Search results for: plant science

Authors: Arūnas Gudinavičius, Andrius Šuminas

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The analysis of scholarly journals formats is fragmented and needs to be studied from a point of view of scientific communication. While PDF is to the author’s best knowledge probably the most popular digital format of XXI century, but there are more formats available: HTML, EPUB, etc. Our aim is to analyze how these formats important to the readers and what is their contribution to scientific communication. We want to investigate how printed journals are still popular between scholars and does different formats are preferred between fields of science . In most cases, publishing of scientific journals are examined from a narrow perspective of a particular university science affair administrators or research funding institution. We believe that more data o n formats used in scholarly periodicals currently published in Lithuania as well as in Eastern Europe are needed. Science communication is often analyzed as a directed chain of information in the author-publisher-reader cycle. The paper is focusing on the publishing part of this chain. A distinction is made between formal and informal forms of scientific communication, which is relevant in today's context, when both forms of communication intertwine and complement each other. In our research, we will analyze formal documentary (formats of publication of scientific articles) communication - scientific information recorded in a certain medium and formatted in certain format (printed, PDF, HTML, EPUB, etc.). In our research, we will analyze the stage of publication of research results in scientific journals and their dissemination through specific publication formats. The paper is to systematize and analyze the various types of formats of scientific journal published in XXI century in Lithuania (small publishing market). The research analyses the case of small European country and presents publishing formats characteristics of the publication of scientific periodicals.

Keywords: scientific communication, scientific journals, publishing formats, reading

Procedia PDF Downloads 92

Authors: Talal S. Abdullah, Shahin Mehraban, Geraint Lodwig, Nicholas P. Lavery

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The defining property of Interstitial Free (IF) steels is formability, comprehensively measured using the Lankford coefficient (r-value) on uniaxial tensile test data. The contributing factors supporting this feature are grain size, orientation, and elemental additions. The processes that effectively modulate these factors are the casting procedure, hot rolling, and heat treatment. An existing methodology is well-practised in the steel Industry; however, large-scale production and experimentation consume significant proportions of time, money, and material. Introducing small-scale rapid alloy prototyping (RAP) as an alternative process would considerably reduce the drawbacks relative to standard practices. The aim is to finetune the existing fundamental procedures implemented in the industrial plant to adapt to the RAP route. IF material is remelted in the 80-gram coil induction melting (CIM) glovebox. To birth small grains, maximum deformation must be induced onto the cast material during the hot rolling process. The rolled strip must then satisfy the polycrystalline behaviour of the bulk material by displaying a resemblance in microstructure, hardness, and formability to that of the literature and actual plant steel. A successful outcome of this work is that small-scale RAP can achieve target compositions with similar microstructures and statistically consistent mechanical properties which complements and accelerates the development of novel steel grades.

Keywords: rapid alloy prototyping, plastic anisotropy, interstitial free, miniaturised tensile testing, formability

Procedia PDF Downloads 109

Authors: Jafar Ahmadi, Zhohreh Asiaban, Sedigheh Fabriki Ourang

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Brassinosteroids (BRs) regulate cell elongation, vascular differentiation, senescence and stress responses. BRs signal through the BES1/BZR1 family of transcription factors, which regulate hundreds of target genes involved in this pathway. In this research a comprehensive genome-wide analysis was carried out in BES1/BZR1 gene family in Arabidopsis thaliana, Cucumis sativus, Vitis vinifera, Glycin max, and Brachypodium distachyon. Specifications of the desired sequences, dot plot and hydropathy plot were analyzed in the protein and genome sequences of five plant species. The maximum amino acid length was attributed to protein sequence Brdic3g with 374aa and the minimum amino acid length was attributed to protein sequence Gm7g with 163aa. The maximum Instability index was attributed to protein sequence AT1G19350 equal with 79.99 and the minimum Instability index was attributed to protein sequence Gm5g equal with 33.22. Aliphatic index of these protein sequences ranged from 47.82 to 78.79 in Arabidopsis thaliana, 49.91 to 57.50 in Vitis vinifera, 55.09 to 82.43 in Glycin max, 54.09 to 54.28 in Brachypodium distachyon 55.36 to 56.83 in Cucumis sativus. Overall, data obtained from our investigation contributes a better understanding of the complexity of the BES1/BZR1 gene family and provides the first step towards directing future experimental designs to perform systematic analysis of the functions of the BES1/BZR1 gene family.

Keywords: BES1/BZR1, brassinosteroids, phylogenetic analysis, transcription factor

Procedia PDF Downloads 334

Authors: Muccifora S., Rinallo C., Bellani L.

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Calcium (Ca²+) is an element essential to the plant being involved in plant growth and development. At high concentrations, it is toxic and can influence every stage, process and cellular activity of plant life. Given its toxicity, cells implement mechanisms to compartmentalize calcium in a vacuole, endoplasmic reticulum, mitochondria, plastids and cell wall. One of the most effective mechanisms to reduce the excess of calcium, thus avoiding cellular damage, is its complexation with oxalic acid to form calcium oxalate crystals that are no longer osmotically or physiologically active. However, the sequestered calcium can be mobilized when the plant needs it. Calcium crystals can be accumulated in the vacuole of specialized sink-cells called idioblasts, with different crystalline forms (druse, raphyde and styloid) of diverse physiological meanings. Actinidia deliciosa cv. Hayward presents raphydes and styloid localized in idioblasts in cells of photosynthetic and non-photosynthetic tissues. The purpose of this work was to understand if there is a relationship between the age of Actinidia leaves and the presence, distribution, dimension and shape of oxalate crystals by means of light, fluorescent, polarized and transmission electron microscopy. Three vines from female plants were chosen at the beginning of the season and used throughout the study. The leaves with petioles were collected at various stages of development from the bottom to the shoot of the plants monthly from April to July. The samples were taken in corresponding areas of the central and lateral parts of the leaves and of the basal portion of the petiole. The results showed that in the leaves, the number of raphyde idioblasts decreased with the progress of the growing season, while the styloid idioblasts increased progressively, becoming very numerous in the upper nodes of July. In June and in July samples, in the vacuoles of the highest nodes, a portion regular in shape strongly stained with rubeanic acid was present. Moreover, the chlortetracycline (CTC) staining for localization of free calcium marked the wall of the idioblasts and the wall of the cells near vascular bundles. In April petiole samples, moving towards the youngest nodes, the raphydes idioblast decreased in number and in the length of the single raphydes. Besides, crystals stained with rubeanic acid appeared in the vacuoles of some cells. In June samples, numerous raphyde idioblasts oriented parallel to vascular bundles were evident. Under the electron microscope, numerous idioblasts presented not homogeneous electrondense aggregates of material, in which a few crystals (styloids) in the form of regular holes were scattered. In July samples, an increase in the number of styloid idioblasts in the youngest nodes and little masses stained with CTC near styloids were observed. Peculiar cells stained with rubeanic acid were detected and hypothesized to be involved in the formation of the idioblasts. In conclusion, in Actinidia leaves and petioles, it seems to confirm the hypothesis that the formation of styloid idioblasts can be correlated to increasing calcium levels in growing tissues.

