Search results for: improvement of properties

Authors: Biruk Hundito Lodebo

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The main purpose of this study was to investigate the problems of sports commitment and athlete satisfaction of Oromia league football clubs in the West, East and Horro Guduru wollega zones. The descriptive survey method was designed and approached as a quantitative method. The data was collected by questionnaires. The research data was collected from sports commitment and athlete satisfaction variables. The target population of this study was (3x30=90) and the researcher selected by using purposive sampling techniques. The data were analysed by SPSS Software (Version 20). Such as mean standard deviation, one-way ANOVA and correlational analysis. The level of significance is 0.05 alpha level. The researchers' hypothesis of this study was: (1) There is no significant difference between sports commitments and player satisfaction indices in all selected Oromia league football wollega zones. (2)There is no significant difference between sports commitments and player satisfaction indices in all selected Oromia league football wollega zones.(3)There is no correlation between the variables of sports commitments and player satisfaction indices in all selected Oromia league football wollega zones. Finally, the study findings indicated that: (a) There is no significant difference between sports commitment and athlete satisfaction of Oromia league football clubs. (b) There is no significant difference between player age and sports commitment in Oromia league football clubs in the West, East and Horro Guduru wollega zones. (c) There is no significant difference between player age and athlete satisfaction in Oromia league football clubs in the West, East and Horro Guduru wollege zones. Based on the research findings the following recommendations were forwarded: The club management and players should be made a positive linkage and improvement between sports commitments and player satisfaction, All clubs management staff and coaching staff should promote Sports commitment and player satisfaction. Workshops and short-term training can be held for all of sports management staff and players.

Keywords: sports commetmnet, Athet satisfaction, football, Oromia league

Procedia PDF Downloads 103

Authors: Ahmed M. Al-Mahbashi, Mosleh A. Al-Shamrani, Muawia Dafalla

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Mixtures of sand and clay are frequently used to serve for specific purposes in several engineering practices. In environmental engineering, liner layers and cover layers are common for controlling waste disposal facilities. These layers are exposed to moisture and temperature fluctuation specially when existing in unsaturated condition. The relationship between soil suction and water content for these materials is essential for understanding their unsaturated behavior and properties such as retention capacity and unsaturated follow (hydraulic conductivity). This study is aimed at investigating retention capacity for two sand-natural expansive clay mixtures (15% (C15) and 30% (C30) expansive clay) at two ambient temperatures within the range of 5 -50 °C. Soil water retention curves (SWRC) for these materials were determined at these two ambient temperatures using different salt solutions for a wide range of suction (up to 200MPa). The results indicate that retention capacity of C15 mixture underwent significant changes due to temperature variations. This effect tends to be less visible when the clay fraction is doubled (C30). In addition, the overall volume change is marginally affected by high temperature within the range considered in this study.

Keywords: soil water retention curve, sand-expansive clay liner, suction, temperature

Procedia PDF Downloads 139

Authors: Alireza Rafie Boldaji, Ahmad Saboonchi

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Chokes are commonly used in oil and gas production systems. A choke is a restriction basically designed to control flow rates of oil and gas wells, to prevent the downstream disturbances from propagating upstream (critical flow), and to protect the surface equipment facilities against slugging at high flowing pressures. There are different methods to calculate the multiphase flow rate, one of the multiphase flow measurement methods is the separation and measurement by on¬e-phaseFlow meter, another common method is the use of movable separator, their operations are very labor-intensive and costly. The current method used is based on the flow differential pressure on both sides of choke. Three groups of correlations describing two-phase flow through wellhead chokes were examined. The first group involved simple empirical equations similar to those of Gilbert, the second group comprised derived equations of two-phase flow incorporating PVT properties, and third group is computational method. In the article we calculate the flow of oil and gas through choke with simulation of this two phase flow bye computational fluid dynamic method, we use Ansys- fluent for this simulation and finally compared results of computational simulation whit empirical equations, the results show good agreement between experimental and numerical results.

Keywords: CFD, two-phase, choke, critical

Procedia PDF Downloads 277

Authors: Ziaul Islam, Asad Sultan, Sarzamin Khan

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Organic acids and micro encapsulated phyto essential oils have revealed great potential as an antibiotic replacement and as an additive to work tremendously for the health maintenance of broiler chicken. To explore more about organic acids, a total of 600 day-old broiler chicks (Cobb-500) were procured from a local hatchery and distributed into 5 treatment groups having 6 replicates of 20 birds each; the duration of the biological trial was of 35 days. Group T1 served as a control group that were fed on corn soy-based diet only. T2 were fed with a diet having 6% poultry by-product meal (PBM) diet, T3, T4, and T5 were served as the same diet as T2 but supplemented with an organic acid, phyto essential oils alone, and a combination, respectively. The findings declared significant improvement (p<0.05) in body weight gain and FCR in groups T3, T4, and T5 while feed intake was not affected. European broiler performance indicators like production efficiency factor (EPEF) and broiler index (EBI) were improved significantly (p<0.05) by the treatments T3, T4, and T5 compared with T1 and T2. Carcass evaluation depicted significantly better (p<0.05) dressed and eviscerated weight along with carcass yield (T3, T4, T5). Broilers fed organic acid and phyto essential oils supplemented diet had significantly lower (p<0.05) Clostridium perfringens, Escherichia coliand Salmonella and increased Lactobacillus counts. Likewise, antibody titer against ND, IB, and IBD were also significantly (p<0.05) improved by the treatments T3, T4 and T5compared with the T1and T2. Litter moisture content was significantly (p<0.05) reduced by treatmentsT3, T4, and T5 on day 28 and 35 compared with the T1 and T2. These findings of the present study revealed that supplementation of organic acids blend and phyto-essential oils as an as an substitute to improve the performance of broilers without the use of feed antibiotics in broilers fed with 6% poultry by-product meal based diet.

