345 research outputs found

    Influence of temperature on continuous high gravity brewing with yeasts immobilized on spent grains

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    Flavor compounds’ formation and fermentative parameters of continuous high gravity brewing with yeasts immobilized on spent grains were evaluated at three different temperatures (7, 10 and 15 °C). The assays were performed in a bubble column reactor at constant dilution rate (0.05 h−1) and total gas flow rate (240 ml/min of CO2 and 10 ml/min of air), with high-gravity all-malt wort (15°Plato). The results revealed that as the fermentation temperature was increased from 7 to 15 °C, the apparent and real degrees of fermentation, rate of extract consumption, ethanol volumetric productivity and consumption of free amino nitrogen (FAN) increased. In addition, beer produced at 15 °C presented a higher alcohols to esters ratio (2.2–2.4:1) similar to the optimum values described in the literature. It was thus concluded that primary high-gravity (15°Plato) all-malt wort fermentation by continuous process with yeasts immobilized on spent grains, can be carried out with a good performance at 15 °C.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP).Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

    Optimal fermentation conditions for maximizing the ethanol production by Kluyveromyces fragilisfrom cheese whey powder

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    Cheese whey powder (CWP) is an attractive raw material for ethanol production since it is a dried and concentrated form of CW and contains lactose in addition to nitrogen, phosphate and other essential nutrients. In the present work, deproteinized CWP was utilized as fermentation medium for ethanol production by Kluyveromyces fragilis. The individual and combined effects of initial lactose concentration (50-150 kg m-3), temperature (25-35 ºC) and inoculum concentration (1-3 kg m-3) were investigated through a 23 full factorial central composite design, and the optimal conditions for maximizing the ethanol production were determined. According to the statistical analysis, in the studied range of values, only the initial lactose concentration had a significant effect on ethanol production, resulting in higher product formation as the initial substrate concentration was increased. Assays with initial lactose concentration varying from 150 to 250 kg m-3 were thus performed and revealed that the use of 200 kg m-3 initial lactose concentration, inoculum concentration of 1 kg m-3 and temperature of 35 ºC were the best conditions for maximizing the ethanol production from CWP solution. Under these conditions, 80.95 kg m-3 of ethanol was obtained after 44 h of fermentation.The authors acknowledge the financial support from "CAPES/Grices (BEX2150/07-7) and Lactogal for supplying cheese whey powder

    Optimization of ethanol production from cheese whey powder by Kluyveromyces fragilis using factorial design and response surface methodology

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    The individual and combined effects of initial lactose concentration, temperature and inoculum concentration on ethanol production from cheese whey powder by Kluyveromyces fragilis were investigated. A 2 3 full-factorial central composite design (CCD) and response surface methodology (RSM) were employed in order to determine the optima conditions that maximize the ethanol production. Statistical analysis of results showed that, in the range studied, only the initial lactose concentration had a significant effect on ethanol production. Response surface data showed maximum ethanol production at inoculum concentration between 1 and 3 g/L and temperature between 25 and 35ºC when the initial lactose concentration was 150 g/L.CAPES/Grices - BEX2150/07-7

    Internet of robotic things : converging sensing/actuating, hypoconnectivity, artificial intelligence and IoT Platforms

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    The Internet of Things (IoT) concept is evolving rapidly and influencing newdevelopments in various application domains, such as the Internet of MobileThings (IoMT), Autonomous Internet of Things (A-IoT), Autonomous Systemof Things (ASoT), Internet of Autonomous Things (IoAT), Internetof Things Clouds (IoT-C) and the Internet of Robotic Things (IoRT) etc.that are progressing/advancing by using IoT technology. The IoT influencerepresents new development and deployment challenges in different areassuch as seamless platform integration, context based cognitive network integration,new mobile sensor/actuator network paradigms, things identification(addressing, naming in IoT) and dynamic things discoverability and manyothers. The IoRT represents new convergence challenges and their need to be addressed, in one side the programmability and the communication ofmultiple heterogeneous mobile/autonomous/robotic things for cooperating,their coordination, configuration, exchange of information, security, safetyand protection. Developments in IoT heterogeneous parallel processing/communication and dynamic systems based on parallelism and concurrencyrequire new ideas for integrating the intelligent “devices”, collaborativerobots (COBOTS), into IoT applications. Dynamic maintainability, selfhealing,self-repair of resources, changing resource state, (re-) configurationand context based IoT systems for service implementation and integrationwith IoT network service composition are of paramount importance whennew “cognitive devices” are becoming active participants in IoT applications.This chapter aims to be an overview of the IoRT concept, technologies,architectures and applications and to provide a comprehensive coverage offuture challenges, developments and applications

