Recent advancement of turbulent flow measurement techniques

Advancements of the fluctuating density gradient cross beam laser Schlieren technique, the fluctuating line-reversal temperature measurement and the development of the two-dimensional drag-sensing probe to a three-dimensional drag-sensing probe are discussed. The three-dimensionality of the instantaneous momentum vector can shed some light on the nature of turbulence especially with swirling flow. All three measured fluctuating quantities (density, temperature, and momentum) can provide valuable information for theoreticians

Righting the Titled Scale: Expansion of Artists\u27 Rights in the United States

This Note focuses on the expansion of artists\u27 rights in the United States, specifically the moral rights of paternity and integrity. It explores the history of judicial denial of moral rights and the attempt to gain protection through traditional causes of action. The Note then analyzes barriers to adoption of the moral rights doctrine, with emphasis on the challenge to traditional property concepts. The California Art Preservation Act of 1980 and the 1984 Artists\u27 Authorship Act of New York are discussed and evaluated. This Note recommends adoption of the California statute as the model for future artists\u27 rights legislation and defends property rights restrictions imposed by the Act on the basis of support of legal precedent and the justification of protection of the public interest

Righting the Titled Scale: Expansion of Artists\u27 Rights in the United States

This Note focuses on the expansion of artists\u27 rights in the United States, specifically the moral rights of paternity and integrity. It explores the history of judicial denial of moral rights and the attempt to gain protection through traditional causes of action. The Note then analyzes barriers to adoption of the moral rights doctrine, with emphasis on the challenge to traditional property concepts. The California Art Preservation Act of 1980 and the 1984 Artists\u27 Authorship Act of New York are discussed and evaluated. This Note recommends adoption of the California statute as the model for future artists\u27 rights legislation and defends property rights restrictions imposed by the Act on the basis of support of legal precedent and the justification of protection of the public interest

Magnetic and thermodynamic properties of Sr_{2}LaFe_{3}O_{9}

Using a Dirac-Heisenberg Hamiltonian with biquadratic exchange interactions, we study the effect of iron disproportionation on the magnetic ordering, and describe the first-order magnetic transition occurring in the perovskite Sr_{2}LaFe_{3}O_{9}. Upon fitting the experimental data, we give an estimate of the exchange integrals for the antiferromagntic and ferromagnetic interactions, in agreement with previous works on kindered compounds. Spin-wave theory yields a magnon spectrum with a gapless antiferromagnetic mode together with two gapped ferromagnetic ones.Comment: 8 pages of RevTex, 5 figures (available upon request), submitted to J. Mag. Mag. Ma

Development and analysis of business models in the South African motor body repair sector

Every enterprise makes use of a business model either explicitly or implicitly. A business model is an abstract of a business plan and is complimentary to the firm’s business strategy. It shows linkages within a business process as it transforms inputs into outputs, and how the enterprise creates and delivers value to its customers. Through a case study research two business models used by South African auto-body repairers were developed and analysed. One is for auto-body repair shops that are recognised by the South African Insurance Association, the panel system, and the other is not. The business models are presented as causal loop diagrams. Design parameters used to describe the architecture were content, structure, governance and complimentaries. These business models were used to explain low margins experienced in this sector. The business model helps small enterprise entrepreneurs, stakeholders in the automotive sector and policy makers to understand the logic of auto-body repair shops

