Search results for: elevation angle

Authors: Marcelo Sifuentes López

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Strategic performance definition and follow-up processes have to be clear in order to provide value in today’s competitive world. Customer expectations must be linked to internal organization strategic objectives leading to profitability and supported by visibility and flexibility among others.By taking a whole picture of the supply chain, the executive, and its team will define the current supply chain situation and an insight into potential opportunities to improve processes and provide value to main stakeholders. A systematic performance evaluation process based on operational and financial indicators defined by customer requirements needs to be implemented and periodically reviewed in order to mitigate costs and risks on time.Supplier long term relationship and collaboration plays a key role using resources available, real-time communication, innovation and new ways to capitalize global opportunities like emerging markets; efforts have to focus on the reduction of uncertainties in supply and demand. Leadership has to promote consistency of communication and execution involving suppliers, customers, and the entire organization through the support of a strategic sourcing methodology that assure the targeted competitive strategy and sustainable growth. As customer requirements and expectations are met, results could be captured in a casual picture like a “selfie”; where outcomes could be perceived from any desired angle by them; or like most “selfies”, can be taken with a camera held at arm's length by a third party company rather than using a self-timer.

Keywords: supply chain management, competitive advantage, value creation, collaboration and innovation, global marketplace

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Authors: Hong Lu, Yongquan Zhang, Wei Fan, Xiangang Su

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Bent mandrel has been widely used as precise mould in automobile industry, shipping industry and aviation industry. To improve the versatility and efficiency of turning method of bent mandrel with fixed rotational center, an instantaneous machining model based on cutting parameters and machine dimension is prospered in this paper. The spiral-like tool path generation approach in non-axisymmetric turning process of bent mandrel is developed as well to deal with the error of part-to-part repeatability in existed turning model. The actual cutter-location points are calculated by cutter-contact points, which are obtained from the approach of spiral sweep process using equal-arc-length segment principle in polar coordinate system. The tool offset is set to avoid the interference between tool and work piece is also considered in the machining model. Depend on the spindle rotational angle, synchronization control of X-axis, Z-axis and C-axis is adopted to generate the tool-path of the turning process. The simulation method is developed to generate NC program according to the presented model, which includes calculation of cutter-location points and generation of tool-path of cutting process. With the approach of a bent mandrel taken as an example, the maximum offset of center axis is 4mm in the 3D space. Experiment results verify that the machining model and turning method are appropriate for the characteristics of bent mandrel.

Keywords: bent mandrel, instantaneous machining model, simulation method, tool-path generation

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Authors: Ankita Singh, Chandan Gorain, Amirul I. Mallick

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Successful adherence of the mucosal epithelial cells is the key early step for Campylobacter jejuni pathogenesis (C. jejuni). A set of Surface Exposed Colonization Proteins (SECPs) are among the major factors involved in host cell adherence and invasion of C. jejuni. Among them, constitutively expressed surface-exposed lipoprotein adhesin of C. jejuni, JlpA, interacts with intestinal heat shock protein 90 (hsp90α) and contributes in disease progression by triggering pro-inflammatory response via activation of NF-κB and p38 MAP kinase pathway. Together with its ability to express in the bacterial surface, higher sequence conservation and predicted predominance of several B cells epitopes, JlpA protein reserves its potential to become an effective vaccine candidate against wide range of Campylobacter sps including C. jejuni. Given that chickens are the primary sources for C. jejuni and persistent gut colonization remain as major cause for foodborne pathogenesis to humans, present study explicitly used chickens as model to test the immune-protective efficacy of JlpA protein. Taking into account that gastrointestinal tract is the focal site for C. jejuni colonization, to extrapolate the benefit of mucosal (intragastric) delivery of JlpA protein, a food grade Nisin inducible Lactic acid producing bacteria, Lactococcus lactis (L. lactis) was engineered to express recombinant JlpA protein (rJlpA) in the surface of the bacteria. Following evaluation of optimal surface expression and functionality of recombinant JlpA protein expressed by recombinant L. lactis (rL. lactis), the immune-protective role of intragastric administration of live rL. lactis was assessed in commercial broiler chickens. In addition to the significant elevation of antigen specific mucosal immune responses in the intestine of chickens that received three doses of rL. lactis, marked upregulation of Toll-like receptor 2 (TLR2) gene expression in association with mixed pro-inflammatory responses (both Th1 and Th17 type) was observed. Furthermore, intragastric delivery of rJlpA expressed by rL. lactis, but not the injectable form, resulted in a significant reduction in C. jejuni colonization in chickens suggesting that mucosal delivery of live rL. lactis expressing JlpA serves as a promising vaccine platform to induce strong immune-protective responses against C. jejuni in chickens.

Keywords: chickens, lipoprotein adhesion of Campylobacter jejuni, immuno-protection, Lactococcus lactis, mucosal delivery

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Authors: Esther Liyanage, Indrajith Liyanage, A. A. J. Rajaratne

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During the 30 year civil war in Sri Lanka, a large number of individuals were injured and disabled. These disabilities have reduced their daily physical activities which may cause reduction in flexibility of upper limb, shoulder girdle, lower back and lower limb. Muscle flexibility is important for a healthy lifestyle. The main objective of the study was to assess the upper limb, shoulder girdle and lower back, hamstring flexibility of the intact lower limb in disabled individuals in the North and Eastern parts of Sri Lanka. Back saver sits and reach test and shoulder scratch test described in FITNESS GRAM was used in the study. A total of 125 disabled soldiers with lower limb disabilities were recruited for the study. Flexibility of the lower back and hamstring muscles of uninjured lower limb was measured using back saver sit and reach test described by Wells and Dillon (1952). Upper limb and shoulder girdle flexibility was assessed using shoulder stretch test. Score 0-3 was given according to the ability to reach Superior medial angle of the opposite scapula, top of the head or the mouth. The results indicate that 31 (24.8%) disabled soldiers have lower limb flexibility less than 8, 2 (1.6 % ) have flexibility of 8, 2 (1.6 %) have flexibility of 8.5, 11 ( 8.8% ) have flexibility of 9, 14 (11.2 %) have flexibility of 9.5, 23 (18.4 %) have flexibility of 10, 17 (13.6 %) have 10.5 flexibility, 13 (10.4%) have 11 flexibility, 2 (1.6%) have 11.5 flexibility, 10 (8 %) have flexibility of 12 and 3 (2.34 %) have flexibility of 12.5. Six disabled soldiers (4.8%) have upper limb flexibility of 2 and remaining 95.2% have normal upper limb flexibility (score 3). A reduction in the flexibility of muscles in lower body and lower limbs was seen in 25% disabled soldiers which could be due to reduction in their daily physical activities.

