Volvo has offered a new 6-gear automatic transmission powershift for C30, S40 and V50 with 2.0-liter diesels. The new automatic not only maintains power while changing gear but also helps economize up to 8% of fuel.

The transmission uses a greased double clutch which enables to change gear smoothly and accurately (which is typical of automatic transmissions) at the same time the effectiveness of shifting is in no way inferior to that of a mechanical transmission. The usage of the new systems aims at reducing fuel consumption in comparison to traditional automatic transmissions.

The new Powershift has been developed in collaboration with the experts from Getrag, a partner of the Swedish company in the sphere of creating transmissions. The gear-box acts as two parallel mechanic transmissions. Two disks of the greased double clutch work separately. One part of the clutch is responsible for odd gears (1, 3, 5 and reverse), the other one – for even gears (2, 4 and 6). If one part of the clutch is active the other one is inactive. Thus, while the engine accelerates on the first gear the second one gets into the “ready” mode. As soon as it turns on the third get ready etc. With such a configuration of shifting there is no loss of power and engine tractions, the transmission changes gear accurately and sharply, supporting the required acceleration of the car. Each clutch uses its own actuating cable: one revolves inside the other. The inner one transits the torque for the 1, 3, 5 and reverse gears; and the outer one revolves the 2, 4 and 6 gears. The electrohydraulic unit controls the work of both the cables.

The new transmission enables the driver to use an automatic transmission for sequential forced shifting like in the automatic transmission Volvo Geartronic. The only difference is that Powershift even in the manual mode doesn’t allow power loss of the engine and doesn’t show typical pauses while changing gear plus it doesn’t need such components as a fluid converter, epicyclic gear etc.

Owing to the new system of double clutch the transmission Powershift is able to collaborate with a high-torque engine and in fact doesn’t put forth any restrictions to the choice of gear ratios, so it is installed on the modern powerful diesels. According to the senior development and research vice-president of Volvo, the novelty enables 8% fuel economy in comparison to a traditional automatic transmission which in its turn is crucial for the reduction of harmful emissions which contaminate the environment.

The new transmission is installed on Volvo C30, S40 and V50 with 2.0-liter 4-cylinder turbo diesels.

No More Manual Transmission Clutch Fluid – ZF and Volvo Robotic Transmissions. New TSI by VW

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Total Rating: 5/5

Pedestrian protection: 2/5

Children protection: 3/5

Front crash: 15 (94%)

Side crash: 18 (100%)

Total: 36 (90%)

Additional: 3 (%)

Pedestrian protection: 11 (31%)

Children protection: 32 (54%)

Front impact

The body of the car resisted the impact well. The sensors on the dummies have shown that the knees of the front passengers are well protected, and Mercedes has provided the information on the results of tests for people of other height and body built. The results are the same.

Side impact

In side crash tests Mercedes got the highest marks for safety.

Children protection

The holding systems used in the crash-tests:

• 18-month kid - Romer Baby Safe plus opposite the direction of the motion
• 3-year-old child - Romer Duo plus forward the direction of the motion

As an option for C-class comes a system that automatically switches off a front airbag if a children’s seat is installed on the front seat. Without this system the installation of such a seat is forbidden (as it is impossible to switch the airbag off manually). But the warning sign can be easily removed which doesn’t meet the requirements of EuroNCAP. The presence of ISOFIX is not marked in a proper way.

Pedestrian protection

The bumper of the car got the highest marks for the protection of pedestrians’ legs. Other elements of the front end of the car have low protection level.

Basic Safety systems installed on the car in Europe:

• Front air-bags
• Side air-bags for head and body
• Front safety belts with preload system and strain limiter
• The alarm of the unfastened front belts
• ISOFIX fastenings of the rear side seats

Crash Ratings: 2007 Mazda 2

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Total Rating: 5/5

Pedestrian protection: 2/4

Children protection: 4/5

Front crash: 16 (100%)

Side crash: 17 (95%)

Total: 34 (85%)

Pedestrian protection: 18 (50%)

Children protection: 37 (62%)

At the front crash a slight fault caused a delay in the reaction of airbags that’s why the protection of passengers didn’t work properly. Mazda had studied the case introduced changes in the program of airbag management in order to prevent such accidents. Now all the new cars are equipped with the renewed program and all the previously released ones – modified. After the modification another crash tests was conducted, the above seen results are the results of this second test.

