Impresor offset en hoja.

Real Decreto 347, de 6 de marzo de 1998, por el que se establece el certificado de profesionalidad de la ocupación de impresor de offset en hoja. Acompañado de dos anexos, uno sobre el referente ocupacional que incluye los datos y denominación de la ocupación, familia profesional a la que pertenece, perfil y competencias profesionales, y el segundo sobre el referente formativo que incluye los contenidos teórico-prácticos, los módulos que lo componen y su duración, objetivos específicos y criterios de evaluación, además de los requisitos personales y materiales.

Eina per al desenvolupament de reflectors de conjunts òptics

Avui en dia, una bona il·luminació vial és molt important, tant per als conductors com per als vianants. Els fanals o conjunts òptics estan compostos per una font de llum que és la làmpada, el reflector i la carcassa que els protegeix. Trobar la forma exacta d’un reflector amb unes propietats òptiques en particular és de gran importància en el sector luminotècnic. En aquest projecte es vol dissenyar i desenvolupar una sistema capaç d’ajudar a obtenir el reflector adequat, un programari que permeti dissenyar un reflector a partir d’una boca qualsevol, i mitjançant una làmpada, capturar la intensitat de llum que el reflector projecta sobre al terra o una superfície del carrer. L’aplicació desenvolupada vol facilitar el procés de selecció d’un bon reflector als enginyers luminotècnics

spotlight europe #2012/04, June 2012: Can mobility offset unemployment?

Almost a quarter of the young people in the EU are unemployed. And once again it is the crisis-ridden states that have been hit hardest. But in other countries such as France, Sweden, and Luxembourg, younger members of the workforce, far more than their older counterparts, are also finding it difficult to get a job. Freedom of movement within the EU could help to provide them with new opportunities. All that is needed is the right kind of support.

spotlight europe #2012/04, Juni 2012: Mobil statt arbeitslos? = Can mobility offset unemployment?

No abstract.

Spatial offset of test field elements from surround elements affects the strength of motion aftereffects

Static movement aftereffects (MAEs) were measured after adaptation to vertical square-wave luminance gratings drifting horizontally within a central window in a surrounding stationary vertical grating. The relationship between the stationary test grating and the surround was manipulated by varying the alignment of the stationary stripes in the window and those in the surround, and the type of outline separating the window and the surround [no outline, black outline (invisible on black stripes), and red outline (visible throughout its length)]. Offsetting the stripes in the window significantly increased both the duration and ratings of the strength of MAEs. Manipulating the outline had no significant effect on either measure of MAE strength. In a second experiment, in which the stationary test fields alone were presented, participants judged how segregated the test field appeared from its surround. In contrast to the MAE measures, outline as well as offset contributed to judged segregation. In a third experiment, in which test-stripe offset wits systematically manipulated, segregation ratings rose with offset. However, MAE strength was greater at medium than at either small or large (180 degrees phase shift) offsets. The effects of these manipulations on the MAE are interpreted in terms of a spatial mechanism which integrates motion signals along collinear contours of the test field and surround, and so causes a reduction of motion contrast at the edges of the test field.

A study on the performance of the partial PIC CDMA detector in the presence of time offset errors

This paper investigates the effect of time offset errors on the partial parallel interference canceller (PIC) and compares the performance of it against that of the standard PIC. The BER performances of the standard and partial interference cancellers are simulated in a near far environment with varying time offset errors. These simulations indicate that whilst timing errors significantly affect the performance of both these schemes, they do not diminish the gains that are realised by the partial PIC over that of the standard PIC.

Correcting for local oscillator phase offset in a DVB-T compliant receiver under multipath conditions

In 1997, the UK implemented the worlds first commercial digital terrestrial television system. Under the ETS 300 744 standard, the chosen modulation method, COFDM, is assumed to be multipath resilient. Previous work has shown that this is not necessarily the case. It has been shown that the local oscillator required for demodulation from intermediate-frequency to baseband must be very accurate. This paper shows that under multipath conditions, standard methods for obtaining local oscillator phase lock may not be adequate. This paper demonstrates a set of algorithms designed for use with a simple local oscillator circuit which will allow correction for local oscillator phase offset to maintain a low bit error rate with multipath present.

