bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Bifurcation Analysis and Persistence of the Food Chain Ecological Model with Toxicant
Authors: Majeed Azhar Abbas , Kadhim Atheer Jawad 
Published: March 2021

Abstract
In this work, the occurrence conditions of both local Bifurcation and persistence were studied, Saddle-node bifurcation appears near fourth point, near the first point, the second point and the third point a transcritical bifurcation occurred but no pitchfork bifurcation happened near any of the four equilibrium points. In addition to study conditions for Hopf-bifurcation near positive stable point that is the fourth point. Besides discuss persistence occurrence as globally property of the food chain of three species include prey, first predator and top predator with impact of toxin in all species and harvesting effect on the predator’s only. Numerical results for the set of hypothetical of parameters come to confirm our analytical results about illustration the occurrence of local bifurcation and persistence of this model.
A Systematic Review of Data Aggregation Techniques in Wireless Sensor Networks
Authors: Idan Saeedi Iman Dakhil , Al-Qurabat Ali Kadhum M. 
Published: March 2021

AbstractA Wireless Sensor Network (WSN) consists of a number of sensor nodes which can sense, communicate, and store data, and it has a battery capacity. Data aggregation can be defined as a procedure applied for the elimination of redundant transmissions, and it provides fused information to the base stations, that in turn improve the energy effectiveness and increases the life span of energy constrained WSNs. The current article presents a systematic review of data aggregating schemes in flat and hierarchical WSNs, which are compared in light of different factors, including the node heterogeneity, mobility of aggregator nodes, and types of networks and algorithms. By comparing these remarkable techniques, a set of aspects are suggested to be dealt with in future works. Index words: Data aggregation, WSNs, network lifetime, Flat Network, Hierarchical network.
The Implementation of the Trapezoidal Fuzzy Number toward the Solution of the A Fuzzy Inventory Model with Shortages
Authors: Iswarya T. , Karpagavalli SG. 
Published: March 2021

Abstract
In this paper, fuzzy inventory model with shortages has been considered. Trapezoidal fuzzy number with Weibull distribution is used to fuzzify the data of an inventory model. All the parameters used in the inventory model is converted to trapezoidal fuzzy numbers using function principle. We find the estimate of the total inventory cost by defuzzifing the trapezoidal fuzzy numbers using the the graded mean integration. The optimum total cost for the inventory model is found.
Radiological Risk Assessment of Oil waste in the Oilfields at Zubair district of Basrah
Authors: Khudheir Mohammed 
Published: March 2021

Abstract
The specific activities of natural radionuclides in several samples were collected from the areas that exposed to triple-aggression which is Zubair province at Basrah governorate exactly. Those samples were studied and that concentrations calculated by using Gamma spectrometry system based on HpG detector with efficiency 40% was used for analysis of NORM. Then radiological risk of the natural radioactivity was estimated for study area that caused from exist the radionuclides in surface soil and water samples. The results have been revealed the contamination that occurring in some sites of Zubair district belonging to the natural radioactive material. Activity concentrations in Bq/kg of 238U, 232Th, and 40K with mean values of 95.8 Bq/kg, 31.6 Bq/kg, and 482.18 Bq/kg respectively. The outcome of soil samples were appeared higher values when compared with international calibrations. Whereas the results of Gamma absorbed dose (nGry/h), the exposure dose rate (µR/h) have mean values non-detected like; 52.5, 12.8 respectively, where under the international average by UNSCEAR 2008. Since the Radium equivalent activity (Ra-eq) has value 295.8 Bq/kg is higher than the standardizations.
Unmanned Aerial Vehicle (UAV) Application for Updating of Urban Database
Authors: Trung Le Van , Nhat Nguyen Huu , Nhut Mai Cong 
Published: March 2021

