Sites In City Research Articles

Cultural Heritage Sites Risk Assessment and Management Using a Hybridized Technique Based on GIS and SWOT-AHP in the Ancient City of Ibb, Yemen

ABSTRACT The conservation of Cultural Heritage (CH) sites is vital for conserving a nation’s historical, architectural, and socio-cultural identity, especially in areas like Yemen, where such sites are threatened by natural hazards, urban development, and various anthropogenic activities. This study addresses these challenges by introducing a comprehensive risk assessment and management framework, with a focused case study on the ancient city of Ibb – a region with significant CH. The study employs a novel hybridized approach that combines Geographic Information Systems (GIS) with the Strength, Weakness, Opportunity, and Threat (SWOT) – Analytic Hierarchy Process (AHP) to identify thirteen critical factors influencing site suitability. These factors are classified into natural and anthropogenic categories and are systematically analyzed using GIS techniques. Additionally, the study identified and evaluated 16 SWOT factors using structured questionnaire surveys, which inform an integrated SWOT and AHP methodology. The findings revealed that the study area is mainly classified from very high to very low-risk areas, representing very high (37.2%), high (24.3%), moderate (17.7%), low (12.3%), and very low (8.5%), of the total study area, indicating that most of them are in highly hazardous environments, necessitating urgent attention and the implementation of protective measures. This study offers valuable insights and optimization strategies for safeguarding the CH sites of the ancient City of Ibb. It is particularly useful for policymakers, conservationists, and local stakeholders, providing a scalable approach that can be adapted to manage risks at other CH sites facing similar threats, thus making a significant contribution to the field of heritage risk management.

Analysis of the manufacturing craft of the painted gold foils applied on the lacquerware of the Jin Yang Western Han Dynasty tomb in Taiyuan, Shanxi, China

Seven pieces of gold foils for surface decoration of the lacquerware were excavated in the late Western Han Dynasty tomb in the area of the Jin Yang (晋阳) Ancient City site in Taiyuan (太原), Shanxi (山西), China. These gold foils portray images of the carriage, the leopard, the tigers, the ox, and the dancer with fluttering sleeves, etc., with black lines outlining the contours and red paint depicting vivid patterns. The study used Stereo Microscopes, Metallurgical Microscopy, Environmental Scanning Electron Microscopy coupled with Energy-Dispersive X-ray Spectroscopy (ESEM-EDS), and Laser Raman Spectroscopy (LRS) to analyse the thickness of the gold foils, the alloy composition, the composition of the paint and other surface attachments, and investigate the manufacturing process. As the results show, the thickness of the gold foils is about 26 μm. The composition is a gold-silver alloy with about 96% Au/(Au + Ag) (surface) and 98% Au/(Au + Ag) (cross-section). The metallurgical observation shows that the gold foils underwent heating and forging. The black lines on the front side are Chinese ink lines, with cracking and peeling phenomenon, and parallel polishing lines can be seen at the peeling places, while no polishing lines are observed on the back side. Some red paint made of cinnabar is above the black lines, and the binder is organic. Some lacquer residues are found on the back. According to the results of the study, the manufacturing process of the gold foils applied on the lacquerware is as follows: the gold foils are obtained by heating and forging, the front sides of the gold foils are polished, the shapes are carved out, and the gold foils are pasted on the lacquerware when the lacquerware’s surface is not yet dry. The gold foils are painted with black Chinese ink and red cinnabar pigment. The study’s results offer important references for understanding the manufacturing craft of the gold foils applied on the lacquerware in the late Western Han Dynasty of China and guide the conservation of the lacquerware decorated with painted gold foils.

Patient Perceptions of Illness Causes and Treatment Preferences for Obsessive-Compulsive Disorder: A Mixed-Methods Study.

