Search results for: slope stabilization

Authors: Ella Sèdé Maforikan

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Accurate land cover mapping is essential for effective environmental monitoring and natural resources management. This study focuses on assessing the classification performance of two satellite datasets and evaluating the impact of different input feature combinations on classification accuracy in the Beterou catchment, situated in the northern part of Benin. Landsat-8 and Sentinel-2 images from June 1, 2020, to March 31, 2021, were utilized. Employing the Random Forest (RF) algorithm on Google Earth Engine (GEE), a supervised classification categorized the land into five classes: forest, savannas, cropland, settlement, and water bodies. GEE was chosen due to its high-performance computing capabilities, mitigating computational burdens associated with traditional land cover classification methods. By eliminating the need for individual satellite image downloads and providing access to an extensive archive of remote sensing data, GEE facilitated efficient model training on remote sensing data. The study achieved commendable overall accuracy (OA), ranging from 84% to 85%, even without incorporating spectral indices and terrain metrics into the model. Notably, the inclusion of additional input sources, specifically terrain features like slope and elevation, enhanced classification accuracy. The highest accuracy was achieved with Sentinel-2 (OA = 91%, Kappa = 0.88), slightly surpassing Landsat-8 (OA = 90%, Kappa = 0.87). This underscores the significance of combining diverse input sources for optimal accuracy in land cover mapping. The methodology presented herein not only enables the creation of precise, expeditious land cover maps but also demonstrates the prowess of cloud computing through GEE for large-scale land cover mapping with remarkable accuracy. The study emphasizes the synergy of different input sources to achieve superior accuracy. As a future recommendation, the application of Light Detection and Ranging (LiDAR) technology is proposed to enhance vegetation type differentiation in the Beterou catchment. Additionally, a cross-comparison between Sentinel-2 and Landsat-8 for assessing long-term land cover changes is suggested.

Keywords: land cover mapping, Google Earth Engine, random forest, Beterou catchment

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Authors: Clara Voyvodic

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Transitions from conflict to peace are by no means smooth nor linear, particularly from the perspective of those living through them. Over the last few decades, the changing focus in peacebuilding studies has come to appreciate the everyday experience of communities and how that provides a lens through which the relative success or efficacy of these transitions can be understood. In particular, the demobilization of a significant conflict actor is not without consequences, not just for the macro-view of state stabilization and peace, but for the communities who find themselves without a clear authority of territorial control. In Colombia, the demobilization and disarmament of the FARC guerilla group provided a brief respite to the conflict and a major political win for President Manuel Santos. However, this victory has proven short-lived. Drawing from extensive field research in Colombia within the last year, including interviews with local communities and actors operating in these regions, field observations, and other primary resources, this paper examines the post-accord transitions in Colombia and the everyday security experiences of local communities in regions formerly controlled by the FARC. In order to do so, the research focused on a semi-ethnographic approach in the northern region of the department of Antioquia and the coastal area of the border department of Nariño that documented how individuals within these marginalized communities have come to understand and negotiate their security in the years following the accord and the demobilization of the FARC. This presentation will argue that the removal of the FARC as an informal governance actor opened a space for multiple actors to attempt to control the same territory, including the state. This shift has had a clear impact on the everyday security experiences of the local communities. With an exploration of the dynamics of local governance and its impact on lived security experiences, this research seeks to demonstrate how distinct patterns of armed group behavior are emerging not only from a vacuum of control left by the FARC but from an increase in state presence that nonetheless remains inconsistent and unpersuasive as a monopoly of force in the region. The increased multiplicity of actors, particularly the state, has meant that the normal (informal) rules for communities to navigate these territories are no longer in play as the identities, actions, and intentions of different competing groups have become frustratingly opaque. This research provides a prescient analysis on how the shifting dynamics of territorial control in a post-peace accord landscape produce uncertain realities that affect the daily lives of the local communities and endanger the long-term prospect of human-centered security.

Keywords: armed actors, conflict transitions, informal governance, post-accord, security experiences

Procedia PDF Downloads 109

Authors: Yassine Messaoud, Gordon Nigh, Faouzi Messaoud, Han Chen

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The effect of climate change on tree growth in boreal and temperate forests has received increased interest in the context of global warming. However, most studies were conducted in small areas and with a limited number of tree species. Here, we examined the height growth responses of seventeen tree species to climate change in Western North America. 37009 stands from forest inventory databases in Canada and USA with varying establishment date were selected. Dominant and co-dominant trees from each stand were sampled to determine top tree height at 50 years breast height age. Height was related to historical mean annual and summer temperatures, annual and summer Palmer Drought Severity Index, tree establishment date, slope, aspect, soil fertility as determined by the rate of carbon organic matter decomposition (carbon/nitrogen), geographic locations (latitude, longitude, and elevation), species range (coastal, interior, and both ranges), shade tolerance and leaf form (needle leaves, deciduous needle leaves, and broadleaves). Climate change had mostly a positive effect on tree height growth. The results explained 62.4% of the height growth variance. Since 1880, height growth increase was greater for coastal, high shade tolerant, and broadleaf species. Height growth increased more on steep slopes and high soil fertility soils. Greater height growth was mostly observed at the leading range and upward. Conversely, some species showed the opposite pattern probably due to the increase of drought (coastal Mediterranean area), precipitation and cloudiness (Alaska and British Columbia) and peculiarity (higher latitudes-lower elevations and vice versa) of western North America topography. This study highlights the role of the species ecological amplitude and traits, and geographic locations as the main factors determining the growth response and its magnitude to the recent global climate change.

Keywords: Height growth, global climate change, species range, species characteristics, species ecological amplitude, geographic locations, western North America

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Authors: W. A. Nalaka Wijesooriya

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The increasing paddy production, stabilization of domestic rice consumption and the increasing dynamism of rice processing and domestic markets call for a rethinking of the general direction of the rice milling industry in Sri Lanka. The main purpose of the study was to explore levels of concentration in rice milling industry in Polonnaruwa and Hambanthota which are the major hubs of the country for rice milling. Concentration indices reveal that the rice milling industry in Polonnaruwa operates weak oligopsony and is highly competitive in Hambanthota. According to the actual quantity of paddy milling per day, 47 % is less than 8Mt/Day, while 34 % is 8-20 Mt/day, and the rest (19%) is greater than 20 Mt/day. In Hambanthota, nearly 50% of the mills belong to the range of 8-20 Mt/day. Lack of experience of the milling industry, poor knowledge on milling technology, lack of capital and finding an output market are the major entry barriers to the industry. Major problems faced by all the rice millers are the lack of a uniform electricity supply and low quality paddy. Many of the millers emphasized that the rice ceiling price is a constraint to produce quality rice. More than 80% of the millers in Polonnaruwa which is the major parboiling rice producing area have mechanical dryers. Nearly 22% millers have modern machineries like color sorters, water jet polishers. Major paddy purchasing method of large scale millers in Polonnaruwa is through brokers. In Hambanthota major channel is miller purchasing from paddy farmers. Millers in both districts have major rice selling markets in Colombo and suburbs. Huge variation can be observed in the amount of pledge (for paddy storage) loans. There is a strong relationship among the storage ability, credit affordability and the scale of operation of rice millers. The inter annual price fluctuation ranged 30%-35%. Analysis of market margins by using series of secondary data shows that farmers’ share on rice consumer price is stable or slightly increases in both districts. In Hambanthota a greater share goes to the farmer. Only four mills which have obtained the Good Manufacturing Practices (GMP) certification from Sri Lanka Standards Institution can be found. All those millers are small quantity rice exporters. Priority should be given for the Small and medium scale millers in distribution of storage paddy of PMB during the off season. The industry needs a proper rice grading system, and it is recommended to introduce a ceiling price based on graded rice according to the standards. Both husk and rice bran were underutilized. Encouraging investment for establishing rice oil manufacturing plant in Polonnaruwa area is highly recommended. The current taxation procedure needs to be restructured in order to ensure the sustainability of the industry.

