Wednesday 14 November 2018

Sun Power Tricycles and How to build a Solar Powered Trike



Travel for free with the power of the sun!


Solar-Powered Tricycles: Zero emissions while transporting thousands of people

In Nigeria, mass transit systems are chaotic and in many places non-existent; no Nigerian city has an intra-city rail system and only Lagos has a bus rapid transport scheme. Commuters have to rely on small buses (most of which are old and creaking), taxis and auto rickshaws or tricycles (popularly called keke).

These tricycles which are capable of carrying up to 4 passengers ferry hundreds of thousands of passengers in towns and cities across the country, mostly across short distances. They have provided jobs for thousands of tricycle drivers. However, they are heavy air polluters and have been banned in countries such as India and Sri Lanka. Whilst India and Sri Lanka are using the force of law to outlaw the smoking rickshaws, many other countries are voluntarily replacing them with cleaner versions running on compressed natural gas (CNG) or liquefied natural gas (LPG).

Despite the fact that there are no attempts in Nigeria to either phase them out or enforce higher standards on them, one entrepreneur is planning to change all of that.

Arthur Okeyika through his Arthur Energy Company has developed a tricycle which runs entirely on solar energy. The benefits are obvious: it is clean and non-polluting with zero emissions, and also doesn't need fuel, the cost of which has been rising in Nigeria.

The solar-powered tricycle does not just hold an advantage over its conventional counterpart in how clean it is ¨C it also trumps it in terms of performance. Possessing a 100 amps battery with a lifetime of 3-5 years, the solar-powered tricycle can travel distances of up to 170 kilometres on a single charge.

All of this translates into enormous cost savings for the tricycle operators: although a solar-powered tricycle costs N950,000 compared to the conventional tricycle which costs about N550,000, the absence of fuelling costs and the lower maintenance costs far outweigh the cost difference between the two models.

"A conventional tricycle operator makes about N7000 daily and spends about N1500 daily on fuel. He also spends about N40,000 annually on maintenance of his tricycle. When you take away the cost of fuelling and steep maintenance costs with the solar-powered tricycle, it gives him the power to earn up to N400,000 more yearly. This is almost the cost of a new conventional tricycle," said Mr. Okeyika.

Mr. Okeyika who has set up an assembly plant in the town of Onitsha in Anambra State envisions that the solar-powered tricycle will create a value chain from the sourcing of components for its assembly, which is currently at 80% locally sourced, to solar charging and servicing stations for the tricycles ¨C all of which will create lots of jobs.

Mr. Okeyika, who said he was inspired by his experience in electrical engineering and training in solar power, dreams of eventually making solar cars.

However, his current challenge is raising the financing for the assembly plant in order to meet his current target of assembly of 240 tricycles a month.

He has been knocking on the doors of commercial banks, the Anambra State Government, the Bank of Industry and the National Automotive Design and Development Council in order to access the needed financing via loans and grants.

 Nigeria has identified transportation as one of the priority sectors for emissions reduction in its low carbon growth strategy called the Nationally Determined Contributions (NDCs), which are part of the Paris Climate Agreement.

Although estimates for the number of tricycles in Nigeria are hard to come by, it is undeniable that a large-scale adoption of solar kekes or even complete replacement of conventional ones can go a long way in achieving these NDC targets.

Conventional auto rickshaws (also known as keke) run on dirty fuel which results in emissions that can lead to major health risks. The pollution from these tricycles can cause serious health problems like lung cancer and asthma, which could be a major public health issue for densely populated cities across Nigeria. India discovered this on time, therefore, in 1998, the country  passed a law that allowed only auto rickshaws running on compressed natural gas (CNG) to operate. Studies have shown that this transition from petrol to CNG has led to a significant reduction of air pollutants in the cities.  Nigeria could emulate this example and yet take it a step further with the introduction of solar powered keke in order to cut emissions and improve air quality, which would indirectly reduce health cost significantly.

It is also encouraging that there are currently no regulations that will hamper the adoption of solar-powered tricycles. But governments can also encourage adoption through the use of deliberate policies:

For example, the use of conventional tricycles has grown in many states as a result of the banning of motorcycles for transport. In some of the states, the tricycles were subsidized by government. Similar subsidies can be given for the purchase of the solar-powered tricycle.

Also, the National Automotive Design and Development Council which is responsible for the development of a domestic car manufacturing industry and funded by a 2% auto duty collected on each imported car could give grants to cleaner modes of transport.

Nigeria will not be the first place where a solar-powered tricycle has debuted ¨C a similar one was developed by a Spanish startup early this year, while a hybrid tricycle which runs on a combination of electric, solar and pedal power was developed as far back as 2014 in the United States.

However, neither of these solar-powered tricycle models has gotten widespread adoption, especially in regions and cities that use it most for mass transportation. Thus, it potentially puts Nigeria in the position of being the first country to use such an innovation on a wide scale and being a leader in adopting renewable energy technology for keke transportation.

The purpose of this project is to build a vehicle that:


-Provides free, 'green' transportation for short distances (<10 miles), thus it must never
plug into a wall socket, or emit any pollutants.

-Charges while at work

-Is cheap, simple, and low maintenance.

-Draws attention to the practical application of green energies, and promotes Fossil Fuel alternatives.

-Reduces excess automobile wear and pollution from cold driving / short, in town trips.

-This is a is a project for Dr. Reza Toosi's 'Energy and the Environment, a global perspective' class at California State University, Long Beach. We look at the sources, technologies, and impacts of energy on our environment.

Link to other class projects, some of Dr. Toosi's ENG-302i lectures, and other interesting videos.

http://www.csulb.edu/~rtoossi/engr302i

Short video:

http://www.youtube.com/watch?v=sIiJp4aKDHM

Step 1: Acquire a Vehicle

Picture of Acquire a Vehicle
5 More Images
Find a lightweight vehicle with low rolling resistance. A two, three or four wheeler will do, depending on how much work you want to do, but the concept is the same. Four wheeled vehicles may be regulated under different laws. Of course the best vehicle is one that you already have, if you happen to have a three or four wheeled pedal powered vehicle. In the interest of simplicity, a three wheeler was chosen for my project. This Schwinn Meridian Trike was $250 new, readily available locally, and the basket provides a convenient location for batteries and solar panels with minimal fabrication.

The first thing to be done was completely disassemble the trike and paint it a bright 'fern' green. This step may not be necessary, but I felt that it was in my case since this is a school project that is supposed to grab your attention, and let you know that it is a true green vehicle. It is a vehicle that does not use gas, and does not plug in to a wall socket, which would defeat the purpose since electricity from the grid likely comes from a non-renewable energy source. It runs on pure solar energy.

Before painting the frame, I used this stage as an opportunity to reinforce the frame where the Batteries were going to mount. Lead acid Batteries are heavy, but they are relatively cheap.
One tube was welded in to distribute the load over 4 points on the axle carrier instead of two.
It also ties the rear sub-frame together, which makes the tube the load bearer rather than the weld beads, which may eventually fatigue and fail.

High pressure (65psi) tubes were equipped and the Trike was meticulously assembled in order to minimize rolling resistance.

While the welder was out a battery mount was fabricated, and bolts welded to the basket to be used as battery mount studs making removal easier. 12 volt LED's were put in the reflectors and wired as brake lights through the brake levers that cut the motor when you brake. They are wired through only one of the three 12 volt batteries.

Step 2: Drivetrain / Running Gear

The drivetrain consists of your electrical system and electric motor. The Electric Hub Motor kit was purchased from (www.Goldenmotor.com), costs $259 and consists of a front wheel with an integrated brushless 36 Volt electric motor as part of the hub, along with the necessary components such as a twist grip throttle, brake levers that are wired to cut power to the motor, battery level indicator, and the motor-speed controller, 36V battery charger and a battery pack connector. Not sure if the kit is still available but they still sell everything needed. The customer service is basically an owners forum, which did prove useful in diagnosing a bent pin in on of the electrical connections.

The motor install requires a simple front wheel change, and routing the wires back to the controller which will be mounted under the rear basket. Slack must be left in the wires around the steering tube / fork juncture so they will not be in tension even at the maximum steering angle. The grips and brake levers are replaced with the new ones, and their wires also routed back to the controller.

Choosing the right battery is a compromise between price, weight, and range vs. charge time. Lots of money can be spent on batteries, but since I was on a budget, I had to take what I could get. I took a multi-meter to a local industrial liquidation warehouse and found 3 batteries for $20 each, and have worked good so far. (3) -12 volt, 20 Amp/hour batteries are run in series to make 36 volts. 20A/hr provides long range, with the trade-off being a longer charge time. Abattery cut of switch was added so the rider does not have to unplug the battery pack to shut the electrical system off.

