185 research outputs found
Polish device for FOCCoS/PFS slit system
The Fiber Optical Cable and Connector System, FOCCoS, for the Prime Focus
Spectrograph, PFS, is responsible for transporting light from the Subaru
Telescope focal plane to a set of four spectrographs. Each spectrograph will be
fed by a convex curved slit with 616 optical fibers organized in a linear
arrangement. The slit frontal surface is covered with a special dark composite,
made with refractory oxide, which is able to sustain its properties with
minimum quantities of abrasives during the polishing process; this stability is
obtained This stability is obtained by the detachment of the refractory oxide
nanoparticles, which then gently reinforce gently the polishing process and
increase its the efficiency. The surface roughness measured in several samples
after high performance polishing was about 0.01 microns. Furthermore, the time
for obtaining a polished surface with this quality is about 10 times less than
the time required for polishing a brass, glass or ceramic surface of the same
size. In this paper, we describe the procedure developed for high quality
polishing of this type of slit. The cylindrical polishing described here, uses
cylindrical concave metal bases on which glass paper is based. The polishing
process consists to use grid sequences of 30 microns, 12 microns, 9 microns, 5
microns, 3 microns, 1 micron and, finally, a colloidal silica on a chemical
cloth. To obtain the maximum throughput, the surface of the fibers should be
polished in such a way that they are optically flat and free from scratches.
The optical fibers are inspected with a microscope at all stages of the
polishing process to ensure high quality. The efficiency of the process may be
improved by using a cylindrical concave composite base as a substrate suitable
for diamond liquid solutions. Despite this process being completely by hand,
the final result shows a very high quality
Association between phase angle, anthropometric measurements, and lipid profile in HCV-infected patients
OBJECTIVE: The objective of this study was to investigate the associations between phase angle, anthropometric measurements, and lipid profile in patients chronically infected with the hepatitis C virus. METHODS: A total of 160 consecutive patients chronically infected with the hepatitis C virus and who received treatment at the hepatitis C outpatient unit of our hospital from April 2010 to May 2011 were prospectively evaluated. Bioelectrical impedance analysis, anthropometric measurements, and serum lipid profile analysis were performed. RESULTS: Twenty-five patients were excluded. A total of 135 patients with a mean age of 49.8¡11.4 years were studied. Among these patients, 60% were male. The phase angle and BMI means were 6.5¡0.8°and 26.5¡4.8 kg/ m2, respectively. Regarding anthropometric variables, mid-arm circumference, mid-arm muscle circumference, and arm muscle area had a positive correlation with phase angle. In contrast, when analyzing the lipid profile, only HDL was inversely correlated with phase angle. However, in multiple regression models adjusted for age and gender, only mid-arm circumference (p = 0.005), mid-arm muscle circumference (p = 0.003), and arm muscle circumference (p = 0.001) were associated with phase angle in hepatitis C virus-infected patients.CONCLUSIONS: In conclusion, phase angle is positively correlated with anthropometric measures in our study. However, there is no association between phase angle and lipid profile in these patients. Our results suggest that phase angle is related to lean body mass in patients chronically infected with hepatitis C virus
Multi-fibers connectors systems for FOCCoS-PFS-Subaru
The Fiber Optical Cable and Connector System (FOCCoS), provides optical
connection between 2400 positioners and a set of spectrographs through optical
fibers cables as part of PFS instrument for Subaru telescope. The optical fiber
cable will be segmented in 3 parts along the route, cable A, cable B and cable
C, connected by a set of multi-fiber connectors. The company USCONEC produces
the multi-fiber connector under study. The USCONEC 32F model can connect 32
optical fibers in a 4 x 8 matrix arrangement. The ferrules are made of a
durable composite, Polyphenylene Sulfide (PPS) based thermoplastic. The
connections are held in place by a push-on/pull-off latch, and the connector
can also be distinguished by a pair of metal guide pins that protrude from the
front of the connector. Two fibers per connector will be used for monitoring
the connection procedure. It was found to be easy to polish and it is small
enough to be mounted in groups. Highly multiplexed instruments like PFS require
a fiber connector system that can deliver excellent optical performance and
reliability. PFS requires two different types of structures to organize the
connectors. The Tower Connector system, with 80 multi-fiber connectors, will be
a group of connectors for connecting cable B (Telescope Structure) with cable C
(Positioners Plate). The Gang Connector system is a group of 8 gang connectors,
each one with 12 multi-fibers connectors, for connecting cable B (Telescope
Structure) with cable A (Spectrograph). The bench tests with these connector
systems and the chosen fibers should measure the throughput of light and the
stability after many connections and disconnections. In this paper we describe
tests and procedures to evaluate the throughput and FRD increment. The lifetime
of the ferrules is also in evaluation
Slit device for FOCCoS, PFS, Subaru
The Fiber Optical Cable and Connector System, FOCCoS, subsystem of the Prime
Focus Spectrograph, PFS, for Subaru telescope, is responsible to feed four
spectrographs with a set of optical fibers cables. The light injection for each
spectrograph is assured by a convex curved slit with a linear array of 616
optical fibers. In this paper we present a design of a slit that ensures the
right direction of the fibers by using masks of micro holes. This kind of mask
is made by a technique called electroforming, which is able to produce a nickel
plate with holes in a linear sequence. The precision error is around 1micron in
the diameter and 1 micron in the positions of the holes. This nickel plate may
be produced with a thickness between 50 and 200 microns, so it may be very
flexible. This flexibility allows the mask to be bent into the shape necessary
for a curved slit. The concept requires two masks, which we call Front Mask,
and Rear Mask, separated by a gap that defines the thickness of the slit. The
