Search results for: exogenous variation
2262 Perceived Benefits of Technology Enhanced Learning by Learners in Uganda: Three Band Benefits
Authors: Kafuko M. Maria, Namisango Fatuma, Byomire Gorretti
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Mobile learning (m-learning) is steadily growing and has undoubtedly derived benefits to learners and tutors in different learning environments. This paper investigates the variation in benefits derived from enhanced classroom learning through use of m-learning platforms in the context of a developing country owing to the fact that it is still in its initial stages. The study focused on how basic technology-enhanced pedagogic innovation like cell phone-based learning is enhancing classroom learning from the learners’ perspective. The paper explicitly indicates the opportunities presented by enhanced learning to a conventional learning environment like a physical classroom. The findings were obtained through a survey of two universities in Uganda in which data was quantitatively collected, analyzed and presented in a three banded diagram depicting the variation in the obtainable benefits. Learners indicated that a smartphone is the most commonly used device. Learners also indicate that straight lectures, student to student plus student to lecturer communication, accessing learning material and assignments are core activities. In a TEL environment support by smartphones, learners indicated that they conveniently achieve the prior activities plus discussions and group work. Learners seemed not attracted to the possibility of using TEL environment to take lectures, as well as make class presentations. The less attractiveness of these two factors may be due to the teacher centered approach commonly applied in the country’s education system.Keywords: technology enhanced learning, m-learning, classroom learning, perceived benefits
Procedia PDF Downloads 2312261 Exogenous Ascorbic Acid Increases Resistance to Salt of Carthamus tinctorius
Authors: Banu Aytül Ekmekçi
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Salinity stress has negative effects on agricultural yield throughout the world, affecting production whether it is for subsistence or economic gain. This study investigates the inductive role of vitamin C and its application mode in mitigating the detrimental effects of irrigation with diluted (10, 20 and 30 %) NaCl + water on carthamus tinctorius plants. The results show that 10% of salt water exhibited insignificant changes, while the higher levels impaired growth by reducing seed germination, dry weights of shoot and root, water status and chlorophyll contents. However, irrigation with salt water enhanced carotenoids and antioxidant enzyme activities. The detrimental effects of salt water were ameliorated by application of 100 ppm ascorbic acid (vitamin C). The inductive role of vitamin was associated with the improvement of seed germination, growth, plant water status, carotenoids, endogenous ascorbic acid and antioxidant enzyme activities. Moreover, vitamin C alone or in combination with 30% NaCl water increased the intensity of protein bands as well as synthesized additional new proteins with molecular weights of 205, 87, 84, 65 and 45 kDa. This could increase tolerance mechanisms of treated plants towards water salinity.Keywords: salinity, stress, vitamin c, antioxidant, NaCl, enzyme
Procedia PDF Downloads 5132260 Conflation Methodology Applied to Flood Recovery
Authors: Eva L. Suarez, Daniel E. Meeroff, Yan Yong
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Current flooding risk modeling focuses on resilience, defined as the probability of recovery from a severe flooding event. However, the long-term damage to property and well-being by nuisance flooding and its long-term effects on communities are not typically included in risk assessments. An approach was developed to address the probability of recovering from a severe flooding event combined with the probability of community performance during a nuisance event. A consolidated model, namely the conflation flooding recovery (&FR) model, evaluates risk-coping mitigation strategies for communities based on the recovery time from catastrophic events, such as hurricanes or extreme surges, and from everyday nuisance flooding events. The &FR model assesses the variation contribution of each independent input and generates a weighted output that favors the distribution with minimum variation. This approach is especially useful if the input distributions have dissimilar variances. The &FR is defined as a single distribution resulting from the product of the individual probability density functions. The resulting conflated distribution resides between the parent distributions, and it infers the recovery time required by a community to return to basic functions, such as power, utilities, transportation, and civil order, after a flooding event. The &FR model is more accurate than averaging individual observations before calculating the mean and variance or averaging the probabilities evaluated at the input values, which assigns the same weighted variation to each input distribution. The main disadvantage of these traditional methods is that the resulting measure of central tendency is exactly equal to the average of the input distribution’s means without the additional information provided by each individual distribution variance. When dealing with exponential distributions, such as resilience from severe flooding events and from nuisance flooding events, conflation results are equivalent to the weighted least squares method or best linear unbiased estimation. The combination of severe flooding risk with nuisance flooding improves flood risk management for highly populated coastal communities, such as in South Florida, USA, and provides a method to estimate community flood recovery time more accurately from two different sources, severe flooding events and nuisance flooding events.Keywords: community resilience, conflation, flood risk, nuisance flooding
Procedia PDF Downloads 1032259 Effects of the Slope Embankment Variation on Influence Areas That Causes the Differential Settlement around of Embankment
Authors: Safitri W. Nur, Prathisto Panuntun L. Unggul, M. Ivan Adi Perdana, R. Dary Wira Mahadika
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On soft soil areas, high embankment as a preloading needed to improve the bearing capacity of the soil. For sustainable development, the construction of embankment must not disturb the area around of them. So, the influence area must be known before the contractor applied their embankment design. For several cases in Indonesia, the area around of embankment construction is housing resident and other building. So that, the influence area must be identified to avoid the differential settlement occurs on the buildings around of them. Differential settlement causes the building crack. Each building has a limited tolerance for the differential settlement. For concrete buildings, the tolerance is 0,002 – 0,003 m and for steel buildings, the tolerance is 0,006 – 0,008 m. If the differential settlement stands on the range of that value, building crack can be avoided. In fact, the settlement around of embankment is assumed as zero. Because of that, so many problems happen when high embankment applied on soft soil area. This research used the superposition method combined with plaxis analysis to know the influences area around of embankment in some location with the differential characteristic of the soft soil. The undisturbed soil samples take on 55 locations with undisturbed soil samples at some soft soils location in Indonesia. Based on this research, it was concluded that the effects of embankment variation are if more gentle the slope, the influence area will be greater and vice versa. The largest of the influence area with h initial embankment equal to 2 - 6 m with slopes 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8 is 32 m from the edge of the embankment.Keywords: differential settlement, embankment, influence area, slope, soft soil
