Identification of black plastics realized with the aid of Raman spectroscopy and fuzzy radial basis function neural networks classifier

To accomplish the effective classifier and secure the accurate classification capabilities of black plastics, a comprehensive design methodology of fuzzy radial basis function neural networks is developed with the aid of principal component analysis and particle swarm optimization. Plastics recycling is the competitive method which can deal with the shortage of natural resource. To recycle and reuse the waste plastics, this study is given as the key issue to identify and classify waste plastics by resin type such as polyethylene terephthalate, polypropylene, polystyrene, etc. To complement the weak points of recognition and classification of the near-infrared radiation equipment, Raman spectroscopy is used to obtain qualitative as well as quantitative analysis of black plastics. To improve the identification performance of black plastics, an intelligent computing algorithm such as fuzzy radial basis function neural networks classifier and preprocessing algorithm as principal component analysis are applied to analyze and classify the obtained spectrum of black plastics. Finally, to optimize the structure as well as parameters of fuzzy radial basis function neural networks, particle swarm optimization technique is used. The obtained experimental results show that the proposed network architecture exhibits high classification capabilities in practical applications.     

Some aspects of the life history of the subarctic copepodNeocalanus cristatus (Calanoida) in Sagami Bay,central Japan

A typical subarctic copepod,Neocalanus cristatus, occurred in the mesopelagic layer (500 to 1000 m) in Sagami Bay, central Japan, throughout the year. Specimens were collected from 1982 to 1986. A small number of adult females were distributed from 800 to 900 m only, but no adult males were collected. This species appeared to be abundant in April and August, when intermediate Oyashio water flowed strongly into Sagami Bay. Mean prosome lengths of copepodite stages IV and V and adults were 4.33, 6.87 and 6.87 mm, respectively. The condition factor [wet wt/(prosome length)³ × 100] of copepodite stage V did not vary remarkably, and mean values ranged from 4.7 to 5.0. Prosome length, body weight and condition factor ofN. cristatus collected from Sagami Bay were smaller than those of copepods in the northern North Pacific.N. cristatus transported from the north cannot molt to adult stages (except for those originating in mesopelagic waters) due to the adverse environmental conditions in Sagami Bay; instead, they die in the mesopelagic layer and sink to the bathypelagic layer (1 000 to 1 400 m), close to the bottom. Since nauplii and early copepodite stages did not occur in any season,N. cristatus probably do not reproduce in Sagami Bay.     

Observations of aerosol-bound ionic compositions at Cheju Island,Korea

To investigate the regional cycle of aerosols and their ionic constituents, three field intensive campaigns were conducted during fall and winter of 1997 and spring of 1998. The concentrations of most ionic species were found to decrease significantly across fall, winter, and spring such that the sum for all cation (and anion) species of each season is computed as: 193 > 96 > 73.7 nequiv m(-3) (and 240 > 104 > 51.5 nequiv m(-3)). To examine the fundamental characteristics of aerosol compositions in the study area, we conducted correlation analysis in various manners. The results indicated that the concentrations of major ionic species were strongly affected by some meteorological parameters including wind speed. It was also seen that relative strengths of correlations between important parameters (e.g., between wind speed and most of major inorganic species) maintain close relationships with the factors associated with the air mass origin. In addition, the results of factor analysis indicated the existence of at least three major sources in the study area which include: sea-salt aerosol, secondary aerosol, and organic aerosol component. The springtime occurrence of unexpectedly low concentrations of most ionic constituents is found to sensitively reflect the influence of the inflow of southeasterly winds that prevailed during spring, while it is not common for that season of the year. Because most of those changes are closely tied with the variabilities in the regional circulation patterns for each measurement period, assessment of the ionic composition in concert with the temporal variations of meteorological conditions provided valuable insights into the source signals of different air masses that passed by the study area.     

