Search results for: optimum moisture content
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 7903

Search results for: optimum moisture content

7783 Extraction of Aromatic Hydrocarbons from Lub Oil Using Sursurfactant as Additive

Authors: Izza Hidaya, Korichi Mourad

Abstract:

Solvent extraction is an affective method for reduction of aromatic content of lube oil. Frequently with phenol, furfural, NMP(N-methyl pyrrolidone). The solvent power and selectivity can be further increased by using surfactant as additive which facilitate phase separation and to increase raffinate yield. The aromatics in lube oil were extracted at different temperatures (ranging from 333.15 to 343.15K) and different concentration of surfactant (ranging from 0.01 to 0.1% wt).The extraction temperature and the amount of sulfate lauryl éther de sodium In phenoll were investigated systematically in order to determine their optimum values. The amounts of aromatic, paraffinic and naphthenic compounds were determined using ASTM standards by measuring refractive index (RI), viscosity, molecular weight and sulfur content. It was found that using 0,01%wt. surfactant at 343.15K yields the optimum extraction conditions.

Keywords: extraction, lubricating oil, aromatics, hydrocarbons

Procedia PDF Downloads 505
7782 Finite Element Modeling of Heat and Moisture Transfer in Porous Material

Authors: V. D. Thi, M. Li, M. Khelifa, M. El Ganaoui, Y. Rogaume

Abstract:

This paper presents a two-dimensional model to study the heat and moisture transfer through porous building materials. Dynamic and static coupled models of heat and moisture transfer in porous material under low temperature are presented and the coupled models together with variable initial and boundary conditions have been considered in an analytical way and using the finite element method. The resulting coupled model is converted to two nonlinear partial differential equations, which is then numerically solved by an implicit iterative scheme. The numerical results of temperature and moisture potential changes are compared with the experimental measurements available in the literature. Predicted results demonstrate validation of the theoretical model and effectiveness of the developed numerical algorithms. It is expected to provide useful information for the porous building material design based on heat and moisture transfer model.

Keywords: finite element method, heat transfer, moisture transfer, porous materials, wood

Procedia PDF Downloads 387
7781 The Effect of Nanoclay on the Hydraulic Conductivity of Clayey Sand Soils

Authors: Javad Saeidaskari, Mohammad Hassan Baziar

Abstract:

Soil structures have been frequently damaged during piping, earthquake and other types of failures. As far as adverse circumstances were developed subsequent to piping or other similar failure types, hydraulic parameters of soil such as hydraulic conductivity should be considered. As a result, acquiring an approach to diminish soil permeability is inevitable. There are many ground improvement methods to reduce seepage, which are classified under soil treatment and stabilization methods. Recently, one of the soil improvement methods is known as nanogeotechnology. This study aims to investigate the influence of Cloisite 30B nanoclay on permeability of compacted clayey sand soils. The samples are prepared by mixing two soil types, including Kaolin clay and Firouzkooh sand, in 1:9 and 1:5 clay:sand (by mass) proportions. In experimental procedure, initially, the optimum water content and maximum dry unit weight of each samples were obtained for compaction. Then, series of permeability tests were conducted by triaxial apparatus on prepared specimens with identical relative density of 95% of maximum dry density and water content of 1% wet of optimum for different weight percentages of nanoclay (1% to 4%). Therefore, in this paper, the effect of time on treated specimen was appraised, as well as two approaches of manual mixing and ball milling were compared to reveal the importance of dispersion issue. The results show that adding nanoclay up to 3%, as its optimum content, causes notable reduction in permeability (1.60e-03 to 5.51e-05 cm/s and 3.32e-04 to 8.44e-07 cm/s in samples with 1:9 and 1:5 mixture proportions, respectively). The hydraulic conductivity of treated clayey sand (1:5 mixture proportion with 3% nanoclay) decreases gradually from 8.44e-07 to 3.00e-07 cm/s within 90 days and then tends to be consistent. The influence of mixing method on permeability results shows that the utilization of ball mill mixing effectively leads to lower values than those of manual mixing, in other words, by adding 3% nanoclay, hydraulic conductivity of specimen declines from 8.44e-07 to 2.00e-07 cm/s. In order to evaluate the interaction between soil particles and, to ensure proper dispersion of nanoparticles through clayey sand mixture, they were magnified by means of scanning electron microscope (SEM). In conclusion, the nanoclay particles in vicinity of moisture can cause soil stabilization to prevent water penetration, which eventually result in lower usage of clay and operation costs.

Keywords: nanoclay, cloisite 30b, clayey sand, hydraulic conductivity

Procedia PDF Downloads 338
7780 The Intensity of Root and Soil Respiration Is Significantly Determined by the Organic Matter and Moisture Content of the Soil

Authors: Zsolt Kotroczó, Katalin Juhos, Áron Béni, Gábor Várbíró, Tamás Kocsis, István Fekete

Abstract:

Soil organic matter plays an extremely important role in the functioning and regulation processes of ecosystems. It follows that the C content of organic matter in soil is one of the most important indicators of soil fertility. Part of the carbon stored in them is returned to the atmosphere during soil respiration. Climate change and inappropriate land use can accelerate these processes. Our work aimed to determine how soil CO2 emissions change over ten years as a result of organic matter manipulation treatments. With the help of this, we were able to examine not only the effects of the different organic matter intake but also the effects of the different microclimates that occur as a result of the treatments. We carried out our investigations in the area of the Síkfőkút DIRT (Detritus Input and Removal Treatment) Project. The research area is located in the southern, hilly landscape of the Bükk Mountains, northeast of Eger (Hungary). GPS coordinates of the project: 47°55′34′′ N and 20°26′ 29′′ E, altitude 320-340 m. The soil of the area is Luvisols. The 27-hectare protected forest area is now under the supervision of the Bükki National Park. The experimental plots in Síkfőkút were established in 2000. We established six litter manipulation treatments each with three 7×7 m replicate plots established under complete canopy cover. There were two types of detritus addition treatments (Double Wood and Double Litter). In three treatments, detritus inputs were removed: No Litter No Roots plots, No Inputs, and the Controls. After the establishment of the plots, during the drier periods, the NR and NI treatments showed the highest CO2 emissions. In the first few years, the effect of this process was evident, because due to the lack of living vegetation, the amount of evapotranspiration on the NR and NI plots was much lower, and transpiration practically ceased on these plots. In the wetter periods, the NL and NI treatments showed the lowest soil respiration values, which were significantly lower compared to the Co, DW, and DL treatments. Due to the lower organic matter content and the lack of surface litter cover, the water storage capacity of these soils was significantly limited, therefore we measured the lowest average moisture content among the treatments after ten years. Soil respiration is significantly influenced by temperature values. Furthermore, the supply of nutrients to the soil microorganisms is also a determining factor, which in this case is influenced by the litter production dictated by the treatments. In the case of dry soils with a moisture content of less than 20% in the initial period, litter removal treatments showed a strong correlation with soil moisture (r=0.74). In very dry soils, a smaller increase in moisture does not cause a significant increase in soil respiration, while it does in a slightly higher moisture range. In wet soils, the temperature is the main regulating factor, above a certain moisture limit, water displaces soil air from the soil pores, which inhibits aerobic decomposition processes, and so heterotrophic soil respiration also declines.