Thermal fractionation of air in polar firn by seasonal temperature gradients

Air withdrawn from the top 5-15 m of the polar snowpack (firn) shows anomalous enrichment of heavy gases during summer, including inert gases. Following earlier work, we ascribe this to thermal diffusion, the tendency of a gas mixture to separate in a temperature gradient, with heavier molecules migrating toward colder regions. Summer warmth creates a temperature gradient in the top few meters of the firn due to the thermal inertia of the underlying firn and causes gas fractionation by thermal diffusion. Here we explore and quantify this process further in order to (1) correct for bias caused by thermal diffusion in firn air and ice core air isotope records, (2) help calibrate a new technique for measuring temperature change in ice core gas records based on thermal diffusion [Severinghaus et al., 1998], and (3) address whether air in polar snow convects during winter and, if so, whether it creates a rectification of seasonality that could bias the ice core record. We sampled air at 2-m-depth intervals from the top 15 m of the firn at two Antarctic sites, Siple Dome and South Pole, including a winter sampling at the pole. We analyzed 15N/14N, 40Ar/36Ar, 40Ar/38Ar, 18O/16O of O2, O2/N2, 84Kr/36Ar, and 132Xe/36Ar. The results show the expected pattern of fractionation and match a gas diffusion model based on first principles to within 30%. Although absolute values of thermal diffusion sensitivities cannot be determined from the data with precision, relative values of different gas pairs may. At Siple Dome, δ40Ar/4 is 66 ± 2% as sensitive to thermal diffusion as δ15N, in agreement with laboratory calibration; δ18O/2 is 83 ± 3%, and δ84Kr/48 is 33 ± 3% as sensitive as δ15N. The corresponding figures for summer South Pole are 64 ± 2%, 81 ± 3%, and 34 ± 3%. Accounting for atmospheric change, the figure for δO2/N2/4 is 90 ± 3% at Siple Dome. Winter South Pole shows a strong depletion of heavy gases as expected. However, the data do not fit the model well in the deeper part of the profile and yield a systematic drift with depth in relative thermal diffusion sensitivities (except for Kr, constant at 34 ± 4%), suggesting the action of some other process that is not currently understood. No evidence for wintertime convection or a rectifier effect is seen

Epitaxial Growth of La1/3_{1/3}Sr2/3_{2/3}FeO3_3 thin films by laser ablation

We report on the synthesis of high quality La$_{1/3}$Sr$_{2/3}$FeO$_3$ (LSFO) thin films using the pulsed laser deposition technique on both SrTiO$_3$ (STO) and LaAlO$_3$ (LAO) substrates (100)-oriented. From X-Ray diffraction (XRD) studies, we find that the films have an out-of-plane lattice parameter around 0.3865nm, almost independent of the substrate (i.e. the nature of the strains). The transport properties reveal that, while LSFO films deposited on STO exhibit an anomaly in the resistivity vs temperature at 180K (corresponding to the charge-ordered transition and associated with a transition from a paramagnetic to an antiferromagnetic state), the films grown on LAO display a very small magnetoresistance behavior and present an hysteresis around 270K under the application of a 4T magnetic field. The changes in transport properties between both substrates are discussed and compared with the corresponding single crystals.Comment: 9 pages, 4 figure

Ondelettes and phase cell cluster expansions, a vindication

Y. Meyer has recently developed a particularly useful o.n. basis for L 2 ( R d ). Expansions using this basis, i.e. expansions into “ondelettes” or “wavelets,” have yielded important new results in soft and hard analysis. The expansion into ondelettes of a boson scalar field naturally leads to phase cell cluster expansions, a formalism already developed by the authors using other related bases. Adoption of ondelettes expansions into the phase cell program gives improvements of some extant results, and excises an early error.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46467/1/220_2005_Article_BF01206144.pd

Superconducting properties of RuSr2GdCu2O8 studied by SQUID magnetometry

For polycrystalline RuSr2GdCu2O8 (Ru-1212), distinct peaks have been reported in d.c. magnetization in the superconducting state of the sample. Sr2GdRuO6 (Sr-2116), the precursor for the preparation of Ru-1212, shows similar peaks in the same temperature regime. Based on measurements performed on both bulk and powdered samples of Ru-1212 and Sr-2116, we exclude the possibility, that the observed behavior of the magnetization of Ru-1212 is due to Sr-2116 impurities. The effect is related to the superconductivity of Ru-1212, but it is not an intrinsic property of this compound. We provide evidence that the observation of magnetization peaks in the superconducting state of Ru-1212 is due to flux motion generated by the movement of the sample in an inhomogeneous field, during the measurement in the SQUID magnetometer. We propose several tests, that help to decide, whether the features observed in a SQUID magnetization measurement of Ru-1212 represent a property of the compound or not.Comment: 22 pages, 9 figure