Keywords: disability, flexibility, rehabilitation, quality of life

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Authors: Kbab H, Hamitouche T

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In recent years, significant progress has been accomplished in the field of aerospace propulsion and propulsion systems. These developments are associated with efforts to enhance the accuracy of the analysis of aerothermodynamic phenomena in the engine. This applies in particular to the flow in the nozzles used. One of the most remarkable processes in this field is thrust vectoring by means of devices able to orientate the thrust vector and control the deflection of the exit jet in the engine nozzle. In the study proposed, we are interested in the fluid thrust vectoring using a second injection in the nozzle divergence. This fluid injection causes complex phenomena, such as boundary layer separation, which generates a shock wave in the primary jet upstream of the fluid interacting zone (primary jet - secondary jet). This will cause the deviation of the main flow, and therefore of the thrust vector with reference to the axis nozzle. In the modeling of the fluidic thrust vector, various parameters can be used. The Mach number of the primary jet and the injected fluid, the total pressures ratio, the injection rate, the thickness of the upstream boundary layer, the injector position in the divergent part, and the nozzle geometry are decisive factors in this type of phenomenon. The complexity of the latter challenges researchers to understand the physical phenomena of the turbulent boundary layer encountered in supersonic nozzles, as well as the calculation of its thickness and the friction forces induced on the walls. The present study aims to numerically simulate the thrust vectoring by secondary injection using the ANSYS-FLUENT, then to analyze and validate the results and the performances obtained (angle of deflection, efficiency...), which will then be compared with those obtained by other authors.

Keywords: CD Nozzle, TVC, SVC, NPR, CFD, NPR, SPR

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Authors: Elene Zhuravliova, Tamar Barbakadze, Irina Kalandadze, Elnari Zaalishvili, Lali Shanshiashvili, David Mikeladze

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Background: Multiple sclerosis (MS) is an inflammatory, neurodegenerative disease, which is accompanied by demyelination and autoimmune response to myelin proteins. Among post-translational modifications, which mediate the modulation of inflammatory pathways during MS, methylation is the main one. The methylation of DNA, also amino acids lysine and arginine, occurs in the cell. It was found that decreased trans-methylation is associated with neuroinflammatory diseases. Therefore, abnormal regulation of the methyl cycle could induce demyelination through the action on PAD (peptidyl-arginine-deiminase) gene promoter. PAD takes part in protein citrullination and targets myelin basic protein (MBP), which is affected during demyelination. To determine whether MBP charge isomers are changing the methyl cycle, we have estimated the concentrations of methyl cycle metabolites in MBP-activated primary astrocytes and oligodendrocytes. For this purpose, the action of the citrullinated MBP- C8 and the most cationic MBP-C1 isomers on the primary cells were investigated. Methods: Primary oligodendrocyte and astrocyte cell cultures were prepared from whole brains of 2-day-old Wistar rats. The methyl cycle metabolites, including homocysteine, S-adenosylmethionine (SAM), and S-adenosylhomocysteine (SAH), were estimated by HPLC analysis using fluorescence detection and prior derivatization. Results: We found that the action of MBP-C8 and MBP-C1 induces a decrease in the concentration of both methyl cycle metabolites, S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH), in astrocytes compared to the control cells. As for oligodendrocytes, the concentration of SAM was increased by the addition of MBP-C1, while MBP-C8 has no significant effect. As for SAH, its concentration was increased compared to the control cells by the action of both MBP-C1 and MBP-C8. A significant increase in homocysteine concentration was observed by the action of the MBP-C8 isomer in both oligodendrocytes and astrocytes. Conclusion: These data suggest that MBP charge isomers change the concentration of methyl cycle metabolites. MBP-C8 citrullinated isomer causes elevation of homocysteine in astrocytes and oligodendrocytes, which may be the reason for decreased astrocyte proliferation and increased oligodendrocyte cell death which takes place in neurodegenerative processes. Elevated homocysteine levels and subsequent abnormal regulation of methyl cycles in oligodendrocytes possibly change the methylation of DNA that activates PAD gene promoter and induces the synthesis of PAD, which in turn provokes the process of citrullination, which is the accompanying process of demyelination. Acknowledgment: This research was supported by the SRNSF Georgia RF17_534 grant.

Keywords: myelin basic protein, astrocytes, methyl cycle metabolites, homocysteine, oligodendrocytes

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Authors: Hari Singh, Abhishek Kamboj, Sudhir Kumar

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This investigation proposes a grey-based Taguchi method to solve the multi-response problems. The grey-based Taguchi method is based on the Taguchi’s design of experimental method, and adopts Grey Relational Analysis (GRA) to transfer multi-response problems into single-response problems. In this investigation, an attempt has been made to optimize the drilling process parameters considering weighted output response characteristics using grey relational analysis. The output response characteristics considered are surface roughness, burr height and hole diameter error under the experimental conditions of cutting speed, feed rate, step angle, and cutting environment. The drilling experiments were conducted using L27 orthogonal array. A combination of orthogonal array, design of experiments and grey relational analysis was used to ascertain best possible drilling process parameters that give minimum surface roughness, burr height and hole diameter error. The results reveal that combination of Taguchi design of experiment and grey relational analysis improves surface quality of drilled hole.

Keywords: metal matrix composite, drilling, optimization, step drill, surface roughness, burr height, hole diameter error

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Authors: Ayelet Hersch, Corrine Serfaty, Sigal Portnoy

