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Sample records for r-btp extraction resins

  1. The kinetics of fossil resin extraction from a flotation concentrate

    Energy Technology Data Exchange (ETDEWEB)

    Li, L.; Yu, Q.; Miller, J.D. [Univ. of Utah, Salt Lake City, UT (United States)

    1995-11-01

    The kinetics of fossil resin extraction from a flotation concentrate by heptane were investigated as a function of process variables using monosize particles. Experimental results provide for a better understanding of the refining process and the basis for subsequent design and construction of a continuous resin refining circuit. Based on the effect of process variables (particle size, stirring speed, and temperature) the resin extraction rate appears to be controlled by surface solvation phenomena. The initial extraction rate was found to be inversely proportional to the initial particle size and a kinetic model is being developed to describe the experimental results.

  2. Ultrasonic extraction of resins from an historic textile.

    Science.gov (United States)

    Rezić, I; Krstić, D; Bokić, Lj

    2008-01-01

    Ultrasound assisted extraction was applied on the historical textile as the most appropriate sample preparation step for the identification of the resinous binder. Fragile silk banner from the 19th century was analyzed for the presence of different resins. After the ultrasonic extraction with ethyl acetate in the ultrasonic bath, resinous materials and unknown sample from the banner were separated by thin layer chromatography. The multiple developments in benzene-methanol (95:5) system as mobile phase and silica gel layer as stationary phase were applied, and afterwards the video densitometry determination of the components was performed by means of video camera HV-C20. The shellac resin was determined as an important part of the complex binder.

  3. Long term stability of cannabis resin and cannabis extracts

    DEFF Research Database (Denmark)

    Lindholst, Christian

    2010-01-01

      The aim of the present study was to investigate the stability of cannabinoids in cannabis resin slabs and cannabis extracts upon long-term storage. The levels of tetrahydrocannabinol (THC), cannabinol (CBN), cannabidiol (CBD) and cannabigerol (CBG) on both neutral and acidic form were measured...... stored in extracted form at room temperature the degradation rate of acidic THC increased significantly relative to resin material with concentration halve-lives of 35 and 91 days in daylight and darkness, respectively. Once cannabis material is extracted into organic solvents, care should be taken...

  4. ADSORPTION OF GOLD ON TBP EXTRACTING RESIN FROM HCl SOLUTION

    Institute of Scientific and Technical Information of China (English)

    GaoHaoqi; CaoZhikai; 等

    1998-01-01

    Adsorption of gold on TBP extracting resin from HCl solution was researched.All the effects of factors,such as solution acidity,TBP content,temperature,etc.,on adsorption equilibrium were discussed and the equilibrium equation was formulated.The breakthough time of adsorption process with fixed bed was studied through experiment.

  5. Long term stability of cannabis resin and cannabis extracts

    DEFF Research Database (Denmark)

    Lindholst, Christian

    2010-01-01

      The aim of the present study was to investigate the stability of cannabinoids in cannabis resin slabs and cannabis extracts upon long-term storage. The levels of tetrahydrocannabinol (THC), cannabinol (CBN), cannabidiol (CBD) and cannabigerol (CBG) on both neutral and acidic form were measured...... at room temperature, 4 °C and - 20 °C for up to 4 years. Acidic THC degrades exponentially via decarboxylation with concentration halve-lives of approximately 330 and 462 days in daylight and darkness, respectively. The degradation of neutral THC seems to occur somewhat slower. When cannabinoids were...... stored in extracted form at room temperature the degradation rate of acidic THC increased significantly relative to resin material with concentration halve-lives of 35 and 91 days in daylight and darkness, respectively. Once cannabis material is extracted into organic solvents, care should be taken...

  6. 45Ti extraction using hydroxamate resin

    DEFF Research Database (Denmark)

    Gagnon, K.; Severin, Gregory; Barnhart, T. E.

    2012-01-01

    As an attractive radionuclide for positron emission tomography, this study explores the extraction and reactivity of 45Ti produced via the 45Sc(p,n)45Ti reaction on a GE PETtrace. Using a small hydroxamate column, we have demonstrated an overall recovery of >50% of 45Ti in ~1 mL of 1M oxalic acid...

  7. Extractables Screening of Polypropylene Resins used in Pharmaceutical Packaging for Safety Hazards.

    Science.gov (United States)

    Jenke, Dennis

    2017-05-15

    Pharmaceutical products are packaged in containers so that they can be manufactured, distributed and used. Because extractables from such containers are precursors of leachable impurities in the product, extractables represent potential hazards to user safety. Polypropylene resins are frequently used as materials of construction for packaging of liquid parenteral drug products. Thus extractables profiling of polypropylene resins may be an effective means of hazard identification associated with the resin's safe use. Twenty-one PP resins were extracted using aqueous and organic extraction solvents and the resulting extracts were screened for extractables using appropriate general chemistry, chromatographic and spectroscopic methodologies. The resulting extractables profiles were toxicologically reviewed by a defined process to identify potential hazards given a specified therapeutic application involving chronic use of a large volume aqueous parenteral drug product (LVP). The organic extractables profiles of individual PP resins were variable in terms of the individual extractable identified and their extracted levels, consistent with high variability in PP resin formulations and PP manufacturing. However, the profiles were similar in terms of the groups of extractable measured. Thus, for example, all the resins had extractables associated with antioxidants as all the resins contained antioxidants but the specific extractables for a given resin depended on the specific antioxidants present in that resin. Few of the targeted extractable elements were present in the extracts at measurable levels although most resins had measurable levels of extracted aluminum, silicon and alkali and alkaline earths. A worst case extractables profile (all the extractables measured in individual resins at their highest levels) was toxicologically reviewed considering an aqueous large volume parenteral (LVP) drug product. This review established certain extractables as potential hazards

  8. SYNTHESES OF POLYSTYRENE RESINS CONTAINING POLYETHER OLIGOMERS AND THEIR EXTRACTION FOR GOLD (Ⅲ)

    Institute of Scientific and Technical Information of China (English)

    DONG Shihua; LIU Shi; XU Yuwu

    1994-01-01

    Three polystyrene resins containing polyether oligomers as extractants were synthesized and their extraction properties were studied. Gold (Ⅲ) ion could be extracted rapidly by the resins (T1/2<1min.)with high efficiency and capacity (for LS-B resin that were 99.8% and 95.8mg/gR respectively) from aqueous solution but most of the co-existing metal ions such as Pd (Ⅱ),Cu(Ⅱ), Zn (Ⅱ), Pb (Ⅱ) and Cd (Ⅱ) were remained. The extraction capacity and stripping percentage for gold (Ⅲ) remained unchanged in four extraction-stripping cycles. The resins also showed good column extraction-elution properties.

  9. Cloud point extraction of Δ9-tetrahydrocannabinol from cannabis resin.

    Science.gov (United States)

    Ameur, S; Haddou, B; Derriche, Z; Canselier, J P; Gourdon, C

    2013-04-01

    A cloud point extraction coupled with high performance liquid chromatography (HPLC/UV) method was developed for the determination of Δ(9)-tetrahydrocannabinol (THC) in micellar phase. The nonionic surfactant "Dowfax 20B102" was used to extract and pre-concentrate THC from cannabis resin, prior to its determination with a HPLC-UV system (diode array detector) with isocratic elution. The parameters and variables affecting the extraction were investigated. Under optimum conditions (1 wt.% Dowfax 20B102, 1 wt.% Na2SO4, T = 318 K, t = 30 min), this method yielded a quite satisfactory recovery rate (~81 %). The limit of detection was 0.04 μg mL(-1), and the relative standard deviation was less than 2 %. Compared with conventional solid-liquid extraction, this new method avoids the use of volatile organic solvents, therefore is environmentally safer.

  10. Separation of matrine and oxymatrine from Sophora flavescens extract through cation exchange resin coupled with macroporous absorption resin

    Directory of Open Access Journals (Sweden)

    Chen Haohao

    2016-06-01

    Full Text Available A simple method for separation of matrine and oxymatrine from Sophora flavescens was developed with cation exchange resin coupled with macroporous resin. Based on the adsorption characteristics of matrine and oxymatrine, 001×732 cation exchange resin was used to absorb target alkaloids for removing most of the foreign matter, while BS-65 macroporous resin was chosen to purify these alkaloids. The result showed that the equilibrium adsorption data of matrine and oxymatrine on 001×732 resin and BS-65 resin at 30°C was fitted to Langmuir isotherm and Freundlich isotherm, respectively. The contents of matrine and oxymatrine were increased from 0.73% and 2.2% in the crude extract of the root of Sophora flavescens to 67.2% and 66.8% in the final eluent products with the recoveries of 90.3% and 86.9%, respectively.

  11. Selenium extraction: development on extraction chromatographic resins compatible with Diffusive Gradient in Thin film (DGT)

    Science.gov (United States)

    Rad, S.; Dirks-Fandrei, C.; Happel, S. A.; Bombard, A.; Cary, L.

    2016-12-01

    Measurement of Selenium is of importance regarding public health as the ratio between beneficial daily intake and toxicity is rather low [1], [2]. Also from the radiological perspective, Se-79 as a long-lived fission nuclide (T1/2=2.8x105y) with high mobility in environment, is of concern regarding waste management and decommissioning [3], [4]. Due to the existence of different oxidation states Selenium has a complex speciation chemistry which makes extraction and separation schemes not straightforward. The aim of this research is to develop extraction methods for Selenium based on extraction chromatographic resins allowing for the extraction of Se(VI), as well as Se(IV), from water samples for later use on DGT (Diffusive Gradients in Thin films) devices. Extraction chromatographic resins have been tested and characterized for Se and other elements. For Se(VI) a commercially available Aliquat 336 based extraction chromatographic resin (TEVA resin[5]) was found to be most suitable, for Se(IV) a newly developed extraction chromatographic resin based on Piazselenol chemistry was found to be most effective, data on the selectivity of this resin will be presented. The extraction of Se(IV) and Se(VI) by these resins was tested on water sampled in Lille City, where a high Se spatial variability has been observed. Concentrations in groundwater can reach 30µg/L as a consequence; most Se-contaminated wells are no longer exploited by the water operators. One of the applications of this development is to be able to measure Se concentrations insitu in contaminated areas including very complex object such as hyporheic zone. [1] Cary L. et al. Applied Geochemistry 48 (2014) 70-82 [2] Chen C. et al. Biological Trace Element Research Vols. 71-72 (1999) 131-138 [3] http://www.irsn.fr/FR/Larecherche/publications-documentation/fiches-radionucleides/Documents/environnement/Selenium_Se79_v2.pdf last access 03/03/2016 [4] Uchida et al. WM2009 Conference, March 1-5, 2009, Phoenix, AZ [5

  12. In Vitro Color Change of Three Dental Veneering Resins in Tea, Coffee and Tamarind Extracts

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    S. Muttagi

    2011-09-01

    Full Text Available Objective: To study the in vitro color changes of three dental resin veneering materials when immersed in tea, coffee and tamarind extracts.Materials and Methods: The color changes of heat polymerized tooth colored acrylic resin (Stellondetrey, B, F14, DPI Dental products of India Ltd, Mumbai, auto polymerized tooth colored acrylic resin (DPI, B, QV5, DPI Dental products of India Ltd, Mumbai andlight polymerized resin composite (Herculite XRV, Enamel A2, part no. 22860, lot no. 910437, Kerr Corporation, West Collins Avenue, Orange, CA, USA when immersed in water extracts of tea (Tata Tea Ltd. Bangalore, India, coffee (Tata Coffee Ltd. Coorg, Indiaand tamarind were evaluated using computer vision systems. The color images were recorded in R (red, G (green and B (blue form and converted into H (hue, S (saturationand V (value.Results: Significant color change occurred for auto polymerized tooth colored acrylic resin in tamarind extract, for heat polymerized tooth colored acrylic resin in tea extract andfor light polymerized resin composite in coffee extract. Auto polymerized tooth colored acrylic resin samples showed an overall higher color change. However, for all the material samples coffee extract produced more color change.Conclusion: These results suggest that the color stability of the resins is influenced by the presence of secondary metabolites such as tartaric acid, tannins, caffeine, saponins and phenols in tamarind, tea and coffee extracts.

  13. Wound healing activity of ethanolic extract of Shorea robusta Gaertn. f. resin.

    Science.gov (United States)

    Wani, T A; Chandrashekara, H H; Kumar, D; Prasad, R; Gopal, A; Sardar, K K; Tandan, S K; Kumar, D

    2012-04-01

    The ethanolic extract of S. robusta resin (10 and 30 % w/w applied locally in excised and incised wounds) produced a dose-dependent acceleration in wound contraction and increased hydroxyproline content and tensile strength of wounds in rats. The results demonstrate wound healing activity of ethanolic extract of S. robusta resin.

  14. Ion Exchange Extraction of Boron from Aqueous Fluids by Amberlite IRA 743 Resin

    Institute of Scientific and Technical Information of China (English)

    肖应凯; 廖步勇; 刘卫国; 肖云; SWIHART,GeorgeH.

    2003-01-01

    The ion exchange characteristics d Amherlite IRA 743 resin for extracting boron from aqueous fluids have been investigated in detail. The results show that AmherHte IRA 743 resin, a boron specific ion exchange resin, can quantitatively extract boron as the B (OH)4- spedes from weakly basle solution. Some exchangeable anions such as CI- and SO42- are present, resulting in an increase in pH value of the loeded solution within the nan, and the boron in natural aqueous fluids with low nH is also extracted by Amberlite IRA 743 resin. However, the voiume of loaded solution must be restricted. The maximum voiume of loaded solution giving quantitative extraction of boron decreases for sample soh.,tiom of lower pH value. Warm HCI solution is more effective than room temperature HCI solution for eluting boron from Amberllte IRA 743 resin.

  15. REMOVAL OF ACID-SOLUBLE LIGNIN FROM BIOMASS EXTRACTS USING AMBERLITE XAD-4 RESIN

    OpenAIRE

    Thomas James Schwartz; Martin Lawoko

    2010-01-01

    This paper describes a method for the removal of acid-soluble lignin from acid hydrolyzed hemicelluloses extracted from a mixture of northern hardwood chips, by using Amberlite XAD-4 resin, which was shown to remove 100% of furan derivatives and 90% of acid-soluble lignin. Subsequent fermentation of the resin treated hydrolyzates gave ethanol yields as high as 97% of theoretical and showed a marked increase in fermentation rate. Regeneration of resin performed with 75% acetone was 85% efficie...

  16. Radiolytic stability of some recently developed ion exchange and extraction chromatographic resins containing diphosphonic acid groups

    Energy Technology Data Exchange (ETDEWEB)

    Chiarizia, R.; Horwitz, E.P.

    2000-01-01

    The effect of {sup 60}Co irradiation on the Diphonix{trademark}, Diphosil and Diphonix-CS chelating ion exchange resins, and on two Dipex{trademark} extraction chromatographic resins containing the P,P{prime}-di(2-ethylhexyl) methanediphosphonic acid (H{sub 2}DEH[MDP]) impregnated in the pores of a polymeric support (Dipex-1) and of silica (Dipex-2), respectively, has been investigated. The resins have been irradiated while in contact with HNO{sub 3} (Diphonix, Diphosil and Dipex resins) or NaOH (Diphonix-DS resin) up to an absorbed dose of about 200 Mrad. As a probe of the resin radiolytic degradation, metal uptake (both equilibrium and kinetics) and capacity measurements have been performed. Results show that the Diphonix-CS resin properties are practically unaffected by irradiation under the experimental conditions used in this work. The Diphonix, Diphosil, and especially the Dipex resins suffer substantial capacity losses, but their affinity for actinide ions is not seriously compromised. On the other hand, the kinetics of metal uptake by the silica based Diphosil and Dipex-2 resins becomes substantially slower indicating that, from a radiolytic degradation standpoint, polymeric materials perform better than silica as supports for H{sub 2}DEH[MDP] containing extraction chromatographic resins.

  17. Enrichment and separation of chlorogenic acid from the extract of Eupatorium adenophorum Spreng by macroporous resin.

    Science.gov (United States)

    Liu, Boyan; Dong, Beitao; Yuan, Xiaofan; Kuang, Qirong; Zhao, Qingsheng; Yang, Mei; Liu, Jie; Zhao, Bing

    2016-01-01

    A simple and efficient chromatographic method for separation of chlorogenic acid from Eupatorium adenophorum Spreng extract was developed. The adsorption properties of nine macroporous resins were evaluated. NKA-II resin showed much better adsorption/desorption properties. The adsorption of chlorogenic acid on NKA-II resin at 25°C was well fitted to Langmuir isotherm model and pseudo-second-order kinetic model. The dynamic adsorption and desorption experiments were carried out on columns packed with NKA-II resin to optimize the separation process. The content of chlorogenic acid in the product increased to 22.17%, with a recovery yield of 82.41%.

  18. The transverse strength of acrylic resin after Coleus amboinicus, Lour extract solution immersion

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    Devi Rianti

    2006-12-01

    Full Text Available A laboratoric experimental study was conducted on the transverse strength of acrylic resin after Coleus amboinicus, Lour extract solution immersion. The aim of this study is to know the difference of acrylic resin transverse strengths caused by immersion time variations in a concentrate solution. The study was carried out on unpolished acrylic resin plates with 65 × 10 × 2,5 mm dimension; solution with 15% Coleus amboinicus, Lour extract, and 30, 60, 90 days immersion times to measure the transverse strength and sterilized aquadest was used as control. Acrylic resin plates transverse strength was measured using Autograph AG-10 TE. The data was analyzed using One-Way Anova and LSD with 5% degree of significance. The result showed that longer immersion time will decrease the transverse strength of the acrylic resin plates. After 90 days immersion time, the transverse strength decrease is still above the recommended standard transverse strength.

  19. Adsorption of saponin compound in Carica papaya leaves extract using weakly basic ion exchanger resin

    Science.gov (United States)

    Abidin, Noraziani Zainal; Janam, Anathasia; Zubairi, Saiful Irwan

    2016-11-01

    Adsorption of saponin compound in papaya leaves juice extract using Amberlite® IRA-67 resin was not reported in previous studies. In this research, Amberlite® IRA-67 was used to determine the amount of saponin that can be adsorbed using different weights of dry resin (0.1 g and 0.5 g). Peleg model was used to determine the maximum yield of saponin (43.67 mg) and the exhaustive time (5.7 days) prior to a preliminary resin-saponin adsorption study. After adsorption process, there was no significant difference (p>0.05) in total saponin content (mg) for sample treated with 0.1 g (3.79 ± 0.55 mg) and sample treated with 0.5 g (3.43 ± 0.51 mg) dry weight resin. Long-term kinetic adsorption of resin-saponin method (>24 hours) should be conducted to obtain optimum freed saponin extract. Besides that, sample treated with 0.1 g dry weight resin had high free radical scavenging value of 50.33 ± 2.74% compared to sample treated with 0.5 g dry weight resin that had low free radical scavenging value of 24.54 ± 1.66% dry weights. Total saponin content (mg), total phenolic content (mg GAE) and free radical scavenging activity (%) was investigated to determine the interaction of those compounds with Amberlite® IRA-67. The RP-HPLC analysis using ursolic acid as standard at 203 nm showed no peak even though ursolic acid was one of the saponin components that was ubiquitous in plant kingdom. The absence of peak was due to weak solubility of ursolic acid in water and since it was only soluble in solvent with moderate polarity. The Pearson's correlation coefficient for total saponin content (mg) versus total phenolic content (mg GAE) and radical scavenging activity (%) were +0.959 and +0.807. Positive values showed that whenever there was an increase in saponin content (mg), the phenolic content (mg GAE) and radical scavenging activity (%) would also increase. However, as the resin-saponin adsorption was carried out, there was a significant decrease of radical scavenging activity

  20. REMOVAL OF GLUCORAPHENIN FROM THE EXTRACT OF RADISH PIGMENT BY ANION EXCHANGE RESIN 201×7

    Institute of Scientific and Technical Information of China (English)

    ZhouXiaohua; ChenQi

    1998-01-01

    A method for removimg glucoraphenin from the extract of Radish pigment by anion exchange resin 201×7 was studied.The adsorption capacity of 201×7 resin for glucoraphenin was 72.8mg/ml resin,the equilibrium time 55 minutes,and the optinum pH5.5.All glucoraphenin that had been adsorbed on 201×7 resin was eluted by 1.5BV.hr-1, eluent in whinc concentration of NaOH was 0.05mol·L-1 at the flow rate of 1.5BV/h.Extracting solution of deglucoraphenin was enriched by vacuum and spray drying.A powder product of Radish pigment was obtained and E1cm1%=4.30.

  1. REMOVAL OF ACID-SOLUBLE LIGNIN FROM BIOMASS EXTRACTS USING AMBERLITE XAD-4 RESIN

    Directory of Open Access Journals (Sweden)

    Thomas James Schwartz

    2010-09-01

    Full Text Available This paper describes a method for the removal of acid-soluble lignin from acid hydrolyzed hemicelluloses extracted from a mixture of northern hardwood chips, by using Amberlite XAD-4 resin, which was shown to remove 100% of furan derivatives and 90% of acid-soluble lignin. Subsequent fermentation of the resin treated hydrolyzates gave ethanol yields as high as 97% of theoretical and showed a marked increase in fermentation rate. Regeneration of resin performed with 75% acetone was 85% efficient with respect to acid soluble lignin.

  2. Extraction of high quality DNA from seized Moroccan cannabis resin (Hashish.

    Directory of Open Access Journals (Sweden)

    Moulay Abdelaziz El Alaoui

    Full Text Available The extraction and purification of nucleic acids is the first step in most molecular biology analysis techniques. The objective of this work is to obtain highly purified nucleic acids derived from Cannabis sativa resin seizure in order to conduct a DNA typing method for the individualization of cannabis resin samples. To obtain highly purified nucleic acids from cannabis resin (Hashish free from contaminants that cause inhibition of PCR reaction, we have tested two protocols: the CTAB protocol of Wagner and a CTAB protocol described by Somma (2004 adapted for difficult matrix. We obtained high quality genomic DNA from 8 cannabis resin seizures using the adapted protocol. DNA extracted by the Wagner CTAB protocol failed to give polymerase chain reaction (PCR amplification of tetrahydrocannabinolic acid (THCA synthase coding gene. However, the extracted DNA by the second protocol permits amplification of THCA synthase coding gene using different sets of primers as assessed by PCR. We describe here for the first time the possibility of DNA extraction from (Hashish resin derived from Cannabis sativa. This allows the use of DNA molecular tests under special forensic circumstances.

  3. Aminoalkylated Merrifield Resins Reticulated by Tris-(2-chloroethyl Phosphate for Cadmium, Copper, and Iron (II Extraction

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    Mokhtar Dardouri

    2015-01-01

    Full Text Available We aimed to synthesize novel substituted polymers bearing functional groups to chelate heavy metals during depollution applications. Three polyamine functionalized Merrifield resins were prepared via ethylenediamine (EDA, diethylenetriamine (DETA, and triethylenetetramine (TETA modifications named, respectively, MR-EDA, MR-DETA, and MR-TETA. The aminoalkylated polymers were subsequently reticulated by tris-(2-chloroethyl phosphate (TCEP to obtain new polymeric resins called, respectively, MR-EDA-TCEP, MR-DETA-TCEP, and MR-TETA-TCEP. The obtained resins were characterized via attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR, elemental analysis (EA, and thermogravimetric (TGA, thermodynamic (DTA, and differential thermogravimetric (DTG analysis. The synthesized resins were then assayed to evaluate their efficiency to extract metallic ions such as Cd2+, Cu2+, and Fe2+ from aqueous solutions.

  4. [Purification technology of procymidone residues in ginseng extracts by macroporous resins].

    Science.gov (United States)

    Cui, Li-Li; Zheng, Pei-He; Wang, Ying-Ping

    2014-07-01

    The macroporous resin separation technology has been mainly applied in the enrichment of saponins, flavonoids, alkaloids and other ingredients, and used in the removal of heavy metal impurities and pesticide residues in recent years. This paper focuses on the synthesis of the new-type macroporous adsorption resin LKS-11 according to the molecular structure characteristics of procymidone. Specifically, the selective absorptive property and other advantages of macroporous resin were utilized to analyze the procymidone removal efficiency in ginseng extracts from different sources. The type of macroporous resins, absorptive property and desorption conditions were observed respectively by static and dynamic adsorption methods to determined the optimum process conditions. According to the results, LKS-11 showed a good absorptive property to procymidone in ginseng extracts and provided a theoretical basis for studies on the removal of procymidone residues from ginseng extracts by using macroporous adsorption resin. Because of no secondary pollution on samples, low production and operation costs, high procymidone removal efficiency and high product recovery rate, this method is suitable to be applied in production.

  5. N-Acetyl cysteine restores viability and function of rat odontoblast-like cells impaired by polymethylmethacrylate dental resin extract.

    Science.gov (United States)

    Yamada, Masahiro; Kojima, Norinaga; Att, Wael; Hori, Norio; Suzuki, Takeo; Ogawa, Takahiro

    2009-01-01

    There is concern that dental-resin materials directly loaded on a prepared tooth adversely affect dental pulp tissue by releasing the resin chemicals through dentinal tubes. This study determined whether self-curing polymethyl methacrylate (PMMA)-based dental resin extract adversely affected the viability and function of odontoblast-like cells and whether the cytotoxicity of this resin, if any, could be eliminated by N-acetyl cysteine, an antioxidant amino acid derivative. Odontoblast-like cells isolated from rat maxillary incisor dental pulp tissue were exposed to a PMMA resin extract with or without N-acetyl cysteine for 1 h and then cultured in osteoblastic media. The percentage of viable cells 24 h after seeding was 20% in cells exposed to the resin extract without N-acetyl cysteine, whereas 45% of cells were viable after exposure to the N-acetyl cysteine-supplemented extract. The cells that had been exposed to the extract showed a strong tendency for apoptosis associated with the increased reactive oxygen species production and decreased intracellular glutathione level, which was improved by the addition of N-acetyl cysteine. N-Acetyl cysteine supplementation almost completely restored the significantly reduced alkaline phosphatase activity and matrix mineralization by the resin extract. These results conclusively demonstrated that exposure of odontoblast-like cells to the resin extract impaired the cell viability and function and, more intriguingly, N-acetyl cysteine supplementation to the extract significantly prevented these toxic effects.

  6. Ionic-liquid-impregnated resin for the microwave-assisted solid-liquid extraction of triazine herbicides in honey.

    Science.gov (United States)

    Wu, Lijie; Song, Ying; Hu, Mingzhu; Yu, Cui; Zhang, Hanqi; Yu, Aimin; Ma, Qiang; Wang, Ziming

    2015-09-01

    Microwave-assisted ionic-liquid-impregnated resin solid-liquid extraction was developed for the extraction of triazine herbicides, including cyanazine, metribuzin, desmetryn, secbumeton, terbumeton, terbuthylazine, dimethametryn, and dipropetryn in honey samples. The ionic-liquid-impregnated resin was prepared by immobilizing 1-hexyl-3-methylimidazolium hexafluorophosphate in the microspores of resin. The resin was used as the extraction adsorbent. The extraction and enrichment of analytes were performed in a single step. The extraction time can be shortened greatly with the help of microwave. The effects of experimental parameters including type of resin, type of ionic liquid, mass ratio of resin to ionic liquid, extraction time, amount of the impregnated resin, extraction temperature, salt concentration, and desorption conditions on the extraction efficiency, were investigated. A Box-Behnken design was applied to the selection of the experimental parameters. The recoveries were in the range of 80.1 to 103.4% and the relative standard deviations were lower than 6.8%. The present method was applied to the analysis of honey samples.

  7. Separation and purification of rebaudioside A from extract of Stevia Rebaudiana leaves by macroporous adsorption resins

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    Anvari Masoumeh

    2016-03-01

    Full Text Available The separation and purification of rebaudioside A from Stevia rebaudiana crude extracts (Steviosides by macroporous resin were optimized by Taguchi orthogonal array (OA experimental design methodology. This approach was applied to evaluate the influence of five factors (adsorption temperature, desorption time, elution solution ratio, adsorption volume and type of resin on the rebaudioside A yield. The percentage contribution of each factor was also determined. The results showed that elution solution ratio and adsorption volume made the greatest (59.6% and the lowest (1.3% contribution, respectively. The results showed that the Taguchi method is able to model the purification of rebaudioside A process well (R2 > 0.998 and can therefore be applied in future studies conducted in various fields. Adsorption temperature 35°C, desorption time 60min, elution solution ratio 3, adsorption volume 200ml and HPD-400 as resin were the best conditions determined by the Taguchi method.

  8. Chronic swelling from entrapment of acrylic resin in a surgical extraction site

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    Weiting Ho

    2010-01-01

    Full Text Available When acrylic resin is inadvertently embedded in oral tissue, it can result in a pronounced chronic inflammatory response. This report describes a case in which temporary crown and bridge resin was forced into a surgical extraction site after the two adjacent teeth were prepared for a bridge immediately following extraction of a maxillary premolar. The patient experienced swelling at the extraction site over a ten month period despite treatment with antibiotics and anti-inflammatory drugs. After detection and removal of the foreign body, the symptoms resolved. The episode contributed to periodontal bone loss around an adjacent tooth. While morbidity of this nature is rare, this case reinforces the need to investigate persistent signs of inflammation and account for dental materials that are lost during the course of treatment.

  9. Genetic toxicology of dental composite resin extracts in somatic cells in vivo.

    Science.gov (United States)

    Arossi, Guilherme Anziliero; Dihl, Rafael Rodrigues; Lehmann, Mauricio; Reguly, Maria Luiza; de Andrade, Heloísa Helena Rodrigues

    2010-07-01

    The aim of this study was to assess the potential genetic toxicity associated to nine aqueous extracts from dental composite resins (Charisma, Fill Magic, Fill Magic Flow, Durafill, TPH Spectrum, Concept, Natural Look, Filtek Z250 and Filtek P60) and one random extract. Homologous mitotic recombination, point and chromosomal mutation effects were determined in somatic proliferative cells of Drosophila melanogaster exposed to aqueous extracts of the clinically used composites. Reproducible increases in clone mutant spot frequencies induced by diluted extract of Fill Magic Flow were observed. These increments were exclusively associated to the induction of homologous recombination - a genetic phenomenon involved in the loss of heterozygosis. The other eight composite resins and the random extract had no statistically significant effect on total spot frequencies - suggesting that they are non-genotoxic in the somatic mutation and recombination test assay, which agrees with the applications they have in dentistry. These findings - supported by numerous studies showing a positive correlation between carcinogenicity in man and genotoxicity in the Drosophila wing spot test - point to the potential risks some composite resins pose to the health of patients and dentistry personnel.

  10. Effect of apricot tree resin hydroethanolic extract on skin wound healing in rats

    Directory of Open Access Journals (Sweden)

    Karim Javadabadi

    2017-03-01

    Full Text Available Background : Impairment of wound healing in chronic diseases is a therapeutic challenge. In terms of anti-inflammatory and regenerative effects of hydro-alcoholic extract of apricot gum tree this extract used on skin wound healing in rats. Materials and Methods: 28 Wistar male rats were divided into four groups: group I, normal without surgery, group II, control group without treatment, group III, a wound treatment with Vaseline, and group I˅, wound care therapy apricot tree resin extract. In the treated and placebo groups after anesthesia applied induction circular wound area of 280 square millimeters behind rats, but treated groups continued treatment for 21 days. Daily treatment was done with hydro-alcoholic extract of apricot tree gum. Wound size is measured every day by analyzing digital images for 21 days and then rats killed and samples were fixed in formalin. Slices were stained with hematoxylin and eosin. Tissue sections were studied qualitatively and quantitatively, to check regeneration of cells, the collagen fibers, angiogenesis, and distribution of inflammatory cells. Normal data analyzed using Tukey test and data with non-normal distribution were compared between groups by Mann-Whitney test. Results: Use of apricot tree resin, reduces the blood vessels from the second week onwards, reduction of inflammatory cells and increased collagen fibers and tissue epithelialization. Conclusion: Apricot tree resin extract can promote wound healing faster made substantial improvements.

  11. Extracting gold from pyrite roster cinder by ultra-fine-grinding and resin-in-pulp

    Institute of Scientific and Technical Information of China (English)

    危俊婷; 严规有; 郭炳昆; 高桂兰

    2003-01-01

    The ultra-fine-grinding and resin-in-pulp with pH value of 10 are used to extract gold from pyrite roster cinder. During leaching process, aluminium oxide ball is used as stirring medium, hydrogen peroxide as leaching agent and sodium hexametaphosphate as grinding agent. With AM-26 resin as absorber and sulfocarbamide as eluent, gold is recovered from cyanide pulp of pyrite roster cinder by resin-in-pulp. The effects of contact time, temperature and acidity etc. on the gold absorption are investigated by static methods and dynamic method respectively. The effects of flow rate of solution on dynamic adsorption and elution of gold are studied. The results show that AM-26 resin has good adsorbability in cyanide solution, and gold can be easily eluated from the loaded resin with 0. 1mol/L hydrochloric acid and lmol/L sulfocabamide. The adsorption rate and the elution of gold exceed 98%. When leaching time is 2 h, mass ratio of liquid to solid 4: 1, consumption of sodium cyanide 3 kg/t, concentration of hydrogen peroxide and sodium hexametaphosphate 0. 05% respectively, adsorption time 30 min, temperature 10-30 ℃, volume of resin 3 mL, ratio of eluent to resin (10-20): 1, velocity of eluent 1.5 mL/min, the leaching rate of gold reaches 85%. Compared with traditional leaching technology, it can reduce leaching time, avoid complex filter process, decrease sodium cyanide consumption and increase leaching rate of gold by 35%.

  12. Comparison of extracts and toxicities of organic compounds in drinking water concentrated by single and composite XAD resins.

    Science.gov (United States)

    Zhou, Xue; Xiang, Lunhui; Wu, Fenghong; Peng, Xiaoling; Xie, Hong; Wang, Jiachun; Yang, Kedi; Lu, Wenqing; Wu, Zhigang

    2013-12-01

    We compared extracts and toxicities of organic compounds (OCs) in drinking water concentrated by composite XAD-2/8 resin (mixed with an equal volume of XAD-2 and XAD-8 resins) with those extracted by single XAD-2 (non-polar) and XAD-8 (polar) resins. Drinking water was processed from raw water of the Han River and the Yangtze River in Wuhan section, China. The extraction efficiency of all resins was controlled at 30%. The types of extracted OCs were detected by gas chromatography-mass spectrometry, and the cytotoxicity and genotoxicity were assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and comet assays, respectively, in human hepatoma HepG2 cells. Our results showed that XAD-2/8 extracted a larger variety of OCs, compared with XAD-8 and XAD-2. The cytotoxicity and genotoxicity of extracted OCs were in the order of XAD-8> XAD-2/8> XAD-2 at almost all tested concentrations after 24 h treatment (P < 0.05). Our findings suggest that single XAD resin selectively extracts either polar or non-polar OCs, which would lead to over- or under-estimation of the toxicity of drinking water. Nevertheless, composite resin extracts both polar and non-polar OCs, and could be utilized as a useful extraction technique to evaluate the level and toxicity of OCs in drinking water.

  13. Extractant selection strategy for solvent-impregnated resins in fermentations

    NARCIS (Netherlands)

    Berg, C. van den; Roelands, C.P.M.; Bussmann, P.J.Th.; Goetheer, E.L.V.; Verdoes, D.; Wielen, L. van der

    2008-01-01

    The application of extractants in whole-cell biocatalysis can have a positive impact on industrial fermentations, in terms of productivity, total amount of product produced, and cell growth. When a product is continuously removed from the microorganism surroundings, product inhibition will be dimini

  14. A salting out and resin procedure for extracting Schistosoma mansoni DNA from human urine samples

    Directory of Open Access Journals (Sweden)

    Rodrigues Nilton B

    2010-04-01

    Full Text Available Abstract Background In this paper a simple and cheap salting out and resin (InstaGene matrix® resin - BioRad DNA extraction method from urine for PCR assays is introduced. The DNA of the fluke Schistosoma mansoni was chosen as the target since schistosomiasis lacks a suitable diagnostic tool which is sensitive enough to detect low worm burden. It is well known that the PCR technique provides high sensitivity and specificity in detecting parasite DNA. Therefore it is of paramount importance to take advantage of its excellent performance by providing a simple to handle and reliable DNA extraction procedure, which permits the diagnosis of the disease in easily obtainable urine samples. Findings The description of the extraction procedure is given. This extraction procedure was tested for reproducibility and efficiency in artificially contaminated human urine samples. The reproducibility reached 100%, showing positive results in 5 assay repetitions of 5 tested samples each containing 20 ng DNA/5 ml. The efficiency of the extraction procedure was also evaluated in a serial dilution of the original 20 ng DNA/5 ml sample. Detectable DNA was extracted when it was at a concentration of 1.28 pg DNA/mL, revealing the high efficiency of this procedure. Conclusions This methodology represents a promising tool for schistosomiasis diagnosis utilizing a bio-molecular technique in urine samples which is now ready to be tested under field conditions and may be applicable to the diagnosis of other parasitic diseases.

  15. Preparation of extractive resins for producing terbium-161; Preparacion de resinas extractivas para produccion de terbio-161

    Energy Technology Data Exchange (ETDEWEB)

    De la Cruz B, C. C.; Monroy G, F. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)], e-mail: fabiola.monroy@inin.gob.mx

    2009-10-15

    This paper presents the development of a methodology for extractive resins preparation to base of HDEHP, which allows to separation of Tb from Gd generating an own technology of preparation of these resins. The study included the extractive resins preparation from 6 different supports: kieselguhr Dg, alumina, red volcanic rock, chiluca, quarry and fluorite; two treatment types of of supports and varied concentrations of HDEHP extractant (di(2-etil hexyl) orthophosphoric acid), in order to determine which resin has improved efficiency of Gd and Tb separation, and radionuclide purity of {sup 161}Tb. Resins were prepared to base of kieselguhr to determine the most appropriate silicon deposition process. Two silicon deposition treatments were realized: treatment I , by contact with silicon deposition solution (dimethyldichlorosilane / heptane 1:30) and treatment II by contact with vapors of dimethyldichlorosilane in vacuum. The extractant retention was carried out to different concentrations of HDEHP / acetone: 1:4, 1:8, 1:15, 1:20, 1:30 and 1:40. According to the results, there is not direct relation of HDEHP concentration used in extractive resins preparation to base of kieselguhr over the efficiency of Gd and Tb separation and of radionuclide purity of {sup 161}Tb. The effect of support in the efficiency of Gd and Tb separation was studied to prepare resins with the supports kieselguhr, alumina, quarry, chiluca, volcanic rock and fluorite, using the silicon deposition treatment II for the supports and a concentration of HDEHP / acetone 1:20, for extractant retention. Only resins based on kieselguhr could separate to Gd from Tb quantitatively, the resin at a concentration of HDEHP / Acetone 1:20 was the best results obtained in Gd and Tb separation, achieving a separation efficiency greater than 90% and a radionuclide purity higher than 99%. (Author)

  16. Experiments on decolourization with 122-resin for extraction of gibberellins from solid medium under different conditions

    Institute of Scientific and Technical Information of China (English)

    WUHong-sheng; FANJia-qing; SHIGuang-hui; ZHAONan-hai

    2004-01-01

    The extracting liquid of gibberellins (Gibberella fujikurol) from solid medium for was decolorized separately with 75%,95% alcohol, and distilled water in static adsorption and vibrating way for different durations. The results showed that the content of GA3 in efflux extracted with alcohol is 10% higher than that with distilled water. With the increase of the durations of extraction,the content of GA3 increases and the dissolution of pigments also increase. For extraction of GA3 cultured in solid medium, the best decolorizing result was obtained when it was extracted with 75%-95% alcohol in static way for 1-3 h, or in a vibrating way for 30-60 min, and then to decolor in a static way for 30-60 min in 122 resin column.

  17. Cu Purification Using an Extraction Resin for Determination of Isotope Ratios by Multicollector ICP-MS

    Directory of Open Access Journals (Sweden)

    Akio Makishima

    2014-06-01

    Full Text Available A new simple and quick method has been established for separation of Cu from solutions using an extraction chromatographic resin utilizing Aliquat® 336 (commercially available as TEVA™ resin and Cu(I. This method involves the use of a one milliliter column containing 0.33 mL TEVA™ resin on 0.67 mL Amberchrom® CG-71C acrylic resin. Copper was adsorbed on the column by forming Cu(I with 0.15% ascorbic acid in 0.05 mol·L−1 HBr, while other major elements except Zn showed no adsorption. After removal of the major elements (Na, Mg, Al, P, K, Ca, Cr, Mn, Fe, Co and Ni, Cu was recovered using 2 mol·L−1 HNO3. The recovery yield and total blank were 102% ± 2% and 0.25 ng, respectively. To evaluate the separation method, Cu isotope ratios were determined by a standard-sample-standard bracketing method using multicollector inductively coupled plasma-mass spectrometry (ICP-MS, with a repeatability of 0.04‰ and 0.25‰ (SD, for the standard solution and the solutions from low S (<0.1% S silicate standards, respectively.

  18. THE EXTRACTION OF GOLD FROM CYANIDE SOLUTION BY α—ALKYL SUBSTITUTED PYRIDINE RESIN

    Institute of Scientific and Technical Information of China (English)

    GANWeitang; LIUYouying; 等

    1992-01-01

    In this paper,we have studied the adsorption properties of gold by α-alkyl substituted pyridine resin( BPR) in alkaline solution.The single and dual component kinetic mass transfer process of Au(I),Ag(I) and other metal cyanide ions were also investigated.The results obtained show that the mass transfer rates of the cyanide ions in the resin phase are closely related to the molar ratio and the configuration of metal cyanide ions. The elution kinetics of Au(I) and other cyanide ions by NH4SCN has been investigated systematically.The intraparticle diffusion coefficient and activation energy of Au(I),Ag(I),Ni(I) Fe(Ⅲ) cyanide anions were determined in CI,NO3,OH-type BPR resin at different temperatures.It is found from the experimental results that the mechanism for extracting Au(I),Ag(I) and other metal cyanide anions by BPR resin belongs to ion exchange process.The difference of activation entropy of some metal cyanide anions(ΔS-ΔS-) was evaluated.

  19. Extraction behaviour of Am(III) and Eu(III) from nitric acid medium in TEHDGA-HDEHP impregnated resins

    Energy Technology Data Exchange (ETDEWEB)

    Saipriya, G.; Kumar, T. [Bhabha Atomic Research Centre Facilities, Kalpakkam (India). Kalpakkam Reprocessing Plant; Kumaresan, R.; Nayak, P.K.; Venkatesan, K.A.; Antony, M.P. [Indira Gandhi Center for Atomic Research, Kalpakkam (India). Fuel Chemistry Div.

