Search results for: isolated structures

Authors: Temami Oussama, Bessais Lakhdar, Hamadi Djamal, Abderrahmani Sifeddine

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The analysis of complex structures encourages the engineer to make simplifying assumptions, sometimes attempting the analysis of the whole structure as complex as it is, and it can be done using the finite element method (FEM). In the modeling of complex structures by finite elements, various elements can be used: beam element, membrane element, solid element, plates and shells elements. These elements formulated according to the classical formulation and do not generally share the same nodal degrees of freedom, which complicates the development of a compatible model. The compatibility of the elements with each other is often a difficult problem for modeling complicated structure. This compatibility is necessary to ensure the convergence. To overcome this problem, we have proposed finite elements with a rotational degree of freedom. The study used is based on the strain approach formulation with 2D and 3D formulation with different degrees of freedom at each node. For the comparison and confrontation of results; the finite elements available in ABAQUS/Standard are used.

Keywords: compatibility requirement, complex structures, finite elements, modeling, strain approach

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Authors: Annarita Zarrillo

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This research is part of adaptive architecture, reflecting the evolution that the world of architectural design is going through. Today's architecture is no longer seen as a static system but, conversely, as a dynamic system that changes in response to the environment and the needs of users. One of the major forms of adaptivity is represented by kinetic structures. This study aims to underline the importance of experimentation on physical scale models for the study of dynamic structures and to present the case study of a modular kinetic structure designed through the use of parametric design software and created as a prototype in the laboratories of the Royal Danish Academy in Copenhagen.

Keywords: adaptive architecture, architectural application, kinetic structures, modular prototype

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Authors: Azam Fazelpour, Saeed R. Dehghani, Vlastimil Masek, Yuri S. Muzychka

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This study employs a method based on image analyses and structure information to detect accumulated ice on known structures. The icing of marine vessels and offshore structures causes significant reductions in their efficiency and creates unsafe working conditions. Image processing methods are used to measure ice loads automatically. Most image processing methods are developed based on captured image analyses. In this method, ice loads on structures are calculated by defining structure coordinates and processing captured images. A pyramidal structure is designed with nine cylindrical bars as the known structure of experimental setup. Unsymmetrical ice accumulated on the structure in a cold room represents the actual case of experiments. Camera intrinsic and extrinsic parameters are used to define structure coordinates in the image coordinate system according to the camera location and angle. The thresholding method is applied to capture images and detect iced structures in a binary image. The ice thickness of each element is calculated by combining the information from the binary image and the structure coordinate. Averaging ice diameters from different camera views obtains ice thicknesses of structure elements. Comparison between ice load measurements using this method and the actual ice loads shows positive correlations with an acceptable range of error. The method can be applied to complex structures defining structure and camera coordinates.

Keywords: camera calibration, ice detection, ice load measurements, image processing

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Authors: Fdhila Walid, Bayar Sihem, Khouidi Bochra, Maâtouk Fethi, Ben Amor Feten, Hajer Hentati, Mahdhi Abdelkarim

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The presence of resistant bacteria in the oral cavity can be the major cause of dental antibiotic prophylaxis failure. Multidrug efflux has been described for many organisms, including bacteria and fungi as part of their drugs resistance strategy. The potential use of probiotic bacteria can be considered as a new alternative in the prevention or cure of oral cavity diseases. In this study, different Bacillus strains isolated from the environment were isolated and characterized using biochemical and molecular procedures. The inhibitory activity against different pathogenic bacteria and yeast strains was tested using diffusion agar assay method. Our data revealed that the tested strains have an antimicrobial effect against the pathogenic strains such as Streptococcus mutants. The inhibitory effect was variable depending from the probiotic and pathogenic strains. The obtained result demonstrated that Bacillus can be used as a potential candidates probiotic and help in the prevention and treatment of oral infections, including dental caries, periodontal disease and halitosis. Our data, partly encourage the use of probiotic strains because they do not produce acid which can contribute to faster installation decay and these are spore-forming bacteria that can withstand the stress of the oral cavity (acids, alkalis, and salty foods).

Keywords: probiotic, pathogenic bacteria, yeast, oral cavity

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Authors: Pareshkumar Umedbhai Patel

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Variety of microbes were isolated from surface of fruit and vegetables to get idea about normal flora of their surface. The process of isolation of microbes involved use of sterilized cotton swabs to wipe the surface of the samples. For isolation of Bacteria, yeast and fungi microbiological media used were nutrient agar medium, GYE agar medium and MRBA agar medium respectively. The microscopical and macroscopical characteristics of all the isolates were studied. Different plants with known antimicrobial activity were selected for obtaining samples for extraction e.g. Ficus (Ficus religosa) stem, Amla (Phyllanthus emblica) fruit, Tulsi (Ocimum tenuiflorum) leaves and Lemon grass (Cymbopogon citratus) oil. Antimicrobial activity of these samples was tested initially against known bacteria followed by study against microbes isolated from surface of vegetables and fruits. During the studies carried out throughout the work, lemongrass oil and Amla extract were found superior. Lemongrass oil and Amla extract respectively inhibited growth of 65% and 42% microbes isolated from fruit and vegetable surfaces. Rest two studied plant extracts showed only 11% of inhibition against the studied isolates. The results of isolate inhibition show the antibacterial effect of lemongrass oil better than the rest of the studied plant extracts.