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Stroke survivors commonly report persistent fatigue and sleep disruptions during rehabilitation and post-recovery. While limited research has explored the impact of stroke on a patient's chronotype, there is a gap in understanding the differences in cognitive performance based on treatment timing. Study objectives: (a) To characterize the sleep chronotype in sub-acute post-stroke individuals. (b) Explore cognitive task performance differences during preferred and non-preferred hours. (c) Examine the relationships between sleep quality and cognitive performance. For this intra-subject study, twenty participants (mean age 60.2±8.6) post-first stroke (6-12 weeks post stroke) underwent assessments at preferred and non-preferred chronotypic times. The assessment included demographic surveys, the Munich Chronotype Questionnaire, Montreal Cognitive Assessment (MoCA), Rivermead Behavioral Memory Test (RBMT), a fatigue questionnaire, and 4-5 days of actigraphy (wrist-worn wGT3X-BT, ActiGraph) to record sleep characteristics. Four sleep quality indices were extracted from actigraphy wristwatch recordings: The average of total sleep time per day (minutes), the average number of awakenings during the sleep period per day, the efficiency of sleep (total hours of sleep per day divided by hours spent in bed per day, averaged across the days and presented as percentage), and the Wake after Sleep Onset (WASO) index, indicating the average number of minutes elapsed from the onset of sleep to the first awakening. Stroke survivors exhibited an earlier sleep chronotype post-injury compared to pre-injury. Enhanced attention, as indicated by higher RBMT scores, occurred during preferred hours. Specifically, 30% of the study participants demonstrated an elevation in their final scores during their preferred hours, transitioning from the category of "mild memory impairment" to "normal memory." However, no significant differences emerged in executive functions, attention tasks, and MoCA scores between preferred and non-preferred hours. The Wake After Sleep Onset (WASO) index correlated with MoCA/RBMT scores during preferred hours (r=0.53/0.51, p=0.021/0.027, respectively). The number of awakenings correlated with MoCA letter task performance during non-preferred hours (r=0.45, p=0.044). Enhanced attention during preferred hours suggests a potential relationship between chronotype and cognitive performance, highlighting the importance of personalized rehabilitation strategies in stroke care. Further exploration of these relationships could contribute to optimizing the timing of cognitive interventions for stroke survivors.

Keywords: sleep chronotype, chronobiology, circadian rhythm, rehabilitation timing

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Authors: Mohd Tahseen Islam Talukder, Sheikh Adnan Enam, Latifa Akter Lithi, Soebur Rahman

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Composite structures have made significant advances in construction applications during the last few decades. Composite structures are composed of structural steel shapes and reinforced concrete combined with shear connectors, which benefit each material's unique properties. Significant research has been conducted on different types of connectors’ behavior and shear capacity. Moreover, the AISC 360-16 “Specification for Steel Structural Buildings” consists of a formula for channel shear connectors' shear capacity. This research compares the behavior of C type and L type shear connectors using Finite Element Analysis. Experimental results from published literature are used to validate the finite element models. The 3-D Finite Element Model (FEM) was built using ABAQUS 2017 to investigate non-linear capabilities and the ultimate load-carrying potential of the connectors using push-out tests. The changes in connector dimensions were analyzed using this non-linear model in parametric investigations. The parametric study shows that by increasing the length of the shear connector by 10 mm, its shear strength increases by 21%. Shear capacity increased by 13% as the height was increased by 10 mm. The thickness of the specimen was raised by 1 mm, resulting in a 2% increase in shear capacity. However, the shear capacity of channel connectors was reduced by 21% due to an increase of thickness by 2 mm.

Keywords: finite element method, channel shear connector, angle shear connector, ABAQUS, composite structure, shear connector, parametric study, ultimate shear capacity, push-out test

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Authors: Syed Muhammad Awais Tahir, Syed Hossein Raza Hamdani

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In the last two years, there has been a substantial increase in the rate of satellite launches. To keep up with the technology, it is imperative that the launch cost must be made affordable, especially in developing and underdeveloped countries. Launch cost is directly affected by the launch vehicle’s aerodynamic performance. Pegasus-XL SLV (Satellite Launch Vehicle) has been serving as a commercial SLV for the last 26 years, commencing its commercial flight operation from the six operational sites all around the US and Europe, and the Marshal Islands. Aerodynamic heating and drag contribute largely to Pegasus’s flight performance. The objective of this study is to reduce the aerodynamic heating and drag on Pegasus’s body significantly for supersonic and hypersonic flight regimes. Aerodynamic data for Pegasus’s first flight has been validated through CFD (Computational Fluid Dynamics), and then drag and aerodynamic heating is reduced by using a combination of a forward-facing cylindrical spike and a conical aero-disk at the actual operational flight conditions. CFD analysis using ANSYS fluent will be carried out for Mach no. ranges from 0.83 to 7.8, and AoA (Angle of Attack) ranges from -4 to +24 degrees for both simple and spiked-configuration, and then the comparison will be drawn using a variety of graphs and contours. Expected drag reduction for supersonic flight is to be around 15% to 25%, and for hypersonic flight is to be around 30% to 50%, especially for AoA < 15⁰. A 5% to 10% reduction in aerodynamic heating is expected to be achieved for hypersonic regions. In conclusion, the aerodynamic performance of air-launched Pegasus-XL SLV can be further enhanced, leading to its optimal fuel usage to achieve a more economical orbital flight.

Keywords: aerodynamics, pegasus-XL, drag reduction, aerodynamic heating, satellite launch vehicle, SLV, spike, aero-disk

Procedia PDF Downloads 101

Authors: Bambang Antoro, Lasito Soebari, Geoffrey de Jong, Fernandy Meiriyanto, Michael Siahaan, Eko Wibowo, Pormando Silalahi, Ruswanto, Adi Budirumantyo

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The Ertsberg East Skarn System (EESS) is located in the Ertsberg Mining District, Papua, Indonesia. EESS is a sub-vertical zone of copper-gold mineralization hosted in both diorite (vein-style mineralization) and skarn (disseminated and vein style mineralization). Deep Mill Level Zone (DMLZ) is a mining zone in the lower part of East Ertsberg Skarn System (EESS) that product copper and gold. The Deep Mill Level Zone deposit is located below the Deep Ore Zone deposit between the 3125m to 2590m elevation, measures roughly 1,200m in length and is between 350 and 500m in width. DMLZ planned start mined on Q2-2015, being mined at an ore extraction rate about 60,000 tpd by the block cave mine method (the block cave contain 516 Mt). Mineralization and associated hydrothermal alteration in the DMLZ is hosted and enclosed by a large stock (The Main Ertsberg Intrusion) that is barren on all sides and above the DMLZ. Late porphyry dikes that cut through the Main Ertsberg Intrusion are spatially associated with the center of the DMLZ hydrothermal system. DMLZ orebody hosted in diorite and skarn, both dominantly by vein style mineralization. Percentage Material Mined at DMLZ compare with current Reserves are diorite 46% (with 0.46% Cu; 0.56 ppm Au; and 0.83% EqCu); Skarn is 39% (with 1.4% Cu; 0.95 ppm Au; and 2.05% EqCu); Hornfels is 8% (with 0.84% Cu; 0.82 ppm Au; and 1.39% EqCu); and Marble 7 % possible mined waste. Correlation between Ertsberg intrusion, major structure, and vein style mineralization is important to determine characteristic orebody in DMLZ Mine. Generally Deep Mill Level Zone has 2 type of vein filling mineralization from both hosted (diorite and skarn), in diorite hosted the vein system filled by chalcopyrite-bornite-quartz and pyrite, in skarn hosted the vein filled by chalcopyrite-bornite-pyrite and magnetite without quartz. Based on orientation the stockwork vein at diorite hosted and shallow vein in skarn hosted was generally NW-SE trending and NE-SW trending with shallow-moderate dipping. Deep Mill Level Zone control by two main major faults, geologist founded and verified local structure between major structure with NW-SE trending and NE-SW trending with characteristics slickenside, shearing, gauge, water-gas channel, and some has been re-healed.