Keywords: conduct, performance, structure (SCP), rice millers

Procedia PDF Downloads 304

Authors: Xiquan Weng, Chaoge Wang, Guoqin Xu, Wentao Lin

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Objective: Cold exposure and exercise serve as two powerful physiological stimuli to launch the conversion of fat-accumulating white adipose tissue (WAT) into energy-dissipating brown adipose tissue (BAT). So far, it remains to be elucidated whether exercise plus cold exposure can produce an addictive effect on promoting WAT browning. Methods: 64 SD rats were subjected to high-fat and high-sugar diets for 9-week and successfully established an obesity model. They were randomly divided into 8 groups: normal control group (NC), normal exercise group (NE), continuous cold control group (CC), continuous cold exercise group (CE), intermittent cold control group (IC) and intermittent cold exercise group (IE). For continuous cold exposure, the rats stayed in a cold environment all day; For intermittent cold exposure, the rats were exposed to cold for only 4h per day. The protocol for treadmill exercises were as follows: 25m/min (speed), 0°C (slope), 30mins each time, an interval for 10 mins between two exercises, twice/two days, lasting for 5 weeks. Sampling were conducted on the 5th weekend. The body length and weight of the rats were measured, and the Lee's index was calculated. The visceral fat rate (VFR), subcutaneous fat rate (SFR), brown fat rate (BrFR) and body fat rate (BoFR) were measured by Micro-CT LCT200, and the expression of UCP1 protein in inguinal fat was examined by Western-blot. SPSS 22.0 was used for statistical analysis of the experimental results, and the ANOVA analysis was performed between groups (P < 0.05 was significant). Results: (1) Compared with the NC group, the weight of obese rats was significantly declined in the NE, CE and IE groups (P < 0.05), the Lee's index of obese rats significantly declined in the CE group (P < 0.05). Compared with the NE group, the weight of obese rats was significantly declined in the CE and IE groups (P < 0.05). (2)Compared with the NC group, the VFR and BoFR of the rats significantly declined in the NE, CE and IE groups (P < 0.05), the SFR of the rats significantly declined in the CE and IE groups (P < 0.05), and the BFR of the rats was significantly higher in the CC and IC groups (P < 0.05), respectively. Compared with the NE group, the VFR and BoFR of the rats significantly declined in the CE group (P < 0.05), the SFR of the rats was significantly higher in the CC and IS groups (P < 0.05), and the BrFR of the rats was significantly higher in the IC group (P < 0.05). (3)Compared with the NC group, the up-regulation of UCP1 protein expression in the inguinal fat of the rats was significant in the NE, CC, CE, IC and IE groups (P < 0.05). Compared with the NE group, the up-regulation of UCP1 protein expression in the inguinal fat of the rats was significant in the CC, CE and IE groups (P < 0.05). Conclusions: Exercise in the continuous and intermittent cold, especially in the former, can effectively decline the weight and body fat rate of obese rats. This is related to the effect of cold and exercise on the browning of white fat in rats.

Keywords: cold, browning of white fat, exercise, obesity

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Authors: Estelle Ardanouy, Helene Delage, Pascal Zesiger

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Morphological awareness contributes to the acquisition of reading and spelling in typical learners as well as in children with learning disorders. Indeed, the acquisition of phoneme-grapheme correspondences is not sufficient to master spelling, especially in inconsistent orthographic systems such as English or French. Several meta-analyses show the benefit of explicit training in derivational morphology on reading and spelling in old children (who have already learned the main grapheme-phoneme correspondences), but highlight the lack of studies with younger children, particularly in French. In this study, we chose to focus on the efficiency of an intensive training in derivational morphology on spelling skills in French-speaking four-graders (9-10 years of age). The training consisted of 1) learning how to divide words into morphemes (ex: para/pente in French, paraglider in English), as well as 2) working on the meaning of affixes in relation to existing words (ex: para/pente: to protect against – para - the slope -pente). One group of pupils (N = 37, M age = 9.5) received this experimental group training in morphology while an alternative training group (N = 34, M age = 9.6) received a visuo-semantic training based on visual cues to memorize the spelling difficulties of complex words (such as the doubling of “r” in “verre” in French -or "glass" in English-which are represented by the drawing of two glasses). Both trainings lasted a total of 15 hours at a rate of four 45 minutes sessions per week, resulting in five weeks of training in the school setting. Our preliminary results show a significant improvement in the experimental group in the spelling of affixes on the trained (p < 0.001) and untrained word lists (p <0.001), but also in the root of words on the trained (p <0.001) and untrained word lists group (p <0.001). The training effect is also present on both trained and untrained morphologically composed words. By contrast, the alternative training group shows no progress on these previous measures (p >0.15). Further analyses testing the effects of both trainings on other measures such as morphological awareness and reading of morphologically compose words are in progress. These first results support the effectiveness of explicitly teaching derivational morphology to improve spelling in school-aged children. The study is currently extended to a group of children with developmental dyslexia because these children are known for their severe and persistent spelling difficulties.

Keywords: developmental dyslexia, derivational morphology, reading, school-aged children, spelling, training

Procedia PDF Downloads 155

Authors: Mohamed Abdelkareem

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Remote sensing data contributed on predicting the prospective areas of water resources. Integration of microwave and multispectral data along with climatic, hydrologic, and geological data has been used here. In this article, Sentinel-2, Landsat-8 Operational Land Imager (OLI), Shuttle Radar Topography Mission (SRTM), Tropical Rainfall Measuring Mission (TRMM), and Advanced Land Observing Satellite (ALOS) Phased Array Type L‐band Synthetic Aperture Radar (PALSAR) data were utilized to identify the geological, hydrologic and structural features of Wadi Asyuti which represents a defunct tributary of the Nile basin, in the eastern Sahara. The image transformation of Sentinel-2 and Landsat-8 data allowed characterizing the different varieties of rock units. Integration of microwave remotely-sensed data and GIS techniques provided information on physical characteristics of catchments and rainfall zones that are of a crucial role for mapping groundwater prospective zones. A fused Landsat-8 OLI and ALOS/PALSAR data improved the structural elements that difficult to reveal using optical data. Lineament extraction and interpretation indicated that the area is clearly shaped by the NE-SW graben that is cut by NW-SE trend. Such structures allowed the accumulation of thick sediments in the downstream area. Processing of recent OLI data acquired on March 15, 2014, verified the flood potential maps and offered the opportunity to extract the extent of the flooding zone of the recent flash flood event (March 9, 2014), as well as revealed infiltration characteristics. Several layers including geology, slope, topography, drainage density, lineament density, soil characteristics, rainfall, and morphometric characteristics were combined after assigning a weight for each using a GIS-based knowledge-driven approach. The results revealed that the predicted groundwater potential zones (GPZs) can be arranged into six distinctive groups, depending on their probability for groundwater, namely very low, low, moderate, high very, high, and excellent. Field and well data validated the delineated zones.

Keywords: GIS, remote sensing, groundwater, Egypt

Procedia PDF Downloads 77

Authors: M. Kozłowski, M. Kadela

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Foamed concrete is known for its low self-weight and excellent thermal and acoustic properties. For many years, it has been used worldwide for insulation to foundations and roof tiles, as backfill to retaining walls, sound insulation, etc. However, in the last years it has become a promising material also for structural purposes e.g. for stabilization of weak soils. Due to favorable properties of foamed concrete, many interests and studies were involved to analyze its strength, mechanical, thermal and acoustic properties. However, these studies do not cover the investigation of fracture energy which is the core factor governing the damage and fracture mechanisms. Only limited number of publications can be found in literature. The paper presents the results of experimental investigation and numerical campaign of foamed concrete based on three-point bending test of beams with initial notch. First part of the paper presents the results of a series of static loading tests performed to investigate the fracture properties of foamed concrete of varying density. Beam specimens with dimensions of 100×100×840 mm with a central notch were tested in three-point bending. Subsequently, remaining halves of the specimens with dimensions of 100×100×420 mm were tested again as un-notched beams in the same set-up with reduced distance between supports. The tests were performed in a hydraulic displacement controlled testing machine with a load capacity of 5 kN. Apart from measuring the loading and mid-span displacement, a crack mouth opening displacement (CMOD) was monitored. Based on the load – displacement curves of notched beams the values of fracture energy and tensile stress at failure were calculated. The flexural tensile strength was obtained on un-notched beams with dimensions of 100×100×420 mm. Moreover, cube specimens 150×150×150 mm were tested in compression to determine the compressive strength. Second part of the paper deals with numerical investigation of the fracture behavior of beams with initial notch presented in the first part of the paper. Extended Finite Element Method (XFEM) was used to simulate and analyze the damage and fracture process. The influence of meshing and variation of mechanical properties on results was investigated. Numerical models simulate correctly the behavior of beams observed during three-point bending. The numerical results show that XFEM can be used to simulate different fracture toughness of foamed concrete and fracture types. Using the XFEM and computer simulation technology allow for reliable approximation of load–bearing capacity and damage mechanisms of beams made of foamed concrete, which provides some foundations for realistic structural applications.

