“Free,” means you do not need a subscription or membership to access the resource (like you do for certain databases Engineering Village, Web of Science). Most of the time you can view only abstracts or table of contents; in some cases you can view the full text of articles.
ArXiv - Formerly known as the Los Alamos National Laboratory E-Print Archive – contains research papers in the area of physics and related disciplines, mathematics, nonlinear sciences, computational linguistics, and neuroscience.
BioMedCentral - All original research articles published by BioMed Central are made freely and permanently accessible online immediately upon publication. Peer – reviewed scientific articles in all areas of medical research and biology.
Chemistry Central - Chemistry Central publishes a range of online open access journals, and provides links to other online open access journals of interest published by BioMed Central all aspects of research in chemistry peer review
Directory of Open Access Journals - This service covers free, full text, quality controlled scientific and scholarly journals, aimed to cover all subjects and languages. There are now 4159 journals in the directory that are searchable at article level. As of today 277020 articles are included in the DOAJ service.
Highwire Press Free Full-text Journals – Currently provides access to 31 journals in a wide range of subject areas, but focuses mainly on medical journals.
OAIster - A freely-accessible site for searching only OAIster records OAIster is a union catalog of millions of records representing open archive resources
PhysMathCentral - Provides immediate open access to peer-reviewed physics and mathematics research
PoS – Proceedings of Science – Was created in 2005 as a collection of free full text conference proceedings in the areas of Astronomy, Biophysics, Mathematics, Neuroscience, Physics and Science Communication.
Registry of Open Access Repositories - Provides timely information about the growth and status of repositories throughout the world. Open access to research maximizes research access and thereby also research impact, making research more productive and effective.
Scitation - Abstracts from 22 AIP journals and other science and engineering societies.
Agricola - AGRICultural OnLine Access Full text
AIP Conference Proceedings - The American Institute of Physics Conference Proceedings report findings presented at many of the most important scientific meetings around the world. They are valuable as topical status reports providing quick access to information before it appears in the traditional journal literature. (Full text still being added)
American Concrete Institute - Abstracts only of ACI periodicals and publications (note: you must be an online recipient of the Journal title to access the full text article).
ASABE Technical Library - Search all recent technical documents published by the American Society of Agricultural and Biological Engineers. Anyone can view the abstracts. Access to the full text is via ASABE membership or site license.
ASCE - The ASCE Research Library is a comprehensive online tool for locating articles of interest across all disciplines of civil engineering. The Research Library provides you with unprecedented access to more than 73,000 full-text papers from ASCE Journals and Proceedings published. Approximately 4,000 new papers will be added each year. A Research Library subscription is not required to use the search and browse features or to view tables of contents and abstracts. Downloading full-text digital papers is available only to Research Library or online journal subscribers.
ASME Digital Library - Primary repository of current and archival literature featuring: ASME's Transaction Journals from 1990 to the present; ASME's Conference Proceedings from 2002 to the present; ASME Press E-Books selected from 1999 to the present.
CABI Global Health - Global Health database for public health information includes resources and critical advice from key health organizations such as the World Health Organization (WHO) and Centres for Disease Control (CDC).
CiteSeer - This is a scientific literature digital library and search engine that focuses primarily on the literature in computer and information science.
Cold Regions - The Antarctic Bibliography covers all disciplines related to the region including biological and geological sciences, medical sciences, meteorology, oceanography, atmospheric and terrestrial physics, expeditions, logistics equipment and supplies, and tourism. The Antarctic Bibliography is produced with support from the National Science Foundation with contributions from the Scott Polar Research Institute, University of Cambridge. Some full text, abstracts, option to purchase articles
Copper Development Association - Provides access to its Copper Data Center database free of charge, covers awareness of copper, related technologies, and the role of copper in the environment. Abstracts, document delivery available
EiCompendex - Comprehensive engineering literature databases. It contains over ten million references and abstracts taken from over 5,600 scholarly journals, trade magazines, conference proceedings and technical reports. Online coverage is from 1969 to the present. Purchase of a day pass is available for $49.95 (as of May 2010)
E-Print Network, - This covers scientific and technical information and has over 1.6 million documents. The E-Print Network searches a substantial number of e-print databases, pre-print servers, institutional repositories and multidisciplinary collections. It also includes over three thousand professional societies and more than thirty-one thousand individual researcher’s web sites.
Google Scholar - Enables you to search specifically for scholarly literature, including peer-reviewed papers, theses, books, preprints, abstracts and technical reports from all broad areas of research. Links to free full text when available.
GeoScienceWorld - Comprehensive Internet resource for research and communications in the geosciences, built on a core database aggregation of peer-reviewed journals indexed, linked, and inter-operable with GeoRef
ICE Virtual Library - Institute of Civil Engineers UK is the most comprehensive online civil engineering resource in the world. Here you can search the full archive back to 1836, browse our internationally renowned journals and books, and take advantage of our powerful searching tools to find the information you need. Some free content, plus abstracts
IEEE Xplore Digital Library - Free simple searching from its front, welcome, page and anyone can view simple abstracts from the search results. To see either the full text, full abstracts or use the full search capabilities a licensed subscription is required.
