Search results for: supplementary cementitious material

Authors: Asad Hanif, Pavithra Parthasarathy, Zongjin Li

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Thermal insulating composites help to reduce the total power consumption in a building by creating a barrier between external and internal environment. Such composites can be used in the roofing tiles or wall panels for exterior surfaces. This study purposes to develop lightweight cement-based composites for thermal insulating applications. Waste materials like silica fume (an industrial by-product) and fly ash cenosphere (FAC) (hollow micro-spherical shells obtained as a waste residue from coal fired power plants) were used as partial replacement of cement and lightweight filler, respectively. Moreover, aerogel, a nano-porous material made of silica, was also used in different dosages for improved thermal insulating behavior, while poly vinyl alcohol (PVA) fibers were added for enhanced toughness. The raw materials including binders and fillers were characterized by X-Ray Diffraction (XRD), X-Ray Fluorescence spectroscopy (XRF), and Brunauer–Emmett–Teller (BET) analysis techniques in which various physical and chemical properties of the raw materials were evaluated like specific surface area, chemical composition (oxide form), and pore size distribution (if any). Ultra-lightweight cementitious composites were developed by varying the amounts of FAC and aerogel with 28-day unit weight ranging from 1551.28 kg/m³ to 1027.85 kg/m³. Excellent mechanical and thermal insulating properties of the resulting composites were obtained ranging from 53.62 MPa to 8.66 MPa compressive strength, 9.77 MPa to 3.98 MPa flexural strength, and 0.3025 W/m-K to 0.2009 W/m-K as thermal conductivity coefficient (QTM-500). The composites were also tested for peak temperature difference between outer and inner surfaces when subjected to heating (in a specially designed experimental set-up) by a 275W infrared lamp. The temperature difference up to 16.78 ^oC was achieved, which indicated outstanding properties of the developed composites to act as a thermal barrier for building envelopes. Microstructural studies were carried out by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) for characterizing the inner structure of the composite specimen. Also, the hydration products were quantified using the surface area mapping and line scale technique in EDS. The microstructural analyses indicated excellent bonding of FAC and aerogel in the cementitious system. Also, selective reactivity of FAC was ascertained from the SEM imagery where the partially consumed FAC shells were observed. All in all, the lightweight fillers, FAC, and aerogel helped to produce the lightweight composites due to their physical characteristics, while exceptional mechanical properties, owing to FAC partial reactivity, were achieved.

Keywords: aerogel, cement-based, composite, fly ash cenosphere, lightweight, sustainable development, thermal conductivity

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Authors: Yong-Jun Jeon, Hyung-Pil Park, Min-Jae Song, Baeg-Soon Cha

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Following the recent trend of having increased demand in producing lighter-weight car bodies for improvement of automobile safety and gas mileage, there is a forming method that makes use of hot-stamping technique, which satisfies all conditions mentioned above. Hot-stamping is a forming technique with advantages of excellent formability, good dimensional precision and others since it is a process in which steel plates are heated up to temperatures of at least approximately 900°C after which forming is conducted in die at room temperature followed by rapid cooling. In addition, it has characteristics of allowing for improvement in material strength through achievement of quenching effect by having simultaneous forming and rapid cooling of material of high temperatures. However, there is insufficient information on the changes in material strength according to changes in material temperature with regards to material heating method and forming process in hot-stamping. Accordingly, this study aims to design and press die for T-type product of the scale models of the center pillar and to understand the changes in material strength in relation to changes in forming methods of hot-stamping process. Thus in order to understand the changes in material strength due to quenching effect among the hot-stamping process, material strength and material forming precision were to be studied while varying the forming and forming method when forming. For test methods, material strength was observed by using boron steel that has boron additives, which was heated up to 950°C, after which it was transferred to a die and was cooled down to material temperature of 400°C followed by air cooling process. During the forming and cooling process here, experiment was conducted with forming parameters of 2 holding rates and 3 flange heating rates wherein changing appearance in material strength according to changes forming method were observed by verifying forming strength and forming precision for each of the conditions.

Keywords: hot-stamping, formability, quenching, forming, press die, forming methods

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Authors: Jasna Prester, Najla Podrug, Davor Filipović

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Manufacturing companies invest a significant amount of sales into material resources for production. In our sample, 58% of sales is used for manufacturing inputs, while only 24% of sales is used for salaries. This means that if a company is looking to reduce costs, the greater potential is in reduction of material costs than downsizing. This research shows that manufacturing companies in Croatia did realize material savings in last three years. It is also shown by which technologies they achieved materials cost savings. Through literature research, we found research gap as to which technologies reduce material consumption. As methodology of research four regression analyses are used to prove our findings.

