Littérature scientifique sur le sujet « Fluorine introduct »

The research progress of fluorine-containing acrylate monomers and their polymers has been discussed. These monomers were classified systematically according to chemical structure, such as perfluoroalkylinyl esters monomers, methyl trifluoroacrylate monomers, and so on. The synthesis of fluorinate acrylate and their polymerization were introduced. In addition, the features of these fluoride-containing chemicals were discussed as well as their applications on fabrics and research trend.

A large amount of fluorine−containing wastewater was produced with the rapid development of the industry. Excessive fluoride content in water will not only endanger ecological security but also pose threat to human health. In this study, common new adsorbents for defluorination, such as metal−based adsorbents, natural adsorbents, and nanomaterial adsorbents were reviewed for its physicochemical properties and fluorine removal efficiency. The fluorine removal mechanism of different adsorbents was introduced in detail, and the future work of the removal of fluorine using novel adsorbents was proposed. This research also introduces the application of the coupling of the adsorption method with the technology of chemical precipitation, filtration, and super−magnetic separation to treat high concentration of fluoride wastewater. A good selection of process combinations according to different needs can achieve high−efficiency defluorination in water. Finally, some existing problems of practical operation of fluorine using removal materials in the environment are summarized, hoping to contribute to the future research of fluorine removal materials.

This paper introduced fluorite resource profiles on the basis of elaborated China fluorite resource utilization status, focusing on analysis of fluorite in the fluorine chemical industry, discusses the problems of our country in the fluorine chemical industry development and firefly stone rational use of resources and the sustainable development of China's fluorine chemical industry recommendations.

An additional photodetector array BLPP-369 was installed on a «Grand-Potok» complex for rapid atomic-emission determination of the fluorine concentration in fluorite samples. Introduction of fluorite samples was carried out using the spill-injection method simultaneously with high pure calcium oxide introduction using the second conveyor belt. The use of an additional photodetector array with a spectral range of 528 – 536 nm provides the possibility of expanding the spectrum of CaF molecular lines with the intensity sufficient for determination of fluorine concentrations in fluorite samples. A calibration curve for fluorine determination in a concentration range of 0.12 – 47.63% was plotted using measurement results for 200 fluorite samples. Integration of the additional photodetector array provided increased detection limit for the mass fractions of fluorine up to the maximum possible concentrations in fluorite samples. The observed effect simplifies and speeds up the analysis in the absence of the necessity to dilute the sample, thus reducing the error of measurements. The results show that there is no need to introduce additional buffer mixtures (except CaO) and use reference lines to determine the fluorine concentration, which also simplifies the measurement procedure.

We demonstrate fluorine intercalation into Bi2Sr2CaCu2O8+x (BSCCO) flakes, as thick as 100 nm, by back-gating a single crystalline LaF3 substrate. Element-sensitive analysis not only confirms the presence of fluorine in BSCCO after gating but also reveals lateral diffusion of fluorine in BSCCO. Transport measurements further demonstrate the hole-doping effect of fluoride ions in BSCCO through effective modulation of the superconducting transitions. Our work introduces a distinct type of ions (F−) that can be intercalated into materials via solid state back-gating. It broadens the toolbox of ion back-gating and is useful for addressing exotic phenomena in the heavily hole doped regime.

It has been proved that among the factors influencing the level of dental caries and the course of this disease, the amount of fluoride that enters the body is a determining factor. Under normal conditions the main source is drinking water. The anti-carious effect is inherent in fluoride, as contained in natural waters, and artificially introduced into the water. Once in the body, fluoride is firmly attached to the enamel. At the same time in the enamel prisms represented by hydroxyapatite, one of the hydroxyl groups is replaced by fluorine, forming a hard-to-solve fluorapatite. This view of the mechanism of the anti-carious effect of fluoride is quite reasonable.