Effect of soil aggregation on the biodegradation of phenanthrene aged in soil

A study was conducted to determine the possible role of soil aggregates in the sequestration of phenanthrene and thus in the declined biodegradation of the hydrocarbon. Phenanthrene aged in Lima loam (2-mm aggregates) showed declined biodegradation with time of aging to the test bacterium P5-2 capable of using sorbed phenanthrene. In contrast, the compound aged in a soil reconstructed with 68% clay-silt and 32% sand that had been separated from the Lima loam was readily mineralized. The percentages of each fraction used were the same as those of the original soil. Biodegradation of aged phenanthrene was not affected significantly by varying the ratios of each fraction in reconstructed mixtures. In experiments with Lima loam, its clay-silt fraction, and its sand fraction, mineralization extent was much lower in soil aggregates compared with the other samples while all had similar organic carbon content of ca. 1.51%. This suggests that aggregation may be another important determinant in the reduced biodegradation of aged phenanthrene.     

Potential of anaerobic digestion for material recovery and energy production in waste biomass from a poultry slaughterhouse

This study was carried out to assess the material and energy recovery by organic solid wastes generated from a poultry slaughterhouse. In a poultry slaughterhouse involving the slaughtering of 100,000 heads per day, poultry manure & feather from the mooring stage, blood from the bleeding stage, intestine residue from the evisceration stage, and sludge cake from the wastewater treatment plant were discharged at a unit of 0.24, 4.6, 22.8, and 2.2 Mg day^?1, consecutively. The amount of nitrogen obtained from the poultry slaughterhouse was 22.36 kg 1000 head^?1, phosphate and potash were 0.194 kg 1000 head^?1 and 0.459 kg 1000 head^?1, respectively. As regards nitrogen recovery, the bleeding and evisceration stages accounted for 28.0% and 65.8% of the total amount of recovered nitrogen. Energy recovered from the poultry slaughterhouse was 35.4 N m³ 1000 head^?1 as CH₄. Moreover, evisceration and wastewater treatment stage occupied 88.1% and 7.2% of the total recovered CH₄ amount, respectively.     

Interpreting complex geochemistry of groundwater in a coastal paddy field near a mine using isotopic signatures of sulfate and water

Environmental Geochemistry and Health - In the area around the abandoned Seoseong mine, South Korea, coastal paddy fields undergo seawater intrusion and possible sulfate reduction. Here, channel...     

Long-term trends in airborne SO2 in an air quality monitoring station in Seoul,Korea, from 1987 to 2013

Atmospheric concentration of sulfur dioxide (SO₂) was intermittently measured at an air quality monitoring (AQM) station in the Yong-san district of Seoul, Korea, between 1987 and 2013. The SO₂ level was compared with other important pollutants concurrently measured, including methane (CH₄), carbon monoxide (CO), nitric oxide (NO), nitrogen dioxide (NO₂), ozone (O₃), and particulate matter (PM₁₀). If split into three different periods (period 1, 1987–1988, period 2, 1999–2000, and period 3, 2004–2013), the respective mean [SO₂] values (6.57 ± 4.29, 6.30 ± 2.44, and 5.29 ± 0.63 ppb) showed a slight reduction across the entire study period. The concentrations of SO₂ are found to be strongly correlated with other pollutants such as CO (r = 0.614, p = 0.02), which tracked reductions in reported emissions due to tighter emissions standards enacted by the South Korean government. There was also a clear seasonal trend in the SO₂ level, especially in periods 2 and 3, reflecting the combined effects of domestic heating by coal briquettes and meteorological conditions. Although only a 16% concentration reduction was achieved during the 27-year study duration, this is significant if one considers rapid urbanization, an 83.2% increase in population, and rapid industrialization that took place during that period.

Implications: Since 1970, a network of air quality monitoring (AQM) stations has been operated by the Korean Ministry of Environment (KMOE) for routine nationwide monitoring of air pollutant concentrations in urban/suburban areas. To date, the information obtained from these stations has provided a platform for analyzing long-term trends of major pollutant species. In this study, we examined the long-term trends of SO₂ levels and relevant environmental parameters monitored continuously in the Yong-san district of Seoul between 1987 and 2013. The data were analyzed over various time scales (i.e., monthly, seasonal, and annual intervals). The results obtained from this study will allow us to assess the effectiveness of abatement strategy and to predict future concentrations trends in association with future abatement strategies and technologies.     

