Search

The motorcycles are unignorable near-ground pollutant emission sources that increase the human exposure in the dense area. However, the information of the polycyclic aromatic hydrocarbons (PAHs) emissions under different scenarios of engine and emission control for motorcycle is limited. This study focused on the PAH emissions from two fuel-injection types of motorcycles, including the premixed fuel-injection (PFi) with carburetor and electronic fuel-injection (EFi). Specifically, the effects of throttle opening (TO), secondary air system (SAS), oxygen sensor (OS), oxidation catalytic converter (OCC), and three-way catalytic converter (TWC) on PAH emissions are investigated. Results show that the PAH emission concentrations increase 227-727%, 351-492%, and 155-408% by the increasing TO ratio, unworking SAS, and OS units in both motorcycles. For the PFi engine, the OCC unit is found to be more effective in PAH control (31-89%) than the SAS system (72-80%), especially under low TO operation. For the EFi engine which dominates the motorcycle market recently, the oxygen sensor for more accurate combustion control shows a better PAH reduction (36-76%) than TWC system (21-66%). The ultra-fine particulate phase PAHs, which is hardly removed by catalyst, needs to be further considered. Moreover, the total PAH emission level of the EFi engine is still about ten times higher than that of the PFi. By the annual emission calculation for three densely populated countries, the recent evolution significantly reduces the annual hydrocarbon (HC), carbon monoxide (CO), and nitrogen oxide (NOx) emissions but have unignorable PAH emissions. These emissions continuously affect the human health in the near-ground urban air and need to be considered in the next generation of motorcycle design.

There have been questions that are directed toward the outcome of using an exemplar in moral and character education. Meanwhile, the role of the narrative in the context of moral and character educ...

Exposure to the vinyl monomer acrylonitrile (AN) is primarily occupational. AN is also found in cigarette smoke. AN can be detoxified to form N-acetyl-S-(2-cyanoethyl)-cysteine (CEMA) or activated to 2-cyanoethylene oxide (CEO) and detoxified to form N-acetyl-S-(1-cyano-2-hydroxyethyl)-cysteine (CHEMA) and N-acetyl-S-(2-hydroxyethyl)-cysteine (HEMA). These urinary mercapturic acids (MAs) are considered to be potential biomarkers of AN exposure. This study assessed personal AN exposure, urinary MAs (CEMA, CHEMA, and HEMA), and cotinine (a biomarker of cigarette smoke) in 80 AN-exposed and 23 non-exposed factory workers from urine samples provided before and after work shifts. Unambiguous linear correlations were observed between levels of urinary CEMA and CHEMA with personal AN exposures, indicating their potential as chemically-specific biomarkers for AN exposures. AN exposure was the dominant factor in MA formation for AN-exposed workers, whereas urinary cotinine used as a biomarker showed that cigarette smoke exposure was the primary factor for non-exposed workers. The CHEMA/CEMA and (CHEMA+HEMA)/CEMA ratios in this human study differ from those in similar studies of AN-treated rats and mice in literature, suggesting a possible dose- and species-dependent effect in AN metabolic activation and detoxification.

The particulate polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) of various sizes produced from the waste incinerators might have different toxicities, deposition characteristics, and potential health effects in the respiratory system, and their total toxicity equivalent (TEQ) concentration has been strictly regulated in recent years. There is a knowledge gap on the effects of air pollution control devices on particle size distributions (PSDs) of PCDD/Fs and their TEQ deposition. A hazardous waste thermal treatment plant equipped with an advanced scrubber, a cyclone demister, and activated carbon adsorption coupled with a baghouse filtration was investigated in this study. An 8-stage impactor was used to collect the particle distribution of PM

A 43-year-old healthy man presented to the emergency department with an approximately 10-day history of severe neck pain, bilateral arm numbness, neck stiffness and fever. There was no history of trauma. The range of neck motion was limited. Plain radiography of the neck was performed (figure 1). Figure 1 Plain radiography of the neck. Which is the most likely diagnosis? 1. Fracture of the cervical spine 2. Cervical spine …