Keywords: organic acid, phyto essential oils, growth performance, PBM, gut health, microbiota, immunity

Procedia PDF Downloads 128

Authors: Moustafa Ali Elwan, Ibrahim Salem Abdelrafa, Ashraf Moharm

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Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most commonly prescribed oral and topical drugs worldwide. Moreover, NSAIDs are responsible for most of all adverse drug reactions. For several decades, there are numerous attempts to use the cutaneous layers as a gate into the body for the local delivery of the therapeutic agent. Transdermal drug delivery is a validated technology contributing significantly to global pharmaceutical care. Transdermal Drug Delivery systems can be improved by using therapeutic agents. Moreover, Transdermal Drug Delivery systems can be improved by using chemical enhancers like ultrasound or iontophoresis. Iontophoresis provides a mechanism to enhance the penetration of hydrophilic and charged molecules across the skin. Objective: to compare the drug administration by ‘iontophoresis’ versus the oral rule. Methods: This study was conducted at the Faculty of Physical Therapy, Modern University for technology and information, Cairo, Egypt, on 20 participants (8 female & 12 male) who complained of tennis elbow. Their mean age was (25.45 ± 3.98) years, and all participants were assessed in many aspects: Pain threshold was assessed by algometer. Range of motion was assessed by electro goniometer, and isometric strength was assessed by a portable hand-held dynamometer. Then Participants were randomly assigned into two groups: group A was treated with oral NSAID (diclofenac) while group B was treated via administration of NSAIDs (diclofenac) via an iontophoresis device. All the participants were subjected to blood samples analysis in both pre-administration of the drug and post-administration of the drug for 24 hours (sample/every 6 hours). Results: The results demonstrated that there was a significant improvement in group b, “iontophoresis NSAIDs group,” more than in group B,” oral NSAIDs group,” in all measurements ‘ pain threshold, strength, and range of motion. Also, the iontophoresis method shows higher maximum plasma concentrations (Cmax) and concentration-time curves than the oral method.

Keywords: diclofenac, iontophoresis, NSAIDs, oral, tennis elbow

Procedia PDF Downloads 115

Authors: Arpita Roy, Navneeta Bharadvaja

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Cancer is an uncontrolled growth of abnormal cells in the body. It is one of the most serious diseases on which extensive research work has been going on all over the world. Structure-based drug designing is a computational approach which helps in the identification of potential leads that can be used for the development of a drug. Plumbagin is a naphthoquinone derivative from Plumbago zeylanica roots and belongs to one of the largest and diverse groups of plant metabolites. Anticancer and antiproliferative activities of plumbagin have been observed in animal models as well as in cell cultures. Plumbagin shows inhibitory effects on multiple cancer-signaling proteins; however, the binding mode and the molecular interactions have not yet been elucidated for most of these protein targets. In this investigation, an attempt to provide structural insights into the binding mode of plumbagin against four cancer receptors using molecular docking was performed. Plumbagin showed minimal energy against targeted cancer receptors, therefore suggested its stability and potential towards different cancers. The least binding energies of plumbagin with COX-2, TACE, and CDK6 are -5.39, -4.93, -and 4.81 kcal/mol, respectively. Comparison studies of plumbagin with different receptors showed that it is a promising compound for cancer treatment. It was also found that plumbagin obeys the Lipinski’s Rule of 5 and computed ADMET properties which showed drug likeliness and improved bioavailability. Since plumbagin is from a natural source, it has reduced side effects, and these results would be useful for cancer treatment.

Keywords: cancer, receptor, plumbagin, docking

Procedia PDF Downloads 143

Authors: Feng Xu, Zhaozhi Liu, Junhua Xu, Xiaolong Tang, Dunwen Zuo

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Chemical vapor deposition (CVD) diamond coated cutting tool has excellent cutting performance, it is the most ideal tool for the processing of nonferrous metals and alloys, composites, nonmetallic materials and other difficult-to-machine materials efficiently and accurately. Depositing CVD diamond coating on the cemented carbide with high cobalt content can improve its toughness and strength, therefore, it is very important to research on the preparation technology and cutting properties of CVD diamond coated cemented carbide cutting tool with high cobalt content. The preparation technology of boron-doped diamond (BDD) coating has been studied and the coated drills were prepared. BDD coating were deposited on the drills by using the optimized parameters and the SEM results show that there are no cracks or collapses in the coating. Cutting tests with the prepared drills against the silumin and aluminum base printed circuit board (PCB) have been studied. The results show that the wear amount of the coated drill is small and the machined surface has a better precision. The coating does not come off during the test, which shows good adhesion and cutting performance of the drill.

Keywords: cemented carbide with high cobalt content, CVD boron-doped diamond, cutting test, drill

Procedia PDF Downloads 440

Authors: P. Ninduangdee, V. I. Kuprianov

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Palm kernel shell is an important bioenergy resource in Thailand. However, due to elevated alkali content in biomass ash, this oil palm residue shows high tendency to bed agglomeration in a fluidized-bed combustion system using conventional bed material (silica sand). In this study, palm kernel shell was burned in the conical fluidized-bed combustor (FBC) using alumina and dolomite as alternative bed materials to prevent bed agglomeration. For each bed material, the combustion tests were performed at 45kg/h fuel feed rate with excess air within 20–80%. Experimental results revealed rather weak effects of the bed material type but substantial influence of excess air on the behaviour of temperature, O2, CO, CxHy, and NO inside the reactor, as well as on the combustion efficiency and major gaseous emissions of the conical FBC. The optimal level of excess air ensuring high combustion efficiency (about 98.5%) and acceptable level of the emissions was found to be about 40% when using alumina and 60% with dolomite. By using these alternative bed materials, bed agglomeration can be prevented when burning the shell in the proposed conical FBC. However, both bed materials exhibited significant changes in their morphological, physical and chemical properties in the course of the time.