Keywords: foamed concrete, fracture energy, three-point bending, XFEM

Procedia PDF Downloads 273

Authors: Getalem E. Haylia

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The Ribb dam is one of the irrigation projects in the Upper Blue Nile basin, Ethiopia, to irrigate the Fogera plain. Reservoir sedimentation is a major problem because it reduces the useful reservoir capacity by the accumulation of sediments coming from the watersheds. Estimates of sediment yield are needed for studies of reservoir sedimentation and planning of soil and water conservation measures. The objective of this study was to simulate the Ribb dam catchment sediment yield using SWAT model and to estimate Ribb reservoir effective life according to trap efficiency methods. The Ribb dam catchment is found in North Western part of Ethiopia highlands, and it belongs to the upper Blue Nile and Lake Tana basins. Soil and Water Assessment Tool (SWAT) was selected to simulate flow and sediment yield in the Ribb dam catchment. The model sensitivity, calibration, and validation analysis at Ambo Bahir site were performed with Sequential Uncertainty Fitting (SUFI-2). The flow data at this site was obtained by transforming the Lower Ribb gauge station (2002-2013) flow data using Area Ratio Method. The sediment load was derived based on the sediment concentration yield curve of Ambo site. Stream flow results showed that the Nash-Sutcliffe efficiency coefficient (NSE) was 0.81 and the coefficient of determination (R²) was 0.86 in calibration period (2004-2010) and, 0.74 and 0.77 in validation period (2011-2013), respectively. Using the same periods, the NS and R² for the sediment load calibration were 0.85 and 0.79 and, for the validation, it became 0.83 and 0.78, respectively. The simulated average daily flow rate and sediment yield generated from Ribb dam watershed were 3.38 m³/s and 1772.96 tons/km²/yr, respectively. The effective life of Ribb reservoir was estimated using the developed empirical methods of the Brune (1953), Churchill (1948) and Brown (1958) methods and found to be 30, 38 and 29 years respectively. To conclude, massive sediment comes from the steep slope agricultural areas, and approximately 98-100% of this incoming annual sediment loads have been trapped by the Ribb reservoir. In Ribb catchment, as well as reservoir systematic and thorough consideration of technical, social, environmental, and catchment managements and practices should be made to lengthen the useful life of Ribb reservoir.

Keywords: catchment, reservoir effective life, reservoir sedimentation, Ribb, sediment yield, SWAT model

Procedia PDF Downloads 154

Authors: Zoi Konsoula

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Vegetable oils, which are rich in polyunsaturated fatty acids, are susceptible to oxidative deterioration. The lipid oxidation of oils results in the production of rancid odors and unpleasant flavors as well as the reduction of their nutritional quality and safety. Traditionally, synthetic antioxidants are employed for their retardation or prevention of oxidative deterioration of oils. However, these compounds are suspected to pose health hazards. Consequently, recently there has been a growing interest in the use of natural antioxidants of plant origin for improving the oxidative stability of vegetable oils. The genus Salvia (sage) is well known for its antioxidant activity. In the Cypriot flora Salvia fruticosa is the most distributed indigenous Salvia species. In the present study, extracts were prepared from S. fruticosa aerial parts using various solvents and their antioxidant activity was evaluated by the 1,1-diphenyl-2-picrylhydrazine (DPPH) radical scavenging and Ferric Reducing Antioxidant Power (FRAP) method. Moreover, the antioxidant efficacy of all extracts was assessed using corn oil as the oxidation substrate, which was subjected to accelerated aging (60 °C, 30 days). The progress of lipid oxidation was monitored by the determination of the peroxide, p-aniside, conjugated dienes and trienes value according to the official AOCS methods. Synthetic antioxidants (butylated hydroxytoluene-BHT and butylated hydroxyanisole-BHA) were employed at their legal limit (200 ppm) as reference. Finally, the total phenolic (TPC) and flavonoid content (TFC) of the prepared extracts was measured by the Folin-Ciocalteu and aluminum-flavonoid complex method, respectively. The results of the present study revealed that although all sage extracts prepared from S. fruticosa exhibited antioxidant activity, the highest antioxidant capacity was recorded in the methanolic extract, followed by the non-toxic, food grade ethanol. Furthermore, a positive correlation between the antioxidant potency and the TPC of extracts was observed in all cases. Interestingly, sage extracts prevented lipid oxidation in corn oil at all concentrations tested, however, the magnitude of stabilization was dose dependent. More specifically, results from the different oxidation parameters were in agreement with each other and indicated that the protection offered by the various extracts depended on their TPC. Among the extracts, the methanolic extract was more potent in inhibiting oxidative deterioration. Finally, both methanolic and ethanolic sage extracts at a concentration of 1000 ppm exerted a stabilizing effect comparable to that of the reference synthetic antioxidants. Based on the results of the present study, sage extracts could be used for minimizing or preventing lipid oxidation in oils and, thus, prolonging their shelf-life. In particular, given that the use of dietary alcohol, such as ethanol, is preferable than methanol in food applications, the ethanolic extract prepared from S. fruticosa could be used as an alternative natural antioxidant.

Keywords: antioxidant activity, corn oil, oxidative deterioration, sage

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Authors: Revaz Gvelesiani

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The problem of compliance between the state economic policy and entrepreneurial policy of businesses is primarily manifested in the contradictions related to the congruence between entrepreneurship development and self-development strategies. Among various types (financial, monetary, social, etc.) of the state economic policy aiming at the development of entrepreneurship, economic order policy is of special importance. Its goal is to set the framework for both public and private economic activities and achieve coherence between the societal value system and the formation of the economic order framework. Economic order policy, in its turn, involves intrinsic contradiction between the social and the competitive order. Competitive order is oriented on the principle of success, while social order _ on the criteria of need satisfaction, which contradicts, at least partly, to the principles of success. Thus within the economic order policy, on the one hand, the state makes efforts to form social order and expand its frontiers, while, on the other hand, market is determined to establish functioning competitive order and ensure its realization. Locating the adequate spaces for and setting the rational border between the state (social order) and the private (competitive order) activities, represents the phenomenon of the decisive importance from the entrepreneurship development strategy standpoint. In the countries where the above mentioned spaces and borders are “set” correctly, entrepreneurship agents (small, medium-sized and large businesses) achieve great success by means of seizing the respective segments and maintaining the leading positions in the internal, the European and the world markets for a long time. As for the entrepreneurship self-development strategy, above all, it involves: •market identification; •interactions with consumers; •continuous innovations; •competition strategy; •relationships with partners; •new management philosophy, etc. The analysis of compliance between the entrepreneurship strategy and entrepreneurship culture should be the reference point for any kind of internationalization in order to avoid shocks of cultural nature and the economic backwardness. Stabilization can be achieved only when the employee actions reflect the existing culture and the new contents of culture (targeted culture) is turned into the implicit consciousness of the personnel. The future leaders should learn how to manage different cultures. Entrepreneurship can be managed successfully if its strategy and culture are coherent. However, not rarely enterprises (organizations) show various forms of violation of both personal and team actions. If personal and team non-observances appear as the form of influence upon the culture, it will lead to global destruction of the system and structure. This is the entrepreneurship culture pathology that complicates to achieve compliance between the entrepreneurship strategy and entrepreneurship culture. Thus, the intrinsic contradictions of entrepreneurship development and self-development strategies complicate the task of reaching compliance between the state economic policy and the company entrepreneurship policy: on the one hand, there is a contradiction between the social and the competitive order within economic order policy and on the other hand, the contradiction exists between entrepreneurship strategy and entrepreneurship culture within entrepreneurship policy.

Keywords: economic order policy, entrepreneurship, development contradictions, self-development contradictions

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Authors: Tony R. Walker, N. Devin MacAskill, Andrew Thalhiemer

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Sydney Harbour, Nova Scotia has long been subject to effluent and atmospheric inputs of metals, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) from a large coking operation and steel plant that operated in Sydney for nearly a century until closure in 1988. Contaminated effluents from the industrial site resulted in the creation of the Sydney Tar Ponds, one of Canada’s largest contaminated sites. Since its closure, there have been several attempts to remediate this former industrial site and finally, in 2004, the governments of Canada and Nova Scotia committed to remediate the site to reduce potential ecological and human health risks to the environment. The Sydney Tar Ponds and Coke Ovens cleanup project has become the most prominent remediation project in Canada today. As an integral part of remediation of the site (i.e., which consisted of solidification/stabilization and associated capping of the Tar Ponds), an extensive multiple media environmental effects program was implemented to assess what effects remediation had on the surrounding environment, and, in particular, harbour sediments. Additionally, longer-term natural sediment recovery rates of select contaminants predicted for the harbour sediments were compared to current conditions. During remediation, potential contributions to sediment quality, in addition to remedial efforts, were evaluated which included a significant harbour dredging project, propeller wash from harbour traffic, storm events, adjacent loading/unloading of coal and municipal wastewater treatment discharges. Two sediment sampling methodologies, sediment grab and gravity corer, were also compared to evaluate the detection of subtle changes in sediment quality. Results indicated that overall spatial distribution pattern of historical contaminants remains unchanged, although at much lower concentrations than previously reported, due to natural recovery. Measurements of sediment indicator parameter concentrations confirmed that natural recovery rates of Sydney Harbour sediments were in broad agreement with predicted concentrations, in spite of ongoing remediation activities. Overall, most measured parameters in sediments showed little temporal variability even when using different sampling methodologies, during three years of remediation compared to baseline, except for the detection of significant increases in total PAH concentrations noted during one year of remediation monitoring. The data confirmed the effectiveness of mitigation measures implemented during construction relative to harbour sediment quality, despite other anthropogenic activities and the dynamic nature of the harbour.

