bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impacts of future scenarios on the nitrogen loss from agricultural supply chains in the Chesapeake Bay
Authors: Gomez Michael , Grady Caitlin , Wainger Lisa , Cibin Raj , Abler David , Bosch Darrell , Kaye Jason 
Published: June 2024

Abstract
Excessive nitrogen (N) pollution in the Chesapeake Bay is threatening ecological health. This study presents a multilayer N flow network model where each network layer represents a stage in the production step from raw agricultural commodities such as corn to final products such as packaged meat. We use this model to assess the impacts of alternative future agricultural production and land use changes on multiple pathways of N pollution within the Chesapeake Bay Watershed (CBW). We analyzed N loss via all pathways under multiple future scenarios, considering crop-specific projections based on empirical data and US Department of Agriculture projections. We found two model parameters, fertilizer nitrogen application rate (FNAR) and feed conversion ratio (FCR), to be particularly important for seeing measurable N loss reductions in the Bay. Our results indicate a large increase in N loss under the business-as-usual trajectory in geographic locations with intensive agricultural production. We found that numerous management scenarios including improvements in FNAR and FCR, N losses fall short of the 25% total maximum daily load targets. Our work suggests that achieving the CBW N loss reduction goals will necessitate large deviations from business as usual. Our model also highlights substantial regional variations in nitrogen loss across the U.S., with central regions like the Corn Belt and Central Valley of California experiencing the highest losses from crop-related stages, while eastern areas such as the Chesapeake Bay exhibit major losses from live animal production, underscoring the need for region-specific management strategies. Thus, implementation of effective N management strategies, combined with improved crop residue management, remains pivotal in mitigating N pollution in the Chesapeake Bay.
Stability analysis of a stochastic port-Hamiltonian car-following model
Authors: Rüdiger Barbara , Tordeux Antoine , Ugurcan Baris E 
Published: June 2024

Abstract
Port-Hamiltonian systems are pertinent representations of many nonlinear physical systems. In this study, we formulate and analyse a general class of stochastic car-following models with a systematic port-Hamiltonian structure. The model class is a generalisation of classical car-following approaches, including the optimal velocity model of Bando et al (1995 Phys. Rev. E 51 1035), the full velocity difference model of Jiang et al (2001 Phys. Rev. E 64 017101), and recent stochastic following models based on the Ornstein–Uhlenbeck process. In contrast to traditional models where the interaction is totally asymmetric (i.e. depending only on the speed and distance to the predecessor), the port-Hamiltonian car-following model also depends on the distance to the follower. We determine the exact stability condition of the finite system with N vehicles and periodic boundaries. The stable system is ergodic with a unique Gaussian invariant measure. Other properties of the model are studied using numerical simulation. It turns out that the Hamiltonian component improves the flow stability and reduces the total energy in the system. Furthermore, it prevents the problematic formation of stop-and-go waves with oscillatory dynamics, even in the presence of stochastic perturbations.
Large sampling intervals for learning and predicting chaotic systems with reservoir computing
Authors: Xie Qingyan , Yan Zixiang , Zhao Hui , Gao Jian , Xiao Jinghua 
Published: June 2024

Abstract
Reservoir computing (RC) is an efficient artificial neural network for model-free prediction and analysis of dynamical systems time series. As a data-based method, the capacity of RC is strongly affected by the time sampling interval of training data. In this paper, taking Lorenz system as an example, we explore the influence of this sampling interval on the performance of RC in predicting chaotic sequences. When the sampling interval increases, the prediction capacity of RC is first enhanced then weakened, presenting a bell-shaped curve. By slightly revising the calculation method of the output matrix, the prediction performance of RC with small sampling interval can be improved. Furthermore, RC can learn and reproduce the state of chaotic system with a large time interval, which is almost five times larger than that of the classic fourth-order Runge–Kutta method. Our results show the capacity of RC in the applications where the time sampling intervals are constrained and laid the foundation for building a fast algorithm with larger time iteration steps.
Locate hyperbolas on Ground Penetrating Radar slices with auto filter selection algorithm
Authors: Tam N H , Trung Đ H , Van N T 
Published: June 2024

