Search results for: wood combustion

Authors: Yih-Chien Chen, Yue-Xuan Du, Min-Zhe Weng

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Carbon monoxide is a substance produced by the incomplete combustion. It is toxic even at concentrations of less than 100ppm. Since it is colorless and odorless, it is difficult to detect. CO sensors have been developed using a variety of physical mechanisms, including semiconductor oxides, solid electrolytes, and organic semiconductors. Many works have focused on using semiconducting sensors composed of sensitive layers such as ZnO, TiO₂, and NiO with high sensitivity for gases. However, these sensors working at high temperatures increased their power consumption. On the other hand, the dielectric resonator (DR) is attractive for gas detection due to its large surface area and sensitivity for external environments. Materials that are to be employed in sensing devices must have a high-quality factor. Numerous researches into the fergusonite-type structure and related ceramic systems have explored. Extensive research into RENbO₄ ceramics has explored their potential application in resonators, filters, and antennas in modern communication systems, which are operated at microwave frequencies. Nd(Ti₀.₅W₀.₅)O₄ ceramics were synthesized herein using the conventional mixed-oxide method. The Nd(Ti₀.₅W₀.₅)O₄ ceramics were prepared using the conventional solid-state method. Dielectric constants (εᵣ) of 15.4-19.4 and quality factor (Q×f) of 3,600-11,100 GHz were obtained at sintering temperatures in the range 1425-1525°C for 4 h. The dielectric properties of the Nd(Ti₀.₅W₀.₅)O₄ ceramics at microwave frequencies were found to vary with the sintering temperature. For a further understanding of these microwave dielectric properties, they were analyzed by densification, X-ray diffraction (XRD), and by making microstructural observations.

Keywords: dielectric constant, dielectric resonators, sensors, quality factor

Procedia PDF Downloads 235

Authors: Luísa P. Cruz-Lopes, Hugo Costa e Silva, Idalina Domingos, José Ferreira, Luís Teixeira de Lemos, Bruno Esteves

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The liquefaction process of cork based tree barks has led to an increase of interest due to its potential innovation in the lumber and wood industries. In this particular study the bark of Quercus cerris (Turkish oak) is used due to its appreciable amount of cork tissue, although of inferior quality when compared to the cork provided by other Quercus trees. This study aims to optimize alkaline catalysis liquefaction conditions, regarding several parameters. To better comprehend the possible chemical characteristics of the bark of Quercus cerris, a complete chemical analysis was performed. The liquefaction process was performed in a double-jacket reactor heated with oil, using glycerol and a mixture of glycerol/ethylene glycol as solvents, potassium hydroxide as a catalyst, and varying the temperature, liquefaction time and granulometry. Due to low liquefaction efficiency resulting from the first experimental procedures a study was made regarding different washing techniques after the filtration process using methanol and methanol/water. The chemical analysis stated that the bark of Quercus cerris is mostly composed by suberin (ca. 30%) and lignin (ca. 24%) as well as insolvent hemicelluloses in hot water (ca. 23%). On the liquefaction stage, the results that led to higher yields were: using a mixture of methanol/ethylene glycol as reagents and a time and temperature of 120 minutes and 200 ºC, respectively. It is concluded that using a granulometry of <80 mesh leads to better results, even if this parameter barely influences the liquefaction efficiency. Regarding the filtration stage, washing the residue with methanol and then distilled water leads to a considerable increase on final liquefaction percentages, which proves that this procedure is effective at liquefying suberin content and lignocellulose fraction.

Keywords: liquefaction, Quercus cerris, polyalcohol liquefaction, temperature

Procedia PDF Downloads 310

Authors: Hassan Athari, Alireza Ruhi Sales, Amin Pourafshar, Seyyed Mehdi Pestei, Marc. A. Rosen

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In order to achieve high efficiency and high specific work with lower emissions, the use of advanced gas turbine cycles for power generation is useful and advantageous. Here, evaporative inlet air cooling is analyzed thermodynamically in the form of air film blade cooling of gas turbines. As the ambient temperature increases during summer months, the performance of gas turbines particularly the output power and energy efficiency are significantly decreased. The utilization of evaporative inlet cooling in gas turbine cycles increases gas turbine performance, which can assist to solve the problem in meeting the increasing demands for electrical power and offsetting shortages during peak load times. In the present research, because of the importance of turbine blade cooling, the turbine is investigated with cold compressed air used for cooling the turbine blades. The investigation of the basic and modified cycles shows that, by adding an evaporative cooler to a simple gas turbine cycle, for a turbine inlet temperature of 1400 °C, an ambient temperature of 45 °C and a relative humidity of 15%, the specific work can reach 331 (kJ/kg air), while the maximum specific work of a simple cycle for the same conditions is 273.7 (kJ/kg air). The exergy results reveal that the highest exergy destruction occurs in the combustion chamber, where the large temperature differences and highly exothermic chemical reactions are the main sources of the irreversibility.

Keywords: energy, exergy, wet compression, air-film cooling blade, gas turbine

Procedia PDF Downloads 123

Authors: T. S. Desak Ketut, A.n. Isna, A.a. Ayu, D. P. Ririn, Suharjono Hadiatullah

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The requirement of paper from year to year rise rapidly. The raising of cellulose requirement in paper production caused increasing of wood requirement with the effect that limited forest areal because of deforestation. Alternative cellulose that can be used for making paper is microbial cellulose. The objective of this research are to know the effectivity fermentation media Spirogyra sp. by Gluconacetobacter xylinum for cellulose production as material for the making of paper and to know effect composition bacterial cellulose composite product of Gluconacetobacter xylinum in Spirogyra sp. The method, was used, is as follow, 1) the effect assay from variation composition of fermentation media to bacterial cellulose production by Gluconacetobacter xylinum. 2) The effect assay of composition bacterial cellulose fermentation producted by Gluconacetobacter xylinum in extracted Spirogyra media to paper quality. The result of this research is variation fermentation media Spirogyra sp. affect to production of cellulose by Gluconacetobacter xylinum. Thus, result showed by the highest value and significantly different in thickness parameter, dry weight and wet weight of nata in sucrose concentration 7,5 % and urea 0,75 %. Composition composite of bacterial cellulose from fermentation product by Gluconacetobacter xylinum in media Spirogyra sp. affect to paper quality from wet nata and dry nata. Parameters thickness, weight, water absorpsion, density and gramatur showed highest result in sucrose concentration 7,5 % and urea concentration 0,75 %, except paper density from dry nata had highest result in sucrose and urea concentration 0%.