As a functional decorative material on the surface of printing and packaging, coating plays the role of increasing gloss, wear resistance, and antifouling. It has broad application prospects in high-end printed materials such as posters, art reproductions, and maps. In this paper, dodecafluoroheptyl methacrylate was used as the fluorine-containing monomer, which was used to modify the epoxy resin and introduce fluoride first. Under the action of polymerization inhibitor and catalyst, the epoxy resin was further modified by ring opening, esterification, and neutralization with acrylic acid, maleic anhydride, and organic base as raw materials. Additionally, a fluorine-containing coating with hydrophobic and oleophobic properties was obtained finally. The effects of fluorine modification of epoxy resin and synthetic polymer were characterized by infrared spectrometer and photoelectron spectroscopy. The results showed that fluorine monomer could be successfully grafted to the molecular body of epoxy resin, and fluorine had been introduced into the surface of the polymer film. Using the contact angle tester, combined with the performance parameters such as grafting rate, thermal stability, adhesion, and gloss, the effects of the amount of fluorine monomer on the properties of the synthetic coating were discussed. The results showed that the hydrophobic and oleophobic properties of the copolymer film surface were closely related to the amount of fluorine monomer. When the molar ratio of the epoxy group to dodecafluoroheptyl methacrylate was 26:1, the mass fraction of fluorine on the film surface was 18.09%, and the contact angles of water and ethylene glycol were 121.8° and 78.2° respectively. At the same time, the printability of self-made hydrophobic and oleophobic coating was tested in this paper. The liquid repellency of inkjet printing before and after glazing and the influence of the coating on the optical properties of printed images were discussed and studied too. The results showed that the coating synthesized by the experiment was suitable for inkjet printing. It had improved the printing quality performance and the functional modification on the surface of inkjet printings, such as liquid repellency, gloss, and color reproduction.

As an important strategic non-metallic mineral resource, fluorite has been widely used in various industrial fields, such as metallurgy, optics and semiconductor manufacturing, as well as fluorine-related chemical engineering. Since the major gangue minerals of fluorite ore are silicate and carbonate ones, flotation is the main beneficiation method for the concentration. Compared with the relatively easy operation for silicate-type fluorite ore, fluorite concentration from calcite has always been the most difficult challenge in the field of mineral processing. In this review, analyses of the fundamental reasons for the difficulties of flotation separation of fluorite from calcite are performed, from the similar surface properties of both calcium minerals to the deterioration by the interference of dissolved ions in the pulp during grinding and flotation. Recent achievements in the flotation separation of fluorite from calcite as the main contents are comprehensively summarized, covering all aspects of flotation reagents of collectors, depressants and modifiers. Finally, successful examples of industrial practices forfluorite and calcite flotation separation are introduced. This overview provides a detailed and comprehensive reference source for the current research status of fluorite and calcite flotation separation, and some suggestions for future research are provided.

Incorporation of [18F]fluorine into PET radiotracer structure has traditionally been accomplished via nucleophilic pathways. The [18F]fluoride is generated in an aqueous solution via proton irradiation of oxygen-18 enriched water and must to be introduced into water-free organic solutions in order to generate reactive species. Thus nucleophilic 18F-fluorination traditionally included steps for [18F]fluoride concentration on the anion exchange resin, followed by removal of residual water via azeotropic distillation with MeCN, a time-consuming process associated with radioactivity losses and difficult automation. To circumvent this, several adsorption/elution protocols were developed based on the minimization of water content in traditional kryptofix-based [18F]fluoride eluents. The use of pre-dried KOH/kryptofix solutions, tertiary alcohols, and strong organic bases was found to be effective. Advances in transition metal-mediated SNAr approaches for radiolabeling of non-activated aromatic substrates have prompted development of alternative techniques for reactive [18F]fluoride species generation, such as organic solutions of non-basic alkyl ammonium and pyridinium sulfonates, etc. For radiofluorinations of iodonium salts precursors, a “minimalist” approach was introduced, avoiding the majority of pitfalls common to more complex methods. These innovations allowed the development of new time-efficient and convenient work-up procedures that are easily implementable in modern automated synthesizers. They will be the subject of this review.

The content of fluoride was determined with an ion-specific electrode on 59 samples of honey from 47 localities in Finland. The concentrations ranged from 25 to 550/µg/kg and the mean for all the localities was 85.7 µg F-/kg fresh weight honey. The concentrations were lowest in eastern and northern Finland, where the amount of fluoride in the soil is small, and higher on the coast and areas where more fluoride occurs in the groundwater and bedrock. However, the highest levels of fluoride in honey were detected in the vicinity of Helsinki and some other places where the amount in the groundwater is not especially high. The higher levels in some honey may be due to fluorides introduced into the environment by the activity of man. The effects of fluoride on human health are discussed.

