Search results for: balance water
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 9749

Search results for: balance water

5339 Hydrogeochemistry Preliminary Study of Groundwater Conservation in Buton Island, Southeast Sulawesi, Indonesia

Authors: M. S. M. Prahastomi, Riki Sunaryo, Lorasa Ximanes

Abstract:

The research takes place in EP Area, in the Northern part of Buton, Southeast Sulawesi Province, Indonesia. It is one example of karst areas that have good water resources potential. The landscape is in the form of valleys and hills which is good enough for recharge zone and discharge zones of groundwater. However, the geological characteristics of karst dissolution and a complex geological structure are quite influential to the groundwater flow system in the region. The Discharge of groundwater to the surface can be caused by a fracture in the rock, Underground River due to dissolution, and the contact between permeable rocks with impermeable rocks. In the concept of hydrogeology, groundwater is one of the components of the hydrological cycle which is closely linked to the availability of water under the surface, precipitation, infiltration, percolation, evapotranspiration, and surface runoff. Conceptually, the condition of recharge and discharge areas can be identified through a research distribution springs in a region. The understanding of the condition and the nature of the potential catchment area of groundwater flow, mainly from the catchment area to the discharge area, is urgently needed. This research aimed to assess the general geological conditions of the study area, which is expected to provide an overview of groundwater flow events that used by the public as well as industry. Behavioral characteristics of groundwater become an integral part in the search for potential groundwater in the study area. As for the research methods used hydrogeology mapping and laboratory works.

Keywords: Buton Island, groundwater conservation, hydrogeochemistry preliminary, karst

Procedia PDF Downloads 315
5338 Optimizing Hydrogen Production from Biomass Pyro-Gasification in a Multi-Staged Fluidized Bed Reactor

Authors: Chetna Mohabeer, Luis Reyes, Lokmane Abdelouahed, Bechara Taouk

Abstract:

In the transition to sustainability and the increasing use of renewable energy, hydrogen will play a key role as an energy carrier. Biomass has the potential to accelerate the realization of hydrogen as a major fuel of the future. Pyro-gasification allows the conversion of organic matter mainly into synthesis gas, or “syngas”, majorly constituted by CO, H2, CH4, and CO2. A second, condensable fraction of biomass pyro-gasification products are “tars”. Under certain conditions, tars may decompose into hydrogen and other light hydrocarbons. These conditions include two types of cracking: homogeneous cracking, where tars decompose under the effect of temperature ( > 1000 °C), and heterogeneous cracking, where catalysts such as olivine, dolomite or biochar are used. The latter process favors cracking of tars at temperatures close to pyro-gasification temperatures (~ 850 °C). Pyro-gasification of biomass coupled with water-gas shift is the most widely practiced process route for biomass to hydrogen today. In this work, an innovating solution will be proposed for this conversion route, in that all the pyro-gasification products, not only methane, will undergo processes that aim to optimize hydrogen production. First, a heterogeneous cracking step was included in the reaction scheme, using biochar (remaining solid from the pyro-gasification reaction) as catalyst and CO2 and H2O as gasifying agents. This process was followed by a catalytic steam methane reforming (SMR) step. For this, a Ni-based catalyst was tested under different reaction conditions to optimize H2 yield. Finally, a water-gas shift (WGS) reaction step with a Fe-based catalyst was added to optimize the H2 yield from CO. The reactor used for cracking was a fluidized bed reactor, and the one used for SMR and WGS was a fixed bed reactor. The gaseous products were analyzed continuously using a µ-GC (Fusion PN 074-594-P1F). With biochar as bed material, it was seen that more H2 was obtained with steam as a gasifying agent (32 mol. % vs. 15 mol. % with CO2 at 900 °C). CO and CH4 productions were also higher with steam than with CO2. Steam as gasifying agent and biochar as bed material were hence deemed efficient parameters for the first step. Among all parameters tested, CH4 conversions approaching 100 % were obtained from SMR reactions using Ni/γ-Al2O3 as a catalyst, 800 °C, and a steam/methane ratio of 5. This gave rise to about 45 mol % H2. Experiments about WGS reaction are currently being conducted. At the end of this phase, the four reactions are performed consecutively, and the results analyzed. The final aim is the development of a global kinetic model of the whole system in a multi-stage fluidized bed reactor that can be transferred on ASPEN PlusTM.

Keywords: multi-staged fluidized bed reactor, pyro-gasification, steam methane reforming, water-gas shift

Procedia PDF Downloads 120
5337 Comparison of Microleakage of Composite Restorations Using Fifth and Seventh Generation of Bonding Agents

Authors: Karina Nabilla, Dedi Sumantri, Nurul T. Rizal, Siti H. Yavitha

Abstract:

Background: Composite resin is the most frequently used material for restoring teeth, but still failure cases are seen which leading to microleakage. Microleakage might be attributed to various factors, one of them is bonding agent. Various generations of bonding agents have been introduced to overcome the microleakage. The aim of this study was to evaluate the microleakage of composite restorations using the fifth and seventh bonding agent. Methods: Class I cavities (3X2X2 mm) were prepared on the occlusal surfaces of 32 human upper premolars. Teeth were classified into two groups according to the type of bonding agent used (n =16). Group I: Fifth Generation of Bonding Agent-Adper Single Bond2. Group II: Seventh Generation of Bonding Agent-Single Bond Universal. All cavities were restored with Filtek Z250 XT composite resin, stored in sterile aquades water at 370C for 24 h. The root apices were sealed with sticky wax, and all the surfaces, except for 2 mm from the margins, were coated with nail varnish. The teeth were immersed in a 1% methylene blue dye solution for 24 h, and then rinsed in running water, blot-dried and sectioned longitudinally through the center of restorations from the buccal to palatal surface. The sections were blindly assessed for microleakage of dye penetration by using a stereomicroscope. Dye penetration along margin was measured in µm then calculated into the percentage and classified into scoring system 1 to 3. Data were collected and statistically analyzed by Chi-Square test. Result: There was no significant difference (p > 0,05) between two groups. Conclusion: Fifth generation of bonding agent revealed less leakage compared to the seventh generation even statistically there was no significant difference.

