Stand-up preaching: Homiletical insights from contemporary comedians

Stand-Up Preaching, as per the subject line, promises homiletic insights from contemporary comedians. I must admit that Myers engages with contemporary comedians and the theory of comedy, as far as I can discern, in the most thorough manner possible in a single book. The list of comedians he contemplates is exceptionally comprehensive, and it seems that every well-known comedian who has set foot on American soil has at least been mentioned. I found myself, throughout the book, researching the comedians he introduced for further context on these personalities and backgrounds. In that respect, this is a brilliantly researched work by Myers

Prophets at loggerheads. Accusations of adultery in Jeremiah 23:9-15

The focus of this article is on one aspect of the raging conflict between the prophetic parties addressed in Jeremiah 23:9-15. In this section the aspect of disloyalty to Yahweh is raised as hampering factor for being a true prophet. The research investigates the relationship between doing evil (cf. words such as adultery and ungodly/profane conduct) and the effect on the land (cf curse on the land, the land mourns, pastures drying up – 23:10-11). The research also entertains the relation with the next set of verses (23:13-15) which explicitly mentions the worship of Baal, the vegetation god, as reason for the disloyalty. The false prophets, with their adulterous way of living, are part of a leadership that failed the people of Judah and Yahweh

Childhood vulnerabilities in South Africa: Some ethical perspectives

Read a review of Grobbelaar, J. & Jones, C. (Eds), (Stellenbosch, African Sun Media, Sun Press, 2020), 328pp. Price: R375 (hardcopy); R300 (e-book), ISBN:978-1-928480-94-5, e-ISBN: 978-1-928480-95-2. [email protected] / +27 21 201 007

Contemplating Allan Boesak’s fascination with preaching “Truth to power”

Preaching can rightly be called “foolishness”, an outdated form of communication and a feeble form of art. In democratic South Africa, preaching is certainly not assigned a place among the ranks of professions conveying “development”. Allan Boesak, however, has not been swayed by the excommunication of preaching since the dawn of democracy. In this article, I will contemplate Boesak’s fascination with preaching “Truth to power”. Boesak, as a son of liberation and Black theology, is known for aspiring to a new world through the biblical witness. In essence, preaching the biblical truths to power. Therefore, when academics contemplate the state of preaching and express concern with regards to how power operates in our society and faith communities, Boesak certainly has a contribution to make. I briefly examine how power operates in the South African society. Boesak’s publications and sermons are contemplated in the hope of uncovering his fascination with preaching truth to power. I conclude with some thoughts on how Boesak preaches truth to power for both the dismal state of preaching and how power operates in South Africa

Local Environment of Ferromagnetically Ordered Mn in Epitaxial InMnAs

The magnetic properties of the ferromagnetic semiconductor In0.98Mn0.02As were characterized by x-ray absorption spectroscopy and x-ray magnetic circular dichroism. The Mn exhibits an atomic-like L2,3 absorption spectrum that indicates that the 3d states are highly localized. In addition, a large dichroism at the Mn L2,3 edge was observed from 5-300 K at an applied field of 2T. A calculated spectrum assuming atomic Mn2+ yields the best agreement with the experimental InMnAs spectrum. A comparison of the dichroism spectra of MnAs and InMnAs show clear differences suggesting that the ferromagnetism observed in InMnAs is not due to hexagonal MnAs clusters. The temperature dependence of the dichroism indicates the presence of two ferromagnetic species, one with a transition temperature of 30 K and another with a transition temperature in excess of 300 K. The dichroism spectra are consistent with the assignment of the low temperature species to random substitutional Mn and the high temperature species to Mn near-neighbor pairs.Comment: 10 pages, 4 figures, accepted by Applied Physics Letter

Optical properties of Mn4+ ions in GaN:Mn codoped with Mg acceptors

The optical properties of Mn-Mg codoped epitaxial GaN were studied. Addition of Mg acceptors quenches the weak manganese-related photoluminescence (PL) band at 1.3 eV in GaN:Mn and a series of sharp PL peaks are observed at 1 eV in codoped epilayers. The change in PL spectra indicates that Mg addition stabilizes the Mn4+ charge state by decreasing the Fermi level. The 1 eV PL peaks are tentatively attributed to intra center transitions involving Mn4+ ions. Spin allowed 3d-shell 4T2-4T1 transitions and their phonon replicas are involved. The relative intensities of the sharp peaks are strongly dependent on the excitation wavelength, indicating the optically active Mn4+ centers involved in the separate peaks are different. The temperature dependence of the PL spectrum suggests the presence of at least three distinct Mn4+ complex centers.Comment: 14 pages, 3 figures, 1 table, accepted by Appl. Phys. Let

Imaging Pulsed Laser Deposition oxide growth by in-situ Atomic Force Microscopy

To visualize the topography of thin oxide films during growth, thereby enabling to study its growth behavior quasi real-time, we have designed and integrated an atomic force microscope (AFM) in a pulsed laser deposition (PLD) vacuum setup. The AFM scanner and PLD target are integrated in a single support frame, combined with a fast sample transfer method, such that in-situ microscopy can be utilized after subsequent deposition pulses. The in-situ microscope can be operated from room temperature (RT) up to 700$^\circ$C and at (process) pressures ranging from the vacuum base pressure of 10$^{-6}$ mbar up to 1 mbar, typical PLD conditions for the growth of oxide films. The performance of this instrument is demonstrated by resolving unit cell height surface steps and surface topography under typical oxide PLD growth conditions.Comment: 8 pages, 8 figure

Determining the energetics of vicinal perovskite oxide surfaces

The energetics of vicinal SrTiO$_3$(001) and DyScO$_3$(110), prototypical perovskite vicinal surfaces, has been studied using topographic atomic force microscopy imaging. The kink formation and strain relaxation energies are extracted from a statistical analysis of the step meandering. Both perovskite surfaces have very similar kink formation energies and exhibit a similar triangular step undulation. Our experiments suggest that the energetics of perovskite oxide surfaces is mainly governed by the local oxygen coordination.Comment: 16 pages, 4 figure

A novel framework for parameter selection of the Autocorrelation Change detection method using 250m MODIS time-series data in the Gauteng province of South Africa

Human settlement expansion is one of the most prominent types of land cover change in South Africa. These changes typically occur in areas that are covered by natural vegetation. Methods that can rapidly indicate areas having a high probability of change are very valuable to analysts as this can be used to direct their attention to high probability change areas for further evaluation. MODIS time-series data (8-daily composite) at a resolution of 500 m has been proven to be an effective data source for detecting human settlements in South Africa and it was proposed in Kleynhans et al., 2012 that a Temporal Autocorrelation Change detection method (TACD) be used to detect the formation of new settlements in the Gauteng province of South Africa. In this paper, the TACD that was proposed by Kleynhans et al., 2012 is adapted to be usable with variable sampled temporal resolutions for 250m MODIS data by using a novel framework for parameter selection. The proposed method is applied to variably sampled 250m MODIS time-series data ranging from daily to semi-annually and a comparison of change detection accuracy vs. false alarm rate is done in each instance. Key results indicate that there is little difference in performance between daily sampled and 2-monthly sampled 250m MODIS time-series data for the use case evaluated in this paper