Search results for: water losses

Authors: V. A. Okenyi, K. Yang, P. A. M. Basheer

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Concrete structures in service are constantly under the influence of load. Microstructural cracks often develop in them and considering those in the marine environment; these microcracks often serve as a means for transportation of harmful fluids into the concrete. This paper studies the influence of flexural tensile stress that structural elements undergo on the transport properties of such concrete in the tensile zone of the structural member. Reinforced concrete beams of 1200mm ⨉ 230mm ⨉ 150mm in dimension in a four-point bending set up were subjected to various levels of the loading required to cause a microcrack width of 100µm. The use of Autoclam permeability tests, sorptivity tests as well as the Permit chloride ion migration tests were employed, and results showed that air permeability, sorptivity and water permeability all increased as the load increased in the concrete tensile zone. For air permeability, an increase in stress levels led to more permeability, and the addition of steel macrofibers had no significant effect until at 75% of stress level where it decreased air permeability. For sorptivity, there was no absorption into concrete when no load was added, but water sorptivity index was high at 75% stress levels and higher in steel fiber reinforced concrete (SFRC). Steel macrofibers produced more water permeability into the concrete at 75% stress level under the 100µm crack width considered while steel macrofibers helped in slightly reducing the migration of chloride into concrete by 8.8% reduction, compared to control samples at 75% stress level. It is clear from this research that load-induced cracking leads to an increase in fluid permeability into concrete and the effect of the addition of steel macrofiber to concrete for durability is not significant under 100µm crack width.

Keywords: durability, microcracks, SFRC, stress Level, transport properties

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Authors: Llham Lhoume, Rachid Tadili, Nora Arbaoui

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One of the most crucial ways to combat food insecurity is to minimize crop losses, food drying is one of the most organic, effective, low-cost and energy-efficient food preservation methods. In this regard, we undertake in this study an experimental evaluation and analysis of the thermal performance of different natural convection drying systems: a solar greenhouse dryer, an indirect solar dryer with a single compartment and a solar dryer with two compartments. These systems have been implemented at the Solar Energy and Environment Laboratory of Mohammed V University (Morocco). The objective of this work is to study the feasibility of converting a solar greenhouse into a solar dryer for use during the summer. On the other hand, to study the thermal performances of this greenhouse dryer by comparing it with other solar dryers. The experimental study showed that the drying of verbena leaves took 6 hours in the indirect dryer 1, 3 hours in the indirect dryer, 2 and 4 hours in the greenhouse dryer, but the amortization period of the solar greenhouse dryer is lower than the other two solar dryers. The results of this study provide key information on the implementation and performance of these systems for drying a food of great global interest.

Keywords: solar energy, drying, agriculture, biotechnologie

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Authors: Tahira Pirzada, Zahra Ashrafi, Saad Khan

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We present a facile and sustainable solid templating approach to fabricate highly porous, flexible and superhydrophobic aerogels of composite nanofibers of cellulose diacetate and silica which are produced through sol gel electrospinning. Scanning electron microscopy, contact angle measurement, and attenuated total reflection-Fourier transform infrared spectrometry are used to understand the structural features of the resultant aerogels while thermogravimetric analysis and differential scanning calorimetry demonstrate their thermal stability. These aerogels exhibit a self-supportive three-dimensional network abundant in large secondary pores surrounded by primary pores resulting in a highly porous structure. Thermal crosslinking of the aerogels has further stabilized their structure and flexibility without compromising on the porosity. Ease of processing, thermal stability, high porosity and oleophilic nature of these aerogels make them promising candidate for a wide variety of applications including acoustic and thermal insulation and oil and water separation.

Keywords: hybrid aerogels, sol-gel electrospinning, oil-water separation, nanofibers

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Authors: Xu Mengyuan, Xu Lei

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Behind the rapid development of Chinese city, the contradiction of frequent urban waterlogging and the shortage of water resources is deepening. In order to solve this problem, introduce the low impact development "sponge city" construction mode in the process of the construction of new urbanization in China, make our city " resilience to adapt" environmental change and natural disaster. Firstly this paper analyses the basic reason of urban waterlogging, then introduces the basic connotation and realization approach of “sponge city”. Finally, study on the project in Lishui Guazhou, focuses on the analysis of the "urban ecological corridor" construction strategy and the positive impact on city in the construction of “sponge city”. Meanwhile, we put forward the ”local conditions” and ”sustainable” as the construction ideas, make use of ecological construction leading city development, explore the ecological balance through the city to enhance the regional value, and providing reference and reflection for the development and future of the “sponge city” in China.

Keywords: urban water logging, sponge city, urban ecological corridor, sustainable development, China

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Authors: Nikhil Verma, Akshay Kant Mishra, Rishabh Rastogi, Bikarama Prasad Yadav

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Emerging fire incidents are the protuberant contributor out turning into life loss, property damage and importantly firefighters. It insinuates that a firefighting and rescue operation of the existing equipment or apparatus and their proficiency is limited, particularly in annihilating firefighting environments. The proposed methodology will help in developing a technology which can be useful in minimizing the risks and losses due to fire. In this paper, design and development of combat mini vehicle comprising of multi-purpose nozzle system is proposed which can target diverse fires simultaneously at distinct time and location. Basically, the system is semi-automated type protection system which can be manoeuvred by controller. Designing of robust vehicle based on semi-automated protection type system is consummated using SolidWorks platform. Concept of developing a robust vehicle will help to fight fires in multiple directions reducing the time required to douse multiple fires.