Procedia PDF Downloads 4082258 Metabolomics Fingerprinting Analysis of Melastoma malabathricum L. Leaf of Geographical Variation Using HPLC-DAD Combined with Chemometric Tools
Authors: Dian Mayasari, Yosi Bayu Murti, Sylvia Utami Tunjung Pratiwi, Sudarsono
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Melastoma malabathricum L. is an Indo-Pacific herb that has been traditionally used to treat several ailments such as wounds, dysentery, diarrhea, toothache, and diabetes. This plant is common across tropical Indo-Pacific archipelagos and is tolerant of a range of soils, from low-lying areas subject to saltwater inundation to the salt-free conditions of mountain slopes. How the soil and environmental variation influences secondary metabolite production in the herb, and an understanding of the plant’s utility as traditional medicine, remain largely unknown and unexplored. The objective of this study is to evaluate the variability of the metabolic profiles of M. malabathricum L. across its geographic distribution. By employing high-performance liquid chromatography-diode array detector (HPLC-DAD), a highly established, simple, sensitive, and reliable method was employed for establishing the chemical fingerprints of 72 samples of M. malabathricum L. leaves from various geographical locations in Indonesia. Specimens collected from six terrestrial and archipelago regions of Indonesia were analyzed by HPLC to generate chromatogram peak profiles that could be compared across each region. Data corresponding to the common peak areas of HPLC chromatographic fingerprint were analyzed by hierarchical component analysis (HCA) and principal component analysis (PCA) to extract information on the most significant variables contributing to characterization and classification of analyzed samples data. Principal component values were identified as PC1 and PC2 with 41.14% and 19.32%, respectively. Based on variety and origin, the high-performance liquid chromatography method validated the chemical fingerprint results used to screen the in vitro antioxidant activity of M. malabathricum L. The result shows that the developed method has potential values for the quality of similar M. malabathrium L. samples. These findings provide a pathway for the development and utilization of references for the identification of M. malabathricum L. Our results indicate the importance of considering geographic distribution during field-collection efforts as they demonstrate regional metabolic variation in secondary metabolites of M. malabathricum L., as illustrated by HPLC chromatogram peaks and their antioxidant activities. The results also confirm the utility of this simple approach to a rapid evaluation of metabolic variation between plants and their potential ethnobotanical properties, potentially due to the environments from whence they were collected. This information will facilitate the optimization of growth conditions to suit particular medicinal qualities.Keywords: fingerprint, high performance liquid chromatography, Melastoma malabathricum l., metabolic profiles, principal component analysis
Procedia PDF Downloads 1622257 Genetic Divergence and Morphogenic Analysis of Sugarcane Red Rot Pathogen Colletotrichum falcatum under South Gujarat Condition
Authors: Prittesh Patel, Ramar Krishnamurthy
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In the present study, nine strains of C. falcatum obtained from different places and cultivars were characterized for sporulation, growth rate, and 18S rRNA gene sequence. All isolates had characteristic fast-growing sparse and fleecy aerial mycelia on potato dextrose agar with sickle shape conidia (length x width: varied from 20.0 X 3.89 to 25.52 X 5.34 μm) and blackish to orange acervuli with setae (length x width: varied from 112.37X 2.78 to 167.66 X 6.73 μm). They could be divided into two groups on the base of morphology; P1, dense mycelia with concentric growth and P2, sparse mycelia with uneven growth. Genomic DNA isolation followed by PCR amplification with ITS1 and ITS4 primer produced ~550bp amplicons for all isolates. Phylogeny generated by 18S rRNA gene sequence confirmed the variation in isolates and mainly grouped into two clusters; cluster 1 contained CoC671 isolates (cfNAV and cfPAR) and Co86002 isolate (cfTIM). Other isolates cfMAD, cfKAM, and cfMAR were grouped into cluster 2. Remaining isolates did not fall into any cluster. Isolate cfGAN, collected from Co86032 was found highly diverse of all the nine isolates. In a nutshell, we found considerable genetic divergence and morphological variation within C. falcatum accessions collected from different areas of south Gujarat, India and these can be used for the breeding program.Keywords: Colletotrichum falcatum, ITS, morphology, red rot, sugarcane
Procedia PDF Downloads 1272256 Effect of Different Carbon Fabric Orientations on the Fracture Properties of Carbon Fabric Reinforced Polymer Composites
Authors: S. F. Halim, H. F. Naguib, S. N. Lawandy, R. S. Hegazy, M. N. Baheg
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The main drawbacks of the traditional carbon fabric reinforced epoxy resin (CFRP) are low strain failure, delamination between composites layers, and low impact resistance due to the brittleness of epoxy resin. The aim of this study is to enhance the fracture properties of the CFRP composites laminates via the variation of composite's designs. A series of composites were fabricated in which bidirectional (00/900) carbon fabric (CF) layers were laid inside the resin matrix with orientation codes as F1 [(00, 900)/ (00, 900)], F2 [(900, 00)/ (00, 900)] and F3 [(00,900)/ (900, 00). The mechanical and dynamic properties of the composites were estimated. In addition, the morphology of samples surface was examined by scanning electron microscope (SEM) after impact fracture. The results revealed that the CFRP properties could be tailored fitting specific applications by controlling the fabric orientation inside the CFRP composite design. F2 orientation [(900, 00)/ (00.900)] showed the highest tensile and flexural strength values. On the other hand, the impact strength values of composites were in the order F1 > F2 > F3. The storage modulus, loss modulus, and glass transition temperature Tg values obtained from the dynamic mechanical analysis (DMA) examination was in the order F1 > F2 > F3. The variation in the properties of the composite was clearly explained by the SEM micrographs as the failure of F3 orientation properties was referred to as the complete breakage of the CF layers upon fracture.Keywords: carbon fiber, CFRP, composites, epoxy resins, flexural strength
Procedia PDF Downloads 1282255 Variation in Complement Order in English: Implications for Interlanguage Syntax
Authors: Juliet Udoudom