The diet-body offset in human nitrogen isotopic values: a controlled dietary study

The ‘trophic level enrichment’ between diet and body results in an overall increase in nitrogen isotopic values as the food chain is ascended. Quantifying the diet–body Δ15N spacing has proved difficult, particularly for humans. The value is usually assumed to be +3-5‰ in the archaeological literature. We report here the first (to our knowledge) data from humans on isotopically known diets, comparing dietary intake and a body tissue sample, that of red blood cells. Samples were taken from 11 subjects on controlled diets for a 30-d period, where the controlled diets were designed to match each individual’s habitual diet, thus reducing problems with short-term changes in diet causing isotopic changes in the body pool. The Δ15Ndiet-RBC was measured as +3.5‰. Using measured offsets from other studies, we estimate the human Δ15Ndiet-keratin as +5.0-5.3‰, which is in good agreement with values derived from the two other studies using individual diet records. We also estimate a value for Δ15Ndiet-collagen of ≈6‰, again in combination with measured offsets from other studies. This value is larger than usually assumed in palaeodietary studies, which suggests that the proportion of animal protein in prehistoric human diet may have often been overestimated in isotopic studies of palaeodiet.

Offset Lithography

A group of students are shown working in the Offset Lithography Department at the New York Trade School. Several presses can be seen in the room. Black and white photograph.

Paper dimensional stability in sheet-fed offset printing : Papperets dimensionsstabilitet i en arkoffsetpress

In offset printing, dampening solution is used to create a good balance in the process. If too much water is transferred to the paper, the sheet can change its size between the printing units, due to water absorption, and cause a problem with the colour register. This phenomenon is usually referred to as fanout. In this degree project, an investigation was made to see if the paper dimensions changed through its way in the sheet-fed printing process. The instrument Luchs Register Measuring Systems (Lynx) was used, and a method for measuring if the paper changed its dimensions with this instrument, was developed. Paper qualities with three different grammages were used, 90, 130 and 250 gsm. This investigation showed that all paper qualities changed their size with widening in the gripper edge in the range of 10 - 70 µm and in the trailing edge the increase was 10 - 130 µm. The elongations of the papers were in the range of 10- 300 µm. The papers with lowest grammage changed more than the heavier. To see if the print had been affected of the widening and elongation, print quality parameters like relative contrast, dot gain and mottle were correlated with the Lynx data from the sheets. The group of papers that gave correlations were in 130 gsm. The sheets had visual doubling and the combined standard deviation from the Lynx marks K3, K5 and K21 correlated with dot gain. When the variations increased so did the dot gain and this indicates that the doubling was due to the widening. There was also a correlation between the standard deviation from K3 and Mottle. The sheets widened with an average of 30 µm in the gripper edge and since there probably were doubling due to widening it also affected the Mottle values. What the widening depends on is hard to tell. Since widening was so small, it could be due to water absorption, papers being ironed out or maybe the sheets have been flattened out. It probably needs a more detailed investigation to find out what causes the widening. Further investigations about how print quality is affected by the register accuracy of a printing machine should include a print form with measuring areas close to the Lynx marks. The measuring areas should contain fine hairlines, negative text printed with at least two colours and some pictures to evaluate together with standard measuring should give a good knowledge about the subject.

Print quality study of a laboratory offset press

PAPRO operates within the Forest Research company and their mission is to develop value-addingindustry solutions. At present there are no good ways for mills to easily test the printing quality on newsprintpaper. There is a great need for a fast way to do this on different paper qualities; with a laboratory-offset press this can be both a time and money saving method. At PAPRO Forest Research, NewZealand, a laboratory offset press has been developed and designed, during the past seven years, concerningthis issue. Earlier projects were made concerning the press, e.g. to establish the optimal settings.The mission with this project was to partly determine the present variability of the print quality andto evaluate if the fountain solution, distilled water and 2% Diol green concentrate, used at the momentmixed with different percentages of Isopropanol could decrease the variability and contribute to morestabile results. Throughout the whole project the print quality showed a high variation and was evenmore variable when the Isopropanol was added. All in all 50 print rounds times twelve printed paperstrips was carried out through the project divided into three parts. To analyse the print quality, amicroscope with an image capture camera has been used. Data from the taken images was analysedand inserted into charts to see the variations.The conclusions of the whole project are not satisfying because no final evaluations were possible tomake. Main conclusions are that the additive of Isopropanol to the ordinary fountain solution, used atpresent, only contributed to more unstable results of the print quality. And it seems to be difficult toget some stable results from the lab press as long as the room where it is placed is not fully conditionedas required for the process of offset printing. And the fact that the airbrush which applies theamount of fountain solution is also variable, as shown in earlier projects, which contributes to unstableresults as well. For further work more exact parameters as a conditioned room are required and thepossibility to further design the laboratory press to use waterless offset printing instead.