Obsessive-compulsive disorder (OCD) is a condition with high patient morbidity and mortality. Research shows that eliciting patient explanations about illness causes and treatment preferences promotes cross-cultural work and engagement in health services. These topics are in the Cultural Formulation Interview (CFI), a semi-structured interview first published in DSM-5 that applies anthropological approaches within mental health services to promote person-centered care. This study focuses on the New York City site of an international multi-site study that used qualitative-quantitative mixed methods to: (1) analyze CFI transcripts with 55 adults with OCD to explore perceived illness causes and treatment preferences, and (2) explore whether past treatment experiences are related to perceptions about causes of current symptoms. The most commonly named causes were circumstantial stressors (n=16), genetics (n=12), personal psychological traits (n=9), an interaction between circumstantial stressors and participants' brains (n=6), and a non-specific brain problem (n=6). The most common treatment preferences were psychotherapy (n=42), anything (n=4), nothing (n=4), and medications (n=2). Those with a prior medication history had twice the odds of reporting a biological cause, though this was not a statistically significant difference. Our findings suggest that providers should ask patients about illness causes and treatment preferences to guide treatment choice.

Can we see differences between the 14C activities of urban (Zagreb) and rural (Cvetković) sites (central Croatia)?

Radiocarbon (Δ14C) was measured for four years (2019–2022) in Zagreb (Croatia) and in Cvetković village near Jastrebarsko (Zagreb County, Croatia) to see whether there are differences between the city site and the rural one because of the fossil fuel combustion. The δ13CCO2 was measured as grab samples once in a month in period December 2020–November 2022. The bomb-produced 14C has been globally distributed across the planet, but the combustion of fossil fuels that do not contain 14C causes a local effect of lowering Δ14C. Zagreb is considered to be a location with heavy fossil fuel combustion as compared to the Cvetković (rural site). Monthly 14C activity at Zagreb is constantly below the 14C activity at Cvetković. Mean 14C activity at Zagreb (Δ14CZagreb = −18.4 ± 2.6 ‰) is lower than that in Cvetković (Δ14CCve = −2.9 ± 2.1 ‰) due to fossil fuel combustion in the city of Zagreb. This is especially pronounced during winter when the mean value in Zagreb is Δ14CZagreb = −26.0 ± 4.3 ‰ and in Cvetković Δ14CCve = −5.9 ± 3.4 ‰.Natural gas consumption was used as the proxy for fossil fuel combustion, and it shows better correlation with Δ14C in Zagreb than in Cvetković. The Δ14C difference, Δ14CCve ‒ Δ14CZagreb, becomes statistically negligible when natural gas consumption is small.No difference is observed on δ13CCO2; in Zagreb mean δ13CCO2 is −11.0 ± 1.3 ‰, and in Cvetković −11.4 ± 1.4 ‰. Lower δ13CCO2 values are observed in winter (Zagreb −11.9 ± 1.1 ‰, −12.2 ± 1.5 ‰ Cvetković) than in summer (−10.1 ± 0.8 ‰ vs. −10.4 ± 1.0 ‰) at both locations. Together with higher Δ14C in Cvetković, it indicates that at the area of Cvetković biogenic samples of modern origin (biomass, wood) as energy source for heating is more pronounced.

Exploring new discoveries of steel fining in a Western Han Dynasty city in southwest China: A case study of steel fining remains excavated from the ancient Xindu city in Sichuan Province

AbstractArchaeological discoveries and historical documents show that the Chengdu Plain was the most important iron production center in the southwest region of China during the Qin and Han dynasties. However, due to the lack of archaeological evidence, the iron production technology of cities in the Chengdu Plain during the Qin and Han dynasties remains unclear. The Xindu city site is located in Qingbaijiang District, Chengdu Sichuan Province. It was an important city site in the Chengdu Plain during the Han and Jin dynasties. During excavation of the Xindu city site, archaeologists unearthed a large number of metallurgical remains such as slags and tuyeres, as well as two severely damaged hearth bases near the western city wall. Scientific analysis results suggest that the metallurgical remains are related to the steel fining process and could be dated back to the Western Han Dynasty. The metallurgical remains in the Xindu city are the earliest known artifacts associated with the steel fining process in southwest China. This discovery also marks the first identification of iron industry workshops in a Han Dynasty city in the Chengdu Plain. The findings reveal a different industrial layout pattern from previously discovered Han Dynasty metallurgical sites in the Chengdu Plain. Additionally, this discovery provides archaeometallurgical evidence for the central government's development in southwest China during the Han Dynasty.

