481 research outputs found
Nanoindentation study of the interfacial zone between cellulose fiber and cement matrix in extruded composites
[EN] The present study shows the application of the nanoindentation technique to evaluate the properties of
the cellulose fiber-cement matrix interfacial zone in composites prepared with an auger extruder. The
degree of strength of the bond between fiber and matrix is recognized as important variable that influences
macro-mechanical properties, such as modulus of rupture and toughness of cement based
composites. The nanoindentation measurements showed the highest hardness and elastic modulus in
the part inner of the cellulosic fiber after hydration process due to precipitation and re-precipitation of
cement hydration products. These results indicate that mineralization of the cellulosic fibers can affect
the stress distribution and interfacial bond strength in the cement based composite.The authors acknowledge by financial support provided by Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP, process no 2013/03823-8), Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES, process no 3886/2014) and Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq, process no 152069/2016), in Brazil. Special thanks for Fibria and Infibra for providing raw materials the development of this work.Teixeira, R.; Tonoli, G.; Santos, S.; Rayón, E.; Amigó, V.; Savastano, HJ.; Rocco Lahr, F. (2018). Nanoindentation study of the interfacial zone between cellulose fiber
and cement matrix in extruded composites. Cement and Concrete Composites. 85:1-8. https://doi.org/10.1016/j.cemconcomp.2017.09.018S188
Effects of a Multimodal Exercise Program on Clinical, Functional Mobility and Cognitive Parameters of Idiopathic Parkinson\u27s Disease Patients
Yield and morphology of Nopalea cochenillifera under N fertilization and biological inoculation
Received: August 15th, 2023 ; Accepted: October 30th, 2023 ; Published: November 9th, 2023 ;
Correspondence: [email protected]; [email protected] objective was to evaluate the effect of inoculation with Azospirillum brasilense
and levels of nitrogen fertilization on the productive aspects of the spineless cactus (Nopalea
cochenillifera). The experiment was carried in Ribeirão do Largo, Southwest region of the state
of Bahia, from April 2019 to April 2020. The experiment was carried out in a 2×4 factorial, in a
randomized block design with eight treatments and four replications. The treatments consisted of
the absence or inoculation with Azospirillum brasilense and nitrogen fertilization levels 0, 50,
100 and 150 kg–
¹ of N ha–¹
. There was a positive effect for the use of the bacteria on cladode area
index, height, number of secondary, tertiary and total cladodes, total weight for cladodes of all
orders and also for final weight per ha–¹
. There was a significant effect of the use of the inoculant
for the levels of total soluble sugars and starch, where there was a decrease in the values for the
treatments submitted to the use of the bacteria. There was a quadratic effect for the weight of the
tertiary cladodes, number of tertiary cladodes and total of spineless cactus when submitted to
nitrogen fertilization levels. There was a linear test for cladodes area index when nitrogen
fertilization was used. The use of Azospirillum brasilense is positive for the cultivation of
spineless cactus, improving development and increasing crop productivity
Carbohydrate and protein metabolism of marandu grass affected by nitrogen fertilisation and number of cuts
Received: June 18th, 2023 ; Accepted: September 30th, 2023 ; Published: October 23rd, 2023 ; Correspondence: [email protected] the metabolism of tropical grasses in response to management practises
imposed in pastoral environments allows for improvements in the management and use of mineral
fertilisers. This study aimed to quantify metabolite content in different plant parts of Marandu
grass (Urochloa brizantha), with a specific focus on the influence of nitrogen fertilisation and its
effects following successive cuts. The treatments corresponded to four nitrogen (N) rates
(0, 75, 150, and 225 kg N ha-1
) and the number of cuts (one, two and three cuts). The plants were
fractionated into leaves, stems, and roots to assess the content of water-soluble carbohydrates
(WSC), starch, albumin, globulin, prolamin, and glutelin content. N fertilisation influenced the
WSC and starch content in different parts of the plant, varying according to the cuts made. In the
leaves and roots, fertilisation reduced the content of WSC and starch with one cut, as these were
utilised as energy sources for assimilating the excess nitrogen in the soil. There was an increase
in the concentration of all protein groups with nitrogen fertilisation in all parts of the plant with
one cut. In plants cut two and three times, N fertilisation led to specific increases and decreases
in different parts of the plants as an adaptive strategy for allocating resources as the number of
cuts increased. Our results broaden our understanding of carbohydrate and protein metabolism in
tropical grasses, thereby providing subsidies for the rational use of nitrogen fertilisers
Bibliometric analysis on the use of natural fibers in construction materials
Received: February 2nd, 2021 ; Accepted: August 3rd, 2021 ; Published: August 30th, 2021 ; Correspondence: [email protected] to the increasing interest of the population in the sustainability theme, there was
a consequent growth in publications related to the theme in the area of civil construction. Agroindustrial waste has become an environmental problem, and with that natural fibers have found
space in the reuse of waste due to its characteristics and possibilities of improving the mechanical
properties of its products. In order to achieve sustainable construction demand, along with the
need to reuse waste, studies have begun to analyze the application of natural fibers in construction
materials. The documents provided by the Web of Science (WOS) database through research
carried out with the search for the terms ‘Natural Fibers’ and ‘Building materials’ restricted to
the period 2010–2020 in the main WOS collection. The institutions involved with the
publications, the countries of origin of the documents, the year of publication, the keywords used
by the authors and the number of citations for each document were analyzed using bibliometrics
in the VOSVIEWER (VOS) software. The result of the analysis shows an increase in documents
related to the theme over the years, and that the countries with the most studies in the area are
China (16), USA (14) and Brazil (11), respectively. The results presented after analysis of the
keywords show that natural fiber (61 occurrences), mechanical properties (44 occurrences) and
composites (31 occurrences) are the words with the highest occurrence among the analyzed
documents. The present study shows the growth of research related to the theme, in addition to
discriminating countries, institutions and authors, which allows monitoring the scientific
expansion of the theme and guiding future studies
Long-Term Multimodal Exercise Program Improves Motor and Non-Motor Parameters of People with Parkinson’s Disease
Hepatic arterioportal malformation in a dog - case report
ABSTRACT Arterioportal communications are complex hepatic vascular abnormalities. These are rarely seen in dogs and typically manifest as neurological, gastrointestinal, and developmental changes. This report describes clinical, laboratory and imaging findings associated with hepatic arterioportal malformation in a male Shih-Tzu dog aged 12 months. The diagnosis was achieved using computed tomographic angiography. The therapeutic approach selected consisted of palliative medical management (diuretics) combined with dietary protein restriction (3.6 g/100 kcal) provided by hepatic diet and gut activity modulation using lactulose. Surgical intervention was not recommended due to the complexity of vascular changes and portal hypertension. Despite initial clinical improvement, the patient died of disease-related complications seven months after diagnosis. Computed tomographic angiography was vital for accurate diagnosis and treatment selection, that needs to be more investigated
Método da histerese por auto-ajuste para minimização de esforço de controle no separador submarino VASPS
High-frequency electroacupuncture versus carprofen in an incisional pain model in rats
Comparative leaf anatomy and morphology of some Brazilian species of Crotalaria L. (Leguminosae: Papilionoideae: Crotalarieae)
- …