Keywords: fire douse vehicle, multiple fires, multi-purpose nozzle, semi-automated system

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Authors: Mohamed M. Zaki, Maha M. Hady

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Salmonella spp. have been categorized as the world’s biggest threats to human health and poultry products are mostly incriminated sources. In Egypt, it was found that S. enteritidis and S. typhimurium are the most prevalent ones in poultry farms. It is recommended to eliminate salmonella from living bird by competing for salmonella contamination in feed in order to establish a healthy gut. The Feed acidifiers are the group of feed additives containing low-molecular-weight organic acids and/ or their salts which act as performance promoters by lowering the pH in the gut, optimizes digestion and inhibit bacterial growth. The inclusion of organic acid in pure form nonetheless effective in feed, yet, it is difficult to handle in feed mills as it is corrosive and produce more losses during pelleting process. The current study aimed at to evaluate the impact of incorporation of sodium diformate (SDF) and a commercial acidifier, CA (a mixture of butyric and propionic acids and their ammonium salts) at 0.4% dietary levels on broilers performance and the control S. enteritidis infection. Two hundreds and seventy unsexed cobb chickens were allotted in one of three treatments (90/ group) which were, the control (no acidifier, C- &C+), the 0.4% SDF (SDF- & SDF +) and the 0.4% CA (CA- & CA +) dietary levels for 35 days. Before the allocation of the groups, ten extra birds and a diet sample were bacteriologically examined to ensure negative contamination with salmonella. The birds were raised on deep-litter separated pens and had free access to feed and water all the time. The experimentally formulated diets were kept at 40C. After 24h access to the different dietary treatments, all the birds in the positive groups (n=15/ replicate) were inoculated intra-crop with 0.2 ml of 24 h broth culture of S. entertidis containing 1X 107 organisms while the negative-treated groups were inoculated with the same amount of the negative broth and second inoculation was done at 22 d of age. Colocal swabs were collected individually from all birds 2 h pre-inoculation to assure the absence of salmonella, then 1, 3, 5, 7, 21 days post-inoculation to recover salmonella. Performance parameter (body weight gain and feed efficiency) were calculated. Mortalities were recorded and reisolation of the salmonella was adopted to ensure it was the inoculated ones. The results revealed that the dietary acidification with sodium diformate significantly improved broilers performance and tends to produce heavier birds as compared to the negative control and CA groups. Moreover, the dietary inclusion of both acidifiers at level of 0.4% was able to eliminate mortalities completely at the relevant inoculation time. Regarding the shedding of S. enteritidius in positive groups, the SDF treatment resulted in significant (p<0.05) cessation of the shedding at 3 days post-inoculation compared to 7 days post-inoculation for the CA-group. In conclusion, sodium diformate at 0.4% dietary level in broiler diets has a valuable effect not only on broilers performance but also by eliminating S. enteritidis the main source of salmonella contamination in poultry farms which is feed.

Keywords: acidifier, broilers, Salmonalla spp, sodium diformate

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Authors: K. Nikilsha, Lakshmi Manohar, Debayan Chatterjee

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Landscape is a setting that informs the way of life of a set of people, and the repository of intangible values and human meanings that nurture our very existence. Along with the linkage that it forms with our lives, it can be argued that landscape and memory cannot be separated, as landscape is the nucleus of our memories. In this context, this paper studies landscape evolution of a region with unique geographic setting, where the dependency of the inhabitants on its resources, led to the formation of certain peculiar beliefs and taboos that formed the basis of a set of unwritten rules and guidelines which they still follow as a part of their lifestyle. One such example is Kuttanad, a low lying region in Kerala which is a complex mosaic of fragmented agricultural landscape incorporating coastal backwaters, rivers, marshes, paddy fields and water channels. The more the physical involvement with the resources, the more was the inhabitants attachment towards it. This attachment of the inhabitants to the place is very strong because the creation of this land was the result of the toil of the low caste labourers who strived day and night to create Kuttanad, which was reclaimed from water with the help of the finance supplied by their landlords. However, the greatest challenge faced by them is posed by the forces of water in the form of floods. As this land is fed by five rivers, even the slight variation in rainfall in its watershed area can cause a large imbalance in the water level causing the reclaimed land to be inundated. The effects of climate change including increase in rainfall, rise in sea level and change of seasons can act as a catalyst to this damage. Hasty urbanization has led to the conversion of paddy fields to housing plots and coconut/plantain fields giving no regard to the traditional systems which had once respected nature and combated floods and draughts through the various cultural practices and taboos practiced by the people. Thus it is essential to look back at the landscape evolution of Kuttanad and to recognise methods used traditionally in the region to establish a cultural landscape, and to understand how climate change and urbanisation shall pose a challenge to the existing landscape and lifestyle. This research also explores the possibilities of alternative and sustainable approaches for resilient urban development learned from Kuttanad as a case study.

Keywords: ecological conservation, landscape and ecological engineering, landscape evolution, man-made landscapes

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Authors: Negin Binesh, Mohammad Hossein Niksokhan, Amin Sarang

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Best Management Practices (BMPs) are considered as one of the most important structural adaptive measures to climate change and urban development challenges in recent decades. However, not every location is appropriate for applying BMPs in the watersheds. In this paper, location prioritization of two kinds of BMPs was done: Pourous pavement and Detention pond. West Flood-Diversion (WFD) catchment in northern parts of Tehran, Iran, was considered as the case study. The methodology includes integrating the results of Storm Water Management Model (SWMM) into Fuzzy Analytic Hierarchy Process (FAHP) method using Geographic Information System (GIS). The results indicate that mostly suburban areas of the watershed in northern parts are appropriate for applying detention basin, and downstream high-density urban areas are more suitable for using permeable pavement.