    Review : beer production : spoilage microorganisms and detection methods

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    A cerveja é uma bebida que apresenta características desfavoráveis para a multiplicação de vários microrganismos, sendo reconhecida como um produto de considerável estabilidade microbiológica. Porém, algumas espécies de microrganismos, incluindo bactérias Gram-positivas (Lactobacillus e Pediococcus), Gram-negativas (Pectinatus e Megasphaera) e leveduras selvagens (Saccharomyces e não-Saccharomyces) são capazes de se multiplicar nesta bebida, conferindo características indesejáveis, tais como turbidez e mudanças sensoriais, as quais prejudicam a qualidade do produto final. Este fato tem motivado uma série de pesquisas visando ao desenvolvimento de métodos rápidos e específicos para a detecção dos microrganismos deteriorantes da cerveja. Apesar de a detecção desses microrganismos, por cultivo em meios de laboratório, nem sempre proporcionar a especificidade e sensibilidade requerida, o uso de diferentes meios seletivos e condições de incubação continua sendo o método preferido pelas cervejarias. O presente artigo apresenta uma revisão da literatura sobre os principais microrganismos deteriorantes da cerveja, incluindo as causas que favorecem sua multiplicação e os métodos que podem ser empregados para sua detecção.Beer is a beverage that presents unfavourable features for the growth of several microorganisms, being recognized as a product of considerable microbiological stability. However, some species of microorganisms, including Gram-positive (Lactobacillus and Pediococcus) and Gram-negative bacteria (Pectinatus and Megasphaera) and wild yeasts (Saccharomyces and non-Saccharomyces) are able to grow in this beverage, providing undesirable characteristics, such as turbidity and sensory changes, which damage the quality of the final product. This fact has motivated a number of research projects aiming at the development of fast and specific methods for the detection of beer spoilage microorganisms. Although the detection of these microorganisms by cultivation in laboratory media does not always provide the required specificity and sensibility, the use of different selective media and incubation conditions still represent the method preferred by breweries. The present article is a literature review about the main beer spoilage microorganisms, including the causes that favour their growth and the methods that can be used for their detection

    Coastal hydrogeological system of Mar Piccolo (Taranto, Italy)

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    The Mar Piccolo basin is an internal sea basin located along the Ionian coast (Southern Italy), and it is surrounded primarily by fractured carbonate karstic environment. Because of the karstic features, the main continental water inflow is from groundwater discharge. The Mar Piccolo basin represents a peculiar and sensitive environment and a social emergency because of sea water and sediments pollution. This pollution appears to be caused by the overlapping effects of dangerous anthropogenic activities, including heavy industries and commercial and navy dockyards. The paper aims to define the contribution of subaerial and submarine coastal springs to the hydrological dynamic equilibrium of this internal sea basin. A general approach was defined, including a hydrogeological basin border assessment to detect inflowing springs, detailed geological and hydrogeological conceptualisation, in situ submarine and subaerial spring measurements, and flow numerical modelling. Multiple sources of data were obtained to define a relevant geodatabase, and it contained information on approximately 2,000 wells, located in the study area (1,600 km2). The conceptualisation of the hydrogeological basin, which is 978 km2 wide, was supported by a 3D geological model that interpolated 716 stratigraphic logs. The variability in hydraulic conductivity was determined using hundreds of pumping tests. Five surveys were performed to acquire hydro-geochemical data and spring flow-yield measurements; the isotope groundwater age was assessed and used for model validation. The mean annual volume exchanged by the hydrogeological basin was assessed equal to 106.93 106 m3. The numerical modelling permitted an assessment of the mean monthly yield of each spring outflow (surveyed or not), travel time, and main path flow

    High gravity batch and continuous processes for beer production: evaluation of fermentation performance and beer quality

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    This study deals with two innovative brewing processes, high gravity batch and complete continuous beer fermentation systems. The results show a significant influence of the variables such as concentration and temperature on the yield factor of the substrate into ethanol and consequently on the productivity of the high gravity batch process. The technological feasibility of continuous production of beer based on yeast immobilization on cheap alternative carriers was also demonstrated. The influence of process parameters on fermentation performance and quality of the obtained beers was studied by sensorial analysis. No significant difference in the degree of acceptance between the obtained products and some traditional market brands was found.FAPESP; CAPES; CNPq (Brazil); Malteria do Vale, Wallerstein Industrial e Commercial, Corn Products Brasil; Johnson-Diversey; FCT/Portugal; MŠMT Czech Republic; Unicer S.A