Keywords: palm kernel shell, fluidized-bed combustion, alternative bed materials, combustion and emission performance, bed agglomeration prevention

Procedia PDF Downloads 247

Authors: Makhan Maharjan, Mani Ulaganathan, Vanchiappan Aravindan, Srinivasan Madhavi, Jing-Yuan Wang, Tuti Mariana Lim

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The ever-increasing energy demand has made research to develop high performance energy storage systems that are able to fulfill energy needs. Supercapacitors have potential applications as portable energy storage devices. In recent years, there have been huge research interests to enhance the performances of supercapacitors via exploiting novel promising carbon precursors, tailoring textural properties of carbons, exploiting various electrolytes and device types. In this work, we employed orange peel (waste material) as the starting material and synthesized activated carbon by pyrolysis of KOH impregnated orange peel char at 800 °C in argon atmosphere. The resultant orange peel-derived activated carbon (OP-AC) exhibited BET surface area of 1,901 m² g-1, which is the highest surface area so far reported for the orange peel. The pore size distribution (PSD) curve exhibits the pores centered at 11.26 Å pore width, suggesting dominant microporosity. The high surface area OP-AC accommodates more ions in the electrodes and its well-developed porous structure facilitates fast diffusion of ions which subsequently enhance electrochemical performance. The OP-AC was studied as positive electrode in combination with different negative electrode materials, such as pre-lithiated graphite (LiC6) and Li4Ti5O12 for making hybrid capacitors. The lithium ion capacitor (LIC) fabricated using OP-AC with pre-lithiated graphite delivered high energy density of ~106 Wh kg–1. The energy density for OP-AC||Li4Ti5O12 capacitor was ~35 Wh kg⁻¹. For comparison purpose, configuration of OP-AC||OP-AC capacitors were studied in both aqueous (1M H2SO4) and organic (1M LiPF6 in EC-DMC) electrolytes, which delivered the energy density of 8.0 Wh kg⁻¹ and 16.3 Wh kg⁻¹, respectively. The cycling retentions obtained at current density of 1 A g⁻¹ were ~85.8, ~87.0 ~82.2 and ~58.8% after 2500 cycles for OP-AC||OP-AC (aqueous), OP-AC||OP-AC (organic), OP-AC||Li4Ti5O12 and OP-AC||LiC6 configurations, respectively. In addition, characterization studies were performed by elemental and proximate composition, thermogravimetry analysis, field emission-scanning electron microscopy, Raman spectra, X-ray diffraction (XRD) pattern, Fourier transform-infrared, X-ray photoelectron spectroscopy (XPS) and N2 sorption isotherms. The morphological features from FE-SEM exhibited well-developed porous structures. Two typical broad peaks observed in the XRD framework of the synthesized carbon implies amorphous graphitic structure. The ratio of 0.86 for ID/IG in Raman spectra infers high degree of graphitization in the sample. The band spectra of C 1s in XPS display the well resolved peaks related to carbon atoms in various chemical environments. The presence of functional groups is also corroborated from the FTIR spectroscopy. Characterization studies revealed the synthesized carbon to be promising electrode material towards the application for energy storage devices. Overall, the intriguing properties of OP-AC make it a new alternative promising electrode material for the development of high energy lithium ion capacitors from abundant, low-cost, renewable biomass waste. The authors gratefully acknowledge Agency for Science, Technology and Research (A*STAR)/ Singapore International Graduate Award (SINGA) and Nanyang Technological University (NTU), Singapore for funding support.

Keywords: energy storage, lithium-ion capacitors, orange peels, porous activated carbon

Procedia PDF Downloads 229

Authors: Ashok D. Satpute

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Ayurveda, the ancient Indian Medical system is practiced all over India and abroad, is rich in natural source of medicines, including marine products. The marine drugs which prominently used are pravala (coral), mukta (pearl), kapardika (cowry).Shukti (oyster shell), shankha (conch), agnijara (amber) etc. Except agnijara (amber) all are rich in calcium. Interestingly they are not used as supplements in calcium deficiency as done in conventional medical practice. They are used as medicines in the disease like fever, tuberculosis, bleeding disorders, eye problems, digestive complaints etc. Many scientific studies have shown their potent medicinal value. Each has its own properties and used therapeutically after subjecting them to various purificatory processes which are called shodhana in which several medicinal plants are used which also help in enhancing therapeutical activity. Then these purified marine products are subjected to marana (incineration) process and obtained in the form of Bhasma (a finest form of medicine). Agnijara, a derivative of whale is useful as aphrodisiac and prescribed in neuromuscular disorders and tetanus. The ancient scriptures written in Sanskrit language thousands of years back have rich information about all these natural marine products and their medicinal usage.

Keywords: Ayurveda, bhasma, marana, shodhana

Procedia PDF Downloads 277

Authors: Natalia Wojarnik

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The paper aims to present the analysis of a Reddit confessions corpus. The interpretation focuses on the use of emotional language, in particular emotive verbs, in the context of personal pronouns. The analysis of the linguistic properties answers the question of what the Reddit users confess about and who is the subject of confessions. The study reveals that the specific language patterns used in Reddit confessions reflect the language of depression and the language used by patients during different stages of their psychotherapy sessions. The paper concludes that Reddit users are more willing to confess about their own experiences, not rarely very private and intimate, extensively using the first person singular pronoun I. It indicates that the Reddit users use the language of depression and the language used by psychotherapy patients. The language they use is very emotionally impacted and includes many emotive verbs such as want, feel, need, hate, love. This finding in Reddit confessions correlates with the extensive use of stative affective verbs in the first stages of the psychotherapy sessions. Lastly, the paper refers to the positive and negative lexicon and helps determine how online posts can serve as a depression detector and “talking cure” for the users.

