Search results for: voltage stress

Authors: S. J. Higgs, E. Van Eck, K. Heynis, S. H. Broadberry

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Engagement with non-human animals is a rapidly-growing field of study within the animal science and social science sectors, with human-interactions occurring in many forms; interactions, encounters and animal-assisted therapy. To our knowledge, there has been a wide array of research published on domestic and livestock human-animal interactions, however, there appear to be fewer publications relating to zoo animals and the effect these interactions have on the animal, human and establishment. The aim of this study was to identify if there were any perceivable benefits from the human-animal interaction for the cheetah, the human and the establishment. Behaviour data were collected before, during and after the interaction on the behaviour of the cheetah and the human participants to highlight any trends with nine interactions conducted. All 35 participants were asked to fill in a questionnaire prior to the interaction and immediately after to ascertain if their perceptions changed following an interaction with the cheetah. An online questionnaire was also distributed for three months to gain an understanding of the perceptions of human-animal interactions from members of the public, gaining 229 responses. Both questionnaires contained qualitative and quantitative questions to allow for specific definitive answers to be analysed, but also expansion on the participants perceived perception of human-animal interactions. In conclusion, it was found that participants’ perceptions of human-animal interactions saw a positive change, with 64% of participants altering their opinion and viewing the interaction as beneficial for the cheetah (reduction in stress assumed behaviours) following participation in a 15-minute interaction. However, it was noted that many participants felt the interaction lacked educational values and therefore this is an area in which zoological establishments can work to further improve upon. The results highlighted many positive benefits for the human, animal and establishment, however, the study does indicate further areas for research in order to promote positive perceptions of human-animal interactions and to further increase the welfare of the animal during these interactions, with recommendations to create and regulate legislation.

Keywords: Acinonyx jubatus, encounters, human-animal interactions, perceptions, zoological establishments

Procedia PDF Downloads 182

Authors: Shalini Adiga, Shashikant Chetty, Jisha, Shobha Kamath

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Background: Moderate impairment of learning and memory has been observed in both type 1 and 2 diabetes mellitus in humans and experimental animals. A Change in glucose utilization and oxidative stress that occur in diabetes are considered the main reasons for cognitive dysfunction. Objective: Costus igneus (CI) which is known to possess hypoglycemic activity was evaluated in this study for its effect on learning and memory in normal and diabetic rats. Methods: Wistar rats were divided into control, CI-alcoholic extract treated normal (250 and 500mg/kg), diabetic control and CI-treated diabetic groups. CI treatment was continued for 4 weeks. For induction of diabetes, a single dose of streptozotocin was injected (30 mg/kg i.p). Entrance latency and time spent in the dark room during acquisition and at 24 and 48h after an aversive shock in a passive avoidance model was used as an index of learning and memory. Glutathione and malondialdehyde levels in brain and blood glucose were measured. Data was analysed using ANOVA. Results: During the three trials in exploration test, the diabetic control rats exhibited no significant change in entrance latency or in the total time spent in the dark compartment. During retention testing, the entrance latency of the diabetic treated groups was two times less at 24h and three times less at 48h after aversive stimulus as compared to diabetic rats. The normal drug-treated rats showed similar behaviour as the saline control. Treatment with CI significantly reduced the raised blood sugar and MDA levels of diabetic rats. Conclusion: Costus igneus prevented the cognitive dysfunction in diabetic rats which can be attributed to its antioxidant and antihyperglycemic activities.

Keywords: Costus igneous, diabetes, learning and memory, cognitive dysfunction

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Authors: JinWoog Lee, SeongHyeok Lee, ChanYong Choi, Yujin Lim, Hojin Cho

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Primary function of the trackbed in a conventional railway track system is to decrease the stresses in the subgrade to be in an acceptable level. A properly designed trackbed layer performs this task adequately. Many design procedures have used assumed and/or are based on critical stiffness values of the layers obtained mostly in the field to calculate an appropriate thickness of the sublayers of the trackbed foundation. However, those stiffness values do not consider strain levels clearly and precisely in the layers. This study proposes a method of computation of stiffness that can handle with strain level in the layers of the trackbed foundation in order to provide properly selected design values of the stiffness of the layers. The shear modulus values are dependent on shear strain level so that the strain levels generated in the subgrade in the trackbed under wheel loading and below plate of Repeated Plate Bearing Test (RPBT) are investigated by finite element analysis program ABAQUS and PLAXIS programs. The strain levels generated in the subgrade from RPBT are compared to those values from RC (Resonant Column) test after some consideration of strain levels and stress consideration. For comparison of shear modulus G obtained from RC test and stiffness moduli Ev2 obtained from RPBT in the field, many numbers of mid-size RC tests in laboratory and RPBT in field were performed extensively. It was found in this study that there is a big difference in stiffness modulus when the converted Ev2 values were compared to those values of RC test. It is verified in this study that it is necessary to use precise and increased loading steps to construct nonlinear curves from RPBT in order to get correct Ev2 values in proper strain levels.

Keywords: modulus, plate load test, resonant column test, trackbed foundation

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Authors: M. Bazrafshan, M. B. de Rooij, D. J. Schipper

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Frictional hysteresis is the phenomenon in which mechanical contacts are subject to small (compared to contact area) oscillating tangential displacements. In the presence of adhesion at the interface, the contact repulsive force increases leading to a higher static friction force and pre-sliding displacement. This paper proposes a boundary element model (BEM) for the adhesive frictional hysteresis contact at the interface of two contacting bodies of arbitrary geometries. In this model, adhesion is represented by means of a Dugdale approximation of the total work of adhesion at local areas with a very small gap between the two bodies. The frictional contact is divided into sticking and slipping regions in order to take into account the transition from stick to slip (pre-sliding regime). In the pre-sliding regime, the stick and slip regions are defined based on the local values of shear stress and normal pressure. In the studied cases, a fixed normal force is applied to the interface and the friction force varies in such a way to start gross sliding in one direction reciprocally. For the first case, the problem is solved at the smooth interface between a ball and a flat for different values of work of adhesion. It is shown that as the work of adhesion increases, both static friction and pre-sliding distance increase due to the increase in the contact repulsive force. For the second case, the rough interface between a glass ball against a silicon wafer and a DLC (Diamond-Like Carbon) coating is considered. The work of adhesion is assumed to be identical for both interfaces. As adhesion depends on the interface roughness, the corresponding contact repulsive force is different for these interfaces. For the smoother interface, a larger contact repulsive force and consequently, a larger static friction force and pre-sliding distance are observed.

