Effect of ZnCl<Subscript>2</Subscript> impregnation ratio on pore structure of activated carbons prepared from cattle manure compost: application of N<Subscript>2</Subscript> adsorption-desorption isotherms

Activated carbons were prepared from cattle manure compost (CMC) by ZnCl₂ activation with various ZnCl₂/CMC mass ratios. Based on the N₂ adsorption-desorption isotherms, mathematical models including the Dubinin-Radushkevich (DR) equation, the α_s plot, and the Horvath-Kawazoe method were used to analyze the pore structural characteristics of the prepared activated carbons. It was found that for carbons possessing both micro-and mesopores, the DR method provided a more accurate estimation than the α_s method for the extent of microporosity. The effect of the ZnCl₂ impregnation ratio on the pore structure was discussed using the DR method. The results revealed that pore evolution involved three distinct regions with increases in the amount of impregnated ZnCl₂: raising the ZnCl₂/CMC mass ratio from 0.00 to 0.50 resulted in a 19-fold increase in micropore volume (V_me ^D) but caused no change in the mesopore volume (V_me ^D); increasing the ZnCl₂/CMC mass ratio from 0.50 to 1.00 led to an increment in V_mi ^D of about 50% and in V_me ^D of 170%; while raising the ratio from 1.50 to 2.50 caused a slight decrease in V_mi ^D but a 200% increment in the value of V_me ^D.     

Coagulation characteristics of humic acid modified with glucosamine or taurine

To suppress the coagulation of humic acid (HA) in aqueous solutions, HA was modified with hydrophilic amines, such as glucosamine or taurine. These amines were attached to carboxyl groups in HA via amide bond formation. The degree of modification (R(m)) was estimated to be 21-38%. Infrared spectra of the modified HAs were also consistent with the presence of amide bonds. Acid-base titration showed that the average acid-dissociation constant (pK(app)) of the HA samples was increased by the modification. The Ca(2+) binding capacity of HA decreased with an increase in R(m) value. Critical pH or Ca(2+) concentration, at which HA coagulation occurs, was increased as the result of the modification. These critical points for taurine-HA were higher than those for glucosamine-HA. This is mainly due to electrostatic repulsion by sulfonate groups in taurine. These results indicate that the coagulation of HA is suppressed by modifying the molecules with glucosamine or taurine.     

Behavior of potassium in bread by ion chromatography

Public attention was aroused when mutagenicity was found in potassium bromate (KBrO₃) which has been used as an oxidizing agent in baking bread. Ion chromatography was found to be very useful for analyzing bromide and bromate ions in food. The residual condition of potassium bromate added to bread in the baking process was clarified.It was found that the residual rate of bromate ions in bread was approximately 30% at the added level of 100 μg/g, but it decreased markedly when the added levels went down. At 40 μg/g no residue was detected.     

Extinction-effective population index: incorporating life-history variations in population viability analysis

Viability status of populations is a commonly used measure for decision-making in the management of populations. One of the challenges faced by managers is the need to consistently allocate management effort among populations. This allocation should in part be based on comparison of extinction risks among populations. Unfortunately, common criteria that use minimum viable population size or count-based population viability analysis (PVA) often do not provide results that are comparable among populations, primarily because they lack consistency in determining population size measures and threshold levels of population size (e.g., minimum viable population size and quasi-extinction threshold). Here I introduce a new index called the "extinction-effective population index," which accounts for differential effects of demographic stochasticity among organisms with different life-history strategies and among individuals in different life stages. This index is expected to become a new way of determining minimum viable population size criteria and also complement the count-based PVA. The index accounts for the difference in life-history strategies of organisms, which are modeled using matrix population models. The extinction-effective population index, sensitivity, and elasticity are demonstrated in three species of Pacific salmonids. The interpretation of the index is also provided by comparing them with existing demographic indices. Finally, a measure of life-history-specific effect of demographic stochasticity is derived.     

Evaluation of the water quality of the Hakata River based on diatoms

We investigated the epilithic diatom assemblage of samples collected from three sites of the Hakata River, Fukuoka, Japan, on November 26, 2008. Each taxon was photographed and identified. The 1747 diatom frustules collected were classified into 33 taxa belonging to 17 genera. Nitzschia fonticola was abundant at all sites. The DAIpo (the diatom assemblage index to organic water pollution) values for sites 1, 2, and 3 were 50.2, 44.1 and 48.0, respectively, indicating that the water quality of the Hakata River was at β-mesosaprobic level.     

