Transportation is another sector that has increased its relative share of primary energy use. This sector has serious concerns as it is a significant source of CO2 emissions and other airborne pollutants, and it is almost totally based on oil as its energy source. An important aspect of future changes in transportation depends on what happens to the available oil resources, production and prices. At present, 95% of all energy for transportation comes from oil. (more…)
Under both former President Bush and new President Obama, the U.S. government has vowed to reduce reliance on imported oil. The ...
Global energy consumption in the last half century has increased very rapidly and is expected to continue to grow over the next ...
From prehistory until the Industrial Revolution, most energy sources used by humans were localized (i.e., available within 5–10 mil ...
Do we have the resources? Rudolf Diesel developed the diesel engine which ran on biodiesel vegetable oil in the late 1800s. At the ...
One study that does address the peak-oil scenario directly is a 2005 report conducted for the National Energy Technology Labora ...
The word “laser” is an acronym for “light amplification by the stimulated emission of radiation.” Lasers of all kinds consist of several basic components: an active medium, an outside energy source, and an optical cavity with carefully designed mirrors on both ends. One of the mirrors is 100 percent reflective while the other is somewhat less reflective, so a beam can be emitted. The active medium is inside the optical cavity and is excited with an external energy source (typically electricity). For the cavity to emit laser radiation, the active medium has to achieve an unusual energy state called “population inversion.” (more…)
The first known laser was made by Theodore Maiman at Hughes Research Laboratories in Malibu, California, in 1960, but the seeds ...
Different lasers use different materials as the active medium. The medium can be either solid, liquid, or gas, and there are ad ...
There are literally thousands of uses for lasers. One of the largest applications is telecommunications—sending a signal throug ...
It is known that laser printers print faster, but swallow a large amount of energy, even if the printer is in the energy saving ...
Fabrication techniques developed for integrated circuit (IC) production have been refined to the extent of supporting a multi-b ...
Although some scientists and critics still dispute that human caused greenhouse gases are causing climate change, the majority of scientists and climate experts assert that global warming is a serious problem that could have devastating consequences unless action is taken to reduce fossil fuel emissions. In 2007, for example, the Nobel Prize–winning Intergovernmental Panel on Climate Change (IPCC), a scientific body charged by the United Nations with summarizing the best climate science, concludes that evidence of the warming of our climate is “unequivocal.” (more…)
Still hotly debated by some, human-induced global warming is now accepted in the scientific community. Earth’s average yearly tempe ...
Since the early 1960s, climate change and air quality have become major and often controversial issues in many countries and am ...
Addressing global warming, however, is a highly complex and daunting endeavor. Many climate experts have urged the world to stabili ...
Earth’s climate is a complex system of interacting natural components. These components include the atmosphere, the ocean, and the ...
Options for dealing with the threats of climate change include both adaptation to inevitable changes and mitigation, or lessening, ...
Reductions in carbon intensity, C/E, the carbon emitted per unit of energy generated, reflect the degree to which societies decarbonize their energy sources. The long-term trend has been a shift from coal to oil to natural gas––hydrocarbons with decreasing C/H ratios emitting progressively less CO2 per joule. However, the increasing use of clean low-carbon fuels is not sustainable without somehow disposing of excess carbon because it opposes the trend in the abundance of fossil fuels, with coal resources being the most abundant followed by oil and gas. (more…)
The global cycling of carbon involves both biological and physical processes. Only the biological components are discussed here. Pl ...
The flux of carbon among terrestrial, aquatic, and atmospheric pools is at least partially controlled by photosynthetic process ...
It is of interest to examine potential sources of greenhouse gases sources or atmospheric CO2 by analysis of the global distrib ...
Climate change caused by the enhanced greenhouse effect is one of the most significant global environmental issues. Increased emiss ...
The global carbon cycle involves both biological and physical processes. Only the biological components are discussed here. Pla ...
Scientists study Earth’s climate not just from observation but also from a theoretical perspective. Modern-day climate models successfully reproduce the key features of Earth’s climate, including the variations in wind patterns around the globe, the major ocean current systems such as the Gulf Stream, and the seasonal changes in temperature and rainfall associated with Earth’s annual revolution around the sun. The models also reproduce some of the more complex natural oscillations of the climate system. Just as the atmosphere displays random day-to-day variability that we term “weather,” the climate system produces its own random variations, on timescales of years. (more…)
Earth’s climate is a complex system of interacting natural components. These components include the atmosphere, the ocean, and the ...
Still hotly debated by some, human-induced global warming is now accepted in the scientific community. Earth’s average yearly tempe ...
Options for dealing with the threats of climate change include both adaptation to inevitable changes and mitigation, or lessening, ...
Although some scientists and critics still dispute that human caused greenhouse gases are causing climate change, the majority of s ...
Since preindustrial times, ambient concentrations of the greenhouse gases have exhibited substantial increases, inter alia CO2 ...
Addressing global warming, however, is a highly complex and daunting endeavor. Many climate experts have urged the world to stabilize greenhouse gas concentrations in the atmosphere around 450 to 550 parts per million (ppm)—that is, no more than 450 to 550 units of greenhouse gases for every million units of air in the earth’s atmosphere. This approach, experts say, could keep average global temperatures at no more than 3.6° Fahrenheit (2° Celsius) above preindustrial levels, which could avoid some of the worst, irreversible consequences of climate change. (more…)
Although some scientists and critics still dispute that human caused greenhouse gases are causing climate change, the majority of s ...