This study provides an investigation of atmospheric PM2.5, PM10, SO2, NO2, CO, and O3 in the period from 2015–2017 in the southwestern and central part of Taiwan. In addition, the seasonal distribution of six AQI classes and corresponding primary pollutants were further analyzed. The daily AQIs were 15–194 in 2015, 17–213 in 2016, and 16–184 in 2017, respectively. During the three year period, in the studied area, the mean proportions of levels with Grade I, II, III, IV, V, and VI were 3%–31%, 30%–57%, 17%–46%, 0%–12%, 0%–1% and 0% in spring; were 38%–76%, 21%–57%, 0%–10%, 0%–2%, 0% and 0% in summer; were 2%–45%, 34%–77%, 13%–36%, 0%–18%, 0% and 0% in fall, and were 0%–12%, 38%–67%, 24%–41%, 1%–22%, 0% and 0% in winter. Generally, it was found that summer has the best air quality and that winter has the worst, where spring and fall are similar in terms of air quality. PM2.5 was the typical primary air pollutant when the AQI classes were 51–200, followed by O3 in summer, spring and fall, and PM10 in winter. As for class 201–300, the primary air pollutant was O3 and the 300–500 class did not occur.

In the early 2000s, some scholars suggested integrative ethical education as an approach to reconcile the gap between cognitive-development education, based on rule ethics, and traditional characte...

A series of electrostatic precipitator-selective catalytic reductions can capture particulate matters and oxidize polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs) in most of industrial and vehicle emissions; however, the catalyst is easily poisoned by sulfur and metals during long-term operation. A catalytic fiber filter was developed, which coats a thin catalytic layer on the filter to reduce particulate matters and PCDD/Fs. Even though it exhibits high removal efficiencies, it still has similar poisoning issues. In this study, an attempt is made to distribute V2O5/TiO2 powders into ceramic fibers (Al2O3·SiO2·H2O) to form a self-protected catalytic ceramic fiber filter used to treat diesel engine generator emissions at 150–350 °C. The highest removal efficiency of PCDD/F toxicity was 99.4% at 175 °C. However, the de novo synthesis occurred within a range of 250–350 °C and lowered the removal efficiency. Additionally, the particle removals approached 94.4–98.5%, while those of carbon monoxide and nitrogen oxides were > 90 and > 50% at different temperatures, respectively. Consequently, the catalytic ceramic fiber filter may be effective to inhibit both traditional and PCDD/F emissions under specific operational conditions. Air quality control policies could thus be more stringent, and after this new technique is employed, the environment would be cleaner and healthier.

In 2017, the seasonal variations in the wet deposition fluxes of total-PCDD/Fs-WHO2005-TEQ in ambient air were evaluated in Taiwan. The results showed the annual wet deposition fluxes of total-PCDD/Fs-WHO2005-TEQ to be 42.5 pg WHO2005-TEQ m–2 month–1, and the seasonal distributions were 53.3, 62.9, 26.7 and 27.1 pg WHO2005-TEQ m–2 month–1 in spring, summer, autumn and winter, respectively. The average Stot of total-PCDD/Fs-WHO2005-TEQ was 12300. There were obvious seasonal variations in Stot, for which the values were 13840, 6540, 8280 and 20540 in spring, summer, autumn, and winter, respectively. The average concentration of total-PCDD/Fs-WHO2005-TEQ in the rain were 0.453, 0.176, 0.218 and 0.649 pg WHO2005-TEQ L–1 in spring, summer, autumn and winter, respectively. Atmospheric deposition is the major removal pathway for PCDD/Fs. The results of this study provide an evaluation of the adverse effects of PCDD/Fs exposure on human health, and provide a reason for the government to be concerned and to enact better control on air pollution.

Air pollution was getting worse and worse with the development of economic, and atmospheric deposition was an important mechanic for the removal of air pollutants. During 2017, the average dry deposition fluxes of total-PCDD/Fs-WHO2005-TEQ in various areas in Taiwan range between 57 (Lienchiang County in autumn) and 589 pg WHO2005-TEQ m–2 month–1 (Keelung City in winter), with an average of 221 pg WHO2005-TEQ m–2 month–1. The average total deposition fluxes of total-PCDD/Fs-WHO2005-TEQ in various areas in Taiwan range between 65 (Lienchiang County in autumn) and 681 pg WHO2005-TEQ m–2 month–1 (Keelung City in winter), with an average of 263 pg WHO2005-TEQ m–2 month–1. The fractions of dry deposition fluxes contribute to the total deposition fluxes range between 37.8% (Yilan County in winter) and 99.9% (Kaohsiung City in winter), with an average of 82.1%.

