A comparative study of two conductive inkjet inks for fabrication of RF circuit structures

Two commercially available silver inks were inkjet printed to fabricate the seed tracks (seed layers) of radio frequency (RF) circuit structures on a high frequency substrate material. One of them is a nanoparticle based ink, and the other, a non-particle based organic silver complex ink. Subsequent to printing, these seed layers were copper plated using an electroless copper plating process, to impart the desired thickness to the circuit structures. The inkjet printing-electroless plating process combination was validated with the example of an S-band filter and an RF transmission line. Prior to the fabrication of the circuit structures, the substrates were plasma treated, in order to modify their surface and promote mechanical interlocking with the printed structures.\ud Finally, experiments were conducted to determine the solderability\ud of inkjet printed as well as printed-plated structures. Conclusions on\ud the suitability of the two inks for RF circuit fabrication have been\ud drawn based on experimental results

Surface Modification of a PCB Substrate for Better Adhesion of Inkjet Printed Circuit Structures

The robustness and service life of inkjet printed electronic circuit structures are highly influenced by the state of the interface between these structures and the substrate. In the case of polymeric substrate materials, surface modification is necessary to realise a favourable interface, as these materials are generally not very receptive to chemical bond formation with the deposited ink. This paper deals with the surface modification of a high frequency laminate (substrate) using two different techniques to improve interfacial adhesion. The techniques deployed are CF4/O2 based plasma treatment and micro structuring using pulsed laser. The plasma treatment parameters were varied systematically using a statistical design of experiments. Substrates with varying surface characteristics, resulting from different plasma treatment parameters, were subjected to post-processing steps including surface energy and surface roughness measurements. Similarly, the influence of laser treatment parameters on surface characteristics of the substrate was also studied in detail. The outcomes of these two surface modification techniques are discussed in this paper

Caretta – A multiple protein structure alignment and feature extraction suite

The vast number of protein structures currently available opens exciting opportunities for machine learning on proteins, aimed at predicting and understanding functional properties. In particular, in combination with homology modelling, it is now possible to not only use sequence features as input for machine learning, but also structure features. However, in order to do so, robust multiple structure alignments are imperative. Here we present Caretta, a multiple structure alignment suite meant for homologous but sequentially divergent protein families which consistently returns accurate alignments with a higher coverage than current state-of-the-art tools. Caretta is available as a GUI and command-line application and additionally outputs an aligned structure feature matrix for a given set of input structures, which can readily be used in downstream steps for supervised or unsupervised machine learning. We show Caretta's performance on two benchmark datasets, and present an example application of Caretta in predicting the conformational state of cyclin-dependent kinases.</p

Adhesion Characterisation of Inkjet Printed Silver Tracks

Introduction: The ever-growing need for fast prototypes and reduced manufacturing throughput times in the electronics industry has lead to worldwide research aimed at developing novel techniques and process chains. Inkjet Printing is a versatile, flexible and relatively simple process that might fit the bill. It falls under Printed Electronics and is an additive fabrication technique. Typically, metal nanoparticle-based inks and polymer-based inks can be used in combination with inkjet printing to fabricate conducting tracks and circuit components (e. g. resistors, capacitors etc.), respectively

Higher Order Effects in the Dielectric Constant of Percolative Metal-Insulator Systems above the Critical Point

The dielectric constant of a conductor-insulator mixture shows a pronounced maximum above the critical volume concentration. Further experimental evidence is presented as well as a theoretical consideration based on a phenomenological equation. Explicit expressions are given for the position of the maximum in terms of scaling parameters and the (complex) conductances of the conductor and insulator. In order to fit some of the data, a volume fraction dependent expression for the conductivity of the more highly conductive component is introduced.Comment: 4 pages, Latex, 4 postscript (*.epsi) files submitted to Phys Rev.

Dataset of the phospholipidome and transcriptome of Campylobacter jejuni under different growth conditions

The membrane phospholipid composition is not a stable bacterial characteristic but can change in response to altered environmental conditions. Here we provide the dataset of the phospholipidome and transcriptome of the microaerophilic human pathogen Campylobacter jejuni under different environmental conditions. These data have been used in Cao (2020), The unique phospholipidome of the enteric pathogen C. jejuni: Lysolipids are required for motility at low oxygen availability. Here the abundance of each phospholipid is shown during the growth of C. jejuni for 0-108 h under low and high oxygen conditions (0.3 vs 10% O2). The phospholipid data were obtained by applying high performance liquid chromatography tandem-mass spectrometry (LC-MS/MS). The transcriptomic data obtained by RNA-seq show the differential expressed genes between logarithmic and stationary grown bacteria. In addition, our data might serve as a reference information for further in-depth investigation to understand the relation between specific phospholipids and the activity of membrane associated proteins

Senior manager competency profiling : the case of local government sector in the emerging country

Local, district, and metropolitan municipalities as spheres of government should deploy a highly competent and professional management corps to address complex integrated development planning demands, local service delivery issues, and various governance-related dynamics (Polo & Kantola, 2019). However, official oversight, performance reports, and media scrutiny regularly reveal that the current South African situation fails to meet these requirements. Corruption, maladministration, political factionalism, and managerial incompetence have led to violent public protests (SACN, 2016). This paper assesses the current competency profile of senior managers in the South African local government sector, focusing on their integrated development planning responsibilities. The methodology followed a qualitative design involving an intensive literature review on international management competency models, document analyses to assess official statutory and regulatory prescriptions for senior managers, and semi-structured interviews with senior managers in sampled municipalities. The study established that most challenges faced by municipalities stem from a lack of senior management competency. Recommendations are made to address the current competency deficit.http://www.virtusinterpress.org/-Journal-of-Governance-and-.htmlam2022School of Public Management and Administration (SPMA

The strategy to align road safety education to the Further Education and Training band curriculum

Road safety education is a complex phenomenon which should be viewed holistically if taken into account the interconnectedness of education, infrastructure and enforcement. Effective road safety education is specifically important for learners in the Further Education and Training (FET) band, as they are active contributors to a community. The greatest criticism against road safety education is that it is aimed at changing learners’ knowledge about the subject, but not necessarily influencing their attitudes as road users. The aim of this discussion article is to explore a strategy to integrate road safety education into the formal curriculum of specifically schools responsible for the FET band. By applying the desktop research method, the article conceptualises what the specific purpose of the FET band is and what the possible focus of road safety education and training should be. The article then explores international common practices in road safety education and training, and considers the necessary synergy between education, engineering and enforcement. The article uses secondary data collected from documents which are then thematically analysed. A coordinated and comprehensive education and training strategy is needed, facilitating partnerships in various sectors to implement such education in the FET band, in multidisciplinary ways, in a contextualised curriculum.http://www.tandfonline.com/loi/raer20hj2018School of Public Management and Administration (SPMA