Electric airplanes are not in the immediate future, but better batteries a few decades out or hybrid power sources make it likely they'll appear in some manned applications. If you can distribute propellers on the airplane it is possible to build more efficient wings. NASA is building an experimental airplane to test ideas as part of its Leading Edge Asynchronous Propeller Technology (LEAPTech) project. A special wing that will house 18 electric motors will be fitted to a small private airplane to test the concept.
Although the range is limited to about 200 miles with conventional batteries aerodynamic efficiency, propulsion efficiency, emissions, noise, safety, vibration. operation costs and greenhouse emissions are improved - sometimes dramatically.
A doubling of battery energy density (mass) seems likely in the next decade - that would make this type of airplane practical for many applications. It is also possible to imagine a hybrid system with a small fossil fuel engine with a generator supplying power directly the the motors - possibly with a small battery to supply extra power for takeoffs. The improvements allowed by the improved wing result in overall improvements before better batteries are available.
Any time you want to make an exact copy of an object with a 3-D printer, the first step is to produce a high-resolution scan of the object with a 3-D camera that measures its height, width, and depth. Such 3-D imaging has been around for decades, but the most sensitive systems generally are too large and expensive to be used in consumer applications. A cheap, compact yet highly accurate new device known as a nanophotonic coherent imager (NCI) promises to change that. Using an inexpensive silicon chip less than a millimeter square in size, the NCI provides the highest depth-measurement accuracy of any such nanophotonic 3-D imaging device.
The technically inclined may want to look at the paper
Nanophotonic coherent imager
Firooz Aflatouni,1,2 Behrooz Abiri,1 Angad Rekhi,1 and Ali Hajimiri1
1Department of Electrical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
2Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
Abstract: An integrated silicon nanophotonic coherent imager (NCI), with a 4 × 4 array of coherent pixels is reported. In the proposed NCI, on-chip optical processing determines the intensity and depth of each point on the imaged object based on the instantaneous phase and amplitude of the optical wave incident on each pixel. The NCI operates based on a modified time-domain frequency modulated continuous wave (FMCW) ranging scheme, where concurrent time-domain measurements of both period and the zero-crossing time of each electrical output of the nanophotonic chip allows the NCI to overcome the traditional resolution limits of frequency domain detection. The detection of both intensity and relative delay enables applications such as high-resolution 3D reflective and transmissive imaging as well as index contrast imaging. We demonstrate 3D imaging with 15μm depth resolution and 50μm lateral resolution (limited by the pixel spacing) at up to 0.5-meter range. The reported NCI is also capable of detecting a 1% equivalent refractive index contrast at 1mm thickness.
Somewhat more practical-minded researchers based in Brooklyn, New York, are aiming to produce cultured meat at a company called Modern Meadow (the names of these companies, you will have noticed, border on the Orwellian). Gabor Forgacs, a theoretical physicist who changed midcareer to developmental biology, and his son, Andras, are incubating beef cells and mixing them with pectin and spices to create a range of products, including “baked steak chips.” Their original company, Organovo, intended to produce living tissue for drug testing; food seemed to be an equally achievable goal. Of course, Modern Meadow has its own Silicon Valley angel: Peter Thiel.
In theory, cultured meat can be scaled and may offer something closer to real meat than any other inventions in the works. By its nature, it would offer the complex flavors of meat. But it is still in the basic-research phase. The problems are many: scientists must figure out how to build intramuscular fat, sinew, cartilage, and even bone, and a structure to mimic veins and blood vessels that will keep the cells fed so they don’t become gangrenous. The work is so expensive that the steps forward are likely to come from trying to produce organs for transplant—which are “worth millions of dollars a pound instead of $10 a pound,” as Myhrvold points out.
Like the Gold video, Stainless opens up with numerous beauty shots directly from the foundry floor as the molten 316L is processed into what foundries call "sticks." The molten metal passes out of the bottom of a crucible (typically located on the top floor of a multi-story foundry) through a valve and into a series of shaping steps that form each stick as the metal's viscosity rises in the transformation back into a solid. This process is very precisely controlled in order to properly form the final stick's grain structure and hardness. Apple is producing the watches in enough volume that they can easily specify the exact alloy composition of the entire crucible of material, as well as define the precise temper, hardness and stick dimensions.
