R&D and Technology Transfer: Firm-Level Evidence from Chinese Industry

The capacity of developing economies to narrow the gap in living standards with the OECD nations depends critically on their ability to imitate and innovate new technologies. Toward this end, developing economies have access to three avenues of technological advance: technology transfer, domestic R&D, and foreign direct investment. This paper examines the contributions of each of these avenues, as well as their interactions, to productivity and knowledge production within Chinese industry. Based on a large data set for China’s large and medium-size enterprises, the estimation results show that technology transfer – whether domestic or foreign – affects productivity only through its interactions with in-house R&D. Foreign direct investment does not appear to facilitate the adoption of market-mediated foreign technology transfer. Firms wishing to produce patentable knowledge do not benefit from technology transfer; patentable knowledge is created exclusively through in-house R&D operations.http://deepblue.lib.umich.edu/bitstream/2027.42/39968/3/wp582.pd

The Sources and Sustainability of China's Economic Growth

China’s economic transformation is proceeding at different rates across different regions and sectors, and China’s most advanced regional sector, coastal industry, still lags well behind the world’s technology frontier. This paper explores the implications of these internal and international productivity disparities for China’s ability to sustain rapid economic growth. When China’s GDP catches up to U.S. GDP, Chinese living standards still will be only one quarter those of the United States. If, at that time, productivity in some major regions and sectors remains far below the average, coastal industry may have to achieve productivity that approaches or even exceeds U.S. productivity. Coastal industry’s productivity growth is then likely to slow substantially, impeding China’s overall economic growth. The paper examines the need for policies that facilitate economic integration across regions, to enable the lagging regions and sectors to catch up to coastal industry, and the prospects for continued institutional reform.China, macroeconomics, economic growth, China GDP

The Hydraulics of Waste Stabilization Ponds

The treatment efficiency of waste stabilization ponds depends primarily on the biological factors of type of waste and organic loading. However, the biological activity in a pond is greatly influenced by the environmental conditions of temperature, wind, sunlight, and the hydraulic flow patterns. In the past little attention has been given to the hydraulic characteristics of waste stabilization ponds such as the gross flow patterns within stabilization ponds as affected by the shape of the pond or lagoon, the presence of dead spaces, and positioning of inlets and outlets and the degree of density stratification. These hydraulic flow characteristics will have an effect on the dispersion and the average detention time of the waste and on the organic (BOD) and pathogenic organism removal efficiency of the treatment process. This research evaluated the effects of these hydraulic flow characteristics on the treatment efficiency by using certain information that can be obtained from the age distribution function of the fluid particles within a continuous flow process vessel. The age ddistribution function represents a history of the time of retention of the various fluid particles in the vessel and is generated by injecting a tracer into the process vessel and monitoring the outlet from the vessel. The concentration vs. time curves at the outlets, which lead to the age distribution functions for a waste or a tracer, were made dimensionless to aid in the evaluation of each experiment. The prototype experimental data taken to establish exisiting flow patterns were obtained on the waste stabilization ponds of the city of Logan, Utah. Fluorometric techniques using rhodamind WT dye were used to trace the pollutant. A hydraulic model of the ponds 20 feet by 40 feet by 3 feet deep was constructed at the Utah Water Research Laboratory. This model, after verification, was used to generate data on the effects of inlet and outlet types and location, density stratification, lenth to width ratio, and baffling on the hydraulic flow characteristics. The information gained from the tracer concentration vs. time curves was used in conjuction with the first order reaction equation to predict treatment efficiences for various pond designs for determining optimum conditions. Finally, a mathematical model of the mixing process is presented and outlet concentration vs. time curves generated by the model are compared with experimental results. This mathematical model can be used in conjunction with the first order reaction equation to predict treatment efficiencies

Structure-Function Studies of the cAMP-Dependent Protein Kinase \u3ci\u3eIn Vitro\u3c/i\u3e and in Intact Cells

There are 518 protein kinase genes in the human genome; this constitutes about 1.7% of all human genes. The cAMP-dependent protein kinase (PKA) serves as the prototypic model for the study of kinases because it contains a conserved catalytic core shared with all eukaryotic kinases, it is the simplest kinase, and it is one of the best-characterized serine/threonine kinases. PKA is ubiquitous in mammals and regulates multiple physiological mechanisms such as the cell cycle, apoptosis, cell motility, energy metabolism, and gene transcription through a well-defined intracellular signaling pathway. While PKA clearly has a central physiological role it is still unclear how PKA mediates multiple physiological mechanisms at the cellular level. Four approaches were used to explore this question using two PKA catalytic subunits, Cα and Cγ, which share 83% identity in primary structure but differ in function. The first approach sought to identify differences in primary structure between Cγ and Cα, which may define functional differences between them. To this end chimeras were generated, swapping the carboxyl and amino termini between Cα and Cγ and were evaluated for functionality through CREB-mediated reporter assays. Wild type Cα and Cγ induced CREB-mediated transcriptional activation, but the chimeras failed to exhibit any activity. The second approach sought to characterize phosphorylation differences between purified PKA-Cγ and PKA-Cα that defines their physiological function. Two novel phosphorylation sites were identified on both isoforms by tandem mass spectrometry analysis (Cγ S14 and Cα/Cγ S259). It was also determined that Cγ expressed in Sf9 insect cells, like Cα expressed in mammalian cells, is phosphorylated at T197 and S338 and the modification at T197 is important to the function of both isoforms. The third approach sought to characterize the kinetic mechanism of PKA-Cγ through determination of the rate for the reaction-limiting step, which was found to be 9-times slower than that of Cα. The final approach sought to identify Cγ expression in the cell through the use of a new Cγ-specific antibody. Cγ expression was identified following differentiation of U-937 cells suggesting a novel function for Cγ in the cell

