Calvin in word and deed: A communicological appreciation

John Calvin’s views on the role of the preacher, as well as the manner in which he applied these views in practice, are examined by using a simplified linear model of communication. Firstly, Calvin’s view on the role of the preacher is examined – as expressed in the Institutes, his letters and commentaries. From a communication perspective, it is clear that, from what Calvin said, he thoroughly saw himself as a servant, relying on the Word of God – a servant who had to execute his assignment in obedience to what God (communicator in the model) expected from him as an instrument in His hands. Secondly, in addition to Calvin’s views on his role as a preacher, it was also established how he acted in some demanding situations. The consistency of his thinking was illustrated by comparing what he did to what he said. The examination revealed that Calvin’s action was to bring the Word. Calvin’s actions were therefore consistent with the views articulated in his writings. Thirdly, from his letters to persecuted followers, we can deduce Calvin’s views on the practical application of the ideas which he stated in the Institutes and other publications. The article concludes that, if measured against the simplified linear communication model, it can be assumed that Calvin saw himself as a communication medium or channel used by God to convey His message and not as a communicator following his own agenda

Bile peritonitis and miliary tuberculosis : A case report

ArticleThe original publication is available at http://www.samj.org.zaABSTRACT: We report an unusual case of bile peritonitis in a child. The literature on bile peritonitis is reviewed, and its treatment is discussed. According to the literature, bile peritonitis has a good prognosis provided operation is early. Patients in whom bile is septic at the time of surgery have an increased morbidity and a considerable mortality.Publishers' versio

Connectivity of consecutive-d digraphs

AbstractThe concept of consecutive-d digraph is proposed by Du, Hsu and Hwang. It generalizes the class of de Bruijin digraphs, the class of Imase-Itoh digraphs and the class of generalized de Bruijin graphs. We modify consecutive-d digraphs by connecting nodes with a loop into a circuit and deleting all loops. The result in this paper shows that the link-connectivity or the connectivity of modified consecutive-d digraphs get better

The production of reduced-alcohol wines using Gluzyme Mono® 10.000 BG-treated grape juice

High alcohol wines have become a major challenge in the international wine trade. Several physical processes areused to produce wines with reduced-alcohol content, all of which involve the selective extraction of ethanol basedon volatility or diffusion. In this study, the possibility of Gluzyme Mono® 10.000 BG (Gluzyme) (Novozymes, SouthAfrica) to reduce the glucose content of synthetic grape juice before fermentation was investigated in order to producewine with reduced-alcohol content. Gluzyme is a glucose oxidase preparation from Aspergillus oryzae, currently usedin the baking industry. Glucose oxidase catalyses the oxidation of glucose to gluconic acid and hydrogen peroxide(H2O2) in the presence of molecular oxygen. Gluzyme was initially used in synthetic grape juice, where differentenzyme concentrations and factors influencing its efficiency were investigated under winemaking conditions. Theresults showed up to 0.5% v/v less alcohol at an enzyme concentration of 20 kU compared to the control samples.This reduction in alcohol was increased to 1 and 1.3% v/v alcohol at pH 3.5 and pH 5.5 respectively in aerated (8mg/L O2) synthetic grape juice using 30 kU enzyme. Secondly, Gluzyme was used to treat Pinotage grape mustbefore fermentation. Gluzyme-treated wines at 30 kU enzyme concentration after fermentation contained 0.68%v/v less alcohol than the control wines. A decrease in acetic acid concentration of the treated compared to controlwines was also observed

Crush pillar support - designing for controlled pillar failure

The aim of any mine design is to ensure that the excavations remain stable for the period they will be in use. Various pillar systems are used to ensure that underground stopes remain stable and that mining activities do not affect the surface infrastructure through either surface subsidence or seismicity. Intermediate-depth platinum mines make use of in-stope pillars designed to fail while the pillars are being cut at the mining face. The pillar stress exceeds the loading capacity and the pillars crush as a result. The aim of the paper is to provide an overview of in-stope crush pillars. This will include the application, behaviour, function, mechanism, impact, and design of a crush pillar system.This paper was first presented at the, Platinum Conference 2014, 20–24 October 2014, Sun City South Africa.The work described in this paper forms part of the PhD study of Michael du Plessis at the University of Pretoria.http://www.saimm.co.za/journal-papersam201

Investigating the use of polymer-modified cementitious thin spray-on liners as stope face support

