Search results for: Glass Construction material

Authors: Heitor Oliveira, Gabriele De-Waal, Juergen Schmenger, Lynsey Godfrey, Tibor Kovacs

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Rheolaser MASTER™ makes use of multiple scattering of light, caused by scattering objects in a continuous medium (such as droplets and particles in colloids), to characterize the viscoelasticity of soft materials. It offers an alternative to conventional rheometers to characterize viscoelasticity of products such as hair cosmetics. Up to six simultaneous measurements at controlled temperature can be carried out simultaneously (10-15 min), and the method requires only minor sample preparation work. Conversely to conventional rheometer based methods, no mechanical stress is applied to the material during the measurements. Therefore, the properties of the exact same sample can be monitored over time, like in aging and stability studies. We determined the elastic index (EI) of water/emulsion mixtures (1 ≤ fat alcohols (FA) ≤ 5 wt%) and emulsion/gel-network mixtures (8 ≤ FA ≤ 17 wt%) and compared with the elastic/sorage mudulus (G’) for the respective samples using a TA conventional rheometer with flat plates geometry. As expected, it was found that log(EI) vs log(G’) presents a linear behavior. Moreover, log(EI) increased in a linear fashion with solids level in the entire range of compositions (1 ≤ FA ≤ 17 wt%), while rheometer measurements were limited to samples down to 4 wt% solids level. Alternatively, a concentric cilinder geometry would be required for more diluted samples (FA > 4 wt%) and rheometer results from different sample holder geometries are not comparable. The plot of the rheolaser output parameters solid-liquid balance (SLB) vs EI were suitable to monitor product aging processes. These data could quantitatively describe some observations such as formation of lumps over aging time. Moreover, this method allowed to identify that the different specifications of a key raw material (RM < 0.4 wt%) in the respective gel-network (GN) product has minor impact on product viscoelastic properties and it is not consumer perceivable after a short aging time. Broadening of a RM spec range typically has a positive impact on cost savings. Last but not least, the photon path length (λ*)—proportional to droplet size and inversely proportional to volume fraction of scattering objects, accordingly to the Mie theory—and the EI were suitable to characterize product destabilization processes (e.g., coalescence and creaming) and to predict product stability about eight times faster than our standard methods. Using these parameters we could successfully identify formulation and process parameters that resulted in unstable products. In conclusion, Rheolaser allows quick and reliable characterization of viscoelastic properties of hair cosmetics that are related to their performance and stability. It operates in a broad range of product compositions and has applications spanning from the formulation of our hair cosmetics to fast release criteria in our production sites. Last but not least, this powerful tool has positive impact on R&D development time—faster delivery of new products to the market—and consequently on cost savings.

Keywords: colloids, hair cosmetics, light scattering, performance and stability, soft materials, viscoelastic properties

Procedia PDF Downloads 172

Authors: Mitchell Gallagher

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This investigation explores the relationship between Chinese government ministers' tweets and publicized anti-US propaganda political cartoons by Chinese state media. Defining "anti-US" tweets as expressions with negative impressions about the United States, its policies, or cultural values, the study considers their context-dependent nature. Analyzing social media's growing role, this research probes the Chinese government's attitudes toward the United States. While China traditionally adhered to a non-interference stance, instances of verbal and visual retorts occurred, driven by efforts to enhance soft power and counter unfavorable portrayals. To navigate global challenges, China embraced proactive image construction, utilizing political cartoons as a messaging tool. As Sino-American political relations continue deteriorating, it has become increasingly commonplace for Chinese officials to circulate anti-US messages and negative impressions of the United States via tweets. The present study is committed to inspecting the nature and frequency of political cartoons casting the United States in an unfavorable light, with the aim of gaining a comprehensive understanding the degree to which the Chinese government and state-affiliated media are aligned in their corresponding messaging.

Keywords: China, political cartoons, propaganda, twitter, social media

Procedia PDF Downloads 72

Authors: Karl-Erich Lindenschmidt, Apurba Das, Joel Trudell, Keanne Russell

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In this presentation, we explore options for mitigating ice-jam flooding along the Athabasca River in western Canada. Not only flood hazard, expressed in this case as the probability of flood depths and extents being exceeded, but also flood risk, in which annual expected damages are calculated. Flood risk is calculated, which allows a cost-benefit analysis to be made so that decisions on the best mitigation options are not based solely on flood hazard but also on the costs related to flood damages and the benefits of mitigation. The river ice model is used to simulate extreme ice-jam flood events with which scenarios are run to determine flood exposure and damages in flood-prone areas along the river. We will concentrate on three mitigation options – the placement of a dike, artificial breakage of the ice cover along the river, the installation of an ice-control structure, and the construction of a reservoir. However, any mitigation option is not totally failsafe. For example, dikes can still be overtopped and breached, and ice jams may still occur in areas of the river where ice covers have been artificially broken up. Hence, for all options, it is recommended that zoning of building developments away from greater flood hazard areas be upheld. Flood mitigation can have a negative effect of giving inhabitants a false sense of security that flooding may not happen again, leading to zoning policies being relaxed. (Text adapted from Lindenschmidt [2022] "Ice Destabilization Study - Phase 2", submitted to the Regional Municipality of Wood Buffalo, Alberta, Canada)