Keywords: calcium oxalate crystals, actinidia deliciosa, light and electron microscopy, idioblasts

Procedia PDF Downloads 80

Authors: Thangavelu Muthukumar, Thotapalli Parvathaleswara Sastry

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Collagen is the most abundantly available connective tissue protein, which is being used as a biomaterial for various biomedical applications. Presently, fish wastes are disposed improperly which is causing serious environmental pollution resulting in offensive odour. Fish scales are promising source of Type I collagen. Medicinal plants have been used since time immemorial for treatment of various ailments of skin and dermatological disorders especially cuts, wounds, and burns. Developing biomaterials from the natural sources which are having wound healing properties within the search of a common man is the need of hour, particularly in developing and third world countries. With these objectives in view we have developed a wound dressing material containing fish scale collagen (FSC) incorporated with Macrotyloma uniflorum plant extract (PE). The wound dressing composite was characterized for its physiochemical properties using conventional methods. SEM image revealed that the composite has fibrous and porous surface which helps in transportation of oxygen as well as absorbing wound fluids. The biomaterial has shown 95% biocompatibility with required mechanical strength and has exhibited antimicrobial properties. This biomaterial has been used as a wound dressing material in experimental wounds of rats. The healing pattern was evaluated by macroscopic observations, panimetric studies, biochemical, histopathological observations. The results showed faster healing pattern in the wounds treated with CSPE compared to the other composites used in this study and untreated control. These experiments clearly suggest that CSPE can be used as wound/burn dressing materials.

Keywords: collagen, wound dressing, Macrotyloma uniflorum, burn dressing

Procedia PDF Downloads 412

Authors: Mustapha Saidu, Bilyaminu Mohammed

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The study was conducted in Udubo Grazing Reserve between July 2019 and October 2019 to assess forage utilization for pasture-based livestock production in reserve. The grazing land was cross-divided into grids, where 15 coordinates were selected as the sample points. Grids of one-kilometer interval were made. The grids were systematically selected 1 grid after 7 grids. 1 × 1-meter quadrat was made at the coordinate of the selected grids for measurement, estimation, and sample collection. The results of the study indicated that Zornia glochidiatah has the highest percent of species composition (42%), while Mitracarpus hirtus has the lowest percent (0.1%). Urochloa mosambicensis has 48 percent of height removed and 27 percent used by weight, Zornia glochidiata 60 percent of height removed and 57 percent used by weight, Alysicapus veginalis has 55 percent of height removed, and 40 percent used by weight, and Cenchrus biflorus has 40 percent of height removed and 28 percent used by weight. The target is 50 percent utilization of forage by weight during a grazing period as well as at the end of the grazing season. The study found that Orochloa mosambicensis, Alysicarpus veginalis, and Cenchrus biflorus had lower percent by weight which is normal, while Zornia glochidiata had a higher percent by weight which is an indication of danger. The study recommends that the identification of key plant species in pasture and rangeland is critical to implementing a successful grazing management plan. There should be collective action and promotion of historically generated grazing knowledge through public and private advocacies.

Keywords: forage, grazing reserve, live stock, pasture, plant species

Procedia PDF Downloads 84

Authors: Mohammad Abdollahi

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Tomato (Lycopersicon esculentum Mill.) is one of the most popular, widely grown and the second most important vegetable crop, after potatoes. Nematodes have been identified as one of the major pests affecting tomato production throughout the world. The most destructive nematodes are the genus Meloidogyne. Most widespread and devastating species of this genus are M. incognita, M. javanica, and M. arenaria. These species can cause complete crop loss under adverse growing conditions. There are several potential methods for management of the root knot nematodes. Although the chemicals are widely used against the phytonematodes, because of hazardous effects of these compounds on non-target organisms and on the environment, there is a need to develop other control strategies. Nowadays, non-chemical measures are widely used to control the plant parasitic nematodes. Biocontrol of phytonematodes is an important method among environment-friendly measures of nematode management. There are some soil-inhabiting fungi that have biocontrol potential on phytonematodes, which can be used in nematode management program. The fungus Metarhizium anisopliae, originally is an entomopathogenic bioagent. Biocontrol potential of this fungus on some phytonematodes has been reported earlier. Recently, use of organic soil amendments as well as the use of bioagents is under special attention in sustainable agriculture. This research aimed to reduce the pesticide use in control of root-knot nematode, Meloidogyne javanica in tomato. The effects of M. anisopliae IMI 330189 and different levels of oak tree debris on M. javanica were determined. The combination effect of the fungus as well as the different rates of soil amendments was determined. Pots were filled with steam pasteurized soil mixture and the six leaf tomato seedlings were inoculated with 3000 second stage larvae of M. javanica/kg of soil. After eight weeks, plant growth parameters and nematode reproduction factors were compared. Based on the results of our experiment, combination of M. anisopliae IMI 330189 and oak debris caused more than 90% reduction in reproduction factor of nematode, at the rates of 100 and 150 g/kg soil (P ≤ 0.05). As compared to control, the reduction in number of galls was 76%. It was 86% for nematode reproduction factor, showing the significance of combined effect of both tested agents. Our results showed that plant debris can increase the biological activity of the tested bioagent. It was also proved that there was no adverse effect of oak debris, which potentially has antimicrobial activity, on antagonistic power of applied bioagent.

