Multi-objective green design model to mitigate environmental impact of construction of mega columns for super-tall buildings.

The mega columns used in super-tall buildings are several meters in size; thus, a greater quantity of construction materials are required than for a general column. Considering the environmental impact, research on a green design model for super-tall buildings is necessary. This design model should minimize both CO2 emissions and cost in the mega-column construction and design phases with consideration of the member or building size. In this regard, a multi-objective green design model (MOGDM) capable of minimizing construction cost and reducing CO2 emissions is proposed in this study. The MOGDM is applied to the design of mega columns for a super-tall building and its performance is evaluated based on the average environmental impact reduction rate (AER) and the average increase-in-cost reduction rate (AICR); these indexes are developed to assess the CO2 emission and construction cost reduction capability. Under the loading scenarios considered in this study, the average AER and AICR for the MOGDM output are 6.76% and 58.02%, respectively. Thus, the evaluation results confirm that the MOGDM proposed in this study can effectively reduce CO2 emissions and cost in the design and construction phases of mega columns for super-tall buildings.

Elucidation of the bacterial communities associated with the harmful microalgae Alexandrium tamarense and Cochlodinium polykrikoides using nanopore sequencing.

Interactions between microalgae and bacteria are often obligatory for harmful algal blooms (HABs). Here, we investigated the specific bacterial communities associated with Alexandrium tamarense and Cochlodinium polykrikoides, which cause ecological and economic damage during their blooms. To this end, the bacterial metagenome was selectively isolated from the two dinoflagellates and subsequently used for 16S rRNA analysis via the Nanopore MinION and Illumina sequencing platforms. Although the full-length 16S rRNA reads from the MinION platform showed high correlation in higher taxonomic ranks to the partial-length 16S rRNA reads from the Illumina platform, there was less correlation at the genus and species levels. MinION reads that are similar in the V3-V4 hypervariable regions with Illumina reads are classified to different taxonomies due to the extra information encoded in the full-length 16S rRNA reads. This indicates that bias arising from the short length Illumina reads can be supplemented by MinION reads. Furthermore, integrated analysis of the Illumina and MinION data showed that A. tamarense was predominantly enriched in the Roseobacter clade and C. polykrikoides was enriched in Gammaproteobacteria and Alphaproteobacteria. These results suggest that the association of different bacterial communities with A. tamarense and C. polykrikoides may be required for HABs.

Periphyton effects on bacterial assemblages and harmful cyanobacterial blooms in a eutrophic freshwater lake: a mesocosm study.

Periphyton comprises a broad range of autotrophic and heterotrophic organisms that grow on submerged surfaces in aquatic environments. To investigate the ecological roles of periphyton and their symbiotic bacterial assemblages related to the control of cyanobacterial blooms, mesocosm experiments were performed in a eutrophic lake that is usually infested with harmful cyanobacterial blooms. Our results showed that periphyton, together with their symbionts, reduced Chl-a concentrations (up to 94%), improved water clarity and effectively controlled cyanobacterial blooms in the treatment mesocosm. Planktonic bacterial compositions varied greatly in the pre-bloom/bloom/post-bloom periods in both mesocosms and were mainly influenced by total dissolved nitrogen (TDN) concentrations. The phylum Cyanobacteria was the major component in the water samples until bloom peak, but it was replaced by Actinobacteria in the post-bloom period. However, periphyton niches were dominated by Alphaproteobacteria throughout the experiments, Cyanobacteria proportion being lower. Overall, the results indicated that periphyton and their unique bacterial partners could effectively compete with cyanobacteria and improve water quality. Their underlying interaction mechanism was also suggested to explain how periphyton and their symbionts can reduce cyanobacterial blooms in eutrophic water.

Effects of Environmental Factors on Cyanobacterial Production of Odorous Compounds: Geosmin and 2-Methylisoborneol.

Geosmin and 2-methylisoborneol (2-MIB), responsible for earthy or musty smell, are a major concern for safe drinking water supplies. This study investigated the effects of environmental factors on odorous compound production and cell growth in cyanobacterial strains. Anabaena sp. FACHB-1384, a 2-MIB producer, was sensitive to low temperature (<20°C). However, geosmin producers, Anabaena sp. Chusori and Anabaena sp. NIER, were sensitive to high light intensity (>100 µmol/m2/sec), but not to low temperature. Geosmin concentrations increased under higher nitrate concentrations, being linearly proportional to cell density. A P-limited chemostat showed that P-stress decreased the geosmin productivity and extracellular geosmin amount per cell in Anabaena sp. NIER. However, only 2-MIB productivity was reduced in Planktothrix sp. FACHB-1374 under P-limitation. The extracellular 2-MIB amount per cell remained constant at all dilution rates. In conclusion, high light intensity and P-stress can contribute to the lower incidence of geosmin, whereas 2-MIB reduction could be attainable at a lower temperature.

