size of about 1 and 5 µm were obtained from the first method using conditions of 24 hr aging time, 170°C and 24 hr crystallization. Modernites with high crystallinity were formed using agitation system in the crystallization process. It was also found that the aging time of 2 hr and 24 hr did not much affect the formation of mordenite crystals. Analcime crystals were formed in spherical shape and facet on surface with the size between 13-15 µm by the second method using the conditions of 30 minutes aging time, 170°C and 24 hr crystallization without calcination. By increasing water content, the crystallization process was slowed down and resulted in smaller analcime crystals. Larger size of analcime crystals were observed when the samples were calcined at 300°C and 580°C. Higher calcination temperature led to higher crystal growth and resulted in larger crystal size. Finally, mordenite and analcime was used as fillers in zeolite/Nafion composite membrane to solve the fuel cross over problem in direct alcohol fuel cell.

Keywords: analcime, hydrothermal synthesis, mordenite, zeolite

Procedia PDF Downloads 254

Authors: Aarushi Agarwal, Tara Singh, I.L Singh, Anju Lata Singh, Trayambak Tiwari

Abstract:

Simple discrimination in near absence of attention has been widely observed. Dual-task studies with natural scenes studies have been claimed as being preattentive in nature that facilitated categorization simultaneously with the attentional demanding task. So in this study, multiple images at the periphery are presented, initiating parallel processing in near absence of attention. For the central demanding task rotated letters were presented in both conditions, while in periphery natural and animal images were presented. To understand the breakpoint of ability to perform in near absence of attention one, two and three peripheral images were presented simultaneously with central task and subjects had to respond when all belong to the same category. Individual participant performance did not show a significant difference in both conditions central and peripheral task when the single peripheral image was shown. In case of two images high-level parallel processing could take place with little attentional resources. The eye tracking results supports the evidence as no major saccade was made in a large number of trials. Three image presentations proved to be a breaking point of the capacities to perform outside attentional assistance as participants showed a confused eye gaze pattern which failed to make the natural and animal image discriminations. Thus, we can conclude attention and awareness being independent mechanisms having limited capacities.

Keywords: attention, dual task pardigm, parallel processing, break point, saccade

Procedia PDF Downloads 209

Authors: Zeynep Karacor, Rahime Hulya Ozturk

Abstract:

Located in developing countries but with the successful performance in recent years have shown in emerging economies , the labor factor has undoubtedly an important place in Turkish economy. The theorists have emphasized the importance of labor and human capital factors for many years. The importance of human capital is emerging in the process of determining the labor force participation rate. It is relatively easy to employ qualified labor force but employment of unskilled labor is particularly difficult. Another factor affecting the gender differences are employment opportunities in the labor force. In our country, the employment conditions of men and women differ. Factors causing these differentials are inherent job requirements, the social structure of society, women's point of view, working hours, working conditions. Crisis in our country in recent years have significantly affect the labor force participation rates. In particular, women's labor force participation rates have shown a decrease in crisis.In crisis female laborforce leave their job and go their home. It is the sole provider of social perception of men so in crisis period it is considered that woman lost their job. In the first part of this study the current situation in the world of female participation in the labor force in Turkey will examine. In the second part of the study literature will be examined. In the third and last part of the study factors of determinants of female labor force participation rate analysis will done by Granger Causality Analysis.

Keywords: female labour force, employment, labor force, Turkey

Procedia PDF Downloads 275

Authors: A. Zuchowska, A. Buta, M. Mazurkiewicz-Pawlicka, A. Malolepszy, L. Stobinski, Z. Brzozka

Abstract:

In recent years, graphene-based materials are finding more and more applications in biological science. As a thin, tough, transparent and chemically resistant materials, they appear to be a very good material for the production of implants and biosensors. Interest in graphene derivatives also resulted at the beginning of research about the possibility of their application in cancer therapy. Currently, the analysis of their potential use in photothermal therapy and as a drug carrier is mostly performed. Moreover, the direct anticancer properties of graphene-based materials are also tested. Nowadays, cytotoxic studies are conducted on in vitro cell culture in standard culture vessels (macroscale). However, in this type of cell culture, the cells grow on the synthetic surface in static conditions. For this reason, cell culture in macroscale does not reflect in vivo environment. The microfluidic systems, called Lab-on-a-chip, are proposed as a solution for improvement of cytotoxicity analysis of new compounds. Here, we present the evaluation of cytotoxic properties of graphene oxide (GO) on breast, liver and colon cancer cell line in a microfluidic system in two spatial models (2D and 3D). Before cell introduction, the microchambers surface was modified by the fibronectin (2D, monolayer) and poly(vinyl alcohol) (3D, spheroids) covering. After spheroid creation (3D) and cell attachment (2D, monolayer) the selected concentration of GO was introduced into microsystems. Then monolayer and spheroids viability/proliferation using alamarBlue® assay and standard microplate reader was checked for three days. Moreover, in every day of the culture, the morphological changes of cells were determined using microscopic analysis. Additionally, on the last day of the culture differential staining using Calcein AM and Propidium iodide were performed. We were able to note that the GO has an influence on all tested cell line viability in both monolayer and spheroid arrangement. We showed that GO caused higher viability/proliferation decrease for spheroids than a monolayer (this was observed for all tested cell lines). Higher cytotoxicity of GO on spheroid culture can be caused by different geometry of the microchambers for 2D and 3D cell cultures. Probably, GO was removed from the flat microchambers for 2D culture. Those results were also confirmed by differential staining. Comparing our results with the studies conducted in the macroscale, we also proved that the cytotoxic properties of GO are changed depending on the cell culture conditions (static/ flow).