Keywords: Croatia, materials savings strategies, technologies, return on sales

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Authors: O. Eren, L. Zakar

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Recycling steel building components is key to the sustainability of a structure’s end-of-life, as it is the most economical solution. In this paper the effects of usage of recycled steel material in tall buildings aspects are investigated.

Keywords: building, recycled material, steel, structure

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Authors: Timur Mukhametkaliyev

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The earthen material possesses low compression strength, and it is highly sensitive to the water content. Different binders can be added (Portland cement or lime) to improve the durability and the mechanical characteristics of earthen material, but the production of these binders has high embodied energy and results in an increase in world CO₂ emission. Geopolymers are binders which can be synthesized at low temperature in alkaline solutions from raw materials consisting of amorphous aluminosilicates. Geopolymers are an attractive substitution of Portland cement and can be used as an excellent stabilization for earthen material. In this study, earthen material stabilized with geopolymer binder for use in construction 3D printing was developed. Construction 3D printing offers freedom of design, waste minimisation, customisation, reduced labour, and automation. For successful 3D printing, the properties of used material are the most important aspects because they require adaptability for extrusion and controlled time of hardening for the binder.

Keywords: 3D printing, building construction, geopolymer, architecture

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Authors: Moulay Smaïne Ghembaza, Mokhtar Dadouch, Nour-Said Ikhlef

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Soil treatment is to make use soil that does not have the characteristics required in a given context. We limit ourselves in this work to the field of road earthworks where we have chosen to develop a local material in the region of Sidi Bel Abbes (Algeria). This material has poor characteristics not meeting the standards used in road geo technics. To remedy this, firstly, we were trying to improve the Proctor Standard characteristics of this material by mechanical treatment increasing the compaction energy. Then, by a chemical treatment, adding some cement dosages, our results show that this material classified A1h a increase maximum dry density and a reduction in the water content of compaction. A comparative study is made on the optimal properties of the material between the two modes of treatment. On the other hand, after treatment, one finds a decrease in the plasticity index and the methylene blue value. This material exhibits a change of class. Therefore, soil class CL turned into a soil class composed CL-ML (Silt of low plasticity). This observation allows this material to be used as backfill or sub grade.

Keywords: treatment of soil, cement, subgrade, Atteberg limits, classification, optimum proctor properties

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Authors: Yu-Zhou Zheng, Wen-Wei Wang

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In this paper, a new strengthening technique for reinforced concrete (RC) beams is proposed by combining Basalt Fibre Reinforced Polymer (BFRP) grid and Engineered Cementitious Composites (ECC) as a composite reinforcement layer (CRL). Five RC beams externally bonded with the CRL at the soffit and one control RC beam was tested to investigate their flexural behaviour. The thickness of BFRP grids (i.e., 1mm, 3mm and 5mm) and the sizes of CRL in test program were selected as the test parameters, while the thickness of CRL was fixed approximately at 30mm. The test results showed that there is no debonding of CRL to occur obviously in the strengthened beams. The final failure modes were the concrete crushing or the rupture of BFRP grids, indicating that the proposed technique is effective in suppressing the debonding of externally bonded materials and fully utilizing the material strengths. Compared with the non-strengthened beam, the increments of crack loading for strengthened beams were 58%~97%, 15%~35% for yield loading and 4%~33% for the ultimate loading, respectively. An analytical model is also presented to predict the full-range load-deflection responses of the strengthened beams and validated through comparisons with the test results.

Keywords: basalt fiber-reinforced polymer (BFRP) grid, ECC, RC beams, strengthening

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Authors: Tahani Farah, Hanène Souli, Jean-Marie Fleureau, Guillaume Kermouche, Jean-Jacques Fry, Benjamin Girard, Denis Aelbrecht

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In this work, the bio-clogging of two soils with different granulometries is presented. The durability of the clogging is also studied under cycles of hydraulic head and under cycles of desaturation- restauration. The studied materials present continuous grain size distributions. The first one corresponding to the "material 1", presents grain sizes between 0.4 and 4 mm. The second material called "material 2" is composed of grains with size varying between 1 and 10 mm. The results show that clogging occurs very quickly after the injection of nutrition and an outlet flow near to 0 is observed. The critical hydraulic head is equal to 0.76 for "material 1", and 0.076 for "material 2". The durability tests show a good resistance to unclogging under cycles of hydraulic head and desaturation-restauration for the "material 1". Indeed, the flow after the cycles is very low. In contrast, "material 2", shows a very bad resistance, especially under the hydraulic head cycles. The resistance under the cycles of desaturation-resaturation is better but an important increase of the flow is observed. The difference of behavior is due to the granulometry of the materials. Indeed, the large grain size contributes to the reduction of the efficiency of the bio-clogging treatment in this material.

