Search results for: open volumetric air receiver
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 3515

Search results for: open volumetric air receiver

3095 Polygeneration Solar Thermal System

Authors: S. K. Deb, B. C. Sarma

Abstract:

The concentrating solar thermal devices using low cost thin metallic reflector sheet of moderate reflectance can generate heat both at higher temperature for the receiver at it’s focus and at moderate temperature through direct solar irradiative heat absorption by the reflector sheet itself. Investigation on well insulated rear surface of the concentrator with glass covers at it’s aperture plane for waste heat recovery against the conventional radiative, convective & conductive heat losses for a bench model with a thermal analysis is the prime motivation of this study along with an effort to popularize a compact solar thermal polygeneration system.

Keywords: concentrator, polygeneration, aperture, renewable energy, exergy, solar energy

Procedia PDF Downloads 509
3094 Stability of a Biofilm Reactor Able to Degrade a Mixture of the Organochlorine Herbicides Atrazine, Simazine, Diuron and 2,4-Dichlorophenoxyacetic Acid to Changes in the Composition of the Supply Medium

Authors: I. Nava-Arenas, N. Ruiz-Ordaz, C. J. Galindez-Mayer, M. L. Luna-Guido, S. L. Ruiz-López, A. Cabrera-Orozco, D. Nava-Arenas

Abstract:

Among the most important herbicides, the organochlorine compounds are of considerable interest due to their recalcitrance to the chemical, biological, and photolytic degradation, their persistence in the environment, their mobility, and their bioacummulation. The most widely used herbicides in North America are primarily 2,4-dichlorophenoxyacetic acid (2,4-D), the triazines (atrazine and simazine), and to a lesser extent diuron. The contamination of soils and water bodies frequently occurs by mixtures of these xenobiotics. For this reason, in this work, the operational stability to changes in the composition of the medium supplied to an aerobic biofilm reactor was studied. The reactor was packed with fragments of volcanic rock that retained a complex microbial film, able to degrade a mixture of organochlorine herbicides atrazine, simazine, diuron and 2,4-D, and whose members have microbial genes encoding the main catabolic enzymes atzABCD, tfdACD and puhB. To acclimate the attached microbial community, the biofilm reactor was fed continuously with a mineral minimal medium containing the herbicides (in mg•L-1): diuron, 20.4; atrazine, 14.2, simazine, 11.4, and 2,4-D, 59.7, as carbon and nitrogen sources. Throughout the bioprocess, removal efficiencies of 92-100% for herbicides, 78-90% for COD, 92-96% for TOC and 61-83% for dehalogenation were reached. In the microbial community, the genes encoding catabolic enzymes of different herbicides tfdACD, puhB and, occasionally, the genes atzA and atzC were detected. After the acclimatization, the triazine herbicides were eliminated from the mixture formulation. Volumetric loading rates of the mixture 2,4-D and diuron were continuously supplied to the reactor (1.9-21.5 mg herbicides •L-1 •h-1). Along the bioprocess, the removal efficiencies obtained were 86-100% for the mixture of herbicides, 63-94% for for COD, 90-100% for COT, and dehalogenation values of 63-100%. It was also observed that the genes encoding the enzymes in the catabolism of both herbicides, tfdACD and puhB, were consistently detected; and, occasionally, the atzA and atzC. Subsequently, the triazine herbicide atrazine and simazine were restored to the medium supply. Different volumetric charges of this mixture were continuously fed to the reactor (2.9 to 12.6 mg herbicides •L-1 •h-1). During this new treatment process, removal efficiencies of 65-95% for the mixture of herbicides, 63-92% for COD, 66-89% for TOC and 73-94% of dehalogenation were observed. In this last case, the genes tfdACD, puhB and atzABC encoding for the enzymes involved in the catabolism of the distinct herbicides were consistently detected. The atzD gene, encoding the cyanuric hydrolase enzyme, could not be detected, though it was determined that there was partial degradation of cyanuric acid. In general, the community in the biofilm reactor showed some catabolic stability, adapting to changes in loading rates and composition of the mixture of herbicides, and preserving their ability to degrade the four herbicides tested; although, there was a significant delay in the response time to recover to degradation of the herbicides.

Keywords: biodegradation, biofilm reactor, microbial community, organochlorine herbicides

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3093 Comparison of Quality of Life One Year after Bariatric Intervention: Systematic Review of the Literature with Bayesian Network Meta-Analysis

Authors: Piotr Tylec, Alicja Dudek, Grzegorz Torbicz, Magdalena Mizera, Natalia Gajewska, Michael Su, Tanawat Vongsurbchart, Tomasz Stefura, Magdalena Pisarska, Mateusz Rubinkiewicz, Piotr Malczak, Piotr Major, Michal Pedziwiatr

Abstract:

