Search results for: soft ground

Authors: M. Arunachalam, M. Pandey

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Nacre, a biological material that forms the inner-layer of sea shells can achieve high toughness and strength by way of staggered arrangement of strong tablets with soft and weak organic interface. Under applied loads the tablets slide over the adjacent tablets, thus generating inelastic deformation and toughness on macroscopic scale. A two dimensional finite element based homogenization methodology is adopted for obtaining the effective material properties of Nacre using a representative volume element (RVE) at finite deformations. In this work, the material behaviour for tablet and interface are assumed to be Isotropic elastic and Isotropic elastic-perfectly plastic with strain softening respectively. Numerical experiments such as uniaxial tension test along X, Y directions and simple shear test are performed on the RVE with uniform displacement and periodic constraints applied at the RVE boundaries to obtain the anisotropic homogenized response and maximum local stresses within each constituents of Nacre. Homogenized material model is then tested for macroscopic structure under three point bending condition and the results obtained are comparable with the results obtained for detailed microstructure based structure, thus homogenization provides a bridge between macroscopic scale and microscopic scale and homogenized material properties obtained from microstructural (RVE) analysis could be used in large scale structural analysis.

Keywords: finite element, homogenization, inelastic deformation, staggered arrangement

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Authors: Chien-Chun Hung, Chun-Fong Wu

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It is important for a commander to have real-time information to aware situations and to make decision in the battlefield. Results of modern technique developments have brought in this kind of information for military purposes. Unmanned aerial vehicle (UAV) is one of the means to gather intelligence owing to its widespread applications. It is still not clear whether or not the mini UAV with short-range wireless transmission system is used as a reconnaissance system in Taiwanese. In this paper, previous experience on the research of the sort of aerial vehicles has been applied with a data-relay system using the ZigBee modulus. The mini UAV developed is expected to be able to collect certain data in some appropriate theaters. The omni-directional antenna with high gain is also integrated into mini UAV to fit the size-reducing trend of airborne sensors. Two advantages are so far obvious. First, mini UAV can fly higher than usual to avoid being attacked from ground fires. Second, the data will be almost gathered during all maneuvering attitudes.

Keywords: mini UAV, reconnaissance, wireless transmission, ZigBee modulus

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Authors: Chiang Wei, Hui-Chung Yeh, Yen-Chang Chen

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The objective of this study is to estimate the rainfall using the new generation Himawari-8 meteorological satellite with multi-band, high-bit format, and high spatiotemporal resolution, ground rainfall data at the Chen-Yu-Lan watershed of Joushuei River Basin (443.6 square kilometers) in Central Taiwan. Accurate and fine-scale rainfall information is essential for rugged terrain with high local variation for early warning of flood, landslide, and debris flow disasters. 10-minute and 2 km pixel-based rainfall of Typhoon Megi of 2016 and meiyu on June 1-4 of 2017 were tested to demonstrate the new generation Himawari-8 meteorological satellite can capture rainfall variation in the rugged mountainous area both at fine-scale and watershed scale. The results provide the valuable rainfall information for early warning of future disasters.

Keywords: estimation, Himawari-8, rainfall, satellite imagery

Procedia PDF Downloads 194

Authors: Hadi Molaei, Yasavoli Davoud, Keshavarz, Mozhde Poordana

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The present study aimed was to prediction the academic performance based on academic motivation, self-efficacy and Resiliency in the students. The present study was descriptive and correlational. Population of the study consisted of all students in Arak schools in year 1393-94. For this purpose, the number of 304 schools students in Arak was selected using multi-stage cluster sampling. They all questionnaires, self-efficacy, Resiliency and academic motivation Questionnaire completed. Data were analyzed using Pearson correlation and multiple regressions. Pearson correlation showed academic motivation, self-efficacy, and Resiliency with academic performance had a positive and significant relationship. In addition, multiple regression analysis showed that the academic motivation, self-efficacy and Resiliency were predicted academic performance. Based on the findings could be conclude that in order to increase the academic performance and further progress of students must provide the ground to strengthen academic motivation, self-efficacy and Resiliency act on them.

Keywords: academic motivation, self-efficacy, resiliency, academic performance

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Authors: İsmail Şimşekoğlu, Serkan Yılmaz

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There have been great improvements in technology that caused epoch-making changes in aviation. Thus, we can control air vehicles from ground without pilots in them: The UAVs. Due to UAV’s lack of need of pilots and their small size make them have crucial importance for us. UAVs have variety of usage area, especially in military. However, as soldiers we believe that we can use UAVs for better purposes. In this essay we indicate the usage of UAVs for the sake of saving nature from destruction of disasters by expressing what happened in the past and what can possibly happen in the future, especially in firefighting, preventing avalanches and decreasing the effects of floods. These three disasters cause hazardous consequences to the nature. Wildfires endanger so many lives by burning and destroying what comes in their paths. The numbers of avalanches are increased with the global warming. The changes of seasons triggered floods all over the world that threaten the city life. Besides all of these people may lose their lives in order to intrude these disasters. Drones will do the job without involving people lives. Thus it will diminish the risks so drones will be used for the sake of nature and people.