Il presente lavoro è stato incentrato sulla radiosintesi e caratterizzazione di una serie di derivati PSMA-617 diversamente funzionalizzati, con l'obiettivo di implementare dei metodi “general purpose” per l'introduzione del fluoro-18, in condizioni “mild”, in macromolecole di potenziale interesse come radiofarmaci PET. Sono stati considerati tre diversi approcci, scegliendo la molecola PSMA-617 come modello; il fluoro-18 è stato introdotto: i) tramite "click chemistry", ii) coordinando opportuni chelanti con [18F]AlF2+, e iii) per sostituzione nucleofila di gruppi uscenti potenzialmente interessanti. Poiché i precursori per la marcatura radioattiva non sono disponibili in commercio, essi sono stati completamente sintetizzati. Inoltre, le radiosintesi dei tre approcci considerati sono state completamente automatizzate. Infine i composti radiomarcati sono stati testati in vivo, utilizzando una camera PET per piccoli animali, allo scopo di valutarne le proprietà farmacocinetiche e di biodistribuzione in vivo. 1) Introduzione tramite CuAAC “click chemistry” Questo sottoprogetto ha avuto per oggetto la marcatura radioattiva con fluoro-18 di un derivato PSMA-617 tramite "click chemistry". La cicloaddizione [3+2] azide-alchino terminale catalizzata da rame (CuAAC) è considerata uno dei modi migliori per introdurre fluoro-18 su macromolecole in condizioni “mild”. La sintesi chimica dei precursori è stata condotta con una resa complessiva di circa il 19%. Quindi è stata implementata una radiosintesi “dual steps”. Il prodotto radiomarcato con fluoro-18 è stato ottenuto con elevata purezza (purezza radiochimica >99%, tempo di radiosintesi 112 min, ~6% di RCY non corretta, ~30 GBq/μmol). Inoltre, è risultato essere stabile in vitro e nel plasma umano. 2) Introduzione del fluoro-18 mediante chimica [18F](AlF)2+ Questo sottoprogetto prevedeva invece la radiomarcatura con [18F]AlF2+ di due derivati di PSMA-617 funzionalizzati con i chelanti NODA e RESCA. La sintesi chimica dei precursori è stata portata a termine con una resa complessiva di ~ 31% per il derivato PSMA-617-NODA e ~ 25% per il derivato PSMA-617-RESCA. In seguito è stata eseguita la radiosintesi. Per i due derivati sono state confrontate le condizioni di radiomarcatura, e la stabilità in vitro e in vivo: nel caso di PSMA-617-NODA, l'introduzione del complesso [18F]AlF2+ è stata possibile solo mediante riscaldamento a 110°C e il prodotto finale è risultato stabile sia in soluzione e nel plasma umano (purezza radiochimica >99%, tempo di radiosintesi 59 min, ~23% di RCY non corretto, attività molare >170 GBq/μmol). Viceversa, per quanto riguarda PSMA-617-RESCA, l'introduzione del complesso [18F]AlF2+ avviene a temperatura ambiente, ma il prodotto finale è risultato essere meno stabile sia in soluzione che nel plasma umano (purezza radiochimica >99%, tempo di radiosintesi 42 min, ~40% di RCY non corretto, attività molare >90 GBq/μmol). Infine, i due radiofarmaci sono stati testati in vivo su topi inoculati con tumore prostatico e glioblastoma umano. 3) Introduzione diretta di fluoro-18 (SN2) L’ultimo sottoprogetto era infine incentrato sulla marcatura radioattiva con fluoro-18 tramite reazione di sostituzione nucleofila (SN2) diretta di due derivati di PSMA-617 funzionalizzati rispettivamente con ammide nicotinica 2-trimetilammonio e ammide bromoacetica. La sintesi chimica dei precursori è stata effettuata con una resa complessiva di circa il 22% per il precursore funzionalizzato con 2-trimetilammonio nicotinammide e di circa il 10% per il precursore funzionalizzato con ammide bromoacetica. In seguito, la marcatura radioattiva del derivato dell'ammide nicotinica di PSMA-617 2-trimetilammonio è stata eseguita con successo (purezza radiochimica> 99%, tempo di sintesi 63 min, ~ 20% di RCY non corretto,> 1000 GBq/μmol), mentre la radiomarcatura del precursore funzionalizzato con ammide bromoacetica non ha dato l’esito desiderato.
The present work has been focused on the radiosynthesis and characterization of a series of PSMA-617 derivatives functionalized in different ways, aimed to implement general purpose methods for the introduction of fluorine-18, in mild conditions, in macromolecules of potential interest as PET radiopharmaceuticals. Three different approaches have been considered, choosing PSMA-617 as a suitable model, due to its well established and suitable in vivo behaviour; fluorine-18 was introduced: i) via “click chemistry”, ii) by coordination of suitable chelators with [18F]AlF2+, and iii) via nucleophilic substitution of potentially new leaving groups. As the precursors for radiolabelling were not commercially available, they have been fully synthesized in the course of the present work. Moreover, radiosynthesis of the three approaches were completely automated. Finally, a further aim was the in vivo testing of the radiolabelled compounds, using small animal PET camera, to at least evaluate their pharmacokinetic and biodistribution properties, in vivo. 1) Introduction via CuAAC “click chemistry” This sub-project focused on the radiolabeling with fluorine-18 of a PSMA-617 derivative via “click chemistry”. The copper-catalyzed azide-alkyne cycloaddition (CuAAC) is considered one of the best ways to introduce fluorine-18 on macromolecules in mild conditions and resulted to be very effective. Chemical synthesis of precursors was conducted with an overall yield of ~19%. Then, a two steps radiosynthesis was implemented. Fluorine-18 radiolabeled product was obtained with high purity (radiochemical purity >99%, radiosynthesis time 112 min, ~6% of not-corrected RCY, ~30 GBq/μmol). Moreover, it resulted to be stable in vitro and in human plasma. Thus, a “general purpose” method for the radiolabeling of macromolecules via CuAAC chemistry was developed. 2) Fluorine-18 introduction by [18F](AlF)2+ chemistry This sub-project focused on the radiolabeling with [18F]AlF2+ of two derivatives of PSMA-617 functionalized with chelators NODA and RESCA. At first, chemical synthesis of precursors was conducted with an overall yield of ~31% for PSMA-617-NODA derivative and ~25% for PSMA-617-RESCA derivative. Then, radiosynthesis was implemented. Radiolabeling conditions and in vitro and in vivo stability were compared for the two derivatives: in case of PSMA-617-NODA, [18F]AlF2+ complex introduction occurred by heating at 110°C, but the final product resulted to be stable both in solution and in human plasma (radiochemical purity >99%, radiosynthesis time 59 min, ~23% of not-corrected RCY, molar activity >170 GBq/μmol). On the other hand, in case of PSMA-617-RESCA, [18F]AlF2+ complex introduction occurred at room temperature, but the final product resulted to be less stable both in solution and in human plasma (radiochemical purity >99%, radiosynthesis time 42 min, ~40% of not-corrected RCY, molar activity >90 GBq/μmol). Finally, the two radiopharmaceuticals were tested in vivo on human prostate tumor and human glioblastoma tumor inoculated mice. 3) Direct fluorine-18 introduction (SN2) The third sub-project focused on the radiolabeling with fluorine-18 via a direct SN2 reaction of two derivatives of PSMA-617 functionalized with 2-trimethylammonium nicotinic amide and bromoacetic amide. At first, chemical synthesis of precursors was performed with an overall yield of ~22% for precursor 2-trimethylammonium nicotinic amide functionalized and ~10% for bromoacetic amide functionalized precursor. Then, radiolabeling of PSMA-617 2-trimethylammonium nicotinic amide derivative was successfully performed (radiochemical purity >99%, synthesis time 63 min, ~20% of not-corrected RCY, >1000 GBq/μmol). Unfortunately, radiolabeling of PSMA-617 bromoacetic amide functionalized precursor did not proceed.