Keywords: bio-clogging, granulometry, permeability, nutrition

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Authors: Mohammad Reza Dousti, Yaman Boluk, Vivek Bindiganavile

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During the past few decades, oil and natural gas consumption have increased significantly. The limited amount of hydrocarbon resources on earth has led to a stronger desire towards efficient drilling, well completion and extracting, with the least time, energy and money wasted. Well cementing is one of the most crucial and important steps in any well completion, to fill the annulus between the casing string and the well bore. However, since it takes place at the end of the drilling process, a satisfying and acceptable job is rarely done. Hence, a large and significant amount of time and energy is then spent in order to do the required corrections or retrofitting the well in some cases. Oil well cement paste needs to be pumped during the cementing process, therefore the rheological and flow behavior of the paste is of great importance. This study examines the use of innovative cellulose-based nanomaterials on the flow properties of the resulting cementitious system. The cementitious paste developed in this research is composed of water, class G oil well cement, bentonite and cellulose nanocrystals (CNC). Bentonite is used as a cross contamination component. Initially, the influence of CNC on the flow and rheological behavior of CNC and bentonite suspensions was assessed. Furthermore, the rheological behavior of oil well cement pastes dosed with CNC was studied using a steady shear parallel-plate rheometer and the results were compared to the rheological behavior of a neat oil well cement paste with no CNC. The parameters assessed were the yield shear stress and the viscosity. Significant changes in yield shear stress and viscosity were observed due to the addition of the CNC. Based on the findings in this study, the addition of a very small dosage of CNC to the oil well cement paste results in a more viscous cement slurry with a higher yield stress, demonstrating a shear thinning behavior.

Keywords: cellulose nanocrystal, flow behavior, oil well cement, rheology

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Authors: Rihab Hentati, Younes Boujelbene

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Nowadays we realize more and more than the value of a company is not only a function of its means of production but depends essentially on the managerial aptitude and orientation to implement the material and human means for generating profitability. Indeed, a productive R&D activity, a good strategy, and innovation are originally supplementary benefits that increase the value of the business. Is this ‘value-added’ closely linked to innovation? The purpose of our research is to Meta-analyze the results of 56 empirical studies in order to explain the overall effect of innovation on performance of small and medium-sized enterprises. In order to justify the differences in the results, we look for the moderating factors that may affect the innovation-performance relationship. We find a positive and significant relationship between innovation and performance in small and medium-sized enterprises. The results also note a positive relationship between entrepreneurial orientation, research and development (R&D), and performance in SMEs. In addition, innovation has a strong impact on performance measured both with accounting and market index. The originality of the article is based on a rigorous synthesis, based on several statistical tools, of an important subject of research in finance.

Keywords: innovation, performance, entrepreneurial orientation, meta-analysis, moderator variables

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Authors: Mohammad Saleem, Mujahid Kamran

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It is shown that causality, the principle that cause must precede effect, leads inter alia, to highly significant result that the velocity of a material particle cannot be even equal to that of light. Consequently, combined with special relativity, it leads to the conclusion that material particles of zero rest mass cannot exist in nature. Thus, causality, a principle without which nature would be incomprehensible, combined with special relativity, forbids the existence of material particles of zero rest mass. For instance, the neutrinos, as is now known, are material particles of non-zero rest mass. The situation changes when we consider the gauge particles. In fact, when the principle of causality was proposed, the concept of gauge particles had not yet been introduced. Now we know that photon, a gauge particle with zero rest mass does exist in nature. Therefore, principle of causality, as generally stated, is valid only for material particles. For gauge particles, in order to make the statement of causality consistent with experiment, it has to be modified: The cause should either precede or be simultaneous with the effect. Combined with special relativity, it allows gauge particles of zero rest mass.

Keywords: causality, gauge particles, material particles, special relativity

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Authors: Yiğit Gürler, İbrahim Şimşek, Müge Savaştaer, Ayberk Karakuş, Alper Taşdemirci

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316L steel is frequently used in the industry due to its easy formability and accessibility in sheet metal forming processes. Numerical and experimental studies are frequently encountered in the literature to examine the mechanical behavior of 316L stainless steel during the forming process. 316L stainless steel is the most common material used in the production of plate heat exchangers and plate heat exchangers are produced by plastic deformation of the stainless steel. The motivation in this study is to determine the appropriate material model during the simulation of the sheet metal forming process. For this reason, two different material models were examined and Ls-Dyna material cards were created using material test data. These are MAT133_BARLAT_YLD2000 and MAT093_SIMPLIFIED_JOHNSON_COOK. In order to compare results of the tensile test & hydraulic bulge test performed both numerically and experimentally. The obtained results were evaluated comparatively and the most suitable material model was selected for the forming simulation. In future studies, this material model will be used in the numerical modeling of the sheet metal forming process.