Keywords: cellulose, fermentation media, , Gluconacetobacter xylinum, paper, Spirogyra sp.

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Authors: Omid Ghaffarzadeh Mollabashi, Sara Khorshidi, Hossein Kermanian Seyed, Majid Zabihzadeh

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The main problem that hinders the intensive use of non-wood raw materials in papermaking industry is the environmental pollution caused by black liquor. As a matter of fact, black liquor of nonwood pulping is discharged to the environment due to the lack of recovery. Traditionally, NaOH pulping produces Na-based black liquor that may increase soil erosion and reduce soil permeability. With substitution of KOH/NH4OH with NaOH as the cooking liquor, K and N can act as a soil fertilizer while offering an environmentally acceptable disposal alternative. For this purpose, rice straw samples were pulped under the following conditions; Constant factors were: straw weight: 100 gram (based on oven dry), liquor to straw ratio 7:1 and maximum temperature, 170 and 180 ºC. Variable factors for KOH cooks were: KOH dosage of 14, 17 and %20 on oven dry of straw and times at maximum temperature of 60 and 90 minutes. For KOH-NH4OH cooks, KOH dosage of 5 and %10 and NH4OH dosage of 25 and %35, both based as oven dry of straw were applied. Besides, time at maximum temperature was 90 minutes. Yield ranges of KOH and KOH-NH4OH pulp samples were obtained from 37.28 to 48.62 and 45.63 to 48.08 percent, respectively. In addition, Kappa number ranged from 21.91 to 29.85 and 55.15 to 56.25, respectively. In comparison with soda, soda-AQ, cold soda, kraft, EDA (dissolving), De-Ethylene Glycol (dissolving), burst and tensile index for KOH pulp was more in similar cooking condition. With an exception of soda pulps, tear index of the mentioned pulp is more than all compared treatments. Therefore, it can be resulted that KOH pulping method is an appropriate choice for making paper of the rice straw. Also, compared to KOH-NH4OH, KOH pulping method is more appropriate choice because of better pulping results.

Keywords: environmentally friendly process, rice straw, NH4OH-KOH pulping, pulp properties

Procedia PDF Downloads 243

Authors: Mohamed El Morsy, Gabriela Achtenová

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Research on damage of gears and gear pairs using vibration signals remains very attractive, because vibration signals from a gear pair are complex in nature and not easy to interpret. Predicting gear pair defects by analyzing changes in vibration signal of gears pairs in operation is a very reliable method. Therefore, a suitable vibration signal processing technique is necessary to extract defect information generally obscured by the noise from dynamic factors of other gear pairs. This article presents the value of cepstrum analysis in vehicle gearbox fault diagnosis. Cepstrum represents the overall power content of a whole family of harmonics and sidebands when more than one family of sidebands is present at the same time. The concept for the measurement and analysis involved in using the technique are briefly outlined. Cepstrum analysis is used for detection of an artificial pitting defect in a vehicle gearbox loaded with different speeds and torques. The test stand is equipped with three dynamometers; the input dynamometer serves as the internal combustion engine, the output dynamometers introduce the load on the flanges of the output joint shafts. The pitting defect is manufactured on the tooth side of a gear of the fifth speed on the secondary shaft. Also, a method for fault diagnosis of gear faults is presented based on order cepstrum. The procedure is illustrated with the experimental vibration data of the vehicle gearbox. The results show the effectiveness of cepstrum analysis in detection and diagnosis of the gear condition.

Keywords: cepstrum analysis, fault diagnosis, gearbox, vibration signals

Procedia PDF Downloads 357

Authors: A. A. Dare, E. U. Iniegbedion

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Industrial furnaces generally involve enclosures of fire typically initiated by the combustion of gases. The fire leads to temperature distribution inside the enclosure. A proper understanding of the temperature and velocity distribution within the enclosure is often required for optimal design and use of the furnace. This study was therefore directed at numerical modeling of temperature distribution inside an enclosure as typical in a furnace. A mathematical model was developed from the conservation of mass, momentum and energy. The stream function-vorticity formulation of the governing equations was solved by an alternating direction implicit (ADI) finite difference technique. The finite difference formulation obtained were then developed into a computer code. This was used to determine the temperature, velocities, stream function and vorticity. The effect of the wall heat conduction was also considered, by assuming a one-dimensional heat flow through the wall. The computer code (MATLAB program) developed was used for the determination of the aforementioned variables. The results obtained showed that the transient temperature distribution assumed a uniform profile which becomes more chaotic with increasing time. The vertical velocity showed increasing turbulent behavior with time, while the horizontal velocity assumed decreasing laminar behavior with time. All of these behaviours were equally reported in the literature. The developed model has provided understanding of heat transfer process in an industrial furnace.

