Semimonthly issues: United States and possessions. $160, all other countries. $175. Cumulated (semiannual and annual) indexes. United States and possessions, $100; all other countries, $115.

Combined subscription to issues and indexes: United States and possessions, $240; all other countries, $270.

Subscribers with combined subscriptions may order additional subscriptions to the semimonthly issues at: United States and possessions, $150; all other countries, $165.

ANNOUNCEMENT OF NASA PUBLICATIONS IN STAR

Scientific and technical reports produced by NASA and its contractors and grantees, or in conjunction with other Government agencies, and other selected documents released by NASA are identified by an asterisk (*) following the accession numbers (e.g., N74-10132*) Prior to their announcement in STAR, these NASA publications are assigned a specific NASA report number, which is shown on the last line of the STAR citation. The nature of NASA publications is specified by the report number series, identified by a prefix to the report number: TR-R, TN-D, TM-X, TT-F. CR, or SP. These series refer respectively to NASA Technical Reports, which contain significant and complete contributions to scientific and technical knowledge. Technical Notes, reports of similar quality but lesser scope. Technical Memorandums, reports containing preliminary data or of specialized utility. Technical Translations, information published in a foreign language and considered to merit NASA distribution in English; Contractor Reports, information generated under NASA-sponsored contracts. grants, or interagency agreements; and Special Publications, which include conference proceedings, monographs, data compilations, sourcebooks, special bibliographies, and other publications derived from or of value to NASA activities. Reports in these series that are printed by NASA are often referred to as "low-numbered" or "low series publications, because the report number is always below 50,000 (8.000 for Technical Translations). Some TM-X and CR reports are numbered above 50,000. These, and TT-F translations above 8,000. are referred to as "high-numbered" or "high series" publications, and are generally available only in microfiche' or facsimile reproductions.

DISTRIBUTION OF NASA PUBLICATIONS

NASA distributes its publications to qualified recipients who have registered as describeo in the next paragraph. (Public availability of NASA reports and other publications announced in STAR is discussed separately in this Introduction.) Automatic distribution of low series NASA reports can be made in either paper (printed) copy or microfiche. High series NASA reports are given automatic distribution only as microfiche. The automatic distribution of a NASA report, in paper copy and/or microfiche, is made under the same subject category in which it is announced in STAR. A printed low series report usually is disseminated four to six weeks prior to its announcement in STAR. Microfiche of both low and high series reports are disseminated concurrently with STAR announcement. Automatic distribution of NASA documents is supplemented by a secondary request service, usually for microfiche copy only. which NASA may provide to qualified registrants.

ELIGIBILITY AND REGISTRATION FOR NASA INFORMATION PRODUCTS AND SERVICES A variety of services, in addition to the distribution of NASA scientific and technical reports and of STAR and its cumulative indexes, is available to organizations of the following types that have registered with NASA to receive specific services or products:

1. NASA offices, research centers, contractors, subcontractors, grantees, and consultants:

2. Other U.S. Government agencies and their contractors:

3. Libraries in the United States that have arrangements with NASA to maintain collections of NASA documents for public reference;

4. Other organizations in the United States having a need for NASA documents in work

(1) A microfiche is a transparent sheet of film, 105 by 148 mm in size, containing as many as 60 to

98 pages of information reduced to micro images (not to exceed 24:1 reduction)

related to aeronautics and space research; QUALITY CONTROL MARK

5. Organizations abroad that have established reciprocal document exchange arrange-
ments with NASA.

Only the central service points or central points of document acquisition and control within
qualified organizations are eligible to register for NASA products and services.

Domestic organizations that may be eligible to receive various classes of NASA publications
and services should address their requests for registration or for further information to:

NASA Scientific and Technical Information Facility

Attn: Registration Activity

P.O. Box 33

College Park, MD 20740

Organizations abroad should direct requests to the same address, but to the attention of:
Foreign Exchange and Acquisitions Branch.

PUBLIC AVAILABILITY OF DOCUMENTS ANNOUNCED IN STAR

The source of documents announced in STAR varies, depending upon the organization
which has issued a document and the form in which the document can be provided. Those
documents that can be obtained on microfiche are indicated in STAR by the # symbol
following the NASA accession number. All documents for which microfiche can be obtained
are also available as facsimile.

Documents that cannot be microfiched but for which one-to-one facsimile can be provided
are indicated by a plus (+) instead of the # sign. Documents for which neither the+nor #
symbol is shown, and for which no availability other than the issuing activity is given, may
present unusual problems of reproducibility. The originator of such a document should be con-
sulted as to its availability.

A source from which a document announced in STAR is available to the public is ordinarily
given on the last line of the citation. The NASA accession number is sufficient when ordering
NASA and NASA-sponsored documents (indicated by an asterisk) from the National Tech-
nical Information Service. When ordering non-NASA documents (no asterisk) from the issu-
ing agency or other sources, particularly NTIS, it is essential that additional bibliographic
information, including the report number, be given.