Introduction: Quality of life after bariatric surgery is an important factor when evaluating the final result of the treatment. Considering the vast surgical options, we tried to globally compare available methods in terms of quality of following the surgery. The aim of the study is to compare the quality of life a year after bariatric intervention using network meta-analysis methods. Material and Methods: We performed a systematic review according to PRISMA guidelines with Bayesian network meta-analysis. Inclusion criteria were: studies comparing at least two methods of weight loss treatment of which at least one is surgical, assessment of the quality of life one year after surgery by validated questionnaires. Primary outcomes were quality of life one year after bariatric procedure. The following aspects of quality of life were analyzed: physical, emotional, general health, vitality, role physical, social, mental, and bodily pain. All questionnaires were standardized and pooled to a single scale. Lifestyle intervention was considered as a referenced point. Results: An initial reference search yielded 5636 articles. 18 studies were evaluated. In comparison of total score of quality of life, we observed that laparoscopic sleeve gastrectomy (LSG) (median (M): 3.606, Credible Interval 97.5% (CrI): 1.039; 6.191), laparoscopic Roux en-Y gastric by-pass (LRYGB) (M: 4.973, CrI: 2.627; 7.317) and open Roux en-Y gastric by-pass (RYGB) (M: 9.735, CrI: 6.708; 12.760) had better results than other bariatric intervention in relation to lifestyle interventions. In the analysis of the physical aspects of quality of life, we notice better results in LSG (M: 3.348, CrI: 0.548; 6.147) and in LRYGB procedure (M: 5.070, CrI: 2.896; 7.208) than control intervention, and worst results in open RYGB (M: -9.212, CrI: -11.610; -6.844). Analyzing emotional aspects, we found better results than control intervention in LSG, in LRYGB, in open RYGB, and laparoscopic gastric plication. In general health better results were in LSG (M: 9.144, CrI: 4.704; 13.470), in LRYGB (M: 6.451, CrI: 10.240; 13.830) and in single-anastomosis gastric by-pass (M: 8.671, CrI: 1.986; 15.310), and worst results in open RYGB (M: -4.048, CrI: -7.984; -0.305). In social and vital aspects of quality of life, better results were observed in LSG and LRYGB than control intervention. We did not find any differences between bariatric interventions in physical role, mental and bodily aspects of quality of life. Conclusion: The network meta-analysis revealed that better quality of life in total score one year after bariatric interventions were after LSG, LRYGB, open RYGB. In physical and general health aspects worst quality of life was in open RYGB procedure. Other interventions did not significantly affect the quality of life after a year compared to dietary intervention.

Keywords: bariatric surgery, network meta-analysis, quality of life, one year follow-up

Procedia PDF Downloads 127
3092 Estimating Evapotranspiration Irrigated Maize in Brazil Using a Hybrid Modelling Approach and Satellite Image Inputs

Authors: Ivo Zution Goncalves, Christopher M. U. Neale, Hiran Medeiros, Everardo Mantovani, Natalia Souza

Abstract:

Multispectral and thermal infrared imagery from satellite sensors coupled with climate and soil datasets were used to estimate evapotranspiration and biomass in center pivots planted to maize in Brazil during the 2016 season. The hybrid remote sensing based model named Spatial EvapoTranspiration Modelling Interface (SETMI) was applied using multispectral and thermal infrared imagery from the Landsat Thematic Mapper instrument. Field data collected by the IRRIGER center pivot management company included daily weather information such as maximum and minimum temperature, precipitation, relative humidity for estimating reference evapotranspiration. In addition, soil water content data were obtained every 0.20 m in the soil profile down to 0.60 m depth throughout the season. Early season soil samples were used to obtain water-holding capacity, wilting point, saturated hydraulic conductivity, initial volumetric soil water content, layer thickness, and saturated volumetric water content. Crop canopy development parameters and irrigation application depths were also inputs of the model. The modeling approach is based on the reflectance-based crop coefficient approach contained within the SETMI hybrid ET model using relationships developed in Nebraska. The model was applied to several fields located in Minas Gerais State in Brazil with approximate latitude: -16.630434 and longitude: -47.192876. The model provides estimates of real crop evapotranspiration (ET), crop irrigation requirements and all soil water balance outputs, including biomass estimation using multi-temporal satellite image inputs. An interpolation scheme based on the growing degree-day concept was used to model the periods between satellite inputs, filling the gaps between image dates and obtaining daily data. Actual and accumulated ET, accumulated cold temperature and water stress and crop water requirements estimated by the model were compared with data measured at the experimental fields. Results indicate that the SETMI modeling approach using data assimilation, showed reliable daily ET and crop water requirements for maize, interpolated between remote sensing observations, confirming the applicability of the SETMI model using new relationships developed in Nebraska for estimating mainly ET and water requirements in Brazil under tropical conditions.

Keywords: basal crop coefficient, irrigation, remote sensing, SETMI

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3091 Assessment of Green Infrastructure for Sustainable Urban Water Management

Authors: Suraj Sharma

Abstract:

Green infrastructure (GI) offers a contemporary approach for reducing the risk of flooding, improve water quality, and harvesting stormwater for sustainable use. GI promotes landscape planning to enhance sustainable development and urban resilience. However, the existing literature is lacking in ensuring the comprehensive assessment of GI performance in terms of ecosystem function and services for social, ecological, and economical system resilience. We propose a robust indicator set and fuzzy comprehensive evaluation (FCE) for quantitative and qualitative analysis for sustainable water management to assess the capacity of urban resilience. Green infrastructure in urban resilience water management system (GIUR-WMS) supports decision-making for GI planning through scenario comparisons with urban resilience capacity index. To demonstrate the GIUR-WMS, we develop five scenarios for five sectors of Chandigarh (12, 26, 14, 17, and 34) to test common type of GI (rain barrel, rain gardens, detention basins, porous pavements, and open spaces). The result shows the open spaces achieve the highest green infrastructure urban resilience index of 4.22/5. To implement the open space scenario in urban sites, suitable vacant can be converted to green spaces (example: forest, low impact recreation areas, and detention basins) GIUR-WMS is easy to replicate, customize and apply to cities of different sizes to assess environmental, social and ecological dimensions.

Keywords: green infrastructure, assessment, urban resilience, water management system, fuzzy comprehensive evaluation

Procedia PDF Downloads 113
3090 A Review of End-of-Term Oral Tests for English-Majored Students of HCMC Open University

Authors: Khoa K. Doan

Abstract:

Assessment plays an essential role in teaching and learning English as it aims to measure the learning outcomes. Designing appropriate test types and procedures for four skills, especially productive skills, is a very challenging task for teachers of English. The assessment scheme is supposed to provide precise measures and fair opportunities for students to demonstrate what they can do with their language skills. This involves content domains, measurement techniques, administrative feasibility, target populations, and potential sources of testing bias. Based on these elements, a review of end-of-term speaking tests for English-majored students at Ho Chi Minh City Open University (Viet Nam) was undertaken for the purpose of analyzing the strengths and limitations of the testing tool for the speaking assessment. It helped to identify what could be done to facilitate the process of teaching and learning in that context.

