Inkjet printing of non-Newtonian fluids

Jet breakup is strongly affected by fluid rheology. In particular,small amounts of polymer can cause substantially different breakup dynamics compared to a Newtonian jet, influencing in-flight fragmentation and detachment from the nozzle. Significant concentrations may also impede jettability. Furthermore, most commercial and industrial inks are inherently colloidal due to the presence of pigment and other additives. Fluids containing a particulate phase are normally shear-thinning and so may have a different characteristic viscosity within the nozzle compared to the ejected ligament. We have developed numerical simulations using a Lagrangian finite element method that captures the free surface automatically, and admits a variety of viscosity dependences, e.g. on the local shear rate (generalized Newtonian fluid) or on the particle concentration (Krieger-Dougherty type models), in addition to several viscoelastic models for polymeric fluids. This method has been benchmarked against experimental data for Newtonian jets. Appropriate rheological models are discussed, and results are presented alongside comparisons with experimental work

Jetting behavior of polymer solutions in drop-on-demand inkjet printing

The jetting of dilute polymer solutions in drop-on-demand printing is investigated. A quantitative model is presented which predicts three different regimes of behaviour depending upon the jet Weissenberg number Wi and extensibility of the polymer molecules. In regime I (Wi L) the chains remain fully extended in the thinning ligament. The maximum polymer concentration at which a jet of a certain speed can be formed scales with molecular weight to the power of (1-3ν), (1-6ν) and -2ν in the three regimes respectively, where ν is the solvent quality coefficient. Experimental data obtained with solutions of mono-disperse polystyrene in diethyl phthalate with molecular weights between 24 - 488 kDa, previous numerical simulations of this system, and previously published data for this and another linear polymer in a variety of “good” solvents, all show good agreement with the scaling predictions of the model

Competition and interaction of polydisperse bubbles in polymer foams

The e®ects of interactions between bubbles of di®erent sizes during bubble growth in a polymeric foam are investigated. Two models are used: a two-dimensional sim-ulation in which both the e®ects of gas di®usion through the polymer and bubble interactions through °uid stresses are included, and a three-dimensional model in which bubbles are assumed to interact only through direct competition for gas, and di®usion of gas into the bubbles is instantaneous. In the two-dimensional model, two di®erent bubble sizes are used in a hexagonal array. For slow gas di®usion, the additional polymer stresses have little e®ect on the ¯nal bubble size distribution. For faster gas di®usion the growth occurs in two phases, just as was found in earlier work for isolated bubbles: an initial rapid viscous phase and a later phase controlled by the rate of polymer relaxation. In this later phase, polymers in the windows between neighbouring bubbles become highly stretched and these regions of high stress determine the dynamics of the growth. In the three-dimensional model we consider the e®ects of rheology on a pair of di®erent-sized spherical bubbles, interacting only through competition for available gas. Viscoelastic e®ects result in a wider distribution of bubble volumes than would be found for a Newtonian °uid. Key words: Polymeric °uid; bubble growth; foam; bubble interactions; size distribution ¤ To whom correspondence should be addressed

The Effects of Physical and Non-physical Investments of Government Expenditure in Education and Health Sectors on Human Development Index in Pekanbaru City

In this current globalization era, human resources investment is necessary for each country to improve the index of human development and economic growth, many countries have succeeded in economic growth by relying on human resources despite not having abundant natural resources. However, the success of resource investment is also strongly influenced by the availability of supporting facilities and infrastructure. Based on data of physical and non-physical investments of government expenditure in education and health sectors from 2007-2017, shows a positive trend with relatively increasing value. Meanwhile, based on data of human development index progress in Pekanbaru city in recent years showed a relatively declining value. This contradicts the theory of endogenous romer which explained that when the government or private sectors invest in human resources, it will encourage the improvement of human resources quality that reflects the progress of human development index. This study uses secondary data, namely government physical and non-physical expenditure data in the field of education and health in Pekanbaru City on Regional Budget in 2010-2017. The independent variable is government physical and non-physical expenditure in education and health sectors. While the dependent variable is the Human Development Index. The analysis method used is OLS (Ordinary Least Square) method where the data used are analyzed quantitatively using statistical analysis, namely multiple linear regression equations. Based on the results of research, government physical expenditure in education and government non-physical expenditure in the health sector does not significantly influence the human development index in Pekanbaru City. While government non-physical expenditure in education and government physical expenditure in health significantly affect the human development index in Pekanbaru City. Furthermore, for physical investment where in this research is the government physical expenditure in education and health sectors simultaneously has a significant effect on the human development index in Pekanbaru City. Whereas for non-physical investment where in this study is government non-physical expenditure in education and health sectors simultaneously has a significant effect on the human development index in Pekanbaru City

