Journal articles: 'Drawbar strength'

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Schreiber, M., and H. D. Kutzbach. "Influence of soil and tire parameters on traction." Research in Agricultural Engineering 54, No. 2 (June 24, 2008): 43–49. http://dx.doi.org/10.17221/3105-rae.

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The drawbar pull, travel reduction (slip), and rolling resistance are the main criteria to describe the traction behaviour of off road vehicles. Besides the engine performance, the drawbar pull is influenced by the traction conditions such as soil and the tire parameters. These traction conditions have to be described by a limited number of parameters which can be easily determined. Empirical equations were used to analyse roughly 850 traction curves measured and published by Steinkampf. As a result, the important parameters to describe the traction conditions are three tire parameters (radius, width, inflation pressure) and five soil parameters (soil cover, upper soil strength, lower soil strength, clay content, moisture content). These parameters with relative values between 0 and 100% are used to establish the equations for the traction prediction. Main steps to achieve this goal are the extension of the traction slip equation by a linear term of slip, and the description of this curve by 4 meaningful characteristic coefficients: the x- and y-coordinates of the κ-maximum (σ κmax, κmax), the y-axis intercept ρe, and the gradient of κ at zero slip (κ’(0)).

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Wang, Bin Jie, Qiang Li, and Zhi Ming Liu. "Research on the Stress Fatigue Assessment about the Hot Spot Stress on the Bogie Frame." Advanced Materials Research 328-330 (September 2011): 1281–86. http://dx.doi.org/10.4028/www.scientific.net/amr.328-330.1281.

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As the loading conditions for the railway vehicles are becoming more and more complex, nominal stress has been unable to fully satisfy the requirements for assessing fatigue strength for weld structures. Hot spots stress is much more closer to the actual stress of a weld structure, it can suit the demand of high speed trains’ fatigue evaluation better. In this paper, on the basis of UIC615-4 standard, the nominal stress of the welded bogie frame was calculated and its fatigue strength was assessed using FEA method. Also, set the joint section between drawbar seat and the transom bottom flange as the object of the study, succeeded in evaluating the hot spot stress of the welded bogie frame. Compared the hot spot stress calculation result with the nominal stress from shell elements, the result shows that hot spot stress is higher than the nominal stress. Using the hot spot stress to assess fatigue has the higher reliability

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Costantini, A., M. Podberscek, and MR Nester. "Site preparation for Pinus establishment in south-eastern Queensland. 2. Effect of cultivation and cultivation width on growth." Australian Journal of Experimental Agriculture 35, no. 8 (1995): 1159. http://dx.doi.org/10.1071/ea9951159.

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The standard site preparation practice used for Pinus plantation establishment on well-drained soils in south-eastern Queensland is blade (subsurface, wing rip) cultivation to a width of 2.0 m and a depth of 0.2 m. This operation requires high drawbar power and is difficult to achieve in high strength soils, or in soils where roots and stumps hinder progress of the blade through the soil. The aim of the study reported in this paper was to better define cultivation growth relationships for Pinus caribaea var. hondurensis plantations in order to determine if site preparation objectives could be achieved with a reduced cultivation effort. A highly significant 'soil type x cultivation' interaction was observed. In contrast to the growth responses observed on hardsetting soils, cultivation did not improve growth on non-hardsetting soils. There is an opportunity therefore to reduce reforestation site preparation costs by only cultivating soils that show a growth response. The cultivation response on hardsetting soils has increased throughout the study period, and is attributed to a reduction in soil penetration resistance. The response however shows diminishing gains with increasing cultivation widths. Blade cultivation widths of 1.2 m were found to capture 97% of the gains that could be expected from widths of 2.0 m. A significant 'family x soil penetration resistance' interaction was observed. An opportunity to increase plantation productivity by targeting better performing families to hardsetting soils is suggested.

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Gil, Imanol, Joseba Mendiguren, Lander Galdos, Endika Mugarra, and Eneko Saenz de Argandoña. "New drawbead tester and numerical analysis of drawbead closure force." International Journal of Advanced Manufacturing Technology 116, no. 5-6 (July 5, 2021): 1855–69. http://dx.doi.org/10.1007/s00170-021-07472-x.

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AbstractCurrently, a great deal of controversy exists regarding the real forces generated in drawbeads during sheet metal forming processes. The present work focuses on the analysis of the uplift force. First, a detailed literature review is carried out to analyse previous experimental procedures used to measure uplift forces. It is found that previous setups do not perfectly replicate the real geometry of industrial drawbeads. In order to obtain reliable forces, an experimental drawbead tester capable of adequately replicating industrial drawbeads is developed. Later, a variety of steels ranging from mild steels to 3rd-generation ultra-high-strength steels are tested and reliable uplift and also restraining force values are obtained. The main purpose of the work is to share with the research community reliable experimental data that allows precise evaluation of the accuracy of current drawbead models and that supports the generation of new numerical and equivalent drawbead models. In parallel to the experimental procedure, a step forward in the understanding of the drawbead closing phenomena is also achieved through a 2D numerical model. The main purpose of the model is to identify the variables that greatly affect uplift force. Going beyond previous studies, in which some variables were analysed, the present work covers, in a holistic manner, the impact that material properties, the geometry of drawbeads and contact behaviour between sheet and drawbead have on the uplift force. It is determined that surprisingly minor geometrical deviations in the drawbead nominal geometry have a large impact on the uplift force.

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FUKIHARU, Hiroshi, Kazuki ISHIKAWA, and Motoyuki YOSHIDA. "Approximate Calculation of Drawbead Force for High-Strength Steeland Verification Experiment." Journal of the Japan Society for Technology of Plasticity 52, no. 610 (2011): 1203–7. http://dx.doi.org/10.9773/sosei.52.1203.

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YAMAMOTO, Noritaka, and Masahiro NEGISHI. "Relationship between the Anterior Drawer Displacement of Tibia and Muscle Strength." Proceedings of the JSME annual meeting 2002.1 (2002): 139–40. http://dx.doi.org/10.1299/jsmemecjo.2002.1.0_139.

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Sirivedin, K., K. Krueger, V. Thoms, Dietmar Suesse, Roland Mueller, and M. Schatz. "Investigation of the Strain Hardening and Bauschinger Effect of Low and High Strength Steel Application in Drawbead-Tester by Experiment and Numerical Simulation." Advanced Materials Research 55-57 (August 2008): 761–64. http://dx.doi.org/10.4028/www.scientific.net/amr.55-57.761.

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The research is aimed to investigate Bauschinger effect and strain hardening by the application of drawbead-tester. Generally, the drawbead is used to control the material flow into the die cavity in sheet metal forming process. When the material is flowing into the drawbead, it may cause the development of strain hardening and/or Bauschinger effect. This work consists of two main equipment particularly developed for the experiments. They are drawbead-tester and three-point bending device. The drawbead-tester provides the possibility to integrate the optical in-process strain analysis system. Whereas the sheet metal was being formed in the drawbead, the local strain of the sheet metal was evaluated. At the same time, the drawbead restraining and holding forces were measured. The three point bending device and numerical simulation method are used to investigate the Bauschinger effect. In the experiment, the cyclic bending forces were measured and compared with the result obtained by numerical simulation.