Keywords: composite restoration, fifth generation of bonding agent, microleakage, seventh generation of bonding agent

Procedia PDF Downloads 256
5336 Photocatalytic Degradation of Nd₂O₃@SiO₂ Core-Shell Nanocomposites Under UV Irradiation Against Methylene Blue and Rhodamine B Dyes

Authors: S. Divya, M. Jose

Abstract:

Over the past years, industrial dyes have emerged as a significant threat to aquatic life, extensively detected in drinking water and groundwater, thus contributing to water pollution due to their improper and excessive use. To address this issue, the utilization of core-shell structures has been prioritized as it demonstrates remarkable efficiency in utilizing light energy for catalytic reactions and exhibiting excellent photocatalytic activity despite the availability of various photocatalysts. This work focuses on the photocatalytic degradation of Nd₂O₃@SiO₂ CSNs under UV light irradiation against MB and RhB dyes. Different characterization techniques, including XRD, FTIR, and TEM analyses, were employed to reveal the material's structure, functional groups, and morphological features. VSM and XPS analyses confirmed the soft, paramagnetic nature and chemical states with respective atomic percentages, respectively. Optical band gaps, determined using the Tauc plot model, indicated 4.24 eV and 4.13 eV for Nd₂O₃ NPs and Nd₂O₃@SiO₂ CSNs, respectively. The reduced bandgap energy of Nd₂O₃@SiO₂ CSNs enhances light absorption in the UV range, potentially leading to improved photocatalytic efficiency. The Nd₂O₃@SiO₂ CSNs exhibited greater degradation efficiency, reaching 95% and 96% against MB and RhB dyes, while Nd₂O₃ NPs showed 90% and 92%, respectively. The enhanced efficiency of Nd₂O₃@SiO₂ CSNs can be attributed to the larger specific surface area provided by the SiO₂ shell, as confirmed by surface area analysis using the BET surface area analyzer through N₂ adsorption-desorption.

Keywords: core shell nanocomposites, rare earth oxides, photocatalysis, advanced oxidation process

Procedia PDF Downloads 42
5335 The Effects of Architectural Anatomy on Improving the Quality of Place Identity: Case Study of Shiraz Opera Hall

Authors: Hamid Reza Zeraatpisheh, Shamsoddin Hashemi, Farshad Negintaji

Abstract:

This study has examined the effects of the architectural anatomy of opera hall on improving the quality of place identity. By measuring the effects of place identity on the inner aspects of human which are influenced by the physical and social environments it has investigated the results of a balance between internal and external environment. To assess the anatomical effects of urban landscape, two components of subjective landscape including perception and diversity and the component of objective landscape including form and order have been measured. The current survey is descriptive and the statistical population has been Shiraz which is a city in Iran. To analyze the data the SPSS software has been used. The results have been investigated in two levels of descriptive and inferential statistics. In the inferential statistics, Pearson correlation coefficient has been used to evaluate the research hypotheses. The results of this study indicate that between the dimensions of landscape, the component of the subjective landscape has the highest impact on the place identity and in the second place, an objective landscape has the impact on the place identity. Anatomical effects have an important role on improving the quality of place identity of Shiraz citizens and in order to enhance the place identity in the urban landscape it is also required that they will be inspired and operated.

Keywords: architectural anatomy, identity, place identity, urban landscape, perception

Procedia PDF Downloads 519
5334 Green Concrete for Sustainable Indonesia Structures: Lightweight Concrete Using Oil Palm Shell as Coarse Aggregate with Superplasticizer and Fly Ash

Authors: Feny Acelia Silaban

Abstract:

The development of Indonesia’s infrastructure in many islands is significantly increased through the years. Based on this condition, concrete materials which are extracted from natural resources are over exploited and slowly becoming rare, thus the demand for alternative materials becomes so urgently crucial. Oil Palm is one of the biggest commodities in Indonesia with the total amount of 31 million tons in the last 2014. The production of palm oil also generates lots of solid wastes in the form of Oil Palm Shell (OPS). Constructing more environmentally sustainable structures can be achieved by producing lightweight concrete using the Oil Palm Shell (OPS). This paper investigated the effects of OPS and combination of Superplasticizer and fly ash proportion of lightweight concrete mix design to the compressive strength, flexure strength, modulus of elasticity, shrinkage behavior, and water absorption. The Oil Palm Shell had undergone special treatment by washing it with hot water and soap to reduce the oil content. This experiment used four different proportions of Superplasticizer with fly ash and 30 % OPS proportion from the weight of total compositions mixture by the result of trial mix. The experiment result showed that using OPS coarse aggregates and Superplasticizer with fly ash, the average of 28-day compressive strength reached 30-35 MPa. The highest 28-day compressive strength comes from 1.2 % Superplasticizer with 5 % fly ash proportion samples with the strength by 33 MPa. The sample with proportion of 1 % Superplasticizer and 7.5 % fly ash has the highest shrinkage value compared to other proportions. The characteristic of OPS as coarse aggregates is in a standard range of natural coarse aggregates. In general, this lightweight concrete using OPS coarse aggregate and Superplasticizer has high potential to be green-structural lightweight concrete alternative in Indonesia.

Keywords: lightweight concrete, oil palm shell, waste materials, superplasticizer

Procedia PDF Downloads 235
5333 Numerical Simulation of the Flowing of Ice Slurry in Seawater Pipe of Polar Ships

Authors: Li Xu, Huanbao Jiang, Zhenfei Huang, Lailai Zhang

Abstract:

In recent years, as global warming, the sea-ice extent of North Arctic undergoes an evident decrease and Arctic channel has attracted the attention of shipping industry. Ice crystals existing in the seawater of Arctic channel which enter the seawater system of the ship with the seawater were found blocking the seawater pipe. The appearance of cooler paralysis, auxiliary machine error and even ship power system paralysis may be happened if seriously. In order to reduce the effect of high temperature in auxiliary equipment, seawater system will use external ice-water to participate in the cooling cycle and achieve the state of its flow. The distribution of ice crystals in seawater pipe can be achieved. As the ice slurry system is solid liquid two-phase system, the flow process of ice-water mixture is very complex and diverse. In this paper, the flow process in seawater pipe of ice slurry is simulated with fluid dynamics simulation software based on k-ε turbulence model. As the ice packing fraction is a key factor effecting the distribution of ice crystals, the influence of ice packing fraction on the flowing process of ice slurry is analyzed. In this work, the simulation results show that as the ice packing fraction is relatively large, the distribution of ice crystals is uneven in the flowing process of the seawater which has such disadvantage as increase the possibility of blocking, that will provide scientific forecasting methods for the forming of ice block in seawater piping system. It has important significance for the reliability of the operating of polar ships in the future.