Keywords: unmanned air vehicles, nature, firefighting, avalanche, flood

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Authors: I. A. Ibrahim, T. A. Elbarbary, N. Abdelaty, A. T. Kandil, H. K. Farhan

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The present work aims to study the leaching of Abu Ghalaga ilmenite ore by hydrochloric acid and simultaneous reduction by iron powder method to dissolve its titanium and iron contents. Iron content in the produced liquor is separated by solvent extraction using TBP as a solvent. All parameters affecting the efficiency of the dissolution process were separately studied including the acid concentration, solid/liquid ratio which controls the ilmenite/acid molar ratio, temperature, time and grain size. The optimum conditions at which maximum leaching occur are 30% HCl acid with a solid/liquid ratio of 1/30 at 80 °C for 4 h using ore ground to -350 mesh size. At the same time, all parameters affecting on solvent extraction and stripping of iron content from the produced liquor were studied. Results show that the best extraction is at solvent/solution 1/1 by shaking at 240 RPM for 45 minutes at 30 °C whereas best striping of iron at H₂O/solvent 2/1.

Keywords: ilmenite ore, leaching, titanium solvent extraction, Abu Ghalaga ilmenite ore

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Authors: S. Athiralakshmi, B.E. Bhojaraja, U. Pruthviraj

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In agriculture, remote sensing is applied for monitoring of plant development, evaluating of physiological processes and growth conditions. Especially valuable are the spatio-temporal aspects of the remotely sensed data in detecting crop state differences and stress situations. In this study, hyperion imagery is used for classifying arecanut crops based on their age so that these maps can be used in yield estimation of crops, irrigation purposes, applying fertilizers etc. Traditional hard classifiers assigns the mixed pixels to the dominant classes. The proposed method uses a sub pixel level classifier called linear spectral unmixing available in ENVI software. It provides the relative abundance of surface materials and the context within a pixel that may be a potential solution to effectively identifying the land-cover distribution. Validation is done referring to field spectra collected using spectroradiometer and the ground control points obtained from GPS.

Keywords: FLAASH, Hyperspectral remote sensing, Linear Spectral Unmixing, Spectral Angle Mapper Classifier.

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Authors: Dalila Oulhaci, Mohammed Zahaf

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The watering technique is essential to maintain a moist perimeter around the roots of the crop. This is the case with topical watering, where the soil around the root system can be kept permanently moist between the two extremes of water content. Moreover, one of the oldest methods used since Roman times throughout North Africa and the Near East was based on the repeated pouring of water into porous earthen vessels buried in the ground. In this context, these two techniques have been combined by replacing the earthen vase with plastic bottles filled with sand which release water through their perforated walls into the surrounding soil. The objective of this work is to first determine the purifying power of the activated sludge treatment plant of Toggourt and then that of the bottled Sawdust filter. For the station, the BOD purification rate was (96.5%), the COD purification rate was (87%) and suspended solids (90%). For the bottle, the BOD removal rate was (35%), and COD removal rate was (12.58%). This work falls within the framework of water saving, sustainable development and environmental protection, and also within the framework of agriculture.

Keywords: wasterwater, sawdust, purification, irrigation, touggourt (Algeria)

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Authors: Hasan Husnu Korkmaz, Serra Zerrin Korkmaz

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The reinforced concrete (RC) framed structures composed of beams, columns, shear walls and the slabs. The other members are assumed to be nonstructural. Especially the brick infill walls which are used to separate the rooms or spaces are just handled as dead loads. On the other hand, if these infills are constructed within the frame bays, they also have higher shear and compression capacities. It is a well-known fact that, brick infills increase the lateral rigidity of the structure and thought to be a reserve capacity in the design. But, brick infills can create unfavorable failure or damage modes in the earthquake action such as soft story or short columns. The increase in the lateral rigidity also causes an over estimation of natural period of the structure and the corresponding earthquake loads in the design are less than the actual ones. In order to obtain accurate and realistic design results, the infills must be modelled in the structural design and their capacities must be included. Unfortunately, in Turkish Earthquake Code, there is no design methodology for the engineers. In this paper, finite element modelling of infilled reinforced concrete structures are studied. The proposed or used method is compared with the experimental results of a previous study. The effect of infills on the structural response is expressed within the paper.

