Modeling energy consumption and CO2 emissions at the urban scale: Methodological challenges and insights from the United States

Local policy makers could benefit from a national, high-resolution inventory of energy consumption and related carbon dioxide (CO₂) emissions based on the Vulcan data product, which plots emissions on a 100 km² grid. We evaluate the ability of Vulcan to measure energy consumption in urban areas, a scale of analysis required to support goals established as part of local energy, climate or sustainability initiatives. We highlight the methodological challenges of this type of analytical exercise and review alternative approaches. We find that between 37% and 86% of direct fuel consumption in buildings and industry and between 37% and 77% of on-road gasoline and diesel consumption occurs in urban areas, depending on how these areas are defined. We suggest that a county-based definition of urban is preferable to other common definitions since counties are the smallest political unit for which energy data are collected. Urban counties, account for 37% of direct energy consumption, or 50% if mixed urban counties are included. A county-based definition can also improve estimates of per-capita consumption.     

Ground influence on the input impedance of transient dipole and bow-tie antennas

In this paper, the influence of a lossy ground on the input impedance of dipole and bow-tie antennas excited by a short pulse is investigated. It is shown that the ground influence on the input impedance of transient dipole and bow-tie antennas is significant only for elevations smaller than 1/5 of the wavelength that corresponds to the central frequency of the exciting pulse. Furthermore, a principal difference between the input impedance due to traveling-wave and standing-wave current distributions is pointed out.     

Effects of ethnicity on treatment attendance, stimulant response/dose, and 14-month outcome in ADHD.

From the Multimodal Treatment Study of Children with Attention- Deficit/Hyperactivity Disorder--a randomized clinical trial of 579 children ages 7-9 years receiving 14 months of medication management, behavioral treatment, combination, or community care--the authors matched each African American and Latino participant with randomly selected Caucasian participants of same sex, treatment group, and site. Although Caucasian children were significantly less symptomatic than African American and Latino children on some ratings, response to treatment did not differ significantly by ethnicity after controlling for public assistance. Ethnic minority families cooperated with and benefited significantly from combination (multimodal) treatment (d = 0.36, compared with medication). This incremental gain withstood statistical control for mother's education, single-parent status, and public assistance. Treatment for lower socioeconomic status minority children, especially if comorbid, should combine medication and behavioral treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

驾驭WindowsXP的八大技巧

许多人都用上了WindowsXP,面对WindowsXP的新面孔,可别被这些五颜六色的外观吓倒了。实际上,WindowsXP是通过集成Windows2000(安全性、可管理性和可靠性)与Windows98/Me(即插即用、易用的用户界面、创新的支持服务)的组合,再加上迷人的外观而形成的操作系统。但是,怎样才能让你自如地驾驭这个新的操作系统呢?还是看看笔     

Generalized approach for modeling minimally invasive surgery as a stochastic process using a discrete Markov model

Minimally invasive surgery (MIS) involves a multidimensional series of tasks requiring a synthesis between visual information and the kinematics and dynamics of the surgical tools. Analysis of these sources of information is a key step in defining objective criteria for characterizing surgical performance. The Blue DRAGON is a new system for acquiring the kinematics and the dynamics of two endoscopic tools synchronized with the endoscopic view of the surgical scene. Modeling the process of MIS using a finite state model [Markov model (MM)] reveals the internal structure of the surgical task and is utilized as one of the key steps in objectively assessing surgical performance. The experimental protocol includes tying an intracorporeal knot in a MIS setup performed on an animal model (pig) by 30 surgeons at different levels of training including expert surgeons. An objective learning curve was defined based on measuring quantitative statistical distance (similarity) between MM of experts and MM of residents at different levels of training. The objective learning curve was similar to that of the subjective performance analysis. The MM proved to be a powerful and compact mathematical model for decomposing a complex task such as laparoscopic suturing. Systems like surgical robots or virtual reality simulators in which the kinematics and the dynamics of the surgical tool are inherently measured may benefit from incorporation of the proposed methodology.     

Bioethanol production from ball milled bagasse using an on-site produced fungal enzyme cocktail and xylose-fermenting Pichia stipitis

Sugarcane bagasse is one of the most promising agricultural by-products for conversion to biofuels. Here, ethanol fermentation from bagasse has been achieved using an integrated process combining mechanical pretreatment by ball milling, with enzymatic hydrolysis and fermentation. Ball milling for 2 h was sufficient for nearly complete cellulose structural transformation to an accessible amorphous form. The pretreated cellulosic residues were hydrolyzed by a crude enzyme preparation from Penicillium chrysogenum BCC4504 containing cellulase activity combined with Aspergillus flavus BCC7179 preparation containing complementary β-glucosidase activity. Saccharification yields of 84.0% and 70.4% for glucose and xylose, respectively, were obtained after hydrolysis at 45 °C, pH 5 for 72 h, which were slightly higher than those obtained with a commercial enzyme mixture containing Acremonium cellulase and Optimash BG. A high conversion yield of undetoxified pretreated bagasse (5%, w/v) hydrolysate to ethanol was attained by separate hydrolysis and fermentation processes using Pichia stipitis BCC15191, at pH 5.5, 30 °C for 24 h resulting in an ethanol concentration of 8.4 g/l, corresponding to a conversion yield of 0.29 g ethanol/g available fermentable sugars. Comparable ethanol conversion efficiency was obtained by a simultaneous saccharification and fermentation process which led to production of 8.0 g/l ethanol after 72 h fermentation under the same conditions. This study thus demonstrated the potential use of a simple integrated process with minimal environmental impact with the use of promising alternative on-site enzymes and yeast for the production of ethanol from this potent lignocellulosic biomass.     

Microelectromechanical systems scanning-mirror-based handheld probe for fluorescence molecular tomography

A novel handheld probe based on a microelectromechanical systems (MEMS) scanning mirror for three-dimensional (3D) fluorescence molecular tomography (FMT) is described. The miniaturized probe consists of a MEMS mirror for delivering an excitation light beam to multiple preselected points at the tissue surface and an optical fiber array for collecting the fluorescent emission light from the tissue. Several phantom experiments based on indocyanine green, an FDA approved near-infrared (NIR) fluorescent dye, were conducted to assess the imaging ability of this device. Tumor-bearing mice with systematically injected tumor-targeted NIR fluorescent probes were scanned to further demonstrate the ability of this MEMS-based FMT for imaging small animals.     

Optimization of Non-Fluorine Sol-Gel Derived YBCO Thin Films

Sol-gel deposition of thin film YBa₂Cu₃O_7– (YBCO) is widely seen as the most cost effective means to manufacture long length HTS wires (A.P. Malozemoff, D.T. Verebelyi, S. Fleshler, D. Aized, and D. Yu, HTS Wire: Status and Prospects, Physica C, 386, 424 (2003)). We present a sol-gel technique for YBCO deposition using low cost starting materials and forming only benign by-products during processing. Optimization has concentrated on producing the correct stoichiometry in the final films. RBS measurements show that copper diffuses into the substrate due to its high mobility at the temperatures required to form the YBCO phase. Therefore a starting stoichiometry of 1:2:3 can produce a film highly copper deficient. In order to compensate for this we have made films with different excesses of copper in the precursor solution. The surface morphologies of these films have been examined by SEM and AFM, and the stoichiometry and cation depth profiles characterized by ion beam analysis. The effect of the varying copper stoichiometry is correlated with the superconducting properties and the surface morphology for films on lanthanum aluminate (LAO) and magnesium oxide (MgO) substrates. The residual carbon concentration in the films is measured by nuclear reaction analysis.