Keywords: contaminated sediment, monitoring, recovery, remediation

Procedia PDF Downloads 216

Authors: Nathaniel Bayode Eniolorunda, Murtala Abubakar Gada, Sheikh Danjuma Abubakar

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The challenge of erosion in the study area is persistent, suggesting the need for a better understanding of the mechanisms that drive it. Thus, the study evolved a predictive erosion model (RUSLE_Sok), deploying Remote Sensing (RS) and Geographical Information System (GIS) tools. The nature and pattern of the factors of erosion were characterized, while soil losses were quantified. Factors’ impacts were also measured, and the morphometry of gullies was described. Data on the five factors of RUSLE and distances to settlements, rivers and roads (K, R, LS, P, C, DS DRd and DRv) were combined and processed following standard RS and GIS algorithms. Harmonized World Soil Data (HWSD), Shuttle Radar Topographical Mission (SRTM) image, Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS), Sentinel-2 image accessed and processed within the Google Earth Engine, road network and settlements were the data combined and calibrated into the factors for erosion modeling. A gully morphometric study was conducted at some purposively selected sites. Factors of soil erosion showed low, moderate, to high patterns. Soil losses ranged from 0 to 32.81 tons/ha/year, classified into low (97.6%), moderate (0.2%), severe (1.1%) and very severe (1.05%) forms. The multiple regression analysis shows that factors statistically significantly predicted soil loss, F (8, 153) = 55.663, p < .0005. Except for the C-Factor with a negative coefficient, all other factors were positive, with contributions in the order of LS>C>R>P>DRv>K>DS>DRd. Gullies are generally from less than 100m to about 3km in length. Average minimum and maximum depths at gully heads are 0.6 and 1.2m, while those at mid-stream are 1 and 1.9m, respectively. The minimum downstream depth is 1.3m, while that for the maximum is 4.7m. Deeper gullies exist in proximity to rivers. With minimum and maximum gully elevation values ranging between 229 and 338m and an average slope of about 3.2%, the study area is relatively flat. The study concluded that major erosion influencers in the study area are topography and vegetation cover and that the RUSLE_Sok well predicted soil loss more effectively than ordinary RUSLE. The adoption of conservation measures such as tree planting and contour ploughing on sloppy farmlands was recommended.

Keywords: RUSLE_Sok, Sokoto, google earth engine, sentinel-2, erosion

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Authors: Vinay Kumar Vanjakula, Frank Adam

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The generation of electricity through wind power is one of the leading renewable energy generation methods. Due to abundant higher wind speeds far away from shore, the construction of offshore wind turbines began in the last decades. However, the installation of offshore foundation-based (monopiles) wind turbines in deep waters are often associated with technical and financial challenges. To overcome such challenges, the concept of floating wind turbines is expanded as the basis of the oil and gas industry. For such a floating system, stabilization in harsh conditions is a challenging task. For that, a robust heavy-weight gravity anchor is needed. Transportation of such anchor requires a heavy vessel that increases the cost. To lower the cost, the gravity anchor is designed with ballast chambers that allow the anchor to float while towing and filled with water when lowering to the planned seabed location. The presence of such a large structure may influence the flow field around it. The changes in the flow field include, formation of vortices, turbulence generation, waves or currents flow breaking and pressure differentials around the seabed sediment. These changes influence the installation process. Also, after installation and under operating conditions, the flow around the anchor may allow the local seabed sediment to be carried off and results in Scour (erosion). These are a threat to the structure's stability. In recent decades, rapid developments of research work and the knowledge of scouring on fixed structures (bridges and monopiles) in rivers and oceans have been carried out, and very limited research work on scouring around a bluff-shaped gravity anchor. The objective of this study involves the application of different numerical models to simulate the anchor towing under waves and calm water conditions. Anchor lowering involves the investigation of anchor movements at certain water depths under wave/current. The motions of anchor drift, heave, and pitch is of special focus. The further study involves anchor scour, where the anchor is installed in the seabed; the flow of underwater current around the anchor induces vortices mainly at the front and corners that develop soil erosion. The study of scouring on a submerged gravity anchor is an interesting research question since the flow not only passes around the anchor but also over the structure that forms different flow vortices. The achieved results and the numerical model will be a basis for the development of other designs and concepts for marine structures. The Computational Fluid Dynamics (CFD) numerical model will build in OpenFOAM and other similar software.

Keywords: anchor lowering, anchor towing, gravity anchor, computational fluid dynamics, scour

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Authors: Samir Verdiyev, Fuad Huseynov, Islam Guliyev, Coşqun İsmayıl

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The Filizchay polymetallic deposit is located on the southern slope of the Greater Caucasus Mountain Range, northwest of Azerbaijan in the Balaken district. Filizchay is the largest polymetallic deposit in the region and the second-largest polymetallic deposit in Europe. The mineral deposits in the region are associated with two different geodynamic evolutions that began with the Mesozoic collision along the Eurasian continent and the formation of a magmatic arc after the collision and continued with subduction in the Cenozoic. The bedrocks associated with Filizchay mineralization are Early Jurassic aged. The stratigraphic sequence of the deposit is consisting of black metamorphic clay shales, sandstones, and ore layers. Shales, sandstones, and siltstones are encountered in the upper and middle sections of the ore body, while only shales are observed at the lowest ranges. The ore body is mainly layered by the geometric structure of the bedrock; folding can be observed in the ore layers along with the bedrock foliation, and just in few points indirect laying due to the metamorphism. This suggests that the Filizchay ore mineralization is syngenetic, which is proved by the mineralization by the bedrock. To determine the ore petrography properties of the Filizchay deposit, samples were collected from the region where the ore is concentrated, and a polished section was prepared. These collected samples were examined under the mineralogical microscope to reveal the paragenesis of the mineralization and to explain the relation of ore minerals to each other. In this study, macroscopically observed minerals and textures of these minerals were used in the cores revealed during drilling exploration made by AzerGold CJS company. As a result of all these studies, it has been determined that there are three main mineralization types in the Filizchay deposit: banded, massive, and veinlet ores. The mineralization is in the massive pyrite; furthermore, the basis of the ore-mass contains pyrite, chalcopyrite, sphalerite, and galena. The pyrite in some parts of the ore body transformed to pyrrhotite as a result of metamorphism. Pyrite-chalcopyrite, pyrite-sphalerite-galena, pyrite-pyrrhotite mineral assemblages were determined during microscopic studies of mineralization. The replacement texture is more developed in Filizchay ores. The banded polymetallic type mineralization and near bedrocks are cut by quartz-carbonate veins. The geotectonic position and lithological conditions of the Filizchay deposit, the texture, and interrelationship of the sulfide mineralization indicate that it is a sedimentary-exhalative type of Au-Cu-Ag-Zn-Pb polymetallic deposit that is genetically related to the massive sulfide deposits.

Keywords: Balaken, Filizchay, metamorphism, polymetallic mineralization

Procedia PDF Downloads 168

Authors: Peter Carter

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Comprehensive climate change indicators and trends inform the state of the climate (system) with respect to present and future climate change scenarios and the urgency of mitigation and adaptation. With data records now going back for many decades, indicator trends can complement model projections. They are provided as datasets by several climate monitoring centers, reviewed by state of the climate reports, and documented by the IPCC assessments. Up-to-date indicators are provided here. Rates of change are instructive, as are extremes. The indicators include greenhouse gas (GHG) emissions (natural and synthetic), cumulative CO2 emissions, atmospheric GHG concentrations (including CO2 equivalent), stratospheric ozone, surface ozone, radiative forcing, global average temperature increase, land temperature increase, zonal temperature increases, carbon sinks, soil moisture, sea surface temperature, ocean heat content, ocean acidification, ocean oxygen, glacier mass, Arctic temperature, Arctic sea ice (extent and volume), northern hemisphere snow cover, permafrost indices, Arctic GHG emissions, ice sheet mass, sea level rise, and stratospheric and surface ozone. Global warming is not the most reliable single metric for the climate state. Radiative forcing, atmospheric CO2 equivalent, and ocean heat content are more reliable. Global warming does not provide future commitment, whereas atmospheric CO2 equivalent does. Cumulative carbon is used for estimating carbon budgets. The forcing of aerosols is briefly addressed. Indicator interactions are included. In particular, indicators can provide insight into several crucial global warming amplifying feedback loops, which are explained. All indicators are increasing (adversely), most as fast as ever and some faster. One particularly pressing indicator is rapidly increasing global atmospheric methane. In this respect, methane emissions and sources are covered in more detail. In their application, indicators used in assessing safe planetary boundaries are included. Indicators are considered with respect to recent published papers on possible catastrophic climate change and climate system tipping thresholds. They are climate-change-policy relevant. In particular, relevant policies include the 2015 Paris Agreement on “holding the increase in the global average temperature to well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels” and the 1992 UN Framework Convention on Climate change, which has “stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system.”

