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1
Souza, Thiago Sampaio de, Vinícius Siqueira Gazal, Vinicius José Fernandes, Ana Carolina Campos de Oliveira, and Elen De Lima Aguiar-Menezes. "Influence of Food Resource Size on the Foraging Behavior of Nasutitermes corniger (Motschulsky)." Sociobiology 65, no. 2 (July 9, 2018): 291. http://dx.doi.org/10.13102/sociobiology.v65i2.2844.
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In general, termite foraging can be affected by physical and chemical factors linked to food. This study investigated if the wood length of Eucalyptus grandis W. Hill ex Maiden, as a food resource, influences the behavior of foraging events of Nasutitermes corniger (Motschulsky). Nests with mature and active colonies were collected in the field and transferred to glass cubes connected to a test arena under laboratory conditions. Wooden blocks of E. grandis, with a 2.5 x 2.0 cm rectangular cross section, were offered to termites in three different lengths: 5, 10 and 15 cm. Each test was repeated with 20 nests and lasted 60 minutes, when the following behavioral events and their duration were observed: initial exploration, initial recruitment and mass recruitment. At the end of each test, the quantities of termites (total, workers and soldiers) and gnawing workers were determined. The results show that longer blocks favored a higher occurrence of exploration and initial recruitment. However, the highest mass recruitment occurred with the 10 cm blocks. The length of the wood influenced the total number of termites recruited and gnawing workers; both were highest for the 10 cm blocks. There was no significant difference in relation to exploration time of the blocks and number of workers and soldiers recruited. Therefore, we conclude that wood length is a factor that can affect N. corniger foraging.
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Kamble, Zunjarrao, Rajesh Kumar Mishra, Bijoya Kumar Behera, Martin Tichý, Viktor Kolář, and Miroslav Müller. "Design, Development, and Characterization of Advanced Textile Structural Hollow Composites." Polymers 13, no. 20 (October 14, 2021): 3535. http://dx.doi.org/10.3390/polym13203535.
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The research is focused on the design and development of woven textile-based structural hollow composites. E-Glass and high tenacity polyester multifilament yarns were used to produce various woven constructions. Yarn produced from cotton shoddy (fibers extracted from waste textiles) was used to develop hybrid preforms. In this study, unidirectional (UD), two-dimensional (2D), and three-dimensional (3D) fabric preforms were designed and developed. Further, 3D woven spacer fabric preforms with single-layer woven cross-links having four different geometrical shapes were produced. The performance of the woven cross-linked spacer structure was compared with the sandwich structure connected with the core pile yarns (SPY). Furthermore, three different types of cotton shoddy yarn-based fabric structures were developed. The first is unidirectional (UD), the second is 2D all-waste cotton fabric, and the third is a 2D hybrid fabric with waste cotton yarn in the warp and glass multifilament yarn in the weft. The UD, 2D, and 3D woven fabric-reinforced composites were produced using the vacuum-assisted resin infusion technique. The spacer woven structures were converted to composites by inserting wooden blocks with an appropriate size and wrapped with a Teflon sheet into the hollow space before resin application. A vacuum-assisted resin infusion technique was used to produce spacer woven composites. While changing the reinforcement from chopped fibers to 3D fabric, its modulus and ductility increase substantially. It was established that the number of crossover points in the weave structures offered excellent association with the impact energy absorption and formability behavior, which are important for many applications including automobiles, wind energy, marine and aerospace. Mechanical characterization of honeycomb composites with different cell sizes, opening angles and wall lengths revealed that the specific compression energy is higher for regular honeycomb structures with smaller cell sizes and a higher number of layers, keeping constant thickness.
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Rebouças, Patricia Oliveira, Cândida Aguiar, Vinina Ferreira, Geni Sodré, Carlos Carvalho, and Miriam Gimenes. "The Cavity-Nesting Bee Guild (Apoidea) in a Neotropical Sandy Coastal Plain." Sociobiology 65, no. 4 (October 11, 2018): 706. http://dx.doi.org/10.13102/sociobiology.v65i4.3339.
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Some solitary bees establish their nests in preexisting cavities. Such nesting behavior facilitates the investigation of their life history, as well as the monitoring of their populations in natural, semi-natural and cropped habitats. This study aimed to evaluate the acceptance of artificial substrates by cavity-nesting bees in a heterogeneous landscape. We investigated the percentage of occupation of the different trap-nests, the monthly fluctuations in the nesting activity, offspring sex ratio, mortality and parasitism, in two phytophysiognomies: herbaceous-shrub restinga (site 1) and arboreal restinga (site 2). We used as trap-nests, bamboo canes, large and small straws of cardboard inserted into solid wooden blocks. Five bee species established 193 nests, from which 386 adults emerged. Centris tarsata Smith was the most abundant species. Large straws were signifi cantly more occupied than small straws (χ² = 19.951; df = 1; p < 0.0001). Offspring mortality rate for unknown reasons was signifi cant diff erent between sites, 11% (site 1) and 20% (site 2) (χ² = 4.203; df = 1; p = 0.04). The cavity-nesting bee guild had similar composition in both phytophysiognomies, there was a similar rate of occupation of trap-nests in both sites, as well as dominance of C. tarsata nests. Offspring mortality and parasites attack rates seem to be the more distinctive aspects between the herbaceous shrub and arboreal restinga sampled. Our study indicated that remnant fragments of coastal native habitats may be important nesting sites for the maintenance of bee populations, some of which have been indicated as candidates for management as pollinators of cultivated plants in Brazil.
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Wang, C. X., B. H. Li, X. L. Dong, and G. F. Li. "First Report of Stem Canker on Cherry Caused by Phomopsis perniciosa in Shandong Peninsula, Eastern China." Plant Disease 95, no. 10 (October 2011): 1316. http://dx.doi.org/10.1094/pdis-04-11-0341.
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Cherry is a main fruit tree species in Shandong Peninsula, which is one of the most important cherry-production areas of China. A stem canker disease was first noted in a 15-year-old cherry orchard in Yantai, Shandong Peninsula in May 2009. Canker and branch dieback were the main symptoms of the disease and cracks often appeared at the margins of sunken cankers, which exposed the wooden stem. In later stages from April to May, black pycnidia were observed on the surface of cankered bark and cirri containing α-conidia were extruded under wet conditions. Wooden tissue under the diseased bark was dark brown, in contrast to the healthy tissue that was yellowish green. On the basis of morphological characteristics, the pathogen was putatively identified as Phomopsis perniciosa (1). Pycnidia were smaller in naturally infected branches than when produced on potato dextrose agar (PDA) medium (180 to 365 × 65 to 226 μm). Cultures of the pathogen appeared creamy white with concentric rings on PDA at 25°C and a mass of α-conidia (5.75 to 11.13 × 2.08 to 3.46 μm) and β-conidia (31.24 to 34.68 × 1.45 to 1.82 μm) were produced within 3 weeks. Alpha-conidia were hyaline, fusiform-elliptic to oblong-elliptic, and biguttulate. Beta-conidia were hyaline and unicellular, filiformia, leviter arcuata vel hamata. Total DNA was extracted from three monoconidial isolates collected from different infected trees. The internal transcribed spacer (ITS) region was amplified using the universal primers ITS1 (5′-TCCGTAGGTGAACCTGCGG-3′) and ITS4 (5′-CCTCCGCTTATTGATATGC-3′). The ITS amplicons were sequenced (582 bp) from three isolates and no nucleotide variation was observed. BLAST analysis of the obtained ITS sequences showed that isolate 230101 had 99% homology with a Phomopsis sp. (GenBank Accession No. AB302248) isolated from fruit trees in Japan. The nucleotide sequence from isolate 230101 has been deposited in GenBank (Accession No. JF812647). Pathogenicity of the isolate was confirmed by inoculating branches of 3-year-old cherry trees with either conidia or hyphae. Inoculations were performed by making an incision with a sterile scalpel at the dissected area to expose the tissue under the bark. An agar plug (4 × 4 mm) containing 5-day-old cultured hyphae or 50 μl of a conidium suspension containing 106 α-conidia per ml was placed on each of the inoculation sites, wrapped with moist cheesecloth, and sealed with Parafilm. Control trees were treated similarly with sterile blocks of PDA or water, respectively. For each inoculation technique, five shoots were inoculated and the inoculation treatments were replicated three times. All inoculated and control trees were kept in a greenhouse and watered as needed. After 10 days, cankers and necrotic lesions developed on all shoots inoculated with P. perniciosa and the control trees did not display any symptoms. The same pathogen was reisolated from symptomatic branches. Phomopsis spp. are known to cause cankers and dieback of several woody hosts (2), but no reports have been found that the pathogen causes cherry canker and dieback in China. References: (1) P. K. Chi et al. Flora Fungorum Sinicorum-Phomopsis 34:127, 2007. (2) D. P. Weingartner and E. J. Klos. Phytopathology 65:105, 1975.