Keywords: herbal extracts, vegetables, fruits, antimicrobial activity

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Authors: M. Ezati Kooshki , H. Pourmohamad

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Leaf spring dampers are used for commercial vehicles and heavy tracks. The main function of this damper in these vehicles is protection against damage and providing comfort for drivers by creating suspension between road and vehicle. This paper presents a new device, circular leaf spring damper, which is frequently used on vehicles, aiming to gain seismic protection of structures. Finite element analyses were conducted on several one-story structures using finite element software (Abaqus, v6.10-1). The time history analysis was conducted on the records of Kobe (1995) and San Fernando (1971) ground motions to demonstrate the advantages of using leaf spring in structures as compared to simple bracing system. This paper also suggests extending the use of this damper in structures, considering its large control force despite high cycle fatigue properties and low prices.

Keywords: bracing system, finite element analysis, leaf spring, seismic protection, time history analysis

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Authors: Fadila Mohamed Mahmoud., Derkaoui I., Krimi Z.

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Date palm is a plant which presents a very good adaptation to the difficult conditions of the environment in particular to the drought and saline stress even at high temperatures. This adaptation is related on the biology of the plant and to the presence of a microflora endophyte which live inside its tissues. Fifteen endophytics fungi isolated from date palm were tested in vitro in the presence of various NaCl concentrations to select halotolerantes isolates. These same endophytes were tested for their colonizing capacity by the description of the production of secondary metabolites more particularly the enzymes (pectinases, proteases, and phosphorylases), and the production of antibiotics and growth hormones. Significant difference was observed between the isolates with respect to the tests carried out.

Keywords: Date palm, Halotolerantes, endophyte, Secondary metabolites.

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Authors: Kun Xue, Lvlan Miu, Jiarui Li

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Jetting structures are widely found in particle rings or shells dispersed by the central explosion. In contrast, some explosive dispersal of particles only results in a dispersed cloud without distinctive structures. Employing the coupling method of the compressible computational fluid mechanics and discrete element method (CCFD-DEM), we reveal the underlying physics governing the formation of the jetting structure, which is related to the competition between the shock compaction and gas infiltration, two major processes during the shock interaction with the granular media. If the shock compaction exceeds the gas infiltration, the discernable jetting structures are expected, precipitated by the agglomerates of fast-moving particles induced by the heterogenous network of force chains. Otherwise, particles are uniformly accelerated by the interstitial flows, and no distinguishable jetting structures are formed. We proceed to devise the phase map of the jetting formation in the space defined by two dimensionless parameters which characterize the timescales of the shock compaction and the gas infiltration, respectively.

Keywords: compressible multiphase flows, DEM, granular jetting, pattern formation

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Authors: Lukas Ded

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Studying the tissue structure and histogenesis in the natural, 3D context is challenging but highly beneficial process. Contrary to classical approach of the physical tissue sectioning and subsequent imaging, it enables to study the relationships of individual cellular and histological structures in their native context. Recent developments in the tissue clearing approaches and microscopic volume imaging/data processing enable the application of these methods also in the areas of developmental and reproductive biology. Here, using the CLARITY tissue procedure and 3D confocal volume imaging we optimized the protocol for clearing, staining and imaging of the mice seminiferous tubules isolated from the testes without cardiac perfusion procedure. Our approach enables the high magnification and fine resolution axial imaging of the whole diameter of the seminiferous tubules with possible unlimited lateral length imaging. Hence, the large continuous pieces of the seminiferous tubule can be scanned and digitally reconstructed for the study of the single tubule seminiferous stages using nuclear dyes. Furthermore, the application of the antibodies and various molecular dyes can be used for molecular labeling of individual cellular and subcellular structures and resulting 3D images can highly increase our understanding of the spatiotemporal aspects of the seminiferous tubules development and sperm ultrastructure formation. Finally, our newly developed algorithms for 3D data processing enable the massive parallel processing of the large amount of individual cell and tissue fluorescent signatures and building the robust spermatogenic models under physiological and pathological conditions.