Keywords: boundary element model, frictional hysteresis, adhesion, roughness, pre-sliding

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Authors: Amir Ali, Laura Yael Mendoza

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The application of nanomaterials is becoming the most effective strategy of elicitation to produce a desirable level of plant biomass with complex medicinal compounds. This study was designed to check the influence of phytosynthesized iron nanoparticles (FeNPs) on physical growth characteristics, antioxidant status, and production of steviol glycosides of in vitro grown Stevia rebaudiana. Effect of different concentrations of iron nanoparticles replacement of iron sulfate in MS medium (stock solution) on invitro stevia plant growth following positive control (MS basal medium), negative control (iron sulfate devoid medium), iron sulfate devoid MS medium and supplemented with FeNPs at different concentrations (5.6 mg/L, 11.2 mg/L, 16.8 mg/L, 22.4 mg/L) was evaluated. The iron deficiency leads to a drastic reduction in plant growth. In contrast, applying FeNPs leads to improvement in plant height, leave diameter, improved leave morphology, etc., in a concentration-dependent manner. Furthermore, the stress caused by FeNPs at 16.8 mg/L in cultures produced higher levels of total phenolic content (3.7 ± 0.042 mg/g dry weight: DW) and total flavonoid content (1.9 ± 0.022 mg/g DW and antioxidant activity (78 ± 4.6%). In addition, plants grown in the presence of FeNPs at 22.4 mg/L resulted in higher enzymatic antioxidant activities (SOD = 3.5 ± 0.042 U/mg; POD = 2.6 ± 0.026 U/mg; CAT = 2.8 ± 0.034 U/mg and APx = 3.6 ± 0.043 U/ mg), respectively. Furthermore, exposure to a higher dose of FeNPs (22.4 mg/L) exhibited the maximum amount of stevioside (stevioside: 4.6 ± 0.058 mg/g (DW) and rebaudioside A: 4.9 ± 0.068 mg/g DW) as compared to other doses. The current investigation confirms the effectiveness of FeNPs in growth media. It offers a suitable prospect for commercially desirable production of S. rebaudiana biomass with higher sweet glycosides profiles in vitro.

Keywords: cell culture, stevia, iron nanoparticles, antioxidants

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Authors: Rahmi Aksoy

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The western part of Konya consists of an area of block faulted basin and ranges. Present day topography is characterized by alternating elongate mountains and depressions trending east-west. A number of depressions occur in the region. One of the large depressions is the E-W trending Kızılören-Küçükmuhsine (KK basin) basin bounded on both sides by normal faults and located on the west of the Konya city. The basin is about 5-12 km wide and 40 km long. Ranges north and south of the basin are composed of undifferentiated low grade metamorphic rocks of Silurian-Cretaceous age and smaller bodies of ophiolites of probable Cretaceous age. The basin fill consists of the upper Miocene-lower Pliocene fluvial, lacustrine, alluvial sediments and volcanic rocks. The younger and undeformed Plio-Quaternary basin fill unconformably overlies the older basin fill and is composed predominantly of conglomerate, mudstone, silt, clay and recent basin floor deposits. The paleostress data on the striated fault planes in the basin indicates NW-SE extension and associated with an NE-SW compression. The eastern end of the KK basin is cut and terraced by the active Konya fault zone. The Konya fault zone is NE trending, east dipping normal fault forming the western boundary of the Konya depression. The Konya depression consists mainly of Plio-Quaternary alluvial complex and recent basin floor sediments. The structural data gathered from the Konya fault zone support normal faulting with a small amount of dextral strike-slip tensional tectonic regime that shaped under the WNW-ESE extensional stress regime.

Keywords: central Anatolia, fault kinematics, Kızılören-Küçükmuhsine basin, Konya fault zone, neotectonics

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Authors: Cagri Mollamahmutoglu, Ali Mercan, Aykut Levent

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Studies concerning the microstructures are becoming more important as the utilization of various micro-electro mechanical systems (MEMS) are increasing. Thus in recent years, thermal buckling and vibration analysis of microstructures have been subject to many investigations that are utilizing different numerical methods. In this study, thermal effects on mechanical response of a functionally graded (FG) Timoshenko micro-beam are presented in the framework of a mixed finite element formulation. Size effects are taken into consideration via modified couple stress theory. The mixed formulation is based on a function which in turn is derived via Gateaux Differential scientifically. After the resolution of all field equations of the beam, a potential operator is carefully constructed. Then this operator is used for the manufacturing of the functional. Usual procedures of finite element approximation are utilized for the derivation of the mixed finite element equations once the potential is obtained. Resulting finite element formulation allows usage of C₀ type simple linear shape functions and avoids shear-locking phenomena, which is a common shortcoming of the displacement-based formulations of moderately thick beams. The developed numerical scheme is used to obtain the effects of thermal loads on the static bending, free vibration and buckling of FG Timoshenko micro-beams for different power-law parameters, aspect ratios and boundary conditions. The versatility of the mixed formulation is presented over other numerical methods such as generalized differential quadrature method (GDQM). Another attractive property of the formulation is that it allows direct calculation of the contribution of micro effects on the overall mechanical response.

Keywords: micro-beam, functionally graded materials, thermal effect, mixed finite element method

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Authors: Patricia M. B. Saint-Vincent, Anna Furches, Stephanie Galanie, Erica Teixeira Prates, Piet Jones, Nancy Engle, David Kainer, Wellington Muchero, Daniel Jacobson, Timothy J. Tschaplinski

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Uridine diphosphate-glycosyltransferases (UGTs) are enzymes that catalyze sugar transfer to a variety of plant metabolites. UGT substrates, which include plant secondary metabolites involved in lignification, demonstrate new activities and incorporation when glycosylated. Knowledge of UGT function, substrate specificity, and enzyme products is important for plant engineering efforts, especially related to increasing plant biomass through lignification. UGTs in Populus trichocarpa, a biofuel feedstock, and model woody plant, were selected from a pool of gene candidates using rapid prioritization strategies. A functional genomics workflow, consisting of a metabolite genome-wide association study (mGWAS), expression of synthetic codon-optimized genes, and high-throughput biochemical assays with mass spectrometry-based analysis, was developed for determining the substrates and products of previously-uncharacterized enzymes. A total of 40 UGTs from P. trichocarpa were profiled, and the biochemical assay results were compared to predicted mGWAS connections. Assay results confirmed seven of 11 leaf mGWAS associations and demonstrated varying levels of substrate specificity among candidate UGTs. P. trichocarpa UGT substrate processing confirms the role of these newly-characterized enzymes in lignan, flavonoid, and phytohormone metabolism, with potential implications for cell wall biosynthesis, nitrogen uptake, and biotic and abiotic stress responses.

Keywords: Populus, metabolite-gene associations, GWAS, bio feedstocks, glycosyltransferase

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Authors: Maram Shahad Dana Anfal

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This research paper presents the design of a surveillance drone with computer-aided durability and model analyses that provides a cost-effective and efficient solution for various applications. The quadcopter's design is based on a lightweight and strong structure made of materials such as aluminum and titanium, which provide a durable structure for the quadcopter. The structure of this product and the computer-aided durability system are both designed to ensure frequent repairs or replacements, which will save time and money in the long run. Moreover, the study discusses the drone's ability to track, investigate, and deliver objects more quickly than traditional methods, makes it a highly efficient and cost-effective technology. In this paper, a comprehensive analysis of the quadcopter's operation dynamics and limitations is presented. In both simulation and experimental data, the computer-aided durability system and the drone's design demonstrate their effectiveness, highlighting the potential for a variety of applications, such as search and rescue missions, infrastructure monitoring, and agricultural operations. Also, the findings provide insights into possible areas for improvement in the design and operation of the drone. Ultimately, this paper presents a reliable and cost-effective solution for surveillance applications by designing a drone with computer-aided durability and modeling. With its potential to save time and money, increase reliability, and enhance safety, it is a promising technology for the future of surveillance drones. operation dynamic equations have been evaluated successfully for different flight conditions of a quadcopter. Also, CAE modeling techniques have been applied for the modal risk assessment at operating conditions.Stress analysis have been performed under the loadings of the worst-case combined motion flight conditions.

