The Size and Distribution of Two Minority Population Groups in Texas

The Size and Distribution of Two Minority Population Groups in TexasBureau of Business Researc

Optimization of the extraordinary magnetoresistance in semiconductor-metal hybrid structures for magnetic-field sensor applications

Semiconductor-metal hybrid structures can exhibit a very large geometrical magnetoresistance effect, the so-called extraordinary magnetoresistance (EMR) effect. In this paper, we analyze this effect by means of a model based on the finite element method and compare our results with experimental data. In particular, we investigate the important effect of the contact resistance $\rho_c$ between the semiconductor and the metal on the EMR effect. Introducing a realistic $\rho_c=3.5\times 10^{-7} \Omega{\rm cm}^2$ in our model we find that at room temperature this reduces the EMR by 30% if compared to an analysis where $\rho_c$ is not considered.Comment: 4 pages; manuscript for MSS11 conference 2003, Nara, Japa

New Capital Estimates for China

Data on physical capital are an indispensable part of economic growth and efficiency studies. In the case of China, fixed asset time series are usually derived either by aggregating gross fixed capital formation data over time, net of depreciation, or by correcting the limited official fixed asset data available. These procedures, to varying degrees, ignore that (i) gross fixed capital formation does not equal investment, (ii) investment does not equal the value of fixed assets newly created through investment, (iii) depreciation is an accounting measure that has no impact on changes in the production capacity of fixed assets, (iv) official fixed asset data, where available, incorporate significant revaluations in the 1990s, and (v) the variable 'net fixed assets,' frequently used in the literature, is an inappropriate measure of fixed assets for the purpose of growth or efficiency studies. This paper derives economy-wide fixed asset values for 1954-2002, correcting for these shortcomings. It also uses the so far unexplored method of combining economy-wide depreciation data (in the income approach to the calculation of gross domestic product) with an economy-wide depreciation rate to directly yield economy-wide fixed assets. The fixed asset time series derived here are contrasted with each other as well as with those presented in the literature. The reliability of the different series is evaluated, leading to the recommendation of a specific choice of fixed asset time series.Capital, fixed assets, investment, national income accounting, production function estimations, measurement of economic growth, Chinese statistics

China’s Economic Growth 1978-2025: What We Know Today about China’s Economic Growth Tomorrow

Views of the future China vary widely. While some believe that the collapse of China is inevitable, others see the emergence of a new superpower that increasingly poses a threat to the U.S. This paper examines the economic growth prospects of China over the next two decades. Extrapolating past real GDP growth rates into the future, the size of the Chinese economy surpasses that of the U.S. in purchasing power terms between 2012 and 2015; by 2025, China is likely to be the world's largest economic power by almost any measure. The extrapolations are supported by two types of considerations. First, China’s growth patterns of the past 25 years since the beginning of economic reforms match well those identified by standard economic development and trade theories (structural change, catching up, and factor price equalization). Second, decomposing China’s GDP growth into growth of labor and other variables, the near-certain information available today about the quantity and quality of Chinese laborers through 2015, if not several years after, allows inferences about future GDP growth. Short of some cataclysmic event, demographics alone suggests China’s continued economic rise. If talent is randomly distributed in the world population and if agglomeration of talent is important, then the odds are strongly in China’s favor.economic growth, growth accounting, growth forecasts, development theories, human capital formation, education (all: China)