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YAMAMOTO, Noritaka, and Koji YAMAMOTO. "Effects of Training on the Anterior Drawer Displacement of Tibia and Muscle Strength." Proceedings of Conference of Tokai Branch 2003.52 (2003): 161–62. http://dx.doi.org/10.1299/jsmetokai.2003.52.161.

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Bernhardt, Ida Stange, Helene Nissen-Lie, Christian Moltu, John McLeod, and Marit Råbu. "“It’s both a strength and a drawback.” How therapists’ personal qualities are experienced in their professional work." Psychotherapy Research 29, no. 7 (June 27, 2018): 959–70. http://dx.doi.org/10.1080/10503307.2018.1490972.

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10

Jiao, Zhi Jie, Jian Ping Li, and Jie Sun. "A Pilot Rolling Mill Designed for High Strength Steels." Materials Science Forum 654-656 (June 2010): 210–13. http://dx.doi.org/10.4028/www.scientific.net/msf.654-656.210.

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High strength steels, such as austenitic stainless steel, Transformation Induced Plasticity (TRIP) steel and silicon steel, have significant work hardening during cold rolling, which in turn induces a quickly increased rolling force. Tension plays a very important role in the reduction of the rolling force. However, coiler tension control system used in the classic experimental rolling mill requires long-scale strip, which cannot be satisfied for most experimental cases. To overcome this drawback, a new pilot rolling mill has been developed. The horizontally located hydraulic cylinders and clamps have been used to apply tension to the rolled short-scale strip. With this rolling mill, the austenitic stainless steel strip, TRIP steel strip and other high strength strips have been studied.

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Zyryanova, Valentina N., Evgeniya V. Lytkina, and Arzana P. Ochur-Ool. "Improving Water Resistance of Magnesium Binding Substances by the Introduction of Mineral Fillers." Defect and Diffusion Forum 410 (August 17, 2021): 790–98. http://dx.doi.org/10.4028/www.scientific.net/ddf.410.790.

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Magnesia binders provide strength to the stone, but have one drawback-low resistance and salt resistance. Increasing water and salinity tolerance, mechanical strength of the hardening magnesia binders can be achieved by introducing the system of micro-aggregates. The quality criteria that determine the activity of the micro filler are: high chemical resistance to water, aggressive media, high mechanical strength. Among the effective microfillers composite magnesia binders include diopside, wollastonite. It is shown that the introduction of 60-80 wt%. wollastonite or diopside with a specific surface of 2000-3500 cm2/g provides significant improvement in strength and water resistance that allows you to lengthen the lifespan and maintain the required quality of products based on composite of magnesia binders.

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Urbański, Marek. "Compressive Strength of Modified FRP Hybrid Bars." Materials 13, no. 8 (April 17, 2020): 1898. http://dx.doi.org/10.3390/ma13081898.

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A new type of HFRP hybrid bars (hybrid fiber reinforced polymer) was introduced to increase the rigidity of FRP reinforcement, which was a basic drawback of the FRP bars used so far. Compared to the BFRP (basalt fiber reinforced polymer) bars, modification has been introduced in HFRP bars consisting of swapping basalt fibers with carbon fibers. One of the most important mechanical properties of FRP bars is compressive strength, which determines the scope of reinforcement in compressed reinforced concrete elements (e.g., column). The compression properties of FRP bars are currently ignored in the standards (ACI, CSA). The article presents compression properties for HFRP bars based on the developed compression test method. Thirty HFRP bars were tested for comparison with previously tested BFRP bars. All bars had a nominal diameter of 8 mm and their nonanchored (free) length varied from 50 to 220 mm. Test results showed that the ultimate compressive strength of nonbuckled HFRP bars as a result of axial compression is about 46% of the ultimate strength. In addition, the modulus of elasticity under compression does not change significantly compared to the modulus of elasticity under tension. A linear correlation of buckling load strength was proposed depending on the free length of HFRP bars.

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Марутян, А. С. "OPTIMIZATION OF TREE STRUCTURES WITH HALF-DRAWER GRIDS." Вестник ГГНТУ. Технические науки, no. 3(21) (December 14, 2020): 39–50. http://dx.doi.org/10.34708/gstou.2020.39.71.006.

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Приведено новое техническое решение в виде дополнительных стержней I-образной, Y-образной, Ψ-образной формы в полураскосных решетках для стержневых (ферменных) конструкций. Показана эффективность их применения в фермах, у которых грузовыми являются не только верхние (сжатые) пояса, но также и нижние (растянутые). Повышена степень унификации ферменной конструкции из гнутосварных профилей (профильных труб) прямоугольного сечения за счет повторного использования в верхнем поясе расчетного сечения, принятого для нижнего пояса. При этом ресурсы несущей способности разнятся между ними в пределах 3-4-процентного порога, что обеспечивает необходимую и достаточную равнопрочность обоих поясов при их унификации. Соединительные узлы верхнего пояса с дополнительными полураскосами разных очертаний позволяют опереть на них определенное количество прогонов с уменьшенными размерами грузовых площадей. Увеличение общего количества прогонов приводит к их облегчению, что представляет собой весьма важный фактор для несущих конструкций, рассчитанных на особые нагрузки и воздействия, а также для объектов повышенной ответственности. Выявлена перспективность применения нового технического решения в составе несущих и связевых систем различных зданий и сооружений. A new technical solution is presented in the form of additional I-shaped, Y-shaped, Ψ-shaped rods in half-diagonal lattices for rod (truss) structures. The effectiveness of their use in farms is shown, in which not only the upper (compressed) belts, but also the lower (extended) ones, are cargo. The degree of unification of the truss structure from bent welded profiles (profile pipes) of a rectangular section due to the reuse in the upper zone of the design section adopted for the lower belt is increased. At the same time, the resources of the bearing capacity differ between them within a 3… 4 percent threshold, which ensures the necessary and sufficient equal strength of both zones when unifying them. The connecting nodes of the upper belt with additional half-braces of different shapes allow to support a certain number of runs with reduced sizes of cargo areas. An increase in the total number of runs leads to their facilitation, which is a very important factor for load-bearing structures designed for special loads and impacts, as well as for objects of increased responsibility. The prospects of applying a new technical solution as a part of the bearing and communication systems of various buildings and structures are revealed.

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Abbass, Wasim, and M. Iqbal Khan. "Mechanical properties of Hybrid steel/PVA fibers reinforced high strength concrete." MATEC Web of Conferences 199 (2018): 11005. http://dx.doi.org/10.1051/matecconf/201819911005.