Keywords: 316L, mechanical characterization, metal forming, Ls-Dyna

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Authors: Juneseok You, Chanho Park, Kuehwan Jang, Sungsoo Na

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Sensing of nanotoxic materials is strongly important, as their engineering applications are growing recently and results in that nanotoxic material can harmfully influence human health and environment. In current study we report the quartz crystal microbalance (QCM)-based, in situ and real-time sensing of nanotoxic-material by frequency shift. We propose the in situ detection of nanotoxic material of zinc oxice by using QCM functionalized with a taget-specific DNA. Since the mass of a target material is comparable to that of an atom, the mass change caused by target binding to DNA on the quartz electrode is so small that it is practically difficult to detect the ions at low concentrations. In our study, we have demonstrated the in-situ and fast detection of zinc oxide using the quartz crystal microbalance (QCM). The detection was derived from the DNA hybridization between the DNA on the quartz electrode. The results suggest that QCM-based detection opens a new avenue for the development of a practical water-testing sensor.

Keywords: nanotoxic material, qcm, frequency, in situ sensing

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Authors: Herviyanti, Gusnidar, M. Harianti

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The objective of this research were: a) using low-rank coal (subbituminous) as main humate material sources because this material will not be anthracite, and cannot using to be an energy sources b) to examine residual effects of humic matter from subbituminous which was combined with P fertilizers to adsorp Al and Fe metal, improving soil fertility, and increasing P fertilizing efficiency and Oxisol productivity. Therefore, optimalization crop productivity of upland rice can be achieved. The experiment was designed using a 3 x 4 factorial with 3 replications in randomly groups design. The 1st factor was 3 ways incubating humate material with P-fertilizer, which are: I1 = Incubation of humate material 1 week, then incubation P-fertilizers 1 week; I2 = Incubation of humate materials and P fertilizers directly into the soil for 2 weeks; and I3 = humate material and P fertilizer mixed for 1 week, then incubation to the soil for 1 week. The 2nd factor was residual effects of humate material and P-fertilizer combination which are 4 doses H1 = 400 ppm (0.8 Mg/ha) + 100% R; H2 = 400 ppm + 75% R; H3 = 800 ppm (1.6 Mg/ha) + 100% R,; and H4 = 800 ppm + 75% R. The 2nd year research results showed that the best treatment was founded residue effect of 800 ppm humate material and 100% R P-fertilizer doses in I3 way incubation that is equal to 6.19 t ha-1 upland rice yield. However, this result is almost the same as residual effects of 800 ppm humate material + 75% R P-fertilizer doses and upland rice yield the 1st year. It was concluded that addition of humate material can given the efficiency of P-fertilizer using up to 25% until the 2nd season planted.

Keywords: humate materials, P-fertilizer, subbituminous, upland rice

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Authors: Hachmi Toifane, Pierre Tittelein, Anh Dung Tran Le, Laurent Zalewsi

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This study introduces a composite material composed of bio-sourced phase-change material (PCM) of plant origin combined with hemp shives, developed in response to environmental challenges in the construction sector. The state of the art emphasizes the low thermal storage capacity of bio-based materials and highlights increasing need for developing sustainable materials that offer optimal thermal, mechanical, and hydric performances. The combining of PCM's thermal properties and hygric properties of hemp shives results in a material that combines lightness, strength, and hygrothermal regulation. Various formulations are being assessed and compared to conventional hemp concrete. Thermal characterization includes the measurements of thermal conductivity and numerical simulations to evaluate the thermal storage capacity. The results indicate that the addition of PCM significantly enhances the material's thermal storage capacity, positioning this one as a promising, eco-friendly solution for sustainable construction and for improving the energy efficiency of buildings.

Keywords: hemp composite, bio-sourced phase change material, thermal storage, hemp shives

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Authors: Jeeja Menon, M. S. Ravikumar

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With the advent of green technology and the concept of zero energy buildings, there is an emerging trend in the utilization of indigenous materials like soil as a construction material. However, fine soils like clays and sand have undesirable properties and stabilization of these soils is essential before it is used to develop a building unit. Eco cement or Ground Granulated Blast Furnace Slag (GGBS), a waste byproduct formed during the manufacture of iron has cementitious properties and has the potential of replacing cement which is the most common stabilizer used for improving the geotechnical properties of soil. This paper highlights the salient observations obtained by the investigations into the effect of GGBS as a stabilizer for clayey sand. The index and engineering properties of the soil on the addition of different percentages (0%, 2%, 4%, 5% & 6% of the dry weight of the soil) of GGBS are tested to arrive at the optimum binder content. The criteria chosen for evaluation are the unconfined compressive strength values of different soil- binder composition. The test results indicate that there are significant strength improvements by the addition of GGBS in the soil, and the optimum GGBS content was determined as 5%. Moreover, utilizing waste binders for developing an ecofriendly, less energy induced building units as well as for stabilizing soil will also contribute to the solid waste management, which is the current environmental crisis of the world.