    Obtention and characterization of distilled beverage from cheese whey fermentation

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    O presente estudo visou a produção e caracterização de uma nova bebida alcoólica através da fermentação descontínua do soro de queijo e posterior destilação do produto fermentado. Os ensaios fermentativos foram conduzidos a 35 °C e 150 rpm por 92 h, em um bioreator de 7 L (volume total) empregando a levedura Kluyveromyces fragilis. O destilado foi separado em três frações de acordo com a concentração de etanol: a cabeça (>80% v/v), o coração (80-40% v/v) e a cauda (<40% v/v). A fração do coração foi diluída para um teor alcoólico de 40% v/v e os principais compostos voláteis (ésteres e alcoóis superiores) foram determinados por Cromatografia Gasosa com detector de ionização de chama (CG-DIC) e Cromatografia Gasosa com Espectrometria de Massa (CG-EM). A fração do coração foi também submetida a análise sensorial por um painel de julgadores treinados visando estabelecer descritores visuais, olfativos e gustativos. Com este trabalho concluiu-se que é possível obter uma bebida destilada com odor e gosto agradáveis a partir da fermentação do soro de queijo

    An Instrument For Investigation of the Cosmic Microwave Background Radiation at Intermediate Angular Scales

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    We describe an off-axis microwave telescope for observations of the anisotropy in the cosmic microwave background (CMB) radiation on angular scales between 0.5 deg and 3 deg. The receiver utilizes cryogenic high-electron-mobility transistor (HEMT) amplifiers and detects the total power in multiple 3 GHz wide channels. Both frequency and polarization information are recorded allowing discrimination between CMB radiation and potential foreground sources and allowing checks for systematic effects. The instrumental radiometric offset is small (~1 mK). Data are taken by rapidly sampling while sweeping the beam many beamwidths across the sky. After detection, a spatio-temporal filter is formed in software which optimizes the sensitivity in a multipole band in the presence of atmospheric fluctuations. Observations were made from Saskatoon, Saskatchewan (SK), Canada during the winter of 1993 with six channels between 27.6 and 34.0 GHz, in 1994 with twelve channels between 27.6 and 44.1 GHz, and in 1995 with six channels between 38.2 and 44.1 GHz. The performance of the instrument and assessment of the atmospheric noise at this site are discussed.Comment: latex file is called inst.tex. 30 pages with 14 Postscript figures. Uses aas2pp4.sty (included). Submitted to Ap

    Performance of ePix10K, a high dynamic range, gain auto-ranging pixel detector for FELs

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    ePix10K is a hybrid pixel detector developed at SLAC for demanding free-electron laser (FEL) applications, providing an ultrahigh dynamic range (245 eV to 88 MeV) through gain auto-ranging. It has three gain modes (high, medium and low) and two auto-ranging modes (high-to-low and medium-to-low). The first ePix10K cameras are built around modules consisting of a sensor flip-chip bonded to 4 ASICs, resulting in 352x384 pixels of 100 μ\mum x 100 μ\mum each. We present results from extensive testing of three ePix10K cameras with FEL beams at LCLS, resulting in a measured noise floor of 245 eV rms, or 67 e^- equivalent noise charge (ENC), and a range of 11000 photons at 8 keV. We demonstrate the linearity of the response in various gain combinations: fixed high, fixed medium, fixed low, auto-ranging high to low, and auto-ranging medium-to-low, while maintaining a low noise (well within the counting statistics), a very low cross-talk, perfect saturation response at fluxes up to 900 times the maximum range, and acquisition rates of up to 480 Hz. Finally, we present examples of high dynamic range x-ray imaging spanning more than 4 orders of magnitude dynamic range (from a single photon to 11000 photons/pixel/pulse at 8 keV). Achieving this high performance with only one auto-ranging switch leads to relatively simple calibration and reconstruction procedures. The low noise levels allow usage with long integration times at non-FEL sources. ePix10K cameras leverage the advantages of hybrid pixel detectors with high production yield and good availability, minimize development complexity through sharing the hardware, software and DAQ development with all other versions of ePix cameras, while providing an upgrade path to 5 kHz, 25 kHz and 100 kHz in three steps over the next few years, matching the LCLS-II requirements.Comment: 9 pages, 5 figure
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