891 resultados para Imposition (Printing)


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In this report, we describe the microfabrication and integration of planar electrodes for contactless conductivity detection on polyester-toner (PT) electrophoresis microchips using toner masks. Planar electrodes were fabricated by three simple steps: (i) drawing and laser-printing the electrode geometry on polyester films, (ii) sputtering deposition onto substrates, and (iii) removal of toner layer by a lift-off process. The polyester film with anchored electrodes was integrated to PT electrophoresis microchannels by lamination at 120 degrees C in less than 1 min. The electrodes were designed in an antiparallel configuration with 750 mu m width and 750 gm gap between them. The best results were recorded with a frequency of 400 kHz and 10 V-PP using a sinusoidal wave. The analytical performance of the proposed microchip was evaluated by electrophoretic separation of potassium, sodium and lithium in 150 mu m wide x 6 mu m deep microchannels. Under an electric field of 250 V/cm the analytes were successfully separated in less than 90 s with efficiencies ranging from 7000 to 13 000 plates. The detection limits (S/N = 3) found for K+, Na+, and Li+ were 3.1, 4.3, and 7.2 mu mol/L, respectively. Besides the low-cost and instrumental simplicity, the integrated PT chip eliminates the problem of manual alignment and gluing of the electrodes, permitting more robustness and better reproducibility, therefore, more suitable for mass production of electrophoresis microchips.

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A variety of substrates have been used for fabrication of microchips for DNA extraction, PCR amplification, and DNA fragment separation, including the more conventional glass and silicon as well as alternative polymer-based materials. Polyester represents one such polymer, and the laser-printing of toner onto polyester films has been shown to be effective for generating polyester-toner (PeT) microfluidic devices with channel depths on the order of tens of micrometers. Here, we describe a novel and simple process that allows for the production of multilayer, high aspect-ratio PeT microdevices with substantially larger channel depths. This innovative process utilizes a CO(2) laser to create the microchannel in polyester sheets containing a uniform layer of printed toner, and multilayer devices can easily be constructed by sandwiching the channel layer between uncoated cover sheets of polyester containing precut access holes. The process allows the fabrication of deep channels, with similar to 270 mu m, and we demonstrate the effectiveness of multilayer PeT microchips for dynamic solid phase extraction (dSPE) and PCR amplification. With the former, we found that (i) more than 65% of DNA from 0.6 mu L of blood was recovered, (ii) the resultant DNA was concentrated to greater than 3 ng/mu L., (which was better than other chip-based extraction methods), and (iii) the DNA recovered was compatible with downstream microchip-based PCR amplification. Illustrative of the compatibility of PeT microchips with the PCR process, the successful amplification of a 520 bp fragment of lambda-phage DNA in a conventional thermocycler is shown. The ability to handle the diverse chemistries associated with DNA purification and extraction is a testimony to the potential utility of PeT microchips beyond separations and presents a promising new disposable platform for genetic analysis that is low cost and easy to fabricate.

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This paper compares the analytical performance of microchannels fabricated in PDMS, glass, and polyester-toner for electrophoretic separations. Glass and PDMS chips were fabricated using well-established photolithographic and replica-molding procedures, respectively. PDMS channels were sealed against three different types of materials: native PDMS, plasma-oxidized PDMS, and glass. Polyester-toner chips were micromachined by a direct-printing process using an office laser printer. All microchannels were fabricated with similar dimensions according to the limitations of the direct-printing process (width/depth 150 mu m/12 mu m). LIF was employed for detection to rule out any losses in separation efficiency due to the detector configuration. Two fluorescent dyes, coumarin and fluorescein, were used as model analytes. Devices were evaluated for the following parameters related to electrophoretic separations: EOF, heat dissipation, injection reproducibility, separation efficiency, and adsorption to channel wall.

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In this photo, members of the Stripping Class in the Lithography Department of the New York Trade School are shown at work. Original caption reads, "Members of the Stripping Class. Equipment loaned by the United States Printing & Litho. Company and Local #1." Black and white photograph.