Keywords: assessment, oral tests, speaking, testing

Procedia PDF Downloads 293
3089 On Boundary Values of Hardy Space Banach Space-Valued Functions

Authors: Irina Peterburgsky

Abstract:

Let T be a unit circumference of a complex plane, E be a Banach space, E* and E** be its conjugate and second conjugate, respectively. In general, a Hardy space Hp(E), p ≥1, where functions act from the open unit disk to E, could contain a function for which even weak nontangential (angular) boundary value in the space E** does not exist at any point of the unit circumference T (C. Grossetete.) The situation is "better" when certain restrictions to the Banach space of values are applied (more or less resembling a classical case of scalar-valued functions depending on constrains, as shown by R. Ryan.) This paper shows that, nevertheless, in the case of a Banach space of a general type, the following positive statement is true: Proposition. For any function f(z) from Hp(E), p ≥ 1, there exists a function F(eiθ) on the unit circumference T to E** whose Poisson (in the Pettis sense) is integral regains the function f(z) on the open unit disk. Some characteristics of the function F(eiθ) are demonstrated.

Keywords: hardy spaces, Banach space-valued function, boundary values, Pettis integral

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3088 Effects of EMS on Foot Drop Associated with Grade III Wound: A Case Report

Authors: Mirza Obaid Baig, MaimoonaYaqub

Abstract:

A 51 year old lady; known case of diabetes mellitus, post wound debridement i.e. 4 open wounds of grade III presented to us with foot drop, with prominent sensory deficit over right lower leg/foot i.e. 0 on Nottingham scale for impaired sensation, marked pedal edema and 5/10 – 6/10 pain on VAS during day and night respectively, Wounds were poorly granulated and foul smelling. Physiotherapy sessions were planned including twice a day electrical muscle stimulation sessions, strategies to decrease edema and improve muscle action which resulted in noticeable improvement in motor and sensory ability, pain levels, edema and psychological status of patient. Thus, this study gives evidence of the effect of Electrical muscle stimulation in grade III open wounds associated with motor/sensory weakness post-surgery.

Keywords: EMS, foot drop, grade III wound, diabetes mellitus

Procedia PDF Downloads 395
3087 Identifying Chaotic Architecture: Origins of Nonlinear Design Theory

Authors: Mohammadsadegh Zanganehfar

Abstract:

Since the modernism, movement, and appearance of modern architecture, an aggressive desire for a general design theory in the theoretical works of architects in the form of books and essays emerges. Since Robert Venturi and Denise Scott Brown’s published complexity and contradiction in architecture in 1966, the discourse of complexity and volumetric composition has been an important and controversial issue in the discipline. Ever since various theories and essays were involved in this discourse, this paper attempt to identify chaos theory as a scientific model of complexity and its relation to architecture design theory by conducting a qualitative analysis and multidisciplinary critical approach through architecture and basic sciences resources. As a result, we identify chaotic architecture as the correlation of chaos theory and architecture as an independent nonlinear design theory with specific characteristics and properties.

Keywords: architecture complexity, chaos theory, fractals, nonlinear dynamic systems, nonlinear ontology

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3086 Comparisons of Surveying with Terrestrial Laser Scanner and Total Station for Volume Determination of Overburden and Coal Excavations in Large Open-Pit Mine

Authors: B. Keawaram, P. Dumrongchai

Abstract:

The volume of overburden and coal excavations in open-pit mine is generally determined by conventional survey such as total station. This study aimed to evaluate the accuracy of terrestrial laser scanner (TLS) used to measure overburden and coal excavations, and to compare TLS survey data sets with the data of the total station. Results revealed that, the reference points measured with the total station showed 0.2 mm precision for both horizontal and vertical coordinates. When using TLS on the same points, the standard deviations of 4.93 cm and 0.53 cm for horizontal and vertical coordinates, respectively, were achieved. For volume measurements covering the mining areas of 79,844 m2, TLS yielded the mean difference of about 1% and the surface error margin of 6 cm at the 95% confidence level when compared to the volume obtained by total station.

Keywords: mine, survey, terrestrial laser scanner, total station

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3085 Effects of Clozapine and Risperidone Antipsychotic Drugs on the Expression of CACNA1C and Behavioral Changes in Rat ‘Ketamine Model of Schizophrenia

Authors: Mehrnoosh Azimi Sanavi, Hamed Ghazvini, Mehryar Zargari, Hossein Ghalehnoei, Zahra Hosseini-khah

Abstract:

Objectives: Calcium Voltage-Gated Channel Subunit Alpha1 C (CACNA1C) is one of the most important genes associated with schizophrenia. Methods: 45 male Wistar rats were divided into 5 groups: saline, control, ketamine, clozapine, and risperidone. Animals in ketamine, risperidone, and clozapine groups received ketamine (30 mg/ kg-i.p.) for 10 days. After the last injection of ketamine, we started injecting clozapine (7.5 mg/kg-i.p.) risperidone (1 mg/kg-i.p.) for up to 28 days. Twenty-four hours after the last injection, open field, social interaction, and elevated plus-maze tests, and gene expression in the hippocampus were performed. Results: The results of the social interaction test revealed a significant decrease in cumulative time with ketamine compared with the saline group and an increase with clozapine and risperidone compared with the ketamine group. Moreover, results from the elevated plus-maze test demonstrated a critical decrease in open-arm time and an increase in close-arm time with ketamine compared with saline, as well as an increase in open-arm time with risperidone compared with ketamine. Further results revealed a significant increase in rearing and grooming with ketamine compared to saline, as well as a decrease with risperidone and clozapine compared to ketamine. There were no significant differences in CACNA1C gene expression between groups in the rat hippocampus. In brief, the results of this study indicated that clozapine and risperidone could partially improve cognitive impairments in the rat. However, our findings demonstrated that this treatment is not related to CACNA1C gene expression.

