7,350 research outputs found
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China and the United States—A Comparison of Green Energy Programs and Policies
[Excerpt] China is the world’s most populous country with over 1.3 billion people. It has experienced tremendous economic growth over the last three decades with an annual average increase in gross domestic product of 9.8% during that period. This has led to an increasing demand for energy, spurring China to add an average of 53 gigawatts (gw) of electric capacity each year over the lastten years to its power generation capabilities.
China has set ambitious targets for developing its renewable energy resources with a major push of laws, policies, and incentives in the last few years. The wind power sector is illustrative of China’s accomplishments, as installed wind power capacity has gone from 0.567 gw in 2003 to 12.2 gw in 2008, and China surpassed the United States in 2010 with over 41 gw of installed wind power capacity. Notably, however, approximately one-third of that capacity is not yet connected to the power grid. Plans already exist to grow China’s wind power capacity to 100 gw by 2020. A similar goal exists for the solar photovoltaic power sector which China intends to increase generating capacity from 0.14 gw as of 2009 to over 1.8 gw by 2020. A hold on large and medium-scale hydropower project development has been lifted, with a virtual doubling of hydropower capacity planned. Most recently, China pledged ahead of the Copenhagen talks in 2009 that 15% of total energy consumption will come from non-fossil fuel sources by the year 2020. The 12th Five Year Plan will encompass 2011 to 2015, and will further formalize the link to green energy with specific deployment goals and investment. China recognizes that developing its domestic renewable energy industry and building its manufacturing capacity will help it meet energy demands at home and win advantages in future export markets.
The key piece of legislation in recent years for advancing renewable electricity in China is the Renewable Energy Law of 2005. The law was designed to “promote the development and utilization of renewable energy, improve the energy structure, diversify energy supplies, safeguard energy security, protect the environment, and realize the sustainable development of the economy and society.” Renewable energy is subsidized by a fee charged to all electricity users in China of about 0.029 cents per kilowatt-hour, and was originally based on the incremental cost difference between coal and renewable energy power generation.
However, energy efficiency and conservation are officially China’s top energy priority. These are considered the “low-hanging fruit” in the quest to reduce energy use and cut demand. Energy conservation investment projects have priority over energy development projects under the Energy Conservation Law of 1997, with government-financed projects being selected on “technological, economic and environmental comparisons and validations of the projects.” China is the world’s largest market for new construction, and new building standards have been in development since 2005 with national energy design criteria for residential buildings. In the power generation sector, many smaller, less efficient coal-fired power plants have been closed.
In contrast to China, some argue that the United States does not have a comprehensive national policy in place for promotion of renewable energy technologies, with some observers saying that the higher costs of renewable electricity are not conducive to market adoption. However, for both countries, the reasons for increasing the use of renewable energy are diverse, and include energy security, energy independence, cleaner air, and more recently anthropogenic climate change, sustainability concepts, and economic development. Creating new, higher quality jobs could reasonably be said to be primary drivers of policy goals in both the United States and China
Genome-wide mapping reveals single-origin chromosome replication in Leishmania, a eukaryotic microbe
Background
DNA replication initiates on defined genome sites, termed origins. Origin usage appears to follow common rules in the eukaryotic organisms examined to date: all chromosomes are replicated from multiple origins, which display variations in firing efficiency and are selected from a larger pool of potential origins. To ask if these features of DNA replication are true of all eukaryotes, we describe genome-wide origin mapping in the parasite Leishmania.
Results
Origin mapping in Leishmania suggests a striking divergence in origin usage relative to characterized eukaryotes, since each chromosome appears to be replicated from a single origin. By comparing two species of Leishmania, we find evidence that such origin singularity is maintained in the face of chromosome fusion or fission events during evolution. Mapping Leishmania origins suggests that all origins fire with equal efficiency, and that the genomic sites occupied by origins differ from related non-origins sites. Finally, we provide evidence that origin location in Leishmania displays striking conservation with Trypanosoma brucei, despite the latter parasite replicating its chromosomes from multiple, variable strength origins.