Keywords: eco cement, GGBS, index properties, stabilization, unconfined compressive strength

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Authors: Samir Lecheb, Ahmed Chellil, Hamza Mechakra, Brahim Safi, Houcine Kebir

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In this paper we studied fracture and dynamic behavior of vertical axis wind turbine blade, the VAWT is a historical machine, it has many properties, structure, advantage, component to be able to produce the electricity. We modeled the blade design then imported to Abaqus software for analysis the modes shapes, frequencies, stress, strain, displacement and stress intensity factor SIF, after comparison we chose the idol material. Finally, the CTS test of glass epoxy reinforced polymer plates to obtain the material fracture toughness Kc.

Keywords: blade, crack, frequency, material, SIF

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Authors: Yoftahe Nigussie Worku

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This report unveils a meticulous project focused on the design intricacies of a Fire Tube Boiler tailored for the efficient generation of saturated steam. The overarching objective is to produce 2000kg/h of saturated steam at 12-bar design pressure, achieved through the development of an advanced fire tube boiler. This design is meticulously crafted to harmonize cost-effectiveness and parameter refinement, with a keen emphasis on material selection for component parts, construction materials, and production methods throughout the analytical phases. The analytical process involves iterative calculations, utilizing pertinent formulas to optimize design parameters, including the selection of tube diameters and overall heat transfer coefficients. The boiler configuration incorporates two passes, a strategic choice influenced by tube and shell size considerations. The utilization of heavy oil fuel no. 6, with a higher heating value of 44000kJ/kg and a lower heating value of 41300kJ/kg, results in a fuel consumption of 140.37kg/hr. The boiler achieves an impressive heat output of 1610kW with an efficiency rating of 85.25%. The fluid flow pattern within the boiler adopts a cross-flow arrangement strategically chosen for inherent advantages. Internally, the welding of the tube sheet to the shell, secured by gaskets and welds, ensures structural integrity. The shell design adheres to European Standard code sections for pressure vessels, encompassing considerations for weight, supplementary accessories (lifting lugs, openings, ends, manhole), and detailed assembly drawings. This research represents a significant stride in optimizing fire tube boiler technology, balancing efficiency and safety considerations in the pursuit of enhanced saturated steam production.

Keywords: fire tube, saturated steam, material selection, efficiency

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Authors: Tariq Bashir, Muhammad Waseem Tahir, Ulf Stigh, Behnaz Baghaie, Mikael Skrifvars

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Absorption of moisture may cause many problems in a composite material, such as delamination, degradation of the strength and increase in the weight. For small coupons, the increase in weight may be negligible, however, for large structures increase in weight due to moisture absorption may be quite significant. Polyamides (PA6, PA66) absorb more moisture as compared to other thermoplastics. There are many parameters which affect the moisture absorption of the composite material for example temperature, pressure, type of matrix and fibers, thickness of the material and relative humidity (RH) etc. So, it is utmost important to investigate the impact of moisture on PA66 based composites which can be done by characterizing the mechanical properties of composite materials both for dry and wet conditions. In this study, laminates of C/PA66 composite are manufactured by first heating the commingled material in conventional oven at a temperature of 220 °C followed by pressing in a manual hot press for 20 minutes with preheated platen at 220 °C. To observe the moisture absorption of the composite, coupons of the material were placed in a climate chamber at five different conditions 0, 25, 50, 75 and 100% RH for 24 hours. Five specimens were used for each condition. These coupons were weighed before placing in the climate chamber and just after removing from the chamber to observe the moisture absorption of the material. The mechanical characterization such as tensile strength, flexural modulus, impact strength and DMTA of C/PA66 material are performed at 0, 50 and 100 % RH. The work is going on for the testing of the material and results will be presented in full paper.

