2,485 research outputs found

    Microestructura de quesos blancos turcos bajos en grasa producidos industrialmente, influencia de la homogenización de la crema

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    The microstructure and fat globule distribution of reduced and low fat Turkish white cheese were evaluated. Reduced and low fat cheeses were manufactured from 1.5% and 0.75% fat milk respectively which were standardized unhomogenized and homogenized cream in a dairy plant. Homogenized and non-homogenized creams and cheese whey were analyzed for fat globule distribution and cheese samples were also analyzed for microstructure characteristics. According to the results, the homogenization of cream decreased the size of fat globules; and showed that a large number of fat particles were dispersed in the in matrix and improved the lubrication of cheese microstructure. According to the micrographs for the fat, which was not removed, they exhibited a more extended matrix with a few small fat globules compared to the defatted micrographs. Homogenization of cream produces small fat globules and unclustured fat globules were found in the resulting whey. These results are important for dairy processors for using cream homogenization as a processing tool at the industrial level.Se estudia la microestructura y distribución de los glóbulos de grasa de quesos blancos turcos bajos en grasa. Quesos con reducida y baja cantidad en grasa fueron fabricados conteniendo entre el 1,5% y 0,75% de grasa de leche, respectivamente, y con cremas homogeneizadas y no homogeneizadas, en una planta de lácteos. Las cremas homogeneizadas y no homogeneizadas y el suero de los quesos se analizaron para determinar la distribución de los glóbulos de grasa y también se analizaron las características de la microestructura de muestras de queso. De acuerdo con los resultados, la homogeneización de la crema reduce el tamaño de los glóbulos de grasa, mostrando un gran número de partículas de grasa dispersa en la matriz de caseína que mejoró la lubricación de la microestructura del queso. De acuerdo con las micrografías de la grasa que no se elimina, estas exhiben una matriz más amplia en la que hay pocos glóbulos de grasa en comparación con las micrografías de las muestras desgrasadas. La homogenización de la crema produce pequeños glóbulos de grasa y el suero resultante contiene glóbulos de grasa no incrustados. Estos resultados son importantes para los procesadores de productos lácteos, y muestran la utilidad de la homogeneización de crema como una herramienta del procesamiento a nivel industrial

    Sampling-based Algorithms for Optimal Motion Planning

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    During the last decade, sampling-based path planning algorithms, such as Probabilistic RoadMaps (PRM) and Rapidly-exploring Random Trees (RRT), have been shown to work well in practice and possess theoretical guarantees such as probabilistic completeness. However, little effort has been devoted to the formal analysis of the quality of the solution returned by such algorithms, e.g., as a function of the number of samples. The purpose of this paper is to fill this gap, by rigorously analyzing the asymptotic behavior of the cost of the solution returned by stochastic sampling-based algorithms as the number of samples increases. A number of negative results are provided, characterizing existing algorithms, e.g., showing that, under mild technical conditions, the cost of the solution returned by broadly used sampling-based algorithms converges almost surely to a non-optimal value. The main contribution of the paper is the introduction of new algorithms, namely, PRM* and RRT*, which are provably asymptotically optimal, i.e., such that the cost of the returned solution converges almost surely to the optimum. Moreover, it is shown that the computational complexity of the new algorithms is within a constant factor of that of their probabilistically complete (but not asymptotically optimal) counterparts. The analysis in this paper hinges on novel connections between stochastic sampling-based path planning algorithms and the theory of random geometric graphs.Comment: 76 pages, 26 figures, to appear in International Journal of Robotics Researc

    Fixed-point realization of fast nonlinear Fourier transform algorithm for FPGA implementation of optical data processing