Emissions of particulate matter and associated polycyclic aromatic hydrocarbons from agricultural diesel engine fueled with degummed, deacidified mixed crude palm oil blends

Mixed crude palm oil(MCPO),the mixture of palm fiber oil and palm kernel oil,has become of great interest as a renewable energy source.It can be easily extracted from whole dried palm fruits.In the present work,the degummed,deacidified MCPO was blended in petroleum diesel at portions of 30% and 40% by volume and then tested in agricultural diesel engines for long term usage.The particulates from the exhaust of the engines were collected every 500 hr using a four-stage cascade air sampler.The 50% cut-off aerodynamic diameters for the first three stages were 10,2.5 and 1μm,while the last stage collected all particles smaller than 1μm.Sixteen particle bounded polycyclic aromatic hydrocarbons(PAHs) were analyzed using a high performance liquid chromatography.The results indicated that the size distribution of particulate matter was in the accumulation mode and the pattern of total PAHs associated with fine-particles(< 1μm) showed a dominance of larger molecular weight PAHs(4-6 aromatic rings),especially pyrene.The mass median diameter,PM and total PAH concentrations decreased when increasing the palm oil content,but increased when the running hours of the engine were increased.In addition,Commercial petroleum diesel(PB0) gave the highest value of carcinogenic potency equivalent(BaP eq) for all particle size ranges.As the palm oil was increased,the BaP eq decreased gradually.Therefore the degummed-deacidified MCPO blends are recommended for diesel substitute.     

Metabolism of potassium bromate in rats I. In vivo studies

Potassium Bromate was administered orally to rats and its fate in the body was studied. The bromate was rapidly absorbed from the digestive tract and was partly excreted in the urine within two hours of administration. No bromate was detected in body organs or in the blood 24 hours after dosing. Excretion of bromate into the urine was proportional to the dose, except that at 2.5mg/kg or less no excretion was observed. The administration of bromate increased the bromide concentration in various organs and in urine.     

Factors which affect the occurrence of cannibalism and the broad-headed "cannibal" morph in larvae of the salamander Hynobius retardatus

Cannibalism in amphibian larvae may be suppressed among siblings in comparison to distant relatives or nonkin, even when a "cannibal" morph that can consume conspecifics shows adaptive advantages. Two experimental studies were undertaken to analyze factors which affect the frequency of cannibalism and the occurrence of the broad-headed "cannibal" morph in larvae of the salamander Hynobius retardatus. The first experiment investigated whether or not the broad-headed "cannibal" morph is only induced after performing cannibalism. Because the broad-headed "cannibal" morph was observed in larval populations that showed no cannibalism, it was concluded that the "cannibal" morph could be induced without actual cannibalism. Second, possible factors affecting the occurrence of the broad-headed "cannibal" morph were analyzed with respect to the density of larvae, level of food supply, and kinship among larvae, alone or in combination. Appearance of the broad-headed "cannibal" morph was affected by interactive effects of density2kinship: although the morph was induced significantly more often at a higher density if the conspecifics were distantly or not related, it was strongly suppressed even at high density if larval kinship was very close or among siblings. In contrast, the frequency of cannibalism was independently affected by larval density, level of food supply, and kinship among larvae: it was significantly larger at high than at low larval densities, at low than at high food supply, and in mixed-sibling groups than in pure sibships. These results suggest that the "cannibal" morphs in H. retardatus are induced even without cannibalism at a high density of conspecifics in mixed-sibling groups, but the occurrence of this morph, which continuously consumes conspecifics, is suppressed among siblings.     

Evolution of water chemistry in natural acidic environments in Yangmingshan,Taiwan

In Yangmingshan National Park, located in the northern part of the Taiwan Island, there is a very rare area where fish (Channa asiatica) live in spite of acid environments. The origin of the acid in local acid ponds and rivers and the evolution of the water chemistry are discussed on the basis of sulfur stable isotope ratios and chemical equilibria. One of the sources of the acid is sulfuric acid, which is derived from the oxidation of hydrogen sulfide in volcanic gas gushing out from fumaroles around the area and from acid deposition supplied from Taipei City. It is also derived from the oxidation of pyrite: the sulfur stable isotope ratios of delta 34S of +1@1000 to +4@1000 (relative to CDT) of sulfate in acid pond waters (pH 3-4) could be related to those of hydrogen sulfide in volcanic gas, pyrite in local pond sediments and soils, and sulfate in rain water. One acid source is sulfuric and hydrochloric acids arising in springs from geothermal activity: the delta 34S values were characterised by +13@1000 to +17@1000 sulfate-S, which was provided by a disproportionation reaction of sulfur dioxide in the depths. Another acid source could be the oxidation of iron(II). Under acidic conditions, the water-rock reaction gives rise to high concentrations of aluminium and iron. While flowing down surface streams, iron(II) is oxidised to iron(III) and then hydrolysed to cause further acidification under oxic conditions. The concentrations of iron and aluminium are controlled by redox and dissolution equilibria.     

The effect of bidirectional opinion diffusion on social license to operate

This is a companion paper to an earlier work in which an agent-based model is proposed by Nakagawa et al. for exploring the emergent phenomena of social license to operate (SLO) of a mining company. In this paper, the structure of the original model is described, along with the enhanced ability for the two-way diffusion of information and opinion among agents. This is achieved through the addition of a global “dialogue” variable, which dictates the extent to which higher influence agents accept opinion from agents of lower influence. Initial findings suggest that the bidirectional diffusion of information has a large effect on the time that the modelling population takes to reach a Social License consensus, and the effect is especially pronounced for low dialogue values. In other words, the Social License of communities characterized by a low preference for dialogue (as opposed to “top-down” mandated communication) will be largely affected by small changes in the preference for dialogue. Findings also suggest that as a modelling community becomes more and more open to dialogue, the effect on the time to consensus becomes less and less pronounced until it becomes negligible at a fairly low dialogue level.