scholarly journals Application and Development Progress of Cr-Based Surface Coatings in Nuclear Fuel Element: I. Selection, Preparation, and Characteristics of Coating Materials

Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 808 ◽  
Author(s):  
Huan Chen ◽  
Xiaoming Wang ◽  
Ruiqian Zhang
Keyword(s):  
Nuclear Fuel ◽  
Selection Process ◽  
Zirconium Alloys ◽  
Surface Coatings ◽  
Coating Materials ◽  
Preparation Methods ◽  
Advantages And Disadvantages ◽  
Nuclear Fuel Element ◽  
Short Period ◽  
Fuel Design

To cope with the shortcomings of nuclear fuel design exposed during the Fukushima Nuclear Accident, researchers around the world have been directing their studies towards accident-tolerant fuel (ATF), which can improve the safety of fuel elements. Among the several ATF cladding concepts, surface coatings comprise the most promising strategy to be specifically applied in engineering applications in a short period. This review presents a comprehensive introduction to the latest progress in the development of Cr-based surface coatings based on zirconium alloys. Part I of the review is a retrospective look at the application status of zirconium alloy cladding, as well as the development of ATF cladding. Following this, the review focuses on the selection process of ATF coating materials, along with the advantages and disadvantages of the current mainstream preparation methods of Cr-based coatings worldwide. Finally, the characteristics of the coatings obtained through each method are summarized according to some conventional performance evaluations or investigations of the claddings. Overall, this review can help assist readers in getting a thorough understanding of the selection principle of ATF coating materials and their preparation processes.

Domestic and Foreign Research and Utilization Status of Zirconium Resources

2013 ◽  
Vol 821-822 ◽  
pp. 854-859
Author(s):  
Zhi Jie Wu ◽  
Yun Gang Li ◽  
Zong Ying Cai ◽  
Jun Zhou ◽  
Yong Zhi Huang
Keyword(s):  
Zirconium Alloys ◽  
Chemical Equipment ◽  
Nuclear Industry ◽  
Preparation Methods ◽  
Military Industry ◽  
Comprehensive Utilization ◽  
Advantages And Disadvantages ◽  
Zirconium Compounds ◽  
Important Position ◽  
Development Tendency

Zirconium resources and materials are important strategic materials, occupying the important position in national military industry. The applications of zirconium resources such as zirconium, zirconium alloys and zirconium compounds in chemical equipment, nuclear industry and ceramic industry are introduced. The distribution of zirconium resources in the domestic and abroad and several methods for preparing zirconium are also introduced. At the same time discussing the advantages and disadvantages of preparation methods, and pointing out that the electrolytic deoxidization method has broad application prospects. At last, the development tendency of the comprehensive utilization of zirconium resources in China is discussed.

scholarly journals Bodipy-Loaded Micelles Based on Polylactide as Surface Coating for Photodynamic Control of Staphylococcus aureus

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 223
Author(s):  
Enrico Caruso ◽  
Viviana Teresa Orlandi ◽  
Miryam Chiara Malacarne ◽  
Eleonora Martegani ◽  
Chiara Scanferla ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pathogenic Bacteria ◽  
Surface Coatings ◽  
Supramolecular System ◽  
Amphiphilic Copolymers ◽  
Oxygen Penetration ◽  
Short Period ◽  
Excellent Activity ◽  
Coating Matrix ◽  
Photodynamic Control

Decontaminating coating systems (DCSs) represent a challenge against pathogenic bacteria that may colonize hospital surfaces, causing several important infections. In this respect, surface coatings comprising photosensitizers (PSs) are promising but still controversial for several limitations. PSs act through a mechanism of antimicrobial photodynamic inactivation (aPDI) due to formation of reactive oxygen species (ROS) after light irradiation. However, ROS are partially deactivated during their diffusion through a coating matrix; moreover, coatings should allow oxygen penetration that in contact with the activated PS would generate 1O2, an active specie against bacteria. In the attempt to circumvent such constraints, we report a spray DCS made of micelles loaded with a PS belonging to the BODIPY family (2,6-diiodo-1,3,5,7-tetramethyl-8-(2,6-dichlorophenyl)-4,4′-difluoroboradiazaindacene) that is released in a controlled manner and then activated outside the coating. For this aim, we synthesized several amphiphilic copolymers (mPEG–(PLA)n), which form micelles, and established the most stable supramolecular system in terms of critical micelle concentration (CMC) and ∆Gf values. We found that micelles obtained from mPEG–(PLLA)2 were the most thermodynamically stable and able to release BODIPY in a relatively short period of time (about 80% in 6 h). Interestingly, the BODIPY released showed excellent activity against Staphylococcus aureus even at micromolar concentrations.