    2016-07-01

    The extraction behaviour of Am(III) and Eu(III) from nitric acid medium was studied in the solvent impregnated resins containing extractants such as tetra-bis(2-ethylhexyl)diglycolamide (TEHDGA) or bis-(2-ethylhexyl)phosphoric acid (HDEHP) or mixture of TEHDGA+HDEHP. The rate of extraction of Am(III) and Eu(III) from 1 M nitric acid and the effect of various parameters, such as the concentration of nitric acid in aqueous phase and concentration of TEHDGA and HDEHP in resin phase, on the distribution coefficient of Am(III) and Eu(III) was studied. The distribution coefficient of Am(III) and Eu(III) in HDEHP-impregnated resin decreased and that in TEHDGA-impregnated resin increased, with increase in the concentration of nitric acid. However, in (TEHDGA+HDEHP) - impregnated resin, synergic extraction was observed at lower nitric acid concentration and antagonism at higher nitric acid concentration. The mechanism of Am(III) and Eu(III) extraction in the combined resin was investigated by slope analysis method. The extraction of various metal ions present in the fast reactor simulated high-level liquid waste was studied. The separation factor of Am(III) over Eu(III) was studied using citrate-buffered diethylenetriaminepentaacetic acid (DTPA) solution.

  20. Extraction of Tc(VII) and Re(VII) on TRU resin

    Energy Technology Data Exchange (ETDEWEB)

    Guerin, Nicolas; Riopel, Remi; Kramer-Tremblay, Sheila [Canadian Nuclear Laboratories (CNL), Chalk River, ON (Canada). Radiobiology and Health Branch; De Silva, Nimal; Cornett, Jack [Ottawa Univ., ON (Canada). Dept. of Earth and Environmental Sciences; Dai, Xiongxin [China Institute for Radiation Protection, Beijing (China)

    2017-06-01

    TRU resin can be used to rapidly and selectively extract Tc(VII) and Re(VII). The retention capacity curves of Tc(VII) and Re(VII) for HNO{sub 3}, HCl, H{sub 2}SO{sub 4} and H{sub 3}PO{sub 4} solutions were studied and prepared. Tc(VII) and Re(VII) were simultaneously extracted in 2 M H{sub 2}SO{sub 4} and 1.5 M H{sub 3}PO{sub 4} and were effectively separated from Mo(VI) and Ru(III). Tc(VII) and Re(VII) remained strongly bonded to the resin even after washing using a large volume of 2 M H{sub 2}SO{sub 4} at a relatively high flow rate. Also, they were both completely eluted from the resin using 15 mL of near boiling water, an eluent directly compatible for ICP-MS instrument measurements.

  1. Extraction behaviour of Am(III) and Eu(III) from nitric acid medium in CMPO-HDEHP impregnated resins

    Energy Technology Data Exchange (ETDEWEB)

    Saipriya, K.; Kumar, T. [Bhabha Atomic Research Centre Facilities (India). Kalpakkam Reproscessing Plants; Kumaresan, R.; Nayak, P.K.; Venkatesan, K.A.; Antony, M.P. [Indira Gandhi Center for Atomic Research, Kalpakkam (India). Fuel Chemistry Div.

    2016-05-01

    Chromatographic resin containing extractants such as octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) or bis-(2-ethylhexyl)phosphoric acid (HDEHP) or mixture of extractants (CMPO + HDEHP) in an acrylic polymer matrix was prepared and studied for the extraction of Am(III) and Eu(III) over a range of nitric acid concentration. The effect of various parameters such as concentration of nitric acid in aqueous phase and the concentration of CMPO and HDEHP in the resin phase was studied. The distribution coefficient of Am(III) and Eu(III) in the impregnated resin increased with increased in the concentration of nitric acid for CMPO-impregnated resin, whereas a reverse trend was observed in HDEHP impregnated resin. In case of resin containing both the extractants, synergism was observed at low nitric acid concentration and antagonism at high nitric acid concentration. The mechanism of extraction was probed by slope analysis method at 0.01 and 2 M nitric acid concentrations. Citrate-buffered DTPA was used for the selective separation of Am(III), and a separation factor of 3-4 was obtained at pH 3.

  2. Extraction of Carbon Dioxide From Seawater by Ion Exchange Resin. Part 2. Using Strong Base Anion Exchange Resin

    Science.gov (United States)

    2009-09-29

    Figure 1. Table 2 - Resin Properties of Static Experiments Using Amberjet 4400 in OH Form (150 minute contact time). Sample Concentration (Molar...0.271 1 36 17.9 0.0075 150 0.267 134 19.0 Table 4 - Resin Properties of Static Experiments Using Amberjet 4400 in Cl Form (150 minute contact time

  3. Chemically modified polymeric resins for solid-phase extraction and group separation prior to analysis by liquid or gas chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, L.W.

    1993-07-01

    Polystyrene divinylbenzene was modified by acetyl, sulfonic acid, and quaternary ammonium groups. A resin functionalized with an acetyl group was impregnated in a PTFE membrane and used to extract and concentrate phenolic compounds from aqueous samples. The acetyl group created a surface easily wetted, making it an efficient adsorbent for polar compounds in water. The membrane stabilized the resin bed. Partially sulfonated high surface area resins are used to extract and group separate an aqueous mixture of neutral and basic organics; the bases are adsorbed electrostatically to the sulfonic acid groups, while the neutraons are adsorbed hydrophobically. A two-step elution is then used to separate the two fractions. A partially functionalized anion exchange resin is used to separate organic acids and phenols from neutrals in a similar way. Carboxylic acids are analyzed by HPLC and phenols by GC.

  4. Improved resins and novel materials and methods for solid phase extraction and high performance liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Freeze, Ronald [Iowa State Univ., Ames, IA (United States)

    1997-10-08

    Solid-phase extraction (SPE) has grown to be one of the most widely used methods for isolation and preconcentration of a vast range of compounds from aqueous solutions. By modifying polymeric SPE resins with chelating functional groups, the selective uptake of metals was accomplished. The resin, along with adsorbed metals, was vaporized in the ICP and detection of the metals was then possible using either mass or emission spectroscopy. Drug analyses in biological fluids have received heightened attention as drug testing is on the increase both in sports and in the work environment. By using a direct-injection technique, biological fluids can be injected directly into the liquid chromatographic system with no pretreatment. A new surfactant, a sulfonated form of Brij-30 (Brij-S) is shown to prevent the uptake of serum proteins on commercial HPLC columns by forming a thin coating on the silica C18 surface. Excellent separations of eight or more drugs with a wide range of retention times were obtained. The separations had sharper peaks and lower retention times than similar separations performed with the surfactant sodium dodecylsulfate (SDS). Quantitative recovery of a number of drugs with limits of detection near 1 ppm with a 5 μl injection volume were obtained. Finally, a method for solid-phase extraction in a syringe is introduced. The system greatly reduced the volume of solvent required to elute adsorbed analytes from the SPE bed while providing a semi-automated setup. SPE in a syringe consists of a very small bed of resin-loaded membrane packed into a GC or HPLC syringe. After extraction, elution was performed with just a few μl of solvent. This small elution volume allowed injection of the eluent directly from the syringe into the chromatographic system, eliminating the handling problems associated with such small volumes.

  5. An improved extraction chromatographic resin for the separation of uranium from acidic nitrate media

    Energy Technology Data Exchange (ETDEWEB)

    Dietz, M.L.; Horwitz, E.P.; Sajdak, L.R.; Chiarizia, R. [Chemistry Division, Argonne National Laboratory, 60439 Argonne, IL (United States)

    2001-07-06

    The preparation and characterization of a new extraction chromatographic resin exhibiting extraordinarily strong retention of hexavalent uranyl ion over a wide range of nitric acid concentrations and very high selectivity for U(VI) over Fe(III) and numerous other cations is described. This new material (designated U/TEVA-2) comprises a novel liquid stationary phase consisting of an equimolar mixture of diamyl amylphosphonate (DA[AP]) and Cyanex 923{sup registered} (a commercially available trialkyl-phosphine oxide, TRPO) sorbed on silanized silica or Amberchrom CG-71. Cyanex 923 is shown to be preferable to a related TRPO, Cyanex 925{sup registered}, due to its lower viscosity and higher selectivity for U(VI) over Fe(III). The retention of uranyl nitrate by the U/TEVA-2 resin, as measured by the k' values (number of free column values to peak maximum) is >5000 from approximately 0.1 to 8 M HNO{sub 3}. The ability of the new resin to strongly and selectively retain U(VI) from such a wide range of acid concentrations, along with its favorable physical properties, make it a good candidate for application in the separation and preconcentration of U(VI) from complex environmental, biological, and nuclear waste samples for subsequent determination.

  6. An improved extraction chromatographic resin for the separation of uranium from acidic nitrate media.

    Science.gov (United States)

    Dietz, M L; Horwitz, E P; Sajdak, L R; Chiarizia, R

    2001-07-01

    The preparation and characterization of a new extraction chromatographic resin exhibiting extraordinarily strong retention of hexavalent uranyl ion over a wide range of nitric acid concentrations and very high selectivity for U(VI) over Fe(III) and numerous other cations is described. This new material (designated U/TEVA-2) comprises a novel liquid stationary phase consisting of an equimolar mixture of diamyl amylphosphonate (DA[AP]) and Cyanex 923((R)) (a commercially available trialkyl-phosphine oxide, TRPO) sorbed on silanized silica or Amberchrom CG-71. Cyanex 923 is shown to be preferable to a related TRPO, Cyanex 925((R)), due to its lower viscosity and higher selectivity for U(VI) over Fe(III). The retention of uranyl nitrate by the U/TEVA-2 resin, as measured by the k' values (number of free column values to peak maximum) is >5000 from approximately 0.1 to 8 M HNO(3). The ability of the new resin to strongly and selectively retain U(VI) from such a wide range of acid concentrations, along with its favorable physical properties, make it a good candidate for application in the separation and preconcentration of U(VI) from complex environmental, biological, and nuclear waste samples for subsequent determination.

  7. Novel polymeric resin for solid phase extraction and determination of lead in waters

    Energy Technology Data Exchange (ETDEWEB)

    Karaaslan, Nagihan M.; Cengiz, Emine; Yaman, Mehmet [Science Faculty, Department of Chemistry, Firat University, Elazig (Turkey); Senkal, B. Filiz [Science and Arts Faculty, Department of Chemistry, Istanbul Technical University, Istanbul (Turkey)

    2010-11-15

    Interest in preconcentration techniques for the determination of metals at ultratrace levels still continues increasingly because of some disadvantages of flameless atomic absorption spectrometry and the high costs of other sensitive methods in compared to flame atomic absorption spectrometry (FAAS). Among preconcentration techniques, solid-phase extraction is the most popular because of a number of advantages. In this work, thiol-containing sulfonamide resin was synthesized, characterized, and applied as a new sorption material for solid phase extraction and determination of lead in natural water samples. The optimization of experimental conditions was performed using the parameters including pH, contact time, and volumes of initial and elution solutions. After preconcentration procedure, FAAS was used for determinations. The synthesized resin exhibits the superiority in compared to the other adsorption reagents because of the fact that there is no necessity of any complexing reagent as well as high sorption capacity. Consequently, 280-fold improvement in the sensitivity of analytical scheme was achieved by combining the slotted tube atom trap-atomic absorption spectrometry (STAT-FAAS) and the developed preconcentration method. The limit of detection was found to be 0.15 ng mL{sup -1}. The Pb{sup 2+} concentrations in the studied water samples were found to be in the range of 0.9-6.7 ng mL{sup -1}. (Copyright copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. A method for analyzing the δ18O of resin-extractable soil inorganic phosphate.

    Science.gov (United States)

    Weiner, Tal; Mazeh, Shunit; Tamburini, Federica; Frossard, Emmanuel; Bernasconi, Stefano M; Chiti, Tommaso; Angert, Alon

    2011-03-15

    Improved tools for tracing phosphate transformations in soils are much needed, and can lead to a better understanding of the terrestrial phosphorus cycle. The oxygen stable isotopes in soil phosphate are still not exploited in this regard. Here we present a method for measuring the oxygen stable isotopes in a fraction of the soil phosphate which is rapidly available to plants, the resin-extractable P. This method is based on extracting available phosphate from the soil with anion-exchange membranes, soil organic matter removal by a resin, purification by precipitation as cerium phosphate, and finally precipitation as silver phosphate. The purified silver phosphate samples are then measured by a high-temperature elemental analyzer (HT-EA) coupled in continuous flow mode to an isotope ratio mass spectrometer. Testing the method with Mediterranean and semi-arid soils showed no artifacts, as well as good reproducibility in the same order as that of the HT-EA analytical uncertainty (0.3‰). Copyright © 2011 John Wiley & Sons, Ltd.

  9. SYNTHESES OF RESINS IMPREGNATED WITH POLYETHER OR POLYTHIOETHER OLIGOMERS AND THEIR EXTRACTION FOR GOLD(Ⅲ) and palladium(Ⅱ)

    Institute of Scientific and Technical Information of China (English)

    DONGShihua; LIUShi; 等

    1992-01-01

    Six novel resins impregnated with polyether or polythioether oligomers have been synthesized and their extraction properties have also been investigated.Gold(Ⅲ) and /or palladium (Ⅱ) coulld be extracted repidly by the resins with high percentage and capacities from aqueous solution but most of the co-existing base metal ions were remained.The extraction capacities and stripping percentage were approximately unchanged after four extraction-elution cycles and the resins also showed excellent column extraction-elution properties.

  10. The Effects of Boswellia Resin Extract on Dopaminergic Cell line, SK-N-SH, against MPP+-Induced Neurotoxicity

    Directory of Open Access Journals (Sweden)

    Sareh Kazmi

    2011-10-01

    Full Text Available Introduction: Oxidative stress and neuroinflammation are involved in neurodegeneration procedure in Parkinson’s disease. Recently, neuroprotective potential of Boswellia resin has been demonstrated. Therefore, this study examined whether administration of Boswellia resin would attenuate MPP+- induced neuronal death in SK-N-SH- cell line, a human dopaminergic neurons- in vitro. Methods: Boswellia resin extract was added to culture medium (10μg/ml before and after exposure of SK-N-SH cell line to MPP+ (1000μM. Cell viability and apoptosis features were assessed using MTT and Hoechst staining, respectively. Results: Treatment with Boswellia resin 2 and 3h prior to MPP ° exposure and up to 60 minutes after MPP ° exposure significantly increased cell viability compare to untreated cells. Apoptotic features were also reduced significantly by Boswellia resin (10 μg/ml compare to that of control untreated cells. Discussion: Boswellia resin has neuroprotective effects on dopaminergic neurons which can be applicable in Parkinson’s disease.

  11. EXTRACTION AND SEPARATION OF RADISH RED PIGMENT FROM A WASTE WATER OF SALTING RADISH BY D61 RESIN

    Institute of Scientific and Technical Information of China (English)

    ZhouXiaohua; KangJajie; 等

    1996-01-01

    Extraction and separation of Radish red pigment from a waste water of salting Radish was studied on D61 resin.The exchange capacity of adsorption the pigment was equal to 60.91mg·g-1 wet resin,and the equilibium time only 40mins.All Radish red pigment adsorbed on D61 resin was eluted using a eluent in which concentraction of HCl or alcohol was 0.1mol·L-1 or 80% at 50℃ when the flow rate was at 2BV·hm-1.Stability of D61 resin was very well,and while the resin was recycled fifteen times, the exchange capacity was only decreased 11.9%,and the exchange capacity didn′t changed.Because of negative ion of mustard oil,it could′t be adsorbed on the resin.Finally, a paste product with yield of 1.96mg·100ml-1 waste water was obtained after alcohol evaporation and vacuum drying.

  12. Review: Resin Composite Filling

    OpenAIRE

    Desmond Ng; Jimmy C. M. Hsiao; Keith C. T. Tong; Harry Kim; Yanjie Mai; Keith H. S. Chan

    2010-01-01

    The leading cause of oral pain and tooth loss is from caries and their treatment include restoration using amalgam, resin, porcelain and gold, endodontic therapy and extraction. Resin composite restorations have grown popular over the last half a century because it can take shades more similar to enamel. Here, we discuss the history and use of resin, comparison between amalgam and resin, clinical procedures involved and finishing and polishing techniques for resin restoration. Although resin ...

  13. Meta-analysis of dragon’s blood resin extract as radio-protective agent

    Directory of Open Access Journals (Sweden)

    Subaika Mahmood

    2017-09-01

    Full Text Available In health sciences, much efforts had been made in past years to explore the radio-protective agents from natural resources due to rapid exposure of radiations to environment such as space traveling, radiotherapy and largely growing telecommunication industry. It becomes crucial to find natural sources for radio-protection. In correspondence, dragon’s blood (DB is a traditional Chinese medicinal plant that possesses great medicinal values due to the presence of several phenolic compounds. For a long time, DB has been used in treatment of blood stasis, inflammation, oxidative stress, immune suppression and tumors, but recently it has been extensively used as radio-protective agent. There is no comprehensive review on radio- protective characterization of DB resin extract in literature. In our review, an attempt has been made to highlight unique and inherent radio-protection in liver, brain, kidney, lung, spleen and cerebrum. This review will help people in exploring the radioactive protectants from natural resources.

  14. Effect of grape seed extract against biodegradation of composite resin-dentin shear bond strength

    Science.gov (United States)

    Generosa, D. M.; Suprastiwi, E.; Asrianti, D.

    2017-08-01

    This study aimed to analyze the effect of grape seed extract (GSE) on resin-dentin shear bond strength. A group of 48 dentin samples were divided into 6 groups. The six groups, each with eight specimens, included group 1 (control), group 2 (control + NaOCl 10%), group 3 (2.9% GSE application before etching), group 4 (2.9% GSE application before etching + NaOCl 10%), group 5 (2.9% GSE application after etching), and group 6 (2.9% GSE application after etching + NaOCl 10%). Shear bond strengths were measured using a universal testing machine. Statistical analysis was done with the Kruskal-Wallis test and the Mann-Whitney U test. The highest median value was in group 3, and the lowest value was in group 5. GSE can improve the shear bond strength (p = 0.002 and 0.001), but it has no effect on reducing biodegradation (p = 0.141).

  15. Two novel extraction chromatography resins containing multiple diglycolamide-functionalized ligands: preparations, characterization and actinide uptake properties

    NARCIS (Netherlands)

    Ansari, S.A.; Mohapatra, P.K.; Iqbal, M.; Huskens, Jurriaan; Verboom, Willem

    2014-01-01

    Two extraction chromatography resins were prepared for the first time by impregnating multiple diglycolamide-functionalized ligands such as diglycolamide-calix[4]arene (C4DGA) and tripodal diglycolamide (T-DGA) on Chromosorb-W, an inert solid support, for the removal of hazardous actinides like Am(I

  16. Recent Development Prospect of Adsorbing and Extracting Gold with Extraction Resins%萃取树脂吸萃金研究进展

    Institute of Scientific and Technical Information of China (English)

    李海梅; 高学珍; 袁延旭; 刘军深

    2011-01-01

    Extraction resins are participate adsorbers which are based on the incorporation of extractants into porous carriers such as polymer supports by physical adsorption. They possess a combination of the advantageous features of both liquid - liquid extraction and ion exchange. This paper reviews the current situation and prospect of adsorbing and extracting gold with extraction resins process according to the types of extraction resins. The mechanism of sorption is basically similar to the case of solvent extraction. The effective separation of gold can be obtained under properly - controlled conditions. This technology will open up a new approach for the separation of gold.%萃取树脂是通过物理方式将萃取剂固定于某种适宜的多孔载体(如聚合物)上的吸附剂.它具有液液萃取和离子交换的优点.文章按萃取树脂的类型对其吸萃金的研究现状进行了综述.萃取树脂吸萃金离子的机理与溶剂萃取法相似,控制合适的条件可以实现金的有效分离.预计萃取树脂技术将为金分离开拓一条新途径.

  17. Effects of Balsamodendron mukul Gum Resin Extract on Articular Cartilage in Papain-induced Osteoarthritis.

    Science.gov (United States)

    Manjhi, Jayanand; Gupta, Maneesh; Sinha, Anvesha; Rawat, Beena; Rai, Durg V

    2016-07-01

    Context • Osteoarthritis (OA) is one of the most prevalent chronic diseases of the musculoskeleton, causing functional disability among older adults. Management of OA includes conventional pharmacological treatments consisting primarily of nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen, physiotherapy, and surgical procedures. The medications are not ideal therapeutic agents; NSAIDs in particular can cause serious side effects. Objective • The study was conducted to investigate the effects of Balsamodendron mukul (BDM) gum resin extract on cartilage damage and microstructural changes in the subchondral bone of rats with papain-induced, osteoarthritic knee joints. Design • The authors designed a parallel randomized, controlled study to examine the effects of 3 concentrations of BDM on OA in a murine model. Setting • The present study was undertaken at the research laboratory, Faculty of Biological Engineering, Shobhit University (Modipuram, Meerut, India). Intervention • OA was induced by intra-articular injections of 0.2 mL of 4% papain solution and 0.1 mL of 0.03 M cysteine through the patellar ligament using a 26-gauge, 1.27-cm needle. The rats in the sham group received same volume of isotonic sodium chloride solution. The rats were divided into 6 groups : (1) control group-fresh rats, with ages and genders similar to those of the other groups but with no induction of OA and no treatments; (2) sham group-rats receiving a sham induction of OA using an intra-articular injection of saline of the same volume as the papain given to all OA rats but no treatments; (3) OA group-rats induced with OA but receiving no treatments; (4) OA + BDM (10%) group-rats induced with OA that received a 10% dose of BDM; (5) OA + BDM (20%) group-rats induced with OA that received a 20% dose of BDM; and (6) OA + BDM (40%) group-rats induced with OA that received a 40% dose of BDM. Rats in the treatment groups were fed their respective doses of BDM extract for 30 d

  18. Two solid-phase recycling method for basic ionic liquid [C4mim]Ac by macroporous resin and ion exchange resin from Schisandra chinensis fruits extract.

    Science.gov (United States)

    Ma, Chun-hui; Zu, Yuan-gang; Yang, Lei; Li, Jian

    2015-01-22

    In this study, two solid-phase recycling method for basic ionic liquid (IL) 1-butyl-3-methylimidazolium acetate ([C4mim]Ac) were studied through a digestion extraction system of extracting biphenyl cyclooctene lignans from Schisandra chinensis. The RP-HPLC detection method for [C4mim]Ac was established in order to investigate the recovery efficiency of IL. The recycling method of [C4mim]Ac is divided into two steps, the first step was the separation of lignans from the IL solution containing HPD 5000 macroporous resin, the recovery efficiency and purity of [C4mim]Ac achieved were 97.8% and 67.7%, respectively. This method cannot only separate the lignans from [C4mim]Ac solution, also improve the purity of lignans, the absorption rate of lignans in [C4mim]Ac solution was found to be higher (69.2%) than that in ethanol solution (57.7%). The second step was the purification of [C4mim]Ac by the SK1B strong acid ion exchange resin, an [C4mim]Ac recovery efficiency of 55.9% and the purity higher than 90% were achieved. Additionally, [C4mim]Ac as solvent extraction of lignans from S. chinensis was optimized, the hydrolysis temperature was 90°C and the hydrolysis time was 2h.

  19. Releasing Pattern of Applied Phosphorus and Distribution Change of Phosphorus Fractions in the Acid Upland Soils with Successive Resin Extraction

    Directory of Open Access Journals (Sweden)

    Arief Hartono

    2008-05-01

    Full Text Available The releasing pattern of applied P in the acid upland soils and the soil properties influencing the pattern were studied. Surface horizons of six acid upland soils from Sumatra, Java and Kalimantan were used in this study. The releasing pattern of applied P (300 mg P kg-1 of these soils were studied by successive resin extraction. P fractionation was conducted to evaluate which fractions released P to the soil solution after successive resin extraction. The cumulative of resin-Pinorganic (Pi release of soils was fitted to the first order kinetic. Regression analyses using factor scores obtained from the previous principal components analyses was applied to determine soil properties influencing P releasing pattern. The results suggested that the maximum P release was significantly (P < 0.05 increased by acidity plus 1.4 nm mineral-related factor (PC2 i.e. exchangeable Al and 1.4 nm minerals (smectite and vermiculite and decreased by oxide related factor (PC1 i.e. aluminum (Al plus 1/2 iron (Fe (by ammonium oxalate, crystalline Al and Fe oxides, cation exchange capacity, and clay content. P fractionation analysis after successive resin extraction showed that both labile and less labile in the form of NaHCO3-Pi and NaOH-Pi fractions, respectively, can be transformed into resin-Pi when in the most labile resin-Pi is depleted. Most of P released in high oxides soils were from NaOH-Pi fraction while in low oxides soils were from NaHCO3-Pi. P release from the former fraction resulted in the maximum P release lower than that of the latter one. When NaHCO3-Pi was high, NaOH-Pi was relatively more stable than NaHCO3-Pi despite resin-Pi removal. NaHCO3-Pi and NaOH-Pi are very important P fractions in replenishing resin-Pi in these acid upland soils.

  20. Solid phase extractive preconcentration of uranium(VI) using quinoline-8-ol anchored chloromethylated polymeric resin beads.

    Science.gov (United States)

    Praveen, R S; Metilda, P; Daniel, S; Rao, T Prasada

    2005-10-31

    A new chelating polymeric sorbent has been developed using Merrifield chloromethylated resin anchored with quinoline-8-ol (HQ). The modified polymeric resin was characterized by FT-IR spectroscopy and elemental analysis. The HQ anchored resin showed superior binding affinity for U(VI) over Th(IV) and La(III). The influence of various physicochemical parameters on the recovery of U(VI) were optimized by both static and dynamic methods. The phase exchange kinetic studies performed for U(VI) revealed that XAD-16. The developed HQ anchored polymeric resin is highly selective as none of the extraneous species were found to have any deleterious effect. Solid phase extraction (SPE) studies performed using HQ anchored polymeric resin offered enrichment factor of 100 and the lowest concentration below which recoveries become non-quantitative is 5mugl(-1). The accuracy of the developed SPE method in conjunction with Arsenazo III procedure was tested by analyzing marine sediment (MESS-3) and soil (IAEA-Soil 7) reference materials. Furthermore, the above procedure has been successfully employed for the analysis of real soil and sediment samples.

  1. Biobased carbon content of resin extracted from polyethylene composite by carbon-14 concentration measurements using accelerator mass spectrometry.

    Science.gov (United States)

    Taguchi, Kazuhiro; Kunioka, Masao; Funabashi, Masahiro; Ninomiya, Fumi

    2014-01-01

    An estimation procedure for biobased carbon content of polyethylene composite was studied using carbon-14 ((14)C) concentration ratios as measured by accelerated mass spectrometry (AMS). Prior to the measurement, additives and fillers in composites should be removed because they often contain a large amount of biobased carbon and may shift the estimation. Samples of resin with purity suitable for measurement were isolated from composites with a Soxhlet extractor using heated cyclohexanone. After cooling of extraction solutions, the resin was recovered as a fine semi-crystalline precipitate, which was easily filtered. Recovery rates were almost identical (99%), even for low-density polyethylene and linear low-density polyethylene, which may have lower crystallinity. This procedure could provide a suitable approach for estimation of biobased carbon content by AMS on the basis of the standard ASTM D 6866. The biobased carbon content for resin extracted from polyethylene composites allow for the calculation of biosynthetic polymer content, which is an indicator of mass percentage of the biobased plastic resin in the composite.

  2. Comparison in the extraction properties of Pu(IV) in piperidinium and pyrrolidinium nitrate anchored anion exchange resins

    Energy Technology Data Exchange (ETDEWEB)

    Selvan, B. Robert; Suneesh, A.S.; Venkatesan, K.A.; Antony, M.P.; Vasudeva Rao, P.R. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Fuel Chemistry Div.

    2016-07-01

    Piperidinium nitrate (Pip-NO{sub 3}) and pyrrolidinium nitrate (Pyr-NO{sub 3}) functional groups were anchored on a poly(styrene-divinylbenzene) matrix and evaluated the resultant anion exchange resin for the extraction of plutonium from nitric acid medium. The distribution coefficient (K{sub d}, mL/g) of Pu(IV) in these resins increased with the concentration of nitric acid, reaching a maximum K{sub d} at 7 M nitric acid, followed by decrease. The extraction of Pu(IV) increased with the duration of equilibration followed by the establishment of equilibrium, occurred within four hours of equilibration. The kinetic data were fitted with pseudo-first order and pseudo-second order rate equations. The apparent plutonium exchange capacity was determined to be ∝256 mg/g for Pip-NO{sub 3} resin and 285 mg/g for Pyr-NO{sub 3} resin at 7 M nitric acid. The radiolytic degradation of Pip-NO{sub 3} and Pyr-NO{sub 3} in presence of nitric acid (7 M) was studied upto a dose of 200 KGy and the results are reported in this paper.

  3. Curcumin and Boswellia serrata gum resin extract inhibit chikungunya and vesicular stomatitis virus infections in vitro.

    Science.gov (United States)

    von Rhein, Christine; Weidner, Tatjana; Henß, Lisa; Martin, Judith; Weber, Christopher; Sliva, Katja; Schnierle, Barbara S

    2016-01-01

    Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that causes chikungunya fever and has infected millions of people mainly in developing countries. The associated disease is characterized by rash, high fever, and severe arthritis that can persist for years. CHIKV has adapted to Aedes albopictus, which also inhabits temperate regions including Europe and the United States of America. CHIKV has recently caused large outbreaks in Latin America. No treatment or licensed CHIKV vaccine exists. Traditional medicines are known to have anti-viral effects; therefore, we examined whether curcumin or Boswellia serrata gum resin extract have antiviral activity against CHIKV. Both compounds blocked entry of CHIKV Env-pseudotyped lentiviral vectors and inhibited CHIKV infection in vitro. In addition, vesicular stomatitis virus vector particles and viral infections were also inhibited to the same extent, indicating a broad antiviral activity. Although the bioavailability of these compounds is rather poor, they might be used as a lead structure to develop more effective antiviral drugs or might be used topically to prevent CHIKV spread in the skin after mosquito bites.

  4. Effects of croton urucurana extracts and crude resin on Anagasta kuehniella (Lepidoptera: Pyralidae

    Directory of Open Access Journals (Sweden)

    Luciana Barboza Silva

    2009-06-01

    Full Text Available Hundreds of plant species have been studied in order to find out the active ingredient responsible for their insecticidal activity against the pests of economic importance. To verify the insecticidal activity in the husk of stem of Croton urucurana Baillon 1864 (Euphorbiaceae against Anagasta kuehniella Zeller 1879 (Lepidoptera: Pyralidae, the methanolic (EMeOH extract, dichloromethane fraction (FDM, ethyl acetate fraction (FAE and crude resin, incorporated into an artificial diet were evaluated. EMeOH (0.5, 1.0 and 2.0% and crude resin (2.0% interfered with neither the weight nor the survival of fourth instar larvae and other analyzed parameters. FDM (2.0% fraction caused mortality of 65%, and the artificial diet containing 2.0, 1.0 and 0.5% FAE caused 100, 55 and 68% mortality respectively when compared with the control, confirming the least efficiency rates of food conversion for FDM(2.0% and FAE(1.0%. The tryptic analysis performed with the midgut fluid of fourth-instar larvae demonstrated that tryptic and chymiotryptic activities for the larvae fed artificial diet containing EMeOH and crude resin were not different.Atualmente centenas de plantas são investigadas para se conhecer os princípios ativos responsáveis pela atividade inseticida contra as diversas pragas de importância econômica. Com o objetivo de verificar a atividade inseticida das cascas do caule de Croton urucurana Baillon 1864 (Euphorbiaceae em relação a Anagasta kuehniella Zeller 1879 (Lepidoptera: Pyralidae, avaliou-se o extrato metanólico (EMeOH, fração diclorometano (FDM, a fração acetato de etila (FAE e a resina in natura, os quais foram adicionados à dieta artificial. O EMeOH (0,5, 1,0 e 20,% e a resina in natura (2,0%, não interferiram no peso, sobrevivência das larvas de 4ª ínstar, bem como nos demais parâmetros analisados. A fração FDM (2,0% causou mortalidade de 65%, e a dieta artificial contendo 2,0, 1,0, e 0,5% de FAE causou 100, 55 e 68% de

  5. Enrichment and Purification of Deoxyschizandrin and γ-Schizandrin from the Extract of Schisandra chinensis Fruit by Macroporous Resins

    Directory of Open Access Journals (Sweden)

    Ying Zhang

    2012-03-01

    Full Text Available In present study, the performance and separation characteristics of 21 macroporous resins for the enrichment and purification of deoxyschizandrin and γ-schizandrin, the two major lignans from Schisandra chinensis extracts, were evaluated. According to our results, HPD5000, which adsorbs by the molecular tiers model, was the best macroporous resin, offering higher adsorption and desorption capacities and higher adsorption speed for deoxyschizandrin and γ-schizandrin than other resins. Columns packed with HPD5000 resin were used to perform dynamic adsorption and desorption tests to optimize the technical parameters of the separation process. The results showed that the best adsorption time is 4 h, the rate of adsorption is 0.85 mL/min (4 BV/h and the rate of desorption is 0.43 mL/min (2 BV/h. After elution with 90% ethanol, the purity of deoxy-schizandrin increased 12.62-fold from 0.37% to 4.67%, the purity of γ-schizandrin increased 15.8-fold from 0.65% to 10.27%, and the recovery rate was more than 80%.

  6. Separation and purification of both tea seed polysaccharide and saponin from camellia cake extract using macroporous resin.

    Science.gov (United States)

    Yang, Pengjie; Zhou, Mingda; Zhou, Chengyun; Wang, Qian; Zhang, Fangfang; Chen, Jian

    2015-02-01

    A novel method to separate and purify tea seed polysaccharide and tea seed saponin from camellia cake extract by macroporous resin was developed. Among four kinds of resins (AB-8, NKA-9, XDA-6, and D4020) tested, AB-8 macroporous resin possessed optimal separating capacity for the two substances and thus was selected for the separation, in which deionized water was used to elute tea seed polysaccharide, 0.25% NaOH solution to remove the undesired pigments, and 90% ethanol to elute tea seed saponin. Further dynamic adsorption/desorption experiments on AB-8 resin-based column chromatography were conducted to obtain the optimal parameters. Under optimal dynamic adsorption and desorption conditions, 18.7 and 11.8% yield of tea seed polysaccharide and tea seed saponin were obtained with purities of 89.2 and 96.0%, respectively. The developed method provides a potential approach for the large-scale production of tea seed polysaccharide and tea seed saponin from camellia cake. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Preparation of extraction resin for radio lanthanides separation; Preparacion de resina de extraccion para separacion de radiolantanidos

    Energy Technology Data Exchange (ETDEWEB)

    Cruz B, C.C. de la; Monroy G, F. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)]. e-mail: delacruzbc@hotmail.com

    2008-07-01

    The present work presents the methodology that was developed for the preparation of one extractant resin with the aim of HDEHP, to separate radio lanthanides with serial atomic numbers. In this case it is exemplified with the separation of the following elements: Gadolinium-161 and the Terbium-161; this last radioisotope it is a beta emitting ({beta}{sup -}) that has a great potential to be used in therapy, also in nuclear medicine and in oncology, this is due to the high penetration power of their {beta}{sup -} particles that can kill to the cancerous cells and to inhibit the growth of the same ones. To be able to separate them it is necessary to appeal to extremely selective separation techniques, since the chemical properties of these elements are very similar. The chromatography is one of the more used analytical tools, this is due to its great sensibility and the selectivity in the compounds separation, in particular the use of the extractive chromatography has shown the feasibility of carrying out this type of separations for this type of elements. The resin with base of HDEHP was absorbed in an inert support under diverse preparation conditions. The extractant properties of the resin, in relation to the elements Gd and Tb (distribution coefficients), its were determined by means of the dynamic method, using as eluent solutions of nitric acid. The Gd-159 was prepared by irradiation of Gd-168 with thermal neutrons and the Tb-161 it is the result of the radioactive decay of the Gd-161 that is produced in turn with the irradiation with neutrons of Gd-160. The coefficients of distribution of Gd and Tb, using the prepared resin under diverse conditions are presented. (Author)

  8. Efficiency of Polyphenol Extraction from Artificial Honey Using C18 Cartridges and Amberlite® XAD-2 Resin: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Chua Yung An

    2016-01-01

    Full Text Available A comparative study of the extraction efficiency of nine known polyphenols [phenolic acids (benzoic acid, dihydroxybenzoic acid, gallic acid, trans-cinnamic acid, and vanillic acid and flavonoids (naringenin, naringin, quercetin, and rutin] was conducted by deliberately adding the polyphenols to an artificial honey solution and performing solid phase extraction (SPE. Two SPE methods were compared: one using Amberlite XAD-2 resin and another one using a C18 cartridge. A gradient high performance liquid chromatography system with an RP18 column and photodiode array detector was utilized to analyze the extracted polyphenols. The mean percent of recovery from the C18 cartridges was 74.2%, while that from the Amberlite XAD-2 resin was 43.7%. The recoveries of vanillic acid, naringin, and rutin were excellent (>90%; however, gallic acid was not obtained when C18 cartridges were used. Additionally, the reusability of Amberlite XAD-2 resin was investigated, revealing that the mean recovery of polyphenols decreased from 43.7% (1st extraction to 29.3% (3rd extraction. It was concluded that although Amberlite XAD-2 resin yielded a higher number of compounds, C18 cartridges gave a better extraction recovery. The lower recovery seen for the Amberlite XAD-2 resin also cannot be compensated by repeated extractions due to the gradual decrease of extraction recovery when reused.

  9. Preliminary extraction of tannins by 1-butyl-3-methylimidazole bromide and its subsequent removal from Galla chinensis extract using macroporous resins.

    Science.gov (United States)

    Lu, Chunxia; Luo, Xiaoling; Lu, Liliang; Li, Hongmin; Chen, Xia; Ji, Yong

    2013-03-01

    In recent years, ionic liquids have become increasingly attractive as 'green solvents' used in the extraction of bioactive compounds from natural plant. However, the separation of ionic liquid from the target compounds was difficult, due to their low vapour pressure and high stabilities. In our study, ionic liquid-based ultrasonic and microwave-assisted extraction was used to obtain the crude tannins, then the macroporous resin adsorption technology was further employed to purify the tannins and remove the ionic liquid from crude extract. The results showed that XDA-6 had higher separation efficiency than other tested resins, and the equilibrium experimental data were well fitted to Langmuir isotherms. Dynamic adsorption and desorption were performed on XDA-6 packed in glass columns to optimise the separation process. The optimum conditions as follows: the ratio of column height to diameter bed was 1:8, flow rate 1 BV/h (bed volume per hour), 85% ethanol was used as eluant while the elution volume was 2 BV. Under the optimised conditions, the adsorption and desoption rate of tannins in XDA-6 were 94.81 and 91.63%, respectively. The content of tannins was increased from 70.24% in Galla chinensis extract to 85.12% with a recovery of 99.06%. The result of ultra-performance liquid chromatography (UPLC)-MS/MS analysis showed that [bmim]Br could be removed from extract.

  10. SEQUENTIAL EXTRACTION OF PHOSPHORUS BY MEHLICH-1 AND ION EXCHANGE RESIN FROM B HORIZONS OF FERRIC AND PERFERRIC LATOSOLS (OXISOLS

    Directory of Open Access Journals (Sweden)

    Danilo de Lima Camêlo

    2015-08-01

    Full Text Available In general, Latosols have low levels of available P, however, the influence of the parent material seems to be decisive in defining the pool and predominant form of P in these soils. This study evaluated P availability by extraction with Mehlich-1 (M-1 and Ion Exchange Resin (IER, from samples of B horizons of Ferric and Perferric Latosols developed from different parent materials. To this end, in addition to the physical and chemical characterization of soils, 10 sequential extractions were performed with M-1 and IER from samples of B horizons (depth between 0.8 and 1.0 m. Total contents of Ca, P, Fe, Al, and Ti were determined after digestion with nitric, hydrofluoric and perchloric acids. The effects of sequential P extractions on Fe oxides were also evaluated from the analyses of dithionite-citrate-bicarbonate and ammonium acid oxalate. The high similarity between contents of P accumulated after sequential extractions with M-1 and IER in soils developed on tuffite indicated a predominance of P-Ca. Higher contents of P after a single IER extraction show greater efficiency in P removal from highly weathered soils, as from the Latosols studied here. The P contents also show the high sensitivity of extractant M-1 in highly buffered soils. Furthermore, a single extraction with extractant M-1 or IER is not sufficient to estimate the amount of labile P in these soils.

  11. Solid-liquid extraction of Gd(Ⅲ) and separation possibilities of rare earths from phosphoric acid solutions using Tulsion CH-93 and Tulsion CH-90 resins

    Institute of Scientific and Technical Information of China (English)

    S.Radhika; V.Nagaraju; B.Nagaphani Kumar; M.Lakshmi Kantam; B.Ramachandra Reddy

    2012-01-01

    Solid-liquid extraction of gadolinium was investigated from phosphoric acid medium using commercial amino phosphonic acid resin,Tulsion CH-93.The experimental conditions studied included equilibration time,acid concentration,mass of the resin,metal concentration,loading and elution.The percent extraction of Gd(Ⅲ) was studied as a function of phosphoric acid (0.05-3 mol/L) using Tulsion CH-93 resin.The corresponding lgD vs.equilibrium pH plot gave straight line with a slope of 1.8.The percent extraction decreased with acid concentration increasing,conforming ion exchange mechanism.Under observed experimental conditions the loading capacity of Tulsion CH-93 for gadolinium was 10.6 mg/g.Among several eluants screened,the quantitative elution of Gd(Ⅲ) from loaded Tulsion CH-93 was obtained with ammonium oxalate (0.15 mol/L).The extraction behavior of commonly associated metals with gadolinium was studied as a function of phosphoric acid concentration.Tulsion CH-93 resin showed selective extraction towards heavy rare earths (Lu and Yb) which could be separated from other rare earths at 3 mol/L H3PO4,similar to wet phosphoric acid (3-5 mol/L).On the other hand Gd(Ⅲ) and other rare earths were studied with chelating resin Tulsion CH-90.Light rare earths were highly extracted and these could be separated from heavy rare earths and Gd.