Keywords: heat source, modelling, enclosure, furnace

Procedia PDF Downloads 235

Authors: M. Kashfi, K. Jahani

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Sound attenuation in absorptive silencers has been analyzed in this paper. The structure of such devices is as follows. When the rigid duct of an expansion chamber has been lined by a packed absorptive material under a perforated membrane, incident sound waves will be dissipated by the absorptive liners. This kind of silencer, usually are applicable for medium to high frequency ranges. Several conditions for different absorptive materials, variety in their thicknesses, and different shapes of the expansion chambers have been studied in this paper. Also, graphs of sound attenuation have been compared between empty expansion chamber and duct of silencer with applying liner. Plane waves have been assumed in inlet and outlet regions of the silencer. Presented results that have been achieved by applying finite element method (FEM), have shown the dependence of the sound attenuation spectrum to flow resistivity and the thicknesses of the absorptive materials, and geometries of the cross section (configuration of the silencer). As flow resistivity and thickness of absorptive materials increase, sound attenuation improves. In this paper, diagrams of the transmission loss (TL) for absorptive silencers in five different cross sections (rectangle, circle, ellipse, square, and rounded rectangle as the main geometry) have been presented. Also, TL graphs for silencers using different absorptive material (glass wool, wood fiber, and kind of spongy materials) as liner with three different thicknesses of 5 mm, 15 mm, and 30 mm for glass wool liner have been exhibited. At first, the effect of substances of the absorptive materials with the specific flow resistivity and densities on the TL spectrum, then the effect of the thicknesses of the glass wool, and at last the efficacy of the shape of the cross section of the silencer have been investigated.

Keywords: transmission loss, absorptive material, flow resistivity, thickness, frequency

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Authors: Leonardo E. Pacheco, Carlos A. Díaz

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An alternative way of addressing the difficult to recover the useless heat is through an ejector refrigeration cycle for vehicles applications. A group of thermo-compressor supply the mechanical compressor function at conventional refrigeration compression system. The thermo-compressor group recovers the thermal energy from waste streams (exhaust gases product in internal combustion motors, gases burned in wellhead among others) to eliminate the power consumption of the mechanical compressor. These types of alternative cooling system (air-conditioners) present a kind of advantages in both the increase in energy efficiency and the improvement of the COP of the system being studied from their its mechanical simplicity (decrease of moving parts). An ejector refrigeration cycle represents a significant step forward in the optimization of the efficient use of energy in the process of air conditioning and an alternative to reduce the environmental impacts. On one side, with the energy recycling decreases the temperature of the gases thrown into the atmosphere, which contributes to the principal beneficiaries of the average temperature of the planet. In parallel, mitigating the environmental impact caused by the production and handling of conventional cooling fluids commonly available in the market, causing the destruction of the ozone layer. This work had studied the operation of the multiejector cooling system for a truck with a 420 HP engine at different rotation speed. The operation condition limits and the COP of multi-ejector cooling systems applied in a truck are analyzed for a variable rpm range from to 800–1800 rpm.

Keywords: ejector system, exhaust gas, multiejector cooling system, recovery energy

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Authors: B. Białecka, Z. Adamczyk, M. Cempa

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The use of ultrasounds in zeolization of fly ash can increase the efficiency of this process. The molar ratios of the reagents, as well as the time and temperature of the synthesis, are the main parameters determining the type and properties of the zeolite formed. The aim of the work was to create hydrosodalite in a short time (8h), with low NaOH concentration (3 M) and in low temperature (80°C). A zeolite material contained in fly ash from hard coal combustion in one of Polish Power Plant was subjected to hydrothermal alkaline synthesis. The phase composition of the ash consisted mainly of glass, mullite, quartz, and hematite. The dominant chemical components of the ash were SiO₂ (over 50%mas.) and Al₂O₃ (more than 28%mas.), whereas the contents of the remaining components, except Fe₂O₃ (6.34%mas.), did not exceed 4% mas. The hydrothermal synthesis of the zeolite material was carried out in the following conditions: 3M-solution of NaOH, synthesis time – 8 hours, 40 kHz-frequency ultrasounds during the first two hours of synthesis. The mineral components of the input ash as well as product after synthesis were identified in microscopic observations, in transmitted light, using X-ray diffraction (XRD) and electron scanning microscopy (SEM/EDS). The chemical composition of the input ash was identified by the method of X-ray fluorescence (XRF). The obtained material apart from phases found in the initial fly ash sample, also contained new phases, i.e., hydrosodalite and NaP-type zeolite. The chemical composition in micro areas of grains indicated their diversity: i) SiO₂ content was in the range 30-59%mas., ii) Al₂O₃ content was in the range 24-35%mas., iii) Na₂O content was in the range 6-15%mas. This clearly indicates that hydrosodalite forms hypertrophies with NaP type zeolite as well as relict grains of fly ash. A small amount of potassium in the examined grains is noteworthy, which may indicate the substitution of sodium with potassium. This is confirmed by the high value of the correlation coefficient between these two components.

Keywords: fly ash, hydrosodalite, ultrasounds, zeolite

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Authors: Selman Cagman

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A detailed analysis is made within an organized industrial zone (OIZ) that has 1165 production facilities such as manufacturing of furniture, fabricated metal products (machinery and equipment), food products, plastic and rubber products, machinery and equipment, non-metallic mineral products, electrical equipment, textile products, and manufacture of wood and cork products. In this OIZ, a field study is done by choosing some facilities that can represent the whole OIZ sectoral distribution. In this manner, there are 207 facilities included to the site visit, and there is a 17 questioned survey carried out with each of them to assess their inputs, outputs, and waste amounts during manufacturing processes. The survey result identify that MDF/Particleboard and chipboard particles, textile, food, foam rubber, sludge (treatment sludge, phosphate-paint sludge, etc.), plastic, paper and packaging, scrap metal (aluminum shavings, steel shavings, iron scrap, profile scrap, etc.), slag (coal slag), ceramic fracture, ash from the fluidized bed are the wastes come from these facilities. As a result, there are 5 industrial symbiosis projects established with this study. One of the projects is a 2.840 kW capacity Integrated Biomass Based Waste Incineration-Energy Production Facility running on 35.000 tons/year of MDF particles and chipboard waste. Another project is a biogas plant with 225 tons/year whey, 100 tons/year of sesame husk, 40 tons/year of burnt wafer dough, and 2.000 tons/year biscuit waste. These two plants investment costs and operational costs are given in detail. The payback time of the 2.840 kW plant is almost 4 years and the biogas plant is around 6 years.

