ACTIVITIES SUPPORTING SEX EDUCATION TO ADOLESCENCE IN HANOI NOWADAYS

Activities supporting sex education in schools are basic ones with the purpose of organizing models to contribute to the completion of sex education for students, meeting the requirements of students’ life and society diversity. These activities include: classroom activities, extra-curricular activities, awareness raising activities for students and educational forces, and counseling activities. The article assesses the current situation of sex education in schools nowadays, thereby proposing some feasible solutions

Multi-source in DF cooperative networks with the PSR protocol based full-duplex energy harvesting over a Rayleigh fading channel: performance analysis

Due to the tremendous energy consumption growth with ever-increasing connected devices, alternative wireless information and power transfer techniques are important not only for theoretical research but also for saving operational costs and for a sustainable growth of wireless communications. In this paper, we investigate the multi-source in decode-and-forward cooperative networks with the power splitting protocol based full-duplex energy harvesting relaying network over a Rayleigh fading channel. In this system model, the multi-source and the destination communicate with each other by both the direct link and an intermediate helping relay. First, we investigate source selection for the best system performance. Then, the closed-form expression of the outage probability and the symbol error ratio are derived. Finally, the Monte Carlo simulation is used for validating the analytical expressions in connection with all main possible system parameters. The research results show that the analytical and simulation results matched well with each other.Web of Science68327526

Outage probability analysis in DF power-splitting full-duplex relaying network with impact of Co-channel interference at the destination

Nowadays, improving the WPCN efficiency problem is the leading research direction in the communication network. In this research, the outage probability (OP) analysis in DF power-splitting (PS) full-duplex (FD) relaying network with impact of co-channel interference at the destination is proposed and investigated. In the system model section, we present the DF PS FD Relaying Network with Impact of Co-channel interference at the destination. Then in the system performance section, we analyze and derive the closed-form expression of the OP and investigate the effect of the main system parameters on the system network performance. Then, we perform the Monte Carlo simulation to verify the analytical section. This research can provide a new recommendation for the communication network

Clean Energy and Sustainable Development lab activity report, 2014-09-31 to 2015-12-31

The Clean Energy and Sustainable Development laboratory – CleanED – was established in December 2014 with support from USTH and French Embassy in Hanoi. In September 2015, CleanED lab counted five researchers from France and Vietnam, five doctoral fellows and two internationally qualified staff. This international and interdisciplinary research team gets the mission to contribute to the green growth of the energy sector in Vietnam. Its expertise ranges from engineering to public policy on:Natural resources characterization and managementBiomass and waste to energy conversion process technologiesEnergy systems optimization from smart grid to national plan

Sr[Mg3SiN4]Eu2+ phosphor: solution for enhancing the optical properties of the 5600K remote-packaging WLEDs

In the last decade, light-emitting diodes (LEDs), which based on spontaneous light emission in semiconductors can be considered as the main light sources for civil and industrial purposes. In this paper, we presented and investigated the effect of the Sr[Mg3SiN4]Eu2+ concentration on the optical properties of the 5600K remote-packaging WLEDs (RP-WLEDs). We use the Mat Lab and the LightTool software to investigate the effect of the Sr[Mg3SiN4]Eu2+ concentration on the CRI, CQS, D-CCT and LO of the 5600K RP-WLEDs. From the result, we can state that the concentration of the Sr[Mg3SiN4]Eu2+ influenced on the CRI, CQS, D-CCT and LO of the RP-WLEDs. The red Sr[Mg3SiN4]Eu2+ phosphor can be considered as the novel recommendation for LEDs industry

Socio-economic impacts of co-firing in Vietnam: The case of Ninh Binh Coal Power Plant