Keywords: drone, material, solidwork, hypermesh

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Authors: Ivan A. Sandoval Salazar, Silvia F. Valderrama

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The microalgae oil emerges as a promising source of raw material for many industrial applications. Thus, this study had as a main focus on the cultivation of the microalgae species Desmodesmus sp. in laboratory scale with a view to maximizing biomass production and triglyceride content in the lipid fraction. Initially, culture conditions were selected to optimize biomass production, which was subsequently subjected to nutritional stress by varying nitrate and phosphate concentrations in order to increase the content and productivity of fatty acids. The culture medium BOLD 3N, nitrate and phosphate, light intensity 250,500 and 1000 μmol photons.m².s⁻¹, photoperiod of 12:12 were evaluated. Under the best conditions of the tests, a maximum cell division of 1.13 div.dia⁻¹ was obtained on the sixth day of culture, beginning of the exponential phase, and a maximum concentration of 8.42x107 cell.mL⁻¹ and dry biomass of 3.49 gL⁻¹ on the 20th day, in the stationary phase. The lipid content in the first stage of culture was approximately 8% after 12 days and at the end of the culture in the stationary phase ranged from 12% to 16% (20 days). In the microalgae grown at 250 μmol fotons.m2.s-1 the fatty acid profile was mostly polyunsaturated (52%). The total of unsaturated fatty acids, identified in this species of microalga, reached values between 70 and 75%, being qualified for use in the food and pharmaceutical industry. In addition, this study showed that the cultivation conditions influenced mainly the production of polyunsaturated fatty acids, with the predominance of γ-linolenic acid. However, in the cultures submitted to the highest the intensity of light (1000 μmol photons.m².s⁻¹) and low concentrations of nitrate and phosphate, saturated and monounsaturated fatty acids, which present greater oxidative stability, were identified mainly (60 to 70 %) being qualified for the production of biodiesel and for oleochemistry.

Keywords: microalgae, Desmodesmus sp, fatty acids, biodiesel

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Authors: Kali Prasad Sarma, Sanghita Dutta

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Deepor Beel (DB), the lone Ramsar site and an important wetland of the Brahmaputra valley in the state of Assam. The local people from fourteen peripheral villages traditionally utilize the wetland for harvesting vegetables, flowers, aquatic seeds, medicinal plants, fish, molluscs, fodder for domestic cattle etc. Therefore, it is of great importance to understand the concentration and distribution of trace metals in water-sediment system of the beel in order to protect its ecological environment. DB lies between26°05′26′′N to 26°09′26′′N latitudes and 90°36′39′′E to 91°41′25′′E longitudes. Water samples from the surface layer of water up to 40cm deep and sediment samples from the top 5cm layer of surface sediments were collected. The trace metals in waters and sediments were analysed using ICP-OES. The organic Carbon was analysed using the TOC analyser. The different mineral present in the sediments were confirmed by X-ray diffraction method (XRD). SEM images were recorded for the samples using SEM, attached with energy dispersive X-ray unit, with an accelerating voltage of 20 kv. All the statistical analyses were performed using SPSS20.0 for windows. In the present research, distribution, source apportionment, temporal and spatial variability, extent of pollution and the ecological risk of eight toxic trace metals in sediments and water of DB were investigated. The average concentrations of chromium(Cr) (both the seasons), copper(Cu) and lead(Pb) (pre-monsoon) and zinc(Zn) and cadmium(Cd) (post-monsoon) in sediments were higher than the consensus based threshold concentration(TEC). The persistent exposure of toxic trace metals in sediments pose a potential threat, especially to sediment dwelling organisms. The degree of pollution in DB sediments for Pb, Cobalt (Co) Zn, Cd, Cr, Cu and arsenic (As) was assessed using Enrichment Factor (EF), Geo-accumulation index (Igeo) and Pollution Load Index (PLI). The results indicated that contamination of surface sediments in DB is dominated by Pb and Cd and to a lesser extent by Co, Fe, Cu, Cr, As and Zn. A significant positive correlation among the pairs of element Co/Fe, Zn/As in water, and Cr/Zn, Fe/As in sediments indicates similar source of origin of these metals. The effects of interaction among trace metals between water and sediments shows significant variations (F =94.02, P < 0.001), suggesting maximum mobility of trace metals in DB sediments and water. The source apportionment of the heavy metals was carried out using Principal Component Analysis (PCA). SEM-EDS detects the presence of Cd, Cu, Cr, Zn, Pb, As and Fe in the sediment sample. The average concentration of Cd, Zn, Pb and As in the bed sediments of DB are found to be higher than the crustal abundance. The EF values indicate that Cd and Pb are significantly enriched. From source apportionment studies of the eight metals using PCA revealed that Cd was anthropogenic in origin; Pb, As, Cr, and Zn had mixed sources; whereas Co, Cu and Fe were natural in origin.

Keywords: Deepor Beel, enrichment factor, principal component analysis, trace metals

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Authors: P. Panwalkar, K. Veravalli, R. Gwynn, M. Tofighi, R. Clement, A. Mofidi

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When operating on tibial plateau fracture especially medial tibial plateau, it has regularly been said “where do I put my thumb to reduce the fracture”. This refers to the ideal placement of the buttress device to hold the fracture till union. The aim of this study was to see if one can identify this sweet spot using a CT scan. Methods: Forty-five tibial plateau fractures with medial plateau involvement were identified and included in the study. The preoperative CT scans were analysed and the medial plateau involvement pattern was classified based on modified radiological classification by Yukata et-al of stress fracture of medial tibial plateau. The involvement of part of plateau was compared with position of buttress plate position which was classified as medial posteromedial or both. Presence and position of the buttress was compared with ability to achieve and hold the reduction of the fracture till union. Results: Thirteen fractures were type-1 fracture, 19 fractures were type-2 fracture and 13 fractures were type-3 fracture. Sixteen fractures were buttressed correctly according to the potential deformity and twenty-six fractures were not buttressed and three fractures were partly buttressed correctly. No fracture was over butressed! When the fracture was buttressed correctly the rate of the malunion was 0%. When fracture was partly buttressed 33% were anatomically united and 66% were united in the plane of buttress. When buttress was not used, 14 were malunited, one malunited in one of the two planes of deformity and eleven anatomically healed (of which 9 were non displaced!). Buttressing resulted in statistically significant lower mal-union rate (x2=7.8, p=0.0052). Conclusion: The classification based on involvement of medial condyle can identify the placement of buttress plate in the tibial plateau. The correct placement of the buttress plate results in predictably satisfactory union. There may be a correlation between injury shape of the tibial plateau and the fracture type.

