USING EXPERIMENTAL PLANNING TO OPTIMIZE THE HYDROLYSIS OF SUGAR CANE BAGASSE INTO FERMENTABLE SUGARS FOR BIOETHANOL PRODUCTION BY FUNGAL ENZYME MIXTURE

In this study, the unpretreated sugar cane bagasse was milled to a particle size of 0.5 – 1 mm and be used as material for bioconversion into fermentable sugars by using an enzyme cocktail acted synergistically. Experimental planning was used to optimize the enzyme conversion through assessment and analysis of individual parameter. As the result, the optimal condition for enzymatic conversion of sugar cane bagasse into reducing sugar product are at pH = 5, 400C, and 48 h incubation in rate of enzyme (Cell/Xyl, AltFAE, XpoAE) and substrate (bagasse meal) is 3.1. From the above application, the mathematical model is found to describe equation of the bioconversion of bagasse into reducing sugars: = 206.946 + 29.954x1 + 5.501x2 + 7.323x3 + 2.288x2x3 – 7.011; and using flexible algorithm of nonlinear planning to identify optimal conditions of enzyme mixture of conversion into reducing sugars that the reaction reached max = 251.86 mg per gram bagasse with x1 = 1.215, x2 = 1.215, x3 = 1.215 or Cell/Xyl = 1 ml (100U), AltFAE = 0.5 ml (7.56U), XpoAE = 0.4 ml (10.8U) on the test range. Experimental verification has the same result in constant conditons and reached total reducing sugars of 260.2 mg per gram substrate.In this study, the unpretreated sugar cane bagasse was milled to a particle size of 0.5 – 1 mm and be used as material for bioconversion into fermentable sugars by using an enzyme cocktail acted synergistically. Experimental planning was used to optimize the enzyme conversion through assessment and analysis of individual parameter. As the result, the optimal condition for enzymatic conversion of sugar cane bagasse into reducing sugar product are at               pH = 5, 40 oC, and 48 h incubation in rate of enzyme (Cell/Xyl, AltFAE, XpoAE) and substrate (bagasse meal) is 3.1. From the above application, the mathematical model is found to describe equation of the bioconversion of bagasse into reducing sugars: = 206.946 + 29.954x1 + 5.501x2 + 7.323x3 + 2.288x2x3 – 7.011; and using flexible algorithm of nonlinear planning to identify optimal conditions of enzyme mixture of conversion into reducing sugars that the reaction reached max = 251.86 mg per gram bagasse with x1 = 1.215, x2 = 1.215, x3 = 1.215 or Cell/Xyl = 1 ml (100U), AltFAE = 0.5 ml (7.56U), XpoAE = 0.4 ml (10.8U) on the test range. Experimental verification has the same result in constant conditons and reached total reducing sugars of 260.2 mg per gram substrate

Physical Model Test for Soft Soil With or Without Prefabricated Vertical Drain with Loading

The paper builds a physical model of testing in the laboratory with the parametric tempered glass box 0.5  0.5 1.2 m (length  width  depth) containing saturated clay to study the settlement and consolidation when loading increased gradually over time. The research covers herein to present the monitoring of settlement and pore water pressure, settlement calculation, numerical simulation using PLAXIS software V8.2 based on the results of soil physical and mechanical tests before and after loading in case of having or not prefabricated vertical drain (PVD). In case of no PVD, the calculation and numerical simulation using the soil parameters before loading have the differential settlement from the monitoring data, approximately 3.86 mm (10.45%), 0.41 mm (1.11%) respectively. Meanwhile, the deviation in the case using data after loading is about 2.29 mm (6.20%), 0.21 mm (0.56%) respectively. In case of PVD, the calculation and numerical simulation with the testing result of before loading deviation from the settlement monitoring by subsidence meter is 2.91 mm (7.88%), 44.42 mm (120.28%), calculation and simulation with the testing result of after loading deviation is 0.80 mm (2.17%), 1.26 mm (3.41%). In the case of having PVD, the difference in calculation, subsidence observation, and numerical simulation between the mechanical properties before and after loading is significant, when using the mechanical data after loading then the results are quite close to the subsidence of observation and simulation rather than before loading.