Keywords: adaptive measures, BMPs, location prioritization, urban flooding

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Authors: Felicia Orah Rein Moshe

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Soil erosion has become a priority global concern, impairing water quality and degrading ecosystem services. In Mediterranean climates, following a long dry period, the onset of rain occurs when agricultural soils are often bare and most vulnerable to erosion. Early storms transport sediments and sediment-bound pollutants into streams, along with dissolved chemicals. This results in loss of valuable topsoil, water quality degradation, and potentially expensive dredged-material disposal costs. Information on the provenance of fine sediment and priority sources of adsorbed pollutants represents a critical need for developing effective control strategies aimed at source reduction. Modifying sediment traps designed for marine systems, this study tested a cost-effective method to collect suspended sediments on a catchment scale to characterize stream water quality during first-flush storm events in a flashy Eastern Mediterranean coastal perennial stream. This study investigated the Kishon Basin, deploying sediment traps in 23 locations, including 4 in the mainstream and one downstream in each of 19 tributaries, enabling the characterization of sediment as a vehicle for transporting chemicals. Further, it enabled direct comparison of sediment-bound pollutants transported during the first-flush winter storms of 2020 from each of 19 tributaries, allowing subsequent ecotoxicity ranking. Sediment samples were successfully captured in 22 locations. Pesticides, pharmaceuticals, nutrients, and metal concentrations were quantified, identifying a total of 50 pesticides, 15 pharmaceuticals, and 22 metals, with 16 pesticides and 3 pharmaceuticals found in all 23 locations, demonstrating the importance of this transport pathway. Heavy metals were detected in only one tributary, identifying an important watershed pollution source with immediate potential influence on long-term dredging costs. Simultaneous sediment sampling at first flush storms enabled clear identification of priority tributaries and their chemical contributions, advancing a new national watershed monitoring approach, facilitating strategic plan development based on source reduction, and advancing the goal of improving the farm-stream interface, conserving soil resources, and protecting water quality.

Keywords: adsorbed pollution, dredged material, heavy metals, suspended sediment, water quality monitoring

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Authors: Hamidreza Babaali, Alireza Mojtahedi, Nasim Soori, Saba Soori

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Hydraulic jump is one of the effective ways of energy dissipation in stilling basins that the ‎energy is highly dissipated by jumping. Adverse slope surface at the end stilling basin is ‎caused to increase energy dissipation and stability of the hydraulic jump. In this study, the adverse slope ‎has been added to end of United States Bureau of Reclamation (USBR) II stilling basin in hydraulic model of Nazloochay dam with scale 1:40, and flow simulated into stilling basin using Flow-3D ‎software. The numerical model is verified by experimental data of water depth in ‎stilling basin. Then, the parameters of water level profile, Froude Number, pressure, air ‎entrainment and turbulent dissipation investigated for discharging 300 m³/s using K-Ɛ and Re-Normalization Group (RNG) turbulence ‎models. The results showed a good agreement between numerical and experimental model‎ as ‎numerical model can be used to optimize of stilling basins.‎

Keywords: experimental and numerical modelling, end adverse slope, flow ‎parameters, USBR II stilling basin

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Authors: Mehran Nozari-Asbemarz, Italo Pisano, Simin Arshi, Edmond Magner, James J. Leahy

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Integrating electrolytic synthesis with renewable energy makes it feasible to address urgent environmental and energy challenges. Conventional water electrolyzers concurrently produce H₂ and O₂, demanding additional procedures in gas separation to prevent contamination of H₂ with O₂. Moreover, the oxygen evolution reaction (OER), which is sluggish and has a low overall energy conversion efficiency, does not deliver a significant value product on the electrode surface. Compared to conventional water electrolysis, integrating electrolytic hydrogen generation from water with thermodynamically more advantageous aqueous organic oxidation processes can increase energy conversion efficiency and create value-added compounds instead of oxygen at the anode. One strategy is to use renewable and sustainable carbon sources from biomass, which has a large annual production capacity and presents a significant opportunity to supplement carbon sourced from fossil fuels. Numerous catalytic techniques have been researched in order to utilize biomass economically. Because of its safe operating conditions, excellent energy efficiency, and reasonable control over production rate and selectivity using electrochemical parameters, electrocatalytic upgrading stands out as an appealing choice among the numerous biomass refinery technologies. Therefore, we propose a broad framework for coupling H2 generation from water splitting with oxidative biomass upgrading processes. Four representative biomass targets were considered for oxidative upgrading that used a hierarchically porous CoFe-MOF/LDH @ Graphite Paper bifunctional electrocatalyst, including glucose, ethanol, benzyl, furfural, and 5-hydroxymethylfurfural (HMF). The potential required to support 50 mA cm-2 is considerably lower than (~ 380 mV) the potential for OER. All four compounds can be oxidized to yield liquid byproducts with economic benefit. The electrocatalytic oxidation of glucose to the value-added products, gluconic acid, glucuronic acid, and glucaric acid, was examined in detail. The cell potential for combined H₂ production and glucose oxidation was substantially lower than for water splitting (1.44 V(RHE) vs. 1.82 V(RHE) for 50 mA cm-2). In contrast, the oxidation byproduct at the anode was significantly more valuable than O₂, taking advantage of the more favorable glucose oxidation in comparison to the OER. Overall, such a combination of HER and oxidative biomass valorization using electrocatalysts prevents the production of potentially explosive H₂/O₂mixtures and produces high-value products at both electrodes with lower voltage input, thereby increasing the efficiency and activity of electrocatalytic conversion.