Keywords: soil biology, organic matter, nutrition, DIRT, soil respiration

Procedia PDF Downloads 56
7779 Termite Mound Floors: Ready-to-Use Ecological Materials

Authors: Yanné Etienne

Abstract:

The current climatic conditions necessarily impose the development and use of construction materials with low or no carbon footprint. The Far North Region of Cameroon has huge deposits of termite mounds. Various tests in this work have been carried out on these soils with the aim of using them as construction materials. They are mainly geotechnical tests, physical and mechanical tests. The different tests gave the following values: uniformity coefficient (4.95), curvature coefficient (1.80), plasticity index (12.85%), optimum moisture content (6.70%), maximum dry density (2.05 g.cm-³), friction angles (14.07°), and cohesion of 100.29 kN.m2. The results obtained show that termite mound soils, which are ecological materials, are plastic and water-stable can be used for the production of load-bearing elements in construction.

Keywords: termite mound soil, ecological materials, building materials, geotechnical tests, physical and mechanical tests

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7778 Effects of Roasting as Preservative Method on Food Value of the Runner Groundnuts, Arachis hypogaea

Authors: M. Y. Maila, H. P. Makhubele

Abstract:

Roasting is one of the oldest preservation method used in foods such as nuts and seeds. It is a process by which heat is applied to dry foodstuffs without the use of oil or water as a carrier. Groundnut seeds, also known as peanuts when sun dried or roasted, are among the oldest oil crops that are mostly consumed as a snack, after roasting in many parts of South Africa. However, roasting can denature proteins, destroy amino acids, decrease nutritive value and induce undesirable chemical changes in the final product. The aim of this study, therefore, was to evaluate the effect of various roasting times on the food value of the runner groundnut seeds. A constant temperature of 160 °C and various time-intervals (20, 30, 40, 50 and 60 min) were used for roasting groundnut seeds in an oven. Roasted groundnut seeds were then cooled and milled to flour. The milled sundried, raw groundnuts served as reference. The proximate analysis (moisture, energy and crude fats) was performed and the results were determined using standard methods. The antioxidant content was determined using HPLC. Mineral (cobalt, chromium, silicon and iron) contents were determined by first digesting the ash of sundried and roasted seed samples in 3M Hydrochloric acid and then determined by Atomic Absorption Spectrometry. All results were subjected to ANOVA through SAS software. Relative to the reference, roasting time significantly (p ≤ 0.05) reduced moisture (71%–88%), energy (74%) and crude fat (5%–64%) of the runner groundnut seeds, whereas the antioxidant content was significantly (p ≤ 0.05) increased (35%–72%) with increasing roasting time. Similarly, the tested mineral contents of the roasted runner groundnut seeds were also significantly (p ≤ 0.05) reduced at all roasting times: cobalt (21%–83%), chromium (48%–106%) and silicon (58%–77%). However, the iron content was significantly (p ≤ 0.05) unaffected. Generally, the tested runner groundnut seeds had higher food value in the raw state than in the roasted state, except for the antioxidant content. Moisture is a critical factor affecting the shelf life, texture and flavor of the final product. Loss of moisture ensures prolonged shelf life, which contribute to the stability of the roasted peanuts. Also, increased antioxidant content in roasted groundnuts is essential in other health-promoting compounds. In conclusion, the overall reduction in the proximate and mineral contents of the runner groundnuts seeds due to roasting is sufficient to suggest influences of roasting time on the food value of the final product and shelf life.

Keywords: dry roasting, legume, oil source, peanuts

Procedia PDF Downloads 264
7777 Utilization of Fly Ash Amended Sewage Sludge as Sustainable Building Material

Authors: Kaling Taki, Rohit Gahlot, Manish Kumar

Abstract:

Disposal of Sewage Sludge (SS) is a big issue especially in developing nation like India, where there is no control in the dynamicity of SS produced. The present research work demonstrates the potential application of SS amended with varying percentage (0-100%) of Fly Ash (FA) for brick manufacturing as an alternative of SS management. SS samples were collected from Jaspur sewage treatment plant (Ahmedabad, India) and subjected to different preconditioning treatments: (i) atmospheric drying (ii) pulverization (iii) heat treatment in oven (110°C, moisture removal) and muffle furnace (440°C, organic content removal). Geotechnical parameters of the SS were obtained as liquid limit (52%), plastic limit (24%), shrinkage limit (10%), plasticity index (28%), differential free swell index (DFSI, 47%), silt (68%), clay (27%), organic content (5%), optimum moisture content (OMC, 20%), maximum dry density (MDD, 1.55gm/cc), specific gravity (2.66), swell pressure (57kPa) and unconfined compressive strength (UCS, 207kPa). For FA liquid limit, plastic limit and specific gravity was 44%, 0% and 2.2 respectively. Initially, for brick casting pulverized SS sample was heat treated in a muffle furnace around 440℃ (5 hours) for removal of organic matter. Later, mixing of SS, FA and water by weight ratio was done at OMC. 7*7*7 cm3 sample mold was used for casting bricks at MDD. Brick samples were then first dried in room temperature for 24 hours, then in oven at 100℃ (24 hours) and finally firing in muffle furnace for 1000℃ (10 hours). The fired brick samples were then cured for 3 days according to Indian Standards (IS) common burnt clay building bricks- specification (5th revision). The Compressive strength of brick samples (0, 10, 20, 30, 40, 50 ,60, 70, 80, 90, 100%) of FA were 0.45, 0.76, 1.89, 1.83, 4.02, 3.74, 3.42, 3.19, 2.87, 0.78 and 4.95MPa when evaluated through compressive testing machine (CTM) for a stress rate of 14MPa/min. The highest strength was obtained at 40% FA mixture i.e. 4.02MPa which is much higher than the pure SS brick sample. According to IS 1077: 1992 this combination gives strength more than 3.5 MPa and can be utilized as common building bricks. The loss in weight after firing was much higher than the oven treatment, this might be due to degradation temperature higher than 100℃. The thermal conductivity of the fired brick was obtained as 0.44Wm-1K-1, indicating better insulation properties than other reported studies. TCLP (Toxicity characteristic leaching procedure) test of Cr, Cu, Co, Fe and Ni in raw SS was found as 69, 70, 21, 39502 and 47 mg/kg. The study positively concludes that SS and FA at optimum ratio can be utilized as common building bricks such as partitioning wall and other small strength requirement works. The uniqueness of the work is it emphasizes on utilization of FA for stabilizing SS as construction material as a replacement of natural clay as reported in existing studies.

