Search results for: peak
1096 An Improved Total Variation Regularization Method for Denoising Magnetocardiography
Authors: Yanping Liao, Congcong He, Ruigang Zhao
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The application of magnetocardiography signals to detect cardiac electrical function is a new technology developed in recent years. The magnetocardiography signal is detected with Superconducting Quantum Interference Devices (SQUID) and has considerable advantages over electrocardiography (ECG). It is difficult to extract Magnetocardiography (MCG) signal which is buried in the noise, which is a critical issue to be resolved in cardiac monitoring system and MCG applications. In order to remove the severe background noise, the Total Variation (TV) regularization method is proposed to denoise MCG signal. The approach transforms the denoising problem into a minimization optimization problem and the Majorization-minimization algorithm is applied to iteratively solve the minimization problem. However, traditional TV regularization method tends to cause step effect and lacks constraint adaptability. In this paper, an improved TV regularization method for denoising MCG signal is proposed to improve the denoising precision. The improvement of this method is mainly divided into three parts. First, high-order TV is applied to reduce the step effect, and the corresponding second derivative matrix is used to substitute the first order. Then, the positions of the non-zero elements in the second order derivative matrix are determined based on the peak positions that are detected by the detection window. Finally, adaptive constraint parameters are defined to eliminate noises and preserve signal peak characteristics. Theoretical analysis and experimental results show that this algorithm can effectively improve the output signal-to-noise ratio and has superior performance.Keywords: constraint parameters, derivative matrix, magnetocardiography, regular term, total variation
Procedia PDF Downloads 1461095 Patterns of Change in Perception of Imagined and Physically Induced Pain over the Course of Repeated Thermal Stimulations
Authors: Boroka Gács, Tibor Szolcsányi, Árpad Csathó
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Background: Individuals frequently show habituation to repeated noxious heat. However, given the defensive function of human pain processing, it is reasonable to assume that individuals imagine that they would become increasingly sensitive to repeated thermal pain stimuli. To the best of the authors' knowledge, no previous studies have, however, been addressed to this assumption. Therefore, in the current study, we investigated how healthy human individuals imagine the intensity of repeated thermal pain stimulations, and compared this with the intensity ratings given after physically induced thermal pain trials. Methods: Healthy participants (N = 20) gave pain intensity ratings in two conditions: imagined and real thermal pain. In the real pain condition thermal pain stimuli of two intensities (minimal and moderate pain) were delivered in four consecutive trials. The duration of the peak temperature was 20s, and stimulation was always delivered to the same location. In each trial, participants rated the pain intensity twice, 5s and 15s after the onset of the peak temperature. In the imagined pain condition, participants were subjected to a reference pain stimulus and then asked to imagine and rate the same sequence of stimulations as in the induced pain condition. Results: Ratings of imagined pain and physically induced pain followed opposite courses over repeated stimulation: Ratings of imagined pain indicated sensitization whereas ratings for physically induced pain indicated habituation. The findings were similar for minimal and moderate pain intensities. Conclusions: The findings suggest that, rather than habituating to pain, healthy individuals imagine that they would become increasingly sensitive to repeated thermal pain stimuli.Keywords: habituation, imagined pain, pain perception, thermal stimulation
Procedia PDF Downloads 2321094 Mature Field Rejuvenation Using Hydraulic Fracturing: A Case Study of Tight Mature Oilfield with Reveal Simulator
Authors: Amir Gharavi, Mohamed Hassan, Amjad Shah
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The main characteristics of unconventional reservoirs include low-to ultra low permeability and low-to-moderate porosity. As a result, hydrocarbon production from these reservoirs requires different extraction technologies than from conventional resources. An unconventional reservoir must be stimulated to produce hydrocarbons at an acceptable flow rate to recover commercial quantities of hydrocarbons. Permeability for unconventional reservoirs is mostly below 0.1 mD, and reservoirs with permeability above 0.1 mD are generally considered to be conventional. The hydrocarbon held in these formations naturally will not move towards producing wells at economic rates without aid from hydraulic fracturing which is the only technique to assess these tight reservoir productions. Horizontal well with multi-stage fracking is the key technique to maximize stimulated reservoir volume and achieve commercial production. The main objective of this research paper is to investigate development options for a tight mature oilfield. This includes multistage hydraulic fracturing and spacing by building of reservoir models in the Reveal simulator to model potential development options based on sidetracking the existing vertical well. To simulate potential options, reservoir models have been built in the Reveal. An existing Petrel geological model was used to build the static parts of these models. A FBHP limit of 40bars was assumed to take into account pump operating limits and to maintain the reservoir pressure above the bubble point. 300m, 600m and 900m lateral length wells were modelled, in conjunction with 4, 6 and 8 stages of fracs. Simulation results indicate that higher initial recoveries and peak oil rates are obtained with longer well lengths and also with more fracs and spacing. For a 25year forecast, the ultimate recovery ranging from 0.4% to 2.56% for 300m and 1000m laterals respectively. The 900m lateral with 8 fracs 100m spacing gave the highest peak rate of 120m3/day, with the 600m and 300m cases giving initial peak rates of 110m3/day. Similarly, recovery factor for the 900m lateral with 8 fracs and 100m spacing was the highest at 2.65% after 25 years. The corresponding values for the 300m and 600m laterals were 2.37% and 2.42%. Therefore, the study suggests that longer laterals with 8 fracs and 100m spacing provided the optimal recovery, and this design is recommended as the basis for further study.Keywords: unconventional, resource, hydraulic, fracturing
Procedia PDF Downloads 2941093 Beam Spatio-Temporal Multiplexing Approach for Improving Control Accuracy of High Contrast Pulse
Authors: Ping Li, Bing Feng, Junpu Zhao, Xudong Xie, Dangpeng Xu, Kuixing Zheng, Qihua Zhu, Xiaofeng Wei
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In laser driven inertial confinement fusion (ICF), the control of the temporal shape of the laser pulse is a key point to ensure an optimal interaction of laser-target. One of the main difficulties in controlling the temporal shape is the foot part control accuracy of high contrast pulse. Based on the analysis of pulse perturbation in the process of amplification and frequency conversion in high power lasers, an approach of beam spatio-temporal multiplexing is proposed to improve the control precision of high contrast pulse. In the approach, the foot and peak part of high contrast pulse are controlled independently, which propagate separately in the near field, and combine together in the far field to form the required pulse shape. For high contrast pulse, the beam area ratio of the two parts is optimized, and then beam fluence and intensity of the foot part are increased, which brings great convenience to the control of pulse. Meanwhile, the near field distribution of the two parts is also carefully designed to make sure their F-numbers are the same, which is another important parameter for laser-target interaction. The integrated calculation results show that for a pulse with a contrast of up to 500, the deviation of foot part can be improved from 20% to 5% by using beam spatio-temporal multiplexing approach with beam area ratio of 1/20, which is almost the same as that of peak part. The research results are expected to bring a breakthrough in power balance of high power laser facility.Keywords: inertial confinement fusion, laser pulse control, beam spatio-temporal multiplexing, power balance