Abstract
Ground Penetrating Radar (GPR) is a geophysical method of using high frequency electromagnetic waves to study shallow objects below the ground. In the GPR sections, the position of point anomalies is represented as reflected hyperbola. In some cases, the reflected hyperbolas on the GPR cross-section have a relatively large number and overlap which making the positioning very complicated and time-consuming. This article presents the development of an automatic selection algorithm with the aim of accurately determining the position of hyperbolas on GPR cross-sections. The automatic selection algorithm is a combination of an edge detection algorithm and the establishment of filtering conditions based on image and physical properties of geological objects. The algorithm is applied to determine the hyperbolic position of several GPR cross-sections at specific locations and provides relatively accurate results. This result will enhance the accuracy in problems related to drawing tree root maps, underground construction, landslide surveys, subsidence, and soil pollution research.
Groundwater geochemistry and hydro-geochemical processes in coastal area South Phan Thiet, Binh Thuan Province, Vietnam
Authors: Luyen N T T , Van L T T , Thien N M , Tien N B B , Tuan L H , Du N H , Dung N T 
Published: June 2024

Abstract
As one of the largest dragon fruit areas and many tourism projects, the southern coastal area of Phan Thiet (including three communes: Tien Thanh, Thuan Quy, and Tan Thanh) has been a bright spot in the economy of Binh Thuan. Economic development puts pressure on water resources, especially groundwater resources, the main supply for irrigation and domestic water in the region. In this research, 19 groundwater samples from the Holocene and Pleistocene aquifers were collected in February 2023 and analyzed for the concentration of Ca2+, Mg2+, Na+, K+, NH4
+, NO3
−, PO4
3-, Cl−, HCO3
–, and SO4
2-, thereby evaluating groundwater geochemistry, hydro-geochemical processes, and the suitability for irrigation purposes. The rank of cations in the aquifers of the region is Na+ > Ca2+ ∼ Mg2+, and Ca2+ ∼ Mg2+ > Na+ respectively. The concentrations of major anions in the study area are in order Cl− > HCO3
− > SO4
2- respectively. The predominant processes in the aquifer involve the interplay between rock and water as well as anthropogenic activity. The saturation indices of dolomite, gypsum, and halite are under-saturated in all collecting sample sites. According to the quality evaluation for irrigation, 14 of the 19 samples with % sodium levels less than 60 are suitable, while the others should be treated before use. The study area also indicated nitrate pollution (4/19 groundwater samples exceeding 15 mgN L−1 of the Nitrate limited for groundwater, National technical regulation on underground water quality). It is recommended that local authorities have strategies to supply water for different purposes, control pollution sources, and treat water waste to protect these aquifers.
Analysis of bed changes in the segment of the Tien river flowing through Tan Chau
Authors: Kim Tran Thi , Huy Nguyen Dam Quoc , Phung Nguyen Ky , Nga Tra Nguyen Quynh , Bay Nguyen Thi 
Published: June 2024

Abstract
The segment of the Tien River flowing through Tan Chau town is a meandering section with complex flow patterns, influenced by the flow dynamics and the lack of upstream sediment supply. This has resulted in the formation of deep erosional channels that affect the bank stability. This study focuses on evaluating the bed change of the Tien River within Tan Chau town through the analysis of measurement data and some scenarios from numerical modeling. The findings reveal that the Tan Chau - Hong Ngu curved section experiences severe channel erosion, particularly concentrated in the topographic channel and inclined towards the concave bank of Tan Chau (the inner bank). An analysis of causative factors indicates that reduced sediment supply due to dam construction and sand mining activities have led to changes in the riverbed, deeper erosion, and bank erosion near the sand mining area. The results quantifies the sediment deficit in the area at 0.86%, while the impact of sand mining in this area is 0.26%. The findings from this research provide a database to support local planning for bank protection projects and disaster mitigation measures due to bank erosion.
Erosion - accretion study in Cua Lo area, Nui Thanh district, Quang Nam province
Authors: Quy Ngo Tran Thien , Trung Pham Ba , Khin Lau Va 
Published: June 2024

