Search results for: earth size

Authors: Gloria Ogungbade, Ogaba Oche, Moses Duruji, Chris Ehiobuche, Lady Ajayi

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Human’s continued sustenance on earth and the quality of living are heavily dependent on the environment. The major components of the environment being air, water and land are the supporting pillars of the human existence, which they depend on directly or indirectly for survival and well-being. Unfortunately, due to some of the human activities on the environment, there seems to be a war between humans and the environment, which is evident in his over-exploitation and inadequate management of the basic components of the environment. Since the discovery of crude oil in the Niger Delta, the region has experienced various forms of degradation caused by pollution from oil spillage, gas flaring and other forms of environmental pollution, as a result of reckless way and manner with which oil is being exploited by the International Oil Corporations (IOCs) operating within the region. The Nigerian government on the other, not having strong regulations guiding the activities of the operations of these IOCs, has done almost nothing to curtail the activities of these IOCs because of the revenue generated the IOCs, as such the region is deprived of the basic social amenities and infrastructures. The degree of environmental pollution suffered within the region affects their major sources of livelihood – being fishing and farming, and has also left the region in poverty, which has led to a large number of people migrating to the urban areas to escape poverty. This paper investigates how environment degradation impact urbanization and security in the region.

Keywords: environmental degradation, environmental pollution, gas flaring, oil spillage, urbanization

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Authors: Sylvester S. Horvey, Jones Mensah

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The growing complexities and dynamics in the business environment have led to a new approach to risk management, known as enterprise risk management (ERM). ERM is a system and an approach to managing the risks of an organization in an integrated manner to achieve the corporate goals and strategic objectives. Regardless of the diversities in the business environment, ERM has become an essential factor in managing individual and business risks because ERM is believed to enhance shareholder value and firm growth. Despite the growing number of literature on ERM, the question about what factors drives ERM remains limited. This study provides a comprehensive literature review of the main factors that contribute to ERM implementation. Google Scholar was the leading search engine used to identify empirical literature, and the review spanned between 2000 and 2020. Articles published in Scimago journal ranking and Scopus were examined. Thirteen firm characteristics and sixteen articles were considered for the empirical review. Most empirical studies agreed that firm size, institutional ownership, industry type, auditor type, industrial diversification, earnings volatility, stock price volatility, and internal auditor had a positive relationship with ERM adoption, whereas firm size, institutional ownership, auditor type, and type of industry were mostly seen be statistically significant. Other factors such as financial leverage, profitability, asset opacity, international diversification, and firm complexity revealed an inconclusive result. The growing literature on ERM is not without limitations; hence, this study suggests that further research should examine ERM determinants within a new geographical context while considering a new and robust way of measuring ERM rather than relying on a simple proxy (dummy) for ERM measurement. Other firm characteristics such as organizational culture and context, corporate scandals and losses, and governance could be considered determinants of ERM adoption.

Keywords: enterprise risk management, determinants, ERM adoption, literature review

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Authors: Merouane Salhi, Mohamed Roudane, Abdelkader Kirad

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In this work, we present a new form of characteristics method, which is a technique for solving partial differential equations. Typically, it applies to first-order equations; the aim of this method is to reduce a partial differential equation to a family of ordinary differential equations along which the solution can be integrated from some initial data. This latter developed under the real gas theory, because when the thermal and the caloric imperfections of a gas increases, the specific heat and their ratio do not remain constant anymore and start to vary with the gas parameters. The gas doesn’t stay perfect. Its state equation change and it becomes for a real gas. The presented equations of the characteristics remain valid whatever area or field of study. Here we need have inserted the developed Prandtl Meyer function in the mathematical system to find a new model when the effect of stagnation pressure is taken into account. In this case, the effects of molecular size and intermolecular attraction forces intervene to correct the state equation, the thermodynamic parameters and the value of Prandtl Meyer function. However, with the assumptions that Berthelot’s state equation accounts for molecular size and intermolecular force effects, expressions are developed for analyzing the supersonic flow for thermally and calorically imperfect gas. The supersonic parameters depend directly on the stagnation parameters of the combustion chamber. The resolution has been made by the finite differences method using the corrector predictor algorithm. As results, the developed mathematical model used to design 2D minimum length nozzles under effect of the stagnation parameters of fluid flow. A comparison for air with the perfect gas PG and high temperature models on the one hand and our results by the real gas theory on the other of nozzles shapes and characteristics are made.

Keywords: numerical methods, nozzles design, real gas, stagnation parameters, supersonic expansion, the characteristics method

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Authors: Michael Ryan, Rosemary E. Borgerding, Kimberly L. Oliver

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The objective of this study was to assess the effectiveness of a sports nutrition intervention on body composition in high-school athletes. The study aimed to improve the food and water intake of high-school athletes, evaluate the cost-effectiveness of the intervention, and assess changes in body fat. Data were collected through observations, questionnaires, and interviews. Additionally, bioelectrical impedance analysis was performed to assess the body composition of athletes both before and after the intervention. Athletes (n=25) participated in researcher-monitored training sessions three times a week over the course of 12 weeks. During these sessions, in addition to completing their auxiliary sports training, participants were exposed to educational interventions aimed at improving their nutrition. These included discussions regarding current eating habits, nutritional guidelines for athletes, and individualized recommendations. Food was also made available to athletes for consumption before and after practice. Meals of balanced macronutrient composition were prepared and provided to athletes on four separate occasions throughout the intervention, either prior to or following a competitive event such as a tournament or game. A paired t-test was used to determine the statistical significance of the changes in body fat percentage. The results showed that there was a statistically significant difference between pre and post-intervention body fat percentage (p= .006). Cohen's d of 0.603 was calculated, indicating a moderate effect size. In conclusion, this study provides evidence that a sports nutrition intervention that combines food availability, explicit prescription, and education can be effective in improving the body composition of high-school athletes. However, it's worth noting that this study had a small sample size, and the conclusions cannot be generalized to a larger population. Further research is needed to assess the scalability of this study. This preliminary study demonstrated the feasibility of this type of nutritional intervention and laid the groundwork for a larger, more extensive study to be conducted in the future.