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Han, Xiaoli, Jian Dai, Wei Qian, Baolong Li, Yuanjun Jin, and Ting Jiang. "Effect of column foot tenon on behavior of larch column base joints based on concrete plinth." BioResources 15, no. 3 (July 9, 2020): 6648–67. http://dx.doi.org/10.15376/biores.15.3.6648-6667.
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The wooden columns in timber structures of ancient buildings have column foot tenons of various sizes. The main reason for these differences is their use for different roof loads. Six full-scale specimens with different sizes of column foot tenon were designed and manufactured. The tree species used for the specimens was larch. The quasi-static test was conducted on the specimens that were used in timber structures of ancient buildings. The effects of column foot tenon size on the mechanical properties of larch wooden columns were studied. The moment-rotational angle hysteretic curves, moment-rotational angle skeleton curves, ductility, stiffness degradation, energy dissipation capacity, slippages between the wooden column and the plinth, and the damage of the column foot tenons were examined. The test results showed that the column foot tenon played an important role in the mechanical behavior of the wooden column under low-cycle reversed cyclic loading. The rotation of the column foot tenon improved the energy dissipation capacity of the wooden column. As the rotational angle of the column base increased, the column foot tenon had different degrees of damage. Different sizes of column foot tenon had their own advantages and hysteretic behavior.
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Gomes, Caroline J. S., André Danderfer Filho, Ana Maria A. Posada, and Anielle C. da Silva. "The role of backstop shape during inversion tectonics physical models." Anais da Academia Brasileira de Ciências 82, no. 4 (December 2010): 997–1012. http://dx.doi.org/10.1590/s0001-37652010000400021.
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The style of deformation of rocks from basin-infilling sequences in positively inverted natural basins was discussed upon the results of laboratory experiments carried out in sandboxes with sand packs laid down in the space between two wooden blocks. The space simulated stages of crustal extension leading to (1) a half graben due to extension above a listric extensional detachment, with the blocks simulating the footwall and hanging wall, or (2) a graben, with the blocks simulating the external margins that drifted apart above a horizontal detachment. Combinations of two different angles were used to simulate the dip of curved normal faults along the internal face of the wooden blocks. Backstops in the half graben had a convex up internal face. Backstops in the graben had a concave up internal face. Shortening as partitioned in forward and backward movements within the sand packs, and the kinematics of contraction was largely influenced by the convex or concave internal faces. A buttress effect characterized by rotation of the sand pack close to the footwall was stronger for footwall with steeper-dipping internal faces. The results were compared to other physical experiments and applied to an inverted basin found in nature.
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Nur Hidayah, A. H., Md Nor Hasanan, and P. J. Ramadhansyah. "Physical Properties of Porous Concrete Paving Blocks with Different Sizes of Coarse Aggregate." Advanced Materials Research 1113 (July 2015): 86–92. http://dx.doi.org/10.4028/www.scientific.net/amr.1113.86.
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This research studies the properties of Porous Concrete Paving Blocks (PCPB) with different sizes of coarse aggregate. Coarse aggregate (CA) is the main component in manufacturing PCPB. Three different sizes of coarse aggregate were used; 1) CA 5 – 10 mm as a control, 2) CA 5 – 8 mm and 3) CA 8 – 10 mm. Furthermore, a series of test were conducted such as density, compressive strength, porosity and skid resistance test to determine the properties of the blocks. It was found that the size of coarse aggregate affects the strength and porosity of the blocks. The strength was reduced approximately in the range 5 % to 17 % from the control blocks. However, it is vice versa with porosity result which porosity of the blocks increased in between 5 % to 10 %. This shows that the blocks suitable for use in vehicle area where help in reduce the water ponding on pavement surface and also increased the skid resistance between the vehicle tires and pavement.
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İşleyen, Ümmü K., Rahim Ghoroubi, Ömer Mercimek, Özgür Anil, and Recep Tuğrul Erdem. "Behavior of glulam timber beam strengthened with carbon fiber reinforced polymer strip for flexural loading." Journal of Reinforced Plastics and Composites 40, no. 17-18 (April 9, 2021): 665–85. http://dx.doi.org/10.1177/0731684421997924.
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In the last 20 years, the use of wooden structures and their dimensions have gradually increased. The wood application has increased in different structures such as multistory buildings, sports, industrial facilities, road and railway bridges, power transmission lines, and towers. The widespread use and size of wood structures have increased the research on developing special types of wood products supported by composite materials. Laminated wood elements are the leading composite wood materials. Laminated wooden beams allow making much larger openings than standard solid wood structural elements. The development of the sizes and usage areas of wooden structures has increased the capacity of glulam structural elements and reveals the need to improve their performance. Carbon fiber reinforced polymers (CFRPs) are the most suitable options for increasing the bearing capacity values of glulam beams and improving general load–displacement behaviors. In this study, the use of CFRP strips in different layouts to increase glulam wooden beams and the application of CFRP fan-type anchors in the CFRP strip endpoints are the studied variables. Anchored and non-anchored glulam wooden beams reinforced with CFRP strips with different layouts were tested using a three-point bending test. The ultimate load capacity, initial stiffness, displacement ductility ratio, energy dissipation capacity, failure mechanisms, and general load–displacement behavior of wooden beam test specimens were obtained and interpreted as a result of the experiments.
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Ovsyannikov, Sergey I., and Vladislav Yurevich Dyachenko. "Wooden Nano-Composite Materials and Prospects of their Application in Wooden Housing Construction." Materials Science Forum 931 (September 2018): 583–88. http://dx.doi.org/10.4028/www.scientific.net/msf.931.583.
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Nano-composite material is a completely new class of material that combines wood pulp and some porous materials of artificial and natural origin. This is an artificially created material consisting of a polymer matrix of the porous natural or synthetic material. The number of micro or macro-pores in the composite can be different for different wood species variety of micro and macro capillaries varying in average from 25 to 35% of the wood volume. The change in wood properties occurs at the structuring of water-insoluble molecules smaller than 3 nm and that is a part of the filler. Industrial technology of deep processing of wood-based nanotechnology allows the manufacture of new products such as laminated wood structures with nano-device that have properties not existing in nature: 1. The wood becomes hydrophobic, it is characterised by almost complete lack of absorption by the body of the wood, which leads to almost full, the lack of swelling and the change of the geometrical sizes of the material; 2. The absence of cracking. As the penetrating substance is evenly distributed between micro and macro pores and uniformly fills all the frame structure, there are additional internal stresses, typical for products made of natural wood; 3. The use of such technology ensures high 10-25% of the density if you increase strength by 20%, which also increases the seismic resistance and mi CNTI products and structures.