Keywords: Carbon/Polyamide 66 composites, structural composites, mechanical characterizations, wet and dry conditions

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Authors: Mohammad Momeenul Islam, U. Johnson Alengaram, Mohd Zamin Jumaat, Iftekhair Ibnul Bashar

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Palm oil industry produces millions of tonnes of industrial wastes and these wastes create huge storage and environmental problems. In order to solve these problems various research works have been performed for past decades. The commonly available wastes are Oil palm shells (OPS) and Palm oil fuel ash (POFA). These materials have already acquired well recognition as alternate of conventional construction materials. OPS has been used as coarse aggregate and compressive strength was found up to 56 MPa for 56-day. It is said that 30 grade Oil Palm shell concrete (OPSC) is possible without adding any cementitious materials. The maximum modulus of elasticity for OPSC was found 18.6 GPa. The Oil palm shell concrete (OPSC) are used in country areas and nearby areas where the palm oil factories are located for houses, road-kerbs, drain blocks, etc. In case of superstructure like beams and slab are also produced by utilizing OPS. Many experimental works have been performed to establish POFA as a substituting binding material in replace of Ordinary Portland cement (OPC). Throughout the research it has been showed that up to 20% of cement by mass can be replaced by POFA. POFA is one of the most enriched pozzolanic materials. The main purpose of this review is to discuss the usage and opportunity of the palm oil industrial wastes as construction materials following the previous experimental research work.

Keywords: construction materials, oil palm shells (OPS), palm oil fuel ash (POFA), aggregates

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Authors: Dhval Chauhan, Mahesh Chudasama

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This study has been undertaken to give a review of Polyethylene Terephthalate Glycol (PETG) material used in Fused Deposition Modelling (FDM). This paper offers a review of the existing literature on polyethylene terephthalate glycol (PETG) material, the objective of the paper is to providing guidance on different process parameters that can be used to improve the strength of the part by performing various testing like tensile, compressive, flexural, etc. This work is target to find new paths that can be used for further development of the use of fiber reinforcement in PETG material.

Keywords: PETG, FDM, tensile strength, flexural strength, fiber reinforcement

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Authors: Soraya Hoornam, Zeinab Sanaee

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Lithium-ion batteries are widely used for providing energy for mobile electronic devices. Graphite is a traditional anode material that was used in almost all commercialized lithium-ion batteries. It gives a specific capacity of 372 mAh/g for lithium storage. But there are multiple better choices for storing lithium that propose significantly higher specific capacities. As an example, silicon-based materials can be mentioned. In this regard, SiO₂ material can offer a huge specific capacity of 1965 mAh/g. Due to this high lithium storage ability, large volume change occurs in this electrode material during insertion and extraction of lithium, which may lead to cracking and destruction of the electrode. The use of nanomaterials instead of bulk material can significantly solve this problem. In addition, if we insert lithium in the active material of the battery before its cycling, which is called pre-lithiation, a further enhancement in the performance is expected. Here, we have fabricated an anode electrode of the battery using SiO₂ nanomaterial mixed with Graphite and assembled a lithium-ion battery half-cell with this electrode. Next, a pre-lithiation was performed on the SiO₂ nanoparticle-containing electrode, and the resulting anode material was investigated. This electrode has great potential for high-performance lithium-ion batteries.

Keywords: SiO₂ nanoparticles, lithium-ion battery, pre-lithiation, anode material

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Authors: Angela McCaskill

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Accounting graduates in most United States universities are not being adequately taught International Financial Reporting Standards (IFRS). As such they are not prepared with the knowledge and skills necessary to remain competitive in international businesses. One of the reasons behind the ill preparation is the lack of specific international accounting instruction available in the U.S. This paper explores the importance of IFRS education through the lenses of graduate accounting majors. The paper specifically explores graduate accounting major’s preparedness in IFRS based on their recent completion of a Master in Accountancy degree where IFRS had been integrated. The data for the study was collected via face-to face and telephone/Skype interviews and questionnaires. After the interview the participants also agreed to answer two supplementary questions. The participants were to determine the amounts that should be reported on the balance sheet under (1) IFRS and (2) U.S. GAAP. These questions intended to test their knowledge of both sets of standards. The sample consisted of on-line and brick and mortar university students enrolled in their graduate program during the period from spring semester 2016 to summer semester 2016. This study shows that a separate course should be devoted to teaching IFRS and convergence related issues. There is a direct correlation between the knowledge level of those students taking an IFRS course and the successful completion of the supplementary questions compared to those who only had IFRS instruction mixed into their U.S. GAAP based instruction. Students who took an international accounting course were better prepared for the IFRS conversion than those who did not have a separate course. Academically, universities need to take a deeper look into the needs of their students and do better at incorporating international standards in their curriculum.

