Chemical Information Bulletin

Created as a supplement for "the regular journals of the American Chemical Society," this publication contains annotated bibliographies of chemical documentation literature as well as information about meetings, conferences, awards, scholarships, and other news from the American Chemical Society (ACS) Division of Chemical Information (CINF)

MILD Combustion: A Technical Review Towards Open Furnace Combustion

Moderate or Intense Low oxygen Dilution (MILD) combustion is one of the best alternative new technologies for clean and efficient combustion. MILD combustion has been proven to be a promising combustion technology for industrial applications with decreased energy consumption due to the uniformity of temperature distribution, also producing low NO and CO emissions. This article provides a review and discussion of the recent research and development in MILD. Furthermore, the problems and focuses are summarized with some suggestions and therefore presented on upgrading an application of MILD in the future. Currently MILD combustion has been applied in closed furnace. For closed furnace, the preheating supply air is no longer required since the recirculation inside the enclosed furnace will self preheats the supply air and self dilutes the oxygen in the combustion chamber. The possibility of using open furnace MILD combustion was discussed and reviewed

The use of metal hydrides in fuel cell applications

This paper reviews state-of-the-art developments in hydrogen energy systems which integrate fuel cells with metal hydride-based hydrogen storage. The 187 reference papers included in this review provide an overview of all major publications in the field, as well as recent work by several of the authors of the review. The review contains four parts. The first part gives an overview of the existing types of fuel cells and outlines the potential of using metal hydride stores as a source of hydrogen fuel. The second part of the review considers the suitability and optimisation of different metal hydrides based on their energy efficient thermal integration with fuel cells. The performances of metal hydrides are considered from the viewpoint of the reversible heat driven interaction of the metal hydrides with gaseous H2. Efficiencies of hydrogen and heat exchange in hydrogen stores to control H2 charge/discharge flow rates are the focus of the third section of the review and are considered together with metal hydride-fuel cell system integration issues and the corresponding engineering solutions. Finally, the last section of the review describes specific hydrogen-fuelled systems presented in the available reference data.IS

Analytical Strategies for Drug Residues in Various Matrices in a Regulatory Laboratory.

Abstract Today, in modern farming practices veterinary drugs are given to food-producing animals. The generic term “veterinary drugs” covers a broad variety of classes of chemical compounds and the list of drugs is enormous and it is a significant analytical challenge in regulatory control to provide monitoring programmes. The major concerns in veterinary drug usage are the presence of harmful residues that may be introduced into the human food chain. The aim of this research is the development of analytical methods capable of screening and confirming increased numbers of these residues in target matrices by Gas Chromatography Tandem Mass Spectrometry (GC-MS/MS) and Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS). The focus is on Non-Steroidal Anti Inflammatory Drugs (NSAIDs) residues in food of animal origin. The research resulted in the development and validation of methods for the analysis of NSAIDs in milk. The second topic under investigation was in the field of post-mortem forensic toxicology. Forensic toxicological activities are important in society and great efforts to implement rapid analytical procedures in a forensically credible manner is continuous across the globe. The main objectives of the research work in post-mortem forensic toxicology were to address the issues concerning the availability of rapid novel unequivocal confirmatory analytical methodologies for forensically important drugs. The aim of this work was to develop single fast, simple and reliable sample preparation procedures in blood and urine with detection by hybrid LC-MS as analytical strategies in a forensic laboratory for the determination of drugs of abuse in this study which were previously not available. All analytical methodologies developed in blood, milk and urine matrices were validated in accordance with EU legislation; Commission Decision 2002/657/EC. This validation legislation is concerned with the interpretation of results and the performance of analytical methods. Validation criteria were examined using protocols laid down in this legislation. These included specificity, accuracy, precision, repeatability, reproducibility, decision limits (CCa), detection capabilities (CCb) and in addition measurement uncertainty (MU). The methods developed for the NSAIDs residues in milk had accuracies ranging from 73-109 % and the precision for all analytes ranged from 2-30%. The CCa and the CCb values ranged from 0.46-0.79 ng mL-1 and the MU ranged from 9-90%. The methods developed for the forensically important drugs in blood and urine had accuracies ranging from 80-113% and the precision for all analytes ranged from 4-22%. The CCa and the CCb values ranged from 0.005-0.05 ug mL-1 and the MU ranged from 13-47%. To ensure that methods were suitable for purpose the methods were evaluated in international proficiency testing schemes and results were satisfactory. In addition some of the methods were accredited in accordance with ISO17025 guidelines. A number of different analysts were trained on the new methodologies developed in this work thus providing further evidence of the development of rugged analytical methods and satisfactory results were obtained using quality control material. In addition the methods have replaced previous methods in The State Laboratory for the monitoring of NSAIDs and are used routinely at present in theRepublic ofIreland in national monitoring programmes. The methods developed for blood and urine in the forensic toxicology section of this thesis have replaced previous methods in national forensic toxicology monitoring programmes in the past number of years at The State Laboratory and are used in toxicology testing for the law courts in forensic and Coroner’s cases in Ireland. The method in this thesis for forensic drugs in blood is submitted for accreditation in 2012 as satisfactory results were obtained using quality control and international proficiency test samples in the past number of years

