Systematic description and key to isolants from Atacama Desert, Chile

Isolation and identification of desert soil microorganism from Chil

The Effect of Health Changes and Long-term Health on the Work Activity of Older Canadians

Using longitudinal data from the Canadian National Population Health Survey (NPHS), we study the relationship between health and employment among older Canadians. We focus on two issues: (1) the possible endogeneity of self- reported health, particularly "justification bias", and (2) the relative importance of health changes and long-term health in the decision to work. The NPHS contains the HUI3, an "objective" health index which has been gaining popularity in empirical work. We contrast estimates of the impact of health on employment using self-assessed health, the HUI3, and a "purged" health measure similar to that employed by Bound et al. (1999) and Disney et al. (2003). A direct test suggests that self-assessed health suffers from justification bias. However, the HUI3 provides estimates that are similar to the "purged" health measure. We also corroborate recent U.S. and U.K. findings that changes in health are important in the work decision.Health; Health Changes; Employment; Older Workers; NPHS

The Effect of Health Changes and Long-term Health on the Work Activity of Older Canadians

Using longitudinal data from the Canadian National Population Health Survey (NPHS), we study the relationship between health and employment among older Canadians. We focus on two issues: (1) the possible problems with self- reported health, including endogeneity and measurement error, and (2) the relative importance of health changes and long-term health in the decision to work. We contrast estimates of the impact of health on employment using self-assessed health, an objective health index contained in the NPHS - the HUI3, and a "purged" health stock measure. Our results suggest that health has an economically significant effect on employment probabilities for Canadian men and women aged 50 to 64, and that this effect is underestimated by simple estimates based on self-assessed health. We also corroborate recent U.S. and U.K. findings that changes in health are important in the work decision.health, health changes, employment, older workers

Coherence properties of infrared thermal emission from heated metallic nanowires

Coherence properties of the infrared thermal radiation from individual heated nanowires are investigated as function of nanowire dimensions. Interfering the thermally induced radiation from a heated nanowire with its image in a nearby moveable mirror, well-defined fringes are observed. From the fringe visibility, the coherence length of the thermal emission radiation from the narrowest nanowires was estimated to be at least 20 um which is much larger than expected from a classical blackbody radiator. A significant increase in coherence and emission efficiency is observed for smaller nanowires.Comment: 4 pages,figures include

Mechanical properties of prestressing steel at elevated temperature and after cooling

The mechanical properties of prestressing steel at elevated temperatures and after cooling are essential to the fire resistance design and post-fire evaluation of residual load-carrying capacity of prestressed concrete structures. Although previous tests have provided useful results of mechanical properties of prestressing steel at elevated temperatures, the data obtained are somewhat scattered and still insufficient. Furthermore, few empirical formulas fitting the deterioration of prestressing steel at elevated temperatures and after cooling can be found. This study therefore aims to extend the existing database with reliable data obtained by an accurate testing system. The study focuses on the mechanical properties of prestressing steel at elevated temperatures and after cooling by employing the central core wire of prestressing strand. Grade 1860 strands to GB/T5224 mostly used in Mainland China and Grade 1860 strands to BS5896 used in European countries are tested. The results are obtained using the steady-state method and compared with those from available literature and design standards.postprin

Bosonic Super Liouville System: Lax Pair and Solution

We study the bosonic super Liouville system which is a statistical transmutation of super Liouville system. Lax pair for the bosonic super Liouville system is constructed using prolongation method, ensuring the Lax integrability, and the solution to the equations of motion is also considered via Leznov-Saveliev analysis.Comment: LaTeX, no figures, 11 page

SHOP2: An HTN Planning System

The SHOP2 planning system received one of the awards for distinguished performance in the 2002 International Planning Competition. This paper describes the features of SHOP2 which enabled it to excel in the competition, especially those aspects of SHOP2 that deal with temporal and metric planning domains

Transesterification of oil extracted from different species of algae for biodiesel production

In the current study, biodiesel production efficiency of Chlorella vulgaris, Rhizoclonium hieroglyphicum and mixed algae culture was measured by transesterification process. Growth rate of algal species was measured on the basis of increase in their dry matter in various media. Protein, carbohydrates and lipids in all selected algae were measured on dry matter basis. Extracted oil was analyzed for water contents, iodine value, saponification value, acid number and fatty acid composition. Transesterification of algal oil was performed by using sodium methoxide as a catalyst. Yield of biodiesel from extracted oil was calculated for C. vulgaris (95%), R. hieroglyphicum (91%) and mixed algae culture (92%). Produced biodiesel was analyzed for kinematic viscosity (4.9, 5.0 and 4.7 mm2/s), flash point (160, 156 and 155°C), specific gravity (0.91, 0.914 and 0.912 g/ml), cetain number (51, 49 and 47 min), iodine value (47, 53 and 49 mg/g), acid number (0.49, 0.5 and 0.46 mg.KOH/g), carbon residue (0.01, 0.02 and 0.01 mass%), sulfated ash (0.007, 0.003 and 0.004 mass%), sulphur (0.013, 0.012 and 0.01 wt%) and water contents (15, 23 and 17 mg/kg) for C. vulgaris, R. hieroglyphicum and mixed algae culture, respectively. Properties of biodiesel were compared with ASTM standards and it was found with high quality biodiesel.Key words: Biodiesel, oil extraction, algae, transesterification