Apple chooses to not show what is likely the most unique and important step in the production of the Watch; cold forging. In production forging, a blank of metal is placed between two extraordinarily hard steel dies that have the bottom and top halves formed into open faced molds. The hammer - a piece of capital equipment roughly the size of a house laid on it's end - slams the dies closed with force measured in tens of thousands of tonnes. Under such pressure, the metal reaches a state called "plastic deformation" and literally bends, compresses and flows into the shaped cavities of the die. For complex, or high-precision forging, multiple dies with successively deeper cavities are used to gradually tease the material into the desired shape.
Forging produces what's called a "net shape" part; the process is unable to create precision holes, pockets, threads and other features that will require a trip to the CNC mills. What forging does do is create parts of exceptional strength. In the textbook graphic above, we see an illustration of the grain structure for a cast, machined and forged component. We can see the forged variant has an intact grain lattice that is flowing and curving to meet the final shape of the part, leading to tremendous strength,
A few years ago the Department of Energy introduced its SuperTruck program to spur efficiency improvements in large tractor-trailer trucks.
Improving the efficiency of long-haul tractor-trailers is one of the many ways that the United States can reduce the amount of petroleum we use and the carbon pollution we produce. Commercial trucks, which include Class 8 vehicles, haul as much as 80% of the goods transported in the country. Although they only make up 4% of vehicles on the road, they use about 20% of the fuel consumed.
Increasing these vehicles’ efficiency can also benefit our overall economy. In general, the long-haul truck fleet is quick to adopt technologies that improve fuel efficiency and lower costs for owner-operators. Based on the current price of diesel, these technologies should save truck operators more than $20,000 per year on fuel costs.
Lowering these trucks’ fuel costs reduces the amount companies need to spend on transportation and can allow retailers to charge less for their goods. If all Class 8 trucks in the U.S. were SuperTrucks, the country would consume nearly 300 million fewer barrels of oil and spend nearly $30 billion less on fuel each year.
We're a long way from practical pure electric airplanes, but a variety of hybrids might make sense. A few groups are advancing technology. Siemens has flown a small general aviation test plane, but more significantly is working on components.
A good lightweight electric motor can produce as much as 1 kilowatt per kilogram of weight and the best automobile electric motors are around 2 kW/kg. The new Siemens motor produces over 5 kW/kg - an amazing power to weight ratio that far exceeds internal combustion engines in cars. Its speed range is such that gearing to the propeller isn't necessary.
This could lead to greater flexibility in airframe design. Some motors may be distributed along the wing with a small gas turbine running a generator located in the airframe. The "transmission" would be power cables. As battery technology progresses one can a hybrid with batteries being used for the power demands of takeoff. Or perhaps an electric motor could be integrated with a turbofan motor connected to a battery to supply more power for takeoff. Ultimately metal air batteries would have power densities such that pure electric airplanes are possible.
A gasoline powered car turns about 75% of the energy you buy into waste heat. Electric cars are much more efficient - something like 20% of the energy is lost at the car (ignoring the efficiency of gasoline and electricity production). The concentration of cars in cities can be high enough to raise the temperature - on warm days that can increase cooling costs.
In a paper published in Nature's Science Reports the impact of moving from internal combustion to electric cars is studied to Beijing. (of course you do better moving to even more efficient transit - public transit and cycling)
Hidden Benefits of Electric Vehicles for Addressing Climate Change
1College of Electrical and Information Engineering, Hunan University, Changsha 410082, China,
2Centre for Systems Integration and Sustainability, Michigan State University, RM 115, S. Harrison RD, East Lansing, MI, 48823, USA,
3Centre for Energy, Environmental and Economic Systems Analysis, Argonne National Laboratory, 9700 S. Cass Avenue, Bldg. 221Argonne, IL 60439, USA.
There is an increasingly hot debate on whether the replacement of conventional vehicles (CVs) by electric vehicles (EVs) should be delayed or accelerated since EVs require higher cost and cause more pollution than CVs in the manufacturing process. Here we reveal two hidden benefits of EVs for addressing climate change to support the imperative acceleration of replacing CVs with EVs. As EVs emit much less heat than CVs within the same mileage, the replacement can mitigate urban heat island effect (UHIE) to reduce the energy consumption of air conditioners, benefitting local and global climates. To demonstrate these effects brought by the replacement of CVs by EVs, we take Beijing, China, as an example. EVs emit only 19.8% of the total heat emitted by CVs per mile. The replacement of CVs by EVs in 2012 could have mitigated the summer heat island intensity (HII) by about 0.946C, reduced the amount of electricity consumed daily by air conditioners in buildings by 14.44 million kilowatt-hours (kWh), and reduced daily CO2 emissions by 10,686 tonnes.