Keywords: Compressive strength, Curing, Fly Ash, Sewage Sludge.

Procedia PDF Downloads 90
7776 Numerical Investigation of Hygrothermal Behavior on Porous Building Materials

Authors: Faiza Mnasri, Kamilia Abahri, Mohammed El Ganaoui, Slimane Gabsi

Abstract:

Most of the building materials are considered porous, and composed of solid matrix and pores. In the pores, the moisture can be existed in two phases: liquid and vapor. Thus, the mass balance equation is comprised of various moisture driving potentials that translate the movement of the different existing phases occupying pores and the hygroscopic behavior of a porous construction material. This study suggests to resolve a hygrothermal mathematical model of heat and mass transfers in different porous building materials by a numerical investigation. Thereby, the evolution of temperature and moisture content fields has been processed. So, numerous series of hygrothermal calculation on several cases of wall are exposed. Firstly, a case of monolayer wall of massive wood has been treated. In this part, we have compared the numerical solution of the model on one and two dimensions and the effect of dimensional space has been evaluated. In the second case, three building materials (concrete, wood fiberboard and wooden insulation) are tested separately with the same boundary conditions and their hygrothermal behavior are compared. The evaluation of the exchange of heat and air at the interface between the wall and the interior ambiance is carried.

Keywords: building materials, heat transfer, moisture diffusion, numerical solution

Procedia PDF Downloads 276
7775 Physicochemical Characterization of Waste from Vegetal Extracts Industry for Use as Briquettes

Authors: Maíra O. Palm, Cintia Marangoni, Ozair Souza, Noeli Sellin

Abstract:

Wastes from a vegetal extracts industry (cocoa, oak, Guarana and mate) were characterized by particle size, proximate and ultimate analysis, lignocellulosic fractions, high heating value, thermal analysis (Thermogravimetric analysis – TGA, and Differential thermal analysis - DTA) and energy density to evaluate their potential as biomass in the form of briquettes for power generation. All wastes presented adequate particle sizes to briquettes production. The wastes showed high moisture content, requiring previous drying for use as briquettes. Cocoa and oak wastes had the highest volatile matter contents with maximum mass loss at 310 ºC and 450 ºC, respectively. The solvents used in the aroma extraction process influenced in the moisture content of the wastes, which was higher for mate due to water has been used as solvent. All wastes showed an insignificant loss mass after 565 °C, hence resulting in low ash content. High carbon and hydrogen contents and low sulfur and nitrogen contents were observed ensuring a low generation of sulfur and nitrous oxides. Mate and cocoa exhibited the highest carbon and lignin content, and high heating value. The dried wastes had high heating value, from 17.1 MJ/kg to 20.8 MJ/kg. The results indicate the energy potential of wastes for use as fuel in power generation.

Keywords: agro-industrial waste, biomass, briquettes, combustion

Procedia PDF Downloads 193
7774 Mathematical Modeling of Eggplant Slices Drying Using Microwave-Oven

Authors: M.H. Keshek, M.N. Omar, A.H. Amer

Abstract:

Eggplant (Solanum melongena L.) is considered one of the most important crops in summer season, and it is grown in most cultivated area in Egypt. Eggplant has a very limited shelf life for freshness and physiological changes occur after harvest. Nowadays, microwave drying offers an alternative way to drying agricultural products. microwave drying is not only faster but also requiring less energy consumption than conventional drying. The main objective of this research was to evaluate using the microwave oven in Eggplant drying, to determine the optimum drying time of higher drying efficiency and lower energy consumption. The eggplants slices, having a thickness of about 5, 10, 15, and 20 mm, with diameter 50±2 mm was dried using microwave oven (KOR-9G2B) using three different levels were 450, 630, and 810 Watt (50%, 70%, and 90% of 900 Watt). The results show that, the initial moisture content of the eggplant slices was around 93 % wet basis (13.28 g water/g dry matter). The results indicated that, the moisture transfer within the sample was more rapidly during higher microwave power heating (810 watt) and lower thickness (5 mm) of the eggplant slices. In addition, the results show that, the drying efficiency increases by increasing slices thickness at power levels 450, 630 and 810 Watt. The higher drying efficiency was 83.13% occurred when drying the eggplant slices 20 mm thickness in microwave oven at power 630 Watt. the higher total energy consumption per dry kilogram was 1.275 (kWh/ dry kg) occurred at used microwave 810 Watt for drying eggplant slices 5 mm thickness, and the lower total energy consumption per dry kilogram was 0.55 (kWh/ dry kg) occurred at used microwave 810 Watt for drying eggplant slices 20 mm thickness.

Keywords: microwave drying, eggplant, drying rate, drying efficiency, energy consumption

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7773 Studies on the Effect of Dehydration Techniques, Treatments, Packaging Material and Methods on the Quality of Buffalo Meat during Ambient Temperature Storage

Authors: Tariq Ahmad Safapuri, Saghir Ahmad, Farhana Allai

Abstract:

The present study was conducted to evaluate the effect dehydration techniques (polyhouse and tray drying), different treatment (SHMP, SHMP+ salt, salt + turmeric), different packaging material (HDPE, combination film), and different packaging methods (air, vacuum, CO2 Flush) on quality of dehydrated buffalo meat during ambient temperature storage. The quality measuring parameters included physico-chemical characteristics i.e. pH, rehydration ratio, moisture content and microbiological characteristics viz total plate content. It was found that the treatment of (SHMP, SHMP + salt, salt + turmeric increased the pH. Moisture Content of dehydrated meat samples were found in between 7.20% and 5.54%.the rehydration ratio of salt+ turmeric treated sample was found to be highest and lowest for controlled meat sample. the bacterial count log TPC/g of salt + turmeric and tray dried was lowest i.e. 1.80.During ambient temperature storage ,there was no considerable change in pH of dehydrated sample till 150 days. however the moisture content of samples increased in different packaging system in different manner. The highest moisture rise was found in case of controlled meat sample HDPE/air packed while the lowest increase was reported for SHMP+ Salt treated Packed by vacuum in combination film packed sample. Rehydration ratio was found considerably affected in case of HDPE and air packed sample dehydrated in polyhouse after 150 days of ambient storage. While there was a very little change in the rehydration ratio of meat samples packed in combination film CO2 flush system. The TPC was found under safe limit even after 150 days of storage. The microbial count was found to be lowest for salt+ turmeric treated samples after 150 days of storage.