In this study, the atmospheric PM2.5, increases/decreases of the PM2.5, the PM2.5/PM10 ratio, total PCDD/Fs-TEQ concentrations, PM2.5-bound total PCDD/Fs-TEQ content, and PCDD/F gas-particle partition in Taiwan were investigated for the period 2013 to 2017. In Taiwan, the annual average PM2.5 concentrations were found to be 28.9, 24.1, 21.4, 20.2, and 19.9 µg m–3 in 2013, 2014, 2015, 2016, and 2017, respectively, which indicated that the annual variations in PM2.5 levels were decreasing during the study period. The average increases (+)/decreases (–) of PM2.5 concentrations were –16.7%, –11.1%, –5.75%, and –1.73% from 2013 to 2014, from 2014 to 2015, from 2015 to 2016, and from 2016 to 2017, respectively. Based to the relationship between PM10 values and total PCDD/F concentrations obtained from previous studies, we estimated that in 2017, the annual average total PCDD/Fs-TEQ concentrations ranged between 0.0148 (Lienchiang County) and 0.0573 pg WHO2005-TEQ m–3 (Keelung City), and averaged 0.0296 pg WHO2005-TEQ m–3, while the PM2.5-bound total PCDD/Fs-TEQ content ranged from 0.302 (Kaohsiung City) to 0.911 ng WHO2005-TEQ g–1 (Keelung City), at an average of 0.572 ng WHO2005-TEQ g–1. These values are suggested to be validated in the future study because the sources and formations of PM10 and PM2.5 in different areas were diverse, and may be not closely related to combustion sources. The seasonal variations in the gas fraction of total PCDD/Fs-WHO2005-TEQ concentrations were 68.6%, 86.6%, 82.3%, and 52.3% in the spring, summer, autumn, and winter, respectively. Due to the fact that Taiwan is located mostly in the sub-tropical zone, which had annual average temperatures between 23.0 and 24.4°C, averaging 23.8°C during the study period, the majority of PCDD/Fs-TEQ were dominant in the gas phase.

The emission factor (EF), the weight of potentially toxic elements (PTEs) per unit energy or weight of sinter produced were evaluated for coal-fired boilers and sintering furnaces integrated in a steel plant. From three coal-fired boilers, 15 samples were taken while 22 samples were taken from four sintering furnaces. Investigations were performed on the EF of lead, cadmium, mercury, arsenic and chromium (VI). The coefficient of variance for the first 3 samples from each PTE was used to decide whether 2 more samples were necessary for the investigation. Three samples were sufficient for Cr (VI), however, 5 samples were required for Pb, Cd, Hg, and As, since the variances in concentrations of the first three samples exceeded 20%. The ranges for the ratio of the laboratory-based EF to the default EF applied by the Environment Protection Administration (EPA Taiwan) for Pb, Cd, Hg, and As for the coal-fired boiler were 0.08–0.013, 0.014–0.017, 0.019–0.033, 0.047–0.066 and for the sintering furnaces were 0.059–0.232, 0.05–0.151, 0.05–0.364, and 0.067–0.824. The ratio for Cr (VI)- was constant at 0.005 for all the coal fired boilers while it ranged from 0.057–0.709 for the sintering furnaces. Whilst source identification, enrichment factors, and spatial distributions for PTEs are often studied, laboratory-based investigations on the EFs for PTEs from industrial plants are rarely performed. This study filled the information gap and compared the obtained EFs with the EPA default values. To avoid overcharging industrial plants equipped with the best available technology for emission control, the EPA should apply field investigations and laboratory-based EFs instead of the default EPA EFs to calculate air pollution fees. Insights from this investigation can be applied to promote the adoption of appropriate air pollution control devices to cut down the emission of PTEs.

Fine particulate matter (PM2.5) is found as a harmful object if inhaled by people which is caused enormous health problem. It is found as high level in public facility of bus station where a lot of passengers and workers might expose to PM2.5 emission from idling diesel engine (buses). This research evaluated the restriction of idling vehicle as a control strategy of PM2.5 level in bus station by measuring the level of PM2.5 and chemical properties in both upwind and exposure sites for comparable data. The sampling work took place in weekend/weekday and before/after vehicle-idling-restriction applied. Originally, the exposure site showed 7% higher PM2.5 level, non-neutralized nitrate content, anthropogenic metal elements, and higher mobile source contribution evaluated by chemical mass balance (CMB8.2) model. After the prohibition of idling operation of heavy-duty diesel vehicles, the PM2.5 mass concentrations at exposure site were reduced close to the upwind site. Additionally, the nitrate content was reduced from background. Moreover, the contributions of several anthropogenic metals (Zn, Pb, Mn, Cu, Cr, V, Ni, and Ti) in PM2.5 were reduced, when the crustal element (Na, Mg, Al, K, and Ca) were much increased after restriction. Finally, the mobile contribution was also decreased to only 33.7–34.5%. Consequently, these finding verified the prohibition policy of idling vehicle is going well as a control strategy to manage the PM2.5 emission and local hotspot in public facility (bus station).

