rapid determination of residual hexane in oils by gas chromatography using pyrolyzer

A simple, direct gas Chromatographic (GC) tech-nique is described for the quantitative determination of residual hexane in extracted vegetable oils. The method is rapid and sensitive to one ppm hexane. A platinum boat, on which sample oil was placed, is inserted into a pyrolysis chamber in a pyrolyzer at-tached to a GC, and heated at 150 C for 60 sec to carry the evaporated hexane into the GC with a carrier gas. In the method, the column of GC may be used without the possibility of contamination because the sample is not injected directly into the GC. The method should be useful for the quality con-trol of solvent extracted oil products.     

Functional cloning of a cDNA encoding Mei2-like protein from Arabidopsis thaliana using a fission yeast pheromone receptor deficient mutant

Aromatherapy has been defined as 'the art--and science--of using essential plant oils in treatments ... a truly holistic therapy, taking into account mind, body and spirit ...' (Davis 1991). Aromatherapy is a valuable means of maintaining optimum health, particularly when the dis-ease of the body or mind is related to stress. The process of hospitalization is a potentially stressful experience that has been well researched (Broome et al 1990, Kachoyeanos & Friedhoff 1993, Strachan 1993, Taylor 1991). This paper examines the ways in which massage and aromatherapy could be of benefit to hospitalized children, particularly those infected with Human Immunodeficiency Virus (HIV). Wright (1995) states that nurses should encourage self-healing by 'putting the patient in the best condition for nature to act'. Aromatherapy massage has the potential to achieve this through inducing relaxation and reducing the stressful aspects of hospitalization. Thus, the author would like to propose the use of this valuable skill as an extension of the nursing role.     

Generation of metastatic variants of Eker renal carcinoma cell lines for experimental investigation of renal cancer metastasis

We and others have demonstrated that a mutation in Tsc2 is the rate-limiting step for renal carcinogenesis in the Eker rat model. Although inactivation of Tsc2 results in development of renal tumors, it is not sufficient for metastatic renal cell carcinomas (RCs) in the Eker rat. To investigate the additional genetic event(s) necessary for cancer metastasis, we have established highly metastatic S-Lk9d-SLM cell lines from a non-metastatic RC cell line (Lk9dL) by co-implantation with a foreign body (gelatin sponge). Since these cell lines were remarkably different in metastatic performance (all and none, respectively) despite having the same genetic background, they should be useful experimental tools to investigate metastasis-promoting events in renal carcinogenesis.     

C-Mode Scan and Resolution Improvement Techniques for Ultrasonic Diagnosis

This paper presents a new method for obtaining plane images perpendicular to the axis of the transducer and discusses some resolution improvement techniques utilizing a computer. The method, called C-mode scan, is carried out by successive application of a conventional B-mode scan, and supplies more information such as the outline, size, and extent of a lesion such as a breast tumor. To improve the resolution of a transducer, a deconvolution technique together with non-linear filtering are employed from a spectral point of view. Several clinical images produced by C-mode and the computer improvement of resolution are demonstrated.     

Analysis for optimum threshold voltage and load current of E-D-type GaAs DCFL circuits

A GaAs MESFET E-D invertor was analysed to estimate the optimum threshold voltage VT for a switching FET, and the optimum load current IL for a load FET, that will minimise the invertor switching time. The calculated results show that the optimum VT lies at around 0.2 V, and the optimum IL is about 55% of the saturation current of the switching FET.     

The high performance liquid chromatographic determination of total malondialdehyde in vegetable oil with dansyl hydrazine

A simple high-performance liquid chromatographic (h.p.l.c.) method has been developed for determining total malondialdehyde (MDA), including free MDA and MDA released from its precursor in vegetable oils. Free MDA was reacted with dansyl hydrazine in an acidic medium, and the product, 1-dansyl-pyrazole(DP), was determined by h.p.l.c. The reaction releasing MDA from its precursor requires Fe³⁺ in 5% hydrochloric acid medium. Recoveries of free MDA and tetramethoxypropane (used as an MDA precursor) in vegetable oils were satisfactory. During autoxidation, a remarkable difference between the DP values of methyl oleate, methyl linoleate and some vegetable oils, and that of methyl linolenate was observed. Only methyl linolenate released MDA during autoxidation. For autoxidised methyl linolenate the DP value correlated with the thiobarbituric acid(TBA) value, although the DP value was only 30% of the TBA value.     

Drift Collection Calorimetry Using a Combined Radiator and Field Shaping Structure of Lead Glass Tubing

A design for a drift collection calorimeter having a combined radiator and electric field shaping structure made of fused lead glass tubing is described. Reduction of a surface layer of lead oxide in a hydrogen oven is used to form a high resistance metallic layer on the interior of the tubes. This layer is used as a continuous voltage divider for drift field shaping. The EGS shower Monte Carlo code was used to model the performance of the proposed calorimeter. The effects of choice of the tube geometry, gas pressure and sampling scheme (digital vs. conventional) are discussed. The possibility of using this type of radiator/drift field structure in liquid argon is briefly considered.     

A finite element method for contact problems related to fracture mechanics

A finite element method for contact problems in crack mechanics is developed on the basis of the penalty function method. The method is successfully applied to three important problems in fracture mechanics: a crack propagated from a pin hole, a two-point supported specimen with an edge crack loaded by a stamp, and a thick plate with a through-wall crack under bending force.     

In situ high-temperature visible microspectroscopy for volcanic materials

In situ high-temperature visible microspectroscopy has been developed in order to study color change kinetics of volcanic materials. Olivine thin sections put on a synthetic alumina plate are heated on a heating stage at 600-800 degrees C under a visible microspectroscope. Changes in visible absorption spectra are monitored every 60 s for 5 hours. The obtained high-temperature visible spectra showed a gradual increase with time in absorbance in the shorter wavelength region (400-600 nm). The 430 nm absorbance (ligand field transition of Fe3+ increased more with time at higher temperatures. Assuming diffusional transport in plane sheets, apparent diffusion coefficients were determined at temperatures of 600-800 degrees C. The activation energy for this diffusion in olivine is 208 +/- 17 kJ/mol. This activation energy value is similar to those for the metal vacancy diffusion in olivine. This newly developed in situ high-temperature visible microspectroscopy can provide kinetic measurements of visible spectral change of materials at high temperatures such as volcanic materials.