MULTIMEDIA MONITORING OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHs) IN A LARGE INDUSTRIAL CITY: PHASE DISTRIBUTION AND EMISSION SOURCE IDENTIFICATION

Department of Urban and Environmental Engineering (Environmental Science and Engineering)Ulsan is one of the largest industrial cities of South Korea and has several main industrial areas, including petrochemical, non-ferrous, shipbuilding, and automobile complexes. These industrial activities contribute to the need for monitoring of pollutants, especially the polycyclic aromatic hydrocarbons (PAHs), in Ulsan since the petrochemical and non-ferrous industrial activities are believed to be one of the important emission sources of PAHs. This dissertation aims to investigate PAHs (i.e., concentrations, profiles, phase distribution, and exchange) in the multimedia environment of Ulsan, including the air, soils, overland runoff, and surface water. Moreover, types (e.g., coal combustion and biomass burning) and areas (i.e., local and regional areas) of the PAH emission sources were also identified. The diagnostic ratios, principal component analysis (PCA), and positive matrix factorization (PMF) were used to identify the emission source types. The emission source areas of PAHs were identified using hybrid receptor models and conditional bivariate probability function. Moreover, the fugacity approach and Whitman???s two-film model were applied to investigate the multimedia exchange of PAHs between the air-water and air-soil. Regarding the atmospheric PAHs, winter and spring had the highest and lowest PAH concentrations, respectively. Fractions of the gaseous or 3- and 4-ring PAHs were high in summer, and those of the particulate or 5- and 6-ring PAHs increased in winter. For the seasonal emission sources of PAHs, pyrogenic (e.g., coal combustion) source was dominant in winter. Other types of the pyrogenic (e.g., industrial fuel combustion) and petrogenic sources were the main PAH sources in summer and fall. In spring, two types of the pyrogenic sources, diesel and coal combustion, were identified as the main PAH sources in this season. Regarding the areas of emission sources, the particulate PAHs in Ulsan could be more affected by distant sources in the spring and winter, such as long-range transport from northeastern China (e.g., Beijing, Tianjin, and Hebei), northern China (e.g., Jilin and Liaoning), and North Korea. In contrast, the gaseous PAHs were affected by local emissions (i.e., industrial and vehicle emissions) mostly throughout the year. Particularly, in summer and fall, the local emission sources could more affect the gaseous and particulate PAHs compared to the outside sources (i.e., trans-boundary transport from China). However, the opposite trend was observed in spring and winter, that is, PAHs originated from northeastern China, northern China, and North Korea could contribute to those in Ulsan. The PAHs in other environmental media (i.e., overland runoff, surface water, and soils) of Ulsan were also studied to understand the interaction of PAHs in the air to those in the other media. For PAHs in the runoff and surface water, the runoff PAHs reached their highest concentrations in April (middle spring), which could be strongly affected by meteorological conditions before the sampling events (i.e., the long dry period and the lower rainfall amount). Moreover, the contributions of the dissolved PAHs were mostly higher than those of particulate ones, especially in July (summer) when the higher water temperature could lead to the desorption of PAHs from the particulate to the dissolved phase. Regarding the source identification, PAHs in the runoff and surface water could share similar emission sources, which were mixed sources from both petrogenic and pyrolysis sources. Additionally, the PAHs in the runoff of July could be also originated from coal/coke/heavy oil combustion as a result of industrial emissions and local advection. Regarding the multimedia exchange, the surface water could be a source for most of the atmospheric PAHs in Ulsan. However, the contribution of the water to the atmospheric PAHs (i.e., volatilization from the water to the air) could be not important. The soil could be a source or a sink of the atmospheric PAHs, mostly depending on the molecular weights of the compounds (i.e., a source for 3-ring PAHs and a sink for 4-ring species). Additionally, the PAHs in Ulsan mostly distributed in the soil, followed by the air, and the surface water. The highest distributions of PAHs in the soil could be because of their strong affinity to the soil organic matter, leading to their accumulation in the soil. The PAHs secondly distributed in the air, however, the atmospheric PAHs in Ulsan should be concerned due to the effect of trans-boundary transport and local advection from the industrial complexes. Overall, this dissertation can contribute to the understanding of PAHs in the multimedia environment, including the air, overland runoff, surface water, and soils, and can support the decision-making related to the environmental issues in Ulsan. Based on this dissertation, further studies should more focus on other PAH compounds, such as oxygenated and halogenated PAHs, in the air and soil of Ulsan. Moreover, trans-boundary transport of PAHs and other organic compounds should be further studied to more understand the effect of long-range transport on air pollution in Ulsan.clos

Quality Assurance of Higher Education in Vietnam: The Impact of Autonomy Policy

The autonomous university model is recognized as a method of advanced university governance to improve training quality . In Vietnam, university autonomy has made many positive changes in training quality in recent years. This study examines if there is a difference in the QA activities of academic programs between two types of higher education institutions: the public universities with financial autonomy and the public universities without financial autonomy. A quantitative method was used to analyze the survey data from 593 participants. An independent T-test was used to analyze the differences between the two types of institutions. The results indicated statistical differences in most activities in seven research areas. The quantitative result provided strong evidence of the impact of autonomy policy on two types of higher education institutions, which was not addressed in the national report on autonomy policy in 2022. Some recommendations were made to improve the QA activities toward continuous quality improvement

Quantifying antimicrobial access and usage for paediatric diarrhoeal disease in an urban community setting in Asia.