Spatiotemporal variations of atmospheric mercury at urban and suburban areas in Southern Vietnam megacity: A preliminary year-round measurement study

Atmospheric mercury (Hg) pollution studies in peninsular Southeast Asia (PSEA) are currently experiencing shortage on spatiotemporal coverage due to limited observation data. Therefore, our study provided year-round (May 2022–April 2023) atmospheric Hg data at two urban and one suburban site in Ho Chi Minh City (HCMC) Vietnam - a megacity in PSEA. Higher total gaseous Hg (TGM) levels at 2 urban sites of 2.49 ± 0.86 ng m−3 (Nguyen Van Cu) and 2.12 ± 0.49 ng m−3 (Linh Trung) were observed as compared to the suburban site of 1.76 ± 0.50 ng m−3 (Can Gio) which suggests the influence of anthropogenic Hg sources. Higher TGM concentration in October 2022–January 2023 as opposed to May 2022–September 2022 at all 3 sites reflected the influence of abrupt change in air mass origins and transport pathways in southern Vietnam. Backward trajectories (BWTs) and concentration-weighted trajectory (CWT) models further suggested East Asian outflow from northeast (NE) direction as a prominent TGM source in HCMC. Our two case studies in June and December 2022 helped to distinguish the impacts of local accumulation besides long-range atmospheric Hg transport towards TGM levels in HCMC. We also attempted to address TGM public health concerns wherein a minimal hazard quotient (HQ < 1) implied insignificant Hg health risk via inhalation pathways. Our study strives to offer crucial information to fill the Hg data gap as well as seeks to explore the impact of monsoon drives on Hg pollution in the PSEA region.

Деструктивные явления при некачественном прогреве монолитных железобетонных конструкций

The growth of the number of the building floors inevitably leads to an increase in the construction period and, consequently, to the need for monolithic reinforced concrete structures in winter. Electric heating by means of heating cables is the most widespread method of concrete curing in winter conditions in the Central region of Russia. The risk of defects in monolithic reinforced concrete structures increases under certain conditions. This risk is related to various types of technological process faults. The main types of monolithic structures defects have been repeatedly described. But there are practically no papers describing the types and causes of defects associated with failures during electric heating of concrete. The author has developed a block diagram of the main defects, and the main reasons for their occurrence have been identified. The paper summarizes the experience gained during two winter periods at the construction sites of Moscow city belonging to unique buildings and structures. Operational and quality inspection of the construction was performed. The author identified groups of defect causes: cable installation and installation errors; heating regime errors. The author identified specific types of defects for each group, and also gave recommendations on their avoidance in the future. The paper provides a ‘check list’ of parameters that must be checked during electric heating with heating cables. The checklist shows the control points that minimize the risk of defects.

Plastic Analysis with a Plasmonic Nano-Gold Sensor Coated with Plastic-Binding Peptides.

