Transfer Control for Resilient End-to-End Transport

Residing between the network layer and the application layer, the transport layer exchanges application data using the services provided by the network. Given the unreliable nature of the underlying network, reliable data transfer has become one of the key requirements for those transport-layer protocols such as TCP. Studying the various mechanisms developed for TCP to increase the correctness of data transmission while fully utilizing the network's bandwidth provides us a strong background for our study and development of our own resilient end-to-end transport protocol. Given this motivation, in this thesis, we study the different TCP's error control and congestion control techniques by simulating them under different network scenarios using ns-3. For error control, we narrow our research to acknowledgement methods such as cumulative ACK - the traditional TCP's way of ACKing, SACK, NAK, and SNACK. The congestion control analysis covers some TCP variants including Tahoe, Reno, NewReno, Vegas, Westwood, Westwood+, and TCP SACK

ResTP: A Configurable and Adaptable Multipath Transport Protocol for Future Internet Resilience

Motivated by the shortcomings of common transport protocols, e.g., TCP, UDP, and MPTCP, in modern networking and the belief that a general-purpose transport-layer protocol, which can operate efficiently over diverse network environments while being able to provide desired services for various application types, we design a new transport protocol, ResTP. The rapid advancement of networking technology and use paradigms is continually supporting new applications. The configurable and adaptable multipath-capable ResTP is not only distinct from the standard protocols by its flexibility in satisfying the requirements of different traffic classes considering the characteristics of the underlying networks, but by its emphasis on providing resilience. Resilience is an essential property that is unfortunately missing in the current Internet. In this dissertation, we present the design of ResTP, including the services that it supports and the set of algorithms that implement each service. We also discuss our modular implementation of ResTP in the open-source network simulator ns-3. Finally, the protocol is simulated under various network scenarios, and the results are analyzed in comparison with conventional protocols such as TCP, UDP, and MPTCP to demonstrate that ResTP is a promising new transport-layer protocol providing resilience in the Future Internet (FI)

Vietnam's socioeconomic status influence on the passport power

Passports are indeed becoming increasingly important in our interconnected world. As the world becomes more interconnected through trade, travel, and digital communication, the need for international travel has grown. Passports are essential for individuals to move across borders, whether for tourism, business, or personal reasons. International education and employment opportunities have become more accessible and desirable. Students and professionals often need passports to study or work abroad. Countries with stable political and economic conditions tend to have passports that grant their citizens greater visa-free access to other nations. As a result, passport strength can be a reflection of a country's overall stability and standing in the world. Many countries enter into bilateral or multilateral agreements to allow visa-free travel between their citizens. A strong passport, with visa-free access to many countries, can simplify travel and reduce costs and administrative burdens. Indeed, a country's socioeconomic status can have a significant impact on its passport power. The socioeconomic factors of a nation, such as its economic strength, political stability, and human development indicators, often correlate with the global acceptance and strength of its passport.  While socioeconomic factors are important, it's essential to remember that passport power is a complex interplay of various elements, including diplomatic relations, international agreements, and economic strength. Therefore, while socioeconomic status is a crucial element, it is just one piece of the puzzle in determining a passport's global influence

Food Loss and Food Waste as Global Issues

ABSTRACTThe entire world is facing significant challenges in the coming decades. It has been demonstrated that many countries must prepare themselves to face a considerable rise in food consumption and corresponding food waste. There must be a cooperation of consumers, retailers, producers and government to solve this complex issue. Their efforts to decrease food waste would offer a significant sustainable alternative to scale up food manufacturing that leading to a stabling food security internally and internationally. Governments and businesses should develop food loss and food waste prevention throughout the entire supply chain. There should be a higher effort on decreasing post-harvest losses in early stages in the food value chain in the developing countries. Meanwhile, in the developed countries, the government should have policies to reduce food waste at consumer level which could minimize food being unnecessarily thrown away. Governments should also support the establishment of independent organizations which could facilitate and assess efforts to decrease food waste, such as the WRAP in the UK in grocery and hospitality supply chain.Keywords: food loss, food waste, food value chain, reuse, cycl

Food Loss and Food Waste as Global Issues

The entire world is facing significant challenges in the coming decades. It has been demonstrated that many countries must prepare themselves to face a considerable rise in food consumption and corresponding food waste. There must be a cooperation of consumers, retailers, producers and government to solve this complex issue. Their efforts to decrease food waste would offer a significant sustainable alternative to scale up food manufacturing that leading to a stabling food security internally and internationally. Governments and businesses should develop food loss and food waste prevention throughout the entire supply chain. There should be a higher effort on decreasing post-harvest losses in early stages in the food value chain in the developing countries. Meanwhile, in the developed countries, the government should have policies to reduce food waste at consumer level which could minimize food being unnecessarily thrown away. Governments should also support the establishment of independent organizations which could facilitate and assess efforts to decrease food waste, such as the WRAP in the UK in grocery and hospitality supply chain. Keywords: food loss, food waste, food value chain, reuse, cycl

Layered double hydroxides as containers of inhibitors in organic coatings for corrosion protection of carbon steel

