Search results for: partial discharges

Authors: Bencheikh Messaouda, Aidoud Assia, Salima Boukour, Benamara Fatima Zohra, Boukhatem Ghania, Zegueur Chaouki Salah Eddine

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The utilization of waste materials in civil engineering has gained widespread attention in recent years due to their adverse effects on the environment. One such waste material is coffee grounds, a black residue generated daily across the country after coffee brewing. Instead of disposing of it, there is a growing interest in repurposing it for various agricultural and industrial applications. Utilizing coffee grounds in geotechnical engineering, such as in road embankments, presents an opportunity for its valorization. The study aims to contribute to the valorization of coffee grounds by enhancing the physical and mechanical properties of clayey soils through their incorporation at varying weight percentages (3%, 6%, 9%, 12%) as partial replacements in these soils. This not only addresses the issue of coffee ground waste but also makes a tangible contribution to sustainable development. The findings demonstrate that incorporating coffee grounds generally has positive effects on the physical and mechanical properties of clayey soil. However, the extent of these effects depends on factors such as the quantity of coffee grounds added, the particle size of the grounds, and the characteristics of the soil. Additionally, coffee grounds can improve the compression and tensile strength of clayey soil, resulting in increased stability and reduced susceptibility to deformation under external forces.

Keywords: clay soil, coffee grounds, optimizing, improvement, valorization, waste

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Authors: Aasheesh Raturi, Vimal Kothiyal, P. D. Semalty

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We studied mechanical properties of Eucalyptus tereticornis using FT-NIR spectroscopy. Firstly, spectra were pre-processed to eliminate useless information. Then, prediction model was constructed by partial least squares regression. To study the influence of pre-processing on prediction of mechanical properties for NIR analysis of wood samples, we applied various pretreatment methods like straight line subtraction, constant offset elimination, vector-normalization, min-max normalization, multiple scattering. Correction, first derivative, second derivatives and their combination with other treatment such as First derivative + straight line subtraction, First derivative+ vector normalization and First derivative+ multiplicative scattering correction. The data processing methods in combination of preprocessing with different NIR regions, RMSECV, RMSEP and optimum factors/rank were obtained by optimization process of model development. More than 350 combinations were obtained during optimization process. More than one pre-processing method gave good calibration/cross-validation and prediction/test models, but only the best calibration/cross-validation and prediction/test models are reported here. The results show that one can safely use NIR region between 4000 to 7500 cm-1 with straight line subtraction, constant offset elimination, first derivative and second derivative preprocessing method which were found to be most appropriate for models development.

Keywords: FT-NIR, mechanical properties, pre-processing, PLS

Procedia PDF Downloads 321

Authors: Golayeh Yousefi, Mehdi Homaee, Ali Akbar Norouzi

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Ongoing monitoring of soil contamination by heavy metals is critical for ecosystem stability and environmental protection, and food security. The conventional methods of determining these soil contaminants are time-consuming and costly. Spectroscopy in the visible near-infrared (VNIR) - short wave infrared (SWIR) region is a rapid, non-destructive, noninvasive, and cost-effective method for assessment of soil heavy metals concentration by studying the spectral properties of soil constituents. The aim of this study is to derive spectral bands and important ranges that are sensitive to heavy metals and can be used to estimate the concentration of these soil contaminants. In other words, the change in the spectral properties of spectrally active constituents of soil can lead to the accurate identification and estimation of the concentration of these compounds in soil. For this purpose, 325 soil samples were collected, and their spectral reflectance curves were evaluated at a range of 350-2500 nm. After spectral preprocessing operations, the partial least-squares regression (PLSR) model was fitted on spectral data to predict the concentration of Cu and Ni. Based on the results, the spectral range of Cu- sensitive spectra were 480, 580-610, 1370, 1425, 1850, 1920, 2145, and 2200 nm, and Ni-sensitive ranges were 543, 655, 761, 1003, 1271, 1415, 1903, 2199 nm. Finally, the results of this study indicated that the spectral data contains a lot of information that can be applied to identify the soil properties, such as the concentration of heavy metals, with more detail.

Keywords: heavy metals, spectroscopy, spectral bands, PLS regression

Procedia PDF Downloads 59

Authors: R. M. Srivastava, Subbanna A.R.N.S, Md Abbas Ahmad, S. P.More, Shivashankar, B. Kalyanbabu

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The similar morphology associated with high genetic variability poses problems in phylogenetic studies of Helicoverpa armigera (Hubner). To identify genetic variation of North Western Himalayan population’s, partial (Mid to terminal region) cytochrome c oxidase subunit I (COX-1) gene was amplified and sequenced for three populations collected from Pantnagar, Almora, and Chinyalisaur. The alignment of sequences with other two populations, Nagpur representing central India population and Anhui, China representing complete COX-1 sequence revealed unanimity in middle region with eleven single nucleotide polymorphisms (SNPs) in Nagpur populations. However, the consensus is missing when approaching towards terminal region, which is associated with 15 each SNPs and pair base substitutions in Chinyalisaur populations. In minimum evolution tree, all the five populations were majorly separated into two clades, one comprising of only Nagpur population and the other with rest. Amongst, North Western populations, Chinyalisaur one is promising by farming a separate clade. The pairwise genetic distance ranges from 0.025 to 0.192 with the maximum between H. armigera populations of Nagpur and Chinyalisaur. This genetic isolation of populations can be attributed to a key role of topological barriers of weather and mountain ranges and temporal barriers due to cropping patterns.