International audienceCo-firing biomass with coal is a relatively low-cost technology to utilize biomass for electricity production compared to dedicated biomass power plant. Co-firing could help to reduce the negative impact of coal power plants to economy, environment and society. Vietnam has potential to develop co-firing base on the abundant of biomass resources and because Vietnam will continue to build more coal-fired power plant in the next 2 decades as stated in the latest National Power Development Plan.Among the co-firing technologies, direct co-firing is the most suitable for Vietnam context. Despite of low biomass ratio, direct co-firing offers low investment cost and could utilize most of the biomass feedstock. Vietnam has huge biomass potential, especially the agriculture and forestry residues. These biomasses should be considered first as feedstock for co-firing. Biomass pellets is also a good choice in term of technical features and local supply. However, the price of pellets is not yet competitive with coal or agricultural residues.Economic benefit of co-firing would be higher in the plants that has following features: assess to stable biomass supply, biomass price competitive with coal, incentives and support in term of market for renewable energy utilization and waste reduction. Vietnam should start experimenting co-firing in the coal power plants that located in the area where biomass resource is available, easy to collect and deliver to the plant, using imported coal such as Vinh Tan 2, Duyen Hai 1, Long Phuoc 1…; or the plants that are soon or already depreciated such as Ninh Binh, Uong Bi or Pha Lai to utilize the existing infrastructures.The case study of co-firing 5% rice straw with coal in Ninh Binh Coal Power Plant shows that co-firing could bring benefit to the plant owner in the condition that lack supporting mechanism for co-firing as well as with the absent of carbon credit. Farmers and workers that work in biomass supply chain also benefit from co-firing, especially farmers. In addition, co-firing provide significant positive externalities, in which the most notable is health benefit from reducing air-borne pollutants. Greenhouse gas emissions reduction adds a small part to the overall benefit of co-firing

Phân tích chi phí-lợi ích của đồng đốt sinh khối với than: Trường hợp nhà máy nhiệt điện Ninh Bình

National audienceĐồng đốt sinh khối với than là công nghệ tận dụng sinh khối để phát điện với mức chi phí thấp hơn rấtnhiều so với việc xây dựng nhà máy điện sinh khối. Đồng đốt giúp giảm bớt tác động của nhiệt điện thanđến kinh tế, môi trường và xã hội. Việt Nam có tiềm năng phát triển công nghệ này do có tiềm năng lớn vềsinh khối cũng như do Việt Nam sẽ tiếp tục phát triển các nhà máy nhiệt điện than trong vòng 2 thập kỷ tớitheo như Quy hoạch điện mới nhất.Trong số các công nghệ đồng đốt, đồng đốt trực tiếp là công nghệ phù hợp nhất đối với điều kiện Việt Namhiện nay. Mặc dù tỉ lệ đồng đốt thấp nhưng chi phí chuyển đối thấp nhất và có thể tận dụng hầu hết cácloại sinh khối. Việt Nam có nguồn sinh khối dồi dào, đặc biệt là nguồn phụ phẩm, phế phẩm nông nghiệp.Đây là các nguồn sinh khối nên được cân nhắc sử dụng trước tiên cho đồng đốt. Viên nén sinh khối cũnglà một lựa chọn tốt cho đồng đốt xét về các đặc tính kỹ thuật cũng như nguồn cung trong nước. Tuy nhiêngiá cả của viên nén chưa thực sự cạnh tranh được với than cũng như với nguồn phụ phẩm phế phẩm nôngnghiệp.Hiệu quả về mặt kinh tế của đồng đốt sinh khối với than sẽ cao hơn tại các nhà máy có các điều kiện nhưsau: sử dụng lò đốt than, tiếp cận được với nguồn cung sinh khối ổn định và có mức giá cạnh tranh, có giáthan cao, có các điều kiện ưu tiên về thị trường cũng như cơ chế đối với sử dụng năng lượng tái tạo vàgiảm rác thải. Việt Nam nên bắt đầu thí điểm với các nhà máy nhiệt điện than nằm tại các vùng có trữlượng sinh khối cao, thuận lợi cho việc thu gom và vận chuyển sinh khối, sử dụng than nhập khẩu có nguồncung than không ổn định và giá than cao như Vĩnh Tân 2, Duyên Hải 1, Long Phước 1...; hoặc các nhàmáy sắp hết thời gian khấu hao như Ninh Bình, Uông Bí hay Phả Lại 1 để tận dụng cơ sở hạ tầng sẵn có.Phân tích trường hợp đồng đốt 5% rơm với than tại nhà máy nhiệt điện Ninh Bình cho thấy đồng đốt đãmang lại hiệu quả kinh tế cho nhà máy trong điều kiện không có cơ chế chính sách hỗ trợ cho đồng đốtcũng như chưa có thị trường cacbon và doanh thu từ bán tro xỉ than. Mặt khác, lợi ích mà đồng đốt đemlại cho xã hội cũng như môi trường là rất đáng kể, đặc biệt là đối với người nông dân và sức khỏe cộngđồng. Các lợi ích này, nếu có cơ chế chia sẽ hợp lý sẽ có thể hỗ trợ cho nhà máy áp dụng đồng đốt đạthiệu quả cao hơn về mặt kinh tế

ANISOTROPIC POROCHEMOELECTROELASTIC SOLUTIONS FOR APPLICATIONS IN FIELD OPERATIONS AND LABORATORY CHARACTERIZATION OF SHALE