Keywords: industrial symbiosis, energy, biogas, waste to incineration

Procedia PDF Downloads 83

Authors: Shyh-Ming Chern, Te-Hsiu Tang

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Hemicellulose is one of the major constituents of all plant cell walls, making up 15-25% of dry wood. It is a biopolymer from many different sugar monomers, including pentoses, like xylose, and hexoses, like mannose. In an effort to gasify real biomass in subcritical and supercritical water in a single process, it is necessary to understand the gasification of hemicellulose, in addition to cellulose and lignin, in subcritical and supercritical water. In the present study, xylose is chosen as the model compound for hemicellulose, since it has the largest amount in most hardwoods. Xylose is gasified in subcritical and supercritical water for the production of higher-valued gaseous products. Experiments were conducted with a 16-ml autoclave batch-type reactor. Hydrogen peroxide is adopted as the oxidant in an attempt to promote the gasification yield. The major operating parameters for the gasification include reaction temperature (400 - 600°C), reaction pressure (5 - 25 MPa), the concentration of xylose (0.05 and 0.30 M), and level of oxidant added (0 and 0.25 chemical oxygen demand). 102 experimental runs were completed out of 46 different set of experimental conditions. Product gases were analyzed with a GC-TCD and determined to be mainly composed of H₂ (10 – 74 mol. %), CO (1 – 56 mol. %), CH₄ (1 – 27 mol. %), CO₂ (10 – 50 mol. %), and C₂H₆ (0 – 8 mol. %). It has been found that the gas yield (amount of gas produced per gram of xylose gasified), higher heating value (HHV) of the dry product gas, and energy yield (energy stored in the product gas divided by the energy stored in xylose) all increase significantly with rising temperature and moderately with reducing pressure. The overall best operating condition occurred at 873 K and 10 MPa, with a gas yield of 54 mmol/g of xylose, a gas HHV of 440 kJ/mol, and an energy yield of 1.3. A seemingly unreasonably energy yield of greater than unity resulted from the external heating employed in the experiments to drive the gasification process. It is concluded that xylose can be completely gasified in subcritical and supercritical water under proper operating conditions. The addition of oxidant does not promote the gasification of xylose.

Keywords: gasification, subcritical water, supercritical water, xylose

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Authors: Neha Budhwani

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Polycyclic aromatic hydrocarbons (PAHs) are formed during the pyrolysis of scrap tyres to produce tyre pyrolytic oil (TPO). Due to carcinogenic, mutagenic, and toxic properties PAHs are priority pollutants. Hence it is essential to remove PAHs from TPO before utilising TPO as a petroleum fuel alternative (to run the engine). Agricultural wastes have promising future to be utilized as biosorbent due to their cost effectiveness, abundant availability, high biosorption capacity and renewability. Various low cost adsorbents were prepared from natural sources. Uptake of PAHs present in tyre pyrolytic oil was investigated using various low-cost adsor¬bents of natural origin including sawdust (shiham), coconut fiber, neem bark, chitin, activated charcol. Adsorption experiments of different PAHs viz. naphthalene, acenaphthalene, biphenyl and anthracene have been carried out at ambient temperature (25°C) and at pH 7. It was observed that for any given PAH, the adsorption capacity increases with the lignin content. Freundlich constant kf and 1/n have been evaluated and it was found that the adsorption isotherms of PAHs were in agreement with a Freundlich model, while the uptake capacity of PAHs followed the order: activated charcoal> saw dust (shisham) > coconut fiber > chitin. The partition coefficients in acetone-water, and the adsorption constants at equilibrium, could be linearly correlated with octanol–water partition coefficients. It is observed that natural adsorbents are good alternative for PAHs removal. Sawdust of Dalbergia sissoo, a by-product of sawmills was found to be a promising adsorbent for the removal of PAHs present in TPO. It is observed that adsorbents studied were comparable to those of some conventional adsorbents.

Keywords: natural adsorbent, PAHs, TPO, coconut fiber, wood powder (shisham), naphthalene, acenaphthene, biphenyl and anthracene

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Authors: Birtukan Atinkut Asmare

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Climate change disproportionately affects many Africans who heavily rely on climate-exposed sectors such as rain-fed agriculture and fishing, rendering them highly vulnerable. Gender plays a significant role, as men and women experience unequal impacts and vulnerabilities due to gender norms, labor divisions, resource access, and power dynamics. Drawing on an integrated framework, this study sheds light on the gendered impacts of climate change on household’s livelihood, their vulnerability, and adaptation in rural Ethiopia's Lake Tana Basin. This study utilized mixed research methods, integrating diverse qualitative techniques such as focus group discussions, key informant interviews, and field observations, along with quantitative data gathered through household surveys. The findings reveal that women-headed households were more vulnerable to climate change than male-headed households. Flood was the major climate-induced hazards in the area that threatened the lives and livelihoods of households. In response to climate change, households undertook different adaptation measures such as agroforestry practices, crop diversification, seasonal migration, petty trading, charcoal and fuel wood sales. However, the adaptation strategies were slightly varied based on the gender of the household head. Women-headed households specifically engaged in fuelwood collection and selling and petty trading activities. The main constraints for adaptation were limited access to technologies, extension services, information, and financial services. Therefore, this research urges attention from research, policy, and advisory services on rural households who are trying to survive in the face of climate change.