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The high strength concrete exhibits improved compressive strength with drawback of brittle failure due to lack of tensile strength which can be catered by the addition of fibers. The efficient use of fibers with hybridization at macro and micro level can improve mechanical properties of high strength concrete. The effect of hybridization of hooked end steel macro fibers (60 mm) and PVA micro fibers (12 mm) with different dosages was investigated in this research work. The different percentage of steel and PVA were hybridized to find out the best combination of hybridized fibers in high strength concrete. The compressive and flexural properties of high strength concrete along with complete load vs deflection behaviour of hybrid fiber reinforced concrete were investigated. The results revealed that hybridization of macro and micro fibers provided better improvement in flexural performance. It was observed from the results that the hybrid combination of fibers of 1% macro steel fiber and 0.15% micro PVA fibers proved to be the best for enhancement in flexural performance of high strength concrete.

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Dvornikov, Leonid T., and Viktor A. Korneyev. "Design of a device for rocks strength properties determining to solve the tasks of rock rock-cutting machines design." MATEC Web of Conferences 224 (2018): 02084. http://dx.doi.org/10.1051/matecconf/201822402084.

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The article presents methods for rocks strength properties determining in mining machines engineering in Russia, CIS countries and Europe. It is shown that general drawback of methods considered is lack of possibility of carrying out instant tests at various points in rock massif. Criteria are given for the method of rocks strength properties determining as applied to mining engineering tasks. Based on established criteria, the fundamentally new method has been developed. Technical devices are proposed for the method implementation in testing individual samples and rock massif. Construction of the laboratory stand estimating energy intensity of rock destruction is presented. Relationship between its value, coefficient of strength according to the M.M. scale of Protodyakonov and average particle size of the destroyed rock is shown.

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Kotoul, Michal, and Petr Skalka. "Computational Analysis of Crack Bridging in Bioglass^®-Based Porous Scaffolds by Using Polymer Coatings." Solid State Phenomena 258 (December 2016): 325–28. http://dx.doi.org/10.4028/www.scientific.net/ssp.258.325.

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The main drawback still impairing the use of bioactive glasses in load-bearing applications is their intrinsic brittleness. The addition of coating constituted by polyvinyl alcohol (PVA) and microfibrillated cellulose (MFC) PVA/MFC led to a 10 fold increase of compressive strength and a 20 fold increase of tensile strength in comparison with non-coated scaffolds. Crack bridging by polymer coating was identified by fractographic observations as a main toughening mechanism. In this contribution a detailed computational analysis of crack bridging due to coating film fibrils is presented and an improvement of fracture resistance of coated scaffolds is explained.

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Fuchs, D., S. Schurer, T. Tobie, and K. Stahl. "A model approach for considering nonmetallic inclusions in the calculation of the local tooth root load-carrying capacity of high-strength gears made of high-quality steels." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 233, no. 21-22 (April 5, 2019): 7309–17. http://dx.doi.org/10.1177/0954406219840676.

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Demands for higher performance have caused a need for improved component characteristics, e.g. through surface strengthening of gears and increased cleanliness of gear steels. Unfortunately, a resultant drawback is that cracks in such high-strength gears are more often initiated in the material matrix at nonmetallic inclusions and not at the surface. In standardized calculation methods, the degree of cleanliness of steels is not yet directly correlated to the tooth root load-carrying capacity. This paper considers the effects of nonmetallic inclusions in the steel matrix on the tooth root strength based on the theoretical approach of Murakami.

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Jakob, Matthias, Gregor Stemmer, Ivana Czabany, Ulrich Müller, and Wolfgang Gindl-Altmutter. "Preparation of High Strength Plywood from Partially Delignified Densified Wood." Polymers 12, no. 8 (August 11, 2020): 1796. http://dx.doi.org/10.3390/polym12081796.

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Wood and natural fibers exhibit an advantageous combination of good mechanics at comparably low density. Nevertheless, comparing absolute strength and stiffness, wood is clearly inferior to materials such as metals and engineered composites. Since there is a strong correlation between wood density and wood mechanical performance, densification by transversal compression suggests itself as a route towards improved mechanics. Partially delignified densified spruce veneers with excellent tensile properties were produced by means of an alkaline (AL) and an organosolv (OS) approach. Plywood specimens were manufactured using treated veneers glued with a phenol-resorcinol-formaldehyde adhesive and were compared with plywood samples made of native spruce veneers (Ref) and spruce veneer densified after plasticization by water impregnation (H2O). Roughly, the bending strength and the modulus of elasticity of plywood from partially delignified densified wood were improved by a factor of 2.4 and 3.5, respectively. Interlaminar shear strength did not match this improvement after partial delignification. Together with excessive thickness swelling, this might be a drawback of partially delignified densified wood in need for further research.

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Müller, Werner, and Andreas Wöhlecke. "Influence of Rib Stiffness and Limited Long-Term Junction Strength on Geogrid Performance." Transportation Infrastructure Geotechnology 7, no. 2 (October 31, 2019): 175–90. http://dx.doi.org/10.1007/s40515-019-00095-6.

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Abstract The description of the behavior of geogrids in reinforced soil constructions usually ignores long-term behavior and possible failure modes of junctions between longitudinal and transverse ribs. Two proposals have been made during recent years to overcome this drawback. The first analytic approach applies only to rigid geogrids and assumes a specific tensile-shear failure mode of geogrid junctions. The second numerical approach applies also for non-rigid geogrids and takes into account different modes of junction failure. This note discusses the two approaches focusing on the effects of rib stiffness and limited strength, different failure modes and degradation of junctions. It is shown that the mentioned effects should be considered in geogrid design, because they may alter significantly the long-term geogrid performance.

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Wiener, Johannes, Hannes Kaineder, Otmar Kolednik, and Florian Arbeiter. "Optimization of Mechanical Properties and Damage Tolerance in Polymer-Mineral Multilayer Composites." Materials 14, no. 4 (February 4, 2021): 725. http://dx.doi.org/10.3390/ma14040725.

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Talcum reinforced polypropylene was enhanced with a soft type of polypropylene in order to increase the impact strength and damage tolerance of the material. The soft phase was incorporated in the form of continuous interlayers, where the numbers of layers ranged from 64 to 2048. A blend with the same material composition (based on wt% of the used materials) and the pure matrix material were investigated for comparison. A plateau in impact strength was reached by layered architectures, where the matrix layer thickness was as small or smaller than the largest talcum particles. The most promising layered architecture, namely, 512 layers, was subsequently investigated more thoroughly using instrumented Charpy experiments and tensile testing. In these tests, normalised parameters for stiffness and strength were obtained in addition to the impact strength. The multilayered material showed remarkable impact strength, fracture energy and damage tolerance. However, stiffness and strength were reduced due to the addition of the soft phase. It could be shown that specimens under bending loads are very compliant due to a stress-decoupling effect between layers that specifically reduces bending stiffness. This drawback could be avoided under tensile loading, while the increase in toughness remained high.

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Usman, Aliyu, Muslich Hartadi Sutanto, and Madzlan Napiah. "Effect of Recycled Plastic in Mortar and Concrete and the Application of Gamma Irradiation - A Review." E3S Web of Conferences 65 (2018): 05027. http://dx.doi.org/10.1051/e3sconf/20186505027.