Keywords: accounting education, global accounting standards, international accounting, IFRS and U.S. GAAP convergence, IFRS, U.S. GAAP

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Authors: Sandeep Das

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Terminal post is one of the most important features of a Battery. The design and manufacturing of post are very much critical especially when threaded inserts (Bolt-on type) are used since all the collected energy is delivered from the lead part to the threaded insert (Cu or Cu alloy). Any imperfection at the interface may cause Voltage drop, high resistance, high heat generation, etc. This may be because of sudden change of material properties from lead to Cu alloys. To avoid this problem, a scheme of material gradation is proposed for achieving continuous variation of material properties for the Post used in commercially available lead acid battery. The Functionally graded (FG) material for the post is considered to be composed of different layers of homogeneous material. The volume fraction of the materials used corresponding to each layer is calculated by considering its variation along the direction of current flow (z) according to a power law. Accordingly, the effective properties of the homogeneous layers are estimated and the Post composed of this FG material is modeled using the commercially available ANSYS software. The solid 186 layered structural solid element has been used for discretization of the model of the FG Post. A thermal electric analysis is performed on the layered FG model. The model developed has been validated by comparing the results of the existing Post model& experimental analysis

Keywords: ANSYS, functionally graded material, lead-acid battery, terminal post

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Authors: Bi Yan-Qiang, Shang Yonghong, Lin Boying, Ji Xinyan, Li Xiyuan

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The heat-resistant material has important application in the aerospace field. The reliability of the connection between the heat-resisting material and the body determines the success or failure of the project. In this paper, lock-in infrared thermography non-destructive testing technology is used to detect the stability of the thermal-resistant structure. The phase relationship between the temperature and the heat flow is calculated by the numerical method, and the influence of the heating frequency and power is obtained. The correctness of the analysis is verified by the experimental method. Through the research, it can provide the basis for the parameter setting of heat flux including frequency and power, improve the efficiency of detection and the reliability of connection between the heat-resisting material and the body.

Keywords: infrared non-destructive, thermal insulation material, reliability, connection

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Authors: Saidu Ibrahim, Winston M. W. Shakantu

Abstract:

The problem of construction material waste remains unresolved, as a significant percentage of the materials delivered to some project sites end up as waste which might result in additional project cost. Cost overrun is a problem which affects 90% of the completed projects in the world. The argument on how to eliminate it has been on-going for the past 70 years, but there is neither substantial improvement nor significant solution for mitigating its detrimental effects. Research evidence has proposed various construction cost overruns and material-waste management approaches; nonetheless, these studies failed to give a clear indication on the framework and the equation for managing construction material waste and cost overruns. Hence, this research aims to develop a conceptual framework and a mathematical equation for managing material waste and cost overrun in the construction industry. The paper adopts the desktop methodological approach. This involves comparing the causes of material waste and those of cost overruns from the literature to determine the possible relationship. The review revealed a relationship between material waste and cost overrun that; increase in material waste would result to a corresponding increase in the amount of cost overrun at both the pre-contract and the post contract stages of a project. It was found from the equation that achieving an effective construction material waste management must ensure a “Good Quality-of-Planning, Estimating, and Design Management” and a “Good Quality- of-Construction, Procurement and Site Management”; a decrease in “Design Complexity” which would reduce “Material Waste” and subsequently reduce the amount of cost overrun by 86.74%. The conceptual framework and the mathematical equation developed in this study are recommended to the professionals of the construction industry.

Keywords: conceptual framework, cost overrun, material waste, project stags

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Authors: Takashi Sakai, Yuri Shimomura

Abstract:

The crystal orientation is a factor that affects the microscopic material properties. Crystal orientation determines the anisotropy of the polycrystalline material. And it is closely related to the mechanical properties of the material. In this paper, for pure copper polycrystalline material, two different methods; X-Ray Diffraction (XRD) and Electron Backscatter Diffraction (EBSD); and the crystal orientation were analyzed. In the latter method, it is possible that the X-ray beam diameter is thicker as compared to the former, to measure the crystal orientation macroscopically relatively. By measurement of the above, we investigated the change in crystal orientation and internal tissues of pure copper.

Keywords: bending, electron backscatter diffraction, X-ray diffraction, microstructure, IPF map, orientation distribution function

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Authors: Faci Youcef, Ahmed Mebtouche, Djillali Allou, Maalem Badredine

Abstract:

The inclination of the bolt in a fastened joint of composite material during a tensile test can be influenced by several parameters, including material properties, bolt diameter and length, the type of composite material being used, the size and dimensions of the bolt, bolt preload, surface preparation, the design and configuration of the joint, and finally testing conditions. These parameters should be carefully considered and controlled to ensure accurate and reliable results during tensile testing of composite materials with fastened joints. Our work focuses on the effect of the stacking sequence and the geometry of specimens. An experimental test is carried out to obtain the inclination of a bolt during a tensile test of a composite material using acoustic emission and digital image correlation. Several types of damage were obtained during the load. Digital image correlation techniques permit the obtaining of the inclination of bolt angle value during tensile test. We concluded that the inclination of the bolt during a tensile test of a composite material can be related to the damage that occurs in the material. It can cause stress concentrations and localized deformation in the material, leading to damage such as delamination, fiber breakage, matrix cracking, and other forms of failure.