Front crash

The power structure of the body resisted the hit well. The knees of the driver and front passenger are properly protected. Mazda has released all the necessary information that proves the same protection of knees for people of different height and built.

Side crash

One of the rear doors opened at a side impact that’s why Mazda didn’t count up 1 point.

Children protection

The holding systems used in the crash-tests:

• 18-month kid - Fair “Bobsy” G 0/1 ISOFIX opposite the direction of the motion
• 3-year-old child - Fair “Bobsy” G 0/1 ISOFIX forward the direction of the motion

Mazda got the highest ranking for the protection of a 3-year-old dummy. At the same time the mark for children protection includes other parameters. One can switch off the front airbag to place a children seat. Without this measure the placement of a seat with the back ahead is prohibited. The warning sign is stuck to the sun visor, but it is not visible when it is folded. The presence of ISOFIX isn’t marked properly.

Pedestrian protection

The car is quite good at declining the consequences of a crash for a pedestrian’s legs – the bumper got “good” mark for this kind of protection. Other elements of the car are not that safe for pedestrians.

Basic Safety systems installed on the car in Europe:

• Front air-bags
• Side air-bags for head and body
• Front safety belts with preload system and strain limiter
• The alarm of the unfastened front belts
• ISOFIX fastenings of the rear side seats

Crash Ratings: 2007 Honda Civic

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Total Rating: 4/5

Pedestrian protection: 3/4

Children protection: 4/5

Front crash: 11 (69%)

Side crash: 16 (89%)

Total: 30 (75%)

Pedestrian protection: 24 (67%)

Children protection: 38 (64%)

The latest generation of Civic has already undergone EuroNCAP tests, but Honda has made certain changes into the construction of safety systems in 2008 model line. Thus the time of response of preload devices decreased for more effective work of safety belts. The previous airbag gave way to a modern one with two modes. The side airbag has been modernized as well and has bigger capacity.

Front crash

The new airbag wasn’t able to prevent the driver’s head touch the steering-wheel, but it is the only factor according to which the new Civic in inferior to the previous generation. At the same time now the protection of any area is not lower than the “sufficient” level. As before the body has stood the crash well enough, but a few elements of the front panel might injure the knees of the driver.

Side crash

The load on the chest of the driver has got lower, but it still exceeds the safe figure.

Children safety

The holding systems used in the crash-tests:

• 18-month kid - Fair “Bobsy” G 0/1 ISOFIX opposite the direction of the motion
• 3-year-old child - Fair “Bobsy” G 0/1 ISOFIX forward the direction of the motion

In order to equip the front seat with a children’s seat, the airbag can be switched off by Honda dealer. A special warning sign draws attention to the fact that it is dangerous to place the seat with the airbag turned on. Only the presence of ISOFIX fastenings are not indicated properly.

Pedestrian protection

The changes in safety systems didn’t touch the body of the car and that’s why pedestrian protection remained at the same level. Nevertheless, 3 stars in not a bad result in this discipline. The front bumper and the front edge of the cowling well decrease the outcome of a collision for a pedestrian. Moreover, the cowling shows good figures in the area where a child’s head touches it.

Basic Safety systems installed on the car in Europe:

• Front air-bags
• Side air-bags for head and body
• Front safety belts with preload system and strain limiter
• The alarm of the unfastened front belts
• ISOFIX fastenings of the rear side seats

How ABS Works: ABS Dynamics. Part 3

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It should be mentioned that you need to press brakes to the full to make ABS work most effectively. However the owners of car equipped with the system Brake Assist do not have to do it, because the system automatically increases pressure in braking mainline thus assisting an undecided driver. At the same time the system is idle at normal braking. But if you press the pedal abruptly Brake Assist sees it as a signal for an emergency braking and activates.