  12. Characterization of Group V Dubnium Homologs on DGA Extraction Chromatography Resin from Nitric and Hydrofluoric Acid Matrices

    Energy Technology Data Exchange (ETDEWEB)

    Despotopulos, J D; Sudowe, R

    2012-02-21

    somewhere between Nb and Pa. Much more recent studies have examined the properties of Db from HNO{sub 3}/HF matrices, and suggest Db forms complexes similar to those of Pa. Very little experimental work into the behavior of element 114 has been performed. Thermochromatography experiments of three atoms of element 114 indicate that the element 114 is at least as volatile as Hg, At, and element 112. Lead was shown to deposit on gold at temperatures about 1000 C higher than the atoms of element 114. Results indicate a substantially increased stability of element 114. No liquid phase studies of element 114 or its homologs (Pb, Sn, Ge) or pseudo-homologs (Hg, Cd) have been performed. Theoretical predictions indicate that element 114 is should have a much more stable +2 oxidation state and neutral state than Pb, which would result in element 114 being less reactive and less metallic than Pb. The relativistic effects on the 7p{sub 1/2} electrons are predicted to cause a diagonal relationship to be introduced into the periodic table. Therefore, 114{sup 2+} is expected to behave as if it were somewhere between Hg{sup 2+}, Cd{sup 2+}, and Pb{sup 2+}. In this work two commercially available extraction chromatography resins are evaluated, one for the separation of Db homologs and pseudo?homologs from each other as well as from potential interfering elements such as Group IV Rf homologs and actinides, and the other for separation of element 114 homologs. One resin, Eichrom's DGA resin, contains a N,N,N',N'-tetra-n-octyldiglycolamide extractant, which separates analytes based on both size and charge characteristics of the solvated metal species, coated on an inert support. The DGA resin was examined for Db chemical systems, and shows a high degree of selectivity for tri-, tetra-, and hexavalent metal ions in multiple acid matrices with fast kinetics. The other resin, Eichrom's Pb resin, contains a di-t-butylcyclohexano 18-crown-6 extractant with isodecanol solvent

  13. Extraction of anthocyanins from black bean canning wastewater with macroporous resins.

    Science.gov (United States)

    Wang, Xiaoxi; Hansen, Conly; Allen, Karin

    2014-02-01

    This study investigated purification of anthocyanins from black bean canning wastewater by column chromatography with 5 types of macroporous resins (Diaion Hp20, Sepabeads Sp70, Sepabeads Sp207, Sepabeads Sp700, and Sepabeads Sp710). By-product of canned black beans was partially purified by filtration, in anticipation of higher performance during column chromatography. Equilibrium adsorption isotherms were measured and analyzed using Langmuir and Freundlich isotherm models. Both Langmuir (all R² ≥ 0.98) and Freundlich (all R² ≥ 0.97) models can describe the adsorption process of anthocyanins from black bean canning wastewater using the tested resins. The adsorption and desorption behaviors of anthocyanins were studied using a dynamic method on the 5 types of resins, and Sp700 presented the highest adsorption capacity (39 ± 4 mg/g; P canning wastewater.

  14. Purification of gamma-amino butyric acid (GABA) from fermentation of defatted rice bran extract by using ion exchange resin

    Science.gov (United States)

    Tuan Nha, Vi; Phung, Le Thi Kim; Dat, Lai Quoc

    2017-09-01

    Rice bran is one of the significant byproducts of rice processing with 10 %w/w of constitution of whole rice grain. It is rich in nutrient compounds, including glutamic acid. Thus, it could be utilized for the fermentation with Lactobateria for synthesis of GABA, a valuable bioactive for antihypertensive effects. However, the concentration and purity of GABA in fermentation broth of defatted rice bran extract is low for production of GABA drug. This research focused on the purification of GABA from the fermentation broth of defatted rice bran extract by using cation exchange resin. The results indicate that, the adsorption isotherm of GABA by Purelite C100 showed the good agreement with Freundlich model, with high adsorption capacity. The effects of pH and concentration of NaCl in eluent on the elution were also investigated. The obtained results show that, at the operating conditions of elution as follows: pH 6.5, 0.8 M of NaCl in eluent, 0.43 of bed volume; concentration of GABA in accumulative eluent, the purity and recovery yield of GABA were 743.8 ppm, 44.0% and 84.2%, respectively. Results imply that, it is feasible to apply cation exchange resin for purification of GABA from fermentation broth of defatted rice bran extract.

  15. Review: Resin Composite Filling

    Science.gov (United States)

    Chan, Keith H. S.; Mai, Yanjie; Kim, Harry; Tong, Keith C. T.; Ng, Desmond; Hsiao, Jimmy C. M.

    2010-01-01

    The leading cause of oral pain and tooth loss is from caries and their treatment include restoration using amalgam, resin, porcelain and gold, endodontic therapy and extraction. Resin composite restorations have grown popular over the last half a century because it can take shades more similar to enamel. Here, we discuss the history and use of resin, comparison between amalgam and resin, clinical procedures involved and finishing and polishing techniques for resin restoration. Although resin composite has aesthetic advantages over amalgam, one of the major disadvantage include polymerization shrinkage and future research is needed on reaction kinetics and viscoelastic behaviour to minimize shrinkage stress.

  16. Enrichment and purification of total flavonoids from Flos Populi extracts with macroporous resins and evaluation of antioxidant activities in vitro.

    Science.gov (United States)

    Wan, Pengfei; Sheng, Zunlai; Han, Qiang; Zhao, Yulin; Cheng, Guangdong; Li, Yanhua

    2014-01-15

    Enrichment and purification of total flavonoids from Flos Populi extracts were studied using five macroporous resins. The static tests indicated that NKA-9 resin was appropriate and its adsorption data were well fitted to the Langmuir and Freundlich isotherms. To optimize the separation process, dynamic adsorption and desorption tests were carried out. The optimal adsorption parameters were initial concentrations in sample solution of 7.64mg/mL, pH of 5.0, sample loading amount of 2.3BV, flow rate of 2BV/h, temperature of 25°C. The optimal desorption parameters were deionized water and 20% ethanol each 5BV, then 60% ethanol of 10 BV, flow rate of 2BV/h. After one run treatment with NKA-9 resin, the content of total flavonoids in the product increased from 11.38% to 53.41%, and the recovery yield was 82.24%. The results showed that NKA-9 resin revealed a good ability to enrichment total flavonoids from Flos Populi, and the method can be referenced for the enrichment of total flavonoids from other materials. The antioxidant activities of the purified flavonoids were further evaluated in vitro. It showed that the DPPH radical scavenging increased from 59.46% to 82.63% at different concentrations (0.06-0.14mg/mL). At different concentrations (0.6-1.4mg/mL), the hydroxyl radical scavenging increased from 35.39% to 74.12%. Moreover, the reducing ability and total oxidant capacity appeared to be dose-dependent of flavonoids. It indicated that the purified flavonoids can be used as a source of potential antioxidant.

  17. The effect of Psidium guajava Linn leaf extract on Candida albicans adherence and the transversal strength of acrylic resin

    Directory of Open Access Journals (Sweden)

    Amiyatun Naini

    2008-03-01

    Full Text Available Denture stomatitis is an inflammation of oral cavity due to removable denture wearing. Prevention of denture stomatitis can be effectively done by using mouth rinsing. Currently, Indonesian government is actively promoting traditional herbal medicine as an alternative medicine such as Psidium guajava Linn leaf which has an anti bacterial and anti fungal ability. The purpose of this study was to know the effective concentration and soaking duration to reduce Candida albicans without lowering transversal strength of acrylic resin. This experimental laboratory study was using heat cured acrylic resin plate without surface polishing. The concentration of Psidium guajava Linn leaf extract used in this study were 32%, 34%, 36%, and 38% respectively with 15 minutes, 30 minutes, 1 hour and 8 hours soaking duration. The transversal strength was measured in the same concentration with 2 days, 10 days and 60 days soaking duration. Sterile aquadest was used as control. Two direction ANOVA and LSD test were used in data analysis. The result showed significant difference in the number of Candida albicans colony among concentrations and soaking durations. Significant difference was also found in transversal strength among concentrations and soaking durations. It is concluded that the extract of Psidium guajava Linn leaf in 38% concentration with 8 hours soaking duration will lower the Candida albicans colony, whereas 38% concentration with 60 days soaking duration will lower the transversal strength but it is still above the standard value.

  18. Novel polysiloxane resin functionalized with dicyclohexano-18-crown-6 (DCH18C6): Synthesis, characterization and extraction of Sr(II) in high acidity HNO3 medium.

    Science.gov (United States)

    Ye, Gang; Bai, Feifei; Wei, Jichao; Wang, Jianchen; Chen, Jing

    2012-07-30

    A novel kind of polysiloxane resin functionalized with dicyclohexano-18-crown-6 (DCH18C6) was synthesized through a post-modification approach. The DCH18C6 moieties bearing amino groups were firstly prepared, followed by covalent grafting to a silica precursor P-(CH(2))(3)-Cl (Where P represents a 3-dimentional polymerized silica matrix) based on nucleophilic substitution reaction. (29)Si and (13)C solid-state NMR, FT-IR, XPS, TGA, ESEM and elemental analysis were employed to systematically characterize the structure, thermal property and surface morphology of the functionalized resin. The results indicated that the DCH18C6 ligands were successfully bonded to the polysiloxane resin with a satisfactory grafting degree (33.6wt.%). Due to the robust organosilica framework and the covalent immobilization of the ligands, the functionalized resin had excellent thermal stability and acid resistance. Batch experiments showed that the resin could effectively separate Sr(II) in high acidity mediums. The distribution coefficient (K(d)) of 43.6cm(3)/g could be achieved in 5.0mol/L HNO(3) solution. The influences of contact time and acidity of HNO(3) on the resin's extraction performance were examined. The reusability and the selectivity to Sr(II) over interference ions were investigated. The DCH18C6-functionalized resin might be potentially applied for the radiostrontium removal in the high level liquid waste (HLLW).

  19. Effects of an acetone extract of Boswellia carterii Birdw. (Burseraceae) gum resin on adjuvant-induced arthritis in lewis rats.

    Science.gov (United States)

    Fan, A Y; Lao, L; Zhang, R X; Zhou, A N; Wang, L B; Moudgil, K D; Lee, D Y W; Ma, Z Z; Zhang, W Y; Berman, B M

    2005-10-03

    Ruxiang (Gummi olibanum), the dried gum resin of Boswellia carterii (BC), has been used in traditional Chinese medicine to alleviate pain and inflammation for thousands of years. In this random, blinded study, the anti-arthritic effects of a BC extract were observed and compared to vehicle control in a Lewis rat adjuvant arthritis model (n=8/group). Arthritis was induced by injecting CFA subcutaneously into the base of the tail, and the extract was administered orally (i.g.) for 10 consecutive days beginning on day 16 after the injection. Arthritic scores, paw edema, and the local tissue pro-inflammatory cytokines tumor necrosis factor alpha (TNF-alpha) and interleukin-1 beta (IL-1beta) were assessed. Toxicity and adverse effects of the extract were evaluated. At 0.90 g/kg per day, BC significantly decreased arthritic scores between days 20 and 25 (p<0.05) and reduced paw edema on days 18, 20 and 22 compared to control (p<0.05). It also significantly suppressed local tissue TNF-alpha and IL-1beta (p<0.05). No major adverse effects were observed in animals during the repeated-dose treatment profile although mild fur discoloration was noted. The data show that BC extract has significant anti-arthritic and anti-inflammation effects and suggest that these effects may be mediated via the suppression of pro-inflammatory cytokines.

  20. Preparative separation and purification of Rebaudioside A from Stevia rebaudiana Bertoni crude extracts by mixed bed of macroporous adsorption resins.

    Science.gov (United States)

    Li, Jie; Chen, Zhenbin; Di, Duolong

    2012-05-01

    The separation and purification of Rebaudioside A (RA) from Stevia rebaudiana Bertoni crude extracts (Steviosides) by macroporous adsorption resin (MAR) mixed bed were systematically investigated. MAR mixed bed of HPD750-LSA40-LSA30-DS401 was selected due to its better separation degree. Based on the kinetics/thermodynamics experiment of the mixed bed, it was found that the experimental data fitted better to the pseudo-second-order model, and intra-particle diffusion was rate-limiting step. The adsorption isotherm was consistent with IV equilibrium adsorption isotherm classified by Brunauer. Furthermore, the influencing factors for the separation of RA based on HPLC were also investigated. Under the optimal conditions, the separation degree for RA (DAS) increased from 0.771 to 1.54. Moreover, the experimental results showed that the purity of the obtained product increased from 60% to 97%.

  1. Flavonoid dimers from the total phenolic extract of Chinese dragon's blood, the red resin of Dracaena cochinchinensis.

    Science.gov (United States)

    Pang, Dao-Ran; Su, Xiao-Qin; Zhu, Zhi-Xiang; Sun, Jing; Li, Yue-Ting; Song, Yue-Lin; Zhao, Yun-Fang; Tu, Peng-Fei; Zheng, Jiao; Li, Jun

    2016-12-01

    Eight new flavonoid dimers, named cochinchinenins I-M (1-5), including three pairs of enantiomers (1a/1b-3a/3b) and two optically pure flavonoid dimers (4-5), along with a known analogue (6), were isolated from total phenolic extract of the red resin of Dracaena cochinchinensis (Chinese dragon's blood). The planar structures of 1-5 were elucidated by extensive spectroscopic analysis including HRESIMS and 1D/2D NMR. Their absolute configurations were determined on the basis of experimental and calculated electronic circular dichroism (ECD) data. Compounds 4 and 5 exhibited significant inhibition of nitric oxide production in lipopolysaccharide-stimulated BV-2 microglial cells with IC50 value of 4.9±0.4 and 5.4±0.6μM, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Hydrophobic features of EPS extracted from anaerobic granular sludge: an investigation based on DAX-8 resin fractionation and size exclusion chromatography.

    Science.gov (United States)

    Cao, Feishu; Bourven, Isabelle; Lens, Piet N L; van Hullebusch, Eric D; Pechaud, Yoan; Guibaud, Gilles

    2017-04-01

    The hydrophobic fractionation of extracellular polymeric substances (EPS) extracted from anaerobic granular sludge was performed on the DAX-8 resin (two elution pH conditions, i.e., pH 2 and pH 5 were tested). The impact of seven different EPS extraction methods on EPS hydrophobicity features was assessed. The results showed that the extraction methods and bulk solution pH influenced dramatically the biochemical composition of the EPS, and in turn, the hydrophobicity determined. Besides, EPS extracting reagents i.e., formaldehyde, ethanol, sodium dodecyl sulfate (SDS), and Tween 20 not only introduced extra carbon content in the total organic carbon (TOC) measurement but also interacted with the DAX-8 resin. By comparing the apparent molecular weight (aMW) distribution of untreated and pH-adjusted EPS samples, more complete EPS aMW information was preserved at pH 5. Thus, elution at pH 5 was preferred in this study for the qualitative analysis of EPS hydrophobic features. The hydrophobic fraction of EPS retained by the resin at pH 5 was ascribed to a wide aMW range, ranging from >440 to 0.3 kDa. Within this range, EPS molecules ranging from 175 to 31 kDa were mostly retained by the DAX-8 resin, which indicates that these EPS molecules are highly hydrophobic.

  3. Efficient extraction and preparative separation of four main isoflavonoids from Dalbergia odorifera T. Chen leaves by deep eutectic solvents-based negative pressure cavitation extraction followed by macroporous resin column chromatography.

    Science.gov (United States)

    Li, Lu; Liu, Ju-Zhao; Luo, Meng; Wang, Wei; Huang, Yu-Yan; Efferth, Thomas; Wang, Hui-Mei; Fu, Yu-Jie

    2016-10-15

    In this study, green and efficient deep eutectic solvent-based negative pressure cavitation-assisted extraction (DES-NPCE) followed by macroporous resin column chromatography was developed to extract and separate four main isoflavonoids, i.e. prunetin, tectorigenin, genistein and biochanin A from Dalbergia odorifera T. Chen leaves. The extraction procedure was optimized systematically by single-factor experiments and a Box-Behnken experimental design combined with response surface methodology. The maximum extraction yields of prunetin, tectorigenin, genistein and biochanin A reached 1.204, 1.057, 0.911 and 2.448mg/g dry weight, respectively. Moreover, the direct enrichment and separation of four isoflavonoids in DES extraction solution was successfully achieved by macroporous resin AB-8 with recovery yields of more than 80%. The present study provides a convenient and efficient method for the green extraction and preparative separation of active compounds from plants.

  4. Efficiency of Polyphenol Extraction from Artificial Honey Using C18 Cartridges and Amberlite® XAD-2 Resin: A Comparative Study

    OpenAIRE

    Chua Yung An; Md. Murad Hossain; Fahmida Alam; Md. Asiful Islam; Md. Ibrahim Khalil; Nadia Alam; Siew Hua Gan,

    2016-01-01

    A comparative study of the extraction efficiency of nine known polyphenols [phenolic acids (benzoic acid, dihydroxybenzoic acid, gallic acid, trans-cinnamic acid, and vanillic acid) and flavonoids (naringenin, naringin, quercetin, and rutin)] was conducted by deliberately adding the polyphenols to an artificial honey solution and performing solid phase extraction (SPE). Two SPE methods were compared: one using Amberlite XAD-2 resin and another one using a C18 cartridge. A gradient high perfor...

  5. Evaluation of tri-n-octylamine oxide as phenol extractant in a solvent impregnated resin

    NARCIS (Netherlands)

    Burghoff, B.; Cuypers, R.; Ettinger, van M.; Sudhölter, E.J.R.; Zuilhof, H.; Haan, de A.B.

    2009-01-01

    Tri-n-ocytlamine oxide (TOAO) is evaluated as alternative to the state-of-the-art phenol extractants tri-n-octylphosphine oxide (TOPO) and Cyanex 923. Liquid¿liquid equilibrium experiments show that TOAO in 1,3-dimethylnaphthalene achieves higher phenol distribution coefficients in an extractant con

  6. Evaluation of tri-n-octylamine oxide as phenol extractant in a solvent impregnated resin

    NARCIS (Netherlands)

    Burghoff, B.; Cuypers, R.; Ettinger, van M.; Sudhölter, E.J.R.; Zuilhof, H.; Haan, de A.B.

    2009-01-01

    Tri-n-ocytlamine oxide (TOAO) is evaluated as alternative to the state-of-the-art phenol extractants tri-n-octylphosphine oxide (TOPO) and Cyanex 923. Liquid¿liquid equilibrium experiments show that TOAO in 1,3-dimethylnaphthalene achieves higher phenol distribution coefficients in an extractant con

  7. Separation of cyclotron-produced 44Sc from a natural calcium target using a dipentyl pentylphosphonate functionalized extraction resin

    Science.gov (United States)

    Valdovinos, H.F.; Hernandez, R.; Barnhart, T.E.; Graves, S.; Cai, W.; Nickles, R.J.

    2014-01-01

    Significant interest in 44Sc as a radioactive synthon to label small molecules for positron emission tomography (PET) imaging has been recently observed. Despite the efforts of several research groups, the ideal 44Sc production and separation method remains elusive. Herein, we propose a novel separation method to obtain 44Sc from the proton irradiation of calcium targets based on extraction chromatography, which promises to greatly simplify current production methodologies. Using the commercially available Uranium and Tetravalent Actinides (UTEVA) extraction resin we were able to rapidly ( 80% of the activity generated at end of bombardment (EoB) in small ~1 M HCl fractions (400 μL). The chemical purity of the 44Sc eluates was evaluated through chelation with DOTA and DTPA, and by trace metal analysis using microwave induced plasma atomic emission spectrometry. The distribution coefficients (Kd) of Sc(III) and Ca(II) in UTEVA were determined in HCl medium in a range of concentrations from zero to 12.1 M The 44Sc obtained with our method proved to be suitable for the direct labeling of small biomolecules for PET imaging, with excellent specific activities and radiochemical purity. PMID:25464172

  8. Chromium speciation by solid phase extraction on Dowex M 4195 chelating resin and determination by atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Saygi, Kadriye Ozlem; Tuzen, Mustafa [Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat (Turkey); Soylak, Mustafa [Erciyes University, Faculty of Science and Arts, Chemistry Department, 38039 Kayseri (Turkey)], E-mail: msoylak@gmail.com; Elci, Latif [Pamukkale University, Faculty of Science and Arts, Chemistry Department, 20020 Denizli (Turkey)

    2008-05-30

    A solid phase extraction procedure has been established for chromium speciation in natural water samples prior to determination by atomic absorption spectrometry. The procedure is based on the solid phase extraction of the Cr(VI)- Dowex M 4195 chelating resin. After oxidation of Cr(III) to Cr(VI) by using H{sub 2}O{sub 2}, the presented method was applied to the determination of the total chromium. The level of Cr(III) is calculated by difference of total chromium and Cr(VI) levels. The procedure was optimized for some analytical parameters including pH, eluent type, flow rates of sample and eluent, matrix effects, etc. The presented method was applied for the speciation of chromium in natural water samples with satisfactory results (recoveries >95%, RSDs <10%). In the determinations of chromium species, flame atomic absorption spectrometer was used. The results were checked by using NIST SRM 2711 Montana soil and GBW 07603 Bush branched and leaves.

  9. Tunable aqueous polymer-phase impregnated resins-technology-a novel approach to aqueous two-phase extraction.

    Science.gov (United States)

    van Winssen, F A; Merz, J; Schembecker, G

    2014-02-14

    Aqueous Two-Phase Extraction (ATPE) represents a promising unit operation for downstream processing of biotechnological products. The technique provides several advantages such as a biocompatible environment for the extraction of sensitive and biologically active compounds. However, the tendency of some aqueous two-phase systems to form intensive and stable emulsions can lead to long phase separation times causing an increased footprint for the required mixer-settler devices or the need for additional equipment such as centrifuges. In this work, a novel approach to improve ATPE for downstream processing applications called 'Tunable Aqueous Polymer-Phase Impregnated Resins' (TAPPIR(®))-Technology is presented. The technology is based on the immobilization of one aqueous phase inside the pores of a solid support. The second aqueous phase forms the bulk liquid around the impregnated solids. Due to the immobilization of one phase, phase emulsification and phase separation of ATPE are realized in a single step. In this study, a biodegradable and sustainable aqueous two-phase system consisting of aqueous polyethylene glycol/sodiumcitrate solutions was chosen. The impregnation of different macroporous glass and ceramic solids was investigated and could be proven to be stable. Additionally, the separation of the dye Patent blue V was successfully performed with the TAPPIR(®)-Technology. Thus, the "proof of principle" of this technology is presented.

  10. Hydro-alcoholic Extract of Commiphora mukul Gum Resin May Improve Cognitive Impairments in Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Salehi

    2015-02-01

    Full Text Available Background Diabetes causes cognitive impairment. Medicinal plants due to different mechanisms, such as antioxidant activities may improve diabetes and relieve its symptoms. Commiphora mukul (Burseraceae has a significant antioxidant activity. Objectives This study aimed to examine the effect of hydro- alcoholic extract of C. mukul on passive-avoidance learning and memory in streptozotocin (STZ induced diabetic male rats. Materials and Methods Thirty-two adult male Wistar rats were randomly allocated to four groups: normal, diabetic, normal + extract of C. mukul and diabetic + extract of C. mukul groups with free access to regular rat diet. Diabetes was induced in male rats by single interaperitoneal injection of 60 mg/kg STZ. After the confirmation of diabetes, 300 mg/kg C. mukul extract was orally administered to the extract-treated groups. Control groups received normal saline at the same time. Passive-avoidance memory was tested eight weeks after the STZ treatment, and blood glucose and body weight were measured in all groups at the beginning and end of the experiment. Results In the present study, diabetes decreased learning and memory. Although the administration of C. mukul extract did not affect the step-through latency (STLa and the number of trials of the diabetic groups during the first acquisition trial, a significant decrease was observed in STLr and also a significant increase in time spent in the dark compartment (TDC and number of crossing (NOC in the retention test (after 24 and 48 hours. Although no significant difference was observed in body weight of diabetic + extract of C. mukul (DE and diabetic control (DC groups, the plasma glucose of DE group was significantly lower in comparison to DC group. Conclusions Commiphora mukul extract can improve passive-avoidance learning and memory impairments in the STZ-induced diabetic rats. This improvement may be due to the antioxidant, acetylcholinesterase inhibitory activity, anti

  11. Mechanistic Study of Silver Nanoparticle's Synthesis by Dragon's Blood Resin Ethanol Extract and Antiradiation Activity.

    Science.gov (United States)

    Hasan, Murtaza; Iqbal, Javed; Awan, Umer; Saeed, Yasmeen; Ranran, Yuan; Liang, Yanli; Dai, Rongji; Deng, Yulin

    2015-02-01

    Biological synthesis of nanoparticles is best way to avoid exposure of hazardous materials as compared to chemical manufacturing process which is a severe threat not only to biodiversity but also to environment. In present study, we reported a novel method of finding antiradiation compounds by bioreducing mechanism of silver nanoparticles formation using 50% ethanol extract of Dragons blood, a famous Chinese herbal plant. Color change during silver nanoparticles synthesis was observed and it was confirmed by ultra violet (UV) visible spectroscopy at wave length at 430 nm after 30 min of reaction at 60 °C. Well dispersed round shaped silver nanoparticles with approximate size (4 nm to 50 nm) were measured by TEM and particle size analyser. Capping of biomolecules on Ag nanoparticles was characterized by FTIR spectra. HPLC analysis was carried out to find active compounds in the extract. Furthermore, antiradiation activity of this extract was tested by MTT assay in vitro after incubating the SH-SY5Y cells for 24 h at 37 °C. The results indicate that presence of active compounds in plant extract not only involves in bioreduction process but also shows response against radiation. The dual role of plant extract as green synthesis of nanoparticles and exhibit activity against radiation which gives a new way of fishing out active compounds from complex herbal plants.

  12. Effect of Green Tea Extract as Antioxidant on Shear Bond Strength of Resin Composite to in-Office and Home-Bleached Enamel.

    Science.gov (United States)

    F, Sharafeddin; F, Farshad; B, Azarian; A, Afshari

    2016-09-01

    Shear bond strength (SBS) of home and office bleached enamel will be compromised by immediate application of composite restoration. Antioxidant agent may overcome this problem. This in vitro study assessed the effect of green tea extract on shear bond strength of resin composite to in-office and home-bleached enamel. In this experimental study, 40 extracted intact human incisors were embedded in cylindrical acrylic resin blocks (2.5 ×1.5 cm), with the coronal portion above the cemento enamel junction out of the block. Then, after bleaching labial enamel surfaces of 20 teeth with 15% carbamide peroxide 6 hours a day for 5 days, they were randomly divided into two groups: A1 and A2 (n = 10), depending upon whether or not they are treated with antioxidant. Labial enamel surfaces of the remaining 20 teeth were bleached with 38% hydrogen peroxide before being randomly divided into groups B1 and B2 (n = 10), again depending on whether or not the antioxidant was used in their treatment . The experimental groups (A2,B2) were treated with 5% solution of green tea extract before resin composite restoration was done by a cylindrical Teflon mould (5×2 mm). Shear bond strength of the specimens was tested under a universal testing machine (Zwick/Roell Z020). The SBS data were analyzed by using One-way ANOVA and Tukey HSD tests (p < 0.05). There were no statistically significant differences between shear bond strength of the control group (A1) and treated group (A2), but there were statistically significant differences between the groups B1 and B2 (p < 0.05). Application of antioxidant did not increase the shear bond strength of home-bleached enamel to resin composite but its application increased the shear bond strength of in-office bleached enamel to resin composite.

  13. Effect of Green Tea Extract as Antioxidant on Shear Bond Strength of Resin Composite to in-Office and Home-Bleached Enamel

    Directory of Open Access Journals (Sweden)

    Sharafeddin F

    2016-09-01

    Full Text Available Statement of Problem: Shear bond strength (SBS of home and office bleached enamel will be compromised by immediate application of composite restoration. Antioxidant agent may overcome this problem. Objectives: This in vitro study assessed the effect of green tea extract on shear bond strength of resin composite to in-office and home-bleached enamel. Materials and Methods: In this experimental study, 40 extracted intact human incisors were embedded in cylindrical acrylic resin blocks (2.5 ×1.5 cm, with the coronal portion above the cemento enamel junction out of the block. Then, after bleaching labial enamel surfaces of 20 teeth with 15% carbamide peroxide 6 hours a day for 5 days, they were randomly divided into two groups: A1 and A2 (n = 10, depending upon whether or not they are treated with antioxidant. Labial enamel surfaces of the remaining 20 teeth were bleached with 38% hydrogen peroxide before being randomly divided into groups B1 and B2 (n = 10, again depending on whether or not the antioxidant was used in their treatment . The experimental groups (A2,B2 were treated with 5% solution of green tea extract before resin composite restoration was done by a cylindrical Teflon mould (5×2 mm. Shear bond strength of the specimens was tested under a universal testing machine (Zwick/Roell Z020. The SBS data were analyzed by using One-way ANOVA and Tukey HSD tests (p < 0.05. Results: There were no statistically significant differences between shear bond strength of the control group (A1 and treated group (A2 but there were statistically significant differences between the groups B1 and B2 (p < 0.05. Conclusions: Application of antioxidant did not increase the shear bond strength of home-bleached enamel to resin composite but its application increased the shear bond strength of in-office bleached enamel to resin composite.

  14. Process for purification of monoclonal antibody expressed in transgenic Lemna plant extract using dextran-coated charcoal and hexamer peptide affinity resin.

    Science.gov (United States)

    Naik, Amith D; Menegatti, Stefano; Reese, Hannah R; Gurgel, Patrick V; Carbonell, Ruben G

    2012-10-19

    The production of therapeutic proteins using transgenic plants offers several advantages, including low production cost, absence of human pathogens, presence of glycosylation mechanisms, and the ability to fold complex therapeutic proteins into their proper conformation. However, impurities such as phenolic compounds and pigments encountered during purification are quite different from those faced during purification from mammalian cell culture supernatants. This paper deals with the development of a pretreatment and affinity separation process for the purification of a monoclonal antibody from transgenic Lemna plant extract. A pretreatment step is described using dextran-coated charcoal for the removal of pigments and phenolic compounds without reducing the antibody concentration. Then, the peptide affinity ligand HWRGWV coupled to a commercial polymethacrylate resin is used for the capture and purification of MAb from the pretreated plant extract. The final yield and purity of the MAb obtained were 90% and 96% respectively. The performance of the hexamer peptide resin after the pretreatment step was found to be similar to that obtained with a commercial Protein A resin.

  15. Determination of oil reservoir radiotracer (S{sup 14}CN{sup -}) in a single step using a plastic scintillator extractive resin

    Energy Technology Data Exchange (ETDEWEB)

    Bagan, H.; Tarancon, A. [Departament de Quimica Analitica, Universitat de Barcelona, Diagonal 645, E-08028 Barcelona (Spain); Stavsetra, L. [Department for Reservoir and Exploration Technology, Institute for Energy Technology (IFE), Instituttveien 18, N-2027 Kjeller (Norway); Rauret, G. [Departament de Quimica Analitica, Universitat de Barcelona, Diagonal 645, E-08028 Barcelona (Spain); Garcia, J.F., E-mail: jfgarcia@ub.edu [Departament de Quimica Analitica, Universitat de Barcelona, Diagonal 645, E-08028 Barcelona (Spain)

    2012-07-29

    Highlights: Black-Right-Pointing-Pointer A new procedure for S{sup 14}CN{sup -} radiotracer determination using PS resin was established. Black-Right-Pointing-Pointer The minimum detectable activity for a 100 mL sample is 0.08 Bq L{sup -1}. Black-Right-Pointing-Pointer The minimum quantifiable activity for a 100 mL sample is 0.31 Bq L{sup -1}. Black-Right-Pointing-Pointer PS resin is capable to quantify S{sup 14}CN{sup -} radiotracer samples with errors lower than 5%. Black-Right-Pointing-Pointer PS resin is also capable to quantify complex matrices obtained from oil reservoirs. - Abstract: The analysis of radiotracers is important in the study of oil reservoir dynamics. One of the most widely used radiotracer is S{sup 14}CN{sup -}. Prior to activity measurements by Liquid Scintillation (LS), routine determinations require the pretreatment steps of purification and concentration of the samples using anion exchange columns. The final elution media produces samples with high salt concentration that may lead to problems with phase separation during the LS measurement. Plastic Scintillation (PS) is an alternative technique that provides a solid surface that can be used as a platform for the immobilisation of selective extractants to obtain a PS resin. The proposed procedure unifies chemical separation and sample measurement preparation in a single step, serving to reduce the number of reagents needed and manpower required for the analysis while also avoiding mixed waste production by LS. The objective of this study is to develop a PS resin for the determination of {sup 14}C-labelled thiocyanate radiotracer in water samples. For this purpose, the immobilisation procedure was optimised, including optimisation of the proportion of PS microspheres:extractant and the use of a control blank to monitor the PS resin immobilisation process. The breakthrough volume was studied and the detection and quantification limits for 100 mL of sample were determined to be 0.08 Bq L{sup -1

  16. Release and protein binding of components from resin based composites in native saliva and other extraction media.

    Science.gov (United States)

    Rothmund, Lena; Shehata, Mostafa; Van Landuyt, Kirsten L; Schweikl, Helmut; Carell, Thomas; Geurtsen, Werner; Hellwig, Elmar; Hickel, Reinhard; Reichl, Franz-Xaver; Högg, Christof

    2015-05-01

    Unpolymerized (co)monomers and additives can be released from resin based composites (RBCs) and can enter the human organism. In this study, the binding of ingredients from composites to salivary proteins and plasma proteins was investigated. The composites investigated were Admira(®) flow, Venus(®) Diamond flow, Filtek™ Supreme XTE flow, Tetric EvoCeram(®), Tetric EvoFlow(®). The samples (n=4) were polymerized according to the instructions of the manufacturer of RBCs. The samples were immersed into native saliva, protein-free saliva (artificial saliva), water and ethyl acetate, and incubated at 37°C for 24h or 72h. The eluates were analyzed by gas chromatography/mass spectrometry. To determine the binding to salivary proteins, the concentration of (co)monomers and additives detected in native saliva was compared to the concentration of (co)monomers and additives detected in protein-free saliva, water and ethyl acetate respectively. To assess the affinity of TEGDMA, EGDMA, DEGDMA, PMGDMA, BPA, and DCHP to human serum albumin (HSA) and human α1-acid glycoprotein (AGP), a plasma protein binding assay (ABNOVA, Transil XL PPB Prediction Kit TMP-0212-2096) was performed. The statistical significance (psaliva was significantly lower than the concentration released in protein-free saliva or water (Admira(®) flow: concentration of TEGDMA after 72h: 0.08 mmol/L (native saliva), 0.34 mmol/L (protein-free saliva), 0.39 mmol/L (water)). The concentrations of HEMA, EGDMA, DDDMA and CQ released in native saliva remained even below the detection limit, compared to the other extraction media. Protein binding of the tested methacrylates to HSA+AGP was 82-85%, the binding of DCHP was 96.6%, and the binding of BPA was 95.2%. Artificial saliva or water as extraction medium does not reflect the real physiological situation in the body. Salivary and plasma proteins may bind (co)monomers and additives and may thereby contribute to a lower bioavailability of leachables from RBCs

  17. Phosphorus extracted by ion exchange resins and mehlich-1 from oxisols (latosols treated with different phosphorus rates and sources for varied soil-source contact periods

    Directory of Open Access Journals (Sweden)

    Irio Fernando de Freitas

    2013-06-01

    Full Text Available Despite the large number of studies addressing the quantification of phosphorus (P availability by different extraction methods, many questions remain unanswered. The aim of this paper was to compare the effectiveness of the extractors Mehlich-1, Anionic Resin (AR and Mixed Resin (MR, to determine the availability of P under different experimental conditions. The laboratory study was arranged in randomized blocks in a [(3 x 3 x 2 + 3] x 4 factorial design, with four replications, testing the response of three soils with different texture: a very clayey Red Latosol (LV, a sandy clay loam Red Yellow Latosol (LVA, and a sandy loam Yellow Latosol (LA, to three sources (triple superphosphate, reactive phosphate rock from Gafsa-Tunisia; and natural phosphate from Araxá-Minas Gerais at two P rates (75 and 150 mg dm-3, plus three control treatments (each soil without P application after four contact periods (15, 30, 60, and 120 days of the P sources with soil. The soil acidity of LV and LVA was adjusted by raising base saturation to 60 % with the application of CaCO3 and MgCO3 at a 4:1 molar ratio (LA required no correction. These samples were maintained at field moisture capacity for 30 days. After the contact periods, the samples were collected to quantify the available P concentrations by the three extractants. In general, all three indicated that the available P-content in soils was reduced after longer contact periods with the P sources. Of the three sources, this reduction was most pronounced for triple superphosphate, intermediate for reactive phosphate, while Araxá phosphate was least sensitive to the effect of time. It was observed that AR extracted lower P levels from all three soils when the sources were phosphate rocks, while MR extracted values close to Mehlich-1 in LV (clay and LVA (medium texture for reactive phosphate. For Araxá phosphate, much higher P values were determined by Mehlich-1 than by the resins, because of the acidity of

  18. Determination of some trace metals by FAAS after solid-phase extraction with amberlite XAD-1180/TAN chelating resin.

    Science.gov (United States)

    Yilmaz, Vedat; Kartal, Senol

    2012-01-01

    A new chelating resin was synthesized by immobilizing 1-(2-thiazolylazo)-2-naphthol through the -N=N- group on Amberlite XAD-1180. The resin was used for the preconcentration of Cd(II), Co(II), Cu(II), Mn(II), Ni(II), and Pb(II) ions and their determination by flame atomic absorption spectrometry (FAAS). The influences of some analytical parameters, such as the pH, volume of the sample, flow rates of the sample and eluent, matrix components, amount of the resin, and amount and type of the eluent on the recovery, were investigated. Those metals retained on the resin at pH 8.5 were eluted with 25 mL of 2 mol L(-1) HNO(3). The sorption capacity of the resin was determined, except for Pb(II). The recoveries were found to be ≥95%, and the relative standard-deviation values were ≤4.3%. The detection limits were in the range of 0.1 - 3.6 µg L(-1). For the accuracy of the method, the analysis of a certified reference material was performed. This method was applied to environmental water samples.

  19. Pre-Harvest Dropped Kinnow ( Citrus reticulata Blanco) Waste Management through the Extraction of Naringin and Pectin from their Peels using Indigenous Resin

    Science.gov (United States)

    Laxmi Deepak Bhatlu, M.; Katiyar, Prashant; Singh, Satya Vir; Verma, Ashok Kumar

    2016-09-01

    About 10-20 % kinnow fruits are dropped in preharvest stage which are waste and are problem to farmer as these create nuisance by rotting and insect rearing ground. The peels of these dropped fruits as well as peels from kinnow processing may be good source of naringin and pectin. Naringin is used in pharmaseutics while pectin is used in food industry. For recovery of naringin and pectn, peels of preharvest dropped kinnow fruits were boiled in water. The extract was passed through macroporus polymeric adsorbent resin Indion PA 800, naringin was adsorbed on it. The adsorbed naringin was desorbed with ethanol. This solution was passed through membrane filter and filtrate was evaporated to obtain naringin. The extract remaining after adsorption of naringin was used to recover pectin using acid extraction method. The recovery of naringin and pectin was about 52 and 58 % respectively. The naringin finally obtained had 91-93 % purity.

  20. Pre-Harvest Dropped Kinnow (Citrus reticulata Blanco) Waste Management through the Extraction of Naringin and Pectin from their Peels using Indigenous Resin

    Science.gov (United States)

    Laxmi Deepak Bhatlu, M.; Katiyar, Prashant; Singh, Satya Vir; Verma, Ashok Kumar

    2016-09-01

    About 10-20 % kinnow fruits are dropped in preharvest stage which are waste and are problem to farmer as these create nuisance by rotting and insect rearing ground. The peels of these dropped fruits as well as peels from kinnow processing may be good source of naringin and pectin. Naringin is used in pharmaseutics while pectin is used in food industry. For recovery of naringin and pectn, peels of preharvest dropped kinnow fruits were boiled in water. The extract was passed through macroporus polymeric adsorbent resin Indion PA 800, naringin was adsorbed on it. The adsorbed naringin was desorbed with ethanol. This solution was passed through membrane filter and filtrate was evaporated to obtain naringin. The extract remaining after adsorption of naringin was used to recover pectin using acid extraction method. The recovery of naringin and pectin was about 52 and 58 % respectively. The naringin finally obtained had 91-93 % purity.

  1. Solid phase extraction of chromium(VI) from aqueous solutions by adsorption of its diphenylcarbazide complex on an Amberlite XAD-4 resin column.

    Science.gov (United States)

    Rajesh, N; Jalan, Rohit Kumar; Hotwany, Pinky

    2008-02-11

    A method has been developed for the solid phase extraction of chromium(VI) based on the adsorption of its diphenylcarbazide complex on an Amberlite XAD-4 resin column. The influence of acidity, stability of the column, sample volume, flow rate and interfering ions were studied in detail. The adsorbed complex could be eluted using acetone-sulfuric acid mixture and the concentration of chromium was determined using visible spectrophotometry. A detection limit of 6 microg L(-1) could be achieved. A preconcentration factor of 27 could be obtained for 400 mL sample volume. The validity of the method was checked in spiked water samples and electroplating wastewater.

  2. Final report on the safety assessment of capsicum annuum extract, capsicum annuum fruit extract, capsicum annuum resin, capsicum annuum fruit powder, capsicum frutescens fruit, capsicum frutescens fruit extract, capsicum frutescens resin, and capsaicin.

    Science.gov (United States)

    2007-01-01

    Capsicum-derived ingredients function as skin-conditioning agents--miscellaneous, external analgesics, flavoring agents, or fragrance components in cosmetics. These ingredients are used in 19 cosmetic products at concentrations as high as 5%. Cosmetic-grade material may be extracted using hexane, ethanol, or vegetable oil and contain the full range of phytocompounds that are found in the Capsicum annuum or Capsicum frutescens plant (aka red chiles), including Capsaicin. Aflatoxin and N-nitroso compounds (N-nitrosodimethylamine and N-nitrosopyrrolidine) have been detected as contaminants. The ultraviolet (UV) absorption spectrum for Capsicum Annuum Fruit Extract indicates a small peak at approximately 275 nm, and a gradual increase in absorbance, beginning at approximately 400 nm. Capsicum and paprika are generally recognized as safe by the U.S. Food and Drug Administration for use in food. Hexane, chloroform, and ethyl acetate extracts of Capsicum Frutescens Fruit at 200 mg/kg resulted in death of all mice. In a short-term inhalation toxicity study using rats, no difference was found between vehicle control and a 7% Capsicum Oleoresin solution. In a 4-week feeding study, red chilli (Capsicum annuum) in the diet at concentrations up to 10% was relatively nontoxic in groups of male mice. In an 8-week feeding study using rats, intestinal exfoliation, cytoplasmic fatty vacuolation and centrilobular necrosis of hepatocytes, and aggregation of lymphocytes in the portal areas were seen at 10% Capsicum Frutescens Fruit, but not 2%. Rats fed 0.5 g/kg day-1 crude Capsicum Fruit Extract for 60 days exhibited no significant gross pathology at necropsy, but slight hyperemia of the liver and reddening of the gastric mucosa were observed. Weanling rats fed basal diets supplemented with whole red pepper at concentrations up to 5.0% for up to 8 weeks had no pathology of the large intestines, livers, and kidneys, but destruction of the taste buds and keratinization and erosion of

  3. Solid Phase Extraction and Determination of Nickel in Water Samples by Using Novel Thiol-Containing Sulfonamide Polymeric Resin and Atomic Absorption Spectrophotometer

    Institute of Scientific and Technical Information of China (English)

    Nagihan M Karaaslan; B Filiz Senkal; Cigdem Er; Halim Avci; Mehmet Yaman

    2011-01-01

    Interest in preconcentration techniques for the determination of metals at ultratrace levels still continues increasingly because of some disadvantages of flameless atomic absorption spectrometry as well as the high costs of other sensitive methods in compared to flame atomic absorption spectrometry.In this study,thiol-containing sulfonamide resin was synthesized,characterized and applied as a new sorption material for solid phase extraction of nickel in drinking water samples.After preconcentration procedure,flame atomic absorption spectrometry was used for determinations.Optimum parameters were found to be pH=3.2,contact time =20 min and eluate volume=3 mL.The limit of detection was found to be 0.75 ng · mL-1.The synthesized resin exhibits the superiority in compared to the other adsorption reagents because of the fact that there is no necessity of any complexing reagent,high sorption capacity as well as the relatively fast extraction rate.The Ni concentrations in the studied 21 kind of water samples were found to be in the range of BDL-4.0 ng ·mL-1.