Step 3: Charging System / Solar Panels

The solar panels need to be as large as possible to maximize the available wattage, but they also must provide the right voltage. Solar panels produce a range of voltages, which peak and drop, but the nominal voltage of the panel is what matters for selecting the right charge controller. I purchased 3 Q-cell brand mono-crystalline solar panels that I found on Ebay for $110 each. They produce 21.8 Volts peak and 17 volts nominal, at about 1.2 amps nominal. With the 3 panels wired in series, this makes around 66 volts peak and 51 Volts nominal, which is plenty over the 42V needed to charge the batteries. a basket was added in the front to accommodate the third solar panel.

From Ohm's law Power (P) is equal to voltage (V) times current (I), (P=V*I), so the panels produce ((17Volts*3)*1.2 Amps)= 61.2 Watts nominal, and over 80 Watts peak. A Maximum power point tracking (MPPT) charge controller tricks the panels by hiding the battery load from them and allowing them to operate at their peak power when conditions allow.

A charge controller was purchased from www.solarsellers.com, where Mr John Drake was very helpful in assisting me and ordering a custom charge controller for my application. The controller basically takes the varying voltage / amperage input from the solar panel array and converts it into a constant voltage (42V) or current, to optimize charging the 36 volt source. Maximum input voltage to the controller is 100 Volts, so the peak of 66 Volts will not harm the controller. The controller is a Maximum power point tracking (MPPT) type, which charges faster as more sun is available, rather than at a set rate as most controllers do.

In order to charge the batteries in a practical amount of time, they need to charge about as fast or faster than the provided 110V wall socket to 36V charger/converter, which charges at a rate of 1.5 amps. At 1.2 amps the panels do not quite achieve this, but with the MPPT Controller it takes right around the same amount of time for a charge. The bike is stored in a location that gets a few hours of sun every day (where I live the sun is pretty reliable), which keeps the batteries topped off and ready to go whenever needed.

And for those of you wondering, the electric motor draws up to 20 Amps, and the 1.2+ Amps added by the solar panels do not make it go faster, since the 1.2 amps are routed through the controller and only serve to charge the batteries. The motor speed controller does not see this extra Amperage, and outputs just the same as without panels, except the batteries will stay charged slightly longer, (extending your range) with the net drain being (20-1.2)A= 18.8A rather than 20A without the panels. The motor only pulls 20 Amps when taking off though, so the draw is much less when at cruising speed. The motor speed controller cuts the voltage off at 32V to keep the batteries from going below 10.5V, but I monitor the voltage and try not to discharge the batteries below 36V.

Step 4: Solar Panel Mounts

Picture of Solar Panel Mounts
2 More Images
Now you have to figure out how your going to mount the panels on your vehicle. Hinges were welded on the baskets to mount the panels and allow them to tilt for access to the basket, with rubber hold-downs on the other side to keep them from opening while riding.

Once your wires are all routed and zip tied, your batteries and panels held securely down, double check every thing and you are ready to go.

Performance:
This Solar Powered Trike does about 15-18 mph depending on the weight of the rider. The furthest I have gone is a little over 10 miles with small hills and little pedaling, and the battery meter still read full (green) at the end of the trips.

At ten miles, the voltage drops to around 36V, safely above the controller's cut-off voltage. If the batteries are kept from discharging too low the panels take about the same amount of time as the plug in charger, since both the plug in charger and the solar charge controller charge with constant wattage. With constant wattage charging, Power, (P), and Ohm's law again (P=V*I), the charging current goes down as the voltage goes up, as the batteries near their fully charged state.

What this means is if you keep the voltage from dropping too low, the panels provide adequate current to match the charging speed of the plug-in charger, but if it drops below a certain point the panels are slower at charging. This is easily avoided since my typical trip range is around 3 miles or less, semi daily at most, so low voltage not an issue, but on longer trips I bring the multi-meter.

Cost Breakdown:
The Trike cost a little over $910 to build

Schwinn Meridian Trike
$250.00 www.K-Mart.com

Q-cell Mono-crystalline Solar panels:
$330.00 www.Ebay.com....

Charge Controller:
$ 95.00 www.solarseller.com

Electric Hub Motor Kit
$260.00 www.goldenmotor.com- also sells regenerative braking motor speed controllers

Batteries
$ 60.00 Earl's industrial liquidation, Hawthorne, CA

High pressure tubes $ 15.00 Any bicycle store

Total $910.00

Other solar trikes / information

http://www.solartrike.com

http://www.therapyproducts.com/products_sunnybike.html

http://www.csulb.edu/~rtoossi/engr302i

http://www.kyosemi.co.jp/product/pro_ene_sun_e.html

http://www.nanosolar.com/

The last picture is a scan of a page straight out of Dr Reza Toossi's book,
Energy and the Environment, Sources, Technologies, and Impacts.

Aerogel The Lightest Material On Earth

Aerogel is making its way into all kinds of new applications

Aerogel is a synthetic porous ultralight material derived from a gel, in which the liquid component for the gel has been replaced with a gas. The result is a solid with extremely low density and low thermal conductivity. Nicknames include frozen smoke, solid smoke, solid air, solid cloud, blue smoke owing to its translucent nature and the way light scatters in the material. It feels like fragile expanded polystyrene to the touch. Aerogels can be made from a variety of chemical compounds.

Aerogel was first created by Samuel Stephens Kistler in 1931, as a result of a bet with Charles Learned over who could replace the liquid in "jellies" with gas without causing shrinkage.

Aerogels are produced by extracting the liquid component of a gel through supercritical drying. This allows the liquid to be slowly dried off without causing the solid matrix in the gel to collapse from capillary action, as would happen with conventional evaporation. The first aerogels were produced from silica gels. Kistler's later work involved aerogels based on alumina, chromia and tin dioxide. Carbon aerogels were first developed in the late 1980s.

Aerogel is not a single material with a set chemical formula, instead the term is used to group all materials with a certain geometric structure.

 

This is an aerogel.

A classic silica aerogel monolith (image credit Prof. C. Jeffrey Brinker)

And so is this.
A flexible, mechanically strong silica aerogel made from methyltrimethoxysilane (image credit Prof. Venkateswara Rao)
A flexible, mechanically strong silica aerogel made from methyltrimethoxysilane (image credit Prof. Venkateswara Rao)
And so are these.
A resorcinol-formaldehyde polymer aerogel (left) and a carbon aerrogel (right)
A resorcinol-formaldehyde polymer aerogel (left) and an electrically-conductive carbon aerrogel (right)
And so are these.
Colorful lanthanide oxide aerogels made by epoxide-assisted gelation of metal salts (image credit Lawrence Livermore National Laboratory)
Colorful lanthanide oxide aerogels made by epoxide-assisted gelation of metal salts (image credit Lawrence Livermore National Laboratory)
Transition metal oxide aerogels including an iron oxide (rust) aerogel (top) (image credit Lawrence Livermore National Laboratory)
Transition metal oxide aerogels including an iron oxide (rust) aerogel (top) (image credit Lawrence Livermore National Laboratory)


Properties
A flower is on a piece of aerogel which is suspended over a flame from a Bunsen burner. Aerogel has excellent insulating properties, and the flower is protected from the flame.

Despite the name, aerogels are solid, rigid, and dry materials that do not resemble a gel in their physical properties: the name comes from the fact that they are made from gels. Pressing softly on an aerogel typically does not leave even a minor mark; pressing more firmly will leave a permanent depression. Pressing extremely firmly will cause a catastrophic breakdown in the sparse structure, causing it to shatter like glass (a property known as friability), although more modern variations do not suffer from this. Despite the fact that it is prone to shattering, it is very strong structurally. Its impressive load-bearing abilities are due to the dendritic microstructure, in which spherical particles of average size (2–5 nm) are fused together into clusters. These clusters form a three-dimensional highly porous structure of almost fractal chains, with pores just under 100 nm. The average size and density of the pores can be controlled during the manufacturing process.

Aerogel is a material that is 99.8% air. Aerogels have a porous solid network that contains air pockets, with the air pockets taking up the majority of space within the material. The lack of solid material allows aerogel to be almost weightless.

Aerogels are good thermal insulators because they almost nullify two of the three methods of heat transfer – conduction (they are mostly composed of insulating gas) and convection (the microstructure prevents net gas movement). They are good conductive insulators because they are composed almost entirely of gases, which are very poor heat conductors. (Silica aerogel is an especially good insulator because silica is also a poor conductor of heat; a metallic or carbon aerogel, on the other hand, would be less effective.) They are good convective inhibitors because air cannot circulate through the lattice. Aerogels are poor radiative insulators because infrared radiation (which transfers heat) passes through them.

Owing to its hygroscopic nature, aerogel feels dry and acts as a strong desiccant. People handling aerogel for extended periods should wear gloves to prevent the appearance of dry brittle spots on their skin.

The slight color it does have is due to Rayleigh scattering of the shorter wavelengths of visible light by the nano-sized dendritic structure. This causes it to appear smoky blue against dark backgrounds and yellowish against bright backgrounds.