STUDY ON APPLICABILITY OF THE CONTACT OXIDATION PROCESS IN REMOVAL OF ORGANIC POLLUTANTS FROM TEXTILE WASTEWATER

Joint Research on Environmental Science and Technology for the Eart

ẢNH HƯỞNG CỦA NỀN ĐÁY CÁT VÀ ĐÁ SỐNG LÊN CHẤT LƯỢNG MÔI TRƯỜNG BỂ NUÔI CÁ CẢNH BIỂN

Marine ornamental aquarium is more and more popular. Nowadays, biofiltration system can convert nitrogen from toxic forms (NH4+/NH3, NO2-) into a less toxic form (NO3-), which creates a better water quality for the development of ornamental fishes in aquarium tank. This experiment was carried out to evaluate the efficiency of environmental quality by supplementation of sand and live rock in aquarium tank. There were two treatments with rock and sand supplement to the bottom of the tanks (NT1) and tanks without rock and sand added (NT2). There were 3 replicates for each treatment and the experiments were carried out in ten weeks. Results showed that sand and live rock could improve water quality and play as good place for fish and other creature hiding and reduce the water used. Water temperatures were 28.69oC (NT1) and 28.80oC (NT2), pH was about 8.13, salinity ranged from 34‰ to 35‰ in both treatments. NH4+was 0.035 ± 0.003 mgN/ml in the two treatments. After 2 weeks of putting fish in the experimental tanks NO2- values were 0.023 mgN/l (in treatment NT2) and 0.018 mgN/l (in treatment NT1). The average values of NO2- for whole experimental period in the NT1 and NT2 were 0.008 ± 0.001 mgN/l and 0.010 ± 0.002 mgN/l, respectively (P = 0.061). NO3- values were not significantly different between the two treatments (P 0.05). However, the ratio of NO2-/NO3- in NT1 was lower compared to this value in NT2 (NT1: 0.15 ± 0.03% and NT2: 0.39 ± 0.09%, P = 0.018). This paper provides an important reference to help aquarists to design and control their ornamental aquarium tank suitably.Hệ thống lọc sinh học là nơi sinh sống của các vi khuẩn ni trat hóa - các vi khuẩn có vai trò chuyển hóa ni tơ thải ra từ cá và vật nuôi ở dạng độc (NH4+/NH3) sang dạng ít độc hơn (NO3-). Các vi khuẩn này sống bám trên các giá thể như đá và cát. Thí nghiệm đánh giá hiệu quả cải thiện chất lượng môi trường của việc bổ sung nền đáy cát và đá vào bể nuôi cá cảnh biển. Thí nghiệm bao gồm 2 nghiệm thức. Nghiệm thức 1 (NT1): Bổ sung đá sống và cát vào bể nuôi và nghiệm thức 2 (NT2): Bể nuôi có đáy trần. Mỗi nghiệm thức có kết quả thí nghiệm cho thấy, bổ sung nền đáy cát và đá sống vào bể nuôi đã đem lại hiệu quả cải thiện rõ rệt các muối dinh dưỡng nitơ từ dạng có độc hại cho vật nuôi sang dạng ít độc hơn. Nhiệt độ 28,69oC (NT1) và 28,80oC (NT2), pH xấp xỉ 8,13 và độ mặn dao động 34–35‰ ở cả 2 nghiệm thức thí nghiệm. NH4+ở cả 2 nghiệm thức có giá trị trung bình 0,035 ± 0,003 mgN/ml. Sau 2 tuần thả cá, hàm lượng NO2- 0,023 mgN/l (NT2) và 0,018 mgN/l (NT1). NO2- trung bình ở NT1 và NT2 lần lượt là 0,008 ± 0,001 mgN/l và 0,010 ± 0,002 mgN/l (P = 0,061). Hàm lượng NO3- giữa 2 nghiệm thức không khác nhau có ý nghĩa thống kê (P 0,05). Tuy nhiên, tỷ lệ NO2-/NO3- ở NT1 nhỏ hơn có ý nghĩa thống kê so với NT2 (NT1: 0,15% ± 0,03% và NT2: 0,39% ± 0,09%, P = 0,018). Ngoài ra việc bổ sung nền đáy cát và đá sống tạo sinh cảnh và tạo nơi ẩn nấp cho cá. Đồng thời cũng giúp hạn chế thay nước và vệ sinh nền đáy của bể nuôi có đáy cát và đá sống. Kết quả nghiên cứu là cở sở khoa học quan trọng để bổ sung đá sống và cát trong bể nuôi cá cảnh tại Bảo tàng Hải dương học

Unravelling the economic impact of climate change in Vietnam's Mekong River Delta and Southeast region

Vietnam faces a heightened susceptibility to natural disasters stemming from climate change, yet the impact of these disasters varies markedly across its regions. Consequently, it is imperative to scrutinize the climatic factors affecting the regional economy, with a particular dearth of research addressing the nexus between natural threats and the economies of the Mekong River Delta and the Southeast region of Vietnam. The primary objective is to investigate how temperature fluctuations, rising sea levels, storms, and forest fires can detrimentally affect agriculture, forestry, and infrastructure in these regions. The present research uses the secondary data from Vietnam's General Statistics Office and the German Agency for International Cooperation. Employing quantitative analysis, the study endeavours to assess and compare the influence of climate change elements on the economic trajectories of the Mekong River Delta and the Southeast region. The findings reveal that the Mekong River Delta is disproportionately impacted by economic losses attributed to rising sea levels when juxtaposed with other regions in Vietnam. Firstly, the escalating sea levels significantly jeopardize residential and agricultural land in the Mekong River Delta (1). Secondly, while wildfires inflict damage on forestry in both the Mekong River Delta and the Southeast area, their overall impact is deemed negligible (2). Thirdly, the study ascertains that houses in the Mekong River Delta and the Southeast region remain relatively unscathed by storms (3). However, it is noted that specific storms have inflicted substantial damage on both regions (4). In light of these findings, future research should delve deeper into the analysis of storm risks in the Mekong River Delta and the Southeast region. Such insights are crucial for enhancing our understanding of the vulnerabilities and devising effective strategies to mitigate the economic repercussions of climate change in these pivotal areas