Keywords: agriculture, climate change impacts, ethiopia, gender

Procedia PDF Downloads 34

Authors: Nursigit Bintoro, Abadi Barus, Catur Setyo Dedi Pamungkas

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Indonesia is an agrarian country have almost population work as farmers. One of the popular agriculture commodity in Indonesia is paddy and corn. Production of paddy and corn are increased, but not balanced to the development of appropriate technology to farmers. Methods of drying applied with farmers still using sunshine. Drying by this method has some drawbacks, such as differences moisture content of corn grains, time used to dry around 3 days, and less quality of the products obtained. Beside it, the method of drying by using sunshine can’t do when the rainy season arrives. On this season the product obtained has less quality. One solution to the above problems is to create a dryer with simple technology. That technology is made silo dryer from webbing bamboo and wood. This technology is applicable to be applied to farmers' groups as well as the creation technology is quite cheap. The experiment material used in this research will be obtained from the corn grains. The equipment used are woven bamboo with a height of 3 meters and have capacity of up to 900 kgs as a silo, gas, burner, blower, bucket elevators, thermocouple, Arduino microcontroller 2560. This tools automatically records all the data of temperature and relative humidity. During on drying, each 30 minutes take 9 sample for measuring moisture content with moisture meter. By using this technology, farmers can save time, energy, and cost to the drying their agriculture product. In addition, by using this technology have good quality moisture content of grains and have a longer shelf life because the temperature when the heating process is controlled. Therefore, this technology is applicable to be applied to the public because the materials used to make the dryer easier to find, cheaper, and manufacture of the dryer made simple with good quality.

Keywords: grains, dryer, moisture content, appropriate technology

Procedia PDF Downloads 326

Authors: Ada Garus

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This paper presents the outcomes of the sustainability assessment of food delivery with a last-mile delivery service introduced in a real-world case study. The methodology used in the sustainability assessment integrates multi-criteria decision-making analysis, sustainability pillars, and scenario analysis to best reflect the conflicting needs of stakeholders involved in the last mile delivery system. The case study provides an application of the framework to the food delivery system of the Joint Research Centre of the European Commission where three alternative solutions were analyzed I) the existent state in which individuals frequent the local cantine or pick up their food, using their preferred mode of transport II) the hypothetical scenario in which individuals can only order their food using the delivery droid system III) a scenario in which the food delivery droid based system is introduced as a supplement to the current system. The environmental indices are calculated using a simulation study in which decision regarding the food delivery is predicted using a multinomial logit model. The vehicle dynamics model is used to predict the fuel consumption of the regular combustion engines vehicles used by the cantine goers and the electricity consumption of the droid. The sustainability assessment allows for the evaluation of the economic, environmental, and social aspects of food delivery, making it an apt input for policymakers. Moreover, the assessment is one of the first studies to investigate automated delivery droids, which could become a frequent addition to the urban landscape in the near future.

Keywords: innovations in transportation technologies, behavioural change and mobility, urban freight logistics, innovative transportation systems

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Authors: Ibetombi Soibam

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Li-Zn-Ni ferrite having the compositional formula Li0.4-0.5xZn0.2NixFe2.4-0.5xO4 where x = 0.02 ≤ x ≤0.1 in steps of 0.02 was fabricated by the citrate precursor method. In this method, metal nitrates and citric acid was used to prepare the gel which exhibit self-propagating combustion behavior giving the required ferrite sample. The ferrite sample was given a pre-firing at 650°C in a programmable conventional furnace for 3 hours with a heating rate of 5°C/min. A series of the sample was finally given conventional sintering (CS) at 1040°C after the pre-firing process. Another series was given microwave sintering (MS) at 1040°C in a programmable microwave furnace which uses a single magnetron operating at 2.45 GHz frequency. X- ray diffraction pattern confirmed the spinel phase structure for both the series. The theoretical and experimental density was calculated. It was observed that densification increases with the increase in Ni concentration in both the series. However, samples sintered by microwave technique was found to be denser. The microstructure of the two series of the sample was examined using scanning electron microscopy (SEM). Dielectric properties have been investigated as a function of frequency and composition for both series of samples sintered by CS and MS technique. The variation of dielectric constant with frequency show dispersion for both the series. It was explained in terms of Koop’s two layer model. From the analysis of dielectric measurement, it was observed that the value of room temperature dielectric constant decreases with the increase in Ni concentration for both the series. The microwave sintered samples show a lower dielectric constant making microwave sintering suitable for high-frequency applications. The possible mechanisms contributing to all the above behavior is being discussed.

Keywords: citrate precursor, dielectric constant, ferrites, microwave sintering

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Authors: Pavel V. Balabanov, Daria A. Liubimova, Aleksandr P. Savenkov

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The increase of technogenic and natural accidents, accompanied by air pollution, for example, by combustion products, leads to the necessity of respiratory protection. This work is devoted to the development of a calorimetric method and a device which allow investigating quickly the kinetics of carbon dioxide sorption by chemo-sorbents on the base of potassium superoxide in order to assess the protective properties of respiratory protective closed-circuit apparatus. The features of the traditional approach for determining the sorption properties in a thin layer of chemo-sorbent are described, as well as methods and devices, which can be used for the sorption kinetics study. The authors of the paper developed an approach (as opposed to the traditional approach) based on the power measurement of internal heat sources in the chemo-sorbent layer. The emergence of the heat sources is a result of the exothermic reaction of carbon dioxide sorption. This approach eliminates the necessity of chemical analysis of samples and can significantly reduce the time and material expenses during chemo-sorbents testing. The error of determining the volume fraction of adsorbed carbon dioxide by the developed method does not exceed 12%. Taking into account the efficiency of the method, we consider that it is a good alternative to traditional methods of chemical analysis under the assessment of the protection sorbents quality.

Keywords: carbon dioxide chemisorption, exothermic reaction, internal heat sources, respiratory protective apparatus

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Authors: Jeni A. Popescu, Sorin G. Tomescu, Valeriu A. Vilag

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The paper focuses on the potential methods of increasing the performance of a microturbine by combining additional elements available for utilization in a cogeneration plant. The activity is carried out within the framework of a project aiming to develop, manufacture and test a microturbine functional model with high potential in energetic industry utilization. The main goal of the analysis is to determine the parameters of the fluid flow passing through each section of the turbine, based on limited data available in literature for the focus output power range or provided by experimental studies, starting from a reference cycle, and considering different cycle options, including simple, intercooled and recuperated options, in order to optimize a small cogeneration plant operation. The studied configurations operate under the same initial thermodynamic conditions and are based on a series of assumptions, in terms of individual performance of the components, pressure/velocity losses, compression ratios, and efficiencies. The thermodynamic analysis evaluates the expected performance of the microturbine cycle, while providing a series of input data and limitations to be included in the development of the experimental plan. To simplify the calculations and to allow a clear estimation of the effect of heat transfer between fluids, the working fluid for all the thermodynamic evolutions is, initially, air, the combustion being modelled by simple heat addition to the system. The theoretical results, along with preliminary experimental results are presented, aiming for a correlation in terms of microturbine performance.