Keywords: cytochrome c oxidase subunit I, northwestern Himalayan population, Helicoverpa armigera (Noctuidae: Lepidoptera), phylogenetic relationship, genetic variation

Procedia PDF Downloads 287

Authors: Philip Edinger, Christian Ludwig

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The formation and control of tars remain one of the major challenges in the implementation of biomass gasification technologies. Robust, on-line analytical methods are needed to investigate the fate of tar compounds when different measures for their reduction are applied. This work establishes an on-line UV-Vis method, based on a liquid quench sampling system, to monitor tar compounds in biomass gasification processes. Recorded spectra from the liquid phase were analyzed for their tar composition by means of a classical least squares (CLS) and partial least squares (PLS) approach. This allowed for the detection of UV-Vis active tar compounds with detection limits in the low part per million by volume (ppmV) region. The developed method was then applied to two case studies. The first involved a lab-scale reactor, intended to investigate the decomposition of a limited number of tar compounds across a catalyst. The second study involved a gas scrubber as part of a pilot scale wood gasification plant. Tar compound quantification results showed good agreement with off-line based reference methods (GC-FID) when the complexity of tar composition was limited. The two case studies show that the developed method can provide rapid, qualitative information on the tar composition for the purpose of process monitoring. In cases with a limited number of tar species, quantitative information about the individual tar compound concentrations provides an additional benefit of the analytical method.

Keywords: biomass gasification, on-line, tar, UV-Vis

Procedia PDF Downloads 241

Authors: Sonali Panigrahy, Manjunatha K., Sudip Barman

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Electrocatalytic reduction methods hold significant promise in addressing the urgent need to mitigate excessive greenhouse gas emissions, particularly carbon dioxide (CO₂). A highly effective catalyst is essential for achieving the conversion of CO₂ into valuable products due to the complex, multi-electron, and multi-product nature of the CO₂ reduction process. The electrochemical reduction of CO₂, driven by renewable energy sources, presents a valuable opportunity for simultaneously reducing CO₂ emissions while generating valuable chemicals and fuels, with syngas being a noteworthy product. Silver-based electrodes have been the focus of extensive research due to their low overpotential and remarkable selectivity in promoting the generation of carbon monoxide (CO) in the electrocatalytic carbon dioxide reduction reaction (CO₂RR). In this study, we delve into the synthesis of carbon-supported silver nanoparticles (Ag/C), which serve as efficient electrocatalysts for the reduction of CO₂. The as-prepared catalyst, Ag/C, is not only cost-effective but also highly proficient in facilitating the conversion of CO₂ and H₂O into syngas, which is a customizable mixture of hydrogen (H₂) and carbon monoxide (CO). The highest faradic efficiency for the production of CO on Ag/C was calculated to be 56.4% at -1.4 V vs Ag/AgCl. The maximum partial current density for the generation of CO was determined to be -9.4 mA cm-2 at a potential of -1.6 V vs Ag/AgCl. This research demonstrates the potential of Ag/C as an electrocatalyst to enable the sustainable production of syngas, contributing to the reduction of CO₂ emissions and the synthesis of valuable chemical precursors and fuels.

Keywords: CO₂, carbon monooxide, electrochemical, silver

Procedia PDF Downloads 51

Authors: Zhuoyuan Wang, Benson T. H. Lim, Imriyas Kamardeen

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Effective service quality management has long been touted as a means of improving project and organisational performance. Particularly, in construction projects, main contractors are often seen as a broker between clients and subcontractors, and their service quality is thus associated with the overall project affinity and outcomes. While a considerable amount of research has focused on the aspect of clients-main contractors, very little research has been done to explore the effect of contractors’ service quality on subcontractors’ behaviours and so project outcomes. In addressing this gap, this study surveyed 97 subcontractors in the Chinese Construction industry and data was analysed using the Partial Least Square (PLS) Structural Equation Modelling (SEM) technique. The overall findings reveal that subcontractors categorised main contractors’ service quality into three dimensions: assurance; responsiveness; reliability and empathy. Of these, it is found that main contractors’ ‘assurance’ and ‘responsiveness’ positively influence subcontractors’ intention to engage in contractual behaviours. The results further show that the subcontractors’ intention to engage in organizational citizenship behaviours is associated with how flexible and committed the main contractors are in reliability and empathy. Collectively, both subcontractors’ contractual and organizational citizenship behaviours positively influence the overall project outcomes. In conclusion, the findings inform contractors different strategies towards managing and gaining subcontractors’ behaviour commitment in a socially connected, yet complex and uncertain, business environment.

