Changes of benthic macroinvertebrates in Thi Vai River and Cai Mep Estuaries under polluted conditions with industrial wastewater

The pollution on the Thi Vai River has been spreading out rapidly over the two lasted decades caused by the wastewater from the industrial parks in the left bank of Thi Vai River and Cai Mep Estuaries. The evaluation of the benthic macroinvertebrate changes was very necessary to identify the consequences of the industrial wastewater on water quality and aquatic ecosystem of Thi Vai River and Cai Mep Estuaries. In this study, the variables of benthic macroinvertebrates and water quality were investigated in Thi Vai River and Cai Mep Estuaries, Southern Vietnam. The monitoring data of benthic macroinvertebrates and water quality parameters covered the period from 1989 to 2015 at 6 sampling sites in Thi Vai River and Cai Mep Estuaries. The basic water quality parameters were also tested including pH, dissolved oxygen (DO), total nitrogen, and total phosphorus. The biodiversity indices of benthic macroinvertebrates were applied for water quality assessment. The results showed that pH ranged from 6.4 – 7.6 during the monitoring. The DO concentrations were in between 0.20 – 6.70 mg/L. The concentrations of total nitrogen and total phosphorous ranged from 0.03 – 5.70 mg/L 0.024 – 1.380 mg/L respectively. Macroinvertebrate community in the study area consisted of 36 species of polychaeta, gastropoda, bivalvia, and crustacea, of which, species of polychaeta were dominant in species number. The benthic macroinvertebartes density ranged from 0 – 2.746 individuals/m2 with the main dominant species of Neanthes caudata, Prionospio malmgreni, Paraprionospio pinnata, Trichochaeta carica, Maldane sarsi, Capitella capitata, Terebellides stroemi, Euditylia polymorpha, Grandidierella lignorum, Apseudes vietnamensis. The biodiversity index values during the monitoring characterized for aquatic environmental conditions of mesotrophic to polytrophic. Besides, species richness positively correlated with DO, total nitrogen, and total phosphorus. The results confirmed the advantage of using benthic macroinvertebrates and their indices for water quality assessment

Оптимизация тепловых режимов диодных лазеров

Разработаны химический и вакуумные методы формирования металлических покрытий с высокой адгезией к различным поверхностям на базе многофункциональных ионно-лучевых и магнетронных распылительных систем, в том числе применительно к медным и алмазным теплоотводящим основаниям для диодных лазеров. Определены оптимальные условия сборки диодных лазеров и линеек на основе разработанных способов металлизации и достигнуто существенное улучшение выходных характеристик приборов

Моделирование процессов электротеплового взаимодействия в диодной лазерной системе

PARASHCHUK V. V., RUSAKOV K. I., VU DOAN MIEN, VU VAN LUC, PHAM VAN TRUONG Simulation of processes of thermal and electro thermal interactions in diode laser systemИсследованы теплофизические характеристики современных теплопередающих материалов и промоделированы процессы теплового и электротеплового взаимодействий в диодной лазерной системе. Предложен метод расчета тепловых полей, позволяющий учитывать реальную топологию и оптимизировать конструкцию разрабатываемых приборов

PILOT SCALE STUDY ON AMMONIUM REMOVAL IN PHAP VAN WATER PLANT, HANOI CITY

Joint Research on Environmental Science and Technology for the Eart

Changes of Benthic Macroinvertebrates in Thi Vai River and Cai Mep Estuaries Under Polluted Conditions with Industrial Wastewater

The pollution on the Thi Vai River has been spreading out rapidly over the two lasted decades caused by the wastewater from the industrial parks in the left bank of Thi Vai River and Cai Mep Estuaries. The evaluation of the benthic macroinvertebrate changes was very necessary to identify the consequences of the industrial wastewater on water quality and aquatic ecosystem of Thi Vai River and Cai Mep Estuaries. In this study, the variables of benthic macroinvertebrates and water quality were investigated in Thi Vai River and Cai Mep Estuaries, Southern Vietnam. The monitoring data of benthic macroinvertebrates and water quality parameters covered the period from 1989 to 2015 at 6 sampling sites in Thi Vai River and Cai Mep Estuaries. The basic water quality parameters were also tested including pH, dissolved oxygen (DO), total nitrogen, and total phosphorus. The biodiversity indices of benthic macroinvertebrates were applied for water quality assessment. The results showed that pH ranged from 6.4 – 7.6 during the monitoring. The DO concentrations were in between 0.20 - 6.70 mg/L. The concentrations of total nitrogen and total phosphorous ranged from 0.03 - 5.70 mg/L 0.024 - 1.380 mg/L respectively. Macroinvertebrate community in the study area consisted of 36 species of polychaeta, gastropoda, bivalvia, and crustacea, of which, species of polychaeta were dominant in species number. The benthic macroinvertebartes density ranged from 0 - 2.746 individuals/m−1 with the main dominant species of Neanthes caudata, Prionospio malmgreni, Paraprionospio pinnata, Trichochaeta carica, Maldane sarsi, Capitella capitata, Terebellides stroemi, Euditylia polymorpha, Grandidierella lignorum, Apseudes vietnamensis. The biodiversity index values during the monitoring characterized for aquatic environmental conditions of mesotrophic to polytrophic. Besides, species richness positively correlated with DO, total nitrogen, and total phosphorus. The results confirmed the advantage of using benthic macroinvertebrates and their indices for water quality assessment