Today, the world’s electricity consumption is growing rapidly, and therefore energy demands are also increasing. In the past few decades, various measures have been taken to improve equipment and system design to increase production and transmission efficiency and reduce power consumption. This article proposes a novel Internet of Things (IoT)-based temperature control power extender with two working modes of cooling and heating to solve power shortages. The power is turned on or off accurately and in a timely manner through a temperature-sensing element, thereby avoiding unnecessary power consumption to achieve the goal of energy-saving. This can directly power on or off the power extender through the Internet. It can also use a 2.4G Wi-Fi wireless transmission to transmit, for example, real-time temperature information, the switch status and the master–slave mode. Related data can be controlled, collected and uploaded to the cloud. Each proposed power extender’s temperature setting in a large-scale field can be set uniformly, and no staff is wasted to set the temperature separately. Taking a general industrial electric fan as an example, if it is changed to drive with this temperature control extension cable, and assuming that the industrial electric fan is activated for 900 s per hour, its power-saving rate is 74.75%.

To understand the contributions of a raw material storage site for iron ore, coal, limestone, and sinter to ambient air fine particulate matter (PM2.5), the concentrations and chemical fingerprints for resuspended and ambient air PM2.5 were compared. Investigations were done for 15 piles of raw materials, including 5 iron piles, 5 coal piles, 3 stone piles, and a single pile each for coke and sinter. Additionally, four sites, including A, B, C, and D, in the storage site surroundings were chosen to investigate the ambient air PM2.5 concentrations. The concentrations, compositions, and i and j values for PM2.5 varied significantly by season in the four sites under investigation. The chemical fingerprints of the PM2.5 showed that water-soluble ions were the most important component in all sites. Specifically, SO42– and NO3– were the predominant water-soluble ions in winter and summer, respectively. The most dominant components in the iron ore, coal, limestone, coke, and sinter piles were iron, carbon, Ca2+ and carbon, carbon and SO42–, and Fe and Ca2+, respectively. During the summer, PM2.5 concentrations ranged from 13.7–18.0 µg m–3, where the chemical composition of water-soluble ions, metals, carbon accounted for 54.2%, 5.7%, and 23.7% respectively. During winter, the concentrations ranged from 44.7–48.0 µg m–3, where the water-soluble ions, metals, carbon components accounted for 49.2%, 8.1%, and 17.4% respectively. From the chemical mass balance, the main sources of PM2.5 in sites B, C, and D were stationary sources, mobile sources, and secondary organic aerosols. To effectively address the air pollution threat associated with the surroundings of a raw material storage site, the environmental protection agency should formulate measures to effectively reduce the contribution of resuspended dust and other pollution sources to ambient air PM2.5.

Currently, the 1st generation and 2nd generation solar water heating tanks&rsquo, design is unsatisfactory in the current use situation. When hot water is used with the hot water being consumed, thus cold water will be added into the same tank at the same time, resulting in a significant drop in the temperature of the hot water in the tank and making it necessary to use an additional electric heating rod for reheating. To address this shortcoming, a 3rd generation solar water heating tank was designed to improve the situation. In other words, a &ldquo, movable dividing disk&rdquo, is added inside the tank to completely isolate the hot water from the cold water so that the entire tank of hot water can be 100% utilized. However, when the hot water is exhausted, the 3rd generation solar water heating tank must adopt an electric heating rod to reheat the entire tank of water or make an additional small heating tank. To solve this problem, this article develops the 4th generation intelligent energy-saving solar water heating tank, in which a &ldquo, fixed dividing disk&rdquo, is installed inside the water heating tank to create a cold-water heating zone of about 10% of the total capacity for local heating. This allows for an efficient and faster hot water supply, saving about 90% of energy when the first tank of hot water is used up and a separate electric heating rod is used for heating.

Atmospheric particles are a major problem that could lead to harmful effects on human health, especially in densely populated urban areas. Chiayi is a typical city with very high population and traffic density, as well as being located at the downwind side of several pollution sources. Multiple contributors for PM2.5 (particulate matter with an aerodynamic diameter ≥2.5 μm) and ultrafine particles cause complicated air quality problems. This study focused on the inhibition of local emission sources by restricting the idling vehicles around a school area and evaluating the changes in surrounding atmospheric PM conditions. Two stationary sites were monitored, including a background site on the upwind side of the school and a campus site inside the school, to monitor the exposure level, before and after the idling prohibition. In the base condition, the PM2.5 mass concentrations were found to increase 15% from the background, whereas the nitrate (NO3−) content had a significant increase at the campus...