This paper investigates the use of a thin spray-on liner (TSL) as stope face support in narrow width tabular stopes. The application of areal support is difficult in these stopes because of the small stoping width and the large area of hanging wall that is exposed by the long face lengths and regular blasting. A simple analytical model of a collapsing block supported by a TSL is explored to determine the parameters to be considered for underground use of the liners. Most literature on TSL focusses mostly on specialised laboratory testing. Almost no large scale testing to determine TSL strengths, when it is applied to blocky rock masses, has been conducted. To simulate the discontinuous nature of the hanging wall in mining stopes, a large scale rig and test methodology was developed. Four different polymer-modified cementitious TSL products were tested and the results are described in the paper. For the particular experimental setup and a curing time of 24 h, the maximum load carrying capacity of the strongest TSL was 305 kg, while a 50 mm thick shotcrete had a capacity exceeding 1100 kg. The test results indicate that care should be exercised when attempting to use a TSL as a structural element in support systems.http://www.elsevier.com/locate/ijrmms2022-04-22hj2021Mining Engineerin

Evaluation of a limit equilibrium model to simulate crush pillar behaviour

This paper describes the evaluation of a limit equilibrium model to simulate the behaviour of crush pillars in platinum mines. An analytical model was derived to calculate the residual average pillar stress (APS) values of the crush pillars. The values predicted by this model were compared to the numerical values obtained from TEXAN simulations. In general, the limit equilibrium model appears to be very attractive for simulating pillar failure as the gradual crushing of the outside of the pillar and the transfer of stress to the intact core can be replicated. The value of the TEXAN crush pillar model was further demonstrated by simulating an idealized layout with crush pillars between two adjacent panels. The simulations illustrated that oversized pillars will not crush close to the face and this may lead to seismic failure in the back area. An important finding of the study is that closure measurements may prove to be a very valuable diagnostic measure in crush pillars layouts. Distinct differences in magnitudes of closure were simulated for a scenario where the pillars crush as expected, compared to the scenario where an oversized pillar is left. Experimental closure data collected in a crush pillar stope provided further evidence regarding the value of closure measurements in these layouts.This work forms part of the PhD study of Mr M. du Plessis at the University of Pretoria.http://www.saimm.co.za/ai201

Three-dimensional random Voronoi tessellations: From cubic crystal lattices to Poisson point processes

We perturb the SC, BCC, and FCC crystal structures with a spatial Gaussian noise whose adimensional strength is controlled by the parameter a, and analyze the topological and metrical properties of the resulting Voronoi Tessellations (VT). The topological properties of the VT of the SC and FCC crystals are unstable with respect to the introduction of noise, because the corresponding polyhedra are geometrically degenerate, whereas the tessellation of the BCC crystal is topologically stable even against noise of small but finite intensity. For weak noise, the mean area of the perturbed BCC and FCC crystals VT increases quadratically with a. In the case of perturbed SCC crystals, there is an optimal amount of noise that minimizes the mean area of the cells. Already for a moderate noise (a>0.5), the properties of the three perturbed VT are indistinguishable, and for intense noise (a>2), results converge to the Poisson-VT limit. Notably, 2-parameter gamma distributions are an excellent model for the empirical of of all considered properties. The VT of the perturbed BCC and FCC structures are local maxima for the isoperimetric quotient, which measures the degre of sphericity of the cells, among space filling VT. In the BCC case, this suggests a weaker form of the recentluy disproved Kelvin conjecture. Due to the fluctuations of the shape of the cells, anomalous scalings with exponents >3/2 is observed between the area and the volumes of the cells, and, except for the FCC case, also for a->0. In the Poisson-VT limit, the exponent is about 1.67. As the number of faces is positively correlated with the sphericity of the cells, the anomalous scaling is heavily reduced when we perform powerlaw fits separately on cells with a specific number of faces

Introduction to the functional RG and applications to gauge theories

These lectures contain an introduction to modern renormalization group (RG) methods as well as functional RG approaches to gauge theories. In the first lecture, the functional renormalization group is introduced with a focus on the flow equation for the effective average action. The second lecture is devoted to a discussion of flow equations and symmetries in general, and flow equations and gauge symmetries in particular. The third lecture deals with the flow equation in the background formalism which is particularly convenient for analytical computations of truncated flows. The fourth lecture concentrates on the transition from microscopic to macroscopic degrees of freedom; even though this is discussed here in the language and the context of QCD, the developed formalism is much more general and will be useful also for other systems.Comment: 60 pages, 14 figures, Lectures held at the 2006 ECT* School "Renormalization Group and Effective Field Theory Approaches to Many-Body Systems", Trento, Ital