Keywords: confessions, emotional language, emotive verbs, pronouns, first person pronoun, language of depression, depression detection, psychotherapy language

Procedia PDF Downloads 119

Authors: Marina Nisnevitch, Anton Valkov, Faina Nakonechny, Kate Adar Raik, Yamit Mualem

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Photosensitizers are dye compounds belonging to various chemical groups that in all the cases have a developed structure of conjugated double bonds. Under illumination with visible light, the photosensitizers are excited and transfer the absorbed energy to the oxygen dissolved in an aqueous phase, leading to production of a reactive oxygen species which cause irreversible damage to bacterial cells. When immobilized onto a solid phase, photosensitizers preserve their antibacterial properties. In the present study, photosensitizers were immobilized in polyethylene or propylene and tested for antimicrobial activity against Gram-positive S. aureus, S. epidermidis and Streptococcus sp. For this purpose, water-soluble photosensitizers, Rose Bengal sodium salt, and methylene blue as well as water-insoluble hematoporphyrin and Rose Bengal lactone, were immobilized by dissolution in melted polymers to yield 3 mm diameter rods and 3-5 mm beads. All four photosensitizers were found to be effective in the eradication of Gram-positive bacteria under illumination by a white luminescent lamp or sunlight. The immobilized photosensitizers can be applied for continuous water disinfection; they can be easily removed at the end of the treatment and reused.

Keywords: antimicrobial polymers, gram-positive bacteria, immobilization of photosensitizers, photodynamic antibacterial activity

Procedia PDF Downloads 242

Authors: Swapnila V. Vanshiv, Hemant P. Joshi, Atul B. Aware

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Current study illustrates the formulation of floating microspheres for purpose of gastroretention of Dipyridamole which shows pH dependent solubility, with the highest solubility in acidic pH. The formulation involved hollow microsphere preparation by using solvent evaporation technique. Concentrations of rate controlling polymer, hydrophilic polymer, internal phase ratio, stirring speed were optimized to get desired responses, namely release of Dipyridamole, buoyancy of microspheres, entrapment efficiency of microspheres. In the formulation, the floating microspheres were prepared by using ethyl cellulose as release retardant and HPMC as a low density hydrophilic swellable polymer. Formulated microspheres were evaluated for their physical properties such as particle size and surface morphology by optical microscopy and SEM. Entrapment efficiency, floating behavior and drug release study as well the formulation was evaluated for in vivo gastroretention in rabbits using gamma scintigraphy. Formulation showed 75% drug release up to 10 hr with entrapment efficiency of 91% and 88% buoyancy till 10 hr. Gamma scintigraphic studies revealed that the optimized system was retained in the gastric region (stomach) for a prolonged period i.e. more than 5 hr.

Keywords: Dipyridamole microspheres, gastroretention, HPMC, optimization method

Procedia PDF Downloads 385

Authors: H. Merzouka, D. T. Talantikitea, S. Fettouchib, L. Nessarkb

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Recently New nanosized materials studies are in huge expansion worldwide. They play a fundamental role in various industrial applications thanks their unique and functional properties. Moreover, in recent years, a great effort has been made in design and control fabrication of nano-structured semiconductors such as zinc sulphide. In recent years, much attention has been accorded in doped and co-doped ZnS to improve the ZnS films quality. We present in this work preparation and characterization of ZnS and Cu doped ZnS thin films. Nanoparticles ZnS and Cu doped ZnS films are prepared by chemical bath deposition method (CBD), for various dopant concentrations. Thin films are deposed onto commercial microscope glass slides substrates. Thiourea is used as sulfide ion source, zinc acetate as zinc ion source and copper acetate as Cu ion source in alkaline bath at 90 °C. X-ray diffraction (XRD) analyses are carried out at room temperature on films and powders with a powder diffractometer, using CuK radiation. The average grain size obtained from the Debye–Scherrer’s formula is around 10 nm. Films morphology is examined by scanning electron microscopy. IR spectra of representative sample are recorded with the FTIR between 400 and 4000 cm-1. The transmittance is more than 70 % is performed with the UV–VIS spectrometer in the wavelength range 200–800 nm. This value is enhanced by Cu doping.

Keywords: Cu doped ZnS, nanostructured, thin films, CBD, XRD, FTIR

Procedia PDF Downloads 443

Authors: Rohollah Ghasemi, Arvin Ghorbani

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This study investigates the effect of austempering temperature on microstructure and scratch behavior of the austempered heat-treated compacted graphite irons. The as-cast was used as base material for heat treatment practices. The samples were extracted from as-cast ferritic CGI pieces and were heat treated under austenitising temperature of 900°C for 60 minutes which followed by quenching in salt-bath at different austempering temperatures of 275°C, 325°C and 375°C. For all heat treatments, an austempering holding time of 30 minutes was selected for this study. Light optical microscope (LOM) and scanning electron microscope (SEM) and electron back scattered diffraction (EBSD) analysis confirmed the ausferritic matrix formed in all heat-treated samples. Microscratches were performed under the load of 200, 600 and 1000 mN using a sphero-conical diamond indenter with a tip radius of 50 μm and induced cone angle 90° at a speed of 10 μm/s at room temperature ~25°C. An instrumented nanoindentation machine was used for performing nanoindentation hardness measurement and microscratch testing. Hardness measurements and scratch resistance showed a significant increase in Brinell, Vickers, and nanoindentation hardness values as well as microscratch resistance of the heat-treated samples compared to the as-cast ferritic sample. The increase in hardness and improvement in microscratch resistance are associated with the formation of the ausferrite matrix consisted of carbon-saturated retained austenite and acicular ferrite in austempered matrix. The maximum hardness was observed for samples austempered at 275°C which resulted in the formation of very fine acicular ferrite. In addition, nanohardness values showed a quite significant variation in the matrix due to the presence of acicular ferrite and carbon-saturated retained austenite. It was also observed that the increase of austempering temperature resulted in increase of volume of the carbon-saturated retained austenite and decrease of hardness values.