碩士
國立雲林科技大學
工業化學與災害防治研究所
94
In this study, the reactive fluorine POSS was introduced in polyimide structure to form a curing framework of PI-OFG nanocomposite and it was expected to enhance the thermal and mechanical properties and decreased the dielectric constant of PI. The OFG chemical structure was characterized by FTIR and 1H-NMR. The OFG possessed average four epoxy and four fluorine groups. In the thermal properties, the OFG was able to cured with PAA to form curing structure during the imidization. Due to the curing structure of PI-OFG nanocomposite, the Tg of PI was increased with increasing OFG. The thermal stability of PI-OFG was decreased with increasing OFG, due to the damage of curing structure of PI-OFG and low thermal stability of OFG. The 14Si-NMR revealed the curing structure was broken of PI-OFG. In mechanical property, the lower OFG content of PI-OFG possessed good mechanical property. For high OFG content, the OFG aggregation form phase interconnected to decrease the mechanical property. In morphology, the lower OFG content of PI-OFG (OFG3、7 wt%) displayed good dispersion (<10 nm). The model compound results show that the curing reaction of OFG and PAA POSS was earlier than imidization of PAA. For higher OFG content, the poor miscibility between OFG and PAA to form severe POSS aggregation (phase interconnected). The factors of decreasing the dielectric constant of polymer was free volume, hydrophobic and polarity of polymer. In free volume, the relative porosity and free volume was determined by measurement of density of polymer. The relative porosity and free volume of PI-OFG were increased with increasing OFG(PI：FFV=0.044；PI-OFG 15wt%：FFV=0.319；PI：Ψr =0.044；PI-OFG 15wt%：Ψr =0.044). The hydrophobic and polarity of PI-OFG was measured by static contact angle and it revealed that the decreasing polarity and increasing hydrophobic of PI-OFG(PI：γs=47.7 mN/m；PI-OFG 15wt%：γs =29.0 mＮ/m；PI： =0.044；PI-OFG 15wt%： =0.319). Therefore, the OFG was introduced into the PI structure to enhance the thermal and mechanical properties and reducing the dielectric constant of PI.