scholarly journals Review on stationary phases and coating methods of MEMs gas chromatography columns

2020 ◽  
Vol 39 (1) ◽  
pp. 247-259
Author(s):  
Liu Yang ◽  
Molin Qin ◽  
Junchao Yang ◽  
Genwei Zhang ◽  
Jiana Wei
Keyword(s):  
Gas Chromatography ◽  
Microelectromechanical Systems ◽  
Stationary Phases ◽  
Preparation Methods ◽  
Site Analysis ◽  
Advantages And Disadvantages ◽  
Coating Methods ◽  
On Line ◽  
Inorganic Adsorbents ◽  
Gas Chromatography Columns

Abstract Gas chromatography (GC) is an important and widely used technique for separation and analysis in the field of analytical chemistry. Micro gas chromatography has been developed in response to the requirement for on-line analysis and on-site analysis. At the core of micro gas chromatography, microelectromechanical systems (MEMs) have the advantages of small size and low power consumption. This article introduces the stationary phases of micro columns in recent years, including polymer, carbon materials, silica, gold nanoparticles, inorganic adsorbents and ionic liquids. Preparation techniques ranging from classical coating to unusual sputtering of stationary phases are reviewed. The advantages and disadvantages of different preparation methods are analyzed. The paper introduces the separation characteristics and application progress of MEMs columns and discusses possible developments.

scholarly journals Impact of anti-biofouling surface coatings on the properties of nanomaterials and their biomedical applications

2018 ◽  
Vol 6 (1) ◽  
pp. 9-24 ◽  
Author(s):  
Yuancheng Li ◽  
Yaolin Xu ◽  
Candace C. Fleischer ◽  
Jing Huang ◽  
Run Lin ◽  
...  
Keyword(s):  
Surface Coating ◽  
Biomedical Applications ◽  
Biological Systems ◽  
Surface Coatings ◽  
Specific Interactions ◽  
Coating Materials

Various anti-biofouling surface coating materials for nanoparticles have been reviewed for the reduction of their non-specific interactions with biological systems.

Factors Affecting Gelation of Lidocaine Hydrochloride-Loaded Polyelectrolyte Complex Thermosensitivity Gel for Dry Socket Treatment

2021 ◽  
Vol 901 ◽  
pp. 111-116
Author(s):  
Nuttawut Supachawaroj ◽  
Sucharat Limsitthichaikoon
Keyword(s):  
Polyelectrolyte Complex ◽  
Gelation Time ◽  
Lidocaine Hydrochloride ◽  
Gelation Temperature ◽  
High Concentration ◽  
Preparation Methods ◽  
Factors Affecting ◽  
Dry Socket ◽  
Short Period ◽  
Gel Preparation

Dry socket disease, a pocket wound caused by the tooth extraction that resulted in severe acute pain which requires a topical analgesic with rapidly pain reduction and suppress the pain until the wound healed. This study aimed to investigate factors affecting gelation temperature and gelation time of lidocaine hydrochloride (LH)-loaded polyelectrolyte complex (PEC) thermosensitivity gel for treating dry socket wound. The first factor was investigated the effects of the ratio of three different types of polymers as chitosan (CS), hyaluronic acid (HA) and poloxamer407 (P407) on the phase transition caused by temperature. The second factor was examined the effects of gel preparation methods. The results showed that increasing concentration of the cationic polymer as CS induced the separation of the solution to gel (sol-to-gel) system due to the charge of CS and the charge of PEC. The ratio of HA:P407 affected the gel forming which high concentration of P407 reduced the gelation temperature while low concentration of HA disturbed the sol-to-gel state causing coagulation. The viscosity, spreadability, and swelling were significantly increased due to the concomitant increased in each polymer, HA and P407. The particle of the formulation observed under microscope was found to be less than 1 µm. Phase inversion from sol-to-gel was found after a min at 23°C. Since gelation temperature of the purposed formula is supposed to form gel below 37°C within a short period of injection. The results of the study indicate the suitable sol-to-gel forming in the appropriate temperature and time which should be used for further investigation in the efficacy and safety.

