2,267 research outputs found

    Laboratory simulations of local winds in the atmospheric boundary layer via image analysis

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    In the atmospheric boundary layer, under high pressure conditions and negligible geostrophic winds, problems associated with pollution are the most critical. In this situation local winds play a major role in the evaluation of the atmospheric dynamics at small scales and in dispersion processes. These winds originate as a result of nonuniform heating of the soil, either when it is homogeneous or in discontinuous terrain in the presence of sea and/or slopes. Depending on the source of the thermal gradient, local winds are classified into convective boundary layer, sea and land breezes, urban heat islands, and slope currents. Local winds have been analyzed by (i) simple analytical models; (ii) numerical models; (iii) field measurements; (iv) laboratory measurements through which it is impossible to completely create the necessary similarities, but the parameters that determine the phenomenon can be controlled and each single wind can be separately analyzed. The present paper presents a summary of laboratory simulations of local winds neglecting synoptic winds and the effects of Coriolis force. Image analysis techniques appear suitable to fully describe both the individual phenomenon and the superposition of more than one local wind. Results do agree with other laboratory studies and numerical experiments

    Structure, rotational dynamics, and superfluidity of small OCS-doped He clusters

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    The structural and dynamical properties of OCS molecules solvated in Helium clusters are studied using reptation quantum Monte Carlo, for cluster sizes n=3-20 He atoms. Computer simulations allow us to establish a relation between the rotational spectrum of the solvated molecule and the structure of the He solvent, and of both with the onset of superfluidity. Our results agree with a recent spectroscopic study of this system, and provide a more complex and detailed microscopic picture of this system than inferred from experiments.Comment: 4 pages. TeX (requires revtex4) + 3 ps figures (1 color

    Fluid-Dynamic Characterization and Efficiency Analysis in Plastic Separation of the Hydraulic Separator Multidune

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    Recovery of useable plastics from post-consumer and manufacturing waste remains a major recycling challenge. The global consumption of plastics was reported to be 230 million tonnes in 2005 of which 47.5 million tonnes were produced in Europe (25 European Union countries + Norway and Switzerland). Of the European production, only 22 million tonnes were reported as having been collected. Of this collected waste, 4 million tonnes were recycled as a manufacturing feedstock (18%) and 6.4 million tonnes went into energy recovery (29%), with the balance (11.6 million tonnes) probably being disposed in landfills. The recycling of plastics is a process essential to reduce the efflux of materials to landfills and to decrease the production of raw materials. In recent years awareness of the importance of environmental protection has led to the development of different techniques for plastic recycling. One issue related to the recycling of this material is the presence in the market of many types of plastics (polymers with additives), often with similar characteristics that make them difficult to differentiate in the recovery phase. The separator “Multidune” is a hydraulic separator by density. Its name derives from the characteristic undulate profile of the channel where separation occurs. The channel is constructed from a sequence of closed parallel cylindrical tubes welded together in plane which are then sliced down the lateral mid-plane and the lower complex is laterally shifted relative to the upper complex. The Multidune allows solid particle separation according to their specific weight and the velocity field establishing within the apparatus. Previous investigations suggested the flow within the Multidune is organized into three main patterns. Principally, a longitudinal transport flow takes place, where the velocity is high. A particle belonging to this region can move from one camera to another. The second region is the lower recirculation zone with high values of the vorticity field. Particles belonging to this region undergo the vertical impulse of the fluid. The thrust is proportional to the vertical velocity component and, in conjunction with gravity and buoyancy, determines the destiny of a particle. If the thrust is larger than the net weight of the particle, an interaction with the principal transport flow occurs and, consequently, the particle will move to the following chamber. The third region is the upper recirculation zone whose dimensions are smaller than the other recirculation zone. If a particle moves from the principal flow to the secondary vorticity zone, it will have the chance to come back to the previous chamber, assuming the principal transport flow thrust does not prevent it from falling out. Because of the role played by velocity, the fluid dynamic investigation of the Multidune apparatus is a preliminary step to carry out in order to investigate its capability in separating solid particles. For this reason a novel experimental campaign was set up and image analysis was employed to detect the velocity field within the apparatus

    Evaluation of product development process using EMVS

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    This paper evaluates a PDP model application in an auto parts company, leader in its segment. From the application of lean thinking in the supply chain and the EMVS performance analysis methodology for PDP, a check list is created to avoid waste in project management. In this paper, we show that EMVS can be positively impacted through active management of knowledge within a project. This paper suggests that the value-enabling portion of a project manager's role requires aligning knowledge across these three key domains regarding PDP Gates (Phases) at company manufacturers of auto parts, Lean Thinking and Value Stream, and methodology for managing projects through performance-term rates and costs. The results show that the methodology has positive aspects, but its implementation takes time and has repercussions throughout the supply chain. Further this research try to explain the types of wastes and view of new products' development is enhanced and associates a manufacturing strategy focus on EMVS performance analysis and lean thinking, PDP and value stream mapping  showing the important of contribution this tools at reduction of waste

    Affinity between bitumen and aggregate in hot mix asphalt by hyperspectral imaging and digital picture analysis

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    This study investigated the viability of quantifying the affinity between aggregate and bitumen by means of different imaging techniques. Experiments were arranged in accordance with the rolling-bottle test, as indicated in UNI EN 12697-11, “Test methods for hot bituminous conglomerates—Part 11”. Digital image processing (DIP) techniques have only recently been used for such quantification. The data gathered with a multi-sensor optical platform equipped with VIS–NIR and SWIR spectrometers were compared with DIP outcomes. Data were processed using the unsupervised ISODATA and the supervised parallelepiped algorithms. The exposed aggregate index (EAI) and the bitumen index (BIT) were calculated to retrieve the bitumen percentage coverage of different mixtures. The comparison with the results obtained employing the traditional 6, 24, 48 and 72 testing hours reveals the possibility to implement a standardized analysis methodology combining digital and hyperspectral imagery to highlight potential inaccuracies deriving from the visual interpretation

    Evolution of Metastasis Study Models toward MetastasisOn-A-Chip: The Ultimate Model?

