Consulta: subjectFacets:"Hardness"
Registros recuperados: 14
Data/hora: 11/06/2024 02:11:06

Poly (l-lactide acid) improves complete nano-hydroxyapatite bone scaffolds through the microstructure rearrangement
Provedor de dados: 69
Autores: Shuai,Cijun; Nie,Yi; Gao,Chengde; Lu,Haibo; Hu,Huanlong; Wen,Xuejun; Peng,Shuping.
Cracks often occur when nano-hydroxyapatite bone scaffolds are fabricated with selective laser sintering, which affect the performance of scaffolds. In this study, a small amount of poly (l-lactide acid) (PLLA) was added into nano-hydroxyapatite (nano-HAP) powder by mechanical blending in order to improve the sintering properties. The nano-HAP powder combined with 1wt % PLLA was sintered under different laser power (5W, 7.5W, 10W, 12.5W, 15W and 20W). The fabricated scaffolds were characterized using Scanning Electron Microscope (SEM), X-ray Diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and Micro Hardness Tester. The results showed that nano-HAP particles grew up quickly with the laser power increasing, and there were many strip-like...
Tipo: Journal article
Palavras-chave: Hardness; Microstructure; Nano-hydroxyapatite; Thermal properties.
Ano: 2012
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582012000600004

PHYSICAL-MECHANICAL CHARACTERIZATION OF Eucalyptus urophylla WOOD
Provedor de dados: 70
Autores: Lahr,Francisco A. R.; Nogueira,Marta C. De J. A.; Araujo,Victor A. De; Vasconcelos,Juliano S.; Christoforo,André L.
ABSTRACT: Eucalyptus urophylla consists in a wood-producing species, which offers a natural multiple raw material of good quality for applications in rural and civil constructions. However, Eucalyptus urophylla still has a small utilization as building parts and elements, resulting from the possible ignorance and low diffusion of its structural possibilities. Thereby, the present research aims to measure the main thirteen mechanical properties of Eucalyptus urophylla wood for two different moisture contents, 12% and 30% (green wood). Furthermore, in these two conditions of moisture content evaluation, volumetric mass densities were also evaluated. At the end of this evaluation, which included 2688 determinations, all the obtained results were statistically...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Timor White Gum; Strength modulus; Cracking; Shear stress; Hardness; Density.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162017000500900

Freshwater parameters in the state of Rio Grande do Sul, southern Brazil, and their influence on fish distribution and aquaculture
Provedor de dados: 83
Autores: Souza,Carine de F.; Pereira Junior,Waterloo; Garcia,Luciano de O.; Santos,Felipe C. dos; Baldisserotto,Bernardo.
ABSTRACT This study analyzed the relationship between several water quality parameters (pH, hardness, alkalinity, turbidity, iron and manganese) levels measured over a 16 year period with fish distribution and aquaculture in the state of Rio Grande do Sul, Southern Brazil. The mean pH values were within a neutral range (6.5-7.5), but the maximum and minimum values reached inappropriate levels for fish farming in some cities. Alkalinity levels were very low (except in the southwest region of the state), which may have contributed to pH variation. Hardness, turbidity, iron (except the region near Caçapava do Sul City) and manganese were within safe ranges for fish farming; however, turbidity levels occasionally increased to levels outside the safe range. In...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Alkalinity; Hardness; Iron; PH; Turbidity.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252016000300205