Keywords: schizophrenia, ketamine, clozapine, risperidone

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3084 Hydroponic Cultivation Enhances the Morpho-Physiological Traits and Quality Flower Production in Tagetes patula L

Authors: Ujala, Diksha Sharma, Mahinder Partap, Ashish R. Warghat, Bhavya Bhargava

Abstract:

In soil-less agriculture, hydroponic is considered a potential farming system for the production of uniform quality plant material in significantly less time. Therefore, for the first time, the current investigation corroborates the effect of different cultivation conditions (open-field, poly-house, and hydroponic) on morpho-physiological traits, phenolic content, and essential oil components analysis in three flower color variants (yellow, scarlet red, and orange) of Tagetes patula. The results revealed that the maximum plant height, number of secondary branches, number of flowers, photosynthesis, stomatal conductance, and transpiration rate were observed under the hydroponic system as compared to other conditions. However, the maximum content of gallic acid (0.82 mg/g DW), syringic acid (3.98 mg/g DW), epicatechin (0.48 mg/g DW), p-coumaric acid (7.28 mg/g DW), protocatechuic acid (0.59 mg/g DW), ferulic acid (2.58 mg/g DW), and luteolin (8.24 mg/g DW) were quantified maximally under open-field conditions. However, under hydroponic conditions, the higher content of vanillic acid (0.43 mg/g DW), caffeic acid (0.49 mg/g DW), and quercetin (0.92 mg/g DW) were quantified. Moreover, a total of nineteen volatile components were identified in the essential oil of different flower color variants of T. patula cultivated under different conditions. The major reported volatile components in essential oil were (-)-caryophyllene oxide, trans-β-caryophyllene, trans-geraniol, 3 methyl-benzyl alcohol, and 2,2’:5’,2”-terthiophene. It has also been observed that the volatile component percentage range in all variants was observed in open-field (70.85 % to 90.54 %), poly-house (59.03 % to 77.93 %), and hydroponic (68.78 % to 89.41 %). In conclusion, the research highlighted that morpho-physiological performance with flower production was enhanced in the hydroponic system. However, phenolic content and volatile components were maximally observed in open-field conditions. However, significant results have been reported under hydroponic conditions in all studied parameters, so it could be a potential strategy for quality biomass production in T. patula.

Keywords: Tagetes patula, cultivation conditions, hydroponic, morpho-physiology

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3083 Influence of Synergistic Modification with Tung Oil and Heat Treatment on Physicochemical Properties of Wood

Authors: Luxi He, Tianfang Zhang, Zhengbin He, Songlin Yi

Abstract:

Heat treatment has been widely recognized for its effectiveness in enhancing the physicochemical properties of wood, including hygroscopicity and dimensional stability. Nonetheless, the non-negligible volumetric shrinkage and loss of mechanical strength resulting from heat treatment may diminish the wood recovery and its product value. In this study, tung oil was used to alleviate heat-induced shrinkage and reduction in mechanical properties of wood during heat treatment. Tung oil was chosen as a modifier because it is a traditional Chinese plant oil that has been widely used for over a thousand years to protect wooden furniture and buildings due to its biodegradable and non-toxic properties. The effects of different heating media (air, tung oil) and their effective treatment parameters (temperature, duration) on the changes in the physical properties (morphological characteristics, pore structures, micromechanical properties), and chemical properties (chemical structures, chemical composition) of wood were investigated by using scanning electron microscopy, confocal laser scanning microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, and dynamic vapor sorption. Meanwhile, the correlation between the mass changes and the color change, volumetric shrinkage, and hygroscopicity was also investigated. The results showed that the thermal degradation of wood cell wall components was the most important factor contributing to the changes in heat-induced shrinkage, color, and moisture adsorption of wood. In air-heat-treated wood samples, there was a significant correlation between mass change and heat-induced shrinkage, brightness, and moisture adsorption. However, the presence of impregnated tung oil in oil-heat-treated wood appears to disrupt these correlations among physical properties. The results of micromechanical properties demonstrated a significant decrease in elastic modulus following high-temperature heat treatment, which was mitigated by tung oil treatment. Chemical structure and compositional analyses indicated that the changes in chemical structure primarily stem from the degradation of hemicellulose and cellulose, and the presence of tung oil created an oxygen-insulating environment that slowed down this degradation process. Morphological observation results showed that tung oil permeated the wood structure and penetrated the cell walls through transportation channels, altering the micro-morphology of the cell wall surface, obstructing primary water passages (e.g., vessels and pits), and impeding the release of volatile degradation products as well as the infiltration and diffusion of water. In summary, tung oil treatment represents an environmentally friendly and efficient method for maximizing wood recovery and increasing product value. This approach holds significant potential for industrial applications in wood heat treatment.