Keywords: ice slurry, seawater pipe, ice packing fraction, numerical simulation

Procedia PDF Downloads 350
5332 Growth and Yield Assessment of Two Types of Sorghum-Sudangrass Hybrids as Affected by Deficit Irrigation

Authors: A. Abbas Khalaf, L. Issazadeh, Z. Arif Abdullah, J. Hassanpour

Abstract:

In order to evaluate the growth and yield properties of two Sorghum-Sudangrass hybrids under different irrigation levels, an investigation was done in the experiment site of Collage of Agriculture, University of Duhok, Kurdistan region of Iraq (36°5´38 N, 42°52´02 E) in the years 2015-16. The experiment was conducted under Randomized Complete Block Design (RCBD) with three replications, which main factor was irrigation treatments (I100, I75 and I50) according to evaporation pan class A and type of Sorghum-Sudangrass hybrids (KH12SU9001, G1) and (KH12SU9002, G2) were factors of subplots. The parameters studied were: plant height (cm), number of green leaves per plant; leaf area (m2/m2), stem thickness (mm), percent of protein, fresh and dry biomass (ton.ha-1) and also crop water productivity. The results of variance analysis showed that KH12SU9001 variety had more amount of leaf area, percent of protein, fresh and dry biomass yield in comparison to KH12SU9002 variety. By comparing effects of irrigation levels on vegetative growth and yield properties, results showed that amount of plant height, fresh and dry biomass weight was decreased by decreasing irrigation level from full irrigation regime to 5 o% of irrigation level. Also, results of crop water productivity (CWP) indicated that improvement in quantity of irrigation would impact fresh and dry biomass yield significantly. Full irrigation regime was recorded the highest level of CWP (1.28-1.29 kg.m-3).

Keywords: deficit irrigation, growth, sorghum-sudangrass hybrid, yield

Procedia PDF Downloads 118
5331 Determination of Proximate, Mineral, and Heavy Metal Contents of Fish from the Lower River Niger at Agenebode, Edo State, Nigeria

Authors: Agbugui M. O., Inobeme A.

Abstract:

Fish constitutes a vital component of human diets due to their rich nutritional compositions. They serve as a remarkable source of proteins, vitamins, and fatty acids, which are indispensable for the effective growth and development of humans. The need to explore the nutritional compositions of various species of fish in different water bodies becomes paramount. Presently, consumer concern is not just on food's nutritional value but also on the safety level. Environmental contamination by heavy metals has become an issue of pressing concern in recent times. Heavy metals, due to their ubiquitous nature, are found in various water bodies as they are released from various anthropogenic activities. This work investigated the proximate compositions, mineral contents, and heavy metals concentrations of four different species of fish (P. annectens, L. niloticus, G. niloticus, and H. niloticus) collected from the lower Niger at Agenebode using standard procedures. The highest protein contents were in Gymnarchus niloticus (37.32%), while the least was in Heterotis niloticus (20.41%). Protopterus annectens had the highest carbohydrate content (34.55%), while Heterotis niloticus had the least (12.24%). The highest lipid content (14.41%) was in Gymnarchus niloticus. The highest concentration of potassium was 21.00 ppm. The concentrations of heavy metals in ppm ranged from 0.01 – 1.4 (Cd), 0.07 – 2.89 (Pb), 0.02 – 16.4 (Hg), 0.88 – 5.1 (Cu) and 1.2 – 8.23 (Zn). The concentrations of Hg, Cd and Pb in some of the samples investigated were higher than the permissible limits based on international standards. There is a pressing need for further study focusing on various species of animals and plants in the area due to the alarming contents of these metals; remedial measures could also be ensured for safety.

Keywords: trace metals, nutritional value, human health, crude protein, lipid content

Procedia PDF Downloads 74
5330 Effect of Fermentation Time on Some Functional Properties of Moringa (Moringa oleifera) Seed Flour

Authors: Ocheme B. Ocheme, Omobolanle O. Oloyede, S. James, Eleojo V. Akpa

Abstract:

The effect of fermentation time on some functional properties of Moringa (Moringa oleifera) seed flour was examined. Fermentation, an effective processing method used to improve nutritional quality of plant foods, tends to affect the characteristics of food components and their behaviour in food systems just like other processing methods. Hence the need for this study. Moringa seeds were fermented naturally by soaking in potable water and allowing it to stand for 12, 24, 48 and 72 hours. At the end of fermentation, the seeds were oven dried at 600C for 12 hours and then milled into flour. Flour obtained from unfermented seeds served as control: hence a total of five flour samples. The functional properties were analyzed using standard methods. Fermentation significantly (p<0.05) increased the water holding capacity of Moringa seed flour from 0.86g/g - 2.31g/g. The highest value was observed after 48 hours of fermentation The same trend was observed for oil absorption capacity with values between 0.87 and 1.91g/g. Flour from unfermented Moringa seeds had a bulk density of 0.60g/cm3 which was significantly (p<0.05) higher than the bulk densities of flours from seeds fermented for 12, 24 and 48. Fermentation significantly (p<0.05) decreased the dispersibility of Moringa seed flours from 36% to 21, 24, 29 and 20% after 12, 24, 48 and 72 hours of fermentation respectively. The flours’ emulsifying capacities increased significantly (p<0.05) with increasing fermentation time with values between 50 – 68%. The flour obtained from seeds fermented for 12 hours had a significantly (p<0.05) higher foaming capacity of 16% while the flour obtained from seeds fermented for 0, 24 and 72 hours had the least foaming capacities of 9%. Flours from seeds fermented for 12 and 48 hours had better functional properties than flours from seeds fermented for 24 and 72 hours.

Keywords: fermentation, flour, functional properties, Moringa

Procedia PDF Downloads 655
5329 Oncology and Phytomedicine in the Advancement of Cancer Therapy for Better Patient Care

Authors: Hailemeleak Regassa

Abstract:

Traditional medicines use medicinal plants as a source of ingredients, and many modern medications are indirectly derived from plants. Consumers in affluent nations are growing disenchanted with contemporary healthcare and looking for alternatives. Oxidative stress is the primary cause of multiple diseases, and exogenous antioxidant supplementation or strengthening the body's endogenous antioxidant defenses are potential ways to counteract the negative effects of oxidative damage. Plants can biosynthesize non-enzymatic antioxidants that can reduce ROS-induced oxidative damage. Aging often aids the propagation and development of carcinogenesis, and older animals and older people exhibit increased vulnerability to tumor promoters. Cancer is a major public health issue, with several anti-cancer medications in clinical use. Potential drugs such as flavopiridol, roscovitine, combretastatin A-4, betulinic acid, and silvestrol are in the clinical or preclinical stages of research. Methodology: Microbial Growth media, Dimethyl sulfoxide (DMSO), methanol, ethyl acetate, and n-hexane were obtained from Himedia Labs, Mumbai, India. plant were collected from the Herbal Garden of Shoolini University campus, Solan, India (Latitude - 30.8644° N and longitude - 77.1184° E). The identity was confirmed by Dr. Y.S. Parmar University of Horticulture and Forestry, Nauni, Solan (H.P.), India, and documented in Voucher specimens - UHF- Herbarium no. 13784; vide book no. 3818 Receipt No. 086. The plant materials were washed with tap water, and 0.1% mercury chloride for 2 minutes, rinsed with distilled water, air dried, and kept in a hot air oven at 40ºc on blotting paper until all the water evaporated and became well dried for grinding. After drying, the plant materials were grounded using a mixer grinder into fine powder transferred into airtight containers with proper labeling, and stored at 4ºc for future use (Horablaga et al., 2023). The extraction process was done according to Altemimi et al., 2017. The 5g powder was mixed with 15 ml of the respective solvents (n-hexane, ethyl acetate, and methanol), and kept for 4-5 days on the platform shaker. The solvents used are based on their increasing polarity index. Then the extract was centrifuged at 10,000rpm for 5 minutes and filtered using No.1 Whatman filter paper.