Abstract
This paper describes a new approach for urban land use management by using Unmanned Aerial Vehicles (UAV). Experimental result covers 121 ha (1.21 km2) at Binh Tho ward, Thu Duc district of the Ho Chi Minh city and shows that UAV technology is most suitable and cost effective for cadastral mapping and updating the database with high accuracy. In this research, 36 GCPs (Ground Control Points) and 2433 parcel boundaries (GIS data) were used to compare the achieved accuracy of UAV method in which 10381 orthophoto imageries produced had a resolution of 1.8 cm (with flying altitude 70 m) to be used to inform urban database. This technology opens a new way that is most suitable and cost effective for small areas, where digital maps and 3D models need to be produced in a short period of time with high data quality and accuracy. There are no significant barriers to imbed the technology at the local level and it can speed up the process of updating database in developing the Spatial Data Infrastructure (SDI) of the smart city.
Sustainable Urban Drainage System Model for The Nhieu Loc – Thi Nghe Basin, Ho Chi Minh City
Authors: Dung Le Thi , Phu Vo Le , Lan Nguyen Hoang My , Tien Nguyen Thi Cam , Hiep Luu Dinh 
Published: March 2021

Abstract
In recent years, Ho Chi Minh City has been faced with stark challenges in urban flooding affected by the impact of climate change in associated with the rapid urbanization and unadequate urban planning. Although many flood mitigation solutions were invested and implemented such as upgrading drainage systems, transport infrastructure, flood control pumps, etc. the problem remains unsolved and even worse. The purpose of this study is to propose a calculation model of the sustainable urban drainage system (SuDS) integrated with of GIS and remote sensing technology to assess and predict flooding degree in a specific basin in HCMC. Further, the results of this calculation model are just a pre-testing and pre-simulation of the proposed model for future studies on the application of sustainable urban drainage techniques, including rainwater harvesting, green roofs, urban green space and pervious pavement.
Developing Integrated Index for Evaluating the Urban Natural Environmental Quality from Remote Sensing Technology
Authors: Phuong Dinh Thi Kim , Ha Nguyen Ngan , Han Tham Thi Ngoc , Van Tran Thi 
Published: March 2021

Abstract
Environmental quality (EQ) has always been paid more attention in big cities, where urbanization is on the rise because it greatly affects urban natural ecosystems and people’s health. The paper presents the results of applying Landsat satellite images to evaluate the Natural Environmental Quality (NEQ) from the integrated index NEQI (Natural Environmental Quality Index) through the calculation of biophysical variables, including vegetation index NDVI, water surface index NDWI, construction index NDBI and land surface temperature LST. The study area is the north of Ho Chi Minh City (HCMC), divided into 3 sub-regions for analysis, including 13 old inner-city districts, 6 new inner-city districts, and 4 suburban districts. The results showed that there is a difference in NEQI between inner and suburban areas. Low NEQI is concentrated in urban areas with high urbanization rate, industrial zones, areas with large impervious surface areas and low greenery density. In the suburbs, in contrast, NEQ is better than in the inner city. If considering by the acquisited time of two satellite images in February of 2005 and 2020, the NEQ of the study area showed signs of decreasing and gradually expanding area from the inner city to the suburbs. Particularly in the suburbs, due to the urbanization process in recent years, there are spontaneous and unplanned development areas, so NEQ has changed towards a decrease. The results of the study can be used to support urban environmental planning and management.
Assessment of meteorological drought in the Vietnamese Mekong delta in period 1985-2018
Authors: Quang C N X , Hoa H V , Giang N N H , Hoa N T 
Published: March 2021

Abstract
Drought is one of a major natural disaster that causes tremendous damage to the ecological environment and social-economic in the Vietnamese Mekong Delta (VMD). Drought characteristics are invaluable knowledge for better management of water resources and agriculture production, especially under climate change context. This study investigated the spatiotemporal trend, intensity, duration, and frequency of meteorological droughts over VMD by using the Standardized Precipitation Evaporation Index (SPEI). The SPEI at multiple time scales (3, 6 and 12 months) are determined by using the monthly precipitation and temperature data between 1985 and 2018 obtained from ten meteorological stations in VMD namely Ba Tri, Cang Long, Soc Trang, Bac Lieu, Rach Gia, Ca Mau, Chau Doc, Can Tho, Cao Lanh, and My Tho. SPEI detected ten extreme drought events from 1985-2018 that matches with the historical extreme drought events reported in VMD. It means SPEI could be a useful indicator to support for drought management and mitigation in the future. The extreme drought event from October 2013 to September 2016 was the highest intensity and most prolonged duration from 1985-2018. The El Niño is considered to strongly influence on extreme drought events in VMD as all extreme drought events are highly associated with El Niño periods. The intensity, duration and frequency of drought events increased from 1985 to 2018. Drought events are more severe in VMD in recent years. Extreme drought also tends to cover for over VMD region. Adaption measures are essential to cope with drought disaster, especially in the agricultural and aquacultural sectors.
Mapping Land use/land cover using a combination of Radar Sentinel-1A and Sentinel-2A optical images
Authors: Nguyen T T H , Chau T N Q , Pham T A , Tran T X P , Phan T H , Pham T M T 
Published: March 2021