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Antonietti, Alessandro, and Beatrice Nava. "Solution of an Insight Problem at Different Age Levels." Perceptual and Motor Skills 80, no. 3_suppl (June 1995): 1215–18. http://dx.doi.org/10.2466/pms.1995.80.3c.1215.
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The purpose was to study performance on an insight problem by 3-to 25-yr.-olds. A task involving restructuring and requiring two wooden blocks be fitted together to form a tetrahedron was presented to five groups of 20 subjects each from kindergarten, primary school, secondary school, high school, and a university. The frequencies of solvers within each group increased from the first age group to the third but then remained constant. Solution times and frequencies of solutions attempted were not significantly different among the five groups. Perhaps insight does not follow the same developmental trend as other thinking processes.
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El-Emam, Magdi, and Adil Al-Tamimi. "Strength and Deformation Characteristics of Dune Sand Earth Blocks Reinforced with Natural and Polymeric Fibers." Sustainability 14, no. 8 (April 18, 2022): 4850. http://dx.doi.org/10.3390/su14084850.
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In this paper, we present a strength and deformation evaluation of earth blocks reinforced with different types of fiber. A natural palm tree fiber and two other types of synthetic polyolefin fibers were used to improve earth blocks’ strength and stiffness. The soil used to cast the earth blocks was composed of dune sand, which is extensively available in the United Arab Emirates and most Gulf Cooperation Council (GCC) deserts, and clayey silt soil acquired from Al-Ain city, UAE. Sixteen different mixes were prepared for this study. Two identical earth blocks were cast in a wooden mold from each mix to form a total of 32 blocks. After compaction, the blocks were consolidated under pre-specified pressure, air dried, and tested to failure in the compression machine. The main parameters investigated in this study were clay content, fiber types and percentages, and cement content. The results indicate that the addition of natural or polymeric fiber to cast earth blocks significantly improved their compressive strength. The maximum compressive strength of improved blocks showed an increase of more than 30% above the maximum compressive strength recorded for identical soil blocks without fiber. In addition, the post-peak and pre-peak strength behaviors of the earth blocks are different with different fiber contents. Finally, the addition of 0.5% cement to the fiber-reinforced blocks showed a negligible effect on the peak compressive strength. However, cement content improved the early stage (small strain) stiffness of earth blocks.
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Zavalis, Mindaugas. "ANALYSIS OF BEHAVIOUR OF CALCIUM SILICATE HOLLOW BLOCKS MASONRY SUBJECTED TO THE CONCENTRATED LOAD." Engineering Structures and Technologies 12, no. 2 (January 26, 2021): 39–45. http://dx.doi.org/10.3846/est.2020.14041.
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Loading of masonry with concentrated load is a sufficiently common case of loading which occurs due to structures of various purposes and sizes which lean against masonry wall, column or partition wall. Reinforced concrete or metal beams, reinforced beams, wooden structures of roof or span are leaned against masonry structures most usually. Investigations show that masonry structures under concentrated load withstand higher loads than structures of which the whole surface area is compressed. In most cases traditional bricks’ masonry under concentrated load was investigated. Its head joints are filled with mortar. This paper describes the experimental and numerical modeling results of investigation of calcium silicate hollow blocks masonry with thin layered mortar and unfilled head joints compressed by concentrated load. The more dangerous case when the edge of masonry unit (wall) is affected by concentrated load was chosen for analysis. Preliminary investigations have shown that the bed joints transmiss horizontal stresses. The stress distribution angle is close to 60°, i.e. close to stress distribution in masonry with filled head joints.
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ICHIMIYA, Koichi, and Seiji IWAMA. "307 Behavior of Thermal Plumes from Heated Blocks with Different Sizes." Proceedings of Yamanashi District Conference 2009 (2009): 76–77. http://dx.doi.org/10.1299/jsmeyamanashi.2009.76.
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Chen, Ying-ping, Chung-Yao Chuang, and Yuan-Wei Huang. "Inductive linkage identification on building blocks of different sizes and types." International Journal of Systems Science 43, no. 12 (December 2012): 2202–13. http://dx.doi.org/10.1080/00207721.2011.566639.
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Szczepanski, Marcin, Ahmed Manguri, Najmadeen Saeed, and Daniel Chuchala. "The Effect of Openings’ Size and Location on Selected Dynamical Properties of Typical Wood Frame Walls." Polymers 14, no. 3 (January 26, 2022): 497. http://dx.doi.org/10.3390/polym14030497.
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The wooden frame constructions are now popular in many developed countries of the world. Many of these locations where such buildings are constructed are exposed to seismic and other shocks which are generated by human activities. This paper discusses the effect of the size and location of openings in the wooden frame walls under dynamic loadings. Natural frequencies of such frames with and without openings have been determined. Three 14 m high walls with different widths, including 3, 6, and 12 m, have been considered. Dynamic analysis has been made using finite element method structural analysis software Dlubal RFEM 5.17. The results show that the effect of the size and location of the openings on the natural frequency is significant. Numerically speaking, the relative change of the natural frequencies of a wall without and with an opening in a specific place could be up to 30%. In addition, the change of the natural frequency for the location of the openings is more sensitive than that to the sizes. Furthermore, the appropriate sizes and locations of openings of the wooden frame walls have been suggested. The appropriate size and place were found to be small openings in the top of the walls.
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Hoxha, E., B. Soust-Verdaguer, M. Scherz, and A. Passer. "Benefits of wooden structure reuse: the case of an Austrian building." IOP Conference Series: Earth and Environmental Science 1078, no. 1 (September 1, 2022): 012031. http://dx.doi.org/10.1088/1755-1315/1078/1/012031.
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Abstract The building sector is responsible for 39% of greenhouse gas (GHG) emissions; thus, it has a significant amount of potential to reduce the effects of climate change. Several active- and passive solutions and strategies have been developed and proposed in the literature. Among them, wood is highlighted as a promising solution to minimize GHG from buildings. However, the benefits, especially in the circular economy, are not fully evaluated due to methodological choices. Motivated by this knowledge gap, this article aims to evaluate the benefits of wood reuse compared to traditional building construction solutions. For this purpose, we have calculated the environmental impacts of a building situated in Graz, Austria. Four different scenarios are considered. The first scenario is a fully reinforced concrete building. The second scenario is a structural beam-column made from reinforced concrete with walls made of concrete blocks. The third scenario is a beam-column made from reinforced concrete with external walls based on clay blocks. Finally, the last scenario is a full wooden building. Following the standardized life cycle assessment (LCA) method, global warming potential (GWP) is calculated through a 0/0 approach. These evaluations were made possible by correlating the impacts released from producing wooden elements and the uptake of biogenic carbon from the forest. Without considering the possibility of material reuse, the wooden structure has a 5 % lower GWP value than the reinforced concrete building. Comparatively, the other building scenarios have almost similar impacts as the building in reinforced concrete. In the case of material reuse, the wooden structure building shows potential to develop projects with 44% lower environmental impacts.
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Tomašić, Ivan, and Zrinaka Vidovic-Tisanic. "Potential of Medium to More Fractured Natural Stone Deposits." Key Engineering Materials 548 (April 2013): 39–47. http://dx.doi.org/10.4028/www.scientific.net/kem.548.39.