Keywords: ambient temperature, dehydration technique, rehydration ratio, SHMP (sodium hexa meta phosphate), HDPE (high density polyethelene)

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7772 Proximate Composition and Sensory Properties of Complementary Food from Fermented Acha (Digitaria exilis), Soybean and Orange-Flesh Sweet Potato Blends

Authors: N. C. Okoronkwo, I. E. Mbaeyi-Nwaoha, C. P. Agbata

Abstract:

Childhood malnutrition is one of the most persistent public health problems throughout developing countries, including Nigeria. Demographic and Health survey data from twenty-one developing countries indicated that poor complementary feeding of children aged 6- 23 months contributes to negative growth trends. To reduce malnutrition among children in the society, formulation of complimentary food rich in essential nutrient for optimum growth and development of infants is essential. This study focused on the evaluation of complementary food produced by solid-state fermentation of Acha and Soybean using Rhizopus oligosporus (2710) and Orange-fleshed sweet potatoes (OFSP) using Lactobacillus planterum (B-41621). The raw materials were soaked separately, each in four volumes of 0.9M acetic acid for 16 hours, rinsed with clean water, steam cooked and cooled. Solid-state fermentation (SSF) was carried out by inoculating Acha and Soybean with spore suspension (1x 10⁶spores/ml) of Rhizopus oligosporus (2710) and OFSP with spore suspension (1x 106spores/ml) of Lactobacillus planterum (B-41621). Fermentation which lasted for 72hours was carried out with 24hours sampling. The samples were blended in the following ratios: Acha and soybean 100: 100 (AS), Acha/soybean and OFSP 50: 50(ASO), made into gruel and compared with a commercial infant formula (Cerelac) which served as the control (CTRL). The samples were analyzed for proximate composition using AOAC methods and sensory attributes using a hedonic scale. Results showed that moisture, crude protein, fibre and ash content increased significantly (p<0.05) as fermentation progressed, while carbohydrate and fat content decreased. The protein, moisture, fibre and ash content ranged from 17.10-19.02%, 54.97-56.27%, 7.08-7.60% and2.09-2.38%, respectively, while carbohydrate and fat content ranged from 12.95-10.21% and 5.81-4.52%, respectively. In sensory scores, there were no significant (p>0.05) difference between the average mean scores of colours, texture and consistency of the samples. The sensory score for the overall acceptability ranged from 6.20-7.80. Sample CTRL had the highest score, while sample ASO had the least score. There was no significant (p>0.05) difference between samples CTRL and AS. Solid-state fermentation improved the nutritional content and flavour of the developed complementary food, which is needed for infant growth and development.

Keywords: Complementary food, malnutrition, proximate composition, solid-state fermentation

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7771 Effects of Moisture on Fatigue Behavior of Asphalt Concrete Mixtures Using Four-Point Bending Test

Authors: Mohit Chauhan, Atul Narayan

Abstract:

Moisture damage is the continuous deterioration of asphalt concrete mixtures by the loss of adhesive bond between the asphalt binder and aggregates, or loss of cohesive bonds within the asphalt binder in the presence of moisture. Moisture has been known to either cause or exacerbates distresses in asphalt concrete pavements. Since moisture would often retain for a relatively long duration at the bottom of asphalt concrete layer, the movement of traffic loading in this saturated condition would cause excess stresses or strains within the mixture. This would accelerate the degradation of the adhesion and cohesion within the mixture and likely to contribute the development of fatigue cracking in asphalt concrete pavements. In view of this, it is important to investigate the effect of moisture on the fatigue behavior of asphalt concrete mixtures. In this study, changes in fatigue characteristics after moisture conditioning were evaluated by conducting four-point beam fatigue tests on dry and moisture conditioned specimens. For this purpose, mixtures with two different types of binders were prepared and saturated with moisture using 700 mm Hg vacuum. Beam specimens, in this way, were taken to a saturation level of 65-75 percent. After preconditioning specimens in this degree of saturation and 60°C for a period of 24 hours, they were subjected to four point beam fatigue tests in strain-controlled mode with a strain amplitude of 400 microstrain. The results were then compared with the fatigue test results obtained with beam specimens that were not subjected to moisture conditioning. Test results show that the conditioning reduces both fatigue life and initial flexural stiffness of specimen significantly. The moisture conditioning was also found to increase the rate of reduction of flexural stiffness. Moreover, it was observed that the fatigue life ratio (FLR), the ratio of the fatigue life of the moisture conditioned sample to that of the dry sample, is significantly lower than the flexural stiffness ratio (FSR). The study indicates that four-point bending test is an appropriate tool with FLR and FSR as the potential parameters for moisture-sensitivity evaluation.

Keywords: asphalt concrete, fatigue cracking, moisture damage, preconditioning

Procedia PDF Downloads 127
7770 Inversion of PROSPECT+SAIL Model for Estimating Vegetation Parameters from Hyperspectral Measurements with Application to Drought-Induced Impacts Detection

Authors: Bagher Bayat, Wouter Verhoef, Behnaz Arabi, Christiaan Van der Tol

Abstract:

The aim of this study was to follow the canopy reflectance patterns in response to soil water deficit and to detect trends of changes in biophysical and biochemical parameters of grass (Poa pratensis species). We used visual interpretation, imaging spectroscopy and radiative transfer model inversion to monitor the gradual manifestation of water stress effects in a laboratory setting. Plots of 21 cm x 14.5 cm surface area with Poa pratensis plants that formed a closed canopy were subjected to water stress for 50 days. In a regular weekly schedule, canopy reflectance was measured. In addition, Leaf Area Index (LAI), Chlorophyll (a+b) content (Cab) and Leaf Water Content (Cw) were measured at regular time intervals. The 1-D bidirectional canopy reflectance model SAIL, coupled with the leaf optical properties model PROSPECT, was inverted using hyperspectral measurements by means of an iterative optimization method to retrieve vegetation biophysical and biochemical parameters. The relationships between retrieved LAI, Cab, Cw, and Cs (Senescent material) with soil moisture content were established in two separated groups; stress and non-stressed. To differentiate the water stress condition from the non-stressed condition, a threshold was defined that was based on the laboratory produced Soil Water Characteristic (SWC) curve. All parameters retrieved by model inversion using canopy spectral data showed good correlation with soil water content in the water stress condition. These parameters co-varied with soil moisture content under the stress condition (Chl: R2= 0.91, Cw: R2= 0.97, Cs: R2= 0.88 and LAI: R2=0.48) at the canopy level. To validate the results, the relationship between vegetation parameters that were measured in the laboratory and soil moisture content was established. The results were totally in agreement with the modeling outputs and confirmed the results produced by radiative transfer model inversion and spectroscopy. Since water stress changes all parts of the spectrum, we concluded that analysis of the reflectance spectrum in the VIS-NIR-MIR region is a promising tool for monitoring water stress impacts on vegetation.