Procedia PDF Downloads 1441092 Development of a Sensitive Electrochemical Sensor Based on Carbon Dots and Graphitic Carbon Nitride for the Detection of 2-Chlorophenol and Arsenic
Authors: Theo H. G. Moundzounga
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Arsenic and 2-chlorophenol are priority pollutants that pose serious health threats to humans and ecology. An electrochemical sensor, based on graphitic carbon nitride (g-C₃N₄) and carbon dots (CDs), was fabricated and used for the determination of arsenic and 2-chlorophenol. The g-C₃N₄/CDs nanocomposite was prepared via microwave irradiation heating method and was dropped-dried on the surface of the glassy carbon electrode (GCE). Transmission electron microscopy (TEM), X-ray diffraction (XRD), photoluminescence (PL), Fourier transform infrared spectroscopy (FTIR), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS) were used for the characterization of structure and morphology of the nanocomposite. Electrochemical characterization was done by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The electrochemical behaviors of arsenic and 2-chlorophenol on different electrodes (GCE, CDs/GCE, and g-C₃N₄/CDs/GCE) was investigated by differential pulse voltammetry (DPV). The results demonstrated that the g-C₃N₄/CDs/GCE significantly enhanced the oxidation peak current of both analytes. The analytes detection sensitivity was greatly improved, suggesting that this new modified electrode has great potential in the determination of trace level of arsenic and 2-chlorophenol. Experimental conditions which affect the electrochemical response of arsenic and 2-chlorophenol were studied, the oxidation peak currents displayed a good linear relationship to concentration for 2-chlorophenol (R²=0.948, n=5) and arsenic (R²=0.9524, n=5), with a linear range from 0.5 to 2.5μM for 2-CP and arsenic and a detection limit of 2.15μM and 0.39μM respectively. The modified electrode was used to determine arsenic and 2-chlorophenol in spiked tap and effluent water samples by the standard addition method, and the results were satisfying. According to the measurement, the new modified electrode is a good alternative as chemical sensor for determination of other phenols.Keywords: electrochemistry, electrode, limit of detection, sensor
Procedia PDF Downloads 1351091 Catalytic Synthesis and Characterization of N-(4-(Tert-Butyl) Benzyl)-1-(4-Tert-Butyl) Phenyl)-N-Methyl Methanaminium Chloride from Tert-Butyl Benzyl Derivatives
Authors: Muhammad A. Muhammad
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Butenafine (N-4-tert-butyl benzyl-N-methyl-1-naphthylene methylamine hydrochloride) is a benzylamine antimycotic (antifungal) agent that has a broad spectrum of action. The quest for improved antimycotic action brought about many research on the structure-activity properties of butenafine in relation to other antifungal agents. Of all those research, only little or no effort was recorded on the substituents attached to the aromatic systems in butenafine. In this research, N-(4-(tert-butyl) benzyl)-1-(4-tert-butyl) phenyl)-N-methyl methanaminium chloride, which is a butenafine analogue was synthesised from tert-butyl benzyl derivatives, by reductive amination using various solvents through a direct approach, where 1,2-dichloroethane gave the best solvent action at 40 °C (Yield: 75%) and of all the reducing agents used, sodium borohydride was found to give the best reducing action in the presence of silica chloride at room temperature (Yield: 50%). Characterization of the compound by 1H NMR showed a singlet peak of 18 hydrogen atoms with a chemical shift at 1.3-1.5 ppm for the presence of 6 methyl groups in the two tert-butyl substituents, the 13C NMR also indicated the presence of the two tert-butyl substituents by the peak with a chemical shift at 31-32 ppm for the six methyl carbon atoms, the IR indicated the presence of a tertiary ammonium ion by a strong band at 2460 cm-1 and finally the EIS-MS confirmed the molar mass of the compound by a mass to charge ratio of 324.2693. These results suggested that the target molecule was actually synthesised and therefore, 1,2-dichloroethane is a good solvent for this synthesis, and the most suitable reducing agent is sodium borohydride.Keywords: antimicrobial agents, antimycotic agents, butenafine, chemotherapeutic agents, semisynthetic agents
Procedia PDF Downloads 2901090 A Comparison of Tsunami Impact to Sydney Harbour, Australia at Different Tidal Stages
Authors: Olivia A. Wilson, Hannah E. Power, Murray Kendall
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Sydney Harbour is an iconic location with a dense population and low-lying development. On the east coast of Australia, facing the Pacific Ocean, it is exposed to several tsunamigenic trenches. This paper presents a component of the most detailed assessment of the potential for earthquake-generated tsunami impact on Sydney Harbour to date. Models in this study use dynamic tides to account for tide-tsunami interaction. Sydney Harbour’s tidal range is 1.5 m, and the spring tides from January 2015 that are used in the modelling for this study are close to the full tidal range. The tsunami wave trains modelled include hypothetical tsunami generated from earthquakes of magnitude 7.5, 8.0, 8.5, and 9.0 MW from the Puysegur and New Hebrides trenches as well as representations of the historical 1960 Chilean and 2011 Tohoku events. All wave trains are modelled for the peak wave to coincide with both a low tide and a high tide. A single wave train, representing a 9.0 MW earthquake at the Puysegur trench, is modelled for peak waves to coincide with every hour across a 12-hour tidal phase. Using the hydrodynamic model ANUGA, results are compared according to the impact parameters of inundation area, depth variation and current speeds. Results show that both maximum inundation area and depth variation are tide dependent. Maximum inundation area increases when coincident with a higher tide, however, hazardous inundation is only observed for the larger waves modelled: NH90high and P90high. The maximum and minimum depths are deeper on higher tides and shallower on lower tides. The difference between maximum and minimum depths varies across different tidal phases although the differences are slight. Maximum current speeds are shown to be a significant hazard for Sydney Harbour; however, they do not show consistent patterns according to tide-tsunami phasing. The maximum current speed hazard is shown to be greater in specific locations such as Spit Bridge, a narrow channel with extensive marine infrastructure. The results presented for Sydney Harbour are novel, and the conclusions are consistent with previous modelling efforts in the greater area. It is shown that tide must be a consideration for both tsunami modelling and emergency management planning. Modelling with peak tsunami waves coinciding with a high tide would be a conservative approach; however, it must be considered that maximum current speeds may be higher on other tides.Keywords: emergency management, sydney, tide-tsunami interaction, tsunami impact
Procedia PDF Downloads 2351089 Reproductive Behaviour of the Red Sea Immigrant Lagocephalus sceleratus (Gmelin, 1789) from the Mediterranean Coast, Egypt
Authors: Mahmoud Farrag, Alaa Elhaweet, El-Sayed Akel, Mohsen Moustafa