Aerogels by themselves are hydrophilic, but chemical treatment can make them hydrophobic. If they absorb moisture they usually suffer a structural change, such as contraction, and deteriorate, but degradation can be prevented by making them hydrophobic. Aerogels with hydrophobic interiors are less susceptible to degradation than aerogels with only an outer hydrophobic layer, even if a crack penetrates the surface.
Knudsen effect

Aerogels may have a thermal conductivity smaller than that of the gas they contain. This is caused by the Knudsen effect, a reduction of thermal conductivity in gases when the size of the cavity encompassing the gas becomes comparable to the mean free path. Effectively, the cavity restricts the movement of the gas particles, decreasing the thermal conductivity in addition to eliminating convection. For example, thermal conductivity of air is about 25 mW/m·K at STP and in a large container, but decreases to about 5 mW/m·K in a pore 30 nanometers in diameter.
Structure

Aerogel structure results from a sol-gel polymerization, which is when monomers (simple molecules) react with other monomers to form a sol or a substance that consists of bonded, cross-linked macromolecules with deposits of liquid solution between them. When the material is critically heated the liquid is evaporated out and the bonded, cross-linked macromolecule frame is left behind. The result of the polymerization and critical heating is the creation of a material that has a porous strong structure classified as aerogel. Variations in synthesis can alter the surface area and pore size of the aerogel. The smaller the pore size the more susceptible the aerogel is to fracture.
Waterproofing

Aerogel contains particles that are 2–5 nm in diameter. After the process of creating aerogel, it will contain a large amount of hydroxyl groups on the surface. The hydroxyl groups can cause a strong reaction when the aerogel is placed in water, causing it to catastrophically dissolve in the water. One way to waterproof the hydrophilic aerogel is by soaking the aerogel with some chemical base that will replace the surface hydroxyl groups (–OH) with non-polar groups (–OR), a process which is most effective when R is an aliphatic group.
Porosity of aerogel

There are several ways to determine the porosity of aerogel: the three main methods are gas adsorption, mercury porosimetry, and scattering method. In gas adsorption, nitrogen at its boiling point is adsorbed into the aerogel sample. The gas being adsorbed is dependent on the size of the pores within the sample and on the partial pressure of the gas relative to its saturation pressure. The volume of the gas adsorbed is measured by using the Brunauer, Emmit and Teller formula (BET), which gives the specific surface area of the sample. At high partial pressure in the adsorption/desorption the Kelvin equation gives the pore size distribution of the sample. In mercury porosimetry, the mercury is forced into the aerogel porous system to determine the pores' size, but this method is highly inefficient since the solid frame of aerogel will collapse from the high compressive force. The scattering method involves the angle-dependent deflection of radiation within the aerogel sample. The sample can be solid particles or pores. The radiation goes into the material and determines the fractal geometry of the aerogel pore network. The best radiation wavelengths to use are X-rays and neutrons. Aerogel is also an open porous network: the difference between an open porous network and a closed porous network is that in the open network, gases can enter and leave the substance without any limitation, while a closed porous network traps the gases within the material forcing them to stay within the pores. The high porosity and surface area of silica aerogels allow them to be used in a variety of environmental filtration applications.
Materials
A 2.5 kg brick is supported by a piece of aerogel with a mass of 2 g.
Silica

Silica aerogel is the most common type of aerogel, and the most extensively studied and used. It is silica-based and can be derived from silica gel or by a modified Stober process. The lowest-density silica nanofoam weighs 1,000 g/m3, which is the evacuated version of the record-aerogel of 1,900 g/m3. The density of air is 1,200 g/m3 (at 20 °C and 1 atm). As of 2013, aerographene had a lower density at 160 g/m3, or 13% the density of air at room temperature.

The silica solidifies into three-dimensional, intertwined clusters that make up only 3% of the volume. Conduction through the solid is therefore very low. The remaining 97% of the volume is composed of air in extremely small nanopores. The air has little room to move, inhibiting both convection and gas-phase conduction.

Silica aerogels also have a high optical transmission of ~99% and a low refractive index of ~1.05.

It has remarkable thermal insulative properties, having an extremely low thermal conductivity: from 0.03 W/(m·K) in atmospheric pressure down to 0.004 W/(m·K) in modest vacuum, which correspond to R-values of 14 to 105 (US customary) or 3.0 to 22.2 (metric) for 3.5 in (89 mm) thickness. For comparison, typical wall insulation is 13 (US customary) or 2.7 (metric) for the same thickness. Its melting point is 1,473 K (1,200 °C; 2,192 °F).

Until 2011, silica aerogel held 15 entries in Guinness World Records for material properties, including best insulator and lowest-density solid, though it was ousted from the latter title by the even lighter materials aerographite in 2012 and then aerographene in 2013.
Carbon

Carbon aerogels are composed of particles with sizes in the nanometer range, covalently bonded together. They have very high porosity (over 50%, with pore diameter under 100 nm) and surface areas ranging between 400–1,000 m2/g. They are often manufactured as composite paper: non-woven paper made of carbon fibers, impregnated with resorcinol–formaldehyde aerogel, and pyrolyzed. Depending on the density, carbon aerogels may be electrically conductive, making composite aerogel paper useful for electrodes in capacitors or deionization electrodes. Due to their extremely high surface area, carbon aerogels are used to create supercapacitors, with values ranging up to thousands of farads based on a capacitance density of 104 F/g and 77 F/cm3. Carbon aerogels are also extremely "black" in the infrared spectrum, reflecting only 0.3% of radiation between 250 nm and 14.3 µm, making them efficient for solar energy collectors.

The term "aerogel" to describe airy masses of carbon nanotubes produced through certain chemical vapor deposition techniques is incorrect. Such materials can be spun into fibers with strength greater than Kevlar, and unique electrical properties. These materials are not aerogels, however, since they do not have a monolithic internal structure and do not have the regular pore structure characteristic of aerogels.
Metal oxide

Metal oxide aerogels are used as catalysts in various chemical reactions/transformations or as precursors for other materials.

Aerogels made with aluminium oxide are known as alumina aerogels. These aerogels are used as catalysts, especially when "doped" with a metal other than aluminium. Nickel–alumina aerogel is the most common combination. Alumina aerogels are also being considered by NASA for capturing hypervelocity particles; a formulation doped with gadolinium and terbium could fluoresce at the particle impact site, with the amount of fluorescence dependent on impact energy.

One of the most notable differences between silica aerogels and metal oxide aerogel is that metal oxide aerogels are often variedly colored.
Aerogel     Color
Silica, alumina, titania, zirconia     Clear with Rayleigh scattering blue or white
Iron oxide     Rust red or yellow, opaque
Chromia     Deep green or deep blue, opaque
Vanadia     Olive green, opaque
Neodymium oxide     Purple, transparent
Samaria     Yellow, transparent
Holmia, erbia     Pink, transparent


Other

Organic polymers can be used to create aerogels. SEAgel is made of agar. Cellulose from plants can be used to create a flexible aerogel.

Chalcogel is an aerogel made of chalcogens (the column of elements on the periodic table beginning with oxygen) such as sulfur, selenium and other elements. Metals less expensive than platinum have been used in its creation.

Aerogels made of cadmium selenide quantum dots in a porous 3-D network have been developed for use in the semiconductor industry.

Aerogel performance may be augmented for a specific application by the addition of dopants, reinforcing structures and hybridizing compounds. Aspen Aerogels makes products such as Spaceloft which are composites of aerogel with some kind of fibrous batting.


Aerogels are a diverse class of porous, solid materials that exhibit an uncanny array of extreme materials properties. Most notably aerogels are known for their extreme low densities (which range from 0.0011 to ~0.5 g cm-3). In fact, the lowest density solid materials that have ever been produced are all aerogels, including a silica aerogel that as produced was only three times heavier than air, and could be made lighter than air by evacuating the air out of its pores. That said, aerogels usually have densities of 0.020 g cm-3 or higher (about 15 times heavier than air). But even at those densities, it would take 150 brick-sized pieces of aerogel to weigh as much as a single gallon of water! And if Michaelangelo’s David were made out of an aerogel with a density of 0.020 g cm-3, it would only weigh about 4 pounds (2 kg)! Typically aerogels are 95-99% air (or other gas) in volume, with the lowest-density aerogel ever produced being 99.98% air in volume.
Essentially an aerogel is the dry, low-density, porous, solid framework of a gel (the part of a gel that gives the gel its solid-like cohesiveness) isolated in-tact from the gel’s liquid component (the part that makes up most of the volume of the gel). Aerogels are open-porous (that is, the gas in the aerogel is not trapped inside solid pockets) and have pores in the range of <1 to 100 nanometers (billionths of a meter) in diameter and usually <20 nm.
Aerogels are dry materials (unlike “regular” gels you might think of, which are usually wet like gelatin dessert). The word aerogel refers to the fact that aerogels are derived from gels–effectively the solid structure of a wet gel, only with a gas or vacuum in its pores instead of liquid. Learn more about gels, aerogels, and how aerogels are made.

Technical Definition

By definition,
An aerogel is an open-celled, mesoporous, solid foam that is composed of a network of interconnected nanostructures and that exhibits a porosity (non-solid volume) of no less than 50%.
The term “mesoporous” refers to a material that contains pores ranging from 2 to 50 nm in diameter.
Generally speaking, most of the pores in an aerogel fall within this size range. In practice, most aerogels exhibit somewhere between 90 to 99.8+% porosity and also contain a significant amount of microporosity (pores less than 2 nm in diameter).