Keywords: seismic loading, brick infills, finite element analysis, reinforced concrete, earthquake code

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Authors: Magdeline Pakeng Mohlala, R. L. Molatudi, M. A. Mofokeng

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Cowpea (Vigna unguiculata (L.) Walp) is an important annual leguminous crop in semi-arid and tropics. Most of cowpea grain production in South Africa is mainly used for domestic consumption, as seed planting and little or none gets to be used in industrial processing; thus, there is a need to expand the utilization of cowpea through industrial processing. Agronomic traits contribute to the understanding of the association between yield and its component traits to facilitate effective selection for yield improvement. The aim of this study was to evaluate cowpea genotypes using grain yield and canning quality traits. The field experiment was conducted in two locations in Limpopo Province, namely Syferkuil Agricultural Experimental farm and Ga-Molepo village during 2017/2018 growing season and canning took place at ARC-Grain Crops Potchefstroom. The experiment comprised of 100 cowpea genotypes laid out in a Randomized Complete Block Designs (RCBD). The grain yield, yield components, and canning quality traits were analysed using Genstat software. About 62 genotypes were suitable for canning, 38 were not due to their seed coat texture, and water uptake was less than 80% resulting in too soft (mushy) seeds. Grain yield for RV115, 99k-494-6, ITOOK1263, RV111, RV353 and 53 other genotypes recorded high positive association with number of branches, pods per plant, and number of seeds per pod, unshelled weight and shelled weight for Syferkuil than at Ga-Molepo are therefore recommended for canning quality.

Keywords: agronomic traits, canning quality, genotypes, yield

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Authors: Shail N. Shah, K. K. Baraya, A. Madhusudan Achari

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Loop Heat Pipe is a passive two-phase heat transfer device which can be used without any external power source to transfer heat from source to sink. The main aim of this paper is to have modelling of water-based LHP at varying heat loads. Through figures, how the fluid flow occurs within the loop has been explained. Energy Balance has been done in each section. IC (Iterative Convergence) scheme to find out the SSOT (Steady State Operating Temperature) has been developed. It is developed using Dev C++. To best of the author’s knowledge, hardly any detail is available in the open literature about how temperature distribution along the loop is to be evaluated. Results for water-based loop heat pipe is obtained and compared with open literature and error is found within 4%. Parametric study has been done to see the effect of different parameters on pressure drop and SSOT at varying heat loads.

Keywords: loop heat pipe, modelling of loop heat pipe, parametric study of loop heat pipe, functioning of loop heat pipe

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Authors: HoYoung Son, DongHoon Shin, WooYoung Jung

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This study presented the seismic fragility framework of concrete weir structure subjected to strong seismic ground motions and in particular, concrete aging condition of the weir structure was taken into account in this study. In order to understand the influence of concrete aging on the weir structure, by using probabilistic risk assessment, the analytical seismic fragility of the weir structure was derived for pre- and post-deterioration of concrete. The performance of concrete weir structure after five years was assumed for the concrete aging or deterioration, and according to after five years’ condition, the elastic modulus was simply reduced about one–tenth compared with initial condition of weir structures. A 2D nonlinear finite element analysis was performed considering the deterioration of concrete in weir structures using ABAQUS platform, a commercial structural analysis program. Simplified concrete degradation was resulted in the increase of almost 45% of the probability of failure at Limit State 3, in comparison to initial construction stage, by analyzing the seismic fragility.

Keywords: weir, FEM, concrete, fragility, aging

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Authors: A.Chen Chao-Chang, Phong Pham-Quoc

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Chemical-mechanical polishing (CMP) process has been widely applied on fabricating integrated circuits (IC) with a soft polishing pad combined with slurry composed of micron or nano-scaled abrasives for generating chemical reaction to remove substrate or film materials from wafer. During CMP process, pad uniformity usually works as a datum surface of wafer planarization and pad asperities can dominate the microscopic pad-slurry-wafer interaction. However, pad topography can be changed by related mechanism factors of CMP and it needs to be re-conditioned or dressed by a diamond dresser of well-distributed diamond grits on a disc surface. It is still very complicated to analyze and understand kinematic of diamond dressing process under the effects of input variables including oscillatory of diamond dresser and rotation speed ratio between the pad and the diamond dresser. This paper has developed a generic geometric model to clarify the kinematic modeling of diamond dressing processes such as dresser/pad motion, pad cutting locus, the relative velocity of the diamond abrasive grits on pad surface, and overlap of cutting for prediction of pad surface topography. Simulation results focus on comparing and analysis kinematics of the diamond dressing on certain CMP tools. Results have shown the significant parameters for diamond dressing process and also discussed. Future study can apply on diamond dresser design and experimental verification of pad dressing process.