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Complement ordering principles of natural language phrases (XPs) stipulate that Head terms be consistently placed phrase initially or phrase-finally, yielding two basic theoretical orders – Head – Complement order or Complement – Head order. This paper examines the principles which determine complement ordering in English V- and N-bar structures. The aim is to determine the extent to which complement linearisations in the two phrase types are consistent with the two theoretical orders outlined above given the flexible and varied nature of natural language structures. The objective is to see whether there are variation(s) in the complement linearisations of the XPs studied and the implications which such variations hold for the inter-language syntax of English and Ibibio. A corpus-based approach was employed in obtaining the English data. V- and -N – bar structures containing complement structures were isolated for analysis. Data were examined from the perspective of the X-bar and Government – theories of Chomsky’s (1981) Government-Binding format. Findings from the analysis show that in V – bar structures in English, heads are consistently placed phrase – initially yielding a Head – Complement order; however, complement linearisation in the N – bar structures studied exhibited parametric variations. Thus, in some N – bar structures in English the nominal head is ordered to the left whereas in others, the head term occurs to the right. It may therefore be concluded that the principles which determine complement ordering are both Language – Particular and Phrase – specific following insights provided within Phrasal Syntax.Keywords: complement order, complement–head order, head–complement order, language–particular principles
Procedia PDF Downloads 3482254 Annual and Seasonal Variations in Air Quality Index of the National Capital Region, India
Authors: Surinder Deswal, Vineet Verma
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Air Quality Index (AQI) is used as a tool to indicate the level of severity and disseminate the information on air pollution to enable the public to understand the health and environmental impacts of air pollutant concentration levels. The annual and seasonal variation of criteria air pollutants concentration based on the National Ambient Air Quality Monitoring Programme has been conducted for a period of nine years (2006-2014) using the AQI system. AQI was calculated using IND-AQI methodology and Maximum Operator Concept is applied. An attempt has been made to quantify the variations in AQI on an annual and seasonal basis over a period of nine years. Further, year-wise frequency of occurrence of AQI in each category for all the five stations is analysed, which presents in depth analysis of trends over the period of study. The best air quality was observed in the Noida residential area, followed by Noida industrial area during the study period; whereas, Bulandshahar industrial area and Faridabad residential area were observed to have the worst air quality. A shift in the worst air quality from winter to summer season has also been observed during the study period. Further, the level of Respirable Suspended Particulate Matter was found to be above permissible limit at all the stations. The present study helps in enhancing public awareness and calls for the need of immediate measures to be taken to counter-effect the cause of the increasing level of air pollution.Keywords: air quality index, annual trends, criteria pollutants, seasonal variation
Procedia PDF Downloads 2812253 Exploring the Influence of High-Frequency Acoustic Parameters on Wave Behavior in Porous Bilayer Materials: An Equivalent Fluid Theory Approach
Authors: Mustapha Sadouk
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This study investigates the sensitivity of high-frequency acoustic parameters in a rigid air-saturated porous bilayer material within the framework of the equivalent fluid theory, a specific case of the Biot model. The study specifically focuses on the sensitivity analysis in the frequency domain. The interaction between the fluid and solid phases of the porous medium incorporates visco-inertial and thermal exchange, characterized by two functions: the dynamic tortuosity α(ω) proposed by Johnson et al. and the dynamic compressibility β(ω) proposed by Allard, refined by Sadouki for the low-frequency domain of ultrasound. The parameters under investigation encompass porosity, tortuosity, viscous characteristic length, thermal characteristic length, as well as viscous and thermal shape factors. A +30% variation in these parameters is considered to assess their impact on the transmitted wave amplitudes. By employing this larger variation, a more comprehensive understanding of the sensitivity of these parameters is obtained. The outcomes of this study contribute to a better comprehension of the high-frequency wave behavior in porous bilayer materials, providing valuable insights for the design and optimization of such materials across various applications.Keywords: bilayer materials, ultrasound, sensitivity analysis, equivalent fluid theory, dynamic tortuosity., porous material
Procedia PDF Downloads 852252 Spatial Variation in Urbanization and Slum Development in India: Issues and Challenges in Urban Planning
Authors: Mala Mukherjee
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Background: India is urbanizing very fast and urbanisation in India is treated as one of the most crucial components of economic growth. Though the pace of urbanisation (31.6 per cent in 2011) is however slower and lower than the average for Asia but the absolute number of people residing in cities and towns has increased substantially. Rapid urbanization leads to urban poverty and it is well represented in slums. Currently India has four metropolises and 53 million plus cities. All of them have significant slum population but the standard of living and success of slum development programmes varies across regions. Objectives: Objectives of the paper are to show how urbanisation and slum development varies across space; to show spatial variation in the standard of living in Indian slums; to analyse how the implementation of slum development policies like JNNURM, Rajiv Awas Yojana varies across cities and bring different results in different regions and what are the factors responsible for such variation. Data Sources and Methodology: Census 2011 data on urban population and slum households and amenities have been used for analysing the regional variation of urbanisation in 53 million plus cities of India. Special focus has been put on Kolkata Metropolitan Area. Statistical techniques like z-score and PCA have been employed to work out Standard of Living Deprivation score for all the slums of 53 metropolises. ARC-GIS software is used for making maps. Standard of living has been measured in terms of access to basic amenities, infrastructure and assets like drinking water, sanitation, housing condition, bank account, and so on. Findings: 1. The first finding reveals that migration and urbanization is very high in Greater Mumbai, Delhi, Bangaluru, Chennai, Hyderabad and Kolkata; but slum population is high in Greater Mumbai (50% population live in slums), Meerut, Faridabad, Ludhiana, Nagpur, Kolkata etc. Though the rate of urbanization is high in southern and western states but the percentage of slum population is high in northern states (except Greater Mumbai). 2. Standard of Living also varies widely. Slums of Greater Mumbai and North Indian Cities score fairly high in the index indicating the fact that standard of living is high in those slums compare to the slums in eastern India (Dhanbad, Jamshedpur, Kolkata). Therefore, though Kolkata have relatively lesser percentage of slum population compare to north and south Indian cities but the standard of living in Kolkata’s slums is deplorable. 3. It is interesting to note that even within Kolkata Metropolitan Area slums located in the southern and eastern municipal towns like Rajpur-Sonarpur, Pujali, Diamond Harbour, Baduria and Dankuni have lower standard of living compare to the slums located in the Hooghly Industrial belt like Titagarh, Rishrah, Srerampore etc. Slums of the Hooghly Industrial Belt are older than the slums located in eastern and southern part of the urban agglomeration. 4. Therefore, urban development and emergence of slums should not be the only issue of urban governance but standard of living should be the main focus. Slums located in the main cities like Delhi, Mumbai, Kolkata get more attention from the urban planners and similarly, older slums in a city receives greater political attention compare to the slums of smaller cities and newly emerged slums of the peripheral parts.Keywords: urbanisation, slum, spatial variation, India