Keywords: cogeneration, microturbine, performance, thermodynamic analysis

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Authors: A. Majczak, G. Baranski, K. Pietrykowski

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Due to the growing popularity of light aircraft, it has become necessary to develop aircraft engines for this type of construction. One of engine system, designed to increase efficiency and reduce weight, is the engine with opposed pistons. In such an engine, the combustion chamber is formed by two pistons moving in one cylinder. Therefore, this type of engines run in a two-stroke cycle, so they have many advantages such as high power and torque, high efficiency, or a favorable power-to-weight ratio. Tests of one of the available aircraft engines with opposing piston system fueled with diesel oil were carried out on an engine dynamometer equipped with an eddy current brake and the necessary measuring and testing equipment. In order to get to know the basic parameters of the engine, the tests were carried out under partial load conditions for the following torque values: 40, 60, 80, 100 Nm. The rotational speed was changed from 1600 to 2500 rpm. Measurements were also taken for designated points of propeller characteristics. During the tests, the engine torque, engine power, fuel consumption, intake manifold pressure, and oil pressure were recorded. On the basis of the measurements carried out for particular loads, the power curve, hourly and specific fuel consumption curves were determined. Characteristics of charge pressure as a function of rotational speed as well as power, torque, hourly and specific fuel consumption curves for propeller characteristics were also prepared. The obtained characteristics make it possible to select the optimal points of engine operation.

Keywords: aircraft, diesel, engine testing, opposed piston

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Authors: Divya Ramaseshan

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The indigenous beauty of a space supported by its local context is unmatchable. India, known to be a hub for varied cultural significance, has one of the best uses of vernacularism. This paper focuses on the traditional houses present in Thirumayilai, Mylapore, one of the oldest and most populous cities in Chennai. The Mylapore houses are known for their Agraharam style with thinnai, courtyard, and sloping roof characteristics. These homes had a combined influence of Indian, Islamic as well as Neo-classical architecture in their design. The design of the houses reflects the lives of Brahmin communities which have almost vanished from sight now. According to the growing demands of local residents as well as urbanization, many houses have been renovated. Some of those structures have been conserved in certain streets showcasing their historical identity. Other structures have either been demolished or redesigned based on people’s needs. Those structures have been identified and studied to understand the comparative features that have been changed. Many of those were in direct relevance to the city’s climate, family size, socializing habits, and local materials. Being a temple town, Mylapore has contour variations sloping towards various water bodies. These factors have been considered for building homes as well. The study aims to list down the possible design guidelines that could be effective in today’s construction field. The pros and cons are analyzed, and the respective methodologies are framed. Our modern construction technologies have brought in the best visual aesthetics in a short frame of time, but the serene touch of teak wood, walking through paved stones, daydreaming in the sunlit courtyards, and chitchatting in porticos are always cherished. Architects around the world are trying hard to achieve such appreciated design elements in upcoming projects with the best use of modern technology. This will also improvise people’s mental health in the comfort of their homes.

Keywords: Agraharam, Mylapore, traditional, vernacularism

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Authors: M. Pilar Valles-gonzalez, Alejandro Gonzalez Meije, Ana Pastor Muro, Maria Garcia-Martinez, Beatriz Gonzalez Caballero

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This paper studies a failure case of a fuel pressure supply tube from an aircraft engine. Multiple fracture cases of the fuel pressure control tube from aircraft engines have been reported. The studied set was composed of the mentioned tube, a welded connecting pipe, where the fracture has been produced, and a union nut. The fracture has been produced in one most critical zones of the tube, in a region next to the supporting body of the union nut to the connector. The tube material was X6CrNiTi18-10, an austenitic stainless steel. Chemical composition was determined using an X-Ray fluorescence spectrometer (XRF) and combustion equipment. Furthermore, the material has been mechanical, by hardness test, and microstructural characterized using a stereomicroscope and an optical microscope. The results confirmed that it is within specifications. To determine the macrofractographic features, a visual examination and a stereo microscope of the tube fracture surface have been carried out. The results revealed a tube plastic macrodeformation, surface damaged, and signs of a possible corrosion process. Fracture surface was also inspected by scanning electron microscopy (FE-SEM), equipped with a microanalysis system by X-ray dispersive energy (EDX), to determine the microfractographic features in order to find out the failure mechanism involved in the fracture. Fatigue striations, which are typical from a progressive fracture by a fatigue mechanism, have been observed. The origin of the fracture has been placed in defects located on the outer wall of the tube, leading to a final overload fracture.

Keywords: aircraft engine, fatigue, FE-SEM, fractography, fracture, fuel tube, microstructure, stainless steel

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Authors: David P. Horton, Gary Lynch-Wood

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Western populations are aging, prone to various lifestyle health problems, and increasing their demand for health and social care services. This demand has created enormous fiscal and regulatory challenges. In response, government institutions have deployed strategies of behavior modification to encourage people to exercise greater personal responsibility over their health and care needs (i.e., welfare responsibilisation). Policy strategies are underpinned by the assumption that people if properly supported, will make better health and lifestyle selections. Not only does this absolve governments of the responsibility for meeting all health and care needs, but it also enables government institutions to assert fiscal control over welfare spending. Looking at the regulation of health and social care in the UK, the authors identify and outline a suite of regulatory tools that are designed to extract and manage the resources of health and social care services users and to encourage them to make (‘better’) use of these resources. This is important for our understanding of how health and social care regulation is responding to ongoing social and economic challenges. It is also important because there has been a failure to systematically examine the relevance of resources for regulation, which is surprising given that resources are crucial to how and whether regulation succeeds or fails. In particular, drawing from the regulatory welfare state concept, the authors analyse the key legal and regulatory changes and mechanisms that have been introduced since the 2008 financial crisis, focusing on critical measures such as the Health and Social Care Act and regulations introduced under the National Health Service Act. The authors show how three types of user resources (i.e., tangible, labor, and data) are being used to assert fiscal control and increase welfare responsibilisation. Amongst other things, the paper concludes that service users have become more than rule followers and targets of behavioral modification; rather, they are producers of resources that regulatory systems have come to rely on.