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The present work aimed to study the reproductive strategy of the common lesspsian puffer fish Lagocephalus sceleratus (Gmeln, 1879) from the Egyptian Mediterranean Waters. It is a famous migratory species plays an important role in the field of fisheries and ecology of aquatic ecosystem. The obtained results illustrated seven maturity stages of gonads as; I- Thread like stage: II- Immature stage (Virgin stage), III- Maturing stage (Developing Virgin and recovering spent), IV - Nearly ripe stage, V- Fully ripe; VI-Spawning stage, VII- Spent stage. Sex ratio, exhibited males had higher number than females representing 52.44 % of the total fishes with sex ratio 1: 0.91. Fish length corresponding to 50% maturation was 38.5 cm for males and 41 cm for females. The corresponding ages (age at first maturity) are equal to 2.14 and 2.27 years for male and female respectively. The gonado somatic index (GSI) increased from April for both sexes with peak in June (8.567±4.729) for males and May (6.769±4.662) for females, then the sharp decrease was observed in October showing prolong spawning season from April to September for both sexes. The hepato somatic indices (HSI) for males were lower values than those of females, it were high from December to early spawning (April & May), with the peak in April (5.217 ± 2.167) for males, and in March (5.453± 1.792) for females, then these values started to decrease towards the end of spawning period. The ova diameter ranged from 0.02 to 0.85mm, the mature ova ranged from 0.16 to 0.85mm and showed progressive increase from April towards September during spawning period introducing one peak of mature and ripe eggs. The absolute fecundity increased as the fish grew in weight and length; it was ranged from 260288 to 2372931 for fish weight and ranged from 698 to 3285 cm for length with an average of 1449522±720975. The relative fecundity ranged from 373 to 722 for fish weight with an average of 776±231, while it range from 5784 to 32957 for fish length groups ranged from 43-45 to 70-72 cm with an average of 24478 ±10011 eggs. Histological characters of gonads during the year of study indicating this fish species has prolonged spawning season from April to September where ripe oocytes were observed during this period. This species is considered totally or uni spawner with synchronous group as it contained one to two developmental stages at the same gonad and releases its ripe ova in one batch during the spawning season. These results illustrated more adaptation of this species in new habitat.Keywords: reproductive biology, histology, Lagocephalus sceleratus, Mediterranean Sea, Egypt
Procedia PDF Downloads 4281088 Diagnostic and Prognostic Use of Kinetics of Microrna and Cardiac Biomarker in Acute Myocardial Infarction
Authors: V. Kuzhandai Velu, R. Ramesh
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Background and objectives: Acute myocardial infarction (AMI) is the most common cause of mortality and morbidity. Over the last decade, microRNAs (miRs) have emerged as a potential marker for detecting AMI. The current study evaluates the kinetics and importance of miRs in the differential diagnosis of ST-segment elevated MI (STEMI) and non-STEMI (NSTEMI) and its correlation to conventional biomarkers and to predict the immediate outcome of AMI for arrhythmias and left ventricular (LV) dysfunction. Materials and Method: A total of 100 AMI patients were recruited for the study. Routine cardiac biomarker and miRNA levels were measured during diagnosis and serially at admission, 6, 12, 24, and 72hrs. The baseline biochemical parameters were analyzed. The expression of miRs was compared between STEMI and NSTEMI at different time intervals. Diagnostic utility of miR-1, miR-133, miR-208, and miR-499 levels were analyzed by using RT-PCR and with various diagnostics statistical tools like ROC, odds ratio, and likelihood ratio. Results: The miR-1, miR-133, and miR-499 showed peak concentration at 6 hours, whereas miR-208 showed high significant differences at all time intervals. miR-133 demonstrated the maximum area under the curve at different time intervals in the differential diagnosis of STEMI and NSTEMI which was followed by miR-499 and miR-208. Evaluation of miRs for predicting arrhythmia and LV dysfunction using admission sample demonstrated that miR-1 (OR = 8.64; LR = 1.76) and miR-208 (OR = 26.25; LR = 5.96) showed maximum odds ratio and likelihood respectively. Conclusion: Circulating miRNA showed a highly significant difference between STEMI and NSTEMI in AMI patients. The peak was much earlier than the conventional biomarkers. miR-133, miR-208, and miR-499 can be used in the differential diagnosis of STEMI and NSTEMI, whereas miR-1 and miR-208 could be used in the prediction of arrhythmia and LV dysfunction, respectively.Keywords: myocardial infarction, cardiac biomarkers, microRNA, arrhythmia, left ventricular dysfunction
Procedia PDF Downloads 1231087 Evaluation of Visco-Elastic Properties and Microbial Quality of Oat-Based Dietetic Food
Authors: Uchegbu Nneka Nkechi, Okoye Ogochukwu Peace
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The evaluation of the visco-elastic properties and microbial quality of a formulated oat-based dietetic food were investigated. Oat flour, pumpkin seed flour, carrot flour and skimmed milk powder were blended in varying proportions to formulate a product with codes OCF, which contains 70% oat flour, 10 % carrot flour, 10 % pumpkin seed flour and 10% skimmed milk powder, OCF which contains 65 % oat flour, 10 % carrot flour, 10 % pumpkin seed flour and 15 % skimmed milk powder, OCF which contains 60 % oat flour, 10 % carrot flour, 10 % pumpkin seed flour and 20 % skimmed milk powder, OCF which contains 55 % oat flour, 10 % carrot flour, 10 % pumpkin seed flour and 25 % skimmed milk powder and OF with 95 % oat as the commercial control. All the samples were assessed for their proximate composition, microbial quality and visco-elastic properties. The moisture content was highest at sample OF (10.73%) and lowest at OCF (7.10%) (P<0.05). Crude protein ranged from 13.38%-22.86%, with OCF having the highest (P<0.05) protein content and OF having the lowest. Crude fat was 3.74% for OCF and 6.31% for OF. Crude fiber ranged from 3.58% - 17.39% with OF having the lowest (P<0.05) fiber content and OCF having the highest. Ash content was 1.30% for OCF and 2.75% for OCF. There was no mold growth in the samples. The total viable ml/wl count ranged from 1.5×10³ cfu/g - 2.6×10³ cfu/g, with OCF having the lowest and OF having the highest (P<0.05) total viable count. The peak viscosity of the sample ranged from 75.00 cP-2895.00 cP, with OCF having the lowest and OF having the highest value. The final viscosity was 130.50 cP in OCF and 3572.50 cP in OF. The setback viscosity was 58.00 cP in OCF and 1680.50 cP in OF. The peak time was 6.93 mins in OCF to 5.57 mins in OF. There was no pasting temperature for all samples except the OF, which had 86.43. Sample OF was the highest in terms of overall acceptability. This study showed that the oat-based composite flour produced had a nutritional profile that would be acceptable for the aged population.Keywords: dietetic, pumpkin, visco-elastic, microbial
Procedia PDF Downloads 1921086 Assessment the Implications of Regional Transport and Local Emission Sources for Mitigating Particulate Matter in Thailand
Authors: Ruchirek Ratchaburi, W. Kevin. Hicks, Christopher S. Malley, Lisa D. Emberson