  4. Improvement of skin condition in striae distensae: development, characterization and clinical efficacy of a cosmetic product containing Punica granatum seed oil and Croton lechleri resin extract

    Science.gov (United States)

    Bogdan, Cătălina; Iurian, Sonia; Tomuta, Ioan; Moldovan, Mirela

    2017-01-01

    Striae distensae are a frequent skin condition associated with pregnancy, weight change or lack of skin elasticity. The aim of this research was to obtain a topical product containing herbal active ingredients with documented antioxidant and anti-inflammatory activity (Punica granatum seed oil and Croton lechleri resin extract) and demonstrate its positive effect on prevention and treatment of striae distensae. First, the cream base formulation was optimized through experimental design. Secondly, the cream containing the two active ingredients was investigated in an interventional nonrandomized clinical trial. The clinical outcome was assessed through biophysical parameters and ultrasonographic evaluation. The state of the skin was evaluated by biophysical measurements and ultrasonography at the beginning of the study and after 3 and 6 weeks. The experimental design was successfully used to set the best ranges for the technological and formulation factors to obtain a cosmetic formulation with optimal characteristics. The study of clinical efficacy on the optimal formulation revealed an increase in the dermis thickness, hydration and elasticity values in both groups after 6 weeks of cream application. The new oil-in-water cream containing P. granatum seed oil and C. lechleri resin extract can be helpful in the prevention or improving of skin changes associated with striae. PMID:28280300

  5. Azocalix[4]pyrrole Amberlite XAD-2: new polymeric chelating resins for the extraction, preconcentration and sequential separation of Cu(II), Zn(II) and Cd(II) in natural water samples.

    Science.gov (United States)

    Jain, Vinod K; Mandalia, Hiren C; Gupte, Hrishikesh S; Vyas, Disha J

    2009-10-15

    Two novel azocalix[4]pyrrole Amberlite XAD-2 polymeric chelating resins were synthesized by covalently linking diazotized Amberlite XAD-2 with calix[4]pyrrole macrocycles. The chelating resins were used for extraction, preconcentration and sequential separation of metal ions such as Cu(II), Zn(II) and Cd(II) by column chromatography prior to their determination by UV/vis spectrophotometry or flame atomic absorption spectrophotometry (FAAS) or inductively coupled plasma atomic emission spectroscopy (ICP-AES). Various parameters such as effect of pH on absorption, concentration of eluting agents, flow rate, total sorption capacity, exchange kinetics, preconcentration factor, distribution coefficient, breakthrough capacity and resin stability, were optimized for effective separation and preconcentration. The resin showed good ability for the separation of metal ions from binary and ternary mixture on the basis of pH of absorption and concentration of eluting agents. The newly synthesized resins showed good potential for trace enrichment of Cu(II), Zn(II) and Cd(II) metal ions, especially for Cu(II), as compared to the earlier reported resins. The synthesized resins were recycled at least 8-10 times without much affecting column sorption capacity. The presented method was successfully applied for determination of Cu(II), Zn(II) and Cd(II) in natural and ground water samples.

  6. Chelating resin-based extraction of DNA from dental pulp and sex determination from incinerated teeth with Y-chromosomal alphoid repeat and short tandem repeats.

    Science.gov (United States)

    Tsuchimochi, Tsukasa; Iwasa, Mineo; Maeno, Yoshitaka; Koyama, Hiroyoshi; Inoue, Hiroyuki; Isobe, Ichiro; Matoba, Ryoji; Yokoi, Motoo; Nagao, Masataka

    2002-09-01

    A procedure utilizing Chelex 100, chelating resin, was adapted to extract DNA from dental pulp. The procedure was simple and rapid, involved no organic solvents, and did not require multiple tube transfers. The extraction of DNA from dental pulp using this method was as efficient, or more so, than using proteinase K and phenol-chloroform extraction. In this study, the Chelex method was used with amplification and typing at Y-chromosomal loci to determine the effects of temperature on the sex determination of the teeth. The extracted teeth were incinerated in a dental furnace for 2 minutes at 100 degrees C, 200 degrees C, 300 degrees C, 400 degrees C, and 500 degrees C. After the isolation of DNA from the dental pulp by the Chelex method, alphoid repeats, and short tandem repeats, the human Y chromosome (DYZ3), DYS19, SYS389, DYS390, and DYS393 could be amplified and typed in all samples incinerated at up to 300 degrees C for 2 minutes. The DYS389 locus in some samples could not be amplified at 300 degrees C for 2 minutes. An autopsy case is described in which genotypings of DYS19, DYS390, and DYS393 from dental pulp obtained from a burned body were needed. The data presented in this report suggest that Chelex 100-based DNA extraction, amplification, and typing are possible in burned teeth in forensic autopsy cases.

  7. Biobased carbon content of resin extracted from polyethylene composite by carbon-14 concentration measurements using accelerator mass spectrometry

    OpenAIRE

    Taguchi, Kazuhiro; Kunioka, Masao; Funabashi, Masahiro; Ninomiya, Fumi

    2014-01-01

    An estimation procedure for biobased carbon content of polyethylene composite was studied using carbon-14 (14C) concentration ratios as measured by accelerated mass spectrometry (AMS). Prior to the measurement, additives and fillers in composites should be removed because they often contain a large amount of biobased carbon and may shift the estimation. Samples of resin with purity suitable for measurement were isolated from composites with a Soxhlet extractor using heated cyclohexanone. Afte...

  8. Ionic Liquid-Based Vacuum Microwave-Assisted Extraction Followed by Macroporous Resin Enrichment for the Separation of the Three Glycosides Salicin, Hyperin and Rutin from Populus Bark

    Directory of Open Access Journals (Sweden)

    Fengli Chen

    2014-07-01

    Full Text Available An effective ionic liquid vacuum microwave-assisted method was developed for extraction of the thermo- and oxygen-sensitive glycosides salicin, hyperin and rutin from Populus bark due to the strong solvating effects of ionic liquids on plant cell walls. In this study, [C4mim]BF4 solution was selected as the extracting solution for extraction of the target analytes. After optimization by single factor experiments and response surface methodology, the optimum condition parameters were achieved, which included 1.0 M [C4mim]BF4, 2 h soaking time, −0.08 MPa vacuum, 20 min microwave irradiation time, 400 W microwave irradiation power and 25 mL/g liquid/solid ratio. Under the optimum conditions, higher extraction yields of salicin (35.53 mg/g, hyperin (1.32 mg/g and rutin (2.40 mg/g were obtained. Compared with other extraction methods, the developed method provided higher yields of the three target components after a relatively shorter extraction time (20 min. No obvious degradation of the target analytes was observed under the optimum conditions in performed stability studies and the proposed method had a high reproducibility. Meanwhile, after adsorption and desorption on macroporous D101 resin, the target analytes can be effectively separated from the [C4mim]BF4 ionic liquid extraction solution and the yields of salicin, hyperin and rutin were 89%, 82% and 84%, respectively. The recovered [C4mim]BF4 ionic liquid presented a good extraction effect on the three analytes after recycling five times.

  9. Ionic liquid-based vacuum microwave-assisted extraction followed by macroporous resin enrichment for the separation of the three glycosides salicin, hyperin and rutin from Populus bark.

    Science.gov (United States)

    Chen, Fengli; Mo, Kailin; Liu, Zhaizhi; Yang, Fengjian; Hou, Kexin; Li, Shuangyang; Zu, Yuangang; Yang, Lei

    2014-07-07

    An effective ionic liquid vacuum microwave-assisted method was developed for extraction of the thermo- and oxygen-sensitive glycosides salicin, hyperin and rutin from Populus bark due to the strong solvating effects of ionic liquids on plant cell walls. In this study, [C4mim]BF4 solution was selected as the extracting solution for extraction of the target analytes. After optimization by single factor experiments and response surface methodology, the optimum condition parameters were achieved, which included 1.0 M [C4mim]BF4, 2 h soaking time, -0.08 MPa vacuum, 20 min microwave irradiation time, 400 W microwave irradiation power and 25 mL/g liquid/solid ratio. Under the optimum conditions, higher extraction yields of salicin (35.53 mg/g), hyperin (1.32 mg/g) and rutin (2.40 mg/g) were obtained. Compared with other extraction methods, the developed method provided higher yields of the three target components after a relatively shorter extraction time (20 min). No obvious degradation of the target analytes was observed under the optimum conditions in performed stability studies and the proposed method had a high reproducibility. Meanwhile, after adsorption and desorption on macroporous D101 resin, the target analytes can be effectively separated from the [C4mim]BF4 ionic liquid extraction solution and the yields of salicin, hyperin and rutin were 89%, 82% and 84%, respectively. The recovered [C4mim]BF4 ionic liquid presented a good extraction effect on the three analytes after recycling five times.

  10. Application of alkyl polyglycoside surfactant in ultrasonic-assisted extraction followed by macroporous resin enrichment for the separation of vitexin-2″-O-rhamnoside and vitexin from Crataegus pinnatifida leaves.

    Science.gov (United States)

    Han, Feng; Guo, Yupin; Gu, Huiyan; Li, Fenglan; Hu, Baozhong; Yang, Lei

    2016-02-15

    An alkyl polyglycoside (APG) surfactant was used in ultrasonic-assisted extraction to effectively extract vitexin-2″-O-rhamnoside (VOR) and vitexin (VIT) from Crataegus pinnatifida leaves. APG0810 was selected as the surfactant. The extraction process was optimized for ultrasonic power, the APG concentration, ultrasonic time, soaking time, and liquid-solid ratio. The proposed approach showed good recovery (99.80-102.50% for VOR and 98.83-103.19% for VIT) and reproducibility (relative standard deviation, n=5; 3.7% for VOR and 4.2% for VIT) for both components. The proposed sample preparation method is both simple and effective. The use of APG for extraction of key herbal ingredients shows great potential. Ten widely used commercial macroporous resins were evaluated in a screening study to identify a suitable resin for the separation and purification of VOR and VIT. After comparing static and dynamic adsorption and desorption processes, HPD100B was selected as the most suitable resin. After column adsorption and desorption on this resin, the target compounds VOR and VIT can be effectively separated from the APG0810 extraction solution. Recoveries of VOR and VIT were 89.27%±0.42% and 85.29%±0.36%, respectively. The purity of VOR increased from 35.0% to 58.3% and the purity of VIT increased from 12.5% to 19.9%. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Elaboration of extracting, incinerable and/or conducting resins, for the grouped conversion of actinides; Conception de resines extractantes, incinerables et/ou conductrices, pour la conversion groupee d'actinides

    Energy Technology Data Exchange (ETDEWEB)

    Mokhtari, H. [Paris-11 Univ., 91 - Orsay (France)]|[CEA Valrho, Lab. de Chimie des Actinides (LCA), 30 - Marcoule (France)

    2006-07-01

    The first results obtained in the framework of the study called PEACE (Process for the Elaboration of Actinide Carbide from ion Exchange resin) concern the fixation of neodymium(III) (simulating trivalent actinides) on two carboxylic resins: the first one is of gel type and the second one of macroporous type. A kinetic study of the exchange NH{sub 4}{sup +}/Nd{sup 3+} has shown that: 1)neodymium is fixed under the form of a complexed or hydrolyzed specie of neodymium of charge 2+ 2)a high charge rate is reached (40% in mass for the dried resin which corresponds to an exchange capacity of 11 meq/g dry of introduced resin) 3)the exchange kinetics is better for the macroporous resin than for the gel resin. A heat treatment of the macroporous resin charged in neodymium has been carried out until the carbonization by the mean of thermal gravimetric analyses carried out under air and argon. A carbon/neodymium ratio of about 5 is obtained after carbonization under argon. Scanning electron microscopy analyses carried out on the macroporous resin charged in neodymium have revealed a conservation of the sphericity and a consequent reduction of the resin balls diameter after heat treatment and an homogeneous distribution of neodymium inside the sphere. (O.M.)

  12. Improvement of skin condition in striae distensae: development, characterization and clinical efficacy of a cosmetic product containing Punica granatum seed oil and Croton lechleri resin extract

    Directory of Open Access Journals (Sweden)

    Bogdan C

    2017-02-01

    Full Text Available Cătălina Bogdan,1 Sonia Iurian,2 Ioan Tomuta,2 Mirela Moldovan1 1Department of Dermatopharmacy and Cosmetics, 2Department of Pharmaceutical Technology and Biopharmacy, Faculty of Pharmacy, University of Medicine and Pharmacy Iuliu Hatieganu, Cluj-Napoca, Romania Abstract: Striae distensae are a frequent skin condition associated with pregnancy, weight change or lack of skin elasticity. The aim of this research was to obtain a topical product containing herbal active ingredients with documented antioxidant and anti-inflammatory activity (Punica granatum seed oil and Croton lechleri resin extract and demonstrate its positive effect on prevention and treatment of striae distensae. First, the cream base formulation was optimized through experimental design. Secondly, the cream containing the two active ingredients was investigated in an interventional nonrandomized clinical trial. The clinical outcome was assessed through biophysical parameters and ultrasonographic evaluation. The state of the skin was evaluated by biophysical measurements and ultrasonography at the beginning of the study and after 3 and 6 weeks. The experimental design was successfully used to set the best ranges for the technological and formulation factors to obtain a cosmetic formulation with optimal characteristics. The study of clinical efficacy on the optimal formulation revealed an increase in the dermis thickness, hydration and elasticity values in both groups after 6 weeks of cream application. The new oil-in-water cream containing P. granatum seed oil and C. lechleri resin extract can be helpful in the prevention or improving of skin changes associated with striae. Keywords: stretch marks, ultrasonography, texture analysis, design of experiments, oil-in-water emulsion

  13. Mutagenic potentials of Amberlite XAD-2-resin extracts obtained from river and drinking waters in the Northwest district of Chiba, Japan.

    Science.gov (United States)

    Kanno, Ayako; Nishi, Iwaki; Kishi, Tomohiro; Kawakami, Tsuyoshi; Takahashi, Yasuo; Onodera, Sukeo

    2010-12-01

    Amberlite XAD-2 resin extracts of river and drinking water sampled from the Northwest district of Chiba Prefecture in each month during the period from January to December 2008 were investigated to characterize and determine their mutagenic potentials and polycyclic aromatic hydrocarbon (PAH) levels. The extracts from the river water were shown to be mutagenic in Salmonella typhimurium TA98 (a flameshift mutagen) without S9 mix, with higher mutagenic responses in summer and early fall seasons. While the drinking water extracts exhibited weak mutagenicity in both the TA98 and TA100 strains (a base-pair substitution mutagen) without S9 mix, with high mutagenic responses in fall and early winter seasons. GC/MS determinations of the water concentrates showed some seasonal scatter in PAH levels in river water. In contrast, comparatively high concentrations of PAHs were observed for drinking water samples collected during warmer seasons. Statistical studies revealed that there is a lower correlation between the levels of flameshift mutagenicity and the concentrations of PAH in the river water concentrations, but a higher correlation between them in the drinking water samples.

  14. The Effect of Aloe Vera, Pomegranate Peel, Grape Seed Extract, Green Tea, and Sodium Ascorbate as Antioxidants on the Shear Bond Strength of Composite Resin to Home-bleached Enamel.

    Science.gov (United States)

    Sharafeddin, Farahnaz; Farshad, Farnaz

    2015-12-01

    Immediate application of bonding agent to home- bleached enamel leads to significant reduction in the shear bond strength of composite resin due to the residual oxygen. Different antioxidant agents may overcome this problem. This study aimed to assess the effect of different antioxidants on the shear bond strength of composite resin to home-bleached. Sixty extracted intact human incisors were embedded in cylindrical acrylic resin blocks (2.5×1.5 cm), with the coronal portion left out of the block. After bleaching the labial enamel surface with 15% carbamide peroxide, they were randomly divided into 6 groups (n=10). Before performing composite resin restoration by using a cylindrical Teflon mold (5×2 mm), each group was treated with one of the following antioxidants: 10% sodium ascorbate solution, 10% pomegranate peel solution, 10% grape seed extract, 5% green tea extract, and aloe vera leaf gel. One group was left untreated as the control. The shear bond strength of samples was tested under a universal testing machine (ZwickRoell Z020). The shear bond strength data were analyzed by one-way ANOVA and post hoc Tukey tests (pbond strength of bleached enamel. Different antioxidants used in this study had the same effect on the shear bond strength of home-bleached enamel, and none of them caused a statistically significant increase in its value.

  15. Decoloration of Raffinose Extract Solutions via Macroporous Resin Adsorption%棉籽糖提取液树脂吸附脱色

    Institute of Scientific and Technical Information of China (English)

    段舒然; 鲍宗必; 闻光东; 陈丽芬; 杨亦文

    2016-01-01

    Raffinose extract solutions contain considerable amounts of colored impurities, and those hydrophobic pigments can be removed by organic solvent extraction. However, there are still water-soluble pigments that can affect the product purity and crystallization processes. In this study, decoloration performance using several resins (HZ-801, HZ-803, HZ-806, HZ-818, D303 and D313) was compared with activated carbon, and the adsorption conditions were optimized according to raffinose decoloration ratio and loss ratio. The results show that HZ-818 is the best candidate with the highest decoloration ratio of 77.1% and loss ratio of 2.4%. The process shows the best cost-effectiveness when the dosage is 2.0 g resin per 10 mL solution under contact time of 9 h. The spent resin can be regenerated with 60% aqueous ethanol and the recycled resins are further used with decoloration ratio up to 94.0%.%棉籽糖的提取液中含有大量的有色杂质,经有机溶剂脱酚处理除去大部分疏水性色素,仍有少量水溶性色素残留,它们的存在会影响棉籽糖产品的纯度、色泽及结晶过程。研究以脱色率和棉籽糖损失率为指标,对比了HZ-801、HZ-803、HZ-806和HZ-818等四种大孔吸附树脂及D313、D303弱碱性阴离子交换树脂与活性炭的脱色性能,考察了影响静态吸附脱色的操作条件及脱色动力学,结果表明:HZ-818树脂为棉籽糖提取液的最佳脱色树脂,单次脱色率最高,达77.1%,棉籽糖损失率2.4%;树脂用量为2.0 g树脂/10 mL溶液、脱色时间为9 h时脱色过程较为经济。吸附色素的树脂可通过60%的乙醇水溶液进行再生,再生后树脂对原料液进行脱色实验,脱色率达94.0%。

  16. Water-compatible dummy molecularly imprinted resin prepared in aqueous solution for green miniaturized solid-phase extraction of plant growth regulators.

    Science.gov (United States)

    Wang, Mingyu; Chang, Xiaochen; Wu, Xingyu; Yan, Hongyuan; Qiao, Fengxia

    2016-08-01

    A water-compatible dummy molecularly imprinted resin (MIR) was synthesized in water using melamine, urea, and formaldehyde as hydrophilic monomers of co-polycondensation. A triblock copolymer (PEO-PPO-PEO, P123) was used as porogen to dredge the network structure of MIR, and N-(1-naphthyl) ethylenediamine dihydrochloride, which has similar shape and size to the target analytes, was the dummy template of molecular imprinting. The obtained MIR was used as the adsorbent in a green miniaturized solid-phase extraction (MIR⬜mini-SPE) of plant growth regulators, and there was no organic solvent used in the entire MIR⬜mini-SPE procedure. The calibration linearity of MIR⬜mini-SPE⬜HPLC method was obtained in a range 5⬜250ngmL(↙1) for IAA, IPA, IBA, and NAA with correlation coefficient (r) Ⱕ0.9998. Recoveries at three spike levels are in the range of 87.6⬜100.0% for coconut juice with relative standard deviations Ⱔ8.1%. The MIR⬜mini-SPE method possesses the advantages of environmental friendliness, simple operation, and high efficiency, so it is potential to apply the green pretreatment strategy to extraction of trace analytes in aqueous samples.

  17. Glyoxal-Urea-Formaldehyde Molecularly Imprinted Resin as Pipette Tip Solid-Phase Extraction Adsorbent for Selective Screening of Organochlorine Pesticides in Spinach.

    Science.gov (United States)

    Yang, Chen; Lv, Tianwei; Yan, Hongyuan; Wu, Gaochan; Li, Haonan

    2015-11-01

    A new kind of glyoxal-urea-formaldehyde molecularly imprinted resin (GUF-MIR) was synthesized by a glyoxal-urea-formaldehyde (GUF) gel imprinting method with 4,4'-dichlorobenzhydrol as a dummy template. The obtained GUF-MIR was characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) and applied as a selective adsorbent of miniaturized pipet tip solid-phase extraction (PT-SPE) for the separation and extraction of three organochlorine pesticides (dicofol (DCF), dichlorodiphenyl dichloroethane (DDD), and tetradifon) in spinach samples. The proposed pretreatment procedures of spinach samples involved only 5.0 mg of GUF-MIR, 0.7 mL of MeOH-H2O (1:1, v/v) (washing solvent), and 0.6 mL of cyclohexane-ethyl acetate (9:1, v/v) (elution solvent). In comparison with other adsorbents (such as silica gel, C18, NH2-silica gel, and neutral alumina (Al2O3-N)), GUF-MIR showed higher adsorption and purification capacity for DCF, DDD, and tetradifon in aqueous solution. The average recoveries at three spiked levels ranged from 89.1% to 101.9% with relative standard deviations (RSDs) ≤ 7.1% (n = 3). The presented GUF-MIR-PT-SPE method combines the advantages of molecularly imprinted polymers (MIPs), GUF, and PT-SPE and can be used in polar solutions with high affinity and selectivity to the analytes in complex samples.

  18. Rapid determination of strontium-90 by solid phase extraction using DGA Resin® for seawater monitoring

    Science.gov (United States)

    Tazoe, H.; Obata, H.; Yamagata, T.; Karube, Z.; Yamada, M.

    2015-12-01

    Strontium-90 concentrations in seawater exceeding the background level have been observed at the accidents of nuclear facilities, such as Chernobyl and Fukushima. However, analytical procedure for strontium-90 in seawater is still quite complicated and challenging. Here we show a simple and rapid analytical technique for the determination of strontium-90 in seawater samples without time-consuming separation of strontium from calcium. The separation with DGA Resin® is used to determine the abundance of strontium-90, which selectively collects yttrium-90, progeny of strontium-90. Naturally occurring radioactive nuclides (such as potassium, lead, bismuth, uranium, and thorium) and anthropogenic radionuclides (such as cesium, barium, lanthanum, and cerium) were separated from yttrium. Through a sample separation procedure, a high chemical yield of yttrium-90 was achieved at 93.9 % for seawater. The result of IAEA 443 certified seawater analysis was in good agreement with the certified value. At 20 hrs counting a lower detection limit of 1.5 mBq L-1 was obtained from 3 L of seawater. The proposed method can finish analyzing 8 samples per day, which is a reasonably fast throughput in actual seawater monitoring. Reproducibility was found to be 3.4 % according to 10 separate analyses of natural seawater samples from the vicinity of Fukushima Daiichi Nuclear Power Plant in September 2013.

  19. 大孔吸附树脂纯化甘草提取物中甘草酸的研究%Macroporous Adsorption Resin Purification of Glycyrrhizic Acid in Glycyrrhiza Extract Research

    Institute of Scientific and Technical Information of China (English)

    丁利营; 李红艳

    2014-01-01

    Objective To study the best macroporous resin purification process for Glycyrrhizic acid from glycyrrhiza glabra. Methods Glycyrrhizic acid content in macroporous resin purification as the investigation index, select the best macroporous resin from 24 kinds of macroporous resins for Glycyrrhizic acid from liquorice extract, and determine the optimum process conditions for this purification. Results AB-8 macroporous adsorption resin has the best purification ef ect for glycyrrhizic acid, and the optimum process conditions:liquorice extract concentration is 0.11mg/ml, diameter/height is 1:8, liquorice extract volume is 2 times of the resin, the rates of using liquorice extract and elution both are 2bv/h, remove impurities with 30%&50%ETOH, and accumulate glycyrrhizic acid by using 80%ETOH. After purification, the purity of the product is 60.74%, the yield rate is 3.29%, the transfer rate is 76.72%. Conclusion Using AB-8 macroporous adsorption resin can purify glycyrrhizic acid very wel .%目的研究光果甘草中甘草酸的最佳大孔树脂纯化工艺。方法以大孔吸附树脂纯化物中甘草酸的含量为考察指标,从24种大孔吸附树脂中筛选出纯化甘草粗提物中甘草酸的最佳大孔吸附树脂,并确定纯化甘草酸的最佳工艺条件。结果 AB-8大孔吸附树脂纯化甘草酸效果最佳,最佳工艺条件院上柱液浓度为0.11mg/mL,径高比为1:8,上样体积为所用树脂2BV,上样速度与洗脱速度均为2BV/h,用30%、50%的乙醇除杂,用80%乙醇富集甘草酸。纯化后产品纯度为60.74%,收率为3.29%,转移率为76.33%。结论采用AB-8大孔吸附树脂可较好地纯化甘草酸。

  20. Epoxy resins.

    Science.gov (United States)

    Bray, P G

    1999-01-01

    Epoxy resins have an extraordinarily broad range of commercial applications, especially as protective surface coatings and adhesives. Epoxy resin systems include combinations of epoxy monomers, hardeners, reactive diluents, and/or a vast array of other additives. As a result, an epoxy resin system may have a number of chemical ingredients with the potential for attendant health hazards. Most, but not all, of these health hazards arise in the occupational setting. The most frequent adverse effects are irritation or allergic mechanisms involving the dermal and respiratory systems. Sensitization usually is caused by low molecular weight or short-chain compounds. This review discusses the diagnosis, treatment, and prevention of epoxy resin-related adverse health effects.

  1. Determination of copper, lead and iron in water and food samples after column solid phase extraction using 1-phenylthiosemicarbazide on Dowex Optipore L-493 resin.

    Science.gov (United States)

    Yildiz, Ozden; Citak, Demirhan; Tuzen, Mustafa; Soylak, Mustafa

    2011-02-01

    A novel solid phase extraction procedure for determination of copper, lead and iron in natural water and food samples has been established in the presented work. 1-Phenylthiosemicarbazide (1-PTSC) as ligand and Dowex Optipore L-493 resin as adsorbent were used in a mini chromatographic column. Various analytical conditions for the quantitative recoveries of analyte ions including pH, amounts of adsorbent, eluent, sample volume, etc. were investigated. The recovery values for analyte ions were higher than 95%. The determination of copper, lead and iron was performed by flame atomic absorption spectrometry. The influences of some alkali, alkali earth and transition metals on the recoveries of analyte ions were investigated. The preconcentration factor was 62.5. The limit of detections of the understudied analytes (k=3, N=21) were 0.64 μg L(-1) for copper, 0.55 μg L(-1) for lead and 0.82 μg L(-1) for iron. The relative standard deviation was found to be lower than 6%. The accuracy of the method was confirmed with certified reference material (GBW 07605 Tea). The method was successively applied for the determination of copper, lead and iron in water and some food samples including cheese, bread, baby food, pekmez, honey, milk and red wine after microwave digestion.

  2. Resin composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Peutzfeldt, Anne; Lussi, Adrian;

    2014-01-01

    OBJECTIVE: To investigate how the modulus of elasticity of resin composites influences marginal quality in restorations submitted to thermocyclic and mechanical loading. METHODS: Charisma, Filtek Supreme XTE and Grandio were selected as they were found to possess different moduli of elasticity...... of resin composite (p=0.81) on the quality of dentine margins was observed, before or after loading. Deterioration of all margins was evident after loading (p....008). CONCLUSIONS: The resin composite with the highest modulus of elasticity resulted in the highest number of gap-free enamel margins but with an increased incidence of paramarginal enamel fractures. CLINICAL SIGNIFICANCE: The results from this study suggest that the marginal quality of restorations can...

  3. Report on use of XAD resins in racing chemistry.

    Science.gov (United States)

    Johnston, G. H.

    1976-01-01

    This report comprises a summary of the work done with XAD resin extraction by racing chemists and reported in the Association of Official Racing Chemists publications. It is apparent that the use of XAD resins is becoming more popular in racing laboratories as a technique for routine screening and also for the extraction of certain conjugated drugs. Most laboratories employ variations on the original Brinkmann Drug-Skreen Technique. Comparisons of the efficiency of extraction of drugs from horse urine by XAD-2 resin and by chloroform column extraction indicate that some drugs can be extracted with equal or greater efficiency by the resin technique. PMID:1000159

  4. The Effect of Aloe Vera, Pomegranate Peel, Grape Seed Extract, Green Tea, and Sodium Ascorbate as Antioxidants on the Shear Bond Strength of Composite Resin to Home-bleached Enamel

    Directory of Open Access Journals (Sweden)

    Farahnaz Sharafeddin

    2015-12-01

    Full Text Available Statement of the Problem: Immediate application of bonding agent to home- bleached enamel leads to significant reduction in the shear bond strength of composite resin due to the residual oxygen. Different antioxidant agents may overcome this problem. Purpose: This study aimed to assess the effect of different antioxidants on the shear bond strength of composite resin to home-bleached. Materials and Method: Sixty extracted intact human incisors were embedded in cylindrical acrylic resin blocks (2.5×1.5 cm, with the coronal portion left out of the block. After bleaching the labial enamel surface with 15% carbamide peroxide, they were randomly divided into 6 groups (n=10. Before performing composite resin restoration by using a cylindrical Teflon mold (5×2 mm, each group was treated with one of the following antioxidants: 10% sodium ascorbate solution, 10% pomegranate peel solution, 10% grape seed extract, 5% green tea extract, and aloe vera leaf gel. One group was left untreated as the control. The shear bond strength of samples was tested under a universal testing machine (ZwickRoell Z020. The shear bond strength data were analyzed by one-way ANOVA and post hoc Tukey tests (p< 0.05. Results: No significant difference existed between the control and experimental groups. Moreover, there was no statistically significant difference between the effects of different antioxidants on the shear bond strength of bleached enamel. Conclusion: Different antioxidants used in this study had the same effect on the shear bond strength of home-bleached enamel, and none of them caused a statistically significant increase in its value.

  5. Separation of vitexin-4″-O-glucoside and vitexin-2″-O-rhamnoside from hawthorn leaves extracts using macroporous resins.

    Science.gov (United States)

    Li, Hongjuan; Liu, Ying; Jin, Haizhu; Liu, Sujing; Fang, Shengtao; Wang, Chunhua; Xia, Chuanhai

    2015-12-15

    Vitexin-4″-O-glucoside and vitexin-2″-O-rhamnoside are the major flavonoids of hawthorn leaves. In this work, the adsorption and desorption characteristics of vitexin-4″-O-glucoside and vitexin-2″-O-rhamnoside on seven macroporous resins were evaluated. Among the tested resins, the HPD-400 resin showed the best adsorption and desorption capacities. Adsorption isotherms were constructed for the HPD-400 resin and well fitted to Langmuir and Freundlich models. Dynamic adsorption and desorption tests were performed on column packed with the HPD-400 resin to optimize the chromatographic parameters. After one run treatment with the HPD-400 resin, the contents of vitexin-4″-O-glucoside and vitexin-2″-O-rhamnoside in the product were increased 8.44-fold and 8.43-fold from 0.720% and 2.63% to 6.08% and 22.2% with recovery yields of 79.1% and 81.2%, respectively. These results show that the developed method is a promising basis for the large-scale purification of vitexin-4″-O-glucoside and vitexin-2″-O-rhamnoside from hawthorn leaves and other plant materials.

  6. Scintillating 99Tc Selective Ion Exchange Resins

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell Greenhalgh; Richard D. Tillotson

    2012-07-01

    Scintillating technetium (99Tc) selective ion exchange resins have been developed and evaluated for equilibrium capacities and detection efficiencies. These resins can be utilized for the in-situ concentration and detection of low levels of pertechnetate anions (99TcO4-) in natural waters. Three different polystyrene type resin support materials were impregnated with varying amounts of tricaprylmethylammonium chloride (Aliquat 336) extractant, several different scintillating fluors and wavelength shifters. The prepared resins were contacted batch-wise to equilibrium over a wide range of 99TcO4- concentrations in natural water. The measured capacities were used to develop Langmuir adsorption isotherms for each resin. 99Tc detection efficiencies were determined and up to 71.4 ± 2.6% was achieved with some resins. The results demonstrate that a low level detection limit for 99TcO4- in natural waters can be realized.

  7. Solid-Phase Extraction of Trace Amounts of Uranium(VI in Environmental Water Samples Using an Extractant-Impregnated Resin Followed by Detection with UV-Vis Spectrophotometry

    Directory of Open Access Journals (Sweden)

    Ahmad Hosseini-Bandegharaei

    2013-01-01

    Full Text Available A stable extractant-impregnated resin (EIR containing Chrome Azurol B was prepared using Amberlite XAD-2010 as a porous polymeric support. The new EIR was employed for trace separation and preconcentration of U(VI ion followed by spectrophotometric determination with the arsenazo III procedure. CAB/XAD-2010 exhibited excellent selectivity for U(VI ion over coexisting ions. Experimental parameters including pH, contact time, shaking speed, and ionic strength were investigated by batch extraction methods. Maximum sorption of U(VI ions occurred at pH 4.3–6.9. The capacity of EIR was found to be 0.632 mmol·g−1. Equilibrium was reached in 25 min and the loading half-time, t1/2, was less than 6 min. The equilibrium adsorption isotherm of U(VI was fitted with the Langmuir adsorption model. In addition, a column packed with CAB/XAD-2010 was used for column-mode separation and preconcentration of U(VI ion. For the optimization of the dynamic procedure, effects of sample volume, sample and eluent flow rate, eluent concentration, and its volume were investigated. The preconcentration factors for U(VI were found out to be 160. But, for convenience, a preconcentration factor of 150 was utilized for the column-mode preconcentration. The dynamic procedure gave a detection limit of 5.0×10-10 mol·L−1 (0.12 μg·L−1 for U(VI ion. The proposed dynamic method showed good performance in analyzing environmental water samples.

  8. Comparison of Cashew Nut Shell Liquid (CNS Resin with Polyester Resin in Composite Development

    Directory of Open Access Journals (Sweden)

    C. C. Ugoamadi

    2013-12-01

    Full Text Available Natural resins can compete effectively with the synthetic ones in composite development. In this research, cashew nuts were picked and processed for the extraction of the resin content. The resin (natural resin so obtained was mixed with cobalt amine (accelerator, methyl ethyl ketone peroxide (catalyst to develop two sets of composite specimens – specimens without fibres and specimens reinforced with glass fibres. This method of sample specimen development was repeated with polyester (synthetic resin. Compressive and tensile strength tests conducted proved that composites developed with cashew nut shell liquid (CNSL resin were comparable to those developed with polyester resin. In the results, CNSL has an ultimate compressive strength of 55MPa compared to that of polyester resin with an ultimate strength of 68MPa. The result of tensile strength proved cashew nut shell liquid resin (with ultimate strength of 44MPa to be better than polyester resin with 39MPa as ultimate tensile strength. This means that natural resins could be a better substitute for the synthetic ones when the required quantities of fibers (reinforcements and fillers are used in the fibre-reinforced plastic composite developments.

  9. First example of diglycolamide-grafted resins: synthesis, characterization, and actinide uptake studies

    NARCIS (Netherlands)

    Mohapatra, Prasanta; Ansari, Seraj A.; Iqbal, M.; Huskens, Jurriaan; Verboom, Willem

    2014-01-01

    Two diglycolamide (DGA)-functionalized chelating extraction resins were prepared for the first time by grafting onto a silica matrix and were evaluated for their actinide ion uptake behavior. The resins with one and two DGA moieties, termed as resin-I and resin-II, were quite efficient for the

  10. First example of diglycolamide-grafted resins: synthesis, characterization, and actinide uptake studies

    NARCIS (Netherlands)

    Mohapatra, Prasanta; Ansari, Seraj A.; Iqbal, M.; Huskens, Jurriaan; Verboom, Willem

    2014-01-01

    Two diglycolamide (DGA)-functionalized chelating extraction resins were prepared for the first time by grafting onto a silica matrix and were evaluated for their actinide ion uptake behavior. The resins with one and two DGA moieties, termed as resin-I and resin-II, were quite efficient for the actin

  11. 大孔树脂对桑黄多糖提取液中色素的吸附与解吸特性研究%Adsorption and desorption characteristics of macroporous resins to pigments of Phellinus linteus polysaccharide extraction

    Institute of Scientific and Technical Information of China (English)

    秦俊哲; 程伟; 杜军国

    2013-01-01

    In order to select a kind of resin which is better on purification of polysaccharide extracted from the fruiting bodies of Phellinus Igniarius. Compared the effects of DA201 and other 5 kinds of macroporous resins in the proessing of decolorization and removal effects of liquid protein. On static adsorption and desorption experiments, select the DA201 resin for static adsorption kinetics and desorption characteristics, investigated the resin saturated adsorption, decolorization rate, protein removing rate and total sugar retention rate. The results show: DA201 resin showed a good effects of deproteinization and decolorization, and total sugar retention rate was high. For the specific polysaccharide extraction, flow rate at 1. 0 mL/min, DA201 resin column to make protein and pigment adsorption reached saturation, need continuous sampling 10 multiple column volume (BV) at least, distilled water and 50% ethanol elution desorption effects was suitable. DA201 resin was suitable for the decolorization of polysaccharide,In order to make full use of DA201 resin adsorption properties, the string column method can be considered in industrial production.%为了选择对桑黄多糖提取液纯化效果较好的树脂,比较了DA201等5种大孔吸附树脂对桑黄多糖提取液的脱色和除蛋白质效果.对5种树脂进行静态吸附与解吸试验,选择DA201树脂研究静态吸附动力学曲线及其解吸特性,考察树脂的饱和吸附量、脱色率、蛋白质脱除率及总糖的保留率.DA201树脂对桑黄多糖提取液中的蛋白质和色素的吸附较多,表明其脱蛋白和脱色效果较好,且多糖的回收率较高.对于特定的多糖提取液,流速1.0 mL/min,过DA201树脂柱要使蛋白质和色素达到吸附饱和,需要连续进样10多个柱床体积(BV),蒸馏水和50%乙醇洗脱解吸效果均较好.DA201树脂较适于桑黄多糖提取液的初步纯化,为了充分发挥DA201树脂的吸附性能,工业生产上可考虑采用串柱法.

  12. 大孔吸附树脂富集枸杞子中总黄酮的工艺研究%Extraction Research of Total Flavonoids from Lycii Fructus by Macroporous Adsorption Resin

    Institute of Scientific and Technical Information of China (English)

    胡晓莲; 张华

    2013-01-01

    Objective To study the optimum extraction technology of flavonoids from Lycii fructus by macroporous adsorption resin and improve the purity of product. Methods Optimizing suitable macroporous adsorption resin and process parameters, and using colorimetric method for the determination of Lycii fructus. Results The appropriate adsorption resin was DA-201, sample loading was 10bed volume (BV), sample concentration was 15 mg/mL, the flow rate was lBV /h, pH 3; desorption experimental elution agent was 40 % ethanol, and amount of ethanol was 8 BV. The yield was 75.85 %, and the purity of flavonoids was 35.70 %. Conclusion Under the certain process condition, flavonoids can be effective extracted and purified by DA201 type resin, and the resin can be reused with a good application prospect.%  目的筛选富集纯化枸杞子中总黄酮的大孔吸附树脂并确立其工艺参数,以提高产品纯度。方法优选大孔吸附树脂,并考察其工艺参数,采用比色法测定枸杞含量。结果筛选合适的吸附树脂DA-201,得到最佳的工艺参数为:上样量10柱床体积(BV),上样液浓度15 mg/mL,上样液流速1 BV/h,上样液pH3;解吸洗脱剂乙醇浓度为40%,乙醇用量8 BV。富集纯化总黄酮得率75.85%,总黄酮纯度35.70%。结论 DA-201型树脂在所确定的工艺条件下富集纯化总黄酮效果良好,树脂可重复利用,成本低,具有很好的应用前景。

  13. Resin Catalyst Hybrids

    Institute of Scientific and Technical Information of China (English)

    S. Asaoka

    2005-01-01

    @@ 1Introduction: What are resin catalyst hybrids? There are typically two types of resin catalyst. One is acidic resin which representative is polystyrene sulfonic acid. The other is basic resin which is availed as metal complex support. The objective items of this study on resin catalyst are consisting of pellet hybrid, equilibrium hybrid and function hybrid of acid and base,as shown in Fig. 1[1-5].

  14. Two-step Resin Adsorption for Purification of Stevia Glycosides from Stevia Rebaudiana Aqueous Extract%两步树脂法从甜叶菊水提液中纯化甜菊糖苷

    Institute of Scientific and Technical Information of China (English)

    唐乐乐; 叶发银; 杨瑞金; 华霄; 赵伟; 张文斌

    2012-01-01

    采用两步树脂法从甜叶菊水提液中提取纯化甜菊糖苷。第一步主要是脱色,通过比较大孔树脂D293、D296、JN-1、JN-2、D890和D201处理甜叶菊水提液的脱色率、甜菊糖苷保留率和解吸性能,发现JN-1的效果最好。在优化条件下,甜叶菊水提液经JN-1处理,甜菊糖苷纯度由原来的42.65%提高到67.33%,收率达到84.87%;第二步的主要目的是提高产品纯度,通过比较大孔树脂AB-8、JNF-1、X-5、NKA-II和D101对甜菊糖苷的吸附-解吸性能和得到的纯化液的甜菊糖苷纯度,发现JNF-1的效果最好。在优化的条件下,JN-1处理后的甜菊糖苷溶液进一步采用JNF-1吸附,溶液的甜菊糖苷纯度提高至92.92%,收率91.08%。%A new method for purification of steviol glycosides from Stevia Rebaudiana crude extracts by macro- porous adsorption resin (MAR) was systematically investigated. The purification procedure consisted of two steps. In the first step, the main purpose was decolorization, and several types of macroporous resins including D293, D296, JN-1, JN-2, D890 and D201 were used in order to choose the best resin. JN-1 resin was selected according to their decolorization ratio, the retention of steviol glycosides ratio and desorption ratio. In order to increase the purity, a sec- ond step of refining was added by screening various types of macroporous resins (AB-8, JNF-1, X-5, NKA-II and D101). The results demonstrated that JNF-1 resin was the most suitable resin. The purity of steviol glycosides after the first step JN-1 was from 42.65% to 67.33% with a recovery of 84.87%. The purity of steviol glycosides in- creased to 92.92% with a recovery of 91.08% after the second step JNF-1.