The electronics will do its best while braking on heterogeneous surfaces.

Nevertheless, even such a sophisticated system as ABS has its disadvantages. For instance, it can lose to average brakes on snow, ice or sand and even blank the advantages of studded tires. On ice studs enable maximal deceleration at maximal relative sliding when they stick into ice and furrow it. ABS, in its turn, unbrakes the wheels and doesn’t allow studs to do their job and thus increases the braking distance. The same happens on ground roads (sand, breakstone, clay) and on the surfaces covered with snow.

The presence of ABS is not the reason for not using studded tires. While blocking studs will stick in the ice anyway thus enabling more reliable deceleration.

Car equipped with ABS in this case have a longer braking distance because the constantly unblocking wheels do not create a “plough effect.” On such surfaces blocked wheels have maximal braking effectiveness – they heap up rollers of ground or snow in front of them. So you have to remember: on icy, snow covered or ground surface the braking distance of a car without ABS can be shorter.

ABS can queer your pitch even on an uneven surface. If one wheel hangs up in the air for a moment, the deceived electronics will save you from sliding and will immediately decrease pressure in other mainlines. The car will unpleasantly wag its “tail” and the braking distance will increase. So you have to remember that a faultless suspension is one of the major factors of reliable work of ABS.

Progress gives birth to more sophisticated systems. Operating more data they can adapt to the type of road surface and brake according to inbuilt presets. Of course, the electronics cannot be treated as the panacea, the statistics is a stubborn thing: a properly set ABS saves around 20% of braking distance and gives the driver a chance to maneuver. It goes without saying that these precious meters can save your life and health.

How ABS Works: ABS Dynamics. Part 2

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Almost any ABS consists of a control unit, modulator which changes the pressure in hydraulic mainline, wheel side speed sensors mounted on the inner parts of a wheel hub.

The progressive humankind realized the harm of blocked wheels only in the 70s of the previous century. The pioneer company was Mercedes which in collaboration with Bosch developed a system that was installed on Mercedes S-class in 1979. The basic principle of the system was shaped then and later on it was only modernized.

The modern electronics (ABS, anti-slide system, ESP) considers not only the frequency of wheel rotation in order to keep the transversal and longitudinal dynamics of a car. The angles of the rotation of the steering wheel, body roll degree, acceleration are also under control. The pressure in braking system is generated according to the all received data plus sometimes even the track of the engine is changed.

The major purpose of ABS is to control the speed of the rotation of the wheel by changing the pressure in the braking system mainlines. In order to control side speed one has to know its value and how it is changed with time. Each wheel is equipped with a sensor which gives out electronic impulses with the frequency proportional to the rotation speed. This information goes to the control unit of ABS.

If during braking the side speed of a wheel is approaching 0 the electronic brain will immediately decide to “unbrake” it. The pressure will decrease until the wheel gains enough rotation. Then ABS will again increase the pressure in the mainline and brake the wheel. The cycle will repeat until the car stops or the driver will release the brakes to the position when there is no need for ABS.

The existing systems have quite a precise setting and enable maximal effectiveness of braking.

Some might say: it doesn’t require much wisdom. One can brake in a broken manner without the help of ABS. It is partially correct. Such a method can be used in car not equipped with ABS. When wheels block you brake, when they are “released” you get an opportunity to correct the trajectory of your motion. Of course, the braking distance increase.

But unfortunately, not a single (even the most experienced and talented one) can enable portioned braking with the frequency ABS can. The system can block-unblock wheel 15 times per second. Moreover, if such a braking is carried out by a driver it affects all the braking mechanisms, while ABS controls each wheel separately.

The majority of the modern ABS systems work with EBD (Electronic Brake Distribution) – a system that distributes braking force and meters the intensiveness of braking for each wheel.