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Exploitation and processing of small stone blocks and tombolons has a major impact on profitability. It is pointed out that the natural stone needs to be rationally used in deposits. Resources of rock mass tend to be greatly increased due to the utilization of different sizes of blocks in deposits or quarries. This approach encourages the application of Lasky's relationship in the deposits of natural stone and quarries. Based on this relationship we can simply say that if the sizes of stone blocks and other stone products decrease arithmetically, then reserves increase geometrically or exponentially. On the presented examples, the utilization of the rock mass was analysed by the application of two different technologies of exploitation. Besides, if the exploitation of stone blocks of different sizes achieves high utilization of the rock mass, then exploitation of aggregates and fillers increases much more. It is necessary to emphasize the existence of the border area based on favourable discontinuity density and spatial discontinuity position. Decision should be made whether to apply I or II variant of the exploitation (making vertical and horizontal cuttings or separation of the blocks along natural discontinuities, or using slanting cuts). The example is shown and analysed as a two-dimensional problem.
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Mirzaei, Sajad, Nima Bohlooli Arkhazloo, Farzad Bazdidi-Tehrani, Jean-Benoit Morin, Abdelhalim Loucif, and Mohammad Jahazi. "Influence of Spacers and Skid Sizes on Heat Treatment of Large Forgings within an Industrial Electric Furnace." Energies 16, no. 7 (March 23, 2023): 2936. http://dx.doi.org/10.3390/en16072936.
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The influence of stacking patterns, through the different spacer and skid sizes, on the transient temperature distribution uniformity of large-size forgings in a 112-m3 electrical heat treatment furnace was investigated by conducting CFD simulations and real-scale experimental validation. A 3D CFD model of the electrical furnace was generated, including a heat-treating chamber, axial flow fans, large size blocks, skids, and spacers. Real-scale temperature measurements on instrumented test blocks during the heat treatment process were carried out to validate the CFD simulations. Results indicated that the CFD model was capable enough to determine the transient temperature evolution of the blocks with a maximum average deviation of about 6.62% compared to the experimental measurements. It was found that significant temperature non-uniformities of up to 379 K on the surfaces of the blocks due to the non-optimum stacking pattern were experienced by the blocks. Such non-uniformities could be reduced between 24% to 32% if well-adapted spacer and skid sizes were used in the stacking configurations. Based on simulation results and experimental validation work, optimum spacer and skid sizes for uniform temperature distribution were proposed for different stacking patterns.
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Fischer, K., SG Gebhardt-Henrich, and A. Steiger. "Behaviour of golden hamsters (Mesocricetus auratus) kept in four different cage sizes." Animal Welfare 16, no. 1 (February 2007): 85–93. http://dx.doi.org/10.1017/s0962728600030967.
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AbstractCages for laboratory and pet hamsters are usually small. Using video recordings, the behaviour of sixty female golden hamsters (Mesocricetus auratus), housed individually in four different cage sizes, was compared in order to draw conclusions about their welfare. The cage sizes were 1,800 cm2, 2,500 cm2, 5,000 cm2, and 10,000 cm2. Enrichment items and litter depth were standardised and all cages were equipped with a running-wheel (30 cm diameter). Stereotypic wire-gnawing, usage of the provided space, weight gain, and reactions to mild husbandry stressors were used as welfare indicators. Stereotypic wire-gnawing was observed in all cage sizes, but hamsters in small cages gnawed significantly longer and more frequently. There were no significant differences in running-wheel activity. In small cages hamsters made use of the roof of their wooden shelters as an additional platform more often than in big cages, which could suggest that they needed more space. Therefore, the welfare of pet golden hamsters in cages with a minimal ground floor area of 10,000 cm2 seemed to be enhanced compared with smaller cages.
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Zhu, Jinbin, Liang Wang, Limin Xiao, and Guangjun Qin. "uDMA: An Efficient User-Level DMA for NVMe SSDs." Applied Sciences 13, no. 2 (January 10, 2023): 960. http://dx.doi.org/10.3390/app13020960.
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The Non-Volatile Memory Express (NVMe) SSD provides high I/O performance for current computer systems, and direct memory access (DMA) is the critical enabling mechanism for direct I/O. However, the lengthy I/O stack becomes a new bottleneck that degrades the potential of NVMe SSD. This paper reveals that existing user-level DMA introduces additional overhead for pinning memory used by DMA from the user space. Moreover, it cannot adapt to I/O requests of different data sizes. This paper proposes an efficient and dynamically adaptive user-level DMA (uDMA) mechanism that can adapt to I/O requests for different data sizes and lighten the I/O software stack by amortizing per-request latency. The critical component of uDMA is the pinned memory pool, which avoids frequently pinning new memory blocks by reusing allocated and pinned memory blocks. In addition, it effectively connects the discrete pinned memory blocks by the scatter/gather lists, improving the utilization of the pinned memory pool. Compared with the latest user-level DMA method, uDMA has an improvement of at least 17% under various data sizes.
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Rawding, Molly, and Jean Kelly. "Changing the whole." Teaching Children Mathematics 25, no. 4 (January 2019): 256. http://dx.doi.org/10.5951/teacchilmath.25.4.0256.
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Students benefit from hands-on tasks exploring number, area, and fractional relationships when the value of a whole changes. This activity uses pattern blocks to explore different designs with different constraints (e.g., a target value, a set number of blocks, or a final shape) while changing the value of the whole. For example, if the trapezoid is worth 1 1/2, create different sizes of triangles and find their value.
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Wiese, Francis K., Ian L. Jones, and D. Nettleship. "Experimental Support for a New Drift Block Design to Assess Seabird Mortality from Oil Pollution." Auk 118, no. 4 (October 1, 2001): 1062–68. http://dx.doi.org/10.1093/auk/118.4.1062.
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Abstract Seabird mortality from large oil spills and chronic oil pollution is often significant. Total mortality estimates are derived from counts of dead birds that wash ashore and are corrected for numbers lost at sea. Past attempts to estimate proportion of birds that die at sea and wash ashore have included several experiments using carcasses and different types of wooden drift blocks. Results varied greatly depending on environmental conditions and distance from shore where blocks or carcasses were released. Wind seemed to be the predominant factor determining movement over large distances, whereas tidal currents influenced deposition on specific beaches. Determining timing and location of arrival of dead birds on beaches are crucial for accurate mortality estimates. Drift experiments using beached birds that have already drifted at sea for an undetermined length of time are inaccurate due to natural buoyancy loss and decomposition. To determine accuracy of drift block designs used in the past, we compared drift characteristics and patterns between four drift block designs and fresh murre (Uria spp.) carcasses. Our experiments showed that drift blocks used in the past have none of the drift characteristics of dead seabirds, because they have much larger areas exposed to wind and hence drift much faster and farther than murre carcasses. Past mortality estimates using those blocks are therefore doubtful. The drift block design that most accurately mimicked murre carcass drift during our experiments was a 9 × 9 × 14.5 cm wooden block with a 450 gram steel weight that adjusts buoyancy and area exposed to the wind. We propose that in areas where murres are predominant victims of oil spills, that block design be used for all future estimates of oiled seabird mortality.
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Dudzik, Piotr, Ewa Terczynska, and Krzysztof Tytkowski. "MODELING AS THE WAY OF ACQUIRING KNOWLEDGE." Boletim da Aproged, no. 34 (December 2018): 25–29. http://dx.doi.org/10.24840/2184-4933_2018-0034_0003.
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Changes taking currently place in upbringing and teaching, force teachers to constantly search for newer methods of transmitting knowledge to their students. Young people beginning their studies are brought up in different ways of gaining recognition skills than they were a few years ago. Children play with blocks, building various structures and learning the shapes and features of single blocks, but they must be able to imagine the overall effects in their work. During our geometry classes, we refer to wooden models of solids like pyramids and prisms, so that building models from blocks becomes more natural and less hard. With this in mind, we came up with an idea to prepare a number of models that students could cut from a single piece of paper and then fold it to confront a 2D illustration with the corresponding 3D model. In this paper, assumptions according to the model that we made, as well as solutions and some examples, are presented.