Keywords: ice jam, flood hazard, flood risk river ice modelling, flood risk

Procedia PDF Downloads 185

Authors: Mehmet Yavuz Hüseyinca, Şuayip Küpeli

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Sandstones from Upper Eocene - Oligocene Tepeköy formation (Member of Mezgit Group) that exposed on the eastern edge of Tuz Gölü (Salt Lake) were analyzed for their rare earth element (REE) contents. Average concentrations of ΣREE, ΣLREE (Total light rare earth elements) and ΣHREE (Total heavy rare earth elements) were determined as 31.37, 26.47 and 4.55 ppm respectively. These values are lower than UCC (Upper continental crust) which indicates grain size and/or CaO dilution effect. The chondrite-normalized REE pattern is characterized by the average ratios of (La/Yb)cn = 6.20, (La/Sm)cn = 4.06, (Gd/Lu)cn = 1.10, Eu/Eu* = 0.99 and Ce/Ce* = 0.94. Lower values of ΣLREE/ΣHREE (Average 5.97) and (La/Yb)cn suggest lower fractionation of overall REE. Moreover (La/Sm)cn and (Gd/Lu)cn ratios define less inclined LREE and almost flat HREE pattern when compared with UCC. Almost no Ce anomaly (Ce/Ce*) emphasizes that REE were originated from terrigenous material. Also depleted LREE and no Eu anomaly (Eu/Eu*) suggest an undifferentiated mafic provenance for the sandstones.

Keywords: central Anatolia, provenance, rare earth elements, REE, Tepeköy sandstone

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Authors: Thirsa Sherry, Utkarsh Shrivastav, Kannan B. T., Iynthezhuton K.

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The field of aerodynamics and aeroacoustics remains one of the most poignant and well-researched fields of today. The current paper aims to investigate the predominant problem concerning the effects of noise of varying frequencies and waveforms on airflow surrounding an airfoil. Using a single speaker beneath the airfoil at different positions, we wish to simulate the effects of sound directly impinging on an airfoil and study its direct effects on airflow. We wish to study the same using smoke visualization methods with incense as our smoke-generating material in a variable-speed subsonic wind tunnel. Using frequencies and wavelengths similar to those of common engine noise, we wish to simulate real-world conditions of engine noise interfering with airflow and document the arising trends. These results will allow us to look into the real-world effects of noise on airflow and how to minimize them and expand on the possible relation between waveforms and noise. The parameters used in the study include frequency, Reynolds number, waveforms, angle of attack, and the effects on airflow when varying these parameters.

Keywords: engine noise, aeroacoustics, acoustic excitation, low speed

Procedia PDF Downloads 93

Authors: Ahmed Tafraoui, Gilles Escadeillas, Thierry Vidal

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The southern Algeria is known for its huge sand dunes that cover part of its territory (Sahara). This sand has features that allow a glimpse of a recovery in the construction field in the form of Ultra High Performance Concrete (UHPC). This type of concrete using a large amount of silica fume, ultra fine addition that gives very high performance but is also relatively rare and expensive. Replacing it with another addition to equivalent properties, such as metakaolin, can also be considered. The objective of this study is to both enhance the sand dunes of Erg south west western Algeria but also reduce manufacturing costs of Ultra High Performance Concrete to incorporating metakaolin to instead of silica fume. Performances to determine mechanical performance are instantaneous, compression and bending. Initially, we characterized the Algerian sand dune. Then, we have to find a formulation of UHPC, adequate in terms of implementation and to replace silica fume by metakaolin. Finally, we studied the actual value of the sand dune. Concrete obtained have very high mechanical performance, up to a compressive strength of 250 MPa, a tensile strength of 45 MPa by bending with the method of heat treatment. This study shows that the enhancement of dune sand studied is quite possible in UHPC, and in particular UHPC bundles and the replacement of silica fume by metakaolin do not alter the properties of these concretes.