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Air pollution problems in Thailand have improved over the last few decades, but in some areas, concentrations of coarse particulate matter (PM₁₀) are above health and regulatory guidelines. It is, therefore, useful to investigate how PM₁₀ varies across Thailand, what conditions cause this variation, and how could PM₁₀ concentrations be reduced. This research uses data collected by the Thailand Pollution Control Department (PCD) from 17 monitoring sites, located across 12 provinces, and obtained between 2011 and 2015 to assess PM₁₀ concentrations and the conditions that lead to different levels of pollution. This is achieved through exploration of air mass pathways using trajectory analysis, used in conjunction with the monitoring data, to understand the contribution of different months, an hour of the day and source regions to annual PM₁₀ concentrations in Thailand. A focus is placed on locations that exceed the national standard for the protection of human health. The analysis shows how this approach can be used to explore the influence of biomass burning on annual average PM₁₀ concentration and the difference in air pollution conditions between Northern and Southern Thailand. The results demonstrate the substantial contribution that open biomass burning from agriculture and forest fires in Thailand and neighboring countries make annual average PM₁₀ concentrations. The analysis of PM₁₀ measurements at monitoring sites in Northern Thailand show that in general, high concentrations tend to occur in March and that these particularly high monthly concentrations make a substantial contribution to the overall annual average concentration. In 2011, a > 75% reduction in the extent of biomass burning in Northern Thailand and in neighboring countries resulted in a substantial reduction not only in the magnitude and frequency of peak PM₁₀ concentrations but also in annual average PM₁₀ concentrations at sites across Northern Thailand. In Southern Thailand, the annual average PM₁₀ concentrations for individual years between 2011 and 2015 did not exceed the human health standard at any site. The highest peak concentrations in Southern Thailand were much lower than for Northern Thailand for all sites. The peak concentrations at sites in Southern Thailand generally occurred between June and October and were associated with air mass back trajectories that spent a substantial proportion of time over the sea, Indonesia, Malaysia, and Thailand prior to arrival at the monitoring sites. The results show that emissions reductions from biomass burning and forest fires require action on national and international scales, in both Thailand and neighboring countries, such action could contribute to ensuring compliance with Thailand air quality standards.Keywords: annual average concentration, long-range transport, open biomass burning, particulate matter
Procedia PDF Downloads 1771085 Quantitative Analysis of Potential Rainwater Harvesting and Supply to a Rural Community at Northeast of Amazon Region, Brazil
Authors: N. Y. H. Konagano
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Riverside population of Brazilian amazon suffers drinking water scarcity, seeking alternative water resources such as well and rivers, ordinary polluted. Although Amazon Region holds high annual river inflow and enough available of underground water, human activities have compromised the conservation of water resources. In addition, decentralized rural households make difficult to access of potable water. Main objective is to analyze quantitatively the potential of rainwater harvesting to human consumption at Marupaúba community, located in northeast of Amazon region, Brazil. Methods such as historical rainfall data series of municipality of Tomé-Açu at Pará state were obtained from Hydrological Information System of National Water Agency (ANA). Besides, Rippl method was used to calculate, mainly, volume of the reservoir based on difference of water demand and volume available through rainwater using as references two houses (CA I and CA II) as model of rainwater catchment and supply. Results presented that, from years 1984 to 2017, average annual precipitation was 2.607 mm, average maximum precipitation peak was 474 mm on March and average minimum peak on September was 44 mm. All months, of a year, surplus volume of water have presented in relation to demand, considering catchment area (CA) I = 134.4m² and demand volume =0.72 m³/month; and, CA II = 81.84 m² and demand volume = 0.48 m³/month. Based on results, it is concluded that it is feasible to use rainwater for the supply of the rural community Marupaúba, since the access of drinking water is a human right and the lack of this resource compromises health and daily life of human beings.Keywords: Amazon Region, rainwater harvesting, rainwater resource, rural community
Procedia PDF Downloads 1441084 Mitigation of Wind Loads on a Building Using Small Wind Turbines
Authors: Arindam Chowdhury, Andres Tremante, Mohammadtaghi Moravej, Bodhisatta Hajra, Ioannis Zisis, Peter Irwin
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Extreme wind events, such as hurricanes, have caused significant damage to buildings, resulting in losses worth millions of dollars. The roof of a building is most vulnerable to wind-induced damage due to the high suctions experienced by the roof in extreme wind conditions. Wind turbines fitted to buildings can help generate energy, but to our knowledge, their application to wind load mitigation is not well known. This paper presents results from an experimental study to assess the effect of small wind turbines (developed and patented by the first and second authors) on the wind loads on a low rise building roof. The tests were carried out for an open terrain at the Wall of Wind (WOW) experimental facility at Florida International University (FIU), Miami, Florida, USA, for three cases – bare roof, roof fitted with wind turbines placed closer to the roof edges, and roof with wind turbines placed away from the roof edges. Results clearly indicate that the presence of the wind turbines reduced the mean and peak pressure coefficients (less suction) on the roof when compared to the bare deck case. Furthermore, the peak pressure coefficients were found to be lower (less suction) when the wind turbines were placed closer to the roof, than away from the roof. Flow visualization studies using smoke and gravel clearly showed that the presence of the turbines disrupted the formation of vortices formed by cornering winds, thereby reducing roof suctions and preventing lift off of roof coverings. This study shows that the wind turbines besides generating wind energy, can be used for mitigating wind induced damage to the building roof. Future research must be directed towards understanding the effect of these wind turbines on other roof geometries (e.g. hip/gable) in different terrain conditions.Keywords: wall of wind, wind loads, wind turbine, building
Procedia PDF Downloads 2431083 Determination of the Runoff Coefficient in Urban Regions, an Example from Haifa, Israel
Authors: Ayal Siegel, Moshe Inbar, Amatzya Peled
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This study examined the characteristic runoff coefficient in different urban areas. The main area studied is located in the city of Haifa, northern Israel. Haifa spreads out eastward from the Mediterranean seacoast to the top of the Carmel Mountain range with an elevation of 300 m. above sea level. For this research project, four watersheds were chosen, each characterizing a different part of the city; 1) Upper Hadar, a spacious suburb on the upper mountain side; 2) Qiryat Eliezer, a crowded suburb on a level plane of the watershed; 3) Technion, a large technical research university which is located halfway between the top of the mountain range and the coast line. 4) Keret, a remote suburb, on the southwestern outskirts of Haifa. In all of the watersheds found suitable, instruments were installed to continuously measure the water level flowing in the channels. Three rainfall gauges scattered in the study area complete the hydrological requirements for this research project. The runoff coefficient C in peak discharge events was determined by the Rational Formula. The main research finding is the significant relationship between the intensity of rainfall, and the impervious area which is connected to the drainage system of the watershed. For less intense rainfall, the full potential of the connected impervious area will not be exploited. As a result, the runoff coefficient value decreases as do the peak discharge rate and the runoff yield from the storm event. The research results will enable application to other areas by means of hydrological model to be be set up on GIS software that will make it possible to estimate the runoff coefficient of any given city watershed.Keywords: runoff coefficient, rational method, time of concentration, connected impervious area.