Keywords: biological control, nematode management, organic soil, Quercus branti, root knot nematode, soil amendment

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Authors: O. U. Nwosu, C. O. Osuagwu, N. Nnawugwu, C. T. Amanze

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Phytoremediation is a green and sustainable approach to decontaminate and restore contaminated sites while maintaining the biological activity and physical structure of soils. A pot experiment was conducted for a period of 70 days to evaluate the remediation potentials of Vetiveira zizanioides, Heianthus annuus L., Zea mays, and Glycine max in concurrent removal of anthracene and Pb in co-contaminated soil. Sandy loam soils were polluted with Pb chloride salt and anthracene at three different levels (50mg/kg of Pb, 100mg/kg of Pb, and 100mg/kg of Pb+100mg/kg of anthracene) and laid out in a completely randomized design with three replicates. Shoot dry matter weight was significantly reduced (p≤0.05) in comparison to control treatments by 33%, 32%, 40%, and 6.7% when exposed to 100mg kg⁻¹ of Pb, respectively in G.max, H.annuus, Z.mays, and vetiver. There was 42%, 41%, 48%, and 7.1% growth inhibition of shoot dry matter weight of G.max, H.annuus, Z.mays, and vetiver relative to control treatments when 100 mg Pb kg⁻¹ was mixed with 100 mgkg⁻¹ anthracene. Root and shoot metal concentration in G.max, H.annuus, Z.mays, and vetiver increased with increasing concentration of Pb. Translocation factor (TF < 1) obtained for G.max, Z.mays, and vetiver suggests that these plant species predominantly retain Pb in the root portion, while the TF value (TF≥1) obtained for H.annuus suggests that it predominantly retains Pb in the shoot portion. The extractable anthracene decreased significantly (p ≤ 0.05) in soil planted with G.max, H.annuus, Z.mays, and vetiver, as well as in pots without plants. This accounted for 53% to 71% of anthracene dissipation in planted soil and 40% dissipation in unplanted soil. This result suggested that the plant species used are a promising candidate for phytoremediation.

Keywords: phytoremediation, heavy metals, polyaromatic hydrocarbon, co-contaminated soil

Procedia PDF Downloads 116

Authors: Pawitchaya Srijaiwong, Surin Khomfoi

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There are several solutions to supply electricity to an island in Thailand such as diesel generation, submarine power cable, and renewable energy power generation. However, each alternative has its own limitation like fuel and pollution of diesel generation, submarine power cable length resulting in loss of cable and cost of investment, and potential of renewable energy in the local area. This paper shows microgrid system which is a new alternative for power supply to an island. It integrates local power plant from renewable energy, energy storage system, and microgrid controller. The suitable renewable energy power generation on an island is selected from geographic location and potential evaluation. Thus, photovoltaic system and hydro power plant are taken into account. The capacity of energy storage system is also estimated by transient stability study in order to supply electricity demand sufficiently under normal condition. Microgrid controller plays an important role in conducting, communicating and operating for both sources and loads on an island so that its functions are discussed in this study. The conceptual design of microgrid operation is investigated in order to analyze the reliability and power quality. The result of this study shows that microgrid is able to operate in parallel with the main grid and in case of islanding. It is applicable for electricity supply to an island and a remote area. The advantages of operating microgrid on an island include the technical aspect like improving reliability and quality of power system and social aspects like outage cost saving and CO₂ reduction.

Keywords: energy storage, islanding, microgrid, renewable energy

Procedia PDF Downloads 323

Authors: Achirawatt Tungsombatsanti, Toansakul Santiboon, Kamon Ponkham

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Strategies of the STEM education was aimed to prepare of an interdisciplinary and applied approach for the instructional of science, technology, engineering, and mathematics in an integrated students for enhancing engagement of their science skills to the Problem-Based Learning (PBL) method in Borabu School with a sample consists of 80 students in 2 classes at the 12th grade level of their learning achievements on electromagnetic issue. Research administrations were to separate on two different instructional model groups, the 40-experimental group was designed with the STEM instructional experimenting preparation and induction in a 40-student class and the controlling group using the PBL was designed to students identify what they already know, what they need to know, and how and where to access new information that may lead to the resolution of the problem in other class. The learning environment perceptions were obtained using the 35-item Physics Laboratory Environment Inventory (PLEI). Students’ creating attitude skills’ sustainable development toward physics were assessed with the Test Of Physics-Related Attitude (TOPRA) The term scaling was applied to the attempts to measure the attitude objectively with the TOPRA was used to assess students’ perceptions of their science attitude toward physics. Comparisons between pretest and posttest techniques were assessed students’ learning achievements on each their outcomes from each instructional model, differently. The results of these findings revealed that the efficiency of the PLB and the STEM based on criteria indicate that are higher than the standard level of the 80/80. Statistically, significant of students’ learning achievements to their later outcomes on the controlling and experimental physics class groups with the PLB and the STEM instructional designs were differentiated between groups at the .05 level, evidently. Comparisons between the averages mean scores of students’ responses to their instructional activities in the STEM education method are higher than the average mean scores of the PLB model. Associations between students’ perceptions of their physics classes to their attitudes toward physics, the predictive efficiency R2 values indicate that 77%, and 83% of the variances in students’ attitudes for the PLEI and the TOPRA in physics environment classes were attributable to their perceptions of their physics PLB and the STEM instructional design classes, consequently. An important of these findings was contributed to student understanding of scientific concepts, attitudes, and skills as evidence with STEM instructional ought to higher responding than PBL educational teaching. Statistically significant between students’ learning achievements were differentiated of pre and post assessments which overall on two instructional models.

Keywords: learning instructional managements, problem-based learning, STEM education, method, enhancement, students learning achievements, science attitude, physics classes

Procedia PDF Downloads 224

Authors: E. Kayitesi, S. Moyo, V. Mavumengwana

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Cleome gynandra (spider plant) is an African green leafy vegetable categorized as an indigenous, underutilized and has been reported to contain essential phenolic compounds. Phenolic compounds play a significant role in human diets due to their proposed health benefits. These compounds however may be affected by different processing methods such as cooking and drying. Cleome gynandra was subjected to boiling, steam blanching, and drying processes and analysed for Total Phenolic Content (TPC), Total Flavonoid Content (TFC), antioxidant activity and flavonoid composition. Cooking and drying significantly (p < 0.05) increased the levels of phenolic compounds and antioxidant activity of the vegetable. The boiled sample filtrate exhibited the lowest TPC followed by the raw sample while the steamed sample depicted the highest TPC levels. Antioxidant activity results showed that steamed sample showed the highest DPPH, FRAP and ABTS with mean values of 499.38 ± 2.44, 578.68 ± 5.19, and 214.39 ± 12.33 μM Trolox Equivalent/g respectively. An increase in quercetin-3-rutinoside, quercetin-rhamnoside and kaempferol-3-rutinoside occurred after all the cooking and drying methods employed. Cooking and drying exerted positive effects on the vegetable’s phenolic content, antioxidant activity as a whole, but with varied effects on the individual flavonoid molecules. The results obtained help in defining the importance of African green leafy vegetable and resultant processed products as functional foods and their potential to exert health promoting properties.