Keywords: Ultra High Performance Concrete, sand dune, formulations, silica fume, metakaolin, strength

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Authors: Arkadiusz Urzędowski, Dorota Wójcicka-Migasiuk, Andrzej Sachajdak, Magdalena Paśnikowska-Łukaszuk

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Due to the impact of climate changes and inevitability to reduce greenhouse gases, the need to use low-carbon and sustainable construction has increased. In this work, it is investigated how texture of the surface building materials and radiative heat transfer phenomenon in flat multilayer can be correlated. Attempts to test the surface emissivity are taken however, the trustworthiness of measurement results remains a concern since sensor size and thickness are common problems. This paper presents an experimental method to studies surface emissivity with use self constructed thermal sensors and thermal imaging technique. The surface of building materials was modified by mechanical and chemical treatment affecting the reduction of the emissivity. For testing the shaping surface of materials and mapping its three-dimensional structure, scanning profilometry were used in a laboratory. By comparing the results of laboratory tests and performed analysis of 3D computer fluid dynamics software, it can be shown that a change in the surface coverage of materials affects the heat transport by radiation between layers. Motivated by recent advancements in variational inference, this publication evaluates the potential use a dedicated data processing approach, and properly constructed temperature sensors, the influence of the surface emissivity on the phenomenon of radiation and heat transport in the entire partition can be determined.

Keywords: heat transfer, surface roughness, surface emissivity, radiation

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Authors: Parisa Göker

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With the birth of Islam, the definitions of paradise in Quran have spread across three continents since 7^th century, showing itself in the palace gardens as a reflection of Islamic Culture. The design characteristics of Islamic gardens come forth with the influence of religious beliefs, as well as taking its form as per the cultural, climatic and soil characteristics of its geography, and showing its difference. It is possible to see these differences from the garden examples that survived to present time from the civilizations in the lands of Islamic proliferation. The main material of this research is the Islamic gardens in Iran and Spain. Field study was carried out in Alhambra Palace in Spain, Granada and Shah Goli garden in Iran, Tabriz. In this study, the birth of Islamic gardens, spatial perception of paradise, design principles, spatial structure, along with the structural/plantation materials used are examined. Also the characteristics and differentiation of the gardens examined in different cultures and geographies have been revealed. In the conclusion section, Iran and Spain Islamic garden samples were evaluated and their properties were determined.

Keywords: Islamic civilization, Islamic architecture, cultural landscape, Islamic garden

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Authors: Shraddha Mahore Manjrekar

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Culture has been an integral part of the civilizations in the world. Architectural works, in the material form of buildings, are often perceived as cultural symbols and as works of art. Historical civilizations are often identified with their surviving architectural achievements. Author has observed and thought about the relation of Indian traditional cultural beliefs and their relation to the sustainable environment. There are some unwritten norms regarding the use of resources and the environment in Indian continent, that have been commonly accepted by the people for building houses and settlements since the Vedic period . The research has been done on the chanting and prayers done in a number of houses and temples in Madhya Pradesh and Maharashtra. After doing some research, it was also found that resource assessment had also been done for the entire country, and an idea of conservation of these resources was imbibed in the common people by means of some traditions, customs and beliefs. The sensitization and gratefulness about natural resources have been observed in the major beliefs and customs. This paper describes few of such beliefs and customs that are directly linked with the built environment and landscape.

Keywords: Indian culture, sacred groves, sustainability in built environment, sustainability practices

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Authors: Inba Blesso P., Senthil Kumar P.

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The main consideration of any tire manufacturing process is wear resistance. One of the factors that cause tire wear is improper removal of vent and flash from the tire surface. The contact point between tyre surface and vent is highly supposed to wear. When the vehicle running at higher speed with heavy load, the tire vent and flash is wearing initially and it makes few of the tire surface material to wear along with it. Hence, provision must be given to efficient removal vent and flash thereby tire wear. Human efforts in trimming of tire vent results in time consuming and inaccurate output. Hence, this lead to the reduction in production rate and profit. Thus, the development of automated system can helps to attain minimum time consumption and provide a possible way to get the profitable production. Semi-automated system that employs Pneumatic actuators and sequencing circuits are focused in this study. By implementing this, one can achieve the accurate results with reduction in time and profitable output.

Keywords: tire manufacturing, pneumatic system, vent and flash removal, engineering and technology

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Authors: A. Melouah, M. Diaf

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The III-N nitride semiconductors appear to be excellent host materials, in particular, GaN epilayers doped with Erbium ions have shown a highly reduced thermal quenching of the Er luminescence intensity from cryogenic to elevated temperatures. The remarkable stability may be due to the large energy band gap of the material. Two methods are used for doping the Gallium nitride films with Erbium ions; ion implantation in the wafers obtained by (CVDOM) and in-situ incorporation during epitaxial growth of the layers by (MBE). Photoluminescence (PL) spectroscopy has been the main optical technique used to characterize the emission of Er-doped III-N semiconductor materials. This technique involves optical excitation of Er3+ ions and measurement of the spectrum of the light emission as a function of energy (wavelength). Excitation at above band gap energy leads to the creation of Electron-Hole pairs. Some of this pairs may transfer their energy to the Er3+ ions, exciting the 4f-electrons and resulting in optical emission. This corresponds to an indirect excitation of the Er3+ ions by electron-hole pairs. The direct excitation by the optical pumping of the radiation can be obtained.

