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The purpose of this paper is to carry out a comprehensive experimental investigation into the role of screen and conductive carbon material formulation on line conductivity and printing capability in the screen printing process, to provide design knowledge and further understanding of the screen printing for printed carbon.

A full factorial experiment was carried out where six carbon materials were printed through ten screens to a polyester substrate under a set of standard conditions.

Material characterization showed that viscosity and the corresponding viscous and elastic material modulli increased with solids content and that the elastic properties at low shear are significant. The solids carbon content materials were unable to produce the minimum printable line features possible with the low carbon materials. Increasing the solids contents reduced the final cured line resistance, reduced the printed line width, increased the film thickness, increased the cross sectional area and reduced the material resistivity. Material resistivities were around 700 to 950 μΩcm were obtained in the printed lines.

Lower material resistivities were obtained with higher solids materials and it is postulated that the increased visco‐elastic nature of the solids content materials, play a role in determining the microscopic structure of the cured film through alignment of the carbon graphite platelets.

A dataset which allows material, screen and print characteristics has been created allowing process optimization and formulation development to be accelerated.

The work provides insight into the role of material properties and process settings on the electrical and physical characteristics of printed carbon.

THE Birmingham Induction on February 13th was in every way satisfactory to those who participated. A writer in our “Letters on Our Affairs” has given in brief the substance of the event. It fulfilled the anticipations we made in our last number: the attendance was really representative; and there was an agreeable meeting of many of Mr. Cashmore's older and younger contemporaries, as well as a large concourse of his neighbours, to share in the dignified ceremony in which Dr. Esdaile initiated the President into his office. We ventured last month to refer to the quality of the retiring President's occasional speeches. That at Birmingham was a masterpiece of apparently unstudied ceremonial speech‐making. No doubt it will be available elsewhere. Those who spoke—from the Lord Mayor, who chaired the meeting, to Mr. Duncan Gray, who returned thanks for the Lord Mayor's hospitality— rose to an occasion on which all was pleasant and unjarred by any slip or inharmonious note. It was a happy augury for the year to come.

The aims of this annual review of the literature were set out at some length in the first article in the series (Aslib Proceedings, vol. 5, no. 1, February 1953, pp. 27–39), but for the benefit of those who have not seen that paper, and also for others who might like to be reminded of the limitations of the series, it is proposed to recapitulate briefly the main points. This series is intended to assist those who need some guidance in selecting from the mass of literature now being published on librarianship and documentation those items most likely to be of assistance in planning and organizing their own work. It is particularly designed for the relatively inexperienced worker, whether special librarian or information officer, working in a small organization without the assistance of more experienced colleagues. Consequently, all theoretical discussions, however important, have been ignored unless it has been felt that they can be of practical assistance in solving day‐to‐day library problems, and descriptions of the practice of large general libraries have been omitted unless it appears that they are capable of adaptation to other conditions. Moreover, since the series is not intended to be used as a bibliographical tool (this purpose being adequately served by existing bibliographies) but as a guide to current reading, no attempt has been made to restrict the list to work actually published during the year under review, but it is hoped that the list is representative of items likely to have been received in British libraries during 1953. Every endeavour has been made, however, to see that the articles in the series shall between them cover the whole of the literature adequately and that no important items are missed.

The purpose of this paper is to optimize the key parameters (mesh count, paper type and ink type) in screen printing, which are affecting the printed ink volume. The objective of the optimization was to maximize the color reliability by decreasing the color difference (ΔE value) of the prints while minimizing the ink consumption. Screen printing is still dominating the printing industry to make cost-effective production when high volumes are needed.

The experiment was designed using the Taguchi method, and the samples were prepared with screen-printing by using the standard squeegee angle and pressure. The effect of mesh count, ink type and paper type on ink consumption was evaluated with using analysis of variances and main effects plots of S/N ratio and standard deviation.

The factors ink type, paper type and mesh count were found significant for ink consumption due to their Probability (P) values which were lower than 0.05. It was determined that the mesh count was the most critical variable with the analysis of variance. The analysis showed that the selection of an optimum mesh count was the key to controlling the amount of the deposited ink. Although mesh counts were inversely proportional with the ink consumptions, they did not affect the color differences as expected.

The optimization of process parameters, that are most effective on the print quality, is necessary to minimize the ink usage and lower the costs and environmental impact without exceeding the desired ΔE value limits.

The resistivity of cured conductive ink films are dependent on a wide range of process parameters. An early indication of the resistivity that is likely to result following curing can enable these parameters to be optimised and, therefore, improve product quality. This paper aims to report on the use of alternating current (AC) impedance measurement techniques on curing printed ink films as a means of assessing the resistivity likely to be attained following the curing process.