Keywords: Cleome gynandra, phenolic compounds, cooking, drying, health promoting properties

Procedia PDF Downloads 162

Authors: Laura Rodriguez Amaya

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Advances in science, technology, engineering, and mathematics (STEM) are viewed as important to countries’ national economies and their capacities to be competitive in the global economy. However, many countries experience low numbers of students entering these disciplines. To strengthen the professional STEM pipelines, it is important that students are retained in these disciplines at universities. Scholars agree that to retain students in universities’ STEM degrees, it is necessary that STEM course content shows the relevance of these academic fields to their daily lives. By increasing students’ understanding on the importance of these degrees and careers, students’ motivation to remain in these academic programs can also increase. An effective way to make STEM content relevant to students’ lives is the use of geospatial technologies and geovisualization in the classroom. The Geospatial Revolution, and the science and technology associated with it, has provided scientists and engineers with an incredible amount of data about Earth and Earth systems. This data can be used in the classroom to support instruction and make content relevant to all students. The purpose of this study was to find out the prevalence use of geospatial technologies and geovisualization as teaching practices in a USA university. The Teaching Practices Inventory survey, which is a modified version of the Carl Wieman Science Education Initiative Teaching Practices Inventory, was selected for the study. Faculty in the STEM disciplines that participated in a summer learning institute at a 4-year university in the USA constituted the population selected for the study. One of the summer learning institute’s main purpose was to have an impact on the teaching of STEM courses, particularly the teaching of gateway courses taken by many STEM majors. The sample population for the study is 97.5 of the total number of summer learning institute participants. Basic descriptive statistics through the Statistical Package for the Social Sciences (SPSS) were performed to find out: 1) The percentage of faculty using geospatial technologies and geovisualization; 2) Did the faculty associated department impact their use of geospatial tools?; and 3) Did the number of years in a teaching capacity impact their use of geospatial tools? Findings indicate that only 10 percent of respondents had used geospatial technologies, and 18 percent had used geospatial visualization. In addition, the use of geovisualization among faculty of different disciplines was broader than the use of geospatial technologies. The use of geospatial technologies concentrated in the engineering departments. Data seems to indicate the lack of incorporation of geospatial tools in STEM education. The use of geospatial tools is an effective way to engage students in deep STEM learning. Future research should look at the effect on student learning and retention in science and engineering programs when geospatial tools are used.

Keywords: engineering education, geospatial technology, geovisualization, STEM

Procedia PDF Downloads 249

Authors: Anna Keuchenius

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Broadly speaking, scientific development is studied in either a qualitative manner with a focus on the behavior and interpretations of academics, such as the sociology of science and science studies or in a quantitative manner with a focus on the analysis of publications, such as scientometrics and bibliometrics. Both come with a different set of methodologies and few cross-references. This paper contributes to the bridging of this divide, by on the on hand approaching the process of scientific progress from a qualitative sociological angle and using on the other hand quantitative and computational techniques. As a case study, we analyze the diffusion of Granovetter's hypothesis from his 1973 paper 'On The Strength of Weak Ties.' A network is constructed of all scientists that have referenced this particular paper, with directed edges to all other researchers that are concurrently referenced with Granovetter's 1973 paper. Studying the structure and growth of this network over time, it is found that Granovetter's hypothesis is used by distinct communities of scientists, each with their own key-narrative into which the hypothesis is fit. The diffusion within the communities shares similarities with the diffusion of an innovation in which innovators, early adopters, and an early-late majority can clearly be distinguished. Furthermore, the network structure shows that each community is clustered around one or few hub scientists that are disproportionately often referenced and seem largely responsible for carrying the hypothesis into their scientific subfield. The larger implication of this case study is that the diffusion of scientific hypotheses and ideas are not the spreading of well-defined objects over a network. Rather, the diffusion is a process in which the object itself dynamically changes in concurrence with its spread. Therefore it is argued that the methodology presented in this paper has potential beyond the scientific domain, in the study of diffusion of other not well-defined objects, such as opinions, behavior, and ideas.

Keywords: diffusion of innovations, network analysis, scientific development, sociology of science

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Authors: Piyush V. Surjagade, Jiamei Deng, Paul Doney, S. R. Shimjith, A. John Arul

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In sophisticated and complex systems such as nuclear power plants, maintaining the system's stability in the presence of uncertainties and disturbances and obtaining a fast dynamic response are the most challenging problems. Thus, to ensure the satisfactory and safe operation of nuclear power plants, this work proposes a new fast, robust optimal switching control strategy for pressurized water reactor-type nuclear power plants. The proposed control strategy guarantees a substantial degree of robustness, fast dynamic response over the entire operational envelope, and optimal performance during the nominal operation of the plant. To improve the robustness, obtain a fast dynamic response, and make the system optimal, a bank of controllers is designed. Various controllers, like a baseline proportional-integral-derivative controller, an optimal linear quadratic Gaussian controller, and a robust adaptive L1 controller, are designed to perform distinct tasks in a specific situation. At any instant of time, the most suitable controller from the bank of controllers is selected using the switching logic unit that designates the controller by monitoring the health of the nuclear power plant or transients. The proposed switching control strategy optimizes the overall performance and increases operational safety and efficiency. Simulation studies have been performed considering various uncertainties and disturbances that demonstrate the applicability and effectiveness of the proposed switching control strategy over some conventional control techniques.

Keywords: switching control, robust control, optimal control, nuclear power control

Procedia PDF Downloads 127

Authors: I. Hilia, C. Hange, F. Hakala, M. Matheus, C. Jansen, J. Hidinwa, O. Awofolu

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The article reports on the occurrences, level, and mobility of selected trace metals in environmental samples. The conceptual basis was to examine the possible influence of anthropogenic activities and the impact on human and environmental health. Environmental samples (soil, plant and lower animal) were randomly collected from stratified study/sampling areas, preserved and pre-treated before analysis. Mineral acid digestion procedure was employed for the isolation of metallic contents in samples, and elemental qualitative and quantitative analysis was by ICP-OES. Analytical protocol was validated through the quality assurance process and was found acceptable with quantitative metallic recoveries in the range of 85-90%; hence considered applicable for the analyses of environmental samples. The mean concentration of analysed metals in soil samples ranged from 53.2- 2532.8 mg/kg (Cu); 59.5- 2020.1 mg/kg (Zn); 1.80 – 21.26 mg/kg (Cd) and 19.6- 140.9 mg/kg (Pb). The mean level in grass samples ranged from 9.33 – 38.63 mg/kg (Cu); 64.20-105.18 mg/kg (Zn); 0.28–0.73 mg/kg (Cd) and 0.53 -16.26 mg/kg (Pb) while the mean level in lower animal sample (beetle) varied from 9.6 - 105.3 mg/kg (Cu); 134.1-297.2 mg/kg (Zn); 0.63 – 3.78 (Cd) and 8.0 – 29.1 mg/kg (Pb) across sample collection points (SCPs) 1-4 respectively. Metallic transfer factors (TFs) were in the order Zn >Cd > Cu > Pb with metal Pollution Indices (MPIs) in the order SCP1 > SCP2 > SCP3 > SCP4. About 60-70 % of analysed metals were above the maximum allowable limits (MALs) in soil and plant samples. Results obtained revealed the general prevalence of analysed metals at all sampled sites with indication of metallic mobility across the food chain which portrayed dire consequences for environmental and human health. Systematic environmental remediation and pollution abatement strategies are recommended.