Evaluar la alfabetización científica en el programa de la OECD para la evaluación internacional de estudiantes (PISA)

Este trabajo se refiere a qué se está evaluando y por qué, en el Programme for International Student Assessment (PISA) conducido por la OECD. El trabajo se ocupa de las razones para el programa y considera la definición de alfabetización científica que subyace a los materiales de evaluación, cómo se pone ésta en acción en el enfoque y los materiales de evaluación, y la forma en que se difundirán los resultados.This presentation concerns what is being assessed, and why, in the OECD Programme for International Student Assessment (PISA). The paper deals with the reasons for the programme and considers the definition of scientific literacy which underpins the test materials, how it is played out in the test approach and the form in which the results are to be reported

Analisis Pertumbuhan Ekonomi terhadap Penyerapan Tenaga Kerja Dilihat dari Tingkat Pendidikan di Kabupaten Indragiri Hilir

The aim of this study include: provide an overview of inventory and laborrequirements as well as provide an overview of the economic opportunitiesavailable as the foundation to move development of strategic sectors.Research carried out in the region Indragiri Hilir. Analysis of the presentcondition and future employment through employment elasticity analysis methods. For the data used in the context of this study is data from BPS.Results of research conducted showed that the economy Indragiri Hilir in2012 grew by 7.47% and employment growth of 4.14%, with elasticity of 0.54. So that the number of job opportunities in the year 2012 as many as 304 792 people. While economic forecasts Indragiri Hilir in 2015 grew by 7.72% and employment growth of 4.87%, with employment elasticity of 0.5363. Estimated GDP at constant 2000 prices Indragiri Downstream of Rp. 10012.91 billion and employment opportunities created as many as 342 002 people

Pengaruh Sub Sektor Pariwisata Terhadap Pendapatan Asli Daerah (Pad) Kota Bukittinggi

This study aims to determine how the number of attractions, the number of tourists and hotel occupancy rates to Revenue (PAD) Bukittinggi. The methods used in data collection in this study is a literature study, obtained from related institutions, reverensi books, as well as economic journals. The data used in this research is quantitative data. In discussing this issue with the author using an analysis tool used is multiple linear analysis with SPSS version 21.0. The hypothesis can be made from this study are: Variable number of attractions, excursions, and hotel occupancy rates expected to have a positive relationship and a significant effect on local revenue (PAD) Bukittinggi.From the testing that has been done, simultaneous test (F test) showed that the number of variables and the number of tourist attractions and no significant positive effect on revenue (PAD) variable occupancy rates and significant positive effect on the variable revenue. Test partial regression (t test) showed that a variable number of attractions, the number of tourists and hotel occupancy rates positive and significant effect on the variable local revenues, is consistent with the hypothesis that has been proposed. The effect (R2) by these two independent variables together against the dependent variable was 97,1% while the remaining 2,9% is influenced by other variables outside variables that exist in this study

Morehead State University Speech Team & Individual Events Team History, 1923-1992

A history of the Forensic Program at Morehead State University from 1923 to 1992, written by Harlen Hamm in 1993.https://scholarworks.moreheadstate.edu/college_histories/1289/thumbnail.jp

Analisis Industri Kecil Unggulan Di Kota Pekanbaru

This research was conducted in the city of Pekanbaru with the object of research areas 12 districts in the city of Pekanbaru in the period 2008 to 2015. This study aims to determine the small industries be featured in a small industrial city of Pekanbaru and where small industries in Pekanbaru City spatially concentrated. This study uses secondary data, employment data is a small industrial branches every district in the city of Pekanbaru. The data were analyzed using descriptive analysis of quantitative analysis tool location quotient (LQ) and spatial concentration. The results of the research with the analysis of location quotient on employment show that in 2008 and 2015 small industries into a small industry featured in Pekanbaru City ie industrial branches of small craft in which branches of industry such craft is superior in District Tampan, District Bukit Raya, District Marpoyan Damai, Distric Tenayan Rayat, District Lima Puluh, District Sail, District Pekanbaru Kota, District Sukajadi, District Rumbai, and District Rumbai Pesisir. Based on the calculation of spatial concentration, a small industrial city of Pekanbaru concentrated in District Payung Sekaki on branch small industrial metals