Increased 3HV Concentration in the Bacterial Production of 3-Hydroxybutyrate (3HB) and 3-Hydroxyvalerate (3HV) Copolymer with Acid-Digested Rice Straw Waste

Bacterial synthesis of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) copolymer [P(3HB-co-3HV)] using the hydrolysate of rice straw waste as a carbon source was affected by the composition of the hydrolysate, which depends highly on the rice straw pretreatment condition. Acid digestion with 2 % sulfuric acid generated larger production of P(3HB-co-3HV) than 6 % sulfuric acid, but 3HV concentration in the copolymer produced with 2 % acid hydrolysate was only 8.8 % compared to 18.1 % with 6 % acid hydrolysate. To obtain a higher 3HV mole fraction for enhanced flexibility of the copolymer, an additional heating was conducted with the 2 % acid hydrolysate after removal of residual rice straw. As the additional heating time increased a higher concentration of levulinic acid was generated, and consequently, the mole fraction of 3HV in P(3HB-co-3HV) increased. Among the conditions tested (i.e., 20-, 40-, 60-min), 60-min additional heating following 2 % sulfuric acid digestion achieved the highest 3HV mole fraction of 22.9 %. However, a longer heating time decreased the P(3HB-co-3HV) productivity, probably due to the increased intermediates concentrations acting as inhibitors in the hydrolysates. Therefore, the use of additional heating needs to consider both the increase in the 3HV mole fraction and the decrease in the P(3HB-co-3HV) productivity.     

Recycling of cathode ray tube panel glasses as aggregates of concrete blocks and clay bricks

While the cathode ray tube (CRT) funnel containing lead could be transported to a smelting facility to recover lead, which could be an available option in domestic, a proper technology to recycle a CRT panel must be developed. Thus, it was suggested that CRT panel glass be used as aggregates of concrete blocks and clay bricks. Samples of blocks and bricks were fabricated with CRT powders and tested to measure their strength and absorption rate to determine their qualities, and environmental soundness was determined by measuring the leaching rate of hazardous metals. For concrete blocks, CRT panel glass powders incorporated as aggregates up to 40 % replacing stone powder was proposed as the proper condition for manufacturing blocks. Around 2 % of CRT panel incorporated into clay brick to substitute Kaoline was suggested to fabricate the best quality of clay brick. Results of leaching test met the criteria with much less concentration of hazardous metals, even lead compound containing in the CRT funnel. To conclude, the use of CRT panel powder after crushing it to the proper size as an aggregate of concrete blocks or clay bricks could be one of the appropriate alternatives to recycle for CRT glass waste being generated drastically in a short term.     

Carbon dioxide utilization with carbonation using industrial waste-desulfurization gypsum and waste concrete

In this study, we propose a process making calcium carbonate and calcium sulfate and recovering absorbent using ammonia absorbent, carbon dioxide, and industrial waste. The main objective of this study is to confirm the possibility of carbon capture and utilization based on waste materials. We assumed desulfurization gypsum and construction waste (ready mixed concrete washing water, waste concrete, etc.) are CaSO₄, Ca(OH)₂, respectively. And concentration of simulated carbon dioxide gas was 15 vol% similar to flue gas. Calcium carbonate was produced by combination reaction between ionic CO₂ in absorbent and metal ion in the solid waste. Experiments were conducted at normal temperature and pressure. Furthermore, the generated products were characterized by X-ray diffraction, and scanning electron microscope.     

