In routine determinations of selenium (Se) by flow injection hydride generation atomic absorption spectrometry (Fi-HG-AAS) technique a home-made equipment from commercially available components were used. An electrically heated quartz tube was used as atomiser. Blank and Se-standard solutions were analysed after wet digestion using an oxidising acid mixture (HNO3/HClO4). An absorption signal at...

A fully automated, continuous-flow-through type analyzer was developed to observe rapid changes in the concentration of total inorganic carbon (CT) in coastal zones. Seawater and an H3PO4 solution were fed into the analyzer's mixing coil by two high-precision valveless piston pumps. The CO2 was stripped from the seawater and moved into a carrier gas, using a newly developed continuous-flow-thro...

The susceptibility of some components of sediment acid-volatile sulfide (AVS) to chemical oxidation is a critical factor impacting accurate measurement of AVS in sediment samples. This well-documented susceptibility to oxidation led to the requirement for oxygen-free conditions in the analytical method developed for AVS. In light of this acute potential to oxidize, the serendipitous finding tha...

Limits of detection (LODs) in ion mobility spectrometry (IMS) strictly depend on ionization of the analyte. Especially challenging is ionization of compounds with relatively low proton affinity (PA) such as aromatic compounds. To change the course of ion-molecule reactions and enhance the performance of the IMS spectrometer, substances called dopants are introduced into the carrier gas. In this...

We have developed an equilibrator inlet-proton transfer reaction-mass spectrometry (EI-PTRMS) system for the high-resolution measurement of the concentrations of multiple volatile organic compounds (VOCs) dissolved in seawater. The equilibration of six VOCs (dimethyl sulfide (DMS), isoprene, propene, acetone, acetaldehyde, and methanol) between seawater samples and the carrier gas, and the resp...

Introduction: Enstatite chondrites have remarkable properties: they were formed in a reducing environment, they are putatively similar to precursor material of Earth, Venus, or Mercury, have a terrestrial oxygen isotopic composition and an uncommon noble gas signature [1-5]. Trapped noble gases in Echondrites are intermediate between solar and chondritic composition and consist of two component...

Means to overcome tumor hypoxia have been the subject of clinical investigations since the 1960's; however these studies have yet to find a treatment which is widely accepted. It has been known for nearly a century that hypoxic cells are more resistant to radiotherapy than aerobic cells, and tumor hypoxia is a major factor leading to the resistance of tumors to radiation treatment as well as se...

background and objectives: beta-thalassemia continues to be a cause of significant burden to the society particularly in the poorer developing countries. although sophisticated methods of screening have become available, a hunt for a cheap, rapid, objective screening method still remains elusive. thus, the objectives are to study the validity of naked-eye-single-tube-osmotic-fragility-test (nes...

A numerical investigation into the particle-turbulence interaction behaviour of dilute gas-particle flows over a backward-facing step geometry is reported. An Eulerian two-fluid model with additional turbulence transport equations for particles is employed. RNG based k-ε model is used as the turbulent closure wherein additional transport equations are solved to better represent the combined gas...

A new inductively coupled plasma (ICP) torch with an air-cooling system has been designed and developed for both argon and helium plasma. The same torch and impedance-matching network could be used to generate stable Ar- and He-ICP. The torch consists of three concentric quartz tubes. The carrier gas, plasma gas, and cooling gas flow through the intervals between each tube. In an experiment, it...