Keywords: photoluminescence, Erbium, GaN, semiconductor materials

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Authors: Yoftahe Nigussie Worku

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This study focused on designing a Fire tube boiler to generate saturated steam with a 2000kg/h capacity at a 12bar design pressure. The primary project goal is to achieve efficient steam production while minimizing costs. This involves selecting suitable materials for component parts, employing cost-effective construction methods, and optimizing various parameters. The analysis phase employs iterative processes and relevant formulas to determine key design parameters. This includes optimizing the diameter of tubes for overall heat transfer coefficient, considering a two-pass configuration due to tube and shell size, and using heavy oil fuel no.6 with specific heating values. The designed boiler consumes 140.37kg/hr of fuel, producing 1610kw of heat at an efficiency of 85.25%. The fluid flow is configured as cross flow, leveraging its inherent advantages. The tube arrangement involves welding the tubes inside the shell, which is connected to the tube sheet using a combination of gaskets and welding. The design of the shell adheres to the European Standard code for pressure vessels, accounting for weight and supplementary accessories and providing detailed drawings for components like lifting lugs, openings, ends, manholes, and supports.

Keywords: efficiency, coefficient, saturated steam, fire tube

Procedia PDF Downloads 59

Authors: Tshilenge Kabongo, John Kabuba

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The distillery wastewater has become major issues in sanitation sectors. One of the solutions to overcome this sewage is to install the Wastewater Treatment Plant. Economic analysis is fundamentally required for its viability. Integrated anaerobic digestion and advanced oxidation (AD-AOP) in the treatment of distillery wastewater (DWW), anaerobic digestion achieved sufficient biochemical oxygen demand (BOD) and chemical oxygen demand (COD) removals of 95% and 75%, respectively, and methane production of 0.292 L/g COD removed at an organic loading rate of 15 kg COD/m3/d. However, a considerable amount of biorecalcitrant compounds still existed in the anaerobically treated effluent, contributing to a residual COD of 4.5 g/L and an intense dark brown color. To remove the biorecalcitrant color and COD, ozonation, which is an AOP, was introduced as a post-treatment method to AD. Ozonation is a highly competitive treatment technique that can be easily applied to remove the biorecalcitrant compounds, including color, and turbidity. In the ozonation process carried out for an hour, more than 80% of the color was removed at an ozone dose of 45 mg O3/L/min (corresponding to 1.8 g O3/g COD). Thus, integrating AD with the AOP can be effective for organic load and color reductions during the treatment of DWW. The deliverable established the best configuration of the AD-AOP system, where DWW is first subjected to AD followed by AOP post-treatment. However, for establishing the feasibility of the industrial application of the integrated system, it is necessary to carry out the economic analysis. This may help the starting point of the wastewater treatment plant construction and its operation and maintenance costs.

Keywords: distillery wastewater, economic analysis, integrated anaerobic digestion, ozonolysis, treatment

Procedia PDF Downloads 134

Authors: Nasser Ghassembaglou, Abdullah Bolek, Oktay Yilmaz, Ertan Oznergiz, Hikmet Kocabas, Safak Yilmaz

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High quality air filters production using nanofibers, as a functional material, has frequently been investigated. As it is more environmentally friendly, melting method has been selected to produce nanofibers. Spun-bond production systems consist of extruder, spin-pump, nozzle package and attenuators. Spin-pump makes molten polymer steady, which flows through extruder. Fibers are formed by regular melts passing through nuzzle holes under high pressure. Attenuator prolongs fibers to micron size to be collected on a conveyor. Different designs of attenuator systems have been studied in this research; new analysis have been done on existed designs considering fibers effect on air flow; it was comprehended that, at fibers presence, there is an air flow which agglomerates fibers as a negative effect. So some new representations have been designed and CFD analysis have been done on them. Afterwards, one of these representations selected as the most optimum and effective design which is brought in this paper.