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Surikova, Olga V., Victor E. Kuzmichev, and Galina I. Surikova. "Improvment of Clothes Fit for Different Female Bodies." Autex Research Journal 17, no. 2 (June 27, 2017): 111–19. http://dx.doi.org/10.1515/aut-2016-0003.
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Abstract The factors influencing for fit and suit of women’s clothing have been studied. The main reason of misfit is the nonconformity between the front and back width of pattern block, the corresponding body sizes taken across the hipline, and the textile materials properties. To predict the behavior of textile fabrics in real clothes including the shear deformation and wrinkles appearing, the special test and device have been designed. The developed method of pattern block making includes the test of clothes proportionality based on the female bodies sizes, pattern block indexes, and textile fabrics properties. Features of “figure-clothes” systems in-cluding the vertical designing lines, styles, volume of clothes, ease allowance and its distribution between the back, armhole, and front of the pattern blocks were taken into consideration. Recommendations in terms of selecting the proper design of style for different sizes of female bodies have been made.
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Abd Halim, N. H., H. Md Nor, R. P. Jaya, A. Mohamed, M. H. Wan Ibrahim, N. I. Ramli, and F. M. Nazri. "Permeability and Strength of Porous Concrete Paving Blocks at Different Sizes Coarse Aggregate." Journal of Physics: Conference Series 1049 (July 2018): 012028. http://dx.doi.org/10.1088/1742-6596/1049/1/012028.
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North, Sarah M. "Effectiveness of Virtual Reality in the Motivational Processes of Learners." International Journal of Virtual Reality 2, no. 1 (January 1, 1996): 21–33. http://dx.doi.org/10.20870/ijvr.1996.2.1.2607.
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This brief article reports on the use of virtual reality and its effectiveness on improving and maintaining learners' intrinsic motivation or interest. Research suggests that interest contributes to learning. Therefore a study of the impact of interests is essential to an understanding of intrinsic motivation. Since the virtual environment provides a sense of presence, it may be possible to create scenarios to stimulate the learners' curiosity and interest. Eighteen students, 11 males and 7 females, between 21 and 32 years old, served as subjects for the study. The experiment consisted of the physical world environment using wooden blocks, and the virtual world using virtual blocks. Both worlds used color and shape as variables. The two variables consisted of three shapes (sphere, pyramid, and cube), and three colors (red, green, and blue). In both worlds, the wooden blocks and virtual blocks had to be manipulated and arranged in nine different patterns. The first experiment started with a two-block pattern. At each step the difficulty was increased by increasing the number of blocks. The subject's score was based on a ten-point scale instrument administered at the end of each experiment. The scores ranged from very weak to very strong. The results were used to identify a significant difference between the subjects' performance in the virtual world and in physical world with respect to curiosity, interest, and sense of control. The interest level comparison indicated that for all subjects scores in the virtual world were always higher than the scores in the physical world. The sense of control level comparison indicated that in the beginning scores in the virtualworld were not always higher than the scores in the physical world. However, after orientation to navigation through the virtual environment, the mean score gradually rose. This research demonstrates that the virtual world is more useful than the physical world (with respect of color and shape) in increasing the memory span of the learner.
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Nur Hidayah, A. H., Md Nor Hasanan, and P. J. Ramadhansyah. "Porous Concrete Paving Blocks Using Coarse Aggregate." Applied Mechanics and Materials 554 (June 2014): 111–15. http://dx.doi.org/10.4028/www.scientific.net/amm.554.111.
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The objective of the study is to investigate the potential of using Porous Concrete Paving Blocks (PCPB) as a part of paving surface. Laboratory tests were conducted to compare and examine the effect of particle sizes of coarse aggregate. Two coarse aggregate sizes were selected; passing 8 mm retains 5 mm and passing 10 mm retains 8 mm. The fine aggregate was eliminated from mixes. The water to cement ratio used was 0.35. Compressive strength and skid resistance tests were performed to evaluate the properties of PCPB. The test results indicated that there was a reduction in the strength when coarse aggregate at different size was used. Scanning electron microscopy showed that voids, poor bonding and lack of adhesion at the boundaries of the aggregate with cement paste contributing to the low PCPB strength. However, both PCPB specimens provide 30 % to 40 % increase in skid resistance compared to Concrete Paving Blocks (CPB).
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Jannat, Nusrat, Rafal Latif Al-Mufti, Aseel Hussien, Badr Abdullah, and Alison Cotgrave. "Influence of Sawdust Particle Sizes on the Physico-Mechanical Properties of Unfired Clay Blocks." Designs 5, no. 3 (September 14, 2021): 57. http://dx.doi.org/10.3390/designs5030057.
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Sawdust, which is a waste/by-product of the wood/timber industry, can be utilised as a valuable raw material in building material production due to its abundance and low cost. However, the application of sawdust in the manufacture of unfired clay blocks has received little investigation. Furthermore, the impact of different sawdust particle sizes on the properties of unfired clay blocks has not been studied. Therefore, this study screened sawdust at three different particle sizes: SP-a (212 μm < x < 300 μm), SP-b (425 μm < x < 600 μm) and SP-c (1.18 mm < x < 2.00 mm), to examine their effects on the physical and mechanical properties of unfired clay blocks. The density, linear shrinkage, capillary water absorption and flexural and compressive strengths were among the tests performed. Different sawdust percentages, i.e., 2.5%, 5%, 7.5% and 10% of the total weight of the clay, were considered. The tests results show that when sawdust was added to the mixture, the density of the samples reduced for all particle sizes. However, the linear shrinkage increased in SP-a samples but decreased in the other two particle size samples as the sawdust percentage increased from 2.5% to 10%. On the other hand, the capillary water absorption coefficient increased while the strength decreased with increasing sawdust content for all three groups. The highest compressive strength (CS) and flexural strength (FS) were achieved at 2.5% of sawdust content. Furthermore, it was observed that SP-b (CS—4.74 MPa, FS—2.00 MPa) samples showed the highest strength followed by SP-a (CS—4.09 MPa, FS—1.69 MPa) and SP-c (CS—3.90 MPa, FS—1.63 MPa) samples. Consequently, good-quality unfired clay blocks can be manufactured using sawdust up to 2.5% with particle sizes ranging between 600 and 425 μm.
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Zhao, Xinli, Shanyang Wei, Yunyun Chu, and Na Wang. "Numerical Simulation of Fire Suppression in Stilted Wooden Buildings with Fine Water Mist Based on FDS." Buildings 13, no. 1 (January 12, 2023): 207. http://dx.doi.org/10.3390/buildings13010207.
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In this paper, to reflect a real fire combustion situation of stilted buildings with a typical wooden structure, we used FDS numerical simulation software to study the suppression effect of a fine-water-mist fire-extinguishing system under different working conditions. The influences of different mist droplet diameters, spray flows, and nozzle densities on the temperature change in the combustion area were analyzed and compared. The particle sizes of fog droplets exhibited a significant impact, indicating that the smaller the particle size, the faster the vaporization rate and the better the cooling effect. The cooling effect was better when the particle size was 150 μm or less when compared to the particle sizes of 200 and 300 μm. As the spray flow rate and nozzle density were increased, the fire field temperature decreased, and the cooling effect was enhanced, optimal at a water-mist flow rate of 8 L/min. Therefore, given the possible working conditions, the spray flow rate and the nozzle density should be high, while a suitable droplet size should be selected to achieve the best fire-extinguishing effect.