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The utilization of a large amount of waste in concrete production is considered the best alternative for solving the issues associated with improper disposal. Plastic waste is considered as one of such waste and could be utilized in several applications. The drawback associated with the utilization of a large amount of plastic waste is the decrease in the mechanical properties of the mortar or concrete as the case may be. This paper presents a detailed review about waste recycled plastics and research published on the effect of non-irradiated recycled plastic on the mechanical properties of cement mortar and cement concretes as either fillers or aggregates and the application of gamma radiation on the recycled plastic waste. The effect of recycled waste plastic on compressive strength, flexural strength and splitting tensile strength is discussed in this paper.

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S. J, Numair Abdul Musawwir. "Experimental Study on Strength Parameters of Roofing Tiles Incorpating Pumice Powder." International Journal for Research in Applied Science and Engineering Technology 9, no. VI (June 14, 2021): 2263–69. http://dx.doi.org/10.22214/ijraset.2021.34811.

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Our experimental investigation is being carried out to find out an alternative for tiles made from terracotta, because these tiles get easily cracked having less in strength. This drawback is likely motivated to conduct investigation to deliver the product by not this limitation. So, we have implemented work by using material called ‘pumice’. Naturally it will absorb the heat and emit cooling to the atmosphere. At early stage pumice powder were added in the range 2.5%, 5%, and 7.5%. Conventionally available materials do not offer acceptable solutions. Prices of corrugated G.I. sheets are continuously escalating, and their use in not preferred because of thermal discomfort. Use of cement sheets is not recommended because of health hazards associated with asbestos. In India there is an acute shortage of locally available cheap roofing materials. Home-builders particularly the poor, are in dire need of cost-effective materials to build their homes with. In addition, mass rural housing programmers supported by Central and State Governments are increasingly looking at low-cost building techniques.

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A. Sabit, Hiba, and Aamer N. Abbas. "STRUCTURAL BEHAVIOR OF HYBRID REINFORCED CONCRETE COUPLED BEAMS CONTAINING REACTIVE POWDER CONCRETE AND HIGH STRENGTH CONCRETE." Journal of Engineering and Sustainable Development 25, no. 02 (March 1, 2021): 68–77. http://dx.doi.org/10.31272/jeasd.25.2.8.

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Reactive powder concrete and high strength concrete have superior mechanical and structural properties, however, the major drawback of this new construction material is its high cost compared to traditional concrete. This study presents an experimental investigation on the structural behavior of hybrid rectangular cross section (coupled) reinforced concrete beams poured with normal and high strength concrete (HSC) at compression chord, normal strength concrete (NSC) at ribs, and reactive powder concrete (RPC) at tension chord. The experimental work consists of pouring and testing four specimens with dimensions (1100mm length, 100 mm width, and 400 mm height). First specimen, rectangular solid normal concrete beam for comparison with specimens, second specimen, coupled beam poured with normal strength concrete at top chord, and two other specimens of coupled beams cast with high strength concrete with two compressive strength (50 MPa and 70 MPa) at top chord. The effect of top chord concrete type at each specimen on ultimate load capacity, energy absorption, deflection and cracking load are studied in this investigation. Experimental results showed that the ultimate load carrying capacity and energy absorption increased to 76.9 % and 108.33 % respectively, compared with the solid specimen and recorded a reduction in deflection values through loading life and cracking load when using higher compressive strength of high strength concrete in compression chord in addition to reactive powder concrete in tension zone.

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Chi, Hiep Le, Pavlína Hájková, Su Le Van, Petr Louda, and Lukáš Voleský. "Water Absorption Properties of Geopolymer Foam after Being Impregnated with Hydrophobic Agents." Materials 12, no. 24 (December 11, 2019): 4162. http://dx.doi.org/10.3390/ma12244162.

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Geopolymer foam is classified as a lightweight material with high porous in its matrix which has great offer for applications requiring fire-resistant, thermal, and acoustic properties. However, the high sensitivity to humid environments can be a major barrier of geopolymer foam that limits the variety of applications of this material. Based on this drawback, two types of hydrophobic agent (Lukosil M130 and Lukofob ELX) were used as an impregnator to treat the surface of geopolymer foam samples. This paper presented the results of water absorption properties of the untreated and treated geopolymer foam composites. The obtained properties were flexural strength, compressive strength, density, total water absorption, the rate of water absorption, and water absorption coefficient. The results showed that the samples after being impregnated with hydrophobic agents improved significantly their waterproof property especially using Lukosil M130. Moreover, the samples treated with Lukosil M130 had positive impact on their mechanical strength.

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M., Vahini, K. Manjunatha, Venkatesh, and Basappa Meti. "Study on Effect of Superplasticizer on GGBS Blended Geopolymer Concrete." Energy and Earth Science 2, no. 2 (September 4, 2019): p45. http://dx.doi.org/10.22158/ees.v2n2p45.

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Geopolymer concrete is an alternate to conventional concrete with reduced carbon emission, embodied energy and global warming potential and transforming waste product into an useful material. Geopolymer concrete is produced by mixing highly alkaline activator solution with alumino silicate source materials. Geopolymer concrete is highly viscous or sticky in nature, to overcome this drawback, an attempt has been made to study the effect of naphthalene based superplasticizer on geopolymer concrete blended with GGBS. Fly ash was replaced by GGBS at 20% increment levels, keeping a constant superplasticizer dosage at 3% by weight of binding material. Workability and strength characteristics were compared with those of geopolymer concrete blended with GGBS without superplasticizer. Up to certain replacement level of fly ash with GGBS, results in decrease of strength parameters with increase in workability, further replacement results in increase of strength with reduced workability with the addition of superplasticizer.

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Zhang, Pin Le. "Seismic Performance Investigation of Different Kinds of Shear Walls." Applied Mechanics and Materials 501-504 (January 2014): 1615–18. http://dx.doi.org/10.4028/www.scientific.net/amm.501-504.1615.

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Shear wall systems are the most commonly used lateral load resisting systems in high seismic zones because they provide significant lateral strength, stiffness, and deformation capacity. The work further investigates the seismic performance of different kinds of shear walls. Classified and brief comments about the seismic performance and the exist drawback of different kinds of shear walls and its application are conducted. Lastly, some useful suggestions and a new structure are proposed for the further research.

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Firat, Mehmet, and Orhan Cicek. "A FE technique to improve the accuracy of drawbead models and verification with channel drawing experiments of a high-strength steel." International Journal of Advanced Manufacturing Technology 55, no. 1-4 (December 1, 2010): 107–19. http://dx.doi.org/10.1007/s00170-010-3048-x.

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Zhao, Li Hui, Han Gu, and Qing Quan Hong. "Shape Optimization of Lower Control Arm under Typical Road Conditions." Advanced Materials Research 430-432 (January 2012): 1996–99. http://dx.doi.org/10.4028/www.scientific.net/amr.430-432.1996.