Unraveling the Catalytic Mechanism of Nitrile Hydratases

To elucidate a detailed catalytic mechanism for nitrile hydratases (NHases), the pH and temperature dependence of the kinetic constants kcat and Km for the cobalt-type NHase from Pseudonocardia thermophila JCM 3095 (PtNHase) were examined. PtNHase was found to exhibit a bell-shaped curve for plots of relative activity versus pH at pH 3.2–11 and was found to display maximal activity between pH 7.2 and 7.8. Fits of these data provided pKES1 and pKES2 values of 5.9 ± 0.1 and 9.2 ± 0.1 (kcat′ = 130 ± 1 s-1), respectively, and pKE1 and pKE2 values of 5.8 ± 0.1 and 9.1 ± 0.1 (kcat′/Km′ = (6.5 ± 0.1) × 103 s-1 mm-1), respectively. Proton inventory studies indicated that two protons are transferred in the rate-limiting step of the reaction at pH 7.6. Because PtNHase is stable at 60 °C, an Arrhenius plot was constructed by plotting ln(kcat) versus 1/T, providing Ea = 23.0 ± 1.2 kJ/mol. The thermal stability of PtNHase also allowed ΔH0 ionization values to be determined, thus helping to identify the ionizing groups exhibiting the pKES1 and pKES2 values. Based on ΔH0ion data, pKES1 is assigned to βTyr68, whereas pKES2 is assigned to βArg52, βArg157, or αSer112 (NHases are α2β2-heterotetramers). A combination of these data with those previously reported for NHases and synthetic model complexes, along with sequence comparisons of both iron- and cobalt-type NHases, allowed a novel catalytic mechanism for NHases to be proposed

Where are LIGO's Big Black Holes?

In LIGO's O1 and O2 observational runs, the detectors were sensitive to stellar mass binary black hole coalescences with component masses up to $100\,M_\odot$, with binaries with primary masses above $40\,M_\odot$ representing $\gtrsim90\%$ of the total accessible sensitive volume. Nonetheless, of the 5.9 detections (GW150914, LVT151012, GW151226, GW170104, GW170608, GW170814) reported by LIGO-Virgo, the most massive binary detected was GW150914 with a primary component mass of $\sim36\,M_\odot$, far below the detection mass limit. Furthermore, there are theoretical arguments in favor of an upper mass gap, predicting an absence of black holes in the mass range $50\lesssim M\lesssim135\,M_\odot$. We argue that the absence of detected binary systems with component masses heavier than $\sim40\,M_\odot$ may be preliminary evidence for this upper mass gap. By allowing for the presence of a mass gap, we find weaker constraints on the shape of the underlying mass distribution of binary black holes. We fit a power-law distribution with an upper mass cutoff to real and simulated BBH mass measurements, finding that the first 3.9 BBHs favor shallow power law slopes $\alpha \lesssim 3$ and an upper mass cutoff $M_\mathrm{max} \sim 40\,M_\odot$. This inferred distribution is entirely consistent with the two recently reported detections, GW170608 and GW170814. We show that with $\sim10$ additional LIGO-Virgo BBH detections, fitting the BH mass distribution will provide strong evidence for an upper mass gap if one exists.Comment: includes more detailed analysis of mass ratio distribution; accepted for publication in ApJ

New Capital Estimates for China

Data on physical capital are an indispensable part of economic growth and efficiency studies. In the case of China, economy-wide fixed asset series are usually derived by aggregating gross fixed capital formation (net of depreciation) over time, and sectoral/ownership-specific series by correcting the limited official fixed asset data available. These procedures, to varying degrees, ignore that (i) gross fixed capital formation does not equal investment, (ii) investment does not equal the value of fixed assets newly created through investment, (iii) depreciation is an accounting measure that bears no necessary relation to changes in the production capacity of fixed assets, (iv) official fixed asset data, where available, incorporate significant revaluations in the 1990s, and (v) “net fixed assets” do not measure the contribution of fixed assets to production. This paper derives economy-wide fixed asset values for 1953-2003, correcting for these shortcomings. It uses both the traditional, cumulative approach and a new, so far unexplored method of combining economy-wide depreciation values and an economy-wide depreciation rate to directly yield economy-wide fixed assets. The derived fixed asset time series are evaluated in a comparison with each other as well as with series in the literature, leading to the recommendation of a specific choice of fixed asset time series.Capital, investment, national income accounting, production function estimations, Chinese statistics, fixed assets, measurement of economic growth