Keywords: construction firms, organisational citizenship behaviour, service quality, social exchange theory

Procedia PDF Downloads 184

Authors: Lei Zhao, Zhe Yuan, Wenyue Kuang

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This paper studies two-warehouse inventory models for a deteriorating item considering that the demand is influenced by inventory levels. The problem mainly focuses on the optimal order policy and the optimal order cycle with inventory-level-dependent demand in two-warehouse system for retailers. It considers the different deterioration rates and the inventory holding costs in owned warehouse (OW) and rented warehouse (RW), and the conditions of transportation cost, allowed shortage and partial backlogging. Two inventory models are formulated: last-in first-out (LIFO) model and first-in-first-out (FIFO) model based on the policy choices of LIFO and FIFO, and a comparative analysis of LIFO model and FIFO model is made. The study finds that the FIFO policy is more in line with realistic operating conditions. Especially when the inventory holding cost of OW is high, and there is no difference or big difference between deterioration rates of OW and RW, the FIFO policy has better applicability. Meanwhile, this paper considers the differences between the effects of warehouse and shelf inventory levels on demand, and then builds retailers’ inventory decision model and studies the factors of the optimal order quantity, the optimal order cycle and the average inventory cost per unit time. To minimize the average total cost, the optimal dispatching policies are provided for retailers’ decisions.

Keywords: FIFO model, inventory-level-dependent, LIFO model, two-warehouse inventory

Procedia PDF Downloads 263

Authors: Hyunuk Kim, Yang No Yun, Muhammad Sohail, Jong-Ho Moon, Young Cheol Park

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Metal-organic frameworks (MOFs), which are emerging absorbents assembled from metal ions and organic ligands, have attracted attention for their permanent porosity and design of tunable pore size. These microporous materials showed interesting properties for CO₂ storage and separation. In particular, MOFs with high surface area and open metal sites showed the remarkable adsorption capacity and selectivity for CO₂. [Mg₂ (DOBDC)] (DOBDC = 2,5-dioxidobenzene-1,4-dicarboxylate) (MOF-74 or CPO-27) is a well-known absorbent showing an exceptionally high CO₂ sorption capacity at low partial pressure and room temperature. In this work, we synthesized [M₂(DOBDC)(DMF)₂] (M = Mg, Co, Ni) and determined their single-crystal structures by X-ray crystallography. The removal of coordinated guest molecules generates Lewis acidic sites and showed high CO₂ adsorption affinity. Both CO₂ adsorption capacity and surface area are much higher than reported values in literature. To fabricate MMMs, microcrystalline [M₂ (DOBDC)(DMF)₂] was synthesized by microwave reaction and dispersed in PDMS solution. The MMMs with a various amount of [M₂ (DOBDC)(DMF) ₂] in PDMS were fabricated by a solution casting method. [M₂ (DOBDC)(DMF)₂]@PDMS membrane showed higher CO2 permeability and CO₂/N₂ selectivity than those of PDMS. Therefore, we believe that MMMs combining polymer and MOFs provide new materials for CO₂ separation technology.

Keywords: metal-organic frameworks, mixed matrix membrane, CO2/N2 separation, polydimethylsiloxane (PDMS)

Procedia PDF Downloads 183

Authors: S. Rostami, S. H. Hosseini, A. A. Torabi, M. Bekhradi

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Introduction: Interest in the use of caffeine as an ergogenic aid has increased since the International Olympic Committee lifted the partial ban on its use. Caffeine has beneficial effects on various aspects of athletic performance, but its effects on training have been neglected. The purpose of this study was to investigate the acute effect of caffeine on testosterone and cortisole in young futsal players. Methods: Twenty-four professional futsal players with 18.3± 1.9 years ingested caffeine doses of 0, 200 and 800 mg in random order 1 hr before an anaerobic-exercise session (RAST test). Samples were taken at the time of caffeine ingestion and 30 min after the session. Data were log-transformed to estimate percent effects with mixed modeling, and effects were standardized to assess magnitudes. fects on training have been neglected. Results: Testosterone concentration showed a small increase of 15% (90% confidence limits, ± 19%) during exercise. Caffeine raised this concentration in a dose-dependent manner by a further small 21% (± 24%) at the highest dose. The 800-mg dose also produced a moderate 52% (± 44%) increase in cortisol. The effect of caffeine on the testosterone: cortisol ratio was a small decline (14%; ± 21%). Discussion and Conclusion: Caffeine has some potential to benefit training outcomes via the anabolic effects of the increase in testosterone concentration, but this benefit might be counteracted by the opposing catabolic effects of the increase in cortisol and resultant decline in the testosterone: cortisol ratio.

Keywords: anabolic, catabolic, performance, testosterone, cortisol ratio, RAST test

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Authors: Athira Babu, M. Nazeer

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Concrete is the most common and versatile construction material used in any type of civil engineering structure. The durability and strength characteristics of concrete make it more desirable among any other construction materials. The manufacture and use of concrete produces wide range of environmental and social consequences. The major component in concrete, cement accounts for roughly 5 % of global CO2 emissions. In order to improve the environmental friendliness of concrete, suitable substitutes are added to concrete. The present study deals with GGBS and silica fume as supplementary cementitious materials. The strength and durability studies were conducted in this ternary blended concrete. Several mixes were adopted with varying percentages of Silica Fume i.e., 5%, 10% and 15%. Binary mix with 50% GGBS was also prepared. GGBS content has been kept constant for the rest of mixes. There is an improvement in compressive strength with addition of Silica Fume.Maximum workability, split tensile strength, modulus of elasticity, flexural strength and impact resistance are obtained for GGBS binary blend. For durability studies, maximum sulphate resistance,carbonation resistance andresistance to chloride ion penetration are obtained for ternary blended concrete. Partial replacement of GGBS and Silica Fume reduces the environmental effects, produces economical and eco-friendly concrete. The study showed that for strength characteristics, binary blended concrete showed better performance while for durability study ternary blend performed better.