Keywords: attenuator, CFD, nanofiber, spun-bond

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Authors: Narayan Gurung, Fawu Wang, Ranjan Kumar Dahal

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Nepal is highly prone to earthquakes and has witnessed at least one major earthquake in 80 to 90 years interval. The Gorkha earthquake, that measured 7.8 RS in magnitude and struck Nepal on 25th April 2015, after 81 years since Mw 8.3 Nepal Bihar earthquake in 1934, was the largest earthquake after Mw 8.3 Nepal Bihar earthquake. In this paper, an attempt has been made to highlight the lessons learnt from the MwW 7.8 Gorkha (Nepal) earthquake. Several types of damage patterns in buildings were observed for reinforced concrete buildings, as well as for unreinforced masonry and adobe houses in the earthquake of 25 April 2015. Many field visits in the affected areas were conducted, and thus, associated failure and damage patterns were identified and analyzed. Damage patterns in non-engineered buildings, middle and high-rise buildings, commercial complexes, administrative buildings, schools and other critical facilities are also included from the affected districts. For most buildings, the construction and structural deficiencies have been identified as the major causes of failure; however, topography, local soil amplification, foundation settlement, liquefaction associated damages and buildings built in hazard-prone areas were also significantly observed for the failure or damages to buildings and hence are reported. Finally, the lessons learnt from Mw 7.8 Gorkha (Nepal) earthquake are presented in order to mitigate impacts of future earthquakes in Nepal.

Keywords: Gorkha earthquake, reinforced concrete structure, Nepal, lesson learnt

Procedia PDF Downloads 202

Authors: Laboratory of Semiconducting, Metallic Materials (LMSM) Biskra Algeria

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InZnSnO2 (IZTO)/β-Ga2O3 Schottky solar barrier photodetector (PhD) exposed to 255 nm was simulated and compared to the measurement. Numerical simulations successfully reproduced the photocurrent at reverse bias and response by taking into account several factors, such as conduction mechanisms and material parameters. By adopting reducing the density of the trap as an improvement. The effect of reducing the bulk trap densities on the photocurrent, response, and time-dependent (continuous conductivity) was studied. As the trap density decreased, the photocurrent increased. The response was 0.04 A/W for the low Ga2O3 trap density. The estimated decay time for the lowest intensity ET (0.74, 1.04 eV) is 0.05 s and is shorter at ∼0.015 s for ET (0.55 eV). This indicates that the shallow traps had the dominant effect (ET = 0.55 eV) on the continuous photoconductivity phenomenon. Furthermore, with decreasing trap densities, this PhD can be considered as a self-powered solar-blind photodiode (SBPhD).

Keywords: IZTO/β-Ga2O3, self-powered solar-blind photodetector, numerical simulation, bulk traps

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Authors: M. Münch, R. Brandt

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Martensitic steels with an ultimate tensile strength beyond 2000 MPa are applied in the powertrain of vehicles due to their excellent fatigue strength and high creep resistance. However, the creep controlling mechanism in martensitic steels at ambient temperatures up to 423 K is not evident. The purpose of this study is to review the low temperature creep (LTC) behavior of martensitic steels at temperatures from 363 K to 523 K. Thus, the validity of a logarithmic creep law is reviewed and the stress and temperature dependence of the creep parameters α and β are revealed. Furthermore, creep tests are carried out, which include stepped changes in temperature or stress, respectively. On one hand, the change of the creep rate due to a temperature step provides information on the magnitude of the activation energy of the LTC controlling mechanism and on the other hand, the stress step approach provides information on the magnitude of the activation volume. The magnitude, the temperature dependency, and the stress dependency of both material specific activation parameters may deliver a significant contribution to the disclosure of the nature of the LTC rate controlling mechanism.

Keywords: activation parameters, creep mechanisms, high strength steels, low temperature creep

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Authors: Sri Wahjuningsih, Nur Ihsan, Hadiah

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In the embryo transfer program, to address the limited production of embryos in vivo, in vitro embryo production has become an alternative approach that is relatively inexpensive. One potential source of embryos that can be developed is to use immature oocytes then conducted in vitro maturation and in vitro fertilization. However, obstacles encountered were oocyte viability mammals have very limited that it cannot be stored for a long time, so we need oocyte cryopreservation. The research was conducted to know the optimal concentration use of ethylene glycol as a cryoprotectant on oocytes freezing.Material use in this research was immature oocytes; taken from abbatoir which was aspirated from follicle with diameter 2-6 mm. Concentration ethylen glycol used were 0,5 M, I M, 1,5 M and 2M. The freezing method used was conventional method combined with a five-step protocol washing oocytes from cryoprotectant after thawing. The result showed that concentration ethylen glycol have the significant effect (P<0.05) on oocytes quality after thawing and in vitro maturation. It was concluded that concentration 1,5 M was the best concentration for freezing oocytes using conventional method.