pitch and the diameter of the holes define the linear geometry of the slit; the
curvature of each mask defines the angular geometry of the slit. Obviously,
this assembly must be mounted inside a structure rigid and strong enough to be
supported inside the spectrograph. This structure must have a CTE optimized to
avoid displacement of the fibers or increased FRD of the fibers when the device
is submitted to temperatures around 3 degrees Celsius, the temperature of
operation of the spectrograph. We have produced two models. Both are mounted
inside a very compact Invar case, and both have their front surfaces covered by
a dark composite, to reduce stray light. Furthermore, we have conducted
experiments with two different internal structures to minimize effects caused
by temperature gradients
Yield and quality of cherry tomato fruits in hydroponic cultivation
Because of the food and industrial importance of tomato, it holds great significance, and is one of the most produced species using the hydroponic cultivation systems. The objective of this study was to evaluate the effects of different concentrations of nutrient solution on the production and quality of cherry tomatoes (Lycopersicon esculentum ‘Samambaia’) grown in a hydroponic system in protected conditions. The experiment was conducted in pots filled with coconut fiber substrate using a randomized complete block design with four replications and six plants per plot. Five concentrations of nutrients were evaluated (50, 75, 100, 125, and 150% of the standard nutrient solution); the solutions produced the following electrical conductivities: 1.8, 2.0, 2.6, 3.4, and 3.9 dS m-1, respectively. At 90 days after transplanting, the tomato fruits were harvested, at which time the production variables and post-harvest quality of mature fruits were determined. The best production and post-harvest quality indexes of cherry tomatoes (‘Samambaia’) were found when using 111% of the standard nutrient solution, corresponding to the concentrations of 9.44, 2.44, 2.22, 6.44, 4.11, 2.44, and 2.78 mmolc L-1, of NO3-, NH4+, P, K, Ca, Mg, and S, respectively; and 66.6, 55.5, 14.4, 1.89, 0.56, and 0.44 mmolc L-1, of Fe, B, Mn, Zn, Cu, and Mo, respectively. Nutrient solutions with electrical conductivity above 2.89 dS m-1 severely reduced the fruit yield of cherry tomatoes
Social distancing measures to control the COVID-19 pandemic: potential impacts and challenges in Brazil.
The COVID-19 pandemic has challenged researchers and policy makers to identify public safety measures forpreventing the collapse of healthcare systems and reducingdeaths. This narrative review summarizes the available evidence on the impact of social distancing measures on the epidemic and discusses the implementation of these measures in Brazil. Articles on the effect of social distancing on COVID-19 were selected from the PubMed, medRXiv and bioRvix databases. Federal and state legislation was analyzed to summarize the strategies implemented in Brazil. Social distancing measures adopted by the population appear effective, particularly when implemented in conjunction with the isolation of cases and quarantining of contacts. Therefore, social distancing measures, and social protection policies to guarantee the sustainability of these measures, should be implemented. To control COVID-19 in Brazil, it is also crucial that epidemiological monitoring is strengthened at all three levels of the Brazilian National Health System (SUS). This includes evaluating and usingsupplementary indicators to monitor the progression of the pandemic and the effect of the control measures, increasing testing capacity, and making disaggregated notificationsand testing resultstransparentand broadly available
Otite externa e média em cães: revisão de literatura / External and media otitis in dogs: literature review
A orelha é considerada o órgão da audição e do equilíbrio, tendo a responsabilidade de manter o autocontrole, a direção da posição do corpo no espaço e a compreensão de ruídos e sons. Divide-se em ouvido externo, ouvido médio e ouvido interno, sendo o ouvido interno o órgão do equilíbrio. A otite é a inflamação do conduto auditivo podendo ser classificada em recorrente, crônica ou aguda de acordo com a evolução do quadro. A otite externa é a patologia mais encontrada no ouvido dos cães, sendo ocasionada por diversos fatores como fungos, parasitas e bactérias e 50% a 89% dos casos possui otite média associada. Os animais acometidos normalmente apresentam sinais clínicos como dor, meneios cefálicos, prurido e secreção, odor fétido, entre outros. Um diagnóstico bem feito é fundamental, pois medicamentos desnecessários ou incorretos podem gerar resistência farmacologia. Em casos de otites médias crônicas, reincidentes e/ou não responsivas aos tratamentos farmacológicos uma abordagem cirúrgica pode ser necessária. O objetivo do presente do trabalho foi revisar a literatura a cerca das principais causas de otite externa e média e as principais formas de tratamento, buscando maior entendimento sobre as otites em cães. O conhecimento atualizado por meio dos médicos veterinários é fundamental, instituindo-se uma correta e eficiente terapia os animais, diminuindo assim as resistências farmacológicas.
The Current Status of Prime Focus Instrument of Subaru Prime Focus Spectrograph
The Prime Focus Spectrograph (PFS) is a new optical/near-infrared multi-fiber
spectrograph design for the prime focus of the 8.2m Subaru telescope. PFS will
cover 1.3 degree diameter field with 2394 fibers to complement the imaging
capability of Hyper SuprimeCam (HSC). The prime focus unit of PFS called Prime
Focus Instrument (PFI) provides the interface with the top structure of Subaru
telescope and also accommodates the optical bench in which Cobra fiber
positioners are located. In addition, the acquisition and guiding cameras
(AGCs), the optical fiber positioner system, the cable wrapper, the fiducial
fibers, illuminator, and viewer, the field element, and the telemetry system
are located inside the PFI. The mechanical structure of the PFI was designed
with special care such that its deflections sufficiently match those of the
HSC's Wide Field Corrector (WFC) so the fibers will stay on targets over the
course of the observations within the required accuracy. In this report, the
latest status of PFI development will be given including the performance of PFI
components, the setup and performance of the integration and testing equipment.Comment: 9 pages, 8 figures, SPIE proceedin
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