IET Digital Library - The Institution of Engineering and Technology was formed by the joining together the IEE (Institution of Electrical Engineers) and the IIE (The Institution of Incorporated Engineers). The IET is the inheritor of the IEE Digital Library service. The IET Digital Library holds more than 85,000 technical papers from all IET journals, magazines, conference publications and seminar digests. Highly cited journals such as Electronics Letters are available alongside 20 IET Research Journal titles, the IET's member magazine Engineering & Technology, plus seminar digests and conference publications. Also available on the IET Digital Library is the IET's online only journal Micro & Nano Letters.
IMechE Proceedings Archive - Full free text of conference proceedings from the institute of Mechanical Engineers (1847 – 1996) and the Institute of Automobile Engineers (1906 – 1947)
OneMine.org - Search over 503,208 pages in 50,795 mining and minerals related documents collected by professional societies around the globe, abstracts available
Physics and Geophysics Abstract Service - Contains bibliographic information from several sources, including NASA's Scientific and Technical Information group (STI), journal publishers, SIMBAD, NED, and table of contents consists of astronomy papers published through the late 1990s, and does not include the current literature.
QUAKELINE® Database - Bibliographic database covering earthquakes, earthquake engineering, natural hazard and disaster mitigation, and related topics. Varied publications are featured, including books, journal articles, conference papers, proceedings, technical reports, CDs, slides, and videos. The database is updated on a monthly basis and currently provides content for over 44,900 records; IS has access to all documents cited in the database. Abstracts
SPIE Digital Library - The SPIE Digital Library is the most extensive resource available on optics and photonics, providing unprecedented access to more than 260,000 technical papers from SPIE Journals and Conference Proceedings from 1990 to the present. (To access full text PDFs of articles a subscription or pay-per-view access is required.)
esp@cenet - User interface developed by the European Patent Office (EPO). Includes patents granted by the Intellectual Property Office since June 2002 and contains 60 million patents updated weekly. This database provides global coverage of patents. The database is organized by patent family or equivalents and full text is available for most patents.
FreePatentsOnline - You will need to set up a free account; all documents are available in a highly-compressed PDF format for fast downloading, with or without searchable text. US patents
GooglePatents - Search the full text of U.S. patents in pdf format it covers the entire collection of issued patents and millions of patent application made available by the USPTO' from patents issued in the 1790s through those most recently issued in the past few months. It does not currently include international patents.
USPTO - United States Patent and TradeMark Office .All patent images from 1976 forward are available in text as well as TIFF image format in the patent search systems. All trademark images are accompanied by descriptions and design search codes which indicate types of images included in a mark on the trademark search systems. Pre-1976 patents are available in TIFF image format only. No text versions are available for these archival images at this time. These images are only accessible by patent number and patent classification codes.
ASTM Digital Library - Is a vast collection of industry-leading standards and technical engineering information. The library covers a broad range of engineering disciplines, including aerospace, biomedical, chemical, civil, environmental, geological, health and safety, industrial, materials science, mechanical, nuclear, petroleum, soil science, and solar engineering. Full text not available, Abstract only.
CSA (Canadian Standards Association) - Serves business, industry, government and consumers in Canada and the global market. By developing standards that focus on real needs, such as enhancing public safety and health and preserving the environment. Full text of the standard can be ordered. Abstracts are free.
IHS Global Engineering Documents - Search the world's largest collection of technical standards. Penrose does not subscribe to the order feature of the database, but you can use it to verify titles and standard numbers.
NSSN - Search engine for standards. Powered by ANSI, no full text
CANADIAN GOVERNMENT / CANADA
ASTIS Database - Arctic Science and Technology Information System (ASTIS) database contains 66,000 records describing publications and research projects about northern Canada. ASTIS,is a project of the Arctic Institute of North America at the University of Calgary, also maintains subset databases about specific regions, subjects and projects.
GEOSCAN Database - Bibliographic database for scientific and technical publications of the Earth Sciences Sector (ESS) of Natural Resources Canada. This database features approximately 60,000 records, including: Publications of the Geological Survey of Canada and the Canada Centre for Remote Sensing and External publications authored by ESS scientists and specialists. GEOSCAN also provides links to publications available online or for free download (GeoPub and MIRAGE), as well as other information regarding ESS programs.
CANMET - Canada’s foremost research centre devoted to value-added structural metals, from design, to pilot-scale processing, to performance evaluation. Research and development activities involving metals and alloys, metal composites, metal powders and the enabling technologies, such as fabrication, coating and welding, that are required for manufacturing products.
National Research Council of Canada - Canada's foremost scientific publisher, the NRC Research Press publishes 16 journals, 15 client journals as well as conference proceedings and is the only Canadian publisher of peer-reviewed scientific monographs.
NRC-CISTI (Canada Institute for Scientific and Technical Information) is Canada's national science library and leading scientific publisher, provides Canada's research and innovation community with tools and services for accelerated discovery, innovation and commercialization.