  15. Preliminary Study of Performance of TTA Resin

    Institute of Scientific and Technical Information of China (English)

    HUANG; Kun; MAO; Guo-shu

    2013-01-01

    TTA(thenoyl trifluoroacetone)extraction can effectively remove large amounts of uranium in the analysis of trace neptunium in the presence of large amounts of uranium.While it is not conducive to achieve the automation of the rapid analysis of neptunium with the TTA solution,the TTA resin was prepared and its properties were studied in this work.TTA resin in this work was a kind of mixture combining styrene-divinylbenzene skeleton with TTA

  16. Fractionation of fulvic acid extracted from lake sediments using XAD resins and the metal complexing ability. Kosho taisekibutsuchu kara chushutsusareta furubosan no XAD jushi kyuchaku ni yoru bunkaku to sakka noryoku

    Energy Technology Data Exchange (ETDEWEB)

    Usui, K.; Kishino, T. (Ube Colege, Yamaguchi (Japan). laboratory of Environmental Science); Higashi, T.; Shindo, H.; Marumoto, T. (Yamaguchi University, Yamaguchi (Japan). Faculty of Agriculture)

    1993-10-10

    Fulvic acid was extracted from lake sediments, and given an adsorption treatment with Amberlite XAD-2 and XAD-8 resins. The copper complexing ability of the treated liquid was discussed using a two binding site model. As a result of deriving the condition stability constants of the treated liquid, it was learned that the fulvic acid can be divided largely into two kinds with different complexing ability by about 100 times, having log K1 = 6.33 to 7.12 and log K2 = 4.35 to 4.66. The majority was composed of fulvic acid having weak complexing ability. The resin treatment separated the fulvic acid nearly completely into an adsorption fraction and a non-adsorption fraction. The fulvic acid in the adsorption fraction showed very little complexing ability. On the other hand, the fulvic acid in the non-adsorption fraction, which is nearly colorless, exhibited a complexing ability of 33 to 45 [mu] mol/g as copper complexing capacity. Further, the amount of the non-adsorption fraction appeared to account for 52% to 69% of the total fulvic acid as judged from the TOC value. 19 refs., 1 fig., 1 tab.

  17. Determination of Some Trace Metals in Environmental Samples by Flame AAS Following Solid Phase Extraction with Amberlite XAD-2000 Resin after Complexing with 8-Hydroxyquinoline

    Institute of Scientific and Technical Information of China (English)

    DURAN Celal; SENTURK H.Basri; GUNDOGDU Ali; BULUT V.Numan; EICi Latif; SOYLAK Mustafa; TUFEKCI,Mehmet; UYGUR Yaprak

    2007-01-01

    A procedure for preconcentration of Mn(Ⅱ), Fe(Ⅱ), Co(Ⅱ), Cu(Ⅱ), Cd(Ⅱ), Zn(Ⅱ), Pb(Ⅱ) and Ni(Ⅱ) based on retention of their complexes with 8-hydroxyquinoline (HQ) on Amberlite XAD-2000 resin in a column was proposed for the analysis of environmental samples by flame AAS. Various parameters such as pH, eluent type, volume,concentration, flow rate and volume of sample solution, and matrix interference effect on the retention of the metal ions were investigated. The optimum pHs for the retention of metal complexes in question were about 6 except for Mn2+ for whose value is 8. The loading capacity of the adsorbent for these metals and their recoveries from the resin under the optimum conditions were in the range 6.82-9.26 mg·g-1 and 95%-101%, respectively. The enrichment factor was calculated as 100 and the limit of detection was in the range 0.3-2.2 μg·L 1 (n=20, blank+3s). The proposed enrichment method was applied to tap water, stream water and vegetable samples. The validation of the procedure was carried out by analysis of certified reference material and standard addition. The analytes were determined with a relative standard deviation lower than 6% in all samples.

  18. Resin collection and social immunity in honey bees

    Science.gov (United States)

    We determined if the use of resins, complex plant secretions with diverse antimicrobial properties, acts as a colony-level immune defense by honey bees. Colonies were enriched with extracts of Brazilian or Minnesotan propolis (a bee mixture of resins and wax) or were left as controls. We measured ge...

  19. Guayule resin detection and influence on guayule rubber

    Science.gov (United States)

    Guayule (Parthenium argentatum) is a natural rubber (cis-1,4-polyisoprene) producing crop, native to North America. Guayule also produces organic resins, complex mixtures of terpenes, triglycerides, guayulins, triterpenoids and other components. During natural rubber extraction, guayule resins can b...

  20. Resin screening for the removal of pyridine-derivatives from waste-water by solvent impregnated resin technology

    NARCIS (Netherlands)

    Bokhove, J.; Schuur, B.; Haan, de A.B.

    2013-01-01

    The selective removal of pyridine derivatives by solvent impregnated resins has been studied. A solvent impregnated resin consists of a macro-porous particle that is impregnated with a solvent. This technology allows the use liquid–liquid extraction in fixed-bed operation, and prevents problems like

  1. 21 CFR 175.380 - Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins.

    Science.gov (United States)

    2010-04-01

    ... required in the production of the resins or added to impart desired physical and technical properties. The optional adjuvant substances may include resins produced by the condensation of allyl ether of mono-, di... percent (by volume) ethyl alcohol in distilled water at 160 °F for 4 hours yields total extractives not...

  2. 改性脂质阴离子交换树脂脱酸工艺的优化%Optimization of Modified Lipid Deacidification with Liquid-liquid Extraction and Anion Exchange Resin

    Institute of Scientific and Technical Information of China (English)

    袁璐; 姜土; 吴炜亮; 朱文亮; 黄秋研; 郑建仙

    2012-01-01

    Deacidification of modified Chinese tallow oil has been investigated using a strategy consisted of twice liquid-liquid extraction and deacidification process of D202 polymeric anion ion exchange.The effects of material ratio,reaction time and dosage of resin were investigated by central composite response design(CCRD) to obtain the optimum process.The optimum parameters were material ratio1:4.91,reaction time 7.28h,dosage of resin 9.23g.Under these optimum process parameters,acid value of modified lipid reduced to 0.11 mgKOH/g after deacidification of D202 resin.The sequences of three factors influenced on the deacidification of modified lipid were dosage of resinextraction timematerial ratio.%以经过2次液-液萃取脱酸的乌桕脂为目标油脂,研究了D202型大孔阴离子交换树脂脱酸工艺的可行性。采用中心组合旋转响应面设计(CCRD)对树脂脱酸工艺中的物料比、反应时间、树脂用量3个工艺参数进行优化,得到阴离子交换树脂脱酸的适宜工艺条件是:改性脂质与正己烷的物料比为1∶4.91,反应时间控制在7.28 h,树脂用量为9.23 g。在此条件下脱酸后,改性脂质的酸价可降低至0.11 mgKOH/g。3个因素对树脂脱酸效果的影响次序为,树脂用量〉反应时间〉物料比。

  3. Influence of curing rate of resin composite on the bond strength to dentin

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Asmussen, E; Peutzfeldt, A

    2007-01-01

    This study determined whether the strength with which resin composite bonds to dentin is influenced by variations in the curing rate of resin composites. Resin composites were bonded to the dentin of extracted human molars. Adhesive (AdheSE, Ivoclar Vivadent) was applied and cured (10 seconds...

  4. EXTRACT

    DEFF Research Database (Denmark)

    Pafilis, Evangelos; Buttigieg, Pier Luigi; Ferrell, Barbra

    2016-01-01

    The microbial and molecular ecology research communities have made substantial progress on developing standards for annotating samples with environment metadata. However, sample manual annotation is a highly labor intensive process and requires familiarity with the terminologies used. We have the...... and text-mining-assisted curation revealed that EXTRACT speeds up annotation by 15-25% and helps curators to detect terms that would otherwise have been missed.Database URL: https://extract.hcmr.gr/....

  5. Purification of total flavonoids from loquat leaves by macroporous resin and corresponding antioxidant capacity

    OpenAIRE

    Huang Suhua; Lin Biaosheng; Li Binbin; Tan Bi; Hong Yanping

    2017-01-01

    Flavonoids is one of the major active compounds in loquat leaves. In this study, the purification process of total flavonoids in loquat leaves by macroporous resin was researched and the antioxidant activity of total flavonoids was determined. The active compounds were extracted by 95% ethanol, and the total flavonoids was purified by macroporous resin. Comparing the static and dynamic adsorption and desorption characters of 6 macroporous resin, the best type of macroporous resin was determin...

  6. Occurrence of polycadinene in fossil and recent resins

    Science.gov (United States)

    Van Aarssen, B. G. K.; de Leeuw, J. W.; Collinson, M.; Boon, J. J.; Goth, K.

    1994-01-01

    Dammars produced by Dipterocarpaceae growing in Southeast Asia are partly composed of a macromolecule with a polycadinene structure. This polymer is the precursor of many specific compounds encountered in crude oils and sediment extracts from South Asia. Until recently there was no evidence for a more widespread geographical occurrence of this resinous polymer. Using different pyrolysis methods it is shown that the polymers present in a resinite from Utah, USA, and in resins contained in resin canals of Eocene fossil fruits from Germany and England are also polycadinenes. The fossil fruits were undoubtedly produced by ancient representatives of mastixioid Cornaceae, a group of plants which was widespread in the Tertiary of Europe and North America and which is not related to Dipterocarpaceae. These findings extend the known occurrence and origin of the sesquiterpenoid type resin polymer. It is to be expected that catagenetic products of these resin polymers should be present in oils, coals, and sediment extracts from areas outside Southeast Asia.

  7. [Radiopacity of composite resins].

    Science.gov (United States)

    Tamburús, J R

    1990-01-01

    The author studied the radiopacity of six composite resins, submitted to radiographic examination in standardized conditions, only with kilovoltage variations. Along with resins it was radiographed an aluminium penetrometer, to compare their optical densities. The results showed that kilovoltagem variations interfered in optical densities of the resins, being more pronounced in 50-55, 55-60 and 60-65 kilovoltages. Despite this, the relations of optical densities as compared with that of penetrometer steps kept unaltered most fo the kilovoltages used.

  8. Biocompatibility of composite resins

    OpenAIRE

    Sayed Mostafa Mousavinasab

    2011-01-01

    Dental materials that are used in dentistry should be harmless to oral tissues, so they should not contain any leachable toxic and diffusible substances that can cause some side effects. Reports about probable biologic hazards, in relation to dental resins, have increased interest to this topic in dentists. The present paper reviews the articles published about biocompatibility of resin-restorative materials specially resin composites and monomers which are mainly based on Bis-GMA and concern...

  9. Comparative study of resin sealant and resin modified glass ionomer as pit and fissure sealant

    Directory of Open Access Journals (Sweden)

    Shirin Malek

    2017-02-01

    Full Text Available The purpose of the present study was to compare the marginal integrity of resin modified glass ionomer cement with that of resin sealant, in vitro. Forty artificial pit and fissure cavities were prepared in occlusal surface of extracted premolar teeth by using ¼ round carbide bur. Cavities were condensed with artificial organic debris followed by cleaning with prophylaxis pumice brush and paste and then separated into two treatment groups. In Group A, 15 fissure cavities were sealed by resin sealant and in Group B, 15 fissure cavities were sealed by resin modified glass ionomer sealant. These specimens were subjected to thermo-cycling followed by dye penetration test. The remaining 5 cavities from each group were analyzed for debris score by the SEM. The results of the microleakage test showed that the efficacy of preventing microleakage of samples sealed by resin modified glass ionomer sealant was higher than the samples sealed by resin sealant. However, no significant differences were found. It can be concluded that use of resin modified glass ionomer sealant is a good alternative for sealing pits and fissures.

  10. RESEARCH ON IMPROVED EPOXY RESINS.

    Science.gov (United States)

    another ’million-modulus’ epoxy resin. Cast resin properties from a series of epoxy resins hardened with several aromatic diamines are reported, but these data are sufficient to advance only speculative conclusions. (Author)

  11. 超声提取白刺中总生物碱及大孔树脂纯化的工艺研究%Ultrasound extraction total alkaloids from Nitraria sibirica Pall and process research of macroporous resin purification

    Institute of Scientific and Technical Information of China (English)

    王玉玲; 曾会明; 张建秋; 马挺军

    2013-01-01

    为优化西伯利亚白刺种籽中总生物碱的提取工艺,采用超声波提取总碱,以硫酸阿托品为对照品,酸性染料比色法测定白刺中总生物碱的含量,探讨料液比、提取温度、时间、乙醇浓度4个因素的影响,确定最佳提取参数.从7种大孔吸附树脂中筛选出对白刺生物碱有最佳分离纯化效果的一种树脂,研究其对生物碱静态、动态吸附、解析效果.研究结果表明,当料液比为1∶20,温度60℃,时间40 min,乙醇浓度70%时,总生物碱提取率(生物碱/种籽重)最高,217.372 9 μg/g D101对白刺总生物碱的吸附、解析效果最好,对其进行动态吸附,可知最佳的工艺条件为上样液pH值为5,流速为0.75 mL/min,乙醇的洗脱浓度为80%.%In order to optimize the extract condition, total alkaloids in Nitraria sibirica was extracted by ultrasound and the content of total alkaloids was determined by the acidic dye colorimetry, the effects of solid-liquid ratio, temperature, time and ethanol concentration on the optimum extraction parameters were investigated, thereby determining the optimal extraction parameters; the best one of isolation and purification from seven kinds of resin were screened out to research its effects on the alkaloids of static, dynamic adsorption. The results show that with the conditions of solid-liquid ratio of 1:20, temperature 60 ℃, time 40 minutes, ethanol concentration of 70%, the highest total alkaloid extract rate was 217.372 9 μg/g; the adsorption and resolution effects of D101 on N. sibirica's total alkaloids were the best, the dynamic adsorption tests proved that the optimum process conditions were: sample solution pH 5, flow rate 0.75mL/min, ethanol concentration 80%.

  12. Profiling and Preparation of Metabolites from Pyragrel in Human Urine by Online Solid-Phase Extraction Coupled with High Performance Liquid Chromatography Tandem Mass Spectrometry Followed by a Macroporous Resin-Based Purification Approach.

    Science.gov (United States)

    Zhao, Xin; Jiang, Jingjing; Yang, Guang; Huang, Jie; Yang, Guoping; He, Guangwei; Chu, Zhaoxing; Hang, Taijun; Fan, Guorong

    2017-03-21

    Pyragrel, a new anticoagulant drug, is derived from the molecular combination of ligustrazine and ferulic acid. Pyragrel showed significant inhibitory activity against platelet aggregation induced by adenosine diphosphate (ADP), and had been approved for a phase I clinical trial by CFDA. To characterize the metabolites of Pyragrel in human urine after intravenous administration, a reliable online solid-phase extraction couple with high performance liquid chromatography tandem mass spectrometry (online SPE-HPLC-MS(n)) method was conceived and applied. Five metabolites were detected and tentatively identified, which suggested that the major metabolic pathways of Pyragrel in human were double-bond reduction, double-bond oxidation, and then followed by glucuronide conjugation. Two main metabolites were then prepared using β-glucuronide hydrolysis and macroporous resin purification approach followed by preparative high-performance liquid chromatography (PHPLC) method, with their structures confirmed on the basis of nuclear magnetic resonance (NMR) data. This study provided information for the further study of the metabolism and excretion of Pyragrel.

  13. Effects of the crisis in the resin sector on the demography of rural municipalities in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Ortuno Perez, S.; Garcia Robredo, F.; Ayuga Tellez, E.; Fullana Belda, C.

    2013-05-01

    Aim of study: The aim of this work is to test the positive effect of a substantially developed resin sector on rural demographic evolution. This work shows how in the period between 1970 and 2010 the demographic decline in the interior regions of Spain was more pronounced in areas characterized by the importance of resin-producing forest stands compared to other nearby rural municipalities where this natural resource is not present. Area of study: The study area consists of a set of rural municipalities in Central Spain, both resin and non-resin producing, in the provinces of Segovia, Avila, Valladolid, Burgos, Soria, Cuenca and Guadalajara. Material and methods: The relationship between resin production and population in resin and non-resin producing municipalities was modeled by means of linear regression analysis. Main results: Generally speaking, between 1950 and 1970 the production of resin halted demographic decline in the regions where this activity was substantially developed. However, when the resin sector entered into crisis in the 1970s, and the economic repercussions of this activity gradually ceased to be felt, the demographic decline in the regions which had been involved in resin production was much more acute than in other non-resin-producing rural areas. Research highlights: This work shows the relationship between resin extraction activity and population evolution in rural municipalities. Sustainable resin exploitation can contribute to the maintenance and development of rural communities, and should be used as a tool for generating employment in rural areas. (Author) 37 refs.

  14. 协同萃取法回收地浸采铀工艺树脂中铼%Synergistic Extraction of Rhenium from In-Situ Leach Uranium Mining Technology Resin

    Institute of Scientific and Technical Information of China (English)

    彭真; 罗明标; 蒋小辉; 花榕; 廖桢葳

    2011-01-01

    Synergistic extraction of rhenium with primary amines and tributylphosphate was studied. The effects of initial pH value, composition of the extractant, and volume ratio of organic phase to aqueous phase on the extraction of rhenium were studied. The results showed that the synergistic extraction efficiency of rhenium was above 97% at pH 2-10, while dissolving loss of primary amine ( N1923) in acid condition was great. The optimum conditions were obtained with initial pH value of 9.5 with 30% N1923, 50% TBP and 20% sulphonating kerosene as extractant, 3% NaOH as stripping reagent, phase ratio of 1: 1. The extraction efficiency was above 99% , and stripping efficiency was above 97%. The distribution ratio of rhenium increased with the increase of initial concentration of rhenium, and the extraction rate of rhenium was not influenced by the uranium existed in aqueous phase, and hardly influenced by nitrate. During the progress of in-situ sulfuric acid leaching technique of uranium, U and Re in the forms of [ UO2 (SO4 )2 ]2- , [ UO2 (SO4)3]4- , ReO4- were brought into leaching solution, and simultaneously absorbed by anion exchange resin D231. Uranium was stripped by nitrate or chloride from in-situ leach uranium mining technology resin, then rhenium was stripped by 10% NH4NO3 and 8% NH40H. It was effective, for the recovery of rhenium from desorption solution by primary amines and tributylphosphate synergistic extraction that provided parameters for further industry investigation for recovery of rhenium from uranium ore.%介绍了伯胺和磷酸三丁酯协同萃取回收铼的实验研究,考察了水相初始pH值、萃取剂组成、相比(O/W)对铼萃取率的影响.结果表明:协同萃取体系在pH 2~10范围内铼的萃取率均在97%以上,但酸性条件下伯胺N1923溶解损失较大,水相初始pH9.5为最佳萃取酸度,以有机相30% N1923-50%TBP-20%磺化煤油萃取铼效果最佳,并采用3% NaOH反萃铼,

  15. Biocidal quaternary ammonium resin

    Science.gov (United States)

    Janauer, G. E.

    1983-01-01

    Activated carbon (charcoal) and polymeric resin sorbents are widely used in the filtration and treatment of drinking water, mainly to remove dissolved organic and inorganic impurities and to improve the taste. Earlier hopes that activated carbon might "disinfect' water proved to be unfounded. The feasibility of protecting against microbial infestation in charcoal and resin beds such as those to be incorporated into total water reuse systems in spacecraft was investigated. The biocidal effect of IPCD (insoluable polymeric contact disinfectants) in combination with a representative charcoal was assessed. The ion exchange resins (IPCD) were shown to adequately protect charcoal and ion exchange beds.

  16. Biocompatibility of composite resins

    Directory of Open Access Journals (Sweden)

    Sayed Mostafa Mousavinasab

    2011-01-01

    Full Text Available Dental materials that are used in dentistry should be harmless to oral tissues, so they should not contain any leachable toxic and diffusible substances that can cause some side effects. Reports about probable biologic hazards, in relation to dental resins, have increased interest to this topic in dentists. The present paper reviews the articles published about biocompatibility of resin-restorative materials specially resin composites and monomers which are mainly based on Bis-GMA and concerns about their degradation and substances which may be segregated into oral cavity.

  17. Removal of dyes from water using crosslinked aminomethane sulfonic acid based resin.

    Science.gov (United States)

    Kaner, Damla; Saraç, Ayfer; Senkal, Bahire Filiz

    2010-08-01

    A new polymeric resin with amino sulfonic acid pendant functions has been prepared for the extraction of acidic and basic dyes from water. Beaded polymer supports were prepared by suspension polymerization of vinyl benzyl chloride (0.9 mol) and ethylene glycol dimethacrylate (0.1 mol). The resulting copolymer beads were modified with amino methane sulfonic acid. The dye adsorption capacity of the resin was found as 0.16 g dye/g resin for ramazol black and 0.15 g dye/g resin for crystal violet. The pH depending measurements and dye sorption kinetics of the resin were also investigated.

  18. Resin composite repair: Quantitative microleakage evaluation of resin-resin and resin-tooth interfaces with different surface treatments

    OpenAIRE

    Celik, Cigdem; Cehreli, Sevi Burcak; Arhun, Neslihan

    2015-01-01

    Objective: The aim was to evaluate the effect of different adhesive systems and surface treatments on the integrity of resin-resin and resin-tooth interfaces after partial removal of preexisting resin composites using quantitative image analysis for microleakage testing protocol. Materials and Methods: A total of 80 human molar teeth were restored with either of the resin composites (Filtek Z250/GrandioSO) occlusally. The teeth were thermocycled (1000×). Mesial and distal 1/3 parts of the res...

  19. 顶空气相色谱法测定大孔树脂提取物中的残留溶剂研究%Determination of residual solvents in macroporous resin extracts by Head-space capillary gas chromatography

    Institute of Scientific and Technical Information of China (English)

    刘冬; 杨敬芝; 杜守颖; 张东明; 赵立敏; 陈雯

    2009-01-01

    目的:建立了测定大孔树脂淫羊藿提取物、栀子提取物以及HP中乙醇、正己烷、苯、甲苯、甲基环己烷、二甲苯、苯乙烯、二乙烯苯残留有机溶剂含量的顶空气相色谱法.方法:采用顶空气相色谱法,FID检测器,以20%~50%二甲基亚砜为溶媒,顶空预热温度为90℃,预热时间为10 min,进样口温度为180℃,检测器温度为250℃,以氮气为载气,使用DB-1交联毛细管柱(60m×0.32mm,1 μm),程序升温,实现了各组分的基线分离.结果:乙醇、正己烷、苯、甲苯、甲基环己烷、二甲苯、苯乙烯、二乙烯苯在各自对应的浓度范围内,线性关系良好;乙醇、正己烷、苯、甲苯、甲基环己烷、二甲苯、苯乙烯、二乙烯苯的最小检测限分别为2.72,0.22,0.03,0.03,0.28,0.33,0.03,0.31 μg·mL~(-1);加样回收率均在75%以上,精密度较好.结论:经方法学验证,该方法灵敏、准确、可靠,可适用于大孔树脂淫羊藿提取物、栀子提取物及HP中乙醇、正己烷、苯、甲苯、甲基环己烷、二甲苯、苯乙烯、二乙烯苯等残留有机溶剂的测定.%Objective:This paper reports a Head-space GC method for determination of enthanol,hexane,benzene,toluene,methyl cyclohexane,xylene,styrene,divinyl benzene in macroporous resin extractions.Method:The analytical coluren was DB-1(60m×0.32mm,1μm).The injector temperature was 180℃ and the detector tempemture was 250℃.The column temperature was programmed raised.The carrier gas was nitrogen and the solvent was 20%-50% dimethyl sulfoxide.Results:The stand curve were linear for each solvents in the range of each consistencv.The average recoveries were all more than 75%.Conclusion:This method is simple,rapid and precise,it is suitable for measurement of residual solvents in macroporous resin extracts.

  20. Quantification and Purification of Mulberry Anthocyanins with Macroporous Resins

    Directory of Open Access Journals (Sweden)

    Xueming Liu

    2004-01-01

    Full Text Available Total anthocyanins in different cultivars of mulberry were measured and a process for the industrial preparation of mulberry anthocyanins as a natural food colorant was studied. In 31 cultivars of mulberry, the total anthocyanins, calculated as cyanidin 3-glucoside, ranged from 147.68 to 2725.46 mg/L juice. Extracting and purifying with macroporous resins was found to be an efficient potential method for the industrial production of mulberry anthocyanins as a food colorant. Of six resins tested, X-5 demonstrated the best adsorbent capability for mulberry anthocyanins (91 mg/mL resin. The adsorption capacity of resins increased with the surface area and the pore radius. Residual mulberry fruit juice after extraction of pigment retained most of its nutrients, except for anthocyanins, and may provide a substrate for further processing.

  1. Al2O3 Extraction Technologies from Fly Ash on the Properties of Modified PP Resin%粉煤灰提取Al2O3工艺对PP改性性能的影响

    Institute of Scientific and Technical Information of China (English)

    董金虎

    2012-01-01

    Extract Al2O3 was extracted from fly ash using alkali high-temperature calcinations, obtain two different structures' Al2O3 were obtained by two different technologies at the phase of Al(OH), separated out,and two different A12O3 were used to modify PP resin. The results showed that, the tensile strength of PP modified by sheet Al2O3, was better than the PP modified by flocculent Al2O3, and the elongation and impact strength of PP modified by the two different Al2O3 could have the same modification effect, and the content of sheet AlO3 litter than flocculent Al2O3 when obtained the same modification effect. And when the content of Al2O3 was about 2% , the comprehensive performance of PP modified by sheet Al2O3 was better,and the tensile strength increased about 13 % , and the elongation increased about 18 % , and the impact strength increased 15 % .%采用碱焙烧法从粉煤灰中提取Al2O3,在Al(OH)3析出过程中采用两种不同的工艺方法,可以形成两种结构的Al2O3,并分别将两种Al2O3用于改性PP树脂.结果表明:片状Al2O3改性PP的拉伸强度好于絮状Al2O3,而两种Al2O3改性PP的断裂伸长率、冲击强度可以获得相当的改性效果,且片状Al2O3的用量少于絮状Al2O3.片状Al2O3用量为2%左右时,改性PP的综合性能较好,拉伸强度提高约13%,断裂伸长率提高约18%,冲击强度提高约15%.

  2. Biocompatibility and cytotoxicity of two novel low-shrinkage dental resin matrices.

    Science.gov (United States)

    Jan, Yih-Dean; Lee, Bor-Shiunn; Lin, Chun-Pin; Tseng, Wan-Yu

    2014-06-01

    To reduce the polymerization shrinkage of dental composite resin, we used two different ratios of toluene 2,4-diisocyanate (TDI) or 1,6-hexamethylene diisocyanate (HDI) as functional side chains of bisphenol A-glycidyl methacrylate (bis-GMA) to synthesize two series of new dental resin matrices. This study evaluated the biocompatibility and cytotoxicity of these two series of new resin matrices. Two series of new dental resin matrices with the ratios of TDI or HDI functional side chain to bis-GMA (defined as B group) being 1:4, 1:2, 1:1 and 3:2 (defined as T1/4, T1/2, T1, T3/2, and H1/4, H1/2, H1, H3/2 groups, respectively) were synthesized. Each resin sample was light cured and immersed in the culture medium for 24 hours to make the extract solution. Then, human gingival fibroblasts were cultured in different extract solutions for 72 hours. The cytotoxicities of different resins were evaluated by microtitertetrazolium (MTT) assay, the levels of cell-produced reactive oxygen species (ROS) induced by different extract solutions was measured. Resins of the T1/4 and B groups revealed significantly higher cytotoxicity than resins of other groups. However, resins of the T1 and T3/2 groups exhibited less cytotoxicity. In general, resins of the TDI-modified groups showed equal or less cytotoxicity and induced equal or lower levels of ROS than the corresponding resins of the HDI-modified and B groups. Our results showed that the TDI-modified resin matrices containing more functional side chains were less cytotoxic than the corresponding HDI-modified resin matrices. When the ratio of functional side chain to bis-GMA is increased, the stereo hindrance of resin structure is increased, more toxic resin monomers are trapped in the complicated resin structure, and thus the resin matrix reveals less cytotoxicity. The TDI-modified resin matrices exhibit higher stereo hindrance of resin structure and thus show less cytotoxicity than the corresponding HDI-modified resin matrices

  3. Determination of Human-Health Pharmaceuticals in Filtered Water by Chemically Modified Styrene-Divinylbenzene Resin-Based Solid-Phase Extraction and High-Performance Liquid Chromatography/Mass Spectrometry

    Science.gov (United States)

    Furlong, Edward T.; Werner, Stephen L.; Anderson, Bruce D.; Cahill, Jeffery D.

    2008-01-01

    In 1999, the Methods Research and Development Program of the U.S. Geological Survey National Water Quality Laboratory began the process of developing a method designed to identify and quantify human-health pharmaceuticals in four filtered water-sample types: reagent water, ground water, surface water minimally affected by human contributions, and surface water that contains a substantial fraction of treated wastewater. Compounds derived from human pharmaceutical and personal-care product use, which enter the environment through wastewater discharge, are a newly emerging area of concern; this method was intended to fulfill the need for a highly sensitive and highly selective means to identify and quantify 14 commonly used human pharmaceuticals in filtered-water samples. The concentrations of 12 pharmaceuticals are reported without qualification; the concentrations of two pharmaceuticals are reported as estimates because long-term reagent-spike sample recoveries fall below acceptance criteria for reporting concentrations without qualification. The method uses a chemically modified styrene-divinylbenzene resin-based solid-phase extraction (SPE) cartridge for analyte isolation and concentration. For analyte detection and quantitation, an instrumental method was developed that used a high-performance liquid chromatography/mass spectrometry (HPLC/MS) system to separate the pharmaceuticals of interest from each other and coextracted material. Immediately following separation, the pharmaceuticals are ionized by electrospray ionization operated in the positive mode, and the positive ions produced are detected, identified, and quantified using a quadrupole mass spectrometer. In this method, 1-liter water samples are first filtered, either in the field or in the laboratory, using a 0.7-micrometer (um) nominal pore size glass-fiber filter to remove suspended solids. The filtered samples then are passed through cleaned and conditioned SPE cartridges at a rate of about 15

  4. Preparative Separation and Purification of the Total Flavonoids in Scorzonera austriaca with Macroporous Resins

    OpenAIRE

    Yang Xie; Qiu-Shi Guo; Guang-Shu Wang

    2016-01-01

    The use of macroporous resins for the separation and purification of total flavonoids to obtain high-purity total flavonoids from Scorzonera austriaca was studied. The optimal conditions for separation and purification of total flavonoids in S. austriaca with macroporous resins were as follows: D4020 resin columns were loaded with crude flavonoid extract solution, and after reaching adsorptive saturation, the columns were eluted successively with 5 bed volumes (BV) of water, 5 BV of 5% (v/v) ...

  5. Cementation of residue ion exchange resins at Rocky Flats

    Energy Technology Data Exchange (ETDEWEB)

    Dustin, D.F.; Beckman, T.D.; Madore, C.M.

    1998-03-03

    Ion exchange resins have been used to purify nitric acid solutions of plutonium at Rocky Flats since the 1950s. Spent ion exchange resins were retained for eventual recovery of residual plutonium, typically by incineration followed by the aqueous extraction of plutonium from the resultant ash. The elimination of incineration as a recovery process in the late 1980s and the absence of a suitable alternative process for plutonium recovery from resins led to a situation where spent ion exchange resins were simply placed into temporary storage. This report describes the method that Rocky Flats is currently using to stabilize residue ion exchange resins. The objective of the resin stabilization program is: (1) to ensure their safety during interim storage at the site, and (2) to prepare them for ultimate shipment to the Waste Isolation Pilot Plant (WIPP) in New Mexico. Included in the discussion is a description of the safety concerns associated with ion exchange resins, alternatives considered for their stabilization, the selection of the preferred treatment method, the means of implementing the preferred option, and the progress to date.

  6. Development of a composite resin disclosing agent based on the understanding of tooth staining mechanisms.

    Science.gov (United States)

    Abdallah, Mohamed-Nur; Light, Nathan; Amin, Wala M; Retrouvey, Jean-Marc; Cerruti, Marta; Tamimi, Faleh

    2014-06-01

    To characterize the surface composition of dental enamel and composite resin, assess the ability of dyes with different affinities to stain these surfaces, and use this information to develop a disclosing agent that stains composite resin more than dental enamel. One hundred and ten sound extracted teeth were collected and 60 discs of composite resin, 9 mm diameter and 3 mm thick, were prepared. X-ray photoelectron spectroscopy (XPS) was employed to determine the elemental composition on the different surfaces. A tooth shade spectrophotometer was used to assess the change in shade after staining the surfaces with different dyes. XPS analysis revealed that surfaces of both outer dental enamel and composite resin contained relatively high amounts of carbon, specifically hydrocarbons. Both dental enamel and composite surfaces were stainable with the hydrophobic dye (pcomposite resin was stained more than the dental enamel (pcomposite resin might explain their high affinity to be stained by food and beverages containing hydrophobic molecules. The composite resin is more stainable by hydrophobic dyes than dental enamel. We used this information to develop an agent for disclosing composite resins that could be used to visualize composite resins that need to be removed. Removal of composite resin can be problematic, time consuming and stressful to the dental practitioner. A composite disclosing agent would help the dental practitioner identify the composite resin and facilitate its removal without damaging the adjacent healthy tooth tissues. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Solvent impregnated resins for the removal of low concentration phenol from water

    NARCIS (Netherlands)

    Burghoff, B.; Goetheer, E.L.V.; Haan, A.B. de

    2008-01-01

    The focus of this investigation is the development of a solvent impregnated resin for phenol removal from dilute aqueous solutions. Using a solvent impregnated resin (SIR) eliminates the problem of emulsification encountered in liquid-liquid extraction. Impregnated MPP particles and impregnated XAD1

  8. Agarwood-type Resin from Gyrinops walla Gaertn: A New Discovery

    Directory of Open Access Journals (Sweden)

    S.M.C.U.P. Subasinghe

    2012-10-01

    Full Text Available Agarwood is an expensive resinous product extracted from some members of Aquilaria andGyrinops species of the family Thymalaeaceae. Agarwood essential oil is a highly valued perfumeryproduct in modern cosmetics and traditional Attar. Agarwood extraction from the above species andproduct manufacturing are done in India and Southeast Asian countries. However, overharvesting, lownatural regeneration, and legal restrictions at present, have limited the supply of this product.Gyrinops walla is recorded in the wet zone of Sri Lanka, and it had been very rarely recorded inextreme Southwest India. However, recent reports of the abundance of G. walla in India are hard to find.Studies were not conducted in the past for G. walla on its ability of agarwood resin production and thequality of that resin. This study is the first to identify the agarwood resin formation and the quality of G.walla which can be used as a substitute for that of Aquilaria and other species of Gyrinops.Resinous tissues were extracted from six G. walla trees for the present study from two differentareas, i.e., Labugama and Yagirala of the wet zone of Sri Lanka. The resins were solvent extracted in thelaboratory and the resin quality was tested using gas chromatography analysis. The results indicated anextreme similarity of the compounds of G. walla resin with that of commercially available agarwoodresins. However, further studies should be conducted to identify G. walla distribution and formation ofagarwood.

  9. Evaluation of ion exchange resins for iron control in copper electro-winning solutions; Evaluacion de resinas de intercambio ionico para el control de hierro en soluciones de electro-obtencion de cobre

    Energy Technology Data Exchange (ETDEWEB)

    Parada, F.; Dreisinger, D.; Wilkomirsky, I.

    2010-07-01

    Two commercial resins were evaluated for the extraction of iron from a copper electrowinning solution. Both resins efficiently extract iron. The Mono phosphonic resin has a greater charge capacity than the Diphonix resin and the Diphonix resin shows faster kinetics. Experimental results of the interrupted test and tests with different particle size of resins have demonstrated that extraction kinetics is controlled by diffusion into the particle in both resins. A good agreement with Fick's model for diffusion inside the particles confirms the proposed mechanism. Finally, temperature favors the process kinetics and its effect on the diffusion coefficient follows Arrhenius law, obtaining a value of 4,89 kcal/mol for the Mono phosphonic resin and 4,94 kcal/mol for the Diphenox resin. The aforementioned values are close to typical values for the proposed diffusional control which are 6 to 10 kcal/mol. (Author)

  10. 离子液体/苯并15-冠-5浸渍XAD-7树脂萃取分离锂同位素%Extraction Separation of Lithium Isotopes by Using XAD-7 Resins Impregnated With Ionic Liquid and Benzo-15-Crown-5

    Institute of Scientific and Technical Information of China (English)

    顾玲; 孙晓利; 任冬红; 邱丹; 顾志国; 李在均

    2015-01-01

    Imidazolium-type ionic liquid ([C8 mim][BF4 ],[C8 mim][PF6 ]and [C8 mim] [(SO2 CF3 )2 N])and benzo-15-crown-5 were immobilized on XAD-7 resin to obtain the im-pregnated resin for lithium isotopes separation.IR and SEM characterizations of the impreg-nated resins indicate that ionic liquids and benzo-15-crown-5 are immobilized in the resins successfully and the thermal analysis indicates that the materials are thermally stable.The optimum E was obtained in the initial solution at pH=5.55.The larger extraction percenta-ges and separation factors values were obtained from LiSCN solution and CF3 COOLi solu-tion,respectively.The maximum single-stage isotopes separation factor of 6 Li/7 Li is up to 1.045±0.002.The equilibrium time of extraction is attained in 2.5-3 h.The thermodynamic parameters of the system were presented and revealed that the extraction reaction was a spontaneous process and the temperature had slight influence on the extraction separation of lithium isotopes.The mechanism of extraction system show that 6 Li enriches in the solid phase and 7 Li concentrates in the aqueous phase.The impregnated resins can be regenerated and reused for lithium isotopes separation.%以 XAD-7树脂为支撑担体制备了含有三种不同咪唑型离子液体([C8 mim][BF4]、[C8 mim][PF6]、[C8 mim][(SO2 CF3)2 N])和萃取剂(苯并15-冠-5)的浸渍树脂,并用于锂同位素的萃取分离。浸渍树脂的红外和扫描电镜表征表明,离子液体成功负载到了树脂上;热重分析表明,该浸渍树脂具有良好的热稳定性。在水相初始 pH=5.55时,浸渍树脂具有最佳萃取率。浸渍树脂在 LiSCN 溶液中具有较高的萃取率,而在CF3 COOLi 溶液中呈现较大的单级分离因子,最大单级分离因子达到1.045±0.002。浸渍树脂的萃取平衡时间为2.5~3 h。萃取热力学研究表明,该反应为自发过程,温度对体系的影响较小。6 Li 富集于固相,7 Li 富集在水相。该系列浸渍树脂易于再生,可循环使用。

  11. Resin composite repair: Quantitative microleakage evaluation of resin-resin and resin-tooth interfaces with different surface treatments.

    Science.gov (United States)

    Celik, Cigdem; Cehreli, Sevi Burcak; Arhun, Neslihan

    2015-01-01

    The aim was to evaluate the effect of different adhesive systems and surface treatments on the integrity of resin-resin and resin-tooth interfaces after partial removal of preexisting resin composites using quantitative image analysis for microleakage testing protocol. A total of 80 human molar teeth were restored with either of the resin composites (Filtek Z250/GrandioSO) occlusally. The teeth were thermocycled (1000×). Mesial and distal 1/3 parts of the restorations were removed out leaving only middle part. One side of the cavity was finished with course diamond bur and the other was air-abraded with 50 μm Al2O3. They were randomly divided into four groups (n = 10) to receive: Group 1: Adper Single Bond 2; Group 2: All Bond 3; Group 3: ClearfilSE; Group 4: BeautiBond, before being repaired with the same resin composite (Filtek Z250). The specimens were re-thermocycled (1000×), sealed with nail varnish, stained with 0.5% basic fuchsin, sectioned mesiodistally and photographed digitally. The extent of dye penetration was measured by image analysis software (ImageJ) for both bur-finished and air-abraded surfaces at resin-tooth and resin-resin interfaces. The data were analyzed statistically. BeautiBond exhibited the most microleakage at every site. Irrespective of adhesive and initial composite type, air-abrasion showed less microleakage except for BeautiBond. The type of initial repaired restorative material did not affect the microleakage. BeautiBond adhesive may not be preferred in resin composite repair in terms of microleakage prevention. Surface treatment with air-abrasion produced the lowest microleakage scores, independent of the adhesive systems and the pre-existing resin composite type. Pre-existing composite type does not affect the microleakage issue. All-in-one adhesive resin (BeautiBond) may not be preferred in resin composite repair in terms of microleakage prevention.

  12. System for removing contaminants from plastic resin

    Science.gov (United States)

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    2010-11-23

    A resin recycling system that produces essentially contaminant-free synthetic resin material in an environmentally safe and economical manner. The system includes receiving the resin in container form. A grinder grinds the containers into resin particles. The particles are exposed to a solvent in one or more solvent wash vessels, the solvent contacting the resin particles and substantially removing contaminants on the resin particles. A separator is used to separate the resin particles and the solvent. The resin particles are then placed in solvent removing element where they are exposed to a solvent removing agent which removes any residual solvent remaining on the resin particles after separation.

  13. Stingless bees use terpenes as olfactory cues to find resin sources.

    Science.gov (United States)

    Leonhardt, S D; Zeilhofer, S; Blüthgen, N; Schmitt, Thomas

    2010-09-01

    Insects largely rely on olfactory cues when seeking and judging information on nests, partners, or resources. Bees are known to use volatile compounds-besides visual cues-to find flowers suitable for pollen and nectar collection. Tropical stingless bees additionally collect large amounts of plant resins for nest construction, nest maintenance, nest defense, and to derive chemical constituents for their cuticular profiles. We here demonstrate that stingless bees of Borneo also use olfactory cues to find tree resins. They rely on volatile mono- and sesquiterpenes to locate or recognize known resin sources. Moreover, by modifying resin extracts, we found that stingless bees do not use the entire resin bouquet but relative proportions of several terpenes. In doing so, the bees are able to learn specific tree resin profiles and distinguish between tree species and partly even tree individuals.

  14. Flame Retardant Epoxy Resins

    Science.gov (United States)

    Thompson, C. M.; Smith, J. G., Jr.; Connell, J. W.; Hergenrother, P. M.; Lyon, R. E.

    2004-01-01

    As part of a program to develop fire resistant exterior composite structures for future subsonic commercial aircraft, flame retardant epoxy resins are under investigation. Epoxies and their curing agents (aromatic diamines) containing phosphorus were synthesized and used to prepare epoxy formulations. Phosphorus was incorporated within the backbone of the epoxy resin and not used as an additive. The resulting cured epoxies were characterized by thermogravimetric analysis, propane torch test, elemental analysis and microscale combustion calorimetry. Several formulations showed excellent flame retardation with phosphorous contents as low as 1.5% by weight. The fracture toughness of plaques of several cured formulations was determined on single-edge notched bend specimens. The chemistry and properties of these new epoxy formulations are discussed.

