Correlation between stomach temperatures and ambient water temperatures in free-ranging loggerhead turtles,Caretta caretta

Instruments were attached to loggerhead turtles, Caretta caretta, at Kamoda Point, Japan in 1989 and on the Senri-coast, Japan in 1991. We simultaneously obtained stomach temperatures, ambient water temperatures and diving depths from four free-ranging loggerhead turtles during the internesting periods, using small recorders. These data were analyzed to understand how body temperature was maintained. Ambient water temperatures changed coincidentally when turtles moved up or down, but a stable stomach temperatures was maintained despite water temperature fluctuations of ca. 20 to 90 min in duration. Loggerhead turtles also experienced water temperature fluctuations longer than 24 h. Stomach temperatures responded to those water temperature changes with a time lag of several hours (160, 170, 230 and 240 min). Stomach temperatures were higher than ambient water temperatures throughout the experimental periods. The median values of the thermal difference between stomach and water temperatures were 1.1, 1.3, 1.5 and 1.7°C. The higher stomach temperatures are thought to be caused by metabolic heat production.     

Gas permeability and tortuosity for packed layers of processed municipal solid wastes and incinerator residue.

To make a proper evaluation of gas component movement inside a landfill site, it is important to investigate the different parameters related to gas flow. In this work gas-filled porosity, intrinsic permeability, tortuosity and equivalent pore radius were determined for various packed wastes, such as incineration ash, shredded bulky waste and shredded incombustible waste. These parameters were measured/inferred for samples packed in a column and exposed to a controlled gas flow. The effect of waste conditions, especially the moisture content, on these parameters was also investigated. The intrinsic permeability of such packed wastes was generally in the order of 10(-10) to 10(-9) m2, except for some ash that was one to two orders lower. The tortuosity of waste layer was greater than that of a particulate material and ranged between 2 and 10. The equivalent pore radius was generally in the order of 10(-4) m, which means that gas diffusion is still ordinary in such packed waste layer. The obtained results will be utilized when simulating gas flow inside a landfill site for biogas extraction or site aeration.     

A system dynamics approach for hospital waste management

Healthcare services provided by hospitals may generate some infectious wastes. Although a large percentage of hospital waste is classified as general waste, which has similar nature as that of municipal solid waste and, therefore, could be disposed in municipal landfills, a small portion of infectious waste has to be managed in the proper manner in order to minimize risk to public health. Many factors involved in the hospital waste management system often link to one another, which require a comprehensive analysis to determine the role of each factor in the system. In this paper, we present a hospital waste management model based on system dynamics to determine the interaction among factors in the system using a software package, Stella. A case study of the City of Jakarta, Indonesia is selected. The hospital waste generation is affected by various factors including the number of beds in the hospitals and the NIMBY (not in my back yard) syndrome. To minimize the risk to public health, we found that waste segregation, as well as infectious waste treatment prior to disposal, has to be conducted properly by the hospital management, especially when scavenging takes place in landfill sites in developing countries.     

Recovery of zinc and lead from fly ash from ash-melting and gasification-melting processes of MSW--comparison and applicability of chemical leaching methods

Fly ash generated from MSW ash-melting and gasification-melting plants, known as Melting Furnace Fly Ash (MFA), contains considerable amounts of heavy metals such as Pb and Zn. These metals can be recovered using a smelting furnace after "pre-treatment" for removal of unnecessary elements such as Cl, Sn and Si. Chemical methods have been studied for pretreatment in the past. However, they have been discussed only with regard to treatment cost and the concentration of Pb and Zn recovered, but neither applicability to various types of MFA nor the environmental impact have been considered. In this study, acid, alkaline and ammonia/chloride leaching methods were compared from the standpoints of: (1) applicability to MFA, (2) concentration of Pb and Zn recovered, (3) treatment cost, and (4) environmental impact. Twenty-three samples of MFAs were collected and classified into 4 types based on element contents. A Pb and Zn recovery experiment was conducted for the representative MFA of those types. The results showed: (1) MFA from gasification-melting plants cannot be treated by chemical methods; (2) the other MFA can be treated to an acceptable quality by existing smelting furnaces; (3) only MFA from electric resistance ash-melting plants can be treated easily by the water washing method; and (4) alkaline and ammonia/chloride leaching methods were more effective than acid leaching.     

Investigation of flow structure with moat acting as a water cushion at the toe of an overflowing levee

Environmental Fluid Mechanics - The principle theme of this study is to introduce a novel countermeasure to reduce the energy of the overflowing floodwater by utilization of a water cushion. For...     