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This project was performed at Rochester Institute of Technology to get more understanding and knowledge about AM and FM screenings similarities and differences with considerations of the mottle. By designing a test form conformed to the specific measurements and printing it on Heidelberg's Sunday 2000 press, the project group has evaluated the questions that already existed and the ones that occurred during the project. Hence the first press run left some unexpected phenomenon therefore another press run was performed. Measurements were performed and graphs produced in Excel. The project group evaluated the results and from that able to establish facts and draw conclusions. It has been a great experience for the project group and they have learnt a lot.

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This degree project illustrates newsprint and waterless offset. A new news press was introduced at Drupa-00, Cortina from KBA, which is the first news press dedicated the waterless technique. With actual statistics from the company in question an investigation was made whether their production fits this press. It came out in the investigation that the production of the company, from statistics, fits this press very good. A table was made where different timeschedules were accounted for the new press, with semi- and full automatic plate changing for present and to be added papers. The waterless technology is compared to conventional offset with the difference that the plate is based on a sort of laminatetechnology. Like conventional plates this plate has a base made of aluminium. Lightsensitive photopolymer isunited as a layer or coat on top of the aluminium and a 2µm thin oleophobic siliconlayer is applied on top of the photopolymer. Considering the print, the waterless method has a higher qualitygrade than conventional offset. No water is emulsifiedin the ink, and therefore the printed dot gets a higher density. The loss of dampening solution and higher tack of the ink gives sharper dots. This makes the colourspace bigger why a greater range of colours can be printed. The loss of dampening solution gives a more stable dotgain, which contributes to that a higher screen can be used. The disadvantage is that the plate can't do as many rotations as the conventional plate. A waterless plate makes around 100 000-500 000 rotations before it needs to be removed owing to type- and manufacturer of the plate. The plate is also slightly more sensitive and expensive than conventional plates, around 1,4 - 1,7 × aluminium printing plates. A waterless system can be installed in a conventional printing press by degrees and when large editions are being printed a cooler needs to be installed in the oscillationrollers of the press, since an increase in temperature can make the oleophobic parts of the plate oleophilic. The Cortina is however equipped with a temperature controlsystem at the beginning. To avoid picking, caused by the tacky ink, a blanket with a high “quick release” should be used.

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It always has been a need for the abiltiy to create color proofs. When an error occurs late in the production process, itis allways complicated and difficult to correct the error. In this project, digital proofs been made and discussions havebeen held with several people in the printing industry, in order to examine how well excisting digital proofs, meet thedemand of the market. And how close the digital proofs can come to the actual printsheat from the press. The study hasbeen shown that the one thing that has had the most influence on the outcome for the quality of a digital proof, is theprintshop operator’s knowledge about color management and proofing systems. Many advertising agencies in the graphicindustry think rasterised proofs are not necessesary and expensive. Therefor they prefer a cheaper alternative, whichdoesn’t show colors as well as the rasterised proof, but well enough to be content with it. There are a good awarenessconcerning lack of communication between printshop, reproduction and advertising agency. Advertising agencies thinkthat printshop rarely listen to what they have to say, while the printshop think that the advertising agency doesn’t understandwhat they are trying to tell them. The outcome of the printed proofs in this study can’t be representive for howgood digital proofs are conducted in regular basis in the industry. The divergence between the print press sheat and thedigital proof that was made was bigger than expected. This shows that implementation of ICC profiles in a color managementflow, not alone is the answer to making perfect digital proofs. There are so many other issues that has to be examined,like color management software, measure tools and correct color management module. In order to make a perfectproof, you have to look at the whole picture. In the end, the human eye finally has the last word on wheather theproof is good or not.

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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.

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If a plastic material is used as a print bearer there are a need of a special surface treatment to get agod and durable printing. The most used surface treatment technique for the moment is coronatreatment. This kind of treatment has unfortunately showed not to be so durable in the long term.Plasma treatment which in this case uses different kind of gases in the treatment of polypropyleneis shown as a more effective treatment in this project. When the plasma treated surface has beenprinted is the good quality last much longer and the adhesion between the ink and the surface isremained. To test this adhesion is for the moment a standard used (ASTM D3359). This standardhas appeared unstable and dependent at many different factors, which gives a big variation in thetest results. Because of this has new test methods been carried out to give a more even and morereliable result in the test of the adhesion.