Growth and survival of silver catfish larvae, Rhamdia quelen (Heptapteridae), at different calcium and magnesium concentrations
Provedor de dados: 83
Autores: Silva,Lenise Vargas Flores da; Golombieski,Jaqueline Ineu; Baldisserotto,Bernardo.
Since the relative ratios of Ca2+ and Mg2+ can vary greatly from one water body to another, and lime used for the increase of water hardness or pH can have different ratios of Ca2+ and Mg2+ in its composition, the objective of this study was to analyze the growth and survival of silver catfish, Rhamdia quelen, larvae at different calcium and magnesium concentrations. After fertilization, eggs were randomly divided into 4 treatments (three replicates per treatment) with different concentrations of Ca2+ and Mg2+ at hardness values of 70 mg.L-1 CaCO3 (mg.L-1 : 5.2 Ca2+ and 14.12 Mg2+; 13.11 Ca2+ and 7.11 Mg2+; 20.26 Ca2+ and 2.86 Mg2+; 24.95 Ca2+ and 0.95 Mg2+) and 150 mg.L-1 CaCO3 (mg.L-1 : 5.2 Ca2+ and 32.70 Mg2+; 28.63 Ca2+ and 16.44 Mg2+; 44.68 Ca2+and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hardness; Water quality; Larval development.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252005000200008

Preference behavior of silver catfish, Rhamdia quelen, juveniles in waters with pH gradients: laboratory experiments
Provedor de dados: 83
Autores: Golombieski,Jaqueline Ineu; Becker,Alessandra Janaína; Almeida,Caroline Bruzza; Almeida,Ana Paula Gottlieb; Baldisserotto,Bernardo.
The aim of this study was to determine the preferred pH in silver catfish Rhamdia quelenjuveniles acclimated to different water hardness and the effect of shelters and infection by Ichthyophthirius multifiliis. Fish were acclimated for two weeks at different water hardness levels (4, 24, 50, or 100 mg CaCO3 L-1) and then transferred to a polyethylene tube with a pH gradient ranging from 3.5 to 11.7 and maintaining the same hardness. The position of the fish in the pH gradient was observed at 1, 2, 4, 6, 8, 10, and 12 h after transfer. Acclimation to different water hardness did not change pH preference of uninfected silver catfish (pH 7.30-7.83), and the presence of a shelter at the preferred pH or outside this preferred pH did not change the chosen pH...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Behavior; Calcium; Hardness; Ichthyophthirius multifiliis; Shelter.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013000300661

Hardening and Stability of Plinthic Materials of the Araguaia River Floodplain under Different Drying Treatments
Provedor de dados: 90
Autores: Martins,Angélica Pires Batista; Santos,Glenio Guimarães; Oliveira,Virlei Álvaro de; Maranhão,Deyvid Diego Carvalho; Collier,Leonardo Santos.
ABSTRACT Plinthite and petroplinthite occur frequently in Brazilian soils, but there is little information on the behavior of these materials. The aim of the present study was to assess the effect of different drying periods on the hardening and stability of plinthic materials of soils in the floodplain of the Araguaia River and the João Leite stream in Goiás. Soil samples were collected, with the aid of 0.10 m high and 0.15 m diameter PVC cylinders, directly from the plinthic horizons of five profiles of Plintossolos Argilúvicos (Plinthosols). Plinthite and soil matrix subsamples were obtained from these samples. Homogeneous petroplinthite samples were collected from the concretionary horizon of a Plintossolo Pétrico (Plinthosol) profile, and these were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Deterioration of soil structure; Dryness; Hardness; Iron oxide; Plinthite.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832018000100305

Reversibility of the Hardening Process of Plinthite and Petroplinthite in Soils of the Araguaia River Floodplain under Different Treatments
Provedor de dados: 90
Autores: Martins,Angélica Pires Batista; Santos,Glenio Guimarães; Oliveira,Virlei Álvaro de; Maranhão,Deyvid Diego Carvalho; Collier,Leonardo Santos.
ABSTRACT Although ferruginous materials occur frequently in soils of tropical regions, information about the reversal of the hardening process of these materials is scarce. This study assessed the influence of different chemical treatments and periods of immersion on the reversibility of the hardening process of plinthite and petroplinthite in soils of the Araguaia River plain. Soil samples were collected from the plinthic horizons in 0.10 m high and 0.15 m diameter PVC cylinders and divided into subsamples with a rock hammer. Homogeneous petroplinthite samples were also collected and broken into subsamples with a rock hammer. The plinthite and petroplinthite subsamples were subjected to five immersion treatments: distilled water, calcium carbonate...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Dispersion; Deterioration of structural stability; Hardness; Reagents; Iron oxides.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832018000100307