The present work focuses on the use of layered double hydroxides (LDH) as containers for corrosion inhibitors in an epoxy coating. 2-Benzothiazolylthio-succinic acid (BTSA), used as corrosion inhibitor, was intercalated by co-precipitation in magnesium-aluminum layered double hydroxides. The obtained LDH-BTSA was characterized by infrared spectroscopy, X-ray diffraction and scanning electron microscopy. BTSA release from LDH-BTSA in NaCl solutions was investigated by UV-vis spectroscopy. The inhibitive action of LDH-BTSA on carbon steel corrosion was characterized by electrochemical methods and the protective properties of an epoxy coating containing LDH-BTSA were evaluated by electrochemical impedance spectroscopy. It was shown that the BTSA was intercalated in the layered double hydroxide and its loading was about 33%. The BTSA release was dependent on the NaCl concentration in the electrolyte. The polarization curves obtained on the carbon steel sample showed that the LDH-BTSA is an anodic inhibitor. Its efficiency was about 90% at a concentration of 3 g/l. The impedance results showed that the incorporation of LDH-BTSA (3%) in the epoxy matrix improved the corrosion protection of the carbon steel

HIGH PROTECTION PERFORMANCE OF COATING SYSTEMS BASED ON ZINC RICH PRIMER AND FLUOROPOLYMER COATING

Coating systems based on zinc rich primer and fluoropolymer top coat were exposed for 8 years at different atmospheric stations in Vietnam: Hanoi, Ha Long and Nha Trang. For comparison the coating system with zinc rich primer and polyurethane topcoat was also tested. The degradations of coating systems were evaluated by gloss measurement and electrochemical impedance spectroscopy. The obtained results show that coating systems with zinc rich primer and top coatings based on fluoropolymer  and polyurethane topcoats show very high weather resistance and corrosion protection performance, but the systems with fluoropolymer are better than coating system with polyurethane topcoat

QUÁ TRÌNH CHUYỂN PHA PHI CÂN BẰNG CỦA VẬT LIỆU HAI CHIỀU PENTA-GRAPHENE

Graphene has received enormous attention in the semiconductor industry during the last two decades. However, since graphene is a gapless semiconductor, it has critical challenges to be engineered into semiconductor devices. Recent reports have shown that penta-graphene stands out as a promising semiconductor candidate with an electronic bandgap between 2.2 and 4.3 eV; thus, it can surmount graphene’s obstacles. However, when being heated, penta-graphene can transform its configurations from pentagonal lattices to hexagonal graphene-like heterostructures, resulting in a significant electronic modification. In this paper, we investigate the effect of heating rates on the non-equilibrium phase transition of a two-dimensional penta-graphene by using molecular dynamic simulations. We have shown that, with a fast-heating process, penta-graphene naturally transforms to graphene without a clear phase separation point. Nevertheless, with a sufficiently slow heating protocol, this transition is a first-order phase transition from a pentagonal to a more stable hexagonal configuration. These results provide the possibility to implement penta-graphene in future optoelectronic devices.Graphene đã được chứng minh là vật liệu mang tính đột phá cho ngành vật liệu bán dẫn. Tuy nhiên, với độ rộng vùng cấm gần như bằng không, graphene có những hạn chế nhất định khi được ứng dụng để chế tạo linh kiện điện tử. Các nghiên cứu gần đây cho thấy penta-graphene với độ rộng vùng cấm 2,2–4,3 eV và độ bền cơ – nhiệt cao có thể dung hòa nhược điểm của graphene. Tuy nhiên, khi bị nung nóng, penta-graphene có thể chuyển từ cấu trúc vòng 5 điển hình sang cấu trúc vòng 6 của graphene, nhưng điều kiện cụ thể để quá trình chuyển pha này hình thành vẫn chưa được nghiên cứu chi tiết. Trong bài báo này, chúng tôi nghiên cứu sự ảnh hưởng của tốc độ nung đến tính chất nhiệt động phi cân bằng của penta-graphene bằng phương pháp mô phỏng động học phân tử. Ở tốc độ nung lớn, penta-graphene sẽ dần chuyển sang graphene mà không có điểm chuyển pha rõ nét. Tuy nhiên, nếu penta-graphene được nung rất chậm, quá trình chuyển pha từ penta-graphene sang graphene là quá trình chuyển pha loại I với sự gián đoạn của thông số nhiệt động tại điểm chuyển pha. Kết quả này sẽ góp phần bổ sung các thông số kỹ thuật quan trọng trong việc ứng dụng vật liệu penta-graphene để chế tạo các linh kiện quang – điện tử trong tương lai

Improvement of adherence and anticorrosion properties of an epoxy-polyamide coating on steel by incorporation of an indole-3 butyric acid-modified nanomagnetite

In this study, synthesized magnetite (Fe 3 O 4 ) nanoparticles were treated with a corrosion inhibitor, indole-3 butyric acid (IBA) and incorporated in an epoxy-polyamide coating. The coating was applied on a carbon steel substrate. For comparison, coatings with- out particles or with nontreated Fe 3 O 4 particles were also prepared. The IBA-modified nanomagnetite (IBA–Fe 3 O 4 ) was characterized by infrared spec- troscopy and Zeta potential measurements. The inhibitive action of IBA was shown by electrochemical measurements (polarization curves) performed for a bare carbon steel in 0.1 M NaCl solution containing Fe 3 O 4 or IBA–Fe 3 O 4 nanoparticles. Adherence and anticorrosion properties of the epoxy-based coatings containing Fe 3 O 4 or IBA–Fe 3 O 4 were compared to those of the pure epoxy-polyamide resin by dry and wet adherence measurements and by salt spray test. The results showed significant improvement of the film adherence and higher corrosion protection of the carbon steel in the presence of IBA–Fe 3 O 4 . It was concluded that the IBA effect was restricted to the metal/coating interface