Procedia PDF Downloads 3602251 Genetic Diversity in Capsicum Germplasm Based on Inter Simple Sequence Repeat Markers
Authors: Siwapech Silapaprayoon, Januluk Khanobdee, Sompid Samipak
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Chili peppers are the fruits of Capsicum pepper plants well known for their fiery burning sensation on the tongue after consumption. They are members of the Solanaceae or common nightshade family along with potato, tomato and eggplant. Thai cuisine has gained popularity for its distinct flavors due to usages of various spices and its heat from the addition of chili pepper. Though being used in little quantity for each dish, chili pepper holds a special place in Thai cuisine. There are many varieties of chili peppers in Thailand, and thirty accessions were collected at Rajamangala University of Technology Lanna, Lampang, Thailand. To effectively manage any germplasm it is essential to know the diversity and relationships among members. Thirty-six Inter Simple Sequence Repeat (ISSRs) DNA markers were used to analyze the germplasm. Total of 335 polymorphic bands was obtained giving the average of 9.3 alleles per marker. Unweighted pair-group mean arithmetic method (UPGMA) clustering of data using NTSYS-pc software indicated that the accessions showed varied levels of genetic similarity ranging from 0.57-1.00 similarity coefficient index indicating significant levels of variation. At SM coefficient of 0.81, the germplasm was separated into four groups. Phenotypic variation was discussed in context of phylogenetic tree clustering.Keywords: diversity, germplasm, Chili pepper, ISSR
Procedia PDF Downloads 1522250 Genetic Variations of CYP2C9 in Thai Patients Taking Medical Cannabis
Authors: Naso Isaiah Thanavisuth
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Medical cannabis can be used for treatment including pain, multiple sclerosis, Parkinson's disease, and cancer. However, medical cannabis leads to adverse effects (AEs), which is delta-9-tetrahydrocannabinol (THC). In previous studies, the major of THC metabolism enzymes are CYP2C9. Especially, the variation of CYP2C9 gene consist of CYP2C9*2 on exon 3 and CYP2C9*3 on exon 7 to decrease enzyme activity. Notwithstanding, there is no data describing whether the variant of CYP2C9 genes are apharmacogenetics marker for the prediction of THC-induced AEs in Thai patients. We want to investigate the association between CYP2C9 gene and THC-induced AEs in Thai patients. We enrolled 39 Thai patients with medical cannabis treatment who were classified by clinical data. The CYP2C9*2 and *3 genotyping were conducted using the TaqMan real time PCR assay. All Thai patients who received the medical cannabis consist of twenty-four (61.54%) patients were female, and fifteen (38.46%) were male, with age range 27- 87 years. Moreover, the most AEs in Thai patients who were treated with medical cannabis between cases and controls were tachycardia, arrhythmia, dry mouth, and nausea. Particularly, thirteen (72.22%) medical cannabis-induced AEs were female and age range 33 – 69 years. In this study, none of the medical cannabis groups carried CYP2C9*2 variants in Thai patients. The CYP2C9*3 variants (*1/*3, intermediate metabolizer, IM) and (*3/*3, poor metabolizer, PM) were found, three of thirty-nine (7.69%) and one of thirty-nine (2.56%), respectively. Although, our results indicate that there is no found the CYP2C9*2. However, the variation of CYP2C9 allele might serve as a pharmacogenetics marker for screening before initiating the therapy with medical cannabis for the prevention of medical cannabis-induced AEs.Keywords: CYP2C9, medical cannabis, adverse effects, THC, P450
Procedia PDF Downloads 1192249 Sensitivity and Reliability Analysis of Masonry Infilled Frames
Authors: Avadhoot Bhosale, Robin Davis P., Pradip Sarkar
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The seismic performance of buildings with irregular distribution of mass, stiffness and strength along the height may be significantly different from that of regular buildings with masonry infill. Masonry infilled reinforced concrete (RC) frames are very common structural forms used for multi-storey building construction. These structures are found to perform better in past earthquakes owing to additional strength, stiffness and energy dissipation in the infill walls. The seismic performance of a building depends on the variation of material, structural and geometrical properties. The sensitivity of these properties affects the seismic response of the building. The main objective of the sensitivity analysis is to found out the most sensitive parameter that affects the response of the building. This paper presents a sensitivity analysis by considering 5% and 95% probability value of random variable in the infills characteristics, trying to obtain a reasonable range of results representing a wide number of possible situations that can be met in practice by using pushover analysis. The results show that the strength-related variation values of concrete and masonry, with the exception of tensile strength of the concrete, have shown a significant effect on the structural performance and that this effect increases with the progress of damage condition for the concrete. The seismic risk assessments of the selected frames are expressed in terms of reliability index.Keywords: fragility curve, sensitivity analysis, reliability index, RC frames
Procedia PDF Downloads 3232248 Screening Some Accessions of Lentil (Lens culinaris M.) for Salt Tolerance at Germination and Early Seedling Stage in Eastern Ethiopia
Authors: Azene Tesfaye, Yohannes Petros, Habtamu Zeleke
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To evaluate genetic variation among Ethiopian lentil, laboratory experiment were conducted to screen 12 accessions of lentil (Lens culinaris M.) for salt tolerance. Seeds of 12 Lentil accessions were grown at laboratory (Petri dish) condition with different levels of salinity (0, 2, 4, and 8 dSm-1 NaCl) for 4 weeks. The experimental design was completely randomized design (CRD) in factorial combination with three replications. Data analysis was carried out using SAS software. Average germination time, germination percentage, seedling shoot and root traits, seedling shoot and root weight were evaluated. The two way ANOVA for varieties revealed statistically significant variation among lentil accession, NaCl level and their interactions (p<0.001) with respect to the entire parameters. It was found that salt stress significantly delays germination rate and decreases germination percentage, shoot and root length, seedling shoot and root weight of lentil accessions. The degree of decrement varied with accessions and salinity levels. Accessions 36120, 9235 and 36004 were better salt tolerant than the other accessions. As the result, it is recommended to be used as a genetic resource for the development of lentil accession and other very salt sensitive crop with improved germination under salt stress condition.Keywords: accession, germination, lentil, NaCl, screening, seedling stage