  15. Paramagnetic epoxy resin

    Directory of Open Access Journals (Sweden)

    E. C. Vazquez Barreiro

    2017-01-01

    Full Text Available This work illustrates that macrocycles can be used as crosslinking agents for curing epoxy resins, provided that they have appropriate organic functionalities. As macrocycles can complex metal ions in their structure, this curing reaction allows for the introduction of that metal ion into the resin network. As a result, some characteristic physical properties of the metallomacrocycle could be transferred to the new material. The bisphenol A diglycidyl ether (BADGE, n = 0 and hemin (a protoporphyrin IX containing the Fe(III ion, and an additional chloride ligand have been chosen. The new material has been characterized by differential scanning calorimetry (DSC, thermogravimetric analysis (TGA, Fourier Transform Infrared (FT-IR, Nuclear Magnetic Resonance (NMR, Transmission Electron Microscopy (TEM, and magnetic susceptibility measurements. Fe(III remains in the high-spin state during the curing process and, consequently, the final material exhibits the magnetic characteristics of hemin. The loss of the chlorine atom ligand during the cure of the resin allows that Fe(III can act as Lewis acid, catalyzing the crosslinking reactions. At high BADGE n = 0/hemin ratios, the formation of ether and ester bonds occurs simultaneously during the process.

  16. Dry PMR-15 Resin Powders

    Science.gov (United States)

    Vannucci, Raymond D.; Roberts, Gary D.

    1988-01-01

    Shelf lives of PMR-15 polymides lengthened. Procedure involves quenching of monomer reactions by vacuum drying of PRM-15 resin solutions at 70 to 90 degree F immediately after preparation of solutions. Absence of solvent eliminates formation of higher esters and reduces formation of imides to negligible level. Provides fully-formulated dry PMR-15 resin powder readily dissolvable in solvent at room temperature immediately before use. Resins used in variety of aerospace, aeronautical, and commercial applications.

  17. Resin regeneration device for condensate desalter

    Energy Technology Data Exchange (ETDEWEB)

    Segawa, Yoshihiro [Toshiba Engineering Co. Ltd., Kawasaki, Kanagawa (Japan); Hirose, Yuki

    1998-07-28

    The present invention provides a resin regeneration device for a condensate desalter of a nuclear power plant. Namely, both anionic and cationic exchange resins are supplied in a mixed state from a forwarding water desalting tower to an anionic resin regeneration tower. In the anionic resin generation tower, the resin is once separated to an anionic exchange region layer, a mixed resin layer and an cationic exchange resin layer in this order from the upper portion by water injected from a stirring water injection tube disposed at the bottom. Then, water is injected from a developing water injection tube disposed at the lower portion of the mixed resin layer to develop the cationic exchange resin layer and the mixed resin layer to the upper portion of the cationic resin regeneration tower. Subsequently, the amount of the injection of the developing water is reduced to such a flow rate that only the anionic exchange resin is precipitated. Then, a cationic exchange resin layer is formed at the upper portion and an anion exchange resin layer is formed at the lower portion of the developing water injection tube of the cationic resin regeneration tower. The anionic exchange resin is transferred to the anionic exchange resin regeneration tower in this state. According to the present invention, the mixed resin layer can be separated to anionic and cationic exchange resins easily and reliably. (I.S.)

  18. Branched polymeric media: Perchlorate-selective resins from hyperbranched polyethyleneimine

    KAUST Repository

    Chen, Dennis P.

    2012-10-02

    Perchlorate (ClO4 -) is a persistent contaminant found in drinking groundwater sources in the United States. Ion exchange (IX) with selective and disposable resins based on cross-linked styrene divinylbenzene (STY-DVB) beads is currently the most commonly utilized process for removing low concentrations of ClO4 - (10-100 ppb) from contaminated drinking water sources. However, due to the low exchange capacity of perchlorate-selective STY-DVB resins (∼0.5-0.8 eq/L), the overall cost becomes prohibitive when treating groundwater with higher concentration of ClO4 - (e.g., 100-1000 ppb). In this article, we describe a new perchlorate-selective resin with high exchange capacity. This new resin was prepared by alkylation of branched polyethyleneimine (PEI) beads obtained from an inverse suspension polymerization process. Batch and column studies show that our new PEI resin with mixed hexyl/ethyl quaternary ammonium chloride exchange sites can selectively extract trace amounts of ClO4 - from a makeup groundwater (to below detection limit) in the presence of competing ions. In addition, this resin has a strong-base exchange capacity of 1.4 eq/L, which is 1.75-2.33 times larger than those of commercial perchlorate-selective STY-DVB resins. The overall results of our studies suggest that branched PEI beads provide versatile and promising building blocks for the preparation of perchlorate-selective resins with high exchange capacity. © 2012 American Chemical Society.

  19. Shear bond strength evaluation of resin composite bonded to three different liners: TheraCal LC, Biodentine, and resin-modified glass ionomer cement using universal adhesive: An in vitro study

    OpenAIRE

    Deepa, Velagala L; Bhargavi Dhamaraju; Indira Priyadharsini Bollu; Tandri S Balaji

    2016-01-01

    Aims: To compare and evaluate the bonding ability of resin composite (RC) to three different liners: TheraCal LC TM (TLC), a novel resin-modified (RM) calcium silicate cement, Biodentine TM (BD), and resin-modified glass ionomer cement (RMGIC) using an universal silane-containing adhesive and characterizing their failure modes. Materials and Methods: Thirty extracted intact human molars with occlusal cavity (6-mm diameter and 2-mm height) were mounted in acrylic blocks and divided into th...

  20. Experimental study on gold extraction by resin-in-pulp method in Dongxi gold mine and its production practice%东溪金矿树脂矿浆法提金工艺试验研究与生产实践

    Institute of Scientific and Technical Information of China (English)

    韩春国

    2013-01-01

    The paper stated that production practice of resin-in-pulp (RIP) method for the extraction of gold and demonstrated the effective performance of NK 884 resin in adsorbing gold and silver. The practice proved RIP to be better choice than the previous CIP method for Dongxi gold mine. The gold leaching rate is increased by 1. 01 % adsorption rate 0. 77 % ; technical indexes of silver are more significantly improved with leaching rate increased by 8. 34 % and adsorption rate by 28.43 % .%论述了树脂矿浆法提金工艺的生产实践过程,验证了NK884型树脂对金、银所具有的良好吸附性能.生产实践表明,对东溪金矿而言,树脂矿浆法优于其原有的炭浆法.其中,金的浸出率提高1.01%,吸附率提高0.77%;银的技术指标提高更为显著,浸出率提高8.34%,吸附率提高28.43%.

  1. Sifat Fisis Dan Mekanis Basis Gigi Tiruan Resin Akrilik Polimerisasi Panas Setelah Perendaman Ekstrak Daun Salam (Syzygium Polyanthum Wight)

    OpenAIRE

    Harahap, Fitri Yuniati

    2014-01-01

    Research on the physical and mechanical properties heat cured acrylic resin denture base material immersed bay leaf extract (Syzygium polyanthum wight) has been done. This research aimed to see the effect of immersing time heat cured acrylic resin denture base in the bay leaf extracts for physical and mechanical properties. Samples were immersed in a solution of bay leaf extract with 40% concentration and soaking time 5, 10, 15, 20 and 25 minutes. From the results tests of s...

  2. [Acrylic resin removable partial dentures

    NARCIS (Netherlands)

    Baat, C. de; Witter, D.J.; Creugers, N.H.J.

    2011-01-01

    An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of

  3. Extraction of mercury(II) with sulfurized jojoba oil

    Energy Technology Data Exchange (ETDEWEB)

    Wisniak, J.; Schorr, G.; Zacovsky, D.; Belfer, S. (Ben-Gurion Univ. of the Negev, Beersheba (Israel). Dept. of Chemical Engineering)

    1990-09-01

    Sulfurized jojoba oil containing 12% by weight S has been tested as an extractant for Hg(II) from aqueous solutions. This paper reports on experiments performed with the extractant dissolved in a solvent (liquid--liquid extraction) or adsorbed in an appropriate resin matrix (solid--liquid extraction). The extraction characteristics of both systems have been measured and show that sulfurized jojoba oil exhibits very good possibilities as an extractant. The performance of several resins treated with sulfurized jojoba oil for adsorbing mercury(II) was studied. The morphology of the different resins was examined by using scanning electron microscopy. The sulfurized oil is attached to the resin sites through the sulfur atoms; it is estimated that there are about 2 mol of S active sites per kilogram of resin.

  4. 优化大孔树脂提取分离苋菜红色素的工艺%Optimization of Extraction and Separation of Red Pigment from Amaranthus Paniculatus with Macroporous Adsorption Resin

    Institute of Scientific and Technical Information of China (English)

    林海珠; 张云玲; 胥秀英; 郑一敏; 乔源; 傅善权

    2013-01-01

    AB-8 resin was selected out to purify the red pigment of Amaranthus paniculatus by orthogonal design. The best conditions for isolation of the red pigment of Amaranthus paniculatus were determined as follows: pH 3, adsorption velocity 1.2 mL/min, solution adsorbent 15% ethanol and elution velocity 0.9 mL/min. After AB-8 macroporous resin purification, greatly enhance the pigment quality.%采用正交设计实验筛选AB-8大孔树脂纯化苋菜红色素的最佳工艺条件.其最佳工艺为:上样pH值为3、吸附流速1.2mL/min、洗脱剂浓度为15%乙醇溶液、洗脱流速0.9 mL/min.经过AB-8大孔树脂提纯后,提高了苋菜红色素的品质.

  5. D370型树脂在氰化浸出提金工艺中的应用%Application of D 370 type resin in gold extraction process by cyanide leaching

    Institute of Scientific and Technical Information of China (English)

    韩春国; 高玉玺; 王静

    2012-01-01

    Contrast tests on adsorption capacity and preferential adsorption capability among D370, 201 × 4 and 201 ×7 type resins for gold and silver from cyanide pregnant solutions were carried out. And desorption test on D370 type resin followed, which showed that each technical index significantly exceeds that of 201 × 4 and 201 × 7 type res- ins.%对D 370型、201×4型和201×7型树脂从氰化贵液中吸附金、银的吸附容量以及选择性吸附能力进行了对比试验,并对载金D 370型树脂进行了解吸试验.其结果表明,D 370型树脂的各项技术指标,明显优于201×4型和201×7型树脂.

  6. Evaluation and application of anion exchange resins to measure groundwater uranium flux at a former uranium mill site.

    Science.gov (United States)

    Stucker, Valerie; Ranville, James; Newman, Mark; Peacock, Aaron; Cho, Jaehyun; Hatfield, Kirk

    2011-10-15

    Laboratory tests and a field validation experiment were performed to evaluate anion exchange resins for uranium sorption and desorption in order to develop a uranium passive flux meter (PFM). The mass of uranium sorbed to the resin and corresponding masses of alcohol tracers eluted over the duration of groundwater installation are then used to determine the groundwater and uranium contaminant fluxes. Laboratory based batch experiments were performed using Purolite A500, Dowex 21K and 21K XLT, Lewatit S6328 A resins and silver impregnated activated carbon to examine uranium sorption and extraction for each material. The Dowex resins had the highest uranium sorption, followed by Lewatit, Purolite and the activated carbon. Recoveries from all ion exchange resins were in the range of 94-99% for aqueous uranium in the environmentally relevant concentration range studied (0.01-200 ppb). Due to the lower price and well-characterized tracer capacity, Lewatit S6328 A was used for field-testing of PFMs at the DOE UMTRA site in Rifle, CO. The effect on the flux measurements of extractant (nitric acid)/resin ratio, and uranium loading were investigated. Higher cumulative uranium fluxes (as seen with concentrations>1 ug U/gram resin) yielded more homogeneous resin samples versus lower cumulative fluxes (uranium. Resin homogenization and larger volume extractions yield reproducible results for all levels of uranium fluxes. Although PFM design can be improved to measure flux and groundwater flow direction, the current methodology can be applied to uranium transport studies.

  7. Extraction of lactic acid from fermentation broth with anion exchange resin%阴离子交换树脂分离提取发酵液中的乳酸

    Institute of Scientific and Technical Information of China (English)

    迟国达; 王鹏; 徐伟; 黄臣勇

    2012-01-01

    The domestic anion exchange resin 315 was selected to separate lactic acid from the fermentation broth. Adsorption isotherm, kinetics, effect of dynamic adsorption and elution on lactic acid, acetic acid, pyruvic acid and citric acid were studied. Adsorption isotherm results showed that the Freundlich isotherm e- quation agreed well with the adsorption data of organic acids on anion exchange resin 315, and the characteris- tic parameter of this equation n 〉 1. It displayed that the adsorption process belonged to favorable adsorption. Besides, the adsorption kinetics of organic acids on anion exchange resin 315 was mainly controlled by liquid film diffusion, and it accorded well with the Boyd liquid film diffusion model. The optimum dynamic adsorp- tion and elution conditions were determined: adsorption flow-rate, 1.5 BV/h; pH 1.88 ; eluent, deionized water; elution flow-rate, 1 BV/h. Under these conditions, the lactic could be well separated from the fermen- tation broth to achieve the purpose of increasing the yield of lactic acid products and improving product' purity.%为提高乳酸产品收率和纯度,实验筛选得到国产315型阴离子交换树脂,用于分离提取发酵液中乳酸,并研究其对乳酸、乙酸、丙酮酸及柠檬酸的吸附等温线、吸附动力学和动态吸附及洗脱效果.吸附等温线结果表明,315型树脂对乳酸等有机酸的吸附等温线符合Freundlich方程,特征参数n〉1,属于优惠吸附.吸附动力学研究表明,液膜扩散是吸附过程的主要控制步骤,符合Boyd液膜扩散模型.动态吸附及洗脱实验结果表明,以1.5BV/h、pH1.88上柱吸附,再用1BV/h的去离子水洗脱,可实现发酵液中乳酸的良好分离.

  8. 21 CFR 177.1500 - Nylon resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Nylon resins. 177.1500 Section 177.1500 Food and... Repeated Use Food Contact Surfaces § 177.1500 Nylon resins. The nylon resins listed in paragraph (a) of... packaging food, subject to the provisions of this section: (a) The nylon resins are manufactured...

  9. 21 CFR 177.2440 - Polyethersulfone resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethersulfone resins. 177.2440 Section 177.2440... Components of Articles Intended for Repeated Use § 177.2440 Polyethersulfone resins. Polyethersulfone resins... the purpose of this section, polyethersulfone resins are: (1)...

  10. 21 CFR 177.1655 - Polysulfone resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polysulfone resins. 177.1655 Section 177.1655 Food... of Single and Repeated Use Food Contact Surfaces § 177.1655 Polysulfone resins. Polysulfone resins... purpose of this section, polysulfone resins are: (1)...

  11. 21 CFR 177.1585 - Polyestercarbonate resins.

    Science.gov (United States)

    2010-04-01

    .... Polyestercarbonate resins may be safely used as articles or components of articles intended for use in producing... chloride such that the finished resins are composed of 45 to 85 molepercent ester, of which up to 55 mole... the resins. (3) Residual methylene chloride levels in poly-ester-carbonate resins. Poly-ester...

  12. 21 CFR 178.3930 - Terpene resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Terpene resins. 178.3930 Section 178.3930 Food and... and Production Aids § 178.3930 Terpene resins. The terpene resins identified in paragraph (a) of this... the terpene resins identified in paragraph (b) of this section may be safely used as components...

  13. Indirect resin composites

    Directory of Open Access Journals (Sweden)

    Nandini Suresh

    2010-01-01

    Full Text Available Aesthetic dentistry continues to evolve through innovations in bonding agents, restorative materials, and conservative preparation techniques. The use of direct composite restoration in posterior teeth is limited to relatively small cavities due to polymerization stresses. Indirect composites offer an esthetic alternative to ceramics for posterior teeth. This review article focuses on the material aspect of the newer generation of composites. This review was based on a PubMed database search which we limited to peer-reviewed articles in English that were published between 1990 and 2010 in dental journals. The key words used were ′indirect resin composites,′ composite inlays,′ and ′fiber-reinforced composites.′

  14. Chromatography resin support

    Science.gov (United States)

    Dobos, James G.

    2002-01-01

    An apparatus and method of using an improved chromatography resin support is disclosed. The chromatography support platform is provided by a stainless steel hollow cylinder adapted for being inserted into a chromatography column. An exterior wall of the stainless steel cylinder defines a groove for carrying therein an "O"-ring. The upper surface of the stainless steel column is covered by a fine stainless steel mesh welded to the edges of the stainless steel cylinder. When placed upon a receiving ledge defined within a chromatography column, the "O"-ring provides a fluid tight seal with the inner edge wall of the chromatography cylinder. The stainless steel mesh supports the chromatography matrix and provides a back flushable support which is economical and simple to construct.

  15. Recovery of value-added fossil resin from El-Maghara coal

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, S.S.; Mostafa, S.I. [Central Metallurgical R and D Inst., Cairo (Egypt)

    2003-06-01

    El-Maghara coal was confirmed to contain a substantial amount of fossil resin intimately associated with its macerals. Macroscopic identification as well as physical diagnosis of solvent refined resinite material proved its particular significance and sufficient value to justify a fossil resin industry in Egypt. This resin has thermosetting properties superior to most synthetics resins available from petrochemicals. It could compete in the market as a chemical commodity in high-speed printing and high-performance adhesive applications. It could have also special values as a feedstock for high-density jet fuel after proper hydrogenation. The froth flotation technique was applied to recover this valuable material from El-Maghara ground coal. The solvent extraction method using commercial solvents was used to refine the resinite fraction collected as flotation concentrate. The variables affecting the flotation technique were studied. Characterization of refined resin was applied. (orig.)

  16. Contact allergy to epoxy resin

    DEFF Research Database (Denmark)

    Bangsgaard, Nannie; Thyssen, Jacob Pontoppidan; Menné, Torkil

    2012-01-01

    . Objectives. To evaluate the prevalence of contact allergy to epoxy resin monomer (diglycidyl ether of bisphenol A; MW 340) among patients with suspected contact dermatitis and relate this to occupation and work-related consequences. Patients/methods. The dataset comprised 20 808 consecutive dermatitis...... in an educational programme. Conclusion. The 1% prevalence of epoxy resin contact allergy is equivalent to reports from other countries. The high occurrence of epoxy resin exposure at work, and the limited use of protective measures, indicate that reinforcement of the law is required....

  17. Extraction of extracellular polymeric substances (EPS) from anaerobic granular sludges: comparison of chemical and physical extraction protocols

    NARCIS (Netherlands)

    Abzac, D' P.; Bordas, F.; Hullebusch, E.; Lens, P.N.L.; Guibaud, G.

    2010-01-01

    The characteristics of the extracellular polymeric substances (EPS) extracted with nine different extraction protocols from four different types of anaerobic granular sludge were studied. The efficiency of four physical (sonication, heating, cationic exchange resin (CER), and CER associated with son

  18. Extraction of extracellular polymeric substances (EPS) from anaerobic granular sludges: comparison of chemical and physical extraction protocols

    NARCIS (Netherlands)

    Abzac, D' P.; Bordas, F.; Hullebusch, E.; Lens, P.N.L.; Guibaud, G.

    2010-01-01

    The characteristics of the extracellular polymeric substances (EPS) extracted with nine different extraction protocols from four different types of anaerobic granular sludge were studied. The efficiency of four physical (sonication, heating, cationic exchange resin (CER), and CER associated with

  19. EPOXY RESIN TOUGHENED BY THERMOPLASTICS

    Institute of Scientific and Technical Information of China (English)

    FU Zengli; SUN Yishi

    1989-01-01

    Two kinds of tough ductile heatresisting thermoplastic, namely bisphenol A polysulfone (PSF) and polyethersulfone (PES) were used to toughen thermoset epoxy resin. A systematic study on the relationship between the molecular weight and the terminal group of the thermoplastic modifier and the fracture toughness of the modified resin was carried out. The morphology of PSF modified epoxy resin was surveyed. With the same kind of PSF the structure of the epoxy resin and the toughening effect of PSF was also investigated. The fractography of PSF, particle modified epoxy was examined in detail with SEM. The contribution of every possible energy absorption process has been discussed. Crack pinning mechanism seems to be the most important toughening mechanism for tough ductile thermoplastic PSF particle modified epoxy system.

  20. Bending characteristics of resin concretes

    Directory of Open Access Journals (Sweden)

    Ribeiro Maria Cristina Santos

    2003-01-01

    Full Text Available In this research work the influence of composition and curing conditions in bending strength of polyester and epoxy concrete is analyzed. Various mixtures of resin and aggregates were considered in view of an optimal combination. The Taguchi methodology was applied in order to reduce the number of tests, and in order to evaluate the influence of various parameters in concrete properties. This methodology is very useful for the planning of experiments. Test results, analyzed by this methodology, shown that the most significant factors affecting bending strength properties of resin concretes are the type of resin, resin content and charge content. An optimal formulation leading to a maximum bending strength was achieved in terms of material parameters.

  1. Bulk-Fill Resin Composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Havndrup-Pedersen, Cæcilie; Honoré, Daniel;

    2015-01-01

    the restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization...... for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and three low......-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low-viscosity bulk...

  2. Epoxy hydantoins as matrix resins

    Science.gov (United States)

    Weiss, J.

    1983-01-01

    Tensile strength and fracture toughness of castings of the hydantoin resins cured with methylenedianiline are significantly higher than MY 720 control castings. Water absorption of an ethyl, amyl hydantoin formulation is 2.1 percent at equilibrium and Tg's are about 160 C, approximately 15 deg below the final cure temperature. Two series of urethane and ester-extended hydantoin epoxy resins were synthesized to determine the effect of crosslink density and functional groups on properties. Castings cured with methylenedianiline or with hexahydrophthalic anhydride were made from these compounds and evaluated. The glass transition temperatures, tensile strengths and moduli, and fracture toughness values were all much lower than that of the simple hydantoin epoxy resins. Using a methylene bishydantoin epoxy with a more rigid structure gave brittle, low-energy fractures, while a more flexible, ethoxy-extended hydantoin epoxy resin gave a very low Tg.

  3. Karakteristik Komposit Resin Berkemampuan Mengalir

    Directory of Open Access Journals (Sweden)

    Bambang Irawan

    2015-10-01

    Full Text Available The use of resin composites as posterior restoratives has markedly increased over the past decade. The patients demand for better esthetics, concerns related to possible mercury toxicity from amalgam and improvements in resin composite materials have significantly contributed the popularity of these materials. Early problems related to composites included excessive wear, less of anatomic form, post operative sensitivity, secondary caries and marginal leakage. Marginal adaptation still remains an unavoidable problem for composite restoration, especially at the gingival wall of cervical or Class II restoration. In an attempt to improve marginal sealing, many techniques and lining materials have been designed. To reduce stress generated by polymerization shrinkage, applying and curing of resin composites in layers is often recommended. Using a thick adhesive layer or low-viscosity resin may, due to its elastic properties, serve as a flexible intermediate layer and compensate for the polymerization stress created in resin composite. Flowable composites were created by retaining the same small particle size of traditional hybrid composite but reducing the filler content and allowing the increased resin to reduce the viscosity of the mixture. Flowable composites were introduced in 1996 as liners, fissure sealants and also in tunnel preparations. They have been suggested for Class I, II, III and V cavity restorations, preventive resin restorations and composite, porcelain and amalgam repairing. Their usage as a liner under high filled resins in posterior restorations has been shown to improve the adaptation of composites and effectively achieve clinically acceptable results. This article attempts to give a broad characteristics of different types of flowable composites. 

  4. Karakteristik Komposit Resin Berkemampuan Mengalir

    OpenAIRE

    Bambang Irawan

    2015-01-01

    The use of resin composites as posterior restoratives has markedly increased over the past decade. The patients demand for better esthetics, concerns related to possible mercury toxicity from amalgam and improvements in resin composite materials have significantly contributed the popularity of these materials. Early problems related to composites included excessive wear, less of anatomic form, post operative sensitivity, secondary caries and marginal leakage. Marginal adaptation still remains...

  5. New Low Cost Resin Systems

    Science.gov (United States)

    2006-05-31

    DGEBA ). 30 % of the epoxy groups of RDGE were reacted with the dihydroxyl acid and resulted 3.2 wt% phosphorous and a new epoxide equivalent weight...of 207. Adducts were also made with DGEBA and the dihydroxyl phosphorous based acid but resulted in a substantial increased viscosity and therefore...70 wt% with a standard DGEBA resin, this material accelerated the epoxy reaction too much to make a VaRTM processable resin. Due to the processing

  6. Separation of rare earth by column chromatography using organic resins XAD/DEPHA

    Energy Technology Data Exchange (ETDEWEB)

    Zini, J.; Ferreira, J.C.; Bergamaschi, V.S.; Santos, I.; Carvalho, F.M.S., E-mail: jcferrei@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (CCCH/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Celulas a Combustivel e Hidrogenio

    2013-07-01

    The designation of light and heavy rare earth was used the fractionation used in separation processes. In this study the process of separation of rare earth, in groups, by chromatographic column consisting in fixing of cations these elements in an organic resin Amberlite XAD16 functionalized with the extracting agent DEPHA and another portion functionalized with a mixture of extractors DEPHA/TOP. The preparation of these resins was performed in two forms, one directly as the extracting agent to the resin and the other to be used in ethyl alcohol. Conditioned resins were introduced in chromatographic columns in separation of groups, light and heavy, using a standard solution of cerium nitrate and standard solution of holmium nitrate groups to represent light and heavy respectively. The characterization technique used to identify the rare earth elements was Spectrometry X-Ray Fluorescence (XRF). The results using the technique of chromatography were satisfactory, obtaining 100% separation of the elements. (author)

  7. Separation and Purification of Two Flavone Glucuronides from Erigeron multiradiatus (Lindl. Benth with Macroporous Resins

    Directory of Open Access Journals (Sweden)

    Zhi-feng Zhang

    2009-01-01

    Full Text Available Scutellarein-7-O-β-D-glucuronide (SG and apigenin-7-O-β-D-glucuronide (AG are two major bioactive constituents with known pharmacological effects in Erigeron multiradiatus. In this study, a simple method for preparative separation of the two flavone glucuronides was established with macroporous resins. The performance and adsorption characteristics of eight macroporous resins including AB-8, HPD100, HPD450, HPD600, D100, D101, D141, and D160 have been evaluated. The results confirmed that D141 resin offered the best adsorption and desorption capacities and the highest desorption ratio for the two glucuronides among the tested resins. Sorption isotherms were constructed for D141 resin under optimal ethanol conditions and fitted well to the Freundlich and Langmuir models (R2>0.95. Dynamic adsorption and desorption tests was performed on column packed with D141 resin. After one-run treatment with D141 resin, the two-constituent content in the final product was increased from 2.14% and 1.34 % in the crude extract of Erigeron multiradiatus to 24.63% and 18.42% in the final products with the recoveries of 82.5% and 85.4%, respectively. The preparative separation of SG and AG can be easily and effectively achieved via adsorption and desorption on D141 resin, and the method developed can be referenced for large-scale separation and purification of flavone glucuronides from herbal raw materials.

  8. Effect of proanthocyanidin incorporation into dental adhesive resin on resin-dentine bond strength.

    Science.gov (United States)

    Epasinghe, D J; Yiu, C K Y; Burrow, M F; Tay, F R; King, N M

    2012-03-01

    This study evaluated the effect of proanthocyanidin (PA) incorporation into experimental dental adhesives on resin-dentine bond strength. Four experimental hydrophilic adhesives containing different PA concentrations were prepared by combining 50wt% resin comonomer mixtures with 50wt% ethanol. Proanthocyanidin was added to the ethanol-solvated resin to yield three adhesives with PA concentrations of 1.0, 2.0 and 3.0wt%, respectively. A PA-free adhesive served as the control. Flat dentine surfaces from 40 extracted third molars were etched with 32% phosphoric acid. The specimens were randomly assigned to one of the four adhesive groups. Two layers of one of the four experimental adhesives were applied to the etched dentine and light-cured for 20s. Composite build-ups were performed using Filtek Z250 (3M ESPE). After storage in distilled water at 37°C for 24h, twenty-four bonded teeth were sectioned into 0.9 mm×0.9 mm beams and stressed to failure under tension for bond strength testing. Bond strength data were evaluated by one-way ANOVA and Tukey's test (α=0.05). Interfacial nanoleakage was examined in the remaining teeth using a field-emission scanning electron microscope and analysed using the Chi-square test (α=0.05). No significant difference in bond strength was found amongst PA-free, 1% and 2% PA adhesives. However, incorporation of 3% PA into the adhesive significantly lowered bond strength as demonstrated by a greater number of adhesive failures and more extensive nanoleakage along the bonded interface. Incorporation of 2% proanthocyanidin into dental adhesives has no adverse effect on dentine bond strength. The addition of proanthocyanidin to an experimental adhesive has no adverse effect on the immediate resin-dentine bond strength when the concentration of proanthocyanidin in the adhesive is less than or equal to 2%. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Treatment of a Vertical Root Fracture Using Dual-Curing Resin Cement: A Case Report

    Directory of Open Access Journals (Sweden)

    Nima Moradi Majd

    2012-01-01

    Full Text Available Introduction. Vertical root fracture (VRF is one of the most frustrating complications of root canal treatment. The prognosis of the root with VRF is poor therefore tooth extraction and root amputation are usually the only treatment options. However, bonding of the fracture line with adhesive resin cement during the intentional replantation procedure was recently suggested as an alternative to tooth extraction. Methods. A vertically fractured left maxillary incisor was carefully extracted, fracture line was treated with adhesive resin cement, a retrograde cavity was produced and filled with calcium-enriched mixture (CEM cement, and tooth was replanted. Results. After 12 months the tooth was asymptomatic. The size of periapical radiolucency was noticeably reduced and there was no clinical sign of ankylosis. Conclusion. Using adhesive resin cement to bond the fracture lines extraorally in roots with VRF and intentional replantation of the reconstructed teeth could be considered as an alternative to tooth extraction, especially for anterior teeth.

  10. Gas Chromatography Analysis of Resin and Fatty Acids from Laboratory Generated Bleach Plant Effluents

    Institute of Scientific and Technical Information of China (English)

    Chhaya Sharma; S. Mohanty; S. Kumar; N.J. Rao

    2007-01-01

    Laboratory generated spent bleached liquor from the chlorination, caustic extraction stage of mixed wood kraft pulp processing has been analyzed both qualitatively and quantitatively for various resin & fatty acids by using GC. A number of resin acids,saturated and unsaturated fatty acids, chloro fatty and resin acid have been detected and their concentrations are estimated. The results are compared with results on different agriculture residue/hardwood pulps, which were reported earlier. The concentrations of various compounds detected have also been compared with their reported LC50 values.

  11. PURIFICATION OF FLAVONES OF GINKGO LEAVES BY ADSORPTION HZ-841 RESIN

    Institute of Scientific and Technical Information of China (English)

    ZENG Hui; ZHOU Xiaohua; LI Duanhua

    2004-01-01

    The purification process of total flavones of ginkgo leaves by resin HZ-841 from ethanol extract was studied. First, the total flavone was extracted from the defatted powder of ginkgo L. biloba leaves. Effects of solvents and operation conditions were examined to get a relative high yield and purity in this step. The crude extract was further purified by resin HZ-841. Both adsorption and elution process were studied to obtain an optimized conditions, i.e., pH, flow rate, concentration. A yellow powder was obtained, of which 37.3% was flavones, obviously higher than the basic international standard of 24%.

  12. Elution study of unreacted Bis-GMA, TEGDMA, UDMA, and Bis-EMA from light-cured dental resins and resin composites using HPLC.

    Science.gov (United States)

    Sideridou, Irini D; Achilias, Dimitris S

    2005-07-01

    In the present work the elution of residual monomers from light-cured dental resins and resin composites into a 75% ethanol:water solution was studied using High-Performance Liquid Chromatography (HPLC). The resins studied were made by light-curing of bisphenol A glycol dimethacrylate (Bis-GMA), triethylene glycol dimethacrylate (TEGDMA), urethane dimethacrylate (UDMA), ethoxylated bisphenol A glycol dimethacrylate [Bis-EMA(4)] and mixtures of these monomers. The resin composites were made from two commercial light-cured restorative materials (Z100 MP and Filtek Z250), the resin matrix of which is based on copolymers of these monomers. The effect of the curing time on the amount of monomers eluted was investigated. The concentration of the extractable monomers was determined at several immersion periods from 3 h to 30 days. For all the materials studied, it was observed that the chemical structure of the monomers used for the preparation of the resins, which defines the chemical and physical structure of the corresponding resin, directly affects the amount of eluted monomers, as well as the time needed for the elution of this amount. In the case of composites, it seems that the elution process it is not influenced by the presence of filler. Copyright 2005 Wiley Periodicals, Inc.

  13. 酸石榴汁红色素的树脂吸附及石榴提取物的抗氧化作用研究%Study on Absorption of Red Pigment from Pomegranate Juice with Resin and Antioxidant Activity of Pomegranate Extracts

    Institute of Scientific and Technical Information of China (English)

    朱洁; 陈旭红; 李美瑛; 丁瑞

    2011-01-01

    This article studied the absorption of red pigment from pomegranate juice with resins and antioxidant activity of pomegranate extracts. The results showed that HPD-300 was the best resin for absorption of red pigment of pomegranate juice.Compared with Vc, the DPPH · scavenging ability of the red pigment of pomegranate juice was 91. 48 % at the concentration of 2 mg/mL. The results showed that the red pigment of pomegranate juice has better antioxidant activity.%研究了7种吸附树脂对酸石榴汁红色素的吸附,及酸石榴各部分提取物对DPPH(1,1-Diphenyl-2-picrylhydrazyl;1,1-二苯基-2-苦基肼自由基)的清除作用,并且将提取出的酸石榴汁红色素添加到化妆品配方中,探讨了该配方对于延缓衰老的功效.实验结果表明:HPD-300对酸石榴汁红色素的吸附效果最好;2.0 mg/mL的酸石榴汁红色素对DPPH的清除率达91,48%,表明酸石榴汁红色素具有良好的抗氧化活性,为其在化妆品行业的应用提供依据.

  14. Repeated use of ion-exchange resin membranes in calcareous soils

    Science.gov (United States)

    Sherrod, S.K.; Belnap, J.; Miller, M.E.

    2003-01-01

    This study compared the consistency of nutrient extraction among repeated cycles of ion-exchange resin membrane use. Two sandy calcareous soils and different equilibration temperatures were tested. No single nutrient retained consistent values from cycle to cycle in all treatments, although both soil source and temperature conferred some influence. It was concluded that the most conservative use of resin membranes is single-use.

  15. Adsorption of Chromium(VI) from Aqueous Solutions by Coffee Polyphenol-Formaldehyde/Acetaldehyde Resins

    OpenAIRE

    2013-01-01

    Removal of chromium(VI) from wastewater is essential as it is toxic. Thus, removal of chromium(VI) was performed using coffee polyphenol-formaldehyde/acetaldehyde resins as adsorbents. Adsorbent resins were prepared by condensation of decaffeinated coffee powder with formaldehyde/acetaldehyde and used for the removal of Cr(VI) ions from aqueous solutions. A simple and sensitive solid phase extraction procedure was applied for the determination of chromium at trace levels by spectroscopic meth...

  16. Antimicrobial and Antioxidant Activities of Resins and Essential Oil From Pine (Pinus merkusii, Pinuso ocarpa, Pinus insularis and Agathis (Agathis loranthifolia

    Directory of Open Access Journals (Sweden)

    Mardho Tillah

    2017-04-01

    Full Text Available The most common human pathogen that colonizes in a third of healthy people around the world are Staphylococcus aureus, and one of the materials allegedly able to overcome the pathogen is resin. Resin has been used in folk medicine for thousands of years to treat diseases. The antimicrobial activity of natural resins can be associated with a variety of organic compounds contained in them such as diterpenoids and triterpenoids. This research aimed to explore the antibacterial and antioxidant activities of Pinus merkusii, P. oocarpa, P. insularis, Agathis loranthifolia resins and essential oil. Resin was separated by distillation process to get essential oil and the residue was extracted using n-hexane, ethyl acetate (EtOAc, and methanol (MeOH. Antioxidant activity was performed by DPPH (1,1diphenyl-2-picryl hydrazyl radical scavenging method. The antibacterial activity of resins and essential oil of the samples determined using the disc diffusion method against Staphylococcus aureus and Escherichia coli. The results showed that the yield of resin extract was ranging from 8.44 % to 95.56%. All extracts and essential oil could not inhibit E coli growth but inhibit the S. aureus growth. This experiment concluded that resin n-hexane extract from P.oocarpa was the most potent as antibacterial activity against S. aureus. All of the samples used had less potential antioxidant activity compared to positive control ascorbic acid. Result of this study show that pine resin from Indonesia has potential as an antibacterial agent. 

  17. Selective flotation of fossil resin from Western coal. Final report, July 1, 1990--May 25, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, G.F.; Miller, J.D.

    1992-05-25

    The proof-of-concept test program was designed to clarify a number of concerns that have been raised by coal companies who own the valuable resin resource. First, from laboratory bench-scale flotation experiments, a froth product from cleaner flotation containing more than 80% hexane-extractable resin at higher than 80% recovery can be produced. Pilot-plant testing was initiated to demonstrate the selective flotation of fossil resin and to establish a better confidence level in the new technology. Second, pilot-plant testing was designed to evaluate the effect and impact of random variation in slurry solids concentration and feed grade on this new selective fossil resin flotation technology. The flotation performance obtained under these industrial conditions is more realistic for process evaluation. Third, more accurate operating cost data was to be obtained for economic analysis. Fourth, sufficient quantities of the fossil resin concentrate were to be produced from the test program for evaluation by potential industrial users. Fifth, and finally, optimum levels for the operating variables were to be established. Such information was required for eventual scale-up and design of a fossil resin flotation plant. The pilot-plant proof-of-concept testing of selective resinate flotation has demonstrated that: (1) technically, the new flotation technologies discovered at the University of Utah and then improved upon by Advanced Processing Technologies, Inc. provide a highly efficient means to selectively recover fossil resin from coal. The proof-of-concept continuous flotation circuit (about 0.1 tph) resulted in fossil resin recovery with the same separation efficiency as was obtained from laboratory bench-scale testing (more than 80% recovery at about 80% concentrate grade); and (2) economically, the selective flotation process has been shown to be sufficiently profitable to justify the development of a fossil resin industry based on this new flotation process.

  18. Fourier Transform Near-infrared Spectroscopy of PE Resin used in Analysis of N-hexane Extract%傅里叶变换近红外光谱法应用于聚乙烯树脂的正己烷提取物分析

    Institute of Scientific and Technical Information of China (English)

    王豪; 张樱; 陈平; 邬蓓蕾; 林振兴

    2012-01-01

    采用偏最小二乘法(PLS),建立了傅里叶变换近红外漫反射光谱法检测聚乙烯树脂正己烷提取物的数学模型.分析过程选择了最佳光谱预处理方法、谱区范围及主因子数,并使用内部交叉验证对模型进行验证.实验结果表明,当选择最小-最大归一化的光谱预处理方法,谱区范围7 501.8 ~6 097.9 cm-1和5 025.6 ~4 597.5 cm-1,主因子数8时定量模型的准确度最好,决定系数(R2)和均方差(RMSECV)分别为0.988和0.416,近红外测定值与标准方法测定值基本一致.对297种牌号共1 251个进口聚乙烯树脂正己烷提取物项目的普查结果表明,聚乙烯树脂正己烷提取物项目的总体安全性较低,属于进口聚乙烯需重点关注的安全卫生项目.%Using partial least squares (PLS) regression to establish mathematical model of n-hexane extract in polyethylene resin by Fourier transform near-infrared spectroscopy. The best spectral pretreatment method, spectral area and main factor number were chose and used internal cross-validation to verify the model in the analysis process. It was found that the result determined by near-infrared spectroscopy coincided with that decided by standard method, when the spectrum pretreatment method was minimum-maximum normalized, spectral range were 7 501. 8 cm-1 ~6 097. 9 cm-1 and 5 025. 6 cm-1~4 597. 5 cm-1, and the main factor number was eight. The correlation coefficients (R2 ) and root-mean-square error of cross-validation were 0. 988 and 0. 416 respectively. The survey to n-hexane extract in 1 251 imports polyethylene resin of 297 kinds of grades showed that the item was lower than the overall security, and which should be focused on.

  19. Resin-infiltrated-dentine--a FE-ESEM microscopy investigation.

    Science.gov (United States)

    Eick, J D; Dusevich, V M; de Wet, F A; van der Vyver, P J

    2004-09-01

    The formation of a hybrid layer is essential for bonding of dental composites to dentine. The objective of this study was to examine the effects of various etchants/conditioners and dentine bonding systems on dentine surfaces utilising a Field Emission Environmental SEM (FE-ESEM). Twenty one, freshly extracted human molar teeth were utilised. Dentine without resin application was initially observed both wet and dried in the following conditions: (1) fractured surface, (2) smear layer, and (3) smear layer removed with 37% phosphoric acid. Resin infiltration into dentine was then studied after applying Scotchbond 1, Optibond Solo, Prime & Bond NT, or Prompt L-Pop systems. Scotchbond 1, Optibond Solo, and Prime & Bond NT resins penetrated the dentine tubules and created hybrid layers; although, in some cases Prime & Bond NT only created a partially filled hybrid layer. No polymerised resin or hybrid layer was observed for Prompt L-Pop. The FE-ESEM permitted observation of specimens at near in-vivo wet conditions.

  20. THE SYNTHESIS OF MODIFIED DIPHENYL OXIDE RESIN

    Institute of Scientific and Technical Information of China (English)

    MAOMingfei; LIUZhifang; 等

    2002-01-01

    Modified diphenyl oxide resin was synthesized by co-polymerization of unsaturated acid and diphenyl oxide derivants.And then modified bismaleimide resin and expoxide linear phenolic resin were added into modified diphenyl oxide resin to co-polymerized and modify once more.The system was applied in composites.Their properties wrer investigated and found that they met the requirements as a heat-resisting adhesive.

  1. The effect of flowable and dual-cure resin composite liners on gingival microleakage of posterior resin composites

    Directory of Open Access Journals (Sweden)

    Shirani F.

    2008-11-01

    Full Text Available "nBackground and Aim: Microleakage has been always a major concern in restorative dentistry. The curing contraction of composites still presents a problem with controlling microleakage and postoperative sensitivity. The aim of this study was to investigate the effect of flowable and dual-cure resin composite liners on gingival microleakage of packable resin composite restorations. "nMaterials and Methods: Sixty Class II cavities with cervical margins 1 mm below the CEJ were prepared in 30 extracted human molars. The teeth were randomly divided into five groups of 12 each. In control group, each tooth was restored incrementally with Tetric Ceram composite without applying any liner. In the second and forth groups, flowable materials- Tetric Flow and dual-cure composite resin cement Relay X ARC were placed respectively as a 1-mm thick gingival increment and cured before the resin composite restoration, whereas, in the third and fifth groups liners were cured with the first increment of packable composite.The restored teeth were stored for one week in distilled water at 370C, and thermocycled between 50C and 550C, sealed with nail varnish except the tooth - composite interface in cervical restoration margins and immersed in 2% basic fuchsin for 24 hours. Dye penetration was evaluated using a stereomicroscope with 28x magnification. The data were analyzed by Kruskal-Wallis and Mann-Whitney U-tests with p<0.05 as the level of significance. "nResults: The results of this study indicated that there were significant statistical differences between control - cured flowable liner, control-flowable liner without separately curing, control-cured dual cure composite resin cement groups.However there were no significant differences between dual-cure composite resin cement without separately curing-control,cured flowable liner-cured dual cure composite resin cement, flowable liner without separately curing-dual cure composite resin cement without separately

  2. 21 CFR 872.3140 - Resin applicator.