AbstractKidney-associated pathologies would greatly benefit from noninvasive and robust methods that can objectively quantify changes in renal function. In the past years there has been a growing incentive to develop new applications for fluorine (19F) MRI in biomedical research to study functional changes during disease states. 19F MRI represents an instrumental tool for the quantification of exogenous 19F substances in vivo. One of the major benefits of 19F MRI is that fluorine in its organic form is absent in eukaryotic cells. Therefore, the introduction of exogenous 19F signals in vivo will yield background-free images, thus providing highly selective detection with absolute specificity in vivo. Here we introduce the concept of 19F MRI, describe existing challenges, especially those pertaining to signal sensitivity, and give an overview of preclinical applications to illustrate the utility and applicability of this technique for measuring renal function in animal models.This chapter is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This introduction chapter is complemented by two separate chapters describing the experimental procedure and data analysis.

Halogenation is the reaction by which one or more halogens (i.e. fluorine, chlorine, bromine, iodine) are introduced into an organic compound. Halogenation using chlorine gas is industrially the most important halogenation reaction. This chapter discusses the important uses of chlorination as well as the hazards of working with chlorine gas, before looking at the green issues around chlorine production.

The recent researches aiming at enhancing a higher photocatalytic activity and the visible light responsibility are surveyed. Various factors affecting the photocatalytic activities such as particle size, crystalline phases and facets, metal ion and anion doping in semiconductors are explained in detail. Furthermore, novel attempts such as surface modifications with fluoride or phosphate treatment, the deposition of transition metal ions or noble metals, the combined use of semiconductors or adsorbents, and the additives in solution are briefly introduced. Finally, the effects of the technical treatments such as ultrasonic wave, microwave, and magnetic field on the photocatalytic reactions are described.

Up to this point, the scientific basis for caries control and practical details for delivery of caries control to the individual have been given. We now change tack and consider caries control in populations. In order to follow the health profiles in populations there is an important tool called epidemiology. This literally means ‘the study of what is upon people’. It is derived from Greek where ‘epi’ means upon or among and ‘demos’ is people (population). In other words, epidemiology is the study of the distribution (how often) various diseases occur and why they appear in well-defined populations. It deals with groups of people, not individuals. Data thus obtained are used in public health for developing and monitoring strategies for health care in populations. Moreover, it can tell how diseases are influenced by hereditary factors, by physical and social environments, and human behaviour. All this helps health authorities to develop appropriate preventive interventions and make these as cost-effective as possible. In this chapter, having introduced the concepts of epidemiology, examples of caries control in two populations and its assessment using epidemiological measurements is given. However, the use of epidemiology has already been described in Chapter 4, where Dean’s observations on the relationship between fluoride in water supplies, the resulting dental fluorosis, and the concomitant caries reduction are described (see Chapter 4). In a recording system of any disease it is important to have clear criteria for diagnosis. The following are important: ◆ How valid are the criteria of measurement? Do they record what they are intended to measure? ◆ How reliable are the criteria? Reliability is also covered by the terms reproducibility, and consistency. These terms imply that the same or different examiners can use the criteria in the same way on different occasions and obtain the same result. ◆ The criteria should be clear, simple, and objective. In other words robust. This is particularly important if manifestations of a disease are to be grouped in different categories of severity, as with dental caries.

