The flow structure in the wake of a fractal fence and the absence of an “inertial regime”

Recent theoretical work has highlighted the importance of multi-scale forcing of the flow for altering the nature of turbulence energy transfer and dissipation. In particular, fractal types of forcing have been studied. This is potentially of real significance in environmental fluid mechanics where multi-scale forcing is perhaps more common than the excitation of a specific mode. In this paper we report the first results studying the detail of the wake structure behind fences in a boundary layer where, for a constant porosity, we vary the average spacing of the struts and also introduce fractal fences. As expected, to first order, and in the far-wake region, in particular, the response of the fences is governed by their porosity. However, we show that there are some significant differences in the detail of the turbulent structure between the fractal and non-fractal fences and that these override differences in porosity. In the near wake, the structure of the fence dominates porosity effects and a modified wake interaction length seems to have potential for collapsing the data. With regards to the intermittency of the velocities, the fractal fences behave more similarly to homogeneous, isotropic turbulence. In addition, there is a high amount of dissipation for the fractal fences over scales that, based on the energy spectrum, should be dominated by inter-scale transfers. This latter result is consistent with numerical simulations of flow forced at multiple scales and shows that what appears to be an “inertial regime” cannot be as production and dissipation are both high.     

Quantitative analysis of microbial biomass yield in aerobic bioreactor

We have studied the integrated model of reaction rate equations with thermal energy balance in aerobic bioreactor for food waste decomposition and showed that the integrated model has the capability both of monitoring microbial activity in real time and of analyzing biodegradation kinetics and thermal-hydrodynamic properties. On the other hand, concerning microbial metabolism, it was known that balancing catabolic reactions with anabolic reactions in terms of energy and electron flow provides stoichiometric metabolic reactions and enables the estimation of microbial biomass yield (stoichiometric reaction model). We have studied a method for estimating real-time microbial biomass yield in the bioreactor during food waste decomposition by combining the integrated model with the stoichiometric reaction model. As a result, it was found that the time course of microbial biomass yield in the bioreactor during decomposition can be evaluated using the operational data of the bioreactor (weight of input food waste and bed temperature) by the combined model. The combined model can be applied to manage a food waste decomposition not only for controlling system operation to keep microbial activity stable, but also for producing value-added products such as compost on optimum condition.     

Stable C and N isotope analysis elucidated the importance of zooplankton in a tropical seagrass bed of Santiago Island,Northwestern Philippines

The role of zooplankton in a tropical seagrass ecosystem was investigated in milkfish farms pollution-impacted and -unimpacted seagrass beds in Santiago Island coral reefs, Northwestern Philippines. The aim was to compare between the two sites: (1) abiotic factors and zooplankton community parameters, and (2) the trophic structure using C and N stable isotopes. Low water (98–119?mV) and sediment (–121 to ?138?mV) Oxidation Reduction Potential values indicated a reducing environment in the impacted site. Zooplankton in the impacted site showed the typical community response to eutrophication (low diversity, but high total abundance due to the dominance of the cyclopoid copepod Oithona oculata), generally few elevated δ¹⁵N values, but a significant shift towards depleted ¹³C due to the organic enrichment of fish-farm feeds. Apart from suggesting a highly complex food web with POM and zooplankton as main food sources in the unimpacted site, the Bayesian mixing model simulation generated reduced complexity in feeding interactions between basal sources, zooplankton, and fish including adults of a key fish species, Siganus fuscescens, in the impacted sites. In this study, C and N stable isotope analysis has clarified the importance of zooplankton as fish prey in a seagrass bed food web.     

Simultaneous determination of acidic pesticides in vegetables and fruits by liquid chromatography—tandem mass spectrometry

A sensitive and efficient method has been developed for the simultaneous determination of 73 multi-class acidic pesticides, such as phenoxy acid and sulfonylurea herbicides, in vegetables and fruits. The sample preparation procedure was carefully optimized for the efficient removal of co-extracted matrix components. The method involves extraction of acidic pesticides with acetonitrile containing hydrochloric acid, removal of water from crude extract by salting out, and sequential cleanup by octadecylsilyl silica gel and silica gel columns. For samples containing high amounts of pigments, such as spinach, additional cleanup using a graphitized carbon column was performed prior to liquid chromatography–mass spectrometry (LC–MS/MS) analysis. Recovery tests were performed for five times for each sample of cabbage, spinach, potato, eggplant, orange, and apple fortified at 0.01 mg kg?1. Out of the 73 tested pesticides, 70 for cabbage, 67 for spinach, 69 for potato, 67 for eggplant, 64 for orange, and 70 for apple were within the range of 70–120%, with relative standard deviations below 25%. Nitenpyram and pyrasulfotole showed low recoveries for all the samples tested, probably due to low recoveries from silica gel column. The developed method effectively removed co-extracted matrix components and was highly selective, with no interfering peaks found in the chromatograms of blank samples. The overall results indicate that the developed method is suitable for the quantitative analysis of acidic pesticide residues in vegetables and fruits.     