Procedia PDF Downloads 3461082 Ionic Liquid and Chemical Denaturants Effects on the Fluorescence Properties of the Laccase
Authors: Othman Saoudi
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In this work, we have interested in the investigation of the chemical denaturants and synthesized ionic liquids effects on the fluorescence properties of the laccase from Trametes versicolor. The fluorescence properties of the laccase result from the presence of Tryptophan, which has an aromatic core responsible for the absorption in ultra violet domain and the emission of the photons of fluorescence. The effect Pyrrolidinuim Formate ([pyrr][F]) and Morpholinium Formate ([morph][F]) ionic liquids on the laccase behavior for various volumetric fractions are studied. We have shown that the fluorescence spectrum relative to the [pyrr][F] presents a single band with a maximum around 340 nm and a secondary peak at 361 nm for a volumetric fraction of 20% v/v. For concentration superiors to 40%, the fluorescence intensity decreases and a displacement of the peaks toward higher wavelengths has occurred. For the [morph][F], the fluorescence spectrum showed a single band around 340 nm. The intensity of the principal peak decreases for concentration superiors to 20% v/v. From the plot representing the variation of the λₘₐₓ versus the volumetric concentration, we have determined the concentration of the half-transitions C1/2. These concentrations are equal to 42.62% and 40.91% v/v in the presence of [pyrr][F] and [morph][F] respectively. For the chemical denaturation, we have shown that the fluorescence intensity decreases with increasing denaturant concentrations where the maximum of the wavelength of emission shifts toward the higher wavelengths. We have also determined from the spectrum relative to the urea and GdmCl, the unfolding energy, ∆GD. The results show that the variation of the unfolding energy as a function of the denaturant concentrations varies according to the linear regression model. We have demonstrated also that the half-transitions C1/2 have occurred for urea and GdmCl denaturants concentrations around 3.06 and 3.17 M respectively.Keywords: laccase, fluorescence, ionic liquids, chemical denaturants
Procedia PDF Downloads 5021081 Software Development for Both Small Wind Performance Optimization and Structural Compliance Analysis with International Safety Regulations
Authors: K. M. Yoo, M. H. Kang
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Conventional commercial wind turbine design software is limited to large wind turbines due to not incorporating with low Reynold’s Number aerodynamic characteristics typically for small wind turbines. To extract maximum annual energy product from an intermediately designed small wind turbine associated with measured wind data, numerous simulation is highly recommended to have a best fitting planform design with proper airfoil configuration. Since depending upon wind distribution with average wind speed, an optimal wind turbine planform design changes accordingly. It is theoretically not difficult, though, it is very inconveniently time-consuming design procedure to finalize conceptual layout of a desired small wind turbine. Thus, to help simulations easier and faster, a GUI software is developed to conveniently iterate and change airfoil types, wind data, and geometric blade data as well. With magnetic generator torque curve, peak power tracking simulation is also available to better match with the magnetic generator. Small wind turbine often lacks starting torque due to blade optimization. Thus this simulation is also embedded along with yaw design. This software provides various blade cross section details at user’s design convenience such as skin thickness control with fiber direction option, spar shape, and their material properties. Since small wind turbine is under international safety regulations with fatigue damage during normal operations and safety load analyses with ultimate excessive loads, load analyses are provided with each category mandated in the safety regulations.Keywords: GUI software, Low Reynold’s number aerodynamics, peak power tracking, safety regulations, wind turbine performance optimization
Procedia PDF Downloads 2961080 Cardiorespiratory Fitness and the Cardiometabolic Profile in Inactive Obese Postmenopausal Women: A MONET Study
Authors: Ahmed Ghachem, Johann Colomba, Denis Prud'homme, Martin Brochu
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Background: Inactive obese postmenopausal women, are at greater risk for metabolic complications. On the other hand, high levels of cardiorespiratory fitness (CRF) are associated with a lower risk of metabolic complications. Objective: To compare inactive obese postmenopausal women displaying ‘lower’ vs ‘higher’ levels of CRF for body composition, metabolic profile, inflammatory profile and measures of energy expenditure. Methods: 132 women (age: 57.6 ± 4.8 yrs; BMI: 32.3 ± 4.6 kg/m2; Peak VO2: 17.81 ± 3.02 ml O2•kg-1•min-1) were studied. They were first divided into tertiles based on their CRF. Then, women in the first (< 16.51 ml O2•min-1•kg-1) and second tertiles (16.51 to 19.22 ml O2•min-1•kg-1) were combined (N= 88), and compared with those in the third tertile (> 19.22 ml O2•min-1•kg-1) (N= 44). Variables of interest were: Peak VO2 (stationary bike), body composition (DXA), body fat distribution (CT scan), glucose homeostasis (fasting state and euglycemic/ hyperinsulinemic clamp), fasting lipids, resting blood pressure, inflammatory profile and energy expenditure (DLW). Results: Both CRF groups (lower= 16.0 ± 2.0 ml O2•kg-1•min-1 vs higher= 21.2 ± 1.7 ml O2•kg-1•min-1; p < 0.001) were similar for age. Significant differences were observed between groups for body composition; with lower values for body weight, BMI, fat mass and visceral fat in women with higher CRF (p between 0.001 and 0.005). Also, women with higher CRF had lower values for fasting insulin (13.4 ± 4.5 vs 15.6 ± 6.6 μU/ml; p = 0.03) and CRP levels (2.31 ± 1.97 vs 3.83 ± 3.24 mg/liter; p = 0.001); and higher values for glucose disposal (6.71 ± 1.78 vs 5.92 ± 1.67 mg/kg/min; p = 0.01). However, these differences were no longer significant after controlling for visceral adipose tissue accumulations. Finally, no significant difference was observed between groups for the other variables of interest. Conclusion: Our results suggest that, among inactive overweight/obese postmenopausal women, those with higher CRF levels have a better metabolic profile; which is caused by lower visceral fat accumulations.Keywords: cardiorespiratory fitness, metabolic profile, menopause, obesity
Procedia PDF Downloads 2601079 Plasma Ion Implantation Study: A Comparison between Tungsten and Tantalum as Plasma Facing Components
Authors: Tahreem Yousaf, Michael P. Bradley, Jerzy A. Szpunar
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Currently, nuclear fusion is considered one of the most favorable options for future energy generation, due both to its abundant fuel and lack of emissions. For fusion power reactors, a major problem will be a suitable material choice for the Plasma Facing Components (PFCs) which will constitute the reactor first wall. Tungsten (W) has advantages as a PFC material because of its high melting point, low vapour pressure, high thermal conductivity and low retention of hydrogen isotopes. However, several adverse effects such as embrittlement, melting and morphological evolution have been observed in W when it is bombarded by low-energy and high-fluence helium (He) and deuterium (D) ions, as a simulation conditions adjacent to a fusion plasma. Recently, tantalum (Ta) also investigate as PFC and show better reluctance to nanostructure fuzz as compared to W under simulated fusion plasma conditions. But retention of D ions found high in Ta than W. Preparatory to plasma-based ion implantation studies, the effect of D and He ion impact on W and Ta is predicted by using the stopping and range of ions in the matter (SRIM) code. SRIM provided some theoretical results regarding projected range, ion concentration (at. %) and displacement damage (dpa) in W and Ta. The projected range for W under Irradiation of He and D ions with an energy of 3-keV and 1×fluence is determined 75Å and 135 Å and for Ta 85Å and 155Å, respectively. For both W and Ta samples, the maximum implanted peak for helium is predicted ~ 5.3 at. % at 12 nm and for De ions concentration peak is located near 3.1 at. % at 25 nm. For the same parameters, the displacement damage for He ions is observed in W ~ 0.65 dpa and Ta ~ 0.35 dpa at 5 nm. For D ions the displacement damage for W ~ 0.20 dpa at 8 nm and Ta ~ 0.175 dpa at 7 nm. The mean implantation depth is same for W and Ta, i.e. for He ions ~ 40 nm and D ions ~ 70 nm. From these results, we conclude that retention of D is high than He ions, but damage is low for Ta as compared to W. Further investigation still in progress regarding W and T.Keywords: helium and deuterium ion impact, plasma facing components, SRIM simulation, tungsten, tantalum