The Behavior of PVC Pipe Under the Action of Water Hammer Pressure Waves

Introduction: Hydraulic transients, commonly referred to as water hammer, occur in a hydraulic system whenver the velocity of flow in any one of the pipes in the system is caused to change. The magnitude of the pressure waves generated by a given change in velocity depends on the geometry of the pipe system, the magnitude of the velocity change and the elastic wave velocity in the system componenets. In turn, the elastic wave velocity depends on the modulus of elasticity of the fluid and the pipe material, the size and thickness of the pipe, the method by which the pipe is constrained or tied down and the Poisson\u27s ratio for the material of which the pipe os constructed. The extensive engineering analysis and design of piping systems in which water hammer occurs is relatively common in recent years. Most piping systems in previous years have been constructed of metal or concrete pipe or some other equally rigid material and experimental verification of the theories predicting water hammer wave velocity, intensity and duration has been realized. Recently, however, there has been an increase in the use of plastic material to construct pipes. There has been little coordinated work done on the extent to which the classical theory of hydraulic transients will predict water hammer in these plastic pipes. It appears that use of plastic matierals in constructing water pipe will increase dramatically in the next few years and, therefore, research into the behavior of this pipe under water hammer pressures is justified and timely. Late in 1969 the Johns-Manville Corporation undertook preliminary studies of water hammer occurring in the PVC (polyvinylchloride_ pipe which they manufacture. The results of this work cast considerable doubt as to the validity of applying the classical equations predicint water hammer to PVC pipe. As a result of this conclusion, the Johns-Manville Corporation retained the Utah Water Research Laboratory to generate conclusive results on the behavior of this type of pipe under water hammer pressures

Stability of AdSp×Mq compactifications without supersymmetry

We study the stability of Freund-Rubin compactifications, AdSp×Mq, of (p+q)-dimensional gravity theories with a q-form field strength and no cosmological term. We show that the general AdSp×S^q vacuum is classically stable against small fluctuations, in the sense that all modes satisfy the Breitenlohner-Freedman bound. In particular, the compactifications used in the recent discussion of the proposed bosonic M theory are perturbatively stable. Our analysis treats all modes arising from the graviton and the q form, and is completely independent of supersymmetry. From the masses of the linearized perturbations, we obtain the dimensions of some operators in possible holographic dual CFT’s. Solutions with more general compact Einstein spaces need not be stable, and in particular AdSp×S^n×S^(q-n) is unstable for q~9. We also study the AdS4×S^6 compactification of massive type IIA supergravity, which differs from the usual Freund-Rubin compactification in that there is a cosmological term already in ten dimensions. This nonsupersymmetric vacuum is unstable

A Review of Three-Family Grand Unified String Models

We review the construction and classification of three-family grand unified models within the framework of asymmetric orbifolds in perturbative heterotic superstring. We give a detailed survey of all such models which is organized to aid analysis of their phenomenological properties. We compute tree-level superpotentials for these models. These superpotentials are used to analyze the issues of proton stability (doublet-triplet splitting and R-parity violating terms) and Yukawa mass matrices. To have agreement with phenomenological data all these models seem to require certain degree of fine-tuning. We also analyze the possible patterns of supersymmetry breaking in these models. We find that the supersymmetry breaking scale comes out either too high to explain the electroweak hierarchy problem, or below the electroweak scale unless some degree of fine-tuning is involved. Thus, none of the models at hand seem to be phenomenologically flawless.Comment: 49 pages, Revtex 3.0; one ps figure included. To appear in the Review section of Int.J.Mod.Phy

Physical and chemical differentiation of the luminous star-forming region W49A - Results from the JCMT Spectral Legacy Survey