Keywords: trace metals, pollution, human health, Incidences, ICP-OES

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Authors: Oloruntoba Kayode, Mohd Hisyam Rasidi, Ismail Said

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This study investigates the influence of public space in developing social cohesion among residents in science cities. The study takes into consideration the need for social cohesion in knowledge-based development and focuses on Cyberjaya Malaysia being a science city that is characterized by public spaces. As such, we adopted validated measuring tools for this study we developed a theoretical framework that links public space utilization with people's social cohesion. A total of 211 survey questions were administered by the residents in the study area on public space utilization and their social cohesion potentials. The research framework was validated to confirm its fit using structural equation modeling (SEM). The findings indicated that the observed public space utilization variables significantly influenced people's social cohesion, while group social ties have a positive influence on their collective minds.

Keywords: public space, social cohesion, knowledge-based development, theoretical framework

Procedia PDF Downloads 40

Authors: J. Y. Ijato, A. Adewumi, H. O Yakubu, O. O. Olajide, B. O. Ojo, B. A. Adanikin

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Post-harvest fruit rot pathogens are one of the major factors that are responsible for food security challenges in developing countries like Nigeria. These pathogens also cause fruit food poisoning. Biocidal effects of ethanolic extracts of Khaya grandifoliola, Hyptis suaveolens, Zingiber officinale, Calophyllum inophyllum, Datura stramonium on the mycelia growth of fungal rot pathogens of pineapple fruit was investigated, the ethanolic extracts of these test plants exhibited high significant inhibitory effects on the rot pathogens, the highest ethanolic extract inhibition of Zingiber officinale was on Aspergillus flavus (38.40%) at 1.0g/ml while the least inhibitory effect was on Aspergillus fumigatus (23.10%) at 1.0g/ml, the highest ethanol extract inhibition of Datura stramonium was on Aspergillus tubingensis (24.00%) at 1.0g/ml while the least inhibitory effect was 10.00% on Colletotrichum fruticola at 1.0g/ml, the highest ethanol extract inhibition of Calophyllum inophyllum was on Trichoderma harzianum (18.50%) at 1.0g/ml while the least inhibitory effect was on Aspergillus flavus (15.00%) at 1.0g/ml, the highest ethanol extract inhibition of Hyptis suaveolens was on Aspergillus fumigatus (35.00%) at 1.0g/ml while the least inhibitory effect was on Aspergillus niger (20.00%) at 1.0g/ml, the highest ethanol extract inhibition of Khaya grandifoliola was on Aspergillus flavus (35.00%) at 1.00g/ml while the least inhibitory effect was on Aspergillus fumigates (22.00%) at 1.0g/ml, the antifungal capacity of these test plant extracts on rot causing fungi on pineapple fruit reveals the possibility of their use by farmers and fruit traders as alternative to chemical fungicide that portends great threat to human and environmental health.

Keywords: fruit rot, pathogens, plant extracts, pineapple, food poisoning

Procedia PDF Downloads 104

Authors: Habab Ahmed Hassan Abuzeid

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Organizations are social systems. If one wishes to work in them or to manage them, it is necessary to understand how they operate. Organizations combine science and people–technology and humanity. Unless we have qualified people to design and implement, techniques alone will not produce desirable results. Human behavior in organizations is rather unpredictable. It is unpredictable because it arises from people’s deep-seated needs and value systems. However, it can be partially understood in terms of the framework of behavioral science, management and other disciplines. There is no idealistic solution to organizational problems. All that can be done is to increase our understanding and skills so that human relations at work can be enhanced. In this paper, we consider management of organization behavior utilizing human resources. Study the elements of organization behavior, the effectiveness of mechanism to enhance staff relationships. Many approaches could be applied for healthy organizational environment, it’s highlighted more details in this paper. Organization behavior can raise the employees’ engagement, loyalty and commitment; to accomplish the goal.

Keywords: environment, engagement, human resources, organization behavior

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Authors: Eszter J. Tóth, Alexandra Hoffmann, Csaba Vágvölgyi, Tamás Papp

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Members of the genera Curvularia and Bipolaris are closely related melanin producing filamentous fungi; both of them have the teleomorph states in genus Cochliobolus. While Bipolaris species infect only plants and may cause serious agriculture damages, some Curvularia species was recovered from opportunistic human infections. The human pathogenic species typically cause phaeohyphomycoses, i.e. mould infections caused by melanised fungi, which can manifest as invasive mycoses with frequent involvement of the central nervous system in immunocompromised patients or as local infections (e.g. keratitis, sinusitis, and cutaneous lesions) in immunocompetent people. Although their plant-fungal interactions have been intensively studied, there is only little information available about the human pathogenic feature of these fungi. The aim of this study was to investigate the neutrophil granulocytes’ response to hyphal forms of Curvularia and Bipolaris in comparison with the response to Aspergillus. In the present study Curvularia lunata SZMC 23759 and Aspergillus fumigatus SZMC 23245 both isolated from human eye infection, and Bipolaris zeicola BRIP 19582b isolated from plant leaf were examined. Neutrophils were isolated from heparinised venous blood of healthy donors with dextran sedimentation followed by centrifugation over Ficoll and hypotonic lysis of erythrocytes. Viability and purity of the cells were checked with trypan blue and Wright staining, respectively. Infection of neutrophils was carried out with germinated conidia in a ratio of 5:1. Production of hydrogen peroxide, superoxide anion, and nitrogen monoxide was measured both intracellularly and extracellularly in response to the germinated spores with or without the supernatant and after serum treatment. ROS and NOS production of neutrophils in interaction with the three fungi were compared. It is already known that Aspergillus species induce ROS production of neutrophils only after serum treatment. Although, in case of C. lunata, serum opsonisation also induced an intensive production of reactive species, lower level of production was measured in the lack of serum as well. After interaction with the plant pathogenic B. zeicola, amount of reactive species found to be similar with and without serum treatment. The presence of germination supernatant decreased the reactive species production in case of each fungus. Interaction with Curvularia, Bipolaris and Aspergillus species induced different response of neutrophils. It seems that recognition of C. lunata and B. zeicola is independent of serum opsonisation, albeit it increases the level of the produced reactive species in response for C. lunata. The study was supported by the grant LP2016-8/2016.