Keywords: austempered CGI, austempering, scratch testing, scratch plastic deformation, scratch hardness

Procedia PDF Downloads 136

Authors: Rufai Yakubu And Suleiman Kabiru

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Triterpenoids are a diverse class of secondary metabolites with potential antimicrobial properties. In this study, the crude extracts from ethyl acetate was obtained with ultrasonic extraction method. Using a combined chromatographic separation method to isolate squalene (1) stigmasterol (2), stigmasta-5,22-diene-3-ol acetate (3), γ-sitosterol (4), lupeol (5), taraxasterol (6), and betulinic acid (7) from ethyl acetate extracts. Ethyl acetate crude extracts and isolated compounds were both screened for antimicrobial activity and minimum inhibitory concentration (MIC). For ethyl acetate crude extracts with concentrations of (1.5, 0.75, 0.35, & 0.168 mg/mL) indicated marginal antibacterial activity with a range of 17, 20 and 14 mm zone of inhibition for Staphylococcus aureus, Escherichia coli and Candida albicans and lower minimum inhibitory concentrations ranges from 18.75 µg/ml to 150 µg/mL. Butulinic acid showed the highest activity against E. coli and C. albicans at 15 mm and 15 mm followed by Lupeol against S. aureus, E. coli and C. albicans at 13, 12, 12 mm. Moreso, no antimicrobial activity for both S. aureus and C. albicans with squalene except for E. coli which showed activity at 11 mm with 300 µg/mL (MIC). Thus, abundant triterpenoids in Deinbollia pinnata will be another centered area for antimicrobial drug discovery.

Keywords: triterpenoid, antimicrobial potentials, deinbollia pinnata, aerial parts

Procedia PDF Downloads 70

Authors: Arnab Mondal, Sanjeev Kumar Sharma, Ranjit Kumar Upadhyay

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We study the spatiotemporal dynamics of a neuronal cable. The processes of one- dimensional (1D) and 2D diffusion are considered for a single variable, which is the membrane voltage, i.e., membrane voltage diffusively interacts for spatiotemporal pattern formalism. The recovery and other variables interact through the membrane voltage. A 3D Leech-Heart (LH) model is introduced to investigate the nonlinear responses of an excitable neuronal cable. The deterministic LH model shows different types of firing properties. We explore the parameter space of the uncoupled LH model and based on the bifurcation diagram, considering v_k2_ashift as a bifurcation parameter, we analyze the 1D diffusion dynamics in three regimes: bursting, regular spiking, and a quiescent state. Depending on parameters, it is shown that the diffusive system may generate regular and irregular bursting or spiking behavior. Further, it is explored a 2D diffusion acting on the membrane voltage, where different types of patterns can be observed. The results show that the LH neurons with different firing characteristics depending on the control parameters participate in a collective behavior of an information processing system that depends on the overall network.

Keywords: bifurcation, pattern formation, spatio-temporal dynamics, stability analysis

Procedia PDF Downloads 222

Authors: Ramji Kalidoss, Snekhalatha Umapathy, V. Dhinakaran, J. M. Mathana

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Chemi-resistive sensors used in breathalyzers have become a hotspot between the international breath research communities. These sensors exhibit a significant change in its resistance depending on the temperature it gets heated thus demanding high power leading to non-portable instrumentation. In this work, numerical simulation to identify the suitable combination of substrate and heater profile using COMSOL multiphysics was studied. Ni-Cr and Pt-100 joule resistive heater with various profiles were studied beneath the square and circular alumina substrates. The temperature distribution was uniform throughout the square substrate with the meander shaped pt100 heater with 48 mW power consumption for 200 oC. Moreover, this heater profile induced minimal stress on the substrate with 0.5 mm thick. A novel Graphene based ternary metal oxide nanocomposite (GO/SnO2/TiO2) was coated on the optimized substrate and heater to elucidate the response of diabetes biomarker (acetone). The sensor exhibited superior gas sensing performance towards acetone in the exhaled breath concentration range for diabetes (0.25 – 3 ppm). These results indicated the importance of substrate and heater properties along with sensing material for low power portable breathalyzers.

Keywords: Breath Analysis, Chemical Sensors, Diabetes Mellitus, Graphene Nanocomposites, Heater, Substrate

Procedia PDF Downloads 136

Authors: Sayed Hessam Bahmani, Rolsndo P. Orense

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From an engineering point of view, pumice particles are problematic because of their crushability and compressibility due to their vesicular nature. Currently, information on the geotechnical characteristics of pumice sands is limited. While extensive empirical and laboratory tests can be implemented to characterize their behavior, these are generally time-consuming and expensive. These drawbacks have motivated attempts to study the effects of particle breakage of pumice sand through the Discrete Element Method (DEM). This method provides insights into the behavior of crushable granular material at both the micro and macro-level. In this paper, the results of single-particle crushing tests conducted in the laboratory are simulated using DEM through the open-source code YADE. This is done to better understand the parameters necessary to represent the pumice microstructure that governs its crushing features, and to examine how the resulting microstructure evolution affects a particle’s properties. The DEM particle model is then used to simulate the behavior of pumice sand during consolidated drained triaxial tests. The results indicate the importance of incorporating particle porosity and unique surface textures in the material characterization and show that interlocking between the crushed particles significantly influences the drained behavior of the pumice specimen.