Abstract
The current study used a combination of Sentinel-1A (SE-1A) radar and Sentinel-2A (SE-2A) optical images in mapping land use/land cover (LULC) in Dak Nong province in 2018. The Random Forest (RF) algorithm was adopted to digitally categorize Landsat images into LULC maps according to ten different LULC classes included: evergreen forest, semi-evergreen forest, deciduous forest, plantation, rubber, industrial plants, crop land, residential area, water surface and others. The results indicated an overall accuracy (OA) and kappa coefficient of 81.40%, Kappa = 0.79, respectively. Based on the results of classified image, a 2018 LULC map of the study area was simulated. Accordingly, the natural forests account for 34.27% of the total area of the province, distributed scattered in districts. In which, the evergreen forest occupies the highest area with more than 166.600 ha, equivalent to 74.54% of the total natural forest area, and concentrated in the high mountain areas. Non-forest covers occupy more than 63% area of Dak Nong province. The industrial and agricultural cropland indicated a high area in the study area with a rate of 34.82% and 11.38%, respectively. This shows a strong development in the scale of industrial and agricultural crops in the study area. The objective information on current land use/land cover in this study can serve as the basis for policymakers to orient the local forest resource sustainability strategies. Besides, the study also shows that the use of a combination of Sentinel-1A radar and Sentinel-2A optical image to classify and construct the LU/LC map is a high-efficiency research direction.
Design and performance of small-scale reverse osmosis desalination for brackish water powered by photovoltaic units: a review
Authors: Que Vo Nguyen Xuan , Tuan Doan Van , Huy Nguyen Nhat , Phu Vo Le 
Published: March 2021

Abstract
The reverse osmosis (RO) water desalination system powered by the photovoltaic (PV) unit is commonly used to produce drinking water due to their reasonable price. This review focused to display different designs of small-scale PV powered brackish water RO (PV-BWRO) systems that were installed to improve the water productivity at remote areas. The configuration of BWRO units, which determined the operating cost, permeate flow and amount of rejected water, is of great concerns in this work. The specific energy consumption (SEC), total capital cost and water production cost are also analysed to display the feasibility of application of PV unit for small-scale BWRO desalination system. The single-stage configuration was suitable for most of small-scale BWRO systems owning high recovery rates (i.e., higher than 50%). The PV solar system pairing with batteries was not recommended at production capacities below 5 m3 for their high cost and short lifetime. Independently operated PV-BWRO systems required the highest capital cost while produced the lowest operating and overall production costs compared to hybrid systems.
Photochemical modeling of PM2.5 and design measures for PM2.5 reduction: A case of Ho Chi Minh City, Vietnam
Authors: Ho Bang Quoc , Vu Hoang Ngoc Khue , Nguyen Thi Thu Thuy , Nguyen Thoai Tam , Nguyen Thi Thuy Hang , Khoa Nguyen Thi Dang , Phu Vo Le 
Published: March 2021