The following are the most commonly indicated sources: (Full addresses of these organiza-
tions are listed at the end of this introduction.)

Avail NTIS. Sold by the National Technical Information Service at the price shown in the
citation. If no price is shown in a current STAR citation, it may be ascertained by
referring to Government Reports Announcements or to NTIS. Beginning with docu-
ments announced in Issue 21, 1973, "stocked" reports, such as printed NASA
reports (see above section Announcement of NASA Publications in STAR) are priced
on a step schedule ranging irregularly from $3.00 for a 1-to-25 page report to
$11.00 for 576 to 600 pages, plus $2.00 for each additional 100-page increment.
Demand print reports (those for which a facsimile reproduction will be made to fill
orders) are priced at $4.00 for the first 20 pages plus 25 cents for each five pages
or portions thereof. These prices are not applied retroactively; i.e., reports previously
announced at a certain price continue to be sold at that price. If "Avail: NTIS"
without a price appeared in the citation of a NASA report (asterisked) it is sold at
$3.00 whether printed copy or facsimile is supplied. Because of price changes and
possible surcharges, it is recommended that for any document announced in STAR
before July 1970, NTIS be queried as to the price. Document prices are subject to
change without notice. See p. vi for NTIS document subscription rates. See "Avail:
SOD" below for documents available from both the Superintendent of Documents
and NTIS.

Microfiche. Microfiche is available from NTIS at a standard price of $1.45
(regardless of age) for those documents identified by the # sign following the acces-
sion number (e.g., N74-10869#) and having an NTIS availability shown in the
citation. Standing orders for microfiche of (1) the full collection of NTIS-available
documents announced in STAR with the # symbol. (2) NASA reports only (ident-
ified by an asterisk (*)), (3) NASA-accessioned non-NASA reports only (for those
who wish to maintain an integrated microfiche file of aerospace documents by the
"N" accession number), or (4) any of these classes within one or more STAR
categories, also may be placed with NTIS at greatly reduced prices per title (e.g.
45 cents) over individual requests These availabilities apply only to microfiche with
the standard $1.45 price; any document with a different cited price must be pur-
chased individually at that price. Inquiries concerning NTIS Selective Categories
in Microfiche should be addressed to the Subscription Unit, National Technical
Information Service.

Deposit Accounts and Customers Outside U.S. NTIS encourages its customers
to open deposit accounts to facilitate the purchase of its documents now that
prices vary so greatly.

NTIS customers outside the United States are reminded that they should add the
following handling and postage charges to the standard or announced prices:
hard (paper) copy. $2.50 each document; microfiche. $1.50 each document. For
subscribers outside the United States who receive microfiche through the Selective
Categories in Microfiche program, NTIS will add 15 cents for each title shipped.
Avail: SOD (or GPO). Sold by the Superintendent of Documents, U.S. Government Print-
ing Office, in hard copy. The price and order number are given following the avail-
ability line. (An order received by NTIS for one of these documents will be filled
at the SOD price if hard copy is requested. NTIS will also fill microfiche requests.
at the standard $1.45 price, for those documents identified by a # symbol.)
Avail NASA Public Document Rooms Documents so indicated may be examined at
or purchased from the National Aeronautics and Space Administration, Public
Documents Room (Room 126). 600 Independence Ave., S.W., Washington, D.C.
20546, or public document rooms located at each of the NASA research centers,
the Mississippi Test Facility, and the NASA Pasadena Office at the Jet Propulsion
Laboratory.

Avail: NASA Scientific and Technical Information Office. Documents with this avail-
ability are usually news releases or informational leaflets available without charge in
paper copy

Avail AEC Depository Libraries Organizations in U.S. cities and abroad that maintain col-
lections of U.S. Atomic Energy Commission reports, usually in microfiche form, are
listed in Nuclear Science Abstracts Services available from the USAEC and its
depositories are described in a booklet. Science Information Available from the
Atomic Energy Commission (TID-4550), which may be obtained without charge
from the USAEC Technical Information Center

Avail Univ Microfilms Documents so indicated are dissertations selected from Disser
tation Abstracts and are sold by University Microfilms as xerographic copy (HC) at
$10.00 each and microfilm at $4.00 each regardless of the length of the manu-
script Handling and shipping charges are additional All requests should cite the
author and the Order Number as they appear in the citation

Avail USGS Originals of many reports from the US Geological Survey, which may con-
tain color illustrations, or otherwise may not have the quality of illustrations pre-
served in the microfiche or facsimile reproduction, may be examined by the public
at the libraries of the USGS field offices whose addresses are listed in this Intro-
duction The libraries may be queried concerning the timely availability of specific

documents and the possible utilization of local copying services (eg, color
reproduction).