Contamination with plastics of small dimensions (<1 µm) represents a health concern for many terrestrial and aquatic organisms. This study examined the use of plastic-binding peptides as a coating probe to detect various types of plastic using a plasmon nano-gold sensor. Plastic-binding peptides were selected for polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), and polystyrene (PS) based on the reported literature. Using nAu with each of these peptides to test the target plastics revealed high signal, at 525/630 nm, suggesting that the target plastic limited HCl-induced nAu aggregation. Testing with other plastics revealed some lack of specificity but the signal was always lower than that of the target plastic. This suggests that these peptides, although reacting mainly with their target plastic, show partial reactivity with the other target plastics. By using a multiple regression model, the relative levels of a given plastic could be corrected by the presence of other plastics. This approach was tested in freshwater mussels caged for 3 months at sites suspected to release plastic materials: in rainfall overflow discharges, downstream a largely populated city, and in a municipal effluent dispersion plume. The data revealed that the digestive glands of the mussels contained higher levels of PP, PE, and PET plastic particles at the rainfall overflow and downstream city sites compared to the treated municipal effluent site. This corroborated earlier findings that wastewater treatment could remove nanoparticles, at least in part. A quick and inexpensive screening test for plastic nanoparticles in biological samples with plasmonic nAu-peptides is proposed.

Complex genetic landscape revealed by a population in the eastern Tianshan Mountains of Xinjiang between the 8th and 11th centuries CE

AbstractThe eastern Tianshan Mountain (ETS) region in Xinjiang, China, has played a crucial role as a major highway for large‐scale human migrations and technological exchanges across Eurasia throughout history. Understanding the genetic makeup of past populations holds significant importance in comprehending human mobility in this region. Here, we report genome‐wide ancient DNA for the two individuals whose origins remain uncertain, found at the Dahe ancient city site in the ETS region. Our results indicate that although both individuals display a higher genetic affinity to Asian populations, one individual shows some genetic sharing with South Asians, while the other shares more affinity with populations from Northeastern Asia. Radiocarbon dating shows that the two human remains were not deposited simultaneously. Overall, the combined genetic, physical anthropology and radiocarbon evidence strongly suggests that the ETS region, situated at the heart of the Silk Road, has been a crossroads of diverse populations coexisting between the 8th and 11th centuries. Additionally, the genetic ancestry sharing with the Bronze Age Tarim mummies suggested a long‐term residual of indigenous ancestry in Xinjiang and showed that autochthonous deep Asian ancestry had left their genetic legacy into the historical populations of Xinjiang despite a spanning of over three millennia.

Site-specific probabilistic seismic hazard analysis in Nuweiba, Gulf of Aqaba, Egypt: Combining area source model and active faults

Gulf of Aqaba in Eastern Egypt is characterized by significant seismic activity and high deformation rate, making it a major source of destructive earthquakes in the region. While previous studies have produced probabilistic seismic hazard analysis (PSHA) maps for the region, they have not adequately accounted for active faults or site response in their calculations. This study introduces a newly developed seismic source model for the Gulf of Aqaba, considering area source, active fault source, and a combination of both models to improve seismic hazard assessment for the region. The study incorporates the previously measured average shear-wave velocity for the upper 30 m (Vs30), fundamental frequency (F0), and amplification factor (A0) at some selected sites in Nuweiba city. Accordingly, site-specific PSHA is carried out for the bedrock condition (Vs30 = 800 m/s, according to the Egyptian Building Code) and for the surface of soft sediments using F0, A0, and Vs30. Uncertainties in slip rate, maximum magnitude, and recurrence model are accounted during PSHA computation. Ground motion parameters such as peak ground acceleration (PGA) and spectral acceleration (SA) for various probabilities of exceedance in 50-year lifetime are calculated for both rock site conditions and soft sediments. The maximum calculated PGA and SA are 0.65 g and 1.25 g, respectively, for a 10% probability of exceedance over 50 years at bedrock conditions.

Estimation of landfill gas emissions at the solid waste disposal site of low-population regions with LandGEM and tabasaran–rettenberger mathematical models