Keywords: tung oil, heat treatment, physicochemical properties, wood cell walls

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3082 Pattern of External Injuries Sustained during Bomb Blast Attacks in Karachi, Pakistan from 2000 to 2007

Authors: Arif Anwar Surani, Salman Ali, Asif Surani, Sohaib Zahid, Akbar Shoukat Ali, Zeeshan-Ul-Hassan Usmani, Joseph Varon, Salim Surani

Abstract:

Objective: Terrorism and suicidal bomb blast attacks are commonplace in Karachi, Pakistan. During the years 2000 to 2007, there were over 60 bomb explosions resulting in more than 1500 casualties. These explosions produce a wide variety of external injuries. We undertook this study to evaluate pattern of external injury produced after bomb blast attacks and to compare injury profile resulting from explosions in open versus semi-confined blast environments. Method: A retrospective, cross-sectional, study was conducted to review injuries sustained after bomb blast attacks in Karachi, Pakistan, from January 2000 to October 2007. Emergency medical records and medico legal certificates of patients presented to three major public sector hospitals of Karachi were evaluated using self-design proforma. Results: Data of 481 victims meet inclusion criteria and were incorporated for final analysis. Of these, 63.6% were injured in open spaces and 36.4% were injured in semi-confined blast environments. Lacerations were commonly encountered as external injury (47.7%) followed by penetrating wounds (15.3%). Lower and upper extremities were most commonly affected (38.6% and 19% respectively). Open and semi-confined blast environments produced a specific injury pattern and profile (p=<0.001). Conclusions: Bomb blast attacks in Karachi produce an external injury pattern consistent with other studies, with exception of an increased frequency in penetrating wounds. Semi-confined blast environments were associated with severe injuries. Further studies are required to better classify injuries and their severity based on standardized scoring systems. Effective emergency response systems must be designed to cope with mass causalities following bomb explosions.

Keywords: bomb blast attacks, injury pattern, external injury, open space, semi-confined space, blast environment

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3081 Experimental and Numerical Processes of Open Die Forging of Multimetallic Materials with the Usage of Different Lubricants

Authors: Isik Cetintav, Cenk Misirli, Yilmaz Can, Damla Gunel

Abstract:

This work investigates experimental and numerical analysis of open die forging of multimetallic materials. Multimetallic material production has recently become an interesting research field. The mechanical properties of the materials to be used for the formation of multimetallic materials and the mechanical properties of the multimetallic materials produced will be compared and the material flows of the use of different lubricants will be examined. Furthermore, in this work, the mechanical properties of multimetallic metallic materials produced using different materials will be examined by using different lubricants. The advantages and disadvantages of different lubricants will be approached with the bi-metallic material to be produced. Cylindrical specimens consisting of two different materials were used in the experiments. Specimens were prepared as aluminum sleeve and copper core and upset at different reduction. This metal combination present a material model of which chemical composition is different. ABAQUS software was used for the simulations. Simulation and experimental results have also shown reasonable agreement.

Keywords: multimetallic, forging, experimental, numerical

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3080 Design of a Commercial Off-the-Shelf Patch Antenna with Wide Half Power Beam Width for Global Navigation Satellite Systems Application

Authors: Mannahel Iftikhar, Sara Saeed, Iqra Faryad, Muhammad Subhan

Abstract:

This paper describes the design of a low-cost dual-band stacked rhombus-shaped slot patch antenna. The antenna is designed on L-band with a GPS (L2) bandwidth of 0.08 GHz centered at 1.207 GHz and a GPS (L1) bandwidth of 0.23 GHz centered at 1.575 GHz. The antenna’s dimensions are 8.02×8.02 cm². The antenna has a 3 dB beamwidth of 100° at 1.204 GHz and 117° at 1.575 GHz. The gain of this antenna is 6.5 dBi at 1.575 GHz and 6.43 dBi at 1.207 GHz. The antenna is designed using commercial off-the-shelf components and can be used in any global navigation satellite system receiver covering L1 and L2 communication bands.

Keywords: circular polarization, enhanced beamwidth, stacked patches, GNSS, satellite communication

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3079 Open Fields' Dosimetric Verification for a Commercially-Used 3D Treatment Planning System

Authors: Nashaat A. Deiab, Aida Radwan, Mohamed Elnagdy, Mohamed S. Yahiya, Rasha Moustafa

Abstract:

This study is to evaluate and investigate the dosimetric performance of our institution's 3D treatment planning system, Elekta PrecisePLAN, for open 6MV fields including square, rectangular, variation in SSD, centrally blocked, missing tissue, square MLC and MLC shaped fields guided by the recommended QA tests prescribed in AAPM TG53, NCS report 15 test packages, IAEA TRS 430 and ESTRO booklet no.7. The study was performed for Elekta Precise linear accelerator designed for clinical range of 4, 6 and 15 MV photon beams with asymmetric jaws and fully integrated multileaf collimator that enables high conformance to target with sharp field edges. Seven different tests were done applied on solid water equivalent phantom along with 2D array dose detection system, the calculated doses using 3D treatment planning system PrecisePLAN, compared with measured doses to make sure that the dose calculations are accurate for open fields including square, rectangular, variation in SSD, centrally blocked, missing tissue, square MLC and MLC shaped fields. The QA results showed dosimetric accuracy of the TPS for open fields within the specified tolerance limits. However large square (25cm x 25cm) and rectangular fields (20cm x 5cm) some points were out of tolerance in penumbra region (11.38 % and 10.9 %, respectively). For the test of SSD variation, the large field resulted from SSD 125 cm for 10cm x 10cm filed the results recorded an error of 0.2% at the central axis and 1.01% in penumbra. The results yielded differences within the accepted tolerance level as recommended. Large fields showed variations in penumbra. These differences between dose values predicted by the TPS and the measured values at the same point may result from limitations of the dose calculation, uncertainties in the measurement procedure, or fluctuations in the output of the accelerator.

Keywords: quality assurance, dose calculation, 3D treatment planning system, photon beam

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3078 Evolution of Multimodulus Algorithm Blind Equalization Based on Recursive Least Square Algorithm

Authors: Sardar Ameer Akram Khan, Shahzad Amin Sheikh

Abstract:

Blind equalization is an important technique amongst equalization family. Multimodulus algorithms based on blind equalization removes the undesirable effects of ISI and cater ups the phase issues, saving the cost of rotator at the receiver end. In this paper a new algorithm combination of recursive least square and Multimodulus algorithm named as RLSMMA is proposed by providing few assumption, fast convergence and minimum Mean Square Error (MSE) is achieved. The excellence of this technique is shown in the simulations presenting MSE plots and the resulting filter results.