Abstract
Vietnam’s urban areas have faced with serious environmental pollution issues, including: water pollution, municipal waste and air pollution. Air in Ho Chi Minh city is polluted by PM2.5 (particle matter with the diameter is less than 2.5 μm, so-called PM2.5), O3, CO, NO2 and TSP which greatly affects public health. In 2017, Ho Chi Minh City (HCMC) had 8,640,000 inhabitants with a total of 7,339,552 motorcycles and 637,323 automobiles. There are about 2,500 factories, 2,061,957 household and 5,096 restaurants in the city. The aim of this study is to (i) conduct a detailed air pollution emission inventory for PM2.5; (ii) stimulate PM2.5’s dispersion in HCMC and (iii) propose mitigation measures for PM2.5 in the city. Simulations of air pollution were conducted in HCMC by using TAPM-CTM system model. The model performance was evaluated using observed meteorological data at Tan Son Hoa station and air quality data at the Ho Chi Minh City University of Science. The result states that the sum of air pollutants from main sources of disposal in HCMC is 3,978.32 ton of PM2.5 in 2017. Average maximum 1 hours, 24 hours and annual of PM2.5 concentration in 2017 does not exceed QCVN 05:2013/BTNMT, but it is 1.3 to 2.3 times higher than the WHO’s guideline. Therefore, the PM2.5 in HCMC impacts on public health of HCMC. To control and manage the air’s quality and minimize the generation of PM2.5 in HCMC there are possible solutions such as the control of air pollutants from the main source, the creation of encouraging policy, the regulation of air pollutants in HCMC and the raising people’s awareness of environmental protection.
Effect of fertilizer formulas on some soil agrochemical indicators, growth and productivity
Authors: Tran Q P , Khanh B X , Huong L T T 
Published: March 2021

Abstract
The experiment aimed at identifying and selecting primer fertilizer formulas included 1 control formula: 40 kg N + 90 kg P2O5 + 60 kg K20 + 500 kg of powdered lime, 4 formulas of manure + control and 4 formulas of microbiological organic phosphate + The control was arranged in full randomized blocks and 3 repetitions, monitoring soil chemistry, growth and yield of peanut variety MD7. The results showed that the fertilizer formula influenced plant height from flowering to harvest, the number of leaves on the main stem, number and weight of nodules over time, the number of green leaves remaining when harvested, productivity, economic efficiency and indicators of soil agrochemical. The most suitable fertilizer formula is 1.4 tons of microbiological organic phosphate + control for 1 ha. However, the study recommends that the formula for fertilizing 1.1 tons of microbiological organic phosphate + control will yield the highest VCR ratio of 5.17 times. Adding microbiological organic phosphorus was more effective than equivalent formulas with manure.
Merino sheep nitrogen balance with the addition of mahogany leaves (Swietenia mahagoni) as tannins source in feed
Authors: Azizah E R , Hanim C , Yusiati L M , Kurniawati A 
Published: March 2021

Abstract
This study aimed to compare nitrogen consumption, nitrogen excretion, digested nitrogen, and nitrogen balance in Merino sheep which were given different level of tannins in the feed rations, namely 0%, 1.5%, and 3%. Twelve male Merino sheep aged 15-24 months with the average body weight of 30-35 kg were used in this experiment. There were 14 days of the adaptation period, and 7 days of the collection period. The sheep were confined to individual cages, and a nylon nets were fitted bellow the cages to separate urine and feces. The samples of feed, refusal feed, feces, and urine were analyzed for dry matter (DM) and nitrogen (N) content, and then were used to measure nitrogen consumption, fecal nitrogen, digested nitrogen, urinary nitrogen, and nitrogen balance. The result showed a significant difference (P <0.05) on nitrogen consumption, nitrogen excretion, digested nitrogen, and nitrogen balance. There was a decrease value in the level of tannin addition 1.5%, but increased at the 3% level. It can be concluded that different level of additional tannins up to 3% in Merino sheep feed showed positive nitrogen balance value. Therefore, the protein requirement of Merino sheep could be achieved.
Effect of betel type (Piper sp) and concentration of betel leaf extract on quality and antibacterial activities of glycerine bar soap
Authors: Hafizah I , Aisyah Y , Hasni D 
Published: March 2021

