Décomposition photocatalytique du méthanol sur des nanosphères de TiO₂ chargées de métal

353121\uThe utilization of solar light-driven photocatalysts has attracted an increasing attention in creating green energy and purifying environment from harmful pollutants. In photocatalysis technology, semiconductor-based photocatalysis has diverse applications including the decomposition of organic pollutants. In particular, titanium dioxide (TiO₂)-based photocatalysts have been extensively studied because of their low cost and outstanding physical and chemical properties. However, the photocatalytic performance of TiO₂ is not very high due to the weak light absorption and the fast charge carrier recombination. Therefore, the main target of the research presented in this thesis is to develop new methods to prepare more efficient materials based on TiO₂ for organic pollutants decomposition. For this purpose, the uniform titanate nanodisks (TNDs) with an average diameter of 22 nm were first synthesized by using different types of capping agents, including benzyl alcohol (BA), benzyl ether (BE) and oleylamine (OM). SiO₂ nanospheres (SiO₂ NSs) in nanoscale diameter as the core of the structure were then coated with TNDs using a layer-by-layer deposition technique in the presence of polyethylenimine (PEI) solution to design the TND-PEI/SiO₂ NSs. Based on the developed TND-PEI/SiO₂ NSs, creating a heterojunction between TiO₂ and other visible light active semiconductors is one of the interesting ways to optimize and enhance performance of TiO₂ in the visible region. In order to synthesize these TiO₂-based heterojunction composites, several cation (Cu²⁺, Ni²⁺, and Pt²⁺) solutions were loaded over TND-PEI/SiO₂ NSs to obtain CuO/TiO₂/SiO₂, Ni²⁺/TiO₂/SiO₂ or Pt²⁺/TiO₂/SiO₂ materials, respectively. The co-existence of CuO, Ni²⁺, and Pt²⁺ functioning as co-catalysts led to a remarkable enhancement of the photocatalytic performance of TiO₂. The new developed materials have shown not only high porosity and high specific surface area, but also strong solar light absorption. As a result, the photocatalytic activity of these new materials and the effect of different co-catalysts were investigated in the photocatalytic decomposition of methanol. TiO₂-based heterojunction composites (CuO/TiO₂/SiO₂) was further treated by H₂S. This non-metal doping TiO₂ is a well-known and effective way to decrease the band gap, which can result in the absorption of more visible light. The photodegradation of methanol in aqueous solution was deployed to test the photocatalytic activities of TiO₂-based material and further widens its applications in water treatment. These modifications proved that the light absorption of CuO/TiO₂ was improved compared with Ni²⁺/TiO₂ and Pt²⁺/TiO₂. CuO/TiO₂ material after H₂S treatment was found to exhibit a good performance in the degradation of methanol from aqueous solutions under solar light irradiation

The Interrelationship between Formal and Informal Delcentralization and its Impact on Sub-Central Governance Performance: The Case of Vietnam

Formal and informal institutions are often viewed as complements or substitutes in empirical and theoretical works. However, no evidence of complementarities or substitutes is found in our empirical analysis of the interrelation between formal and informal decentralization across 64 provinces of Vietnam. This paper finds that the formally decentralized system of public service supply is accommodating the informal one, but informal decentralization in public order provision tends to compete with the existing ineffective formal system. This implies that the central government needs to reorganize the system of decentralizing the provision of public goods/services and public in order to make informal institutions complementary rather than rival or free-riding on formal ones.formal decentralization, informal decentralization, sub-central governance, accommodating, and competing

