tition, filed by the Center for Sci­ence in the Public Interest and the Environmental Defense Fund (EDF) under provisions of the Clean Air Act, gives EPA 60 days in which to take definite action on the nine points listed in the petition. If the Government fails to take "ade­quate" action by Jan. 1, 1972, the public interest groups have prom­ised to go to court.

The petition charges that, with the exception of limited action in which the Government reduced the use of leaded gasoline in govern­ment vehicles, the Department of Health, Education, and Welfare and EPA have "totally failed to take any significant action directed at pro­tecting the public from the serious health hazards associated with at­mospheric lead."

Proposals for action in the peti­tion include that by Jan. 1, 1972, EPA:

• Issue a lead criteria document (outlining health hazards and costs and recommending a standard).

• Promulgate an atmospheric lead ambient air quality standard of not in excess of 1.5 microgram/cubic meter, pending the complete elimi­nation of automotive lead emissions on the quickest possible schedule.

• Promulgate a deliberate national phase-out program of lead in gaso­line to achieve total elimination of automotwe lead emissions by Janu­ary 1976 at a rate not less than 20% per year beginning no later than March 31, 1972.

Another point of the petition asks EPA to begin a public education campaign to encourage the use of low-lead and lead-free fuels and to discourage excess emissions result­ing from overbuying of unnecessar­ily high octane fuel.

An EPA spokesman tells C&EN that the agency is working on a re­ply to the petition. He notes, how­ever, that regulations setting lead limits in lead-free gasoline are slated to be released by EPA some­time in December, an action that could possibly placate the public in­terest groups on several points for the time being.

RESEARCH SHIPS: All-aluminum vessel The newest addition to the growing fleet of research and special pur­pose ships is the Alcoa Seaprobe. Though not intended for the more academic océanographie projects, the Alcoa Seaprobe may be more

immediately productive in terms of examining the sea floor for min­erals and archeological artifacts.

The basic purpose of the 243-foot, all-aluminum ship is search and re­covery from depths down to 18,000 feet. The vessel is owned and op­erated by Ocean Search, Inc., a Washington, D.C.-based subsidiary of Aluminum Co. of America. Since being launched in August at Sturgeon Bay, Wis., the vessel has been undergoing shakedown and testing of her recovery systems. She will leave Washington on Nov. 8 for final deepwater tests in the Bahamas.

Propulsion and station keeping are achieved with two Voith-Schneider cycloidal propulsion units. There are no conventional screws or rudders. Control of the propulsion units is exercised with a joy stick on the bridge and a re­peater station in the operations center below deck. The ship can be moved through any vector and can be rotated within its own length to take advantage of the most favorable attitude in any sea.

The working rig of the ship in­cludes a 132-foot derrick which handles the search and recovery gear through a well in the bottom of the ship. Instead of cables, the recovery gear uses a string of 4!/2-inch steel pipe for a lifting capacity of up to 250 tons.

Two possible uses of the Alcoa Seaprobe would be investigation of the sites where two nuclear sub­marines have been lost in recent years, and recovery of manganese nodules which have been discov­ered in the Pacific. However, while not discounting these tasks, F. Worth Hobbs, vice president of Ocean Search, says that they are not currently in the picture. Ini­tial contracts are now under ne­gotiation and are confidential. Mr. Hobbs did note that the fact that the ship's home port is Washington suggests that the Federal Govern­ment will probably be an important customer.

In showing C&EN's Joe Haggin about his ship, Capt. Robert A. Wilson noted that most of the der­rick crew have been oil field rough­necks and that several of the of­ficers, including himself, have served on Glomar Challenger, which is noted for its offshore oil pros­pecting activities. Considering the Alcoa Seaprobe*s unique ability for taking and recovering deepwater coring samples, oil prospecting

All-aluminum research ship

could be prominent in the ship's future activities. The cost of hir­ing the ship varies with the job, but a spokesman for Alcoa stated that the price was in the neighborhood of $10,000 per day.

PLASTICS: Two against paper Plastic paper has a tremendous fu­ture, says Walter S. Young. "In fact, we believe that plastic paper will eventually compete with regu­lar printing papers across a broad spectrum of uses," he says. Mr. Young is general manager of Acro-line Co., a new joint venture formed by Union Carbide Corp. and Mead Corp. to engender such competition by marketing and developing a variety of plastic papers.

Acroline is the first such U.S. ven­ture by a major plastics producer and a major paper company, Mr. Young notes. At least two other U.S. firms are marketing such pa­pers, however. Crown Zellerbach Corp. makes and sells two types of polyolefin papers called Qper and Qkote under a license from Japan Art Paper Co. (C&EN, Jan. 12, 1970, page 15). Du Pont makes a spun-bonded polyethylene paper called Tyvek. The company has thus far been marketing Tyvek through its own salesmen, but will very shortly announce formation of a distribu­tion network of paper companies to sell Tyvek in the commercial print­ing and envelope markets.