Procedia PDF Downloads 3392247 Improving the Biocontrol of the Argentine Stem Weevil; Using the Parasitic Wasp Microctonus hyperodae
Authors: John G. Skelly, Peter K. Dearden, Thomas W. R. Harrop, Sarah N. Inwood, Joseph Guhlin
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The Argentine stem weevil (ASW; L. bonariensis) is an economically important pasture pest in New Zealand, which causes about $200 million of damage per annum. Microctonus hyperodae (Mh), a parasite of the ASW in its natural range in South America, was introduced into New Zealand to curb the pasture damage caused by the ASW. Mh is an endoparasitic wasp that lays its eggs in the ASW halting its reproduction. Mh was initially successful at preventing ASW proliferation and reducing pasture damage. The effectiveness of Mh has since declined due to decreased parasitism rates and has resulted in increased pasture damage. Although the mechanism through which ASW has developed resistance to Mh has not been discovered, it has been proposed to be due to the different reproductive modes used by Mh and the ASW in New Zealand. The ASW reproduces sexually, whereas Mh reproduces asexually, which has been hypothesised to have allowed the ASW to ‘out evolve’ Mh. Other species within the Microctonus genus reproduce both sexually and asexually. Strains of Microctonus aethiopoides (Ma), a species closely related to Mh, reproduce either by sexual or asexual reproduction. Comparing the genomes of sexual and asexual Microctonus may allow for the identification of the mechanism of asexual reproduction and other characteristics that may improve Mh as a biocontrol agent. The genomes of Mh and three strains of Ma, two of which reproduce sexually and one reproduces asexually, have been sequenced and annotated. The French (MaFR) and Moroccan (MaMO) reproduce sexually, whereas the Irish strain (MaIR) reproduces asexually. Like Mh, The Ma strains are also used as biocontrol agents, but for different weevil species. The genomes of Mh and MaIR were subsequently upgraded using Hi-C, resulting in a set of high quality, highly contiguous genomes. A subset of the genes involved in mitosis and meiosis, which have been identified though the use of Hidden Markov Models generated from genes involved in these processes in other Hymenoptera, have been catalogued in Mh and the strains of Ma. Meiosis and mitosis genes were broadly conserved in both sexual and asexual Microctonus species. This implies that either the asexual species have retained a subset of the molecular components required for sexual reproduction or that the molecular mechanisms of mitosis and meiosis are different or differently regulated in Microctonus to other insect species in which these mechanisms are more broadly characterised. Bioinformatic analysis of the chemoreceptor compliment in Microctonus has revealed some variation in the number of olfactory receptors, which may be related to host preference. Phylogenetic analysis of olfactory receptors highlights variation, which may be able to explain different host range preferences in the Microctonus. Hi-C clustering implies that Mh has 12 chromosomes, and MaIR has 8. Hence there may be variation in gene regulation between species. Genome alignment of Mh and MaIR implies that there may be large scale genome structural variation. Greater insight into the genetics of these agriculturally important group of parasitic wasps may be beneficial in restoring or maintaining their biocontrol efficacy.Keywords: argentine stem weevil, asexual, genomics, Microctonus hyperodae
Procedia PDF Downloads 1562246 Evaluation of Mixing and Oxygen Transfer Performances for a Stirred Bioreactor Containing P. chrysogenum Broths
Authors: A. C. Blaga, A. Cârlescu, M. Turnea, A. I. Galaction, D. Caşcaval
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The performance of an aerobic stirred bioreactor for fungal fermentation was analyzed on the basis of mixing time and oxygen mass transfer coefficient, by quantifying the influence of some specific geometrical and operational parameters of the bioreactor, as well as the rheological behavior of Penicillium chrysogenum broth (free mycelia and mycelia aggregates). The rheological properties of the fungus broth, controlled by the biomass concentration, its growth rate, and morphology strongly affect the performance of the bioreactor. Experimental data showed that for both morphological structures the accumulation of fungus biomass induces a significant increase of broths viscosity and modifies the rheological behavior. For lower P. chrysogenum concentrations (both morphological conformations), the mixing time initially increases with aeration rate, reaches a maximum value and decreases. This variation can be explained by the formation of small bubbles, due to the presence of solid phase which hinders the bubbles coalescence, the rising velocity of bubbles being reduced by the high apparent viscosity of fungus broths. By biomass accumulation, the variation of mixing time with aeration rate is gradually changed, the continuous reduction of mixing time with air input flow increase being obtained for 33.5 g/l d.w. P. chrysogenum. Owing to the superior apparent viscosity, which reduces considerably the relative contribution of mechanical agitation to the broths mixing, these phenomena are more pronounced for P. chrysogenum free mycelia. Due to the increase of broth apparent viscosity, the biomass accumulation induces two significant effects on oxygen transfer rate: the diminution of turbulence and perturbation of bubbles dispersion - coalescence equilibrium. The increase of P. chrysogenum free mycelia concentration leads to the decrease of kla values. Thus, for the considered variation domain of the main parameters taken into account, namely air superficial velocity from 8.36 10-4 to 5.02 10-3 m/s and specific power input from 100 to 500 W/m3, kla was reduced for 3.7 times for biomass concentration increase from 4 to 36.5 g/l d.w. The broth containing P. crysogenum mycelia aggregates exhibits a particular behavior from the point of view of oxygen transfer. Regardless of bioreactor operating conditions, the increase of biomass concentration leads initially to the increase of oxygen mass transfer rate, the phenomenon that can be explained by the interaction of pellets with bubbles. The results are in relation with the increase of apparent viscosity of broths corresponding to the variation of biomass concentration between the mentioned limits. Thus, the apparent viscosity of the suspension of fungus mycelia aggregates increased for 44.2 times and fungus free mycelia for 63.9 times for CX increase from 4 to 36.5 g/l d.w. By means of the experimental data, some mathematical correlations describing the influences of the considered factors on mixing time and kla have been proposed. The proposed correlations can be used in bioreactor performance evaluation, optimization, and scaling-up.Keywords: biomass concentration, mixing time, oxygen mass transfer, P. chrysogenum broth, stirred bioreactor
Procedia PDF Downloads 3402245 Effect of Constant and Variable Temperature on the Morphology of TiO₂ Nanotubes Prepared by Two-Step Anodization Method
Authors: Tayyaba Ghani, Mazhar Mehmood, Mohammad Mujahid