OBJECTIVES: Antimicrobial-resistant infections are a major global health issue. Ease of antimicrobial access in developing countries is proposed to be a key driver of the antimicrobial resistance (AMR) epidemic despite a lack of community antimicrobial usage data. METHODS: Using a mixed-methods approach (geospatial mapping, simulated clients, healthcare utilization, longitudinal cohort) we assessed antimicrobial access in the community and quantified antimicrobial usage for childhood diarrhoea in an urban Vietnamese setting. RESULTS: The study area had a pharmacy density of 15.7 pharmacies/km2 (a pharmacy for every 1316 people). Using a simulated client method at pharmacies within the area, we found that 8% (3/37) and 22% (8/37) of outlets sold antimicrobials for paediatric watery and mucoid diarrhoea, respectively. However, despite ease of pharmacy access, the majority of caregivers would choose to take their child to a healthcare facility, with 81% (319/396) and 88% (347/396) of responders selecting a specialized hospital as one of their top three preferences when seeking treatment for watery and mucoid diarrhoea, respectively. We calculated that at least 19% (2688/14427) of diarrhoea episodes in those aged 1 to <5 years would receive an antimicrobial annually; however, antimicrobial usage was almost 10 times greater in hospitals than in the community. CONCLUSIONS: Our data question the impact of community antimicrobial usage on AMR and highlight the need for better education and guidelines for all professionals with the authority to prescribe antimicrobials

Gas/particle partitioning and health risk assessment of atmospheric Polycyclic Aromatic Hydrocarbons (PAHs) at a residential area in Ulsan

?????? ?????? ???????????? ????????? ?????????????????? ??? ???????????????????????????(Polycyclic Aromatic Hydrocarbons: PAHs)??? ?????? ???????????? ?????????????????? ?????? ????????????, ???????????? ??????????????? ????????????. ?????? ??? PAHs??? ??????-?????? ???????????? ????????? ?????? ???????????? ?????????, ???????????? ?????? ??????????????? ????????? ????????? ??????. ??????, ????????? ?????? ??? ???????????? ????????? ????????? ?????? ?????? ?????? ????????? ????????? ???????????? ??????. ??? ??????????????? 9??????(2014??? 12??????2015??? 8???) ?????? ??????????????? ????????? ???????????????????????????????????? ???????????? ????????????????????????????????? ???????????? ???????????? ????????? ????????? ???????????????. ????????? ???????????? ???????????? ?????? ????????????, ???????????????????????????/?????????????????? 21??? PAHs??? ???????????????. ??????-?????? ???????????? ????????? ??????, ??????????????? 5, 6?????? ????????? PAHs?????? ????????? ????????? ?????????. ??????, ????????? ????????? ????????? ??????????????? ?????? ????????? ?????????. ??? ????????? ????????? ?????? ????????? ?????? PAHs??? ???????????? ??? ?????? ????????????, ????????? ????????? ?????? ????????? ????????? ????????? ????????? ??? ??????. ??????????????? ????????? ?????? ?????? ??? ?????? ??????, ?????? ??????, ????????? ?????? ?????? ?????? ???????????? ????????? ????????? ???????????????

Spatial distributions and risk assessment of PCDD/Fs, PCBs, and PCNs in soil collected from South Korea

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and polychlorinated naphthalenes (PCNs) are three groups of structurally similar POPs. Among these POPs, 17 PCDD/Fs and 12 dioxin-like PCBs (dl-PCBs) have been investigated more widely due to their high toxicity to biota and humans. Several PCNs could have similar toxicity to PCDD/Fs and dl-PCBs. The Korean Ministry of Environment has conducted annually nationwide monitoring of them in soil since 2008. In this study, soil samples at 61 national POPs monitoring stations in suburban, urban, and industrial areas were collected. After Soxhlet extraction and cleanup using multi-layer silica gel column, the pollutants were analyzed using GC/HRMS. The mean TEQ concentrations of PCDD/Fs, PCBs, and PCNs (3.25??4.40, 0.42??0.83, and 0.08??0.13 TEQ pg/g, respectively) in the industrial area were higher than those in the other areas. The sum of TEQ concentrations (PCDD/Fs+PCBs+PCNs) in some industrial stations (Banwol, Incheon, and Ulsan, Yeochun, and Pohang) were higher than those of the soil quality guideline from Canada (4 pg TEQ/g). Health risk assessments through ingestion, dermal contact, and inhalation intake were also performed using Korean data. As a result, cancer risks via the ingestion intake were higher than those from the others. The total cancer risks in the industrial area (mean: 3.34??10-7 for children and 3.07??10-7 for adults) were higher than those in other areas. However, cancer risks from the soil samples of South Korea were not exceeded the carcinogenic bench mark level described by US-EPA (1??10-6), suggesting the safe level