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Structure optimization of lower control arm was performed under three proving ground road conditions to find the best drawbead distribution. First, multi-body dynamics analysis was carried on to determine the deficiency of the lower control arm. Then shape optimization was applied based on the widely used optimization method under static loads by converting dynamic load of the three roads to equivalent static loads. Results of the new design show that the strength and stiffness were increased by 24.3% and 42.9% respectively.

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Das, Sourav, Saurabh Kundu, and Arunansu Haldar. "Development of Continuously Cooled High Strength Bainitic Steel through Microstructural Engineering at Tata Steel." Materials Science Forum 702-703 (December 2011): 939–42. http://dx.doi.org/10.4028/www.scientific.net/msf.702-703.939.

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Bainitic steels, which are transformed at very low temperatures, offer an excellent combination of strength and ductility where the strength comes from the nano-structured bainitic plates and thin-film of austenite sandwiched between two bainite sheaves offers the ductility. The main drawback of this structure is the long transformation time which is not ideal for industrial application. Through the microstructural engineering, the extent and kinetics of transformation can be manipulated by judicious selection of alloy composition and process variables. The main challenge is to delay the transformation till the coiling stage and allow the formation of bainite only during the cooling of the coil. In the current work, an approach will be shown, starting from the alloy design based on thermodynamics till the cooling after coiling, which can satisfy the requirements to develop such steel with 1300 MPa UTS combined with 20% elongation (min).

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Ngo, Tu Quynh Loan, Yu-Ren Wang, and Dai-Lun Chiang. "Applying Artificial Intelligence to Improve On-Site Non-Destructive Concrete Compressive Strength Tests." Crystals 11, no. 10 (September 23, 2021): 1157. http://dx.doi.org/10.3390/cryst11101157.

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In the construction industry, non–destructive testing (NDT) methods are often used in the field to inspect the compressive strength of concrete. NDT methods do not cause damage to the existing structure and are relatively economical. Two popular NDT methods are the rebound hammer (RH) test and the ultrasonic pulse velocity (UPV) test. One major drawback of the RH test and UPV test is that the concrete compressive strength estimations are not very accurate when comparing them to the results obtained from the destructive tests. To improve concrete strength estimation, the researchers applied artificial intelligence prediction models to explore the relationships between the input values (results from the two NDT tests) and the output values (concrete strength). In-situ NDT data from a total of 98 samples were collected in collaboration with a material testing laboratory and the Professional Civil Engineer Association. In-situ NDT data were used to develop and validate the prediction models (both traditional statistical models and AI models). The analysis results showed that AI prediction models provide more accurate estimations when compared to statistical regression models. The research results show significant improvement when AI techniques (ANNs, SVM and ANFIS) are applied to estimate concrete compressive strength in RH and UPV tests.

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Buyakova, Natal’ya, Vasiliy Zakaryukin, Andrey Kryukov, and Tu Nguyen. "Electromagnetic safety enhancing in railway electric supply systems." E3S Web of Conferences 58 (2018): 03003. http://dx.doi.org/10.1051/e3sconf/20185803003.

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The methods of simulation modeling of traction power supply systems is developed, allowing analyzing the electromagnetic safety conditions in complex traction power networks equipped with sucking transformers. The effectiveness of the application of the sucking transformers (ST) connected in the rail cut with a distance of 3 km between transformers is small due to rails’ currents. The sucking transformers with return wires do not have this drawback. The use of ST with a return wire allows significantly improving the electromagnetic safety conditions: the level of magnetic field strength is reduced by tens of percent.

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Rovnaník, Pavel, Libor Topolář, Pavel Schmid, and Zbyněk Keršner. "Effect of Spontaneous Drying on Mechanical Parameters of Alkali-Activated Slag Mortar." Advanced Materials Research 969 (June 2014): 144–47. http://dx.doi.org/10.4028/www.scientific.net/amr.969.144.

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Alkali-activated slag is a material which has great potential for use in industrial applications. The main drawback of this material is the high level of autogenous and especially drying shrinkage that affects it, causing the deterioration of its mechanical properties. Mechanical and mechanical fracture parameter values show that an alkali-activated slag composite which is saturated with water is more brittle and exhibits lower strength in comparison with the same material after being surface-dried. These results are essential for the adjustment of testing conditions in order to obtain accurate and reproducible results.

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Budin, Salina, Koay Mei Hyie, Hamid Yussof, Aulia Ishak, and Rosnani Ginting. "Investigation on Mechanical Properties of Blend Virgin and Recycled Acrylonitrile-Butadiene-Styrene (ABS) in Injection Molding." Key Engineering Materials 833 (March 2020): 8–12. http://dx.doi.org/10.4028/www.scientific.net/kem.833.8.

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Acrylonitrile-butadiene-styrene (ABS) is one of the most widely used plastic. The application of ABS increases rapidly in industries recently. The drawback of the increasing demand of ABS is the increment of ABS waste. Huge increment in ABS waste has led to the increasing of environmental pollution. The demand in green technology and sustainability of resources has urged the need of recycling of ABS waste. However, the mechanical properties of the recycled ABS are deteriorated. Hence, this work aims to study the mechanical properties of blend virgin and recycled ABS. The first sample started with 100wt% of virgin ABS. While the second to eleventh samples was a mixing of virgin and recycled ABS at 10wt% incremental recycled ABS. The last sample was prepared using 100wt% of recycled ABS. The results show that the tensile strength of 100wt% of recycled ABS is slightly decreased as compared to 100wt% virgin ABS. Similar trend was observed on traverse rupture strength (TRS) when the TRS for 100wt% of recycled ABS is lower by 8% when compared to 100wt% of virgin ABS. The most significant change is observed on the impact strength. The impact strength for 100wt% of recycled ABS is substantially dropped by 86% as compared to 100wt% of virgin ABS.

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Feldewerth, Gerald B. "TEM study of boron additions to cobalt aluminide." Proceedings, annual meeting, Electron Microscopy Society of America 46 (1988): 546–47. http://dx.doi.org/10.1017/s0424820100104790.

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In recent years an increasing emphasis has been placed on the study of high temperature intermetallic compounds for possible aerospace applications. One group of interest is the B2 aiuminides. This group of intermetaliics has a very high melting temperature, good high temperature, and excellent specific strength. These qualities make it a candidate for applications such as turbine engines. The B2 aiuminides exist over a wide range of compositions and also have a large solubility for third element substitutional additions, which may allow alloying additions to overcome their major drawback, their brittle nature.One B2 aluminide currently being studied is cobalt aluminide. Optical microscopy of CoAl alloys produced at the University of Missouri-Rolla showed a dramatic decrease in the grain size which affects the yield strength and flow stress of long range ordered alloys, and a change in the grain shape with the addition of 0.5 % boron.

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Nansheng, Li, Tang Bo, and Xie Lihui. "Slope Stability Analysis of Earth-Rockfill Dams Using MGA and UST." Journal of Computational Engineering 2015 (June 10, 2015): 1–10. http://dx.doi.org/10.1155/2015/895142.