Inhibition of pyrite oxidation by surface coating: a long-term field study

Pyrite and other iron sulfides are readily oxidized by dissolved oxygen in aqueous phase, producing acidity and Fe²⁺, which causes significant environmental problems. Applications of surface coating agents (Na₂SiO₃ and KH₂PO₄) were conducted at Boeun (Chungbuk, South Korea) outcrop site, and their efficiencies to inhibit the oxidation of sulfide minerals were monitored for a long-term period (449 days). The rock sample showed positive Net Acid Production Potential (NAPP = 20.23) and low Net Acid Generation pH (NAGpH = 2.42) values, suggesting that the rock sample was categorized in the potential acid-forming group. For the monitored time period (449 days), field study results showed that the application of Na₂SiO₃ effectively inhibited the pyrite oxidation as compared to KH₂PO₄. Na₂SiO₃ as a surface coating agent maintained pH 5–6 and reduced oxidation of pyrite surface up to 99.95 and 97.70 % indicated by Fe²⁺ and SO₄ ^2? release, respectively. The scanning electron microscope and energy-dispersive X-ray spectrometer analysis indicated that the morphology of rock surface was completely changed attributable to formation of iron silicate coating. The experimental results suggested that the treatment with Na₂SiO₃ was highly effective and it might be applicable on field for inhibition of iron sulfide oxidation.     

Collective fit perceptions: A multilevel investigation of person–group fit with individual‐level and team‐level outcomes

This study describes a multilevel examination of person–group (PG) fit perceptions in a sample of 1023 individuals working in 92 teams at a private sector R&D firm. Using confirmatory factor analysis and multilevel random coefficient modeling, we provide evidence that perceptions of team‐level collective fit are unique from aggregated individual‐level PG fit perceptions at the individual and team levels. We demonstrate that collective values‐based and abilities‐based fit perceptions showed unique and positive relationships with team cohesion, team efficacy, and team performance, after accounting for aggregated individual perceptions of PG fit. Results also demonstrate that cohesion partially mediates the relationship between collective fit and team performance. Cross‐level effects were also supported, indicating that collective fit explains additional variance in individual‐level outcomes, beyond individual‐level PG fit perceptions. The usefulness of employing a multilevel approach to studying PG fit is discussed. Copyright © 2014 John Wiley & Sons, Ltd.     

Worker drift and egg dumping by queens in wild Bombus terrestris colonies

Wild bumblebee colonies are hard to find and often inaccessible, so there have been few studies of the genetic structure of bumblebees within natural colonies, and hence, it is not clear how frequently events such as worker reproduction, worker drift and queen usurpation take place. This study aimed to quantify the occurrence of natal-worker reproduction, worker drift and drifter reproduction within 14 wild colonies of Bombus terrestris in Central Scotland. Four unlinked microsatellites were used to identify patterns of relatedness of the colonies’ adults and broods. In colonies with queens (queenright colonies), worker reproduction accounted for just 0.83 % of males, increasing to 12.11 % in queenless colonies. Four colonies contained a total of six workers which were not daughters of the queen, and were assumed to be drifters, and four male offspring of drifters. Drifting is clearly not common and results in few drifter offspring overall, although drifters produced approximately seven times more offspring per capita than workers that remained in their natal colony. Unexpectedly, two colonies contained clusters of sister workers and juvenile offspring that were not sisters to the rest of the adults or brood found in the colonies, demonstrating probable egg dumping by queens. A third colony contained a queen which was not a sister or daughter to the other bees in the colony. Although usurping of bumblebee colonies by queens in early season is well documented, this appears to be the first record of egg dumping, and it remains unclear whether it is being carried out by old queens or newly mated young queens.     

Selective recovery of Cu, Zn, and Ni from acid mine drainage

In Korea, the heavy metal pollution from about 1,000 abandoned mines has been a serious environmental issue. Especially, the surface waters, groundwaters, and soils around mines have been contaminated by heavy metals originating from acid mine drainage (AMD) and mine tailings. So far, AMD was considered as a waste stream to be treated to prevent environmental pollutions; however, the stream contains mainly Fe and Al and valuable metals such as Ni, Zn, and Cu. In this study, Visual MINTEQ simulation was carried out to investigate the speciation of heavy metals as functions of pH and neutralizing agents. Based on the simulation, selective pH values were determined to form hydroxide or carbonate precipitates of Cu, Zn, and Ni. Experiments based on the simulation results show that the recovery yield of Zn and Cu were 91 and 94 %, respectively, in a binary mixture of Cu and Zn, while 95 % of Cu and 94 % of Ni were recovered in a binary mixture of Cu and Ni. However, the recovery yield and purity of Zn and Ni were very low because of similar characteristics of Zn and Ni. Therefore, the mixture of Cu and Zn or Cu and Ni could be recovered by selective precipitation via pH adjustment; however, it is impossible to recover selectively Zn and Ni in the mixture of them.     