The concept of solid phase peptide synthesis introduced by Merrifield in 1963 involves elongating a peptide chain on a polymeric support via a two-step repetitive process: removal of the Nα-protecting group and coupling of the next incoming amino acid. A second feature of the solid phase technique is that reagents are added in large excesses which can be removed by simple filtration and washing. Since these operations occur in a single reaction vessel, the entire process is amenable to automation. Essential requirements for a fully automatic synthesizer include a set of solvent and reagent reservoirs, as well as a suitable reaction vessel to contain the solid support and enable mixing with solvents and reagents. Additionally, a system is required for selection of specific solvents and reagents with accurate measurement for delivery to and removal from the reaction vessel, and a programmer to facilitate these automatic operations is necessary. The current commercially available instruments offer a variety of features in terms of their scale (15 mg to 5 kg of resin), chemical compatibility with 9-fluorenylmethyloxycarbonyl/tert-butyl (Fmoc/tBu) and tert-butyloxycarbonyl/ benzyl (Boc/Bzl)-based methods, software (reaction monitoring and feedback control), and flexibility (additional washing and multiple activation strategies). In addition, certain instruments are better suited for the synthesis of more complex peptides such as cyclic, phosphorylated, and glycosylated sequences while others possess the ability to assemble a large number of peptide sequences. The selection of an instrument is dependent on the requirements and demands of an individual laboratory. This chapter will describe the features of the currently available systems. As the field of solid phase synthesis evolved, manufacturers designed systems based on the synergy between chemistry and engineering. A key component to an instrument is the handling of amino acids and their subsequent activation to couple to a polymeric support. The goal of an automated system is to duplicate conditions that provide stability to reactive species that might decompose. Standard protocols for automated synthesis incorporate carbodiimide, phosphonium, and aminium/uronium reagents, preformed active esters, and acid fluorides. For further details on coupling methods, see Chapter 3. A second issue related to coupling chemistry is the time required to dissolve an amino acid and store this solution.

The first three chapters of this book have introduced the basics of what dental caries is and how to detect lesions. The next chapter will consider the concept of caries control and begins by explaining why throughout this book the preferred term is caries control, rather than prevention. Remember, the formation of the dental biofilm, and its metabolism is an ubiquitous natural process; it cannot be prevented. So: Question: Who is susceptible to caries lesion development? Answer: Everyone with teeth, from cradle to grave because the metabolism in the dental biofilm is an ubiquitous, natural process. Lesion development and progression, which may occur over time, are symptoms of the process. We should aim to control these processes so that the development of a clinically visible lesion is avoided. However, if clinical lesions develop and progress these symptoms can be arrested by controlling the environment. Thus, all patients with teeth should know how lesions may form and progress, and how to control this. Please note the emphasis on the patient. It is the patient who controls caries with the support and encouragement of the professional. The goals of medicine (and dentistry) are to promote and preserve health if it is impaired, to restore health, and minimize suffering and distress. These goals are embodied in the word ‘prevention’. It is agreed that, with dental caries, this is basically what the dental profession is doing—and has always been doing. In many ways this has become a mantra—the dentists rightly claim that they are conducting prevention when recommending the population to eat less sugar, use fluorides, brush teeth, and when lesions occur, drill and fill, in order to restore the dentition and reduce pain and discomfort. Unfortunately, when dentists go for restoration—without ensuring that the patient understands how to control further caries lesion development—they indirectly stimulate the repair cycle, which ultimately may lead to loss of teeth (see Chapter 5). Sometimes the filling may be described as ‘treatment’ to contrast it with ‘prevention’. The dentist is paid for fillings (treatment) and minimally rewarded for so-called prevention.

Abstract During the operation of some nuclear facilities in China, a large amount of uranium-containing and fluorine-containing wastewater will be produced, which requires de-uranium and de-fluorine treatment before discharge. The commonly used method for removing fluoride at present is the chemical lime precipitation method, that is, adding lime to fluorine-containing wastewater to combine fluoride ions with calcium ions to form calcium fluoride precipitation that is insoluble in water. This method has the advantages of low cost and easy operation, but it will produce a large amount of uranium-containing calcium fluoride slag. The content of CaF2 in these slags is more than 80%. If the uranium-containing calcium fluoride slag is cleaned and controlled and reused as a non-radioactive waste, it will not only use fluorine resources, but also eliminate the secondary pollution of fluorine. This article mainly introduces the clearance activities of uranium-containing calcium fluoride slags carried out by the nuclear facilities, including process conditions, source item investigation, waste sampling, nuclide concentration analysis, release control evaluation, release destination and quality Guarantee, etc., and provide relevant management and technical advice on the cleaning and control of uranium-containing calcium fluoride slag based on the above-mentioned practice.