Keywords: copper-gold, DMLZ, skarn, structure

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Authors: Serap Kaymakci, Dogan Gundogdu, M. Bugra Yagcioglu

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Erosion (soil erosion) is a phenomenon in which the soil on the slope surface is exposed to natural influences such as wind, rainfall, etc. in open areas. The most natural solution to prevent erosion is to plant surfaces exposed to erosion. However, proper ground and natural conditions must be provided in order for planting to occur. Erosion is prevented in a fast and natural way and the loss of soil is reduced mostly. Lead to allowing plants to hold onto the soil with its three-dimensional and hollow structure are as follows: The types of geomat called MacMat that is used in a case study in Turkey in order to prevent water carry over due to rainfall. The geosynthetic combined with double twisted steel wire mesh. That consists of 95% Zn–5% Al alloy coated double twisted steel wire based that is a reinforced MacMat (geosynthetic three-dimensional erosion control mat) obtained by a polypropylene consisted (mesh type 8x10-Wire diam. 2.70 mm–95% Zn–5% Al alloy coated). That is developed by the progress of the technology. When using reinforced MacMat on top clay liners, fixing pins should not be used as they will rupture the mats. Mats are simply anchored (J Type) in the top trench and, if necessary, in intermediate berm trenches. If the slope angle greater than 20°, it is necessary to use additional rebar depending soil properties also. These applications may have specific technical and installation requirements. In that project, the main purpose is erosion control after that is greening. There is a slope area around the factory which is located in Gebze, İstanbul.

Keywords: erosion, GeoMat, geosynthetic, slope

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Authors: Mallikarjunachari Gangapuram

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The design of stimuli-responsive hydrogel nanocomposite thin films is gaining significant attention in these days due to its wide variety of applications. Soft microrobots, drug delivery, biosensors, regenerative medicine, bacterial adhesion, energy storage and wound dressing are few advanced applications in different fields. In this research work, the nanomechanical properties of composite thin films of 20 microns were tuned by applying homogeneous external DC, and AC magnetic fields of magnitudes 0.05 T and 0.1 T. Polyvinyl alcohol (PVA) used as a matrix material and elliptical hematite nanoparticles (ratio of the length of the major axis to the length of the minor axis is 140.59 ± 1.072 nm/52.84 ± 1.072 nm) used as filler materials to prepare the nanocomposite thin films. Both quasi-static nanoindentation, Nano Dynamic Mechanical Analysis (Nano-DMA) tests were performed to characterize the viscoelastic properties of PVA, PVA+Hematite (0.1% wt, 2% wt and 4% wt) nanocomposites. Different properties such as storage modulus, loss modulus, hardness, and Er/H were carefully analyzed. The increase in storage modulus, hardness, Er/H and a decrease in loss modulus were observed with increasing concentration and DC magnetic field followed by AC magnetic field. Contact angle and ATR-FTIR experiments were conducted to understand the molecular mechanisms such as hydrogen bond formation, crosslinking density, and particle-particle interactions. This systematic study is helpful in design and modeling of magnetic responsive hydrogel nanocomposite thin films for biomedical applications.

Keywords: hematite, hydrogel, nanoindentation, nano-DMA

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Authors: Emi̇ne Avşar Aydin, Nezahat Günenç Tuncel, A. Hami̇t Serbest

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The electromagnetic scattering from a canonical structure is an important issue in electromagnetic theory. In this study, the electromagnetic scattering from a dielectric sphere with oblique incidence is investigated. The incident field is considered as a plane wave with H polarized. The scattered and transmitted field expressions with unknown coefficients are written. The unknown coefficients are obtained by using exact boundary conditions. Then, the sphere is considered as having frequency dependent dielectric permittivity. The frequency dependence is shown by Cole-Cole model. The far scattered field expressions are found respect to different incidence angles in the 1-8 GHz frequency range. The observation point is the angular distance of pi from an incident wave. While an incident wave comes with a certain angle, observation point turns from 0 to 360 degrees. According to this, scattered field amplitude is maximum at the location of the incident wave, scattered field amplitude is minimum at the across incident wave. Also, the scattered fields are plotted versus frequency to show frequency-dependence explicitly. Graphics are shown for some incident angles compared with the Harrington's solution. Thus, the results are obtained faster and more reliable with reciprocal rotation. It is expected that when there is another sphere with different properties in the outer sphere, the presence and location of the sphere will be detected faster. In addition, this study leads to use for biomedical applications in the future.

Keywords: scattering, dielectric sphere, oblique incidence, reciprocal rotation

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Authors: Shubham Sharma, Swarna Jaiswal, Brendan Duffy, Amit Jaiswal

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The key features of any active packaging film are its biodegradability and antimicrobial properties. Biological macromolecules such as polyphenols (ferulic acid (FA) and tannic acids (TA)) are naturally found in plants such as grapes, berries, and tea. In this study, antimicrobial activity screening of several polyphenols was carried out by using minimal inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against two strains of gram-negative bacteria - Salmonella typhimurium, Escherichia coli, and two-gram positive strains - Staphylococcus aureus and Listeria monocytogenes. FA and TA had shown strong antibacterial activity at the low concentration against both gram-positive and gram-negative bacteria. The selected polyphenols FA and TA were incorporated at various concentrations (1%, 5%, and 10% w/w) in the poly(lactide) – poly (butylene adipate-co-terephthalate) (PLA-PBAT) composite film by using the solvent casting method. The effect of TA and FA incorporation in the packaging was characterized based on morphological, optical, color, mechanical, thermal, and antimicrobial properties. The thickness of the FA composite film was increased by 1.5 – 7.2%, while for TA composite film, it increased by 0.018 – 1.6%. FA and TA (10 wt%) composite film had shown approximately 65% - 66% increase in the UV barrier property. As the FA and TA concentration increases from 1% - 10% (w/w), the TS value increases by 1.98 and 1.80 times, respectively. The water contact angle of the film was observed to decrease significantly with the increase in the FA and TA content in the composite film. FA has shown more significant increase in antimicrobial activity than TA in the composite film against Listeria monocytogenes and E. coli. The FA and TA composite film has the potential for its application as an active food packaging.