Keywords: blind equalizations, constant modulus algorithm, multi-modulus algorithm, recursive least square algorithm, quadrature amplitude modulation (QAM)

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3077 Antistress Effects of Hydrangeae Dulcis Folium on Net Handing Stress-Induced Anxiety-Like Behavior in Zebrafish: Possible Mechanism of Action of Adrenocorticotropin Hormone (ACTH) Receptor

Authors: Lee Seungheon, Kim Ba-Ro

Abstract:

In this study, the anti-stress effects of the ethanolic extract of Hydrangeae Dulcis Folium (EHDF) were investigated. To determine the effects of EHDF on physical stress, changes in the whole-body cortisol level and behaviour were monitored in zebrafish. To induce physical stress, we used the net handling stress (NHS). Fish were treated with EHDF for 6 min before they were exposed to stress, and the fish were either evaluated via behavioural tests, including a novel tank test and an open field test or sacrificed to collect body fluid from the whole body. The results indicate that increased anxiety-like behaviours in the novel tank test and open field test under stress were recovered by treatment with EHDF at 5, 10 and 20 mg/L (P < 0.05). Moreover, compared with the normal group, which was not treated with NHS, the whole-body cortisol level was significantly increased by treatment with NHS in the control group. Compared with the control group, pre-treatment with EHDF at concentrations of 5, 10 and 20 mg/L for 6 min significantly prevented the increase in the whole-body cortisol level induced by NHS (P < 0.05). In addition, adrenocorticotropin hormone (ACTH) challenge studies showed that EHDF completely blocked the effects of ACTH (0.2 IU/g, IP) on cortisol secretion. These results suggest that EHDF may be a good anti-stress candidate and that its mechanism of action may be related to its positive effects on cortisol release.

Keywords: net handling stress, zebrafish, hydrangeae dulcis folium, whole-body cortisol, novel tank test, open field test

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3076 An Overview of Adaptive Channel Equalization Techniques and Algorithms

Authors: Navdeep Singh Randhawa

Abstract:

Wireless communication system has been proved as the best for any communication. However, there are some undesirable threats of a wireless communication channel on the information transmitted through it, such as attenuation, distortions, delays and phase shifts of the signals arriving at the receiver end which are caused by its band limited and dispersive nature. One of the threat is ISI (Inter Symbol Interference), which has been found as a great obstacle in high speed communication. Thus, there is a need to provide perfect and accurate technique to remove this effect to have an error free communication. Thus, different equalization techniques have been proposed in literature. This paper presents the equalization techniques followed by the concept of adaptive filter equalizer, its algorithms (LMS and RLS) and applications of adaptive equalization technique.

Keywords: channel equalization, adaptive equalizer, least mean square, recursive least square

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3075 An Open-Source Guidance System for an Autonomous Planter Robot in Precision Agriculture

Authors: Nardjes Hamini, Mohamed Bachir Yagoubi

Abstract:

Precision agriculture has revolutionized farming by enabling farmers to monitor their crops remotely in real-time. By utilizing technologies such as sensors, farmers can detect the state of growth, hydration levels, and nutritional status and even identify diseases affecting their crops. With this information, farmers can make informed decisions regarding irrigation, fertilization, and pesticide application. Automated agricultural tasks, such as plowing, seeding, planting, and harvesting, are carried out by autonomous robots and have helped reduce costs and increase production. Despite the advantages of precision agriculture, its high cost makes it inaccessible to small and medium-sized farms. To address this issue, this paper presents an open-source guidance system for an autonomous planter robot. The system is composed of a Raspberry Pi-type nanocomputer equipped with Wi-Fi, a GPS module, a gyroscope, and a power supply module. The accompanying application allows users to enter and calibrate maps with at least four coordinates, enabling the localized contour of the parcel to be captured. The application comprises several modules, such as the mission entry module, which traces the planting trajectory and points, and the action plan entry module, which creates an ordered list of pre-established tasks such as loading, following the plan, returning to the garage, and entering sleep mode. A remote control module enables users to control the robot manually, visualize its location on the map, and use a real-time camera. Wi-Fi coverage is provided by an outdoor access point, covering a 2km circle. This open-source system offers a low-cost alternative for small and medium-sized farms, enabling them to benefit from the advantages of precision agriculture.

Keywords: autonomous robot, guidance system, low-cost, medium farms, open-source system, planter robot, precision agriculture, real-time monitoring, remote control, small farms

Procedia PDF Downloads 77
3074 Human Capital Mobility of a Skilled Workforce: A Need for a Future of Europe

Authors: Tiron-Tudor Adriana, Farcas Teodora Viorica, Ciolomic Ioana Andreea

Abstract:

The issue of human capital mobility inside Europe is still an open one. Even though there were created some tools in order to better move from one country to another to work and study the number of the people doing this is very low because of various factors presented in this paper. The "rethinking educational" agenda of the European Commission has open the floor for new projects which can create steps towards a European language for skills and competences, qualifications. One of these projects is the Partnership for Exchange of experience in Student on-the-job Training. As part of this project, we are interested to see the situation of the human capital inside EU and the elements that were created until now to support this mobility. Also, the main objective of the project is to make a comparison between the four countries involved in PEST project (Romania, Hungary, Finland, and Estonia), at the education and internship level. The results are helpful for the follow of the project, for identifying where changes can be done and need to be done.

