Synthetic Sebum Makes Slippery Sailboats

sonnejw0 writes "Sea-faring vessels are a major contributor of greenhouse gas production due to a deficit in international laws and inherent inefficiencies at sea, such as barnacle build-up on hulls. Many marine animals avoid the build-up of drag-inducing barnacles through secreting oily residues from their pores or through the nano-molecular arrangement of their skin. Sailors regularly defoul their hulls, removing the barnacles at dry-dock, which requires them to reduce the amount of time they have at sea. Some synthetic chemicals in paints have been used to prevent barnacle build-up but have been found to be toxic to marine animals and thus outlawed by several nations. Now, engineers are trying to replicate the skin of marine animals to produce a slippery hull to which marine bacteria cannot attach, saving fuel costs and improving speeds."

Comments

Oh dear lord

[RenHoek]

The image of a smegma producing sail yacht is now stuck in my head!

Where's the brain bleach when you need it!

Re:Oh dear lord

[NoYob]

Sebum - white shit that causes zits.

I was thinking of ships with zits. Of course, as the ship gets older, it will probably grow out of it. It will be bad for the ships that ship chocolate and potato chips!

Re:Oh dear lord

[morgan_greywolf]

Dude, what what would you do if I told you (truthfully!) that sebum is all over your body? It's all over your hair, your skin, etc.

Yeah. That's because sebum is a term that refers to the natural oils that coat your hair and skin. It's what makes your hair and skin waterproof and what protects them from drying out.

Re:Oh dear lord

[sonnejw0]

Yeah, sebum is the natural oily product of the sebaceous glands that surround hair follicles. Zits are formed when sebaceous glands are blocked, resulting in a build-up for sebum WITHIN the hair follicle and/or gland. This build-up can occur due to a bacterial infection, skin sloughing, or excess sebum itself, excess sebum being produced by the sudden increase of systemic testosterone in pubescent years, as a result of repeated and frequent sexual stimulation post-pubescent, or exogenous oils and saturated fats from processed foods and meats can be secreted and are highly likely to obstruct these very pores.

The sebaceous glands can recalibrate themselves eventually to this increased testosterone concentration, or the testosterone concentration can descrease with age or activity, or the elasticity of the skin can result in increase pore size, allowing greater flow. Massaging of the skin under hot water with soap could be a preventive measure in done regularly and at a young enough age. I would avoid harsh peroxides as they do not attack the underlying cause, even if caused by a bacterial infection it will probably not be entirely effective. The pores need to be cleansed, and peroxides are very effective at damaging DNA resulting in skin cancer later in life.

I am not an M.D., but a Ph.D. student, and I had horrible sebaceous cysts when I was a teenager. So I can commiserate with the issue. Too bad I didn't realize back then that daily fast food was the cause of my problems and not the 'yummy' solution to my psychological needs I thought it was. Now, fast-food makes me sick that I know what is in it and how my teenage years of indiscretion will probably result in a heart-attack in mid-life, not discounting 5 years of misery, physically and psychologically. I bicycle 6 miles a day, now, and cook all of my own foods at home and I love life and social occasions. It's a lot harder to make those kinds of choices as a teenager, though. Peer pressure and the mental cloud of hormones makes it difficult to think for yourself, even when you think you are.

It's a start

[Taco Cowboy]

A surface that inhibits barnacles is only a start, for there are other things one can do to make a ship more eco-friendly

One if obviously a more fuel efficient engine

The other is to improve the design of the propeller to make it more efficient while lessen the drag

Then there is the need for a much lighter material for the construction of the ships

Last but not least, new designs of ships are also needed.

Re:It's a start

[0100010001010011]

Go Nuke. They did it once http://www.atomicengines.com/ships.html, but made it more of a 'show' boat than a work horse.

* The Savannah was designed as a showboat. Her purpose was to demonstrate American technology as part of the "Atoms for Peace" program. Pretty lines and luxurious staterooms were more important than cargo capacity or loading ease.
* She made politically motivated port calls, not economically motivated ones.
* She was a one of a kind ship, required to support a specialized infrastructure by herself.
* There were some difficulties with union negotiations. She spent almost a year tied to the pier because of the deck officers did not want the engineers to make more money than they did.

With the air craft carriers no one seems to have a NIMBY problem. You could move quite a bit of cargo with a few lbs of uranium.

So it'll require hiring some more staff (Like an actual engineer and maybe some armed guards). The US Navy has managed to not have any nuclear powered vessel captured by pirates.

Heck I wouldn't have a huge problem if the US Government wanted to own and operate a super-super cargo ship if it ran on Nuclear energy. The amount of oil those ships burn is measured in thousands of gallons per mile.

Re:It's a start

[Weh]

ehm, have you ever studied ships?

Large ships already have extremely efficient two stroke diesel engines (even over 50% which is extremely high if you consider the carnot max) They also have many devices to recover waste heat.