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The nonlinear Unified Strength Theory (UST), which takes into account the effect of intermediate stress and nonlinear behavior on geotechnical strength, is applied in slope stability analysis of earth-rockfill dams (ERD) in this paper. The biggest drawback for general determination of slip surface is that it must presuppose the shape of slip surface and is unable to identify the critical noncircular slip surface more accurately. This paper proposes an optimal analytic model of slope stability analysis of ERD and employs modified genetic algorithm (MGA) to search for the slip surface on the basis of shear failure criteria of the nonlinear UST without prior assumption of the shape of slip surface. The application of MGA dependent on Matlab toolbox to the slope stability analysis of ERD shows that MGA can consequently overcome the weakness of easily falling into local optimal solutions brought by general optimal algorithms.

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Hsu, Robert Wen-Wei, Cheng-Kung Cheng, and Yang-Hua Lin. "The Functional Assessment of the Untreated and the Reconstructed Posterior Cruciate Ligament Deficient Knee." Journal of Musculoskeletal Research 02, no. 01 (March 1998): 27–34. http://dx.doi.org/10.1142/s0218957798000056.

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Seventeen patients with rupture of the posterior cruciate ligament (PCL), 7 untreated and 10 having reconstruction of the PCL using the medial head of the gastrocnemius and the attached adductor tendon, were recruited for functional evaluation. The clinical functional status of the knee joint was evaluated in accordance with Hughston's criteria and Lysholm's score. The patients' gaits were analyzed using a three-dimensional electrogoniometer and mats. Muscle strength was assessed via Cybex-340; and a KT-1000 arthrometer was used to measure the laxity of the knee joints. Muscle strength tests showed a significant difference ( p < 0.01) in the knee extensors when the injured side was compared with the noninjured side in the untreated group, while no significant difference existed in reconstructed group. The gait analysis revealed that a significant difference existed over the velocity ( p < 0.05) when the reconstructed group was compared with the untreated group. The KT-1000 arthrometer test demonstrated that the anterior and posterior drawer at a knee flexion of 70 degrees and the posterior tibial sag screen at 90 degrees, differed significantly ( p < 0.01) between injured and noninjured limbs in the untreated group. In the reconstructed group only the anterior drawer presented a significant difference ( p < 0.05) between the injured and noninjured limbs. Using Hughston's and Lysholm's criteria, reconstruction was shown to have improved the knees' functions and scores postoperatively ( p < 0.01). The authors concluded that although the overall clinical results along with dynamic function, stability and strength of the extensor of the knee joints with PCL deficiency, were significantly improved after reconstruction using the medial head of the gastrocnemius together with the adductor tendon, yet, the normal perfect knee functions were still not achieved. A more sophisticated reconstructive procedure needs further investigation.

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Schmid, Harald, and Marion Merklein. "Effect on the mechanical properties of sheet metals after the use of drawbeads in deep drawing." MATEC Web of Conferences 190 (2018): 05001. http://dx.doi.org/10.1051/matecconf/201819005001.

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The use of modern and more complex materials leads to a need for detailed knowledge and controlling of the material flow. Next to the blank holder force or the lubrication system, drawbeads are nowadays one common way to bring serial forming processes under control. Although drawbeads are already well investigated regarding their retention forces, the effect on the resulting mechanical properties after a drawbead passage is not analysed in detail yet. This work will show the influence of a common drawbead geometry used in forming processes on typical mechanical properties of sheet metal. Therefore, two different sheet metal materials are preloaded in a modified strip drawing test with industrial used drawbead geometry. In testing, three different pressure levels between 2.5 MPa and 7.5 MPa and three levels of drawing speed between 10 mm/s and 50 mm/s are combined to nine variations which will be examined. Afterwards, specimens are cut out by a laser cutting machine of the drawn strips. Those already preloaded and deformed specimens are then tested under standard conditions with the use of an optical measurement system. The results like tensile strength or elongation at fracture are compared to the initial state and each other and discussed with consideration of pressure and speed levels to work out the main effects. Those results are a contribution for the optimization of deep drawing simulations of parts including drawbeads or to evaluate the influence of drawbeads on forming processes to specify or even expand process limitations.

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Asavavisithchai, Seksak, Natthida Jareankieathbovorn, and Areeya Srichaiyaperk. "Investigation of AC8A Scrap-Recycled Aluminum Foams." Advanced Materials Research 894 (February 2014): 134–37. http://dx.doi.org/10.4028/www.scientific.net/amr.894.134.

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Open-cell Al foam has outstanding properties which are suitable for functional applications. However, a major drawback for widespread employment of Al foam is its high relative cost which can be several times higher than conventional metals. To reduce the cost, a recycled material waste is constructively used instead of expensive base metal. The present study aims to fabricate economical open-cell Al foams using AC8A alloy scrap from lathe machines. The Al foams were fabricated through pressure infiltration casting process at which the cellular pattern was made from commercial reticulated open-cell polyurethane foams with the pore size of 12 ppi. The compressive strength and microhardness of scrap-recycled Al foams are higher than those of pure Al foam. The increase in foam mechanical properties resulted from the change in foam microstructure as the formation of Si hard phase in Al matrix. The strength and microhardness of the foams increase with increasing scrap contents.

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Landfried, Richard, Frank Kern, and Rainer Gadow. "Influence of Titanium Carbide Fraction on Material Properties and EDM of ZrO₂-TiC Ceramics." Key Engineering Materials 611-612 (May 2014): 637–42. http://dx.doi.org/10.4028/www.scientific.net/kem.611-612.637.

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EDM of electrically conductive oxide ceramics with addition of titanium carbide have been successfully applied as wear resistant tool inserts in ceramic injection molding or extrusion. In recent years especially alumina based ceramic composites toughened by zirconia have shown their potential in the field of ED machinable ceramics however revealing some drawbacks resulting from their moderate fracture toughness. This study focuses on the zirconia based ceramics with addition of different amounts of titanium carbide as electrically conductive phase (26-36 vol.-%) in order to improve the toughness of ED machinable ceramics. Additionally the influence of the titanium on removing mechanisms during machining as well as the hardness and strength of the material was investigated. It was found that the use of zirconia as matrix material does improve the toughness and strength compared to alumina based composites whereas the drawback of zirconia based materials concerning machinability and lower hardness can be only partially compensated by adjusting the titanium carbide content.

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Mendiguren, Joseba, Lander Galdos, Eneko Sáenz de Argandoña, and E. Silvestre. "Ludwik’s Model Parameter Identification for V-Bending Simulations with Ti64 and MS1200." Key Engineering Materials 504-506 (February 2012): 889–94. http://dx.doi.org/10.4028/www.scientific.net/kem.504-506.889.