Two-phase photoperiodic cultivation of algal-bacterial consortia for high biomass production and efficient nutrient removal from municipal wastewater.

This study investigated the photoperiodic effects on the biomass production and nutrient removal in the algal-bacterial wastewater treatment, under the following three conditions: (1) a natural 12h:12h LD cycle, (2) a dark-elongated 12h:60h LD cycle, and (3) a two-phase photoperiodic 12h:60h LD, followed by 12h:12h LD cycles. The two-phase photoperiodic operation showed the highest dry cell weight and lipid productivity (282.6mgL(-1)day(-1), 71.4mgL(-1)day(-1)) and most efficient nutrient removals (92.3% COD, 95.8% TN, 98.1% TP). The genetic markers and sequencing analyses indicated rapid increments of bacteria, subsequent growths of Scenedesmus, and stabilized population balances between algae and bacteria. In addition, the two-phase photoperiod provided a higher potential for the algal-bacterial consortia to utilize various organic carbon substrates.

Effects of Titanium Doping Concentration on the Structural and Electrical Properties of Sputtered Indium Oxide Films.

The surface structure and electrical properties of titanium-doped indium oxide (ITiO) films prepared by RF magnetron sputtering were investigated. The doping concentration of TiO2 in the In2O3 target was changed from 1.0 wt.% to 10.0 wt.% with increments of 1.0 wt.%. At a Ti content of 5.0 wt.%, the optimum growth conditions were achieved. The finest value of hall mobility, carrier concentration, and resistivity of the deposited film reached 47.03 cm2Ns, 1.148 x 10(21) cm-3 and 1.14 x 10(-4) Ωcm, respectively. Then the transmittance was achieved up to 82% at 570 nm. The peaks of the XRD spectra became more intense and sharp as the Ti concentration increased up to 2.5 wt.% but a higher Ti content of 10.0 wt.% retarded a growth of In2O3 grains. The surface roughness of the films by examination of surface morphology using AFM also rose with increase of Ti doping concentration.

Effects of the 2008 Global Economic Crisis on National Health Indicators: Results from the Korean National Health and Nutrition Examination Survey.

BACKGROUND: The relationship between economics and health has been of great interest throughout the years. The accumulated data is not sufficient enough to carry out long-term studies from the viewpoint of morbidity, although Korea National Health and Nutrition Examination Survey (KNHANES) was carried out yearly since 1998 in Korea. Thus, we investigated the effect of the 2008 global economic crisis on health indicators of Korea. METHODS: Health indicators were selected by paired t-test based on 2007 and 2009 KNHANES data. Age, gender, body mass index (BMI), smoking, drinking, exercise, education, income, working status, and stress were used as confounding factors, which were analyzed with logistic and probit analyses. Validation was done by comparing gross domestic product (GDP) growth rates and probit analyses results of 2007-2012 KNHANES data. RESULTS: Among several health indicators, the prevalence of hypertension and stress perception was higher after the economic crisis. Factors related with higher hypertension prevalence include older age, male gender, higher BMI, no current tobacco use, recent drinking, lower education levels, and stress perception. Factors related with more stress perception were younger age, female gender, current smoking, lower education levels, and lower income. GDP growth rates, a macroeconomic indicator, are inversely associated with hypertension prevalence with a one-year lag, and also inversely associated with stress perception without time lag. CONCLUSION: The economic crisis increased the prevalence of hypertension and stress perception. In the case of GDP growth rate change, hypertension was an inversely lagging indicator and stress perception was an inversely-related coincident indicator.

Do People Have Healthier Lifestyles in Greener Environments? An Analysis of the Association between Green Environments and Physical Activity in Seven Large Korean Cities.

BACKGROUND: Recent studies suggest that neighborhood environments influence levels of health and disease in individuals. Evidence suggests that green environments have positive effects on physical and psychological health. In this study, we examined the association between public park per person (PPP) and physical activity in 7 large Korean cities with a population of over 1 million. METHODS: We obtained data from the third Korea National Health and Nutritional Survey and data on the area of PPP from the Korean national statistics office. RESULTS: Physical activity and adjusted mean of physical activity increased significantly with PPP. When stratified by family income, physical activity increased significantly in all groups in a PPP-dependent manner. Physical activity significantly increased as PPP increased (coefficient, 16.025; 95% confidence interval, 12.392 to 19.658) before and after adjustment for age, sex, and family income. Physical activity increased in all income groups including the low income group. CONCLUSION: These results show that green park spaces independently promote physical activity and influence healthy lifestyles. Therefore, the importance of PPP for physical activity and health should be emphasized in urban planning.