Keywords: hyperspectral remote sensing, model inversion, vegetation responses, water stress

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7769 Effect of Temperature and Feed Solution on Microencapsulation of Quercetin by Spray Drying Technique

Authors: S. Lekhavat, U. Srimongkoluk, P. Ratanachamnong, G. Laungsopapun

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Quercetin was encapsulated with whey protein and high methoxyl pectin by spray drying technique. Feed solution, consisting of 0.1875 0.125 and 0.0625 % w/w quercetin, respectively, was prepared and then sprays at outlet temperature of 70, 80 and 90 °C. Quercetin contents either in feed solution or in spray dried powder were determined by HPLC technique. Physicochemical properties such as viscosity and total soluble solid of feed solution as well as moisture content and water activity of spray dried powder were examined. Particle morphology was imaged using scanning electron microscope. The results showed that feed solution has total soluble solid and viscosity in range of 1.73-5.60 ºBrix and 2.58-8.15 cP, in that order. After spray drying, the moisture content and water activity value of powder are in range of 0.58-2.72 % and 0.18-0.31, respectively. Quercetin content in dried sample increased along with outlet drying temperature but decreased when total soluble solid increased. It was shown that particles are likely to shrivel when spray drying at high temperature. The suggested conditions for encapsulation of quercetin are feed solution with 0.0625 % (w/w) quercetin and spray drying at drying outlet temperature of 90°C.

Keywords: drying temperature, particle morphology, spray drying, quercetin

Procedia PDF Downloads 245
7768 Formulation and Nutrition Analysis of Low-Sugar Snack Bars

Authors: S. Kongtun-Janphuk, S. Niwitpong Jr., J. Saengsai

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Low-sugar snack bars were formulated with 3 main formulas depending on the main ingredient, which were peanut-green bean-sesame, apple, and prune. The most acceptable formula of each group was obtained by sensory evaluation using a nine-point hedonic scale. The moisture content, total ash, protein, fat and fiber were analyzed by the standard methods of AOAC. The peanut-mung bean-sesame snack bar showed the highest protein content (88.32%) and total fat (0.48%) with the lowest of fiber content (0.01%) while the prune formula showed the lowest protein content (71.91%) and total fat (0.21%) with the highest of fiber content (0.03%). This result indicated that the prune formula could be used as diet food to assist in weight loss program.

Keywords: low-sugar snack bar, diet food, nutrition analysis, food formulation

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7767 Construction and Evaluation of Soybean Thresher

Authors: Oladimeji Adetona Adeyeye, Emmanuel Rotimi Sadiku, Oluwaseun Olayinka Adeyeye

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In order to resuscitate soybean production and post-harvest processing especially, in term of threshing, there is need to develop an affordable threshing machine which will reduce drudgery associated with manual soybean threshing. Soybean thresher was fabricated and evaluated at Institute of Agricultural Research and Training IAR&T Apata Ibadan. The machine component includes; hopper, threshing unit, shaker, cleaning unit and the seed outlet, all working together to achieve the main objective of threshing and cleaning. TGX1835 - 10E variety was used for evaluation because of its high resistance to pests, rust and pustules. The final moisture content of the used sample was about 15%. The sample was weighed and introduced into the machine. The parameters evaluated includes moisture content, threshing efficiency, cleaning efficiency, machine capacity and speed. The threshing efficiency and capacity are 74% and 65.9kg/hr respectively. All materials used were sourced locally which makes the cost of production of the machine extremely cheaper than the imported soybean thresher.

Keywords: efficiency, machine capacity, speed, soybean, threshing

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7766 Dielectric Response Analysis Measurement for Diagnostic Oil-Paper Insulation System on Aged Inter Bus Transformer 3x10 MVA

Authors: Eki Farlen, Akas

Abstract:

Condition assessment of oil-paper-insulated power transformers, particularly of water content, is becoming increasingly important for aged transformers. As insulation ages, it can produce water, which reduces its dielectric strength, accelerates the cellulose ageing process, and causes gas bubbles to form at high temperatures. This paper mainly assesses the life condition of oil-paper insulation system of Inter Bus Transformer (IBT) 30 MVA, 150/30 kV in PT PLN-Substation Jelok that has been operating for 41 years, since 1974. Valuable information about the condition of high voltage insulation may be obtained by measuring its dielectric response. This paper describes in detail the interpretation of Dielectric Response Analysis (DIRANA) measurements and the test result compared to other insulation tests to get deep information for diagnostic, such as Tan delta test, oil characteristic test and Dissolve Gas Analysis (DGA) test. This paper mainly discusses the parameter relationship between moisture content, water content, acidity, oil conductivity and dissipation factor. The result and analysis show that IBT 30 MVA Jelok phase U and W had just been ageing due to high acidity level (>0.2 mgKOH/g) which cause high moisture in cellulose/paper (%) are in wet category about 4.7% and 5% and water content in oil (ppm) about 3.13 ppm and 3.33 ppm at temperature 20°C. High acidity level can make oxidation process and produce water in paper and particle which can decrease the value of Interfacial Tension (IFT) below 22 mN/m (poor category) for both phase U and W. Even if paper insulation of transformer are in wet condition, dissipation factor and capacitance at the same frequency (50 Hz) from both measurement DIRANA test and Tangent delta test give the same result (almost), the results are 0.69% and 0.71% (<1%), it may be acceptable and should not be investigated. The DGA results show that TDCG are in level one (1) condition and there are no found a Key Gases, it means that transformers had no failure during operation like arching, partial discharge and thermal in oil or cellulose.

Keywords: diagnostic, inter-bus transformer, oil-paper insulation, moisture, dissipation factor

Procedia PDF Downloads 265
7765 Influence of Compactive Efforts on the Hydraulic Conductivity of Bagasse Ash Treated Black Cotton Soil

Authors: T. S. Ijimdiya, K. J. Osinubi

Abstract:

This study examines the influence of compactive efforts on hydraulic conductivity behaviour of compacted black cotton soil treated with bagasse ash which is necessary in assessing the performance of the soil - bagasse ash mixture for use as a suitable barrier material in waste containment application. Black cotton soil treated with up to 12% bagasse ash (obtained from burning the fibrous residue from the extraction of sugar juice from sugarcane) by dry weight of soil for use in waste containment application. The natural soil classifies as A-7-6 or CH in accordance with the AASHTO and the Unified Soil Classification System, respectively. The treated soil samples were prepared at molding water contents of -2, 0, +2, and +4 % of optimum moisture contents and compacted using four compactive efforts of Reduced British Standard Light (RBSL), British Standard light (BSL), West African Standard (WAS) and British Standard Heavy (BSH). The results obtained show that hydraulic conductivity decreased with increase in bagasse ash content, moulding water content and compaction energy.