How ABS Works: ABS Dynamics. Part 1

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The first serial car equipped with ABS was Mercedes S-Class in 1979. The system has been offered as an option for a long time and only in 1992 it was included on the list of basic features. At the beginning of the 1980s ABS could be ordered as an option with BNW 7-series.

What is ABS for?

Have you ever happened to detour a suddenly emerged hindrance and brake simultaneously? Of course, you have. It would seem quite easy – push the brakes and turn the steering wheel thus correcting the trajectory. However, everything is easy until a certain moment. If you press brakes to hard than necessary the wheel can block and…

Further there can be two possible variant of the succession of events. Both of them depend on the presence and the absence of ABS (Anti-lock Brake System). There thing is that blocked wheels sliding deprive the driver of the ability to maneuver – the car will simply drift as if the steering wheel is switched off. Only an experienced driver will be able to unblock the wheels in cold blood by releasing brakes for a moment. And then, using the impulse braking gain control and decrease the speed. The second variant is for a car equipped with ABS. The driver only has to push brakes harder and worl with the steering wheel calmly. Do you feel the difference?

During 30 years of existence the system has undergone significant changes. The rapidity of action has increased tenfold. Thus, for instance, the first control units weighed over 7 kg. The modern ones reach not more than 1.5 kg.

Blocking is even more dangerous because is can cause sliding. This can happen when the surface under the wheels is heterogeneous, the load is shifted on the axes due to the previous maneuver or the wheels are equipped with different tires. Moreover, with blocked wheels a car can change the trajectory under some side pressure (road grade or crash). In this case it is almost impossible to correct the trajectory.

In ABS for the estimation of speed inductive sensors of frequency are used. Each new generation of frequency sensors becomes smaller, more precise and reliable. Initially only one sensor was installed (on the speed changer of the rear axis or transmission). Later it was added by two more – on the front wheels. And only the latest ABS include sensors on each wheel with individual modulators. By the way, the first and the most primitive ABS affected the work of all braking systems.

Another negative effect of wheel blocking is the increase of stopping distance. The thing is that static friction force is usually bigger than sliding friction force. Thus for the most effective braking the braking system must generate such a force that the wheels rotate on the edge of blocking. There is an important factor as relative slip. It can vary (depending on the degree of wheel’s dormancy) from 0 to 100% (when wheel in completely blocked).

Experiments show that the maximal effectiveness of braking is reached at 15-20% sliding – it means that the speed wheel’s rotation is by 15-20% lower than the speed of a free-wheeling one. Nipping on ahead I would tell you that during braking the electronics maintains this very rate by periodically blocking and unblocking wheels.

to be continued…

Strata Gas & Oil Issues: Advantages and Disadvantages of Bioethanol. Part 3

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One cannot call the economy of this country dependant on oil. By growing and processing sugar cane Brazil is totally self-sufficient in fuel and electricity. It is undoubtedly optimistic, but even in this rosy picture there are a few negative aspects. The Brazilians cut down Amazon rainforests for new areas for plantation. One can call it a strange and short-sighted politics, and if called as it is – true idiotism. How can we and they live without the lungs of the planet?

Sugar cane in Brazil is grown by thousands of private farms. This causes various problems. Besides ethanol sugar is made from sugar cane. That’s why when in 1980s the cost of sugar increased significantly the production of ethanol was reduced to such a degree that people didn’t have enough of it to fill their cars. Nowadays the government monitors the situation and in 2007 it invested $25 million into the development of new technologies. In the USA this figure reaches $385 million.

The similar situation is in the USA. President Bush has approved the program “20 for 10” which is to help decrease the consumption of petrol by 20% by 2017. How? Ethanol, of course. By 2017 it is planned that the production of ethanol will have increased by 30 billion liters. During the recent years the investments into research reached $12 billion. And that’s just the beginning.