Abstract Mechanical stress problems in integrated circuit devices are becoming more severe as the number of metal interconnect levels increases and new materials such as low-k dielectrics are introduced. We studied dielectric cracking in a four-level Al-Cu interconnect structure that uses hydrogen silsesquioxane (HSQ), a low dielectric constant (low-k) material. The cracks extended down through the passivation layers to the HSQ layer. For the first time we report on passivation dielectric cracks directly related to the level of residual fluorine in a plasma enhanced chemical vapor deposition (PECVD) reactor. It is shown that a silicon nitride pre-coat deposition removes fluorine (F) from the reactor ambient and prevents the dielectric cracks.

Abstract A case study of Fluorine (F)-outgassing is presented in this paper that caused the corrosion of Aluminum bond pad. It will be shown that the source of F-contamination is not the typical residue left behind after the passivation etch with Fluorine-based gas chemistry and the subsequent removal of the etch polymer generated with solvent (chemical) clean. Rather, it is introduced as a result of F-outgas over a period of time from the intermetallic dielectric (IMD) film, fluorosilicate glass (FSG), during the post-fab wafer storage. The methodology used in our failure analysis (FA) lab to identify and characterize this type of failure mode is presented in the paper.

The technique of impurity induced disordering (IID) by using the neutral impurities boron and fluorine introduced by ion implantation has received much attention. As opposed to IID produced by diffusion, implantation by ion beams facilitates abrupt, localized regions in which disordering can be carried out. This permits good lateral and longitudinal control of the disordering process.

Abstract The paper focuses on the pad contamination defect removal technique. The defect is detected at the outgoing inspection step. The failure analysis results showed that the defect is Fluorine type contamination. The failure analysis indicated many source contributors mainly from Fluorine based processes. The focus is in the present work is in the rework method for the removal of this defect. The combination of wet and dry etch processing in the rework routine is utilized for the removal of the defect and preventive action plans for in-line were introduced and implemented to avoid this event in the future. The reliability of the wafer is verified using various tests including full map electrical, electrical sort, gate oxide breakdown (GOI) and wafer reliability level, passivation quick kill to ensure the integrity of the wafer after undergoing the rework routine. The wafer is monitored closely over a period of time to ensure it has no mushroom defect.

Abstract The subcritical fission system could be used to transmute actinide elements from spent fuel into thermal power. Since the subcritical system needs an external neutron source, the D-T Fusion reactor was introduced as a fast neutron source to drive the chain reaction. Fusion driven system based on Spherical tokamak with a 1.7 m major radius has been designed. The breeding blanket has been modified to accommodate space for a 4.8 m length oxide fuel rod. Oxide fuel rods were immersed inside the lithium fluoride salt blanket, which acts as a coolant and liquid tritium breeder. The fully liquid blanket design was taken to reduce structure complexity and maximize tritium breeding volume. The neutronic study has been performed to calculate the neutron multiplication factor, actinide burnup in 400 days cycle and theoretical Tritium Breeding Ratio using MCNPX code. The design goal of fusion driven system with a fully liquid blanket is to reach keff value from 0.8 to 0.9 by burning sufficient actinide while breeding Tritium in Fluoride salt coolant. Various lithium fluoride coolant and reflector options have been simulated with the designed geometry. FLiNaBe salt liquid blanket was used as a reference since it could reach a keff value of 0.942 and able to transmute the actinide element in oxide fuel.

Abstract This study investigates the degradation of YSZ-CoNiCrAlY thermal barrier coatings (TBCs) due to vanadium and phosphorus pentoxides and calcium-magnesium aluminosilicate (CMAS) sand at temperatures up to 1400 °C. The pentoxides are shown to degrade bond coat and topcoat layers through acidic dissolution, while CMAS sand is shown to degrade YSZ layers through ingress and the precipitation of ZrO2 grains. Density functional theory simulations provide insights on reactions at the surface of fluorite-structured oxides and the role of oxygen vacancy clustering. A method to mitigate melt-infiltration attack through electrophoretic deposition is introduced.