Keywords: bagasse ash treatment, black cotton soil, hydraulic conductivity, moulding water contents, compactive efforts

Procedia PDF Downloads 413
7764 Effect of Inclusion of Rubber on the Compaction Characteristics of Cement - MSWIFA- Clayey Soil Mixtures

Authors: Gehan Aouf, Diala Tabbal, Abd El Rahim Sabsabi, Rashad Aouf

Abstract:

The aim of this study is to show the effect of adding cement municipal solid incineration fly ash and rubber as stabilizer materials on weak soil. A detailed experimental study was conducted in order to show the viability of using these admixtures in improving the maximum dry density and optimum moisture content of the composite soil. Soil samples were prepared by adding Rubber and Cement to municipal solid waste incineration fly-ash - oil mix at different percentages. Then, a series of laboratory tests were performed, namely: Sieve analysis, Atterberg limits tests, Unconfined compression test, and Proctor tests. Three different percentages of fly ash (10%, 20%, and 30%) MSWFA by total dry weight of soil and three different percentages of Portland cement (10%, 15%, and 20%) by total dry weight of the mix and 0%, 5%, 10% for Rubber by total dry weight of the mix were used to find the optimum value. The test results reveal that adding MSWIFA to the soil up to 20% increased the MDD of the mixture and decreased the OMC, then an opposite trend for results were found when the percentage of MSWIFA exceeded 20%. This is due to the low specific gravity of MSWIFA and to the greater water absorption of MSWIFA. The laboratory tests also indicate that adding Rubber to the mix Soil-MSWIFA-Cement decreases its MDD due to the low specific gravity of rubber and it affects a slight decrease in OMC because the rubber has low absorption of water.

Keywords: clayey soil, MSWIFA, proctor test, rubber

Procedia PDF Downloads 101
7763 Effect of Different Planting Times and Mulching Materials on Seed Quality and Yield of China Aster Cultivars

Authors: A. A. Bajad, B. P. Sharma, Y. C. Gupta, B. S. Dilt, R. K. Gupta

Abstract:

The present investigations were carried out at the experimental farm of Department of Floriculture and Landscape Architecture, Dr. Y. S. Parmar University of Horticulture and Forestry, Nauni, Solan, H.P. during 2015 and 2016. The experiment was laid out in a Randomized Block Design (factorial) consisting of 48 treatment combinations of four planting dates viz., D1- mid March, D2-mid April, D3-mid May and D4- mid June and two cultivars namely V1- Kamini and V2 -Poornima with six mulching materials M¬0¬- without mulch, M1- Black plastic mulch (100 µ), M2- Silver plastic mulch (100 µ), M3¬- Transparent plastic mulch (100 µ), M3-Transparent plastic mulch (100 µ), M4¬- Pine needle (100 µ) and M5- Grass (1 inch layer). Among different planting times, D4 i.e. mid June planting obtained best results for number of seed per flower (179.38), germination percent (83.92 %), electrical conductivity (0.97 ds/m), seedling length (7.93 cm), seedling dry weight (7.09 mg), seedling vigour index I (763.79), moisture content (7.83 %) and 1000 seed weight (1.94 g). However, seed yield per plant (14.30 g) was recorded to be maximum in mid of March. Among the cultivars, cv. ‘Poornima’ gave best results for number of seed per plant (187.30). However, cv. ‘Kamini’ recorded the best result for seed yield per plant (12.55), electrical conductivity (1.11 ds/m), germination percent (80.47 %), seedling length (6.39 cm), seedling dry weight (5.11 mg), seedling vigour index I (649.49), moisture content (9.28 %) and 1000 seed weight (1.70 g). Silver plastic obtained best results for number of seed per flower (170.10), seed yield per plant (15.66 g), germination percent (80.17 %), electrical conductivity (1.26 ds/m), seedling length (5.88 cm), seedling dry weight (4.46 mg), seedling vigour index I (616.78), Moisture content (9.35 %) and 100 seed weight (1.97 g).

Keywords: cultivars, mulch materials, planting times, flowers

Procedia PDF Downloads 253
7762 Laboratory Study on Behavior of Compacted Soils

Authors: M. M. Mekkakia, M. P Luong, A. Arab

Abstract:

These controlling the water content of compaction are a major concern of fundamental civil engineers. Also, the knowledge of the fundamentals of the behaviour of compacted clay soils is essential to predict and quantify the effects of a change in water content. The study of unsaturated soils is a very complex area which several studies are directed to in recent years. Our job work is to perform tests of Proctor, Oedometer and shear, on samples of unsaturated clay in order to see the influence of water content on the compressibility and the shear strength. The samples were prepared at different amounts of water from water content to optimum water contents close to saturation. This study thus allowed us to measure and monitor the parameters of compressibility and shear strength as a function of water content.

Keywords: laboratory tests, clay, unsaturated soil, atterberg limits, compaction, compressibility, shear

Procedia PDF Downloads 395
7761 Candida antartica Lipase Assisted Enrichment of n-3 PUFA in Indian Sardine Oil

Authors: Prasanna Belur, P. R. Ashwini, Sampath Charanyaa, I. Regupathi

Abstract:

Indian oil sardine (Sardinella longiceps) are one of the richest and cheapest sources of n-3 polyunsaturated fatty acids (n-3 PUFA) such as Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA). The health benefits conferred by n-3 PUFA upon consumption, in the prevention and treatment of coronary, neuromuscular, immunological disorders and allergic conditions are well documented. Natural refined Indian Sardine oil generally contain about 25% (w/w) n-3 PUFA along with various unsaturated and saturated fatty acids in the form of mono, di, and triglycerides. Having high concentration of n-3 PUFA content in the glyceride form is most desirable for human consumption to avail maximum health benefits. Thus, enhancing the n-3 PUFA content while retaining it in the glyceride form with green technology is the need of the hour. In this study, refined Indian Sardine oil was subjected to selective hydrolysis by Candida antartica lipase to enhance n-3 PUFA content. The degree of hydrolysis and enhancement of n-3 PUFA content was estimated by determining acid value, Iodine value, EPA and DHA content (by Gas Chromatographic methods after derivitization) before and after hydrolysis. Various reaction parameters such as pH, temperature, enzyme load, lipid to aqueous phase volume ratio and incubation time were optimized by conducting trials with one parameter at a time approach. Incubating enzyme solution with refined sardine oil with a volume ratio of 1:1, at pH 7.0, for 60 minutes at 50 °C, with an enzyme load of 60 mg/ml was found to be optimum. After enzymatic treatment, the oil was subjected to refining to remove free fatty acids and moisture content using previously optimized refining technology. Enzymatic treatment at the optimal conditions resulted in 12.11 % enhancement in Degree of hydrolysis. Iodine number had increased by 9.7 % and n-3 PUFA content was enhanced by 112 % (w/w). Selective enhancement of n-3 PUFA glycerides, eliminating saturated and unsaturated fatty acids from the oil using enzyme is an interesting preposition as this technique is environment-friendly, cost effective and provide natural source of n-3 PUFA rich oil.