Abstract
Cua Lo, Nui Thanh district, Quang Nam province is an estuary that plays an important role in the province’s socio-economic development. This area is often greatly influenced by natural processes, which have changed the topography of the beach, the shoreline and seabed topography. The seabed topography in Cua Lo areas is being gradually accreted and filled, but the erosion process is strongly occurring in the southern coastal. These processes have happened every year and are getting more and more serious, causing great damage to property and people. By using remote sensing images and combining them with survey data, it is possible to evaluate the changes of the Cua Lo area on a large scale and for a long period. The north bank of Cua Lo has strong sedimentation to the south, with the area being accreted being approximately 19.86 hectares (2010-2014) and 13.64 hectares (2018-2023). The southern of Cua Lo, the shoreline that has been seriously eroded at a rate of 45-50m/year. From the research results, the preliminary determination of the main law of change is the southward movement of the seabed topography.
The proposal of geotourism program in Ho Chi Minh City
Authors: Khanh Le Ngoc Phuong , Hai Ha Quang , Nam Nguyen Thi Que 
Published: June 2024

Abstract
Ho Chi Minh City can be considered as a famous destination of Vietnam attracting millions of visitors per year with varieties of tourist products. Also, many tourist places contain specific geology features which are essential factors for geotourism; however, this field of tourism is ignored these days. “The proposal of geotourism program in Ho Chi Minh” aimed to create geotourism strategy in Ho Chi Minh City with 4 journeys, including: 1) The journey to the North; 2) The journey to the South; 3) The journey to the West; 4) The journey to rewind the clock. It is worth noting that all proposal journeys were based on Reynard’s geo-product system including original offers and derived offers. The original offers contained the destinations having specific geology characteristics. The derived offers consisted of 9 groups: 1) Geo-Info; 2) Geo-routes; 3) Geo-activities; 4) Geo-academics; 5) Geo-houses; 6) Geo-gifts; 7) Geo-cuisine; 8) Geo-festival; 9) Geo-farms. This geotourism proposal’s purposes were raising geology consciousness, creating the diversity of tourist products, and increasing income for the locals.
The level of nitrate and nitrite in some fruits available in the local markets in District 7, Ho Chi Minh City, Vietnam
Authors: Dung T T T , Nhan D T , Chau T B 
Published: June 2024

Abstract
Nitrate and nitrite are main contaminants in fruits that must be controlled due to their potential adverse health effects on humans. The objectives of this study were to analyze levels of nitrate and nitrite in some selected fruits in local markets in District 7, Ho Chi Minh City, and to determine whether estimated dietary exposure to nitrate and nitrite poses a risk to human health. Mango, banana, tomato, and cucumber were collected and tested. Nitrate levels varied widely, ranging from 89 mg/kg to 1104 mg/kg across different fruits. Mango had the highest average nitrate level (588 mg/kg), while tomato had the lowest (109 mg/kg). Nitrite levels in fruits were significantly lower than nitrate levels, ranging from 0.090 mg/kg to 2.60 mg/kg. Mango had the highest average nitrite level (0.77 mg/kg), and cucumber had the lowest (0.01 mg/kg). The nitrate and nitrite health risk quotient (RQ) was within acceptable limits, indicating that nitrate and nitrite intake from fruit consumption poses no health risk to the local population. When the endogenous process of nitrate to nitrite transformation was considered, the EDI of nitrite increased significantly compared to the original calculation, but the result remained within the acceptable limit.
Evaluation of the optimum conditions of an anaerobic Down-flow Stationary Fixed Film reactor for swine wastewater treatment
Authors: Phan N N , Duong Y H , Tran K T , Bui H M , Ngo T T 
Published: June 2024