Keywords: concrete, GGBS, silica fume, ternary blend

Procedia PDF Downloads 460

Authors: Liliane Clark

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Immigrating to a different country may imply having to handle many difficult exertions. There is a particular issue that has to be endured by some immigrants: the children they had to leave behind. It is a phenomenon that occurs with certain frequency. Surprisingly, despite the fact that immigration in the United States is such a large proceeding, there is not much research about the topic in America exploring the trauma of the abandonment caused by this separation and its consequences on the mental health of those children. The term “left behind children” is usually applied to children who were left behind by their parents in their original nation under the care of a noteworthy relative, frequently the grandparents, when they moved to another country. This preliminary research, which is a partial study projected for a doctoral thesis, investigated whether the trauma of abandonment experienced by ten left behind children had affected their emotional development. The Strengths and Difficulties Questionnaire (SDQ) and a brief interview were utilized to assess the information. The SDQ explored scales such as emotional symptoms, conduct problems, hyperactivity, peer problems and prosocial behavior. In this pilot study, the results indicated that all these issues had some sort of significant correlation between them. During the interviews, the participants or their parents identified a range of symptoms: anxiety disorder, eating disorders, panic attacks, psychotic-like experiences, drug use and depression. Hence, it seems that there is a connection between the trauma of abandonment suffered due to the separation and the children’s consequent symptomatic behavior. Further studies are indeed necessary to validate the initial results of this investigation.

Keywords: abandonment, parent migration, psychological problems, trauma

Procedia PDF Downloads 162

Authors: Tio Novita Efriani

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Public sector organizations work in a complex and risky environment. Since the beginning of 2000s, the public sector has paid attention to the need for an effective risk management. The Indonesian public sector has also concerned about this issue and in 2008 it enacted the Government Regulation that gives mandate for the implementation of risk management in government organizations. This paper investigates risk management implementation in the Indonesian public sector organizations and the role of transformational leadership and internal audit activities. Data was collected via survey. A total of 202 effective responses (30% response rate) from employees in 34 government ministries were statistically analyzed by using Partial least square structural equation modelling (PLS-SEM) and the software was SmartPLS 3.0. All the constructs were lower order, except for the risk management implementation construct, which was treated as a second-order construct. A two-stage approach was employed in the analysis of the higher order component. The findings revealed that transformational leadership positively influence risk management implementation. The findings also found that the core and legitimate roles of internal audit in risk management positively affect the implementation of risk management. The final finding showed that internal auditing mediates a relationship between transformational leadership and risk management implementation. These results suggest that the implementation of risk management in the Indonesian public sector was significantly supported by internal auditors and leadership. The findings confirm the importance of transformational leadership and internal audit in the public sector risk management strategies.

Keywords: Indonesian public sector, internal audit, risk management, transformational leadership

Procedia PDF Downloads 176

Authors: Ahmed Ait Hou

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The wing leading edge and nose cone of the space shuttle are fabricated from a reinforced carbon/carbon material. This material attains its durability from a diffusion coating of silicon carbide (SiC) and a glass sealant. During re-entry into the atmosphere, this material is subject to an oxidizing high-temperature environment. The use of thermochemical calculations resulting at the HSC CHEMISTRY software and its database allows us to interpret the phenomena of oxidation and chloridation observed on the wing leading edge and nose cone of the space shuttle during its mission in space. First study is the monitoring of the oxidation reaction of SiC. It has been demonstrated that thermal oxidation of the SiC gives the two compounds SiO₂(s) and CO(g). In the extreme conditions of very low oxygen partial pressures and high temperatures, there is a reaction between SiC and SiO₂, leading to SiO(g) and CO(g). We had represented the phase stability diagram of Si-C-O system calculated by the use of the HSC Chemistry at 1300°C. The principal characteristic of this diagram of predominance is the line of SiC + SiO₂ coexistence. Second study is the monitoring of the chloridation reaction of SiC. The other problem encountered in addition to oxidation is the phenomenon of chloridation due to the presence of NaCl. Indeed, after many missions, the leading edge wing surfaces have exhibited small pinholes. We have used the HSC Chemistry database to analyze these various reactions. Our calculations concorde with the phenomena we announced in research work resulting in NASA LEWIS Research center.

Keywords: thermochchemicals calculations, HSC software, oxidation and chloridation, wings in space

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Authors: Amnah Moghees, Saima Abbas Dar, Muniba Saeed

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Teaching a second language to deaf learners has always been a challenge in Pakistan. Different approaches and strategies have been followed, but they have been resulted into partial or complete failure. The study aims to investigate the language problems faced by adult deaf learners of English as second language in mainstream classrooms. Moreover, the study also determines the factors which are very much involved in language teaching and learning in mainstream classes. To investigate the language problems, data will be collected through writing samples of ten deaf adult learners and ten normal ESL learners of the same class; whereas, observation in inclusive language teaching classrooms and interviews from five ESL teachers in inclusive classes will be conducted to know the factors which are directly or indirectly involved in inclusive language education. Keeping in view this study, qualitative research paradigm will be applied to analyse the corpus. The study figures out that deaf ESL learners face severe language issues such as; odd sentence structures, subject and verb agreement violation, misappropriation of verb forms and tenses as compared to normal ESL learners. The study also predicts that in mainstream classrooms there are multiple factors which are affecting the smoothness of teaching and learning procedure; role of mediator, level of deaf learners, empathy of normal learners towards deaf learners and language teacher’s training.