The USA produces a lot of ethanol, but still less than Brazil. But here it is produced not from sugar cane (it doesn’t grow in the states) but from corn. This variant is less effective, and thus the cost of the American ethanol is higher than that of the Brazilian. Nevertheless, the program is being promoted in a number of states and the governor of the “corn” state Illinois Barack Obama is no exception. New requirements towards the petrol mixture are being introduced: it must contain 10% of ethanol (such a proportion is harmless for traditional engines).

In order to fill a car with a fuel with more than 10% of ethanol you have make special adjustments to the engine. “The brain” of the car has to learn to specify the concentration of ethanol in the mixture and turn on the appropriate modes. As ethanol contains water, fuel line needs modernization. Moreover, it the car is used in the cold conditions the fuel has to be heated before starting the engine.

Will the Americans reach their goals? What is the future of this bioethanol affair? At the moment the answers to these questions are still vague. One thing is obvious, though – the total passage towards ethanol engines is impossible. If we assume that the effectiveness of the reprocessing process is 100%. But in order to convert the states from oil to ethanol we’ll have to cover 75% of the Earth’s surface with the appropriate crops. Roughly speaking even if we manage to cover the Moon with crops it won’t be enough.

Mass cultivation of crops for ethanol production will inevitably affect agriculture. Farmers are no fools – if the demand on corn is high they will grow it everywhere. And who will think about millions of the starving? That’s why many scientists rail at growing biofuel when some people have nothing to eat.

Ethanol issue is inevitably connected to big politics. In the photo you can the US president George Bush and the president of Brazil Luiz Inacio Lula da Silva are happy about the end of the next step of negotiations.

Though, any criticism should be accepted with a sound share of optimism. Of their own record biofuel programs are reasonable and with a decent realization they can bring much use. It should be also mentioned that ubiquitous introduction of ethanol will affect the world economy. And, of course, there will be people who’s interest suffer. Any way you slice it, the introduction of biofuel is not only a scientific and economic issue. It is more a question of big politics.

Strata Gas & Oil Issues: Advantages and Disadvantages of Bioethanol. Part 2

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From about 1000 European bioethanol filling up stations are located in Sweden. This country is planning to reject oil completely in 20 years’ time. The Scandinavians rely on hybrids which consume ethanol. In the picture the employees of Scania unveil a new city bus.

It should be also mentioned that octane number of ethanol is 105. It means that this substance can be burned in the engines with much higher compression ratio. Thus, in fact, the engines made for working on the new energy are to be in no inferior to their petrol or diesel variants. In the respect of economy and power. Not speaking about ecology. The usage of such engines will reduce the emission of carbon compounds by 80% and the emission of CO2 by 30%. But it is strictly forbidden to fill such engines with petrol – the detonation will immediately destroy it.

This is how a typical factory where bioethanol is produced looks like. The major difference of such factory from classic ethanol factories is in the scale of production and the number of fracking fractionators. The “green fuel” is produced right on the field. It is caused by high transportation costs of raw stock.

In the respect of combustion the perspectives of so-called multi-fuel (more frequently bio-fuel) cars look pessimistic. They can be called Flex Fuel, Flexifuel, BioFlex, Tri-Flex or any other way – it depends on the imagination of the manufacturing companies. Some of these cars come as concepts, others – serial models. But all these cars have one huge disadvantage – ethanol is burned ineffectively as the compression ratio cannot be changed by simply pressing a button on the panel.

It is no wonder that the cheapest way of transportation of fluid fuels is a pipeline. But in the case with ethanol there springs up a problem. It is hygroscopic, it means that it absorbs water from the air and thus has high corrosion aggressiveness. That’s why for the time being ethanol is transported via auto transport or railroad.

The situation gets a bit funny: the car drives quite good on Flexifuel petrol, and on E85 (if you have forgotten it is a mixture of 85% of ethanol and 15% of petrol) is goes bad and consumes considerably more. Bioethanol is cheaper than petrol, but not so considerably. It goes without saying that you won’t be able to economize on this kind of fuel. That’s why it is no wonder that the introduction of the new perspective idea is accompanied by constituent control, for instance, in the US and Brazil.