    Science.gov (United States)

    2010-04-01

    ... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3140 Resin applicator. (a) Identification. A resin applicator is a brushlike device intended for use in spreading dental resin on a tooth during application of tooth shade material. (b) Classification. Class I (general controls). The device is exempt from...

  3. Method of removing contaminants from plastic resins

    Science.gov (United States)

    Bohnert,George W.; Hand,Thomas E.; Delaurentiis,Gary M.

    2007-08-07

    A method for removing contaminants from synthetic resin material containers using a first organic solvent system and a second carbon dioxide system. The organic solvent is utilized for removing the contaminants from the synthetic resin material and the carbon dioxide is used to separate any residual organic solvent from the synthetic resin material.

  4. Method for removing contaminants from plastic resin

    Science.gov (United States)

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    2008-12-30

    A method for removing contaminants from synthetic resin material containers using a first organic solvent system and a second carbon dioxide system. The organic solvent is utilized for removing the contaminants from the synthetic resin material and the carbon dioxide is used to separate any residual organic solvent from the synthetic resin material.

  5. 21 CFR 177.1595 - Polyetherimide resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyetherimide resin. 177.1595 Section 177.1595... Components of Single and Repeated Use Food Contact Surfaces § 177.1595 Polyetherimide resin. The polyetherimide resin identified in this section may be safely used as an article or component of an...

  6. 21 CFR 177.1556 - Polyaryletherketone resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyaryletherketone resins. 177.1556 Section 177... Components of Single and Repeated Use Food Contact Surfaces § 177.1556 Polyaryletherketone resins. The poly...) resins (CAS Reg. No. 55088-54-5 and CAS Reg. No. 60015-05-6 and commonly referred to...

  7. 21 CFR 177.1555 - Polyarylate resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyarylate resins. 177.1555 Section 177.1555 Food... of Single and Repeated Use Food Contact Surfaces § 177.1555 Polyarylate resins. Polyarylate resins... contact with food in accordance with the following prescribed conditions: (a) Identity. Polyarylate...

  8. 21 CFR 177.1560 - Polyarylsulfone resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyarylsulfone resins. 177.1560 Section 177.1560... Components of Single and Repeated Use Food Contact Surfaces § 177.1560 Polyarylsulfone resins. Polyarylsulfone resins (CAS Reg. No. 79293-56-4) may be safely used as articles or components of articles...

  9. 40 CFR 721.9495 - Acrylosilane resins.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Acrylosilane resins. 721.9495 Section... Substances § 721.9495 Acrylosilane resins. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified as acrylosilane resins (PMNs P-95-1024/1040) are...

  10. 21 CFR 172.280 - Terpene resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Terpene resin. 172.280 Section 172.280 Food and..., Films and Related Substances § 172.280 Terpene resin. The food additive terpene resin may be safely used... polymer obtained by polymerizing terpene hydrocarbons derived from wood. It has a softening point of...

  11. 21 CFR 177.1680 - Polyurethane resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyurethane resins. 177.1680 Section 177.1680 Food... of Single and Repeated Use Food Contact Surfaces § 177.1680 Polyurethane resins. The polyurethane...) For the purpose of this section, polyurethane resins are those produced when one or more of...

  12. Comparison of Shear Bond Strength of RMGI and Composite Resin for Orthodontic Bracket Bonding.

    Science.gov (United States)

    Yassaei, Soghra; Davari, Abdolrahim; Goldani Moghadam, Mahjobeh; Kamaei, Ahmad

    2014-05-01

    The aim of this study was to compare the shear bond strength (SBS) of resin modified glass ionomer (RMGI) and composite resin for bonding metal and ceramic brackets. Eighty-eight human premolars extracted for orthodontic purposes were divided into 4 groups (n=22). In groups 1 and 2, 22 metal and ceramic brackets were bonded using composite resin (Transbond XT), respectively. Twenty-two metal and ceramic brackets in groups 3 and 4, respectively were bonded using RMGI (Fuji Ortho LC, Japan). After photo polymerization, the teeth were stored in water and thermocycled (500 cycles between 5° and 55°). The SBS value of each sample was determined using a Universal Testing Machine. The amount of residual adhesive remaining on each tooth was evaluated under a stereomicroscope. Statistical analyses were done using two-way ANOVA. RMGI bonded brackets had significantly lower SBS value compared to composite resin bonded groups. No statistically significant difference was observed between metal and ceramic brackets bonded with either the RMGI or composite resin. The comparison of the adhesive remnant index (ARI) scores between the groups indicated that the bracket failure mode was significantly different among groups (Pcomposite resin. RMGIs have significantly lower SBS compared to composite resin for orthodontic bonding purposes; however the provided SBS is still within the clinically acceptable range.

  13. Production of renewable phenolic resins by thermochemical conversion of biomass: A review

    Energy Technology Data Exchange (ETDEWEB)

    Effendi, A.; Gerhauser, H.; Bridgwater, A.V. [Bio-Energy Research Group, Aston University, Birmingham B4 7ET (United Kingdom)

    2008-10-15

    This review covers the production and utilisation of liquids from the thermal processing of biomass and related materials to substitute for synthetic phenol and formaldehyde in phenol formaldehyde resins. These resins are primarily employed in the manufacture of wood panels such as plywood, MDF, particle-board and OSB. The most important thermal conversion methods for this purpose are fast pyrolysis and vacuum pyrolysis, pressure liquefaction and phenolysis. Many feedstocks have been tested for their suitability as sources of phenolics including hard and softwoods, bark and residual lignins. Resins have been prepared utilising either the whole liquid product, or a phenolics enriched fraction obtained after fractional condensation or further processing, such as solvent extraction. None of the phenolics production and fractionation techniques covered in this review are believed to allow substitution of 100% of the phenol content of the resin without impacting its effectiveness compared to commercial formulations based on petroleum derived phenol. This survey shows that considerable progress has been made towards reaching the goal of a price competitive renewable resin, but that further research is required to meet the twin challenges of low renewable resin cost and satisfactory quality requirements. Particular areas of concern are wood panel press times, variability of renewable resin properties, odour, lack of reactive sites compared to phenol and potential for increased emissions of volatile organic compounds. (author)

  14. Biological activity of some naturally occurring resins, gums and pigments against in vitro LDL oxidation.

    Science.gov (United States)

    Andrikopoulos, Nikolaos K; Kaliora, Andriana C; Assimopoulou, Andreana N; Papapeorgiou, Vassilios P

    2003-05-01

    Naturally occurring gums and resins with beneficial pharmaceutical and nutraceutical properties were tested for their possible protective effect against copper-induced LDL oxidation in vitro. Chiosmastic gum (CMG) (Pistacia lentiscus var. Chia resin) was the most effective in protecting human LDL from oxidation. The minimum and maximum doses for the saturation phenomena of inhibition of LDL oxidation were 2.5 mg and 50 mg CMG (75.3% and 99.9%, respectively). The methanol/water extract of CMG was the most effective compared with other solvent combinations. CMG when fractionated in order to determine a structure-activity relationship showed that the total mastic essential oil, collofonium-like residue and acidic fractions of CMG exhibited a high protective activity ranging from 65.0% to 77.8%. The other natural gums and resins (CMG resin 'liquid collection', P. terebinthus var. Chia resin, dammar resin, acacia gum, tragacanth gum, storax gum) also tested as above, showed 27.0%-78.8% of the maximum LDL protection. The other naturally occurring substances, i.e. triterpenes (amyrin, oleanolic acid, ursolic acid, lupeol, 18-a-glycyrrhetinic acid) and hydroxynaphthoquinones (naphthazarin, shikonin and alkannin) showed 53.5%-78.8% and 27.0%-64.1% LDL protective activity, respectively. The combination effects (68.7%-76.2% LDL protection) of ursolic-, oleanolic- and ursodeoxycholic- acids were almost equal to the effect (75.3%) of the CMG extract in comparable doses.

  15. Use of rhodamine WT with XAD-7 resin for determining groundwater flow paths

    Science.gov (United States)

    Close, Murray E.; Stanton, Greg J.; Pang, Liping

    2002-06-01

    A passive sampling system for use with rhodamine WT (RWT) in groundwater tracing experiments was developed to assist in the characterisation of groundwater flow paths. Amberlite XAD-7 resin was found to be suitable for adsorption of RWT, which can then be extracted using an ethanol/water mix and analysed fluorometrically. Batch and column experiments showed that XAD-7 resin has a high RWT capacity. The adsorption was slightly dependent on pH, but was always above 75% under batch conditions. The resin had a high percentage mass recovery at flow velocities around 1.5 m/day, but this decreased with increasing flow velocities. Desorption of RWT off the resin in water is dependent on the flow velocity of water and the time after the peak RWT has passed. The mass of RWT extracted from the resin bags correlated very well with both the RWT mass flux in the water and the peak concentrations observed in the monitoring wells in a field experiment. The results of resin bags were reproducible in the field with a mean coefficient of variation equal to 16%. This method has been successfully applied to two field situations with different flow velocities to indicate groundwater flow paths.

  16. Sorption of Uranium Ions from Their Aqueous Solution by Resins Containing Nanomagnetite Particles

    Directory of Open Access Journals (Sweden)

    Mahmoud O. Abd El-Magied

    2016-01-01

    Full Text Available Magnetic amine resins composed of nanomagnetite (Fe3O4 core and glycidyl methacrylate (GMA/N,N′-methylenebisacrylamide (MBA shell were prepared by suspension polymerization of glycidyl methacrylate with N,N′-methylenebisacrylamide in the presence of nanomagnetite particles and immobilized with different amine ligands. These resins showed good magnetic properties and could be easily retrieved from their suspensions using an external magnetic field. Adsorption behaviors of uranium ions on the prepared resins were studied. Maximum sorption capacities of uranium ions on R-1 and R-2 were found to be 92 and 158 mg/g. Uranium was extracted successfully from three granite samples collected from Gabal Gattar pluton, North Eastern Desert, Egypt. The studied resins showed good durability and regeneration using HNO3.

  17. Occupational exposure to epoxy resins

    NARCIS (Netherlands)

    Terwoert, J.; Kersting, K.

    2014-01-01

    Products based on epoxy resins as a binder have become popular in various settings, among which the construction industry and in windmill blade production, as a result of their excellent technical properties. However, due to the same properties epoxy products are a notorious cause of allergic skin d

  18. Stochastic resin transfer molding process

    CERN Document Server

    Park, M

    2016-01-01

    We consider one-dimensional and two-dimensional models of stochastic resin transfer molding process, which are formulated as random moving boundary problems. We study their properties, analytically in the one-dimensional case and numerically in the two-dimensional case. We show how variability of time to fill depends on correlation lengths and smoothness of a random permeability field.

  19. Occupational exposure to epoxy resins

    NARCIS (Netherlands)

    Terwoert, J.; Kersting, K.

    2014-01-01

    Products based on epoxy resins as a binder have become popular in various settings, among which the construction industry and in windmill blade production, as a result of their excellent technical properties. However, due to the same properties epoxy products are a notorious cause of allergic skin

  20. [Epoxy resin systems and contact dermatitis].

    Science.gov (United States)

    Pietranek, Jolanta Eliza

    2007-01-01

    Contact dermatitis is the major chronic skin disease that represents a global health problem. Its prevalence has been significant increasing in the latest decades. Contact dermatitis substantially alters the social life of patients and affects their work productivity. Epoxy resin systems are a frequent cause of occupational allergic contact dermatitis. Epoxy resins have an extremely wide range of commercial applications. Epoxy resin systems include combinations of epoxy monomers, hardeners, reactive diluents, and/or a vast array of other additives. In occupational settings, sensitization occurs not only to resins, but also to hardeners and reactive diluents. In this article adverse effects of epoxy resin systems are discussed.

  1. A review on solid phase extraction of actinides and lanthanides with amide based extractants.

    Science.gov (United States)

    Ansari, Seraj A; Mohapatra, Prasanta K

    2017-05-26

    Solid phase extraction is gaining attention from separation scientists due to its high chromatographic utility. Though both grafted and impregnated forms of solid phase extraction resins are popular, the later is easy to make by impregnating a given organic extractant on to an inert solid support. Solid phase extraction on an impregnated support, also known as extraction chromatography, combines the advantages of liquid-liquid extraction and the ion exchange chromatography methods. On the flip side, the impregnated extraction chromatographic resins are less stable against leaching out of the organic extractant from the pores of the support material. Grafted resins, on the other hand, have a higher stability, which allows their prolong use. The goal of this article is a brief literature review on reported actinide and lanthanide separation methods based on solid phase extractants of both the types, i.e., (i) ligand impregnation on the solid support or (ii) ligand functionalized polymers (chemically bonded resins). Though the literature survey reveals an enormous volume of studies on the extraction chromatographic separation of actinides and lanthanides using several extractants, the focus of the present article is limited to the work carried out with amide based ligands, viz. monoamides, diamides and diglycolamides. The emphasis will be on reported applied experimental results rather than on data pertaining fundamental metal complexation. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. [Dimensional accuracy of microwave-cured denture base resin].

    Science.gov (United States)

    Uchida, K; Okamoto, F; Ogata, K; Sato, T

    1989-02-01

    Recently, microwave-cured denture base resin was developed, and the resin solved the problem of internal porosity which had been generated by curing the conventional denture base resins with microwave irradiation. In this study, the dimensional accuracy of microwave-cured denture base resin was compared with that of other denture base resins, such as pour-type resin, heat-cured resin and heat-shock resin. From the experiment, the following results were obtained. 1. Dimensional accuracy of microwave-cured denture base resin was better than that of heat-cured resin and heat-shock resin, and was similar to that of pour-type resin. 2. Dimensional accuracy of microwave-cured denture base resin by slow cooling method and rapid cooling method was almost the same. Those findings suggest that microwave-cured denture base resin is valuable in clinic.

  3. Regional bond strengths of adhesive resins to pulp chamber dentin.

    Science.gov (United States)

    Belli, S; Zhang, Y; Pereira, P N; Ozer, F; Pashley, D H

    2001-08-01

    Microleakage of oral microorganisms, which can occur due to the lack of sealing ability of permanent restorative materials, may cause failure of root canal treatments. Although a great deal of research has been done on sealing enamel and coronal dentin with resins, little research has been done on the adhesion of resins to the walls of pulp chambers. The purpose of this study was to evaluate regional bond strengths of two adhesive systems to the walls of pulp chambers. A section was made horizontally through the middle of the pulp chamber of extracted human third molars to divide the chamber into upper and lower halves. The pulp tissue was removed and the tooth segments were then divided into treatment subgroups. The pulp chambers were bonded with C&B Metabond (Parkell) or One-Step (Bisco), with or without 5% NaOCI pretreatment. The microtensile bond strengths of these resins to four different pulp chamber regions (bottom, wall, roof, and pulp horn areas) were then measured using an Instron machine. The data were expressed in MPa and were analyzed by a three-way ANOVA. Statistically significant differences were found among the test groups (p < 0.001). One-Step produced higher bond strengths to all pulp chamber regions except the floor, compared with C&B Metabond. The results indicated that high bond strengths can be achieved between adhesive resins and the various regions of the pulp chamber. This should permit the use of a thick layer of unfilled resin along the floor of the pulp chamber and over the canal orifices as a secondary protective seal after finishing root canal therapy.

  4. STUDIES ON INOSINE EXTRACTION BY ION EXCHANGE METHOD

    Institute of Scientific and Technical Information of China (English)

    HuangXiwen; ShiFang; 等

    1998-01-01

    The adsorption characteristics of inosine from fermentation solution on anion exchange resin under the condition of different pH,resin type are investigated.Besides,the desorption conditions are studied under different temperature.The adsorption and desorption mechanism are described to obtain the optimum technological condition of inosine extraction.

  5. Photoacoustic analysis of dental resin polymerization

    Science.gov (United States)

    Coloiano, E. C. R.; Rocha, R.; Martin, A. A.; da Silva, M. D.; Acosta-Avalos, D.; Barja, P. R.

    2005-06-01

    In this work, we use the photoacoustic technique to monitor the curing process of diverse dental materials, as the resins chemically activated (RCA). The results obtained reveal that the composition of a determined RCA significantly alters its activation kinetics. Photoacoustic data also show that temperature is a significant parameter in the activation kinetics of resins. The photoacoustic technique was also applied to evaluate the polymerization kinetics of photoactivated resins. Such resins are photoactivated by incidence of continuous light from a photodiode. This leads to the polymerization of the resin, modifying its thermal properties and, consequently, the level of the photoacoustic signal. Measurements show that the polymerization of the resin changes the photoacoustic signal amplitude, indicating that photoacoustic measurements can be utilized to monitor the polymerization kinetic and the degree of polymerization of photoactivated dental resins.

  6. Bond strength of self-adhesive resin cements to different treated indirect composites.

    Science.gov (United States)

    Fuentes, M Victoria; Ceballos, Laura; González-López, Santiago

    2013-04-01

    The objective of this study was to determine microtensile bond strength (μTBS) to dentin of three self-adhesive and a total-etch resin cements used for luting different treated indirect composites. Composite overlays (Filtek Z250) were prepared. Their intaglio surfaces were ground with 600-grit SiC papers and randomly assigned to three different surface treatments: no treatment, silane application (RelyX Ceramic Primer), and silane agent followed by a bonding agent (Adper Scotchbond 1 XT). The composite overlays were luted to flat dentin surfaces of extracted human third molars using the following self-adhesive resin cements: RelyX Unicem, Maxcem Elite and G-Cem, and a total-etch resin cement, RelyX ARC. The bonded assemblies were stored in water (24 h, 37 °C) and subsequently prepared for μTBS testing. Beams of approximately 1 mm(2) were tested in tension at 1 mm/min in a universal tester (Instron 3345). Data were analyzed by two-way ANOVA and Student-Newman-Keuls tests (α = 0.05). A significant influence of the resin cement used was detected. Composite surface treatment and the interaction between the resin cement applied and surface treatment did not affect μTBS. Surface treatment of indirect resin composite did not improve the μTBS results of dentin/composite overlay complex. Self-adhesive resin cements tested obtained lower μTBS than the total-etch resin cement RelyX ARC. Specimens luted with Maxcem Elite exhibited the highest percentage of pretesting failures. Surface treatment of indirect resin composite with silane or silane followed by a bonding agent did not affect bond strength to dentin.

  7. Effect of laser preparation on bond strength of a self-adhesive flowable resin.

    Science.gov (United States)

    Yazici, A Rüya; Agarwal, Ishita; Campillo-Funollet, Marc; Munoz-Viveros, Carlos; Antonson, Sibel A; Antonson, Donald E; Mang, Thomas

    2013-01-01

    The aim of this in vitro study was to evaluate the effect of laser treatment on shear bond strength of a self-adhesive flowable resin composite to human dentin. Eighty extracted sound human molar teeth were used for the study. The teeth were sectioned mesiodistally and embedded in acrylic blocks. The dentin surfaces were ground wet with 600-grit silicon carbide (SiC) paper. They were randomly divided into two preparation groups: laser (Er:YAG laser, with 12 Hz, 350 mJ energy) and control (SiC). Each group was then divided into two subgroups according to the flowable resin composite type (n = 20). A self-adhesive flowable (Vertise Flow) and a conventional flowable resin (Premise Flow) were used. Flowable resin composites were applied according to the manufacturer's recommendations using the Ultradent shear bond Teflon mold system. The bonded specimens were stored in water at 37 °C for 24 h. Shear bond strength was tested at 1 mm/min. The data were logarithmically transformed and analyzed using two-way analysis of variance and Student-Newman-Keul's test at a significance level of 0.05. The self-adhesive flowable resin showed significantly higher bond strength values to laser-prepared surfaces than to SiC-prepared surfaces (p flowable resin did not show such differences (p = 0.224). While there was a significant difference between the two flowable resin composites in SiC-prepared surfaces (p flowable resin composite differs according to the type of dentin surface preparation. Laser treatment increased the dentin bonding values of the self-adhesive flowable resin.

  8. Immunomodulatory triterpenoids from the oleogum resin of Boswellia carterii Birdwood.

    Science.gov (United States)

    Badria, Farid A; Mikhaeil, Botros R; Maatooq, Galal T; Amer, Mohamed M A

    2003-01-01

    The immunomodulatory bioassay-guided fractionation of the oleogum resin of frankincense (Boswellia carterii Birdwood) resulted in the isolation and identification of 9 compounds; palmitic acid and eight triterpenoids belonging to lupane, ursane, oleanane, and tirucallane skeleta were isolated form the resin. These triterpenoids are lupeol, beta-boswellic acid, 11-keto-beta-boswellic acid, acetyl beta-boswellic acid, acetyl 11-keto-beta-boswellic acid, acetyl-alpha-boswellic acid, 3-oxo-tirucallic acid, and 3-hydroxy-tirucallic acid. The structures of the isolated compounds were deduced based on spectroscopic evidences. The lymphocyte transformation assay of the isolated compounds proved that the total extract retained more activity than that of any of the purified compounds.

  9. CARBONIZED FIBROUS RESIN AS A NEW SORBENT FOR SAMPLING POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) IN AMBIENT AIR

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new sampling method of ambient air analysis using carbonized fibrous resin as asorbent for polycyclic aromatic hydrocarbons (PAHs) was reported.The physical and chemical properties of the carbonized fibrous resins were measured. Thesample pretreatment with ultrasonic extraction and subsequent clean-up ehition through a silica gelcolumn was optimized. The suitable ultrasonic extraction conditions were selected as follows: resinweight was 1.5 g, ultrasonic extraction time 20 min, volume of extraction solvent 100 mi andextraction operation times 2~3. The concentrated extractable organic matter was submitted to nextstep of clean-up procedure of adsorption chromatography on silica gel column/n-hexane and amixture of dichloromethene:n-hexane solution 2:3 (v/v). The PAHs fractions in the real samplesfrom Changzhou, China were particularly analyzed using GC-MS data system and the data of massspectra, retention times and scan numbers of the real samples were compared with that of thestandards of 16 PAHs listed by the US EPA as "priority pollutants" of the environment. Theanalysis of the real samples indicates that the carbonized fibrous resin is a good sorbent. Thepretreatment of samples of ambient air with carbonized fibrous resin as a sorbent for P,AHs isproved to be reliable and might be used for the procedure of the determination of PAHs inatmospheric environment.

  10. Sulfur geochemistry of hydrothermal waters in Yellowstone National Park, Wyoming, USA. III. An anion-exchange resin technique for sampling and preservation of sulfoxyanions in natural waters

    Science.gov (United States)

    Druschel, G.K.; Schoonen, M.A.A.; Nordstorm, D.K.; Ball, J.W.; Xu, Y.; Cohn, C.A.

    2003-01-01

    A sampling protocol for the retention, extraction, and analysis of sulfoxyanions in hydrothermal waters has been developed in the laboratory and tested at Yellowstone National Park and Green Lake, NY. Initial laboratory testing of the anion-exchange resin Bio-Rad??? AG1-X8 indicated that the resin was well suited for the sampling, preservation, and extraction of sulfate and thiosulfate. Synthetic solutions containing sulfate and thiosulfate were passed through AG1-X8 resin columns and eluted with 1 and 3 M KCl, respectively. Recovery ranged from 89 to 100%. Comparison of results for water samples collected from five pools in Yellowstone National Park between on-site IC analysis (U.S. Geological Survey mobile lab) and IC analysis of resin-stored sample at SUNY-Stony Brook indicates 96 to 100% agreement for three pools (Cinder, Cistern, and an unnamed pool near Cistern) and 76 and 63% agreement for two pools (Sulfur Dust and Frying Pan). Attempts to extract polythionates from the AG1-X8 resin were made using HCl solutions, but were unsuccessful. Bio-Rad??? AG2-X8, an anion-exchange resin with weaker binding sites than the AG1-X8 resin, is better suited for polythionate extraction. Sulfate and thiosulfate extraction with this resin has been accomplished with KCl solutions of 0.1 and 0.5 M, respectively. Trithionate and tetrathionate can be extracted with 4 M KCl. Higher polythionates can be extracted with 9 M hydrochloric acid. Polythionate concentrations can then be determined directly using ion chromatographic methods, and laboratory results indicate recovery of up to 90% for synthetic polythionate solutions using AG2-X8 resin columns. ?? The Royal Society of Chemistry and the Division of Geochemistry of the American Chemical Society 2003.

  11. Sulfur geochemistry of hydrothermal waters in Yellowstone National Park, Wyoming, USA. III. An anion-exchange resin technique for sampling and preservation of sulfoxyanions in natural waters

    Directory of Open Access Journals (Sweden)

    Ball James W

    2003-06-01

    Full Text Available A sampling protocol for the retention, extraction, and analysis of sulfoxyanions in hydrothermal waters has been developed in the laboratory and tested at Yellowstone National Park and Green Lake, NY. Initial laboratory testing of the anion-exchange resin Bio-Rad™ AG1-X8 indicated that the resin was well suited for the sampling, preservation, and extraction of sulfate and thiosulfate. Synthetic solutions containing sulfate and thiosulfate were passed through AG1-X8 resin columns and eluted with 1 and 3 M KCl, respectively. Recovery ranged from 89 to 100%. Comparison of results for water samples collected from five pools in Yellowstone National Park between on-site IC analysis (U.S. Geological Survey mobile lab and IC analysis of resin-stored sample at SUNY-Stony Brook indicates 96 to 100% agreement for three pools (Cinder, Cistern, and an unnamed pool near Cistern and 76 and 63% agreement for two pools (Sulfur Dust and Frying Pan. Attempts to extract polythionates from the AG1-X8 resin were made using HCl solutions, but were unsuccessful. Bio-Rad™ AG2-X8, an anion-exchange resin with weaker binding sites than the AG1-X8 resin, is better suited for polythionate extraction. Sulfate and thiosulfate extraction with this resin has been accomplished with KCl solutions of 0.1 and 0.5 M, respectively. Trithionate and tetrathionate can be extracted with 4 M KCl. Higher polythionates can be extracted with 9 M hydrochloric acid. Polythionate concentrations can then be determined directly using ion chromatographic methods, and laboratory results indicate recovery of up to 90% for synthetic polythionate solutions using AG2-X8 resin columns.

  12. Bioprotective properties of Dragon's blood resin: in vitro evaluation of antioxidant activity and antimicrobial activity.

    Science.gov (United States)

    Gupta, Deepika; Gupta, Rajinder K

    2011-02-17

    Food preservation is basically done to preserve the natural characteristics and appearance of the food and to increase the shelf life of food. Food preservatives in use are natural, chemical and artificial. Keeping in mind the adverse effects of synthetic food preservatives, there is a need to identify natural food preservatives. The aims of this study were to evaluate in vitro antioxidant and antimicrobial activities of Dragon's blood resin obtained from Dracaena cinnabari Balf f., with a view to develop safer food preservatives. In this study, three solvents of varying polarity were used to extract and separate the medium and high polarity compounds from the non-polar compounds of the Dragon's blood resin. The extracts were evaluated for their antimicrobial activity against the food borne pathogens. The antioxidant activities of the extracts were assessed using DPPH and ABTS radical scavenging, FRAP, metal chelating and reducing power assays. Total phenolics, flavonoids and flavonols of extracts were also estimated using the standard methods. Phytochemical analysis of extracts revealed high phenolic content in CH(2)Cl(2) extract of resin. Free radical scavenging of CH(2)Cl(2) extract was found to be highest which is in good correlation with its total phenolic content. All test microorganisms were also inhibited by CH(2)Cl(2) extract. Our result provide evidence that CH(2)Cl(2) extract is a potential source of natural antioxidant compounds and exhibited good inhibitory activity against various food borne pathogens. Thus, CH(2)Cl(2) extract of Dragon's blood resin could be considered as possible source of food preservative.

  13. Bioprotective properties of Dragon's blood resin: In vitro evaluation of antioxidant activity and antimicrobial activity

    Directory of Open Access Journals (Sweden)

    Gupta Rajinder K

    2011-02-01

    Full Text Available Abstract Background Food preservation is basically done to preserve the natural characteristics and appearance of the food and to increase the shelf life of food. Food preservatives in use are natural, chemical and artificial. Keeping in mind the adverse effects of synthetic food preservatives, there is a need to identify natural food preservatives. The aims of this study were to evaluate in vitro antioxidant and antimicrobial activities of Dragon's blood resin obtained from Dracaena cinnabari Balf f., with a view to develop safer food preservatives. Methods In this study, three solvents of varying polarity were used to extract and separate the medium and high polarity compounds from the non-polar compounds of the Dragon's blood resin. The extracts were evaluated for their antimicrobial activity against the food borne pathogens. The antioxidant activities of the extracts were assessed using DPPH and ABTS radical scavenging, FRAP, metal chelating and reducing power assays. Total phenolics, flavonoids and flavonols of extracts were also estimated using the standard methods. Results Phytochemical analysis of extracts revealed high phenolic content in CH2Cl2 extract of resin. Free radical scavenging of CH2Cl2 extract was found to be highest which is in good correlation with its total phenolic content. All test microorganisms were also inhibited by CH2Cl2 extract. Conclusions Our result provide evidence that CH2Cl2 extract is a potential source of natural antioxidant compounds and exhibited good inhibitory activity against various food borne pathogens. Thus, CH2Cl2 extract of Dragon's blood resin could be considered as possible source of food preservative.

  14. Color difference of composite resins after cementation with different shades of resin luting cement.

    Science.gov (United States)

    Cengiz, Esra; Kurtulmus-Yilmaz, Sevcan; Karakaya, Izgen; Aktore, Huseyin

    2017-07-26

    The purpose of this study was to evaluate the color difference of nanohybrid and ormocer-based composite resins with different thicknesses when 4 different shades of resin luting cement were used. 56 disc specimens of each composite resin (Aelite aesthetic enamel, Ceram-X mono) with 0.5 and 1 mm thicknesses were fabricated. Baseline color measurements were performed using a clinical spectrophotometer. The specimens of each thicknesses of each resin were randomly divided into 4 groups according to the shades of resin luting cement (white/A1, yellow/universal/A3, transparent and white opaque) (n = 7). Mixed resin cement was applied onto the resin specimens using a Teflon mold in 0.1 mm thickness. Color measurements of cemented composite resin specimens were repeated and color difference (∆E) between baseline and after cementation measurements was calculated. ANOVA and Tukey's test were used for statistical analysis. The opaque shade had significantly increased ∆E values as compared to the other shades (p resins in terms of ∆E values. The shade of resin cement and the type of the resin affected the final color; however, the thickness of composite resin had no influence on the final color of restoration. Selecting the shade of resin luting cement before cementation of indirect composite laminate restoration is important to achieve final color match.

  15. Preparation of molecularly imprinted adsorptive resin for trapping of ligustrazine from the traditional Chinese herb Ligusticum chuanxiong Hort

    Energy Technology Data Exchange (ETDEWEB)

    Guo Zhifeng [Research Center of Physics and Chemistry Analysis, Hebei University, Analytical Science and Technology Key Lab of Hebei Province, Baoding 071002 (China)], E-mail: GZFVG@hbu.edu.cn; Guo Tingting; Guo Mufan [Research Center of Physics and Chemistry Analysis, Hebei University, Analytical Science and Technology Key Lab of Hebei Province, Baoding 071002 (China)

    2008-04-07

    A highly selective molecularly imprinted adsorptive resin for ligustrazine was prepared by melamine-urea-formaldehyde (MUF) gel. In the experiments, two pieces of MUF gel were synthesized firstly; one was added ligustrazine hydrochloride as the template molecule in it to prepare the imprinted adsorptive resin, and the other was not. Scanning electron microscopy (SEM) revealed that both resins were the porous with a network structure whether or not it was added template molecule. The imprinted adsorptive resin had an absorbability of 85.22% measured by a 200 mg L{sup -1} solution of ligustrazine hydrochloride at room temperature. The resin of MUF without template, on the other hand, displayed an adsorption capacity of almost zero. It illuminated the imprinted adsorptive resin formed ligustrazine recognition sites when the template molecule had been eluted. In the present paper, ligustrazine was effectively separated and enriched from herbs by using a solid-phase adsorptive column filled with the imprinted adsorptive resin. Its eluate, obtained from three kinds of solvents, was analyzed by GC-MS, and the results indicated that the imprinted adsorptive resin showed a high selectivity for ligustrazine. This is believed to be beneficial for extracting natural and highly purified ligustrazine.

  16. Restored viability and function of dental pulp cells on poly-methylmethacrylate (PMMA)-based dental resin supplemented with N-acetyl cysteine (NAC).

    Science.gov (United States)

    Kojima, N; Yamada, M; Paranjpe, A; Tsukimura, N; Kubo, K; Jewett, A; Ogawa, T

    2008-12-01

    This study examines cytotoxicity of poly-methylmethacrylate (PMMA)-based dental temporary filling resin to dental pulp cells, and the potential amelioration of the toxicity with an anti-oxidant amino-acid, N-acetyl cysteine (NAC). Dental pulp cells extracted from rat maxillary incisors were cultured on the resin material with or without NAC incorporation, or on the polystyrene. The cultures were supplied with osteoblastic media, containing dexamethasone. Forty five percent of cells on the PMMA dental resin were necrotic at 24h after seeding. However, this percentage was reduced to 27% by incorporating NAC in the resin, which was the level equivalent to that in the culture on polystyrene. The culture on the untreated resin was found to be negative for alkaline phosphate (ALP) activity at days 5 and 10 or von Kossa mineralized nodule formation at day 20. In contrast, some areas of the cultures on NAC-incorporated resin substrates were ALP and von Kossa positive. Collagen I and dentin sialoprotein genes were barely expressed in day 7 culture on the untreated resin. However, those genes were expressed in the culture on the resin with NAC. These results suggest that the decreased cell viability and the nearly completely suppressed odontoblast-like cell phenotype of dental pulp cells cultured on PMMA dental resin can be salvaged to a biologically significant degree by the incorporation of NAC in the resin.

  17. Uso de carvão ativado e resina de troca iônica para limpeza e concentração de enzimas em extratos de madeira biodegradada = Use of activated charcoal and ion-exchange resin to cleaN up and concentrate enzymes in extracts from biodegraded wood

    Directory of Open Access Journals (Sweden)

    André Ferraz

    2010-10-01

    lignin over hemeperoxidases. Adsorption into activated charcoal showed to be an adequate strategy to reduce the absorbance at 280 nm in all the extracts. Moreover, it allowed to maximize the capacity of an anion exchange resin bed (DEAE-Sepharose used to concentrate the MnPs present in the extracts. It was concluded that the use of activated charcoal followed by adsorption into DEAE Sepharose is a strategy that can be used to concentrate MnPs in extracts obtained during the biodegradation of E. grandis by C. subvermispora.

  18. Resin Diterpenes from Austrocedrus chilensis

    Directory of Open Access Journals (Sweden)

    Verónica Rachel Olate

    2011-12-01

    Full Text Available Seventeen diterpenes belonging to the labdane, abietane and isopimarane skeleton classes were isolated from the resin of the Chilean gymnosperm Austrocedrus chilensis and identified by spectroscopic and spectrometric methods. The diterpene 12-oxo-labda-8(17,13E-dien-19 oic acid is reported for the first time as a natural product and 14 diterpenes are reported for the first time for the species.

  19. Purification of Houttuynia cordata Thunb. Essential Oil Using Macroporous Resin Followed by Microemulsion Encapsulation to Improve Its Safety and Antiviral Activity

    National Research Council Canada - National Science Library

    Pang, Jianmei; Dong, Wujun; Li, Yuhuan; Xia, Xuejun; Liu, Zhihua; Hao, Huazhen; Jiang, Lingmin; Liu, Yuling

    2017-01-01

    .... Herein, we proposed a strategy to prepare H. cordata essential oil (HEO) safely and effectively by combining the solvent extraction and the macroporous resin purification flexibly, and then encapsulating it using microemulsion...

  20. Comparison of four methods of DNA extraction from rice

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    @@ Polyphenols, teroens, and resins make it difficult to obtain high quality genomic DNA from rice. Four extraction methods were compared in our study, and CTAB precipitation was the most practical one.

  1. Adhesion Analysis of Resin/Resin Interface by Molecular Dynamics Simulation

    National Research Council Canada - National Science Library

    MIYAZAKI, Mariko; KANEGAE, Yoshiharu; IWASAKI, Tomio

    2012-01-01

    .... In this paper, a technique for using a molecular dynamics simulation to analyze the adhesion of the interface between adhesive and polyimide, that is the resin/resin interface, has been proposed...

  2. Bonding of resin composite to caries-affected dentin after Carisolv(®) treatment.

    Science.gov (United States)

    Zawaideh, Feda; Palamara, Joseph E A; Messer, Louise B

    2011-01-01

    The purpose of this study was to investigate the effect of Carisolv(®) on resin composite adhesion on caries-affected dentin. Carious lesion specimens (N =46) were prepared from 45 extracted primary molars: Group 1 (N =23)-chemomechanical (Carisolv(®)) treatment; Group 2 (N =23)-rotary instrumentation; and Group 3 (N =23)-caries-free specimens from 20 noncarious primary molars. After caries removal (Groups 1 and 2) or washing and drying (Group 3), a resin composite rod (2-mm high, 0.975-mm diameter) was bonded vertically to dentin. Specimens were stressed at constant displacement (1.0 mm/minute) to failure; treated surfaces were examined under a scanning electron microscope. The mean (±SD) microshear bond strengths of resin composite to dentin were: Group 1=6.69 (±4.08) MPa; Group 2=10.31 (±5.47) MPa; and Group 3=7.16 (±6.64) MPa. The mean bond strength of resin composite of Group 2 significantly exceeded that of Groups 1 (P=.02) and 3 (P=.01); Groups 1 and 3 did not differ significantly. There was no significant association between failure mode and treatment type (P=.22) or mean bond strength (P=.44). Carisolv(®) removed the smear layer or limited its formation, producing demineralization incompletely infiltrated by resin composite. Chemomechanical treatment of caries-affected dentin of primary teeth did not adversely affect resin composite bonding.

  3. Adsorption of Chromium(VI from Aqueous Solutions by Coffee Polyphenol-Formaldehyde/Acetaldehyde Resins

    Directory of Open Access Journals (Sweden)

    Khudbudin Mulani

    2013-01-01

    Full Text Available Removal of chromium(VI from wastewater is essential as it is toxic. Thus, removal of chromium(VI was performed using coffee polyphenol-formaldehyde/acetaldehyde resins as adsorbents. Adsorbent resins were prepared by condensation of decaffeinated coffee powder with formaldehyde/acetaldehyde and used for the removal of Cr(VI ions from aqueous solutions. A simple and sensitive solid phase extraction procedure was applied for the determination of chromium at trace levels by spectroscopic method using 1,5-diphenylcarbazide reagent. The adsorption of Cr(VI on the coffee polyphenol-formaldehyde/acetaldehyde resins was monitored by FTIR and EDX analysis. The metal adsorption parameters such as contact time, pH, Cr(VI ion concentration, and adsorbent dose were investigated. For Cr(VI, the maximum adsorption capacity of coffee polyphenol-formaldehyde resins was 98% at pH 2. The experimental results showed that Cr(VI bound strongly with coffee polyphenol-formaldehyde/acetaldehyde resins and utilization of resins could be improved greatly by reuse.

  4. Evaluation of cuspal deflection in premolar teeth restored with low shrinkable resin composite (in vitro study).

    Science.gov (United States)

    Labib, Labib Mohamed; Nabih, Sameh Mahmoud; Baroudi, Kusai

    2015-01-01

    This study evaluated cuspal deflection in premolar teeth restored with low shrinkable resin composite. A total of 40 human premolars were used for cuspal deflection evaluation in this study. Each group was divided into four equal groups according to the type of resin composite and the adhesive used as follows: group A: Using low shrinkable resin composite (silorane) with its adhesive system; group B: Using low shrinkable composite (silorane) with G-bond; group C: Using Filtek Z350 composite with G-bond; and group D: Using Filtek Z350 composite with AdheSE. Cusp deflection was detected using Universal measuring microscope and laser horizontal metroscope. This study was done to investigate the effect of polymerization shrinkage stresses of two resin composite materials (Filtek Z350 and Filtek P90) on cuspal deflection of mesio-occluso-distal restoration. For this study, the extracted non-carious maxillary second premolars were selected. Forty teeth that showed no more than 5% variation in their dimensions were used. A significant increase in cuspal deflection of cavities restored with the methacrylate-based (Filtek Z350) compared with the silorane (P90) resin-based composites was obtained. The change in the organic matrix or materials formulation of the resin composite using silorane has a positive effect on controlling the cusp deflection.

  5. Imaging resin infiltration into non-cavitated carious lesions by optical coherence tomography.

    Science.gov (United States)

    Schneider, Hartmut; Park, Kyung-Jin; Rueger, Claudia; Ziebolz, Dirk; Krause, Felix; Haak, Rainer

    2017-05-01

    Visualisation of the etching process and resin penetration at white spot carious lesions by spectral domain optical coherence tomography (SD-OCT). The non-cavitated carious lesions (ICDAS code 2) of four visually preselected extracted human molars and premolars were verified as enamel lesions by micro computed tomography (μCT). One region of interest (ROI) per tooth was marked by two drill-holes in occlusal-cervical direction. The lesions were imaged by SD-OCT. Lesions were infiltrated (Icon, DMG) according to the manufacturer's instructions. During each treatment step and after light curing of the infiltrant, the ROIs were imaged again by SD-OCT. Teeth were sectioned through the ROIs and section layers were imaged by scanning electron microscopy in order to compare with the OCT images. The image sequences for etching and infiltration were viewed in time lapse. During the etching process, numerous bubbles formed on the lesion surface. Using OCT, the process of resin penetration into the carious lesion body became visible. The early enamel carious lesion was completely infiltrated by the resin whereas infiltration of the advanced enamel carious lesion was incomplete and inhomogeneous. Resin infiltration can be increased by optimizing the etching process. Optical coherence tomography provides information about the process and degree of resin infiltration. Active acid application before resin infiltration is recommendable. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Gold Loading on Ion Exchange Resins in Non-Ammoniacal Resin-Solution Systems

    OpenAIRE

    Abrar Muslim

    2010-01-01

    The loading of gold using strong base anion exchange resin in non-ammoniac resin-solution (NARS) systems has been studied. The loading of gold onto ion exchange resins is affected by polythionate concentration, and trithionate can be used as the baseline in the system. The results also show that resin capacity on gold loading increases due to the increase in the equilibrium thiosulfate concentration in the NARS system. Gold loading performances show the need of optimization the equilibrium co...