Keywords: cancer, phytomedicine, medicinal plants, oncology

Procedia PDF Downloads 47
5328 The Spatial Analysis of Wetland Ecosystem Services Valuation on Flood Protection in Tone River Basin

Authors: Tingting Song

Abstract:

Wetlands are significant ecosystems that provide a variety of ecosystem services for humans, such as, providing water and food resources, purifying water quality, regulating climate, protecting biodiversity, and providing cultural, recreational, and educational resources. Wetlands also provide benefits, such as reduction of flood, storm damage, and soil erosion. The flood protection ecosystem services of wetlands are often ignored. Due to climate change, the flood caused by extreme weather in recent years occur frequently. Flood has a great impact on people's production and life with more and more economic losses. This study area is in the Tone river basin in the Kanto area, Japan. It is the second-longest river with the largest basin area in Japan, and it is still suffering heavy economic losses from floods. Tone river basin is one of the rivers that provide water for Tokyo and has an important impact on economic activities in Japan. The purpose of this study was to investigate land-use changes of wetlands in the Tone River Basin, and whether there are spatial differences in the value of wetland functions in mitigating economic losses caused by floods. This study analyzed the land-use change of wetland in Tone River, based on the Landsat data from 1980 to 2020. Combined with flood economic loss, wetland area, GDP, population density, and other social-economic data, a geospatial weighted regression model was constructed to analyze the spatial difference of wetland ecosystem service value. Now, flood protection mainly relies on such a hard project of dam and reservoir, but excessive dependence on hard engineering will cause the government huge financial pressure and have a big impact on the ecological environment. However, natural wetlands can also play a role in flood management, at the same time they can also provide diverse ecosystem services. Moreover, the construction and maintenance cost of natural wetlands is lower than that of hard engineering. Although it is not easy to say which is more effective in terms of flood management. When the marginal value of a wetland is greater than the economic loss caused by flood per unit area, it may be considered to rely on the flood storage capacity of the wetland to reduce the impact of the flood. It can promote the sustainable development of wetlands ecosystem. On the other hand, spatial analysis of wetland values can provide a more effective strategy for flood management in the Tone river basin.

Keywords: wetland, geospatial weighted regression, ecosystem services, environment valuation

Procedia PDF Downloads 84
5327 An Investigation of the Barriers to E-Business Implementation in Small and Medium-Sized Enterprises

Authors: Jeffrey Chang, Barun Dasgupta

Abstract:

E-business technologies, whereby business transactions are conducted remotely using the Internet, present unique opportunities and challenges for business. E-business technologies are applicable to a wide range of organizations and small and medium-sized enterprises (SMEs) are no exception. There is an established body of literature about e-business, looking at definitions, concepts, benefits and challenges. In general, however, the research focus has been on larger organizations, not SMEs. In an attempt to redress the balance of research, this paper looks at e-business technologies specifically from a small business perspective. It seeks to identify the possible barriers that SMEs might face when considering adoption of the e-business concept and practice as part of their business process change initiatives and implementation. To facilitate analysis of these barriers a conceptual framework has been developed which outlines the key conceptual and practical challenges of e-business implementation in SMEs. This is developed following a literature survey comprised of three categories: characteristics of SMEs, issues of IS/IT use in SMEs and general e-business adoption and implementation issues. The framework is then empirically assessed against 7 SMEs who have yet to implement e-business or whose e-business efforts have been unsatisfactory. Conclusions from the case studies can be used to verify the framework, and set parameters for further larger scale empirical investigation.

Keywords: business process change, disruptive technologies, electronic business (e-Business), electronic commerce (e-Commerce), ICT adoption, small and medium sized enterprises (SMEs)

Procedia PDF Downloads 520
5326 Vegetables and Fruits Solar Tunnel Dryer for Small-Scale Farmers in Kassala

Authors: Sami Mohamed Sharif

Abstract:

The current study focuses on the design and construction of a solar tunnel dryer intended for small-scale farmers in Kassala, Sudan. To determine the appropriate dimensions of the dryer, the heat and mass balance equations are used, taking into account factors such as the target agricultural product, climate conditions, solar irradiance, and desired drying time. In Kassala, a dryer with a width of 88 cm, length of 600 cm, and height of 25 cm has been built, capable of drying up to 40 kg of vegetables or fruits. The dryer is divided into two chambers of different lengths. The air passing through is heated to the desired drying temperature in a separate heating chamber that is 200 cm long. From there, the heated air enters the drying chamber, which is 400 cm long. In this section, the agricultural product is placed on a slightly elevated net. The tunnel dryer was constructed using materials from the local market. The paper also examines the solar irradiance in Kassala, finding an average of 23.6 MJ/m2/day, with a maximum of 26.6 MJ/m2/day in April and a minimum of 20.2 MJ/m2/day in December. A DC fan powered by a 160Wp solar panel is utilized to circulate air within the tunnel. By connecting the fan and three 12V, 60W bulbs in series, four different speeds can be achieved using a speed controller. Temperature and relative humidity measurements were taken hourly over three days, from 10:00 a.m. to 3:00 p.m. The results demonstrate the promising technology and sizing techniques of solar tunnel dryers, which can significantly increase the temperature within the tunnel by more than 90%.

Keywords: tunnel dryer, solar drying, moisture content, fruits drying modeling, open sun drying

Procedia PDF Downloads 41
5325 Thermal Performance of Fully Immersed Server into Saturated Fluid Porous Medium

Authors: Yaser Al-Anii, Abdulmajeed Almaneea, Jonathan L. Summers, Harvey M. Thompson, Nikil Kapur

Abstract:

The natural convection cooling system of a fully immersed server in dielectric liquid is studied numerically. In present case study, the dielectric liquid represents working fluid and it is in contact with server inside capsule. The capsule includes electronic component and fluid, which can be modelled as saturated porous media. This medium follow Darcy flow regime and assumed to be in balance between its components. The study focus is on role of spatial parameters on thermal behavior of convective heat transfer. Based on server known unit, which is 1U, two parameters Ly and S are changed to test their effect. Meanwhile, wide range of modified Rayleigh number, which is 0.5 to 300, are covered to better understand thermal performance. Navier-Stokes equations are used to model physical domain. Furthermore, successive over relaxation and time marching techniques are used to solve momentum and energy equation. From obtained correlation, the in-between distance S is more effective on Nusselt number than distance to edge Ly by approximately 14%. In addition, as S increase, the average Nusselt number of the upper unit is increased sharply, whereas the lower one keeps on same level.