Dry deposition is one of the major routes by which air pollutants enter the ecosystem, and thus this study investigated the dry deposition characteristics of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and biphenyls (PCBs) in the ambient air of industrial, urban, and rural areas in southern Taiwan from November 2010 to May 2011. Average dry deposition fluxes of total PCDD/Fs and PCBs in the ambient air of four sites were 157-544 pg/m2-day (8.30-27.5 pg ITEQ/ m^2-day) and 289-1010 pg/m^2-day (0.540-1.94 pg WHO-TEQ/m^2-day), respectively. The results showed that particle phase depositions dominated the dry deposition processes for the removal of PCDD/Fs and PCBs from the atmosphere, and the atmospheric deposition flux in the cold season tended to be higher than that during the warm season. The dry deposition velocity of individual PCDD/Fs (0.031-0.546 cm/s) increased as the number of chlorinated substitutes increased, which were similar to those measured or predicted in other Asian countries. Similar patterns of dry deposition velocities were observed for individual PCBs (0.069-3.38 cm/s), due to the fact that low chlorinated PCBs are predominant in gas phase and have lower deposition velocities.

While polybrominated diphenyl ethers (PBDEs) have been used extensively for decades as flame retardants in a variety of consumer and commercial products, concerns about these substances have risen due to their adverse effects on human health. To the best of our knowledge, no study has reported on the dry deposition flux and velocity of individual PBDEs. This study was undertaken to investigate the dry deposition characteristics of PBDEs in the ambient air of southern Taiwan. The average atmospheric concentrations for total PBDEs (sum of thirty BDEs) ranged from 24.0 ± 1.83 to 102 ± 13.3 pg/Nm^3. The calculated dry deposition fluxes of total PBDEs were 13.4-60.4 ng/m^2-day, BDE 209 accounted for over 75% of the total PBDEs. The results showed that particle phase deposition dominated the dry deposition processes for PBDEs, and the same trends have been observed in other semi-volatile organic compounds (SOCs). The dry deposition velocities of individual PBDEs increased along with the number of brominated substitutes, ranging from 0.014 to 0.755 cm/s. Together with the results of the author's previous work, the deposition flux of total PBDEs could reach three orders of magnitude higher than those of PCDD/Fs (157-544 pg/m^2-day) and PCBs (89-1010 pg/m^2-day). Since atmosphere deposition is believed to be the main transfer pathway for SOCs entering food chains, its impact on human exposure to PBDEs is of great importance.

Persistent organic pollutants (POPs), including polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), polybrominated biphenyls (PBBs), and polybrominated diphenyl ethers (PBDEs), have been identified in penguins, lichens, soils, and ornithogenic soils in the Antarctic coastal environment in this study. To the best of our knowledge, no previous study has reported PBDD/F and PBB data from Antarctica. The POP mass contents in penguins were in the following order: PCBs >> PBDEs >> PCDD/Fs; PCBs were the dominant pollutants (6310-144,000 pg/g-lipid), with World Health Organization toxic equivalency values being 2-14 times higher than those of PCDD/Fs. Long-range atmospheric transport is the most primary route by which POPs travel to Antarctica; however, local sources, such as research activities and penguin colonies, also influence POP distribution in the local Antarctic environment. In penguins, the biomagnification factor (BMF) of PCBs was 61.3-3760, considerably higher than that for other POPs. According to BMF data in Adelie penguins, hydrophobic PBDE congeners were more biomagnified at log Kow > 6, and levels decreased at log Kow > 7.5 because larger molecular sizes inhibited transfer across cell membranes.

In this study, we consider congested situation and edge choosing problem simultaneously in the VRP transportation planning and this problem is called the Time Dependent Alternative Vehicle Routing Problem with Time Windows (TDAVRPTW). Given a multi- graph, the problem can be formulated into a mixed integer programming model with continuous dependent travel time functions. Numerical example shows the applicability of the model.

In this paper, we consider the exponentially weighted average codeword length introduced by Campbell as a performance measure for source codes. This criterion assumes that the cost is an exponential function of the codeword length and includes the usual expected codeword length criterion as a special case. Such situations could arise when the cost for encoding and decoding is significant, or if the buffer overflow caused by long codewords is a serious issue. Under Campbell's average codeword length criterion, we derive new upper and lower bounds on the exponentiated expected length of optimal binary prefix codes when partial information about the source symbol probabilities is available.