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    The nonlinear Fourier transform (NFT) based signal processing has attracted considerable attention as a promising tool for fibre nonlinearity mitigation in optical transmission. However, the mathematical complexity of NFT algorithms and the noticeable distinction of the latter from the “conventional” (Fourier-based) methods make it difficult to adapt this approach for practical applications. In our work, we demonstrate a hardware implementation of the fast direct NFT operation: it is used to map the optical signal onto its nonlinear Fourier spectrum, i.e. to demodulate the data. The main component of the algorithm is the matrix-multiplier unit, implemented on field-programmable gate arrays (FPGA) and used in our study for the estimation of required hardware resources. To design the best performing implementation in limited resources, we carry out the processing accuracy analysis to estimate the optimal bit width. The fast NFT algorithm that we analyse, is based on the FFT, which leads to the O(N log^{2}_{2} N) method’s complexity for the signal consisting of N samples. Our analysis revealed the significant demand in DSP blocks on the used board, which is caused by the complex-valued matrix operations and FFTs. Nevertheless, it seems to be possible to utilise further the parallelisation of our NFT-processing implementation for the more efficient NFT hardware realisation

    Investigating Open-World Person Re-identification Using a Drone

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    Abstract. Person re-identification is now one of the most topical and intensively studied problems in computer vision due to its challenging na-ture and its critical role in underpinning many multi-camera surveillance tasks. A fundamental assumption in almost all existing re-identification research is that cameras are in fixed emplacements, allowing the explicit modelling of camera and inter-camera properties in order to improve re-identification. In this paper, we present an introductory study push-ing re-identification in a different direction: re-identification on a mobile platform, such as a drone. We formalise some variants of the standard formulation for re-identification that are more relevant for mobile re-identification. We introduce the first dataset for mobile re-identification, and we use this to elucidate the unique challenges of mobile re-identification. Finally, we re-evaluate some conventional wisdom about re-id models in the light of these challenges and suggest future avenues for research in this area.

    AN EXAMINATION OF THE STRUCTURE OF THE VOCATIONAL OUTCOME EXPECTATIONS SCALE WITH LATINA/O STUDENTS

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    In the current study, we investigated the psychometric properties of a meaningful measure of career development among Latina/o students. A confirmatory factor analysis (CFA) was used to evaluate structural validity of the Vocational Outcome Expectations scale. The results supported a modest one-factor structure for the VOE scale. Internal consistency was good as measured by coefficient alpha. Findings provide support for the reliability and validity of the VOE with Latina/o students. A discussion regarding the usefulness of this measure of career development is provided

    Bioindicative values of microfungi in starch and possible deficiencies of the new Serbian regulation on food hygiene

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    The results of tests on the presence of yeasts and molds in cornstarch [AD ‘IPOK’ Zrenjanin, 2007-2008, made at the time when previous Regulations were valid] were analyzed in terms of bioindicative values of microfungi as indicators of quality and safety of raw material or final food products. Microbiological analysis was used to detect the presence of a number of microorganisms MMI-0001, and a questionnaire was designed at the Department of Public Health in Zrenjanin town (Republic of Serbia), where the anal­yses were done, regarding the microbiological tests on starch. In order to rationalize the analyses and make them more economical, several areas of product quality control (water, food, raw materials, space) were recommended either to be excluded or regarded as optional. Thus, analysis of presence of microfungi as indicators of product quality was categorized as optional. The results obtained from this research suggest a different conclusion because the bacteria in the samples indicated ˮmicrobiologically“, namely bacteriologically, safe samples of food, while, on the contrary, the presence of some microfungi as distinct xerophilous or xerotolerant microorganisms, indicated that the food was mycologically non-safe. The obtained data are crucial for questioning the decision to exclude the earlier required (mycological) analysis of the samples (in the production of starch, or end products, etc.) and categorize such analyses in new Regulations as optional, depending on the manufacturer’s preference. Bioindicative values of microfungi as indicators of the quality of starch, clearly point to the shortsightedness of the new Regulations on food hygiene and safety, where tests on certain microorganisms (in this case, yeasts and molds) are not legally defined as mandatory, but the Law leaves manufacturers a possibility to choose (or not to choose) the testing and frequency of testing on the presence (absence) of microorganisms, which can be risky, both in the production and marketing of the finial products. [Projekat Ministarstva nauke Republike Srbije, br. OI-179079

    The Effect of Sr2+ and Fe3+ Cations and the Stirring Speed on The Precipitation of Barium Sulfate in a Batch System

