Journal of Science Natural Science最新文献_第2页

Detection of mangrove palm coverage at Cu Lao Cham-Hoi An Biospherer reserve using Sentinel-2A data 利用Sentinel-2A数据探测古老滩海安生物圈保护区红树林棕榈树覆盖率

Journal of Science Natural Science Pub Date : 2023-03-01 DOI: 10.18173/2354-1059.2023-0015

Khac Dang Vu

{"title":"Detection of mangrove palm coverage at Cu Lao Cham-Hoi An Biospherer reserve using Sentinel-2A data","authors":"Khac Dang Vu","doi":"10.18173/2354-1059.2023-0015","DOIUrl":"https://doi.org/10.18173/2354-1059.2023-0015","url":null,"abstract":"The mangrove palm grows at the Thu Bon river’s mouth. Mangrove palm has contributed to the conservation of natural ecosystems, and the biological diversity of Cu Lao Cham – Hoi An Biosphere Reserve, as well as the socio-economic development of Hoi An city. However, in recent year, its coverage has been gradually reduced due to human socio-economic activities. This study has used not only the raw bands of the Sentinel-2A image but also some spectral indices have been calculated via the band ratio for classifying land covers. The principal component analysis (PCA) was applied to these all bands to eliminate redundant and noise contributions in data. Mangrove palm was separated from other land cover categories with an object-based image classification approach using Support Vector Machines (SVMs) algorithm because of its high efficiency, performance, and flexibility. The obtained map indicates that mangrove palm principally distributes on the left bank of Thu Bon River with a total area of 147 ha by 2019. The validation, was realized by comparing the classification results with random samples through the visual interpretation of Google Earth high resolution image. The error assessment shows that the overall accuracy is about 88.67% and the Kappa coefficient reaches 0.84. Although there are some differences related to the spatial resolution of Sentinel-2 images, such obtained results may support authorities in decision-making by providing maps able to suggest necessary responses for the conservation of mangrove palms this coastal area.","PeriodicalId":17007,"journal":{"name":"Journal of Science Natural Science","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80165357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Assessment of the variation on maximum daily heat index in Ninh Binh city 宁平市最高日热指数变化的评价

Journal of Science Natural Science Pub Date : 2023-03-01 DOI: 10.18173/2354-1059.2023-0011

Hung Dao Ngoc, Chi Le Hanh, Chien Nguyen Quyet, Phuong Cu Thi, Hiền Nguyễn Thị Thu, Hien Vu Thuc

{"title":"Assessment of the variation on maximum daily heat index in Ninh Binh city","authors":"Hung Dao Ngoc, Chi Le Hanh, Chien Nguyen Quyet, Phuong Cu Thi, Hiền Nguyễn Thị Thu, Hien Vu Thuc","doi":"10.18173/2354-1059.2023-0011","DOIUrl":"https://doi.org/10.18173/2354-1059.2023-0011","url":null,"abstract":"This study was based on heat index (HI) to determine risk thresholds for warning heat stress to communities in Ninh Binh City. The study used correlation evaluation and regression equations, meteorological data for the period 1991 - 2021, and Vietnam climate change scenario data to calculate the maximum daily heat index (HImax) scenario for the country in the period 2024 - 2054. The results showed that, in the future, the trend of HImax will increase by 0.100 °C per year under the RCP 4.5 scenario (Medium Low greenhouse gases concentration scenario) and 0.105 °C per year under the RCP 8.5 scenario (High greenhouse gases concentration scenarios). The number of HImax days at dangerous levels will increase by about 1 day per year with both RCP 4.5 and RCP 8.5 scenarios. In particular, the number of HImax days at extreme danger levels, with the risk of causing stroke, in the period 2024 - 2054 appeared more than before, especially in the period 1941 - 2054, the trend increased sharply. In some last years of this period, the number of HImax days will be extremely dangerous up to 20 - 30 days.","PeriodicalId":17007,"journal":{"name":"Journal of Science Natural Science","volume":"71 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87226407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparison of image classification methods to establishing land cover map at Ha Long city, Quang Ninh province using the Landsat-8 images 利用Landsat-8影像建立广宁省下龙市土地覆盖图的影像分类方法比较

Journal of Science Natural Science Pub Date : 2023-03-01 DOI: 10.18173/2354-1059.2023-0010

Khac Dang Vu

引用次数: 0

Study on the preparation and electrochemical performance of nickel sulfide for the application in an electrochemical capacitor 电化学电容器用硫化镍的制备及其电化学性能研究

Journal of Science Natural Science Pub Date : 2023-03-01 DOI: 10.18173/2354-1059.2023-0004

Hung Nguyen Dinh, Thuy Luong Thi Thu, Khu Le Van

引用次数: 0

Evolutionary Algorithm for the Novel RCPSP Scheduling Problem 新型RCPSP调度问题的进化算法

Journal of Science Natural Science Pub Date : 2023-03-01 DOI: 10.18173/2354-1059.2023-0007