Keywords: pumice sand, triaxial compression, simulation, particle breakage

Procedia PDF Downloads 245

Authors: Yogeeta O. Agrawal, Hitendra S. Mahajan, Sanjay J. Surana

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Methotrexate is effective in controlling recalcitrant psoriasis when administered by the oral or parenteral route long-term. However, the systematic use of this drug may provoke any of a number of side effects, notably hepatotoxic effects. To reduce these effects, clinical studies have been done with topical MTx. It is useful in treating a number of cutaneous conditions, including psoriasis. A major problem in topical administration of MTx currently available in market is that the drug is hydrosoluble and is mostly in the dissociated form at physiological pH. Its capacity for passive diffusion is thus limited. Localization of MTx in effected layers of skin is likely to improve the role of topical dosage form of the drug as a supplementary to oral therapy for treatment of psoriasis. One of the possibilities for increasing the penetration of drugs through the skin is the use of Nanostructured lipid Carriers. The objective of the present study was to formulate and characterize Methotrexate loaded Nanostructured Lipid Carriers (MtxNLCs), to understand in vitro drug release and evaluate the role of the developed gel in the topical treatment of psoriasis. MtxNLCs were prepared by solvent diffusion technique using 3(2) full factorial design.The mean diameter and surface morphology of MtxNLC was evaluated. MtxNLCs were lyophilized and crystallinity of NLC was characterized by Differential Scanning Calorimtery (DSC) and powder X-Ray Diffraction (XRD). The NLCs were incorporated in 1% w/w Carbopol 934 P gel base and in vitro skin deposition studies in Human Cadaver Skin were conducted. The optimized MtxNLCs were spherical in shape, with average particle size of 253(±9.92)nm, zeta potential of -30.4 (±0.86) mV and EE of 53.12(±1.54)%. DSC and XRD data confirmed the formation of NLCs. Significantly higher deposition of Methotrexate was found in human cadaver skin from MtxNLC gel (71.52 ±1.23%) as compared to Mtx plain gel (54.28±1.02%). Findings of the studies suggest that there is significant improvement in therapeutic index in treatment of psoriasis by MTx-NLCs incorporated gel base developed in this investigation over plain drug gel currently available in the market.

Keywords: methotrexate, psoriasis, NLCs, hepatotoxic effects

Procedia PDF Downloads 430

Authors: Marshal D. Kafle, Jun H. Kim, Hyun W. Been, Kyoung M. Min

Abstract:

Fluid viscous damping systems are well suited for many air vehicles subjected to shock and vibration. These damping system work with the principle of viscous fluid throttling through the orifice to create huge pressure difference between compression and rebound chamber and obtain the required damping force. One application of such systems is its use in aircraft door system to counteract the door’s velocity and safely stop it. In exigency situations like crash or emergency landing where the door doesn’t open easily, possibly due to unusually tilting of fuselage or some obstacles or intrusion of debris obstruction to move the parts of the door, such system can be combined with other systems to provide needed force to forcefully open the door and also securely stop it simultaneously within the required time i.e.less than 8seconds. In the present study, a hydraulic system called snubber along with other systems like actuator, gas bottle assembly which together known as emergency power assist system (EPAS) is designed, built and experimentally studied to check the magnitude of angular velocity, damping force and time required to effectively open the door. Whenever needed, the gas pressure from the bottle is released to actuate the actuator and at the same time pull the snubber’s piston to operate the emergency opening of the door. Such EPAS installed in the suspension arm of the aircraft door is studied explicitly changing parameters like orifice size, oil level, oil viscosity and bypass valve gap and its spring of the snubber at varying temperature to generate the optimum design case. Comparative analysis of the EPAS at several cases is done and conclusions are made. It is found that during emergency condition, the systemopening time and angular velocity, when snubber with 0.3mm piston and shaft orifice and bypass valve gap of 0.5 mm with its original spring is used,shows significant improvement over the old ones.

Keywords: aircraft door damper, bypass valve, emergency power assist system, hydraulic damper, oil viscosity

Procedia PDF Downloads 423

Authors: M. Said Ahmed, M. Lebrini, J. Pellé, S. Rioual, B. Lescop, C. Roos

Abstract:

The corrosion behavior of copper exposed in a marine atmosphere polluted and unpolluted by gases, mainly hydrogen sulphide (H2S), from the decomposition of Sargassum algae was studied using the mass loss method and electrochemical measurements. MEB/EDX and XRD were also used for the observation of morphology and surface analysis. To study the impact of this on copper corrosion, four sites more or less impacted by Sargassum algae strandings were selected. The samples were exposed for up to six months. The mass loss results showed that the average corrosion rate of copper was 528 µm/year for the site most affected by Sargassum algae and 9.4 µm/year for the least impacted site after three months of exposure, implying that the presence of Sargassum algae caused an important copper degradation. The morphological structures and properties of the corrosion products obtained at the impacted and non-impacted sites differed significantly. In the absence of Sargassum algae, we obtained mainly Cu2O and Cu2Cl(OH)3. Whereas in the atmosphere with Sargassum algae, CuS product is the main corrosion product obtained. Electrochemical analyses showed that the protection offered by the corrosion product layer was more important and improved with time for the non-impacted sites, whereas on the impacted sites, this protection deteriorated.