Keywords: bioelectrical impedance, body composition, high-school athletes, sports nutrition, sports pedagogy

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Authors: Gaoyuan Wang, Tian Chen

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China’s emission peak and carbon neutrality strategies lead to the transformation of development patterns and call for new green urban design thinking. This paper begins by revealing the evolution of green urban design thinking during the periods of carbon enlightenment, carbon dependency, and carbon decoupling from the perspective of the energy transition. Combined with the current energy situation, national strengths, and technological trends, the emergence of green urban design towards carbon neutrality becomes inevitable. Based on the preliminary analysis of its connotation, the characteristics of the new type of green urban design are generalized as low-carbon orientation, carbon-related objects, carbon-reduction means, and carbon-control patterns. Its theory is briefly clarified in terms of the human-earth synergism, quality-energy interconnection, and form-flow interpromotion. Then, its mechanism is analyzed combined with the core tasks of carbon neutrality, and the scope of design issues is defined, including carbon flow mapping, carbon source regulation, carbon sink construction, and carbon emission management. Finally, a multi-scale spatial response system is proposed across the region, city, cluster, and neighborhood level. The discussion aims to provide support for the innovation of green urban design theories and methods in the context of peak neutrality.

Keywords: carbon neutrality, green urban design, energy transition, theoretical exploration

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Authors: Getinet Gezahegn Gebre

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The study examined the impact of gender differences on Crop productivity in Decha woreda of southwest Kafa zone, located 140 Km from Jimma Town and 460 km southwest of Addis Ababa, between Bonga town and Omo River. The specific objectives were to assess the extent to which the agricultural production system is gender oriented, to examine access and control over productive resources, and to estimate men’s and women’s productivity in agriculture. Cross-sectional data collected from a total of 140 respondents were used in this study, whereby 65 were female-headed and 75 were male-headed households. The data were analyzed by using Statistical Package for Social Science (SPSS). Descriptive statistics such as frequency, mean, percentage, t-test and chi-square were used to summarize and compare the information between the two groups. Moreover, Cobb-Douglas(CD) production function was used to estimate the productivity difference in agriculture between male and female-headed households. Results of the study showed that male-headed households (MHH) own more productive resources such as land, livestock, labor and other agricultural inputs as compared to female-headed households (FHH). Moreover, the estimate of CD production function shows that livestock, herbicide use, land size and male labor were statistically significant for MHH, while livestock, land size, herbicides use and female labor were significant variables for FHH. The crop productivity difference between MHH and FHH was about 68.83% in the study area. However, if FHH had equal access to the inputs as MHH, the gross value of the output would be higher by 23.58% for FHH. This might suggest that FHH would be more productive than MHH if they had equal access to inputs as MHH. Based on the results obtained, the following policy implication can be drawn: accessing FHH to inputs that increase the productivity of agriculture, such as herbicides, livestock and male labor; increasing the productivity of land; and introducing technologies that reduce the time and energy of women, especially for enset processing.

Keywords: gender difference, crop productivity, GDP, efficiency

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Authors: Natalia Koltovaya, Nadezhda Zhuchkina, Ksenia Lyubimova

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We study the biological effects induced by ionizing radiation in view of therapeutic exposure and the idea of space flights beyond Earth's magnetosphere. In particular, we examine the differences between base pair substitution induction by ionizing radiation in model haploid and diploid yeast Saccharomyces cerevisiae cells. Such mutations are difficult to study in higher eukaryotic systems. In our research, we have used a collection of six isogenic trp5-strains and 14 isogenic haploid and diploid cyc1-strains that are specific markers of all possible base-pair substitutions. These strains differ from each other only in single base substitutions within codon-50 of the trp5 gene or codon-22 of the cyc1 gene. Different mutation spectra for two different haploid genetic trp5- and cyc1-assays and different mutation spectra for the same genetic cyc1-system in cells with different ploidy — haploid and diploid — have been obtained. It was linear function for dose-dependence in haploid and exponential in diploid cells. We suggest that the differences between haploid yeast strains reflect the dependence on the sequence context, while the differences between haploid and diploid strains reflect the different molecular mechanisms of mutations.

Keywords: base pair substitutions, γ-rays, haploid and diploid cells, yeast Saccharomyces cerevisiae

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Authors: Roberto Pili, Alessandro Romagnoli, Hartmut Spliethoff, Christoph Wieland

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Internal combustion engines (ICE) are today the most common energy system to drive vehicles and transportation systems. Numerous studies state that 50-60% of the fuel energy content is lost to the ambient as sensible heat. ORC offers a valuable alternative to recover such waste heat from ICE, leading to fuel energy savings and reduced emissions. In contrast, the additional weight of the ORC affects the net energy balance of the overall system and the ORC occupies additional volume that competes with vehicle transportation capacity. Consequently, a lower income from delivered freight or passenger tickets can be achieved. The economic feasibility of integrating an ORC into an ICE and the resulting economic impact of weight and volume have not been analyzed in open literature yet. This work intends to define such a benchmark for ORC applications in the transportation sector and investigates the current situation on the market. The applied methodology refers to the freight market, but it can be extended to passenger transportation as well. The economic parameter X is defined as the ratio between the variation of the freight revenues and the variation of fuel costs when an ORC is installed as a bottoming cycle for an ICE with respect to a reference case without ORC. A good economic situation is obtained when the reduction in fuel costs is higher than the reduction of revenues for the delivered freight, i.e. X<1. Through this constraint, a maximum allowable change of transport capacity for a given relative reduction in fuel consumption is determined. The specific fuel consumption is influenced by the ORC in two ways. Firstly because the transportable freight is reduced and secondly because the total weight of the vehicle is increased. Note, that the generated electricity of the ORC influences the size of the ICE and the fuel consumption as well. Taking the above dependencies into account, the limiting condition X = 1 results in a second order equation for the relative change in transported cargo. The described procedure is carried out for a typical city bus, a truck of 24-40 t of payload capacity, a middle-size freight train (1000 t), an inland water vessel (Va RoRo, 2500 t) and handysize-like vessel (25000 t). The maximum allowable mass and volume of the ORC are calculated in dependence of its efficiency in order to satisfy X < 1. Subsequently, these values are compared with weight and volume of commercial ORC products. For ships of any size, the situation appears already highly favorable. A different result is obtained for road and rail vehicles. For trains, the mass and the volume of common ORC products have to be reduced at least by 50%. For trucks and buses, the situation looks even worse. The findings of the present study show a theoretical and practical approach for the economic application of ORC in the transportation sector. In future works, the potential for volume and mass reduction of the ORC will be addressed, together with the integration of an economic assessment for the ORC.