Keywords: kinematic modeling, diamond dresser, pad cutting locus, CMP

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Authors: Mustafa Abu Ghalia, Yaser Dahman

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A new class of polyurethane (PU) reinforced with green bacterial cellulose nanofibers (BC) were prepared using a solvent casting method, with the goal of fabricating green nanocomposites. Four series classes of BC (1, 2.5, 5, and 10 wt%) were reinforced into PU matrices via BC surface modification and subsequently BC-grafted into PU throughout silane coupling agent to improve BC dispersion and its interfacial interaction. The experiment results from the tensile tester were evaluated according to the response surface method (RSM) for optimizing the impacts of variable parameters, pore size, porosity, and BC contents on the mechanical properties. The compressive strength for PU-5 BC wt% was about 9.8 MPa, and decrease when being generated prosperity to recorded at 4.9 MPa. Nielson model was applied to investigate the BC stress concentration on the PU matrices. Likewise, krenche and Hapli-Tasi model were employed to evaluate the BC nanofiber reinforcement potential and BC orientation into PU matrices. The analysis of variance (ANOVA) demonstrated that only BC loading has a significant effect in increases tensile strength, young’s modulus, and a flexural modulus of the PU-BC nanocomposites. The optimal factors of the variables experiment confirmed to be 5 wt% for BC, 230 for pore size, and 80 % for porosity. Scanning electron microscopy (SEM) micrographs showed that the uniform distribution of nanofibers in the PU matrices with the addition of BC 5 wt %. Hydrolytic degradation revealed that the weight loss in PU-BC scaffold is higher than PU-BC wt %.

Keywords: polyurethane scaffold, mechanical properties, tissue engineering, polyurethane

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Authors: M. R. S. Nasuha, K. Azman, H. Azhan, S. A. Senawi, A. Mardhiah

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Studies on Samarium doped glasses possess lot of interest due to their potential applications for high-density optical memory, optical communication device, the design of laser and color display etc. Sm3+ doped borotellurite glasses of the system (70-x) TeO2-20B2O3-10ZnO-xSm2O3 (where x = 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol%) have been prepared using melt-quenching method. Their physical properties such as density, molar volume and oxygen packing density as well as the optical measurements by mean of their absorption and emission characteristic have been carried out at room temperature using UV/VIS and photoluminescence spectrophotometer. The results of physical properties are found to vary with respect to Sm3+ ions content. Meanwhile, three strong absorption peaks are observed and are well resolved in the ultra violet and visible regions due to transitions between the ground state and various excited state of Sm3+ ions. Thus, the photoluminescence spectra exhibit four emission bands from the initial state, which correspond to the 4G5/2 → 6H5/2, 4G5/2 → 6H7/2, 4G5/2 → 6H9/2 and 4G5/2 → 6H11/2 fluorescence transitions at 562 nm, 599 nm, 645 nm and 706 nm respectively.

Keywords: absorption, borotellurite, down-conversion, emission

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Authors: H. R. Fazlollahi

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Dark Energy origin is unknown and so describing this mysterious component in large scale structure needs to manipulate our theories in general relativity. Although in most models, dark energy arises from extra terms through modifying Einstein-Hilbert action, maybe its origin traces back to fundamental aspects of ground energy of space-time given in quantum mechanics. Hence, diluting space-time in general relativity with quantum mechanics properties leads to the Karolyhazy relation corresponding energy density of quantum fluctuations of space-time. Through generalized uncertainty principle and an eye to Karolyhazy approach in this study we extend energy density of quantum fluctuations of space-time. Also, the application of this idea is considered in late time evolution and we have shown how extra term in generalized uncertainty principle plays as a plausible interaction term role in suggested model.

Keywords: generalized uncertainty principle, karolyhazy approach, agegraphic dark energy, cosmology

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Authors: Areeg Shermaddo, Abedulgader Baktheer

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Solar updraft power plants (SUPPs) made from reinforced concrete (RC) are an innovative technology to generate solar electricity. An up to 1000 m high chimney represents the major part of each SUPP ensuring the updraft of the warmed air from the ground. Numerical simulation of nonlinear behavior of such large mega shell concrete structures is a challenging task, and computationally expensive. A general finite element approach to simulate reinforced concrete bearing behavior is presented and verified on a simply supported beam, as well as the technique of submodeling. The verified numerical approach is extended and consecutively transferred to a more complex chimney structure of a SUPP. The obtained results proved the reliability of submodeling technique in analyzing critical regions of simple and complex mega concrete structures with high accuracy and dramatic decrease in the computation time.