Keywords: active packaging, biodegradable film, polyphenols, UV barrier, tensile strength

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Authors: Merna Ibrahim

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Designing buildings which are sustainable and can control and reduce the solar radiation penetrated from the building facades is such an architectural turn. One of the most important methods of saving energy in a building is carefully designing its facade. Building’s facade is one of the most significant contributors to the energy budget as well as the comfort parameters of a building. Responsive architecture adapts to the surrounding environment causing alteration in the envelope configuration to perform in a more effective way. One of the objectives of the responsive facades is to protect the building’s users from the external environment and to achieve a comfortable indoor environment. Solar radiation is one of the aspects that affects the comfortable indoor environment, as well as affects the energy consumption consumed by the HVAC systems for maintaining the indoor comfortable conditions. The aim of the paper is introducing and comparing between four different proposed responsive facade designs in terms of solar radiation reduction on the west facade of a building located in the hot arid region. In addition, the paper highlights the reducing amount of solar radiation for each proposed responsive facade on the west facade. At the end of the paper, a proposal is introduced which combines the four different axis of movements which reduces the solar radiation the most. Moreover, the paper highlights the definition and aim of the responsive architecture, as well as the focusing on the solar radiation aspect in the hot arid zones. Besides, the paper analyzes an international responsive façade building in Essen, Germany, focusing on the type of responsive facades, angle of rotation, mechanism of movement and the effect of the responsive facades on the building’s performance.

Keywords: kinetic facades, mechanism of movement, responsive architecture, solar radiation

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Authors: Haile Nega Mulata, Seifu Daniel, Umeta Melaku, Wendwesson Ergete, Natesan Gnanasekaran

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Background: In Ethiopia, medicinal plants have been used for various human and animal diseases. In this study, we have examined the potential effect of hydroethanolic extract of Calpurnia aurea seed against hepatotoxicity and haematotoxicity induced by Highly Active Antiretroviral Therapy (HAART) drugs in Albino Wistar rats. Methods: We collected Matured dried seeds of Calpurnia aurea from northern Ethiopia (south Tigray and south Gondar) in June 2013. The powder of the dried seed sample was macerated with 70% ethanol and dried using rotavapor. We have investigated the Preliminary phytochemical tests and in-vitro antioxidant properties. Then, we induced toxicity with HAART drugs and gave the experimental animals different doses of the crude extract orally for thirty-five days. On the 35th day, the animals were fasted overnight and sacrificed by cervical dislocation. We collected the blood samples by cardiac puncture. We excised the liver and brain tissues for further histopathological studies. Subsequently, we analysed serum levels of the liver enzymes- Alanine Aminotransferase, Aspartate Aminotransferase, Alkaline Phosphatase, Total Bilirubin, and Serum Albumin, using commercial kits in Cobas Integra 400 Plus Roche Analyzer Germany. We have also assessed the haematological profile using an automated haematology Analyser (Sysmex KX-2IN). Results: A significant (P<0.05) decrease in serum enzymes (ALT and AST) and total bilirubin were observed in groups that received the highest dose (300mg/kg) of the seed extract. And significant (P<0.05) elevation of total red blood cell count, haemoglobin, and hematocrit percentage was observed in the groups that received the seed extract compared to the HAART-treated groups. The WBC count mean values showed a statistically significant increase (p<0.05) in groups that received HAART and 200 and 300mg/kg extract, respectively. The histopathological observations also showed that the oral administration of varying doses of the crude extract of the seed reversed to a normal state. Conclusion: The hydroethanolic extract of the Calpurnia aurea seed lowered the hepatotoxicity and haematotoxicity in a dose-dependent manner. The antioxidant properties of the Calpurnia aurea seed extract may have possible protective effects against the drug's toxicity.

Keywords: calpurnia aurea, hepatotoxicity, haematotoxicity, antioxidant, histopathology, HAART

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Authors: Aiman Mazhar Qureshi, Ahmed Rachid

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Extreme heat events are emerging human environmental health concerns in dense urban areas due to anthropogenic activities. High spatial and temporal resolution heat maps are important for urban heat adaptation and mitigation, helping to indicate hotspots that are required for the attention of city planners. The Heat Vulnerability Index (HVI) is the important approach used by decision-makers and urban planners to identify heat-vulnerable communities and areas that require heat stress mitigation strategies. Amiens is a medium-sized French city, where the average temperature has been increasing since the year 2000 by +1°C. Extreme heat events are recorded in the month of July for the last three consecutive years, 2018, 2019 and 2020. Poor air quality, especially ground-level ozone, has been observed mainly during the same hot period. In this study, we evaluated the HVI in Amiens during extreme heat days recorded last three years (2018,2019,2020). The Principal Component Analysis (PCA) technique is used for fine-scale vulnerability mapping. The main data we considered for this study to develop the HVI model are (a) socio-economic and demographic data; (b) Air pollution; (c) Land use and cover; (d) Elderly heat-illness; (e) socially vulnerable; (f) Remote sensing data (Land surface temperature (LST), mean elevation, NDVI and NDWI). The output maps identified the hot zones through comprehensive GIS analysis. The resultant map shows that high HVI exists in three typical areas: (1) where the population density is quite high and the vegetation cover is small (2) the artificial surfaces (built-in areas) (3) industrial zones that release thermal energy and ground-level ozone while those with low HVI are located in natural landscapes such as rivers and grasslands. The study also illustrates the system theory with a causal diagram after data analysis where anthropogenic activities and air pollution appear in correspondence with extreme heat events in the city. Our suggested index can be a useful tool to guide urban planners and municipalities, decision-makers and public health professionals in targeting areas at high risk of extreme heat and air pollution for future interventions adaptation and mitigation measures.