Abstract
The Down-flow Stationary Fixed Film (DSFF) reactor is a downstream anaerobic reactor combined with a fixed layer of adhesive media that is capable of handling large organic loads, has cheap investment costs, and has a shorter treatment time than other conventional anaerobic technologies. In this study, the DSFF reactor was used to investigate its potential to remove contaminants from swine wastewater. The optimal operating conditions of the DSFF reactor including hydraulic retention time (HRT), organic concentration, and nutrient ratio were investigated. The obtained results showed that the COD removal efficiency increased from 50% to 79.721% when the influent COD enhanced from 500 to 3000 mg/L. The COD removal efficiency was 85.66%, 61.71% and 50.81% at three different nutritional ratios of C/N/P:250/1.5/1, C/N/P:250/7.5/1, and C/N/P:250/7.5/0.2, respectively. The overall results revealed that the optimal HRT is 12 hours, the optimal COD concentration is between 2000 mg/L and 3000 mg/L, and the optimal nutrient ratio is C/N/P:250/1.5/1. The DSFF reactor effectively manages BOD and phosphorus removal while handling a range of contamination levels in swine wastewater. Furthermore, there is no significant sludge loss and the operation mode is simple. This reactor is potentially appropriate for implementation in pig farming households.
Filling up the water quality database to assess the water quality levels and self-cleaning capacities
Authors: Bui H V , Pham H T , Pham H V 
Published: June 2024

Abstract
The one of water resource’s functions is the self-renewable capacity about quality, quantity and energy. To assess the level or fluctuat trend of water resource functions, a complete set of continuous and representative data is needed. The water quality monitoring of environment management is implementing continuous in Ho Chi Minh City. Because of many causes, the water quality data set is asynchronous by years and observation locations. It causes the many difficulties to researches, studies as the assessment of water’s self-cleaning capacity. With the support of two interpolations equations (the Highest order polynomial fitting Curve Function (HopCEF) and Multivariable Regression Correlative Function (MrCEF)) and GIS tool, the water quality and self-cleaning capacity distributions are zoned/mapped with the fully and continuously data set. The research of water quality and self-cleaning capacity is implemented with the filled quality data set period 2012 – 2022 for urban inner canal system in HCMC. Based on the assessment’s results and the mapped distribution of levels, the fluctuations the quality and self-cleaning capacity of inner canal system are made high visualization. And they are a valuable basis for planning and decision making on the solutions of management agencies in HCMC.
Evaluation of surface water quality and carrying capacity as planned by 2030 in the Lai Giang River basin, Binh Dinh Province, Vietnam
Authors: Nguyen A H , Vu N V 
Published: June 2024

Abstract
The quality of surface water in the river basin under the influence of industrial development and urbanization is one of the issues that need attention in the management of water resources in Binh Dinh province. The study assessed water quality in the Lai Giang river basin gives an overview of the surface water quality situation and predicts future changes in wastewater reception through the 2030 planning scenario. The study corrected the NAM model flow at An Hoa hydrological station with R2 = 0.777 and BIAS = 5%. The results of adjustment of water level and flow in 2016 for R2 are 0.893 and 0.731, respectively. The test of water level and flow in 2017 for R2 is 0.882 and 0.582 respectively, along with the test result of water level in 2021 is 0.689. The calculation of the current carrying capacity in 2021 and the planning scenario in 2030 shows that there is still capability to receive, but consideration should be given to rational use of water resources.
Changes in water balance across climate zones of Vietnam over the past four decades
Authors: Xuan Do Hong , Le Tu Hoang 
Published: June 2024

Abstract
In a warming climate, it is important to understand the characteristics and changes in major components of the water balance. This information is crucial to countries spanning over multiple climate zones such as Vietnam, as such understanding will ensure new water policies are designed and implemented appropriately to support sustainable development. Long-term observations of the major components of the water cycle (i.e., precipitation, evapotranspiration, and runoff), however, are usually unavailable for many regions of the world, including Vietnam, making it challenging to obtain a holistic perspective on large-scale features of water resources. To address this challenge, this study selected seven catchments of Vietnam that have varying climate characteristics (each represents a climate zone of Vietnam) and developed a hydrological model for each of the assessed catchments. The models showed satisfactory performance (the Nash-Sutcliffe efficiency ranges from 0.53 to 0.9 and a percentage bias ranging from -15.1 to 19.4) and were able to reproduce the heterogeneous pattern of hydro-climate conditions across Vietnam. Long-term changes (from 1980 to 2019) in simulated water balance components were then assessed to provide a new perspective on changes in the water cycle across Vietnam in the last four decades.
Identifying impervious surface hot spots in Ho Chi Minh City using object-based classification and spatial statistics
Authors: Nguyen Ngoc Tuyen , Nguyen Nhu Ngoc , Pham Chi Cuong 
Published: June 2024