Keywords: deaf English language learner, empathy, mainstream classrooms, previous language knowledge of learners, role of mediator, language teachers' training

Procedia PDF Downloads 144

Authors: Deva Kanta Phukan

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An investigation is made to carry out to study the thermal-diffusion and diffusion thermo-effects in hydro-magnetic unsteady flow by a mixed convection boundary layer past an impermeable vertical stretching sheet embedded in a conducting fluid-saturated porous medium in the presence of a chemical reaction effect. The velocity of stretching surface, the surface temperature and the concentration are assumed to vary linearly with the distance along the surface. The governing partial differential equations are transformed in to self similar unsteady equations using similarity transformations and solved numerically by the Runge kutta fourth order scheme in association with the shooting method for the whole transient domain from the initial state to the final steady state flow. Numerical results for the velocity, temperature, the concentration, the skin friction , and the Nusselt and Sherwood numbers are shown graphically for various flow parameters. The results reveal that there is a smooth transition of flow from unsteady state to the final steady state. A special case of our results is in good agreement with an earlier published work.

Keywords: heat and mass transfer, boundary layer flow, porous media, magnetic field, Soret number, Dufour’s number

Procedia PDF Downloads 423

Authors: K. Petcharaporn

Abstract:

The external characteristics of tomatoes, such as freshness, color and size are typically used in quality control processes for tomatoes sorting. However, the internal mold infection of intact tomato cannot be sorted based on a visible assessment and destructive method alone. In this study, a non-destructive technique was used to predict the internal mold infection of intact tomatoes by using transmittance visible and near infrared (VIS-NIR) spectroscopy. Spectra for 200 samples contained 100 samples for normal tomatoes and 100 samples for mold infected tomatoes were acquired in the wavelength range between 665-955 nm. This data was used in conjunction with partial least squares-discriminant analysis (PLS-DA) method to generate a classification model for tomato quality between groups of internal mold infection of intact tomato samples. For this task, the data was split into two groups, 140 samples were used for a training set and 60 samples were used for a test set. The spectra of both normal and internally mold infected tomatoes showed different features in the visible wavelength range. Combined spectral pretreatments of standard normal variate transformation (SNV) and smoothing (Savitzky-Golay) gave the optimal calibration model in training set, 85.0% (63 out of 71 for the normal samples and 56 out of 69 for the internal mold samples). The classification accuracy of the best model on the test set was 91.7% (29 out of 29 for the normal samples and 26 out of 31 for the internal mold tomato samples). The results from this experiment showed that transmittance VIS-NIR spectroscopy can be used as a non-destructive technique to predict the internal mold infection of intact tomatoes.

Keywords: tomato, mold, quality, prediction, transmittance

Procedia PDF Downloads 347

Authors: Burcu Inal, Irfan Kandemir

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Sequences of mitochondrial cytochrome oxidase I (COI) gene of twenty-five Turkish and one Greek Myzus cerasi (Fabricus) (Hemiptera: Aphididae) in populations were collected from Prunus avium and Prunus cerasus. The partial coding region of COI studied is 605 bp for all the populations, from which 565 nucleotides were conserved, 40 were variable, 37 were singleton, and 3 sites were parsimony-informative. Four haplotypes were identified based on nucleotide substitutions, and the mean of intraspecific divergence was calculated to be 0.3%. Phylogenetic trees were constructed using Maximum Likelihood, Minimum Evolution, Neighbor-joining, and Unweighed Pair Group Method of Arithmetic Averages (UPGMA) and Myzus persicae (Sulzer) and Myzus borealis Ossiannilson were included as outgroups. The population of M. cerasi from Isparta diverged from the rest of the groups and formed a clade (Haplotype B) with Myzus borealis. The rest of the haplotype diversity includes Haplotype A and Haplotype C with individuals characterized as Myzus cerasi pruniavium and Haplotype D with Myzus cerasi cerasi. M. cerasi diverge into two subspecies and it must be reevaluated whether this pest is monophagous or oligophagous in terms of plant type dependence. The obligated endosymbiont Buchnera aphidicola was also found during this research, but no facultative symbionts could be found. It is expected further studies will be required for a complete barcoding and diversity of bacterial endosymbionts present.

Keywords: bacterial endosymbionts, barcoding, black cherry aphid, nucleotide diversity

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Authors: S. Srednyak

Abstract:

We study a class of functional partial differential equations(FPDEs). This class is suggested by Quantum Field Theory. We derive general properties of solutions to such equations. In particular, we demonstrate that they lead to systems of coupled integral equations with singular kernels. We show that solutions to such hierarchies can be sought among functions with regular singularities at a countable set of subvarieties of the physical space. We also develop a formal analogy of basic constructions of differential geometry on functional manifolds, as this is necessary for in depth study of FPDEs. We also consider the case of linear overdetermined systems of functional differential equations and show that it can be completely solved in terms of formal solutions of a functional equation that is a functional analogy of a system of determined algebraic equations. This development leads us to formally define the functional analogy of algebraic geometry, which we call functional algebraic geometry. We study basic properties of functional algebraic varieties. In particular, we investigate the case of a formally discrete set of solutions. We also define and study functional analogy of discriminants. In the case of fully determined systems such that the defining functionals have regular singularities, we demonstrate that formal solutions can be sought in the class of functions with regular singularities. This case provides a practical way to apply our results to physics problems.