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Flow curves coming from tensile tests together with constant young modulus are widely used by industry when modelling sheet metal bending processes. Unfortunately this modelization strategy based on previous mentioned variables is not accurate enough and leads to big errors due to the springback of the material. This drawback is even more important when high strength steels are bended. Aiming to reduce the springback errors, Ludwik’s hardening material models under bending deformation have been obtained for a Ti6Al4V alloy and for a MS1200 martensitic ultra high strength steel and their accuracy has been compared to the classical models obtained from tensile tests. First of all, classical Ludwik’s hardening models are obtained from tensile tests. Then, using a V-Bending test and inverse simulation, Ludwik hardening model parameters for bending are calculated using a Von Mises yielding criteria. As a result, a model able to represent the bending behaviour of these two materials more accurately without complex code modifications is achieved.

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Truty, Andrzej, and Rafał Obrzud. "Improved Formulation of the Hardening Soil Model in the Context of Modeling the Undrained Behavior of Cohesive Soils." Studia Geotechnica et Mechanica 37, no. 2 (June 1, 2015): 61–68. http://dx.doi.org/10.1515/sgem-2015-0022.

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Abstract The analysis of an important drawback of the well known Hardening Soil model (HSM) is the main purpose of this paper. A special emphasis is put on modifying the HSM to enable an appropriate prediction of the undrained shear strength using a nonzero dilatancy angle. In this light, the paper demonstrates an advanced numerical finite element modeling addressed to practical geotechnical problems. The main focus is put on serviceability limit state analysis of a twin-tunnel excavation in London clay. The two-phase formulation for partially saturated medium, after Aubry and Ozanam, is used to describe interaction between soil skeleton and pore water pressure.

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Tarrés, Soler, Rojas-Sola, Oliver-Ortega, Julián, Espinach, Mutjé, and Delgado-Aguilar. "Flexural Properties and Mean Intrinsic Flexural Strength of Old Newspaper Reinforced Polypropylene Composites." Polymers 11, no. 8 (July 26, 2019): 1244. http://dx.doi.org/10.3390/polym11081244.

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Newspapers have a limited lifespan, and therefore represent a focus of used and disposed paper. While these refuses have a considerable value and can be easily recycled, a considerable fraction ends in landfill. The authors show the possibility of adding value to used newspaper and enlarge its value chain. Old newspaper incorporates a high amount of wood fibers able to be used as reinforcement. On the other hand, this material also incorporates inks and other components inherent to newspaper production. In this work, the authors disintegrate old newspaper to recover and individualize wood fibers. A morphological analysis showed that the recovered fibers had aspect ratios higher than 10, revealing, a priori, their strengthening capabilities. Thereupon, these fibers were compounded with polypropylene at different contents, ranging from 20% to 50% w/w. It is well known that wood fibers are hydrophilic, while polyolefin are hydrophobic. This is a drawback to obtaining strong interfaces. Thus, two sets of composites were produced, with and without a coupling agent. The results showed that uncoupled composites increased the flexural strength of the matrix but reached an equilibrium point from which adding more reinforcement did not changer the flexural strength. On the other hand, the coupled composites showed a linear increase of the flexural strength against the reinforcement content. The flexural moduli of the coupled and uncoupled composites were very similar and evolved linearly with the reinforcement content.

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Yao, Ng Guan, Bin Abd Rashid Mohd Warikh, Buang Zolkepli, N. Nadiah, and S. C. Leng. "Effect of Retrogression Medium to the Mechanical Properties of Aluminum Alloy 7075." Applied Mechanics and Materials 165 (April 2012): 6–11. http://dx.doi.org/10.4028/www.scientific.net/amm.165.6.

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Aluminum alloy 7075 is a useful material in industry due to its light weight, high strength, and resistance to general corrosion properties. The drawback of this alloy is its susceptibility to stress corrosion cracking (SCC). From the previous research, it was found that retrogression and re-aging (RRA) heat treatment is able to improve the SCC resistance of this alloy. In this study, the mechanical properties and microstructure alteration due to RRA was studied. First, the tensile specimens are heat treated to T6 and then retrogressed at 165/185/205°C for 10/30 minutes followed by re-aging at 120°C for 24 hours. The retrogression methods are categorized as standard retrogression and oil retrogression. Next, the specimens were gone through tensile test, hardness test, and microstructure characterization by using SEM. From the mechanical test result, the tensile strength and hardness of the alloy decreased upon the increment of retrogression temperature and time. The highest tensile strength of 638.48 MPa was observed at oil retrogress sample at 165°C for 10 minutes which is slight higher than T6 sample. Besides, different phases of precipitation were reviewed by the Kellers etching process. Also, the volume fraction of η phase is increased upon increasing the retrogression temperature and time.

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44

Smittakorn, Watanachai, Pattraporn Manavithayarak, and Patra Sukmoung. "Improvement of shear capacity for precast segmental box girder dry joints by steel fiber and glass fiber." MATEC Web of Conferences 258 (2019): 04006. http://dx.doi.org/10.1051/matecconf/201925804006.

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The use of precast segmental box girders in the bridge construction projects yields many benefits: economy, high quality, rapid construction, and minimal disruption to site. Previously, precast segments are connected together by epoxy joints. Epoxy fills in the gaps and makes strong connection, but it takes time and effort in the construction process. Later, dry joints have been introduced in the process, and hence the construction could be done much faster. However, there exists some drawback in using the dry joints. The contact surface between segments, especially at shear keys, can hardly be made smooth and well-fitted together. Consequently, the transferred shear strength cannot be developed to its full capacity. This study is an attempt to improve the capacity of shear strength of dry joints by adding steel fiber and glass fiber into concrete mixture. Considering specimens with single shear key, experiments have been conducted for shear capacities of 5 specimen types: ordinary concrete, concrete mixed with 1% and 2% steel fiber, and concrete mixed with 1% and 2% glass fiber. Results from experiments have shown that steel fiber helps increase the shear capacity of dry joints while glass fiber somehow degenerates the shear capacity and the compressive strength of concrete.

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Larrain, Mario, Eduardo Di Rocco, Patricio Riatti, Facundo Ferreyra, and Juan Sebastián Cianciosi. "PCL rupture tibial avulsion in a contact athlete teen with open physis. One case presentation and literature review." Orthopaedic Journal of Sports Medicine 5, no. 1_suppl (January 1, 2017): 2325967117S0001. http://dx.doi.org/10.1177/2325967117s00013.

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Introduction: Given the infrequency and lack of consensus in the treatment of children and adolescents with these injuries, we decided to write this report with the aim of present a case of PCL tibial avulsion in a contact athlete teen with open physis and a review of the literature published. Materials and Methods: RF.male, 13 years, rugby, suffers French tackle and fall on knees flexed. 3 months post-trauma consultation with left knee pain, joint fluid and sport limitation. Whidout instability but "not feeling well". The posterior drawer test + + / ++++, gravitational test +. Rx posterior drawer: 8mm difference between the two nenes. MRI: tibial avulsion PCL. We interpreted as symptomatic PCL injury in athletes, surgery (arthroscopy + posterior approach) is decided reintegration of chondral fragment in 1 time P.OP: no load 4 Weeks . plaster wedge extension 6 weeks, then 3 months and passive immobilizer progressive mobility. Results: 0-90 mobility achieving in 8th week. The 3rd month drawer rx 4mm. MRI posterior translation of the 4th month reintegration of LCP with anchor . 6ª month later minimally elongated drawer with stop net. 11th month continuous strengthening recrearional and sports activities. Discussion and Conclusion: Most avulsion of PCL in patients with open physis probably be for greater strength and endurance ligament compared with the phisis and bone at this age. We suspected in patients with vague knee pain, with or without instability, history of trauma and normal Rx a correct examination and MRI to be essential for diagnosis. We beleave that athletes with open physis, because of the risk of joint degeneration, surgery is justified to restore kinematics, prevent osteoarthritis and resume activity prior to the injury.