Keywords: atmospheric-corrosion, sargassum algae, copper, electrochemical techniques, SEM/EDX and XRD

Procedia PDF Downloads 118

Authors: Mishu Gupta, Rama Gupta

Abstract:

It has been elucidated here that non- autonomous discrete non-linear Schrödinger equation is associated with saturable non-linearity through photo-refractive media. We have investigated the localized solution of non-autonomous saturable discrete non-linear Schrödinger equations. The similarity transformation has been involved in converting non-autonomous saturable discrete non-linear Schrödinger equation to constant-coefficient saturable discrete non-linear Schrödinger equation (SDNLSE), whose exact solution is already known. By back substitution, the solution of the non-autonomous version has been obtained. We have analysed our solution for the hyperbolic and periodic form of gain/loss term, and interesting results have been obtained. The most important characteristic role is that it helps us to analyse the propagation of electromagnetic waves in glass fibres and other optical wave mediums. Also, the usage of SDNLSE has been seen in tight binding for Bose-Einstein condensates in optical mediums. Even the solutions are interrelated, and its properties are prominently used in various physical aspects like optical waveguides, Bose-Einstein (B-E) condensates in optical mediums, Non-linear optics in photonic crystals, and non-linear kerr–type non-linearity effect and photo refracting medium.

Keywords: B-E-Bose-Einstein, DNLSE-Discrete non linear schrodinger equation, NLSE-non linear schrodinger equation, SDNLSE - saturable discrete non linear Schrodinger equation

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Authors: Fedda Y. Alzoubi, Ihsan A. Aljarrah

Abstract:

Silver nanoparticles (AgNPs) are one of the most vital and fascinating nanomaterials among several metallic nanoparticles that are involved in different applications, especially in biomedical applications. Samples of different alkaline water were prepared in order to study the effect of alkalinity of water on the optical properties, size, and morphology of colloidal AgNPs prepared according to the chemical reduction method using the prepared water samples. Ultraviolet-Visible spectrophotometer, Zeta-sizer, and Scanning electron microscope (SEM) have been utilized to carry out this study. Absorption spectra AgNPs in different alkaline water show a surface Plasmon resonance (SPR) peak at the wavelength of 420 nm. The position of this peak is sensitive to the shape of the particles, and in our case, it indicates that the particles are spherical. As the alkalinity increases, the intensity of the SPR peak decreases, indicating the aggregation of particles. Zeta-sizer measurements show that the average diameter for AgNPs in pure water is found to be 53.51 nm, and this value increases as the alkalinity increases. Zeta potential values of samples show that the negatively coated particles are stable in the solution. SEM images insure the spherical shape of the prepared nanoparticles and show that as the alkalinity increases the particles aggregate into larger particles.

Keywords: aggregation, alkalinity, colloid, nanoparticle

Procedia PDF Downloads 127

Authors: Snehal D. Ganjave, Hardik Dodia, Avinash V. Sunder, Swati Madhu, Pramod P. Wangikar

Abstract:

Batch cultivation of recombinant bacteria in shake flasks results in low cell density due to nutrient depletion. Previous protocols on high cell density cultivation in shake flasks have relied mainly on controlled release mechanisms and extended cultivation protocols. In the present work, we report an optimized fed-batch process for high cell density cultivation of recombinant E. coli BL21(DE3) for protein production. A cybernetic model-based, multi-objective optimization strategy was implemented to obtain the optimum operating variables to achieve maximum biomass and minimized substrate feed rate. A syringe pump was used to feed a mixture of glycerol and yeast extract into the shake flask. Preliminary experiments were conducted with online monitoring of dissolved oxygen (DO) and offline measurements of biomass and glycerol to estimate the model parameters. Multi-objective optimization was performed to obtain the pareto front surface. The selected optimized recipe was tested for a range of proteins that show different extent soluble expression in E. coli. These included eYFP and LkADH, which are largely expressed in soluble fractions, CbFDH and GcanADH , which are partially soluble, and human PDGF, which forms inclusion bodies. The biomass concentrations achieved in 24 h were in the range 19.9-21.5 g/L, while the model predicted value was 19.44 g/L. The process was successfully reproduced in a standard laboratory shake flask without online monitoring of DO and pH. The optimized fed-batch process showed significant improvement in both the biomass and protein production of the tested recombinant proteins compared to batch cultivation. The proposed process will have significant implications in the routine cultivation of E. coli for various applications.

Keywords: cybernetic model, E. coli, high cell density cultivation, multi-objective optimization

Procedia PDF Downloads 258

Authors: Sukanya Pradhan, Smita Mohanty, S. K Nayak

Abstract:

Plant oils are a great renewable source for being a reliable starting material to access new products with a wide spectrum of structural and functional variations. Even though petroleum products might also render the same, but it would also impose a high risk factor of environmental and health hazard. Since epoxidized vegetable oils are easily available, eco-compatible, non-toxic and renewable, hence these have drawn much of the attentions in the polymer industrial sector especially for the development of eco-friendly coating materials. In this study a waterborne epoxy coating was prepared from epoxidized soyabean oil by using triethanolamine. Because of its hydrophobic nature, it was a tough and tedius task to make it hydrophilic. The hydrophobic biobased epoxy was modified into waterborne epoxy by the help of a plant based anhydride as curing agent. Physico-mechanical, chemical resistance tests and thermal analysis of the green coating material were carried out which showed good physic-mechanical, chemical resistance properties as well as environment friendly. The complete characterization of the final material was done in terms of scratch hardness, gloss test, impact resistance, adhesion and bend test.