Nanosilica synthesis and application for lead treatment in water

Lead is a naturally occurring element that has high atomic weight (207u) and density (11.3 g/cm3). Their multiple industrial, domestic, agricultural, medical and technological applications have led to their wide distribution in the environment, raising concerns over their potential effects on human health and the environment. At present, extensive application of nanosilica in environmental pollution treatment has led to the development of silica extraction methodologies out of various chemical and waste products. In this study, nanosilica is synthesized by sol-gel method from tetraethoxysilane (TEOS) with base catalysts and volumetric ratio TEOS/C2H5OH/H2O/NH4OH: 5/30/1/1 and identified characteristics by some modern techniques such as Energy-dispersive Xray spectroscopy (EDX), Fourrier Transformation Infrared (FTIR) and X-ray diffraction (XRD), Scanning electron micrograph (SEM), field emission scanning electron microscopy (FESEM). The results showed that the prepared SiO2 nanoparticles were amorphous phase with the average size about 60-100 nm and can be used as an immediately utilization for lead treatment. At the pH of 5, shaking within 1 hours with speed 150rpm/min, lead treatment efficiency is 96.17% for initial Pb2+ concentration 10 mgPb2+/L. Maximum adsorption concentration Qmax = 30.3mg/g, and adsorbent and adsorbate constant b = 0.868 L/g. Therefore, extracted nanosilica from TEOS has high lead treatment efficiency. In addition, synthesis nanosilica from rice husk with similar characteristics is a new research approach to improve application and economic value of the material.Chì là nguyên tố tự nhiên có khối lượng nguyên tử cao(207 đvC), tỉ trọng lớn (11,3 g/cm3) và được ứng dụng phổ biến trong công nghiệp, nông nghiệp, sinh hoạt, y tế và công nghệ. Việc sử dụng rộng rãi chì trong nhiều lĩnh vực làm tăng mối quan ngại về tác động tiềm tàng của chúng đối tới sức khỏe con người và môi trường. Hiện nay việc áp dụng rộng rãi nanosilica vào xử lí ô nhiễm môi trường đã và đang dẫn đến sự phát triển của các phương pháp tách chiết silica từ hóa chất và các phế phụ phẩm. Trong nghiên cứu này, nanosilica được tổng hợp bằng phương pháp sol-gel từ tetraetoxysilan (TEOS) với xúc tác bazo theo tỷ lệ thể tích TEOS/C2H5OH/H2O/NH4OH là 5/30/1/1 và xác định các đặc tính bằng một số kỹ thuật hiện đại như phổ tán sắc năng lượng tia X (EDX), quang phổ hồng ngoại (FTIR) và nhiễu xạ tia X (XRD), kính hiển vi điện tử quét (SEM), kính hiển vi điện tử quét phát xạ trường (FESEM). Kết quả cho thấy các hạt nano SiO2 tách chiết được có pha vô định hình với kích thước trung bình khoảng 60-100 nm và được sử dụng trực tiếp cho xử lí chì. Tại điều kiện pH=5, lắc trong 1 giờ với tốc độ 150 vòng/phút, hiệu quả xử lý chì đạt 96,17% đối với nước nhiễm kim loại chì có nồng độ ban đầu là 10mgPb2+/L. Lượng hấp phụ cực đại Qmax = 30,3mg/g; hằng số đặc trưng của chất hấp phụ và chất bị hấp phụ b = 0,868L/g. Như vậy, hiệu quả xử lý kim loại chì của vật liệu nano silica được tổng hợp từ TEOS là rất cao. Bên cạnh đó, nghiên cứu chế tạo nanosilica từ vỏ trấu với các đặc tính tương tự là một hướng đi mới giúp nâng cao tính ứng dụng và giá trị kinh tế của vật liệu

Peptide Fraction pOh2 Exerts Antiadipogenic Activity through Inhibition of C/EBP-α and PPAR-γ Expression in 3T3-L1 Adipocytes

Many studies have comprehensively examined the venom of Ophiophagus hannah snake. Its venom comprises different compounds exhibiting a wide range of pharmacological activities. In this investigation, four peptide fractions (PFs), ranging from 3 kDa to 10 kDa, isolated from the Vietnamese snake venom of O. hannah were separated by HPLC and investigated for their inhibitory activity on adipogenesis in 3T3-L1 adipocytes. The most effective PF was then further purified, generating two peptides, pOh1 and pOh2. Upon investigation of these two peptides on 3T3-L1 adipocytes, it was revealed that, at 10 μg/mL, pOh2 was able to inhibit the lipid accumulation in 3T3-L1 adipocytes by up to 56%, without affecting cell viability. Furthermore, the pOh2 downregulated the gene expression of important transcription factors C/EBP-α and PPAR-γ. In addition, aP2 and GPDH adipocyte-specific markers were also significantly reduced compared to untreated differentiated cells. Taken together, pOh2 inhibited the expression of key transcription factors C/EBP-α and PPAR-γ and their target genes, aP2 and GPDH, thereby blocking the adipocyte differentiation. In conclusion, this novel class of peptide might have potential for in vivo antiobesity effects