Procedia PDF Downloads 1261078 Facile Synthesis and Characterization of Heterostructure Core-Shell Silver-Silica Nanocomposite for Humidity Sensing
Authors: Fatai O. Oladoyinbo, Felix O. Sanni, Akinwunmi Fatai, Kamoli A. Amusa, Saheed A. Ganiyu, Wasiu B. Ayinde, Tajudeen A. Afolabi, Enock O. Dare
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Silver (Ag) and silica (SiO2) nanoparticles were synthesized using the chemical reduction method from silver nitrate and sodium silicate, respectively. X-ray Diffraction (XRD), High-Resolution Transmission Electron Microscopy (HRTEM), Scanning Electron Microscopy (SEM), Uv-Visible spectroscopy, Energy Dispersive X-ray (EDX) spectroscopy and N2 adsorption-desorption techniques were utilized to characterize the composition and structure of the samples. The crystallinity pattern of Ag nanoparticles was indexed as (111), (200), (220) and (311), which allowed reflections from face-centered cubic silver. XRD of SiO2 showed good porosity with a broad-spectrum band at Bragg’s angle 2θ of 22° while that of Ag-SiO2 showed distinct peaks at 2θ values of 39°, 43°, 66° and 79°. The XRD result agreed perfectly with the SEM and HRTEM images which showed Ag-SiO2 isotropic and anisotropic under the varying concentration of reactants. The elemental composition of Ag-SiO2, as displayed by EDX, confirmed Ag enrichment in the Ag-SiO2 heterostructure. The Uv-Visible peak at 421 nm confirmed the Surface Plasmon Resonance absorption peak of silver nanoparticles. N2 adsorption-desorption result showed a broad band of Ag-SiO2 from 3 to 8 nm, which indicated relatively narrow pore size distributions. Humidity sensing measurements performed in a controlled humidity chamber showed very high sensitivity with a sensitivity factor (SF) of 4.63 and high linearity with a steady decrease in resistance to humidity from 880 Ω at 10% RH to 190 Ω at 100% RH, indicating that Ag-SiO2 nanocomposite is a good sensing material with high sensitivity and linearity.Keywords: silver, silica, nanocomposite, synthesis, heterostructure, core shell
Procedia PDF Downloads 701077 Correction Factors for Soil-Structure Interaction Predicted by Simplified Models: Axisymmetric 3D Model versus Fully 3D Model
Authors: Fu Jia
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The effects of soil-structure interaction (SSI) are often studied using axial-symmetric three-dimensional (3D) models to avoid the high computational cost of the more realistic, fully 3D models, which require 2-3 orders of magnitude more computer time and storage. This paper analyzes the error and presents correction factors for system frequency, system damping, and peak amplitude of structural response computed by axisymmetric models, embedded in uniform or layered half-space. The results are compared with those for fully 3D rectangular foundations of different aspect ratios. Correction factors are presented for a range of the model parameters, such as fixed-base frequency, structure mass, height and length-to-width ratio, foundation embedment, soil-layer stiffness and thickness. It is shown that the errors are larger for stiffer, taller and heavier structures, deeper foundations and deeper soil layer. For example, for a stiff structure like Millikan Library (NS response; length-to-width ratio 1), the error is 6.5% in system frequency, 49% in system damping and 180% in peak amplitude. Analysis of a case study shows that the NEHRP-2015 provisions for reduction of base shear force due to SSI effects may be unsafe for some structures and need revision. The presented correction factor diagrams can be used in practical design and other applications.Keywords: 3D soil-structure interaction, correction factors for axisymmetric models, length-to-width ratio, NEHRP-2015 provisions for reduction of base shear force, rectangular embedded foundations, SSI system frequency, SSI system damping
Procedia PDF Downloads 2561076 Design and Optimization of an Electromagnetic Vibration Energy Converter
Authors: Slim Naifar, Sonia Bradai, Christian Viehweger, Olfa Kanoun
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Vibration provides an interesting source of energy since it is available in many indoor and outdoor applications. Nevertheless, in order to have an efficient design of the harvesting system, vibration converters have to satisfy some criterion in terms of robustness, compactness and energy outcome. In this work, an electromagnetic converter based on mechanical spring principle is proposed. The designed harvester is formed by a coil oscillating around ten ring magnets using a mechanical spring. The proposed design overcomes one of the main limitation of the moving coil by avoiding the contact between the coil wires with the mechanical spring which leads to a better robustness for the converter. In addition, the whole system can be implemented in a cavity of a screw. Different parameters in the harvester were investigated by finite element method including the magnet size, the coil winding number and diameter and the excitation frequency and amplitude. A prototype was realized and tested. Experiments were performed for 0.5 g to 1 g acceleration. The used experimental setup consists of an electrodynamic shaker as an external artificial vibration source controlled by a laser sensor to measure the applied displacement and frequency excitation. Together with the laser sensor, a controller unit, and an amplifier, the shaker is operated in a closed loop which allows controlling the vibration amplitude. The resonance frequency of the proposed designs is in the range of 24 Hz. Results indicate that the harvester can generate 612 mV and 1150 mV maximum open circuit peak to peak voltage at resonance for 0.5 g and 1 g acceleration respectively which correspond to 4.75 mW and 1.34 mW output power. Tuning the frequency to other values is also possible due to the possibility to add mass to the moving part of the or by changing the mechanical spring stiffness.Keywords: energy harvesting, electromagnetic principle, vibration converter, moving coil
Procedia PDF Downloads 2911075 Philosophy, Geometry, and Purpose in Islamic and Gothic Architecture as Two Religious-Based Styles
Authors: P. Nafisi Poor, P. Javid
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Religion and divinity have always held important meaning to humans, and therefore it affects different aspects of life including art and architecture. Numerous works of art are related to religion whether supporting or denying it. Religion and religious scholars have influenced and changed art throughout history. This paper focuses on Islam and Christianity because these two religions have been the most discussed and most popular of all time, starting from the birth of Jesus to the arrival of Mohammad. Based on this popularity, these religions have influenced the arts and especially architecture. Islam on one hand changed Iranian and Arabian architecture and they applied it in different places around the world. From the appearance of Islam at 622 AD to this day, Islamic architecture has been evolving; however, one of the most important periods for this style was between 1501 AD and 1736 AD in Iran. Christianity, on the other hand, changed European architecture especially between 1150 AD and 1450 AD or the so-called "Gothic" era, which begins at medieval time and reaches its peak at International Gothic ages. At both of these periods, designing buildings based on spiritual concepts and divine statements reached its peak, and architects were considering God and religion as their center of attention. This article studies the focus on the religions of Islam and Christianity in terms of architecture and presents a general philosophy of both styles to comprehend the idea behind each one, followed by an analysis of their geometry and architectural aspects derived from the best examples, all to understand the purpose of each style and to realize, which one was more successful in reaching their purpose. Subsequently, a comprehensive review of each building is provided including 3D visualizations to help achieve the goal of the article. These studies can support diverse inquiries about both Islamic and Gothic architecture and can be used as a resource to support studies and research towards designing based on religion or for divine purposes.Keywords: architecture, Gothic, Islamic, religion