Keywords: functional equations, quantum field theory, holomorphic functions, Yang Mills mass gap problem, quantum chaos

Procedia PDF Downloads 46

Authors: Muhammad Alif Bin Razali, Cheng-Gang Xie, Wai Lam Loh

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A venturi device is commonly used as an integral part of a multiphase flowmeter (MPFM) in real-time oil-gas production monitoring. For an accurate determination of individual phase fraction and flowrate, a gas-liquid flow ideally needs to be well mixed in the venturi measurement section. Partial flow mixing is achieved by installing a venturi vertically downstream of the blind-tee pipework that ‘homogenizes’ the incoming horizontal gas-liquid flow. In order to study in-depth the flow-mixing effect of the blind-tee, gas-liquid flows are captured at blind-tee and venturi sections by using a high-speed video camera and a purpose-built transparent test rig, over a wide range of superficial liquid velocities (0.3 to 2.4m/s) and gas volume fractions (10 to 95%). Electrical capacitance sensors are built to measure the instantaneous holdup (of oil-gas flows) at the venturi inlet and throat. Flow regimes and flow (a)symmetry are investigated based on analyzing the statistical features of capacitance sensors’ holdup time-series data and of the high-speed video time-stacked images. The perceived homogenization effect of the blind-tee on the incoming intermittent horizontal flow regimes is found to be relatively small across the tested flow conditions. A horizontal (blind-tee) to vertical (venturi) flow-pattern transition map is proposed based on gas and liquid mass fluxes (weighted by the Baker parameters).

Keywords: blind-tee, flow visualization, gas-liquid two-phase flow, MPFM

Procedia PDF Downloads 107

Authors: Sara Gardideh, Mansoor Barati

Abstract:

The mineral carbonation approach for reducing global warming has garnered interest on a worldwide scale. Due to the benefits of permanent storage and abundant mineral resources, mineral carbonation (MC) is one of the most effective strategies for sequestering CO₂. The combination of mineral processing for primary metal recovery and mineral carbonation for carbon sequestration is an emerging field of study with the potential to minimize capital costs. A detailed study of low-pressures–solid carbonation of ultramafic tailings in a dry environment has been accomplished. In order to track the changing structure of serpentine minerals and their reactivity as a function of temperature (300-900 ᵒC), CO₂ partial pressure (25-90 mol %), and thermal preconditioning, thermogravimetry has been utilized. The incongruent CO₂ van der Waals molecular diameters with the octahedral-tetrahedral lattice constants of serpentine were used to explain the mild carbonation reactivity. Serpentine requires additional thermal-treatment to remove hydroxyl groups, resulting in the chemical transformation to pseudo-forsterite, which is a mineral composed of isolated SiO₄ tetrahedra linked by octahedrally coordinated magnesium ions. The heating treatment above 850 ᵒC is adequate to remove chemically bound water from the lattice. Particles with a diameter < 34 (μm) are desirable, and thermally treated serpentine at 850 ᵒC for 2.30 hours reached 65% CO₂ storage capacity. The decrease in particle size, increase in temperature, and magnetic separation can dramatically enhance carbonation.

Keywords: particle size, thermogravimetry, thermal-treatment, serpentine

Procedia PDF Downloads 66

Authors: K. Petcharaporn, N. Prathengjit

Abstract:

The external characteristics of tomatoes, such as freshness, color and size are typically used in quality control processes for tomatoes sorting. However, the internal mold infection of intact tomato cannot be sorted based on a visible assessment and destructive method alone. In this study, a non-destructive technique was used to predict the internal mold infection of intact tomatoes by using transmittance visible and near infrared (VIS-NIR) spectroscopy. Spectra for 200 samples contained 100 samples for normal tomatoes and 100 samples for mold infected tomatoes were acquired in the wavelength range between 665-955 nm. This data was used in conjunction with partial least squares-discriminant analysis (PLS-DA) method to generate a classification model for tomato quality between groups of internal mold infection of intact tomato samples. For this task, the data was split into two groups, 140 samples were used for a training set and 60 samples were used for a test set. The spectra of both normal and internally mold infected tomatoes showed different features in the visible wavelength range. Combined spectral pretreatments of standard normal variate transformation (SNV) and smoothing (Savitzky-Golay) gave the optimal calibration model in training set, 85.0% (63 out of 71 for the normal samples and 56 out of 69 for the internal mold samples). The classification accuracy of the best model on the test set was 91.7% (29 out of 29 for the normal samples and 26 out of 31 for the internal mold tomato samples). The results from this experiment showed that transmittance VIS-NIR spectroscopy can be used as a non-destructive technique to predict the internal mold infection of intact tomatoes.