What Are Aerogels Made Of?

The term aerogel does not refer to a particular substance, but rather to a geometry which a substance can take on–the same way a sculpture can be made out of clay, plastic, papier-mâché, etc., aerogels can be made of a wide variety of substances, including:
and
  • Metals (such as copper and gold)
Aerogel composites, for example aerogels reinforced with polymer coatings or aerogels embedded with magnetic nanoparticles, are also routinely prepared.
Learn more about the different flavors of aerogels that exist.

Aerogel vs. Silica Aerogel

The term aerogel when used by itself is frequently used to refer specifically to silica aerogels like the blue one shown in the first picture above (although this is like saying “plastic” and specifically meaning, say, polyethylene, despite the fact that there are many other types of plastic such as polypropylene, acrylic, Teflon, Nylon, etc.). In general, the aerogel of a substance is chemically similar to the bulk form of that substance. This said, due to their low densities and length-scale effects arising from having nanostructured features, aerogels often exhibit many dramatically enhanced materials properties over the non-aerogel form of the same substance (for example, significant increases in surface area and catalytic activity), while frequently also exhibiting reductions in other materials properties (such as mechanical strength).

How is Aerogel Made?

So how exactly do you make an aerogel?
As described in the What is Aerogel? section, an aerogel is the intact, dry, ultralow density, porous solid framework of a gel (that is, the part that gives a gel its solid-like cohesiveness) isolated from the gel’s liquid component (which takes up most of the volume in the gel). But how do you isolate such a material from a gel?

The Start of an Aerogel: A Gel

Aerogels start their life out as a gel, physically similar to Jell-O®. A gel is a colloidal system in which a nanostructured network of interconnected particles spans the volume of a liquid medium. Gels have some properties like liquids, such as density, and some properties like solids, such as a fixed shape. In the case of Jell-O, this network of particles is composed of proteins and spans the volume of some sort of fruit juice. A gel is structurally similar to a wet kitchen sponge, only with pores a thousand to a million times smaller. Because a gel’s pores are so small, the capillary forces exerted by the liquid are strong enough to hold it inside the gel and prevent the liquid from simply flowing out. It’s important to remember that gelatin isn’t the only type of gel–in fact, chemists can prepare gels with backbones composed of many organic and inorganic substances and many liquid interiors.
Once a gel is prepared, it must be purified prior to further processing. This is because the chemical reactions that result in the formation of a gel leave behind impurities throughout the gel’s liquid interior that interfere with the drying processes used to prepare aerogel (as described below). Purification is done by simply soaking the gel under a pure solvent (depending on the gel this could be acetone, ethanol, acetonitrile, etc.), allowing impurities to diffuse out and pure solvent to diffuse in. The solvent in which the gel is soaked is typically exchanged with fresh solvent multiple times over the course several days. Depending on the volume and geometry of the gel, diffusive processes can take any where from hours to weeks. A ice-cube size sample can usually be purified in 1 or 2 days.
For more information about gels and gel preparation, see The Sol-Gel Process under The Science of Aerogel.

The Dire Consequences of Evaporatively Drying a Gel

Now, if you’ve ever left Jell-O uneaten and uncovered in the refrigerator for a long while (on the order of a week or so), you may have observed the gel shrinks gradually. This occurs when the liquid trapped in the gel evaporates from the gel’s surface. As molecules of liquid escape into the air, the surrounding liquid molecules are pulled together by capillary action and tug on the framework of the gel. Continued evaporation results in collapse of the framework of the gel, forming a dense, hard substance with less than 10% of the volume of the original gel. This is called xerogel (pronounced zeroGEL). In fact, 1980’s-style hard contact lenses used to be manufactured by drying silica gels into lens-shaped silica xerogels.

Aerogel is the solid framework of a gel isolated from its liquid component, prepared in such a way as to preserve the framework’s pore structure (or at least most of it). In other words, aerogel is what would be left over if you could remove the liquid from a gel without causing it to shrink. This is most effectively done through a special technique called supercritical drying (although as you will see below, there are other ways to make aerogel as well).

The Answer: Supercritical Drying

In general, supercritical drying is used when liquid needs to be removed from a sample that would be damaged by evaporative or other drying techniques. Biological specimens, for example, are often preserved through supercritical drying.
Supercritical drying is a clever technique by which we can pull the rug out from under capillary action (so to speak). As mentioned earlier, capillary action induced by liquid evaporating from a gel’s pores causes the gel to shrink. So what if there were some way to avoid capillary forces to begin with? This is where supercritical drying comes in.
All pure substances (that won’t decompose) have what’s called a critical point–a specific and characteristic pressure and temperature at which the distinction between liquid and gas disappears. For most substances, the critical point lies at a fairly high pressure (>70 atmospheres) and temperature (>400°F). At the critical point, the liquid and vapor phases of a substance merge into a single phase that exhibits the behavior of a gas (in that it expands to fill the volume of its container and can be compressed) but simultaneously possesses the density and thermal conductivity of a liquid. This phase is called a supercritical fluid.
Say we have a sealed container containing a liquid below its critical point inside and equipped with a pressure gauge on top. In fact, a certain amount of liquid will evaporate in the container until the vapor pressure of the liquid is reached in the container, after which no more liquid will evaporate and the gauge will read a corresponding stable pressure. Now if we heat this container, we will notice the pressure in the container increases, since the vapor pressure of a liquid increases with increasing temperature. As the critical point draws near, the pressure in the container squeezes molecules in the vapor close enough together that the vapor becomes almost as dense as a liquid. At the same time, the temperature in the container gets high enough that the kinetic energy of the molecules in the liquid overwhelms the attractive forces that hold them together as a liquid. In short, as the pressure and temperature in the container get closer to the critical point, the liquid phase becomes more gas-like and the vapor phase more liquid-like. Finally, the critical point is reached and the meniscus dividing the two phases blurs away, resulting in a single supercritical phase. As this occurs, the surface tension in the fluid  gradually drops to zero, and thus the ability of the fluid to exert capillary stress does too.

Aerogelification

In the case of making aerogels, a gel is placed in a pressure vessel under a volume of the same liquid held within its pores (lets say ethanol for example). The pressure vessel is then slowly heated to the liquid’s critical temperature. As this happens, the vapor pressure of the liquid increases, causing the pressure in the vessel to increase and approach the critical pressure of the liquid. The critical point is then surpassed, gently transforming the liquid in the gel (as well as the liquid and vapor surrounding the gel) into a supercritical fluid. Once this happens, the ability of the fluid in the gel to exert capillary stress on the gel’s solid framework structure of the gel has decreased to zero.
With supercritical fluid now present throughout the entire vessel and permeating the pores of the gel, the fluid in the gel can be removed. This is done by partially depressurizing the vessel, but not so much as to cause the pressure in the vessel to drop below the critical pressure. The temperature of the vessel must also remain above the critical temperature during this step. The goal is to remove enough fluid from the vessel while the fluid is still supercritical so that when the vessel is fully depressurized/cooled down and drops below the fluid’s critical point, there will simply not be enough substance left in the vessel left for liquid to recondense. This might require several cycles of heating (and thus pressurizing) followed by depressurization (again all done above the critical point). Once enough fluid has been removed from the vessel, the vessel is slowly depressurized and cooled back to ambient conditions. As this happens, the fluid in the vessel passes back through the critical point, but since much of the fluid has been removed and the temperature is still elevated as the vessel depressurizes, the fluid reverts to a gas phase instead of a liquid phase. What was liquid in the gel has been converted into a gas without capillary stress every arising, and an aerogel is left behind.
It is important to note, however, that most of the liquids used in the preparation of gels are organic solvents such as methanol, ethanol, acetone, and acetonitrile, and such liquids are potentially dangerous at the temperatures and pressures required to make them supercritical. To make the aerogelification process less dangerous, the liquid component of a gel can be exchanged with a non-flammable solvent that mixes well with organic solvents–liquid carbon dioxide (see below).
For more information about supercritical drying, see The Science of Aerogel section.