Keywords: CLARITY, spermatogenesis, testis, tissue clearing, volume imaging

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Authors: Giang Tran Thi Huong, Hieu Dong Van, Tung Dao Duy, Saadanov Iskender, Isakeev Mairambek, Tsutomu Omatsu, Yukie Katayama, Tetsuya Mizutani, Yuki Ozeki, Yohei Takeda, Haruko Ogawa, Kunitoshi Imai

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Newcastle disease virus (NDV) is a contagious viral disease of the poultry industry and other birds throughout the world. At present, very little is known about molecular epidemiological data regarding the causes of ND outbreak in commercial poultry farms in Kyrgyzstan. In the current study, the NDV isolated from the one out of three samples from the unvaccinated flock was confirmed as NDV. Phylogenetic analysis indicated that this NDV strain is clustered in the Class II subgenotype VIId, and closely related to the Chinese NDV isolate. Phylogenetic analyses revealed that the isolated NDV strain has an origin different from the 4 NDV strains previously identified in Kyrgyzstan. According to the mean death time (MDT: 61.1 h) and a multibasic amino acid (aa) sequence at the F0 proteolytic cleavage site (¹¹²R-R-Q-K-R-F¹¹⁷), the NDV isolate was determined as mesogenic strain. Several mutations in the neutralizing epitopes (notably, ³⁴⁷E→K) and the global head were observed in the hemagglutinin-neuraminidase (HN) protein of the current isolate. The present study represents the molecular characterization of the coding gene region of NDV in Kyrgyzstan. Additionally, further study will be investigated on the antigenic characterization using monoclonal antibody.

Keywords: Kyrgyzstan, Newcastle disease, genotype, genome characterization

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Authors: Ge Cui, Mei Fang Chien, Chihiro Inoue

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In this research, enrichment culture using an inorganic liquid medium collected soil contaminated with 1,2-dichlorobenzene (1,2-DCB) in Sendai, Japan, was added 1,2-DCB as the sole carbon source to create a stable consortium. The purpose of this research is to analysis dominant microorganisms in the stable consortium and enzyme system which play a role in the degradation of DCBs. The consortium is now at 30 generation and is still being cultured. By the result of PCR-DGGE and clone library, two bacteria are dominant. The bacteria named sk1 was isolated. 40mg/l of 1,2-DCB and 40mg/l of 1,4-DCB were completely degraded after 32 hours and 50 hours, respectively, but no degradation occurred in the case of 1,3-DCB. By PCR, tecA1 (α-subunit of DCB dioxygenase) gene which plays a role degrading DCB to DCB dihydrodiol, and tecB (dehydrogenase) gene which plays a role degrading DCB dihydrodiol to dichlorocatechol were amplified from strain sk1. Bacteria named sk100 was also isolated. 40mg/l of 1,2-DCB was completely degraded after 32 hours, but no degradation occurred in case of 1,3-DCB and 1,4-DCB. By the result of the catalytic core region of dioxygenase amplified by PCR, gene played a role degrading DCB was analyzed. The results of this study concluded that the isolated strains which have not been reported are able to degrade 1,2-DCB stably, and the characterization of degradation and the genomic analysis which is now in progress is helpful to have an overall view of this microbial degradation.

Keywords: DCB, 1, 2-DCB degrading strains, DCB dioxygenase, enrichment culture

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Authors: Abouzar Kaboudian, Ravi Chaithanya Mysa, Boo Cheong Khoo, Rajeev Kumar Jaiman

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Vortex induced vibrations can significantly affect the effectiveness of structures in aerospace as well as offshore marine industries. The oscillatory nature of the forces resulting from the vortex shedding around bluff bodies can result in undesirable effects such as increased loading, stresses, deflections, vibrations and noise in the structures, and also reduced fatigue life of the structures. To date, most studies concentrate on either the free oscillations or the prescribed motion of the bluff bodies. However, the structures in operation are usually subject to the external oscillatory forces (e.g. due to the platform motions in offshore industries). In this work, we present the effects of the external cross-flow forces on the vortex-induced vibrations of an oscillating cylinder. The effects of the amplitude, as well as the frequency of the external force on the fluid-forces on the oscillating cylinder are carefully studied and presented. Moreover, we present the transition of the response to be dominated by the vortex-induced-vibrations to the range where it is mostly dictated by the external oscillatory forces. Furthermore, we will discuss how the external forces can affect the flow structures around a cylinder. All results are compared against free oscillations of the cylinder.

Keywords: circular cylinder, external force, vortex-shedding, VIV

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Authors: Davood Mousanezhad, Ashkan Vaziri

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As a traditional cellular structure, hexagonal honeycombs are known for their high strength-to-weight ratio. Here, we introduce a class of fractal-appearing hierarchical metamaterials by replacing the vertices of the original non-hierarchical hexagonal grid with smaller hexagons and iterating this process to achieve higher levels of hierarchy. It has been recently shown that the isotropic in-plane Young's modulus of this hierarchical structure at small deformations becomes 25 times greater than its regular counterpart with the same mass. At large deformations, we find that hierarchy-dependent elastic buckling introduced at relatively early stages of deformation decreases the value of Poisson's ratio as the structure is compressed uniaxially leading to auxeticity (i.e., negative Poisson's ratio) in subsequent stages of deformation. We also show that the topological hierarchical architecture and instability-induced pattern transformations of the structure under compression can be effectively used to tune the propagation of elastic waves within the structure. We find that the hierarchy tends to shift the existing phononic bandgaps (defined as frequency ranges of strong wave attenuation) to lower frequencies while opening up new bandgaps. Deformation is also demonstrated as another mechanism for opening more bandgaps in hierarchical structures. The results provide new insights into the role of structural organization and hierarchy in regulating mechanical properties of materials at both the static and dynamic regimes.