Avail. HMSO Publications of Her Majesty's Stationery Office are sold in the US by
Pendragon House, Inc. (PHI), Redwood City. California The US. price (including a
service and mailing charge) is given, or a conversion table may be obtained from PHI
Avail BLL (formerly NLL): British Library Lending Division, Boston Spa, Wetherby, York-
shire, England. Photocopies available from this organization at the price shown.
(If none is given, inquiry should be addressed to the BLL.)

Avail: ZLDI. Sold by the Zentralstelle für Luftfahrtdokumentation und Information,
Munich, Federal Republic of Germany, at the price shown in deutschmarks (DM).
Avail: Issuing Activity, or Corporate Author, or no indication of availability. Inquiries as
to the availability of these documents should be addressed to the organization
shown in the citation as the corporate author of the document.

Avail: U.S. Patent Office Sold by Commissioner of Patents. U.S. Patent Office, at the
standard price of 50 cents each, postage free. (See discussion of patents and patent
applications below.)

Other availabilities:

If the publication is available from a source other than the above, the
publisher and his address will be displayed entirely on the availability line or in com-
bination with the corporate author line.

EUROPEAN AVAILABILITY OF NASA AND AGARD DOCUMENTS

Facsimile copy or microfiche of NASA and NASA-sponsored documents identified by both the
symbols # and * and those AGARD reports that are on microfiche may be purchased from:
ESRO/ELDO Space Documentation Service

European Space Research Organization

114, av. Charles de Gaulle

92-Neuilly-sur-Seine, France

NASA PATENTS AND PATENT APPLICATIONS

Patents and patent applications owned by NASA are announced in STAR under appropriate
subject categories and are referenced in the STAR indexes. In the Report/Accession Number
Index, patents are indexed by the NASA Case Number (which appears in lieu of the report
number in other indexes), the U.S. Patent Number, the U.S. Patent Application Serial Number.
and the US Patent Class. Patent applications for which patents have not yet been issued are
Indexed by the NASA Case Number and the U.S. Patent Application Serial Number
NASA patent application specifications are sold by the National Technical Information Service
at the price shown in the citation. Microfiche are sold at the established unit price of $1.45.
The US-Patent-Appl-SN- number should be used in ordering either paper copy or microfiche
from NTIS. Printed copies of patents (which are not microfiched) are available for purchase
at 50 cents per copy from:

Commissioner of Patents
U.S. Patent Office
Washington, DC 20231

When ordering patents, the US Patent Nurnber should be used, and payment must be re-
mitted in advance, preferably by money order or check payable to the Commissioner of
Patents. Prepaid purchase coupons for ordering are also available from the Patent Office
The patents and patent applications announced in STAR are owned by NASA and are avail-
able for royalty-free licensing. Requests for licensing terms and further information should be
addressed to:

Assistant General Counsel for Patent Matters/Code GP-1

Nations! Aeronautics and Space Administration
Washington, DC 20546

In the citation of each NASA-supported document and of some non-NASA documents is a code (e.g., CSCL 05A) that indicates the subject category assigned to it from the COSATI Subject Category List (first ed. December, 1964) published by the Committee on Scientific and Technical Information of the Federal Council for Science and Technology.

INDEXING VOCABULARY

The authority for the indexing vocabulary used in the subject index of this issue of STAR is the NASA Thesaurus. The most recent version is the NASA Thesaurus Alphabetical Update (NASA SP-7040), September 1971, which is available from NTIS as accession number N72-15923 for $6.00 in paper copy. The current cross-reference structuring for each term appears in this volume, together with additional approved terms that may be used in indexing documents announced in other issues of STAR. NASA SP-7040 supersedes the first two volumes (subject terms A–Z) of the three-volume Preliminary Edition of the NASA Thesaurus (NASA SP-7030), December 1967. Volume III of the Preliminary Edition presented the following aids to vocabulary selection of the 1967 terms: hierarchical display of index terms, category terms listing, and permuted index; this has not been updated but may still be useful.

SUBSCRIPTION TO NASA PRINTED DOCUMENTS

The National Technical Information Service offers an annual subscription to printed NASA formal series reports at a per-title price, including handling and postage, of $2.00 domestic, $2.50 foreign. (There are no added charges beyond this for subscribers outside the United States) About 1,000 titles are printed yearly; all must be subscribed to. Included are NASA Technical Reports, Technical Notes. Special Publications (including those printed by the Government Printing Office). Contractor Reports numbered below CR-50,000, Technical Memorandums numbered below TM-X-50,000, and Technical Translations numbered below TT-F-8000. Excluded are NASA patents, Technology Utilization publications (SP-5000 series). NASA continuing bibliographies (SP-7000 series), and Space Vehicle Design Criteria (SP-8000 series). (Continuing bibliographies can be purchased from NTIS on yearly subscription for specific titles and supplements or on an individual-title basis, while the TU and SVDC publications are sold by NTIS only on an individual report basis.) For additional details on subscriptions, inquiries should be directed to NTIS.