Geographical variations in the trophic ecology of Japanese anchovy, Engraulis japonicus, inferred from carbon and nitrogen stable isotope ratios

Carbon and nitrogen stable isotope ratios of Japanese anchovy (Engraulis japonicus) and their stomach contents were examined and compared among various regions around Japan. Geographical variations in the isotope ratios were found between inshore and Pacific offshore regions. While most of the anchovy samples had isotope ratios around −17.6‰ for δ¹³C and 10.0‰ for δ¹⁵N as median values, higher (more enriched) isotope values were found in the anchovy sampled from inshore regions. On the contrary, lower (more depleted) values were found mostly in the anchovy from the Pacific offshore region including the Kuroshio Extension and Kuroshio-Oyashio transition zones. Higher carbon isotope ratios in the inshore regions may reflect a carbon source from benthic primary producers in addition to phytoplankton possibly through the consumption of the larvae of benthic organisms such as bivalves or decapods, which were found in the stomach contents of the inshore anchovy. Variations in the nitrogen isotope ratio may reflect not only differences in the trophic level of prey species, but also variations in the baseline level of food webs. Stable isotope ratios are potentially a useful tool for understanding the stock/population structure and migration of anchovy. The present findings indicate the potential importance of the “inshore–offshore” variations in the biology of Japanese anchovy populations in the northwestern Pacific waters.     

Sequential Determination of Trace Metals in Sea Water by Inductively Coupled Plasma Mass Spectrometry After Electrothermal Vaporization of their Dithiocarmabamate Complexes in Methyl Isobutyl Ketone

A sensitive method for sequential determination of V, Mn, Fe, Co, Ni, Cu, Zn, Mo and Sb in sea water using an inductively coupled plasma mass spectrometry (ICP-MS) after electrothermal vaporization of their dithiocarbamate complexes in methyl isobutyl ketone (MIBK) has been investigated. All analyte elements were simultaneously concentrated 20 fold in a single extract and introduced into the plasma using a graphite rod electrothermal vaporizer (ETV). A sensitivity enhancement due to a chemical modification using a mixed modifier of palladium nitrate and magnesium nitrate was observed for all analyte elements. The limits of detection of the method ranged from 2 ng l-1 for Co to 329 ng l-1 for V. For the replicate determinations of the analyte elements in a sea water sample, the repeatability was within 10% (as a coefficient variation), except for V (12.8%). The recovery test performed on a sea water sample resulted in values ranging from 87% for Sb to 119% for V. With the exception of Mo, the application of this method for the determination of the analyte elements in sea water samples collected from the surface to the depth of 5000 m at the sampling station of 34°12.08N, 141°57.50E (Oct. 12, 1994) in the northwest Pacific Ocean resulted in vertical distributions and concentration ranges which were in a good agreement with those reported in literatures.     

Strontium isotope constraints on the seasonal variation of the provenance of base cations in rain water at Kawakami, Central Japan

The ⁸⁷Sr/⁸⁶Sr ratios in monthly precipitation in the forested basin at Kawakami, central Japan, varied seasonally from 0.709 to 0.711 in spring to as low as 0.7062 ± 0.0004 in autumn over nine years from 1987 to 1995. The seasonal variation can be explained in terms of the mixing of three sources of Sr: sea salt (⁸⁷Sr/⁸⁶Sr 0.70917), soluble eolian minerals originating from deserts in continental Asia ( 0.711), and biogenic materials growing on soils derived from the volcanic rock substrates in the vicinity ( 0.706). It is estimated that the contribution of sea-salt Sr into the Kawakami rain Sr is relatively constant (10 ± 5%) and that more than half of the Sr is of biogenic origin throughout the year except during spring rains when 50% of the Sr is due to the dissolution of Ca-minerals from Asian dusts. The dominant contribution of eolian components to spring rains is consistent with the high concentration of ³H, which is typical of air masses from Asia.     

A hydrodynamic study of a modified model of the Clarke Jet Net

A hydrodynamic study of a modified model of the Clarke Jet Net, a high speed plankton sampler, was made using a wind tunnel and an IBM 7040. Modifications allowed a somewhat larger amount of water filtered than in the original model. By adjusting the size of the net chamber exhaust (water control aperture), an average net chamber velocity of about 100 cm/sec could be obtained at any cruising speed. The curvature of the towing cable of the deep tow of a high speed sampler seemed to be determined mainly by the cable characteristics. The stability, vertical and horizontal, of the modified model was satisfactory.Contribution No. 218 from the Seikai Regional Fisheries Research Laboratory, Nagasaki.