Metal hydride hydrogen compression utilizes a reversible heat-driven interaction of a hydride-forming metal alloy with hydrogen gas. This paper reports on the development of a laboratory scale two-stage Metal Hydride Compressor (MHC) system with a feed pressure of 150 bar delivering high purity H2 gas at outlet pressures up to 875 bar. Stage 1 and stage 2 AB 2 metal hydrides are identified based on experimental characterization of the pressure-composition-temperature (PCT) behavior of candidate materials. The selected metal hydrides are each combined with expanded natural graphite, increasing the thermal conductivity of the composites by an order of magnitude. These composites are integrated in two compressor beds with internal heat exchangers that alternate between hydrogenation and dehydrogenation cycles by thermally cycling between 20 C and 150 C. The prototype compressor achieved compression of hydrogen from 150 bar to 700 bar with an average flow rate of 33.6 g/hr .

ABSTRACTThe Multinational Force and Observers in Sinai is a 13-nation international peacekeeping organization with the mission to implement the security provisions of the 1979 Egyptian–Israeli Treaty of Peace and continues today after approximately four decades. Despite not having significant changes to its core mission of force health protection, the medical team has recently evolved to face several challenges, with a coronavirus pandemic and a fatal helicopter crash. This article describes the medical challenges and experiences of the medical team from August 2019 to December 2020, highlighting changes from previous years. This article also updates three previous articles on the subject published in Military Medicine in 1983, 1991, and 2003.

The complexity of cancer chemotherapy requires pharmacists be familiar with the complicated regimens and highly toxic agents used. This column reviews various issues related to preparation, dispensing, and administration of antineoplastic therapy, and the agents, both commercially available and investigational, used to treat malignant diseases.

The activity of the PCP pincer complex IrH2{C6H3-2,6-(OPBu(t)2)2)}, (3) as a catalyst for the dehydrogenation of the potential liquid organic hydrogen carriers: perhydro-dibenzofuran (4), perhydro-indole (5), N-methyl perhydro-indole (6), 4,4'-bipiperridine (7), 4-amino-methylpiperridine (8), and aminomethylcyclohexane (9) was investigated. Only low levels of dehydrogenation were achieved with 4 at 150 and 200 degrees C except in the presence a hydrogen acceptor, 3,3-dimethyl-1-butene (tbe). At temperatures above 150 degrees C, 3 showed high activity with 5 but only for the release of H2 across the C-N bond. Dehydrogenation of 6 at 150 degrees C was found to release up to 2.9 wt% H2, giving N-methyl tetrahydroindole in 92% yield, but only 7% N-methyl indole. However, efficient dehydrogenation of the aliphatic hydrogens occurred at 200 degrees C giving mixtures that approached a approximately 1:3 equilibrium between N-methyl indole and N-methyl tetrahydroindole at longer reaction times. The pincer catalyst was observed to be effective for the dehydrogenation of 7 and 8 at 200 degrees C but the products polymerize. The catalytic dehydrogenation of 9 was very efficient at 200 degrees C but gave primarily the undesired products dibenzylamine (68%), benzylidenebenzylamine (22%), ammonia and only minor amount of benzonitrile (10%). At 160 degrees C, 85% of the substrate was consumed after 24 h of heating but only a minor amount of cyclohexanecarbonitrile (2%) was detected with the major products being biscyclohexylmethylamine (45%) and cyclohexylmethyl-cyclohexylimine (38%). The nitrile yield is remarkably improved to 97% when the dehydrogenation was carried out at 160 degrees C in the presence of 10 mol% NaOBu(t) but heating the reaction mixtures containing the base to 200 degrees C resulted in the decomposition of the pincer catalyst.