Physical-mechanical properties of multinutrient blocks with different binders for goats and sheep intake
Provedor de dados: 91
Autores: Furtado,Dermeval A.; Castro,Thiago B. de S.; Lopes Neto,Jose P.; Constantino,Rodrigo A.; Cunha,Maria das G. G.; Nascimento,José W. B. do.
ABSTRACT Feed supplementation with multinutrient blocks (MB) for sheep and goats can be a viable alternative in the Brazilian semiarid region, and it is necessary to set an ideal hardness to obtain maximum feed efficiency. Therefore, this study aimed to evaluate the manufacture of MB using five binders: Portland cement, lime, kaolin, Portland cement + kaolin and lime + bentonite, at two percentages (7.5 and 10%) and two healing times (72 and 96 h). The experimental design was completely randomized in a 5 x 2 x 2 factorial scheme (binders, percentages and healing times, respectively), with five repetitions. Using lime in the MBs led to greater resistance in the specimens (208.53 kPa), as well as the greater percentage of binders (10%), ensuring higher...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Water absorption; Hardness; Resistance; Feed supplementation.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662018000800558

Compressive strength of corn kernels subjected to drying under different rest periods
Provedor de dados: 124
Autores: Mabasso,Geraldo Acácio; Siqueira,Valdiney Cambuy; Quequeto,Wellytton Darci; Resende,Osvaldo; Goneli,André Luís Duarte.
ABSTRACT Mechanical properties of agricultural products are essential for a proper project design or processing equipment dimensioning, as well as for establishment of parameters on the supported load. An experiment was set up in a completely randomized design, with five treatments (continuous and intermittent drying under 4, 8, 12, and 16 h of rest period) and four replications, to evaluate the effect of intermittent drying. Corn kernels of the cultivar Cargo TL were harvested with a moisture content of 25.37% wb and submitted to drying in an experimental fixed bed dryer set to a temperature of 100 °C and an airflow of 1.5 m3 min-1 m-2. Drying was performed until the kernels reached a moisture content of 14±0.3% wb. The process was interrupted in the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Intermittent drying; Mechanical properties; Rupture force; Hardness; Drying rate.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902020000400415

การศึกษาความสัมพันธ์ระหว่างลักษณะปรากฏ สมบัติเชิงเคมี-กายภาพและสมบัติการหุงต้มของเมล็ดข้าวโดยการวิเคราะห์ภาพ
Provedor de dados: 106
Autores: Maturada Jinoros; Somkiat Prachayawarakorn; Somchai Soponronnarit.
After harvesting paddy needs to pass through several processing steps before edible grain kernels are obtained. These processes inevitably affect the kernel quality, both in terms of the physical physicochemical and cooking properties. A number of techniques have thus been proposed to evaluate the various quality attributes of rice kernels. Image analysis is one of the promising techniques for analysis of rice kernel appearances with fast and accurate results. Image-analysis results may also be related to the physicochemical and cooking properties of the kernels. This research explored possible relationships between appearances obtained via image analysis and selected physicochemical and cooking properties of rice kernels. In addition to the basic apparent...
Tipo: PhysicalObject
Palavras-chave: Amylose content; Hardness; Parboiled rice; Translucency; Water uptake; Cooking quality; ปริมาณแอมิโลส; ความแข็ง; ข้าวนึ่ง; ความโปร่งแสง; การดูดน้ำ; คุณภาพการหุงต้ม.
Ano: 2012
URL: http://anchan.lib.ku.ac.th/agnet/handle/001/5438