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TiO₂ nanotubes are receiving immense attraction in the field of dye-sensitized solar cells due to their well-defined nanostructures, efficient electron transport and large surface area as compared to other one dimensional structures. In the present work, we have investigated the influence of temperature on the morphology of anodically produced self-organized Titanium oxide nanotubes (TiNTs). TiNTs are synthesized by two-step anodization method in an ethylene glycol based electrolytes containing ammonium fluoride. Experiments are performed at constant anodization voltage for two hours. An investigation by the SEM images reveals that if the temperature is kept constant during the anodizing experiment, variation in the average tube diameter is significantly reduced. However, if the temperature is not controlled then due to the exothermic nature of reactions for the formation of TiNTs, the temperature of electrolyte keep on increasing. This variation in electrolyte bath temperature introduced strong variations in tube diameter (20 nm to 160 nm) along the length of tubes. Current profiles, recorded during the anodization experiment, predict the effect of constant and varying experimental temperatures as well. In both cases, XRD results show the complete anatase crystal structure of nanotube upon annealing at 450 °C. Present work highlights the importance of constant temperature during the anodization experiments in order to develop an ordered array of nanotubes with a uniform tube diameter.Keywords: anodization, ordering, temperature, TiO₂ nanotubes
Procedia PDF Downloads 1712244 A Multi-Objective Programming Model to Supplier Selection and Order Allocation Problem in Stochastic Environment
Authors: Rouhallah Bagheri, Morteza Mahmoudi, Hadi Moheb-Alizadeh
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This paper aims at developing a multi-objective model for supplier selection and order allocation problem in stochastic environment, where purchasing cost, percentage of delivered items with delay and percentage of rejected items provided by each supplier are supposed to be stochastic parameters following any arbitrary probability distribution. In this regard, dependent chance programming is used which maximizes probability of the event that total purchasing cost, total delivered items with delay and total rejected items are less than or equal to pre-determined values given by decision maker. The abovementioned stochastic multi-objective programming problem is then transformed into a stochastic single objective programming problem using minimum deviation method. In the next step, the further problem is solved applying a genetic algorithm, which performs a simulation process in order to calculate the stochastic objective function as its fitness function. Finally, the impact of stochastic parameters on the given solution is examined via a sensitivity analysis exploiting coefficient of variation. The results show that whatever stochastic parameters have greater coefficients of variation, the value of the objective function in the stochastic single objective programming problem is deteriorated.Keywords: supplier selection, order allocation, dependent chance programming, genetic algorithm
Procedia PDF Downloads 3132243 The Effect of AMBs Number of a Dynamics Behavior of a Spur Gear Reducer in Non-Stationary Regime
Authors: Najib Belhadj Messaoud, Slim Souissi
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The non-linear dynamic behavior of a single stage spur gear reducer is studied in this paper in transient regime. Driving and driver rotors are, respectively, powered by a motor torque Cm and loaded by a resistive torque Cr. They are supported by two identical Active Magnetic Bearings (AMBs). Gear excitation is induced by the motor torque and load variation in addition to the fluctuation of meshing stiff-ness due to the variation of input rotational speed. Three models of AMBs were used with four, six and eight magnets. They are operated by P.D controller and powered by control and bias currents. The dynamic parameters of the AMBs are modeled by stiffness and damping matrices computed by the derivation of the electromagnetic forces. The equations of motion are solved iteratively using Newmark time integration method. In the first part of the study, the model is powered by an electric motor and by a four strokes four cylinders diesel engine in the second part. The numerical results of the dynamic responses of the system come to confirm the significant effect of the transient regime on the dynamic behavior of a gear set, particularly in the case of engine acyclism condition. Results also confirm the influence of the magnet number by AMBs on the dynamic behavior of the system. Indeed, vibrations were more important in the case of gear reducer supported by AMBs with four magnets.Keywords: motor, stiffness, gear, acyclism, fluctuation, torque
Procedia PDF Downloads 4592242 Budget Discipline and National Prosperity: The Nigerian Experience
Authors: Ben-Caleb Egbide, Iyoha Francis, Egharevba Mathew, Oduntan Emmanuel
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The prosperity of any nation is determined not just by the availability of resources, but also by the discipline exercised in the management of those resources. This paper examines the functional association between adherence to budgetary estimates or budget discipline (BDISC) and national prosperity proxied by Real Gross Domestic Product (RGDP) and Relative Poverty Index (RPI)/Human Development Index (HDI). Adopting a longitudinal retrospective research strategy, time series data relating to both the endogenous and exogenous variables were extracted from official government publications for 36 years’ (1980-2015 in the case of RGDP and RPI), and for 26 years (1990-2015 in the case of HDI). Ordinary Least Square (OLS), as well as cointegration regressions, were employed to gauge both the short term and long term impact of BDISC on RPI/HDI and RGDP. The results indicated that BDISC is directly related with RGDP but indirectly related with RPI. The implication is that while adherence to budgetary estimate can enhance economic growth, it has the capacity to slow down the rate of poverty in the long run. The paper, therefore, recommend stricter adherence to budgets as a way out of economic under performance in Nigeria and engender the process of promoting human development and national prosperity.Keywords: budget discipline, human development index, national prosperity, Nigeria
Procedia PDF Downloads 2382241 Effect of Modified Atmosphere Packaging and Storage Temperatures on Quality of Shelled Raw Walnuts
Authors: M. Javanmard
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This study was aimed at analyzing the effects of packaging (MAP) and preservation conditions on the packaged fresh walnut kernel quality. The central composite plan was used for evaluating the effect of oxygen (0–10%), carbon dioxide (0-10%), and temperature (4-26 °C) on qualitative characteristics of walnut kernels. Also, the response level technique was used to find the optimal conditions for interactive effects of factors, as well as estimating the best conditions of process using least amount of testing. Measured qualitative parameters were: peroxide index, color, decreased weight, mould and yeast counting test, and sensory evaluation. The results showed that the defined model for peroxide index, color, weight loss, and sensory evaluation is significant (p < 0.001), so that increase of temperature causes the peroxide value, color variation, and weight loss to increase and it reduces the overall acceptability of walnut kernels. An increase in oxygen percentage caused the color variation level and peroxide value to increase and resulted in lower overall acceptability of the walnuts. An increase in CO2 percentage caused the peroxide value to decrease, but did not significantly affect other indices (p ≥ 0.05). Mould and yeast were not found in any samples. Optimal packaging conditions to achieve maximum quality of walnuts include: 1.46% oxygen, 10% carbon dioxide, and temperature of 4 °C.Keywords: shelled walnut, MAP, quality, storage temperature