Keywords: knee, tibial plateau, trauma, CT scan, surgery

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Authors: Jakub Zembrzuski, Bartosz Sobczyk, Mikołaj MIśkiewicz

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Besides designing new constructions, engineers all over the world must face another problem – maintenance, repairs, and assessment of the technical condition of existing bridges. To solve more complex issues, it is necessary to be familiar with the theory of finite element method and to have access to the software that provides sufficient tools which to enable create of sometimes significantly advanced numerical models. The paper includes a brief assessment of the technical condition, a description of the in situ non-destructive testing carried out and the FEM models created for global and local analysis. In situ testing was performed using strain gauges and displacement sensors. Numerical models were created using various software and numerical modeling techniques. Particularly noteworthy is the method of modeling riveted joints of the crossbeam of the viaduct. It is a simplified method that consists of the use of only basic numerical tools such as beam and shell finite elements, constraints, and simplified boundary conditions (fixed support and symmetry). The results of the numerical analyses were presented and discussed. It is clearly explained why the structure did not fail, despite the fact that the weld of the deck plate completely failed. A further research problem that was solved was to determine the cause of the rapid increase in values on the stress diagram in the cross-section of the transverse section. The problems were solved using the solely mentioned, simplified method of modeling riveted joints, which demonstrates that it is possible to solve such problems without access to sophisticated software that enables to performance of the advanced nonlinear analysis. Moreover, the obtained results are of great importance in the field of assessing the operation of bridge structures with an orthotropic plate.

Keywords: bridge, diagnostics, FEM simulations, failure, NDT, in situ testing

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Authors: Valerii Levshakov, Olga Fedorova

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Specific features of ship structures, made from composites, i.e. simultaneous shaping of material and structure, large sizes, complicated outlines and tapered thickness have defined leading role of technology, integrating test results from material science, designing and structural analysis. Main procedures of composite shipbuilding are contact molding, vacuum molding and winding. Now, the most demanded composite shipbuilding technology is the manufacture of structures from fiberglass and multilayer hybrid composites by means of vacuum molding. This technology enables the manufacture of products with improved strength properties (in comparison with contact molding), reduction of production duration, weight and secures better environmental conditions in production area. Mechanized winding is applied for the manufacture of parts, shaped as rotary bodies – i.e. parts of ship, oil and other pipelines, deep-submergence vehicles hulls, bottles, reservoirs and other structures. This procedure involves processing of reinforcing fiberglass, carbon and polyaramide fibers. Polyaramide fibers have tensile strength of 5000 MPa, elastic modulus value of 130 MPa and rigidity of the same can be compared with rigidity of fiberglass, however, the weight of polyaramide fiber is 30% less than weight of fiberglass. The same enables to the manufacture different structures, including that, using both – fiberglass and organic composites. Organic composites are widely used for the manufacture of parts with size and weight limitations. High price of polyaramide fiber restricts the use of organic composites. Perspective area of winding technology development is the manufacture of carbon fiber shafts and couplings for ships. JSC ‘Shipbuilding & Shiprepair Technology Center’ (JSC SSTC) developed technology of dielectric uncouplers for cryogenic lines, cooled by gaseous or liquid cryogenic agents (helium, nitrogen, etc.) for temperature range 4.2-300 K and pressure up to 30 MPa – the same is used for separating components of electro physical equipment with different electrical potentials. Dielectric uncouplers were developed, the manufactured and tested in accordance with International Thermonuclear Experimental Reactor (ITER) Technical specification. Spiral uncouplers withstand operating voltage of 30 kV, direct-flow uncoupler – 4 kV. Application of spiral channel instead of rectilinear enables increasing of breakdown potential and reduction of uncouplers sizes. 95 uncouplers were successfully the manufactured and tested. At the present time, Russian the manufacturers of ship composite structures have started absorption of technology of manufacturing the same using automated prepreg laminating; this technology enables the manufacture of structures with improved operational specifications.

Keywords: fiberglass, infusion, polymeric composites, winding

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Authors: Soheil Heydari, Ailar Hajimohammadi, Nasser Khalili

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Polystyrene, being made from a monomer called styrene, is a rigid and easy-to mould polymer that is widely used for many applications, from foam packaging to disposable containers. Considering that the degradation of waste polystyrene takes up to 500 years, there is an urgent need for a sustainable application for waste polystyrene. This study evaluates the application of waste polystyrene as an asphalt modifier. The inclusion of waste plastics in asphalt is either practised by the dry process or the wet process. In the dry process, plastics are added straight into the asphalt mixture and in the wet process, they are mixed and digested into bitumen. In this article, polystyrene was used as an asphalt modifier in a dry process. However, the mixing process is precisely designed to make sure that the polymer is melted and modified in the binder. It was expected that, due to the rigidity of polystyrene, it will have positive effects on the permanent deformation of the asphalt mixture. Therefore, different mixtures were manufactured with different contents of polystyrene and Marshall specimens were manufactured, and dynamic creep tests were conducted to evaluate the permanent deformation of the modification. This is a commonly repeated loading test conducted at different stress levels and temperatures. Loading cycles are applied to the AC specimen until failure occurs; with the amount of deformation constantly recorded the cumulative, permanent strain is determined and reported as a function of the number of cycles. Also, to our best knowledge, hybrid mixes of polystyrene with crumb rubber and low-density polyethylene were made and compared with a polystyrene-modified mixture. The test results of this study showed that the hybrid mix of polystyrene and low-density polyethylene has the highest resistance against permanent deformation. However, the polystyrene-modified mixture outperformed the hybrid mix of polystyrene and crumb rubber, and both demonstrated way lower permanent deformation than the unmodified specimen.

Keywords: permanent deformation, waste plastics, polystyrene, hybrid plastics, hybrid mix, hybrid modification, dry process

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Authors: Ali H. Daraji, Ye Jianqiao

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The micro electrical devices of the wireless sensor network are continuously developed and become very small and compact with low electric power requirements using limited period life conventional batteries. The low power requirement for these devices, cost of conventional batteries and its replacement have encouraged researcher to find alternative power supply represented by energy harvesting system to provide an electric power supply with infinite period life. In the last few years, the investigation of energy harvesting for structure health monitoring has increased to powering wireless sensor network by converting waste mechanical vibration into electricity using piezoelectric sensors. Optimisation of energy harvesting is an important research topic to ensure a flowing of efficient electric power from structural vibration. The harvesting power is mainly based on the properties of piezoelectric material, dimensions of piezoelectric sensor, its position on a structure and value of an external electric load connected between sensor electrodes. Larger surface area of sensor is not granted larger power harvesting when the sensor area is covered positive and negative mechanical strain at the same time. Thus lead to reduction or cancellation of piezoelectric output power. Optimisation of energy harvesting is achieved by locating these sensors precisely and efficiently on the structure. Limited published work has investigated the energy harvesting for aircraft wing. However, most of the published studies have simplified the aircraft wing structure by a cantilever flat plate or beam. In these studies, the optimisation of energy harvesting was investigated by determination optimal value of an external electric load connected between sensor electrode terminals or by an external electric circuit or by randomly splitting piezoelectric sensor to two segments. However, the aircraft wing structures are complex than beam or flat plate and mostly constructed from flat and curved skins stiffened by stringers and ribs with more complex mechanical strain induced on the wing surfaces. This aircraft wing structure bonded with discrete macro fibre composite sensors was modelled using multiphysics finite element to optimise the energy harvesting by determination of the optimal number of sensors, location and the output resistance load. The optimal number and location of macro fibre sensors were determined based on the maximization of the open and close loop sensor output voltage using frequency response analysis. It was found different optimal distribution, locations and number of sensors bounded on the top and the bottom surfaces of the aircraft wing.