RESEARCH ON FACTORS AFFECTING ONLINE SHOPPING INTENTION OF CUSTOMERS: THE EVIDENCE IN VIETNAM

Objective: The research clarifies the relationships among the four key factors: brand reputation, trust, customer service quality, and online shopping intentions.   Theoretical Framework: The research adopted the E-S-QUAL four dimensions to measure e-service quality, customer trust, and purchase intention in virtual environments. The research explores the role of seller reputation in the relationship between trust and online shopping by building a model with four variables, six hypotheses, and 21 observed variables.   Method: The snowball sampling technique was used. Quantitative research was used to evaluate and test the theoretical model with a sample size of N = 395 through the online survey. This study examined the scale through exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and structural equation modeling (SEM).   Results and Discussion: The results show that the research scales achieve unidirectional reliability, convergent validity, and high discriminant validity. Brand reputation has a positive impact on customer service through trust. Trust has a positive impact on online shopping intention through customer service.   Research Implications: This study only examines the role of brand reputation in the relationship between trust, customer service quality, and online shopping intention. Other important factors that affect this relationship may not be mentioned in the research.   Originality/Value: The article recommends improving Vietnamese consumers' confidence and online shopping intention by offering solutions for consumers, electronic sellers, and related associations and organizations

Trastuzumab: Updated Mechanisms of Action and Resistance in Breast Cancer

HER2-positive breast cancer accounts for 20–30% of all breast cancers and has the second-poorest prognosis among breast cancer subtypes. The approval of trastuzumab in 1998 has significantly improved patients’ outcomes and paved the way for the beginning of advent of targeted approaches in breast cancer treatment. However, primary or acquired resistance to trastuzumab has been increasingly recognized as a major obstacle in the clinical management of this disease. In addition, in clinical practice, there are currently no conclusive biomarkers for patient response to trastuzumab. Therefore, understanding the molecular mechanism of trastuzumab and the development of resistance to this drug are of interest. Such understanding will provide the guidance critically needed for the design of better combination therapy and will allow the appropriate selection of patients who are responsive to trastuzumab-based strategies. In line with that, our review highlights the well-accepted mechanisms of action and resistance to the therapy and discusses the progress that has been made toward successfully overcoming this resistance

Load and resistance factor design of drilled shafts at the service limit state

A practical and efficient procedure for evaluation of drilled shafts at the service limit state is proposed. The procedure uses Load and Resistance Factor Design (LRFD) concepts to achieve target probabilities of failure without requiring case-specific probabilistic analyses. Proposed resistance factors are primarily dependent on four parameters: the normalized load, the coefficient of variation of the geomaterial strength, the target probability of failure, and the shaft length-to-diameter ratio. The proposed procedure can be implemented using several charts or analytical equations provided.Includes bibliographical references (pages 378-381)

PHD Defence: “Now Playing, You: Big Data and the Production of Music Streaming Space†by Robert Prey

Our dear colleague, Robert Prey, will defend his PhD dissertation on Tuesday, November 3rd, 2015 at Harbour Centre, Room 1520 (10:30 am -1:30 pm). Here is the abstract of his dissertation “Now Playing, You: Big Data and the Production of Music Streaming Space”

LMI based antiswing adaptive controller for uncertain overhead cranes

This paper proposes an adaptive anti-sway controller for uncertain overhead cranes. The state-space model of the 2D overhead crane with the system parameter uncertainties is shown firstly. Next, the adaptive controller which can adapt with the system uncertainties and input disturbances is established. The proposed controller has ability to move the trolley to the destination in short time and with small oscillation of the load despite the effect of the uncertainties and disturbances. Moreover, the controller has simple structure so it is easy to execute. Also, the stability of the closed-loop system is analytically proven. The proposed algorithm is verified by using Matlab/Simulink simulation tool. The simulation results show that the presented controller gives better performances (i.e., fast transient response, position tracking, and low swing angle) than the state feedback controller when there exist system parameter variations as well as input disturbances

MA Defence: “Creativity Within Constraints: Encoding, Production, and Representation in Battlestar Galactica†by Philippa Adams

Our dear colleague, Philippa Adams, will defend her MA Thesis on Friday, December 10th, 2015 at Harbour Centre, Room 1520 (2:00 pm - 4:00 pm). Here is the abstract of her thesis “Creativity Within Constraints”