The iridium complexes IrH 2{C 6H 3-2,6-(CH 2PBu t 2) 2 ( 1), IrH 2{C 6H 3-2,6-(CH 2PPr i 2) 2 ( 2), and IrHCl{C 6H 3-2,6-(OPBu t 2) 2 ( 3) have been found to be highly active catalysts for the dehydrogenation of N-ethyl perhydrocarbazole at 200 °C. However, dehydrogenation to the fully unsaturated ethyl carbazole does not occur in most instances. Complex 3 is the most active catalyst and shows reasonable activity even at 150 °C. No signs of dehydrogenation were found in experiments conducted at 100 °C. This apparently reflects the thermodynamic constraints imposed by the high enthalpy of dehydrogenation of the substrate.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTComplex Hydrides for Hydrogen StorageShin-ichi Orimo, Yuko Nakamori, Jennifer R. Eliseo, Andreas Züttel, and Craig M. JensenView Author Information Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan, Hawaii Hydrogen Carriers, LLC, Honolulu, Hawaii 96813, Department of Mobility, Environment, and Energy, EMPA Materials Sciences and Technology, 8600 Dübendorf, Switzerland, and Department of Chemistry, University of Hawaii, Honolulu, Hawaii 96822 Cite this: Chem. Rev. 2007, 107, 10, 4111–4132Publication Date (Web):September 12, 2007Publication History Received7 June 2007Published online12 September 2007Published inissue 1 October 2007https://doi.org/10.1021/cr0501846Copyright © 2007 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views13773Altmetric-Citations1745LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (959 KB) Get e-AlertsSUBJECTS:Amides,Anions,Hydrogen,Kinetics,Organic reactions Get e-Alerts

ABSTRACTThe discovery that dopants, such as Ti, cause NaAlH4 to reversibly desorb H2 at mild conditions has spurred a great deal of research into complex metal hydrides. However, no complex hydride meets the targets for automotive hydrogen storage. Our approach is to accelerate the rate of discovery of improved hydrides and dopants through the combination of Virtual High Throughput Screening (VHTS) and Combinatorial Synthesis and Screening (CSS). Our CSS methods will allow us to screen thousands of samples in a year. These samples will be prepared by ball milling mixtures of hydrides and dopants similar to the established method of preparing Ti doped NaAlH4. VHTS exploits a molecular mechanics method to screen a thousand phases in a month. The combination of combinatorial methods and VHTS will help us discover the most promising complex hydrides for hydrogen storage. We will show the results of our medium throughput CSS and VHTS as applied to the NaAlH4–LiAlH4 – Mg(AlH4)2 mixed alanate compositions.

The lives of Puerto Rican street drug users living on the US mainland are structured by addiction and violence. For some, drugs act as a palliative against the trauma of being exposed to extreme physical or emotional harm. For others, the effects of structural oppression, coupled with the cruel logic of addiction, situates violence just below the surface of lived experience (Singer 1996). This paper will explore the relationship between exposure to violence and drug using behaviors, as well as the degree to which violence becomes a byproduct of those behaviors. Drawing from life history interviews and survey data of drug users in Hartford, Connecticut, we will discuss the ways in which addiction, violent upbringings, and the ruthlessness of narco-capitalism-each operating within the context of Puerto Ricans' status as a colonized people vis a vis the USA-create an atmosphere in which violence becomes a near inevitable part of everyday life. We will also briefly address the complex ethical issues involved in studying violence.

Maps have been used for thousands of years to present and analyze geographic information. One of the most famous and earliest cases of geography and maps being utilized for public health surveillance is the physician John Snow's mapping of cholera in London in the mid-1850s to understand the spread of the disease. By plotting the distribution of cholera deaths in the city on a map, he determined that an unusually high number of deaths were taking place near a specific water pump. Following this finding the pump's handle was removed and the number of cholera deaths dramatically decreased. Since then maps in various forms have helped locate and identify various disease patterns. Recent advances in information technology have resulted in the development of computerized mapping methodologies such as geographic information systems (GIS). A growing number of anthropologists, including researchers at the Hispanic Health Council, have recognized the potential value of GIS for the kinds of work we do and incorporate this methodology.