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Wang, Xing-Yuan, Dou-Dou Zhang, and Na Wei. "Modified No Search Scheme based Domain Blocks Sorting Strategies for Fractal Image Coding." Zeitschrift für Naturforschung A 69, no. 10-11 (November 1, 2014): 511–20. http://dx.doi.org/10.5560/zna.2014-0042.
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AbstractA novel fractal image coding algorithm based on domain blocks sorting strategies and modified no search scheme is proposed in this paper. On one hand, in order to improve the encoding time, a modified no search (MNS) scheme is adopted. Firstly, the image is divided into blocks of different size utilizing an adaptive quadtree partition method. Secondly, one finds the location of the best matching domain block using the MNS scheme for the range blocks, whose sizes are larger than the preset minimum value. Thirdly, the types of the range block and domain block are computed employing the proposed approach, and then the corresponding computation of mean square error (MSE) is determined. The computation of the MSE is reduced and the encoding phase speeds up. On the other hand, the range blocks with the minimal sizes are encoded applying the proposed domain blocks sorting (DBS) method. Contrast experiment results show that the proposed algorithm can obtain good quality of the reconstructed images and shorten the encoding time significantly.
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Alejo, A. O. "Comparison of strength of sandcrete blocks produce with fine aggregate from different sources." Nigerian Journal of Technology 39, no. 2 (July 16, 2020): 332–37. http://dx.doi.org/10.4314/njt.v39i2.2.
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Sandcrete blocks comprise of water, natural sand cement. Sandcrete blocks are the building units used in the construction of wall and partitions. Diverse sizes of sandcrete blocks are used to construct free standing walls and building structure with load and non – load bearing units. This research work investigate and compared strength of sandcrete blocks produced with fine aggregate from different source in Owo local government area. The targeted areas within Owo local government are Emure, Ipele and Shagari. Sieve analysis was conducted on the samples and the result revealed that all the samples are good for sandcrete block production. Thirty six sandcrete cubes samples were mould. The mix proportion 1:6 was used. Batching by volume was adopted. Curing was done by full immersion of sandcrete and compressive strength test was carried out on each specimen at 7, 14. 21 and 28 days respectively. The percentage of fine aggregate used in this research was 100% for all samples. The results revealed that sandcrete blocks produced with fine aggregate from Ipele, Shagari and Emure gives compressive strength of 4,15N/MM2, 3.56N/MM2 and 5.48N/MM2 at 28 days respectively. Based on the result of this research work, it is recommended that Emure fine aggregate (sand) is considered as most suitable out of the samples tested for sandcrete blocks production.
Keywords: Sand, Sandcrete blocks, Compressive strength, Curing, Production practice.
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Wu, Rongteng, and Xiaohong Xie. "A Heterogeneous Parallel LU Factorization Algorithm Based on a Basic Column Block Uniform Allocation Strategy." Mathematical Problems in Engineering 2019 (February 25, 2019): 1–12. http://dx.doi.org/10.1155/2019/3720450.
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Most supercomputers are shipped with both a CPU and a GPU. With the powerful parallel computing capability of GPUs, heterogeneous computing architecture produces new challenges for system software development and application design. Because of the significantly different architectures and programming models of CPUs and GPUs, conventional optimization techniques for CPUs may not work well in a heterogeneous multi-CPU and multi-GPU system. We present a heterogeneous parallel LU factorization algorithm for heterogeneous architectures. According to the different performances of the processors in the system, any given matrix is partitioned into different sizes of basic column blocks. Then, a static task allocation strategy is used to distribute the basic column blocks to corresponding processors uniformly. The idle time is minimized by optimized sizes and the number of basic column blocks. Right-looking ahead technology is also used in systems configured with one CPU core to one GPU to decrease the wait time. Experiments are conducted to test the performance of synchronization and load balancing, communication cost, and scalability of the heterogeneous parallel LU factorization in different systems and compare it with the related matrix algebra algorithm on a heterogeneous system configured with multiple GPUs and CPUs.
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Li, C., H. Chen, X. Han, X. Pan, and D. Niu. "An improved Criminisi method for image inpainting." Journal of Physics: Conference Series 2253, no. 1 (April 1, 2022): 012023. http://dx.doi.org/10.1088/1742-6596/2253/1/012023.
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Abstract The Criminisi method is a classical image inpainting method, which has flaw of unreasonable priority calculation. To overcome this flaw, we propose an improved Criminisi method. To improve the accuracy of a repaired block’s priority, we propose a novel method by considering the continuity of structure and color information between the repaired block and its adjacent blocks. When searching the matching block for a repaired block, we compute the similar between two blocks as the sum of squared differences (SSD). Since different blocks within an image may contain different levels of information, we set block to different sizes to determine the best matching block. Experimental results demonstrate the effectiveness of the proposed method.
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Caswell, Hal, and Silke F. van Daalen. "A Note on the vec Operator Applied to Unbalanced Block-Structured Matrices." Journal of Applied Mathematics 2016 (2016): 1–3. http://dx.doi.org/10.1155/2016/4590817.
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The vec operator transforms a matrix to a column vector by stacking each column on top of the next. It is useful to write the vec of a block-structured matrix in terms of the vec operator applied to each of its component blocks. We derive a simple formula for doing so, which applies regardless of whether the blocks are of the same or of different sizes.
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Jacroux, Mike, and Bonni Kealy-Dichone. "On the E-optimality of blocked main effects plans in blocks of different sizes." Communications in Statistics - Theory and Methods 46, no. 5 (March 17, 2016): 2132–38. http://dx.doi.org/10.1080/03610926.2015.1033427.
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Nadeem, Muhammad, Khadija Noreen, H. M. Kashif Rasheed, Rashid Ahmed, and Mahmood Ul Hassan. "New generators for minimal circular generalised neighbour designs in blocks of two different sizes." Statistics in Transition new series 24, no. 2 (March 15, 2023): 85–92. http://dx.doi.org/10.59170/stattrans-2023-021.
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Minimal neighbour designs (NDs) are used when a response of a treatment (direct effect) is affected by the treatment(s) applied in the neighbouring units. Minimal generalised NDs are preferred when minimal NDs cannot be constructed. Through the method of cyclic shifts (Rule I), the conditions for the existence of minimal circular generalised NDs are discussed, in which v/2 unordered pairs do not appear as neighbours. Certain generators are also developed to obtain minimal circular generalised NDs in blocks of two different sizes, where k2 = 3, 4 and 5. All these designs are constructed using i sets of shifts for k1 and two for k2.
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Amal, Habibi, Syamsul Asri, Andi Ardianti, and Suandar Baso. "Analysis Of Form Coefficient For Measuring Gross Tonnage Of Wooden Ship Based On Domestic Meansurment Method Of Indonesia." EPI International Journal of Engineering 3, no. 2 (January 25, 2021): 165–71. http://dx.doi.org/10.25042/epi-ije.082020.13.
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Most of the traditional wooden boats in Sinjai and Bone Districts were measured using the domestic measurement method, ship owners with sizes <GT 7 and <GT 30 refused to verify their vessels. Ship owners feel disadvantaged in terms of policies, permits, landing fees, subsidized fuel rations and so on. This study aims to determine the characteristics of the size and shape of traditional wooden ships, analyze and compare the results of the calculation of the gross tonnage (GT) of the ship which is calculated based on the actual size and shape of the ship (real body) with the ship calculated using domestic measurement methods and compiling mathematical equations in determining the value of the ship volume factor based on the main size to calculate the GT. The data processing method was carried out by using the Slovin technique with a population of 49 ship data for the determination of the minimum sample and then entered into the interval class. The results showed that the traditional wooden ships in Sinjai and Bone Regencies have geometric characteristics that are not much different from one another, but the main sizes are quite varied. The larger the main size of the ship, the greater the difference in GT calculations when using the volume factor value based on the domestic measurement method compared to using the volume factor value generated by real body calculations. The formula for the volume factor value (Cb or f) = 0.238 Log ((LBH)1/3) + 0.5134 can be used to determine the volume factor, especially for ships operating in the Sinjai and Bone Regencies as well as an initial reference for measurements by measuring experts ship so that moderate measurement results are obtained.