The Hunt Process: Making Supercritical Drying Safer With Liquid Carbon Dioxide

In the early 1980’s, Dr. Arlon Hunt at Lawrence Berkeley National Laboratory developed a technique for preparing aerogels without needing to supercritically extract potentially explosive solvents. In this technique, a gel containing an organic solvent (such as methanol, ethanol, acetone, or acetonitrile) is soaked under liquid carbon dioxide to replace the liquid in the gel with liquid CO2. CO2, which is the product of combustion reactions, is inherently non-flammable (since it’s already oxidized), and has a low critical point of only 31.13°C (88.03°F) and 7.375 MPa (1069.7 psi, or 72.786 times atmospheric pressure). This is compared with, say, methanol, which is very flammable and has a critical point of 239.5°C (463.1°F) and 8.084 MPa (1172.5 psi, 79.783 times atmospheric pressure).
One drawback, however, is that unlike methanol or other organic solvents, CO2 does not exist as a liquid at ambient conditions. In fact, dry ice, the solid form of CO2 (which you can buy at some gas stations and grocery stores), sublimes directly to gaseous CO2 at atmospheric pressure instead of melting. As a result, in order to work with liquid CO2 so that we can soak a gel in it, we have to use CO2 at a pressure where it can exist as a liquid (around 58 times atmospheric pressure at room temperature). This doesn’t really pose much of a problem, though, since we need to do the supercritical extraction in a pressure vessel eventually anyway.
To perform CO2 exchange, a gel is placed in a pressure vessel which is then sealed and slowly pressurized with a tank of liquid CO2 equipped with a siphon tube (like a liquid soap dispenser). Liquid CO2 siphon tanks are common, and can be found in almost any restaurant or bar as the source of carbonation in a soda fountain system. Liquid CO2 entering the vessel will boil instantly, pressurizing the vessel until the vapor pressure of liquid CO2 at room temperature (~58 atm) is reached. At that point, liquid CO2 will siphon into the vessel and cover the gel. Depending on the size of the vessel and the gel, it is common to pre-fill the vessel with organic solvent (whatever is in the gel) to prevent the gel from drying out while waiting for CO2 to siphon in. This organic solvent is then drained off as soon as CO2 starts to siphon in. After liquid CO2 has siphoned in, the gel is simply allowed to soak for a number of hours. The liquid in the vessel is drained out and replaced with new liquid every few hours for a period of time of 1-3 days for small samples and up to a week or two for large samples. As mentioned, liquid CO2 doesn’t exist at ambient conditions, so when liquid CO2 is drained from a pressurized vessel, although the liquid level goes down in the vessel, only gaseous CO2 and churnings of dry ice evolve from the drain valve.
As the gel soaks in the liquid CO2, the organic solvent held within its pores diffuses out, and liquid CO2 diffuses in its place. Once the gel has been thoroughly diffused through with CO2 (and this is up to the researcher’s discretion), supercritical extraction can be performed just as described above.
Learn how to build a supercritical dryer of your own and find a fully-illustrated step-by-step process of performing supercritical drying with CO2 under the Make section.

How Big Can an Aerogel Be Made?

Just as you can only bake a pie as big as your oven, you can only supercritically dry an aerogel as large as your pressure vessel. This means one of three things–either you need a big supercritical dryer, you limit yourself to making small aerogels, or you use a non-supercritical drying technique (see below). Additionally, large continuous volumes (such as cubes or spheres) are generally difficult to make since it takes exponentially longer for solvent from the interior of the gel to diffuse out of the gel as the gel thickness is increased. However, hollow cubes and spheres, flat plates and discs, and rods with thicknesses less than two inches (5 cm), regardless of how big the gel’s other dimensions are, can be easily made.
This said, there are many techniques for preparing aerogel materials called ambigels (often just referred to as aerogels) with subcritical drying techniques. These materials typically have porosities of 50-95% and so they are usually (but not always) a little less dense than supercritically-dried aerogels. Subcritical drying techniques typically require specially-modified gels, in which the solid framework of the gel is chemically changed so that liquid is less able to stick to it and thus exerts only minimal stress on the gel upon evaporation.  Additionally, the liquid in the pores of the gel is frequently replaced with a liquid that has a low surface tension, such as pentane or hexane, so that when the liquid is evaporated little capillary stress can result.  Cabot Corp.’s Nanogel® aerogel granules are made through a subcritical drying technique.

Special Properties of Aerogels

Many aerogels boast a combination of impressive materials properties that no other materials possess simultaneously. Specific formulations of aerogels hold records for the lowest bulk density of any known material (as low as 0.0011 g cm-3), the lowest mean free path of diffusion of any solid material, the highest specific surface area of any monolithic (non-powder) material (up to 3200 m2 g-1), the lowest dielectric constant of any solid material, and the slowest speed of sound through any solid material. It is important to note that not all aerogels have record properties (in fact most don’t, although they may have very good values for many properties)!
By tailoring the production process, many of the properties of an aerogel can be adjusted. Bulk density is a good example of this, adjusted simply by making a more or less concentrated precursor gel. The thermal conductivity of an aerogel can be also be adjusted this way, since thermal conductivity is related to density. Typically, aerogels exhibit bulk densities ranging from 0.5 to 0.01 g cm-3 and surface areas ranging from 100 to 1000 m2 g-1, depending of course on the composition of the aerogel and the density of the precursor gel used to make the aerogel. Other properties such as transparency, color, mechanical strength, and susceptibility to water depend primarily on the composition of the aerogel.
For example, silica aerogels, which are the most widely researched type of aerogel (and the type people typically see in photographs), are usually transparent with a characteristic blue cast due to Rayleigh scattering of the short wavelengths of light off of nanoparticles that make up the aerogel’s framework. Carbon aerogels, on the other hand, are totally opaque and black. Furthermore, iron oxide aerogels are just barely translucent and can be either rust-colored or yellow. As another example, low-density (<0.1 g cm-3) inorganic aerogels are both excellent thermal insulators and excellent dielectric materials (electrical insulators), whereas most carbon aerogels are both good thermal insulators and electrical conductors. Thus it can be seen that by adjusting processing parameters and exploring new compositions, we can make materials with a versatile range of properties and abilities.
<i>The Flower</i>, the <i>Mona Lisa</i> of aerogel pictures, dramatically demonstrating the superinsulating properties of silica aerogel (image credit Lawrence Berkeley National Laboratory)
The Flower, the Mona Lisa of aerogel pictures, dramatically demonstrates the superinsulating properties of silica aerogel by insulating a delicate, moist flower from the raging heat of a Bunsen burner (image credit Lawrence Berkeley National Laboratory)
Aerogels of all sorts hold records for different properties. Here are some:
Records held by some specially-formulated silica aerogels:
  • Lowest density solid (0.0011 g cm-3)
  • Lowest optical index of refraction (1.002)
  • Lowest thermal conductivity (0.016 W m-1 K-1)
  • Lowest speed of sound through a material (70 m s-1)
  • Lowest dielectric constant from 3-40 GHz (1.008)
Record held by a specially-formulated carbon aerogel:
  • Highest specific surface area for a monolithic material (3200 m g-1)
A more in-depth discussion of the properties of silica aerogel and other historically underrepresented types of aerogel can be found in the Flavors of Aerogel section.

What Does an Aerogel Feel Like? How Strong Are They?

To the touch, an inorganic aerogel (such as a silica or metal oxide aerogel) feels something like a cross between a Styrofoam peanut, that green floral potting foam used for potting fake flowers, and a Rice Krispie. Unlike wet gels such as Jell-O, inorganic aerogels are dry, rigid materials and are very lightweight.
In general aerogels are pretty fragile. Inorganic aerogels are friable and and will snap when bent or, in the case of very low density aerogels, when poked, cleaving with an irregular fracture. This said, depending on their density, aerogels can usually hold a gently applied load of up to 2,000 times their weight and sometimes more. But since aerogels are so low in density, it doesn’t take much force to achieve a pressure concentration equivalent to 2,000 times the material’s weight at a given point. The amount of pressure required to crush most aerogels with your fingers is about what it would take to crush a piece of Cap’n Crunch cereal.
Organic polymer aerogels are less fragile than inorganic aerogels and are more like green potting foam in consistency in that they are squish irreversibly. Carbon aerogels, which are derived from organic aerogels, have the consistency of activated charcoal and are very much not squishy.
There are several examples, however, of remarkably strong aerogels that can withstand tens of thousands of times their weight in applied force. A class of polymer-crosslinked inorganic aerogels called x-aerogels are such materials and can even be made flexible like rubber in addition to being mechanically robust (see Flavors of Aerogels). One type of x-aerogel made from vanadia (vanadium oxide) is extraordinarily strong in compression with the highest compressive strength to weight ratio of any known type of aerogel and rivals that of materials such as aerospace-grade carbon fiber composites! Regardless of composition, most types of aerogel can be made stronger simply by making them denser (between 0.1 and 0.5 g cm-3), however only at the expense of their light weight and ultralow thermal conductivity.

A Note About the Spelling and Use of the Word Aerogel

Aerogel is correctly spelled just like that–aerogel–and is pronounced like “air-o-jel”. It is not a proper noun nor is it a trade name and thus should not be specially capitalized, noted with trademark, or placed in quotes in normal use. It should only be capitalized at the beginning of sentence and in titles, like other nouns. It is also not a compound word and should not be spelled with a hyphen or a space. Frequent misspellings include “AeroGel”, “aerojell”, “areogel”, “aerojel”, “aerojell”, “airojell”, “aero-gel”, “aero gel”, and “airgel”. Aerogel is occasionally referred to as “air glass” or “frozen smoke” but these are just nicknames. Brand names that refer to some commercial aerogel materials include Santocel (obsolete), Nanogel, Pyrogel, Cryogel, and Spaceloft - each of which consists of aerogel with a different formulation and composition.
Furthemore, aerogels are most definitely not aerosols, which are colloidal sprays such as those used for hairspray.
When confronted with the question of how to properly use the word aerogel in a sentence, try replacing “aerogel” in your mind with the word “plastic” and think of how you would use that word in a similar context. For example: “plastics are useful materials” = “aerogels are useful materials”, or “plastic has greatly impacted society” = “aerogel can greatly impact society”. Additionally, a sample of aerogel can be referred to as “an aerogel”. As mentioned earlier, “aerogel” by itself is frequently used to refer specifically to silica aerogel, even though there many types of aerogels other than silica aerogel.