A simultaneous equations model of crash frequency by collision type for rural intersections

Safety at roadway intersections is of significant interest to transportation professionals due to the large number of intersections in transportation networks, the complexity of traffic movements at these locations that leads to large numbers of conflicts, and the wide variety of geometric and operational features that define them. A variety of collision types including head-on, sideswipe, rear-end, and angle crashes occur at intersections. While intersection crash totals may not reveal a site deficiency, over exposure of a specific crash type may reveal otherwise undetected deficiencies. Thus, there is a need to be able to model the expected frequency of crashes by collision type at intersections to enable the detection of problems and the implementation of effective design strategies and countermeasures. Statistically, it is important to consider modeling collision type frequencies simultaneously to account for the possibility of common unobserved factors affecting crash frequencies across crash types. In this paper, a simultaneous equations model of crash frequencies by collision type is developed and presented using crash data for rural intersections in Georgia. The model estimation results support the notion of the presence of significant common unobserved factors across crash types, although the impact of these factors on parameter estimates is found to be rather modest.     

Effects of various reaction parameters on solvolytical depolymerization of lignin in sub- and supercritical ethanol

Organosolv lignin was treated with ethanol at sub/supercritical temperatures (200, 275, and 350 °C) for conversion to low molecular phenols under different reaction times (20, 40, and 60 min), solvent-to-lignin ratios (50, 100, and 150 mL g⁻¹), and initial hydrogen gas pressures (2 and 3 MPa). Essential lignin-degraded products, oil (liquid), char (solid), and gas were obtained, and their yields were directly influenced by reaction conditions. In particular, concurrent reactions involving depolymerization and recondensation as well as further (secondary) decomposition were significantly accelerated with increasing temperature, leading to both lignin-derived phenols in the oil fraction and undesirable products (char and gas).     

Fine Particle Removal Performance of a Two-Stage Wet Electrostatic Precipitator Using a Nonmetallic Pre-Charger

ABSTRACT

A novel two-stage wet electrostatic precipitator (ESP) has been developed using a carbon brush pre-charger and collection plates with a thin water film. The electrical and particle collection performance was evaluated for submicrometer particles smaller than 0.01～0.5 μm in diameter by varying the voltages applied to the pre-charger and collection plates as well as the polarity of the voltage. The collection efficiency was compared with that calculated by the theoretical models. The long-term performances of the ESP with and without water films were also compared in tests using Japanese Industrial Standards dust. The experimental results show that the carbon brush pre-charger of the two-stage wet ESP had approximately 10% particle capture, while producing ozone concentrations of less than 30 ppb. The produced amounts of ozone are significantly lower than the current limits set by international agencies. The ESP also achieved a high collection rate performance, averaging 90% for ultrafine particles, as based on the particle number concentration at an average velocity of 1 m/sec corresponding to a residence time of 0.17 sec. Higher particle collection efficiency for the ESP can be achieved by increasing the voltages applied to the pre-charger and the collection plates. The decreased collection efficiency that occurred during dust loading without water films was completely avoided by forming a thin water film on the collection plates at a water flow rate of 6.5 L/min/m2 Zukeran, A., Ikeda, Y., Ehara, Y., Matsuyama, M., Ito, T., Takahashi, T., Kawakami, H. and Takamatsu, T. 1999. Two-Stage-Type Electrostatic Precipitator Re-entrainment Phenomena under Diesel Flue Gases. IEEE. Trans. Ind. Appl, 35: 346–351. [Crossref], [Web of Science ®] , [Google Scholar].

IMPLICATIONS Current two-stage electrostatic precipitators (ESPs) have several technical problems such as a drop in collection efficiencies by small-particle re-entrainment during rapping and corrosion of metallic electrodes of the ESPs by corrosive gases. This paper evaluates a novel two-stage ESP that uses a nonmetallic pre-charger and water film collection plates to avoid the above mentioned problems of other ESPs. This ESP can be used not only for industrial applications but also for residential purposes because it has a high removal performance for fine particles with low ozone generation and maintains its efficiency due to the continuous cleaning of the collection plates with water film.