Keywords: biomass, electrocatalytic, glucose oxidation, hydrogen evolution

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Authors: Vidhya Venugopal, Jeremiah Chinnadurai, Rebekah A. I. Lucas, Tord Kjellstrom, Bruno Lemke

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Introduction: The effects of climate change (CC) are largely discussed across the globe in terms of impacts on the environment and the general population, but the impacts on workers remain largely unexplored. The predicted rise in temperatures and heat events in the CC scenario have health implications on millions of workers in physically exerting jobs. The current health and productivity risks associated with heat exposures are characterized, future risk estimates as temperature rises and recommendations towards developing protective and preventive occupational health and safety guidelines for India are discussed. Methodology: Cross-sectional studies were conducted in several occupational sectors with workers engaged in moderate to heavy labor (n=1580). Quantitative data on heat exposures (WBGT°C), physiological heat strain indicators viz., Core temperature (CBT), Urine specific gravity (USG), Sweat rate (SwR) and qualitative data on heat-related health symptoms and productivity losses were collected. Data were analyzed for associations between heat exposures, health and productivity outcomes related to heat stress. Findings: Heat conditions exceeded the Threshold Limit Value (TLV) for safe manual work in 66% of the workers across several sectors (Avg.WBGT of 28.7°C±3.1°C). Widespread concerns about heat-related health outcomes (86%) were prevalent among workers exposed to high TLVs, with excessive sweating, fatigue and tiredness being commonly reported by workers. The heat stress indicators, core temperature (14%), Sweat rate (8%) and USG (9%), were above normal levels in the study population. A significant association was found between rise in Core Temperatures and WBGT exposures (p=0.000179) Elevated USG and SwR in the worker population indicate moderate dehydration, with potential risks of developing heat-related illnesses. In a steel industry with high heat exposures, an alarming 9% prevalence of kidney/urogenital anomalies was observed in a young workforce. Heat exposures above TLVs were associated with significantly increased odds of various adverse health outcomes (OR=2.43, 95% CI 1.88 to 3.13, p-value = <0.0001) and productivity losses (OR=1.79, 95% CI 1.32 to 2.4, p-value = 0.0002). Rough estimates for the number of workers who would be subjected to higher than TLV levels in the various RCP scenarios are RCP2.6 =79%, RCP4.5 & RCP6 = 81% and at RCP 8.5 = 85%. Rising temperatures due to CC has the capacity to further reduce already compromised health and productivity by subjecting the workers to increased heat exposures in the RCP scenarios are of concern for the country’s occupational health and economy. Conclusion: The findings of this study clearly identify that health protection from hot weather will become increasingly necessary in the Indian subcontinent and understanding the various adaptation techniques needs urgent attention. Further research with a multi-targeted approach to develop strategies for implementing interventions to protect the millions of workers is imperative. Approaches to include health aspects of climate change within sectoral and climate change specific policies should be encouraged, via a number of mechanisms, such as the “Health in All Policies” approach to avert adverse health and productivity consequences as climate change proceeds.

Keywords: heat stress, occupational health, productivity loss, heat strain, adverse health outcomes

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Authors: Fanny Desbiolles, Laure Malleret, Isabelle Laffont-Schwob, Christophe Tiliacos, Anne Piram, Mohamed Sarakha, Pascal Wong-Wah-Chung

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Pharmaceuticals in the environment have become a very hot topic in the recent years. This interest is related to the large amounts dispensed and to their release in urine or faeces from treated patients, resulting in their ubiquitous presence in water resources and wastewater treatment plants (WWTP) effluents. Thereby, many studies focused on the prediction of pharmaceuticals’ behaviour, to assess their fate and impacts in the environment. Carbamazepine is a widely consumed psychotropic pharmaceutical, thus being one of the most commonly detected drugs in the environment. This organic pollutant was proved to be persistent, especially with respect to its non-biodegradability, rendering it recalcitrant to usual biological treatment processes. Consequently, carbamazepine is very little removed in WWTP with a maximum abatement rate of 5 % and is then often released in natural surface waters. To better assess the environmental fate of carbamazepine in aqueous media, its photochemical transformation was undertaken in four natural waters (two French rivers, the Berre salt lagoon, Mediterranean Sea water) representative of coastal and inland water types. Kinetic experiments were performed in the presence of light using simulated solar irradiation (Xe lamp 300W). Formation of short-lifetime species was highlighted using chemical trap and laser flash photolysis (nanosecond). Identification of transformation by-products was assessed by LC-QToF-MS analyses. Carbamazepine degradation was observed after a four-day exposure and an abatement of 20% maximum was measured yielding to the formation of many by-products. Moreover, the formation of hydroxyl radicals (•OH) was evidenced in waters using terephthalic acid as a probe, considering the photochemical instability of its specific hydroxylated derivative. Correlations were implemented using carbamazepine degradation rate, estimated hydroxyl radical formation and chemical contents of waters. In addition, laser flash photolysis studies confirmed •OH formation and allowed to evidence other reactive species, such as chloride (Cl2•-)/bromine (Br2•-) and carbonate (CO3•-) radicals in natural waters. Radicals mainly originate from dissolved phase and their occurrence and abundance depend on the type of water. Rate constants between reactive species and carbamazepine were determined by laser flash photolysis and competitive reactions experiments. Moreover, LC-QToF-MS analyses of by-products help us to propose mechanistic pathways. The results will bring insights to the fate of carbamazepine in various water types and could help to evaluate more precisely potential ecotoxicological effects.

Keywords: carbamazepine, kinetic and mechanistic approaches, natural waters, photodegradation

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Authors: Yusuf, S. I., Saba, A., Olaoye, D. O., Ibrahim J. A., Yahaya H. M., Jatto A. O

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Nuclear Magnetic Resonance (NMR) technology has been applied in several ways to provide vital information about petro-physical properties of reservoirs. However, due to the need to study the molecular behaviours of particles of the fluids in different restricted media, diffusion magnetic resonance equation is hereby applied in spherical coordinates and solved analytically using the method of separation of variables and solution of Legendre equation by Frobenius method. The viscous fluid considered in this research work is unused oil while the non-viscous fluid is water. The results obtained show that water begins to manifest appreciable change at radial adjustment value of 10 and Magnetization of 2.31191995400015x1014 and relaxes finally at 2.30x1014 at radial adjustment value of 1. On the other hand, unused engine oil begins to manifest its changes at radial adjustment value of 40 and Magnetization of 1.466557018x1014and relaxes finally at 1.48x1014 at radial adjustment value of 5.