scholarly journals Application of Gold-Nanoparticle Colorimetric Sensing to Rapid Food Safety Screening

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4166 ◽  
Author(s):  
Guangyang Liu ◽  
Meng Lu ◽  
Xiaodong Huang ◽  
Tengfei Li ◽  
Donghui Xu
Keyword(s):  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Rapid Testing ◽  
Colorimetric Sensing ◽  
Preparation Methods ◽  
Particle Spacing ◽  
Advantages And Disadvantages ◽  
Site Monitoring ◽  
Biological Affinity ◽  
Food Quality And Safety

Due to their unique optical properties, narrow size distributions, and good biological affinity, gold nanoparticles have been widely applied in sensing analysis, catalytic, environmental monitoring, and disease therapy. The color of a gold nanoparticle solution and its maximum characteristic absorption wavelength will change with the particle size and inter-particle spacing. These properties are often used in the detection of hazardous chemicals, such as pesticide residues, heavy metals, banned additives, and biotoxins, in food. Because the gold nanoparticles-colorimetric sensing strategy is simple, quick, and sensitive, this method has extensive applications in real-time on-site monitoring and rapid testing of food quality and safety. Herein, we review the preparation methods, functional modification, photochemical properties, and applications of gold nanoparticle sensors in rapid testing. In addition, we elaborate on the colorimetric sensing mechanisms. Finally, we discuss the advantages and disadvantages of colorimetric sensors based on gold nanoparticles, and directions for future development.

scholarly journals A critical review on the development and performance of polymer/graphene nanocomposites

2018 ◽  
Vol 25 (6) ◽  
pp. 1059-1073 ◽  
Author(s):  
Weifeng Chen ◽  
Hu Weimin ◽  
Dejiang Li ◽  
Shaona Chen ◽  
Zhongxu Dai
Keyword(s):  
Polymer Nanocomposites ◽  
Electronic Conductivity ◽  
Future Research ◽  
Preparation Methods ◽  
Graphene Nanocomposites ◽  
Advantages And Disadvantages ◽  
Solution Blending ◽  
Potential Applications ◽  
New Type ◽  
And Performance

AbstractGraphene (graphene) is a new type of two-dimensional inorganic nanomaterial developed in recent years. It can be used as an ideal inorganic nanofiller for the preparation of polymer nanocomposites because of its high mechanical strength, excellent electrical conductivity and plentiful availability (from graphite). In this review, the preparation methods of graphene/polymer nanocomposites, including solution blending, melt blending and in situ polymerization, are introduced in order to study the relationship between these methods and the final characteristics and properties. Each method has an influence on the final characteristics and properties of the nanocomposites. The advantages and disadvantages of these methods are discussed. In addition, a variety of nanocomposites with different properties, such as mechanical properties, electronic conductivity, thermal conductivity and thermal properties, are summarized comprehensively. The potential applications of these nanocomposites in conductive materials, electromagnetic shielding materials, photocatalytic materials and so on, are briefly presented. This review demonstrates that polymer/graphene nanocomposites exhibit superior comprehensive performance and will be applied in the fields of new materials and novel devices. Future research directions of the nanocomposites are also presented.