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Customers put their printing suppliers to severe claims for shorter production time and faster deliveries.Printers always look for new solutions to increase the satisfaction of their customers. Oneexample of such a solution is web to print, where the customers book their printed matters atInternet.The solution involves design of printed matter by using templates that are made unique for thecustomer's printed matter. Web to print is suitable for reiterated printed matters. By using templatesthe customer doesn´t have to redo their layout for every new edition. Bromma tryck AB hasinvested the system CiPublisher, which is applied for the customer to make their printed matter atInternet.The purpose of the examination work is to investigate the needs of the customers of Brommatryck for a web to print solution and how such a system should be adapted.The result shows that the customer who is in need of a web to print solution wish such a system tobe easy managed and also usable. The customer inquiry also shows that most of the customers primarydesire for start using such a solution is that it will save time and also simplify the process formanufacturing of printing matters.

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This degree theme work aims to evaluate the present ICC-profile and printing ink of Dalarnas Tidningar AB. The companyhas changed printing ink quality and wants to evaluate how the present ICC-profile work with the new printingink. Four different ICC-profiles were included in the comparison.One test printing was accomplished with two different separations. Two new ICC-profile was created, as a comparingmaterial. An densitometer was used to measure the technical parameters of the printing. IT8-charts and RGB-chartswas measured with spectrophotometer. La*b*-values, CMYK-values, graybalance curves, color deflections and colorgamuts was compared on screen and on the printed material.Materials from an earlier testprinting and evalution, made by Stora Enso Kvarnsveden AB 2003, was used to evaluatethe function of Dalarnas Tidningar AB´s ICC-profile with the present printing ink quality. The IT8-chart from todaystestprinting was oppened in a program for textediting to have access to La*b*- and CMYK values. The values from theearlier testprinting was supplied from Stora Enso Kvarnsveden AB.The result of this work shows that the ICC-profile from the company, compared with de other profiles, reproduce darkershadow regions which can make loss of details. An higher saturation is recieved in the red and yellow area while thegreen and blue area lose its intensity. The profile gave images which are some contrastless and with a flat reproduction.Today printing ink quality gives more saturation and intensity in the yellow and blue area compared with former printingink. The dark tone reproduces with decreased luminance, however.

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An inquiring study of literature has been conducted, about the human colour perception (theimpression of colours). The colour has been examined, both as conscious and subconscious signal,and reasons for it’s influence have been exammed.The practical parts of the degree project have been carried out in active collaboration with thecustomer, The Association Hedemora Assistansservice (HASS), which offers handicapped persons astimulating spare time by personal assistance. A graphical profile-programme and an informationfolderhave been produced, easy received by both handicapped (with defective vision) and normallysighted persons. The graphical profile-programme was made in collaboration with the customer.Concerning the information-folder HASS took the main responsibility for the choice of photographswhile layout, text writing, colour-reproduction, original-production and connecting printing workswere made independently. The customer has shown engagement and interest and had a lot of opinionsabout the degree project, of which have been paid attention.

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This project has been made in cooperation with Stora Enso Research Centre Falun (Research). Thebackground of the project is that Research has customers who demand a method to measure the quantityof varnish online in offset printing. The aim with the project is to investigate if any test method correlateswith the quantity of varnish and to improve the understanding of the variables in the varnishingunit. The goal with the project is to develop a functional method. Two printing trials have beenperformed. The aim with the first trial was to investigate how different factors in the printer influencedthe quantity of varnish using reduced factoranalysis. The aim of the second trial was to analyse onlya reduced numbers of factors in the varnishing unit. The methods that were used to measure the varnishingquantity are weighing, IR-analysis, gloss, whiteness and brightness. Results from the projectshow that the weighing method does not work in this study due to basis weight variations of the sheets.The results from weighing did not agree with the results from the other methods. On the other handthere is a strong correation between the IR- and the glossmethods.