ABSTRACT In developing countries, solid waste most commonly ultimately ends up is landfill. Landfill sites release significant amounts of air pollutants, such as methane (CH4) and carbon dioxide. It is thus important to reduce, control, and recycle these gases. In this study, we aimed to calculate gas emissions and energy production from landfill sites serving low-population areas. Future landfill gas production was estimated using LandGEM and Tabasaran – Rettenberger models, based on population and waste volume predictions. In both models, total amount of landfill gas and CH4 produced reached their highest values in 2035. According to the LandGEM model, this will amount to 11,230 and 3,179 Mg/year, respectively, while the Tabasaran – Rettenberger model predicted 14,986 and 4,014 Mg/year, respectively. The volume of landfill gas calculated using the Tabasaran – Rettenberger model was 3.730 million m3/year for 2021, while this was 2.544 million m3/year using the LandGEM model. In 2021, 84007 Mg of waste was disposed of at the landfill site. According to data from the electricity generation plant at the site, the electrical energy generated in 2021 was 5,309 kWh. Comparing the results from these two models with actual landfill data, the Tabasaran – Rettenberger model came closest to the estimate. Therefore, the Tabasaran – Rettenberger model can be used to estimate the potential for gas production at landfill sites in cities with similar waste components.

Unveiling nature’s beat: analyzing the acoustics of an aquatic bug in relation to urban sounds

Anthropophony is a prominent component of soundscapes worldwide and is known to impact biota. While responses to anthropophony in terrestrial and marine animals have been relatively well-studied, there is still a lack of knowledge regarding freshwater animals. In fact, freshwater taxa are among the possibly most threatened groups, and unveiling the reasons for their threat is crucial. We investigated the effect of low-frequency sounds -usually associated with anthropophony- on the stridulation of Krizousacorixa femorata, a common water bug in Mexico City. Using aerial recordings, we estimated the Normalized Difference Soundscape Index (NDSI), which is the most commonly used index to measure anthropophony, to characterize soundscapes in six city sites throughout the year. Additionally, from underwater recordings in the same sites, we obtained the peak frequency (Pf) of the stridulations, as it is the frequency with the highest energy and, therefore, the one that can travel the farthest and can be identified even in the presence of overlapping sounds. Finally, we evaluated the relationships between soundscapes and Pf through a mixed linear model. There was a negative correlation between NDSI and Pf, indicating higher-pitched stridulations at sites with dominant anthropophony. While we cannot rule out other factors contributing to stridulation variation, we remain uncertain about how low-frequency sounds impact freshwater ecosystems and the intricate relationship between soundscapes and aquatic life in urban settings.

Organic residue analysis of the large ceramic jars from the Han&amp;ouml;y City Site in Kashgar, Xinjiang, Northwest China

Organic residue analysis of the large ceramic jars from the Han&amp;ouml;y City Site in Kashgar, Xinjiang, Northwest China

Urbanization exacerbates climate sensitivity of eastern United States broadleaf trees.

Tree growth is a key mechanism driving carbon sequestration in forest ecosystems. Environmental conditions are important regulators of tree growth that can vary considerably between nearby urban and rural forests. For example, trees growing in cities often experience hotter and drier conditions than their rural counterparts while also being exposed to higher levels of light, pollution, and nutrient inputs. However, the extent to which these intrinsic differences in the growing conditions of trees in urban versus rural forests influence tree growth response to climate is not well known. In this study, we tested for differences in the climate sensitivity of tree growth between urban and rural forests along a latitudinal transect in the eastern United States that included Boston, Massachusetts, New York City, New York, and Baltimore, Maryland. Using dendrochronology analyses of tree cores from 55 white oak trees (Quercus alba), 55 red maple trees (Acer rubrum), and 41 red oak trees (Quercus rubra) we investigated the impacts of heat stress and water stress on the radial growth of individual trees. Across our three-city study, we found that tree growth was more closely correlated with climate stress in the cooler climate cities of Boston and New York than in Baltimore. Furthermore, heat stress was a significant hindrance to tree growth in higher latitudes while the impacts of water stress appeared to be more evenly distributed across latitudes. We also found that the growth of oak trees, but not red maple trees, in the urban sites of Boston and New York City was more adversely impacted by heat stress than their rural counterparts, but we did not see these urban-rural differences in Maryland. Trees provide a wide range of important ecosystem services and increasing tree canopy cover was typically an important component of urban sustainability strategies. In light of our findings that urbanization can influence how tree growth responds to a warming climate, we suggest that municipalities consider these interactions when developing their tree-planting palettes and when estimating the capacity of urban forests to contribute to broader sustainability goals in the future.