Keywords: heat vulnerability index, heat mapping, heat health-illness, remote sensing, urban heat mitigation

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Authors: Sung Uk Park, Young Su Kang, Sangmo Kang, Young Kweon Suh

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Mineral product, waste concrete (fine aggregates), waste in the optical field, industry, and construction employ separators to separate solids and classify them according to their size. Various sorting machines are used in the industrial field such as those operating under electrical properties, centrifugal force, wind power, vibration, and magnetic force. Study on separators has been carried out to contribute to the environmental industry. In this study, we perform CFD analysis for understanding the basic mechanism of the separation of waste concrete (fine aggregate) particles from air with a machine built with a rotor with blades. In CFD, we first performed two-dimensional particle tracking for various particle sizes for the model with 1 degree, 1.5 degree, and 2 degree angle between each blade to verify the boundary conditions and the method of rotating domain method to be used in 3D. Then we developed 3D numerical model with ANSYS CFX to calculate the air flow and track the particles. We judged the capability of particle separation for given size by counting the number of particles escaping from the domain toward the exit among 10 particles issued at the inlet. We confirm that particles experience stagnant behavior near the exit of the rotating blades where the centrifugal force acting on the particles is in balance with the air drag force. It was also found that the minimum particle size that can be separated by the machine with the rotor is determined by its capability to stay at the outlet of the rotor channels.

Keywords: environmental industry, separator, CFD, fine aggregate

Procedia PDF Downloads 591

Authors: Manikandan S. P., Sharmila N.

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Pain in the neck, intermediate and anterior, and even low back may occur in one or more locations. Numerous factors can lead to back discomfort, which can manifest into sensations in the other parts of your body. Up to 80% of people will have low back problems at a certain stage of their lives, making spine-related pain a highly prevalent ailment. Roughly twice as commonly as neck pain, low back discomfort also happens about as often as knee pain. According to current studies, using digital devices for extended periods of time and poor sitting posture are the main causes of neck and low back pain. There are numerous monitoring techniques provided to enhance the sitting posture for the aforementioned problems. A sophisticated technique to monitor the extended sitting position is suggested in this research based on this problem. The system is made up of an inertial measurement unit, a T-shirt, an Arduino board, a buzzer, and a mobile app with cloud services. Based on the anatomical position of the spinal cord, the inertial measurement unit was positioned on the inner back side of the T-shirt. The IMU (inertial measurement unit) sensor will evaluate the hip position, imbalanced shoulder, and bending angle. Based on the output provided by the IMU, the data will be analyzed by Arduino, supplied through the cloud, and shared with a mobile app for continuous monitoring. The buzzer will sound if the measured data is mismatched with the human body's natural position. The implementation and data prediction with design to identify balanced and unbalanced posture using a posture monitoring t-shirt will be further discussed in this research article.

Keywords: IMU, posture, IOT, textile

Procedia PDF Downloads 85

Authors: Bong-Su Sin, Jong-Kyu Kim, Se-Il Song, Kwon-Hee Lee

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An automobile ball joint is a pivoting element used to allow rotational motion between the parts of the steering and suspension system. And it plays a role in smooth transmission of steering movement, also reduction in impact from the road surface. A ball joint is under various repeated loadings that may cause cracks and abrasion. This damages lead to safety problems of a car, as well as reducing the comfort of the driver's ride, and raise questions about the ball joint procedure and the whole durability of the suspension system. Accordingly, it is necessary to ensure the high durability and reliability of a ball joint. The structural responses of stiffness and pull-out strength were then calculated to check if the design satisfies the related requirements. The analysis was sequentially performed, following the caulking process. In this process, the deformation and stress results obtained from the analysis were saved. Sequential analysis has a strong advantage, in that it can be analyzed by considering the deformed shape and residual stress. The pull-out strength means the required force to pull the ball stud out from the ball joint assembly. The low pull-out strength can deteriorate the structural stability and safety performances. In this study, two design variables and two noise factors were set up. Two design variables were the diameter of a stud and the angle of a socket. And two noise factors were defined as the uncertainties of Young's modulus and yield stress of a seat. The DOE comprises 81 cases using these conditions. Robust design of a ball joint was performed using the DOE. The pull-out strength was generated from the uncertainties in the design variables and the design parameters. The purpose of robust design is to find the design with target response and smallest variation.

Keywords: ball joint, pull-out strength, robust design, design of experiments

Procedia PDF Downloads 419

Authors: Anjana Rajput, Sandeep Chouksey, Bhaskar Bhandari, Shimpi Chourasia

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Ecologically, grassland is any plant community dominated by grasses, whether they exist naturally or because of management practices. Most forest grasslands are anthropogenic and established plant communities planted for forage production, though some are established for soil and water conservation and wildlife habitat. In Satpura Tiger Reserve, Madhya Pradesh, India, most of the grasslands have been established on evacuated village sites. Total of 42 villages evacuated, and study was carried out in 23 sites to evaluate habitat improvement. Grasslands were classified into three categories, i.e., evacuated sites, established sites, and controlled sites. During the present study impact of various management interventions on grassland health was assessed. Grasslands assessment was done for its composition, status of palatable and non-palatable grasses, the status of herbs and legumes, status of weeds species, and carrying capacity of particular grassland. Presence of wild herbivore species in the grasslands with their abundance, availability of water resources was also assessed. Grassland productivity is dependent mainly on the biotic and abiotic components of the area, but management interventions may also play an important role in grassland composition and productivity. Variation in the status of palatable and non-palatable grasses, legumes, and weeds was recorded and found effected by management intervention practices. Overall in all the studied grasslands, the most dominant grasses recorded are Themeda quadrivalvis, Dichanthium annulatum, Ischaemum indicum, Oplismenus burmanii, Setaria pumilla, Cynodon dactylon, Heteropogon contortus, and Eragrostis tenella. Presence of wild herbivores, i.e., Chital, Sambar, Bison, Bluebull, Chinkara, Barking deer in the grassland area has been recorded through the installation of camera traps and estimated their abundance. Assessment of developed grasslands was done in terms of habitat suitability for Chital (Axis axis) and Sambar (Rusa unicolor). The parameters considered for suitability modeling are biotic and abiotic life requisite components existing in the area, i.e., density of grasses, density of legumes, availability of water, site elevation, site distance from human habitation. Findings of the present study would be useful for further grassland management and animal translocation programmes.