Keywords: Curvularia, neutrophils, NOS, ROS, serum opsonisation

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Authors: S. Vijayakumar, S. B. Rathna Kumar, Navnath D Jagadale

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Learning and teaching are the challenges ahead in the education of the students with hearing impairment using sign language (SHISL). Either the students or teachers face difficulties in the process of learning/teaching. Communication is one of the main barriers while teaching SHISL. Further, the courses of study or the subjects are limited to SHISL at least in countries like India. Students with hearing impairment mainly opt for sign language as a communication mode. Subjects like physics, chemistry, advanced mathematics etc. are not available in the curriculum for the SHISL since their content and ideas are complex. In India, exemption for language papers is being given for the students with hearing impairment. It may give opportunity to them to secure secondary/ higher secondary qualifications. It is a known fact that students with hearing impairment are facing difficulty in their future carrier. They secure neither a higher study nor a good employment opportunity. Vocational training in various trades will land them in few jobs with few bucks in pocket. However, not all of them are blessed with higher positions in government or private sectors in competitive fields or where the technical knowledge is required. E learning with sign language instructions can be used for teaching languages and science subjects. Computer Based Instruction (CBI), Computer Based Training (CBT), and Computer Assisted Instruction (CAI) are now part-and-parcel of Modern Education. It will also include signed video clip corresponding to the topic. Learning language subjects will improve the understanding of concepts in different subjects. Learning other science subjects like their hearing counterparts will enable the SHISL to go higher in studies and increase their height to pluck a fruit of the tree of employment.

Keywords: students with hearing impairment using sign language, hearing impairment, language subjects, science subjects, e-learning

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Authors: Aina Barcelona, Carolyn Oldham, Jordi Colomer, Teresa Serra

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The loss of seagrass meadows worldwide is being tackled by formulating coastal restoration strategies. Seagrass loss results in a network of vegetated patches which are barely interconnected, and consequently, the ecological services they provide may be highly compromised. Hence, there is a need to optimize coastal management efforts in order to implement successful restoration strategies, not only through modifying the architecture of the canopies but also by gathering together information on the hydrodynamic conditions of the seabeds. To obtain information on the hydrodynamics within the patches of vegetation, this study deals with the scale analysis of the minimum lengths of patch management strategies that can be effectively used on. To this aim, a set of laboratory experiments were conducted in a laboratory flume where the plant densities, patch lengths, and hydrodynamic conditions were varied to discern the vegetated patch lengths that can provide optimal ecosystem services for canopy development. Two possible patch behaviours based on the turbulent kinetic energy (TKE) production were determined: one where plants do not interact with the flow and the other where plants interact with waves and produce TKE. Furthermore, this study determines the minimum patch lengths that can provide successful management restoration. A canopy will produce TKE, depending on its density, the length of the vegetated patch, and the wave velocities. Therefore, a vegetated patch will produce plant-wave interaction under high wave velocities when it presents large lengths and high canopy densities.

Keywords: seagrass, minimum patch size, turbulent kinetic energy, oscillatory flow

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Authors: P. G. S. Madushani, L. D. Illeperuma

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Abstract Noise is one of the most common physical hazards in industrial settings. The prevalence of Noise Induced Hearing Loss (NIHL) is on the rise with increasedduration of exposure and the increase in the severity of hearing loss. The purpose of the study was to determine auditory effects among textile workers and to establish associations between the degree of hearing loss and exposure duration, degree of hearing loss and noise level and the proportion of hearing related complaints. A cross sectional descriptive study using purposive sampling was carried out. An interviewer administered questionnaire and Distortion Product Oto Acoustic Emission (DPOAE) hearing screening on 127 (72 female and 55 male) textile workers of the selected textile plant in Seeduwa, Sri Lanka was done (Age: M= 31.16, SD=7.75). Noise measurements were done in six sections of the factory and average noise levels were obtained. Diagnostic hearing evaluations were done for 60 (57.75%) subjects, referred from the DPOAE hearing screening test. The degree of hearing loss and the exposure duration had a significant association in the high frequency region of 4 kHz to 8 kHz (p < 0.05). Noise levels fluctuated between 90.3±0.8 dBA and 50.6. ±0.52 dBA. 30.83% of workers reported having NIHL. Most of the workers (33.9%) complained difficulty in conversing in noisy backgrounds. Other complaints as tinnitus, dizziness, ear fullness and headache were reported in less than 30%. workers who were exposed to noise for more than 15 years were affected with NIHL in the high frequency region. Administrative controls and engineering controls need to be implemented to manage hazardous noise levels in industrial settings. Hearing Conservation Programs should be initiated and implemented for textile workers.

Keywords: textile industry, NIHL, degree of hearing loss, noise levels, auditory effects

Procedia PDF Downloads 139

Authors: Abdelouahab Dehimati, Fatiha Bedjou

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This study focused on the antioxidant and antimicrobial activity of four extracts from the plant Matricaria pubscens (Asteraceae) harvest in the region of Ghardaia, the northern Sahara of Algeria. The different extracts were analyzed for their content of phenolic compounds and their biological activities. The ethanol extract expresses a better extraction yield (44.22%). We have first performed the quantitative colorimetric methods for total polyphenols. Wherein the aqueous extract shows the highest total polyphenol content and total flavonoid (216.66±2.58 mg Eq GA/g and 111.04±0.49 mg Eq Q/g E, respectively) and ethanol extract 50% total tannins content (68.88±2.72 mg Eq AT/g E). The evaluation of the antioxidant activity of extracts of Matricaria pubscens by the arbitrary value IC50. The ethanol 50% extract is expressed strong activity with an IC50 14.19±1.25 mg/m against the DPPH radical and 11.66±0.53 mg/ml against the ABTS radical). In addition, the aqueous extract showed strong reducing power with an IC50 (48.61±1.14 mg/ml). However, the results obtained by the reducing power of phosphomolybdat the test are calculated by the iron maximum absorbance where ethanol extract 50% gives an absorbance of about 1.641 ± 0.01nm. Otherwise, methanol 70% and butanol 80% extracts gave a very large chelating effect of iron with an IC50 (38.38±0.01 μg/ml and 38.58±0.04 μg/ml respectively). By the method of disc Diffuson, the results of the antimicrobial activity are achieved butanolic extract 80% shows high activity towards MRSA (MIC: 3.51mg/ml; BMC>100 mg/ml). Their shares, the extracts were the most active for the antifungal test, the butanol 80% extract was the most active against A. niger (MIC: 12.5 mg/ml; FMC>100 mg/ml). These preliminary results could be used to justify the traditional use of this plant and their phenolic compounds could be exploited for therapeutic purposes, such as antioxidants and antimicrobial effects.