In this study, the porochemoelectroelastic formulation is explained in details and fully expanded to capture the well known anisotropic nature of shale. The formulation is then applied to derive the analytical solutions for rectangular strip sample, cylindrical sample, and inclined wellbore under various loading and in-situ conditions while being exposed to an external fluid. The newly-derived solutions can be considered as necessary extensions of some existing analytical solutions to capture the anisotropic and chemically active nature of shale formations. Numerical examples are also included to illustrate the applications of the derived solutions in shale formations. The results show that ignoring either the porochemoelectroelastic behavior or the anisotropic characteristic of the shale formation will mislead the predictions and assessment of potential problems in laboratory and field operations.In particular, the presence of negative fixed charges on the surface of clay minerals creates an osmotic pressure at the interface of the sample and the external fluid with magnitude proportional to the CEC of the sample. This Donnan-induced pore pressure when coupled with the load-generated pore pressure and the activity-generated pore pressure can result in significant tensile effective stresses and tensile damages in the shale. The results, thus, explain why some shales disintegrate when brought into contact with certain aqueous solutions while others do not.Practical implications for field operations have been drawn for both wellbore drilling and hydraulic fracturing. The analyses show clearly that the effective tangential stresses and, hence, the axial stresses around a wellbore are greatly affected by the formation anisotropic mechanical parameters. In addition, during drilling, the chemically-induced tensile effective radial stress and tangential stress can lead to wellbore spalling which in extreme cases may result in stuck pipe. On the other hand, during hydraulic fracturing, these induced tensile damages can weaken the shale formation leading to a wider fracture width and a shorter fracture length during the fracturing process. In addition, the damaged and weakened formation can exacerbate the problem of proppant embedment resulting in larger fracture closure and reduction of fracture length and productivity. Thus, the results explain why higher clay content intervals are often reported to be more "ductile" compared to lower clay content intervals. Moreover, the use of drilling mud and fracturing fluid having activity similar to the shale formation native pore fluid can help to prevent wellbore spalling and work for the advantage of the fracturing process.In the laboratory testing context, these complex pore pressure, stresses responses and distributions can complicate the interpretation of experimental results for the effects of fluid chemistry on the rock matrix. Practically, it is recommended to gradually adjust the testing fluid salt concentration or applied load to the desired value so that excessive induced stress and pore pressure buildup inside the tested sample become minimal.Finally, analysis for shale electrokinetic effects on pore pressure buildup during diagenesis suggests that, in addition to the intrinsically low permeability of shale, the semi-permeable membrane behavior of the clay matrix can effectively hinder the overall pore fluid diffusion process. As a result, the pore pressure buildup inside a shale formation can be much higher than in a clean sand formation under the same consolidation rate. Hence, taking into account shale electrokinetic effects in basin modeling may give better predictions of overpressure issues in shale

Multisource power splitting energy harvesting relaying network in half-duplex system over block Rayleigh fading channel: System performance analysis

Energy harvesting and information transferring simultaneously by radio frequency (RF) is considered as the novel solution for green-energy wireless communications. From that point of view, the system performance (SP) analysis of multisource power splitting (PS) energy harvesting (EH) relaying network (RN) over block Rayleigh-fading channels is presented and investigated. We investigate the system in both delay-tolerant transmission (DTT), and delay-limited transmission (DLT) modes and devices work in the half-duplex (HD) system. In this model system, the closed-form (CF) expressions for the outage probability (OP), system throughput (ST) in DLT mode and for ergodic capacity (EC) for DTT mode are analyzed and derived, respectively. Furthermore, CF expression for the symbol errors ratio (SER) is demonstrated. Then, the optimal PS factor is investigated. Finally, a Monte Carlo simulation is used for validating the analytical expressions concerning with all system parameters (SP).Web of Science81art. no. 6

Energy harvesting based two-way full-duplex relaying network over a Rician fading environment: performance analysis

Full-duplex transmission is a promising technique to enhance the capacity of communication systems. In this paper, we propose and investigate the system performance of an energy harvesting based two-way full-duplex relaying network over a Rician fading environment. Firstly, we analyse and demonstrate the analytical expressions of the achievable throughput, outage probability, optimal time switching factor, and symbol error ratio of the proposed system. In the second step, the effect of various parameters of the system on its performance is presented and investigated. In the final step, the analytical results are also demonstrated by Monte Carlo simulation. The numerical results proved that the analytical results and the simulation results agreed with each other.Web of Science68112311