Keywords: cellular structures, honeycombs, hierarchical structures, metamaterials, multifunctional structures, phononic crystals, auxetic structures

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Authors: V. Swarnalatha, A. V. Narasimha Rao, P. Pal

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The present research reports the investigation of fast etching of silicon for the fabrication of microelectromechanical systems (MEMS) structures using silicon wet bulk micromachining. Low concentration tetramethyl-ammonium hydroxide (TMAH) and hydroxylamine (NH₂OH) are used as main etchant and additive, respectively. The concentration of NH₂OH is varied to optimize the composition to achieve best etching characteristics such as high etch rate, significantly high undercutting at convex corner for the fast release of the microstructures from the substrate, and improved etched surface morphology. These etching characteristics are studied on Si{100} and Si{110} wafers as they are most widely used in the fabrication of MEMS structures as wells diode, transistors and integrated circuits.

Keywords: KOH, MEMS, micromachining, silicon, TMAH, wet anisotropic etching

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Authors: Mustafa Gulen, Eylem Guzel, Soner Guler

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The studies concentrated on the historical background of Van city show the fact that Van city has had a significant position as a settlement since ancient times and that it has hosted many civilizations during history. With the dominance of Ottoman Empire in 16th century, the region had been re-constructed by building new walls at the southern side of Van Castle. These construction activities had mostly been fulfilled by the usage of mudbrick which had been a fundamental material for thousands of years. As a result of natural disasters, battles and the move at the threshold of 20th century to the new settlement which is 9 kilometers away from the Ancient City Van is an open-air museum with the ruins of churches, mosques and baths. In this study, the usage of mudbrick from past till today in historical structures of Van city is evaluated in detail.

Keywords: historical structures, history, mudbrick, Van city

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Authors: Musa Filibus Gugu

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An investigation was carried out on the effect of garlic powder extract on fungi associated with Irish potato rot in Bokkos, Plateau State, Nigeria. Diseased Irish potatoes were randomly collected from three markets in the study location and fungal species isolated. Isolated fungal species were Fusarium culmorum, Fusarium oxysporum, and Pytophthora infestans. Frequency of occurrence for Fusarium culmorum, Fusarium oxysporum, and Pytophthora infestans was 10%, 34%, and 56%, respectively, using sabauraud dextrose agar, after incubation for 4-7 days. Treatment of Pytophthora infestans with garlic powder extract at concentrations of 0.5g/ml, 0.4g/ml, 0.3gml, 0.2g/ml and 0.1g/ml showed 100%, 92%, 68%, 32% and 10% inhibition zones, respectively. Fusarium culmorum showed 100%, 90%, 40%, 9% and 0% inhibition zones when treated with garlic powder extract at concentrations of 0.5g/ml, 0.4g/ml, 0.3gml, 0.2g/ml and 0.1g/ml, respectively. Garlic powder extract concentrations of 0.5g/ml, 0.4g/ml, 0.3gml, 0.2g/ml and 0.1g/ml showed 100%, 98%, 55%, 30%, 0% inhibition zones, respectively on Fusarium oxysporum. Hence, Restriction of the radial growth of the fungal colonies suggests a good antifungal effect of garlic extract. This can be integrated into the treatment of fungal diseases of Irish potato in Bokkos, Nigeria, as this will help to reduce the indiscriminate use of fungicides, especially in an environment with a struggling economy.

Keywords: fungal rot, garlic extract, inhibition zone, Irish potato

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Authors: Mohammad Nazri Mustafa, Pedram Hatami Abdullah, M. Fakhrur Razi Ahmad Faizul

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With the issuance of Malaysian National Annex 2017 as a part of MS EN 1998-1:2015, the seismic mapping of Malaysian Peninsular including Sabah and Sarawak has undergone some changes in terms of the Peak Ground Acceleration (PGA) value. The revision to the PGA has raised a concern on the safety of oil and gas onshore structures as these structures were not designed to accommodate the new PGA values which are much higher than the previous values used in the original design. In view of the high numbers of structures and buildings to be re-assessed, a risk assessment methodology has been developed to prioritize and rank the assets in terms of their criticality against the new seismic loading. To-date such risk assessment method for oil and gas onshore structures is lacking, and it is the main intention of this technical paper to share the risk assessment methodology and risk elements scoring finalized via Delphi Method. The finalized methodology and the values used to rank the risk elements have been established based on years of relevant experience on the subject matter and based on a series of rigorous discussions with professionals in the industry. The risk scoring is mapped against the risk matrix (i.e., the LOF versus COF) and hence, the overall risk for the assets can be obtained. The overall risk can be used to prioritize and optimize integrity assessment, repair and strengthening work against the new seismic mapping of the country.