Procedia PDF Downloads 1361074 Comparison of FNTD and OSLD Detectors' Responses to Light Ion Beams Using Monte Carlo Simulations and Exprimental Data
Authors: M. R. Akbari, H. Yousefnia, A. Ghasemi
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Al2O3:C,Mg fluorescent nuclear track detector (FNTD) and Al2O3:C optically stimulated luminescence detector (OSLD) are becoming two of the applied detectors in ion dosimetry. Therefore, the response of these detectors to hadron beams is highly of interest in radiation therapy (RT) using ion beams. In this study, these detectors' responses to proton and Helium-4 ion beams were compared using Monte Carlo simulations. The calculated data for proton beams were compared with Markus ionization chamber (IC) measurement (in water phantom) from M.D. Anderson proton therapy center. Monte Carlo simulations were performed via the FLUKA code (version 2011.2-17). The detectors were modeled in cylindrical shape at various depths of the water phantom without shading each other for obtaining relative depth dose in the phantom. Mono-energetic parallel ion beams in different incident energies (100 MeV/n to 250 MeV/n) were collided perpendicularly on the phantom surface. For proton beams, the results showed that the simulated detectors have over response relative to IC measurements in water phantom. In all cases, there were good agreements between simulated ion ranges in the water with calculated and experimental results reported by the literature. For proton, maximum peak to entrance dose ratio in the simulated water phantom was 4.3 compared with about 3 obtained from IC measurements. For He-4 ion beams, maximum peak to entrance ratio calculated by both detectors was less than 3.6 in all energies. Generally, it can be said that FLUKA is a good tool to calculate Al2O3:C,Mg FNTD and Al2O3:C OSLD detectors responses to therapeutic proton and He-4 ion beams. It can also calculate proton and He-4 ion ranges with a reasonable accuracy.Keywords: comparison, FNTD and OSLD detectors response, light ion beams, Monte Carlo simulations
Procedia PDF Downloads 3341073 Ankh Key Broadband Array Antenna for 5G Applications
Authors: Noha M. Rashad, W. Swelam, M. H. Abd ElAzeem
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A simple design of array antenna is presented in this paper, supporting millimeter wave applications which can be used in short range wireless communications such as 5G applications. This design enhances the use of V-band, according to IEEE standards, as the antenna works in the 70 GHz band with bandwidth more than 11 GHz and peak gain more than 13 dBi. The design is simulated using different numerical techniques achieving a very good agreement.Keywords: 5G technology, array antenna, microstrip, millimeter wave
Procedia PDF Downloads 2981072 ZnO Nanoparticles as Photocatalysts: Synthesis, Characterization and Application
Authors: Pachari Chuenta, Suwat Nanan
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ZnO nanostructures have been synthesized successfully in high yield via catalyst-free chemical precipitation technique by varying zinc source (either zinc nitrate or zinc acetate) and oxygen source (either oxalic acid or urea) without using any surfactant, organic solvent or capping agent. The ZnO nanostructures were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometry (XRD), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), UV-vis diffuse reflection spectroscopy (UV-vis DRS), and photoluminescence spectroscopy (PL). The FTIR peak in the range of 450-470 cm-1 corresponded to Zn-O stretching in ZnO structure. The synthesized ZnO samples showed well crystalized hexagonal wurtzite structure. SEM micrographs displayed spherical droplet of about 50-100 nm. The band gap of prepared ZnO was found to be 3.4-3.5 eV. The presence of PL peak at 468 nm was attributed to surface defect state. The photocatalytic activity of ZnO was studied by monitoring the photodegradation of reactive red (RR141) azo dye under ultraviolet (UV) light irradiation. Blank experiment was also separately carried out by irradiating the aqueous solution of the dye in absence of the photocatalyst. The initial concentration of the dye was fixed at 10 mgL-1. About 50 mg of ZnO photocatalyst was dispersed in 200 mL dye solution. The sample was collected at a regular time interval during the irradiation and then was analyzed after centrifugation. The concentration of the dye was determined by monitoring the absorbance at its maximum wavelength (λₘₐₓ) of 544 nm using UV-vis spectroscopic analysis technique. The sources of Zn and O played an important role on photocatalytic performance of the ZnO photocatalyst. ZnO nanoparticles which prepared by zinc acetate and oxalic acid at molar ratio of 1:1 showed high photocatalytic performance of about 97% toward photodegradation of reactive red azo dye (RR141) under UV light irradiation for only 60 min. This work demonstrates the promising potential of ZnO nanomaterials as photocatalysts for environmental remediation.Keywords: azo dye, chemical precipitation, photocatalytic, ZnO
Procedia PDF Downloads 1411071 Design and Analysis of Semi-Active Isolation System in Low Frequency Excitation Region for Vehicle Seat to Reduce Discomfort
Authors: Andrea Tonoli, Nicola Amati, Maria Cavatorta, Reza Mirsanei, Behzad Mozaffari, Hamed Ahani, Akbar Karamihafshejani, Mohammad Ghazivakili, Mohammad Abuabiah
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The vibrations transmitted to the drivers and passengers through vehicle seat seriously effect on the level of their attention, fatigue and physical health and reduce the comfort and efficiency of the occupants. Recently, some researchers have focused on vibrations at low excitation frequency(0.5-5 Hz) which are considered to be the main risk factors for lumbar part of the backbone but they were not applicable to A and B-segment cars regarding to the size and weight. A semi-active system with two symmetric negative stiffness structures (NSS) in parallel to a positive stiffness structure and actuators has been proposed to attenuate low frequency excitation and makes system flexible regarding to different weight of passengers which is applicable for A and B-Segment cars. Here, the 3 degree of freedom system is considered, dynamic equation clearly is presented, then simulated in MATLAB in order to analysis of performance of the system. The design procedure is derived so that the resonance peak of frequency–response curve shift to the left, the isolating range is increased and especially, the peak of the frequency–response curve is minimized. According to ISO standard different class of road profile as an input is applied to the system to evaluate the performance of the system. To evaluate comfort issues, we extract the RMS value of the vertical acceleration acting on the passenger's body. Then apply the band-pass filter, which takes into account the human sensitivity to acceleration. According to ISO, this weighted acceleration is lower than 0.315 m/s^2, so the ride is considered as comfortable.Keywords: low frequency excitation, negative stiffness, seat vehicle, vibration isolation
Procedia PDF Downloads 4291070 Staying Cool in the Heat: How Tropical Finches Behaviorally Adjust to Extreme Heat in the Wild
Authors: Mara F. Müller, Simon C. Griffith, Tara L. Crewe, Mirjam Kaestli, Sydney J. Collett, Ian J. Radford, Hamish A. Campbell