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    The batch system investigation explored the effect of Sr2+ and Fe3+ cations and the stirring speed on the characteristics of precipitated barium sulfate. A series of experiments were conducted to evaluate the rate of barium sulfate precipitation in laboratory equipment from brines containing barium ions (3500 ppm) and varying amounts of Sr2+ and Fe3+ ions (10 and 20 ppm). Kinetic analysis was also performed to explore how stirring speeds (240 and 480 rpm) affect barium sulfate scales' crystallization by increasing the stirring speed and promoting Sr2+ and Fe3+-cation solubility while decreasing the precipitation rate. All solid crystals obtained were mostly pure barite, as the X-ray diffraction (XRD) method confirmed. The SEM micrograph of barite morphology revealed particles with tablet-shaped crystals 2 to 5 nm in size. With the presence of Sr2+ and Fe3+-cation, the shape of barium sulfate was modified into spherical tablets or flower-like clusters of tablets. Meanwhile, the morphological changes could result from increased stirring rates. Moreover, the kinetic results yielded a general reaction rate equation that might be used to estimate barium sulfate deposition in pipelines for various brine, supersaturation, and mixing time durations

    Porphyry Cu-Mo-(Au) Mineralization at Paraga Area, Nakhchivan District, Azerbaijan: Evidence from Mineral Paragenesis, Hyrothermal Alteration and Geochemical Studies

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    The Paraga area is located at the extreme eastern part of Nakhchivan district at the boundary with Armenia. The field study is situated at Ordubad region placed in 9 km from Paraga village and stays at 2300-2800 m height over sea level. It lies within a region of low-grade metamorphic porphyritic volcanic and plutonic rocks. The detailed field studies revealed that this area composed mainly of metagabbro-diorite intrusive rocks with porphyritic character emplaced into meta-andesitic rocks. This complex is later intruded by unmapped olivine gabbroic rocks. The Cu-Mo-(Au) mineralization at Paraga deposit is vein-type mineralization that is essentially related to quartz veins stockwork which cut the dioritic rocks and concentrated at the eastern and northeastern parts of the area with different directions N80W, N25W, N70E and N45E. Also, this mineralization is associated with two shearing zones directed N75W and N15E. The host porphyritic rocks were affected by intense sulfidation, carbonatization, sericitization and silicification with pervasive hematitic alterations accompanied with mineralized quartz veins and quartz-carbonate veins. Sulfide minerals which are chalcopyrite, pyrite, arsenopyrite and sphalerite occurred in two cases either inside these mineralized quartz veins or disseminated in the highly altered rocks as well as molybdenite and also at the peripheries between the altered host rock and veins. Gold found as inclusion disseminated in arsenopyrite and pyrite as well as in their cracks

    Porphyry Cu-Mo-(Au) Mineralization at Paraga Area, Nakhchivan District, Azerbaijan: Evidence from Mineral Paragenesis, Hyrothermal Alteration and Geochemical Studies

    Get PDF
    The Paraga area is located at the extreme eastern part of Nakhchivan district at the boundary with Armenia. The field study is situated at Ordubad region placed in 9 km from Paraga village and stays at 2300-2800 m height over sea level. It lies within a region of low-grade metamorphic porphyritic volcanic and plutonic rocks. The detailed field studies revealed that this area composed mainly of metagabbro-diorite intrusive rocks with porphyritic character emplaced into meta-andesitic rocks. This complex is later intruded by unmapped olivine gabbroic rocks. The Cu-Mo-(Au) mineralization at Paraga deposit is vein-type mineralization that is essentially related to quartz veins stockwork which cut the dioritic rocks and concentrated at the eastern and northeastern parts of the area with different directions N80W, N25W, N70E and N45E. Also, this mineralization is associated with two shearing zones directed N75W and N15E. The host porphyritic rocks were affected by intense sulfidation, carbonatization, sericitization and silicification with pervasive hematitic alterations accompanied with mineralized quartz veins and quartz-carbonate veins. Sulfide minerals which are chalcopyrite, pyrite, arsenopyrite and sphalerite occurred in two cases either inside these mineralized quartz veins or disseminated in the highly altered rocks as well as molybdenite and also at the peripheries between the altered host rock and veins. Gold found as inclusion disseminated in arsenopyrite and pyrite as well as in their cracks
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