Reduction of deficiency of macro- and microelements in foodstuffs (in particular, iodine and fluorine) of ecologically impoverished regions is possible in the development of new products. In this regard, dietary supplements have been introduced into the recipes of meat, fish, vegetable, cereal and curd dishes. The combination of the main raw materials and additives, the functional properties of the products have been studied, and the optimal organoleptic, structural-mechanical, and rheological properties have been established. Additive "Mobi-lux Universal", containing heme iron, organic calcium and iodine, enrich a wide group of products with minerals by creating protein-vegetable combined compositions. Recipes have been developed and technologies have been substantiated for “Morskie” fish cakes, “Pikantny” meat steak, “Raduzhny” fruit and curd dessert, fruit mousses, and “Appetitnaya” rice casserole with apples. The results of a study of the nutritional value of specialized food products based on meat, fish, vegetable, fruit, cereal products and cottage cheese, enriched with the Mobi-lux Universal complex functional additive, vegetable and fruit powders, are presented. More than 20 dishes have been developed and included in corrective diets for schoolchildren. It has been established that the maximum enrichment of meat and fish products is carried out with vitamins: Betacarotene, B6, B12, as well as macro- and microelements: iron, iodine, calcium, sodium, magnesium and fluorine. Protein-containing fish and meat dishes, due to the included additive, make up for 15% of the daily deficiency in these nutrients (iodine, calcium and iron). Dessert, mousse and casserole - to dishes-sources of bio-organic iodine, calcium and iron. This will fully balance the diet of students in the category of 7-11 years old. The developed dishes were tested in the production conditions of catering establishments of educational organizations.

Abstract A piezoelectric, thin film polyvinylidene fluoride (PVDF) material was developed for application as a blood pressure/flow sensor within an artificial heart. In an effort to increase the piezoelectric coefficient, d31, and maximize the sensitivity of the PVDF material, nanoscale pores were introduced into the thin films. The purpose of the pores was to increase the mechanical strain of the material under compressive loading, and thus increase the charge separation and piezoelectric coefficient. Strain tracking under tensile loading was performed to determine the elastic modulus and Poisson’s ratio of the PVDF material, which were then used to model a simulated material in COMSOL Multiphysics software. Simulations were run to determine the d31 piezoelectric coefficient of the material, and the simulated results were compared with experimental results from a previous study. As porosity of the PVDF films increased, the experimental results showed an increase in d31 from 21.3 pC/N to 51.3 pC/N, or 141%. The simulated results showed an increase in d31 from 16.7 pC/N to 47.2 pC/N, or 183%. The similarity between previous experimental results and novel simulated results suggests that the simulated model used is a reliable method for estimating d31 of PVDF.

The phosphorous content in engine oil is found to be the major cause of the poisoning of Catalytic converters in automobiles, hence environmental regulations limiting the phosphorous level in GF4 and GF5 oils have been introduced. Zinc dialkyl dithiophosphate (ZDDP) being the only major source of phosphorous in current engine oils, is also an indispensable component of the additive package in these oils for it has been the primary anti wear — as well as anti oxidant — additive for over fifty years. Efforts are made to replace the ZDDP with other materials with the same properties which would not be harmful to the environment and also an economically feasible substitute. Another solution to this problem is to reduce the amount of ZDDP used while improving its antiwear performance. Anti-wear action of ZDDP, involves its break down reaction with the steel surface by Zn Fe ion exchange and subsequent formation of an amorphous chemisorbed film containing zinc, phosphorus, oxygen and sulfur and also iron in the form of polyphosphates and sulfates of zinc and iron. The efficiency of this mechanism is reduced by parallel reactions between ZDDP and other additives as well as their antagonistic effects. Introduction of a material with catalytic properties which would reduce the negative effects of the presence of the other additives on the anti wear properties of ZDDP is an option that was explored in this paper. Both triboligical wear tests (Ball on cylinder lubricity evaluation tests) as well as mechanism studies (DSC, FT-IR and NMR) were used to evaluate the performance of ZDDP in the presence of the most common additives (i.e. Anti-oxidants, Detergents and Dispersant). Iron Fluoride is also introduced as a potential additive to improve the efficiency of wear protection mechanism of ZDDP. The improvements observed in the presence of the Iron Fluoride will allow further reducing the amount of ZDDP in engine oils containing this material as an additive [1].