Keywords: ABAQUS, nonlinear analysis, submodeling, SUPP

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Authors: Gina Zavaleta-Espejo, Segundo R. Jáuregui-Rosas, Fanny V. Samanamud-Moreno, José Saldaña Jiménez, Anibal Felix-Quintero, Víctor Montero-Del Aguila, Elsi Mejía-Uriarte

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Vicugnapacos "alpaca" fabrics are considered special for their finesse, and the garments in the textile market are very luxurious. It has many special characteristics such as antiallergic, soft, hygroscopic, among others. In this sense, the research aimed to evaluate the antimicrobial activity of alpaca fabrics functionalized with silver nanoparticles on the bacteria Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923. For the functionalization of the fabrics, AgNO3 and different concentrations of trisodium citrate (TSC) 2, 6, and 10 mg. Tissue characterization was performed using Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The determination of the antimicrobial activity of the alpaca tissues was made by the Kirby-Bauer method with alpaca tissue discs functionalized with silver nanoparticles, an experimental design was made in completely randomized blocks with three treatments and a negative control with three repetitions. The results showed that inhibition halos were formed for both bacteria, therefore, the functionalized tissues have a high antimicrobial activity, whose mechanism of action is attributed to the free radicals (ROS) generated by the nanoparticles that cause oxidative damage to the bacteria. proteins and lipids of the bacterial cell wall.

Keywords: antimicrobial, animal fibers, fabrics, functionalization, trisodium citrate

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Authors: Hyung-Joon Kim, Jin-Young Park

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Energy dissipating devices (EDDs) have become more popular as seismic-force-resisting systems for building structures. However, there is little information on the collapse capacities of frames employing EDDs which are an important criterion for their seismic design. This study investigates the collapse capacities of steel frames with TADAS hysteric energy dissipative devices (HEDDs) that become an alternative to steel braced frames. To do this, 5-story steel ordinary concentrically braced frame and steel frame with HEDDs are designed and modeled. Nonlinear dynamic analyses and incremental dynamic analysis with 40 ground motions scaled to maximum considered earthquake are carried out. It is shown from analysis results that the significant enhancement in terms of the collapse capacities is found due to the introduction HEDDs.

Keywords: collapse capacity, incremental dynamic analysis, steel braced frame, TADAS hysteric energy dissipative device

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Authors: Hedaya Ali Al Ameri, Alya A. Arabi

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Measuring the level of carbon storage in mangroves’ biomass has a potential impact in the climate change of UAE. Carbon dioxide is one of greenhouse gases. It is considered to be a main reason for global warming. Deforestation is a key source of the increase in carbon dioxide whereas forests such as mangroves assist in removing carbon dioxide from atmosphere by storing them in its biomass and soil. By using Kauffman and Donato methodology, above- and below-ground biomass and carbon stored in UAE’s natural mangroves were quantified. Carbon dioxide equivalent (CO2eq) released to the atmosphere was then estimated in case of mangroves deforestation in the UAE. The results show that the mean total biomass of mangroves in the UAE ranged from 15.75 Mg/ha to 3098.69 Mg/ha. The estimated CO2eq released upon deforestation in the UAE was found to have a minimal effect on the temperature increase and thus global warming.

Keywords: carbon stored in biomass, mangrove deforestation, temperature change, United Arab Emirate

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Authors: Tammy Shel (Aboody)