Design and simulation of automotive radar for autonomous vehicles

Modern automobile technology is pushing towards maximizing road safety, connected vehicles, autonomous vehicles, etc. Automotive RADAR is core sensor technology used for ADAS (Advanced Driver Assistance Technology), ACC (Adaptive Cruise Control), AEB (Automatic Emergency Braking System), traffic assistance, parking aid, and obstacle/pedestrian detection. Despite being inexpensive, RADAR technology provides robust results in harsh conditions such as harsh weather, extreme temperature, darkness, etc. However, the performance of these systems depends on the position of the RADAR and its characteristics like frequency, beamwidth, and bandwidths. Moreover, the characterization of varied materials like layers of paint, polish, primer, or layer of rainwater needs to be analyzed. This performance can be predicted through real-time simulation using advanced FEM software like Altair FEKO&WinProp. These simulations can provide valuable insight into the performance of the system, allowing engineers to optimize the system for specific use cases. For example, simulation can be used to determine the optimal parameters of the RADAR system for a given application. This information can then be used to design and build a physical model or prototype that is optimized for the desired performance. These simulations play a prominent role in determining appropriate data collection and sensor fusion, which reduces the cost and time required for the development of a physical model or prototype. The continued growth and demand for advanced safety features in vehicles further highlight the importance of RADAR technology in modern automobile technology. By accurately characterizing the environment and simulating the system's behavior in real time, engineers can optimize RADAR systems for specific use cases, contributing to safer and more efficient driving experience

A Bibliometric Review on Realistic Mathematics Education in Scopus Database Between 1972-2019

Despite receiving increasing attention from mathematics education scholars, there has not yet been any overall understanding of the current state of realistic mathematics education (RME). To address this gap, this study aims to provide a review of 288 studies on realistic mathematics education from the Scopus database between 1972 and 2019. Using descriptive and bibliometric analyses, this study addresses four research issues as follows: (i) the total volume, growth trajectory, and geographic distribution; (ii) the most influencing authors and research groups; (iii) the most influencing sources (i.e., journals, books, conferences); and (iv) the most important topics. Several implications for not only mathematics education scholars but also other stakeholders, including policymakers, school managers, mathematics teachers, may not be considered in this study

Megastigmans and other compounds from Antidesma hainanensis Merr.

Four megastigmans 7-megastigmene-3-ol-9-one 3-O-[α-L-arabinofuranosyl-(1→6)-β-D-glucopyranoside]  (1),  alangionoside L (2),  alangioside (3), ampelopsisionoside (4), and other constituents as N–trans-feruloyloctopamide (5), trans-linalool-3,6-oxide-β-D-glucopyranoside (6),  5α,8α-dipioxiergosta-6,22-diene-3β-ol (7), and (Z)-2-hexenyl β-D-glucopyranoside (8) were isolated from the methanol extract of the Antidesma hainanensis leaves. Their chemical structures were successfully determined using NMR and ESI-MS analysis as well as in comparison with the reported data. This is the first report of these compounds from Euphorbiaceae family

PSSA- INTERNATIONAL SOLUTION TO PROTECT THE BIODIVERSITY IN HA LONG BAY - CAT BA MARINE AREA

A Particularly Sensitive Sea Area (PSSA) is an important management tool for biodiversity protection of a marine area. At the time of designation of a Particularly Sensitive Sea Area, an associated protective measure, which meets the requirements of the appropriate legal instrument establishing such measure, must have been approved or adopted by IMO to prevent, reduce, or eliminate the threat or identified vulnerability. Information on each of the Particularly Sensitive Sea Areas (PSSAs) that has been designated by IMO is available on the nautical chart. The Vietnam’s coastal zones and islands are the isolated oceanic habitat of extremely rich marine life in very good condition which is important to the maintenance and dispersal of the marine life of the western tropical Pacific. Vietnam coastal areas are very high risk areas affected by maritime activities, particularly international shipping, therefore in the future identification of some Particularly Sensitive Sea Areas (PSSAs) is necessary. The first Particularly Sensitive Sea Area for Vietnam in Ha Long - Cat Ba was initially proposed in this paper