Keywords: tomato, mold, quality, prediction, transmittance

Procedia PDF Downloads 497

Authors: Jaime E. Munoz, Jose C. Arcos, Oscar E. Bautista, Ivan E. Campos

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The influence of slippage phenomenon over the destabilization and atomization mechanisms induced via surface acoustic waves on a Newtonian, millimeter-sized, drop deposited on a hydrophilic substrate is studied theoretically. By implementing the Navier-slip model and a lubrication-type approach into the equations which govern the dynamic response of a drop exposed to acoustic stress, a highly nonlinear evolution equation for the air-liquid interface is derived in terms of the acoustic capillary number and the slip coefficient. By numerically solving such an evolution equation, the Spatio-temporal deformation of the drop's free surface is obtained; in this context, atomization of the initial drop into micron-sized droplets is predicted at our numerical model once the acoustically-driven capillary waves reach a critical value: the instability length. Our results show slippage phenomenon at systems with partial and complete wetting favors the formation of capillary waves at the free surface, which traduces in a major volume of liquid being atomized in comparison to the no-slip case for a given time interval. In consequence, slippage at the wall possesses the capability to affect and improve the atomization rate for a drop exposed to a high-frequency acoustic field.

Keywords: capillary instability, lubrication theory, navier-slip condition, SAW atomization

Procedia PDF Downloads 137

Authors: Vishaal Subramanian, Annuatha Vinod Kumar, Santosh Kumar Budankayala, M. Senthil Kumar

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This paper discusses the aerodynamic and structural design, simulation and optimization of a mini-High Altitude Long Endurance (HALE) UAV. The applications of this mini HALE UAV vary from aerial topological surveys, quick first aid supply, emergency medical blood transport, search and relief activates to border patrol, surveillance and estimation of forest fire progression. Although classified as a mini UAV according to UVS International, our design is an amalgamation of the features of ‘mini’ and ‘HALE’ categories, combining the light weight of the ‘mini’ and the high altitude ceiling and endurance of the HALE. Designed with the idea of implementation in India, it is in strict compliance with the UAS rules proposed by the office of the Director General of Civil Aviation. The plane can be completely automated or have partial override control and is equipped with an Infra-Red camera and a multi coloured camera with on-board storage or live telemetry, GPS system with Geo Fencing and fail safe measures. An additional of 1.5 kg payload can be attached to three major hard points on the aircraft and can comprise of delicate equipment or releasable payloads. The paper details the design, optimization process and the simulations performed using various software such as Design Foil, XFLR5, Solidworks and Ansys.

Keywords: aircraft, endurance, HALE, high altitude, long range, UAV, unmanned aerial vehicle

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Authors: Yinggang Guo, Zongchun Li

Abstract:

In order to decrease the accumulated survey error of tunnel installation control network of particle accelerator, a sectional control method is proposed. Firstly, the accumulation rule of positional error with the length of the control network is obtained by simulation calculation according to the shape of the tunnel installation-control-network. Then, the RMS of horizontal positional precision of tunnel backbone control network is taken as the threshold. When the accumulated error is bigger than the threshold, the tunnel installation control network should be divided into subsections reasonably. On each segment, the middle survey station is taken as the datum for independent adjustment calculation. Finally, by taking the backbone control points as faint datums, the weighted partial parameters adjustment is performed with the adjustment results of each segment and the coordinates of backbone control points. The subsections are jointed and unified into the global coordinate system in the adjustment process. An installation control network of the linac with a length of 1.6 km is simulated. The RMS of positional deviation of the proposed method is 2.583 mm, and the RMS of the difference of positional deviation between adjacent points reaches 0.035 mm. Experimental results show that the proposed sectional control method can not only effectively decrease the accumulated survey error but also guarantee the relative positional precision of the installation control network. So it can be applied in the data processing of tunnel installation control networks, especially for large particle accelerators.

Keywords: alignment, tunnel installation control network, accumulated survey error, sectional control method, datum

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Authors: Jaroslav Frantík, Jan Najser

Abstract:

This article deals with increasing the energy efficiency of a plant in terms of optimizing the process. The European Union is striving to achieve the climate-energy package in the area increasing of energy efficiency. The goal of energy efficiency is to reduce primary energy consumption by 20% within the EU until 2020. The objective of saving energy consumption in the Czech Republic was set at 47.84 PJ (13.29 TWh). For reducing electricity consumption, it is possible to choose: a) mandatory increasing of energy efficiency, b) alternative scheme, c) combination of both actions. The Czech Republic has chosen for reducing electricity consumption using-alternative scheme. The presentation is focused on the proposal of a technological unit dealing with the gasification process of processing of biomass with an increase of power in the output. The synthesis gas after gasification of biomass is used as fuel in a cogeneration process of reciprocating internal combustion engine with the classic production of heat and electricity. Subsequently, there is an explanation of the ORC system dealing with the conversion of waste heat to electricity with the using closed cycle of the steam process with organic medium. The arising electricity is distributed to the power grid as a further energy source, or it is used for needs of the partial coverage of the technological unit. Furthermore, there is a presented schematic description of the technology with the identification of energy flows starting from the biomass treatment by drying, through its conversion to gaseous fuel, producing of electricity and utilize of thermal energy with minimizing losses. It has been found that using of ORC system increased the efficiency of the produced electricity by 7.5%.