Abstract
Betel is an Asian medical plant that has antibacterial properties. Addition of betel extract to soap during its production steps may affects the quality characteristics, organoleptic and antibacterial activity of glycerine bar soap. This research aims to identify the effect of red and green betel by applying its ethanol extract on soap. This study used a Factorial Completely Randomized Design (FCRD) using the factor of betel types, red betel (S1) and green betel (S2) and concentrations of betel extract, which are 2.5%, 5%, 7.5%, and 10%. The collected data were analysed using the Analysis of Variance test (ANOVA) and continued with the Duncan test Multiple Range Test (DMRT). Test results showed that the soap has moisture contents between 1.24%–5.64%, free alkalis between 0.03%–0.44%, and pH with range 10.72–11.31. Red betel soap has a higher moisture content and free alkali levels as the added betel concentration increases. For its aroma, colours, and transparency, panellists hedonically tended to like the red betel soap more than the green. The transparent soap with addition 2.5% red betel extract has the best quality, as well as organoleptic and antibacterial activity characteristics when compared to other glycerine bar soaps.
Second regrowth phase generative characteristics of alfalfa (Medicago sativa L.) with addition of lighting duration and dolomites
Authors: Suwignyo B , Adnan F , Umami N , Pawening G , Suseno N , Suhartanto B 
Published: March 2021

Abstract
This study determines generative growth characteristics of alfalfa in second regrowth with the addition of dolomite and extended photoperiod. This study used a completely randomized design tested via Least Significant Difference. Dolomite was added at 0, 6 and 12 ton/ha. Photoperiod was varied at 12, 14 and 16 hours. The results conclude that extended photoperiod promoted alfalfa growth. Lengthier exposure to lighting promoted faster flowering and greater proportions of pod emergence and pod ripening. The addition of dolomite levels did not affect generative growth, except in the percentage of pods per plants. The addition of 16-hour lighting duration improved the second regrowth stage of alfalfa as compared to 14 and 12-hour photoperiods. The result yielded 61.63% seed purity and 13.33% seed viability.
Near-infrared spectroscopy (NIRS) as an integrated approach for rapid classification and bioactive quality evaluation of intact Feronia limoni
Authors: Yusnaini R , Ikhsan I , Idroes R , Munawar A A , Arabia T , Saidi N , Nasution R 
Published: March 2021

Abstract

Feronia limoni (Wood-apple) is one of the most researched plants containing bioactive compounds that have biological activity. So far, research on chemical compounds and fruit activity of F. limoni is often carried out using laboratory analysis, such as chromatographic analysis. This study aimed to assess the ability of NIRS to predict organic compounds contained in F. limoni based on its spectrum. Intact F. limoni samples were obtained from five different geographical origins in Aceh Province. Spectra data in form of absorbance spectrum were acquired using a portable sensing device NIRS instrument PSD FTNIRS i16 in wavenumbers 4000-10000 cm-1 or in the wavelength range from 1000 to 2500 nm with resolution windows of 0.02 nm and optical gain 4x. The results showed that NIRS was able to classify F. limoni samples based on geographical origins with the maximum explained variance of two PCs is 93%. Moreover, the respective wavelength related to this classification is 1090, 1270,1390, 1459, 1602,1713, 1912, and 2211 nm which corresponds to C-H, O-H, C-H-O, N-H stretching. It is related to acids, carbohydrates, and the fibre content of F. limoni samples from bent and stretched along the near-infrared region.
Preliminary study of land cover/land use and geomorphic change of the near shoreline of Aceh Jaya Regency: a multi-temporal and multi-image approach
Authors: Sugianto S , Rusdi M , Syahputri Y , Fazlina Y D 
Published: March 2021

AbstractLand cover/land-use change in Aceh Jaya Regency is greatly affected by the community and local government's increasing activities on land. The continuing development may create a problem due to progressing land use and geomorphic changes along the coastal area since the 2004 tsunami. To examine the land cover/land use and the extent of the geomorphic change to the coastline of Aceh Jaya Regency, a detailed study on the historical shoreline positions and land cover/land-use change was carried out. This preliminary study tried to analyze land use/land cover and geomorphic change from 2004 until 2019 along the coastal area of Aceh Jaya in Aceh, Indonesia, by utilizing multi-temporal and multi-image data. Results show that land use/land cover has considerably changed, primarily to vegetation, open land, and a water body that varied in total area during the year of observation. Coastline changed markedly since 2004 with abrasion reaching up to 436.38 meters from the original coastline, and the loss of land area up to 457.90 hectares, and 5.78 hectares of accretion was added. The longest distance of land that has disappeared from the original shoreline was recorded 436.38 meters from the mainland.