Impedance measurements (100 Hz-10 MHz) were performed on curing conductive carbon ink films printed on polyethylene terephthalate substrates during convective heat curing. A jig was designed to incorporate the test structure in an convection oven such that the effect of cure on the structure impedance could be investigated.

The initial impedance was found to decrease with an increase in the measurement frequency. As the ink films were cured, the impedance magnitude across the 100 Hz-10 MHz range converged with the direct current (DC) resistance value. For a given ink, the ratio of initial AC impedance at 10 MHz to final cured resistance was found to be consistent, thus giving a method where final conductivity can be estimated before cure.

Data from printed ink resistance measurements are required to ensure the optimal conductivity of printed devices. However, after the printed structures are fabricated and cured, it is too late to optimise process parameters, leading to significant wastage. AC impedance measurement can give an indication of the final cured resistivity whilst the structure is freshly printed and still in its curing phase, enabling the printing process parameters to be adjusted to improve the resistivity of subsequently printed devices. Measuring AC impedance of printed ink structures in a production environment can, therefore, improve output.

Printed flexible circuits that combined conventional silicon technology will enable the realisation of many value added products such as smart packaging for the fast moving consumer goods (FMCG) industry. This paper aims to describe an investigation into integrating silicon and printable circuits for the FMCG packaging industry and this would allow products with features such as brand protection, time temperature indicators, customer feedback and visual product enhancement. Responding to interest from the FMCG packaging industry, an investigation was carried out which investigated the printing conductive silver ink on common packaging substrates.

Standard IC mounting patterns were screen printed using two conductive silver materials (one high silver content traditional paste and one lower silver content gel polymer) to four plastic and three paper substrates which represent common FMCG substrates (HDPE, BOPP, PET and three paper substrates). Materials were characterised in terms of material rheology whereas prints were characterised through electrical performance and printed film topology.

There was a significant interaction between the substrate, silver ink formulation and the resultant line quality, line topology and conductivity. On paper substrates, the absorption of binder into the substrate resulted in denser silver packing and higher conductivity for the paste material. Higher conductivities were obtained on the substrates capable of withstanding higher curing temperatures. On the polymer substrates higher conductivity could be obtained by lower content silver materials due to the denser particle packing in the cured ink film as a result of its higher solvent/lower solids components.

Further work should examine the interactions for other printing processes commonly used in the FMCG industry such as rotogravure of flexography and should also examine nano particle materials. Further work should also address the mechanical adhesion of silicon logic on the substrates and bottlenecks in processing.

The lower silver content gel material potentially provides material cost reduction by a factor of between 4 and 7 for the same conductivity. The gel material also has potential for more uniform performance across all substrate types. Typically 3.1 Ω/cm resistance values are achieved on all substrates for 300 micron lines.

For those in the field of smart packaging the work has highlighted the interaction between silver materials and non PET/PEN substrates in flexible printed circuits. It has demonstrated the implications of rheology, substrate absorbency and materials processing temperature on circuit design. For those seeking printing process understanding it has provided further validation to support material transfer mechanisms in the screen printing process.

The chapter examines and challenges the assumed necessity of a linkage between remembered series of exchanges, amicable social relations, and prestige found in the work of Marcel Mauss and many subsequent theorists of reciprocity and gift exchange.

The chapter uses the nearly 500 year history of the giving and taking of the Koh-i-noor Diamond by rulers of South and Central Asia, commencing with Babur, the first Mughal emperor, and ending with Queen Victoria, which includes some gift giving and much taking by force, to explore what happens when only two of the three elements Mauss assumed central to understanding gift exchange are present.

Based on a review of the historical material, the chapter demonstrates that though historical narratives or memories of exchanges were central to enhancing the prestige of the parties to the exchange and the diamond itself, that process could and did occur in the absence of any on-going amicable social relations, including in situations in which exchange or transfer of the diamond were coerced and nothing was given in return to the dispossessed former owner of the gem.

By suggesting an alternative configuration of the factors necessary for the association of exchange and prestige, the chapter provides the opportunity to reconsider assumptions common in the literature on gift exchange and further enhance our understanding of this central element of social theory.

We show how to use a smoothed empirical likelihood approach to conduct efficient semiparametric inference in models characterized as conditional moment equalities when data are collected by variable probability sampling. Results from a simulation experiment suggest that the smoothed empirical likelihood based estimator can estimate the model parameters very well in small to moderately sized stratified samples.

In this paper, we review the literature on pay variation (e.g., pay dispersion, pay compression, pay range) in organizations. Pay variation research has increased markedly in the past two decades and much progress has been made in terms of understanding its consequences for individual, team, and organizational outcomes. Our review of this research exposes several levels-related assumptions that have limited theoretical and empirical progress. We isolate the issues that deserve attention, develop an illustrative multilevel model, and offer a number of testable propositions to guide future research on pay structures.