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Mohammed Pirot, Omed, and Sobri Harun. "THE INFLUENCE OF THE CHANNEL BED RECTANGULAR CONFIGURATION ON SEDIMENT TRANSPORTATION." Jurnal Teknologi 85, no. 2 (February 23, 2023): 41–51. http://dx.doi.org/10.11113/jurnalteknologi.v85.18815.
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Sediment transport is the movement of organic and inorganic particles caused by gravity, a moving fluid’s force, the wind, and ice motion. Sediment deposition degrades dams’ safety, leading to environmental pollution and channel area reduction. This study describes the effect of the weir height and spacing of used and non-used rectangular configuration structures on sediment transport rates in an open channel. This project was created using a rectangular open channel (30 cm wide and 60 cm deep). A sharp-crested weir was installed in the channel, and the rectangular wooden configurations were fixed in specific locations on each weir to reduce the bedload transportation rate and sediment motion. The weir heights were different (0.25B, 0.35B, 0.45B, and 0.55B, where B is the channel width). Also, the spacing between the baffle blocks (S) was set to 4Y, 8Y, 12Y, and 16Y, where Y was the maximum water depth without installing blocks and weirs. The results showed that the maximum transported bedload for the lowest weir was 1.4 kg/min, but only 4.4 × 10-3 kg/min was transported for the weir 16.5-cm high with baffle blocks. Using long baffle blocks yielded a worse result than using no blocks. The sediment-transport rate increased to 1.66 kg/min for the 7.5-cm weir due to block configurations. In conclusion, the obtained result contradicts the predicted result, as using baffle blocks increased the sediment transportation rate.
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Bożejko, Wojciech, Zenon Chaczko, Mariusz Uchroński, and Mieczysław Wodecki. "Parallel patterns determination in solving cyclic flow shop problem with setups." Archives of Control Sciences 27, no. 2 (June 1, 2017): 183–95. http://dx.doi.org/10.1515/acsc-2017-0011.
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Abstract The subject of this work is the new idea of blocks for the cyclic flow shop problem with setup times, using multiple patterns with different sizes determined for each machine constituting optimal schedule of cities for the traveling salesman problem (TSP). We propose to take advantage of the Intel Xeon Phi parallel computing environment during so-called ’blocks’ determination basing on patterns, in effect significantly improving the quality of obtained results.
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Agustiani, Riza, and Agustiany Dumeva Putri. "Hypothetical Learning Trajectory (HLT) For Fraction of Blind Students Using Braille Media Fraction Block." Jurnal Didaktik Matematika 8, no. 1 (April 30, 2021): 90–105. http://dx.doi.org/10.24815/jdm.v8i1.18138.
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. Learning fractions is one of difficult topics for students with visual impairments. The aim of this design research is to describe the design process of Hypothetical Learning Trajectory for the addition of fractions using Fraction Block Braille. This research is divided into 3 stages, the preparation for the experiment, the design experiment, and the retrospective analysis. Data collection techniques in this research are walkthrough, observation, interview, and test. This research resulted in a Hypothetical Learning Trajectory design for the addition of fractions contains the following activities: Dividing unit blocks into equal parts, Comparing the sizes of different fraction blocks to get the same size fractions, Comparing the combined sizes of several blocks, Combining several fractions, Determining the fractional block that is the same size as the summed fraction block. The five activities were carried out quite well in the 2-cycle experimental activity. After the implementation of the experimental activities, the students' answers to the practice questions showed that the research subject could understand the material presented.
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Vértesy, Gábor, Antal Gasparics, Ildikó Szenthe, and Sándor Bilicz. "Magnetic Investigation of Cladded Nuclear Reactor Blocks." Materials 15, no. 4 (February 15, 2022): 1425. http://dx.doi.org/10.3390/ma15041425.
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The wall, made of ferromagnetic steel, of a nuclear reactor pressure vessel is covered by an austenitic (very weakly ferromagnetic) cladding. In this work, we investigated how the base material and the cladding can be inspected separately from each other by nondestructive magnetic measurements. It was found that with the proper choice of the magnetizing yoke, these two different materials could be measured independently of each other. The effect of the yoke’s size was studied by the numerical simulation of magnetic flux, pumped into the material during magnetic measurements. Measurements were performed by two different sizes of yokes on pure base material, on base material under cladding and on cladding itself. Experiments verified the results of the simulation. Our results can help for the future practical application of magnetic methods in the regular inspection of nuclear power plants.
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Langr, Daniel, and Ivan Šimeček. "Analysis of Memory Footprints of Sparse Matrices Partitioned Into Uniformly-Sized Blocks." Scalable Computing: Practice and Experience 19, no. 3 (September 14, 2018): 275–92. http://dx.doi.org/10.12694/scpe.v19i3.1358.
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The presented study analyses memory footprints of 563 representative benchmark sparse matrices with respect to their partitioning into uniformly-sized blocks. Different block sizes and different ways of storing blocks in memory are considered and statistically evaluated. Memory footprints of partitioned matrices are then compared with their lower bounds and CSR, index-compressed CSR, and EBF storage formats. The results show that blocking-based storage formats may significantly reduce memory footprints of sparse matrices arising from a wide range of application domains. Additionally, measured consistency of results is presented and discussed, benefits of individual formats for storing blocks are evaluated, and an analysis of best-case and worst-case matrices is provided for in-depth understanding of causes of memory savings of blocking-based formats.
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Lee, Poh Foong, and Donica Pei Xin Kan. "A PILOT STUDY ON THETA FREQUENCY OF PRESCHOOL CHILDREN WITH DIFFERENT PLAYING ACTIVITIES AT PREFRONTAL CORTEX." Biomedical Engineering: Applications, Basis and Communications 29, no. 01 (February 2017): 1750004. http://dx.doi.org/10.4015/s1016237217500041.
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Theta frequency at the prefrontal cortex (PFC) is often related to the cognitive process in early childhood. In the present study, we focused on the types of playing activities that could enhance the theta frequency in preschoolers at their PFC area with study on individual brainwaves. The selected playing activities included LEGO and wooden blocks with and without instruction, iPad apps and flash card comparison. A total of 12 individual cases were analyzed in this study. The mean theta amplitudes of their PFC were measured by an electroencephalogram (EEG). Children brainwaves showed profoundly high theta frequency while playing LEGO without guidance. Meanwhile, tablet-based computer educational tool with pictures, sound, and motion initiated greater theta frequency as compared to the conventional flash card. Brainwaves analysis is a great tool to determine the cognitive development of children, based on the types of activities allocated to them.
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Muss, Wolfgang. "Home Made Silicone Rubber Embedding Molds." Microscopy Today 6, no. 8 (October 1998): 20–23. http://dx.doi.org/10.1017/s1551929500069194.