Introduktion till Certifierad Grafisk Produktion på Jernström Offset

The aim for this thesis was to develop a proposal of documentation, containing rules and procedures, which JernströmOffset needs to acquire the Certified Graphic Production certification. A fundamental part was to study the materialissued by Sveriges Grafiska Mediaförening, to clarify the requirements that must be met to obtain the certification. Therecommendations found in the CGP material must also be considered.Based on the requirements and recommendations of Certified Graphic Production, a mapping of the workflows atJernström Offset was performed. It was done by interviewing employees from different departments at the company,this to get a clear understanding of the operations carried out throughout the production flow and the final qualityfollow-up.During our reviewing process we found that a number of changes, in terms of working environment and practices,must be made at the company. As a result of this we propose some appropriate actions to be implemented.The documentation was finally written, through the requirements and recommendations of Certified GraphicProduction and then applied to Jernström Offset’s work procedures.

Accelerated aging of thick glass second surface silvered reflectors under sandstorm conditions

Concentrated solar power systems are expected to be sited in desert locations where the direct normal irradiation is above 1800 kWh/m2.year. These systems include large solar collector assemblies, which account for a significant share of the investment cost. Solarreflectors are the main components of these solar collector assemblies and dust/sand storms may affect their reflectance properties, either by soiling or by surface abrasion. While soiling can be reverted by cleaning, surface abrasion is a non reversible degradation.The aim of this project was to study the accelerated aging of second surface silvered thickglass solar reflectors under simulated sandstorm conditions and develop a multi-parametric model which relates the specular reflectance loss to dust/sand storm parameters: wind velocity, dust concentration and time of exposure. This project focused on the degradation caused by surface abrasion.Sandstorm conditions were simulated in a prototype environmental test chamber. Material samples (6cm x 6cm) were exposed to Arizona coarse test dust. The dust stream impactedthese material samples at a perpendicular angle. Both wind velocity and dust concentrationwere maintained at a stable level for each accelerated aging test. The total exposure time in the test chamber was limited to 1 hour. Each accelerated aging test was interrupted every 4 minutes to measure the specular reflectance of the material sample after cleaning.The accelerated aging test campaign had to be aborted prematurely due to a contamination of the dust concentration sensor. A robust multi-parametric degradation model could thus not be derived. The experimental data showed that the specular reflectance loss decreasedeither linearly or exponentially with exposure time, so that a degradation rate could be defined as a single modeling parameter. A correlation should be derived to relate this degradation rate to control parameters such as wind velocity and dust/sand concentration.The sandstorm chamber design would have to be updated before performing further accelerated aging test campaigns. The design upgrade should improve both the reliability of the test equipment and the repeatability of accelerated aging tests. An outdoor exposure test campaign should be launched in deserts to learn more about the intensity, frequencyand duration of dust/sand storms. This campaign would also serve to correlate the results of outdoor exposure tests with accelerated exposure tests in order to develop a robust service lifetime prediction model for different types of solar reflector materials.

Parabolic dish reflectors for solar applications approximated by simple surfaces

Two different concentrating mirrors have been constructed that resemble parabolic dish reflectors. Both mirrors are made of slightly curved strips of flat, bendable material. The strips of the most simplified mirror have only large-radius circles and straight lines as boundaries. The necessary equations for making the mirrors have been derived. Also a simple way to make a stiff, lightweight frame and support for the mirror strips has been developed. Models of the mirrors have been built and successfully used for cooking and baking.This report is an extended version of a paper to be published in Solar Energy that contains complete derivations of all mirror design equations.

The vinyl bromide optically pumped far infrared laser: New large offset emissions

We present the results of a study on vinyl bromide for the search for new far infrared (FIR) laser lines. As the pump source, we use a CW waveguide CO2 laser with a tunability of 290 MHz around each line in order to pump large offset vibrational transitions. As a consequence, we obtained 28 new FIR laser emissions; 24 of them have wavelengths greater than 500 mum and are, therefore, suitable to be used in high-field EPR spectroscopy, For each of the new lines, we give the wavelength, the offset of the pumping transition with respect to the center Frequency of the CO2 emission, the polarization relative to that of the pumping laser line, the operating pressure, and the relative intensity. We also present a catalog including data of all of the FIR laser lines observed from this molecule up to now.