Keywords: biomass, efficiency, gasification, ORC system

Procedia PDF Downloads 198

Authors: Anna Paola Micheli, Anna Maria Calce, Loris Di Nallo

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Sustainable finance identifies the process that leads, in the adoption of investment decisions, to take into account environmental and social factors, with the aim of orienting investments towards sustainable and long-term activities. Considering that the topic is at the center of the interest of national agendas, long-term investments will no longer be analyzed only by looking at financial data, but environmental, social, and governance (ESG) factors will be increasingly important and will play a fundamental role in determining the risk and return of an investment. Although this perspective does not deny the orientation to profit, ESG mutual funds represent sustainable finance applied to the world of mutual funds. So the goal of this paper is to verify this attitude, in particular in the energy sector. The choice of the sector is not casual: ESG is the acronym for environmental, social, and governance, and energy companies are strictly related to the environmental theme. The methodology adopted leads to a comparison between a sample of ESG funds and a sample of ESG funds with similar characteristics, using the most important indicators of literature: yield, standard deviation, and Sharpe index. The analysis is focused on equity funds. Results that are partial, due to the lack of historicity, show a good performance of ESG funds, testifying how a sustainable approach does not necessarily mean lower profits. It is clear that these first findings do not involve an absolute preference for ESG funds in terms of performance because the persistence of results is requested. Furthermore, these findings are to be verified in other sectors and in bond funds.

Keywords: mutual funds, ESG, performance, energy

Procedia PDF Downloads 86

Authors: Rouag N., Khalifa M. W., Bencheikh A., Abed H.

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The behavior study of forty-two varieties and genotypes of chickpeas regarding root wilt disease induced by Fusarium oxysporum under the natural conditions of infection was conducted at the ITGC experimental station in Sétif. The infected plants of the different chickpea genotypes have shown multiple symptoms in the field caused by the local strain of Fusarium oxysporum f.sp.cecris belonging to race II of the pathogen. These symptoms ranged from lateral or partial wilting of some ramifications to total desiccation of the plant, sometimes combined with the very slow growth of symptomatic plants. The results of the search for sources of resistance to Fusarium wilt of chickpeas in the 42 genotypes tested revealed that in terms of infection rate, the presence of 7 groups and no genotype showed absolute resistance. While in terms of severity, the results revealed the presence of three homogeneous groups. The first group formed by the most resistant genotypes, in this case, Flip10-368C; Flip11-77C; Flip11-186C; Flip11-124C; Flip11-142C, Flip11-152C; Flip11-69C; Ghab 05; Flip11-159C; Flip11-90C; Flip10-357C and Flip11-37C while the second group is the FLIP genotype 10-382C which was found to be the most sensitive for the natural infection test. Thus, the genotypes of Cicer arietinum L., which have shown significant levels of resistance to Fusarium wilt, can be integrated into breeding and improvement programs.

Keywords: chickpea, Cicer arietinum, Fusarium oxysporum, genotype resistance

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Authors: Zahid Shafait, Jiayu Huang

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Purpose: This study is based on a trait-based theory of emotional intelligence. This study intends to explore the enabling effect of organizational climate, i.e., affiliation, innovation, and fairness, on the emotional intelligence of teachers in Chinese higher education institutes. This study, additionally, intends to investigate the direct impact of teachers’ emotional intelligence on their learning outcomes, i.e., cognitive, social, self-growth outcomes and satisfaction with the university experience. Design/methodology/approach: This study utilized quantitative research techniques to scrutinize the data. Moreover, partial least squares structural equation modeling, i.e., PLS-SEM, was used to assess the hypothetical relationships to conclude their statistical significance. Findings: Results confirmed the supposed associations, i.e., the organizational climate has an enabling effect on emotional intelligence. Likewise, emotional intelligence was concluded to have a direct and positive association with learning outcomes in higher education. Practical implications: This study has investigated abandoned research that is enabling the effects of organizational climate on teachers’ emotional intelligence in Chinese higher education. Organizational climate enables emotionally intelligent teachers to learn efficiently and, at the same time, augments their satisfaction and productivity within an institution. Originality/value: This study investigated the enabling effects of organizational climate on teachers’ emotional intelligence in Chinese higher education that is original in investigated country and sector.

Keywords: organizational climate, emotional intelligence, learning outcomes, higher education

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Authors: F. Javier Benitez, Francisco J. Real, Juan Luis Acero, Francisco Casas

Abstract:

Three emerging contaminants (amitriptyline hydrochloride, methyl salicylate and 2-phenoxyethanol) frequently found in waste-waters were selected to be individually degraded in ultra-pure water by the combined advanced oxidation process constituted by UV radiation and chlorine. The influence of pH, initial chlorine concentration and nature of the contaminants was firstly explored. The trend for the reactivity of the selected compounds was deduced: amitriptyline hydrochloride > methyl salicylate > 2-phenoxyethanol. A later kinetic study was carried out and focused on the specific evaluation of the first-order rate constants and the determination of the partial contribution to the global reaction of the direct photochemical pathway and the radical pathway. A comparison between the rate constant values among photochemical experiments without and with the presence of Cl₂ reveals a clear increase in the oxidation efficiency of the combined process with respect to the photochemical reaction alone. In a second stage, the simultaneous oxidation of mixtures of the selected contaminants in several types of water (ultrapure water, surface water from a reservoir, and two secondary effluents) was also performed by the same combination UV/Cl₂ under more realistic operating conditions. The efficiency of this combined system UV/Cl₂ was compared to other oxidants such as the UV/S₂O₈^2- and UV/H₂O₂ AOPs. Results confirmed that the UV/Cl₂ system provides higher elimination efficiencies among the AOPs tested.

Keywords: emerging contaminants, UV/chlorine advanced oxidation process, amitriptyline, methyl salicylate, 2-phenoxyethanol, chlorination, photolysis

Procedia PDF Downloads 316