The massive and luminous star-forming region W49A is a well known Galactic candidate to probe the physical conditions and chemistry similar to those expected in external starburst galaxies. We aim to probe the physical and chemical structure of W49A on a spatial scale of ~0.8 pc based on the JCMT Spectral Legacy Survey, which covers the frequency range between 330 and 373 GHz. The wide 2x2 arcminutes field and the high spectral resolution of the HARP instrument on JCMT provides information on the spatial structure and kinematics of the cloud. For species where multiple transitions are available, we estimate excitation temperatures and column densities. We detected 255 transitions corresponding to 60 species in the 330-373 GHz range at the center position of W49A. Excitation conditions can be probed for 16 molecules. The chemical composition suggests the importance of shock-, PDR-, and hot core chemistry. Many molecular lines show a significant spatial extent across the maps including high density tracers (e.g. HCN, HNC, CS, HCO+) and tracers of UV-irradiation (e.g. CN and C2H). Large variations are seen between the sub-regions with mostly blue-shifted emission toward the Eastern tail, mostly red-shifted emission toward the Northern clump, and emission peaking around the expected source velocity toward the South-west clump. A comparison of column density ratios of characteristic species observed toward W49A to Galactic PDRs suggests that while the chemistry toward the W49A center is driven by a combination of UV-irradiation and shocks, UV-irradiation dominates for the Northern Clump, Eastern tail, and South-west clump regions. A comparison to a starburst galaxy and an AGN suggests similar C2H, CN, and H2CO abundances (with respect to the dense gas tracer 34CS) between the ~0.8 pc scale probed for W49A and the >1 kpc regions in external galaxies with global star-formation.Comment: Proposed for acceptance in A&A, abstract abridge

A Mathematical Hydrodynamic Circulation Model of Great Salt Lake for Resource Management

In the Great Basin region of this country, the resource which has always been of great importance is water. In Utah, the proper management of the resources of Great Salt Lake and the watersheds tributary to it, has become a topic of increasing concern. Recently, much emphasis has been placed on developing the recreational and industrial resources of Great Salt Lake. For optimum economic and social benefits from future development plans, the lake and its tributary watersheds need to be considered in terms of a single entity. In this regard, the Utah Water Research Laboratory (UWRL) has conducted several studies which involve hydrologic basins tributary to Great Salt Lake. Significantly lacking, however, was a comprehensive study of Great Salt Lake itself. The reserach reported herein is directed towards the development of a comprehensive predictive hydrodynamic model of Great Salt Lake (see Figure 1). This model provides two general types of information. First, it provides circulation patterns within the lake for configurations and conditions imposed by the planner. This information is necessary to predict movement of pollutants, paths of freshwater inflows, and other phenomena which depend on currents. Second, the model provides information on the distribution of salinity throughout the lake. This informatino is vital to the industries around the lake which extract minerals from the brines of the lake. These capabilities of the model will also be valuable in providing data to be used by quality models. It could be argued that because of a lack of field data for model verification, the development of a mathematical model was premature. Some field data on salinity are being collected regularly and the data base is steadily growing. Hopefully, the Utah Separtment of Natural Resources will implement a program of measuring velocities and circulation patterns to provide a data base for calibrating the hydraulic model. In any case, the initial development of a mathematical model is appropriate so that over the next few years, it can be improved and adjusted as more data become available. It seemed unwise to wait for a complete data base before launching a lengthy program of development of a mathematical model. The objectives of the research were as follows: 1. To develop new mathematical models or incorporate existing models of the flow through the Southern Pacific causeway embankment and culverts to act as boundary conditions in mathementical circulation models of the southern and northern arms of the Great Salt Lake. 2. To develop an upper-layer hydrodynamic circulation model of Great Salt Lake. As a first step toward developing a more comprehensive two-layer model, it was recognized that the main function of the lower layer within the lake may be to act as a reservoir for passing salinity from the north arm to the surface layer in the south arm. If this is indeed the case, then an upper-layer model could be constucted based on the assumption that the interface is a horizontal boundary which feeds salinity itno the upper layer in some reasonable fashion to maintain continuity. 3. To attempt to develop a coupled two-layer model of Great Salt Lake. It was proposed to use the finite element technique to generate a hydrodynamic model of the circulation patterns in both the upper and lower layers. The finite element representation incorporates cubic velocity variations in the two layers to more accurately simulate the recircualtion flow patterns caused by wind action on the surface and fresh water flow from the contributing streams. 4. To perform a laboratory experiment devised to evaluate the rate of salinity exchange from the lower high-density layer through the interfacial shear zone into the upper layer. It was believed that the exchange of salinity between the two layers is a direct function of the intensity of the interfacial shear and the resulting turbulent mixing at the interface. 5. To attempt to adjust the model to Great Salt Lake. All available velocity and salinity concentration data collected by the United States Geological Survey (USGS) and the Utah Geological and Mineral Survey (UGMS) during recent years was used. 6. To cooperate with researchers who are studying other aspects of the lake by making the mathematical model available to them. A modeling appraoch utilizing equations based on the fundamental laws of physics, coupled with the application of the versatile finite element method gives the hydrodynamic and convetion-dispersion models of Great Salt Lake the versatility required to examine the spectrum of management alternatives. The predictive capability is greatly enhanced in this approach by minimizing the number of empirical constants to be evlatued. It seems clear that the development of these comprehensive models of the lake is a necessary step in the subsequent development and use of both water quality and management models of this important natural resource