Effect of curing conditions and harvesting stage of maturity on Ethiopian onion bulb drying properties

The study was conducted to investigate the impact of curing conditions and harvesting stageson the drying quality of onion bulbs. The onion bulbs (Bombay Red cultivar) were harvested at three harvesting stages (early, optimum, and late maturity) and cured at three different temperatures (30, 40 and 50 oC) and relative humidity (30, 50 and 70%). The results revealed that curing temperature, RH, and maturity stage had significant effects on all measuredattributesexcept total soluble solids

Structure-Performance Relationships in the Selective Catalytic Reduction of Nitric Oxide with Ammonia over Copper-Based Zeolites

Combustion of diesel fuel in automotive engines leads to the formation of nitrogen oxides (NOx) that are harmful to the environment. The Selective Catalytic Reduction (SCR) is a promising process to minimize tailpipe NOx emissions and meet increasingly strict environmental regulations. During the SCR process, NOx is reduced with ammonia producing nitrogen gas and water. Cu-exchanged zeolites are potential SCR catalysts for practical use due to the wide operational temperature window. However, aging and degradation of the catalysts is inevitable in the harsh hydrothermal tailpipe environment. The aim of this thesis is to understand the detrimental effects of hydrothermal aging to the Cu-exchanged zeolites by means of ex situ and operando spectroscopies, therefore to obtain fundamental insights on the reaction mechanism and deactivation pathways. Obervations from novel microscopes including Scanning Transmission X-ray Microscopy (STXM) and Atom Probe Tomography (APT) indicated the heterogeneity of Cu and Al speciations in hydrothermally aged Cu-exchanged zeolites. Octahedral Al, three-fold coordiated Al, Cu+ and CuxOy coexisted, and a complex interplay between the local structure of zeolite framework and active Cu species within the catalysts was observed. Meanwhile, deactivated Cu species and destruction of zeolite framework were found preferentially located at the edge of a single aged catalyst particle at the nanoscale resolution. Operando UV-Vis Diffuse Reflectance Spectroscopy (DRS) and operando Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) allows to follow the dynamics of active structure and reaction intermediate under NH3-SCR conditions. The hydrothermal aging process was likely casue the aggregation of isolated Cu2+ into [Cux(OH)2x-1]+ oligomers/clusters, which leads to the loss of activity and the production of undesired byproducts. Pseudo-tetrahedral Cu2+ was formed during low-temperature NH3-SCR reaction condition on the steamed catalysts, however, this structure promoted the ammonia oxidation side reaction, which explains the unusal NO conversion profile with a ‘dip’ shape. The results highlight the importance of hydrothermally stable active sites ensuring high catalytic activities during the entire catalysts lifetime. The results described in this thesis are highly relevant for the development of new generations of NH3-SCR catalysts