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Prukkaewkanjana, Kontapond, Seiichi Kawahara, and Jitladda Sakdapipanich. "Influence of Reaction Conditions on the Properties of Nano-matrix Structure Formed by Graft-Copolymerization of Acrylonitrile onto Natural Rubber." Advanced Materials Research 844 (November 2013): 365–68. http://dx.doi.org/10.4028/www.scientific.net/amr.844.365.

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Natural rubber (NR) is one of the most important agriculture products of Thailand, which is an important material with unique and special characteristics used in wide range of applications such as mechanical properties, excellent strength, and elasticity. However, it is inferior in oil resistance due to the presence of hydrogen and carbon in its structure. This inherent drawback of NR has limited its application in industry. In order to expand the use of NR, this research is interested to improve the oil resistance of NR without loss of outstanding properties by grafting NR with acrylonitrile (AN) monomer to form the nano-matrix structure. The influences of the initial monomer concentration and initial initiator concentration were investigated. These effects on structure, mechanical properties and oil resistance properties were studied by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy, tensile machine, and swelling in toluene, respectively. It was found that the tensile strength and oil resistance properties of graft copolymerization of AN onto NR increased with increasing the percentage grafting efficiency of acrylonitrile monomer.

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Warda, Ahmad, Bojana Petković, and Hannes Toepfer. "Scanning method for indoor localization using the RSSI approach." Journal of Sensors and Sensor Systems 6, no. 1 (June 20, 2017): 247–51. http://dx.doi.org/10.5194/jsss-6-247-2017.

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Abstract. This paper presents a scanning method for indoor mobile robot localization using the received signal strength indicator (RSSI) approach. The method eliminates the main drawback of the conventional fingerprint, whose database construction is time-consuming and which needs to be rebuilt every time a change in indoor environment occurs. It directly compares the column vectors of a kernel matrix and signal strength vector using the Euclidean distance as a metric. The highest resolution available in localization using a fingerprint is restricted by a resolution of a set of measurements performed prior to localization. In contrast, resolution using the scanning method can be easily changed using a denser grid of potential sources. Although slightly slower than the trilateration method, the scanning method outperforms it in terms of accuracy, and yields a reconstruction error of only 0. 08 m averaged over 1600 considered source points in a room with dimensions 9.7 m × 4.7 m × 3 m. Its localization time of 0. 39 s makes this method suitable for real-time localization and tracking.

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Ho, Vuong, Aileen Orbecido, and Michael A. Promentilla. "Investigation on mixture design of one-part geopolymer from fly ash and water treatment sludge." MATEC Web of Conferences 156 (2018): 05009. http://dx.doi.org/10.1051/matecconf/201815605009.

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This study presents a one-part geopolymer system from coal fly ash and water treatment sludge. Geopolymer is typically produced from two parts namely the aluminosilicate solids, which is typically sourced out from industrial by-product, and an alkali activator solution which reacts with aluminosilicate solids to form an inorganic polymeric network. For a one-part geopolymer system, the solid binder with activators will just be added with water to address the drawback of corrosive and viscous alkali activator solution. Formulation of the proportion of geopolymer precursors with the two solid alkali activators namely sodium hydroxide and sodium aluminate was conducted using statistical mixture design. Effects of each components as well as interactions between them were evaluated by step-wise regression analysis. It was found that high alkali content decreased the compressive strength of binder. Meanwhile, the incorporation of sludge in this system helps reduce the unit weight of samples. Multiple response surface analysis that maximized compressive strength and minimized unit weight resulted in the optimal combination of 18.9% sludge, 76.1% fly ash and 5.0% NaOH.

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Kivnick, Helen Q., Molly C. Driessen, Chittaphone Santavasy, Clair Wardwell, and Linda Duncan Davis. "“Who’s Been Putting Socks in My Drawer?” Narrative Case Study of an Elder Role Model." Gerontologist 60, no. 5 (August 31, 2019): 831–40. http://dx.doi.org/10.1093/geront/gnz114.

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Abstract Background and Objectives This article presents a narrative-based case study about vital involvement in an elder role model, exploring the dimensions of this man’s current vital involvement and identifying its lifelong expressions that appear, in older adulthood, to have enabled him to become such an exemplar. This case was chosen from a larger study of “Elder Roles Models”, that explores: (i) What about these particular older adults (identified by colleagues, friends, program directors, and service providers) constitutes their “elder role model-hood”; and (ii) How, developmentally, they got to be this way in older adulthood. This case study addresses the first of these questions by identifying five dimensions of vital involvement. Research Design and Methods Case study data were collected through five, semi-structured life-history interviews conducted over the 3 months. Interviews (90–120 minutes, each) were transcribed and analyzed using a thematic analysis approach. Findings Five dimensions emerged as constituting this man’s vital involvement in older adulthood: (i) enacting personal values and strengths; (ii) person–environment reciprocity; (iii) using environmental supports; (iv) enriching the environment; and (v) experience-based perspective. Discussion and Implications Dimensions are contextualized in terms of gerontological and life-cycle research, theory, and practice. A fundamental principle of Erikson’s theory of lifelong psychosocial development, the vital involvement dynamic, is suggested as an “umbrella concept” for integrating disparate gerontological practices, theories, and research, and for conceptualizing older adulthood in the context of the life cycle as a whole.

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Wang, Tao, Xian Lin Xu, Xiao Yang Sui, and Li Na Wang. "The Antistatic Research of Polyester/Nylon Fabrics Finished by Triblock Copolymer Containing Organic Silicon." Advanced Materials Research 535-537 (June 2012): 1569–72. http://dx.doi.org/10.4028/www.scientific.net/amr.535-537.1569.

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Polyester/nylon blend fabric has some advantages, such as high strength, excellent drapability, but the biggest drawback of the blend fabric is the easily formed electrostatic. In this paper, the blend fabric was finished with the triblock copolymer containing organic silicon to improve the antistatic property of the fabric. The influence of the concentration of the finishing agent on the antistatic property was studied emphasisly. And the effect of antistatic, the feeling and the color fastness were analyzed. The results show that the finishing agent of triblock copolymer containing hydrophilic organosilicon with the concentration of 15 g/L can make the fabric achieve the best antistatic effect, the best feeling and the fabric color fastness is less affected.

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Journal articles on the topic 'Drawbar strength'

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