Source apportionment of black carbon using an advanced Aethalometer model in a typical industrial city of China

Black carbon (BC) aerosol can lead to adverse health effects and drive climate change; therefore, the characteristic research and identification of BC sources are essential for lowering emissions. In this study, equivalent black carbon (eBC) measurement was performed using a seven-wavelength Aethalometer (AE33) at an urban site in a typical industrial city (Zibo) of Northern China for the first time. The monitoring was performed from February 2021 to January 2022. The mass absorption cross-section (MAC) of AE33 was optimised using the online elemental carbon (EC) data, and eBC was corrected using the MAC. The corrected annual BC concentration was 1.72 ± 1.18 µg/m3. The diurnal variation of BC depicted a bimodal distribution. Furthermore, the BC concentration on weekends was 18 % lower than on weekdays. The diurnal variation and weekend effect reflect the critical contributions of traffic emission to BC concentration. The source apportionment of BC was calculated by a constraining Aethalometer model, which restricted the Ångström exponent using the online potassium ions. The results revealed that BC was not significantly affected by biomass burning (BCbb) in Zibo. The relative contribution of BCbb was higher in winter than in other seasons. The daily morning peak of BC was primarily influenced by traffic sources, whereas the contribution of biomass burning increased after 17:00 in the evening peak. Our findings suggest that it is more important to control fossil fuel sources for BC emission reduction in Zibo, while it is necessary to strengthen the control of biomass combustion sources in winter.

Culture optimization and regulation mechanism of sporosarcina pasteurii for restoring root splitting fissures in Jinyang ancient city

To master the culture optimization and regulation mechanism of Sporosarcina Pasteurii, this study explored the adaptability of MICP technology for restoring root splitting fissures of plants, and used single factor comparative experimental method to study the characteristics of growth curves and urease activity of Pasteurii in different conditions in earthen sites of Jinyang Ancient City. The conclusions are as follows. The technology of MICP was an ideal method for restoring root splitting fissures of plants, which could meet the requirements of restoring earthen sites by sealing surface fissures, inhibiting root growth of plants and preserving the physical morphology of damaged plant roots and stems. It was recommended to use the medium of M1, with an initial pH of 7.25, a culture temperature of 30 , inoculation age range of 12-13h, and inoculation amount of 3%. The suggestion was to select Pasteurii as restoration solution when the urease activity was at peak period. The conclusions can provide suitable breeding conditions for Pasteurii, providing an important reference for MICP technology to restore root splitting fissures of plants for earthen sites.

Mapping landscape in Longshan period’s hierarchical society (3000–2000BCE) of North Loess Plateau: from archaeological predictive model to GIS spatial analysis

On the North Loess Plateau of China, city civilization, social complexity, and stratification emerged during the Longshan period (3000-2000BCE). Based on Geographic Information System (GIS) analysis and archaeological predictive model, we conducted a comparative analysis of environmental characteristics between sites and non-sites, ordinary and walled city sites, as well as large and smaller city sites. Initially, we developed a Binary Logistic Regression (BLR) model to predict the locations of archaeological sites from this period. Our findings indicate a high predictive accuracy of the model, demonstrating a clear environmental preference by the people of the Longshan Period. The presence or absence of the site was found to be influenced by various factors, including temperature, elevation, river distance, and precipitation. Furthermore, we discovered that walled cities had higher environmental requirements compared to ordinary sites. Terrain and land use played a more significant role in shaping prehistoric cities than climate. Lastly, the landscape in the Shimao site, which served as a most crucial and largest settlement centers on the North Loess Plateau (NLP), resembled that of other minor walled cities. Due to its abundant grassland, Shimao relied more on animal husbandry rather than agriculture. The combination of agriculture and animal husbandry has promoted the urbanization processes.