PREPARATION OF THE SINGLE MODE PLANAR OPTICAL SPLITTER MODULES AND THEIR CHARACTERIZATIONS

Optical splitter modules have been prepared based on 1x8 single mode silica planar waveguide optical splitter chips with 250 µm spacing and v-groove fiber arrays for applications in fiber optic communications. We report the technology of precise optical coupling and packaging of the splitter modules and the measurements of the insertion loss (< 11 dB),  uniformity (< 0.80 dB) and polarization dependence loss (PLD < 0.10 dB) as well as the lateral profile and the image of the input and output lights for the wavelengths of 1310 nm and 1550 nm. The main characteristics of the prepared splitter modules are about the same for the commercial available products. The prepared modules have been tested for operation in the conditions of wide temperature range (5–80°C) and humidity range (50–98%) and no changes in the main characteristics were observed

Zooplankton from can Giuoc River in Southern Vietnam

In this study, the variables of zooplankton and water quality were investigated in the Can Giuoc River, Southern Vietnam. Zooplankton was monitored in April and September 2015 at 5 sampling sites in the river. Some basic water quality parameters were also tested, including pH, total suspended solid (TSS), dissolved oxygen (DO), biological oxygen demand (BOD5), inorganic nitrogen (NH4+), dissolved phosphorus (PO43−), and coliform. The zooplankton biodiversity indices were applied for the water quality assessment

Моделирование процессов электротеплового взаимодействия в диодной лазерной системе

PARASHCHUK V. V., RUSAKOV K. I., VU DOAN MIEN, VU VAN LUC, PHAM VAN TRUONG Simulation of processes of thermal and electro thermal interactions in diode laser systemИсследованы теплофизические характеристики современных теплопередающих материалов и промоделированы процессы теплового и электротеплового взаимодействий в диодной лазерной системе. Предложен метод расчета тепловых полей, позволяющий учитывать реальную топологию и оптимизировать конструкцию разрабатываемых приборов

Формирование высокоадгезионных металлических покрытий для мощных диодных лазеров

PARASHCHUK V. V., BELYAEVA A. K., BARANOV V. V., TELESH E. V., RUSAKOV K. I., VU DOAN MIEN, VU VAN LUC, PHAM VAN TRUONG. Optimization of thermal regimes of diode lasersРазработаны химический и вакуумные методы формирования металлических покрытий с высокой адгезией к различным поверхностям на базе многофункциональных ионно-лучевых и магнетронных распылительных систем, в том числе применительно к медным и алмазным теплоотводящим основаниям для диодных лазеров. Определены оптимальные условия сборки диодных лазеров и линеек на основе разработанных способов металлизации и достигнуто существенное улучшение выходных характеристик приборов

Intelligent robust disturbance rejection control of a ballbot drive micromobility vehicle

We propose a hybrid adaptive control method with robust disturbance rejection for a novel personal micromobility vehicle that uses ballbot drive mechanics with a single spherical wheel. Intelligent control of such a micromobility vehicle is significantly sensitive to discrete events of short duration and high-intensity road disturbances and shocks. Sudden bumps, potholes, pavement or kicks typically cause these events. Our approach combines adaptive disturbance observer (DOB) with two other techniques to achieve better and more robust nonlinear control of a ballbot drive vehicle (BDV) against small to large external disturbances. The proposed hybrid DOB-Based combined control system (DOB-CCS) stabilizes the body position via a DOBbased partial feedback linearization (PFL) strategy while enabling ball movement on the floor by introducing a DOB-based sliding mode control (SMC). The control scheme consists of linearly combined components responsible for maintaining an upright posture about unstable equilibrium points and tracking the motion under disturbances. Simulations, real-platform experiments and respective comparative studies show the efficacy of the proposed method for a BDV to reject external disturbances. The practical performance of the proposed DOB-CCS strategy is experimentally validated and compared with a CCS method. The experimental results indicate less than 0.7 and 1.5 degrees of ballbot's orientation error and robust rejection of disturbances under kicks during balancing and transferring modes, respectivel