Keywords: climate change, climate change indicators, climate change trends, climate system change interactions

Procedia PDF Downloads 80

Authors: Andrea Dragu, Solen Kinayyigit, Valerie Colliere, Karin Karin Philippot, Camelia Bala, Vasile I. Parvulescu

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The production of transportation fuels from biomass has gained a growing attention due to diminishing fossil fuel reserves, rising petroleum prices and increasing concern about global warming. In recent years, renewable hydrocarbons that are completely fungible with fossil fuels have been suggested to be efficiently produced by catalytic deoxygenation of fatty acids and their derivatives viadecarboxylation / decarbonylation. Several triglycerides (tall oil fatty acids) and saturated/unsaturated fatty acids and their corresponding esters were used as feedstocks. Their impact together with the influence of the reaction conditions and the catalyst composition on the nature of the reaction pathways of the deoxygenation of vegetable oils and their derivatives were recently reviewed. Following this state of the art the aim of the present study was the investigation of Pd NPs deposited onto mesoporous carbon supports as active and stable catalysts for the deoxygenation of oleic acid. The catalysts were prepared by the deposition of Pd NPs synthesised following an organometallic route on mesoporous carbons with different characteristics. Experiments were carried out under both batch and flow conditions. They demonstrated that under batch conditions (200 atm; 573K), the extent of the reaction depended, firstly, on the Pd loading and then on the metal dispersion and the oxidation state of palladium, both influenced by the way the support has been treated before the NPs deposition and by the preparation/stabilization methodology of Pd NPs. No aromatic compounds were detected in the reaction products but octadecanol and octadecane were observed in large extents. Under flow conditions (4 atm; 573 K), the conversion of stearic acid was superior to that observed in batch conditions. The product mixture contained over 20% heptadecane. No octadecanol, octadecane, and aromatic compounds were detected. The maxima in performances are obtained after only 0.5 h. After that, the yields in heptadecane suffer from a severe decrease until 3h reaction time. However, at that time, stopping feeding the reactor with oleic acid and flushing the catalyst only with mesitylene recovered the activity and the selectivity of the catalysts. With the complete removal of H2, the analysis revealed the presence of heptadecene in high excess compared to heptadecane (almost 7 to 1), thus suggesting decarbonylation as the main route. ICP-OES measurements indicated no leaching of palladium and simple washing of catalysts with mesitylene allowed recycling without any change in conversion or product distribution. Noteworthy, mesitylene as solvent exhibited no effect in this reaction. In conclusion, this study demonstrates the feasibility of such catalysts for the green production of fuels from biomass.

Keywords: fuels from biomass, green catalyst, Pd nano-particles , recycble catalyst

Procedia PDF Downloads 286

Authors: Yagya Murti Aryal, Bipin Adhikari, Pradeep Gyawali

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The Lesser Himalaya zone of Nepal consists of thrusting and folding belts, which play an important role in the sustainable management of groundwater in the Himalayan regions. The study area is located in the Dolakha and Ramechhap Districts of Bagmati Province, Nepal. Geologically, these districts are situated in the Lesser Himalayas and partly encompass the Higher Himalayan rock sequence, which includes low-grade to high-grade metamorphic rocks. Following the Gorkha Earthquake in 2015, numerous springs dried up, and many others are currently experiencing depletion due to the distortion of the natural groundwater flow. The primary objective of this study is to identify potential groundwater areas and determine suitable sites for artificial groundwater recharge. Two distinct statistical approaches were used to develop models: The Frequency Ratio (FR) and Shannon Entropy (SE) methods. The study utilized both primary and secondary datasets and incorporated significant role and controlling factors derived from field works and literature reviews. Field data collection involved spring inventory, soil analysis, lithology assessment, and hydro-geomorphology study. Additionally, slope, aspect, drainage density, and lineament density were extracted from a Digital Elevation Model (DEM) using GIS and transformed into thematic layers. For training and validation, 114 springs were divided into a 70/30 ratio, with an equal number of non-spring pixels. After assigning weights to each class based on the two proposed models, a groundwater potential map was generated using GIS, classifying the area into five levels: very low, low, moderate, high, and very high. The model's outcome reveals that over 41% of the area falls into the low and very low potential categories, while only 30% of the area demonstrates a high probability of groundwater potential. To evaluate model performance, accuracy was assessed using the Area under the Curve (AUC). The success rate AUC values for the FR and SE methods were determined to be 78.73% and 77.09%, respectively. Additionally, the prediction rate AUC values for the FR and SE methods were calculated as 76.31% and 74.08%. The results indicate that the FR model exhibits greater prediction capability compared to the SE model in this case study.

Keywords: groundwater potential mapping, frequency ratio, Shannon’s Entropy, Lesser Himalaya Zone, sustainable groundwater management

Procedia PDF Downloads 49

Authors: Dong Jiang

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Turnout is the essential equipment on the railway, which also belongs to one of the strongest demanded infrastructural facilities of railway on account of the more seriously frog rail failures. In cooperation with Germany Company (DB Systemtechnik AG), our research team focuses on the quantitative analysis about the frog rails to predict their lifetimes. Moreover, the suggestions for the timely and effective maintenances are made to improve the economy of the frog rails. The lifetime of the frog rail depends strongly on the internal damage of the running surface until the breakages occur. On the basis of Hertzian theory of the contact mechanics, the dynamic loads of the running surface are calculated in form of the contact pressures on the running surface and the equivalent tensile stress inside the running surface. According to material mechanics, the strength of the frog rail is determined quantitatively in form of the Stress-cycle (S-N) curve. Under the interaction between the dynamic loads and the strength, the internal damage of the running surface is calculated by means of the linear damage hypothesis of the Miner’s rule. The emergence of the first Breakage on the running surface is to be defined as the failure criterion that the damage degree equals 1.0. From the microscopic perspective, the running surface of the frog rail is divided into numerous segments for the detailed analysis. The internal damage of the segment grows slowly in the beginning and disproportionately quickly in the end until the emergence of the breakage. From the macroscopic perspective, the internal damage of the running surface develops simply always linear along the lifetime. With this linear growth of the internal damages, the lifetime of the frog rail could be predicted simply through the immediate introduction of the slope of the linearity. However, the superficial abrasion plays an essential role in the results of the internal damages from the both perspectives. The influences of the superficial abrasion on the lifetime are described in form of the abrasion rate. It has two contradictory effects. On the one hand, the insufficient abrasion rate causes the concentration of the damage accumulation on the same position below the running surface to accelerate the rail failure. On the other hand, the excessive abrasion rate advances the disappearance of the head hardened surface of the frog rail to result in the untimely breakage on the surface. Thus, the relationship between the abrasion rate and the lifetime is subdivided into an initial phase of the increased lifetime and a subsequent phase of the more rapid decreasing lifetime with the continuous growth of the abrasion rate. Through the compensation of these two effects, the critical abrasion rate is discussed to reach the optimal lifetime.