Bio monitoring of toxic pollutants in air and leaves of Ficus religiosa in selected sites of Chennai city

Biomonitoring of vehicle exhaust and deposits of heavy metal on the leaves of the trees located on the roadside was carried out. The selected site Chennai metropolitan city, the capital of Tamil Nadu is a large city, hence divided the city into three sites such as North Chennai, Central Chennai and South Chennai. From these sites, we selected Ficus religiosa trees that are located alongside the roads where a greater number of vehicles pass by. We examined the atmospheric polluted gases by means of using gas sensors and the pollutants on the leaf samples from all the selected sites of Chennai city. For the present study, Ficus religiosa was chosen which belongs to the family Moraceae (the Mulberry family) to know the atmospheric air pollution in our surroundings and the heavy metals (lead, copper, nickel) deposition on the leaves of the trees through Atomic Absorption spectrometry. The ultimate aim of this work is to bio monitor and correlate the existing particulate matter present in the atmosphere and heavy metal deposition in the Ficus religiosa tree leaves of selected sites of Chennai city. The findings could be used for further studies about pollution monitoring and improve the tolerance in future.

Metagenomics analysis of water samples collected from the Yamuna River of Agra city, India.

Yamuna River water in Agra city of India is contaminated with toxic pollutants, including heavy metals that cause damage to the environment and human health. At present, the direct use of river water for drinking purposes and household activities lead to the direct exposure of society to the contaminants. In this study, Yamuna River water samples were collected from three different sites in Agra city during the monsoon, summer, and winter seasons. The physico-chemical parameters were estimated along with heavy metals. In physico-chemical parameter, the values found were mostly above the permissible limits. The results water samples contain high levels of cadmium, chromium, lead, and nickel above the desirable levels in most cases. The metagenomic analysis revealed that Proteobacteria, Bacteroidetes, Verrucomicrobia, Actinobacteria, and Planctobacteria were the most abundant phyla with a relative abundance of 61%, 9.34%, 5.23%, 4.64%, and 4.3%, respectively. The Comamonadaceae, the most abundant family consists of the genera involved in hydrogen oxidation, iron reduction, degraders of polycyclic aromatic hydrocarbons, and fermentation. The presence of Pseudomonas, Nitrosomonas sp., Thauera humireducens and Dechloromonas denitrificans (decomposition of sewage and organic matter) and Pseudomonas aeruginosa indicates the presence of heavy metal degrading bacteria in water sample. Functional prediction showed the presence of genes responsible for different metabolic pathways that could help developing new bioremediation strategies. The study concludes the status of water contamination, the presence of complex microbial community and suggests the futuristic use and their role in bioremediation.

Calibration of a passive sampling device for the determination of nitrogen dioxide in ambient air

Nitrogen dioxide (NO2), a common air pollutant, has been widely admitted to be harmful to both the environment and human health, demanding its well-control procedure and corresponding quantification. In this study, NO2 in ambient air was collected by a passive sampling method using the Willems badge diffusive sampler, followed by a derivatization step with the Griess-Saltzman solution, and analyzed by ultraviolet-visible (UV–vis) spectroscopy at 543 nm. The device can be utilized for 168 h of continuous field sampling. The experimental sampling rate (Ke) of (4.02 ± 0.29) × 10−3 m3h−1 with a relative standard deviation (% RSD) of 9.6 % was determined by conducting parallel experiments between an active sampling method (ISO 6768:1998) and the Willems samplers. After exposure time, samplers could be stored for two weeks in a refrigerator at 4 °C before analyzing. The studied passive diffusive sampler was simple, low-cost, easy to reuse; permitted determining the average concentration of NO2 in ambient air. The average NO2 concentrations for 2-hour to 4-hour sampling periods at different studied sampling sites in Ho Chi Minh city (Vietnam) were ranged from 11.5 to 189 μg m−3.