Industry Structure and Labour Market Flexibility in the South African Manufacturing Sector: A Time Series and Panel Data Approach

Our investigation of industry structure in South African manufacturing reveals evidence of imperfect competition. We find an average mark-up of 50% for the period 1970 to 2004. Results suggest that there is no consistent trend in the mark-up over time. This paper extends the analysis of industry structure by linking it to labour market flexibility. We infer the proportion of labour cost that is fixed rather than flexible from the mark-up, and find that two thirds of total labour employed in South African manufacturing is devoted to fixed costs. We find that this proportion falls during the 1980s and rises during the 1990s, suggesting an increase in labour flexibility followed by a decrease.Mark-up, industry structure, labour market flexibility

Ray-optical negative refraction and pseudoscopic imaging with Dove-prism arrays

A sheet consisting of an array of small, aligned Dove prisms can locally (on the scale of the width of the prisms) invert one component of the ray direction. A sandwich of two such Dove-prism sheets that inverts both transverse components of the ray direction is a ray-optical approximation to the interface between two media with refractive indices +n and –n. We demonstrate the simulated imaging properties of such a Dove-prism-sheet sandwich, including a demonstration of pseudoscopic imaging

Classical world arising out of quantum physics under the restriction of coarse-grained measurements

Conceptually different from the decoherence program, we present a novel theoretical approach to macroscopic realism and classical physics within quantum theory. It focuses on the limits of observability of quantum effects of macroscopic objects, i.e., on the required precision of our measurement apparatuses such that quantum phenomena can still be observed. First, we demonstrate that for unrestricted measurement accuracy no classical description is possible for arbitrarily large systems. Then we show for a certain time evolution that under coarse-grained measurements not only macrorealism but even the classical Newtonian laws emerge out of the Schroedinger equation and the projection postulate.Comment: 4 pages, 1 figure, second revised and published versio

Electronic Structure of ZnCNi3

According to a recent report by Park et al, ZnCNi3 is isostructural and isovalent to the superconducting (Tc = 8 K) anti-perovskite, MgCNi3, but shows no indication of a superconducting transition down to 2K. A comparison of calculated electronic structures shows that the main features of MgCNi3, particularly the van Hove singularity near the Fermi energy, are preserved in ZnCNi3. Thus the reported lack of superconductivity in ZnCNi3 is not explainable in terms of Tc being driven to a very low value by a small Fermi level density of states. We propose that the lack of superconductivity, the small value of the linear specific heat coefficient, gamma, and the discrepancy between theoretical and experimental lattice constants can all be explained if the material is assumed to be a C-deficient alpha-ZnCNi3 similar to the analogous non-superconducting phase of MgCNi3

Magnetic Coupling Between Non-Magnetic Ions: Eu3+ in EuN and EuP

We consider the electronic structure of, and magnetic exchange (spin) interactions between, nominally nonmagnetic Eu^3+ ions (4f^6, S=3, L=3, J=0) within the context of the rocksalt structure compounds EuN and EuP. Both compounds are ionic [Eu^3+; N^3- and P^3-] semimetals similar to isovalent GdN. Treating the spin polarization within the 4f shell, and then averaging consistent with the J=0 configuration, we estimate semimetallic band overlaps (Eu 5d with pnictide 2p or 3p) of ~0.1 eV (EuN) and ~1.0 eV (EuP) that increase (become more metallic) with pressure. The calculated bulk modulus is 130 (86) GPa for EuN (EuP). Exchange (spin-spin) coupling calculated from correlated band theory is small and ferromagnetic in sign for EuN, increasing in magnitude with pressure. Conversely, the exchange coupling is antiferromagnetic in sign for EuP and is larger in magnitude, but decreases with compression. Study of a two-site model with S_1*S_2 coupling within the J=0,1 spaces of each ion illustrates the dependence of the magnetic correlation functions on the model parameters, and indicates that the spin coupling is sufficient to alter the Van Vleck susceptibility. We outline a scenario of a spin-correlation transition in a lattice of S=3, L=3, J=0 nonmagnetic ions

Sikap terhadap Kenakalan Remaja dengan Religiositas pada Anggota REKAT (Remaja Katolik) di Surabaya

Kenakalan remaja adalah salah satu perilaku menyimpang yang disebabkan oleh kegagalan individu dalam menjalankan tugas-tugas perkembangannya di masa remaja. Perilaku kenakalan remaja ini juga dilandasi oleh sikap yang dimiliki para remaja. Sikap yang mendukung terhadap kenakalan remaja memiliki potensi untuk memunculkan perilaku kenakalan pada remaja. Upaya pencegahan kenakalan remaja dapat dilakukan dengan pembinaan dari segi agama untuk menumbuhkan religiositas pada remaja dan pengetahuan baik-buruk sehingga akan membentuk sikap yang tidak mendukung pada kenakalan remaja. Salah satu pembinaan keagamaan yang ada adalah pembinaan Remaja Katolik (REKAT). Namun pada Kenyataannya masih ada anggota REKAT yang melakukan kenakalan remaja. Tujuan penelitian ini adalah untuk mengetahui hubungan antara religiositas dengan sikap terhadap kenakalan remaja pada anggota REKAT di Surabaya. Subjek penelitian (N = 108) adalah anggota REKAT di Surabaya yang berusia 12-17 tahun. Pengambilan sampel dilakukan dengan cara incidental sampling dan pengumpulan data dilakukan dengan menggunakan skala. Data yang diperoleh dianalisis menggunakan teknik korelasi non parametrik Kendall\u27s tau-b. Hasil analisis menunjukkan nilai r = 0,426 dengan p < 0.001 yang berarti ada hubungan yang signifikan antara religiositas dengan sikap terhadap kenakalan remaja