Survey of residency program directors’ perceptions of nontraditional pharmacy residency applicants

2019 ◽  
Vol 76 (21) ◽  
pp. 1788-1793
Author(s):  
Amanda J Khalil ◽  
Krutika N Mediwala ◽  
Meera Mehta ◽  
Amy J Yanicak ◽  
Jared S Ham ◽  
...  
Keyword(s):  
Residency Program ◽  
Work Experience ◽  
Selection Process ◽  
Pharmacy Practice ◽  
Program Directors ◽  
Qualitative Assessment ◽  
Secondary Outcome ◽  
Residency Programs ◽  
Advantages And Disadvantages ◽  
Residency Program Directors

Abstract Purpose The attitudes and expectations of residency program directors (RPDs) regarding nontraditional residency applicants (NTAs) were evaluated. Methods This was a cross-sectional, survey-based study targeting RPDs of American Society of Health-System Pharmacists–accredited residency programs. A 14-question survey requesting information related to demographics, perceptions of NTAs compared with traditional applicants, advantages and disadvantages of NTAs, and advice for NTAs was administered electronically to RPDs. The primary outcome of this study was to determine RPDs’ perceptions of NTAs as suitable residency candidates. The secondary outcome evaluated the rate of NTA acceptance into residency programs and a qualitative assessment of RPDs’ advice for NTAs. Results Of the 1,414 RPDs contacted to participate, 328 (23%) completed the survey. RPDs were primarily affiliated with postgraduate year 1 pharmacy practice (52%) or postgraduate year 2 specialty residencies (30%), and 35% reported having an NTA in their program. Most respondents (87%) reported that NTAs are given equal consideration relative to traditional residency applicants. RPDs rated work experience as the most important quality of an NTA, followed closely by the ability to work with others and teachability. Most (277 [85%]) RPDs agreed that NTAs should possess experiences beyond work experience, such as research, leadership, and community service. The biggest concern regarding NTAs was significant time since graduation prior to application. Conclusion The majority of RPDs did not perceive NTAs differently from traditional applicants in the selection process of prospective candidates.

Reliability in Microjoining Processes for Instrumented Nuclear Fuel Element Fabrication

2020 ◽  
Vol 1157 ◽  
pp. 31-37
Author(s):  
Călin Truţă ◽  
Adrian Amzoi ◽  
Dumitru Barbos
Keyword(s):  
Fuel Element ◽  
Nuclear Fuel ◽  
Structural Reliability ◽  
Added Value ◽  
Impedance Match ◽  
Normal Operation ◽  
Local Loss ◽  
Steel Coil ◽  
Nuclear Fuel Element ◽  
Prolonged Contact

The paper presents the assembling flux of thermocouple-instrumented nuclear fuel element for research reactor, from the point of view of the welding / brazing engineer, considering nuclear quality and safety requirements: fuel element structural reliability (no radioactive leaks through joints) and temperature signal reliability (thermocouple sheath integrity), this signal being an essential parameter for reactor normal operation and emergency shut-down. The paper is a real case study for an experimental instrumented element recently developed at INR-Pitesti describing technology choices as balance between fabrication complexity and risk of failure in joining processes, especially in later stages when added value increases. All joints (welded or brazed) fall into microjoining category, and it is shown how some special provisions may influence reliability. Focus is put on brazing thin-walled Inconel sheathed thermocouples, where erosion and local loss of ductility are known issues, leading to sheath rupture. Choosing as filler the less aggressive BNi-9 helped too little. A simple but efficient technique has been developed to address this matter adequate to narrow spaces inside a nuclear fuel element, where no room is available for solutions described in literature e.g. distal preplacing of filler. The solution prevents sheath from having prolonged contact with large volume of molten filler by using locally a miniature barrier (thin stainless-steel coil or sleeve) which only allows capillary wetting, being also a perfect real-time visual indicator of brazing progress and completion. As proved in the present paper, this method along with using filler formulation with lower Carbon content (without organic binder) enhances significantly, 8 times at least, resistance to bending fatigue. A particular vacuum brazing chamber design is employed: narrow quartz tube with external induction coil and top fitting letting outside the long thermocouples attached, reducing much the chamber volume and degassing. Careful impedance match is therefore required to overcome induction power loss due to the larger coil-to-workpiece gap. Additional joining problems are discussed e.g. inherent differential expansion of long parts during induction heating which afterwards may put tension upon braze during solidification and determine delayed cracking, this being avoided through wise order of operations. Another concern is the final precision weld between instrumentation segment having attached the hard-to-handle long thermocouples bunch and nuclear segment with the heavy Uranium pellets. The result of this research is successful assembling of first Romanian prototype with joints exhibiting He leak rate bellow 1E-09 std.cc/sec and overall reliability proved during reactor irradiation testing.

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