Abstract
Impervious surface is often a primary indicator for urbanization. The rapid expansion of impervious surface area (ISA) can lead to a variety of environmental issues such as the change in local climate, urban heat islands, urban flooding, biodiversity loss, and the depletion of air quality. In this paper, satellite data from Landsat 5 TM, Landsat 8 OLI, and Sentinel-2 were employed to extract impervious areas in Ho Chi Minh City (HCMC) from 2009 to 2022 by integrating the object-based image analysis and Kernel density estimation method. Regarding spatial analysis, optimized hot spot analysis (OHSA) and emerging hot spot analysis (EHSA) were used to detect specific spatial distribution and spatio-temporal changes of ISA hot spots over the 12 years. Study results show the hot spots of ISA with 99% confidence interval increased considerably from 28,625 ha in 2009 to 44,400 ha in 2022. Through emerging hot spot analysis, many kinds of ISA hot spots including persistent, new, intensifying, sporadic, and potential hot spots were traced over time. New hot spots had a total area of 14,975 ha, located mainly in Cu Chi, Thu Duc city, whereas potential hot spots, which are likely to become new hot spots in the future, were over 28,000 ha, making up 19% of the study area. Thus, the results from this study can provide a preliminary prediction of ISA distribution for HCMC in the coming years.
Possibility Of Using Sonneratia Caseolaris (L.) Engl) In the Aquaponic Model with White Shrimp combined with Tilapia
Authors: Quoc Dao Phu , Anh Tran Phuong , Trang Le Thi , Trinh Phan Thi Hoai , Mui Ho To Thi Khai 
Published: June 2024

Abstract
The Aquaponic system has been widely implemented in various locations, primarily in freshwater environments, requiring adaptation to be compatible with saltwater ecosystems. The objective of this research is to explore the wastewater treatment capability of the Sonneratia caseolaris in a saltwater environment when applied to a recirculating aquaponic model for white-leg shrimp cultivation. The investigative process involves cultivation and determination of the water treatment coefficient of the Sonneratia caseolaris. The environmental parameters under scrutiny include NH4
+, NO2
−, NO3
−, and total phosphorus per gram of plant biomass. Phase 1 consists of seedling production and model design; when the plants reach three months old, they will be tested with shrimp wastewater to assess their treatment capabilities. The results will provide parameters for operating the model in Phase 2. In Phase 2, the aquaponic model involves shrimp tanks (300 shrimp/1 m3), fish tanks (50 fish/0.5 m3), and the plant’s cultivation system. In Phase 1, the plant demonstrated treatment efficiencies of 90% for NH4
+, 95% for NO2-, 32% for NO3
−, and 27% for total phosphorus after 7 days. The treatment coefficients achieved were as follows (mg/g plants biomass): NH4
+: 0.006, NO2
− 0.005, NO3
− 0.017, total phosphorus: 0.057. Transitioning to Phase 2, the results confirm that the aquaponic model, incorporating Sonneratia caseolaris for water recirculation in shrimp farming, is not only technically feasible for small-scale aquaponic models but also scalable for large-scale farm production. Furthermore, the leaves and fruits of Sonneratia caseolaris can serve as a supplementary herbal source for aquaculture species, enhancing the economic sustainability of the recirculating model.
Assessment of Some Factors Affecting the Choice of Eco-Tourism Destination in Con Dao, Ba Ria -Vung Tau Province
Authors: Dung Pham Thuy 
Published: June 2024

Abstract
The study aims to assess the effect of a number of factors on the decision to choose a destination in order to propose some solutions to attract domestic tourists to ecotourism in Con Dao. The research model includes one dependent variable of the decision to choose the destination with five independent variables which are the factors affecting the decision to choose the destination. Study outcome was that the effect of factors on tourists’ decision to choose a tourist destination is Motivation (0.323); Quality of Service (0.243); Tourism resources (0.235); Experience of tourism (0.104) and Communication (0.095). A number of solutions proposed to attract domestic tourists to Con Dao, namely preserving the natural landscape; embellishing and upgrading historical and cultural relics; improving and upgrading tourism services; strengthening the dissemination of information about Con Dao’s eco-tourism resources; improving the professionalism of staff, and diversifying tourism services.