Keywords: ORC, transportation, volume, weight

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Authors: S. Pal, R. Singh, S. Sivakumar, D. Kunzru

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AOT stabilized reverse micelles of deionized water, dispersed in isooctane have been used to synthesize bimetallic nickel tungsten nanoparticles. Prepared nanoparticles were supported on γ-Al2O3 followed by calcination at 500oC. Characterizations of the nanoparticles were done by TEM, XRD, FTIR, XRF, TGA and BET. XRF results showed that this method gave good composition control with W/Ni weight ratio equal to 3.2. TEM images showed particle size of 5-10 nm. Removal of surfactant after calcination was confirmed by TGA and FTIR.

Keywords: nanoparticles, reverse micelles, nickel, tungsten

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Authors: Preethy Mary Donald, Renjith George

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Oral tori are localized non-neoplastic protuberances of maxilla and mandible. Torus palatinus (TP) is found on the midline of the roof of mouth existing as single growth or in clusters. Torus mandibularis(TM) is located on the lingual aspect of the mandible commonly between canine and premolar region. Etiology of their presence was not clear and was found to be multifactorial. Their variations in relation to age, gender, ethnicity and also the characteristics of TP and TM have become the interest of multiple studies. The objectives of this study were to determine the prevalence of torus palatinus (TP) and torus mandibularis (TM) among patients who have visited outpatient department, Faculty of Dentistry, Melaka Manipal Medical College. 108 patients were examined for the presence of oral tori at the outpatient department, Faculty of Dentistry, Melaka-Manipal Medical College. Factors such as age, gender, ethnicity of the patients and size, shape, location of the oral tori were studied. For TP, Malays (62.96%) have been found to have the highest prevalence than Chinese (43.3%) and Indians (35.71%). For TM, Chinese (7.46%) had predominated compared to Malays (7.41%) and Indians (0%). There is no significant association between occurrence of TP and TM with age, gender and ethnicity. For Torus palatinus, the most common size was Grade 1(1-3mm), most common location was molar region, and the most common shape was spindle. For Torus mandibularis, the most frequent location was canine premolar region and exists in unilateral single or bilateral single fashion. The overall prevalence rates were 47.2% for TP and 6.48% for TM. However, there is no significant association between occurrence of TP and TM with age, gender and ethnicity. The results showed variations in clinical characteristics and support the findings that occurrence of tori is a dynamic phenomenon which is multifactorial owing to the environmental factors such as stress from occlusion and dietary habits. It could be due to the genetic make-up of the individual.

Keywords: torus palatinus, torus mandibularis, age, gender

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Authors: Vipin Bhandari, Anupama Singh, Kopal Gupta

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Solid state fermentation, an eminent bioconversion technique for converting many biological substrates into a value-added product, has proven its role in the biotransformation of crops by nutritionally enriching them. Hence, an effort was made for nutritional enhancement of underutilized crops viz. barnyard millet, amaranthus and horse gram based composite flour using SSF. The grains were given pre-treatments before fermentation and these pre-treatments proved quite effective in diminishing the level of antinutrients in grains and in improving their nutritional characteristics. The present study deals with the enhancement of nutritional characteristics of underutilized crops viz. barnyard millet, amaranthus and horsegram based composite flour using solid state fermentation (SSF) as the principle bioconversion technique to convert the composite flour substrate into a nutritionally enriched value added product. Response surface methodology was used to design the experiments. The variables selected for the fermentation experiments were substrate particle size, substrate blend ratio, fermentation time, fermentation temperature and moisture content having three levels of each. Seventeen designed experiments were conducted randomly to find the effect of these variables on microbial count, reducing sugar, pH, total sugar, phytic acid and water absorption index. The data from all experiments were analyzed using Design Expert 8.0.6 and the response functions were developed using multiple regression analysis and second order models were fitted for each response. Results revealed that pretreatments proved quite handful in diminishing the level of antinutrients and thus enhancing the nutritional value of the grains appreciably, for instance, there was about 23% reduction in phytic acid levels after decortication of barnyard millet. The carbohydrate content of the decorticated barnyard millet increased to 81.5% from initial value of 65.2%. Similarly popping and puffing of horsegram and amaranthus respectively greatly reduced the trypsin inhibitor activity. Puffing of amaranthus also reduced the tannin content appreciably. Bacillus subtilis was used as the inoculating specie since it is known to produce phytases in solid state fermentation systems. These phytases remarkably reduce the phytic acid content which acts as a major antinutritional factor in food grains. Results of solid state fermentation experiments revealed that phytic acid levels reduced appreciably when fermentation was allowed to continue for 72 hours at a temperature of 35°C. Particle size and substrate blend ratio also affected the responses positively. All the parameters viz. substrate particle size, substrate blend ratio, fermentation time, fermentation temperature and moisture content affected the responses namely microbial count, reducing sugar, pH, total sugar, phytic acid and water absorption index but the effect of fermentation time was found to be most significant on all the responses. Statistical analysis resulted in the optimum conditions (particle size 355µ, substrate blend ratio 50:20:30 of barnyard millet, amaranthus and horsegram respectively, fermentation time 68 hrs, fermentation temperature 35°C and moisture content 47%) for maximum reduction in phytic acid. The model F- value was found to be highly significant at 1% level of significance in case of all the responses. Hence, second order model could be fitted to predict all the dependent parameters. The effect of fermentation time was found to be most significant as compared to other variables.