Keywords: bovine, conventional freezing, ethylen glycol, oocytes

Procedia PDF Downloads 364

Authors: Eser Yarar, Fahri Vatansever, A. Tamer Erturk, Sedat Karabay

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In this study, drilling behavior of multi-layer orthotropic polyester composites reinforced with woven polyester fiber and PTFE particle was investigated. Conventional drilling methods have low cost and ease of use. Therefore, it is one of the most preferred machining methods. The increasing range of use of composite materials in many areas has led to the investigation of the machinability performance of these materials. The drilling capability of the synthetic polymer composite material was investigated by measuring the cutting forces using different tool diameters, feed rate and high cutting speed parameters. Cutting forces were measured using a dynamometer in the experiments. In order to evaluate the results of the experiment, the Taguchi experimental design method was used. According to the results, the optimum cutting parameters were obtained for 0.1 mm/rev, 1070 rpm and 2 mm diameter drill bit. Verification tests were performed for the optimum cutting parameters obtained according to the model. Verification experiments showed the success of the established model.

Keywords: cutting force, drilling, polimer composite, Taguchi

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Authors: S. B. Kerur, B. S. Murgayya

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The development of micro and nano particle is challenging task and the study of the behavior of material at the micro level is gaining importance as their behavior at micro/nano level is different. These micro particle are being used as a sensing element to measure and detects the hazardous chemical, gases, explosives and biological agents. In the present study, finite element method is used for static and dynamic analysis of simple and composite cantilever beams of different shapes. The present FE model is validated with available analytical results and various parameters like shape, materials properties, damped and undamped conditions are considered for the numerical study. The results show the effects of shape change on the natural frequency and as these are used with fluid for chemical applications, the effect of damping due to viscous nature of fluid are simulated by considering different damping coefficient effect on the dynamic behavior of cantilever beams. The obtained results show the effect of these parameters can be effectively utilized based on system requirements.

Keywords: micro, FEM, dynamic, cantilever beam

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Authors: Joy Aworo-Okoroh

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Politics is about trust and trust is challenged by the speaker’s ability to manipulate language before the electorate. Critical discourse analysis investigates the role of language in constructing social relationships between a political speaker and his audience. This paper explores the linguistic choices made by President Muhammad Buhari that enshrines his ideologies as well as the socio-political relations of power between him and Nigerians in his speeches. Two speeches of President Buhari –inaugural and Independence Day speeches are analyzed using Norman Fairclough’s perspective on Halliday’s Systemic functional grammar. The analysis is at two levels. The first level of analysis is the identification of transitivity and modality choices in the speeches and how they reveal the covert ideologies. The second analysis is premised on Normal Fairclough’s model, the clauses are analyzed to identify elements of power, hesistation, persuasion, threat and religious statement. It was discovered that Buhari is a dominant character who manipulates the material processes a lot.

Keywords: politics, critical discourse analysis, Norman Fairclough, systemic functional grammar

Procedia PDF Downloads 551

Authors: Mei-Hsiu Chi, Jyh-Yang Wu, Sheng-Gwo Chen

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The diffusion-reaction equations are important Partial Differential Equations in mathematical biology, material science, physics, and so on. However, finding efficient numerical methods for diffusion-reaction systems on curved surfaces is still an important and difficult problem. The purpose of this paper is to present a convergent geometric method for solving the reaction-diffusion equations on closed surfaces by an O(r)-LTL configuration method. The O(r)-LTL configuration method combining the local tangential lifting technique and configuration equations is an effective method to estimate differential quantities on curved surfaces. Since estimating the Laplace-Beltrami operator is an important task for solving the reaction-diffusion equations on surfaces, we use the local tangential lifting method and a generalized finite difference method to approximate the Laplace-Beltrami operators and we solve this reaction-diffusion system on closed surfaces. Our method is not only conceptually simple, but also easy to implement.

Keywords: closed surfaces, high-order approachs, numerical solutions, reaction-diffusion systems

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Authors: Magda Posani, Maria Do Rosario Veiga, Vasco Peixoto De Freitas

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The presented research considers the hygrothermal data acquired in the municipal library of Porto. The library is housed in an XVIII century convent and, among all the rooms in the construction, one, in particular, was chosen for the monitoring campaign because of the presence of a great number of historic books. Temperature and relative humidity, as well as CO₂ concentration, were measured for six consecutive months, in the period December 24th - June 24th. The indoor environment of the building is controlled with a heating and cooling system that is turned on only during the opening hours of the library. The ventilation rate is low because the windows are kept closed, and there is no forced ventilation. The micro-climate is analyzed in terms of users’ comfort and degradation risks for historic books and valuable building surfaces. Through a comparison between indoor and outdoor measured hygrothermal data, indoor relative humidity appears very stable. The influence of the hygroscopicity of books on the stabilization of indoor relative humidity is therefore investigated in detail. The paper finally discusses the benefits given by the presence of historic books in libraries with intermittent heating and cooling. The possibility of obtaining a comfortable and stable indoor climate with low use of HVAC systems in these conditions, while avoiding degradation risks for books and historic building components, is further debated.