Keywords: carrying capacity, dominant grasses, grassland, habitat suitability, management intervention, wild herbivore

Procedia PDF Downloads 122

Authors: G. Roshan Deen, J. S. Pedersen

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Temperature-responsive poly(N-isopropyl acrylamide) PNIPAM microgels crosslinked with a new hydrophobic chemical crosslinker was prepared by surfactant-mediated precipitation emulsion polymerization. The temperature-responsive property of the microgel and the influence of the crosslinker on the swelling behaviour was studied systematically by light scattering and small-angle X-ray scattering (SAXS). The radius of gyration (Rg) and the hydrodynamic radius (Rh) of the microgels decreased with increase in temperature due to the volume phase transition from a swollen to a collapsed state. The ratio of Rg/Rh below the transition temperature was lower than that of hard-spheres due to the lower crosslinking density of the microgels. The SAXS data was analysed by a model in which the microgels were modelled as core-shell particles with a graded interface. The model at intermediate temperatures included a central core and a more diffuse outer layer describing pending polymer chains with a low crosslinking density. In the fully swollen state, the microgels were modelled with a single component with a broad graded surface. In the collapsed state they were modelled as homogeneous and relatively compact particles. The polymer volume fraction inside the microgel was also derived based on the model and was found to increase with increase in temperature as a result of collapse of the microgel to compact particles. The polymer volume fraction in the core of the microgel in the collapsed state was about 60% which is higher than that of similar microgels crosslinked with hydrophilic and flexible cross-linkers.

Keywords: microgels, SAXS, hydrophobic crosslinker, light scattering

Procedia PDF Downloads 423

Authors: Jonathan Iworiso

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Forecasting the equity premium out-of-sample is a major concern to researchers in finance and emerging markets. The quest for a superior model that can forecast the equity premium with significant economic gains has resulted in several controversies on the choice of variables and suitable techniques among scholars. This research focuses mainly on the application of Regression Training (RT) techniques to forecast monthly equity premium out-of-sample recursively with an expanding window method. A broad category of sophisticated regression models involving model complexity was employed. The RT models include Ridge, Forward-Backward (FOBA) Ridge, Least Absolute Shrinkage and Selection Operator (LASSO), Relaxed LASSO, Elastic Net, and Least Angle Regression were trained and used to forecast the equity premium out-of-sample. In this study, the empirical investigation of the RT models demonstrates significant evidence of equity premium predictability both statistically and economically relative to the benchmark historical average, delivering significant utility gains. They seek to provide meaningful economic information on mean-variance portfolio investment for investors who are timing the market to earn future gains at minimal risk. Thus, the forecasting models appeared to guarantee an investor in a market setting who optimally reallocates a monthly portfolio between equities and risk-free treasury bills using equity premium forecasts at minimal risk.

Keywords: regression training, out-of-sample forecasts, expanding window, statistical predictability, economic significance, utility gains

Procedia PDF Downloads 100

Authors: Kanyarat Sikhao, Nichakorn Khondee

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Adjuvant is commonly mixed with agricultural spray solution during foliar application to improve the performance of microbial-based biological control, including better spreading, absorption, and penetration on a plant leaf. This research aims to replace chemical surfactants in adjuvant by biosurfactants for reducing a negative impact on antagonistic microorganisms and crops. Biosurfactant was produced from Brevibacterium casei NK8 and used as a cell-free broth solution containing a biosurfactant concentration of 3.7 g/L. The studies of microemulsion formation and phase behavior were applied to obtain the suitable composition of biosurfactant-based adjuvant, consisting of cell-free broth (70-80%), coconut oil-based fatty alcohol C12-14 (3) ethoxylate (1-7%), and sodium chloride (8-30%). The suitable formula, achieving Winsor Type III microemulsion (bicontinuous), was 80% of cell-free broth, 7% of fatty alcohol C12-14 (3) ethoxylate, and 8% sodium chloride. This formula reduced the contact angle of water on parafilm from 70 to 31 degrees. The non-phytotoxicity against plant seed of Oryza sativa and Brassica rapa subsp. pekinensis were obtained from biosurfactant-based adjuvant (germination index equal and above 80%), while sodium dodecyl sulfate and tween80 showed phytotoxic effects to these plant seeds. The survival of Bacillus subtilis in biosurfactant-based adjuvant was higher than sodium dodecyl sulfate and tween80. The mixing of biosurfactant and plant-based surfactant could be considered as a viable, safer, and acceptable alternative to chemical adjuvant for sustainable organic farming.

Keywords: biosurfactant, microemulsion, bio-adjuvant, antagonistic microorganisms

Procedia PDF Downloads 136

Authors: Muhammad Qadir, Yuncang Li, Cuie Wen

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Surface properties such as topography and physicochemistry of metallic implants determine the cell behavior. The surface of titanium (Ti)-based implant can be modified to enhance the bioactivity and biocompatibility. In this study, a self-organized titania–niobium pentoxide–zirconia (TiO₂–Nb₂O₅–ZrO₂) nanotubular layer on β phase Ti35Zr28Nb alloy was fabricated via electrochemical anodization. Energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and water contact angle measurement techniques were used to investigate the nanotubes dimensions (i.e., the inner and outer diameters, and wall thicknesses), microstructural features and evolution of the hydrophilic properties. The in vitro biocompatibility of the TiO₂–Nb₂O₅–ZrO₂ nanotubes (NTs) was assessed by using osteoblast cells (SaOS2). Influence of anodization parameters on the morphology of TiO₂–Nb₂O₅–ZrO₂ NTs has been studied. The results indicated that the average inner diameter, outer diameter and the wall thickness of the TiO₂–Nb₂O₅–ZrO₂ NTs were ranged from 25–70 nm, 45–90 nm and 5–13 nm, respectively, and were directly influenced by the applied voltage during anodization. The average inner and outer diameters of NTs increased with increasing applied voltage, and the length of NTs increased with increasing anodization time and water content of the electrolyte. In addition, the size distribution of the NTs noticeably affected the hydrophilic properties and enhanced the biocompatibility as compared with the uncoated substrate. The results of this study could be considered for developing nano-scale coatings for a wide range of biomedical applications.

Keywords: Titanium alloy, TiO₂–Nb₂O₅–ZrO₂ nanotubes, anodization, surface wettability, biocompatibility

Procedia PDF Downloads 151

Authors: Younes Abed

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The successful application of in-situ testing of soils heavily depends on development of interpretation methods of tests. The pressuremeter test simulates the expansion of a cylindrical cavity and because it has well defined boundary conditions, it is more unable to rigorous theoretical analysis (i. e. cavity expansion theory) then most other in-situ tests. In this article, and in order to make the identification process more convenient, we propose a relatively simple procedure which involves the numerical identification of some mechanical parameters of a granular soil, especially, the elastic modulus and the friction angle from a pressuremeter curve. The procedure, applied here to identify the parameters of generalised prager model associated to the Drucker & Prager criterion from a pressuremeter curve, is based on an inverse analysis approach, which consists of minimizing the function representing the difference between the experimental curve and the curve obtained by integrating the model along the loading path in in-situ testing. The numerical process implemented here is based on the established finite element program. We present a validation of the proposed approach by a database of tests on expansion of cylindrical cavity. This database consists of four types of tests; thick cylinder tests carried out on the Hostun RF sand, pressuremeter tests carried out on the Hostun sand, in-situ pressuremeter tests carried out at the site of Fos with marine self-boring pressuremeter and in-situ pressuremeter tests realized on the site of Labenne with Menard pressuremeter.