Keywords: methodology, PGA, risk, seismic

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Authors: Ehsan Sadie

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The use of steel braces in concrete structures has been considered by researchers in recent decades due to its easy implementation, economics and the ability to create skylights in braced openings compared to shear wall openings as well as strengthening weak concrete structures to earthquakes. The purpose of this article is to improve and strengthen concrete structures with steel bracing. In addition, cases such as different numbers of steel braces in different openings of concrete structures and interaction between concrete frames and metal braces have been studied. In this paper, by performing static nonlinear analysis and examining ductility, the relative displacement of floors, examining the performance of samples, and determining the coefficient of behavior of composite frames (concrete frames with metal bracing), the behavior of reinforced concrete frames is compared with frame without bracing. The results of analyzes and studies show that the addition of metal bracing increases the strength and stiffness of the frame and reduces the ductility and lateral displacement of the structure. In general, the behavior of the structure against earthquakes will be improved.

Keywords: behavior coefficient, bracing, concrete structure, convergent bracing, earthquake, linear static analysis, nonlinear analysis, pushover curve

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Authors: L. Bokopane, K. Kusakana, H. J. Vermaark

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The success of renewable powered electric vehicle charging station in isolated areas depends highly on the availability and sustainability of renewable resources all year round at a selected location. The main focus of this paper is to discuss the possible charging strategies that could be implemented to find the best possible configuration of an electric Tuk-Tuk charging station at a given location within South Africa. The charging station is designed, modeled and simulated to evaluate its performances. The techno-economic analysis of different feasible supply configurations of the charging station using renewable energies is simulated using HOMER software and the results compared in order to select the best possible charging strategies in terms of cost of energy consumed.

Keywords: electric tuk-tuk, renewable energy, energy Storage, hybrid systems, HOMER

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Authors: Daniela N. Correa-Llantén, Sebastián A. Muñoz-Ibacache, Mathilde Maire, Jenny M. Blamey

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The biosynthesis of nanoparticles by microorganisms, on the contrary to chemical synthesis, is an environmentally-friendly process which has low energy requirements. In this investigation, we used the microorganism Geobacillus wiegelii, strain GWE1, an aerobic thermophile belonging to genus Geobacillus, isolated from a drying oven. This microorganism has the ability to reduce selenite evidenced by the change of color from colorless to red in the culture. Elemental analysis and composition of the particles were verified using transmission electron microscopy and energy-dispersive X-ray analysis. The nanoparticles have a defined spherical shape and a selenium elemental state. Previous experiments showed that the presence of the whole microorganism for the reduction of selenite was not necessary. The results strongly suggested that an intracellular NADPH/NADH-dependent reductase mediates selenium nanoparticles synthesis under aerobic conditions. The enzyme was purified and identified by mass spectroscopy MALDI-TOF TOF technique. The enzyme is a 1-pyrroline-5-carboxylate dehydrogenase. Histograms of nanoparticles sizes were obtained. Size distribution ranged from 40-160 nm, where 70% of nanoparticles have less than 100 nm in size. Spectroscopic analysis showed that the nanoparticles are composed of elemental selenium. To analyse the effect of pH in size and morphology of nanoparticles, the synthesis of them was carried out at different pHs (4.0, 5.0, 6.0, 7.0, 8.0). For thermostability studies samples were incubated at different temperatures (60, 80 and 100 ºC) for 1 h and 3 h. The size of all nanoparticles was less than 100 nm at pH 4.0; over 50% of nanoparticles have less than 100 nm at pH 5.0; at pH 6.0 and 8.0 over 90% of nanoparticles have less than 100 nm in size. At neutral pH (7.0) nanoparticles reach a size around 120 nm and only 20% of them were less than 100 nm. When looking at temperature effect, nanoparticles did not show a significant difference in size when they were incubated between 0 and 3 h at 60 ºC. Meanwhile at 80 °C the nanoparticles suspension lost its homogeneity. A change in size was observed from 0 h of incubation at 80ºC, observing a size range between 40-160 nm, with 20% of them over 100 nm. Meanwhile after 3 h of incubation at size range changed to 60-180 nm with 50% of them over 100 nm. At 100 °C the nanoparticles aggregate forming nanorod structures. In conclusion, these results indicate that is possible to modulate size and shape of biologically synthesized nanoparticles by modulating pH and temperature.