Keywords: energy harvesting, optimisation, sensor, wing

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Authors: Bibha Kumari, Nigel P. Brunton, Dilip K. Rai, Brijesh K. Tiwari

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Edible mushrooms possess numerous functional components like homo- and hetero- β-glucans [β(1→3), β(1→4) and β(1→6) glucosidic linkages], chitins, ergosterols, bioactive polysaccharides and peptides imparting health beneficial properties to mushrooms. Some of the proven biological activities of mushroom extracts are antioxidant, antimicrobial, immunomodulatory, cholesterol lowering activity by inhibiting a key cholesterol metabolism enzyme i.e. 3-hydroxy-3-methyl-glutaryl CoA reductase (HMGCR), angiotensin I-converting enzyme (ACE) inhibition. Application of novel extraction technologies like pulsed electric field (PEF) and high power ultrasound offers clean, green, faster and efficient extraction alternatives with enhanced and good quality extracts. Sequential PEF followed by ultrasound assisted extraction (UAE) were applied to recover bioactive enriched fractions from industrial white button mushroom (Agaricus bisporus) stalk waste using environmentally friendly and GRAS solvents i.e. water and water/ethanol combinations. The PEF treatment was carried out at 60% output voltage, 2 Hz frequency for 500 pulses of 20 microseconds pulse width, using KCl salt solution of 0.6 mS/cm conductivity by the placing 35g of chopped fresh mushroom stalks and 25g of salt solution in the 4x4x4cm3 treatment chamber. Sequential UAE was carried out on the PEF pre-treated samples using ultrasonic-water-bath (USB) of three frequencies (25 KHz, 35 KHz and 45 KHz) for various treatment times (15-120 min) at 80°C. Individual treatment using either PEF or UAE were also investigation to compare the effect of each treatment along with the combined effect on the recovery and bioactivity of the crude extracts. The freeze dried mushroom stalk powder was characterised for proximate compositional parameters (dry weight basis) showing 64.11% total carbohydrate, 19.12% total protein, 7.21% total fat, 31.2% total dietary fiber, 7.9% chitin (as glucosamine equivalent) and 1.02% β-glucan content. The total phenolic contents (TPC) were determined by the Folin-Ciocalteu procedure and expressed as gallic-acid-equivalents (GAE). The antioxidant properties were ascertained using DPPH and FRAP assays and expressed as trolox-equivalents (TE). HMGCR activity and molecular mass of β-glucans will be measured using the commercial HMG-CoA Reductase Assay kit (Sigma-Aldrich) and size exclusion chromatography (HPLC-SEC), respectively. Effects of PEF, UAE and their combination on the antioxidant capacity, HMGCR inhibition and β-glucans content will be presented.

Keywords: β-glucan, mushroom stalks, pulsed electric field (PEF), ultrasound assisted extraction (UAE)

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Authors: G. Wojcik, J. Gindlhuber, A. Syarif, K. Hoetzenecker, P. Bohm, P. Vesely, V. Biasin, G. Kwapiszewska

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Pulmonary fibrosis is a rare disease where uncontrolled wound healing processes damage the lung structure. Intensive changes within the extracellular matrix (ECM) and its interaction with fibroblasts have a major role in pulmonary fibrosis development. Among others, collagen is one of the main components of the ECM, and it is important for lung structure. In IPF, constant production of collagen by fibroblast, through TGFβ1-SMAD2/3 pathways, leads to an uncontrolled deposition of matrix and hence lung remodeling. Abnormal changes in lipid production, alterations in fatty acids (FAs) metabolism, enhanced oxidative stress, and lipid peroxidation in fibrotic lung and fibrotic fibroblasts have been reported; however, the interplay between the collagen and lipids is not yet established. One of the FAs influx regulators is Angiopoietin-like 4 (ANGPTL4), which inhibits lipoprotein lipase work, decreasing the availability of FAs. We hypothesized that altered lipid composition or availability could have the capability to influence the phenotype of different fibroblast populations in the lung and hence influence lung fibrosis. To prove our hypothesis, we aim to investigate lipids and their influence on human, animal, and in vitro levels. In the bleomycin model, treatment with the well-known metabolic drugs Rosiglitazone or Metformin significantly lower collagen production. Similar results were noticed in ANGPTL4 KO animals, where the KO of ANGPTL4 leads to an increase of FAs availability and lower collagen deposition after the bleomycin challenge. Currently, we study the treatment of different FAs on human lung para fibroblasts (hPF) isolated from donors. To understand the lipid composition, we are collecting human lung tissue from donors and pulmonary fibrosis patients for Liquid chromatography-mass spectrometry. In conclusion, our results suggest the lipid influence on collagen deposition during lung fibrosis, but further research needs to be conducted to understand the matter of this relationship.

Keywords: collagen, fibroblasts, lipidomics, lung, pulmonary fibrosis

Procedia PDF Downloads 78

Authors: Enze Zhang

Abstract:

One of the most challenging steps in implementing virtual water content (VWC) analysis of crops is to get properly the total volume of consumptive water use (CWU) and, therefore, the choice of a reliable crop CWU estimation method. In practice, lots of previous researches obtaining CWU of crops follow a classical procedure for calculating crop evapotranspiration which is determined by multiplying reference evapotranspiration by appropriate coefficient, such as crop coefficient and water stress coefficients. However, this manner of calculation requires lots of field experimental data at point scale and more seriously, when current growing conditions differ from the standard conditions, may easily produce deviation between the calculated CWU and the actual CWU. Since evapotranspiration caused by crop planting always plays a vital role in surface water-energy balance in an agricultural region, this study decided to alternatively estimates crop evapotranspiration by Budyko framework. After brief introduce the development process of Budyko framework. We choose a modified Budyko framework under unsteady-state to better evaluated the actual CWU and apply it in an agricultural irrigation area in North China Plain which rely on underground water for irrigation. With the agricultural statistic data, this calculated CWU was further converted into VWC and its subdivision of crops at the annual scale. Results show that all the average values of VWC, VWC_blue and VWC_green show a downward trend with increased agricultural production and improved acreage. By comparison with the previous research, VWC calculated by Budyko framework agree well with part of the previous research and for some other research the value is greater. Our research also suggests that this methodology and findings may be reliable and convenient for investigation of virtual water throughout various agriculture regions of the world.