Climate change caused by the enhanced greenhouse effect is one of the most significant global environmental issues. Increased emiss ...
Options for dealing with the threats of climate change include both adaptation to inevitable changes and mitigation, or lessening, ...
Scientists study Earth’s climate not just from observation but also from a theoretical perspective. Modern-day climate models succe ...
Earth’s climate is a complex system of interacting natural components. These components include the atmosphere, the ocean, and the ...
Fuel cell vehicles are being developed because they promise to meet the requirements expected of automobiles in a market increasingly constrained by environmental and resource limitations. Air pollution and oil dependence have been persistent challenges for vehicles powered by petroleum fuels (gasoline and diesel). Global warming presents a new challenge in the need to limit carbon dioxide (CO) emissions from fossil fuel combustion. (more…)
There are different types of vehicle propulsion systems and the transportation fuels that have been studied for their potential ...
The internal combustion engine has dominated the car and light-truck market for over 100 years. Although remarkable improvement ...
The commercialization prospects for fuel cell vehicles depend not only on their performance and cost, but also on how well th ...
A fuel cell is an electrochemical device that directly converts a fuel to electricity by means of reactions on the surfaces of ...
The leading automotive brands are being focused to produce electric vehicles because they believe they represent a harmony to the e ...
The European Automobile Manufacturers Association (ACEA) has offered, and the European Commission (EC) has accepted, a voluntary commitment to reduce the CO2 emissions from new light-duty passenger vehicles, with firm fleetwide targets of 140 g CO2 /km (B41 mpg for gasoline) by 2008, measured under the new European test cycle (Directives 93/116/EC and 99/100/EC). This represents approximately a 25% reduction from the 1995 average of 187 g/km (B30 mpg) on this cycle. The European cycle is likely to produce lower fuel economy ratings than the U.S. combined urban/ highway cycle, so the ‘‘U.S. equivalent’’ miles per gallon ratings of the year 2008 European fleet will likely be higher than 41 mpg if the targets are met. (more…)
Although the automotive industry is a vigorous sponsor of research and development in vehicle efficiency technology—worldwide, ...
Addressing global warming, however, is a highly complex and daunting endeavor. Many climate experts have urged the world to stabili ...
We know of no studies that have examined vehicle taxation incentives programs elsewhere in the world, but it seems likely that ...
A variety of information programs exist in the major automobile markets to assist potential purchasers of new cars in comparing fue ...
There are various and somewhat complementary reasons to foster the growth of renewable energy sources in Europe. A major incent ...
At present, in the United States and worldwide, motor vehicles are fueled almost exclusively by petroleum based gasoline (or reformulated gasoline) and diesel fuels. Since the first oil price shock in 1973, efforts have been made to seek alternative fuels to displace gasoline and diesel fuels and achieve energy and environmental benefits. Some of the alternative fuels that have been researched and used are liquefied petroleum gas (LPG), compressed natural gas (CNG), liquefied natural gas (LNG), methanol (MeOH), dimethyl ether (DME), Fischer– Tropsch diesel (FTD), hydrogen (H 2 ), ethanol (EtOH), biodiesel, and electricity. Production processes associated with gasoline, diesel, and each of these alternative fuels differ. (more…)
There are different types of vehicle propulsion systems and the transportation fuels that have been studied for their potential ...
Gasoline is used mainly by cars, motorcycles, and light trucks; diesel is used mainly by heavier trucks, buses, and trains. Togethe ...
The energy efficiencies of various fuel production pathways from well to pump. The efficiencies shown are defined as the energy ...
The United States depends heavily on imported oil to fuel its transportation infrastructure. The use of alternative fuel derive ...
Most alternative fuel vehicles on the road today were originally designed for gasoline, but converted for use with an alternative f ...
The fuel cycle for a given transportation fuel includes the following processes: energy feedstock (or primary energy) production; biomass feedstock transportation and storage; fuel production; fuel transportation, storage, and distribution; and vehicle operations that involve fuel combustion air or other chemical energy conversions. The processes that precede vehicle operations are often referred to as the well-to-pump (WTP) stage, the vehicle operations are referred to as the pump-to-wheels (PTW) stage, and the entire fuel cycle is referred to as the well-to-wheels (WTW) cycle. Various models have been developed that allow researchers to conduct fuel cycle analyses of vehicle/fuel systems. The GREET (greenhouse gases, regulated emissions, and energy transportation) model, developed by Argonne National Laboratory, is in the public domain and, so far, more than 1000 users worldwide have used the model to predict the energy use and emissions associated with alternative fuels vehicles. The GREET model and its documents are posted on the Internet at http:// greet.anl.gov. (more…)
The spark-ignition and compression-ignition engine and internal combustion engines technologies that are currently employed in ...
Because different studies have different system boundaries and parametric assumptions, the studies described in Section 7 resulted ...
ISO document 14040 identifies four areas for using life cycle analysis (LCA) results: (1) identifying opportunities to improve ...
It shows Well-to-Wheels Greenhouse Gas emissions of the 23 vehicle/fuel systems. For each system, the bottom bar represents CO2 ...
The combination of well-to-pump results and the energy use and emissions associated with vehicle operation (also called the pum ...