Keywords: composite flour, solid state fermentation, underutilized crops, cereals, fermentation technology, food processing

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Authors: Linyue Jia, Wenbo Du, Zhaohui Wang, Ke Liu, Shubo Li

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Due to the great potential for weight reduction in aerospace and automotive industries, magnesium-rare earth (Mg-RE) based alloys with outstanding mechanical performance have been widely investigated for decades. However, magnesium alloys are still restricted in engineering applications because of their lower strength and ductility. Hence, there are large spaces and challenges in achieving high-performance Mg alloys. This work reports an Mg-Gd-Er-Zn-Zr alloy with ultrahigh strength and good ductility developed via hot extrusion, pre-deformation, and two-stage aging. The extruded alloy comprises fine dynamically recrystallized (DRXed) grains and coarse worked grains with a large aspect ratio. Pre-deformation has little effect on the microstructure and macro-texture and serves primarily to introduce a large number of dislocations, resulting in strain hardening and higher precipitation strengthening during subsequent aging due to more nucleation sites. As a result, the alloy exhibits a yield strength (YS) of 506 MPa, an ultimate tensile strength (UTS) of 549 MPa, and elongation (EL) of 8.2% at room temperature, showing superior strength-ductility balance than the other wrought Mg-RE alloys previously reported. The current study proposes a combination of pre-deformation and two-stage aging to further improve the mechanical properties of wrought Mg alloys for engineering applications.

Keywords: magnesium alloys, mechanical properties, microstructure, pre-deformation, two-stage aging

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Authors: Femy M. Makkar, S. Chandrakaran, N. Sankar

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The concept of reinforced earth has been used in the field of geotechnical engineering since 1960s, for many applications such as, construction of road and rail embankments, pavements, retaining walls, shallow foundations, soft ground improvement and so on. Conventionally, planar geosynthetic materials such as geotextiles and geogrids were used as the reinforcing elements. Recently, the use of three dimensional reinforcements becomes one of the emerging trends in this field. So, in the present investigation, three dimensional geogrid is proposed as a reinforcing material. Laboratory scaled plate load tests are conducted on a model square footing resting on 3D geogrid reinforced sand bed. The performance of 3D geogrids in triangular and square pattern was compared with conventional geogrids and the improvement in bearing capacity and reduction in settlement and heave are evaluated. When single layer of reinforcement was placed at an optimum depth of 0.25B from the bottom of the footing, the bearing capacity of conventional geogrid reinforced soil improved by 1.85 times compared to unreinforced soil, where as 3D geogrid reinforced soil with triangular pattern and square pattern shows 2.69 and 3.05 times improvement respectively compared to unreinforced soil. Also, 3D geogrids performs better than conventional geogrids in reducing the settlement and heave of sand bed around the model footing.

Keywords: 3D reinforcing elements, bearing capacity, heavy, settlement

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Authors: Boukary Lam, Sebastien Deon, Patrick Fievet, Nadia Crini, Gregorio Crini

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Treatment of heavy metal-contaminated industrial wastewater has become a major challenge over the last decades. Conventional processes for the treatment of metal-containing effluents do not always simultaneously satisfy both legislative and economic criteria. In this context, coupling of processes can then be a promising alternative to the conventional approaches used by industry. The polymer-assisted ultrafiltration (PAUF) process is one of these coupling processes. Its principle is based on a sequence of steps with reaction (e.g., complexation) between metal ions and a polymer and a step involving the rejection of the formed species by means of a UF membrane. Unlike free ions, which can cross the UF membrane due to their small size, the polymer/ion species, the size of which is larger than pore size, are rejected. The PAUF process was deeply investigated herein in the case of removal of nickel ions by adding chitosan and carboxymethyl cellulose (CMC). Experiments were conducted with synthetic solutions containing 1 to 100 ppm of nickel ions with or without the presence of NaCl (0.05 to 0.2 M), and an industrial discharge water (containing several metal ions) with and without polymer. Chitosan with a molecular weight of 1.8×105 g mol⁻¹ and a degree of acetylation close to 15% was used. CMC with a degree of substitution of 0.7 and a molecular weight of 9×105 g mol⁻¹ was employed. Filtration experiments were performed under cross-flow conditions with a filtration cell equipped with a polyamide thin film composite flat-sheet membrane (3.5 kDa). Without the step of polymer addition, it was found that nickel rejection decreases from 80 to 0% with increasing metal ion concentration and salt concentration. This behavior agrees qualitatively with the Donnan exclusion principle: the increase in the electrolyte concentration screens the electrostatic interaction between ions and the membrane fixed the charge, which decreases their rejection. It was shown that addition of a sufficient amount of polymer (greater than 10⁻² M of monomer unit) can offset this decrease and allow good metal removal. However, the permeation flux was found to be somewhat reduced due to the increase in osmotic pressure and viscosity. It was also highlighted that the increase in pH (from 3 to 9) has a strong influence on removal performances: the higher pH value, the better removal performance. The two polymers have shown similar performance enhancement at natural pH. However, chitosan has proved more efficient in slightly basic conditions (above its pKa) whereas CMC has demonstrated very weak rejection performances when pH is below its pKa. In terms of metal rejection, chitosan is thus probably the better option for basic or strongly acid (pH < 4) conditions. Nevertheless, CMC should probably be preferred to chitosan in natural conditions (5 < pH < 8) since its impact on the permeation flux is less significant. Finally, ultrafiltration of an industrial discharge water has shown that the increase in metal ion rejection induced by the polymer addition is very low due to the competing phenomenon between the various ions present in the complex mixture.

Keywords: carboxymethyl cellulose, chitosan, heavy metals, nickel ion, polymer-assisted ultrafiltration

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Authors: Seyi Olalekan Olawuyi, Abbyssiania Mushunje

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The potential benefits of agricultural production to improve the welfare condition of smallholder farmers in developing countries is no more a news because it has been widely documented. Yet majority of these farming households suffer from shortfall in production output to meet both the consumption needs and market demand which adversely affects output market participation and by extension welfare condition. Therefore, this study investigated the impacts of output market participation on households’ welfare of cassava-based farmers in Oyo State, Nigeria. Multistage sampling technique was used to select 324 sample size used for this study. The findings from the data obtained and analyzed through composite score and crosstab analysis revealed that there is varying degree of output market participation among the farmers which also translate to the observed welfare profile differentials in the study area. The probit model analysis with respect to the selection equation identified gender of household head, household size, access to remittance, off-farm income and ownership of farmland as significant drivers of output market participation in the study area. Furthermore, the treatment effect model of the welfare equation and propensity score matching (PSM) technique were used as robust checks; and the findings attest to the fact that, complimentarily with other significant variables highlighted in this study, output market participation indeed has a significant impact on farming households’ welfare. As policy implication inferences, the study recommends female active inclusiveness and empowerment in farming activities, birth control strategies, secondary income smoothing activities and discouragement of land fragmentation habits, to boost productivity and output market participation, which by extension can significantly improve farming households’ welfare.