Keywords: health care, regulation, resources, social care

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Authors: Rujira Jitrwung, Kuntima Krekkeitsakul, Weerawat Patthaveekongka, Chiraphat Kumpidet, Jarukit Tepkeaw, Krissana Jaikengdee, Anantachai Wannajampa

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Flue gas discharging from coal fired or gas combustion power plant contains around 12% Carbon dioxide (CO₂), 6% Oxygen (O₂), and 82% Nitrogen (N₂).CO₂ is a greenhouse gas which has been concerned to the global warming. Carbon Capture, Utilization, and Storage (CCUS) is a topic which is a tool to deal with this CO₂ realization. Flue gas is drawn down from the chimney and filtered, then it is compressed to build up the pressure until 8 bar. This compressed flue gas is sent to three stages Pressure Swing Adsorption (PSA), which is filled with activated carbon. Experiments were showed the optimum adsorption pressure at 7bar, which CO₂ can be adsorbed step by step in 1st, 2nd, and 3rd stage, obtaining CO₂ concentration 29.8, 66.4, and 96.7 %, respectively. The mixed gas concentration from the last step is composed of 96.7% CO₂,2.7% N₂, and 0.6%O₂. This mixed CO₂product gas obtained from 3 stages PSA contained high concentration CO₂, which is ready to use for methanol synthesis. The mixed CO₂ was experimented in 5 Liter/Day of methanol synthesis reactor skid by 3 step processes as followed steam reforming, reverse water gas shift, and then hydrogenation. The result showed that proportional of mixed CO₂ and CH₄ 70/30, 50/50, 30/70 % (v/v), and 10/90 yielded methanol 2.4, 4.3, 5.6, and 6.0 Liter/day and save CO₂ 40, 30, 20, and 5 % respectively. The optimum condition resulted both methanol yield and CO₂ consumption using CO₂/CH₄ ratio 43/57 % (v/v), which yielded 4.8 Liter/day methanol and save CO₂ 27% comparing with traditional methanol production from methane steam reforming (5 Liter/day)and absent CO₂ consumption.

Keywords: carbon capture utilization and storage, pressure swing adsorption, reforming, reverse water gas shift, methanol

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Authors: Yang Xiao-Jun, Yu Tian-Hao, Hu Ying-Qi

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Breathing in foreign objects during the operation of the aircraft engine, impurities in the aircraft fuel and products of incomplete combustion can produce deposits on the surface of the turbine blades. These deposits reduce not only the turbine's operating efficiency but also the life of the turbine blades. Based on the small open wind tunnel, the simulation of deposits on the leading edge of the turbine has been carried out in this work. The effect of film cooling on particulate deposition was investigated. Based on the analysis, the adhesive mechanism for the molten pollutants’ reaching to the turbine surface was simulated by matching the Stokes number, TSP (a dimensionless number characterizing particle phase transition) and Biot number of the test facility and that of the real engine. The thickness distribution and growth trend of the deposits have been observed by high power microscope and infrared camera under different temperature of the main flow, the solidification temperature of the particulate objects, and the blowing ratio. The experimental results from the leading edge particulate deposition demonstrate that the thickness of the deposition increases with time until a quasi-stable thickness is reached, showing a striking effect of the blowing ratio on the deposition. Under different blowing ratios, there exists a large difference in the thickness distribution of the deposition, and the deposition is minimal at the specific blow ratio. In addition, the temperature of main flow and the solidification temperature of the particulate have a great influence on the deposition.

Keywords: deposition, experiment, film cooling, leading edge, paraffin particles

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Authors: Raghvendra Singh Yadav, Ivo Kuritka, Jarmila Vilcakova, Pavel Urbanek, Michal Machovsky, David Skoda, Milan Masar

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The elastomer nanocomposites were synthesized by solution mixing method with an elastomer as a matrix and in situ thermally reduced graphene oxide (RGO) and spinel ferrite NiFe₂O₄ nanoparticles as filler. Spinel ferrite NiFe₂O₄ nanoparticles were prepared by the starch-assisted sol-gel auto-combustion method. The influence of filler on the microstructure, morphology, dielectric, electrical and magnetic properties of Reduced Graphene Oxide-Nickel Ferrite-Elastomer nanocomposite was characterized by X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, X-ray photoelectron spectroscopy, the Dielectric Impedance analyzer, and vibrating sample magnetometer. Scanning electron microscopy study revealed that the fillers were incorporated in elastomer matrix homogeneously. The dielectric constant and dielectric tangent loss of nanocomposites was decreased with the increase of frequency, whereas, the dielectric constant increases with the addition of filler. Further, AC conductivity was increased with the increase of frequency and addition of fillers. Furthermore, the prepared nanocomposites exhibited ferromagnetic behavior. This work was supported by the Ministry of Education, Youth and Sports of the Czech Republic – Program NPU I (LO1504).