Keywords: viscous and non-viscous fluid, restricted medium, relaxation times, coefficient of diffusion

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Authors: Mohammad Mokhtari, Gires Usup, Zaidi Che Cob

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Bacteria communities as mediators of the biogeochemical process are the main component of the mangrove ecosystems. Crab burrows by increasing oxic-anoxic interfaces and facilitating the flux rate between sediment and tidal water affect biogeochemical properties of sediments. The effect of fiddler crab burrows on the density and diversity of bacteria were investigated to elucidate the effect of burrow on bacterial distribution. Samples collected from the burrow walls of three species of fiddler crabs including Uca paradussumieri, Uca rosea, and Uca forcipata. Sediment properties including grain size, temperature, Redox potential, pH, chlorophyll, water and organic content were measured from the burrow walls to assess the correlation between environmental variables and bacterial communities. Bacteria were enumerated with epifluorescence microscopy after staining with SYBR green. Bacterial DNA extracted from sediment samples and the community profiles of bacteria were determined with Terminal Restriction Fragment Length Polymorphism (T-RFLP). High endemism was observed among bacterial communities. Among the 152 observed OTU’s, 22 were found only in crab burrows. The highest bacterial density and diversity were recorded in burrow wall. The results of ANOSIM indicated a significant difference between the bacterial communities from the three species of fiddler crab burrows. Only 3% of explained bacteria variability in the constrained ordination model of CCA was contributed to depth, while much of the bacteria’s variability was attributed to coarse sand, pH, and chlorophyll content. Our findings suggest that crab burrows by affecting sediment properties such as redox potential, pH, water, and chlorophyll content induce significant effects on the bacterial communities.

Keywords: bioturbation, canonical corresponding analysis, fiddler crab, microbial ecology

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Authors: S. B. Q. Tran

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Drop condensation is the phenomenon that the tiny drops form when the oversaturated vapour present in the environment condenses on a substrate and makes the droplet growth. Recently, this subject has received much attention due to its applications in many fields such as thin film growth, heat transfer, recovery of atmospheric water and polymer templating. In literature, many papers investigated theoretically and experimentally in macro droplet growth with the size of millimeter scale of radius. However few papers about nanodroplet condensation are found in the literature especially theoretical work. In order to understand the droplet growth in nanoscale, we perform the numerical simulation work to study nanodroplet growth. We investigate and discuss the role of the droplet shape and monomer diffusion on drop growth and their effect on growth law. The effect of droplet shape is studied by doing parametric studies of contact angle and disjoining pressure magnitude. Besides, the effect of pinning and de-pinning behaviours is also studied. We investigate the axisymmetric homogeneous growth of 10–100 nm single water nanodroplet on a substrate surface. The main mechanism of droplet growth is attributed to the accumulation of laterally diffusing water monomers, formed by the absorption of water vapour in the environment onto the substrate. Under assumptions of quasi-steady thermodynamic equilibrium, the nanodroplet evolves according to the augmented Young–Laplace equation. Using continuum theory, we model the dynamics of nanodroplet growth including the coupled effects of disjoining pressure, contact angle and monomer diffusion with the assumption of constant flux of water monomers at the far field. The simulation result is validated by comparing with the published experimental result. For the case of nanodroplet growth with constant contact angle, our numerical results show that the initial droplet growth is transient by monomer diffusion. When the flux at the far field is small, at the beginning, the droplet grows by the diffusion of initially available water monomers on the substrate and after that by the flux at the far field. In the steady late growth rate of droplet radius and droplet height follow a power law of 1/3, which is unaffected by the substrate disjoining pressure and contact angle. However, it is found that the droplet grows faster in radial direction than high direction when disjoining pressure and contact angle increase. The simulation also shows the information of computational domain effect in the transient growth period. When the computational domain size is larger, the mass coming in the free substrate domain is higher. So the mass coming in the droplet is also higher. The droplet grows and reaches the steady state faster. For the case of pinning and de-pinning droplet growth, the simulation shows that the disjoining pressure does not affect the droplet radius growth law 1/3 in steady state. However the disjoining pressure modifies the growth rate of the droplet height, which then follows a power law of 1/4. We demonstrate how spatial depletion of monomers could lead to a growth arrest of the nanodroplet, as observed experimentally.

Keywords: augmented young-laplace equation, contact angle, disjoining pressure, nanodroplet growth

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Authors: R. Bernaoui, P. Ohly

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Our research shows the use of the mobile phone that consolidates the relationship between veterinarians, and that between breeders and veterinarians. On the other hand it asserts that the tool in question is a means of economic development. The results of our survey reveal a positive return to the veterinary community, which shows that the mobile phone has become an effective means of sustainable development through the transfer of a rapid and punctual information inheritance via social networks; including many Internet applications. Our results show that almost all veterinarians use the mobile phone for interprofessional communication. We therefore believe that the use of the mobile phone by livestock operators has greatly improved the working conditions, just as the use of this tool contributes to a better management of the exploitation as long as it allows limit travel but also save time. These results show that we are witnessing a growth in the use of mobile telephony technologies that impact is as much in terms of sustainable development. Allowing access to information, especially technical information, the mobile phone, and Information and Communication of Technology (ICT) in general, give livestock sector players not only security, by limiting losses, but also an efficiency that allows them a better production and productivity.