Keywords: breakage, critical abrasion rate, frog rail, internal damage, optimal lifetime

Procedia PDF Downloads 182

Authors: Tony R. Walker, N. Devin MacAskill, Andrew Thalhiemer

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Sydney Harbour, Nova Scotia, Canada has long been subject to effluent and atmospheric inputs of contaminants, including thousands of tons of PAHs from a large coking and steel plant which operated in Sydney for nearly a century. Contaminants comprised of coal tar residues which were discharged from coking ovens into a small tidal tributary, which became known as the Sydney Tar Ponds (STPs), and subsequently discharged into Sydney Harbour. An Environmental Impact Statement concluded that mobilization of contaminated sediments posed unacceptable ecological risks, therefore immobilizing contaminants in the STPs using solidification and stabilization was identified as a primary source control remediation option to mitigate against continued transport of contaminated sediments from the STPs into Sydney Harbour. Recent developments in contaminant mass flux techniques focus on understanding “mobile” vs. “immobile” contaminants at remediation sites. Forensic source evaluations are also increasingly used for understanding origins of PAH contaminants in soils or sediments. Flux and forensic source evaluation-informed remediation decision-making uses this information to develop remediation end point goals aimed at reducing off-site exposure and managing potential ecological risk. This study included reviews of previous flux studies, calculating current mass flux estimates and a forensic assessment using PAH fingerprint techniques, during remediation of one of Canada’s most polluted sites at the STPs. Historically, the STPs was thought to be the major source of PAH contamination in Sydney Harbour with estimated discharges of nearly 800 kg/year of PAHs. However, during three years of remediation monitoring only 17-97 kg/year of PAHs were discharged from the STPs, which was also corroborated by an independent PAH flux study during the first year of remediation which estimated 119 kg/year. The estimated mass efflux of PAHs from the STPs during remediation was in stark contrast to ~2000 kg loading thought necessary to cause a short term increase in harbour sediment PAH concentrations. These mass flux estimates during remediation were also between three to eight times lower than PAHs discharged from the STPs a decade prior to remediation, when at the same time, government studies demonstrated on-going reduction in PAH concentrations in harbour sediments. Flux results were also corroborated using forensic source evaluations using PAH fingerprint techniques which found a common source of PAHs for urban soils, marine and aquatic sediments in and around Sydney. Coal combustion (from historical coking) and coal dust transshipment (from current coal transshipment facilities), are likely the principal source of PAHs in these media and not migration of PAH laden sediments from the STPs during a large scale remediation project.

Keywords: contaminated sediment, mass flux, forensic source evaluations, remediation

Procedia PDF Downloads 218

Authors: Abel Mahowe

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Furrow erosion is the major problem menacing sustainability of irrigation in Malawi and polluting water bodies resulting in death of many aquatic animals. Many rivers in Malawi are drying due to some poor practices that are being practiced around these water bodies, furrow erosion is one of the cause of sedimentation in these rivers although it has gradual effect on deteriorating of these rivers hence neglected, but has got long term disastrous effect on water bodies. Many aquatic animals also suffer when these sediments are taken into these water bodies. An assessment of effect of manure treatment on furrow erosion was carried out in Sagawika irrigation scheme located in Kasungu District north part of Malawi. The soil on the field was clay loam and had just been tilled. The average furrow slope of 0.2% and was divided into two blocks, A and B. Each block had 20V-shaped furrow having a length of 10 m. Three different manure were used to construct these furrows by mixing it with soil which was moderately moist and 5 furrows from each block were constructed without manure. In each block 5furrow were made using a specific type of manure, and one set of five furrows in each block was made without manure treatment. The types of manure that were used were goat manure, pig manure, and manure from crop residuals. The manure application late was 5 kg/m. The furrow was constructed at a spacing of 0.6 m. Tomato was planted in the two blocks at spacing of 0.15 m between rows and 0.15 m between planting stations. Irrigation water was led from feeder canal into the irrigation furrows using siphons. The siphons discharge into each furrow was set at 1.86 L/S. The ¾ rule was used to determine the cut-off time for the irrigation cycles in order to reduce the run-off at the tail end. During each irrigation cycle, samples of the runoff water were collected at one-minute intervals and analyzed for total sediment concentration for use in estimating the total soil sediment loss. The results of the study have shown that a significant amount of soil is lost in soils without many organic matters, there was a low level of erosion in furrows that were constructed using manure treatment within the blocks. In addition, the results have shown that manure also differs in their ability to control erosion since pig manure proved to have greater abilities in binding the soil together than other manure since they were reduction in the amount of sediments at the tail end of furrows constructed by this type of manure. The results prove that manure contains organic matters which helps soil particles to bind together hence resisting the erosive force of water. The use of manure when constructing furrows in soil with less organic matter can highly reduce erosion hence reducing also pollution of water bodies and improve the conditions of aquatic animals.

Keywords: aquatic, erosion, furrow, soil

Procedia PDF Downloads 261

Authors: Elena Pummer, Holger Schuettrumpf

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By today underground pumped storage plants as an outstanding alternative for classical pumped storage plants do not exist. They are needed to ensure the required balance between production and demand of energy. As a short to medium term storage pumped storage plants have been used economically over a long period of time, but their expansion is limited locally. The reasons are in particular the required topography and the extensive human land use. Through the use of underground reservoirs instead of surface lakes expansion options could be increased. Fulfilling the same functions, several hydrodynamic processes result in the specific design of the underground reservoirs and must be implemented in the planning process of such systems. A combined 3D numerical and experimental approach leads to currently unknown results about the occurring wave types and their behavior in dependence of different design and operating criteria. For the 3D numerical simulations, OpenFOAM was used and combined with an experimental approach in the laboratory of the Institute of Hydraulic Engineering and Water Resources Management at RWTH Aachen University, Germany. Using the finite-volume method and an explicit time discretization, a RANS-Simulation (k-ε) has been run. Convergence analyses for different time discretization, different meshes etc. and clear comparisons between both approaches lead to the result, that the numerical and experimental models can be combined and used as hybrid model. Undular bores partly with secondary waves and breaking bores occurred in the underground reservoir. Different water levels and discharges change the global effects, defined as the time-dependent average of the water level as well as the local processes, defined as the single, local hydrodynamic processes (water waves). Design criteria, like branches, directional changes, changes in cross-section or bottom slope, as well as changes in roughness have a great effect on the local processes, the global effects remain unaffected. Design calculations for underground pumped storage plants were developed on the basis of existing formulae and the results of the hybrid approach. Using the design calculations reservoirs heights as well as oscillation periods can be determined and lead to the knowledge of construction and operation possibilities of the plants. Consequently, future plants can be hydraulically optimized applying the design calculations on the local boundary conditions.

Keywords: energy storage, experimental approach, hybrid approach, undular and breaking Bores, 3D numerical approach

Procedia PDF Downloads 182

Authors: Victorita Radulescu

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Introduction: The optimum exploitation of agricultural land in the presence of an aquifer polluted by the surface sources requires close monitoring of groundwater level in both periods of intense irrigation and in absence of the irrigations, in times of drought. Currently in Romania, in the south part of the country, the Baragan area, many agricultural lands are confronted with the risk of groundwater pollution in the absence of systematic irrigation, correlated with the climate changes. Basic Methods: The non-steady flow of the groundwater from an aquifer can be described by the Bousinesq’s partial differential equation. The finite element method was used, applied to the porous media needed for the water mass balance equation. By the proper structure of the initial and boundary conditions may be modeled the flow in drainage or injection systems of wells, according to the period of irrigation or prolonged drought. The boundary conditions consist of the groundwater levels required at margins of the analyzed area, in conformity to the reality of the pollutant emissaries, following the method of the double steps. Major Findings/Results: The drainage condition is equivalent to operating regimes on the two or three rows of wells, negative, as to assure the pollutant transport, modeled with the variable flow in groups of two adjacent nodes. In order to obtain the level of the water table, in accordance with the real constraints, are needed, for example, to be restricted its top level below of an imposed value, required in each node. The objective function consists of a sum of the absolute values of differences of the infiltration flow rates, increased by a large penalty factor when there are positive values of pollutant. In these conditions, a balanced structure of the pollutant concentration is maintained in the groundwater. The spatial coordinates represent the modified parameters during the process of optimization and the drainage flows through wells. Conclusions: The presented calculation scheme was applied to an area having a cross-section of 50 km between two emissaries with various levels of altitude and different values of pollution. The input data were correlated with the measurements made in-situ, such as the level of the bedrock, the grain size of the field, the slope, etc. This method of calculation can also be extended to determine the variation of the groundwater in the aquifer following the flood wave propagation in envoys.

Keywords: environmental protection, infiltrations, numerical modeling, pollutant transport through soils

Procedia PDF Downloads 128

Authors: Noppadol Poomvises, Prateep Pakdeerod, Anchalee Kongsuk

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In the middle of September 2017, a tropical storm named ‘DOKSURI’ swept through Udon Thani, Northeastern Thailand. The storm dumped heavy rain for many hours and caused large amount of water flowing into Huai Phueng reservoir. Level of impounding water increased rapidly, and the extra water flowed over a service spillway, morning-glory type constructed by concrete material for about 50 years ago. Subsequently, a sinkhole was formed on the dam crest and five points of water piping were found on downstream slope closely to spillway. Three techniques of geophysical investigation were carried out to inspect cause of failures; Electrical Resistivity Imaging (ERI), Multichannel Analysis of Surface Wave (MASW), and Ground Penetrating Radar (GPR), respectively. Result of ERI clearly shows evidence of overtop event and heterogeneity around spillway that implied possibility of previous shape of sinkhole around the pipe. The shear wave velocity of subsurface soil measured by MASW can numerically convert to undrained shear strength of impervious clay core. Result of GPR clearly reveals partial settlements of freeboard zone at top part of the dam and also shaping new refilled material to plug the sinkhole back to the condition it should be. In addition, the GPR image is a main answer to confirm that there are not any sinkholes in the survey lines, only that found on top of the spillway. Integrity interpretation of the three results together with several evidences observed during a field walk-through and data from drilled holes can be interpreted that there are four main causes in this account. The first cause is too much water flowing over the spillway. Second, the water attacking morning glory spillway creates cracks upon concrete contact where the spillway is cross-cut to the center of the dam. Third, high velocity of water inside the concrete pipe sucking fine particle of embankment material down via those cracks and flushing out to the river channel. Lastly, loss of clay material of the dam into the concrete pipe creates the sinkhole at the crest. However, in case of failure by piping, it is possible that they can be formed both by backward erosion (internal erosion along or into embedded structure of spillway walls) and also by excess saturated water of downstream material.