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Silicone rubber embedding molds may be inexpensive In North America, but are not necessarily so elsewhere in the world. Further, commercial molds are available only in standard sizes and only with standard sizes and shapes of cavities for specimen embedding, If, however, one needs to embed specimens of n on standard size or shape, wants more embedding cavities per mold than usually available, or is working where commercial molds are expensive or not easily available, then all is not lost, Embedding molds for specimen blocks can easily be made in the lab from silicone rubber. Further, making embedding blocks allows the use of different silicone rubbers which would be of value with unusual embedding resins, or when embedding must be done in unusual environments (such as extreme cold or heat).
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Gatani, Mariana, Victoria Granero, Juan Carlos Medina, Juliano Fiorelli, Josefina Lerda, Eugenia Sipowicz, and Jerónimo Kreiker. "New Process for Peanut Husks Panels: Incorporation of Castor Oil Polyurethane Adhesive and Different Particle Sizes." Key Engineering Materials 600 (March 2014): 452–59. http://dx.doi.org/10.4028/www.scientific.net/kem.600.452.
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New materials are being developed for architectural and design purposes. The recycling of waste is presented as an opportunity for new applications based on increased industrial waste and raw material shortages. Seeking an alternative to wooden panels, regional waste without sustainable disposal is being used as inputs in the production of lignocellulosic panels. We present the results of two experiments. The first one consists in the development of peanut husks ground-treated and untreated panels made in order to determine the influence of different particle sizes, shapes and their combinations, aiming to the physical and mechanical characterization of compact panels properties. In the second experiment, compact panels with whole peanut husks were made with polyurethane resin using castor oil painting. The object of this study was to analyze the influence of this new resin, without formaldehyde emissions, in the resulting panels physical and mechanical properties. It was concluded that the smaller particles had a positive influence in the panels physical-mechanical properties, and that the property characterization of panels made with castor oil resin was satisfactory for use in interior furniture. Peanut husks panels show good prospects for their integration in the field of design and architecture.
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Hagerman, Shannon M., Melanie D. Jones, Gary E. Bradfield, and Stacey M. Sakakibara. "Ectomycorrhizal colonization of Picea engelmannii × Picea glauca seedlings planted across cut blocks of different sizes." Canadian Journal of Forest Research 29, no. 12 (December 15, 1999): 1856–70. http://dx.doi.org/10.1139/x99-175.
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The purpose of this study, carried out at the Sicamous Creek Silvicultural Systems Trial located in the southern Interior of British Columbia, was to investigate the effects of cut block size and distance from the forest edge on patterns of ectomycorrhizal colonization and diversity at a subalpine forest. Non-mycorrhizal Picea engelmannii Parry ex Engelm. × Picea glauca (Moench) Voss seedlings were planted across cut blocks of three sizes (0.1, 1.0, and 10 ha) and in the uncut forest. In 1996 and 1997, seedlings were harvested after 13 weeks and examined for mycorrhizae. In 1996, diversity and richness of ectomycorrhizal types were significantly greater at forest plots and at plots located 2 m from the forest edge as compared with plots located >16 m into the cut block. In 1997, richness was again significantly reduced beyond 2 m. No differences in any of the diversity measures were detected between the different cut block sizes. The results of this study suggest that proximity to overstory trees may be more important than cut block size for patterns of ectomycorrhizal diversity and colonization. Additionally, polymerase chain reaction - restriction fragment length polymorphism (RFLP) analysis was used to assess the accuracy of morphotyping and, in some cases, to identify the associated fungus by comparison with RFLP patterns generated by sporocarps.
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Jacroux, Mike, and Bonni Kealy-Dichone. "On the use of blocked 2-level main effects plans having blocks of different sizes." Statistics & Probability Letters 107 (December 2015): 362–68. http://dx.doi.org/10.1016/j.spl.2015.09.017.
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Minane, Jacques Remy, Abdou Lawane, Jeremie Madjadoumbaye, Raffaele Vinai, and Brice Zagré. "Development of Cement Stabilised Compressed Blocks Using Coal Bottom Ash: Influence of the Grain Size on Mechanical and Physical Properties of Blocks." Civil and Sustainable Urban Engineering 3, no. 1 (May 23, 2023): 81–94. http://dx.doi.org/10.53623/csue.v3i1.242.
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This study investigated the physical and mechanical properties of cement-stabilized compressed blocks manufactured with coal bottom ash sourced from a power plant in Niger. Three different grain sizes were used for the production of compressed blocks with a hand-operated press. Thermal, hydric, mechanical, and fire resistance properties were assessed on the samples. It was found that the use of finer bottom ash resulted in lighter blocks with a density of about 1.02 mg/m3 and thermal conductivity in the range of 0.27 – 0.41 W/m·K. The size of the bottom ash used for the production of blocks did not significantly affect the value of mechanical strength. The exposure of blocks to temperatures of 200°C and 400°C did not reduce the strength of the samples. Neat bottom ash blocks can offer better thermal properties than typical building materials and provide acceptable mechanical strength.
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Adhikari, Atin, Aniruddha Mitra, Abbas Rashidi, Imaobong Ekpo, Jacob Schwartz, and Jefferson Doehling. "Field Evaluation of N95 Filtering Facepiece Respirators on Construction Jobsites for Protection against Airborne Ultrafine Particles." International Journal of Environmental Research and Public Health 15, no. 9 (September 7, 2018): 1958. http://dx.doi.org/10.3390/ijerph15091958.
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Exposure to high concentrations of airborne ultrafine particles in construction jobsites may play an important role in the adverse health effects among construction workers, therefore adequate respiratory protection is required. The performance of particulate respirators has never been evaluated in field conditions against ultrafine particles on construction jobsites. In this study, respiratory protection levels against ultrafine particles of different size ranges were assessed during three common construction related jobs using a manikin-based set-up at 85 L/min air flow rate. Two NanoScan SMPS nanoparticle counters were utilized for measuring ultrafine particles in two sampling lines of the test filtering facepiece respirator—one from inside the respirator and one from outside the respirator. Particle size distributions were characterized using the NanoScan data collected from outside of the respirator. Two models of N95 respirators were tested—foldable and pleated. Collected data indicate that penetration of all categories of ultrafine particles can exceed 5% and smaller ultrafine particles of <36.5 nm size generally penetrated least. Foldable N95 filtering facepiece respirators were found to be less efficient than pleated N95 respirators in filtering nanoparticles mostly at the soil moving site and the wooden building frameworks construction site. Upon charge neutralization by isopropanol treatment, the ultrafine particles of larger sizes penetrated more compared to particles of smaller sizes. Our findings, therefore, indicate that N95 filtering facepiece respirators may not provide desirable 95% protection for most categories of ultrafine particles and generally, 95% protection is achievable for smaller particles of 11.5 to 20.5 nm sizes. We also conclude that foldable N95 respirators are less efficient than pleated N95 respirators in filtering ultrafine particles, mostly in the soil moving site and the wooden building framework construction site.
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Luan, Li Wen, and Zhong Tao. "Study on the Mechanical Properties and Seismic Performance of Beam-Column Joints of Wooden Structure Building." Applied Mechanics and Materials 483 (December 2013): 305–8. http://dx.doi.org/10.4028/www.scientific.net/amm.483.305.
Full textAbstract:
This paper mainly depends on experiment. Take theory and software analysis as supplement. Using pine and fir as test material, the quantitative analysis, using uniform design method to qualitative pine, fir wood block the relationship between mechanical properties and geometrical parameters in the case of triangle, failure characteristics through experimental phenomenon of different materials and different sizes of wood in the triangle block pressure, finally using finite element analysis software ANSYS/LS-DYNA to simulate and analyze test. By comparing the analysis result of test and software, find out the problems and corresponding correction. The final analysis laid the foundation for the whole static wood structure analysis and dynamic. To provide scientific and technical support for rural residential "seismic safety engineering", thus forming the new wooden structure node and reinforcement for clause.