Keywords: Cassava market participation, households' welfare, propensity score matching, treatment effect model

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Authors: Y. Fekir, K. Mederbal, M. A. Hammadouche, D. Anteur

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The cultural park of the Tassili, occupying a large area of Algeria, is characterized by a rich vegetative biodiversity to be preserved and managed both in time and space. The management of a large area (case of Tassili), by its complexity, needs large amounts of data, which for the most part, are spatially localized (DEM, satellite images and socio-economic information etc.), where the use of conventional and traditional methods is quite difficult. The remote sensing, by its efficiency in environmental applications, became an indispensable solution for this kind of studies. Multispectral imaging sensors have been very useful in the last decade in very interesting applications of remote sensing. They can aid in several domains such as the de¬tection and identification of diverse surface targets, topographical details, and geological features. In this work, we try to extract vegetative areas using fusion techniques between data acquired from sensor on-board the Earth Observing 1 (EO-1) satellite and Landsat ETM+ and TM sensors. We have used images acquired over the Oasis of Djanet in the National Park of Tassili in the south of Algeria. Fusion technqiues were applied on the obtained image to extract the vegetative fraction of the different classes of land use. We compare the obtained results in vegetation end member extraction with vegetation indices calculated from both Hyperion and other multispectral sensors.

Keywords: Landsat ETM+, EO1, data fusion, vegetation, Tassili, Algeria

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Authors: Faruk Elaldi

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There are lots of concrete columns and beams around in our living cities. Those columns are mostly open to aggressive environmental conditions and earthquakes. Mostly, they are deteriorated by sand, wind, humidity and other external applications at times. After a while, these beams and columns need to be repaired. Within the scope of this study, for reinforcement of concrete columns, samples were designed and fabricated to be strengthened with carbon fiber reinforced composite materials and conventional concrete encapsulation and followed by, and they were put into the axial compression test to determine load-carrying performance before column failure. In the first stage of this study, concrete column design and mold designs were completed for a certain load-carrying capacity. Later, the columns were exposed to environmental deterioration in order to reduce load-carrying capacity. To reinforce these damaged columns, two methods were applied, “concrete encapsulation” and the other one “wrapping with carbon fiber /epoxy” material. In the second stage of the study, the reinforced columns were applied to the axial compression test and the results obtained were analyzed. Cost and load-carrying performance comparisons were made and it was found that even though the carbon fiber/epoxy reinforced method is more expensive, this method enhances higher load-carrying capacity and reduces the reinforcement processing period.

Keywords: column reinforcement, composite, earth quake, carbon fiber reinforced

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Authors: Martin Doran, Roy Sterritt, George Wilkie

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NASA, ESA, and NSSC space agencies have plans to put planetary rovers on Mars in 2020. For these future planetary rovers to succeed, they will heavily depend on sensors to detect obstacles. This will also become of vital importance in the future, if rovers become less dependent on commands received from earth-based control and more dependent on self-configuration and self-decision making. These planetary rovers will face harsh environments and the possibility of hardware failure is high, as seen in missions from the past. In this paper, we focus on using Autonomic principles where self-healing, self-optimization, and self-adaption are explored using the MAPE-K model and expanding this model to encapsulate the attributes such as Awareness, Analysis, and Adjustment (AAA-3). In the experimentation, a Pioneer P3-DX research robot is used to simulate a planetary rover. The sonar sensors on the P3-DX robot are used to simulate the sensors on a planetary rover (even though in reality, sonar sensors cannot operate in a vacuum). Experiments using the P3-DX robot focus on how our software system can be adapted with the loss of sonar sensor functionality. The autonomic manager system is responsible for the decision making on how to make use of remaining ‘enabled’ sonars sensors to compensate for those sonar sensors that are ‘disabled’. The key to this research is that the robot can still detect objects even with reduced sonar sensor capability.

Keywords: autonomic, self-adaption, self-healing, self-optimization

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Authors: Se-Mi Lim, Won-Jae Jung, Jin-Sup Kim, Jun-Seok Park, Hyung-Il Chae

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This paper presents a current-mode vertical hall device (VHD) structure using metal layers in a CMOS process. The proposed metal layer based vertical hall device (MLVHD) utilizes vertical connection among metal layers (from M1 to the top metal) to facilitate hall effect. The vertical metal structure unit flows a bias current Ibias from top to bottom, and an external magnetic field changes the current distribution by Lorentz force. The asymmetric current distribution can be detected by two differential-mode current outputs on each side at the bottom (M1), and each output sinks Ibias/2 ± Ihall. A single vertical metal structure generates only a small amount of hall effect of Ihall due to the short length from M1 to the top metal as well as the low conductivity of the metal, and a series connection between thousands of vertical structure units can solve the problem by providing NxIhall. The series connection between two units is another vertical metal structure flowing current in the opposite direction, and generates negative hall effect. To mitigate the negative hall effect from the series connection, the differential current outputs at the bottom (M1) from one unit merges on the top metal level of the other unit. The proposed MLVHD is simulated in a 3-dimensional model simulator in COMSOL Multiphysics, with 0.35 μm CMOS process parameters. The simulated MLVHD unit size is (W) 10 μm × (L) 6 μm × (D) 10 μm. In this paper, we use an MLVHD with 10 units; the overall hall device size is (W) 10 μm × (L)78 μm × (D) 10 μm. The COMSOL simulation result is as following: the maximum hall current is approximately 2 μA with a 12 μA bias current and 100mT magnetic field; This work was supported by Institute for Information & communications Technology Promotion(IITP) grant funded by the Korea government(MSIP) (No.R7117-16-0165, Development of Hall Effect Semiconductor for Smart Car and Device).