Keywords: books, historic buildings, hygroscopicity, relative humidity

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Authors: Jürgen Fleischer, Woramon Pangboonyanon, Dominic Lesage

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Non-metallic lightweight materials such as fiber reinforced plastics (FRP) become very significant at present. Prepregs e.g. SMC and unidirectional tape (UD-tape) are one of raw materials used to produce FRP. This study concerns with the manufacturing steps of handling and preforming of this UD-SMC and focuses on the investigation of gripper characteristics regarding gripping forces in normal and lateral direction, in order to identify suitable operating pressures for a secure gripping operation. A reliable handling and preforming operation results in a higher adding value of the overall process chain. As a result, the suitable operating pressures depending on travelling direction for each material type could be shown. Moreover, system boundary conditions regarding allowable pulling force in normal and lateral directions during preforming could be measured.

Keywords: continuous-discontinuous fiber reinforced plastics, UD-SMC-prepreg, handling, preforming, prepregs, sheet moulding compounds, surface suction gripper

Procedia PDF Downloads 223

Authors: Joon-Ho Lee, Jeong-Hwan Yoon, Jung-Hwan Yoon, Sangmo Kang, Su-Yeon Hong, Hyun-Woo Jeong, Jaeick Chae

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There are several dedicated individual chambers for sports that are supplied and used, but none of them are multi-pressured all-in-one chambers that can provide a sports multi-environment simultaneously. In this study, we design a multi-pressure (positive/atmospheric/negative pressure) integrated vessel that can be used for the sport-multi-artificial environment system. We presented additional vessel designs with enlarged space for the tall users; with reinforcement pads added to reduce the maximum stress in the joints of its shells, and then carried out numerical analysis for the structural analysis with maximum stress and structural safety. Under the targeted allowable pressure conditions, maximum stresses occurred at the joint of the shell, and the entrance, the safety of the structure was checked with the allowable stress of its material.

Keywords: structural analysis, multi-pressure, integrated vessel, sport-multi-artificial environment

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Authors: Supriyono, Sumardiyono, Rendy J. Pramono

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Biodiesel is one of the alternative fuels promising for substituting petrodiesel as energy source which has an advantage as it is sustainable and eco-friendly. Due to the raw material that tends to decompose during storage, biodiesel also has the same characteristic that tends to decompose during storage. Biodiesel decomposition will form higher acid value as the result of oxidation to double bond on a fatty acid compound on biodiesel. Thus, free fatty acid value could be used to evaluate degradation of biodiesel due to the oxidation process. High free fatty acid on biodiesel could impact on the engine performance. Decomposition of biodiesel due to oxidation reaction could prevent by introducing a small amount of antioxidant. The origin of raw materials and the process for producing biodiesel will determine the effectiveness of antioxidant. Biodiesel made from high free fatty acid (FFA) crude palm oil (CPO) by using two steps esterification is vulnerable to oxidation process which is resulted in increasing on the FFA value. Tocopherol also known as vitamin E is one of the antioxidant that could improve the stability of biodiesel due to decomposition by the oxidation process. Tocopherol 0.5% concentration on palm oil biodiesel could reduce 13% of increasing FFA under temperature 80 °C and exposing time 180 minute.

Keywords: antioxidant, palm oil biodiesel, decomposition, oxidation, tocopherol

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Authors: Matthias Haenisch, Marc Godau, Julia Barreiro, Dominik Maxelon

Abstract:

In times of ubiquitous digitalization and the increasing entanglement of humans and technologies in musical practices in the 21st century, it is to be asked, how popular musicians learn in the (post)digital Age. Against the backdrop of the increasing interest in transferring informal learning practices into formal settings of music education the interdisciplinary research association »MusCoDA – Musical Communities in the (Post)Digital Age« (University of Erfurt/University of Applied Sciences Clara Hoffbauer Potsdam, funded by the German Ministry of Education and Research, pursues the goal to derive an empirical model of collective songwriting practices from the study of informal lelearningf songwriters and bands that can be translated into pedagogical concepts for music education in schools. Drawing on concepts from Community of Musical Practice and Actor Network Theory, lelearnings considered not only as social practice and as participation in online and offline communities, but also as an effect of heterogeneous networks composed of human and non-human actors. Learning is not seen as an individual, cognitive process, but as the formation and transformation of actor networks, i.e., as a practice of assembling and mediating humans and technologies. Based on video stimulated recall interviews and videography of online and offline activities, songwriting practices are followed from the initial idea to different forms of performance and distribution. The data evaluation combines coding and mapping methods of Grounded Theory Methodology and Situational Analysis. This results in network maps in which both the temporality of creative practices and the material and spatial relations of human and technological actors are reconstructed. In addition, positional analyses document the power relations between the participants that structure the learning process of the field. In the area of online informal lelearninginitial key research findings reveal a transformation of the learning subject through the specific technological affordances of TikTok and Instagram and the accompanying changes in the learning practices of the corresponding online communities. Learning is explicitly shaped by the material agency of online tools and features and the social practices entangled with these technologies. Thus, any human online community member can be invited to directly intervene in creative decisions that contribute to the further compositional and structural development of songs. At the same time, participants can provide each other with intimate insights into songwriting processes in progress and have the opportunity to perform together with strangers and idols. Online Lelearnings characterized by an increase in social proximity, distribution of creative agency and informational exchange between participants. While it seems obvious that traditional notions not only of lelearningut also of the learning subject cannot be maintained, the question arises, how exactly the observed informal learning practices and the subject that emerges from the use of social media as online learning technologies can be transferred into contexts of formal learning