Keywords: convective cooling of server, darcy flow, liquid-immersed server, porous media

Procedia PDF Downloads 382
5324 Development of the Manufacturing Process of Low Salt-Fermented Soy Sauce

Authors: Young-Ran Song, Byeong-Uk Lim, Sang-Ho Baik

Abstract:

This study was initiated in order to develop a method for soy sauce fermentation at low salt concentrations without decreasing quality. Soy sauce was fermented with the fermentation starter (meju) and different salt contents (8-14%, w/v) by inoculating two strains or not, in which Torulaspora delbrueckii and Pichia guilliermondii strains having different abilities to induce sterilizing effects or enhance flavor production were used. As the results, there were microbial and biochemical differences among prepared soy sauce. First, Staphylococcus and Enterococcus spp. in addition to Bacillus genus that is the most important bacteria in Korean fermented soy product were detected by salt reduction. However, application of yeast starters can inhibit the undesirable bacterial growth. Moreover, PCA bi-plots of major principal components on various biochemical parameters (final pH, total acidity, soluble sugar, reducing sugar, ethanol and 32 volatile flavor compounds) were drawn to demonstrate the physicochemical differences and similarities among the samples. It was confirmed that the soy sauce samples produced with different salt concentrations were clearly different since salt reduction induced low contents of acids, alcohols and esters with higher acidity. However despite low salt concentration, combining two different yeasts appeared to have similar characteristics to the high salt-fermented soy sauce with elevated concentrations of ethanol, some alcohols, and most ketones, hence resulted in a balance of more complex and richer flavors with a flavor profile pattern identical to that of high-salt.

Keywords: Soy sauce, low salt, fermentation, yeast.

Procedia PDF Downloads 369
5323 Factors for Entry Timing Choices Using Principal Axis Factorial Analysis and Logistic Regression Model

Authors: C. M. Mat Isa, H. Mohd Saman, S. R. Mohd Nasir, A. Jaapar

Abstract:

International market expansion involves a strategic process of market entry decision through which a firm expands its operation from domestic to the international domain. Hence, entry timing choices require the needs to balance the early entry risks and the problems in losing opportunities as a result of late entry into a new market. Questionnaire surveys administered to 115 Malaysian construction firms operating in 51 countries worldwide have resulted in 39.1 percent response rate. Factor analysis was used to determine the most significant factors affecting entry timing choices of the firms to penetrate the international market. A logistic regression analysis used to examine the firms’ entry timing choices, indicates that the model has correctly classified 89.5 per cent of cases as late movers. The findings reveal that the most significant factor influencing the construction firms’ choices as late movers was the firm factor related to the firm’s international experience, resources, competencies and financing capacity. The study also offers valuable information to construction firms with intention to internationalize their businesses.

Keywords: factors, early movers, entry timing choices, late movers, logistic regression model, principal axis factorial analysis, Malaysian construction firms

Procedia PDF Downloads 362
5322 Spatio-Temporal Analysis of Land Use and Land Cover Change in the Cocoa Belt of Ondo State, southwestern Nigeria

Authors: Emmanuel Dada, Adebayo-Victoria Tobi Dada

Abstract:

The study evaluates land use and land cover changes in the cocoa belt of Ondo state to quantify its effect on the expanse of land occupied by cocoa plantation as the most suitable region for cocoa raisin in Nigeria. Time series of satellite imagery from Landsat-7 ETM+ and Landsat-8 TIRS covering years 2000 and 2015 respectively were used. The study area was classified into six land use themes of cocoa plantation, settlement, water body, light forest and grassland, forest, and bar surface and rock outcrop. The analyses revealed that out of total land area of 997714 hectares of land of the study area, cocoa plantation land use increased by 10.3% in 2015 from 312260.6 ha in 2000. Forest land use also increased by 6.3% in 2015 from 152144.1 ha in the year 2000, water body reduced from 2954.5 ha in the year 2000 by 0.1% in 2015, settlement land use increased by 3% in 2015 from 15194.6 ha in 2000, light forest and grassland area reduced by 10.4% between 2000 and 2015 and 9.1% reduction in bar surface and rock outcrop land use between the year 2000 and 2015 respectively. The reasons for different ranges in the changes observed in the land use and land cover in the study area could be due to increase in the incentive to cocoa farmers from both government and non-governmental organizations, developed new cocoa breed that thrive better in the light forest, rapid increased in the population of cocoa farmers’ settlements, and government promulgation of forest reserve law.

Keywords: satellite imagery, land use and land cover change, area of land

Procedia PDF Downloads 212
5321 Self-Organized TiO₂–Nb₂O₅–ZrO₂ Nanotubes on β-Ti Alloy by Anodization

Authors: Muhammad Qadir, Yuncang Li, Cuie Wen

Abstract:

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

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

Procedia PDF Downloads 138
5320 System for Monitoring Marine Turtles Using Unstructured Supplementary Service Data

Authors: Luís Pina

Abstract:

The conservation of marine biodiversity keeps ecosystems in balance and ensures the sustainable use of resources. In this context, technological resources have been used for monitoring marine species to allow biologists to obtain data in real-time. There are different mobile applications developed for data collection for monitoring purposes, but these systems are designed to be utilized only on third-generation (3G) phones or smartphones with Internet access and in rural parts of the developing countries, Internet services and smartphones are scarce. Thus, the objective of this work is to develop a system to monitor marine turtles using Unstructured Supplementary Service Data (USSD), which users can access through basic mobile phones. The system aims to improve the data collection mechanism and enhance the effectiveness of current systems in monitoring sea turtles using any type of mobile device without Internet access. The system will be able to report information related to the biological activities of marine turtles. Also, it will be used as a platform to assist marine conservation entities to receive reports of illegal sales of sea turtles. The system can also be utilized as an educational tool for communities, providing knowledge and allowing the inclusion of communities in the process of monitoring marine turtles. Therefore, this work may contribute with information to decision-making and implementation of contingency plans for marine conservation programs.