Keywords: genus Geobacillus, NADPH/NADH-dependent reductase, selenium nanoparticles, biosynthesis

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Authors: Mehran Fadaeinasab, Alireza Basiri, Yalda Kia, Hamed Karimian, Hapipah Mohd Ali, Vikneswaran Murugaiyah

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Two new, rauvolfine C and 3- methyl-10,11-dimethoxyl-6- methoxycarbonyl- β- carboline, along with five known indole alkaloids, macusine B, vinorine, undulifoline, isoresrpiline and rescinnamine were isolated from the bark of Rauvolfia reflexa. All the compounds showed good to moderate cholinesterase inhibitory activity with IC50 values in the range of 8.06 to 73.23 πM, except rauvolfine C that was inactive against acetylcholinesterase (AChE). Rescinnamine, a dual inhibitor was found to be the most potent inhibitor among the isolated alkaloids against both AChE and butyrylcholinesterase (BChE). Molecular docking revealed that rescinnamine interacted differently on AChE and BChE, by means of hydrophobic interactions and hydrogen bonding.

Keywords: Rauvolfia reflexa, indole alkaloids, acetylcholinesterase, butyrylcholinesterase, molecular docking

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Authors: A. Zh. Aupova, A. Ulankyzy, A. Sarsenova, A. Kussayin, Sh. Turarbek, N. Moldagulova, A. Kurmanbayev

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One of the methods of organic waste bioconversion into environmentally-friendly fertilizer is composting. Microorganisms that produce hydrolytic enzymes play a significant role in accelerating the process of organic waste composting. We studied the enzymatic potential (amylase, protease, cellulase, lipase, urease activity) of bacteria isolated from the sewage sludge of Nur-Sultan, Rudny, and Fort-Shevchenko cities, the dacha soil of Nur-Sultan city, and freshly cut grass from the dacha for processing organic waste and identifying active strains. Microorganism isolation was carried out by the cultures enrichment method on liquid nutrient media, followed by inoculating on different solid media to isolate individual colonies. As a result, sixty-one microorganisms were isolated, three of which were thermophiles (DS1, DS2, and DS3). The highest number of isolates, twenty-one and eighteen, were isolated from sewage sludge of Nur-Sultan and Rudny cities, respectively. Ten isolates were isolated from the wastewater of the sewage treatment plant in Fort-Shevchenko. From the dacha soil of Nur-Sultan city and freshly cut grass - 9 and 5 isolates were revealed, respectively. The lipolytic, proteolytic, amylolytic, cellulolytic, ureolytic, and oil-oxidizing activities of isolates were studied. According to the results of experiments, starch hydrolysis (amylolytic activity) was found in 2 isolates - CB2/2, and CB2/1. Three isolates - CB2, CB2/1, and CB1/1 were selected for the highest ability to break down casein. Among isolated 61 bacterial cultures, three isolates could break down fats - CB3, CBG1/1, and IL3. Seven strains had cellulolytic activity - DS1, DS2, IL3, IL5, P2, P5, and P3. Six isolates rapidly decomposed urea. Isolate P1 could break down casein and cellulose. Isolate DS3 was a thermophile and had cellulolytic activity. Thus, based on the conducted studies, 15 isolates were selected as a potential for sewage sludge composting - CB2, CB3, CB1/1, CB2/2, CBG1/1, CB2/1, DS1, DS2, DS3, IL3, IL5, P1, P2, P5, P3. Selected strains were identified on a mass spectrometer (Maldi-TOF). The isolate - CB 3 was referred to the genus Rhodococcus rhodochrous; two isolates CB2 and CB1 / 1 - to Bacillus cereus, CB 2/2 - to Cryseobacterium arachidis, CBG 1/1 - to Pseudoxanthomonas sp., CB2/1 - to Bacillus megaterium, DS1 - to Pediococcus acidilactici, DS2 - to Paenibacillus residui, DS3 - to Brevibacillus invocatus, three strains IL3, P5, P3 - to Enterobacter cloacae, two strains IL5, P2 - to Ochrobactrum intermedium, and P1 - Bacillus lichenoformis. Hence, 60 isolates were isolated from the wastewater of the cities of Nur-Sultan, Rudny, Fort-Shevchenko, the dacha soil of Nur-Sultan city, and freshly cut grass from the dacha. Based on the highest enzymatic activity, 15 active isolates were selected and identified. These strains may become the candidates for bio preparation for sewage sludge processing.

Keywords: sewage sludge, composting, bacteria, enzymatic activity

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Authors: Isaac Quiros-Fernandez, Angel Cid-Arregui

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Tumor-reactive T cell receptors (TCRs) are being subject of intense investigation since they offer great potential in adoptive cell therapies against cancer. However, the identification of tumor-specific TCRs has proven challenging, for instance, due to the limited expansion capacity of tumor-infiltrating T cells (TILs) and the extremely low frequencies of tumor-reactive T cells in the repertoire of patients and healthy donors. We have developed an approach for rapid identification and characterization of neoepitope-reactive TCRs from the T cell repertoire of healthy donors. CD8 T cells isolated from multiple donors are subjected to a first sorting step after staining with HLA multimers carrying the peptide of interest. The isolated cells are expanded for two weeks, after which a second sorting is performed using the same peptide-HLA multimers. The cells isolated in this way are then processed for single-cell sequencing of their TCR alpha and beta chains. Newly identified TCRs are cloned in appropriate expression vectors for functional analysis on Jurkat, NK92, and primary CD8 T cells and tumor cells expressing the appropriate antigen. We have identified TCRs specifically binding HLA-A2 presenting epitopes of tumor antigens, which are capable of inducing TCR-mediated cell activation and cytotoxicity in target cancer cell lines. This method allows the identification of tumor-reactive TCRs in about two to three weeks, starting from peripheral blood samples of readily available healthy donors.