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The integration of philosophy with ethnography, i.e., ethno-philosophy, or any qualitative method, is multi-dimensional. It is, thus, vital to the discourse on caring in the philosophy of education, and in therapy. These two significant dimensions are focal in this proposal’s discussion. The integration of grounded data with philosophy can shed light on cultural, gender, socio-economic and political diversities in the relationships and interactions between and among individuals and societies. This approach can explain miscommunication and, eventually, violent conflicts. The ethno-philosophy study in this proposal focuses on the term caring, through case studies of 5 non-white male and female elementary school teachers in Los Angeles County. The study examined the teachers’ views on caring and, consequently, the implications on their pedagogy. Subsequently, this method turned out to also be a caring approach in therapy. Ethnographic data was juxtaposed with western philosophy. Research discussion unraveled transformable gaps between western patriarchal and feminist philosophy on caring, and that of the teachers. Multiple interpretations and practices of caring were found due to cultural, gender, and socio-economic-political differences. Likewise, two dominant categories emerged. The first is inclusive caring, which is perceived as an ideal, as the compass of humanity that aims towards emancipation from the shackles of inner and external violence. The second is tribal caring, which illuminates the inherently dialectical substantial diversity in the interpretations and praxes of caring. Such angles are absent or minor in traditional western literature. Both categories teach of the incessant dynamic definition of caring, and its subliminal and repressed mechanisms. The multi-cultural aspects can teach us, however, that despite the inclusive common ground we share on caring, and despite personal and social awareness of cultural and gender differences, the hegemonic ruling-class governs the standardized conventional interpretation of caring. Second is the dimension of therapy in ethno-philosophy. Each patient is like a case study per se, and is a self-ethnographer. Thus, the patient is the self-observer and data collector, and the therapist is the philosopher who helps deconstruct into fragments the consciousness that comprises our well-being and self-esteem and acceptance. Together, they both identify and confront hurdles that hinder the pursuit of a more composed attitude towards ourselves and others. Together, they study and re-organize these fragments into a more comprehensible and composed self-acceptance. Therefore, the ethno-philosophy method, which stems from a caring approach, confronts the internal and external conflicts that govern our relationships with others. It sheds light on the dark and subliminal spots in our minds and hearts that operate us. Unveiling the hidden spots helps identify a shared ground that can supersede miscommunication and conflicts among and between people. The juxtaposition of ethnography with philosophy, as a caring approach in education and therapy, emphasizes that planet earth is like a web. Hence, despite the common mechanism that stimulates a caring approach towards the other, ethno-philosophy can help undermine the ruling patriarchal oppressive forces that define and standardize caring relationships, and to subsequently bridge gaps between people.

Keywords: caring, philosophy of education, ethnography, therapy, research

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Authors: M. Ezati Kooshki , H. Pourmohamad

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

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

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Authors: A. Elain, M. Le Fellic, A. Le Pemp, N. Hachet

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Iodinated Compounds (IC) are widely detected contaminants in most aquatic environments including sewage treatment plant, surface water, ground water and even drinking water, up to the µg.L-1 range. As IC contribute in the adsorbable organic halides (AOX) level, their removal or dehalogenation is expected. We report here on the biodegradability of a mixture of IC from an industrial effluent using a microbial consortium adapted to grow on IC as well as the native microorganisms. Both aerobic and anaerobic treatments were studied during batch experiments in 500-mL flasks. The degree of mineralization and recovery of iodide were monitored by HPLC-UV, TOC analysis and potentiometric titration. Providing ethanol as an electron acceptor was found to stimulate anaerobic reductive deiodination of IC while sodium chloride even at high concentration (22 g.l-1) had no influence on the degradation rates nor on the microbial viability. Phylogenetic analysis of 16S RNA gene sequence (MicroSeq®) was applied to provide a better understanding of the degradative microbial community.

Keywords: iodinated compounds, biodegradability, deiodination, electron-accepting conditions, microbial consortium

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Authors: Ilma Robo, Saimir Heta, Vera Ostreni, Elsaida Agrushi, Eduart Kapaj

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Introduction: Cyclic hormonal fluctuations are known from literature to have a clinically visible effects on gingival tissue reactions, to the diagnosed processes of gingival inflammation. Materials and methods: At a total of 47 female patients, ad-hock presented at the University Clinic, were recorded data on effect of hormonal oscillations at periodontal treatment protocol. Oral examination was performed on soft tissue of gingiva and the oral mucous membrane, always respecting the air-drying procedure and then checking with free eye differences in oral mucosal relief. After the patients were informed about the study protocol, the purpose of the study and the ongoing procedure, verbal consensus was required. Results: The study was conducted in a total of 47 patients, out of which 13 patients were under the gingivitis classification, and 24 patients under the periodontal classification. Patients included in the study are divided by age, cycle week respectively 1,2,3 and 4.The younger age of female patients is more prone to the appearance of gingivitis, which is further aggravated by the effects of sexual hormones and the effect of the controlled or non-regulated fluctuations of the latter. Conclusions: The healing process is more fuel-intensive in the absence of high hormone levels, as they are these pro-inflammatory hormones, both in or near the ho Younger women are more open to volunteering in studies that record individual and study data that may last in time.