Optimization of Process Variables for Osmo- freeze drying  of Strawberry Slices Using Response Surface Methodology
Provedor de dados: 111
Autores: KUMAR, VISHAL.
The production of high-quality Osmo freeze-dried strawberry slices was studied by response surface methodology. The osmotic treatment and experiment were conducted according to Box-Bohnken Design. The low and high levels of the process variables were 40% (w/w) and 60% (w/w) for sucrose concentration of osmotic solution; 2 and 4 mm for slice thickness and - 10 and -30 0C for operating temperatures in freeze dryer. Responses studied comprised final moisture content (M), colour Index (L), water activity (aw), rehydration ratio (RR) and overall acceptability (Oa). It was found that effects of all the process variables were significant on all responses. Optimum conditions (desirability = 0.692) obtained by numerical optimization were 51% sucrose concentration;...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Osmotic; Freeze; Rehydration; Hardness; Colour; Water activity.
Ano: 2020
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/5587

Interconnection between microstructure and microhardness of directionally solidified binary Al-6wt.%Cu and multicomponent Al-6wt.%Cu-8wt.%Si alloys
Provedor de dados: 42
Autores: VASCONCELOS,ANGELA J.; KIKUCHI,RAFAEL H.; BARROS,ANDRÉ S.; COSTA,THIAGO A.; DIAS,MARCELINO; MOREIRA,ANTONIO L.; SILVA,ADRINA P.; ROCHA,OTÁVIO L.
An experimental study has been carried out to evaluate the microstructural and microhardness evolution on the directionally solidified binary Al-Cu and multicomponent Al-Cu-Si alloys and the influence of Si alloying. For this purpose specimens of Al-6wt.%Cu and Al-6wt.%Cu-8wt.%Si alloys were prepared and directionally solidified under transient conditions of heat extraction. A water-cooled horizontal directional solidification device was applied. A comprehensive characterization is performed including experimental dendrite tip growth rates (VL) and cooling rates (TR) by measuring Vickers microhardness (HV), optical microscopy and scanning electron microscopy with microanalysis performed by energy dispersive spectrometry (SEM-EDS). The results show, for...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Solidification; Metals and alloys; Electron microscopy; Hardness.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652016000301099

Physico-chemical and cooking characteristics of some rice varieties
Provedor de dados: 52
Autores: González,Rolando J.; Livore,Alberto; Pons,Brigitte.
Some physicochemical and cooking characteristics corresponding to different varieties and commercial samples of rice were analysed. Some mechanical properties determined by both, the viscoelastograf and the Instrom Universal Food Testing Machine were also analysed. Gelatinization time (Gt), gelatinization endotherm and amylose content were determined. The results showed that there was a very good correlation between gelatinization temperature and Gt, while no noticeable correlation among others phsycochemical characteristics was observed. Regarding the mechanical properties, both methods permited to show significant differences among most of the samples. However, when the samples order obtained with hardness (Instrom) values was compared with that...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Rice quality; Amilose; Hardness; Firmness; Cooking time; Gelatinisation.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132004000100010

Physical characteristics of Brazilian wheat and their utilization as an indication of flour extraction
Provedor de dados: 52
Autores: Germani,Rogério; Carvalho,José Luiz Viana de.
An extensive work to determine the test weight (TW), the thousand kernel weight (TKW) and the hardness (HD) of Brazilian wheat, was undertaken for the crop years from 1990 to 1994, with the objetive of drawing the Brazilian wheat physical characteristics and their relationship with flour extraction (FE). The results showed a median TW of 78.2kg/hl, a TKW of 34.2g and the HD was graded as hard. The values varied accordingly with the crop year, the local and year vs. local. Among the locals the wheat from the MS/DF/MG/GO States showed the best results. Correlation coefficients between FE and each of the parameters, TW, TKW and HD were low but significant (P&lt; 5.0%) and, therefore, should not be used as a direct relationship but only as an indicator of FE....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Wheat; Flour extraction; Hectoliter weight; Thousand kernel weight; Hardness.
Ano: 1999
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89131999000100004