Keywords: informal learning, postdigitality, songwriting, actor-network theory, community of musical practice, social media, TikTok, Instagram, apps

Procedia PDF Downloads 127

Authors: Vijay Pal Singh, Yogesh Chandra Kotiyal

Abstract:

Structures are a combination of various load carrying members which transfer the loads to the foundation from the superstructure safely. At the design stage, the loading of the structure is defined and appropriate material choices are made based upon their properties, mainly related to strength. The strength of materials kept on reducing with time because of many factors like environmental exposure and deformation caused by unpredictable external loads. Hence, to predict the strength of materials used in structures, various techniques are used. Among these techniques, Non-Destructive Techniques (NDT) are the one that can be used to predict the strength without damaging the structure. In the present study, the compressive strength of concrete has been predicted using Artificial Neural Network (ANN). The predicted strength was compared with the experimentally obtained actual compressive strength of concrete and equations were developed for different models. A good co-relation has been obtained between the predicted strength by these models and experimental values. Further, the co-relation has been developed using two NDT techniques for prediction of strength by regression analysis. It was found that the percentage error has been reduced between the predicted strength by using combined techniques in place of single techniques.

Keywords: rebound, ultra-sonic pulse, penetration, ANN, NDT, regression

Procedia PDF Downloads 428

Authors: Carmen Viñas Arrebola, Antonio Rodriguez Sanchez, Sheila Varela Lujan, Mariano Gonzalez Cortina, Cesar Porras Amores

Abstract:

The research group TEMA from the School of Building (UPM) is working in the line of energy efficiency and comfort in building. The need to reduce energy consumption in the building construction implies designing new constructive systems. These systems help to reduce both consumption and energy losses in order to achieve adequate thermal comfort for people in any type of building. In existing buildings the best option is the rehabilitation focused on thermal insulation. The aim of this paper is to design, monitor and analyze the first results of thermal behavior of the ETICS system in façades. This retrofitting solution consists of adding thermal insulation on the outside of the building, helping to create a continuous envelope on the façades. The analysis is done by comparing a rehabilitated part of the building with ETICS system and another part which has not been rehabilitated, and it is taken as reference. Both of them have the same characteristics. Temperature measurements were taken with type K thermocouples according to the previous design of the monitoring and in the same period of time. The pilot building of the study is situated in Benimamet Street, in San Cristobal de Los Ángeles, in the south of Madrid. It was built in the late 50s. The 51st entrance hall, which is restored, and the 47th entrance hall, in original conditions, have been studied.

Keywords: comfort in building, energy efficiency in building, ETICS, thermal properties

Procedia PDF Downloads 315

Authors: Kleiner Marques Marra, Tércio Pedrosa

Abstract:

This paper reports the production of uranium-molybdenum alloys, which have been considered promising fuel for test and research nuclear reactors. U-Mo alloys were produced in three molybdenum contents: 5 wt.%, 7 wt.%, and 10 wt.%, using an electric vacuum induction furnace. A boron nitride-coated graphite crucible was employed in the production of the alloys and, after melting, the material was immediately poured into a boron nitride-coated graphite mold. The incorporation of carbon was observed, but it happened in a lower intensity than in the case of the non-coated crucible/mold. It is observed that the carbon incorporation increased and alloys density decreased with Mo addition. It was also noticed that the increase in the carbon or molybdenum content did not seem to change the as-cast structure in terms of granulation. The three alloys presented body-centered cubic crystal structure (g phase), after solidification, besides a seeming negative microsegregation of molybdenum, from the center to the periphery of the grains. There were signs of macrosegregation, from the base to the top of the ingots.

Keywords: uranium-molybdenum alloys, incorporation of carbon, solidification, macrosegregation and microsegregation

Procedia PDF Downloads 151