Keywords: algeria, breeder-veterinarian, digital heritage, networking

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Authors: M. Alipanah, A. Ranjbar, E. Farnad, F. Alipanah

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Entropy generation of an Al2O3-water nanofluid due to heat transfer and fluid friction irreversibility has been investigated in a square cavity subject to different side wall temperatures using a nanofluid for natural convection flow. This study has been carried out for the pertinent parameters in the following ranges: Rayleigh number between 104 to 107 and volume fraction between 0 to 0.05. Based on the obtained dimensionless velocity and temperature values, the distributions of local entropy generation, average entropy generation and average Bejan number are determined. The results are compared for a pure fluid and a nanofluid. It is totally found that the heat transfer and entropy generation of the nanofluid is more than the pure fluid and minimum entropy generation and Nusselt number occur in the pure fluid at any Rayleigh number. Results depict that the addition of nanoparticles to the pure fluid has more effect on the entropy generation as the Rayleigh number goes up.

Keywords: entropy generation, natural convection, bejan number, nuselt number, nanofluid

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Authors: C. Y. Ng, A. M. Johan, A. E. Kajuputra

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Wave-in-deck phenomenon for fixed jacket platforms at shallow water condition has been reported as a notable risk to the workability and reliability of the platform. Reduction in reservoir pressure, due to the extraction of hydrocarbon for an extended period of time, has caused the occurrence of seabed subsidence. Platform experiencing subsidence promotes reduction of air gaps, which eventually allows the waves to attack the bottom decks. The impact of the wave-in-deck generates additional loads to the structure and therefore increases the values of the moment arms. Higher moment arms trigger instability in terms of overturning, eventually decreases the reserve strength ratio (RSR) values of the structure. The mechanics of wave-in-decks, however, is still not well understood and have not been fully incorporated into the design codes and standards. Hence, it is necessary to revisit the current design codes and standards for platform design optimization. The aim of this study is to evaluate the effects of RSR due to wave-in-deck on four-legged jacket platforms in Malaysia. Base shear values with regards to calibration and modifications of wave characteristics were obtained using SESAM GeniE. Correspondingly, pushover analysis is conducted using USFOS to retrieve the RSR. The effects of the contributing factors i.e. the wave height, wave period and water depth with regards to the RSR and base shear values were analyzed and discussed. This research proposal is important in optimizing the design life of the existing and aging offshore structures. Outcomes of this research are expected to provide a proper evaluation of the wave-in-deck mechanics and in return contribute to the current mitigation strategies in managing the issue.

Keywords: wave-in-deck loads, wave effects, water depth, fixed jacket platforms

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Authors: Moses Kolade Ogun, Ina Korner

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To improve on the sustainable resource management in the wastepaper recycling industry, studies into the valorization of wastes generated by the industry are necessary. The industry produces different residues, among which is the deinking sludge (DS). The DS is generated from the deinking process and constitutes a major fraction of the residues generated by the European pulp and paper industry. The traditional treatment of DS by incineration is capital intensive due to energy requirement for dewatering and the need for complementary fuel source due to DS low calorific value. This could be replaced by a biotechnological approach. This study, therefore, investigated the biogas potential of different DS streams (different dewatering degrees) and the influence of the high calcium carbonate content of DS on its biogas potential. Dewatered DS (solid fraction) sample from filter press and the filtrate (liquid fraction) were collected from a partner wastepaper recycling company in Germany. The solid fraction and the liquid fraction were mixed in proportion to realize DS with different water content (55–91% fresh mass). Spiked samples of DS using deionized water, cellulose and calcium carbonate were prepared to simulate DS with varying calcium carbonate content (0– 40% dry matter). Seeding sludge was collected from an existing biogas plant treating sewage sludge in Germany. Biogas potential was studied using a 1-liter batch test system under the mesophilic condition and ran for 21 days. Specific biogas potential in the range 133- 230 NL/kg-organic dry matter was observed for DS samples investigated. It was found out that an increase in the liquid fraction leads to an increase in the specific biogas potential and a reduction in the absolute biogas potential (NL-biogas/ fresh mass). By comparing the absolute biogas potential curve and the specific biogas potential curve, an optimal dewatering degree corresponding to a water content of about 70% fresh mass was identified. This degree of dewatering is a compromise when factors such as biogas yield, reactor size, energy required for dewatering and operation cost are considered. No inhibitory influence was observed in the biogas potential of DS due to the reported high calcium carbonate content of DS. This study confirms that DS is a potential bioresource for biogas production. Further optimization such as nitrogen supplementation due to DS high C/N ratio can increase biogas yield.

Keywords: biogas, calcium carbonate, deinking sludge, dewatering, water content

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Authors: Christian Ogubuchi Ede, Moses Oghenenyoreme Eyankware

