Flow boiling heat transfer capabilities of R134a low GWP substitutes inside a 4\ua0mm id horizontal smooth tube: R600a and R152a

R134a was recognized as probably one of the most important refrigerants of the two past decades. Among the proposed alternative fluids, there are certainly isobutane (R600a) and R152a.\ua0This article presents about 200 new heat transfer coefficient and pressure drop data obtained during flow boiling of R152a and R600a inside a smooth copper tube having an internal diameter of 4\ua0mm.\ua0Three saturation temperatures were considered for each refrigerant, from 5\ua0\ub0C to 20\ua0\ub0C. Furthermore, for each temperature studied, the heat flux was varied between 15 and 30\ua0kW\ua0m 122 and the refrigerant mass flux from 100 to 400\ua0kg\ua0m 122\ua0s 121. After presenting the new data, a critical comparison was proposed between the performance of these refrigerants and R134a. Finally, some classic correlations available in the literature have been implemented. The deviations between the calculated and experimental values were reported and commented

A corpus study of verbal multiword expressions in Brazilian Portuguese

Verbal multiword expressions (VMWEs) such as to make ends meet require special attention in NLP and linguistic research, and annotated corpora are valuable resources for studying them. Corpora annotated with VMWEs in several languages, including Brazilian Portuguese, were made freely available in the PARSEME shared task. The goal of this paper is to describe and analyze this corpus in terms of the characteristics of annotated VMWEs in Brazilian Portuguese. First, we summarize and exemplify the criteria used to annotate VMWEs. Then, we analyze their frequency, average length, discontinuities and variability. We further discuss challenging constructions and borderline cases. We believe that this analysis can improve the annotated corpus and its results can be used to develop systems for automatic VMWE identification

RNA aptamers specific for transmembrane p24 trafficking protein 6 and Clusterin for the targeted delivery of imaging reagents and RNA therapeutics to human β cells

The ability to detect and target β cells in vivo can substantially refine how diabetes is studied and treated. However, the lack of specific probes still hampers a precise characterization of human β cell mass and the delivery of therapeutics in clinical settings. Here, we report the identification of two RNA aptamers that specifically and selectively recognize mouse and human β cells. The putative targets of the two aptamers are transmembrane p24 trafficking protein 6 (TMED6) and clusterin (CLUS). When given systemically in immune deficient mice, these aptamers recognize the human islet graft producing a fluorescent signal proportional to the number of human islets transplanted. These aptamers cross-react with endogenous mouse β cells and allow monitoring the rejection of mouse islet allografts. Finally, once conjugated to saRNA specific for X-linked inhibitor of apoptosis (XIAP), they can efficiently transfect non-dissociated human islets, prevent early graft loss, and improve the efficacy of human islet transplantation in immunodeficient in mice

Zno thin films growth optimization for piezoelectric application

The piezoelectric response of ZnO thin films in heterostructure-based devices is strictly related to their structure and morphology. We optimize the fabrication of piezoelectric ZnO to reduce its surface roughness, improving the crystalline quality, taking into consideration the role of the metal electrode underneath. The role of thermal treatments, as well as sputtering gas composition, is investigated by means of atomic force microscopy and x-ray diffraction. The results show an optimal reduction in surface roughness and at the same time a good crystalline quality when 75% O2 is introduced in the sputtering gas and deposition is performed between room temperature and 573 K. Subsequent annealing at 773 K further improves the film quality. The introduction of Ti or Pt as bottom electrode maintains a good surface and crystalline quality. By means of piezoelectric force microscope, we prove a piezoelectric response of the film in accordance with the literature, in spite of the low ZnO thickness and the reduced grain size, with a unipolar orientation and homogenous displacement when deposited on Ti electrode

High-sensitivity optical humidity sensor based on a thin dielectric waveguide

A low-cost, high-sensitivity humidity sensor based on a low-loss dielectric thin film waveguide (WG) is presented. The guided mode is produced by coupling laser light into the film by optical tunneling through a solid gap deposited on the base of a semi-cylindrical lens. The light reflected from this optical system carries information about the refractive index of the medium neighboring the WG, and is detected by a low-cost CCD linear sensor and analyzed with a microcontroller or personal computer. The technique presents good sensitivity to relative humidity (RH) changes, especially below 10% RH, linear behavior between 20% and 80% RH, and a response time of a few seconds.FAPESPCNP

Alternativas para redução de cobre em caldas usadas no controle do míldio da videira.

bitstream/item/130797/1/Circular-Tecnica-119.pd

The spatial coverage of dairy cattle urine patches in an intensively grazed pasture system

Accurate field data on the paddock area affected by cow urine depositions are critical to the estimation and modelling of nitrogen (N) losses and N management in grazed pasture systems. A new technique using survey-grade global positioning system (GPS) technology was developed to precisely measure the paddock spatial area coverage, diversity and distribution of dairy cattle urine patches in grazed paddocks over time. A 4-year study was conducted on the Lincoln University Dairy Farm (LUDF), Canterbury, New Zealand, from 2003 to 2007. Twelve field plots, each 100m² in area, were established on typical grazing areas of the farm. All urine and dung deposits within the plots were visually identified, the pasture response area (radius) measured and position marked with survey-grade GPS. The plots were grazed as part of the normal grazing rotation of the farm and urine and dung deposits measured at 12-week intervals. The data were collated using spatial (GIS) software and an assessment of annual urine patch coverage and spatial distribution was made. Grazing intensities ranged from 17645 to 30295 cow grazing h/ha/yr. Mean annual areas of urine patches ranged from 0·34 to 0·40m² (4-year mean 0·37±0·009m²), with small but significant variation between years and seasons. Mean annual urine patch numbers were 6240±124 patches/ha/yr. The mean proportional area coverage for a single sampling event or season was 0·058 and the mean proportional annual urine patch coverage was 0·232±0·0071. There was a strong linear relationship between annual cow grazing h/ha and urine patch numbers/ha (R²=0·69) and also annual urine patch area coverage (R²=0·77). Within the stocking densities observed in this study, an annual increase of 10 000 cow grazing h/ha increased urine patch numbers by 1800 urine patches/ha/yr and annual urine patch area coverage by 0·07. This study presents new quantitative data on urine patch size, numbers and the spatial coverage of patches on a temporal basis

Real-Time Treatment Planning Optimisation for Brachytherapy

In this paper, we present an integrated system for real-time dose distribution calculation and treatment planning optimisation for brachytherapy of prostate cancer, with a special emphasis on the visual integration of the dosimetry and target images obtained from the open magnetic resonance system. This system involves a fast method to calculate dose distributions of multiple concurrent radioactive sources, based on the combination of elements from a database of pre-calculated dose distribution maps for single sources, combined linearly to provide the final dose distribution map. Simulated annealing, in conjunction with the inverse planning method, is used to determine the source dwell times at pre-selected locations in order to optimally irradiate thetumour while preserving the surrounding healthy tissues. This algorithm, implemented in FORTRAN, is integrated into a computer-assisted treatment planning tool, written in JAVA, using the runtime class and RMI API of Java. The whole system is now under clinical testing at the Geneva University Hospital