Keywords: polymer-matrix composites, nanoparticles as filler, dielectric property, magnetic property

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Authors: Saâd Oukkass, Abderrahim Bouftou, Rachid Ouchn, L. Lebrun, Miloudi Hlaibi

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We invariably exist in a world steeped in colors, whether in our clothing, food, cosmetics, or even medications. However, most of the dyes we use pose significant problems, being both harmful to the environment and resistant to degradation. Among these dyes, methylene blue and acid yellow 61 stand out, commonly used to dye various materials such as cotton, wood, and silk. Fortunately, various methods have been developed to treat and remove these polluting dyes, among which membrane processes play a prominent role. These methods are praised for their low energy consumption, ease of operation, and their ability to achieve effective separation of components. Adsorption on activated carbon is also a widely employed technique, complementing the basic processes. It proves particularly effective in capturing and removing organic compounds from water due to its substantial specific surface area while retaining its properties unchanged. In the context of our study, we examined two crucial aspects. Firstly, we explored the possibility of selectively extracting methylene blue from a mixture containing another dye, acid yellow 61, using a polymer inclusion membrane (PIM) made of PVA. After characterizing the morphology and porosity of the membrane, we applied kinetic and thermodynamic models to determine the values of permeability (P), initial flux (J0), association constant (Kass), and apparent diffusion coefficient (D*). Subsequently, we measured activation parameters (activation energy (Ea), enthalpy (ΔH#ass), entropy (ΔS#)). Finally, we studied the effect of activated carbon on the processes carried out through the membrane, demonstrating a clear improvement. These results make the membrane developed in this study a potentially pivotal player in the field of membrane separation.

Keywords: dyes, methylene blue, membrane, activated carbon

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Authors: Augustine O. Ani, Ifeyinwa E. Ezemagu, Eunice A. Akuru

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A seven-week study was conducted to evaluate the response of grower turkeys to varying dietary levels of Moringa oleifera leaf meal (MOLM) in a humid tropical environment. A total of 90 twelve weeks old male and female grower turkeys were randomly divided into five groups of 18 birds each in a completely randomized design (CRD) and assigned to five caloric (2.57-2.60 Mcal/kg ME) and isonitrogenous (19.95% crude protein) diets containing five levels (0, 15, 20, 25 and 30%) of MOLM, respectively. Each treatment was replicated three times with 6 birds per replicate housed in a deep litter pen of fresh wood shavings measuring 1.50m x 1.50m. Feed and water were provided to the birds' ad libitum. Parameters measured were: final live weight (FLW) daily weight gain (DWG), daily feed intake (DFI), feed conversion ratio (FCR), protein efficiency ratio (PER), packed cell volume (PCV), haemoglobin concentration (Hb), red blood cell (RBC) count, white blood cell (WBC) count, mean cell volume (MCV), mean cell haemoglobin (MCH) and mean cell haemoglobin concentration (MCHC), feed cost / kg weight gain and apparent nutrient retention. Results showed that grower turkeys fed 20% MOLM diet had significantly (p < 0.05) higher FLW and DWG values (4410.30 g and 34.49 g, respectively) and higher DM and NFE retention values (67.28 and 58.12%, respectively) than turkeys fed other MOLM diets. Feed cost per kg gain decreased significantly (p < 0.05) with increasing levels of MOLM in the diets. The PCV, Hb, WBC, MCV, MCH and MCHC values of grower turkeys fed 20% MOLM diet were significantly (p < 0.05) higher than those of grower turkeys fed other diets. It was concluded that a diet containing 20% MOLM is adequate for the normal growth of grower turkeys in the tropics.

Keywords: Diets, grower turkeys, Moringa oleifera leaf meal, response, tropical environment

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Authors: Issam Lakdhar, Akram Alhussein, Juan Creus

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With the huge increase in world energy consumption, researchers are working to find other alternative sources of energy instead of fossil fuel one causing many environmental problems as the production of greenhouse effect gases. Hydrogen is considered a green energy source, which its combustion does not cause environmental pollution. The transport and the storage of the gas molecules or the other products containing this smallest chemical element in metallic structures (pipelines, tanks) are crucial issues. The dissolve and the permeation of hydrogen into the metal lattice lead to the formation of hydride phases and the embrittlement of structures. To protect the metallic structures, a surface treatment could be a good solution. Among the different techniques, magnetron sputtering is used to elaborate micrometric coatings capable of slowing down or stop hydrogen permeation. In the plasma environment, the deposition parameters of new thin-film metallic glasses Al-Ti-W were optimized and controlled in order to obtain, hydrogen barrier. Many characterizations were carried out (SEM, XRD and Nano-indentation…) to control the composition and understand the influence of film microstructure and chemical composition on the hydrogen permeation through the coatings. The coating performance was evaluated under two hydrogen production methods: chemical and electrochemical (cathodic protection) techniques. The hydrogen quantity absorbed was experimentally determined using the Thermal-Desorption Spectroscopy method (TDS)). An ideal ATW thin film was developed and showed excellent behavior against the diffusion of hydrogen.

Keywords: thin films, hydrogen, PVD, plasma technology, electrochemical properties

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Authors: L. Melzerová, T. Janda, M. Šejnoha, J. Šejnoha

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Two finite element (FEM) models are presented in this paper to address the random nature of the response of glued timber structures made of wood segments with variable elastic moduli evaluated from 3600 indentation measurements. This total database served to create the same number of ensembles as was the number of segments in the tested beam. Statistics of these ensembles were then assigned to given segments of beams and the Latin Hypercube Sampling (LHS) method was called to perform 100 simulations resulting into the ensemble of 100 deflections subjected to statistical evaluation. Here, a detailed geometrical arrangement of individual segments in the laminated beam was considered in the construction of two-dimensional FEM model subjected to in four-point bending to comply with the laboratory tests. Since laboratory measurements of local elastic moduli may in general suffer from a significant experimental error, it appears advantageous to exploit the full scale measurements of timber beams, i.e. deflections, to improve their prior distributions with the help of the Bayesian statistical method. This, however, requires an efficient computational model when simulating the laboratory tests numerically. To this end, a simplified model based on Mindlin’s beam theory was established. The improved posterior distributions show that the most significant change of the Young’s modulus distribution takes place in laminae in the most strained zones, i.e. in the top and bottom layers within the beam center region. Posterior distributions of moduli of elasticity were subsequently utilized in the 2D FEM model and compared with the original simulations.

Keywords: Bayesian inference, FEM, four point bending test, laminated timber, parameter estimation, prior and posterior distribution, Young’s modulus

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