500 research outputs found
Recent RHIC in-situ coating technology developments
To rectify the problems of electron clouds observed in RHIC and unacceptable
ohmic heating for superconducting magnets that can limit future machine
upgrades, we started developing a robotic plasma deposition technique for
coating of the RHIC 316LN stainless steel cold bore tubes based on
staged magnetrons mounted on a mobile mole for deposition of Cu followed by
amorphous carbon (a-C) coating. The Cu coating reduces wall resistivity, while
a-C has low SEY that suppresses electron cloud formation. Recent RF resistivity
computations indicate that 10 {\mu}m of Cu coating thickness is needed. But, Cu
coatings thicker than 2 {\mu}m can have grain structures that might have lower
SEY like gold black. A 15-cm Cu cathode magnetron was designed and fabricated,
after which, 30 cm long samples of RHIC cold bore tubes were coated with
various OFHC copper thicknesses; room temperature RF resistivity measured.
Rectangular stainless steel and SS discs were Cu coated. SEY of rectangular
samples were measured at room; and, SEY of a disc sample was measured at
cryogenic temperatures.Comment: 8 pages, contribution to the Joint INFN-CERN-EuCARD-AccNet Workshop
on Electron-Cloud Effects: ECLOUD'12; 5-9 Jun 2012, La Biodola, Isola d'Elba,
Ital
The impact of foreign direct investment, foreign aid and trade on poverty reduction : evidence from Sub-Saharan African countries
Abstract:Despite postulations on the effects of foreign direct investment (FDI), foreign aid, and trade on growth, empirical evidence from extant research has been mixed. The focus of recent research has shifted from the growth effects of these international flows to their poverty reduction effects. However, results have also been mixed. Most studies have examined the empirical evidence of these flows separately and have mostly conducted single country studies. In this study, we use data from twenty-nine countries in Sub-Saharan Africa between the period 1990–2017 to analyze the effects of FDI, trade, and foreign aid on poverty reduction in a single model using the Feasible Generalized Least Square (FGLS) technique. Our results show that FDI and foreign aid have a negative effect on poverty reduction in the countries studied. These results suggest that the level of FDI required to alleviate poverty has not been reached, and foreign aid have not been properly channeled. However, the results show that trade has a positive and significant impact on poverty reduction, especially in low-income countries. We conclude with policy recommendations
Measurement of the diffractive structure function in deep inelastic scattering at HERA
This paper presents an analysis of the inclusive properties of diffractive
deep inelastic scattering events produced in interactions at HERA. The
events are characterised by a rapidity gap between the outgoing proton system
and the remaining hadronic system. Inclusive distributions are presented and
compared with Monte Carlo models for diffractive processes. The data are
consistent with models where the pomeron structure function has a hard and a
soft contribution. The diffractive structure function is measured as a function
of \xpom, the momentum fraction lost by the proton, of , the momentum
fraction of the struck quark with respect to \xpom, and of . The \xpom
dependence is consistent with the form \xpoma where
in all bins of and
. In the measured range, the diffractive structure function
approximately scales with at fixed . In an Ingelman-Schlein type
model, where commonly used pomeron flux factor normalisations are assumed, it
is found that the quarks within the pomeron do not saturate the momentum sum
rule.Comment: 36 pages, latex, 11 figures appended as uuencoded fil
What we talk about when we talk about "global mindset": managerial cognition in multinational corporations
Recent developments in the global economy and in multinational corporations have placed significant emphasis on the cognitive orientations of managers, giving rise to a number of concepts such as “global mindset” that are presumed to be associated with the effective management of multinational corporations (MNCs). This paper reviews the literature on global mindset and clarifies some of the conceptual confusion surrounding the construct. We identify common themes across writers, suggesting that the majority of studies fall into one of three research perspectives: cultural, strategic, and multidimensional. We also identify two constructs from the social sciences that underlie the perspectives found in the literature: cosmopolitanism and cognitive complexity and use these two constructs to develop an integrative theoretical framework of global mindset. We then provide a critical assessment of the field of global mindset and suggest directions for future theoretical and empirical research
Observation of hard scattering in photoproduction events with a large rapidity gap at HERA
Events with a large rapidity gap and total transverse energy greater than 5
GeV have been observed in quasi-real photoproduction at HERA with the ZEUS
detector. The distribution of these events as a function of the
centre of mass energy is consistent with diffractive scattering. For total
transverse energies above 12 GeV, the hadronic final states show predominantly
a two-jet structure with each jet having a transverse energy greater than 4
GeV. For the two-jet events, little energy flow is found outside the jets. This
observation is consistent with the hard scattering of a quasi-real photon with
a colourless object in the proton.Comment: 19 pages, latex, 4 figures appended as uuencoded fil
Chinese multinationals: host country factors and foreign direct investment location
The study of Chinese multinationals (MNEs) is becoming one of the most promising research topics in the international business literature. After outlining the distinctive characteristics of the internationalization process of Chinese MNEs, this chapter analyzes the influence of various host country factors on the location of Chinese outward foreign direct investment (FDI). From a sample of 189 outward FDI decisions made by 35 mainland Chinese firms in 63 countries, our results show that host market size and the existence of overseas Chinese in the host country are positively associated with the number of Chinese FDIs. However, greater difficulty in doing business and host country political risk have no effect
Microwave determination of the quasiparticle scattering time in YBa2Cu3O6.95
We report microwave surface resistance (Rs) measurements on two very-high-quality YBa2Cu3O6.95 crystals which exhibit extremely low residual loss at 1.2 K (2-6 μΩ at 2 GHz), a broad, reproducible peak at around 38 K, and a rapid increase in loss, by 4 orders of magnitude, between 80 and 93 K. These data provide one ingredient in the determination of the temperature dependence of the real part of the microwave conductivity, σ1(T), and of the quasiparticle scattering time. The other necessary ingredient is an accurate knowledge of the magnitude and temperature dependence of the London penetration depth, λ(T). This is derived from published data, from microwave data of Anlage, Langley, and co-workers and from, high-quality μSR data. We infer, from a careful analysis of all available data, that λ2(0)/λ2(T) is well approximated by the simple function 1-t2, where t=T/Tc, and that the low-temperature data are incompatible with the existence of an s-wave, BCS-like gap. Combining the Rs and λ(T) data, we find that σ1(T), has a broad peak around 32 K with a value about 20 times that at Tc. Using a generalized two-fluid model, we extract the temperature dependence of the quasiparticle scattering rate which follows an exponential law, exp(T/T0), where T0≊12 K, for T between 15 and 84 K. Such a temperature dependence has previously been observed in measurements of the nuclear spin-lattice relaxation rate. Both the uncertainties in our analysis and the implications for the mechanism of high-temperature superconductivity are discussed
Composition of the Top Management Team and Firm International Diversification
This study investigates the impact of various top management team characteristics on firm international diversification. Relying on data from 126 firms in the electronics industry, we find that certain top management team characteristics are related to international expansion. Specifically, results indicate that lower average age, higher average tenure, higher average elite education, higher average international experience, and higher tenure heterogeneity are associated with firm international diversification. The study reinforces the importance of top management team composition in internationalization decisions and suggests further research in this context.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
- …