Keywords: Matricaria pubscens, phenolic compounds, antioxidant activity, antimicrobial activity, IC50, MIC

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Authors: Tatjana Kadifkova Panovska, Svetlana Kulevanova, Blagica Jovanova

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Biological systems possess the ability to neutralize the excess of reactive oxygen species (ROS) and to protect cells from destructive alterations. However, many pathological conditions (cardiovascular diseases, autoimmune disorders, cancer) are associated with inflammatory processes that generate an excessive amount of reactive oxygen species (ROS) that shift the balance between endogenous antioxidant systems and free oxygen radicals in favor of the latter, leading to oxidative stress. Therefore, an additional source of natural compounds with antioxidant properties that will reduce the amount of ROS in cells is much needed despite their broad utilization; many plant species remain largely unexplored. Therefore, the purpose of the present study is to investigate the antioxidant activity of twenty-five selected medicinal and aromatic plant species. The antioxidant activity of the ethanol extracts was evaluated with in vitro assays: 2,2’-diphenyl-1-pycryl-hydrazyl (DPPH), ferric reducing antioxidant power (FRAP), non-site-specific- (NSSOH) and site-specific hydroxyl radical-2-deoxy-D-ribose degradation (SSOH) assays. The Folin-Ciocalteu method and AlCl3 method were performed to determine total phenolic content (TPC) and total flavonoid content (TFC). All examined plant extracts manifested antioxidant activity to a different extent. Cinnamomum verum J.Presl bark and Ocimum basilicum L. Herba demonstrated strong radical scavenging activity and reducing power with the DPPH and FRAP assay, respectively. Additionally, significant hydroxyl scavenging potential and metal chelating properties were observed using the NSSOH and SSOH assays. Furthermore, significant variations were determined in the total polyphenolic content (TPC) and total flavonoid content (TFC), with Cinnamomum verum and Ocimum basilicum showing the highest amount of total polyphenols. The considerably strong radical scavenging activity, hydroxyl scavenging potential and reducing power for the species mentioned above suggest of a presence of highly bioactive phytochemical compounds, predominantly polyphenols. Since flavonoids are the most abundant group of polyphenols that possess a large number of available reactive OH groups in their structure, it is considered that they are the main contributors to the radical scavenging properties of the examined plant extracts. This observation is supported by the positive correlation between the radical scavenging activity and the total polyphenolic and flavonoid content obtained in the current research. The observations from the current research nominate Cinnamomum verum bark and Ocimum basilicum herba as potential sources of bioactive compounds that could be utilized as antioxidative additives in the food and pharmaceutical industries. Moreover, the present study will help the researchers as basic data for future research in exploiting the hidden potential of these important plants that have not been explored so far.

Keywords: ethanol extracts, radical scavenging activity, reducing power, total polyphenols.

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Authors: Batoul Mohamed Abdullatif, Nouf Ali Asiri

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O. basilicum plant was subjected to deficit irrigation using four treatments viz. control, irrigated with 70% of soil water capacity (SWC), Treatment 1, irrigated with 50% SWC, Treatment 2, irrigated with 30% SWC and Treatment 3, irrigated with 10 % SWC. Photosynthesis pigments viz. chlorophyll a, b, and the carotenoids, proline accumulation, and oil quantity were investigated under these irrigation treatments. The results indicate that photosynthesis pigments and oil content of deficit irrigation treatments did not significantly reduced than that of the full irrigation control. Photosynthesis pigments were affected by the stage of growth and not by irrigation treatments. They were high during flowering stage and low during seed formation stage for all treatments. The lowest irrigation plants (10 % SWC) achieved, during flowering stage, 0.72 mg\g\fresh weight of chlorophyll a, compared to 0.43 mg\g\fresh weight in control plant, 0.40 mg\g\fresh weight of chlorophyll b, compared to 0.19 mg\g\fresh weight in control plants and 0.29 mg\g\fresh weight of carotenoids, compared to 0.21 mg\g\fresh weight in control plants. It has been shown that reduced irrigation rates tend to enhance O. basilicum to have high oil quantity reaching a value of 63.37 % in a very low irrigation rate (10 % SWC) compared to 45.38 of control in seeds. Proline was shown to be accumulated in roots to almost double the amount in shoot during flowering stage in treatment 3. This accumulation seems to have a pronounce effect on O. basilicum acclimation to deficit irrigation.

Keywords: deficit irrigation, photosynthesis pigments, proline accumulation, oil quantity, sweet basil flowering formation, seed formation

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Authors: M. Afzal, Salem Safer Alghamdi, Awais Ahmad

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Limited amount of irrigation water is an alarming threat to arid and semiarid agriculture. However, genotypic response differences to water deficit conditions within species have been reported frequently. Present study was conducted in order to measure the genotypic differences among faba bean accessions under Regular Deficit Irrigation (RDI). Five seeds from each accession were sown in 135 silt filled pots (30 x 24 cm). Experiment was planned under split plot arrangement and replicated thrice. Treatments consisted of three RDI levels (100% (control), 60% and 40% of the field capacity) and fifteen faba bean accessions (two local accessions as reference while thirteen from different sources around the world). Irrigation treatment was started from the very first day of sowing. Plant height, shoot dry weight, stomatal conductance and total chlorophyll contents (SPAD reading) were measured one month after germination. Irrigation, faba bean accessions and the all possible interactions has stood significantly high for all studied parameters. Regular deficient irrigation has hampered the plant growth and associated parameters in decreasing order (100% < 60% < 40%). Accessions have responded differently under regular deficient irrigation and some of them are even better than local accession. A highly significant correlation among all parameters has also been observed. It was concluded from results that above parameters could be used as markers to identify the genotypic differences for water deficit stress response. This outcome encouraged the use of superior faba bean genotypes in breeding programs for improved varieties to enhance water use efficiency under stress conditions.