Keywords: virtual water content, Budyko framework, consumptive water use, crop evapotranspiration

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Authors: Suvorov Vasyl, Filipchuk Viktor

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Developmental Dysplasia of the Hip (DDH) is a frequent pathology in pediatric orthopedist’s practice. Neglected or residual cases of DDH in walking patients are usually treated using pelvic osteotomies. Plastic changes take place in hinge points due to acetabulum reorientation during surgery. Classically described hinge points and a traditional division of pelvic osteotomies on reshaping and reorientation are currently debated. The purpose of this article was to evaluate biomechanical changes during the most commonly used pelvic osteotomies (Salter, Dega, Pemberton) for DDH treatment in pediatric patients. Methods: virtual pelvic models of 2- and 6-years old patients were created, material properties were assigned, pelvic osteotomies were simulated and biomechanical changes were evaluated using finite element analysis (FEA). Results: it was revealed that the patient's age has an impact on pelvic bones and cartilages density (in younger patients the pelvic elements are more pliable - p<0.05). Stress distribution after each of the abovementioned pelvic osteotomy was assessed in 2- and 6-years old patients’ pelvic models; hinge points were evaluated. The new term "restriction point" was introduced, which means a place where restriction of acetabular deformity correction occurs. Pelvic ligaments attachment points were mainly these restriction points. Conclusions: it was found out that there are no purely reshaping and reorientation pelvic osteotomies as previously believed; the pelvic ring acts as a unit in carrying out the applied load. Biomechanical overload of triradiate cartilage during Salter osteotomy in 2-years old patient and in 2- and 6-years old patients during Pemberton osteotomy was revealed; overload of the posterior cortical layer in the greater sciatic notch in 2-years old patient during Dega osteotomy was revealed. Level of Evidence – Level IV, prognostic.

Keywords: developmental dysplasia of the hip, pelvic osteotomy, finite element analysis, hinge point, biomechanics

Procedia PDF Downloads 92

Authors: Hsiao-Chien Tsai, Yu-Pin Chen, Ruei-Ming Chen

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Introduction: Osteoarthritis (OA) is characterized by joint destruction and causes chronic disability. One of the prominent symptoms is pain. Alleviating the pain is necessary and urgent for the therapy of OA patients. However, currently, understanding the mechanisms that drive OA-induced pain remains challenging, which hampers the optimistic management of pain in OA patients. Semaphorin 4D (Sema4D) participates in axon guidance pathway and bone remodeling, thus, may play a role in the regulation of pain in OA. In this study, we have established a rat model of OA to find out the mechanisms of OA-induced pain and to deliberate the roles of Sema4D. Methods: Behavioral changes and the pro-inflammatory cytokines (IL-1β, TNF-α, and IL-17) associated with pain were measured during the development of OA. Sema4D expression in cartilage and synovial membrane at 1, 4, and 12 weeks after inducing OA was analyzed. To assess if Sema4D is related to the neurogenesis in OA as an axon repellant, we analyzed the expression of PGP9.5 as well. Results: Synovitis and cartilage degradation were evident histologically during the development of OA. Mechanical hyperalgesia was most severe at week 1, then persisted thereafter. It was associated with stress coping strategies. Similar to the pain behavioral results, levels of IL-1β and TNF-α in synovial lavage fluid were significantly elevated in the OA group at weeks 1 and 4, respectively. Sema4D expression in cartilage and the synovial membrane was also enhanced in the OA group and was correlated with pain and pro-inflammatory cytokines. The marker of neurogenesis, PGP9.5, was also enhanced during the development of OA. Discussion: OA induced mechanical hyperalgesia, which might be through upregulating IL-1β/TNF-α-mediated Sema4D expressions. If anti-Sema4D treatment could reduce OA-induced mechanical hyperalgesia and prevent the subsequent progression of OA needs to be further investigated. Significance: OA can induce mechanical hyperalgesia through upregulation of IL-1β/TNF-α-mediated Sema4D and PGP9.5 expressions. And the upregulation of Sema4D may indicate the severity or active status of OA and OA-induced pain.

Keywords: traumatic osteoarthritis, mechanical hyperalgesia, Sema4D, inflammatory cytokines

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Authors: Elham Shakerian, Reza Afarin

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The hepatic disease causes approximately 2 million deaths/year worldwide. Liver fibrosis is the last stage of numerous chronic liver diseases, and until now there is no definite cure or drug for it. Activation of hepatic stellate cells (HSCs) is the main reason for fibrosis. Transforming growth factor (TGF-β), as a main profibrogenic cytokine, if increased in these cells, leads to liver fibrosis through smad3 signaling pathways and increasing the expressions of Collagen type I and III, and actin-alpha smooth muscle (αSMA) genes. Curcumin (CUR) is a polyphenolic compound and an active ingredient derived from the rhizome of the turmeric plant that exerts effective antioxidant, anti-inflammatory, and antimicrobial activity. It has been shown that daily consumption of curcumin may have a protective effect on the liver against oxidative stress associated with alcohol consumption. In this study, we investigate the role of Curcumin in decreasing HSC activation and treating liver fibrosis. First, the human HSCs were treated with 2 ng/ml of (TGF-β) for 24 hours to become activated, then with Silibinin for 24 hours. Total RNAs were extracted, reversely transcribed into cDNA, Quantitative Real-time PCR, and western blot were performed. The mRNA expression levels of Collagen type I and III, αSMA genes, and the level of smad3 phosphorylation in TGF-β activated human HSCs treated with Curcumin were significantly reduced compared to human HSCs untreated with Curcumin. Curcumin is effective in reducing the expression of fibrogenic genes in the activated human HSCs treated with TGFB through downregulation of the TGF-β/smad3 signaling pathway. Therefore, Curcumin possesses significant antifibrotic properties in hepatic fibrosis

Keywords: hepatic fibrosis, human HSCs, curcumin, fibrogenic genes

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Authors: Gopal Lamichhane, Biswash Sapkota, Grinsun Sharma, Mahendra Adhikari

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Urolithiasis is a condition in which insoluble or less soluble salts like oxalate, phosphate etc. precipitate in urinary tract and causes obstruction in ureter resulting renal colic or sometimes haematuria. It is the third most common disorder of urinary tract affecting nearly 2% of world’s population. Poor urinary drainage, microbial infection, oxalate and calcium containing diet, calciferol, hyperparathyroidism, cysteine in urine, gout, dysfunction of intestine, drought environment, lifestyle, exercise, stress etc. are risk factors for urolithiasis. Wide ranges of treatments are available in allopathic system of medicine but reoccurrence is unpreventable even with the surgical removal of stone or lithotripsy. So, people prefer alternative medicinal systems such as Unani, homeopathic, ayurvedic etc. systems of medicine due to their fewer side effects over allopathic counterpart. Different plants based ethnomedicines are being well established by their continuous effective use in human since long time in treatment of urinary problem. Many studies have scientifically proved those ethnomedicines for antiurolithiatic effect in animal and in vitro model. Plant-based remedies were found to be therapeutically effective for both prevention as well as cure of calcium oxalate urolithiasis. Plants were known to show these effects through a combination of many effects such as antioxidant, diuretic, hypocalciuric, urine alkalinizing effect in them. Berberine, triterpenoids, lupeol are the phytochemicals established for antiurolithiatic effect. Hence, plant-based medicine can be the effective herbal alternative as well as means of discovery of novel drug molecule for curing urolithiatic disorder and should be focused on further research to discover their value in coming future.

