method previously employed by westoo for the determination of alkylmercury compounds was producing very wide picks during g.c. analyses. changing the column temperature, carrier gas flow and pressure did not supersede the problem. therefore change in packing materials was experienced. 5% dc-200 on gas-chrom did not work. a packing material used for chlorinated hydrocarbons w, 80-100 mesh. as th...

In this population based study we have reviewed the files of all patients who underwent an extracapsular cataract extraction (ECCE) between 1984 and 1987, were normotensives prior to surgery, and were followed up for at least 10 months after the ECCE. From a total of 1047 operations 746 qualified for the inclusion criteria; of these, 16 (2.1%) were found to have a consistently raised intraocula...

INTRODUCTION The United Nations Environmental Program (UNEP) has been implemented in an effort to combat the release of selected persistent organic pollutants (POPs). POPs are found in environmental samples such as soils, sludges, solid and semisolid waste, and sediments. POPs are also found in biological samples such as human breast milk, and fish tissue. UNEP is interested in eliminating POPs...

Measuring radioactive xenon isotopes in the atmosphere is an important technique used for monitoring within the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Several process steps are needed to capture and prepare a xenon sample suitable for transfer to a nuclear detector. These processes include air drying, xenon collection, concentration, and purification. The ideal xenon sampling system woul...

Coalbed methane extraction promotes energy exploitation and alleviates the greenhouse effect. This study aimed to analyze technical potential of a high-pressure gas–liquid two-phase jet in increasing coalbed permeability promoting extraction. A well-designed experimental setup was used investigate erosion characteristics jet. Through shock pressure monitoring tests jet, effects pump pressure, m...

The present study proposes novel micro-jet impingement heat sink with effusion holes for flow extraction. The design consists of impingement nozzles surrounded by multiple effusion holes to take away the spent fluid. A three-dimensional numerical model is used for steady, incompressible, laminar flow and conjugate heat transfer for the performance analysis of the proposed design. The computatio...

An efficient and environmental-friendly extraction method has been developed for extraction of ursolic acid (UA) from Hedyotis diffusa by using subcritical water extraction (SWE). The experiments were carried out at different particle sizes (20–100 mesh), extraction temperature (120–200 ◦C), extraction time (10–50 min), solvent/solid ratio (20–40 mL/g), and extraction pressure (0.6–3.0 MPa). Re...

This work investigates the process of extraction of lemon balm (Melissa officinalis L.) by treatment with carbon dioxide at supercritical conditions. The process kinetics is studied at different operational conditions, and the influence of some important regime parameters (pressure, temperature particle size, solvent flow-rate) on the extraction yield is experimentally determined. Besides the i...