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This study assessed the concentration of heavy metals (HMs) in soil, rock, mine dump pile, and water from Oshiri and Ishiagu areas of Ebonyi State. Investigations on mobile fraction equally evaluated the geochemical condition of different HM using UV spectrophotometer for Mineralized and unmineralized rocks, dumps, and soil, while AAS was used in determining the geochemical nature of the water system. Analysis revealed very high pollution of Cd mostly in Ishiagu (Ihetutu and Amaonye) active mine zones and with subordinates enrichments of Pb, Cu, As, and Zn in Amagu and Umungbala. Oshiri recorded sparingly moderate to high contamination of Cd and Mn but out rightly high anthropogenic input. Observation showed that most of the contamination conditions were unbearable while at the control but decrease with increasing distance from the mine vicinity. The potential heavy metal risk of the environments was evaluated using the risk factors such as enrichment factor, index of Geoacumulation, Contamination Factor, and Effect Range Median. Cadmium and Zn showed moderate to extreme contamination using Geoaccumulation Index (Igeo) while Pb, Cd, and As indicated moderate to strong pollution using the Effect Range Median. Results, when compared with the allowable limits and standards, showed the concentration of the metals in the following order Cd>Zn>Pb>As>Cu>Ni (rocks), Cd>As>Pb>Zn>Cu>Ni (soil) while Cd>Zn>As>Pb> Cu (for mine dump pile. High concentrations of Zn and As were recorded more in mine pond and salt line/drain channels along active mine zones, it heightened its threat during the rainy period as it settles into river course, living behind full-scale contaminations to inhabitants depending on it for domestic uses. Pb and Cu with moderate pollution were recorded in surface/stream water source as its mobility were relatively low. Results from Ishiagu Crush rock sites and Fedeco metallurgical and auto workshop where groundwater contamination was seen infiltrating some of the wells points gave rise to values that were 4 times high than the allowable limits. Some of these metal concentrations according to WHO (2015) if left unmitigated pose adverse effects to the soil and human community.

Keywords: water, geo-accumulation, heavy metals, mine and Nigeria.

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Authors: Prem Mohan, Namrata Jariwala

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In recent years 10000 dyes are approximately used by dying industry which makes dyeing wastewater more complex in nature. It is very difficult to treat dyeing wastewater by conventional methods. Here an attempt has been made to treat dyeing wastewater by the conventional and advanced method for removal of COD. Fenton process is the advanced method and activated carbon treatment is the conventional method. Experiments have been done on synthetic wastewater prepared from three different dyes; acidic, disperse and reactive. Experiments have also been conducted on real effluent obtained from industry. The optimum dose of catalyst and hydrogen peroxide in Fenton process and optimum activated carbon dose for each of these wastewaters were obtained. In Fenton treatment, COD removal was obtained up to 95% whereas 70% removal was obtained with activated carbon treatment.

Keywords: activated carbon, advanced oxidation process, dyeing waste water, fenton oxidation process

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Authors: Ana Paula P. dos Santos, Claudia R. Andrade, Edson L. Zaparoli

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Pressure loss in ductworks is an important factor to be considered in design of engineering systems such as power-plants, refineries, HVAC systems to reduce energy costs. Ductwork can be composed by straight ducts and different types of fittings (elbows, transitions, converging and diverging tees and wyes). Duct fittings are significant sources of pressure loss in fluid distribution systems. Fitting losses can be even more significant than equipment components such as coils, filters, and dampers. At the present work, a conventional 90o round elbow under turbulent incompressible airflow is studied. Mass, momentum, and k-e turbulence model equations are solved employing the finite volume method. The SIMPLE algorithm is used for the pressure-velocity coupling. In order to validate the numerical tool, the elbow pressure loss coefficient is determined using the same conditions to compare with ASHRAE database. Furthermore, the effect of Reynolds number variation on the elbow pressure loss coefficient is investigated. These results can be useful to perform better preliminary design of air distribution ductworks in air conditioning systems.

Keywords: duct fitting, pressure loss, elbow, thermodynamics

Procedia PDF Downloads 391

Authors: Patel Himeshkumar Ashokbhai, Suchit Sharma, Arvind Kumar Garg

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The results obtained from settling test of coal fines are used as an important tool to select the dewatering equipment such as thickeners, centrifuges and filters. Coal being hydrophobic in nature does not easily settle when mixed with water. Coal slurry that takes longer time to release water is highly undesirable because it poses additional challenge during sedimentation, centrifuge and filtration. If filter cake has higher than permitted moisture content then it not only creates handling problems but inflated freight costs and reduction in input and productivity for coke oven charges. It is to be noted that coal fines drastically increase moisture percentage in filter cake hence are to be minimized. To increase settling rate of coal fines in slurry chemical substances called flocculants or coagulants are added that cause coal particles to flocculate or coalesce into larger particles. These larger particles settle at faster rate and have higher settling velocity. Other important factors affecting settling rate are flocculent dosage, slurry or pulp density and particle size. Hence in this paper we tried to study the settling characteristic of clean coal fines by varying one of the four factors namely 1. Flocculant Dosage (acryl-amide) 2. pH of the water 3. Bulk density 4. Particle size of clean coal fines in settling experiment and drew important conclusions. Result of this paper will be much useful not only for coal beneficiation plant design but also for cost reduction of coke production facilities.

Keywords: bulk density, coal fines, flocculants, flocculation, settling velocity, pH

Procedia PDF Downloads 324

Authors: Ilham Ihoume, Rachid Tadili, Nora Arbaoui

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One of the most crucial ways to combat food insecurity is to minimize crop losses; food drying is one of the most organic, efficient, low-cost, and energy-saving food preservation methods. In this regard, we undertake in this study an experimental evaluation and analysis of the thermal performance of different natural convection drying systems: a solar greenhouse dryer, an indirect solar dryer with a single compartment, and a solar dryer with two compartments. These systems have been implemented at the Solar Energy and Environment Laboratory of Mohammed V University (Morocco). The objective of this work is to study the feasibility of converting a solar greenhouse into a solar dryer for use during the summer. On the other hand, to study the thermal performances of this greenhouse dryer by comparing it with other solar dryers. The experimental study showed that the drying of verbena leaves took 6 hours in the indirect dryer 1, 3 hours in the indirect dryer, and 2 and 4 hours in the greenhouse dryer, but the amortization period of the solar greenhouse dryer is lower than the other two solar dryers. The results of this study provide key information on the implementation and performance of these systems for drying food of great global interest.