Keywords: accessions, stomatal conductance, total chlorophyll contents, RDI, regular deficient irrigation

Procedia PDF Downloads 289

Authors: Benselama Amel, Ounane S. Mohamed, Bekki Abdelkader

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A collection of 20 isolates from fresh Nodules of the legume plant Lablab purpureus was isolated. These isolates have been authenticated by seedling inoculation grown in jars containing sand. The results obtained after two months of culture have revealed that the 20 isolates (100% of the isolates) are able to nodulate their host plants. The results obtained were analyzed statistically by ANOVA using the software statistica and had shown that the effect of the inoculation has significantly improved all the growth parameters (the height of the plant and the dry weight of the aerial parts and roots, and the number of nodules). We have evaluated the tolerance of all strains of the collection to the major stress factors as the salinity, pH and extreme temperature. The osmotolerance reached a concentration up to 1710mm of NaCl. The strains were also able to grow on a wide range of pH, ranging from 4.5 to 9.5, and temperature, between 4°C and 40°C. Also, we tested the effect of the acidity, aluminum and ferric deficit on the Lablab-rhizobia symbiosis. Lablab purpureus has not been affected by the presence of high concentrations of aluminum. On the other hand, iron deficiency has caused a net decrease in the dry biomass of the aerial part. The results of all the phenotypic characters have been treated by the statistical Minitab software, the numerical analysis had shown that these bacterial strains are divided into two distinct groups at a level of similarity of 86 %. The SDS-PAGE was carried out to determine the profile of the total protein of the strains. The coefficients of similarity of polypeptide bands between the isolates and strains reference (Bradyrhizobium, Mesorizobium sp.) confirm that our strain belongs to the groups of rhizobia.

Keywords: SDS-PAGE, rhizobia, symbiosis, phenotypic characterization, Lablab purpureus

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Authors: T. Vijayashree, A. Gopal

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The aim of the work is to classify and authenticate medicinal plant materials and herbs widely used for Indian herbal medicinal preparation. The quality and authenticity of these raw materials are to be ensured for the preparation of herbal medicines. These raw materials are to be carefully screened, analyzed and documented due to mistaken of look-alike materials which do not have medicinal characteristics.

Keywords: authenticity, standardization, principal component analysis, imaging processing, signal processing

Procedia PDF Downloads 239

Authors: Jianguo Chen, Fenggang Zang, Yu Yang, Liangang Zheng

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Reactor Pressure Vessel (RPV) is an important security barrier in nuclear power plant. Crack like defects may be produced on RPV during the whole operation lifetime due to the harsh operation condition and irradiation embrittlement. During the severe loss of coolant accident, thermal shock happened as the injection of emergency cooling water into RPV, which results in re-pressurization of the vessel and very high tension stress on the vessel wall, this event called Pressurized Thermal Shock (PTS). Crack on the vessel wall may propagate even penetrate the vessel, so the safety of the RPV would undergo great challenge. Many assumptions in structure integrity evaluation make the result of deterministic fracture mechanics very conservative, which affect the operation lifetime of the plant. Actually, many parameters in the evaluation process, such as fracture toughness and nil-ductility transition temperature, have statistical distribution characteristics. So it is necessary to assess the structural integrity of RPV subjected to PTS event by means of Probabilistic Fracture Mechanics (PFM). Structure integrity evaluation methods of RPV subjected to PTS event are summarized firstly, then evaluation method based on probabilistic fracture mechanics are presented by considering the probabilistic characteristics of material and structure parameters. A comprehensive analysis example is carried out at last. The results show that the probability of crack penetrates through wall increases gradually with the growth of fast neutron irradiation flux. The results give advice for reactor life extension.

Keywords: fracture toughness, integrity evaluation, pressurized thermal shock, probabilistic fracture mechanics, reactor pressure vessel

Procedia PDF Downloads 247

Authors: Lachin Mikjtarnejad, Mohsen Farzaneh

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Various microbes, such as fungi and bacteria species, are naturally found in the fruit microbiota, and some of them act as a pathogen and result in fruit rot. Among non-pathogenic microbes, yeasts (single-celled microorganisms belonging to the fungi kingdom) can colonize fruit tissues and interact with them without causing any damage to them. Although yeasts are part of the plant microbiota, there is little information about their interactions with plants in comparison with bacteria and filamentous fungi. According to several existing studies, some yeasts can colonize different plant species and have the biological control ability to suppress some of the plant pathogens. It means those specific yeast-colonized plants are more resistant to some plant pathogens. The major objective of the present investigation is to isolate yeast strains from apple fruit and screen their ability to control Penicillium expansum, the causal agent of blue mold of fruits. In the present study, psychrotrophic and epiphytic yeasts were isolated from apple fruits that were stored at low temperatures (0–1°C). Totally, 42 yeast isolates were obtained and identified by molecular analysis based on genomic sequences of the D1/D2 and ITS1/ITS4 regions of their rDNA. All isolated yeasts were primarily screened by' in vitro dual culture assay against P. expansum by measuring the fungus' relative growth inhibition after 10 days of incubation. The results showed that the mycelial growth of P. expansum was reduced between 41–53% when challenged by promising yeast strains. The isolates with the strongest antagonistic activity belonged to Metschnikowia pulcherrima A13, Rhodotorula mucilaginosa A41, Leucosporidium Scottii A26, Aureobasidium pullulans A19, Pichia guilliermondii A32, Cryptococcus flavescents A25, and Pichia kluyveri A40. The results of seven superior isolates to inhibit blue mold decay on fruit showed that isolates A. pullulans A19, L. scottii A26, and Pi. guilliermondii A32 could significantly reduce the fruit rot and decay with 26 mm, 22 mm and 20 mm zone diameter, respectively, compared to the control sample with 43 mm. Our results show Pi. guilliermondii strain A13 was the most effective yeast isolates in inhibiting P. expansum on apple fruits. In addition, various biological control mechanisms of promising biological isolates against blue mold have been evaluated to date, including competition for nutrients and space, production of volatile metabolites, reduction of spore germination, production of siderophores and production of extracellular lytic enzymes such as chitinase and β-1,3-glucanase. However, the competition for nutrients and the ability to inhibit P. expansum spore growth have been introduced as the prevailing mechanisms among them. Accordingly, in our study, isolates A13, A41, A40, A25, A32, A19 and A26 inhibited the germination of P. expansum, whereas isolates A13 and A19 were the strongest inhibitors of P. expansum mycelia growth, causing 89.13% and 81.75 % reduction in the mycelial surface, respectively. All the promising isolates produced chitinase and β-1,3-glucanase after 3, 5 and 7 days of cultivation. Finally, based on our findings, we are proposing that, Pi. guilliermondiias as an effective biocontrol agent and alternative to chemical fungicides to control the blue mold of apple fruit.

Keywords: yeast, yeast enzymes, biocontrol, post harvest diseases

Procedia PDF Downloads 121