Keywords: ECVET, human capital mobility, partnership exchange, students on the job mobility, vocational education and training

Procedia PDF Downloads 394
3073 The Use of Orthodontic Pacifiers to Prevent Pacifier Induced Malocclusion - A Literature Review

Authors: Maliha Ahmed Suleman, Sidra Ahmed Suleman

Abstract:

Introduction: The use of pacifiers is common amongst infants and young children as a comforting behavior. These non-nutritive sucking habits can be detrimental to the developing occlusion should they persist while the permanent dentition is established. Orthodontic pacifiers have been recommended as an alternative to conventional pacifiers as they are considered to have less interference with orofacial development. However, there is a lack of consensus on whether this is true. Aim and objectives: To review the prevalence of malocclusion associated with the use of orthodontic pacifiers. Methodology: Literature was identified through a rigorous search of the Embase, Pubmed, CINAHL, and Cochrane Library databases. Articles published from 2000 onwards were included. In total, 5 suitable papers were identified. Results: One study showed that the use of orthodontic pacifiers increased the risk of malocclusion, as seen through a greater prevalence of accentuated overjet, posterior crossbites, and anterior open bites in comparison to individuals who did not use pacifiers. However, this study found that there was a clinically significant reduction in the prevalence of anterior open bites amongst orthodontic pacifier users in comparison to conventional pacifier users. Another study found that both types of pacifiers lead to malocclusion; however, they found no difference in the mean overjet and prevalence of anterior open bites amongst conventional and orthodontic pacifier users. In contrast, one study suggested that orthodontic pacifiers do not seem to be related to the development of malocclusions in the primary dentitions, and using them between the ages of 0-3 months was actually beneficial as it prevents thumb-sucking habits. One of the systemic reviews concluded that orthodontic pacifiers do not seem to reduce the occurrence of posterior crossbites; however, they could reduce the development of open bites by virtue of their thin neck design. Whereas another systematic review concluded that there were no differences as to the effects on the stomatognathic system when comparing conventional and orthodontic pacifiers. Conclusion: There is limited and conflicting evidence to support the notion that orthodontic pacifiers can reduce the prevalence of malocclusion when compared to conventional pacifiers. Well-designed randomized controlled trials are required in the future in order to thoroughly assess the effects of orthodontic pacifiers on the developing occlusion and orofacial structures.

Keywords: orthodontics, pacifier, malocclusion, review

Procedia PDF Downloads 50
3072 Study of the Stability of the Slope Open-Pit Mines: Case of the Mine of Phosphates – Tebessa, Algeria

Authors: Mohamed Fredj, Abdallah Hafsaoui, Radouane Nakache

Abstract:

The study of the stability of the mining works in rock masses fractured is the major concern of the operating engineer. For geotechnical works in mines and quarries, it there is not today's general methodology for analysis and the quantification of the risks relating to the dangers inherent in these concrete types (falling boulders, landslides, etc.). The reasons for this are uncertainty, which weighs on available data or lack of knowledge of the values of the parameters required for this analysis type. Stability calculations must be based on reliable knowledge of the distribution of discontinuities that dissect the Rocky massif and the resistance to shear of the intact rock and discontinuities. This study is aimed to study the stability of slope of mine (Kef Sennoun - Tebessa, Algeria). The problem is analyzed using a numerical model based on the finite elements (software Plaxis 3D).

Keywords: stability, discontinuities, finite elements, rock mass, open-pit mine

Procedia PDF Downloads 294
3071 Optimization of Cu (In, Ga)Se₂ Based Thin Film Solar Cells: Simulation

Authors: Razieh Teimouri

Abstract:

Electrical modelling of Cu (In,Ga)Se₂ thin film solar cells is carried out with compositionally graded absorber and CdS buffer layer. Simulation results are compared with experimental data. Surface defect layers (SDL) are located in CdS/CIGS interface for improving open circuit voltage simulated structure through the analysis of the interface is investigated with or without this layer. When SDL removed, by optimizing the conduction band offset (CBO) position of the buffer/absorber layers with its recombination mechanisms and also shallow donor density in the CdS, the open circuit voltage increased significantly. As a result of simulation, excellent performance can be obtained when the conduction band of window layer positions higher by 0.2 eV than that of CIGS and shallow donor density in the CdS was found about 1×10¹⁸ (cm⁻³).

Keywords: CIGS solar cells, thin film, SCAPS, buffer layer, conduction band offset

Procedia PDF Downloads 201
3070 Study of the Influence of the Region, the Depth and the Drying Process on the Chemical Composition of Gelidium sesquipedale

Authors: M. Cherki, I. Taouam, A. Amiri, F. Hmimid, T. Ould Bellahcen

Abstract:

The Moroccan coasts represent an important wealth of red algae which have an economic interest. Among these algae, the Gelidium sesquipedale, which is exploited industrially for its richness in agar. The aim of this study is to establish a general overview of the macronutrient composition of Gelidium sesquipedale and to compare this composition according to three factors: the harvest site (El Jadida, Casablanca and Mohammadia), the harvest depth (coast and depth) and the drying process (open air and oven). Proteins, lipids, and carbohydrates are measured by different methods. The analysis of results show that the protein concentrations of the El Jadida and Mohammadia samples are significantly higher than that of Casablanca (0.026 ± 0.0007 µg/µg DW 0.024 ± 0.001 µg/µg DW and 0.006 ± 0.0007 µg/µg DW, p < 0.05 respectively). However, Casablanca samples are significantly richer in total sugars (0.023 ± 0.002 µg/µg DW, p < 0.05) and less rich in reducing sugars (0.0001 ± 0.00001 µg/µg DW, p < 0.05) compared to other samples. The lipid concentrations of the samples from the three harvest sites do not show any significant difference. With respect to depth, only total protein and total sugar concentrations were significantly higher in the coast versus depth samples (0.035 ± 0.004 µg/µg DW vs. 0.026 ± 0.0007 µg/µg DW and 0.035 ± 0.006 µg/µg DW vs. 0.012 ± 0.005 µg/µg DW p < 0.05 respectively). For the drying process, protein, total sugars and lipid concentrations were significantly higher in open air samples compared to oven samples (0.006 ± 0.0007 µg/µg DW). vs 0.004 ± 0.0003 µg/µg DW, 0.023 ± 0.002 µg/µg DW vs 0.007 ± 0.002 µg/µg DW and 8% vs 4% p < 0.05 respectively). Our results demonstrate that the chemical composition of Gelidium sesquipedale varies according to the harvest region. In addition, samples harvested on the coast and dried in the open air are the richest in macronutrients.