Procedia PDF Downloads 3882240 Effects of Variation of Centers in the Torsional Analysis of Asymmetrical Buildings by Performing Non Linear Static Analysis
Authors: Md Masihuddin Siddiqui, Abdul Haakim Mohammed
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Earthquakes are the most unpredictable and devastating of all natural disasters. The behaviour of a building during an earthquake depends on several factors such as stiffness, adequate lateral strength, ductility, and configurations. The experience from the performance of buildings during past earthquakes has shown that the buildings with regular geometry, uniformly distributed mass and stiffness in plan as well as in elevation suffer much less damage compared to irregular configurations. The three centers namely- centre of mass, centre of strength, centre of stiffness are the torsional parameters which contribute to the strength of the building in case of an earthquake. Inertial forces and resistive forces in a structural system act through the center of mass and center of rigidity respectively which together oppose the forces that are produced during seismic excitation. So these centers of a structural system should be positioned where the structural system is the strongest so that the effects produced due to the earthquake may have a minimal effect on the structure. In this paper, the effects of variation of strength eccentricity and stiffness eccentricity in reducing the torsional responses of the asymmetrical buildings by using pushover analysis are studied. The maximum reduction of base torsion was observed in the case of minimum strength eccentricity, and the least reduction was observed in the case of minimum stiffness eccentricity.Keywords: strength eccentricity, stiffness eccentricity, asymmetric structure, base torsion, push over analysis
Procedia PDF Downloads 2942239 Simulation of Hydraulic Fracturing Fluid Cleanup for Partially Degraded Fracturing Fluids in Unconventional Gas Reservoirs
Authors: Regina A. Tayong, Reza Barati
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A stable, fast and robust three-phase, 2D IMPES simulator has been developed for assessing the influence of; breaker concentration on yield stress of filter cake and broken gel viscosity, varying polymer concentration/yield stress along the fracture face, fracture conductivity, fracture length, capillary pressure changes and formation damage on fracturing fluid cleanup in tight gas reservoirs. This model has been validated as against field data reported in the literature for the same reservoir. A 2-D, two-phase (gas/water) fracture propagation model is used to model our invasion zone and create the initial conditions for our clean-up model by distributing 200 bbls of water around the fracture. A 2-D, three-phase IMPES simulator, incorporating a yield-power-law-rheology has been developed in MATLAB to characterize fluid flow through a hydraulically fractured grid. The variation in polymer concentration along the fracture is computed from a material balance equation relating the initial polymer concentration to total volume of injected fluid and fracture volume. All governing equations and the methods employed have been adequately reported to permit easy replication of results. The effect of increasing capillary pressure in the formation simulated in this study resulted in a 10.4% decrease in cumulative production after 100 days of fluid recovery. Increasing the breaker concentration from 5-15 gal/Mgal on the yield stress and fluid viscosity of a 200 lb/Mgal guar fluid resulted in a 10.83% increase in cumulative gas production. For tight gas formations (k=0.05 md), fluid recovery increases with increasing shut-in time, increasing fracture conductivity and fracture length, irrespective of the yield stress of the fracturing fluid. Mechanical induced formation damage combined with hydraulic damage tends to be the most significant. Several correlations have been developed relating pressure distribution and polymer concentration to distance along the fracture face and average polymer concentration variation with injection time. The gradient in yield stress distribution along the fracture face becomes steeper with increasing polymer concentration. The rate at which the yield stress (τ_o) is increasing is found to be proportional to the square of the volume of fluid lost to the formation. Finally, an improvement on previous results was achieved through simulating yield stress variation along the fracture face rather than assuming constant values because fluid loss to the formation and the polymer concentration distribution along the fracture face decreases as we move away from the injection well. The novelty of this three-phase flow model lies in its ability to (i) Simulate yield stress variation with fluid loss volume along the fracture face for different initial guar concentrations. (ii) Simulate increasing breaker activity on yield stress and broken gel viscosity and the effect of (i) and (ii) on cumulative gas production within reasonable computational time.Keywords: formation damage, hydraulic fracturing, polymer cleanup, multiphase flow numerical simulation
Procedia PDF Downloads 1302238 Studies on Phylogeny of Helicoverpa armigera Populations from North Western Himalaya Region with Help of Cytochromeoxidase I Sequence
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 3092237 Utilization of Sludge in the Manufacturing of Fired Clay Bricks
Authors: Anjali G. Pillai, S. Chadrakaran
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The extensive amount of sludge generated throughout the world, as a part of water treatment works, have caused various social and economic issues, such as a demand on landfill spaces, increase in environmental pollution and raising the waste management cost. With growing social awareness about toxic incinerator emissions and the increasing concern over the disposal of sludge on the agricultural land, the recovery of sewage sludge as a building and construction raw material can be considered as an innovative approach to tackle the sludge disposal problem. The proposed work aims at studying the recycling ability of the sludge, generated from the water treatment process, by incorporating it into the fired clay brick units. The work involves initial study of the geotechnical characteristics of the brick-clay and the sludge. Chemical compatibility of both the materials will be analyzed by X-ray fluorescence technique. The variation in the strength aspects with varying proportions of sludge i.e. 10%, 20%, 30% and 40% in the sludge-clay mix will also be determined by the proctor density test. Based on the optimum moisture content, the sludge-clay bricks will be manufactured in a brick manufacturing plant and the modified brick units will be tested to determine the variation in compressive strength, bulk density, firing shrinkage, shrinkage loss and initial water absorption rate with respect to the conventional clay bricks. The results will be compared with the specifications given in Indian Standards to arrive at the potential use of the new bricks. The durability aspect will be studied by conducting the leachate analysis test using atomic adsorption spectrometry. The lightweight characteristics of the sludge modified bricks will be ascertained with the scanning electron microscope technique which will be indicative of the variation in pore structure with the increase in sludge content within the bricks. The work will determine the suitable proportion of the sludge – clay mix in the brick which can then be effectively implemented. The feasibility aspect of the work will be determined for commercial production of the units. The work involves providing a strategy for conversion of waste to resource. Moreover, it provides an alternative solution to the problem of growing scarcity of brick-clay for the manufacturing of fired clay bricks.Keywords: eco-bricks, green construction material, sludge amended bricks, sludge disposal, waste management