Keywords: damage, inclination, analyzed, carbon

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Authors: Md Iqbal Hossain, Tahmeed Ahmed, Kenneth H. Brown

Abstract:

Objective: To assess the effect of community-based follow up, with or without food-supplementation and/or psychosocial stimulation, as an alternative to current hospital-based follow-up of children with moderate-acute-malnutrition (WHZ < -2 to -3) (MAM). Design/methods: The study was conducted at the ICDDR,B Dhaka Hospital and in four urban primary health care centers of Dhaka, Bangladesh during 2005-2007. The efficacy of five different randomly assigned interventions was compared with respect to the rate of completion of follow-up, growth and morbidity in 227 MAM children aged 6-24 months who were initially treated at ICDDR,B for diarrhea and/or other morbidities. The interventions were: 1) Fortnightly follow-up care (FFC) at the ICDDR,B’s outpatient-unit, including growth monitoring, health education, and micro-nutrient supplementation (H-C, n=49). 2) FFC at community follow-up unit (CNFU) [established in the existing urban primary health-care centers close to the residence of the child] but received the same regimen as H-C (C-C, n=53). 3) As per C-C plus cereal-based supplementary food (SF) (C-SF, n=49). The SF packets were distributed on recruitment and at every visit in CNFU [@1 packet/day for 6–11 and 2 packets/day for 12-24 month old children. Each packet contained 20g toasted rice-powder, 10g toasted lentil-powder, 5g molasses, and 3g soy bean oil, to provide a total of ~ 150kcal with 11% energy from protein]. 4) As per C-C plus psychosocial stimulation (PS) (C-PS, n=43). PS consisted of child-stimulation and parental-counseling conducted by trained health workers. 5) As per C-C plus both SF+PS (C-SF+PS, n=33). Results: A total of 227children (48.5% female), with a mean ± SD age of 12.6 ±3.8 months, and WHZ of - 2.53±0.28 enrolled. Baseline characteristics did not differ by treatment group. The rate of spontaneous attendance at scheduled follow-up visits gradually decreased in all groups. Follow-up attendance and gain in weight and length were greater in groups C-SF, C-SF+PS, and C-PS than C-C, and these indicators were observed least in H-C. Children in the H-C group more often suffered from diarrhea (25 % vs. 4-9%) and fever (28% vs. 8-11%) than other groups (p < 0.05). Children who attended at least five of the total six scheduled follow-up visits gained more in weight (median: 0.86 vs. 0.62 kg, p=0.002), length (median: 2.4 vs. 2.0 cm, p=0.009) than those who attended fewer. Conclusions: Community-based service delivery, especially including supplementary food with or without psychosocial stimulation, permits better rehabilitation of children with MAM compared to current hospital outpatients-based care. By scaling the community-based follow-up including food supplementation with or without psychosocial stimulation, it will be possible to rehabilitate a greater number of MAM children in a better way.

Keywords: community-based management, moderate acute malnutrition, psychosocial stimulation, supplementary food

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Authors: Un-Hwan Park, Jun-Hyeok Heo, In-Sung Lee, Tae-Hyeon Oh, Dae-Kyu Park

Abstract:

Sound absorbing material is used as automotive interior material. Sound absorption coefficient should be predicted to design it. But it is difficult to predict sound absorbing coefficient because it is comprised of several material layers. So, its targets are achieved through many experimental tunings. It causes a lot of cost and time. In this paper, we propose the process to estimate the sound absorption coefficient with multi-layer structure. In order to estimate the coefficient, physical properties of each material are used. These properties also use predicted values by Foam-X software using the sound absorption coefficient data measured by impedance tube. Since there are many physical properties and the measurement equipment is expensive, the values predicted by software are used. Through the measurement of the sound absorption coefficient of each material, its physical properties are calculated inversely. The properties of each material are used to calculate the sound absorption coefficient of the multi-layer material. Since the absorption coefficient of multi-layer can be calculated, optimization design is possible through simulation. Then, we will compare and analyze the calculated sound absorption coefficient with the data measured by scaled reverberation chamber and impedance tubes for a prototype. If this method is used when developing automotive interior materials with multi-layer structure, the development effort can be reduced because it can be optimized by simulation. So, cost and time can be saved.

Keywords: sound absorption material, sound impedance tube, sound absorption coefficient, optimization design

Procedia PDF Downloads 256