United States Department of Energy

About: United States Department of Energy is a government organization based out in Washington D.C., District of Columbia, United States. It is known for research contribution in the topics: Coal & Catalysis. The organization has 13656 authors who have published 14177 publications receiving 556962 citations. The organization is also known as: DOE & Department of Energy.

Synthesis–Structure–Property Relationships for Hyperbranched Aminosilica CO2 Adsorbents

Abstract: Hyperbranched aminosilica (HAS) adsorbents are prepared via the ring-opening polymerization ofaziridine in the presence ofmesoporous silica SBA-15 support. The aminopolymers are covalently bound to the silica support and capture CO 2 reversibly in a temperature swing process. Here, a range of HAS materials are prepared with different organic loadings. The effects of organic loading on the structural properties and CO 2 adsorption properties of the resultant hybrid materials are examined. The residual porosity in the HAS adsorbents after organic loading, as well as the molecular weights and degrees of branching for the separated aminopolymers, are determined to draw a relationship between adsorbent structure and performance. Humid adsorption working capacities and apparent adsorption kinetics are determined from experiments in a packed-bed flow system monitored by mass spectrometry. Dry adsorption isotherms are presented for one HAS adsorbent with a high amine loading at 35 and 75 °C. These combined results establish the relationships between adsorbent synthesis, structure, and CO 2 adsorption properties of the family of HAS materials.

Predicting Financial Crashes Using Discrete Scale Invariance

Abstract: We present a synthesis of all the available empirical evidence in the light of recent theoretical developments for the existence of characteristic log-periodic signatures of growing bubbles in a variety of markets including 8 unrelated crashes from 1929 to 1998 on stock markets as diverse as the US, Hong-Kong or the Russian market and on currencies. To our knowledge, no major financial crash preceded by an extended bubble has occurred in the past 2 decades without exhibiting such log-periodic signatures.

The Salmonella typhimurium/mammalian microsomal assay. A report of the U.S. Environmental Protection Agency Gene-Tox Program.

Abstract: The Salmonella assay has been in use for almost 15 years and can be defined as a routine test for mutagenicity and for predicting potential carcinogenicity It detects the majority of animal carcinogens and consequently plays an important role in safety assessment The test is also routinely used as the frontline screen for environmental samples (complex mixtures) isolated from air, water and food This role will continue to remain an area of growth as or because sample volumes associated with these testing areas are generally very limited and more extensive testing is generally impossible While this test, like all others, has some limitations, it is recommended that it be regularly included in all genetic testing batteries

Operating under stress and strain [electrical power systems control under emergency conditions]

Abstract: Power system control objectives for various levels and types of emergencies, e.g., overloads, faults, frequency drop, equipment damage, control system failure, are defined. Normal system operation, emergency prevention, emergency control, and recovery from emergencies are discussed. The need for ongoing research in power system control and for a concerted effort to develop an approach to system planning, design, and operation that properly recognizes all the system operating states and the state-transition mechanisms is emphasized. (LCL)