Acroline's chief and only product is AcroArt, a filled, high-density polyethylene-based sheet developed in the 1960's by Carbide and Mead. AcroArt competes in the specialty paper area, which has an annual domestic volume of about 7500 tons,

NOV. 15, 1971 C&EN 13

Chemical world This

Young: one and only product

and Mr. Young's immediate task will be to increase market penetra­tion in that area. But he will also, he says, press development of prod­ucts for the 100,000 ton-per-year market currently served by pre­mium coated papers—a market out to AcroArt because of high price.

There is little likelihood, however, that Acroline will attempt to market low-priced plastic papers to com­pete with such products as news­print, paper bags, and wrapping paper, says Acroline's technical manager, Ted J. Collier. Even though AcroArt is strong, durable, and waterproof, he says, its most important selling point is its ability to provide excellent graphic repro­duction. In inexpensive papers, such an ability is not required and plastic paper's high price outweighs all its other advantages.

"AcroArt is a quality product," Mr. Young says, and he shows little concern for the technical advances claimed by Japanese paper com­panies. "We feel we have a few years' lead time" in all the technolo­gies announced, and "we think Acro­line's is the best product available using any technology."

BONE PROSTHESES: Use of metal powders Two scientists at the University of Wisconsin, Madison, are using pow­der metallurgy techniques to make bone prostheses. Dr. Joel Hirsch-horn, a metallurgist, and Dr. An­drew McBeath, an orthopedic sur­geon, say that their porous metal replacements behave almost like real bones, and that they promise to be better than any similar prosth­eses in use today.

Prosthetic devices are used to re­place bones or parts of bones that have been damaged by disease—for example, a hip joint immobilized by arthritis—or shattered by injury. At present, most bone prostheses are made of a biologically inert metal (either by casting the molten metal or by machining a solid in­got) or of methyl methacrylate. Such devices are strong, but they are solid and impervious. Their connection to the remaining natural bone is purely mechanical. In time, the prostheses tend to work loose.

Dr. Hirschhorn says that porous metal prostheses will best solve this problem. He makes a device by putting metal powder (such as stainless steel or titanium) in a rub­ber mold and compressing it, then sintering the compacted powder un­til the grains bind together. The re­sulting prosthesis is filled with tiny holes much like those in natural bone. This porosity allows natural binding: Bony and soft tissues grow into the pores and lock the prosthesis in place.

Dr. McBeath and Dr. Hirschhorn have been testing the prosthetic de­vices in dogs. One dog has been walking around on porous metal hip joints for several months and, ap­parently, is doing well. Dr. Hirsch­horn observes that the hip joint is one of the most commonly used prosthetic devices and that it must stand up to heavy load with fre­quent use. If the porous metal works in hip joints, he says, it will likely work anywhere in the body.

The Wisconsin pair are by no means the only ones working to im­prove attachment of prostheses. In fact, says Dr. Samuel F. Hulbert, head of Clemson University's divi­sion of interdisciplinary studies, the problem is currently "the most widely researched in all of ortho­pedics." He notes that a Clemson team is developing porous ceramic materials. Others are exploring porous metallic, ceramic, and poly­meric substances, and others are seeking materials that form chemi­cal bonds with body tissues.

WATER RECLAMATION: Vapor compression process Resources Conservation Co. (RCC) has started up its first process unit to reclaim waste water using a flat-plate vapor-compression evapora­tive cycle. The 50,000 gallon-per-day unit reclaims cooling-tower water, containing concentrated mineral

ι salts, from a compressor station on a natural gas pipeline owned by El Paso Natural Gas near El Paso, Tex.

RCC claims the process to be the most efficient distillation process in the world and says its two-stage evaporator returns more than 95% of the brine flow as fresh water to the cooling water system for the compressor station. The plant thus serves as a means of water conser­vation in an arid region and pro­duces a brine concentrate that can be disposed of within strict water pollution control requirements at minimum cost, RCC notes.

RCC, headquartered in Tulsa, Okla., is a new company formed in May 1971 as a joint venture of sub­sidiaries of Reading & Bates Off­shore Drilling Co., El Paso Natural Gas Co., and Boeing Co.

The company's equipment is de­signed in basic modules of 50,000 and 100,000 gallon-per-day capaci­ties. Larger units could be built by adding together modular units.

Units for handling cooling tower blowdown and sea water differ. For brine concentration, two stages are used and the volume of con­centrated brine is minimized for subsequent disposal, usually to a solar evaporation pond, says Otto Kirchner, operations manager for the company. For desalination, one stage is used to produce fresh water as half of the feed and to return the remainder to the sea.

A plant, similar to the one just started up, will cost between $375,-000 and $425,000, depending on loca­tion, says William Tyson, general manager of RCC. The El Paso, Tex., plant is more costly than a plant some customers might want, because of a large number of spare equipment items in it to ensure high reliability.

Full details of the operating costs of the new unit have not been dis­closed. The plant is powered en­tirely by electricity and requires 40 to 45 kwh. to produce 1000 gallons of fresh water.

In the plant, incoming brine is passed through a heat exchanger where its temperature is increased to near boiling. After passing through a deaerator, the brine is pumped to the top of the evapora­tive chamber and allowed to run down the outside of hollow alumi­num panels. Water vapor from the chamber is compressed and injected to the interior of the panels where it condenses.

14 C&EN NOV. 15, 1971