Nitrate facilitates cadmium uptake, transport and accumulation in the hyperaccumulator Sedum plumbizincicola

The aims of this study are to investigate whether and how the nitrogen form (nitrate (NO₃ ^–) versus ammonium (NH₄ ⁺)) influences cadmium (Cd) uptake and translocation and subsequent Cd phytoextraction by the hyperaccumulator species Sedum plumbizincicola. Plants were grown hydroponically with N supplied as either NO₃ ^– or NH₄ ⁺. Short-term (36 h) Cd uptake and translocation were determined innovatively and quantitatively using a positron-emitting ¹⁰⁷Cd tracer and positron-emitting tracer imaging system. The results show that the rates of Cd uptake by roots and transport to the shoots in the NO₃ ^– treatment were more rapid than in the NH₄ ⁺ treatment. After uptake for 36 h, 5.6 (0.056 μM) and 29.0 % (0.290 μM) of total Cd in the solution was non-absorbable in the NO₃ ^– and NH₄ ⁺ treatments, respectively. The local velocity of Cd transport was approximately 1.5-fold higher in roots (3.30 cm h^?1) and 3.7-fold higher in shoots (10.10 cm h^?1) of NO₃ ^–- than NH₄ ⁺-fed plants. Autoradiographic analysis of ¹⁰⁹Cd reveals that NO₃ ^– nutrition enhanced Cd transportation from the main stem to branches and young leaves. Moreover, NO₃ ^– treatment increased Cd, Ca and K concentrations but inhibited Fe and P in the xylem sap. In a 21-day hydroponic culture, shoot biomass and Cd concentration were 1.51 and 2.63 times higher in NO₃ ^–- than in NH₄ ⁺-fed plants. We conclude that compared with NH₄ ⁺, NO₃ ^– promoted the major steps in the transport route followed by Cd from solution to shoots in S. plumbizincicola, namely its uptake by roots, xylem loading, root-to-shoot translocation in the xylem and uploading to the leaves. S. plumbizincicola prefers NO₃ ^– nutrition to NH₄ ⁺ for Cd phytoextraction.     

Effects of the reduction of pollution emissions on the economic performance of firms: an empirical analysis focusing on demand and productivity

This paper analyzes whether the reduction of pollution emissions improves a firm’s economic performance through the increase in sales to environmentally conscious customers and the cost reductions associated with the improvement in productivity. Because the selection of the control (end-of-pipe) or prevention (cleaner production) approach differently influences the effect through the improvement in productivity, this is also considered. Using panel data for Japanese manufacturing firms over the period 2002–2008, the findings indicate that firms that have reduced their pollution emissions can increase their economic performance through the increase in demand for their products and an improvement in productivity. However, the latter is conditional, and so the prevention approach is preferred.     

(Z)-11-Pentacosene is the major sex pheromone component inDrosophila virilis (Diptera)

Summary A crude cuticular extract from 3450 virgin 9–13 day old female fruit flies(Drosophila virilis), was subjected to chromatography accompanied by bioassay for sex pheromone activity. After three chromatographic steps, fractions containing active monoenes and dienes were obtained. Chemical analysis by infrared absorption, gas liquid chromatography and gas chromatography/mass spectrometry of the active fraction indicated that active monoenes were comprised chiefly of (Z)-11-pentacosene (abbreviated (Z)-11-C_25:1), (Z)-13-C_27:1, (Z)-13- and (Z)-14-C_29:1. Synthetic monoenes were made, and only (Z)-11-C_25:1 elicited good courtship behaviour in maleD. virilis. Therefore it was concluded that (Z)-11-C_25:1 was a major sex pheromone. A total of 16.2±1.32 µg of cuticular hydrocarbons was isolated from 10 day old females, including 5.9±0.56 µg of (Z)-11-C_25:1. An additive effect was suggested from the higher observed courtship response when using a mixture of active dienes with the active monoene.     

Morphology of the gastric mill in ten species of euphausiids

SEM observation revealed the detailed morphology of the gastric mill in ten species of euphausiids, Bentheuphausia amblyops, Thysanopoda acutifrons, Meganyctiphanes norvegica, Pseudeuphausia latifrons, Euphausia superba, Tessarabrachion oculatum, Thysanoessa longipes, Nematoscelis microps, Nematobrachion boopis, and Stylocheiron maximum. The well-developed gastric mill of euphausiids consists of a pair of cluster spines and a pair of lateral teeth displaying great diversity in morphology. It is suggested that there are three categories of gastric mill and filterpress (gland filter) within euphausiids. One is the well-developed gastric mill with filter-press of B. amblyops; a second is the well-developed gastric mill of M. norvegica, T. oculatum, E. superba, P. latifrons and T. longipes; and the third is the gastric mill without lateral teeth of T. acutifrons, N. microps, N. boopis and S. maximum.     

Larval development of Euphausia nana (Crustacea: Euphausiacea)

The larvae of Euphausia nana Brinton in Sagami Bay and Suruga Bay, Central Japan, are described and illustrated. The furcilia stage is separated into six stages on the basis of the form of the pleopods and the number of terminal telson spines. Furcilia I, no pleopod or non-setose pleopods and seven terminal telson spines. Furcilia II, nonsetose and setose pleopods and seven terminal telson spines. Furcilia III, five pairs of setose pleopods and seven terminal telson spines. Furcilia IV, five pairs of setose pleopods and five terminal telson spines. Furcilia V, five pairs of setose pleopods and three terminal telson spines. Furcilia VI, five pairs of setose pleopods and one terminal telson spine. Segmentation of the antennal endopod and mandible palp occurred at the furcilia V stage. The dominant forms of early furcilia larvae of E. nana differed during different seasons of the year. The total lengths of calyptopis III and furcilia I to VI larvae also showed seasonal changes; they were largest in May and smallest from September to December.