NRC-CNRC - National Research Council (NRC) is the Government of Canada's premier organization for research and development. NRC comprises some 20 institutes and national programs and has been active since 1916.
ETDWEB World Energy Database - The Natural Resources Canada Library is currently able to offer access free of charge to all Canadians. ETDWEB has over 4,172,000 literature references, with direct access to the full text for 245,000 reports not typically available through conventional sources (over 1 million pages). Many thousands more link to sites worldwide where the documents cited can be obtained. Access to ETDEWEB is open to well over 60 countries, and is based on country membership in ETDE, developing country status, or Executive Committee decision.
UNITED STATES GOVERNMENT
Energy Citations Database - (DOE)Energy Citations includes bibliographic records of literature in disciplines of interest to DOE such as chemistry, physics, materials, environmental science, geology, engineering, mathematics, climatology, oceanography, computer science and related disciplines. It includes citations to report literature, conference papers, journal articles, books, dissertations, and patents. It covers research from the Atomic Energy Commission (to 1974), the Energy Research Development Administration (1974-1977), and the Department of Energy (1977-present).
Environmental Publications EPA - EPA publications, with more than 7,000 in stock and 35,000 digital titles, free of charge! EPA’s print publications are available through the National Service Center for Environmental Publications (NSCEP), and EPA's digital publications are stored in the National Environmental Publications Internet Site (NEPIS) database! You can search and retrieve, download, print and/or order only EPA publications from this site.
Information Bridge - Department of Energy (DOE) research and development reports in physics, chemistry, materials, biology, environmental sciences, energy technologies, engineering, computer and information science, renewable energy, and other topics.
NASA Technical Report Server - Valuable resource for students, educators, researchers, and the public for access to NASA's current and historical technical literature since it was first released in 1994. NTRS provides access to approximately 500K aerospace related citations, 90K full-text online documents, and 111K images and videos. NTRS numbers continues to grow over time as new scientific and technical information (STI) is created or funded by NASA. The type of information found in NTRS include: conference papers, images, journal articles, photos, meeting papers, movies, patents, research reports, and technical videos. The NTRS provides access to NASA's current and historical aerospace research and engineering results. NTRS integrates three separate information collections and enables search and retrieval of information through a common interface.
National Council for Science and the Environment - Reports on environmental and related topics. Contain nontechnical information that can be very useful to people interested in environmental policy. Abstracts only.
NFPA (National Fire Protection Association) NFPA provides free read-only versions of their standards. You have to create a free account. No print, copy or cut-paste capability. Uses Real Read .
NIOSHTIC-2 (occupational safety) - A bibliographic database of occupational safety and health publications, documents, grant reports, and other communication products supported in whole or in part by NIOSH.
NTIS (National Technical Information Service) - This is the largest central resource for U.S. government-funded scientific, technical, engineering, and business related information. Searchable database, no free text
Science Accelerator - Gateway to science, including R&D results, project descriptions, accomplishments, and more, via resources made available by the Office of Scientific and Technical Information (OSTI), U.S. Department of Energy. Science Accelerator was developed and is made available by OSTI as a free public service.
Science.gov - Federated search that incorporates DOE Information Bridge and other databases across science and engineering. Searches over 38 databases and 1,950 selected websites, offering 200 million pages of authoritative U.S. government science information, including research and development results.
TRIS online Transportation Research Information services from the U.S. Transportation Research Board. Links to free full text when available.
USGS U.S. Geological Survey - Bibliographic citations for over 70,000 publications. Full product and thematic map content for over 40,000 publications. USGS numbered series begun in 1880
Food and Agriculture Organization FAO - Registration is free but required. Downloads are limited to 4,000 records at a time. International statistics on production, trade, food balances, forestry, land use, irrigation, fertilizer, pesticides, agriculture, food aid, and fisheries.
ITU - International Telecommunications Union - Radio & Telecommunications is the leading United Nations agency for information and communication technology issues, and the global focal point for governments and the private sector in developing networks and services, 3 free downloads/year
United Nations Environmental Programme - Site contains news, general information, procedural reports, findings and contact information for international committees and projects.
WHO Protection of Human Environment - Site contains publications past and present and upcoming, press releases, access to the WHO library, fact sheets and online documents pertaining to sustaining the human environment.
WorldWideScience.org - Global science gateway—accelerating scientific discovery and progress through a multilateral partnership to enable federated searching of national and international scientific databases and portals.
ChemSpider - ChemSpider is the richest single source of structure-based chemistry information. Search engine for free full-text chemical and pharmaceutical literature. All chemical structures available within open access and commercial databases.
Common Chemistry - This database contains the CAS Registry Number®, chemical names (both formal and common), molecular formulas, and structures or sequences for ~7900 chemicals of widespread general public interest.
INCHEM - Chemical safety documents from a WHO sub-organization. Rapid access to internationally peer reviewed information on chemicals commonly used throughout the world, which may also occur as contaminants in the environment and food. It consolidates information from a number of intergovernmental organizations whose goal it is to assist in the sound management of chemicals.