You should not think that if you fill your car with E85 your car even won’t start (as is in the case with hydrogen). In comparison to petrol E85 really has less energetic value, but for burning it less oxygen is required so you can pump more fuel into cylinders. As a result the power of the engine decreases, but not considerably.

I think that we should pay special attention to these countries as in them the introduction of bioethanol has gone far. The Brazilians hate fuel crises since 1973. And they do their best to prevent them. Thus, from 1975 the country faces a huge bio-fuel campaign. You should not get puzzled over the fact that 4.5% of the country’s land is occupied by sugar cane. Each year 1 million Brazilian workers produce over 20 million liters of ethanol.

There is a special branch of agriculture that specializes in cultivating sugar cane in Brazil. This branch has its own traditions and rules. During the production cheap manual labor is widely used which makes the local “sugar kings” incredibly rich. Foreigners are eager to take part in this “ethanol boom” but the local businessmen refuse to sell their manufactures point-blank. And even if they agree they set sky-high prices. It should be mentioned that the government supports them.

Strata Gas & Oil Issues: Advantages and Disadvantages of Bioethanol. Part 1

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The fact that vegetable fuels can be used for engines has been known since the invention of the first cars. But only recently the idea has become relevant. The reason for it – constantly rising oil prices.

Pros and cons of bioethanol

Recently the modern press here or there gives out messages about the danger of shifting to bioethanol. One competent view is almost immediately contradicted by another competent point of view. The criticism is so heavy that is almost naturally causes puzzlement. How can that be: the leading countries adopt strategies which are, if the skeptics are to be believed, totally thoughtless and are a shortcut to global ecological and economical trouble. Where is the truth? Let’s try to find out.

The opponents of burning ethanol in internal-combustion engines have their grounds. They do not try to contradict the fact that exhaust gases of ethanol are much cleaner. It is really so. The major agreement for them is that during the process of producing this type of fuel huge amounts of carbon dioxide are emitted into the air. Thus the ecological effectiveness of ethanol are close to zero. And all the dashing slogans about fighting the global heating become irrelevant once and for all.

In fact, ethanol could be extracted from all the plants, if they contain enough sugar and starch. Potatoes, barley, wheat, sugar beat – anything can be used. But the best variant is sugar cane.

Are they right? Both yes and no. The production of ethanol really impregnates the air with greenhouse gases (GHG) in the amounts comparable to the emissions of internal-combustion engines. But each coin has its tail. During the production of 1 liter of ethanol from a vegetable source the atmosphere gets exactly the same amount of CO2 as was previously consumed by the plants during photosynthesis. Thus it looks like the production of ethanol is photosynthesis vice versa with only major difference, in the former case it requires light, and in the latter – heat is extracted.

It turns out that bioethanol is absolutely neutral as a source of greenhouse gases. It wont make the situation better, but at the same time it will not worsen it. Ehtanol, however, has one huge advantage: positive energy balance. Depending to the type of raw stock it can vary from 1.24 to 8. It means that during the burning process of ethanol more energy is extracted then during the production. In this very respect the “scandal fuel” overtakes petrol or diesel fuel by a factor of ten.

The process of ethanol refilling is in no way different to that of petrol. Still, there chain of such filling stations is only developing. In the US, for instance, at the moment there are about 1.5 thousand spots where you can refill your car with E85.

At the same time, C2H5OH has its disadvantages. Burning 1 liter of ethanol gives 34% less energy than burning the same amount of petrol. It appears that if you refill your car with E85 the fuel consumption will increase up to these 34% - it depends on the concentration of ethanol in each concrete case. But this problem is relevant only for the owners of the cars which initially were equipped for petrol and only later adapted for ethanol.

to be continued…

Probiotics for Children: Top 5 Safest Automobiles for Kids. Part 2

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