Keywords: GSM, marine biology, marine turtles, unstructured supplementary service data (USSD)

Procedia PDF Downloads 190
5319 Phytoextraction of Copper and Zinc by Willow Varieties in a Pot Experiment

Authors: Muhammad Mohsin, Mir Md Abdus Salam, Pertti Pulkkinen, Ari Pappinen

Abstract:

Soil and water contamination by heavy metals is a major challenging issue for the environment. Phytoextraction is an emerging, environmentally friendly and cost-efficient technology in which plants are used to eliminate pollutants from the soil and water. We aimed to assess the copper (Cu) and zinc (Zn) removal efficiency by two willow varieties such as Klara (S. viminalis x S. schwerinii x S. dasyclados) and Karin ((S.schwerinii x S. viminalis) x (S. viminalis x S.burjatica)) under different soil treatments (control/unpolluted, polluted, lime with polluted, wood ash with polluted). In 180 days of pot experiment, these willow varieties were grown in a highly polluted soil collected from Pyhasalmi mining area in Finland. The lime and wood ash were added to the polluted soil to improve the soil pH and observe their effects on metals accumulation in plant biomass. The Inductively Coupled Plasma Optical Emission Spectrometer (ELAN 6000 ICP-EOS, Perkin-Elmer Corporation) was used in this study to assess the heavy metals concentration in the plant biomass. The result shows that both varieties of willow have the capability to accumulate the considerable amount of Cu and Zn varying from 36.95 to 314.80 mg kg⁻¹ and 260.66 to 858.70 mg kg⁻¹, respectively. The application of lime and wood ash substantially affected the stimulation of the plant height, dry biomass and deposition of Cu and Zn into total plant biomass. Besides, the lime application appeared to upsurge Cu and Zn concentrations in the shoots and leaves in both willow varieties when planted in polluted soil. However, wood ash application was found more efficient to mobilize the metals in the roots of both varieties. The study recommends willow plantations to rehabilitate the Cu and Zn polluted soils.

Keywords: heavy metals, lime, phytoextraction, wood ash, willow

Procedia PDF Downloads 212
5318 Biological Soil Crust Effects on Dust Control Around the Urmia Lake

Authors: Abbas Ahmadi, Nasser Aliasgharzad, Ali Asghar Jafarzadeh

Abstract:

Nowadays, drying of the Urmia Lake as a largest saline lake in the world and emerging its saline bed from water has caused the risk of salty dune storms, which threats the health of human society and also plants and animal communities living in the region. Biological soil crusts (BSCs) as a dust stabilizer attracted the attention of Soil conservation experts in recent years. Although the presence of water by the impenetrable lake bed and endorheic basin can be an advantage to create BSCs, but the extraordinary of the lake bed salinity is a factor for prevention of its establishment in the region. Therefore, the present research work has been carried out to investigate the effects of inoculating the Cyanobacteria, algae and their combination to create BSCs for dust control. In this study, an algae attributed to Chlamydomonas sp and a cyanobacteria attributed to Anabaena sp isolated from the soils of Urmia Lake margin were used to create BSC in four soil samples which collected from 0-10 cm of the current margin (A), the previous bed (B), affected lands by lake (C) and Quomtappe sand dune (D). The main characteristics of the A, B and C soil samples are their highly salinity (their ECe are 108, 140 and 118 dS/m, respectively) and sodicity. Also, texture class of the soil A was loamy sand, and other two soils had clay textures. Soil D was Non-saline, but it was sodic with a sandy texture class. This study was conducted separately in each soil in a completely randomized design under four inoculation treatments of non-inoculated (T0), Algae (T1), cyanobacteria (T2) and equal mixture of algae and cyanobacteria (T3) with three replications. In the experiment, the soil was placed into wind tunnel trays, and a suspension containing microorganisms mixed with the trays surface soil. During the experiment, water was sprayed to the trays at the morning and evening of every day. After passing the incubation period (30 days), some characteristics of samples such as pH, EC, cold water extractable carbohydrate (CWEC), hot water extractable carbohydrate (HWEC), sulfuric acid extractable carbohydrate (SAEC), organic matter, crust thickness, penetration resistance, wind erosion threshold velocity and soil loss in the wind tunnel were measured, and Correlation between the measured characteristics was obtained through the SPSS software. Analysis of variance and so comparison between the means of treatments were analyzed with MSTATC software. In this research, Chlorophyll, an amount, was used as an indicator of the microorganism's population in the samples. Based on obtained results, the amount of Chlorophyll a in the T2 treatment of soil A and all treatments of soil D was significantly increased in comparison to the control and crust thickness showed increase in all treatments by microorganism’s inoculation. But effect of the treatments was significant in soils A and D. At all treatment’s inoculation of microorganisms in soil A caused to increase %46, %34 and %55 of the wind erosion threshold velocity in T1, T2 and T3 treatments in comparison to the control, respectively, and in soil D all treatments caused wind erosion threshold velocity became two times more than control. However, soil loss in the wind tunnel experiments was significant in T2 and T3 treatments of these soils and T1 treatment had no effect in reducing soil loss. Correlation between Chlorophyll a and salinity shows the important role of salinity in microbial growth prevention and formation of BSCs in the studied samples. In general, according to the obtained results, it can be concluded that salinity reduces the growth of microorganisms in saline soils of the region, and in soils with fine textures, salinity role in prevention of the microbial growth is clear. Also, using the mix of algae and cyanobacteria together caused the synergistic growth of them and consequently, better protection of the soil against wind erosion was provided.

Keywords: wind erosion, algae, cyanobacteria, carbohydrate

Procedia PDF Downloads 42
5317 Services Sector: A Growth Catalyst for Indian Economy since Economic Reform

Authors: Richa Rai

Abstract:

The purpose of this study is to analyze the role of the services sector in economic development of Indian economy, especially in the post reform period. Due to adoption of liberalization policy in developing economy like India, international transaction in services has been increased at a rapid pace which compensated to the current account of Balance of Payment which was in a pitiable condition. But this increased share of services in GDP is not commensurate with share in employment, which is a matter of great concern for Indian economy. Although the increased share of service in GDP indicates the advanced stage of growth of the economy, but this theory is not applicable in context of Indian economy completely. In the preliminary stage, this study finds a positive correlation between growth of services and export earnings and gross domestic product and this growth of services is not equal in terms of all aspects on Indian economy, and also all components of services has not been increased at an equal rate. This paper seeks to examine the impact of liberalization in post reform era on the growth of services in India. The analysis is done for the period of 1991 to 2013. Data has been collected from the secondary sources, especially from the website of Reserve Bank of India, World Trade Organization, and United Nation Conference on Trade and Development. The data has been analyzed with the help of appropriate statistical tools (Causality Relation and Group t-test).