Keywords: Candida antartica, lipase, n-3 polyunsaturated fatty acids, sardine oil

Procedia PDF Downloads 207
7760 Soil Properties and Yam Performance as Influenced by Poultry Manure and Tillage on an Alfisol in Southwestern Nigeria

Authors: E. O. Adeleye

Abstract:

Field experiments were conducted to investigate the effect of soil tillage techniques and poultry manure application on the soil properties and yam (Dioscorea rotundata) performance in Ondo, southwestern Nigeria for two farming seasons. Five soil tillage techniques, namely ploughing (P), ploughing plus harrowing (PH), manual ridging (MR), manual heaping (MH) and zero-tillage (ZT) each combined with and without poultry manure at the rate of 10 tha-1 were investigated. Data were obtained on soil properties, nutrient uptake, growth and yield of yam. Soil moisture content, bulk density, total porosity and post harvest soil chemical characteristics were significantly (p>0.05) influenced by soil tillage-manure treatments. Addition of poultry manure to the tillage techniques in the study increased soil total porosity, soil moisture content and reduced soil bulk density. Poultry manure improved soil organic matter, total nitrogen, available phosphorous, exchangeable Ca, k, leaf nutrients content of yam, yam growth and tuber yield relative to tillage techniques plots without poultry manure application. It is concluded that the possible deleterious effect of tillage on soil properties, growth and yield of yam on an alfisol in southwestern Nigeria can be reduced by combining tillage with poultry manure.

Keywords: poultry manure, tillage, soil chemical properties, yield

Procedia PDF Downloads 428
7759 The Comparison of Safety Factor in Dry and Rainy Condition at Coal Bearing Formation. Case Study: Lahat Area South Sumatera Province, Indonesia

Authors: Teguh Nurhidayat, Nurhamid, Dicky Muslim, Zufialdi Zakaria, Irvan Sophian

Abstract:

This paper presents the role of climate change as the factor that induces landslide. Case study is located at Lahat Regency, South Sumatera Province, Indonesia. Study area has high economic value of coal reserves (mostly subbituminous – bituminous), which is developable for open pit coal mining in the future. Seams are found in Muara Enim Formation. This formation is at south Sumatera basin which is formed at Tertiary as a result of collision between the indian plate and eurasian plate. South Sumatera basin which is a basin located in back arc basin. This study aims to unravel the relationship between slope stability with different season condition in tropical climate. Undisturbed soil samples were obtained in the field along with other geological data. Laboratory works were carried out to obtain physical and mechanical properties of soils. Methodology to analyze slope stability is bishop method. Bishop methods are used to identify safety factor of slope. Result shows that slopes in rainy season conditions are more prone to landslides than in dry season. In the dry seasons with moisture content is 22.65%, safety factor is 1.28 the slope in stable condition. If rain is approaching with moisture content increasing to 97.8%, the slope began to be critical. On wet condition groundwater levels is increased, followed by γ (unit weight), c (cohesion), and φ (angle of friction) at 18.04, 5,88 kN/m2, and 28,04°, respectively, which ultimately determines the security factor FS to be 1.01 (slope in unstable conditions).

Keywords: rainfall, moisture content, slope analysis, landslide prone

Procedia PDF Downloads 301
7758 Variation with Depth of Physico-Chemical, Mineralogical and Physical Properties of Overburden over Gneiss Basement Complex in Minna Metropolis, North Central Nigeria

Authors: M. M. Alhaji, M. Alhassan, A. M. Yahaya

Abstract:

Soil engineers pay very little or no attention to variation in the mineralogical and consequently, the geotechnical properties of overburden with depth on basement complexes, a situation which can lead to sudden failure of civil engineering structures. Soil samples collected at depths ranging from 0.5m to 4.0m at 0.5m intervals, from a trial pit dogged manually to depth of 4.0m on an overburden over gneiss basement complex, was evaluated for physico-chemical, mineralogical and physical properties. This is to determine the variation of these properties with depth within the profile of the strata. Results showed that sodium amphibolite and feldspar, which are both primary minerals dominate the overall profile of the overburden. Carbon which dominates the lower profile of the strata was observed to alter to gregorite at upper section of the profile. Organic matter contents and cation exchange capacity reduces with increase in depth while lost on ignition and pH were relatively constant with depth. The index properties, as well as natural moisture contents, increases from 0.5m to between 1.0m to 1.5m depth after which the values reduced to constant values at 3.0m depth. The grain size analysis shows high composition of sand sized particles with silts of low to non-plasticity. The maximum dry density (MDD) values are generally relatively high and increases from 2.262g/cm³ at 0.5m depth to 2.410g/cm³ at 4.0m depth while the optimum moisture content (OMC) reduced from 9.8% at 0.5m depth to 6.7% at 4.0m depth.

Keywords: Gneiss basement complex, mineralogical properties, North Central Nigeria, physico-chemical properties, physical properties, overburden soil

Procedia PDF Downloads 129
7757 Band Characterization and Development of Hyperspectral Indices for Retrieving Chlorophyll Content

Authors: Ramandeep Kaur M. Malhi, Prashant K. Srivastava, G.Sandhya Kiran

Abstract:

Quantitative estimates of foliar biochemicals, namely chlorophyll content (CC), serve as key information for the assessment of plant productivity, stress, and the availability of nutrients. This also plays a critical role in predicting the dynamic response of any vegetation to altering climate conditions. The advent of hyperspectral data with an enhanced number of available wavelengths has increased the possibility of acquiring improved information on CC. Retrieval of CC is extensively carried through well known spectral indices derived from hyperspectral data. In the present study, an attempt is made to develop hyperspectral indices by identifying optimum bands for CC estimation in Butea monosperma (Lam.) Taub growing in forests of Shoolpaneshwar Wildlife Sanctuary, Narmada district, Gujarat State, India. 196 narrow bands of EO-1 Hyperion images were screened, and the best optimum wavelength from blue, green, red, and near infrared (NIR) regions were identified based on the coefficient of determination (R²) between band reflectance and laboratory estimated CC. The identified optimum wavelengths were then employed for developing 12 hyperspectral indices. These spectral index values and CC values were then correlated to investigate the relation between laboratory measured CC and spectral indices. Band 15 of blue range and Band 22 of green range, Band 40 of the red region, and Band 79 of NIR region were found to be optimum bands for estimating CC. The optimum band based combinations on hyperspectral data proved to be the most effective indices for quantifying Butea CC with NDVI and TVI identified as the best (R² > 0.7, p < 0.01). The study demonstrated the significance of band characterization in the development of the best hyperspectral indices for the chlorophyll estimation, which can aid in monitoring the vitality of forests.