Keywords: CMOS, vertical hall device, current mode, COMSOL

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Authors: Abdulmohsen Alghadeer, Fahad Al Mahashir, Loai Al Owa, Najim Alshahrani

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Electrical continuity of steel structure members is an essential condition to ensure equipotential and ultimately to protect personnel and assets in industrial facilities. The steel structure is electrically connected to provide a low resistance path to earth through equipotential bonding to prevent sparks and fires in the event of fault currents and avoid malfunction of the plant with detrimental consequences to the local and global environment. The oil and gas industry is commonly establishing steel structure electrical continuity by bare surface connection of coated steel members. This paper presents information pertaining to a real case of exploring and applying different techniques to achieve the electrical continuity in erecting steel structures at a gas plant facility. A project was supplied with fully coated steel members even at the surface connection members that cause electrical discontinuity. This was observed while a considerable number of steel members had already been received at the job site and erected. This made the resolution of the case to use different techniques such as bolt tightening and torqueing, chemical paint stripping and single point jumpers. These techniques are studied with comparative analysis related to their applicability, workability, time and cost advantages and disadvantages.

Keywords: coated Steel, electrical continuity, equipotential bonding, galvanized steel, gas plant facility, lightning protection, steel structure

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Authors: Waqas Ali, Nadeem Majeed

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Requirement engineering is an essence of software development life cycle. The more time we spend on requirement engineering, higher the probability of success. Effective requirement engineering ensures and predicts successful software product. This paper presents the adaptation of requirement engineering practices in small and medium size companies of Pakistan. The study is conducted by questionnaires to show how much of requirement engineering models and practices are followed in Pakistan.

Keywords: requirement engineering, Pakistan, models, practices, organizations

Procedia PDF Downloads 723

Authors: Irianes C. Gozali, Betty J.L. Laglbauer, Muhammad G. Salim, Sila K. Sari, Fahmi Fahmi, Selvia Oktaviyani

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Muncar, located off the eastern coast of Java, is an important fishing port for small-scale fleets which land mobulid rays as retained bycatch, primarily in drift gillnets. Due to overlap with fishing grounds in the Bali Strait, three devil ray species are landed in Muncar, the spinetail devil ray Mobula mobular, the bentfin devil ray Mobula thurstoni, and the Chilean devil ray Mobula tarapacana, which are all listed as Endangered by the International Union for the Conservation of Nature. However, despite the importance of life-history data to better manage stocks, such information is still rare or unavailable for Indonesian mobulid ray populations. Using morphometric data, reproductive assessments, and samples collected from dead specimens at fish markets from 2015-2019, we provide information on the maturity stage, reproductive periodicity, gestation, and size at parturition. A majority of immature individuals of all three devil ray species were recorded (<10% individuals in Mobula mobular to <30% individuals in Mobula thurstoni). Pregnant females of two species, Mobula mobular and Mobula thurstoni were recorded containing embryos of various developmental stages (each with a single embryo in the left functional uterus), while for Mobula tarapacana, no fetuses were found. The largest embryo recorded in M. mobular was within the range of that previously reported for neonates of the species in Indonesia (957 cm, for a 920-994 range), and represents a near-term embryo reflecting size at parturition. Low reproductive output was confirmed for the study-species. Based on this study, we infer that the Bali Straight is likely an important location for devil ray reproduction, which raises concern for the sustainability of mobulid ray populations in the face of bycatch in drift gillnets. Potential management approaches to tackle this issue are discussed.

Keywords: devil ray, mobulid, reproduction, Indonesia

Procedia PDF Downloads 185

Authors: N. Santatriniaina, J. Deseure, T. Q. Nguyen, H. Fontaine, C. Beitia, L. Rakotomanana

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Nowadays, with the increasing of the wafer's size and the decreasing of critical size of integrated circuit manufacturing in modern high-tech, microelectronics industry needs a maximum attention to challenge the contamination control. The move to 300 mm is accompanied by the use of Front Opening Unified Pods for wafer and his storage. In these pods an airborne cross contamination may occur between wafers and the pods. A predictive approach using modeling and computational methods is very powerful method to understand and qualify the AMCs cross contamination processes. This work investigates the required numerical tools which are employed in order to study the AMCs cross-contamination transfer phenomena between wafers and FOUPs. Numerical optimization and finite element formulation in transient analysis were established. Analytical solution of one dimensional problem was developed and the calibration process of physical constants was performed. The least square distance between the model (analytical 1D solution) and the experimental data are minimized. The behavior of the AMCs intransient analysis was determined. The model framework preserves the classical forms of the diffusion and convection-diffusion equations and yields to consistent form of the Fick's law. The adsorption process and the surface roughness effect were also traduced as a boundary condition using the switch condition Dirichlet to Neumann and the interface condition. The methodology is applied, first using the optimization methods with analytical solution to define physical constants, and second using finite element method including adsorption kinetic and the switch of Dirichlet to Neumann condition.

Keywords: AMCs, FOUP, cross-contamination, adsorption, diffusion, numerical analysis, wafers, Dirichlet to Neumann, finite elements methods, Fick’s law, optimization

Procedia PDF Downloads 515

Authors: J. R. Bhalla, Gautam, Gurcharan Singh, Sanjeev Naval

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Mathematics is everywhere behind the every things on the earth as well as in the universe. Predynastic Egyptians of the 5th millennium BC pictorially represented geometric designs. Now a day’s we can made and apply an equation on a complex geometry through applied mathematics. Here we work and focus on to create a formula which apply in the field of civil engineering in new concrete technology. In this paper our target is to make a formula which is applied on “BAUT” Metal Aggregate. In this paper our approach is to make formulation and equation on special “BAUT” Metal Aggregate by Applied Mathematical Study Case 1. BASIC PHYSICAL FORMULATION 2. ADVANCE EQUATION which shows the mechanical performance of special metal aggregates for concrete technology. In case 1. Basic physical formulation shows the surface area and volume manually and in case 2. Advance equation shows the mechanical performance has been discussed, the metal aggregates which had outstandingly qualities to resist shear, tension and compression forces. In this paper coarse metal aggregates is 20 mm which used for making high performance concrete (H.P.C).