Keywords: export earnings, GDP, gross domestic product, liberalization, services

Procedia PDF Downloads 122
5316 A Practice Model for Quality Improvement in Concrete Block Mini Plants Based on Merapi Volcanic Sand

Authors: Setya Winarno

Abstract:

Due to abundant Merapi volcanic sand in Yogyakarta City, many local people have utilized it for mass production of concrete blocks through mini plants although their products are low in quality. This paper presents a practice model for quality improvement in this situation in order to supply the current customer interest in good quality of construction material. The method of this research was to investigate a techno economic evaluation through laboratory test and interview. Samples of twenty existing concrete blocks made by local people had only 19.4 kg/cm2 in average compression strength which was lower than the minimum Indonesian standard of 25 kg/cm2. Through repeat testing in laboratory for fulfilling the standard, the concrete mix design of water cement ratio should not be more than 0.64 by weight basis. The proportion of sand as aggregate content should not be more than 9 parts to 1 part by volume of Portland cement. Considering the production cost, the basic price was Rp 1,820 for each concrete block, comparing to Rp 2,000 as a normal competitive market price. At last, the model describes (a) maximum water cement ratio is 0.64, (b) maximum proportion of sand and cement is 1:9, (c) the basic price is about Rp. 1,820.00 and (d) strategies to win the competitive market on mass production of concrete blocks are focus in quality, building relationships with consumer, rapid respond to customer need, continuous innovation by product diversification, promotion in social media, and strict financial management.

Keywords: concrete block, good quality, improvement model, diversification

Procedia PDF Downloads 503
5315 Flow Field Optimization for Proton Exchange Membrane Fuel Cells

Authors: Xiao-Dong Wang, Wei-Mon Yan

Abstract:

The flow field design in the bipolar plates affects the performance of the proton exchange membrane (PEM) fuel cell. This work adopted a combined optimization procedure, including a simplified conjugate-gradient method and a completely three-dimensional, two-phase, non-isothermal fuel cell model, to look for optimal flow field design for a single serpentine fuel cell of size 9×9 mm with five channels. For the direct solution, the two-fluid method was adopted to incorporate the heat effects using energy equations for entire cells. The model assumes that the system is steady; the inlet reactants are ideal gases; the flow is laminar; and the porous layers such as the diffusion layer, catalyst layer and PEM are isotropic. The model includes continuity, momentum and species equations for gaseous species, liquid water transport equations in the channels, gas diffusion layers, and catalyst layers, water transport equation in the membrane, electron and proton transport equations. The Bulter-Volumer equation was used to describe electrochemical reactions in the catalyst layers. The cell output power density Pcell is maximized subjected to an optimal set of channel heights, H1-H5, and channel widths, W2-W5. The basic case with all channel heights and widths set at 1 mm yields a Pcell=7260 Wm-2. The optimal design displays a tapered characteristic for channels 1, 3 and 4, and a diverging characteristic in height for channels 2 and 5, producing a Pcell=8894 Wm-2, about 22.5% increment. The reduced channel heights of channels 2-4 significantly increase the sub-rib convection and widths for effectively removing liquid water and oxygen transport in gas diffusion layer. The final diverging channel minimizes the leakage of fuel to outlet via sub-rib convection from channel 4 to channel 5. Near-optimal design without huge loss in cell performance but is easily manufactured is tested. The use of a straight, final channel of 0.1 mm height has led to 7.37% power loss, while the design with all channel widths to be 1 mm with optimal channel heights obtained above yields only 1.68% loss of current density. The presence of a final, diverging channel has greater impact on cell performance than the fine adjustment of channel width at the simulation conditions set herein studied.

Keywords: optimization, flow field design, simplified conjugate-gradient method, serpentine flow field, sub-rib convection

Procedia PDF Downloads 281
5314 Cartographic Depiction and Visualization of Wetlands Changes in the North-Western States of India

Authors: Bansal Ashwani

Abstract:

Cartographic depiction and visualization of wetland changes is an important tool to map spatial-temporal information about the wetland dynamics effectively and to comprehend the response of these water bodies in maintaining the groundwater and surrounding ecosystem. This is true for the states of North Western India, i.e., J&K, Himachal, Punjab, and Haryana that are bestowed upon with several natural wetlands in the flood plains or on the courses of its rivers. Thus, the present study documents, analyses and reconstructs the lost wetlands, which existed in the flood plains of the major river basins of these states, i.e., Chenab, Jhelum, Satluj, Beas, Ravi, and Ghagar, in the beginning of the 20th century. To achieve the objective, the study has used multi-temporal datasets since the 1960s using high to medium resolution satellite datasets, e.g., Corona (1960s/70s), Landsat (1990s-2017) and Sentinel (2017). The Sentinel (2017) satellite image has been used for making the wetland inventory owing to its comparatively higher spatial resolution with multi-spectral bands. In addition, historical records, repeated photographs, historical maps, field observations including geomorphological evidence were also used. The water index techniques, i.e., band rationing, normalized difference water index (NDWI), modified NDWI (MNDWI) have been compared and used to map the wetlands. The wetland types found in the north-western states have been categorized under 19 classes suggested by Space Application Centre, India. These enable the researcher to provide with the wetlands inventory and a series of cartographic representation that includes overlaying multiple temporal wetlands extent vectors. A preliminary result shows the general state of wetland shrinkage since the 1960s with varying area shrinkage rate from one wetland to another. In addition, it is observed that majority of wetlands have not been documented so far and even do not have names. Moreover, the purpose is to emphasize their elimination in addition to establishing a baseline dataset that can be a tool for wetland planning and management. Finally, the applicability of cartographic depiction and visualization, historical map sources, repeated photographs and remote sensing data for reconstruction of long term wetlands fluctuations, especially in the northern part of India, will be addressed.

Keywords: cartographic depiction and visualization, wetland changes, NDWI/MDWI, geomorphological evidence and remote sensing

Procedia PDF Downloads 244
5313 Prospects in Development of Ecofriendly Biopesticides in Management of Postharvest Fungal Deterioration of Cassava (Manihot esculenta Crantz)

Authors: Anderson Chidi Amadioha, Promise Chidi Kenkwo, A. A. Markson

Abstract:

Cassava (Manihot esculenta Crantz) is an important food and cash crop that provide cheap source of carbohydrate for food, feed and raw material for industries hence a commodity for feature economic development of developing countries. Despite the importance, its production potentials is undermined by disease agents that greatly reduce yield and render it unfit for human consumption and industrial use. Pathogenicity tests on fungal isolates from infected cassava revealed Aspergillus flavus, Rhizopus stolonifer, Aspergillus niger, and Trichodderma viride as rot-causing organisms. Water and ethanol extracts of Piper guineense, Ocimum graticimum, Cassia alata, and Tagetes erecta at 50% concentration significantly inhibited the radial growth of the pathogens in vitro and their development and spread in vivo. Low cassava rot incidence and severity was recorded when the extracts were applied before than after spray inoculating with spore suspension (1x105 spores/ml of distilled water) of the pathogenic organisms. The plant materials are readily available, and their extracts are biodegradable and cost effective. The fungitoxic potentials of extracts of these plant materials could be exploited as potent biopesticides in the management of postharvest fungal deterioration of cassava especially in developing countries where synthetic fungicides are not only scarce but also expensive for resource poor farmers who produce over 95% of the food consumed.