Keywords: urolithiasis, herbal medicine, ethnomedicine, kidney stone, calcium oxalate

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Authors: Hsyi-En Cheng, Ying-Yi Liou

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Metal-oxide semiconductor (MOS) gas sensors are widely used in the gas-detection market due to their high sensitivity, fast response, and simple device structures. However, the high working temperature of MOS gas sensors makes them difficult to integrate with the appliance or consumer goods. One-dimensional (1-D) nanostructures are considered to have the potential to lower their working temperature due to their large surface-to-volume ratio, confined electrical conduction channels, and small feature sizes. Unfortunately, the difficulty of fabricating 1-D nanostructure electrodes has hindered the development of low-temperature MOS gas sensors. In this work, we proposed a method to fabricate nanotube-arrays, and the SnO₂ nanotube-array sensors with different wall thickness were successfully prepared and examined. The fabrication of SnO₂ nanotube arrays incorporates the techniques of barrier-free anodic aluminum oxide (AAO) template and atomic layer deposition (ALD) of SnO₂. First, 1.0 µm Al film was deposited on ITO glass substrate by electron beam evaporation and then anodically oxidized by five wt% phosphoric acid solution at 5°C under a constant voltage of 100 V to form porous aluminum oxide. As the Al film was fully oxidized, a 15 min over anodization and a 30 min post chemical dissolution were used to remove the barrier oxide at the bottom end of pores to generate a barrier-free AAO template. The ALD using reactants of TiCl4 and H₂O was followed to grow a thin layer of SnO₂ on the template to form SnO₂ nanotube arrays. After removing the surface layer of SnO₂ by H₂ plasma and dissolving the template by 5 wt% phosphoric acid solution at 50°C, upright standing SnO₂ nanotube arrays on ITO glass were produced. Finally, Ag top electrode with line width of 5 μm was printed on the nanotube arrays to form SnO₂ nanotube-array sensor. Two SnO₂ nanotube-arrays with wall thickness of 30 and 60 nm were produced in this experiment for the evaluation of gas sensing ability. The flat SnO₂ films with thickness of 30 and 60 nm were also examined for comparison. The results show that the properties of ALD SnO₂ films were related to the deposition temperature. The films grown at 350°C had a low electrical resistivity of 3.6×10-3 Ω-cm and were, therefore, used for the nanotube-array sensors. The carrier concentration and mobility of the SnO₂ films were characterized by Ecopia HMS-3000 Hall-effect measurement system and were 1.1×1020 cm-3 and 16 cm3/V-s, respectively. The electrical resistance of SnO₂ film and nanotube-array sensors in air and in a 5% H₂-95% N₂ mixture gas was monitored by Pico text M3510A 6 1/2 Digits Multimeter. It was found that, at 200 °C, the 30-nm-wall SnO₂ nanotube-array sensor performs the highest responsivity to 5% H₂, followed by the 30-nm SnO₂ film sensor, the 60-nm SnO₂ film sensor, and the 60-nm-wall SnO₂ nanotube-array sensor. However, at temperatures below 100°C, all the samples were insensitive to the 5% H₂ gas. Further investigation on the sensors with thinner SnO₂ is necessary for improving the sensing ability at temperatures below 100 °C.

Keywords: atomic layer deposition, nanotube arrays, gas sensor, tin dioxide

Procedia PDF Downloads 240

Authors: Hanen Bouaziz, Moez Rafrafi, Ghada Ben Salah, Kamel Jamoussi, Tahia Boudawara, Najiba Zeghal

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The present study investigated the protective role of Hyparrhenia hirta against sodium nitrate (NaNO3)-induced nephrotoxicity. A high-performance liquid chromatography coupled with a mass spectrometer (HPLC-MS) method was developed to separate and identify flavonoids in Hyparrhenia hirta. Seven flavonoids were identified as 3-O-methylquercetin, luteolin-7-O-glucoside, luteolin, apigenin-7-O-glucoside, apigenin-8-C-glucoside, luteolin-8-C-glucoside and luteolin-6-C-glucoside. Wistar rats were randomly divided into three groups: a control group and two treated groups during 50 days with NaNO3 administered either alone in drinking water or co-administered with Hyparrhenia hirta. NaNO3 treatment induced a significant increase in plasma levels of creatinine, urea and uric while urinary level decreased significantly. Nephrotoxicity induced by NaNO3 was characterized by significant increase in creatinine clearance. In parallel, a significant increase in malondialdehyde level along with a concomitant decrease in total glutathione content and superoxide dismutase, catalase and glutathione peroxidase activities were observed in the kidney after NaNO3 treatment. The histopathological changes in kidney after NaNO3 administration were shrunken. There were renal tubule cell degeneration and infiltration of mononuclear cells. Most glomeruli revealed shrinkage, a wide capsular space and a peri-glomerular mononuclear cells infiltration. Hyparrhenia hirta supplementation showed a remarkable amelioration of the abnormalities cited above. The results concluded that the treatment with Hyparrhenia hirta had a significant role in protecting the animals from nitrate-induced kidney dysfunction.

Keywords: flavonoids, hyparrhenia hirta, kidney, nitrate toxicity, oxidative stress, rat

Procedia PDF Downloads 437

Authors: Murad Ghanim

Abstract:

The citrus greening disease, also known as Huanglongbing, caused by the phloem-limited bacterium Candidatus Liberibacter asiaticus (CLas) has resulted in tremendous losses and the death of millions of citrus trees worldwide. CLas is transmitted by the Asian citrus psyllid (ACP) Diaphorina citri. The closely-related bacterium Candidatus Liberibacter solanacearum (CLso), which is associated with vegetative disorders in carrots and the zebra chips disease in potatoes, is transmitted by other psyllid species including Bactericera trigonica in carrots and B. ckockerelli in potatoes. Chemical sprays are currently the prevailing method for managing these diseases for limiting psyllid populations; however, they are limited in their effectiveness. A promising approach to prevent the transmission of these pathogens is to interfere with the vector-pathogen interactions, but our understanding of these processes is very limited. CLas induces changes in the nuclear architecture in the midgut of ACP and activates programmed cell death (apoptosis) in this organ. Strikingly, CLso displayed an opposite effect in the gut of B. trigonica, showing limited apoptosis, but widespread necrosis. Electron and fluorescent microscopy further showed that CLas induced the formation of Endoplasmic reticulum (ER) inclusion- and replication-like bodies, in which it increases and multiplies. ER involvement in bacterial replication is hypothesized to be the first stage of an immune response leading to the apoptotic and necrotic responses. ER exploitation and the subsequent events that lead to these cellular and stress responses might activate a cascade of molecular responses ending up with apoptosis and necrosis. Understanding the molecular interactions that underlay the necrotic/apoptotic responses to the bacteria will increase our knowledge of ACP-CLas, and BT-CLso interactions, and will set the foundation for developing novel, and efficient strategies to disturb these interactions and inhibit the transmission.