Keywords: applied mathematical study case, special metal aggregates, concrete technology, basic physical formulation, advance equation

Procedia PDF Downloads 376

Authors: Pule P. Mpopetsi, Warren M. Potts, Nicola James, Amber Childs

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Increased CO₂ production and the consequent ocean acidification (OA) have been identified as one of the greatest threats to both calcifying and non-calcifying marine organisms. Traditionally, marine fishes, as non-calcifying organisms, were considered to have a higher tolerance to near-future OA conditions owing to their well-developed ion regulatory mechanisms. However, recent studies provide evidence to suggest that they may not be as resilient to near-future OA conditions as previously thought. In addition, earlier life stages of marine fishes are thought to be less tolerant than juveniles and adults of the same species as they lack well-developed ion regulatory mechanisms for maintaining homeostasis. This study focused on the effects of near-future OA on larval Argyrosomus japonicus, an estuarine-dependent marine fish species, in order to identify the tipping point of tolerance for the larvae of this species. Larval A. japonicus in the present study were reared from the egg up to 22 days after hatching (DAH) under three treatments. The three treatments, (pCO₂ 353 µatm; pH 8.03), (pCO₂ 451 µatm; pH 7.93) and (pCO₂ 602 µatm; pH 7.83) corresponded to levels predicted to occur in year 2050, 2068 and 2090 respectively under the Intergovernmental Panel on Climate Change (IPCC) Representative Concentration Pathways (IPCC RCP) 8.5 model. Size-at-hatch, growth, development, and metabolic responses (standard and active metabolic rates and metabolic scope) were assessed and compared between the three treatments throughout the rearing period. Five earlier larval life stages (hatchling – flexion/post-flexion) were identified by the end of the experiment. There were no significant differences in size-at-hatch (p > 0.05), development or the active metabolic (p > 0.05) or metabolic scope (p > 0.05) of fish in the three treatments throughout the study. However, the standard metabolic rate was significantly higher in the year 2068 treatment but only at the flexion/post-flexion stage which could be attributed to differences in developmental rates (including the development of the gills) between the 2068 and the other two treatments. Overall, the metabolic scope was narrowest in the 2090 treatment but varied according to life stage. Although not significantly different, metabolic scope in the 2090 treatment was noticeably lower at the flexion stage compared to the other two treatments, and the development appeared slower, suggesting that this could be the stage most prone to OA. The study concluded that, in isolation, OA levels predicted to occur between 2050 and 2090 will not negatively affect size-at-hatch, growth, development, and metabolic responses of larval A. japonicus up to 22 DAH (flexion/post-flexion stage). The present study also identified the tipping point of tolerance (where negative impacts will begin) in larvae of the species to be between the years 2090 and 2100.

Keywords: climate change, ecology, marine, ocean acidification

Procedia PDF Downloads 138

Authors: Gizem Buldum, Alexander Bismarck, Athanasios Mantalaris

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Cellulose is the most abundant biopolymer on earth and it is currently being utilised in a multitude of industrial applications. Over the last 30 years, attention has been paid to the bacterial cellulose (BC), since BC exhibits unique physical, chemical and mechanical properties when compared to plant-based cellulose, including high purity and biocompatibility. Although Acetobacter xylinum is the most efficient producer of BC, it’s long doubling time results in insufficient yields of the cellulose production. This limits widespread and continued use of BC. In this study, E. coli BL21 (DE3) or E. coli HMS cells are selected as host organisms for the expression of bacterial cellulose synthase operon (bcs) of A.xylinum. The expression system is created based on pET-Duet1 and pCDF plasmid vectors, which carry bcs operon. The results showed that all bcs genes were successfully transferred and expressed in E.coli strains. The expressions of bcs proteins were shown by SDS and Native page analyses. The functionality of the bcs operon was proved by congo red binding assay. The effect of culturing temperature and the inducer concentration (IPTG) on cell growth and plasmid stability were monitored. The percentage of plasmid harboring cells induced with 0.025 mM IPTG was obtained as 85% at 22˚C in the end of 10-hr culturing period. It was confirmed that the high output cellulose production machinery of A.xylinum can be transferred into other organisms.

Keywords: bacterial cellulose, biopolymer, recombinant expression system, production

Procedia PDF Downloads 405

Authors: Siddharth Sarma, Ayush Majumdar, Nidhi Sabu, Mufaddal Jiruwaala, Shilpa Paygude

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Digital Elevation Models (DEMs) are digital representations of the Earth’s topography, which include information about the elevation, slope, aspect, and other terrain attributes. DEMs play a crucial role in various applications, including terrain analysis, urban planning, and environmental modeling. In this paper, TerraEnhance is proposed, a distinct approach for high-resolution DEM generation using Generative Adversarial Networks (GANs) combined with Real-ESRGANs. By learning from a dataset of low-resolution DEMs, the GANs are trained to upscale the data by 10 times, resulting in significantly enhanced DEMs with improved resolution and finer details. The integration of Real-ESRGANs further enhances visual quality, leading to more accurate representations of the terrain. A post-processing layer is introduced, employing high-pass filtering to refine the generated DEMs, preserving important details while reducing noise and artifacts. The results demonstrate that TerraEnhance outperforms existing methods, producing high-fidelity DEMs with intricate terrain features and exceptional accuracy. These advancements make TerraEnhance suitable for various applications, such as terrain analysis and precise environmental modeling.