Keywords: gingiva, hormonal oscillations, female patients, mucosa, periodontal non-surgical treatment

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Authors: Aditya Setyo Rahman, Dwikorita Karnawati, Muzli, Dadang Permana, Sigit Pramono, Fajri Syukur Rahmatullah, Oriza Sativa, Moehajirin, Edy Santoso, Nur Hidayati Oktavia, Ardian Yudhi Octantyo, Robby Wallansha, Juwita Sari Pradita, Nur Fani Habibah, Audia Kaluku, Amelia Chelcea, Yoga Dharma Persada, Anton Sugiharto

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Earthquake vibrations on the surface are not only affected by the magnitude of the earthquake and the distance from the hypocenter but also by the characteristics of the local soil. Variations and changes in soil characteristics from the depth of the bedrock to the surface can cause an amplification of earthquake vibrations that also affect the impact they may have on the surface. Soil characteristics vary widely even at relatively close distances, so for earthquake hazard mapping in cities with earthquake threats, it is necessary to study the characteristics of the local soil on a detailed or micro-scale (microzonation). This study proposes seismic microzonation and liquefaction potential based on microtremor observations. We carried out 143 microtremor observations, and the observation sites were spread across all populated sub-districts in Bengkulu City; the results showed that the dominance of Bengkulu City had medium soil types with a dominant period value of 0.4 < T₀ < 0.6, and there was one location with soft soil characteristics in the river, shaved with T₀ > 0.6. These results correlate with the potential for liquefaction as indicated by a seismic vulnerability index (K𝓰) greater than 5.

Keywords: microtremor, dominant period, microzonation, seismic vulnerability index

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Authors: P. Deepak Kumar, Aishwarya Alok, P. R. Maiti

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Liquid storage tanks have become widespread during the recent decades due to their extensive usage. Analysis of liquid containing tanks is known to be complex due to hydrodynamic force exerted on tank which makes the analysis a complex one. The objective of this research is to carry out analysis of liquid domain along with structural interaction for various geometries of circular tanks considering seismic effects. An attempt has been made to determine hydrodynamic pressure distribution on the tank wall considering impulsive and convective components of liquid mass. To get a better picture, a comparative study of Draft IS 1893 Part 2, ACI 350.3 and Eurocode 8 for Circular Shaped Tank has been performed. Further, the differences in the magnitude of shear and moment at base as obtained from static (IS 3370 IV) and dynamic (Draft IS 1892 Part 2) analysis of ground supported circular tank highlight the need for us to mature from the old code to a newer code, which is more accurate and reliable.

Keywords: liquid filled containers, circular tanks, IS 1893 (part 2), seismic analysis, sloshing

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Authors: Javier A. Maldonado E., Duvert A. Puentes T., Diego F. Villegas B.

Abstract:

The SLAP lesion (Superior Labral Anterior to Posterior) involves the labrum, causing pain and mobility problems in the glenohumeral joint. This injury is common in athletes practicing sports that requires throwing or those who receive traumatic impacts on the shoulder area. This paper determines the biomechanical behavior of soft tissues of the glenohumeral joint when type II SLAP lesion is present. This pathology is characterized for a tear in the superior labrum which is simulated in a 3D model of the shoulder joint. A 3D model of the glenohumeral joint was obtained using the free software Slice. Then, a Finite Element analysis was done using a general purpose software which simulates a compression test with external rotation. First, a validation was done assuming a healthy joint shoulder with a previous study. Once the initial model was validated, a lesion of the labrum built using a CAD software and the same test was done again. The results obtained were stress and strain distribution of the synovial capsule and the injured labrum. ANOVA was done for the healthy and injured glenohumeral joint finding significant differences between them. This study will help orthopedic surgeons to know the biomechanics involving this type of lesion and also the other surrounding structures affected by loading the injured joint.

Keywords: biomechanics, computational model, finite elements, glenohumeral joint, superior labral anterior to posterior lesion

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Authors: Vimuckthi Charika Wickramaratne, Prasansha Kumari

Abstract:

Sport tourism refers to travel which involves either observing or participating in a sporting event apart from their usual environment. Sport tourism in a fast growing sector of the Sri Lankan travelling industry since Cricket are more popular sport game in the country. This study intends to analyze the impact of these popular sport events for creating and developing small scale business in the country. Primary data gathered from 100 small entrepreneurs around Keththarama Cricket Ground in Sri Lanka. Collected data analyzed using descriptive research methods. The study revealed that local and international visitors for cricket games had impacted on small scale business activities such as retail, handicraft, transport, vehicle parking, small restaurant, hotels, foods and beverage industry. In addition, it was identified that these type of small business are sessional income generating activities for the short period.