Keywords: dam inspection, GPR, MASW, resistivity

Procedia PDF Downloads 218

Authors: Loredana E. Nita, Aurica P. Chiriac, Elena Stoleru, Alina Diaconu, Tudorachi Nita

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Self-assembly processes are an attractive method to form new and complex structures between macromolecular compounds to be used for specific applications. In this context, intramolecular and intermolecular bonds play a key role during self-assembling processes in preparation of carrier systems of bioactive substances. Polyelectrolyte complexes (PECs) are formed through electrostatic interactions, and though they are significantly below of the covalent linkages in their strength, these complexes are sufficiently stable owing to the association processes. The relative ease way of PECs formation makes from them a versatile tool for preparation of various materials, with properties that can be tuned by adjusting several parameters, such as the chemical composition and structure of polyelectrolytes, pH and ionic strength of solutions, temperature and post-treatment procedures. For example, protein-polyelectrolyte complexes (PPCs) are playing an important role in various chemical and biological processes, such as protein separation, enzyme stabilization and polymer drug delivery systems. The present investigation is focused on evaluation of the PPC formation between a synthetic polypeptide (poly(aspartic acid) – PAS) and a natural protein (bovine serum albumin - BSA). The PPC obtained from PAS and BSA in different ratio was investigated by corroboration of various techniques of characterization as: spectroscopy, microscopy, thermo-gravimetric analysis, DLS and zeta potential determination, measurements which were performed in static and/or dynamic conditions. The static contact angle of the sample films was also determined in order to evaluate the changes brought upon surface free energy of the prepared PPCs in interdependence with the complexes composition. The evolution of hydrodynamic diameter and zeta potential of the PPC, recorded in situ, confirm changes of both co-partners conformation, a 1/1 ratio between protein and polyelectrolyte being benefit for the preparation of a stable PPC. Also, the study evidenced the dependence of PPC formation on the temperature of preparation. Thus, at low temperatures the PPC is formed with compact structure, small dimension and hydrodynamic diameter, close to those of BSA. The behavior at thermal treatment of the prepared PPCs is in agreement with the composition of the complexes. From the contact angle determination results the increase of the PPC films cohesion, which is higher than that of BSA films. Also, a higher hydrophobicity corresponds to the new PPC films denoting a good adhesion of the red blood cells onto the surface of PSA/BSA interpenetrated systems. The SEM investigation evidenced as well the specific internal structure of PPC concretized in phases with different size and shape in interdependence with the interpolymer mixture composition.

Keywords: polyelectrolyte – protein complex, bovine serum albumin, poly(aspartic acid), self-assembly

Procedia PDF Downloads 220

Authors: Zulkifli Yusop

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The severity of December 2014 flood on the east coast of Peninsular Malaysia has raised concern over the adequacy of existing land use practices and policies. This article assesses flood responses to selective logging, plantation establishment (oil palm and rubber) and their subsequent management regimes. The hydrological impacts were evaluated on two levels: on-site (mostly in the upstream) and off-site to reflect the cumulative impact at downstream. Results of experimental catchment studies suggest that on-site impact of flood could be kept to a minimum when selecting logging strictly adhere to the existing guidelines. However, increases in flood potential and sedimentation rate were observed with logging intensity and slope steepness. Forest conversion to plantation show the highest impacts. Except on the heavily compacted surfaces, the ground revegetation is usually rapid within two years upon the cessation of the logging operation. The hydrological impacts of plantation opening and replanting could be significantly reduced once the cover crop has fully established which normally takes between three to six months after sowing. However, as oil palms become taller and the canopy gets closer, the cover crop tends to die off due to light competition, and its protecting function gradually diminishes. The exposed soil is further compacted by harvesting machinery which subsequently leads to greater overland flow and erosion rates. As such, the hydrological properties of matured oil palm plantations are generally poorer than in young plantation. In hilly area, the undergrowth in rubber plantation is usually denser compared to under oil palm. The soil under rubber trees is also less compacted as latex collection is done manually. By considering the cumulative effects of land-use over space and time, selective logging seems to pose the least impact on flood potential, followed by planting rubber for latex, oil palm and Latex Timber Clone (LTC). The cumulative hydrological impact of LTC plantation is the most severe because of its shortest replanting rotation (12 to 15 years) compared to oil palm (25 years) and rubber for latex (35 years). Furthermore, the areas gazetted for LTC are mostly located on steeper slopes which are more susceptible to landslide and erosion. Forest has limited capability to store excess rainfall and is only effective in attenuating regular floods. Once the hydrologic storage is exceeded, the excess rainfall will appear as flood water. Therefore, for big floods, rainfall regime has a much bigger influence than land use.

Keywords: selective logging, plantation, extreme rainfall, debris flow

Procedia PDF Downloads 321

Authors: Lahcen Daoudi, Fatima Zahra Omdi, Abldelali Gourfi

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In Morocco, as in most Mediterranean countries, water scarcity is a common situation because of low and unevenly distributed rainfall. The expansions of irrigated lands, as well as the growth of urban and industrial areas and tourist resorts, contribute to an increase of water demand. Therefore in the 1960s Morocco embarked on an ambitious program to increase the number of dams to boost water retention capacity. However, the decrease in the capacity of these reservoirs caused by sedimentation is a major problem; it is estimated at 75 million m3/year. Dams and reservoirs became unusable for their intended purposes due to sedimentation in large rivers that result from soil erosion. Soil erosion presents an important driving force in the process affecting the landscape. It has become one of the most serious environmental problems that raised much interest throughout the world. Monitoring soil erosion risk is an important part of soil conservation practices. The estimation of soil loss risk is the first step for a successful control of water erosion. The aim of this study is to estimate the soil loss risk and its spatial distribution in the different fields of Morocco and to prioritize areas for soil conservation interventions. The approach followed is the Revised Universal Soil Loss Equation (RUSLE) using remote sensing and GIS, which is the most popular empirically based model used globally for erosion prediction and control. This model has been tested in many agricultural watersheds in the world, particularly for large-scale basins due to the simplicity of the model formulation and easy availability of the dataset. The spatial distribution of the annual soil loss was elaborated by the combination of several factors: rainfall erosivity, soil erodability, topography, and land cover. The average annual soil loss estimated in several basins watershed of Morocco varies from 0 to 50t/ha/year. Watersheds characterized by high-erosion-vulnerability are located in the North (Rif Mountains) and more particularly in the Central part of Morocco (High Atlas Mountains). This variation of vulnerability is highly correlated to slope variation which indicates that the topography factor is the main agent of soil erosion within these basin catchments. These results could be helpful for the planning of natural resources management and for implementing sustainable long-term management strategies which are necessary for soil conservation and for increasing over the projected economic life of the dam implemented.

Keywords: soil loss, RUSLE, GIS-remote sensing, watershed, Morocco

Procedia PDF Downloads 435

Authors: Shahira M. Ezzat, Marwa I. Ezzat, Mona M. Okba, Esther T. Menze, Ashraf B. Abdel-Naim, Shahnas O. Mohamed

Abstract:

Background: In order to decrease the burden of the high cost of synthetic drugs, it is important to focus on phytopharmaceuticals. The aim of our study was to search for the mechanism of ginger (Zingiber officinale Roscoe) anti-inflammatory potential and to correlate it to its biophytochemicals. Methods: Various extracts viz. water, 50%, 70%, 80%, and 90% ethanol were prepared from ginger rhizomes. Fractionation of the aqueous extract (AE) was accomplished using Diaion HP-20. In vitro anti-inflammatory activity of the different extracts and isolated compounds was evaluated by protein denaturation inhibition, membrane stabilization, protease inhibition, and anti-lipoxygenase assays. In vivo anti-inflammatory activity of AE was estimated by assessment of rat paw oedema after carrageenan injection. Prostaglandin E2 (PGE2), certain inflammation markers (TNF-α, IL-6, IL-1α, IL-1β, INFr, MCP-1MIP, RANTES, and Nox) levels and MPO activity in the paw edema exudates were measured. Total antioxidant capacity (TAC) was also determined. Histopathological alterations of paw tissues were scored. Results: All the tested extracts showed significant (p < 0.1) anti-inflammatory activities. The highest percentage of heat induced albumin denaturation (66%) was exhibited by the 50% ethanol (250 μg/ml). The 70 and 90% ethanol extracts (500 μg/ml) were more potent as membrane stabilizers (34.5 and 37%, respectively) than diclofenac (33%). The 80 and 90% ethanol extracts (500 μg/ml) showed maximum protease inhibition (56%). The strongest anti-lipoxygenase activity was observed for the AE. It showed more significant lipoxygenase inhibition activity than that of diclofenac (58% and 52%, respectively) at the same concentration (125 μg/ml). Fractionation of AE yielded four main fractions (Fr I-IV) which showed significant in vitro anti-inflammatory. Purification of Fr-III and IV led to the isolation of 6-poradol (G1), 6-shogaol (G2); methyl 6- gingerol (G3), 5-gingerol (G4), 6-gingerol (G5), 8-gingerol (G6), 10-gingerol (G7), and 1-dehydro-6-gingerol (G8). G2 (62.5 ug/ml), G1 (250 ug/ml), and G8 (250 ug/ml) exhibited potent anti-inflammatory activity in all studied assays, while G4 and G5 exhibited moderate activity. In vivo administration of AE ameliorated rat paw oedema in a dose-dependent manner. AE (at 200 mg/kg) showed significant reduction (60%) of PGE2 production. The AE at different doses (at 25-200 mg/kg) showed significant reduction in inflammatory markers except for IL-1α. AE (at 25 mg/kg) is superior to indomethacin in reduction of IL-1β. Treatment of animals with the AE (100, 200 mg/kg) or indomethacin (10 mg/kg) showed significant reduction in TNF-α, IL-6, MCP-1, and RANTES levels, and MPO activity by about (31, 57 and 32% ) (65, 60 and 57%) (27, 41 and 28%) (23, 32 and 23%) (66, 67 and 67%) respectively. AE at 100 and 200 mg/kg was equipotent to indomethacin in reduction of NOₓ level and in increasing the TAC. Histopathological examination revealed very few inflammatory cells infiltration and oedema after administration of AE (200 mg/kg) prior to carrageenan. Conclusion: Ginger anti-inflammatory activity is mediated by inhibiting macrophage and neutrophils activation as well as negatively affecting monocyte and leukocyte migration. Moreover, it produced dose-dependent decrease in pro-inflammatory cytokines and chemokines and replenished the total antioxidant capacity. We strongly recommend future investigations of ginger in the potential signal transduction pathways.

Keywords: anti-lipoxygenase activity, inflammatory markers, 1-dehydro-6-gingerol, 6-shogaol

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Authors: Rodrigo De A. Ferrazza, Henry D. M. Garcia, Viviana H. V. Aristizabal, Camilla De S. Nogueira, Cecilia J. Verissimo, Jose Roberto Sartori, Roberto Sartori, Joao Carlos P. Ferreira

Abstract:

Environmental factors adversely influence sustainability in livestock production system. Dairy herds are the most affected by heat stress among livestock industries. This clearly implies in development of new strategies for mitigating heat, which should be based on physiological and metabolic adaptations of the animal. In this study, we incorporated the effect of climate variables and heat exposure time on the thermoregulatory responses in order to clarify the adaptive mechanisms for bovine heat dissipation under intense thermal stress induced experimentally in climate chamber. Non-lactating Holstein cows were contemporaneously and randomly assigned to thermoneutral (TN; n=12) or heat stress (HS; n=12) treatments during 16 days. Vaginal temperature (VT) was measured every 15 min with a microprocessor-controlled data logger (HOBO®, Onset Computer Corporation, Bourne, MA, USA) attached to a modified vaginal controlled internal drug release insert (Sincrogest®, Ourofino, Brazil). Rectal temperature (RT), respiratory rate (RR) and heart rate (HR) were measured twice a day (0700 and 1500h) and dry matter intake (DMI) was estimated daily. The ambient temperature and air relative humidity were 25.9±0.2°C and 73.0±0.8%, respectively for TN, and 36.3± 0.3°C and 60.9±0.9%, respectively for HS. Respiratory rate of HS cows increased immediately after exposure to heat and was higher (76.02±1.70bpm; P<0.001) than TN (39.70±0.71bpm), followed by rising of RT (39.87°C±0.07 for HS versus 38.56±0.03°C for TN; P<0.001) and VT (39.82±0.10°C for HS versus 38.26±0.03°C for TN; P<0.001). A diurnal pattern was detected, with higher (P<0.01) afternoon temperatures than morning and this effect was aggravated for HS cows. There was decrease (P<0.05) of HR for HS cows (62.13±0.99bpm) compared to TN (66.23±0.79bpm), but the magnitude of the differences was not the same over time. From the third day, there was a decrease of DMI for HS in attempt to maintain homeothermy, while TN cows increased DMI (8.27kg±0.33kg d-1 for HS versus 14.03±0.29kg d-1 for TN; P<0.001). By regression analysis, RT and RR better reflected the response of cows to changes in the Temperature Humidity Index and the effect of climate variables from the previous day to influence the physiological parameters and DMI was more important than the current day, with ambient temperature the most important factor. Comparison between acute (0 to 3 days) and chronic (13 to 16 days) exposure to heat stress showed decreasing of the slope of the regression equations for RR and DMI, suggesting an adaptive adjustment, however with no change for RT. In conclusion, intense heat stress exerted strong influence on the thermoregulatory mechanisms, but the acclimation process was only partial.

Keywords: acclimation, bovine, climate chamber, hyperthermia, thermoregulation

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Authors: Fayez Hanna, Viet Tran

Abstract:

A 20 years old lady- primigravida 6 weeks pregnant with unremarkable past history, presented to the emergency department at the Royal Hobart Hospital, Tasmania, Australia, with hyperemesis gravidarum associated with, dehydration and complicated with hematemesis and chest pain resistant. Accordingly, we conducted laboratory investigations which revealed: FBC: WBC 23.9, unremarkable U&E, LFT, lipase and her VBG showed a pH 7.4, pCo2 36.7, cK+ 3.2, cNa+ 142. The decision was made to do a chest X-ray (CXR) after explaining the risks/benefit of performing radiographic investigations during pregnancy and considering the patient's plan for the termination of the pregnancy as she was not ready for motherhood for shared decision-making and consent to look for pneumoperitoneum to suggest perforated viscus that might cause the hematemesis. However, the CXR showed pneumomediastinum but no evidence of pneumoperitoneum or pneumothorax. Consequently, a decision was made to proceed with CT oesophagography with imaging pre and post oral contrast administration to identify a potential oesophageal tear since it could not be excluded using a plain film of the CXR. The CT oesophagography could not find a leak for the administered oral contrast and thus, no oesophageal tear could be confirmed but could not exclude the Mallory-Weiss tear (lower oesophageal tear). Further, the CT oesophagography showed an extensive pneumomediastinum that could not be confirmed to be pulmonary in origin noting the presence of bilateral pulmonary interstitial emphysema and pneumothorax in the apex of the right lung that was small. The patient was admitted to the Emergency Department Inpatient Unit for monitoring, supportive therapy, and symptomatic management. Her hyperemesis was well controlled with ondansetron 8mg IV, metoclopramide 10mg IV, doxylamine 25mg PO, pyridoxine 25mg PO, esomeprazole 40mg IV and oxycodone 5mg PO was given for pain control and 2 litter of IV fluid. The patient was stabilized after 24 hours and discharged home on ondansetron 8mg every 8 hours whereas the patient had a plan for medical termination of pregnancy. Three weeks later, the patient represented with nausea and vomiting complicated by a frank hematemesis. Her observation chart showed HR 117- other vital signs were normal. Pathology showed WBC 14.3 with normal U&E and Hb. The patient was managed in the Emergency Department with the same previous regimen and was discharged home on same previous regimes. Five days later, she presented again with nausea, vomiting and hematemesis and was admitted under obstetrics and gynaecology for stabilization then discharged home with a plan for surgical termination of pregnancy after 3-days rather than the previously planned medical termination of pregnancy to avoid extension of potential oesophageal tear. The surgical termination and follow up period were uneventful. The case is considered rare as pneumomediastinum is a very rare complication of hyperemesis gravidarum where vomiting-induced barotrauma leads to a ruptured oesophagus and air leak into the mediastinum. However no rupture oesophagus in our case. Although the combination of pneumothorax and pneumomediastinum without oesophageal tear was reported only 8 times in the literature, but none of them was due to hyperemesis gravidarum.

Keywords: Pneumothorax, pneumomediastinum, hyperemesis gravidarum, pneumopericardium

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