Keywords: DEM, ESRGAN, image upscaling, super resolution, computer vision

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Authors: Baguma Daniel Kajura

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The study explores socio-economic factors, health related and individual factors that influence the breastfeeding habits of mothers and their effect on the nutritional status of their infants in the Rwenzori region of Western Uganda. A cross-sectional research design was adopted, and it involved the use of self-administered questionnaires, interview guides, and focused group discussion guides to assess the extent to which socio-demographic factors associated with breastfeeding practices influence child malnutrition. Using this design, data was collected from 276 mother-paired infants out of the selected 318 mother-paired infants over a period of ten days. Using a sample size formula by Kish Leslie for cross-sectional studies N= Zα2 P (1- P) / δ2, where N= sample size estimate of paired mother paired infants. P= assumed true population prevalence of mother–paired infants with malnutrition cases, P = 29.3%. 1-P = the probability of mother-paired infants not having malnutrition, so 1-P = 70.7% Zα = Standard normal deviation at 95% confidence interval corresponding to 1.96.δ = Absolute error between the estimated and true population prevalence of malnutrition of 5%. The calculated sample size N = 1.96 × 1.96 (0.293 × 0.707) /0,052= 318 mother paired infants. Demographic and socio-economic data for all mothers were entered into Microsoft Excel software and then exported to STATA 14 (StataCorp, 2015). Anthropometric measurements were taken for all children by the researcher and the trained assistants who physically weighed the children. The use of immunization card was used to attain the age of the child. The bivariate logistic regression analysis was used to assess the relationship between socio-demographic factors associated with breastfeeding practices and child malnutrition. The multivariable regression analysis was used to draw a conclusion on whether or not there are any true relationships between the socio-demographic factors associated with breastfeeding practices as independent variables and child stunting and underweight as dependent variables in relation to breastfeeding practices. Descriptive statistics on background characteristics of the mothers were generated and presented in frequency distribution tables. Frequencies and means were computed, and the results were presented using tables, then, we determined the distribution of stunting and underweight among infants by the socioeconomic and demographic factors. Findings reveal that children of mothers who used milk substitutes besides breastfeeding are over two times more likely to be stunted compared to those whose mothers exclusively breastfed them. Feeding children with milk substitutes instead of breastmilk predisposes them to both stunting and underweight. Children of mothers between 18 and 34 years of age are less likely to be underweight, as were those who were breastfed over ten times a day. The study further reveals that 55% of the children were underweight, and 49% were stunted. Of the underweight children, an equal number (58/151) were either mildly or moderately underweight (38%), and 23% (35/151) were severely underweight. Empowering community outreach programs by increasing knowledge and increased access to services on integrated management of child malnutrition is crucial to curbing child malnutrition in rural areas.

Keywords: infant and young child feeding, breastfeeding, child malnutrition, maternal health

Procedia PDF Downloads 30

Authors: Claudiu Mazilu, Ion Robu, Radu Deju

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At the end of 2011 worldwide there were 124 power reactors shut down, from which: 16 fully decommissioned, 50 power reactors in a decommissioning process, 49 reactors in “safe enclosure mode”, 3 reactors “entombed”, for other 6 reactors it was not yet have specified the decommissioning strategy. The concrete radioactive waste that will be generated from dismantled structures of VVR-S nuclear research reactor from Magurele (e.g.: biological shield of the reactor core and hot cells) represents an estimated amount of about 70 tons. Until now the solid low activity radioactive waste (LLW) was pre-placed in containers and cementation with mortar made from cement and natural fine aggregates, providing a fill ratio of the container of approximately 50 vol. % for concrete. In this paper is presented an innovative technology in which radioactive concrete is crushed and the mortar made from recycled radioactive sand, cement, water and superplasticizer agent is poured in container with radioactive rubble (that is pre-placed in container) for cimentation. Is achieved a radioactive waste package in which the degree of filling of radioactive waste increases substantially. The tests were carried out on non-radioactive material because the radioactive concrete was not available in a good time. Waste concrete with maximum size of 350 mm were crushed in the first stage with a Liebhher type jaw crusher, adjusted to nominal size of 50 mm. Crushed concrete less than 50 mm was sieved in order to obtain useful sort for preplacement, 10 to 50 mm. The rest of the screening > 50 mm obtained from primary crushing of concrete was crushed in the second stage, with different working principles crushers at size < 2.5 mm, in order to produce recycled fine aggregate (sand) for the filler mortar and which fulfills the technical specifications proposed: –jaw crusher, Retsch type, model BB 100; –hammer crusher, Buffalo Shuttle model WA-12-H; presented a series of characteristics of recycled concrete aggregates by predefined class (the granulosity, the granule shape, the absorption of water, behavior to the Los Angeles test, the content of attached mortar etc.), most in comparison with characteristics of natural aggregates. Various mortar recipes were used in order to identify those that meet the proposed specification (flow-rate: 16-50s, no bleeding, min. 30N/mm2 compressive strength of the mortar after 28 days, the proportion of recycled sand used in mortar: min. 900kg/m3) and allow obtaining of the highest fill ratio for mortar. In order to optimize the mortars following compositional factors were varied: aggregate nature, water/cement (W/C) ratio, sand/cement (S/C) ratio, nature and proportion of additive. To confirm the results obtained on a small scale, it made an attempt to fill the mortar in a container that simulates the final storage drums. Was measured the mortar fill ratio (98.9%) compared with the results of laboratory tests and targets set out in the proposed specification. Although fill ratio obtained on the mock-up is lower by 0.8 vol. % compared to that obtained in the laboratory tests (99.7%), the result meets the specification criteria.

Keywords: characteristics, radioactive recycled concrete aggregate, mortars, fill ratio

Procedia PDF Downloads 195

Authors: M. A. Meslem

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For precise geoid determination, we use a reference field to subtract long and medium wavelength of the gravity field from observations data when we use the remove-compute-restore technique. Therefore, a comparison study between considered models should be made in order to select the optimal reference gravity field to be used. In this context, two recent global geopotential models have been selected to perform this comparison study over Northern Algeria. The Earth Gravitational Model (EGM2008) and the Global Gravity Model (GECO) conceived with a combination of the first model with anomalous potential derived from a GOCE satellite-only global model. Free air gravity anomalies in the area under study have been used to compute residual data using both gravity field models and a Digital Terrain Model (DTM) to subtract the residual terrain effect from the gravity observations. Residual data were used to generate local empirical covariance functions and their fitting to the closed form in order to compare their statistical behaviors according to both cases. Finally, height anomalies were computed from both geopotential models and compared to a set of GPS levelled points on benchmarks using least squares adjustment. The result described in details in this paper regarding these two models has pointed out a slight advantage of GECO global model globally through error degree variances comparison and ground-truth evaluation.

Keywords: quasigeoid, gravity aomalies, covariance, GGM

Procedia PDF Downloads 142