Keywords: band, characterization, chlorophyll, hyperspectral, indices

Procedia PDF Downloads 129
7756 Characterization of Candlenut Shells and Its Application to Remove Oil and Fine Solids of Produced Water in Nutshell Filters of Water Cleaning Plant

Authors: Annur Suhadi, Haris B. Harahap, Zaim Arrosyidi, Epan, Darmapala

Abstract:

Oilfields under waterflood often face the problem of plugging injectors either by internal filtration or external filter cake built up inside pore throats. The content of suspended solids shall be reduced to required level of filtration since corrective action of plugging is costly expensive. The performance of nutshell filters, where filtration takes place, is good using pecan and walnut shells. Candlenut shells were used instead of pecan and walnut shells since they were abundant in Indonesia, Malaysia, and East Africa. Physical and chemical properties of walnut, pecan, and candlenut shells were tested and the results were compared. Testing, using full-scale nutshell filters, was conducted to determine the oil content, turbidity, and suspended solid removal, which was based on designed flux rate. The performance of candlenut shells, which were deeply bedded in nutshell filters for filtration process, was monitored. Cleaned water outgoing nutshell filters had total suspended solids of 17 ppm, while oil content could be reduced to 15.1 ppm. Turbidity, using candlenut shells, was below the specification for injection water, which was less than 10 Nephelometric Turbidity Unit (NTU). Turbidity of water, outgoing nutshell filter, was ranged from 1.7-5.0 NTU at various dates of operation. Walnut, pecan, and candlenut shells had moisture content of 8.98 wt%, 10.95 wt%, and 9.95 wt%, respectively. The porosity of walnut, pecan, and candlenut shells was significantly affected by moisture content. Candlenut shells had property of toluene solubility of 7.68 wt%, which was much higher than walnut shells, reflecting more crude oil adsorption. The hardness of candlenut shells was 2.5-3 Mohs, which was close to walnut shells’ hardness. It was advantage to guarantee the cleaning filter cake by fluidization process during backwashing.

Keywords: candlenut shells, filtration, nutshell filter, pecan shells, walnut shells

Procedia PDF Downloads 94
7755 Monitoring Soil Moisture Dynamic in Root Zone System of Argania spinosa Using Electrical Resistivity Imaging

Authors: F. Ainlhout, S. Boutaleb, M. C. Diaz-Barradas, M. Zunzunegui

Abstract:

Argania spinosa is an endemic tree of the southwest of Morocco, occupying 828,000 Ha, distributed mainly between Mediterranean vegetation and the desert. This tree can grow in extremely arid regions in Morocco, where annual rainfall ranges between 100-300 mm where no other tree species can live. It has been designated as a UNESCO Biosphere reserve since 1998. Argania tree is of great importance in human and animal feeding of rural population as well as for oil production, it is considered as a multi-usage tree. Admine forest located in the suburbs of Agadir city, 5 km inland, was selected to conduct this work. The aim of the study was to investigate the temporal variation in root-zone moisture dynamic in response to variation in climatic conditions and vegetation water uptake, using a geophysical technique called Electrical resistivity imaging (ERI). This technique discriminates resistive woody roots, dry and moisture soil. Time-dependent measurements (from April till July) of resistivity sections were performed along the surface transect (94 m Length) at 2 m fixed electrode spacing. Transect included eight Argan trees. The interactions between the tree and soil moisture were estimated by following the tree water status variations accompanying the soil moisture deficit. For that purpose we measured midday leaf water potential and relative water content during each sampling day, and for the eight trees. The first results showed that ERI can be used to accurately quantify the spatiotemporal distribution of root-zone moisture content and woody root. The section obtained shows three different layers: middle conductive one (moistured); a moderately resistive layer corresponding to relatively dry soil (calcareous formation with intercalation of marly strata) on top, this layer is interspersed by very resistant layer corresponding to woody roots. Below the conductive layer, we find the moderately resistive layer. We note that throughout the experiment, there was a continuous decrease in soil moisture at the different layers. With the ERI, we can clearly estimate the depth of the woody roots, which does not exceed 4 meters. In previous work on the same species, analyzing the δ18O in water of xylem and in the range of possible water sources, we argued that rain is the main water source in winter and spring, but not in summer, trees are not exploiting deep water from the aquifer as the popular assessment, instead of this they are using soil water at few meter depth. The results of the present work confirm the idea that the roots of Argania spinosa are not growing very deep.

Keywords: Argania spinosa, electrical resistivity imaging, root system, soil moisture

Procedia PDF Downloads 316
7754 Improvement of Mechanical Properties of Saline Soils by Fly Ash: Effect of Freeze-Thaw Cycles

Authors: Zhuo Cheng, Gaohang Cui, Yang Zheng, Zhiqiang-Pan

Abstract:

To explore the effect of freeze-thaw cycles on saline soil mechanical properties of fly ash, this study examined the influence of different numbers of freezing and thawing cycles, fly ash content, and moisture content of saline soil in unconfined compression tests and triaxial shear tests. With increased fly ash content, the internal friction angle, cohesion, unconfined compressive strength, and shear strength of the improved soil increased at first and then decreased. Using the Desk-Expert 8.0 software and based on significance analysis theory, the number of freeze-thaw cycles, fly ash content, water content, and the interactions between various factors on the mechanical properties of saline soil were studied. The results showed that the number of freeze-thaw cycles had a significant effect on the mechanical properties of saline soil, while the fly ash content had a weakly significant effect. At the same time, interaction between the number of freeze-thaw cycles and the water content had a significant effect on the unconfined compressive strength and the cohesion of saline soil, and the interaction between fly ash content and the number of freeze-thaw cycles only had a significant effect on the unconfined compressive strength.

Keywords: fly ash, saline soil, seasonally frozen area, significance analysis, qualitative analysis

Procedia PDF Downloads 129