Probing sediment burial age, provenance and geomorphic processes in dryland dunes and lake shorelines using portable luminescence data

Luminescence signals from portable optically-stimulated luminescence readers (POSL or port-OSL) can provide expedient insights into sample relative age, and under certain conditions can be simplistically calibrated against existing luminescence chronologies to provide first-order estimates of burial age. This is most straightforward in simple sedimentary systems where samples share a common provenance and geomorphic process history. The spatially extensive southern African dune and palaeolake shoreline luminescence database, for which hundreds of non-light exposed bulk sediments are available, offers a valuable test case to examine the conditions under which POSL-bulk sediment calibration approaches are feasible. To do this we combine measurements of inherent luminescence sensitivity of bulk sediment (BSS) with analysis of sedimentary composition (petrology and presence of calcium carbonate) and texture. We show that BSS, along with POSL IRSL:BSL ratios and petrological data, account for region-to-region variations, whilst internal variability (scatter) within the lake shorelines dataset relates to variations in BSS and sediment texture. At the scale of southern African subcontinent drylands, we see that provenance and geomorphological process history influence sample mineralogical composition and POSL signal characteristic, including BSS

Quality of life after bladder cancer: a prospective study comparing patient-related outcomes after radical surgery or radical radiotherapy for bladder cancer

No description supplie

Youth futures and a masculine development ethos in the regional story of Uttarakhand

Research on the Uttarakhand region, which became a new state in 2000, has focused largely on agrarian livelihoods, religious rituals, development demands, ecological politics and the role of women in regional social movements. This essay discusses another dimension of the regional imaginary—that of a masculine development ethos. Based on ethnographic research and print media sources, this essay focuses on stories, politics, mobilities and imaginations of young men in the years immediately after the achievement of statehood. Despite increased outmigration of youth in search of employment, many young men expressed the dream of maintaining livelihoods in the familiar towns and rural spaces of Uttarakhand, describing their home region as a source of power and agency. In rallies and in print media, young (mostly upper caste) men expressed their disillusionment with the government and the promises of statehood, arguing that their aspirations for development and employment were left unfulfilled. Gendered stories of the region, told in Hindi in rallies and print media, contained references to local places, people and historical events and were produced through local connections and know-how, fostering a regional youth politics. The article argues that Uttarakhand as a region is shaped by the politics of local actors as well as embodied forms of aspiration, affiliation and mobility.IS

Extraction techniques for solid samples

Extraction is normally a laboratory procedure prior to analysis. The choice of extraction technique is often made based on what is available and what has been used before. The skill and experience of the analyst is often the key to the operation of extraction and analysis procedures. Extraction of organic pollutants from solid environmental samples has frequently been done using organic solvents with or without the addition of heat. This process is typified by the technique of Soxhlet extraction. A flow diagram detailing a procedure for the extraction of analytes from soils using Soxhlet extraction is shown. Soxhlet extraction normally requires large volumes of chlorinated solvent to be refluxed through the solid sample for an extended period. Although it is not uncommon for the analyst to assemble several experimental set-ups at the same time, it can be labor-intensive at the start and end of the process. As the process is time-consuming, alternative extraction strategies have been developed based on instrumentation that allows the process to be controlled more effectively. This chapter mainly focuses on these newer instrumental approaches to compare and contrast both their application base and robustness for extraction

Evaluation of on-line methodology for microwave-assisted extraction of polycyclic aromatic hydrocarbons (PAHs) from sediment samples

The development of novel on-line microwave techniques is described for the selective extraction of polycyclic aromatic hydrocarbons from sediment samples. Two flow systems were evaluated, in the first, samples of sediment were slurried in water and on passing through the microwave the analytes were extracted and subsequently trapped onto a C18 cartridge. Elution from the in-line C18 cartridge directly onto an analytical HPLC column was then performed. In the second study, samples were slurried in acetone and passed through the microwave cavity. The effluent was then shaken with 10 ml of hexane in order to pre-concentrate the extracted components, which were detected and quantified by GC-MS. Recoveries from the second technique on average ranged from 62 to 93% (0.28-8.15 µg). Both techniques were compared to the standard EPA method for microwave-assisted solvent extraction. The second method based on acetone, was found to give comparable recoveries to the EPA method, but offered significant improvement in the precision for replicate samples which were found to be in the range 2-7% RSD compared to 6-16% RSD for the batch technique

Cooking up a storm

Microwaves are now being used in a variety of chemical laboratories. By improving the safety features of conventional microwave ovens to give them greater control and feedback capabilities, chemists have been able to increase the potential applications for this technology. Consequently, the ability of microwave ovens to enhance the rates of various physical and chemical reactions is now being exploited in areas such as combinatorial organic synthesis, extraction of organic environmental pollutants, and digestion of samples for elemental analysis

Microwave ovens - out of the kitchen

We are all aware of the advantages cooking or heating meals in a microwave oven can offer, but we may be less familiar with what this technology brings to the field of chemistry. This paper reviews the applications of microwaves in the chemical laboratory, including their use in undergraduate laboratory classes. We show that microwave ovens have successfully made the transition from kitchens to laboratories and the story continues. Perhaps the greatest impact of microwaves in the laboratory over the past 20 years has been in analytical chemistry, where rapid and efficient heating of samples in closed vessels or flow-through systems has revolutionized sample preparation methodology. The use of microwaves in extraction procedures before chromatographic analysis has sharply reduced the total analysis time and has allowed larger numbers of samples to be analyzed. More recently microwave technology has expanded into other branches of chemistry and is now being used in the relatively new field of combinatorial chemistry for fast preparation of large numbers of similar compounds

Variations in the organic impurity profile in Leuckary synthesised amphetamine sulphate by the same chemist

Conventional chemical profiling methods are based on determining and quantifying the illicit substance and identifying the organic impurities present. In the case of synthetic drugs, certain impurities may be route specific