Keywords: granular soils, cavity expansion, pressuremeter test, finite element method, identification procedure

Procedia PDF Downloads 290

Authors: Samuel Akinlabi Ola, Emeka Segun Nnochiri, Stephen Kayode Aderomose, Paul Ayesemhe Edoh

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Fadama soils of Northern Nigeria are generally a problem soil for highway and geotechnical engineers. There has been no consistent conclusion on the effect of the strain rate on the shear strength of soils, thus necessitating the need to clarify this issue with various types of soil. Consolidated undrained tests with pore pressure measurements were conducted at optimum moisture content and maximum dry density using standard proctor compaction. Back pressures were applied to saturate the soil. The shear strength parameters were determined. Analyzing the results and model studies using the Rate Process Theory, functional relationships between the deviator stress and strain rate were determined and expressed mathematically as deviator stress = β0+ β1 log(strain rate) at each cell pressure where β0 and β1 are constants. Also, functional relationships between the pore pressure coefficient Āf and the time to failure were determined and expressed mathematically as pore pressure coefficient, Āf = ψ0+ѱ1log (time to failure) where ψ0 and ѱ1 are constants. For cell pressure between 69 – 310 kN/m2 (10 - 45psi) the constants found for Fadama soil in this study are ψ0=0.17 and ѱ1=0.18. The study also shows the dependence of the angle of friction (ø’) on the rate of strain as it increases from 22o to 25o for an increase in the rate of strain from 0.08%/min to 1.0%/min. Conclusively, the study also shows that within the strain rate utilized in the research, the deviator strength increased with the strain rate while the excess pore water pressure decreased with an increase in the rate of strain.

Keywords: deviator stress, Fadama soils, pore pressure coefficient, rate process

Procedia PDF Downloads 69

Authors: Junya Kouwa, Shinsuke Matsuno, Chihiro Inoue, Takehiro Himeno, Toshinori Watanabe

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Bi-propellant thrusters use impinging jet atomization to atomize liquid fuel and oxidizer. Atomized propellants are mixed and combusted due to auto-ignitions. Therefore, it is important for a prediction of thruster’s performance to simulate the primary atomization phenomenon; especially, the local mixture ratio can be used as indicator of thrust performance, so it is useful to evaluate it from numerical simulations. In this research, we propose a numerical method for considering bi-liquid and the mixture and install it to CIP-LSM which is a two-phase flow simulation solver with level-set and MARS method as an interfacial tracking method and can predict local mixture ratio distribution downstream from an impingement point. A new parameter, beta, which is defined as the volume fraction of one liquid in the mixed liquid within a cell is introduced and the solver calculates the advection of beta, inflow and outflow flux of beta to a cell. By validating this solver, we conducted a simple experiment and the same simulation by using the solver. From the result, the solver can predict the penetrating length of a liquid jet correctly and it is confirmed that the solver can simulate the mixing of liquids. Then we apply this solver to the numerical simulation of impinging jet atomization. From the result, the inclination angle of fan after the impingement in the bi-liquid condition reasonably agrees with the theoretical value. Also, it is seen that the mixture of liquids can be simulated in this result. Furthermore, simulation results clarify that the injecting condition affects the atomization process and local mixture ratio distribution downstream drastically.

Keywords: bi-propellant thrusters, CIP-LSM, free-surface flow simulation, impinging jet atomization

Procedia PDF Downloads 277

Authors: Davendra S. Malik

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Bhimtal lake is located between 290 21’ N latitude and 790 24’ E longitude, at an elevation of 1332m above mean sea level in the Kumaun region of Uttarakhand of Indian subcontinent. The lake surface area is decreasing in water area, depth level in relation to ecological and biological characteristics due to climatic variations, invasive land use pattern, degraded forest zones and changed agriculture pattern in lake catchment basin. The present study is focused on long and short term effects of climate change on aquatic biodiversity and productivity of Bhimtal lake. The meteorological data of last fifteen years of Bhimtal lake catchment basin revealed that air temperature has been increased 1.5 to 2.1oC in summer, 0.2 to 0.8 C in winter, relative humidity increased 4 to 6% in summer and rainfall pattern changed erratically in rainy seasons. The surface water temperature of Bhimtal lake showed an increasing pattern as 0.8 to 2.6 C, pH value decreased 0.5 to 0.2 in winter and increased 0.4 to 0.6 in summer. Dissolved oxygen level in lake showed a decreasing trend as 0.7 to 0.4mg/l in winter months. The mesotrophic nature of Bhimtal lake is changing towards eutrophic conditions and contributed for decreasing biodiversity. The aquatic biodiversity of Bhimtal lake consisted mainly phytoplankton, zooplankton, benthos and fish species. In the present study, a total of 5 groups of phytoplankton, 3 groups of zooplankton, 11 groups of benthos and 15 fish species were recorded from Bhimtal lake. The comparative data of biodiversity of Bhimtal lake since January, 2000 indicated the changing pattern of phytoplankton biomass were decreasing as 1.99 and 1.08% of Chlorophyceae and Bacilleriophyceae families respectively. The biomass of Cynophyceae was increasing as 0.45% and contributing the algal blooms during summer season in lake. The biomass of zooplankton and benthos were found decreasing in winter season and increasing during summer season. The endemic fish species (18 no.) were found in year 2000-05, as while the fish species (15 no.) were recorded in present study. The relative fecundity of major fish species were observed decreasing trends during their breeding periods in lake. The natural and anthropogenic factors were identified as ecological threats for existing aquatic biodiversity of Bhimtal lake. The present research paper emphasized on the effect of changing pattern of different climatic variables on species composition, biomass of phytoplankton, zooplankton, benthos, and fishes in Bhimtal lake of Kumaun region. The present research data will be contributed significantly to assess the changing pattern of aquatic biodiversity and productivity of Bhimtal lake with different time scale.

Keywords: aquatic biodiversity, Bhimtal lake, climate change, lake ecology

Procedia PDF Downloads 217