Keywords: Liberibacter, psyllid, transmission, apoptosis, necrosis

Procedia PDF Downloads 140

Authors: Parmeet Kaur, Nighat Yaseen Sofi, Shakti Kumar Gupta, Veena Pandey, Rajvaedhan Azad

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Nutritional status and prevailing blood glucose level trends amongst hospitalized patients has been linked to clinical outcome. Therefore, the present study was undertaken to assess hospitalized Diabetic Eye Disease (DED) patients' anthropometric and dietary intake trends. DED patients with type 1 or 2 diabetes > 20 years were enrolled. Actual food intake was determined by weighed food record method. Mifflin St Joer predictive equation multiplied by a combined stress and activity factor of 1.3 was applied to estimate caloric needs. A questionnaire was further administered to obtain reasons of inadequate dietary intake. Results indicated validity of joint analyses of body mass index in combination with waist circumference for clinical risk prediction. Dietary data showed a significant difference (p < 0.0005) between average daily caloric and carbohydrate intake and actual daily caloric and carbohydrate needs. Mean fasting and post-prandial plasma glucose levels were 150.71 ± 72.200 mg/dL and 219.76 ± 97.365 mg/dL, respectively. Improvement in food delivery systems and nutrition educations were indicated for reducing plate waste and to enable better understanding of dietary aspects of diabetes management. A team approach of nurses, physicians and other health care providers is required besides the expertise of dietetics professional. To conclude, findings of the present study will be useful in planning nutritional care process (NCP) for optimizing glucose control as a component of quality medical nutrition therapy (MNT) in hospitalized DED patients.

Keywords: nutritional status, diabetic eye disease, nutrition care process, medical nutrition therapy

Procedia PDF Downloads 347

Authors: Andre S. de Lima, Alfredo R. de Faria, Jose J. R. Faria

Abstract:

Accurate prediction of thermal stresses is particularly important for laminated composite structures, as large temperature changes may occur during fabrication and field application. The normal transverse deformation plays an important role in the prediction of such stresses, especially for problems involving thick laminated plates subjected to uniform temperature loads. Bearing this in mind, the present study aims to investigate the thermo-mechanical behavior of laminated composite structures using a new beam element based on global-local superposition, accounting for through-the-thickness effects. The element formulation is based on a global-local superposition in the thickness direction, utilizing a cubic global displacement field in combination with a linear layerwise local displacement distribution, which assures zig-zag behavior of the stresses and displacements. By enforcing interlaminar stress (normal and shear) and displacement continuity, as well as free conditions at the upper and lower surfaces, the number of degrees of freedom in the model is maintained independently of the number of layers. Moreover, the proposed formulation allows for the determination of transverse shear and normal stresses directly from the constitutive equations, without the need of post-processing. Numerical results obtained with the beam element were compared to analytical solutions, as well as results obtained with commercial finite elements, rendering satisfactory results for a range of length-to-thickness ratios. The results confirm the need for an element with through-the-thickness capabilities and indicate that the present formulation is a promising alternative to such analysis.

Keywords: composite beam element, global-local superposition, laminated composite structures, thermal stresses

Procedia PDF Downloads 151

Authors: Ljubica Dokić, Ivana Nikolić, Dragana Šoronja–Simović, Zita Šereš, Biljana Pajin, Nils Juul, Nikola Maravić

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The possibility of application the dietary fibers in production of crackers was observed in this work, as well as their influence on rheological and textural properties on the dough for crackers and influence on sensory properties of obtained crackers. Three different dietary fibers, oat, potato and pea fibers, replaced 10% of wheat flour. Long fermentation process and baking test method were used for crackers production. The changes of dough for crackers were observed by rheological methods of determination the viscoelastic dough properties and by textural measurements. Sensory quality of obtained crackers was described using quantity descriptive method (QDA) by trained members of descriptive panel. Additional analysis of crackers surface was performed by videometer. Based on rheological determination, viscoelastic properties of dough for crackers were reduced by application of dietary fibers. Manipulation of dough with 10% of potato fiber was disabled, thus the recipe modification included increase in water content at 35%. Dough compliance to constant stress for samples with dietary fibers decreased, due to more rigid and stiffer dough consistency compared to control sample. Also, hardness of dough for these samples increased and dough extensibility decreased. Sensory properties of final products, crackers, were reduced compared to control sample. Application of dietary fibers affected mostly hardness, structure and crispness of the crackers. Observed crackers were low marked for flavor and taste, due to influence of fibers specific aroma. The sample with 10% of potato fibers and increased water content was the most adaptable to applied stresses and to production process. Also this sample was close to control sample without dietary fibers by evaluation of sensory properties and by results of videometer method.

Keywords: crackers, dietary fibers, rheology, sensory properties

Procedia PDF Downloads 319

Authors: Ivan Zupan, Tomislav Saric, Suzana Tkalcic

Abstract:

IMUNO-2865® is a commercially available, β–glucan based, natural hemicellulose compound with proven immunostimulative properties in people, domestic and some aquatic animals. During the experimental feeding trial with IMUNO-2865® in juvenile wild-caught chub under laboratory conditions, supplementation resulted in overall higher growth performance for all experimental groups regardless of the concentration of the added compound. The maximum, 5% concentration of the supplement, resulted in highest weight gain and calculated specific growth rate. In sea bream, as economically most important species in the Mediterranean aquaculture, significant increases in numbers of monocytes and heterophils were observed in the group supplemented with 2.5 % of IMUNO-2865® in the feed. An overall increase of erythrocytes was noted by the end of the experiment, although with variable distribution among groups. Blood Ca++ levels, total proteins, and total NH₃ were significantly higher after 60 days of feeding in all treatment groups compared to the control and remained elevated in the treated group following the secession of supplementation. Superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and serum paraoxonase PON1 (U/L) showed similar trends. All these parameters are playing a significant role in either oxygen supplementation of tissues, or anabolic and catabolic processes that on molecular levels contribute to the overall health and immune-building capacity of cells and tissues. The complete lack of mortality in sea bream and presented increases in cellular, biochemical and oxidative stress parameters in the blood suggest that the IMUNO-2865® represents a safe dietary supplement for in aquaculture, with an overall positive and potentially immunostimulative effect on farmed fish.

Keywords: IMUNO-2865®, β–glucans, Mediterranean aquaculture, fish imunnostimulans

Procedia PDF Downloads 139