Keywords: cancer, TCR, tumor antigens, immunotherapy

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Authors: Carlos Alberto Riveros, Edwin Fabián García, Javier Enrique Rivero

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The measured data obtained from sensors in continuous monitoring of civil structures are mainly used for modal identification and damage detection. Therefore when modal identification analysis is carried out the quality in the identification of the modes will highly influence the damage detection results. It is also widely recognized that the usefulness of the measured data used for modal identification and damage detection is significantly influenced by the number and locations of sensors. The objective of this study is the numerical implementation of two widely known optimum sensor placement methods in beam-like structures

Keywords: optimum sensor placement, structural damage detection, modal identification, beam-like structures.

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Authors: Ridzuan Ramli, Norhafzan Junadi, Mohammad D.H. Beg, Rosli M. Yunus

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In this study, microcrystalline cellulose (MCC) was extracted from oil palm empty fruit bunch (EFB) cellulose which was earlier isolated from oil palm EFB fibre. In order to isolate the cellulose, the chlorination method was carried out. Then, the MCC was prepared by simultaneous ultrasonic and alkali treatment from the isolated α-cellulose. Based on mass balance calculation, the yields for MCC obtained from EFB was 44%. For fiber characterization, it is observed that the chemical composition of the hemicellulose and lignin for all samples decreased while composition for cellulose increased. The structural property of the MCC was studied by X-ray diffraction (XRD) method and the result shows that the MCC produced is a cellulose-I polymorph, with 73% crystallinity.

Keywords: oil palm empty fruit bunch, microcrystalline cellulose, ultrasonic, alkali treatment, x-ray diffraction

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Authors: Kahil Amar, Nekmouche Aghiles, Titouche Billal, Hamizi Mohand, Hannachi Naceur Eddine

Abstract:

The ductility is an important parameter in the nonlinear behavior of portal structures reinforced concrete. It may be explained by the ability of the structure to deform in the plastic range, or the geometric characteristics in the map may influence the overall ductility. Our study is based on the influence of geometric slenderness (Lx / Ly) on the overall ductility of these structures, a study is made on a structure has 05 floors with varying the column section of 900 cm², 1600 cm² and 1225 cm². A slight variation in global ductility is noticed as (Lx/Ly) varies; however, column sections can control satisfactorily the plastic behavior of buildings.

Keywords: ductility, nonlinear behavior, pushover analysis, geometric slenderness, structural behavior

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Authors: Johanna Bapela, Heino Heyman, Marion Meyer

Abstract:

Regardless of the significant advances accomplished in reducing the burden of malaria and other tropical diseases in recent years, malaria remains a major cause of mortality in endemic countries. This is especially the case in sub-Saharan Africa where 99% of the estimated global malaria deaths occurs on an annual basis. The emergence of resistant Plasmodium species and the lack of diversified chemotherapeutic agents provide the rationale for bioprospecting for antiplasmodial scaffolds. Crude extracts from twenty indigenous antimalarial plant species were screened for antimalarial activity and then subjected to 1H NMR-based metabolomic analysis. Ten plant extracts exhibited significant in vitro antiplasmodial activity (IC50 ≤ 5 µg/ml). The Principal Component Analysis (PCA) of the acquired 1H NMR spectra could not separate the analyzed plant extracts according to the detected antiplasmodial bioactivity. Application of supervised Orthogonal Projections to Latent Structures–Discriminant Analysis (OPLS-DA) to the 1H NMR profiles resulted in a discrimination pattern that could be correlated to bioactivity. A contribution plot generated from the OPLS-DA scoring plot illustrated the classes of compounds responsible for the observed grouping. Given the preliminary in vitro results, Tabernaemontana elegans Stapf. (Apocynaceae) and Vangueria infausta Burch. subsp. infausta (Rubiaceae) were subjected to further phytochemical investigations. Two indole alkaloids, dregamine and tabernaemontanine possessing antiplasmodial activity were isolated from T. elegans. Two compounds were isolated from V. infausta subsp. infausta and identified as friedelin (IC50 = 3.01 µg/ml) and morindolide (IC50 = 18.5 µg/ml). While these compounds have been previously identified, this is the first account of their occurrence in the genus Vangueria and their antiplasmodial activity. Based on the results of the study, metabolomics can be used to globally identify classes of plant secondary metabolites that are responsible for antiplasmodial activity.

