Diamond growth in premixed propylene-oxygen flames

Diamond film growth in low-pressure premixed propylene/oxygen flames is demonstrated. Well-faceted films are grown at a pressure of 180 Torr and a fuel/oxygen ratio of 0.47. Using propylene as the fuel may greatly improve the economics of flame synthesis of diamond, since propylene is an order of magnitude cheaper than acetylene

Complementarity among International Asset Holdings: Do Banks Have a Special Role?

This paper studies the pattern and structure of cross-border bilateral financial asset holdings. By utilizing an extended dataset and employing a variant of gravity models, we find strong evidence for the presence of complementarities among bank loans, shortand long-term debts, and portfolio equity holdings. The complementarities can be explained by common factors of standard gravity models such as economy size, state of development, and information cost proxies, as well as bilateral trade in goods and services. However, we also find the presence of a direct channel of complementarities among financial asset holdings that cannot be explained by these gravity factors. We proceed to investigate whether the complementarities can be characterized by the models that predict a special role of banks in alleviating information asymmetry. We find supporting evidence for this hypothesis in that international bank lending tends to increase the volume of portfolio asset holdings. This acceleration effect of bank lending is stronger for destination countries with higher degrees of ‘law and order,’ which suggests that cross-border bank lending may not lead to capital market integration, despite reduced information cost, if there is no appropriate infrastructure to facilitate portfolio investment. By investigating the structure of bilateral asset holdings, we also find positive evidence for the information role of banks. The share of bank lending decreases with increasing state of development of destination countries measured by per capita GDP and human capital accumulation, but increases with increasing distance, suggesting that information cost may play an important role in determining the structure of cross-border asset holdings.Cross-border asset holdings; Financial integration; Bank lending

The frequency response of temperature and precipitation in a climate model

Dynamic aspects of the climate's response to forcing are typically explored through transient simulations in the time domain. However, because of the large range of time-scales involved, some features are more easily observed in the frequency domain. We compute the frequency-response of the HadCM3L general circulation model (GCM) to sinusoidal perturbations in solar radiative forcing, with periods between 2^(−1/2) and 2^9 (512) years. The global mean temperature response decreases with increasing frequency, and the frequency scaling at time-scales longer than one year is consistent with the behavior of diffusion into a semi-infinite slab. The land-sea contrast and land-averaged precipitation, however, exhibit relatively little dependency on the frequency of the imposed perturbation, with significant response at both short and long periods. Understanding these relative characteristics of different climate variables in the frequency domain is important to understanding the transient response of the climate system to both anthropogenic and natural (e.g., volcanic) forcings; the frequency response is also relevant in understanding the spectrum of natural variability

Low-cost, open-source contact angle analyzer using a mobile phone, commercial tripods and 3D printed parts

Measurement of contact angle is important in many areas of science and engineering research. Contact angle analyzers are however not easily accessible due to their expensive cost, which hinders their use in research and also in education. In this study we propose a low-cost contact angle analyzer that can be assembled with 3D printed parts. Mobile phone is used for imaging, and the image is analyzed using an open-source ImageJ plugin. Commercial camera tripods are used as platform that provides movement in many degrees of freedom, which are important in leveling of the substrate and proper imaging of droplets. We utilize the tripods to build imaging modules, sample plate module and volume metering module, each of which perform distinct tasks. Especially, we characterize the usefulness of the volume metering module, which helps users dispense same volume of liquid to reduce human error during measurement. The cost of an analyzer is $255.10, which is an order of magnitude lower compared to commercial products. With the advancement in open source software and upgrades in the hardware modules, we expect that the proposed contact angle analyzer to have a positive impact in resource limited research labs and educational environments

Ni-dispersed fullerenes: Hydrogen storage and desorption properties

Our study shows that the H2 storage media using Ni-dispersed fullerenes could be viable alternatives to reversible hydrogen storage. It is demonstrated that a single Ni coated on the fullerene surface can store up to three H2 molecules. Consequently, at high Ni coverage, Ni-dispersed fullerenes are considered to be the novel hydrogen storage media capable of storing ~6.8 wt % H2, thus exceeding the Department of Energy target (6.5 wt %) for automobile applications. Moreover, the H2 desorption activation barrier of 11.8 kcal/mol H2 is ideal for many practical hydrogen storage applications

Diamond films from combustion of methyl acetylene and propadiene

To date diamond films grown with the combustion technique have used either acetylene or, rarely, ethylene as the fuel. However, there are barriers to large scale commercialization of the combustion technique using either fuel. For example, acetylene is relatively expensive and difficult to handle, while the use of ethylene gives relatively low growth rates. In this letter we propose replacing acetylene with MAPPTM gas, a commercial mixture of methyl acetylene and propadiene in liquefied petroleum gas (primarily propylene). MAPP gas is considerably cheaper, safer, and easier to handle than acetylene. Furthermore, the experiments described here suggest that MAPP gas flames are only slightly less efficient than acetylene flames at converting fuel carbon atoms into diamond