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The intensity and frequency of heat waves have been progressively increasing because of climate change. Passerines that inhabit very hot regions are already close to their physiological thermal limit and are thus considered highly susceptible to increased ambient temperatures. However, the extent by which passerines behaviorally compensate for extreme heat in their natural habitat has rarely been assessed due to monitoring challenges. To address this knowledge gap, coded VHF-nano transmitters were attached to a tropical passerine (Gouldian finch, Chloebia gouldiae). Fine-scale activity and movement were monitored throughout the hottest and driest period of the year using an array of static VHF-receivers. The finches were found to typically show a peak activity for a few hours at sunrise and remained relatively quiescent for the rest of the day. However, on extremely hot days (max temperature >38ºC), finches showed higher activity levels earlier in the morning and presented a second peak in the afternoon. Gouldian finches are physiologically challenged when ambient temperatures exceed 38ºC, suggesting the shift in movement activity reflects a behavioral mitigation strategy to extreme heat. These tropical finches already exist on an energetic knife-edge during this time of the year due to resource scarcity. Hence, the increased energetic expenditure to mitigate thermal stress may be detrimental. The study demonstrates the value of VHF-telemetry technology in monitoring the impact of global change on the biology of small-bodied mobile species.Keywords: animal tracking, biotelemetry, climate change, extreme heat, movement activity, radiotelemetry, VHF-telemetry
Procedia PDF Downloads 821069 Evaluation of a Chitin Synthesis Inhibitor Novaluron in the Shrimp Palaemon Adspersus: Impact on Ecdysteroids and Chitin Contents
Authors: Hinda Berghiche, Hamida Benradia, Noureddine Soltani
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Pesticides are widely used in crop production and are known to induce a major contamination of ecosystems especially in aquatic environments. The leaching of a large amount of pollutants derived from agricultural activities (fertilizers, pesticides) might contaminate rivers which diverse into the likes and estuarine and coastal environments affecting several organisms such as crustacean species. In this context, there is searched for new selective insecticides with minimal toxic effects on the environment and human health such as growth insect regulators (GIRs). The current study aimed to examine the impact of novaluron (CE 20%), a potent benzoylphenylurea derivative insecticide on mosquito larvae, against non-target shrimp, Palaemon adspersus (Decapoda, Palaemonidae). The compound was tested at two concentrations (0.91 mg/L and 4.30 mg/L) corresponding respectively to the LC50 and LC90 determined against fourth-instar larvae of Culiseta longiareolata (Diptera, Culicidae). The molting hormone titer was determined in the haemolymph by an enzyme-immunoassay, while chitin was measured in peripheral integument at different stages during the molting cycle. Under normal conditions, the haemolymphatic ecdysteroid concentrations increased during the molting cycle to reach peak at stage D. In the treated series, we note absence of the peak at stage D and an increase at stages B, C and D as compared to the controls. Concerning the chitin amounts, we observe an increase from stage A to stage C followed by a decrease at stage D. Exposition of shrimps to novaluron resulted in a significant decrease of values at all molting stages with a dose-response effect. Thus, the insecticide can present secondary effects on this non-target arthropod species.Keywords: toxicology, novaluron, crustacean, palaemon adspersus, ecdysteroids, cuticle, chitin
Procedia PDF Downloads 2461068 Effect of Two Types of Shoe Insole on the Dynamics of Lower Extremities Joints in Individuals with Leg Length Discrepancy during Stance Phase of Walking
Authors: Mansour Eslami, Fereshte Habibi
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Limb length discrepancy (LLD), or anisomeric, is defined as a condition in which paired limbs are noticeably unequal. Individuals with LLD during walking use compensatory mechanisms to dynamically lengthen the short limb and shorten the long limb to minimize the displacement of the body center of mass and consequently reduce body energy expenditure. Due to the compensatory movements created, LLD greater than 1 cm increases the odds of creating lumbar problems and hip and knee osteoarthritis. Insoles are non-surgical therapies that are recommended to improve the walking pattern, pain and create greater symmetry between the two lower limbs. However, it is not yet clear what effect insoles have on the variables related to injuries during walking. The aim of the present study was to evaluate the effect of internal and external heel lift insoles on pelvic kinematic in sagittal and frontal planes and lower extremity joint moments in individuals with mild leg length discrepancy during the stance phase of walking. Biomechanical data of twenty-eight men with structural leg length discrepancy of 10-25 mm were collected while they walked under three conditions: shoes without insole (SH), with internal heel lift insoles (IHLI) in shoes, and with external heal lift insole (EHLI). The tests were performed for both short and long legs. The pelvic kinematic and joint moment were measured with a motion capture system and force plate. Five walking trials were performed for each condition. The average value of five successful trials was used for further statistical analysis. Repeated measures ANCOVA with Bonferroni post hoc test were used for between-group comparisons (p ≤ 0.05). In both internal and external heel lift insoles (IHLI, EHLI), there was a significant decrease in the peak values of lateral and anterior pelvic tilts of the long leg, hip, and knee moments of a long leg and ankle moment of short leg (p ≤ 0.05). Furthermore, significant increases in peak values of lateral and anterior pelvic tilt of short leg in IHLI and EHLI were observed as compared to Shoe (SH) condition (p ≤ 0.01). In addition, a significant difference was observed between the IHLI and EHLI conditions in peak anterior pelvic tilt of long leg and plantar flexor moment of short leg (p=0.04; p= 0.04 respectively). Our findings indicate that both IHLI and EHLI can play an important role in controlling excessive pelvic movements in the sagittal and frontal planes in individuals with mild LLD during walking. Furthermore, the EHLI may have a better effect in preventing musculoskeletal injuries compared to the IHLI.Keywords: kinematic, leg length discrepancy, shoe insole, walking
Procedia PDF Downloads 1111067 Ultra-High Voltage Energization of Electrostatic Precipitators for Coal Fired Boilers
Authors: Mads Kirk Larsen
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Strict air pollution control is today high on the agenda world-wide. By reducing the particular emission, not only the mg/Nm3 will be reduced – also parts of mercury and other hazardous matters attached to the particles will be reduced. Furthermore, it is possible to catch the fine particles (PM2.5). For particulate control, the precipitators are still the preferred choice and much efforts have been done to improve the efficiencies. Many ESP’s have seen electrical upgrading by changing the traditional 1 phase power system into either 3 phase or SMPS (High Frequency) units. However, there exist a 4th type of power supply – the pulse type. This is unfortunately widely unknown, but may be of great benefit to power plants. The FLSmidth type is called COROMAX® and it is a high voltage pulse generator for precipitators using a semiconductor switch operating at medium potential. The generated high voltage pulses have rated amplitude of 80 kV and duration of 75 μs and are superimposed on a variable base voltage of 60 kV rated voltage. Hereby, achieving a peak voltage of 140 kV. COROMAX® has the ability to increase the voltage beyond the natural spark limit inside the precipitator. Voltage levels may often be twice as high after installation of COROMAX®. Hereby also the migration velocity increases and thereby the efficiency. As the collection efficiency is proportional to the voltage peak and mean values, this also increases the collection efficiency of the fine particles where test has shown 80% removal of particles less than 0.07 micron. Another great advantage is the indifference to back-corona. Simultaneously with emission reduction, the power consumption will also be reduced. Another great advantage of the COROMAX® system is that the emission can be improved without the need to change the internal parts or enlarge the ESP. Recently, more than 150 units have been installed in China, where emissions have been reduced to ultra-low levels.Keywords: eleectrostatic precipitator, high resistivity dust, micropulse energization, particulate removal
Procedia PDF Downloads 294