311 research outputs found

    Production Capacity and Queues in a Bookstore at Porto Velho, Brazil

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    The objective of this work was to study the productive capacity and queues in the services of a bookstore in Porto Velho city, Brazil. To do this, the specific objectives were: (1) to study the productive capacity in the operation units of the bookstore; (2) to carry out an analysis of queuing and flow management in the operation units of the bookstore; and (3) to suggest prospects for the development using the SWOT Matrix analysis tool

    ENERGY HARVESTING TO POWER AN AUTONOMOUS SENSOR FROM MECHANICAL VIBRATIONS

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    This paper describes an approach for harvesting electrical energy from a low-cost piezoelectric element operating at low amplitude vibration to power an autonomous and self-powered sensor. The converter consists of an ordinary piezoelectric buzzer and a steel ball bonded onto it. Furthermore, the design of the CMOS energy processor is presented focusing on the voltage multiplier and for which simulation and measurements results are discussed. This paper presents simple and analytical formulas with high precision to predict the dc output voltage of the voltage multiplie

    NPARSEC : NTT Parallaxes of Southern Extremely Cool objects. Goals, targets, procedures and first results

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    The discovery and subsequent detailed study of T dwarfs have provided many surprises and pushed the physics and modelling of cool atmospheres in unpredicted directions. Distance is a critical parameter for studies of these objects to determine intrinsic luminosities, test binarity and measure their motion in the Galaxy. We describe a new observational programme to determine distances across the full range of T-dwarf subtypes using the New Technology Telescope (NTT)/SOFI telescope/instrument combination. We present preliminary results for ten objects, five of which represent new distances.Peer reviewe

    Intake and Digestibility of Nutrients of Corn and \u3cem\u3eStylosanthes\u3c/em\u3e Silages in Diets for Sheep

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    The low concentration of water soluble carbohydrates, the high buffering capacity and the low autochthonous population of lactic acid bacteria are limiting factors to legume ensiling. However, recent research with tropical legumes has shown that the silages presented an adequate fermentation profile (Liu et al. 2012; Silva et al. 2012; Pereira et al. 2012). Nevertheless, there are few studies on the use of stylosanthes silages cv. Campo Grande (Stylosanthes capitata + Stylosantes macrocephala) for sheep feeding. The objective of this study was to evaluate the intake and digestibility of nutrients of stylosanthes and corn silages in sheep diets

    Thermographic inspection of impact damage in carbon fiber-reinforcing polymer matrix laminates

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    Laminados compósitos com matrizes poliméricas, respectivamente termorrígida e termoplástica, fortalecidas com fibras contínuas de carbono foram submetidos a impacto único transversal com diferentes níveis de energia. Os danos impingidos aos materiais estruturais foram avaliados por termografia ativa infravermelha na modalidade transmissão. Em geral, os termogramas do laminado termoplástico apresentaram indicações mais claras e bem definidas dos danos causados por impacto, se comparados aos do compósito termorrígido. O aquecimento convectivo das amostras por fluxo controlado de ar quente se mostrou mais eficaz que o realizado por irradiação, empregando-se lâmpada de filamento. Observou-se também que tempos mais longos de aquecimento favoreceram a visualização dos danos. O posicionamento da face impactada do espécime, relativamente à câmera infravermelha e à fonte de calor, não afetou a qualidade dos termogramas no caso do laminado termorrígido, enquanto que influenciou significativamente os termogramas do compósito termoplástico. Os resultados permitiram concluir que a termografia infravermelha é um método de ensaio não-destrutivo simples, robusto e confiável para a detecção de danos por impacto tão leve quanto 5 J em laminados compósitos poliméricos reforçados com fibras de carbono.Continuous carbon fiber reinforced thermoset and thermoplastic composite laminates were exposed to single transversal impact with different energy levels. The damages impinged to the structural materials were evaluated by active infrared thermography in the transmission mode. In general, the thermoplastic laminate thermograms showed clearer damage indications than those from the thermosetting composite. The convective heating of the samples by controlled hot air flow was more efficient than via irradiation using a filament lamp. It was also observed that longer heating times improved the damage visualization. The positioning of the specimen's impacted face regarding the infrared camera and the heating source did not affect the thermo-imaging of thermosetting specimens, whereas it substantially influenced the thermograms of thermoplastic laminates. The results obtained allow concluding that infrared thermography is a simple, robust and trustworthy methodology for detecting impact damages as slight as 5 J in carbon fiber composite laminates.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)CNPqMaterials Institute of Brazi

    Oral paracoccidioidomycosis:a retrospective study of 95 cases from a single center and literature review

