Supercritical multicomponent solvent coal extraction

The yield of organic extract from the supercritical extraction of coal with larger diameter organic solvents such as toluene is increased by use of a minor amount of from 0.1 to 10% by weight of a second solvent such as methanol having a molecular diameter significantly smaller than the average pore diameter of the coal

Modeling of secondary organic aerosol yields from laboratory chamber data

Laboratory chamber data serve as the basis for constraining models of secondary organic aerosol (SOA) formation. Current models fall into three categories: empirical two-product (Odum), product-specific, and volatility basis set. The product-specific and volatility basis set models are applied here to represent laboratory data on the ozonolysis of α-pinene under dry, dark, and low-NOx conditions in the presence of ammonium sulfate seed aerosol. Using five major identified products, the model is fit to the chamber data. From the optimal fitting, SOA oxygen-to-carbon (O/C) and hydrogen-to-carbon (H/C) ratios are modeled. The discrepancy between measured H/C ratios and those based on the oxidation products used in the model fitting suggests the potential importance of particle-phase reactions. Data fitting is also carried out using the volatility basis set, wherein oxidation products are parsed into volatility bins. The product-specific model is most likely hindered by lack of explicit inclusion of particle-phase accretion compounds. While prospects for identification of the majority of SOA products for major volatile organic compounds (VOCs) classes remain promising, for the near future empirical product or volatility basis set models remain the approaches of choice

Low Temperature Susceptibility of the Noncentrosymmetric Superconductor CePt_3Si

We report ac susceptibility measurements of polycrystalline CePt_3Si down to 60 mK and in applied fields up to 9 T. In zero field, a full Meissner state emerges at temperatures T/Tc < 0.3, where Tc=0.65 K is the onset transition temperature. Though transport measurements show a relatively high upper critical field Bc2 ~ 4-5 T, the low temperature susceptibility, \chi', is quite fragile to applied field, with \chi' diminishing rapidly in fields of a few kG. Interestingly, the field dependence of \chi' is well described by the power law, 4\pi\chi'=(B/B_c)^{1/2}, where Bc is the field at which the onset of resistance is observed in transport measurements.Comment: 5 figure

Design zero-voltage switching DC-DC buck converter

This report proposes an integrated, high switching frequency, zero-voltage-switching dc-dc buck converter for battery charger application. The design and analysis of dc�dc buck converter with integrated inductor is presented. The converter has been optimized to convert 12V input voltage to 5V at 1.5A maximum load current at 50MHz switching frequency. The converter has been simulated using an ORCAD 16.5 based simulation tool and result show that the switching losses using zero�voltage-switching technique is less compared to conventional buck converter

Transverse Entanglement Migration in Hilbert Space

We show that, although the amount of mutual entanglement of photons propagating in free space is fixed, the type of correlations between the photons that determine the entanglement can dramatically change during propagation. We show that this amounts to a migration of entanglement in Hilbert space, rather than real space. For the case of spontaneous parametric down conversion, the migration of entanglement in transverse coordinates takes place from modulus to phase of the bi-photon state and back again. We propose an experiment to observe this migration in Hilbert space and to determine the full entanglement.Comment: 4 pages, 3 figure

New and Significant Bird Records from Bintan Island, Riau Archipelago, Indonesia in 2018

Pulau Bintan is the largest island in the Riau Archipelago, Indonesia. During two brief visits in 2018, a total of eight species new to the island were recorded, increasing the island&rsquo;s bird checklist to 189 species. These new records are Grey Heron Ardea cinerea, Intermediate Egret Ardea intermedia, Red-wattled Lapwing Vanellus indicus, Horsfield's Bronze-cuckoo Chalcites basalis, Tiger Shrike Lanius tigrinus, White-headed Munia Lonchura maja, Sooty-headed Bulbul Pycnonotus aurigaster and Javan Myna Acridotheres javanicus. Three of our new records appear to be new for the Riau Archipelago, increasing the avifaunal checklist for the archipelago to 232 species. Following years of development, little primary vegetation remains on Bintan Island, and our failure to detect any woodpeckers by sight or sound during our visits is worrying in terms of the importance of these birds to ecosystem sustainability. Nonetheless, the island retains sizeable area of natural forests, including some swamp forest patches, and our new and significant records suggest its avifaunal diversity is still understudied and underestimated. We call for relevant Indonesian government agencies and the Bintan Resorts, which manage the northern portion of the island for tourism development, to strengthen efforts in biodiversity research and conservation, as well as habitat restoration, so as to attain the development goal of making Bintan a true &ldquo;eco-island&rdquo; for international tourism

Public Bikesharing in North America During a Period of Rapid Expansion: Understanding Business Models, Industry Trends & User Impacts, MTI Report 12-29

Public bikesharing—the shared use of a bicycle fleet—is an innovative transportation strategy that has recently emerged in major cities around the world, including North America. Information technology (IT)-based bikesharing systems typically position bicycles throughout an urban environment, among a network of docking stations, for immediate access. Trips can be one-way, round-trip, or both, depending on the operator. Bikesharing can serve as a first-and-last mile connector to other modes, as well as for both short and long distance destinations. In 2012, 22 IT-based public bikesharing systems were operating in the United States, with a total of 884,442 users and 7,549 bicycles. Four IT-based programs in Canada had a total of 197,419 users and 6,115 bicycles. Two IT-based programs in Mexico had a total of 71,611 users and 3,680 bicycles. (Membership numbers reflect the total number of short- and long-term users.) This study evaluates public bikesharing in North America, reviewing the change in travel behavior exhibited by members of different programs in the context of their business models and operational environment. This Phase II research builds on data collected during our Phase I research conducted in 2012. During the 2012 research (Phase I), researchers conducted 14 expert interviews with industry experts and public officials in the United States and Canada, as well as 19 interviews with the manager and/or key staff of IT-based bikesharing organizations. For more information on the Phase I research, please see the Shaheen et al., 2012 report Public Bikesharing in North America: Early Operator and User Understanding. For this Phase II study, an additional 23 interviews were conducted with IT-based bikesharing organizations in the United States, Canada, and Mexico in Spring 2013. Notable developments during this period include the ongoing expansion of public bikesharing in North America, including the recent launches of multiple large bikesharing programs in the United States (i.e., Citi Bike in New York City, Divvy in Chicago, and Bay Area Bike Share in the San Francisco Bay Area). In addition to expert interviews, the authors conducted two kinds of surveys with bikesharing users. One was the online member survey. This survey was sent to all people for whom the operator had an email address.The population of this survey was mainly annual members of the bikesharing system, and the members took the survey via a URL link sent to them from the operator. The second survey was an on-street survey. This survey was designed for anyone, including casual users (i.e., those who are not members of the system and use it on a short-term basis), to take “on-street” via a smartphone. The member survey was deployed in five cities: Montreal, Toronto, Salt Lake City, Minneapolis-Saint Paul, and Mexico City. The on-street survey was implemented in three cities: Boston, Salt Lake City, and San Antonio

Quantum field and uniformly accelerated oscillator

We present an exact treatment of the influences on a quantum scalar field in its Minkowski vacuum state induced by coupling of the field to a uniformly accelerated harmonic oscillator. We show that there are no radiation from the oscillator in the point of view of a uniformly accelerating observer. On the other hand, there are radiations in the point of view of an inertial observer. It is shown that Einstein-Podolsky-Rosen (EPR) like correlations of Rindler particles in Minkowski vacuum states are modified by a phase factor in front of the momentum-symmetric Rindler operators. The exact quantization of a time-dependent oscillator coupled to a massless scalar field was given.Comment: 28 pages, LaTe