Wednesday 24 October 2018

Kodi 能带给你更优雅、舒适的观影体验



如果你是个高清电影爱好者,你一定会考虑如何将客厅的电脑打造成一台强大的家庭影院影音播放中心!然而,简单地接上电脑+键盘鼠标,对着电视上极小的窗口和字体操作半天绝对是一个“糟糕麻烦”的体验。
Kodi (原名 XBMC) 是一款经典免费开源、跨平台且极其强大专业的多媒体影音中心软件播放器,包含了专业的影音内容管理以及解码播放功能一体,提供适合在电视/投影/大屏幕上显示的全屏界面,无线手机遥控操作方式,以及功能相当丰富的插件扩展,绝对是打造家庭影院 (影音中心) 和私人电影库的必备神器

Kodi - 用更优雅专业的方式来播放和管理电影视频音乐

Kodi 能带给你更优雅、舒适的观影体验,可以说是目前同类软件中当之无愧的 No·1。首先,免费开源跨平台+配置要求低的特性让 Kodi 不仅能在 Windows、MacLinux 电脑上使用,甚至在 AndroidiOS 手机/平板以及像「树莓派」这样的微型电脑或很多安卓机顶盒(网络播放器)上流畅运行,兼容性和适用范围极广。


其次,Kodi 是一个万能格式高清播放器,支持解码播放几乎所有流行的音频和视频格式,3D、4K 高清什么的都没问题。它集电影视频、音乐图片管理和播放于一身,不仅能读取本机硬盘、移动硬盘的影音内容,最重要的是它还能通过局域网播放和管理其他电脑、NAS (网络存储服务器) 里的内容。这使得任何人都能轻松将手头上的电脑设备变成客厅中强大无比的网络影音播放机。


再次,Kodi 专为大电视、大尺寸屏幕和投影优化的大字体全屏界面、可以通过手机 APP 实现无线遥控控制、支持 AirPlay / DLNA 无线投射串流等功能特性也让其更加实用方便。

不过,看到这里你可能还觉得它比起普通的播放器没什么特别之处,其实 Kodi 真正的亮点主要还是在于它丰富强大的插件扩展。

贴心强大的插件功能(自动下载电影字幕 / 更新电影封面和介绍信息等)

不夸张地说,丰富强大的插件才是 Kodi 之所以被称为神器的最主要的原因!得益于免费与开源的策略,全球无数开发者为 Kodi 制作了大量实用的插件,这些插件不仅让你的影音中心拥有更多新功能,最重要的是,它能让你看电影的流程变得更加傻瓜便捷!
举个例子,我们从 BT 下载的 电影经常都是一串英文命名,辨别起来十分困难,手动改名字实在是麻烦。Kodi 可以通过不同的「刮削器」插件“自动化”地从豆瓣、时光网等国内外网站中匹配并下载电影的介绍信息 (包括电影名称、剧情介绍、导演、演员、封面图片),让你的视频库看起来超级详细漂亮,简直就像一个专业的视频网站,点播起来简直不能更舒服了!而这一切 都是靠刮削器自动联网完成的。


另外,通过安装不同的「字幕插件」,还可以让 Kodi 播放电影时自动从不同的字幕网站中搜索匹配并下载字幕,这点对懒人来说就一句话——太 TM 爽了!再也不用为找字幕下载而发愁了。当然,Kodi 能做的事情远不止如此,它的插件库简直就像一个宝库,你总能在里面找到更多实用的扩展功能,譬如电视直播、在线音乐/视频点播、百度云网盘播放、以及各种换肤等等。
因此你完全可以根据自己的需求和喜好,选用不同的插件,配置打造出最适合自己使用的私人影音中心。相信我,只要你体验过 Kodi,你绝对不想回到以前对着电视上极小的字体操作半天,还要到处找字幕的“原始低效”的观影方式了。

Kodi (XBMC) 设置与使用入门教程

首 先我们根据设备的操作系统下载相应版本的 Kodi 应用进行安装。目前,Kodi 支持 Windows、Mac、Linux 以及  Android、iOS (需越狱)。另外,还有一些专门用于运行 Kodi 的 Linux 整合版操作系统,启动后整个系统就是 Kodi,适合那些专用做播放器的场合。这些衍生系统常见的有 Kodibuntu (Ubuntu 与 Kodi 的整合版系统,PC适用)、OSMC (原 Raspbmc,整合 Debian 与 Kodi,树莓派适用) 等,大家可以根据需求选择。不同版本的 Kodi 的设置和使用方法均大同小异,部分插件也是通用的,大家可以参考下面的教程

Kodi 设置成中文界面的方法 (解决显示乱码问题)

默认情况下,新安装好的 Kodi 启动后是英文版的界面。但事实上,Kodi 包含多国语言 (包含简繁体中文版),我们可以设置改回简体中文界面。不过,很多人都遇到修改 Kodi 的语言为中文之后整个界面显示乱码的问题,正确的设置方法如下:
  1. 启动 Kodi,进入 System -> Settings -> Appearance -> Skin,将其中的 Fonts 修改成 Arial Based (这是必须的,也是第一步首先要做的步骤,否则就会显示乱码
  2. 然后再进入 System -> Settings -> International -> Language,选择 Chinese (Simple) 确定
  3. 进入 系统->设置->视频->字幕 “首选字幕语言” 以及“下载字幕语言”均选择 Chinese (Simple)

Kodi 怎样添加本机和网络上的电影(视频)、音乐、图片目录?

Kodi 可以添加本机的文件夹,也可以将局域网中其他电脑 / NAS 中的共享文件夹添加进来。也就是说,你可以非常方便地在客厅的 Kodi 中播放寝室电脑里或 NAS 中下载好的电影视频!加上 Kodi 支持各种平台,因此,你可以选用「安卓机顶盒」、「树莓派」、「Mac Mini」、笔记本或组装一台小型 Windows 电脑 (HTPC 迷你主机) 放在客厅用来做专用播放机。
添 加视频源的方法如下:依次点击 视频 -> 文件 -> 添加视频... -> 浏览,可以看到你可以添加本机硬盘的目录,也能添加 SMB (Windows共享) 和 NFS (Mac 或 Linux 使用的共享协议) 的网络路径,在“添加网络位置...”选项里还能添加 HTTP、FTP、WebDAV 等网络路径。


Kodi 能自动搜索出 某些局域网的共享目录,如果它找不到的话,那就需要手动指定一下了。如果共享需要用户名密码的话还是要正确输入的。选择好电影所在的文件夹后,便会出现如 下图的窗口,nfs://xxxx 那个是我的 NAS 的 IP 和电影文件所在的文件夹路径,底部可以为这个“视频源”命名,然后确定下一步。


在最后一步时,我们会看到 Kodi 弹出「设置内容」的窗口,这里可以设置该目录包含电影、剧集、音乐哪种内容,而右边还有一个「选择刮削器」的列表。这个刮削器(插件)是 Kodi 的一大特色,下面我们将会介绍什么是刮削器,并介绍怎么安装 Kodi 的插件。

Kodi 安装电影刮削器插件教程 - 自动联网下载电影海报与简介信息 (豆瓣/时光网)

Kodi 最为强大之处便是支持各种第三方插件,而且插件数量巨多,可以实现看电影几乎所有的周边功能。其中「刮削器」插件可以让 Kodi 匹配目录中的影音文件,并自动从网上下载对应的图文信息对它们进行补充,让你的影音库显得更加“精美专业”。下面以安装「豆瓣电影刮削器」为例子作为介绍吧: 在左边的「该目录包含」一列下,点击上下箭头按钮为目录设置成「电影」类别,这时右边就会列出可用的刮削器了,不过 Kodi 自带的这两对我们都没啥用,点击「获取更多...」,然后 Kodi 就会从它的网上插件库中搜索可下载的刮削器了,其中 douban(豆瓣) 或 MTime(时光网) 就是咱们需要的,按喜好选择即可。其他的大多数是英文的网站,并没有中文信息。


不过在截稿时,我发现豆瓣刮削器无法获取电影封面图片,时光网刮削器则无问题,大家可以自己试试。选择之后,点击「安装」即可。之后我们就能回到目录的「设置内容」窗口来启用这个刮削器了。


应用了刮削器之后,Kodi 便会扫描目录下的文件,并从网上下载对应的电影信息,如果文件较多的话需要一定的时间,待电影信息更新完毕之后,我们的电影库就变得非常酷了!


