Chemical Literature (Chem 184/284)

Lecture 3: Locating Books in the UCSB Library: PEGASUS & MELVYL

Nearly all books and journals in the UCSB Library are arranged by call number, so that materials on related subjects will be grouped together.
The UCSB Library follows the Library of Congress classification system.
- The first group of letters signifies the broad subject area.
- The first group of numbers signifies the more specific subject area.
- The subsequent letters and numbers identify the individual book, and are usually based on the author's name and/or book's title.
"Traditional" subject areas are well grouped:
- QD = chemistry
- QD 241-449 = organic chemistry
- QD 380-388 = organic polymer chemistry
- QD 410-413 = organometallic chemistry
- QD 415-449 = biological chemistry
Other "new" or "interdisciplinary" areas may be more scattered. For example, works containing chemical toxicity information may be found in:
- GE = environmental science
- QP = biochemistry & physiology
- RA includes medical toxicology
- S includes pesticide toxicology
- T includes general toxic chemical data
- TD = environmental engineering

Libraries use catalogs to enable location of items by author, title or subject.
UCSB has two electronic catalogs:
- MELVYL, the UC-wide catalog system, and
- PEGASUS, UCSB's catalog and circulation system.
- Each has its advantages and disadvantages, depending on the type of search you need to do.

Author (Books)
- MEL> f pa lastname, first Example: f pa pauling, linus
- PEG> a lastname, first Example: a pauling, linus
Full Title (books)
- MEL> f xt title of the book Example: f xt the nature of the chemical bond
- PEG> t title of the book Example: t nature of the chemical bond
- Note that both systems automatically truncate the end of exact title searches, and that you must omit initial articles (a, an, the) in PEGASUS searches but need not in MELVYL searches.
Title Words (books)
- MEL> f tw title words Example: f tw vitamin c cold
- PEG> k title words Example: k vitamin c cold
Subject Words
- MEL> f su subject words Example: f su organic chemistry
- PEG> k subject words Example: k organic chemistry
Exact LC Subject Heading
- MEL> f xsu subject heading subheading Example: f xsu chemistry organic handbooks
- PEG> s subject heading--subheading Example: s chemistry organic--handbooks
- Note that in PEGASUS, you must include any hyphenation in the heading; in MELVYL, you do not.

Both systems have subject headings assigned from the Library of Congress Subject Headings lists.
You could look up proper headings in LCSH books, but instead...
1. Do a title word search (MELVYL) or keyword search (PEGASUS)
2. Select one or more relevant records from those you retrieve.
3. Look at the subject heading(s) assigned to those books.
4. If you find new terminology that might prove useful, repeat the search as a subject or keyword search.

Truncation
- MELVYL uses "#" Example: f tw electrochem#
- PEGASUS uses "?", but only in keyword searches. Example: k electrochem?
Combining Searches
- MELVYL allows combinations within a command line. Example: f au cotton and tw group theory
- MELVYL also allows add-on commands Example: 1st command f au cotton, 2nd command and tw group theory. These are very useful for limiting a search (as by date or language) or narrowing a search with additional subject terms.
- PEGASUS only allows single line combinations of keyword searches. Example: k cotton and group theory
Call Number Searching
- PEGASUS allows searching by call number; MELVYL does not.
- Example: c qd401b761986
- Useful for browsing what is available in a given area without running out to the stacks.

Full Title (Journals)
- MEL>f xpe journal title Example: f xpe journal of the american chemical society
- PEG> t journal title Example: t journal of the american chemical society
- Note that both automatically truncate at the end of exact title phrases. PEGASUS searches books and journals together; watch out for the one-word journal titles like Nature, Science
Title Words
- MEL> f pe journal title words Example: f pe eur# journal solid state chem#
- PEG> k journal title words Example: k eur? journal solid state chem?
- Note that both systems require at least three letters to truncate on. Since PEGASUS lumps journals and books together, and lists keyword results in reverse chronological order, MELVYL is usually easier for this type of search.
When to Use PEGASUS vs. MELVYL for Journal Call Numbers
- PEGASUS gives the most detailed holdings information, including current (unbound) issues.
- MELVYL keeps journals in a separate file from books, and so can be easier when you have a single word title (e.g. Nature or Science) or when you have to use truncation.

Some series are individually catalogued because the volumes vary widely in subject, e.g. ACS Symposium Series
If so, the periodical record will say "see call number for individual volumes"
On PEGASUS, use: k series name vol.# Example: k acs symposium 400
On MELVYL, use: f se series name vol.# Example: f se acs symposium 400

Some are listed on MELVYL and PEGASUS, but not many. You will sometimes find them in footnotes, bibliographies or Chemical Abstracts searches.
On catalogs, check the long form of the record for report numbers.
Bring report numbers to SEL desk; we'll check to see if we have them, and verify on NTIS CD or fiche if necessary.

Many US documents listed on PEGASUS, but some of these are unverified records.
Check the location: if it's Government Publications, and there's a call number, it's on the open shelves in GP.
If no call number, the best strategy is to print out all pages of the long form of the PEGASUS record and take it to the Government Documents service desk for retrieval. Sometimes the information must be verified at the Main Reference Desk.

UCSB Library owns few non-UCSB dissertations.
Most UCSB dissertations are grouped together within broad subject areas e.g. QD 47.5 C2 S25 for chemistry dissertations. To find the dissertations from a given department search:
- PEGASUS: k dissertations [department name]
- MELVYL: f su dissertations [department name] ucsb
Look up individual dissertations by author or title word like any other book.

Both PEGASUS and MELVYL are available remotely, either by modem connection to the campus network.
MELVYL is available by TELNET: telnet://melvyl.ucop.edu.
PEGASUS is available by TN3270: tn3270://ccnh.ucsb.edu, a system similar to TELNET used to connect remotely to IBM mainframes.
For both of the above, you must have the appropriate software (telnet or tn3270) loaded on your computer. Both are available on the Web as freeware. See the InfoSurf pages on MELVYL and PEGASUS respectively for links to sources of this software.
MELVYL is available with a WorldWide Web interface.
No password is required for the book catalogs, but MELVYL requires one for the article databases and the UPDATE command.