Keywords: biochemical composition, drying, depth, Gelidium sesquipedale, red algae, region

Procedia PDF Downloads 121
3069 Closed Urban Block versus Open Housing Estates Structures: Sustainability Surveys in Brno, Czech Republic

Authors: M. Wittmann, G. Kopacik, A. Leitmannova

Abstract:

A prominent place in the spatial arrangement of Czech as well as other post-socialist, Central European cities belongs to 19th century closed urban blocks and the open concrete panel housing estates which were erected during the socialism era in the second half of 20th century. The characteristics of these two fundamentally diverse types of residential structures have, as we suppose, a different impact on the sustainable development of the urban area. The characteristics of these residential structures may influence the ecological stability of the area, its hygienic qualities, the intensity and way of using by various social groups, and also, e.g., the prices of real estates. These and many other phenomena indicate the environmental, social and economic sustainability of the urban area. The proposed research methodology assessed specific indicators of sustainability within a range from 0 to 10 points. 5 points correspond to the general standard in the area, 0 points indicates degradation, and 10 points indicate the highest contribution to sustainable development. The survey results are reflected in the overall sustainability index and in the residents’ satisfaction index. The paper analyses the residential structures in the Central European city of Brno, Czech Republic. The case studies of the urban blocks near the city centre and of the housing estate Brno - Vinohrady are compared. The results imply that a considerable positive impact on the sustainable development of the area should be ascribed to the closed urban blocks near the city centre.

Keywords: City of Brno, closed urban block, open housing estate, urban structure

Procedia PDF Downloads 152
3068 Optimal Design of Storm Water Networks Using Simulation-Optimization Technique

Authors: Dibakar Chakrabarty, Mebada Suiting

Abstract:

Rapid urbanization coupled with changes in land use pattern results in increasing peak discharge and shortening of catchment time of concentration. The consequence is floods, which often inundate roads and inhabited areas of cities and towns. Management of storm water resulting from rainfall has, therefore, become an important issue for the municipal bodies. Proper management of storm water obviously includes adequate design of storm water drainage networks. The design of storm water network is a costly exercise. Least cost design of storm water networks assumes significance, particularly when the fund available is limited. Optimal design of a storm water system is a difficult task as it involves the design of various components, like, open or closed conduits, storage units, pumps etc. In this paper, a methodology for least cost design of storm water drainage systems is proposed. The methodology proposed in this study consists of coupling a storm water simulator with an optimization method. The simulator used in this study is EPA’s storm water management model (SWMM), which is linked with Genetic Algorithm (GA) optimization method. The model proposed here is a mixed integer nonlinear optimization formulation, which takes care of minimizing the sectional areas of the open conduits of storm water networks, while satisfactorily conveying the runoff resulting from rainfall to the network outlet. Performance evaluations of the developed model show that the proposed method can be used for cost effective design of open conduit based storm water networks.

Keywords: genetic algorithm (GA), optimal design, simulation-optimization, storm water network, SWMM

Procedia PDF Downloads 216
3067 Numerical Investigation of Flow Behaviour Across a Trapezoidal Bluff Body at Low Reynolds Number

Authors: Zaaraoui Abdelkader, Kerfah Rabeh, Noura Belkheir, Matene Elhacene

Abstract:

The trapezoidal bluff body is a typical configuration of vortex shedding bodies. The aim of this work is to study flow behaviour over a trapezoidal cylinder at low Reynolds number. The geometry was constructed from a prototype device for measuring the volumetric flow-rate by counting vortices. Simulations were run for this geometry under steady and unsteady flow conditions using finite volume discretization. Laminar flow was investigated in this model with rigid walls and homogeneous incompressible Newtonian fluid. Calculations were performed for Reynolds number range 5 ≤ Re ≤ 180 and several flow parameters were documented. The present computations are in good agreement with the experimental observations and the numerical calculations by several investigators.

Keywords: bluff body, confined flow, numerical calculations, steady and unsteady flow, vortex shedding flow meter

Procedia PDF Downloads 255
3066 Irreducible Sign Patterns of Minimum Rank of 3 and Symmetric Sign Patterns That Allow Diagonalizability

Authors: Sriparna Bandopadhyay

Abstract:

It is known that irreducible sign patterns in general may not allow diagonalizability and in particular irreducible sign patterns with minimum rank greater than or equal to 4. It is also known that every irreducible sign pattern matrix with minimum rank of 2 allow diagonalizability with rank of 2 and the maximum rank of the sign pattern. In general sign patterns with minimum rank of 3 may not allow diagonalizability if the condition of irreducibility is dropped, but the problem of whether every irreducible sign pattern with minimum rank of 3 allows diagonalizability remains open. In this paper it is shown that irreducible sign patterns with minimum rank of 3 under certain conditions on the underlying graph allow diagonalizability. An alternate proof of the results that every sign pattern matrix with minimum rank of 2 and no zero lines allow diagonalizability with rank of 2 and also that every full sign pattern allows diagonalizability with all permissible ranks of the sign pattern is given. Some open problems regarding composite cycles in an irreducible symmetric sign pattern that support of a rank principal certificate are also answered.

Keywords: irreducible sign patterns, minimum rank, symmetric sign patterns, rank -principal certificate, allowing diagonalizability

Procedia PDF Downloads 69