我们不仅可以在点播前看看电影简介、海报、预告片,还能按照电影类型、年份之类的进行分类筛选。如果日后文件有增删改动,或者某个电影匹配不出来或匹配错的话也可以手动查询进行修改。另外,除了电影之外,「音乐」同样也有刮削器可以使用,自动下载音乐专辑封面什么的也是一样的,大家可以去试试。

安装 Kodi 电影中文字幕下载插件和更多其他中文插件

在 Kodi 中,默认已经提供了一个联网的「在线插件库」可以供你下载各种各样的插件了。我们可以在 “系统->插件->从库安装” 的列表里面浏览。


库 里有各种类型的插件可供下载,如下图,插件也是分类放置的,大家可以自己挖掘一下。其中「信息提供者」一类就是上面提到的「刮削器」了,从这个入口进来安 装其实也是一样的。不过,你会发现,默认的插件库大多都是英文内容的插件,主要是因为 Kodi 官方插件库的维护者都是老外。而「字幕」一类里原本唯一能支持中文字幕下载的 “Shooter” (射手网) 插件又因网站的关停已经不可用了,所以我们必须另寻办法。



好 在 Kodi 足够的开放,除了 Kodi 自带的插件库外,我们还可以自己添加由国人维护的「Kodi 中文插件库」,这些中文插件库里面就包含了各种适合国情的中文插件,其中就有一些中文字幕插件了,当然还有些其他的福利。下面,我们就来说说怎样为 Kodi 添加中文的插件库吧。

Kodi 添加中文插件库安装教程:

  1. 下载最新的 Kodi 中文插件库安装文件,目前有两个中文插件库可以选择,分别是「Chinese Add-ons Repository - repository.xbmc-addons-chinese.zip」和「HDPFans 中文插件库 - repository.hdpfans.xbmc-addons-chinese.zip」。不同的库里面提供了不同的插件,推荐大家把这两个库都装上吧,日后想安装什么插件也方便一些。
  2. 注意文件下载回去后不要解压,如果是安装到手机/平板或电视盒上的 Kodi,请把文件拷贝到该设备中。
  3. 启动 Kodi,进入 “系统->插件”,这次要点击「从 ZIP 文件安装」,然后选择刚才下载的 zip 文件,待 Kodi 更新完毕,对应的插件库即安装完成。
  4. 再 次进入 “系统->插件->从库安装”,此时便会在库列表中看到多出新安装的库了,如下图,多出的Chinese Add-ons 和 HDPfans 中文插件库就是我刚安装上去的。(最下面那个 Kodi Add-on repository 是 Kodi 官方自带的英文插件库)。

以 “Chinese Add-ons” 中文库为例,点击进入后,选择「字幕」一类,就能看到 163sub、Sub HD、Subom、zimuku 字幕库等字幕网站的插件了,按喜欢选择安装即可。这个中文插件库里还有很多实用的插件,譬如豆瓣电视剧刮削器、优酷视频、Bilibili哔哩哔哩、爱奇 艺、乐视、CNTV 电视直播、搜狐视频等视频插件以及 一听音乐、酷狗、酷我音乐盒、百度、豆瓣电台等音乐插件,还算比较丰富。
而“HDPFans 中文插件库”里面则提供了 MyCloud (百度云、115网盘、迅雷离线等网盘视频图片音乐播放器器)、HDP电视直播、斗鱼直播、115影库、HDP 优酷高清、HDP 公开课、百度云视频等等插件。两个插件库的内容说多不多说少不少,大家根据自己的兴趣去试用吧。
说回 Kodi 的字幕搜索插件,在成功安装后,只需在播放界面中点击右下方的第一个「字幕」图标,选择下载,即能联网进行字幕搜索,即会自动下载并加载显示,总体使用体验非常的方便快捷。而且往往还有多个不同版本的字幕可供选择。


反正,比起平时要到电脑上开启浏览器去访问字幕网站,搜索、下载、解压、拷贝等繁杂的步骤,Kodi + 字幕插件的方式简直是方便到极点。

AirPlay 和 DLNA 无线串流投影以及开启方法

除了可以播放电脑和 NAS 上的视频音乐外, Kodi 还有一个非常好用的功能—— AirPlay 和 UPnP / DLNA 支持。 AirPlay 是苹果的无线音乐视频投射技术,原本需要购买 AppleTV 才能享受这个功能,而利用 Kodi 则可以完全免费实现。
AirPlay 可以将 iPhone / iPad 上的视频或音乐通过 WiFi 直接串流到 Kodi 上播放,如果你把 Kodi 装在客厅大电视和音响上,那么你一定会深深感到这个技术是多么的方便,它能让你手机平板的影音内容轻松跨屏播放。DLNA 也是类似的技术,Android 和 Windows 等设备只能用它,个人认为从易用性和方便性,还是苹果的 AirPlay 更胜一筹。


Kodi 默认并没有启动 AirPlay / DLNA 的支持,需要手动启用。首先进入“系统->服务->ZeroConf”,打开「向其他系统声明服务」的选项。如果提示“启动 ZeroConf 失败”的错误,请在安装了苹果 iTunes 软件后再试。在成功开启“向其他系统声明服务”之后,进入“系统->服务->AirPlay”,允许「启用 AirPlay 支持」即可。(另外,“UPnP / DLNA” 也可以在设置里开启)
不过,Kodi 的 AirPlay 功能仅能用于播放视频和音乐,无法实现屏幕镜像和玩游戏等高级功能。但大多时候这已经够用了,手边有苹果设备的朋友不妨玩一玩吧。

Kodi for Android / iOS 手机版、平板版

Kodi 除了 PC、Mac 和 Linux 的桌面版应用外,同时也提供了 iOS 以及 Android 版,可在手机和平板上运行。它们的界面和操作几乎和 PC 版完全一致,就不多做介绍了,只不过,iOS 版的 Kodi 需要越狱后才能安装。
Kodi Android 安卓版截图
Kodi 同样可以轻松将你的平板或手机变成一个强劲的多媒体中心!当然, 最合适不过的还是在各种安卓电视机顶盒上安装 Kodi 了,绝对能让你的盒子的功能提升一个级别!应该各大盒子的论坛都会有相应的教程吧。

Kodi 手机无线遥控器 APP

为了让 Kodi 更适合在客厅、影音室等场合方便地使用,Kodi 不仅支持很多硬件的遥控器,而且官方还提供了免费的 iOS 和 Android 的远程控制 APP,可以将手机、平板变成 Kodi 的无线遥控器!这个比起拿着鼠标在沙发上的使用体验要强太多了,你甚至还能直接在手机上看到你的影音库并进行选片播放。
[ Official Kodi Remote 遥控器 iPhone 版截图 ]
安装好 Kodi 的遥控器 APP 之后,只需填写 Kodi 所在的正确 IP 地址和端口号即可连接使用。另外,Kodi 其实还可以通过 WEB 进行异地远程控制,不过个人感觉有些鸡肋,就不多介绍了。一般家里使用,遥控器足以应付自如。

总结:

Kodi 完全免费而且开源,集播放、管理于一体,本身播放能力优异,还可借由各种插件增强功能,可配置性强,能根据自己的需要和喜爱,轻松地将电脑变成一台超级好用的专属网络影音播放机。
对于打算 DIY HTPC、搭建家庭影院以及高清电影爱好者而言,Kodi 是一款绝对不应错过的多媒体中心应用。它的强大、方便之处绝能让你心动!当你用过 Kodi 之后,你一定会爱上他……

Kodi 的5个替代品

Kodi 的 5个 替代品

当谈到本地管理媒体,无论平台如何,最受欢迎的选择是柯迪。那里
这个软件就是Kodi得到的赞美很多人发现自己陷入了这个媒体中心,即使他们
在这篇文章中我们他们怎么堆叠?他们是否足以取代科迪?