Propeller designs are already very sophisticated, difficult to improve there.

weight: the weight of the ship is very low relative to the amount of cargo it carries (compared to e.g. a truck). Also, the ship sails at relatively low speeds and mostly in a straight line so acceleration/deceleration losses that increase with mass are not really a factor.

All in all cargo ships are already the most efficient mode of transport on a fuel/cargo weight-distance ratio basis.

Re:It's a start

[smooth wombat]

Heck I wouldn't have a huge problem if the US Government wanted to own and operate a super-super cargo ship if it ran on Nuclear energy. The amount of oil those ships burn is measured in thousands of gallons per mile.

I know you're trying to make a point about using nuclear energy to power ships rather than burning fuel, but let's not go overboard on the amount of fuel being burned per mile. According to WikiAnswers, if a cargo ship travels at 30 mph (roughly 26 knots), it burns 120 gallons per mile.

Granted, as the second item on that page relates, most container ships burn bunker fuel but the calculation is still the same. Even taking into consideration the size of ultra-large cargo ships, they don't use anywhere near thousands of gallons per mile to move across the water.

Re:It's a start

[Red Flayer]

According to WikiAnswers, if a cargo ship travels at 30 mph (roughly 26 knots), it burns 120 gallons per mile.

The largest container ships in the word operate on diesel engines with about 114000 HP at 25.5 knots. The engines consume (at peak efficiency, not regular operating conditions) 0.260 lbs/hp/hr of fuel. Diesel is around 7 lbs/gal, so the calc works out to about 144 gals/mile... at peak efficiency.

I saw your claim and thought, "What about superfreighters?" After some back-of-the-envelope calculation, I'm surprised at their relative fuel efficiency...

However, they're still dirty, dirty ships. One superfreighter releases the same SOx emissions as 50 million passenger cars. So even though the fuel usage isn't as bad as it one might think, there are other reasons why nuclear would be better.

Won't the sailors slip all the time?

[bostei2008]

... stopped reading after the headline...

Fire Hose Liner?

[handy_vandal]

Maybe we can line fire hoses with this amazingly slippery material?

Re:Teflon?

[eric2hill]

The glue that barnacles produce will stick to Teflon.

Here is an old 2005 article similar to this concept that talks about using a "skin" similar to shark skin to combat the barnacles.

Re:Damn, beat me to it

[oldspewey]

Sunlight is said to help ... so hop to it, the basement stairs are right there at the end of the room.

What a first sentence...

[RobVB]

Sea-faring vessels are a major contributor of greenhouse gas production due to a deficit in international laws and inherent inefficiencies at sea, such as barnacle build-up on hulls.

Sea-faring vessels are the single most efficient way of transporting goods we have. The reason they're a big contributor of greenhouse gas production is that our global economy requires that a lot of goods are transported around the world. Try transporting thousands of containers across thousands of miles by truck (please, don't actually try this, it's bad for the environment).

The IMO (wikipedia) is one of the most widely acknowledged international authorities on anything. They've made a lot of internationally respected laws, improving sea transport on many levels, including the environmental effects.

It's true that hull fouling is a problem for ships. It's also true that many (especially large) ships burn Heavy Fuel Oil (HFO), which contains a lot of pollutants (like sulfur) and isn't as clean as, say, diesel oil. It's also true that ships burn a lot of HFO, and it's true that ships further pollute the seas by dumping garbage overboard.

However, while the amounts of HFO burned by, say, the Emma Maersk, are enormous (about 300 metric tonnes per day at full operation), this is almost nothing when compared to trucks. Assuming 300mt/day at a cruise speed of 25 knots (over 45km/h), that equates to roughly 30 tonnes per 100 km. A semi-trailer truck pulling two TEU containers runs at around 30 liter per 100 km (that's around 8 mpg, anyone that can confirm this number?). This means the Emma Maersk, carrying 14000 TEU, uses 1000 times as much fuel as a truck carrying 2 TEU, which makes this ship about 7 times as fuel efficient as trucks.

And another thing: with HFO costing 300-400 dollars per metric ton, the Emma Maersk burns up about 100,000 dollars per day when running at full capacity (this almost never happens, especially now with the economic crisis, but bear with me). That's about 3 million dollars a month in fuel. The Emma Maersk is crewed by a minimum of 13 seafarers, but let's take 20 for easier calculations, since it's probably closer to reality anyway. Suppose each of those 20 people earn 10,000 dollars a month (which is a lot - maybe the Captain, Chief Officer and Chief Engineer make this much... just maybe). That means total crewing costs for this ship would be 200,000 dollars a month, with fuel costs 15 times higher. What I'm trying to say here is this: it's in the companies' best interest to improve their fuel economy. A 7% increase in fuel efficiency would save them more money than not having to pay the crew. I'm fairly certain there are no cheap and easy ways to drastically reduce fuel usage, or they would have thought of it by now.

All of this is not to say that there isn't room for improvement in the maritime transportation business, far from it. This research and other research like it can and will do great things for the shipping industry and the environment. I just didn't like how the summary made the industry the bad guy here.

P.S. If you want to read more about the IMO's actions on air pollution: go nuts.