Keywords: epoxidized soybean oil, waterborne, curing agent, green coating

Procedia PDF Downloads 541

Authors: Sungho Kim, Jaechoul Shin, Yujin Baek, Nakseok Kim, Kyungnam Kim, Shinhaeng Jo

Abstract:

The climate change and increase in heavy traffic have been accelerating damages that cause the problems such as pothole on asphalt pavement. Pothole causes traffic accidents, vehicle damages, road casualties and traffic congestion. A quick and efficient maintenance method is needed because pothole is caused by stripping and accelerates pavement distress. In this study, we propose a rapid and systematic pothole management by developing a pothole automated repairing equipment including a volume measurement system of pothole. Three kinds of cold mix asphalt mixture were investigated to select repair materials. The materials were evaluated for satisfaction with quality standard and applicability to automated equipment. The volume measurement system of potholes was composed of multi-sensor that are combined with laser sensor and ultrasonic sensor and installed in front and side of the automated repair equipment. An algorithm was proposed to calculate the amount of repair material according to the measured pothole volume, and the system for releasing the correct amount of material was developed. Field test results showed that the loss of repair material amount could be reduced from approximately 20% to 6% per one point of pothole. Pothole rapid automated repair equipment will contribute to improvement on quality and efficient and economical maintenance by not only reducing materials and resources but also calculating appropriate materials. Through field application, it is possible to improve the accuracy of pothole volume measurement, to correct the calculation of material amount, and to manage the pothole data of roads, thereby enabling more efficient pavement maintenance management. Acknowledgment: The author would like to thank the MOLIT(Ministry of Land, Infrastructure, and Transport). This work was carried out through the project funded by the MOLIT. The project name is 'development of 20mm grade for road surface detecting roadway condition and rapid detection automation system for removal of pothole'.

Keywords: automated equipment, management, multi-beam sensor, pothole

Procedia PDF Downloads 224

Authors: Moses. O. Eyankware, Benard I. Odoh, Omoleomo O. Omo-Irabor, Alex O. I. Selemo

Abstract:

Knowledge of hydraulic conductivity and transmissivity is essential for the determination of natural water flow through an aquifer. These parameters are commonly estimated from the analysis of electrical conductivity, soil properties and fluid flow data. In order to achieve a faster and cost effective analysis of aquifer parameters in Ochudo City in Abakaliki, this study relied on non-invasive geophysical methods. As part of this approach, Vertical Electrical Sounding (VES) was conducted at 20 sites in the study area for the identification of the vertical variation in subsurface lithology and for the characterization of the groundwater system. The area variously consists of between five to seven geoelectric layers of different thicknesses. Depth to aquifer ranges from 9.94 m-134.0 m while the thickness of the identified aquifer varies between 8.43 m and 44.31 m. Based on the electrical conductivity values of water samples collected from two boreholes and two hand-dug wells within the study area, the hydraulic conductivity was determined to range from 0.10 to 0.433 m/day. The estimated thickness of the aquifer and calculated hydraulic conductivity were used to derive the aquifer transmissivity. The results indicate that this parameter ranges from 1.58-7.56 m²/day with a formation factor of between 0.31-3.6.

Keywords: Asu river group, transmissivity, hydraulic conductivity, abakaliki, vertical electrical sounding (VES)

Procedia PDF Downloads 395

Authors: Franziska Moser, Martin Trautz, Anna-Lena Beger, Manuel Löwer, Jörg Feldhusen, Jürgen Prell, Alexandra Wormit, Björn Usadel, Christoph Kämpfer, Thomas-Benjamin Seiler, Henner Hollert

Abstract:

The demand for bio-based materials and components in architecture has increased in recent years due to society’s heightened environmental awareness. Nowadays, most components are being developed via a substitution approach, which aims at replacing conventional components with natural alternatives who are then being processed, shaped and manufactured to fit the desired application. This contribution introduces a novel approach to the development of bio-based products that decreases resource consumption and increases recyclability. In this approach, natural organisms like plants or trees are not being used in a processed form, but grow into a near net shape before then being harvested and utilized as building components. By minimizing the conventional production steps, the amount of resources used in manufacturing decreases whereas the recyclability increases. This paper presents the approach of technical product harvesting, explains the theoretical basis as well as the matching process of product requirements and biological properties, and shows first results of the growth manipulation studies.

Keywords: design with nature, eco manufacturing, sustainable construction materials, technical product harvesting

Procedia PDF Downloads 500

Authors: Narash Narasimman, Calvin Leong Jia Jun, Raksha Karthik, Paul Englert

Abstract:

Background: Project Grit, a 12-week youth resilience program implemented by Impart and Spartans Boxing Club, aimed to help at-risk adolescents develop resilience through psychoeducation and mental health techniques for dealing with everyday stressors and adversity. The programme consists of two parts-1.5 hours of group therapy followed by 1 hour of boxing. Due to the novelty of the study, 6 male participants, aged 13 to 18, were recruited to participate in the study. Aim: This case study aims to examine the effectiveness of Project Grit in building resilience among at-risk adolescents. Methods: A case study design was employed to capture the complexity and uniqueness of the intervention, without oversimplifying or generalizing it. A 15-year-old male participant with a history of behavioural challenges, delinquency and gang involvement was selected for the study. Teacher, parent and child versions of the Strengths and Difficulties Questionnaire (SDQ) were administered to the facilitators, parents and participants respectively before and after the programme. Relevant themes from the qualitative interviews will be discussed. Results: Scores from all raters revealed improvements in most domains of the SDQ. Total difficulties scores across all raters improved from “very high” to “close to average”. High interrater reliability was observed (κ= .81). The participant reported learning methods to effectively deal with his everyday concerns using healthy coping strategies, developing a supportive social network, and building on his self efficacy. Themes from the subject’s report concurred with the improvement in SDQ scores. Conclusions: The findings suggest that Project Grit is a promising intervention for promoting resilience among at-risk adolescents. The teleological behaviourism framework and the combination of sports engagement and future orientation may be particularly effective in fostering resilience among this population. Further studies need to be conducted with a larger sample size to further validate the effectiveness of Project Grit.

Keywords: resilience, project grit, adolescents, at-risk, boxing, future orientation

Procedia PDF Downloads 63