1.Plex
您应该检查的最佳科迪替代品中的5个
如果没有提到Plex,就不可能谈论Kodi的替代品。该软件可以轻松拥有可以管理媒体的集中式解决方案,就像Kodi一样。Plex的好处是它从服务器而不是专用的PC或设备运行。媒体可以通过应用程序从网络和多个不同的操作系统访问和流式传输。
Plex是完美的选择,因为它可以运行在各种服务器上,而不仅仅是Linux。正式地,它支持Linux,macOS,Windows甚至FreeBSD服务器操作系统。


2.Emby
您应该检查的最佳科迪替代品中的5个长期以来,
Emby被认为是Plex Media Server的开源替代品。像Plex一样,Emby在服务器上运行,并且正式支持Mac,Windows,Linux和BSD服务器操作系统。媒体可以通过Web界面或许多可用于移动甚至游戏机的Emby应用程序访问。



3.Stremio
您应该检查的最佳科迪替代品中的5个
Stremio是Mac,Linux和Windows的本地媒体中心程序,支持播放直播电视和本地媒体。功能包括支持附加组件,自动检测字幕,如果您喜欢像柯迪这样的集中式媒体中心,但需要一个很好的替代方案,请试试这个软件。



4.Media Portal
您应该检查的最佳科迪替代品中的5个
媒体门户是一个仅Windows的媒体中心,与柯迪的运作非常相似。像Kodi一样,用户可以调用直播电视,录制直播电视和安装插件。此外,该软件可以使用不同的外观定制,以及处理多种类型的媒体(音乐,照片等))。




5.Usher
为MacOS提供良好的媒体管理系统?试试Usher。该软件可以在Mac上轻松实现媒体管理,因为它可以处理您的iTunes库,以及系统上的照 片和其他媒体库。这个列表中的很多媒体解决方案充满了功能。像附加组件,DLNA和移动支持这样的东西很好,但不是必需的。Usher是为那些只是寻找一 种简单的方式来管理和观看Mac上的媒体,还有一点。
您应该检查的最佳科迪替代品中的5个
结论
Kodi在很多PC,平板电脑,甚至像Raspberry Pi的爱好板上。不过,这个软件是有些人可能会发现在外观或功能方面有些缺乏。那从Plex到媒体门户网站,那些想要离开Kodi和其他东西的人,这个名单已经覆盖了。

Monday 22 October 2018

Kodi播放器软件特色

Kodi播放器软件特色

Kodi (原名 XBMC) 是一款经典免费开源、跨平台且极其强大专业的多媒体影音中心软件播放器,包含了专业的影音内容管理以及解码播放功能一体,提供适合在电视/投影/大屏幕上显示的全屏界面,无线手机遥控操作方式,以及功能相当丰富的插件扩展,绝对是打造家庭影院 (影音中心) 和私人电影库的必备神器!

KODI是一款开源媒体播放器,原名为XMBC,支持多平台。利用KODI你可以打造属于自己的媒体数据库。
KODI
在开始打造媒体数据库之前,你需要准备:
  • 安装KODI并设置好相关内容
  • 按规则整理你的媒体文件,使用刮削器工具获取媒体信息

安装KODI并设置好相关内容

前往KODI官网下载对应版本进行安装,完成后打开KODI可以看到默认显示语言为英语。如果你需要将显示语言设置为中文可以执行下面的操作:
  1. 选择齿轮设置按钮进入设置界面,点击Interface Settings;
  2. 将Skin选项中的Fonts修改为Arial based(此步操作用于确保中文正常显示);
  3. 将左下角默认显示的Standard修改为Expert;
  4. 进入Regional将Language设置为Chinese (Simple)(国内连接KODI网络不是很稳定,可能需要等待一会才会出现除English以外的其他语言选项)。
完成基本操作后你可以选择安装自己喜欢的插件,网络上有人提供KODI中文插件(不推荐使用,因为大部分不可用)下载。接着你需要设置媒体库,媒体库文件可以是本地、外接硬盘或是网络设备,需要根据自己的实际情况选择,具体的设置步骤可以参看官方文档。电影的刮削器建议选择MTime(时光网),因为TMDB数据抓取不稳定。

按规则整理你的媒体文件,使用刮削器工具获取媒体信息

完成KODI相关设置后你需要将媒体库的中文件按特定规则整理,这样便于刮削器能正确获取到媒体信息。
首先是电影部分:
电影文件官方给出的默认规则是文件夹→文件,其中文件夹与文件名以电影名 (年份)的形式(使用TMDB刮削器需要注意文件名最好是英文)更改,具体设置可以参看官方文档。
Tips:如果你使用TMDB刮削器还有一个方法可方便你获取媒体信息,在单个电影文件夹下创建一个同名的nfo文件,使用文本编辑器打开nfo文件将你从TMDB获取的电影链接粘贴进去。
接着是电视剧部分:
电视剧媒体文件的整理遵循文件夹→文件格式,其中文件夹名设置为电视剧名(由于默认刮削器为TVDB,所以名称设置应使用英文),有同名电视剧时需要加上 年份,文件名的格式则为电视剧名 SXXEXX(其中SXX表示第几季,EXX表示第几集,S为Season简写,E为Episode简写,XX表示具体季数/集数),具体设置可以查看官方文档
 


  1.Kodi播放器(原名 XBMC) 能够播放几乎所有流行的音频和视频格式。   2.Kodi播放器(原名 XBMC) 还被设计用于播放网络媒体,支持各种网络媒体协议,这样你可以把你的媒体库放在家庭网络中或直接播放互联网媒体。
  3.可以这样使用你的媒体:XBMC可以播放CD和DVD光盘或存储在磁盘上的光盘映像文件,播放存储在硬盘的几乎所有流行文件格式,甚至能播放压缩在ZIP和RAR中的文件。
  4. Kodi播放器(原名 XBMC) 还可以扫描你的媒体文件并自动建立你自己的媒体资料库,包括封面图片、内容介绍和海报剧照。
  5. Kodi播放器(原名 XBMC) 还有播放列表和幻灯片功能,天气预报和许多音频视觉效果。


Kodi播放器使用说明

  Kodi播放器软件默认为英文版,可以设置为中文语言界面(和之前版本通用)方法如下:
  1、打开主界面,选择interface System,进入Setting;
Kodi播放器
Kodi播放器
2、首先进入Skin,移动移动▲和▼将Fonts字体更改为Arial based;
  3、然后选择Regional---language;
Kodi播放器
4、进入Language,移动▲和▼切换系统语言为Chinese(Simple);
Kodi播放器
Kodi播放器
5、现在,我们成功将XBMC设置为简体中文界面。


Kodi播放器

  Kodi播放器怎样添加本机和网络上的电影(视频)、音乐、图片目录?
  Kodi 可以添加本机的文件夹,也可以将局域网中其他电脑 / NAS 中的共享文件夹添加进来。也就是说,你可以非常方便地在客厅的 Kodi 中播放寝室电脑里或 NAS 中下载好的电影视频!加上 Kodi 支持各种平台,因此,你可以选用「安卓机顶盒」、「树莓派」、「Mac Mini」、笔记本或组装一台小型 Windows 电脑 (HTPC 迷你主机) 放在客厅用来做专用播放机。
  添加视频源的方法如下:依次点击 视频 -> 文件 -> 添加视频... -> 浏览,可以看到你可以添加本机硬盘的目录,也能添加 SMB (Windows共享) 和 NFS (Mac 或 Linux 使用的共享协议) 的网络路径,在“添加网络位置...”选项里还能添加 HTTP、FTP、WebDAV 等网络路径。
Kodi播放器
Kodi 能自动搜索出某些局域网的共享目录,如果它找不到的话,那就需要手动指定一下了。如果共享需要用户名密码的话还是要正确输入的。选择好电影所在的文件夹后,便会出现如下图的窗口,nfs://xxxx 那个是我的 NAS 的 IP 和电影文件所在的文件夹路径,底部可以为这个“视频源”命名,然后确定下一步。
Kodi播放器

  在最后一步时,我们会看到 Kodi 弹出「设置内容」的窗口,这里可以设置该目录包含电影、剧集、音乐哪种内容,而右边还有一个「选择刮削器」的列表。这个刮削器(插件)是 Kodi 的一大特色,下面我们将会介绍什么是刮削器,并介绍怎么安装 Kodi 的插件。
  Kodi播放器安装电影刮削器插件教程
  Kodi 最为强大之处便是支持各种第三方插件,而且插件数量巨多,可以实现看电影几乎所有的周边功能。其中「刮削器」插件可以让 Kodi 匹配目录中的影音文件,并自动从网上下载对应的图文信息对它们进行补充,让你的影音库显得更加“精美专业”。下面以安装「豆瓣电影刮削器」为例子作为介绍 吧:
Kodi播放器
如上图,在左边的「该目录包含」一列下,点击上下箭头按钮为目录设置成「电影」类别,这时右边就会列出可用的刮削器了,不过 Kodi 自带的这两对我们都没啥用,点击「获取更多...」,然后 Kodi 就会从它的网上插件库中搜索可下载的刮削器了,其中 douban(豆瓣) 或 MTime(时光网) 就是咱们需要的,按喜好选择即可。其他的大多数是英文的网站,并没有中文信息。
Kodi播放器
不过在截稿时,我发现豆瓣刮削器无法获取电影封面图片,时光网刮削器则无问题,大家可以自己试试。选择之后,点击「安装」即可。之后我们就能回到目录的「设置内容」窗口来启用这个刮削器了。
Kodi播放器
应用了刮削器之后,Kodi 便会扫描目录下的文件,并从网上下载对应的电影信息,如果文件较多的话需要一定的时间,待电影信息更新完毕之后,我们的电影库就变得非常酷了!如下图:
Kodi播放器
我们不仅可以在点播前看看电影简介、海报、预告片,还能按照电影类型、年份之类的进行分类筛选。如果日后文件有增删改动,或者某个电影匹配不出来或匹配错的话也可以手动查询进行修改。另外,除了电影之外,「音乐」同样也有刮削器可以使用,自动下载音乐专辑封面什么的也是一样的,大家可以去试试。