Loc Nguyen The, Huu Dang Quoc, Giang Vu Thai

引用次数: 0

Application of pectinase enzyme preparations for extraction and recovery of passion fruit juice (Passiflora edulis) from Cao Bang province 果胶酶制剂在曹邦西番莲果汁提取和回收中的应用

Journal of Science Natural Science Pub Date : 2023-03-01 DOI: 10.18173/2354-1059.2023-0005

Tuan Le Anh, Loi Nguyen Van

{"title":"Application of pectinase enzyme preparations for extraction and recovery of passion fruit juice (Passiflora edulis) from Cao Bang province","authors":"Tuan Le Anh, Loi Nguyen Van","doi":"10.18173/2354-1059.2023-0005","DOIUrl":"https://doi.org/10.18173/2354-1059.2023-0005","url":null,"abstract":"Cao Bang is a province with favorable natural conditions for the development of passion fruit trees (Passiflora edulis). Passion fruit is rich in nutritional values, such as protein, sugar, vitamins, minerals, phenolic acids, and flavonoids. The addition of pectinase enzyme preparation has the effect of breaking down the cell wall of passion fruit flesh, contributing to increasing the yield of fruit juice. The objective of this study is the application of pectinase enzyme preparations to exploit and recover passion fruit juice from Cao Bang province. The study has determined extraction and recovery of passion fruit juice was developed, with the technological parameters being the concentration of pectinase enzyme preparation used as 0.5%, the hydrolysis temperature of 39 oC, the hydrolysis time as 300 minutes, in this condition the recovery efficiency of passion fruit juice was 89.04%. Passion fruit juice has a dark orange yellow color, a very characteristic aroma, a sweet taste mixed with a slightly sour taste, a homogeneous state, a soluble solids content of 12.75 ± 0.25 oBx, and a pH of 2.81 ± 0.02.","PeriodicalId":17007,"journal":{"name":"Journal of Science Natural Science","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85031655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Properties of solutions for a class of parabolic hemivariational inequalities 一类抛物型半变分不等式解的性质

Journal of Science Natural Science Pub Date : 2023-03-01 DOI: 10.18173/2354-1059.2023-0001

Nhung Nguyen Thi

引用次数: 0

The association between overweight, obesity and pre-hypertension, hypertension in students at Dong Hoa High School, Hai Phong city 海防市东华高中学生超重、肥胖与高血压前期的关系

Journal of Science Natural Science Pub Date : 2023-03-01 DOI: 10.18173/2354-1059.2023-0009

Hanh Nguyen Thi Hong, Dao Duong Thi Anh, Trang Nguyen Thi Huyen

{"title":"The association between overweight, obesity and pre-hypertension, hypertension in students at Dong Hoa High School, Hai Phong city","authors":"Hanh Nguyen Thi Hong, Dao Duong Thi Anh, Trang Nguyen Thi Huyen","doi":"10.18173/2354-1059.2023-0009","DOIUrl":"https://doi.org/10.18173/2354-1059.2023-0009","url":null,"abstract":"The increasing prevalence of high blood pressure in adolescents is an alarming global health problem, coupled with the rise in obesity and sedentary lifestyles. The aim of this study was to examine the associations between overweight, obesity, and pre-hypertension, and hypertension among adolescents aged 15 - 17 years in Hai Phong city. The case-control study was conducted on 1,000 students at Dong Hoa High School, Hai Phong city. The control group consisted of 730 students with normal systolic and diastolic blood pressure. The case group included 270 students with pre-hypertension and hypertension according to the diagnostic criteria of the American Academy of Pediatrics. The study results showed that the proportion of students with pre-hypertension and hypertension was quite high, 12.2% and 14.8%, respectively. The prevalence of pre-hypertension and hypertension in male students was significantly higher than in female students (P < 0.001). After adjusting for age and sex, overweight and obesity were statistically significantly associated with the risk of pre-hypertension, and hypertension with OR values of 2.2 (95%CI: 1.4-3.4) and 7.1 (95%CI: 3.0 - 16.5), respectively. Thus, overweight and obesity increases the risk of pre-hypertension and hypertension in adolescents aged 15 - 17 at Dong Hoa High School, Hai Phong city.","PeriodicalId":17007,"journal":{"name":"Journal of Science Natural Science","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84117077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

MOLECULAR DYNAMICS SIMULATION OF MICROSTRUCTURAL CHANGE OF Cu0.6Ni0.2Fe0.2 ALLOY DURING THE COOLING PROCESS Cu0.6Ni0.2Fe0.2合金冷却过程中组织变化的分子动力学模拟

Journal of Science Natural Science Pub Date : 2022-10-01 DOI: 10.18173/2354-1059.2022-0040

Thao Nguyen Thi, Thanh Nguyen Thi Thanh

引用次数: 0

ON EXPONENTIAL STABILITY OF A CLASS OF DELAY DIFFERENTIAL EQUATIONS IN NEOCLASSICAL GROWTH MODELS 新古典增长模型中一类时滞微分方程的指数稳定性

Journal of Science Natural Science Pub Date : 2022-10-01 DOI: 10.18173/2354-1059.2022-0035

Nghia Hoang Tuan

引用次数: 0