Keywords: indirect solar dryer, solar energy, agricultural greenhouse, green energy

Procedia PDF Downloads 93

Authors: Kenneth Fon Mbah, Arash Habibi Lashkari, Ali A. Ghorbani

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Phishing e-mails are a security issue that not only annoys online users, but has also resulted in significant financial losses for businesses. Phishing advertisements and pornographic e-mails are difficult to detect as attackers have been becoming increasingly intelligent and professional. Attackers track users and adjust their attacks based on users’ attractions and hot topics that can be extracted from community news and journals. This research focuses on deceptive Phishing attacks and their variants such as attacks through advertisements and pornographic e-mails. We propose a framework called Phishing Alerting System (PHAS) to accurately classify e-mails as Phishing, advertisements or as pornographic. PHAS has the ability to detect and alert users for all types of deceptive e-mails to help users in decision making. A well-known email dataset has been used for these experiments and based on previously extracted features, 93.11% detection accuracy is obtainable by using J48 and KNN machine learning techniques. Our proposed framework achieved approximately the same accuracy as the benchmark while using this dataset.

Keywords: phishing e-mail, phishing detection, anti phishing, alarm system, machine learning

Procedia PDF Downloads 341

Authors: O. Abramova, L. Abukova, A. Goreva, G. Isaeva

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The present work was made for the purpose of evaluating the interstitial water’s role in the mobilization of metal elements of clay deposits and occurrences in sedimentary formation in the hydro-geological basins. The experiments were performed by using a special facility, which allows adjusting the pressure, temperature, and the frequency of the acoustic vibrations. The dates for study were samples of the oil shales (Baltic career, O₂kk) and clay rocks, mainly montmorillonite composition (Borehole SG-12000, the depth of selection 1000–3600 m, the Azov-Kuban trough, N₁). After interstitial water squeezing from the rock samples, decrease in the original content of the rock forming components including trace metals V, Cr, Co, Ni, Cu, Zn, Zr, Mo, Pb, W, Ti, and others was recorded. The experiments made it possible to evaluate the ore elements output and organic matters with the interstitial waters. Calculations have shown that, in standard conditions, from each ton of the oil shales, 5-6 kg of ore elements and 9-10 kg of organic matter can be escaped. A quantity of matter, migrating from clays in the process of solidification, is changed depending on the lithogenesis stage: more recent unrealized deposits lose more ore and organic materials than the clay rocks, selected from depth over 3000 m. Each ton of clays in the depth interval 1000-1500 m is able to generate 3-5 kg of the ore elements and 6-8 kg of the organic matters. The interstitial waters are a freight forwarder over transferring these matters in the reservoir beds. It was concluded that the interstitial waters which escaped from the study samples are solutions with abnormal high concentrations of the metals and organic matters. In the discharge zones of the sediment basins, such fluids can create paragenetic associations of the sedimentary-catagenetic ore and hydrocarbon mineral resources accumulations.

Keywords: hydrocarbons, ore genesis, paragenesis, pore water

Procedia PDF Downloads 258

Authors: Hamed K. Arzani, Hamid K. Arzani, S.N. Kazi, A. Badarudin

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Numerical investigation into convective heat transfer of CuO-Water based nanofluid in a pipe with return bend under laminar flow conditions has been done. The impacts of Reynolds number and the volume concentration of nanoparticles on the flow and the convective heat transfer behaviour are investigated. The results indicate that the increase in Reynolds number leads to the enhancement of average Nusselt number, and the increase in specific heat in the presence of the nanofluid results in improvement in heat transfer. Also, the presence of the secondary flow in the curve plays a key role in increasing the average Nusselt number and it appears higher than the inlet and outlet tubes. However, the pressure drop curve increases significantly in the tubes with the increase in nanoparticles concentration.

Keywords: laminar forced convection, curve pipe, return bend, nanufluid, CFD

Procedia PDF Downloads 297

Authors: Nicoleta O. Tanase, Ciprian S. Mateescu

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This paper is concerned with the numerical study of the flow through porous media. The purpose of this project is to determine the permeability of a medium and its connection to porosity to be able to identify how the permeability of said medium can be altered without changing the porosity. The numerical simulations are performed in 2D flow configurations with the laminar solvers implemented in Workbench - ANSYS Fluent. The direction of flow of the working fluid (water) is axial, from left to right, and in steady-state conditions. The working fluid is water. The 2D geometry is a channel with 300 mm length and 30 mm width, with a different number of circles that are positioned differently, modelling a porous medium. The permeability of a porous medium can be altered without changing the porosity by positioning the circles differently (by missing the same number of circles) in the flow domain, which induces a change in the flow spectrum. The main goal of the paper is to investigate the flow pattern and permeability under controlled perturbations induced by the variation of velocity and porous medium. Numerical solutions provide insight into all flow magnitudes, one of the most important being the WSS distribution on the circles.

Keywords: CFD, porous media, permeability, flow spectrum

Procedia PDF Downloads 55

Authors: Ahmed N. Shmroukh, Gamal Tag Abdel-Jaber, Rashed D. Aldughpassi

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The feasibility of improving the performance of the proposed solar still unit which operated in very hot climate is investigated numerically and verified with experimental data. This solar desalination unit with proposed auxiliary device as seawater preheating system using petrol based textherm oil was used to produce pure fresh water from seawater. The effective evaporation area of basin is about 1 m². The unit was tested in two main operation modes which are normal and with seawater preheating system. The results showed that, there is good agreement between the theoretical data and the experimental data; this means that the numerical model can be accurately dependable for predicting the proposed solar still performance and design parameters. The results also showed that the fresh water productivity of the solar still in the modified preheating case which is higher than normal case, leads to an increase in productivity of 42%.

Keywords: improving productivity, seawater desalination, solar stills, theoretical model

Procedia PDF Downloads 136