Keywords: cytotoxicity, graphene oxide, monolayer, spheroid

Procedia PDF Downloads 117

Authors: Victor Emery David Jr., Jiang Wenchao, Yasinta John, Md. Sahadat Hossain

Abstract:

Sludge originates from the process of treatment of wastewater. It is the byproduct of wastewater treatment containing concentrated heavy metals and poorly biodegradable trace organic compounds, as well as potentially pathogenic organisms (viruses, bacteria, etc.) which are usually difficult to treat or dispose of. China, like other countries, is no stranger to the challenges posed by an increase of wastewater. Treatment and disposal of sludge have been a problem for most cities in China. However, this problem has been exacerbated by other issues such as lack of technology, funding, and other factors. Suitable methods for such climatic conditions are still unavailable for modern cities in China. Against this background, this paper seeks to describe the methods used for treatment and disposal of sludge from industries and suggest a suitable method for treatment and disposal in Chongqing/China. From the research conducted, it was discovered that the highest treatment rate of sludge in Chongqing was 10.08%. The industrial waste piping system is not separated from the domestic system. Considering the proliferation of industry and urbanization, there is a likelihood that the production of sludge in Chongqing will increase. If the sludge produced is not properly managed, this may lead to adverse health and environmental effects. Disposal costs and methods for Chongqing were also included in this paper’s analysis. Research showed that incineration is the most expensive method of sludge disposal in China/Chongqing. Subsequent research, therefore, considered optional alternatives such as composting. Composting represents a relatively cheap waste disposal method considering the vast population, current technology and economic conditions of Chongqing, as well as China at large.

Keywords: Chongqing/China, disposal, industrial, sludge, treatment

Procedia PDF Downloads 312

Authors: Ayoub Bouazza, Ali Faddouli, Said Amal, Rachid Benhida, Khaoula Khaless

Abstract:

Brine waste generated from reverse osmosis (RO) desalination plants contains various valuable compounds, mainly salts, trace elements, and organic matter. These wastes are up to two times saltier than standard seawater. Therefore, there is a strong economic interest in recovering these salts. The current practice in desalination plants is to reject the brine back to the sea, which affects the marine ecosystem and the environment. Our study aims to bring forth a reliable management solution for the valorisation of waste brines. Natural evaporation, isothermal evaporation at 25°C and 50°C, and evaporation using continuous heating were used to crystallize valuable salts from a reverse osmosis desalination plant brine located on the Moroccan Atlantic coast. The crystallization sequence of the brine was studied in comparison with standard seawater. The X-Ray Diffraction (XRD) of the precipitated solid phases showed similar results, where halite was the main solid phase precipitated from both the brine and seawater. However, Jänecke diagram prediction, along with FREZCHEM simulations, showed that Kainite should crystallize before Epsomite and Carnallite. As the absence of kainite formation in many experiments in the literature has been related to the metastability of kainite and the critical relative humidity conditions, and the precipitation of K–Mg salts is very sensitive to climatic conditions. An evaporation process is proposed as a solution to achieve the predicted crystallization path and to affirm the recovery of Kainite.

Keywords: salts crystallization, reverse osmosis, solar evaporation, frezchem, ZLD

Procedia PDF Downloads 89

Authors: P. S. Jain, K. D. Bobade, S. J. Surana

Abstract:

A simple, selective, precise and Stability-indicating High-performance thin-layer chromatographic method for analysis of Naftopidil both in a bulk and in pharmaceutical formulation has been developed and validated. The method employed, HPTLC aluminium plates precoated with silica gel as the stationary phase. The solvent system consisted of hexane: ethyl acetate: glacial acetic acid (4:4:2 v/v). The system was found to give compact spot for Naftopidil (Rf value of 0.43±0.02). Densitometric analysis of Naftopidil was carried out in the absorbance mode at 253 nm. The linear regression analysis data for the calibration plots showed good linear relationship with r2=0.999±0.0001 with respect to peak area in the concentration range 200-1200 ng per spot. The method was validated for precision, recovery and robustness. The limits of detection and quantification were 20.35 and 61.68 ng per spot, respectively. Naftopidil was subjected to acid and alkali hydrolysis, oxidation and thermal degradation. The drug undergoes degradation under acidic, basic, oxidation and thermal conditions. This indicates that the drug is susceptible to acid, base, oxidation and thermal conditions. The degraded product was well resolved from the pure drug with significantly different Rf value. Statistical analysis proves that the method is repeatable, selective and accurate for the estimation of investigated drug. The proposed developed HPTLC method can be applied for identification and quantitative determination of Naftopidil in bulk drug and pharmaceutical formulation.

Keywords: naftopidil, HPTLC, validation, stability, degradation

Procedia PDF Downloads 389