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    For decades, several attempts have been made to obtain a mimetic model for the study of metastasis, the reason of most of deaths caused by cancer, in order to solve the unknown phenomena surrounding this disease. To better understand this cellular dissemination process, more realistic models are needed that are capable of faithfully recreating the entire and essential tumor microenvironment (TME). Thus, new tools known as tumor-on-a-chip and metastasis-on-a-chip have been recently proposed. These tools incorporate microfluidic systems and small culture chambers where TME can be faithfully modeled thanks to 3D bioprinting. In this work, a literature review has been developed about the different phases of metastasis, the remaining unknowns and the use of new models to study this disease. The aim is to provide a global vision of the current panorama and the great potential that these systems have for in vitro translational research on the molecular basis of the pathology. In addition, these models will allow progress toward a personalized medicine, generating chips from patient samples that mimic the original tumor and the metastatic process to perform a precise pharmacological screening by establishing the most appropriate treatment protocol.Ministerio de Educacion y Formacion Profesional FPU19/02138 BOE-B-2019-44783Ph.D. program of Biomedicine of the University of GranadaConsejeria de Economia, Conocimiento, Empresas y Universidad, Junta de Andalucia (FEDER Funds) P18-FR-2470 B-CTS-230-UGR18 SOMM17/6109/UGRInstituto de Salud Carlos III (FEDER Funds) PIE16-00045 DTS19/00145Junta de Andalucia PIN-0224-2019Chair "Doctors Galera-Requena in cancer stem cell research" CMC-CTS96

    Veterinarski obilazak mliječnih farmi s povećanim brojem somatskih stanica i bakterija iznad zakonom dozvoljenih vrijednosti

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    The EU Directives 92/46 and 92/47 (D.P.R. 54/97 under national legislation) fix the agreed levels of somatic cell counts and total bacterial counts allowed in milk. Over a one year period, a total of 165farms which did not comply with one or more such legal requirements were visited and monitored. This was in order to check and, where necessary, correct the hygienic and sanitary management of the farm. A comparison of the bulk tank milk somatic cell count (BTMSCC) before and after the veterinary visit, shows improvements in all the farms which were tested. In a relatively short time, visited dairy farms with a somatic cell content between 401.000 and 500.000 cells/ml managed to comply with the parameters set down by law, achieving a mean of 304.000 cells/ml. However, those farms with a somatic cell counts between 501.000 and 800.000 cells/ml required further technical action. In fact, despite considerable improvements (mean somatic cell count decreasing from 638.000 cells/ml to 403.000 cells/ml), it was not possible to meet the required levels so rapidly. On these farms, a second veterinary visit was needed as well as more specific milk sampling for bacteriological assay and therapeutic guidelines in order to meet the specified requirements.Smjernicama 92/46. i 92/47. (D.P.R. 54/97). Europska unija je utvrdila maksimalno dozvoljene vrijednosti ukupnog broja bakterija i somatskih stanica u mlijeku. Unutar godine dana posjećeno je 165 farmi koje nisu zadovoljavale svim uvjetima. Posjet je obavljen s ciljem da se snimi postojeća situacija, i, ukoliko je neophodno, da se provedu adekvatne korekcije u higijenskom i sanitarnom vođenju farmi. Usporedbom broja somatskih stanica (BTMSCC) u dobavnim tankovima za mlijeko, prije i poslije veterinarske posjete, uočena su poboljšanja na svim ispitanim farmama. Ispitane mliječne farme s brojem somatskih stanica između 401000 i 500.000 stanica/mL u relativno kratkom vremenu uspjele su smanjiti taj broj na prosječnih 304.000 stanica/mL, što udovoljava propisanim vrijednostima. Međutim, na farmama s brojem somatskih stanica između 501.000 i 800.000 Stanica/mL potrebno je provesti dodatne tehničke mjere. Usprkos značajnom poboljšanju (prosječni broj somatskih stanica smanjene je sa 638.000 stanica/mL na 403.000 stanica/mL), nisu dobivene vrijednosti unutar zakonski propisanih. Ovim farmama bio je potreban dodatni veterinarski posjet kao i specifično bakteriološko ispitivanje te terapeutski naputci s ciljem da se postigne usuglašenost sa specifičnim zahtjevima

    O QUE É FILOSOFIA ECOLÓGICA?

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    Este breve texto esboça algumas ideias básicas da Filosofia Ecológica, enfatizando a importância e o valor de tais idéias para o estudo da mente e da consciência. Estas considerações levam à formação de uma abordagem ecológica, e o que, aqui, denomino Filosofia Ecológica. Em particular, a Filosofia Ecológica oferece uma saída às confusões e contradições que são comuns ao pensamento acadêmico dominante no que se refere à mente e à consciência
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