Procedia PDF Downloads 3052236 Role of Fish Hepatic Aldehyde Oxidase in Oxidative In Vitro Metabolism of Phenanthridine Heterocyclic Aromatic Compound
Authors: Khaled S. Al Salhen
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Aldehyde oxidase is molybdo-flavoenzyme involved in the oxidation of hundreds of endogenous and exogenous and N-heterocyclic compounds and environmental pollutants. Uncharged N-heterocyclic aromatic compounds such phenanthridine are commonly distributed pollutants in soil, air, sediments, surface water and groundwater, and in animal and plant tissues. Phenanthridine as uncharged N-heterocyclic aromatic compound was incubated with partially purified aldehyde oxidase from rainbow trout fish liver. Reversed-phase HLPC method was used to separate the oxidation products from phenanthridine and the metabolite was identified. The 6(5H)-phenanthridinone was identified the major metabolite by partially purified aldehyde oxidase from fish liver. Kinetic constant for the oxidation reactions were determined spectrophotometrically and showed that this substrate has a good affinity (Km = 78 ± 7.6 µM) for hepatic aldehyde oxidase, coupled with a relatively high oxidation rate (0.77± 0.03 nmol/min/mg protein). In addition, the kinetic parameters of hepatic fish aldehyde oxidase towards the phenanthridine substrate indicate that in vitro biotransformation by hepatic fish aldehyde oxidase will be a significant pathway. This study confirms that partially purified aldehyde oxidase from fish liver is indeed the enzyme responsible for the in vitro production 6(5H)-phenanthridinone metabolite as it is a major metabolite by mammalian aldehyde oxidase.Keywords: aldehyde oxidase, fish, phenanthridine, specificity
Procedia PDF Downloads 3642235 Seasonal Variation in 25(OH)D Concentration and Sprint Performance in Elite Athletes with a Spinal Cord Injury
Authors: Robert C. Pritchett, Elizabeth Broad, Kelly L. Pritchett
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Individuals a with spinal cord injuries have been suggested to be at risk for a 25(OH)D insufficiency. However, little is known regarding the relationship between seasonal Vitamin D status and performance in a spinally injured athletic population. Purpose: The purpose of this study was: 1) to examine the seasonal change in 25(OH)D concentrations and 2) to determine whether 25(OH)D status impacts athletic performance in US Paralympic athletes. Methods: 25 (OH)D concentrations were measured in 11 outdoor track athletes ( 5 men/6 females), between fall (October/November) and winter(February). Dietary intake and lifestyle habits were assessed via questionnaire, and performance measurements were assessed using a 20meter sprint test. 25(OH)D concentrations were assessed using a blood spot method (ZRT Laboratory). Results: There was no significant change in 25 (OH) D concentrations across seasons (P=0.505; 31 + 6.35 ng/mL, 29 + 8.72 ng/mL (mean + SD) for Fall and Winter, respectively. In the Fall,42% of the athletes had sufficient levels (>32ng/mL), and 58% were insufficient. (20ng/mL -31ng/mL) where as the winter levels dropped with 33% being sufficient and 58% being insufficient and 1% being deficient (<20ng/mL). There was a weak but significant correlation between a change in 25(OH)D concentrations, and change in 20m sprint time (p<0.05; r=0.408). Conclusion: A substantial proportion of elite athletes with an SCI have low vitamin D status. However, results suggest there was little seasonal variation in 25(OH)D status in elite track athletes with an SCI. Furthermore, any change that was observed demonstrated a very weak relationship with a change in performance.Keywords: 25(oh)d, performance, spinal cord injuries, elite, sprint, concentration
Procedia PDF Downloads 5542234 Effect of Number of Baffles on Pressure Drop and Heat Transfer in a Shell and Tube Heat Exchanger
Authors: A. Falavand Jozaei, A. Ghafouri, M. Mosavi Navaei
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In this paper for a given heat duty, study of number of baffles on pressure drop and heat transfer is considered in a STHX (Shell and Tube Heat Exchanger) with single segmental baffles. The effect of number of baffles from 9 to 52 baffles (baffle spacing variations from 4 to 24 inches) over OHTC (Overall Heat Hransfer Coefficient) to pressure drop ratio (U/Δp ratio). The results show that U/Δp ratio is low when baffle spacing is minimum (4 inches) because pressure drop is high; however, heat transfer coefficient is very significant. Then, with the increase of baffle spacing, pressure drop rapidly decreases and OHTC also decreases, but the decrease of OHTC is lower than pressure drop, so (U/Δp) ratio increases. After increasing baffles more than 12 inches, variation in pressure drop is gradual and approximately constant and OHTC decreases; Consequently, U/Δp ratio decreases again. If baffle spacing reaches to 24 inches, STHX will have minimum pressure drop, but OHTC decreases, so required heat transfer surface increases and U/Δp ratio decreases. After baffle spacing more than 12 inches, variation of shell side pressure drop is negligible. So optimum baffle spacing is suggested between 8 to 12 inches (43 to 63 percent of inside shell diameter) for a sufficient heat duty and low pressure drop.Keywords: shell and tube heat exchanger, single segmental baffle, overall heat transfer coefficient, pressure drop
Procedia PDF Downloads 5442233 Long-Term Monitoring and Seasonal Analysis of PM10-Bound Benzo(a)pyrene in the Ambient Air of Northwestern Hungary
Authors: Zs. Csanádi, A. Szabó Nagy, J. Szabó, J. Erdős
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Atmospheric aerosols have several important environmental impacts and health effects in point of air quality. Monitoring the PM10-bound polycyclic aromatic hydrocarbons (PAHs) could have important environmental significance and health protection aspects. Benzo(a)pyrene (BaP) is the most relevant indicator of these PAH compounds. In Hungary, the Hungarian Air Quality Network provides air quality monitoring data for several air pollutants including BaP, but these data show only the annual mean concentrations and maximum values. Seasonal variation of BaP concentrations comparing the heating and non-heating periods could have important role and difference as well. For this reason, the main objective of this study was to assess the annual concentration and seasonal variation of BaP associated with PM10 in the ambient air of Northwestern Hungary seven different sampling sites (six urban and one rural) in the sampling period of 2008–2013. A total of 1475 PM10 aerosol samples were collected in the different sampling sites and analyzed for BaP by gas chromatography method. The BaP concentrations ranged from undetected to 8 ng/m3 with the mean value range of 0.50-0.96 ng/m3 referring to all sampling sites. Relatively higher concentrations of BaP were detected in samples collected in each sampling site in the heating seasons compared with non-heating periods. The annual mean BaP concentrations were comparable with the published data of the other Hungarian sites.Keywords: air quality, benzo(a)pyrene, PAHs, polycyclic aromatic hydrocarbons
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