Determination of the thermal conductivity of argon and nitrogen over a wide temperature range through data evaluation and shock-tube experiments

Reliable and well-established methods to measure the thermal conductivity of gases are available only in the moderate temperature range, namely, up to about 1000 K. In the present study, a set of the most probable thermal conductivity values of components of gaseous combustion products in a wide range of temperatures has been obtained through an optimum combination of three procedures: critical assessment of available data in the moderate temperature range, experimental determination by the shock-tube method at high temperatures, and theoretacal estimation of temperature dependence in the intermediate temperature range. Among the components of combustion products, one monatomic gas and one diatomic gas, namely, argon and nitrogen, were studied in the present paper. The shock-tube measurements have been performed in the temperature ranges 1000–4500 K for argon and 500–2200 K for nitrogen. The results of the critical evaluation and the shock-tube measurements have been combined with the aid of theoretically assumed temperature dependence of the thermal conductivity.Invited paper presented at the Ninth Symposium on Thermophysical Properties, June 24–27, 1985, Boulder, Colorado, U.S.A.     

A new detection method for the primary cosmic heavy nuclei by the plastic track detector CR-39

A new multiple scanning method is developed and applied to detect cosmic heavy nuclei. The plastic track detectors CR-39 exposed to cosmic heavy nuclei are over-etched in 8.0N NaOH for 94 h at 80°C. We found that the etched cones can easily be scanned on the plastic plates without using an optical microscope. The trajectories of heavy nuclei can be reconstructed with the naked eyes by superposing four or more over-etched plates. The charge detection threshold is obtained by this method, and appears to be 10. The charge resolution is estimated to be 1.0 charge units for iron nuclei. By adopting this method, the scanning time is much shortened and CR-39 plastic chamber size can easily be scaled up. The method is very useful for detecting particles with low flux intensity, like for searching magnetic monopoles or for measuring the high energy spectra of cosmic heavy nuclei.     

Determination of bisphenol A in canned vegetables and fruit by high performance liquid chromatography

A high performance liquid chromatograph y (HPLC) method was developed for the determination of bisphenol A (BPA) that had migrated into canned fruit and vegetables. BPA was extracted with acetonitrile from the solid portion of canned food, and with an OASIS HLB cartridge from the aqueous portion, respectively. Both extracts were cleaned up on a Florisil cartridge. The HPLC separation was carried out on a Wakosil II 3C18 RS column (4.6 × 150mm) with acetonitrile-water (40:60, v/v) as a mobile phase with a flow rate of 0.8 ml/min. BPA was detectable by UV detector at 228 nm and determined with the similarity of chromatographic peak spectrum by multiwavelength detector (similarity index was 0.99 or above). The quantification limits were 10 ng/g for the solid portion and 5 ng/ml for the aqueous portion, respectively. BPA was mainly detected in the solid portion of canned food and found at the maximum level of 11 μg per can. To verify migration into the solid portion of canned food, a partitioning experiment was carried out.     

Effect of extracranial carotid artery stenosis and other risk factors for stroke on periventricular hyperintensity

BACKGROUND AND PURPOSE: The pathogenesis of periventricular hyperintensity (PVH) is still uncertain. We investigated the relationship between PVH and risk factors for cerebrovascular diseases, especially extracranial carotid artery stenosis (ECAS). METHODS: We studied PVH and ECAS in 323 subjects between 1991 and 1994. Using 1.5-T MRI scan images, we measured PVH quantitatively at eight points and evaluated cerebral infarction. Duplex carotid sonography was performed on the carotid arteries bilaterally and used to divide the severity of ECAS into five grades. Risk factors for cerebrovascular diseases and atherosclerotic complications were assessed from the clinical history. RESULTS: Age was significantly correlated with the size of frontal and whole PVH (P < .01). Frontal PVH was significantly more severe in subjects with hypertension (P < .05). Frontal, occipital, and whole PVH were significantly more severe in subjects with a history of cerebrovascular accident (P < .01). Other risk factors and atherosclerotic complications were not correlated with PVH. There were no significant differences in the severity of PVH among the five groups of ECAS. The severity of PVH in each region was not related to ECAS. There was no significant difference in the age of patients in relation to the five grades of ECAS. However, PVH was significantly more severe in subjects with lacunar infarction or infarction of the deep border zone (P < .05). There was no relationship between PVH and cortical infarction or infarction of the cortical border zone. CONCLUSIONS: PVH correlated with age, hypertension, and past history of cerebrovascular disease but not with ECAS. PVH was significantly more severe in lacunar infarction and infarction of the deep border zone. These results suggest that small-vessel disease may underlie the pathogenesis and development of PVH.     

A case of interstitial pneumonia induced by an ACE inhibitor (temocapril hydrochloride)]

A 51-year-old woman who had been treated for years for rheumatoid arthritis presented with a persistent dry cough and shortness of breath three weeks after administration of the ACE inhibitor temocapril hydrochloride against essential hypertension. Chest radiography and computed tomography showed diffuse reticular shadows and ground-grass opacities in both lung fields. Bronchoalveolar lavage fluid analysis showed an increase of lymphocytes and CD8+ T cells (93.3% of lymphocytes), and a decrease of the CD4/8 ratio of the T cell subset (0.04). Histopathological analysis of trans-bronchial lung biopsy specimens showed infiltration of lymphocytes into the alveolar septa and exudation of alveolar macrophages, signs characteristic of interstitial pneumonia. A drug lymphocyte stimulation test was positive for temocapril, but negative for other drugs. On the basis of these findings, we diagnosed temocapril hydrochloride-induced interstitial pneumonia.     

Electron microscopic visualization of collagen aggregates without chemical staining.

Lateral, uni-directional aggregates of collagen, segment-long-spacing crystallites (SLS), were made by dialyzing collagen solutions against acetic acid containing ATP, and were examined by transmission electron microscopes without electron staining. There detected were at least 20 dark (electron dense) cross-striations within SLS. The banding pattern was compared with the biochemical and biophysical properties of the amino acid side chains along the collagen molecule. The banding pattern of unstained SLS was mostly correlated with the intramolecular distribution of basic amino acid residues. Since basic amino acids have relatively large side chains, the distribution of mass (molecular weight of amino acids) along the molecule (local density profile) partially explained the cross-striation. Addition of fractions of molecular weight of ATP to basic residues made the local density profile much better correlate to the banding pattern. We conclude that the electron microscopic banding pattern of unstained SLS was generated by the local amount of material or local density profile along the collagen aggregates, which was enhanced by ATP bound to positively charged basic residues. The concept that the electron density correlates with the amount of material is fundamental in electron microscopy, and it has been proven with biological materials in this paper.