Keywords: ethnopharmacology, Malaria, medicinal plants, metabolomics

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Authors: Odunayo Christy Atewolara-Odule, Olapeju O. Aiyelaagbe

Abstract:

The search for new natural anti-oxidants has grown tremendously over the years because reactive oxygen species (ROS) production and oxidative stress have been linked to a large number of human degenerative diseases, such as cancer, cardiovascular diseases, inflammation, and diabetes. Tapinanthus bangwensis, a parasitic plant commonly known as mistletoe belonging to the Loranthaceae family, is mostly employed traditionally to treat inflammation, cancer, diabetes, and hypertension to mention a few. In this study, air-dried pulverized leaves and stem of Tapinanthus bangwensis were successively extracted with n-hexane, ethyl acetate, and methanol to give the corresponding crude extracts. The extracts were purified by column chromatography and high-performance liquid chromatography to give the isolated compounds. Structural elucidation was done using mass spectrometry, Fourier transform infra-red, 1D and 2D NMR spectroscopy. The antioxidant activity of the compounds was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ascorbic acid as standard. Three compounds; Friedelin, Eudesmic acid (3,4,5-trimethoxybenzoic) and Methyl-3,4,5-trimethoxybenzoate were isolated from the extracts of Tapinanthus bangwensis. Friedelin was isolated from the ethyl acetate extract of the stem while the two other compounds were isolated from the methanol extract of the leaves. The percentages of free radical scavenging activities of the compounds are as follows: Friedelin, 73.69%, methyl-3,4,5-trimethoxybenzoate, 79.33% and eudesmic, 87.68% anti-oxidant activity which were quite comparable to 93.96% given by ascorbic acid. We are reporting, to our best knowledge, for the first time the occurrence of friedelin and eudesmic acid in Tapinanthus bangwensis. The high anti-oxidant activity of these compounds supports the use of this plant in the management of diabetes and hypertension as they will be useful in combating complications arising from the disease.

Keywords: column chromatography, eudesmic acid, friedelin, Tapinanthus bangwensis

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Authors: Djamal Hamadi, Ashraf Ayoub, Ounis Abdelhafid, Chebili Rachid

Abstract:

In this paper, a new computationally-efficient rectangular flat shell finite element named 'ACM_RSBEC' is presented. The formulated element is obtained by superposition of a new rectangular membrane element 'RSBEC' based on the strain approach and the well known plate bending element 'ACM'. This element can be used for the analysis of thin shell structures, no matter how the geometrical shape might be. Tests on standard problems have been examined. The convergence of the new formulated element is also compared to other types of quadrilateral shell elements. The presented shell element ‘ACM_RSBEC’ has been demonstrated to be effective and useful in analysing thin shell structures.

Keywords: finite element, flat shell element, strain based approach, static condensation

Procedia PDF Downloads 387

Authors: Soumya S., Manju Nidagodu Jayakumar, Vellore Kannan Gopinath

Abstract:

Dental pulp inflammation resulting from dental caries often leads to a pathologic condition known as irreversible pulpitis and the currently managed by root canal treatment. Extirpation of the entire pulp tissue is done during this procedure, and the canal space is filled with synthetic materials. Recent studies in the stem cell biology state that some portion of the irreversibly inflamed pulp tissue could be viable with progenitor cells, having the properties similar to that of Mesenchymal stem cells. Hence, we aim to isolate Dental Pulp Stem Cells (DPSCs) from patients diagnosed with severe irreversible pulpitis and characterize the cells for the MSC specific markers. The pulp tissue was collected from the dental clinic and subjected to collagenase/dispase digestion. The isolated cells were expanded in culture, and the phenotypic characterization was done using flow cytometry. MSC specific markers such as CD-90, CD-73, and CD-105 were analysed along with negative markers such as CD-14 and CD-45. The isolated cells expressed positive expression for CD markers with CD90 and CD105 ( > 95%) and CD73 (19%). The cells did not express the negative markers CD-14 and CD-45. The commercially available DPSCs from vital extracted teeth, preferably molar/wisdom teeth with large pulp cavity or incomplete root growth in young patients (aged 15-30 years) showed more than 90% expression for all the CD markers such as CD-90, 73 and 105, whereas negative for CD-14 and CD-45. The DPSCs isolated from inflamed pulp tissue showed a less expression for CD-73 compared to the commercially available DPSCs whereas, as the other two markers were found to show similar percentage of positive expression. This could be attributed to the fact that the pulp population is very heterogeneous and we used the pooled tissue from different patients. Hence the phenotypic characterization and comparison with the commercially available DPSCs proved that the inflamed pulp tissue is a good source of MSC like cells which can be utilized further for regenerative application.

Keywords: collagenase/dispase, dental pulp stem cells, flow cytometry, irreversible pulpitis

Procedia PDF Downloads 223