Keywords: cassava, biopesticides, in vitro, in vivo, pathogens, plant extracts

Procedia PDF Downloads 158
5312 Study of Phase Separation Behavior in Flexible Polyurethane Foam

Authors: El Hatka Hicham, Hafidi Youssef, Saghiri Khalid, Ittobane Najim

Abstract:

Flexible polyurethane foam (FPUF) is a low-density cellular material generally used as a cushioning material in many applications such as furniture, bedding, packaging, etc. It is commercially produced during a continuous process, where a reactive mixture of foam chemicals is poured onto a moving conveyor. FPUFs are produced by the catalytic balancing of two reactions involved, the blowing reaction (isocyanate-water) and the gelation reaction (isocyanate-polyol). The microstructure of FPUF is generally composed of soft phases (polyol phases) and rigid domains that separate into two domains of different sizes: the rigid polyurea microdomains and the macrodomains (larger aggregates). The morphological features of FPUF are strongly influenced by the phase separation morphology that plays a key role in determining the global FPUF properties. This phase-separated morphology results from a thermodynamic incompatibility between soft segments derived from aliphatic polyether and hard segments derived from the commonly used aromatic isocyanate. In order to improve the properties of FPUF against the different stresses faced by this material during its use, we report in this work a study of the phase separation phenomenon in FPUF that has been examined using SAXS WAXS and FTIR. Indeed, we have studied with these techniques the effect of water, isocyanates, and alkaline chlorides on the phase separation behavior. SAXS was used to study the morphology of the microphase separated, WAXS to examine the nature of the hard segment packing, and FTIR to investigate the hydrogen bonding characteristics of the materials studied. The prepared foams were shown to have different levels of urea phase connectivity; the increase in water content in the FPUF formulation leads to an increase in the amount of urea formed and consequently the increase of the size of urea aggregates formed. Alkali chlorides (NaCl, KCl, and LiCl) incorporated into FPUF formulations show that is the ability to prevent hydrogen bond formation and subsequently alter the rigid domains. FPUFs prepared by different isocyanate structures showed that urea aggregates are difficult to be formed in foams prepared by asymmetric diisocyanate, while are more easily formed in foams prepared by symmetric and aliphatic diisocyanate.

Keywords: flexible polyurethane foam, hard segments, phase separation, soft segments

Procedia PDF Downloads 137
5311 Effectiveness of Catalysis in Ozonation for the Removal of Herbizide 2,4 Dichlorophenoxyacetic Acid from Contaminated Water

Authors: S. Shanthi

Abstract:

Catalyzed oxidation processes show extraordinary guarantee for application in numerous wastewater treatment ranges. Advanced oxidation processes are emerging innovation that might be utilized for particular objectives in wastewater treatment. This research work provides a solution for removal a refractory organic compound 2,4-dichlorophenoxyaceticacid a common water pollutant. All studies were done in batch mode in a constantly stirred reactor. Alternative ozonation processes catalysed by transition metals or granular activated carbon have been investigated for degradation of organics. Catalytic ozonation under study are homogeneous catalytic ozonation, which is based on ozone activation by transition metal ions present in aqueous solution, and secondly as heterogeneous catalytic ozonation in the presence of Granular Activated Carbon (GAC). The present studies reveal that heterogeneous catalytic ozonation using GAC favour the ozonation of 2,4-dichlorophenoxyaceticacid by increasing the rate of ozonation and a much higher degradation of substrates were obtained in a given time. Be that it may, Fe2+and Fe3+ ions decreased the rate of degradation of 2,4-dichlorophenoxyaceticacid indicating that it acts as a negative catalyst. In case of heterogeneous catalytic ozonation using GAC catalyst it was found that during the initial 5 minutes of contact solution concentration decreased significantly as the pollutants were adsorbed initially. Thereafter the substrate started getting oxidized and ozonation became a dominates the treatment process. The exhausted GAC was found to be regenerated in situ. The percentage reduction of the substrate was maximum achieved in minimum possible time when GAC catalyst is employed.

Keywords: ozonation, homogeneous catalysis, heterogeneous catalysis, granular activated carbon

Procedia PDF Downloads 230
5310 Chemical Characterization and Prebiotic Effect of Water-Soluble Polysaccharides from Zizyphus lotus Leaves

Authors: Zakaria Boual, Abdellah Kemassi, Toufik Chouana, Philippe Michaud, Mohammed Didi Ould El Hadj

Abstract:

In order to investigate the prebiotic potential of oligosaccharides prepared by chemical hydrolysis of water-soluble polysaccharides (WSP) from Zizyphus lotus leaves, the effect of oligosaccharides on bacterial growth was studied. The chemical composition of WSP was evaluated by colorimetric assays revealed the average values: 7.05±0.73% proteins and 86.21±0.74% carbohydrates, among them 64.81±0.42% are neutral sugar and the rest 16.25±1.62% are uronic acids. The characterization of monosaccharides was determined by high performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) was found to be composed of galactose (23.95%), glucose (21.30%), rhamnose (20.28%), arabinose (9.55%), and glucuronic acid (22.95%). The effects of oligosaccharides on the growth of lactic acid bacteria were compared with those of fructo-oligosaccharide (RP95). The oligosaccharides concentration was 1g/L of man rogosa sharpe broth. Bacterial growth was assessed during 2, 4.5, 6.5, 9, 12, 16 and 24 h by measuring the optical density of the cultures at 600 nm (OD600) and pH values. During fermentation, pH in broth cultures decreased from 6.7 to 5.87±0.15. The enumeration of lactic acid bacteria indicated that oligosaccharides led to a significant increase in bacteria (P≤0.05) compared to the control. The fermentative metabolism appeared to be faster on RP95 than on oligosaccharides from Zizyphus lotus leaves. Both RP95 and oligosaccharides showed clear prebiotic effects, but had differences in fermentation kinetics because of to the different degree of polymerization. This study shows the prebiotic effectiveness of oligosaccharides, and provides proof for the selection of leaves of Zizyphus lotus for use as functional food ingredients.

Keywords: Zizyphus lotus, polysaccharides, characterization, prebiotic effects

Procedia PDF Downloads 390