Efficacy of rapeseed residue and eggshell waste on enzyme activity and soil quality in rice paddy

Addition of plant residue into soils improves soil physiochemical properties and its fertility. Rapeseed residue is an emerging N source to paddy soils via rice-rape double-cropping practice. The objective of this study was to evaluate the effects of rapeseed residue and eggshell waste on chemical changes and enzyme activity in the rice paddy soil. The powdered eggshells at 0, 1, 3, and 5% were applied once to 7.0 kg paddy repacked soils in each pot treated with the rapeseed residue or the conventional N, P, and K fertilisers. Eight rice seedlings (Oriza sativa L. cv. Ilmibyeo) (40 days after sowing) were transplanted to the treated each pot. The contents of total C (TC) and N (TN), and organic matter (OM) were significantly increased in soils treated with the rapeseed residue compared to the N, P, and K fertilisers. With the addition of eggshell containing ～92% CaCO₃, a considerable increase of soil pH was observed in soils treated with the rapeseed residue and the N, P, and K fertilisers, compared to the untreated soil. Activities of β-glucosidase, urease, and arylsulfatase enzymes were higher in soils treated with the rapeseed residue than soils treated with the N, P, and K fertilisers. The eggshell additions at 1, 3, and 5% into soils treated with the rapeseed residue increased enzyme activity mainly resulting from N mineralisation, whereas no change in enzyme activity was observed in the soils treated with the NPK fertiliser. The combined use of the rapeseed residue and the eggshells can be beneficial to improve soil environment.     

Phylogeography of the seaweed Ishige okamurae (Phaeophyceae): evidence for glacial refugia in the northwest Pacific region

Although benthic marine algae are essential components of marine coastal systems that have been influenced profoundly by past and present climate change, our knowledge of seaweed phylogeography is limited. The brown alga Ishige okamurae Yendo occurs in the northwest Pacific, where it occupies a characteristic belt in the exposed intertidal zone. To understand the patterns of genetic diversity and the evolutionary history of this species, we analyzed mitochondrial cox3 from 14 populations (221 individuals) throughout its range. The 17 haplotypes found in this study formed five distinct clades, indicating significant genetic structure. The high differentiation and number of unique (private) haplotypes may result from the recolonization of the species from glacial refugia. Three putative refugia, each with high genetic diversity, were identified: southern Korea (including Jeju Island), northern Taiwan, and central Pacific Japan. Recolonization of I. okamurae was probably determined by ocean currents and changes in sea level during the last glacial period.     

Effects of cyanobacterium Microcystis aeruginosa on the filtration rate and mortality of the freshwater bivalve Corbicula leana

We compared filtering rates (FR) and mortalities between freshwater filter-feeding bivalve Corbicula leana acclimatized (AM) and non-acclimatized (NAM) to an cyanobacterial bloom (mainly Microcystis aeruginosa) over seven days. Both mussel populations were simultaneously stocked into mesocosms constructed in littoral zones of a eutrophic lake at a density of 740 ind. m(-2) for 16 days. NAMs decreased the concentration of chlorophyll-a 50% less than AMs. For the first seven days, the FRs (0.46-0.61) and mortality rate (slope = -30.2, r = -0.95) of NAMs were higher than those of AMs, possibly due to a sudden increase in unselective filtering. From the eighth day NAM mortality decreased rapidly and then stabilized, becoming similar to that of AMs through the end of the experiment. Stocking both AMs and NAMs increased the NH4-N concentration in the water, and the mortality rates of both mussel populations were correlated with NH4-N. In contrast, other nutrients and microcystin concentrations were not significantly associated with mussel mortality. These results indicate that although a sudden introduction of non-acclimatized C. leana may partially control phytoplankton biomass fora short period, previous short-term acclimatization is needed to minimize mussel mortality.