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    The ecoepidemiological panorama of paracoccidioidomycosis (PCM) is dynamic and still ongoing in Brazil. In particular, data about the oral lesions of PCM are barely explored. The aim of this study was to report the clinicopathological features of individuals diagnosed with oral PCM lesions at an oral and maxillofacial pathology service in Rio de Janeiro, Brazil, in the light of a literature review. A retrospective study was conducted on oral biopsies obtained from 1958 to 2021. Additionally, electronic searches were conducted in PubMed, Embase, Scopus, Web of Science, Latin American and Caribbean Center on Health Sciences Information, and Brazilian Library of Dentistry to gather information from large case series of oral PCM. Ninety-five cases of oral PCM were surveyed. The manifestations were more frequent among males (n=86/90.5%), middle-aged/older adults (n=54/58.7%), and white individuals (n=40/51.9%). The most commonly affected sites were the gingiva/alveolar ridge (n=40/23.4%) and lip/labial commissure (n=33/19.3%); however, one (n=40/42.1%) or multiple sites (n=55/57.9%) could also be affected. In 90 (94.7%) patients, ?mulberry-like? ulcerations/moriform appearance were observed. Data from 21 studies (1,333 cases), mostly Brazilian (90.5%), revealed that men (92.4%; male/female: 11.8:1) and individuals in the fifth and sixth decades of life were the most affected (range: 7-89 years), with the gingiva/alveolar ridge, palate, and lips/labial commissure being the sites most frequently affected. The features of oral PCM lesions are similar to those reported in previous studies from Latin America. Clinicians should be aware of the oral manifestations of PCM, with emphasis on the clinicodemographic aspects and differential diagnoses, especially considering the phenomenon of the emergence of reported cases in rural and/or urban areas of Brazil

    Otolith atlas for marine fishes of the southwestern Atlantic occurring along southern Brazil (28° S-34° S)

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    Otoliths are acellular apposition structures composed of approximately 90% of calcium carbonate and other inorganic salts, which develop over a protein matrix located in the inner ear of bony fishes playing an essential role in the senses of balance and hearing. These structures grow throughout a fish’s lifetime. Owing to their species-specific shape, otoliths are an important tool for the identification of fish species in the diet of predators when collected from stomachs and, due to their low water content, are helpful for archaeological, paleontological and anthropological studies for its presence in fossilized remains. This atlas is aimed at the identification of abundant or frequent bony fishes otoliths in the diet of predators and in fossilized remains from the continental shelf and upper continental slope of southern Brazil between Santa Marta Grande cape (28° S) and Chuí (34° S) on the border with Uruguay. It includes the otolith description of 136 bony fishes species, including most of the abundant and frequent species in the region. Easy to use graphics are provided to infer fish size based on otolith measurements. Vouchers of different sizes of otolith of all species included in this atlas are deposited and available for consultation at the Demersal Fisheries Resources and Cephalopods Laboratory (IO-FURG)

    A New PRNG Hardware Architecture Based on an Exponential Chaotic Map

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    Recent works have been claiming efficient hardware architectures, showing a considerable endeavor to implement chaotic maps in the digital domain. However, there is a critical issue with the chaotic degradation in the digital environment due to its finite numeric precision, that it is still an unsettled topic in the research community. Additionally, less attention has been given to synthesize a methodological approach to how to calculate the exponential function in hardware. In this paper, two novel hardware designs to represent the exponential chaotic map have been suggested. We have employed a perturbation method to avoid the chaotic degradation. 64-bit fixed-point and 32-bit floating-point formats were investigated. Moreover, an approximation of Euler's number by a finite series and the Horner's method have been undertaken to further minimize the proposed hardware. Results show that both proposed hardware architectures consume a fewer number of components. The designed systems present a positive Lyapunov exponent, which suggests a chaotic behavior. Ultimately, the NIST SP 800-22 test, the histogram, and the autocorrelation function show that the new hardware architectures present pseudo-random properties

    Chemical Composition and Evaluation of Antitumoral Activity of Leaf and Root Essential Oils of Conyza canadensis (Asteraceae)

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    The leaf and root oils of Conyza canadensis were studied for chemical composition and antitumor activity. The results showed that there is great variation in the composition of the oils obtained from different parts. The main components in the leaf oil were limonene, caryophyllene oxide and espatulenol. In the root oil the major component was the acetylenic ester lachnophyllum methyl ester. It was observed that according to the collection time (6 and 16 hours), significant variations in the content of the main components of this essential oil of leaves can occur. Limonene, spatulenol and caryophyllene oxide presented a distribution of 61% / 5.4% / 12.5% ​​and 38% / 10.7% / 22.3% in oils obtained from plants collected at 6 and 16 hours, respectively. The antitumor activity of the oils showed that leaf oil had a greater potential for inhibition, and this oil was distinguished by the activity against neoplastic cell lines K562 (leukemia) and NCI-ADR / RES (ovary with multidrug resistance phenotype ) with TGI values ​​of 16.8 and 19.0 mg.mL-1, respectively. Comparing the leaf oils and their tumor cell inhibition potentials, it was noted that this activity is higher in the oil with higher contents of monoterpene limonene. DOI: http://dx.doi.org/10.17807/orbital.v11i5.137

    Holographic Vitrification

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    We establish the existence of stable and metastable stationary black hole bound states at finite temperature and chemical potentials in global and planar four-dimensional asymptotically anti-de Sitter space. We determine a number of features of their holographic duals and argue they represent structural glasses. We map out their thermodynamic landscape in the probe approximation, and show their relaxation dynamics exhibits logarithmic aging, with aging rates determined by the distribution of barriers.Comment: 100 pages, 25 figure
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