Conclusions
The demonstration of chromosome replication for a single origin in Leishmania, a microbial eukaryote, has implications for the evolution of origin multiplicity and associated controls, and may explain the pervasive aneuploidy that characterizes Leishmania chromosome architecture
Low Reynolds Number Aerodynamic Characteristics of Several Airplane Configurations Designed to Fly in the Mars Atmosphere at Subsonic Speeds
A 1/4-scale wind tunnel model of an airplane configuration developed for short duration flight at subsonic speeds in the Martian atmosphere has been tested in the Langley Research Center Transonic Dynamics Tunnel. The tunnel was pumped down to extremely low pressures to represent Martian Mach/Reynolds number conditions. Aerodynamic data were obtained and upper and lower surface wind pressures were measured at one spanwise station on some configurations. Three unswept wings of the same planform but different airfoil sections were tested. Horizontal tail incidence was varied as was the deflection of plain and split trailing-edge flaps. One unswept wing configuration was tested with the lower part of the fuselage removed and the vertical/horizontal tail assembly inverted and mounted from beneath the fuselage. A sweptback wing was also tested. Tests were conducted at Mach numbers from 0.50 to 0.90. Wing chord Reynolds number was varied from 40,000 to 100,000 and angles of attack and sideslip were varied from -10deg to 20deg and -10deg to 10deg, respectively
DNA Fingerprinting
The purpose of this IQP was to trace the development and progress of DNA fingerprinting technology as it continues to be a integral part of judicial systems and societies world-wide. Much of the initial DNA fingerprinting methods and techniques have undergone substantial improvements to satiate the bombardment of skeptics, giving the technology more credibility in courts. However, there is still the unresolved issue of privacy laws that continue to complicate the issue of who should submit samples to DNA databases
The He abundance in the metal-deficient blue compact dwarf galaxies Tol 1214-277 and Tol 65
We present high-quality Keck telescope spectroscopic observations of the two
metal-deficient blue compact dwarf (BCD) galaxies Tol 1214-277 and Tol 65.
These data are used to derive the heavy-element and helium abundances. We find
that the oxygen abundances in Tol 1214-277 and Tol 65 are the same,
12+logO/H=7.54+/-0.01, or Zsun/24, despite the different ionization conditions
in these galaxies. The nitrogen-to-oxygen abundance ratio in both galaxies is
logN/O=-1.64+/-0.02 and lies in the narrow range found for the other most
metal-deficient BCDs. We use the five strongest HeI emission lines 3889, 4471,
5876, 6678 and 7065, to correct self-consistently their intensities for
collisional and fluorescent enhancement mechanisms and to derive the He
abundance. Underlying stellar absorption is found to be important for the HeI
4471 emission line in both galaxies, being larger in Tol 65. The weighted He
mass fractions in Tol 1214-277 and Tol 65 are respectively Y=0.2458+/-0.0039
and 0.2410+/-0.0050 when the three HeI emission lines, 4471, 5876 and 6678, are
used, and are, respectively, 0.2466+/-0.0043 and 0.2463+/-0.0057 when the HeI
4471 emission line is excluded. These values are in very good agreement with
recent measurements of the He mass fraction in others of the most
metal-deficient BCDs by Izotov and coworkers. We find that the combined effect
of the systematic uncertainties due to the underlying HeI stellar absorption
lines, ionization and temperature structure of the HII region and collisional
excitation of the hydrogen emission lines is likely small, not exceeding ~2%
(the error is 2sigma). Our results support the validity of the standard big
bang model of nucleosynthesis.Comment: 22 pages, 3 Postscript figures, accepted for publication in the
Astrophysical Journa
Mobile satellite propagation measurements and modeling: A review of results for systems engineers
An overview of Mobile Satellite Service (MSS) propagation measurements and modeling is intended as a summary of current results. While such research is on-going, the simple models presented here should be useful to systems engineers. A complete summary of propagation experiments with literature references is also included
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Regulatory Incentives for Electricity Transmissions-Issues and Cost Concerns
This report will focus on issues related to the need for transmission incentives, and consumer cost concerns related to these incentives. Given the changes that FERC cites in the electric industry, the question arises as to whether the need for transmission incentives continues. FERC is bound by EPACT to make incentives available, and is not proposing to end the incentives. However, with concerns raised over the effects of transmission incentives on consumer rates, implications of related federal policies on the electric power sector, additional FERC regulatory policies for transmission, and the aging of electricity infrastructure among key issues, the need for continuing transmission incentives may be a matter for Congress to consider
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Options for a Federal Renewable Electricity Standard
This report discusses current ideas for a federal Renewable Electricity (or Energy) Standard (RES) and a broader Clean Energy Standard (CES). The goal of this report is to explore how such policies could potentially increase the amounts of renewable electricity generated in the United States, discussing other related
public policy goals and rationales for renewable energy development, and the challenges/drawbacks of RES policy
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