Keywords: sport tourism, small scale business, cricket, entrepreneurs

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Authors: Saurabh Sharma

Abstract:

Introduction: The case study deals with the ground stabilisation of Nabi Karim Metro Station in Delhi, India, wherein an extremely complex geology was encountered while excavating the tunnelling shaft for launching Tunnel Boring Machine. The borelog investigation and the Seismic Refraction Technique (SRT) indicated towards the presence of an extremely hard rocky mass from a depth of 3-4 m itself, and accordingly, the Geotechnical Interpretation Report (GIR) concluded the presence of Grade-IV rock from 3m onwards and presence of Grade-III and better rock from 5-6m onwards. Accordingly, it was planned to retain the ground by providing secant piles all around the launching shaft and then excavating the shaft vertically after leaving a berm of 1.5m to prevent secant piles from getting exposed. To retain the side slopes, rock bolting with shotcreting and wire meshing were proposed, which is a normal practice in such strata. However, with the increase in depth of excavation, the rock quality kept on decreasing at an unexpected and surprising pace, with the Grade-III rock mass at 5-6 m converting to conglomerate formation at the depth of 15m. This worsening of geology from high grade rock to slushy conglomerate formation can never be predicted and came as a surprise to even the best geotechnical engineers. Since the excavation had already been cut down vertically to manage the shaft size, the execution was continued with enhanced cautions to stabilise the side slopes. But, when the shaft work was about to finish, a collapse was encountered on one side of the excavation shaft. This collapse was unexpected and surprising since all measures to stabilise the side slopes had been taken after face mapping, and the grid size, diameter, and depth of the rockbolts had already been readjusted to accommodate rock fractures. The above scenario was baffling even to the best geologists and geotechnical engineers, and it was decided that any further slope stabilisation scheme shall have to be designed in such a way to ensure safe completion of works. Accordingly, following revisions to excavation scheme were made: The excavation would be carried while maintaining a slope based on type of soil/rock. The rock bolt type was changed from SN rockbolts to Self Drilling type anchor. The grid size of the bolts changed on real time assessment. the excavation carried out by implementing a ‘Bench Release Approach’. Aggressive Real Time Instrumentation Scheme. Discussion: The above case Study again asserts vitality of correct interpretation of the geological strata and the need of real time revisions of the construction schemes based on the actual site data. The excavation is successfully being done with the above revised scheme, and further details of the Revised Slope Stabilisation Scheme, Instrumentation Schemes, Monitoring results, along with the actual site photographs, shall form the part of the final Paper.

Keywords: unconfined compressive strength (ucs), rock mass rating (rmr), rock bolts, self drilling anchors, face mapping of rock, secant pile, shotcrete

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Authors: Artur Cichowicz

Abstract:

The last active mine in the Central Rand Goldfields area (50 km x 15 km) ceased operations in 2008. This resulted in the closure of the pumping stations, which previously maintained the underground water level in the mining voids. As a direct consequence of the water being allowed to flood the mine voids, seismic activity has increased directly beneath the populated area of Johannesburg. Monitoring of seismicity in the area has been on-going for over five years using the network of 17 strong ground motion sensors. The objective of the project is to improve strategies for mine closure. The evolution of the seismicity pattern was investigated in detail. Special attention was given to seismic source parameters such as magnitude, scalar seismic moment and static stress drop. Most events are located within historical mine boundaries. The seismicity pattern shows a strong relationship between the presence of the mining void and high levels of seismicity; no seismicity migration patterns were observed outside the areas of old mining. Seven years after the pumping stopped, the evolution of the seismicity has indicated that the area is not yet in equilibrium. The level of seismicity in the area appears to not be decreasing over time since the number of strong events, with Mw magnitudes above 2, is still as high as it was when monitoring began over five years ago. The average rate of seismic deformation is 1.6x1013 Nm/year. Constant seismic deformation was not observed over the last 5 years. The deviation from the average is in the order of 6x10^13 Nm/year, which is a significant deviation. The variation of cumulative seismic moment indicates that a constant deformation rate model is not suitable. Over the most recent five year period, the total cumulative seismic moment released in the Central Rand Basin was 9.0x10^14 Nm. This is equivalent to one earthquake of magnitude 3.9. This is significantly less than what was experienced during the mining operation. Characterization of seismicity triggered by a rising water level in the area can be achieved through the estimation of source parameters. Static stress drop heavily influences ground motion amplitude, which plays an important role in risk assessments of potential seismic hazards in inhabited areas. The observed static stress drop in this study varied from 0.05 MPa to 10 MPa. It was found that large static stress drops could be associated with both small and large events. The temporal evolution of the inter-event time provides an understanding of the physical mechanisms of earthquake interaction. Changes in the characteristics of the inter-event time are produced when a stress change is applied to a group of faults in the region. Results from this study indicate that the fluid-induced source has a shorter inter-event time in comparison to a random distribution. This behaviour corresponds to a clustering of events, in which short recurrence times tend to be close to each other, forming clusters of events.

Keywords: inter-event time, fluid induced seismicity, mine closure, spectral parameters of seismic source

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