  7. Release and toxicity of dental resin composite

    OpenAIRE

    Saurabh K Gupta; Saxena, Payal; Pant, Vandana A.; Pant, Aditya B.

    2012-01-01

    Dental resin composite that are tooth-colored materials have been considered as possible substitutes to mercury-containing silver amalgam filling. Despite the fact that dental resin composites have improved their physico-chemical properties, the concern for its intrinsic toxicity remains high. Some components of restorative composite resins are released in the oral environment initially during polymerization reaction and later due to degradation of the material. In vitro and in vivo studies h...

  8. Color stability of different composite resin materials.

    Science.gov (United States)

    Falkensammer, Frank; Arnetzl, Gerwin Vincent; Wildburger, Angelika; Freudenthaler, Josef

    2013-06-01

    Data are needed to better predict the color stability of current composite resin materials. The purpose of this study was to evaluate the impact of different storage solutions on the color stability of different composite resin materials. Different restorative and adhesive composite resin specimens (dual-polymerizing self-adhesive resin cement, autopolymerizing resin-based composite resin, dual-polymerizing resin-based composite resin, nanohybrid composite resin, and microhybrid composite resin) were fabricated and stored in red wine, black tea, chlorhexidine, sodium fluoride, tea tree oil, or distilled water for 4 weeks at 37°C. Color parameters were measured with a colorimeter before and after storage. Total color differences and specific coordinate differences were expressed as ΔE, ΔL, Δa, and Δb. A 2-way and 1-way analysis of variance (ANOVA) with Bonferroni adjustment for multiple comparisons were applied for statistical calculations (α=.05). Red wine caused the most severe discoloration (ΔE >10), followed by black tea with perceptible (ΔE >2.6) to clinically unacceptable discoloration (ΔE >5.5). Colored mouth rinses discolored the materials to a lesser extent with clinically acceptable values. Dual-polymerizing resin adhesives showed a higher amount of discoloration. Current restorative and adhesive composite resin materials discolor over time under the influence of different storage solutions. The composition related to the polymerizing mode seemed to be a causative factor. Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

  9. Relative Molecular Mass Distribution of BG Resins

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Benzoguanamine-formaldehyde (BG-F) resins are a class of amino resins, which are important cross-linking agents for epoxy, alkyol and acrylic resins, etc. The cross-linking performance is the best one when the polymerization degree is 2-4. This paper discusses the effects of the pH value for polycondensation and the formaldehyde to benzoguanamine mole ratio in a methanol system, and compares the relative molecular mass distribution using the Flory statistics method.

  10. Epoxy Resins Modified with Vegetable Oils

    Institute of Scientific and Technical Information of China (English)

    P.Czub

    2007-01-01

    1 Results The application of modified natural oils, nontoxic, biodegradable and renewable materials, for the modification and the synthesis of epoxy resins were presented. Firstly, the application of epoxidized vegetable oils (soybean, rapeseed, linseed and sunflower):as reactive diluents for epoxy resins was proposed and studied[1-2]. Viscosity reducing ability of epoxidized oils was tested in the compositions with Bisphenol A based low-molecular-weight epoxy resins. The rheological behaviour of the mi...

  11. Chemotaxonomic investigations on resins of the frankincense species Boswellia papyrifera, Boswellia serrata and Boswellia sacra, respectively, Boswellia carterii : a qualitative and quantitative approach by chromatographic and spectroscopic methodology

    OpenAIRE

    Paul, Michael

    2012-01-01

    Extracts from the resin exudates of the frankincense tree again returned into the focus of pharmacological research within the last 20 years. So far, several research groups reported on promising anti-inflammatory, anti-microbial and even anti-tumour effects (in vitro and in vivo). The Boswellic acids are regarded as one of the most potent active agents thereof. However, the resins still contain innumerable amounts of terpenoid compounds. Their interactions, when administered as an extract, a...

  12. Damping Properties of Flexible Epoxy Resin

    Institute of Scientific and Technical Information of China (English)

    WANG Xiang; LIU Hanxing; OUYANG Shixi

    2008-01-01

    Amino-terminated polyethers and amino-terminated polyurethane were used as curing agent to cure the epoxy resin together and get a series of cured products. The damping properties of the composites were studied by DMA test at different measurement frequencies. Damping mechanical tests show that the flexible epoxy resin has higher loss factor than common epoxy. The highest loss factor reaches 1.57. Also the height and position of loss factor peak of the flexible epoxy resin varies by changing the content of amino-terminated polyethers. Results shows that the flexible epoxy resin can be used as damping polymer materials at room temperature or in common frequency range.

  13. Resin composites in minimally invasive dentistry.

    Science.gov (United States)

    Jacobsen, Thomas

    2004-01-01

    The concept of minimally invasive dentistry will provide favorable conditions for the use of composite resin. However, a number of factors must be considered when placing composite resins in conservatively prepared cavities, including: aspects on the adaptation of the composite resin to the cavity walls; the use of adhesives; and techniques for obtaining adequate proximal contacts. The clinician must also adopt an equally conservative approach when treating failed restorations. The quality of the composite resin restoration will not only be affected by the outline form of the preparation but also by the clinician's technique and understanding of the materials.

  14. Advanced resin systems for graphite epoxy composites

    Science.gov (United States)

    Gilwee, W. J.; Jayarajan, A.

    1980-01-01

    The value of resin/carbon fiber composites as lightweight structures for aircraft and other vehicle applications is dependent on many properties: environmental stability, strength, toughness, resistance to burning, smoke produced when burning, raw material costs, and complexity of processing. A number of woven carbon fiber and epoxy resin composites were made. The epoxy resin was commercially available tetraglycidylmethylene dianiline. In addition, composites were made using epoxy resin modified with amine and carboxyl terminated butadiene acrylonitrile copolymer. Strength and toughness in flexure as well as oxygen index flammability and NBS smoke chamber tests of the composites are reported.

  15. Novel silica-based ion exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-01

    Eichrom`s highly successful Diphonixo resin resembles a conventional ion exchange resin in its use of sulfonic acid ligands on a styrene- divinylbenzene matrix. Diphonix resin exhibits rapid exchange kinetics that allow economical operation of ion exchange systems. Unlike conventional resins, Diphonix resin contains chelating ligands that are diphosphonic acid groups that recognize and remove the targeted metals and reject the more common elements such as sodium, calcium and magnesium. This latter property makes Diphonix ideal for many industrial scale applications, including those involving waste treatment. For treatment of low-level, transuranic (TRU) and high- level radioactive wastes, Diphonix`s polystyrene backbone hinders its application due to radiolytic stability of the carbon-hydrogen bonds and lack of compatibility with expected vitrification schemes. Polystyrene-based Diphonix is approximately 60% carbon- hydrogen. In response to an identified need within the Department of Energy for a resin with the positive attributes of Diphonix that also exhibits greater radiolytic stability and final waste form compatibility, Eichrom has successfully developed a new, silica-based resin version of Diphonix. Target application for this new resin is for use in environmental restoration and waste management situations involving the processing of low-level, transuranic and high-level radioactive wastes. The resin can also be used for processing liquid mixed waste (waste that contains low level radioactivity and hazardous constituents) including mixed wastes contaminated with organic compounds. Silica-based Diphonix is only 10% carbon-hydrogen, with the bulk of the matrix silica.

  16. Curing Mechanism of Condensed Polynuclear Aromatic Resin and Thermal Stability of Cured Resin

    Institute of Scientific and Technical Information of China (English)

    Li Shibin; Sun Qiqian; Wang Yuwei; Wu Mingbo; Zhang Zailong

    2015-01-01

    In order to improve the thermal stability of condensed polynuclear aromatic (COPNA) resin synthesized from vacuum residue, 1,4-benzenedimethanol was added to cure COPNA resin. The curing mechanism was investigated by pro-ton nuclear magnetic resonance spectrometry, solid carbon-13 nuclear magnetic resonance spectrometry and Fourier trans-form infrared spectroscopy. Microstructures of the uncured and the cured COPNA resins were studied by scanning electron microscopy and X-ray diffractometry. The thermal stability of COPNA resins before and after curing was tested by thermo-gravimetric analysis. The element composition of the cured COPNA resin heated at different temperatures was analyzed by an element analyzer. The results showed that the uncured COPNA resin reacted with the cross-linking agent during the cur-ing process, and the curing mechanism was conifrmed to be the electrophilic substitution reaction. Compared with the un-cured COPNA resin, the cured COPNA resin had a smooth surface, well-ordered and streamlined sheet structure with more crystalline solids, better molecular arrangement and orientation. The weight loss process of the uncured and cured COPNA resins was divided into three stages. Carbon residue of the cured COPNA resin was 41.65%at 600℃, which was much higher than 25.02%of the uncured COPNA resin, which indicated that the cured COPNA resin had higher thermal stability.

  17. In vitro cytotoxicity of self-curing acrylic resins of different colors

    Directory of Open Access Journals (Sweden)

    Luciana Borges Retamoso

    2014-08-01

    Full Text Available OBJECTIVE: The aim of this study was to assess the in vitro cytotoxicity of acrylic resins of different colors over time. METHODS: Specimens were divided into 4 groups (n = 6 according to the color of the acrylic resin (Orto Class, Clássico, Campinas, São Paulo, Brazil: Group 1: clear acrylic resin; group 2: pink acrylic resin; group 3: blue acrylic resin and group 4: green acrylic resin. All specimens were fabricated according to the mass manipulation technique and submitted to mechanical polishing protocol. The control was performed with an amalgam specimen (C+, a glass specimen (C- and cell control (CC. Specimens were immersed in Minimum Eagle's Medium (MEM and incubated for 24 h at 37o C. The extracts from the experimental material were filtered and mixed with L929 fibroblast. Cytotoxicity was evaluated at 4 different times, 24, 48, 72 and 168 h. After contact, cells were incubated for 24 h and added to 100 µ of 0.01% neutral red dye. The cells were incubated for 3 h for pigment incorporation and fixed. Cells viability was determined by a spectroscopic (BioTek, Winooski, Vermont, USA with a 492-nm wavelength λ=492 nm. RESULTS: There were no statistical differences between the experimental groups and the CC and C- groups. CONCLUSION: Clear, pink, blue and green self-curing acrylic resins fabricated by means of the mass manipulation technique and mechanically polished are not cytotoxic. Neither the pigment added to the self-curing acrylic resin nor the factor of time influenced the cytotoxicity of the material.

  18. In vitro cytotoxicity of self-curing acrylic resins of different colors.

    Science.gov (United States)

    Retamoso, Luciana Borges; da Cunha, Taís de Morais Alves; Pithon, Matheus Melo; dos Santos, Rogério Lacerda; Martins, Fernanda Otaviano; Romanos, Maria Teresa Villela; Tanaka, Orlando Motohiro

    2014-01-01

    The aim of this study was to assess the in vitro cytotoxicity of acrylic resins of different colors over time. Specimens were divided into 4 groups (n = 6) according to the color of the acrylic resin (Orto Class, Clássico, Campinas, São Paulo, Brazil): Group 1, clear acrylic resin; Group 2, pink acrylic resin; Group 3, blue acrylic resin; and Group 4, green acrylic resin. All specimens were fabricated according to the mass manipulation technique and submitted to mechanical polishing protocol. The control was performed with an amalgam specimen (C+), a glass specimen (C-) and cell control (CC). Specimens were immersed in Minimum Eagle's Medium (MEM) and incubated for 24 h at 37ºC. The extracts from the experimental material were filtered and mixed with L929 fibroblast. Cytotoxicity was evaluated at four different times, 24, 48, 72 and 168 h. After contact, cells were incubated for 24 h and added to 100 µ of 0.01% neutral red dye. The cells were incubated for 3 h for pigment incorporation and fixed. Cells viability was determined by a spectroscopic (BioTek, Winooski, Vermont, USA) with a 492-nm wavelength λ=492 nm). There were no statistical differences between the experimental groups and the CC and C- groups. Clear, pink, blue and green self-curing acrylic resins fabricated by means of the mass manipulation technique and mechanically polished are not cytotoxic. Neither the pigment added to the self-curing acrylic resin nor the factor of time influenced the cytotoxicity of the material.

  19. In vivo degradation of resin-dentin bonds in humans over 1 to 3 years.

    Science.gov (United States)

    Hashimoto, M; Ohno, H; Kaga, M; Endo, K; Sano, H; Oguchi, H

    2000-06-01

    The longevity of resin restorations is currently an area of great interest in adhesive dentistry. However, no work has been conducted to investigate the durability of resin-dentin bond structures using human substrate in vivo. The purpose of this study was to investigate the degradation of the resin-dentin bond structures aged in an oral environment for 1, 2, or 3 years. Cavities were prepared in primary molars, and an adhesive resin system (Scotchbond Multi-Purpose) was applied to the cavity. After 1 to 3 years, following the eruption of the succedaneous permanent teeth, the resin-restored teeth were extracted. Immediately after extraction, those teeth were sectioned perpendicular to the adhesive interface and trimmed to produce an hourglass-shaped specimen. Then, a micro-tensile test was performed at a crosshead speed of 1.0 mm/min. The mean bond strengths were statistically compared with one-way ANOVA and Fisher's PLSD test (p bond strength among all 3 groups (p bond structures occurs after aging in the oral cavity.

  20. Analysis and aging of unsaturated polyester resins in contemporary art installations by NMR spectroscopy.

    Science.gov (United States)

    Stamatakis, Georgios; Knuutinen, Ulla; Laitinen, Kai; Spyros, Apostolos

    2010-12-01

    Two original art installations constructed from unsaturated polyester resins (UPR) and four different reference UPR products (before and after UVB aging) were analyzed by high-resolution 1D and 2D nuclear magnetic resonance (NMR) spectroscopy. Breaking strain studies were also conducted for the four UPR model products before and after different aging procedures (moisture, UVB exposure, melt/freeze). NMR analysis of the chemical composition of the UPR resin extracts showed they contain several low MW organic compounds and oligomers rich in polar -OH groups that play a significant role in the degradation behavior of the composite UPR materials. Statistical analysis of the NMR compositional data showed that styrene and benzaldehyde contents can be used to differentiate between fresh and aged UPR samples. The phthalate and propylene glycol unit speciation (esterified, primary or secondary -OH) of the extracts provided evidence that UPR resin C was used in the construction of the two art installations, and direct comparison of (1)H and (13)C NMR spectra verified this compositional similarity. UPR resin C was shown by both NMR and breaking strain studies to be the reference UPR most susceptible to degradation by different aging procedures, a characteristic attributed to the lower styrene content of resin C.

  1. Isolation of lactoperoxidase using different cation exchange resins by batch and column procedures.

    Science.gov (United States)

    Fweja, Leonard Wt; Lewis, Michael J; Grandison, Alistair S

    2010-08-01

    Lactoperoxidase (LP) was isolated from whey protein by cation-exchange using Carboxymethyl resin (CM-25C) and Sulphopropyl Toyopearl resin (SP-650C). Both batch and column procedures were employed and the adsorption capacities and extraction efficiencies were compared. The resin bed volume to whey volume ratios were 0.96:1.0 for CM-25C and 0.64:1.0 for SP-650 indicating higher adsorption capacity of SP-650 compared with CM-25C. The effluent LP activity depended on both the enzyme activity in the whey and the amount of whey loaded on the column within the saturation limits of the resin. The percentage recovery was high below the saturation point and fell off rapidly with over-saturation. While effective recovery was achieved with column extraction procedures, the recovery was poor in batch procedures. The whey-resin contact time had little impact on the enzyme adsorption. SDS PAGE and HPLC analyses were also carried out, the purity was examined and the proteins characterised in terms of molecular weights. Reversed phase HPLC provided clear distinction of the LP and lactoferrin (LF) peaks. The enzyme purity was higher in column effluents compared with batch effluents, judged on the basis of the clarity of the gel bands and the resolved peaks in HPLC chromatograms.

  2. Artificial saliva effect on toxic substances release from acrylic resins

    Directory of Open Access Journals (Sweden)

    Kostić Milena

    2015-01-01

    Full Text Available Background/Aim. Acrylic-based resins are intensively used in dentistry practice as restorative or denture-base materials. The purpose of this study was to analyze the surface structure of denture base resins and the amount of released potentially toxic substances (PTS immediately upon polymerization and incubation in different types of artificial saliva. Methods. Storage of acrylic samples in two models of artificial saliva were performed in a water bath at the temperature of 37 ± 1°C. Analysis of the surface structure of samples was carried out using scanning electronic microscopy analysis immediately after polymerization and after the 30-day incubation. The amounts of PTS per day, week and month extracts were measured using high-pressure liquid chromatography. Results. Surface design and amount of PTS in acrylic materials were different and depended on the types and duration of polymerization. The surfaces of tested acrylates became flatter after immersing in solutions of artificial saliva. The degree of acrylic materials release was not dependent on the applied model of artificial saliva. Conclusion. In order to improve biological features of acrylic resin materials, it was recommended that dentures lined with soft or hard coldpolymerized acrylates should be kept at least 1 to 7 days in water before being given to a patient. So, as to reach high degree of biocompatibility preparation of prosthetic restorations from heat-polymerized acrylate was unnecessary. [Projekat Ministarstva nauke Republike Srbije, br. 41017

  3. In vitro wear of flowable resin composite for posterior restorations.

    Science.gov (United States)

    Shinkai, Koichi; Taira, Yoshihisa; Suzuki, Shiro; Suzuki, Masaya

    2016-01-01

    The purpose of this study was to examine three- and two-body wear values of flowable resin composites for posterior restorations, using a mechanical loading device. The cavities prepared on flattened extracted molars were restored with flowable resin composites (Clearfil Majesty LV: MLV, Estelite Flow Quick: EFQ, Beautifil Flow Plus F00: BFP, and MI Fill: MIF) using accompanying adhesive systems. A universal resin composite (Clearfil Majesty) was used as a control. The specimens were subjected to in vitro three- and two-body wear testing. MLV showed high wear value (three-body: 14.69 µm, two-body: 0.268 mm(3)) compared with other materials tested in both three- and two-body wear tests. BFP showed high three-body wear value (5.78 µm), whereas low two-body wear value (0.008 mm(3)). MIF and EFQ showed equivalent wear values (MIF, three-body: 0.42 µm, two-body: 0.026 mm(3); EFQ, three-body: 1.15 µm, two-body: 0.14 mm(3)) to that of the control in both wear tests.

  4. High Throughput Method of Extracting and Counting Strontium-90 in Urine

    Energy Technology Data Exchange (ETDEWEB)

    Shkrob, I. [Argonne National Lab. (ANL), Argonne, IL (United States); Kaminski, M. [Argonne National Lab. (ANL), Argonne, IL (United States); Mertz, C. [Argonne National Lab. (ANL), Argonne, IL (United States); Hawkins, C. [Argonne National Lab. (ANL), Argonne, IL (United States); Dietz, M. [Argonne National Lab. (ANL), Argonne, IL (United States); Tisch, A. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-03-01

    A method has been developed for the rapid extraction of Sr-90 from the urine of individuals exposed to radiation in a terrorist attack. The method employs two chromatographic ion-exchange materials: Diphonix resin and Sr resin, both of which are commercially available. The Diphonix resin reduces the alkali ion concentrations below 10 mM, and the Sr resin concentrates and decontaminates strontium-90. Experimental and calculational data are given for a variety of test conditions. On the basis of these results, a flowsheet has been developed for the rapid concentration and extraction of Sr-90 from human urine samples for subsequent beta-counting.

  5. Post-irradiation crosslinking of partially cured unsaturated polyester resin

    Energy Technology Data Exchange (ETDEWEB)

    Jurkin, Tanja [Ruder Boskovic Institute, POB 180, Zagreb (Croatia); Pucic, Irina [Ruder Boskovic Institute, POB 180, Zagreb (Croatia)]. E-mail: pucic@rudjer.irb.hr

    2006-09-15

    The post-irradiation crosslinking of unsaturated polyester (UP) resin samples irradiated to different doses was monitored during the 15-days period. The post-reaction sensitivity of three experimental techniques was evaluated. Significant changes were detected by extraction analysis that also included determination of the free styrene content. The most substantial changes were detected by differential scanning calorimetry, even up to 5 days after the irradiation. The sensitivity and reproducibility of FTIR was the lowest. The first two techniques detected the influence of particular reaction periods, at which the radiation crosslinking was terminated, on the post-reaction.

  6. Post-irradiation crosslinking of partially cured unsaturated polyester resin

    Science.gov (United States)

    Jurkin, Tanja; Pucić, Irina

    2006-09-01

    The post-irradiation crosslinking of unsaturated polyester (UP) resin samples irradiated to different doses was monitored during the 15-days period. The post-reaction sensitivity of three experimental techniques was evaluated. Significant changes were detected by extraction analysis that also included determination of the free styrene content. The most substantial changes were detected by differential scanning calorimetry, even up to 5 days after the irradiation. The sensitivity and reproducibility of FTIR was the lowest. The first two techniques detected the influence of particular reaction periods, at which the radiation crosslinking was terminated, on the post-reaction.

  7. Calysolins I-IV, resin glycosides from Calystegia soldanella.

    Science.gov (United States)

    Takigawa, Ayako; Muto, Haruka; Kabata, Kiyotaka; Okawa, Masafumi; Kinjo, Junei; Yoshimitsu, Hitoshi; Nohara, Toshihiro; Ono, Masateru

    2011-11-28

    Four new resin glycosides having intramolecular cyclic ester structures (jalapins), named calysolins I-IV (1-4), were isolated from the methanol extract of leaves, stems, and roots of Calystegia soldanella , along with one known jalapin (5) derivative. The structures of 1-4 were determined on the basis of spectroscopic data and chemical evidence. They fall into two types, one having a 22-membered ring (1 and 4) and the other with a 27-membered ring (2 and 3). The sugar moieties of 1-4 were partially acylated by some organic acids. Compound 4 is the first example of a hexaglycoside of jalapin.

  8. The Extraction and Purification of Stevioside from Stevia

    Institute of Scientific and Technical Information of China (English)

    李涛; 张慧; 王冉冉; 张祥敏; 张万青; 王延霞; 王丽娟; 田浩

    2011-01-01

    tevioside is a natural sweetener extracted from stevia,which is widely used in the food industry and the pharmacy.Centre on the extraction and purification of stevioside,using ADS-7 resin to extract stevioside through one single step,greatly shorten the p

  9. Effect of filler size on wear resistance of resin cement.

    Science.gov (United States)

    Shinkai, K; Suzuki, S; Katoh, Y

    2001-11-01

    The purpose of this study was to evaluate the effect of filler size on the wear of resin cements. Materials tested included four experimental dual-cure resin cements (Kuraray) consisting of different-sized filler particles. A rectangular box cavity was prepared on the flattened occlusal surface of extracted human molars. Ceramic inlays for the cavities were fabricated using the Cerec 2 system. The Cerec inlays were cemented with the respective cements and adhesive systems according to the manufacturer's directions. The restored surface was finished by wet-grinding with an 800-grit silicon carbide paper. Six specimens were prepared for each resin cement. Half of the specimens were subjected to a three-body wear test for 200,000 cycles, and the others were subjected to a toothbrush abrasion test for 30,000 cycles. The worn surface of each restoration was scanned by a profilometer (Surfcom 475 A) at eight different points for each restoration. The wear value was determined by measuring the vertical gap depth on the profilometric tracings. The data were statistically analyzed by one-way analysis of variance (ANOVA) and Scheffe's test. The results showed that, with increase of filler size, the wear value decreased in the toothbrush test and increased in the three-body wear test. The cement with 0.04-microm filler exhibited the lowest wear value among the materials in the three-body wear test, and the same wear value as the cement with 0.97-microm filler in the toothbrush test. Based upon the results of this study, it is concluded that the wear of resin cements was affected by the filler size as well as the mode of wear test.

  10. Dentine sealing provided by smear layer/smear plugs vs. adhesive resins/resin tags.

    Science.gov (United States)

    Carrilho, Marcela R; Tay, Franklin R; Sword, Jeremy; Donnelly, Adam M; Agee, Kelli A; Nishitani, Yoshihiro; Sadek, Fernanda T; Carvalho, Ricardo M; Pashley, David H

    2007-08-01

    The aim of this study was to evaluate the ability of five experimental resins, which ranged from hydrophobic to hydrophilic blends, to seal acid-etched dentine saturated with water or ethanol. The experimental resins (R1, R2, R3, R4, and R5) were evaluated as neat bonding agents (100% resin) or as solutions solvated with absolute ethanol (70% resin/30% ethanol). Fluid conductance was measured at 20 cm H(2)O hydrostatic pressure after sound dentine surfaces were: (i) covered with a smear layer; (ii) acid-etched; or (iii) bonded with neat or solvated resins, which were applied to acid-etched dentine saturated with water or ethanol. In general, the fluid conductance of resin-bonded dentine was significantly higher than that of smear layer-covered dentine. However, when the most hydrophobic neat resins (R1 and R2) were applied to acid-etched dentine saturated with ethanol, the fluid conductance was as low as that produced by smear layers. The fluid conductance of resin-bonded dentine saturated with ethanol was significantly lower than for resin bonded to water-saturated dentine, except for resin R4. Application of more hydrophobic resins may provide better sealing of acid-etched dentine if the substrate is saturated with ethanol instead of with water.

  11. Resin Viscosity Influence on Fiber Compaction in Tapered Resin Injection Pultrusion Manufacturing

    Science.gov (United States)

    Masuram, N. B.; Roux, J. A.; Jeswani, A. L.

    2017-08-01

    Viscosity of the liquid resin effects the chemical and mechanical properties of the pultruded composite. In resin injection pultrusion manufacturing the liquid resin is injected into a specially designed tapered injection chamber through the injection slots present on top and bottom of the chamber. The resin is injected at a pressure so as to completely wetout the fiber reinforcements inside the tapered injection chamber. As the resin penetrates through the fibers, the resin also pushes the fibers away from the wall towards the center of chamber causing compaction of the fiber reinforcements. The fibers are squeezed together due to compaction, making resin penetration more difficult; thus higher resin injection pressures are required to efficaciously penetrate through the compacted fibers and achieve complete wetout. The impact of resin viscosity on resin flow, fiber compaction, wetout and on the final product is further discussed. Injection chamber design predominantly effects the resin flow inside the chamber and the minimum injection pressure required to completely wet the fibers. Therefore, a desirable injection chamber design is such that wetout occurs at lower injection pressures and at low internal pressures inside the injection chamber.

  12. MODIFICATION OF X-5 RESIN AND ADSORPTION PROPERTY OF THE MODIFIED RESINS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Three polymeric adsorbents with hydrogen bonding acceptors, methylamine,N-methyl-acetamide and aminotri(hydroxymethyl)methane modified resins are synthesized fromchloromethylated X-5 resin. Adsorption isotherms of phenol and theophylline onto the three modifiedresins and the original X-5 resin from aqueous solution are measured. The results show thatadsorption of compounds with hydrogen bonding donor onto methylamine and N-methylacetamidemodified resins is enhanced as compared with that onto X-5 resin, and adsorption mechanismbetween the adsorbents and the adsorbates is mainly based on hydrogen bonding and hydrophobicinteraction. While adsorption of compounds with hydrogen bonding donor ontoaminotri(hydroxymethyl)methane modified resin is lowered as compared with that onto X-5 resin, andadsorption mechanism between the adsorbent and the adsorbates is mainly based on hydrophobicinteraction.

  13. TMI-2 purification demineralizer resin study

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, J D; Osterhoudt, T R

    1984-05-01

    Study of the Makeup and Purification System demineralizers at TMI-2 has established that fuel quantities in the vessels are low, precluding criticality, that the high radioactive cesium concentration on the demineralizer resins can be chemically removed, and that the demineralizer resins can probably be removed from the vessels by sluicing through existing plant piping. Radiation measurements from outside the demineralizers establishing that there is between 1.5 and 5.1 (probably 3.3) lb of fuel in the A vessel and less than that amount in the B vessel. Dose rates up to 2780 R per hour were measured on contact with the A demineralizer. Remote visual observation of the A demineralizer showed a crystalline crust overlaying amber-colored resins. The cesium activity in solid resin samples ranged from 220 to 16,900 ..mu..Ci/g. Based on this information, researchers concluded that the resins cannot be removed through the normal pathway in their present condition. Studies do show that the resins will withstand chemical processing designed to rinse and elute cesium from the resins. The process developed should work on the TMI-2 resins.

  14. [Delayed asthma bronchiale due to epoxy resin].

    Science.gov (United States)

    Authried, Georg; Al-Asadi, Haifaa; Møller, Ulla; Sherson, David Lee

    2013-10-28

    Epoxy resin is a low molecular weight agent, which can cause both acute and delayed allergic reactions. However, it is known causing skin reactions with direct or airborne contact. Rarely it can cause airway reactions like asthma bronchiale. We describe a case of a windmill worker who developed delayed asthma bronchiale due to airborne contact with epoxy resin.

  15. Dental resin cure monitoring by inherent fluorescence

    Science.gov (United States)

    Li, Qun; Zhou, Jack X.; Li, Qingxiong; Wang, Sean X.

    2008-02-01

    It is demonstrated that the inherent fluorescence of a dental composite resin can be utilized to monitor the curing status, i.e. degree of conversion of the resin. The method does not require any sample preparation and is potentially very fast for real time cure monitoring. The method is verified by Raman spectroscopy analysis.

  16. Novel silica-based ion exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    Gula, M.; Harvey, J.

    1996-12-31

    Shortcomings of chelating resins have been addressed by a new class of ion exchange resins called dual mechanism bifunctional polymers (DMBPs). DMBPs use hydrophilic cation exchange ligands with rapid uptake kinetics and use chelating ligands for selectivity for one or more metals; result is a resin that quickly recognizes and removes targeted metals from waste, remediation, and process streams. Eichrom`s Diphonix {reg_sign} resin is the first DMBP to be widely released as a commercial product; it is polystyrene based. Objective of this work is to synthesize commercial quantities of a silica-based ion exchange resin with the same or better metal ion selectivity, metal uptake kinetics, and acid stability as Diphonix. Feasibility was determined, however the process needs to be optimized. Studies at Eichrom and ANL of the performance of Diphonix resin over a broad range of HNO3 and HCl conditions and inorganic salt loadings are discussed together with the proposed method of incorporating similar characteristics into a silica-based resin. The new, silica-based resin functionalized with diphosphonic acid ligands can be used in environmental restoration and waste management situations involving processing of low-level, transuranic, and high-level radioactive wastes; it can also be used for processing liquid mixed waste including wastes contaminated with organic compounds.

  17. Shear bond strength between alumina substrate and prosthodontic resin composites with various adhesive resin systems.

    Science.gov (United States)

    AlJehani, Yousef A; Baskaradoss, Jagan K; Geevarghese, Amrita; AlShehry, Marey A; Vallittu, Pekka K

    2015-05-02

    With the increase in demand for cosmetics and esthetics, resin composite restorations and all-ceramic restorations have become an important treatment alternative. Taking into consideration the large number of prosthodontic and adhesive resins currently available, the strength and durability of these materials needs to be evaluated. This laboratory study presents the shear bond strengths of a range of veneering resin composites bonded to all-ceramic core material using different adhesive resins. Alumina ceramic specimens (Techceram Ltd, Shipley, UK) were assigned to three groups. Three types of commercially available prosthodontic resin composites [BelleGlass®, (BG, Kerr, CA, USA), Sinfony® (SF, 3 M ESPE, Dental Products, Germany), and GC Gradia® (GCG, GC Corp, Tokyo, Japan)] were bonded to the alumina substrate using four different adhesive resins. Half the specimens per group (N = 40) were stored dry for 24 hours, the remaining were stored for 30 days in water. The bonding strength, so-called shear bond strengths between composite resin and alumina substrate were measured. Data were analysed statistically and variations in bond strength within each group were additionally evaluated by calculating the Weibull modulus. Bond strengths were influenced by the brand of prosthodontic resin composites. Shear bond strengths of material combinations varied from 24.17 ± 3.72-10.15 ± 3.69 MPa and 21.20 ± 4.64-7.50 ± 4.22 at 24 h and 30 days, respectively. BG resin composite compared with the other resin composites provided the strongest bond with alumina substrate (p resin composite was found to have a lower bond strength than the other composites. The Weibull moduli were highest for BG, which was bonded by using Optibond Solo Plus adhesive resin at 24 h and 30 days. There was no effect of storage time and adhesive brand on bond strength. Within the limitations of this study, the shear bond strengths of composite resins to alumina substrate are related to the composite

  18. Ethylated Urea - Ether - Modified Urea - Formaldehyde Resins,

    Directory of Open Access Journals (Sweden)

    Mathew Obichukwu EDOGA

    2006-07-01

    Full Text Available First, phenol - formaldehyde (PF and urea - formaldehyde (UFII resins were separately conventionally prepared in our laboratory. Also, UF resin synthesized from the acid modified synthesis procedure was synthesized in a purely acid medium of pH 1.0, FU molar ratio of 1.0 and at 50oC (one-stage acid modified-synthesis procedure. Subsequently, the UF resin II was modified during synthesis by incorporating ethylated urea-ether (EUER (i.e. UFIII and glycerol (GLYC (i.e. UFV cured with and without acid curing agent. The structural and physicochemical analyses of the various resin samples were carried out.The results showed that the unmodified UF resin (UF II synthesized in acid medium of pH 1.0, F/U molar ratio 1.0, and at 50oC, cured in absence of acid curing catalyst, showed features in their spectra which are consistent with a tri-, and/or tetra-substituted urea in the reaction to give a 3 - dimensional network cured UF resin. Modification of the UF resin(UF II with ethylated urea-ether and glycerol to produce UF resins III and respectively V prominently increased the absorbance of methylene and ether groups in the spectra which are consistent with increased hydrophobicity and improved hydrolytic stability. For the conventional UF resin (UF I, the only clear distinction between spectra for the UF resin II and UF resins (III/V is the presence of diminished peaks for methylene groups at 2.2 ppm. The relationship between the logarithmic viscosity of cured PF resin with time showed continuos dependence of viscosity with time during cure up to 70 minutes. Similar trends were shown by UF resins (III/V, cured in absence of acid catalyst. In contrast, the conventional UF resins I and UF IV (i.e. UF II cured with NH4CL showed abrupt discontinuity in viscosity with time just after about 20 minutes of cure.

  19. EPOXY RESINS TOUGHENED WITH CARBOXYL TERMINATED POLYETHERS

    Institute of Scientific and Technical Information of China (English)

    YU Yunchao; LI Yiming

    1983-01-01

    Carboxyl terminated polyethers, the adducts of hydroxyl terminated polytetrahydrofuran and maleic anhydride, were used as toughener for epoxy resins. The morphology of the toughened resins was investigated by means of turbidity measurement, dynamic mechanical testing and scanning electron microscope observation. It turned out that the molecular weight and the carboxyl content of the polyether and the cure conditions are important factors, which affect the particle size of the polyether-rich domains and, in turn, the mechanical properties of the cured resin. Carboxyl terminated polytetrahydrofurans have a low glass transition temperature, and in appropriate amount they do not affect the thermal resistance of the resin. These advantages make them preferable as toughener for epoxy resins.

  20. Release and toxicity of dental resin composite.

    Science.gov (United States)

    Gupta, Saurabh K; Saxena, Payal; Pant, Vandana A; Pant, Aditya B

    2012-09-01

    Dental resin composite that are tooth-colored materials have been considered as possible substitutes to mercury-containing silver amalgam filling. Despite the fact that dental resin composites have improved their physico-chemical properties, the concern for its intrinsic toxicity remains high. Some components of restorative composite resins are released in the oral environment initially during polymerization reaction and later due to degradation of the material. In vitro and in vivo studies have clearly identified that these components of restorative composite resins are toxic. But there is a large gap between the results published by research laboratories and clinical reports. The objective of this manuscript was to review the literature on release phenomenon as well as in vitro and in vivo toxicity of dental resin composite. Interpretation made from the recent data was also outlined.

  1. Posterior adhesive composite resin: a historic review.

    Science.gov (United States)

    Fusayama, T

    1990-11-01

    Since development of the BIS-GMA composite resin, there have been many innovations to improve the physical properties for posterior use. Subsequent development of a caries detector and chemically adhesive composite resin has further revolutionally raised the value of composite resin restoration, replacing the traditional restorative system of mechanical approach by the new system of biological approach. In this system only the infected irreversibly deteriorated insensitive tissue, stainable with the caries detector, is removed painlessly. The cavity is immediately filled with the composite resin with no further tissue reduction for retention or resistance form or extension for prevention. Both enamel and dentin walls are etched by a single etchant without lining. The chemical adhesion to the cavity margin and wall minimizes the marginal failure in size and prevalence and prevents secondary caries penetration along the wall. The chemically adhesive composite resin is thus a useful restorative material much kinder to teeth than amalgam.

  2. Removal of Cd (II and Hg(II by chelating resin Chelex-100

    Directory of Open Access Journals (Sweden)

    Afaf Amara-Rekkab

    2015-03-01

    Full Text Available A sensitive, simple method for the determination of amounts of mixture of Hg2+and Cd2+ by spectrophotometry was described based on the formation of the Hg2+- Cd2+- PAN complex in water media. Optimal conditions such as reagent amounts, and pH for the Hg2+- Cd2+ determination were reported. It was found that the 2:1 PAN- Hg2+- Cd2+ complex dominate at pH 13.0. In another hand, the sorption of mixture mercury (II and cadmium (II from aqueous medium on a chelating resin Chelex 100 was studied in batch mode. Since the extraction kinetic was obtained, with a mixture of 0.1 g of resin and 5 mL of mixture at 1 mmol/L of initial concentration, extraction equilibrium was reached within 20 min of mixing. The influence of some parameters such as initial mixture ions concentrations, initial pH of aqueous solution, ion strength and the amounts of resin have been studied at fixed temperature (20±1°C. The optimum pH value level for quantitative sorption was up to 2.6. The best performance obtained was 97.1% of extraction yield equivalent to 15.65 mg/g of resin. The pseudo-first- order, pseudo-second-order models and the intra-particle diffusion model were used to describe the kinetic data and rate constants were evaluated.

  3. The use of Macronet resins to recover gamma-decalactone produced by Rhodotorula aurantiaca from the culture broth.

    Science.gov (United States)

    Alchihab, Mohamed; Aldric, Jean-Marc; Aguedo, Mario; Destain, Jacqueline; Wathelet, Jean-Paul; Thonart, Philippe

    2010-02-01

    During the biotransformation of castor oil into gamma-decalactone, R. aurantiaca produced both the lactone form and its precursor (4-hydroxydecanoic acid). After six days of culture, a maximum yield of gamma-decalactone of 6.5 g/l was obtained. The parameters of gamma-decalactone adsorption on three Macronet resins (MN-202, MN-102 and MN-100) were investigated in water. Adsorption isotherms of gamma-decalactone for the three Macronet resins were linear. The trapping of gamma-decalactone produced by R. aurantiaca on these resins was then carried out. gamma-Decalactone was effectively retained by all the studied Macronet resins. The resin MN-202 trapped gamma-decalactone more efficiently than MN-102 and MN-100. The percentages of gamma-decalactone adsorbed on the resins MN-202, MN-102 and MN-100 were, respectively, 85, 75 and 81%, whereas around 70% of the adsorbed gamma-decalactone was then desorbed. We propose an industrial process that uses Macronet resins to extract gamma-decalactone from culture broth of R. aurantiaca.

  4. A Twofold Comparison between Dual Cure Resin Modified Cement and Glass Ionomer Cement for Orthodontic Band Cementation

    Science.gov (United States)

    Attar, Hanaa El; Elhiny, Omnia; Salem, Ghada; Abdelrahman, Ahmed; Attia, Mazen

    2016-01-01

    AIM: To test the solubility of dual cure resin modified resin cement in a food simulating solution and the shear bond strength compared to conventional Glass ionomer cement. MATERIALS AND METHOD: The materials tested were self-adhesive dual cure resin modified cement and Glass Ionomer (GIC). Twenty Teflon moulds were divided into two groups of tens. The first group was injected and packed with the modified resin cement, the second group was packed with GIC. To test the solubility, each mould was weighed before and after being placed in an analytical reagent for 30 days. The solubility was measured as the difference between the initial and final drying mass. To measure the Shear bond strength, 20 freshly extracted wisdom teeth were equally divided into two groups and embedded in self-cure acrylic resin. Four mm sections of stainless steel bands were cemented to the exposed buccal surfaces of teeth under a constant load of 500 g. Shear bond strength was measured using a computer controlled materials testing machine and the load required to deband the samples was recorded in Newtons. RESULTS: GIC showed significantly higher mean weight loss and an insignificant lower Shear bond strength, compared to dual cure resin Cement. CONCLUSION: It was found that dual cure resin modified cement was less soluble than glass ionomer cement and of comparable bond strength rendering it more useful clinically for orthodontic band cementation. PMID:28028417

  5. Reinforcement of Denture Base Resins

    Directory of Open Access Journals (Sweden)

    T Nejatiant

    2005-10-01

    Full Text Available Introduction: PMMA has been the most popular denture base material because of its advantages including good aesthetics, accurate fit, stability in the oral environment, easy laboratory and clinical manipulation and inexpensive equipments since the 1930’s. However, its fracture resistance is not satisfactory. Aim: The aim of this study is to improve the fracture resistance of denture bases made of PMMA by assessing the effect of resin type, packing and processing variables on biaxial flexural strength (BFS. Materials & methods: 930 discs, 12 mm diameter and 2 mm thick were prepared with the following variables: a. Veined (V and Plain (P PMMA. b. 5 different powder/liquid ratios by volume (1.5:1, 2:1, 2.5:1, 3:1, 3.5:1. c. Conventional (C and Injection packing methods (I. d. Dry heat (D Water bath (W; and e. different curing times. The discs were trimmed and stored in 37°C tap water for 50 hours before carrying out BFS test, according to BS EN ISO 1567: 2001. BFS test was carried out using a tensile-testing machine (Lloyd LRX, Lloyd instruments Ltd (Figure.1 b, with a x-head speed of 1mm/min. ONE-WAY ANOVA analysis and TUKEY’S comparison were carried out (MINITAB. The temperature within the curing baths and inside of curing resin was evaluated by using a thermocouple. Results: BFS of Powder/liquid ratio of 1.5:1 is significantly lower than the other four ratios. Among the last four ratios, 2.5:1 was the strongest one although the difference was not significant. BFS of the plain type of PMMA is significantly higher than the veined type.• BFS of conventionally packed PMMA discs was greater than the injectional packed ones and the difference is significant. Water bath cured resin showed a significant higher BFS compared with dry heat curing. • Changing the curing time in the dry heat bath from 7h @ 75º C and 2hrs @ 95º C to 5hrs @ 75º C and 3hrs @ 95º C and then 2hrs @ 95º C improves BFS of PMMA. In the water bath the trend is identical

  6. The effect of tooth age on colour adjustment potential of resin composite restorations.

    Science.gov (United States)

    Tanaka, A; Nakajima, M; Seki, N; Foxton, R M; Tagami, J

    2015-02-01

    The purpose of this study was to investigate the effect of tooth age on colour adjustment potential of resin composite restorations in human teeth. Twenty extracted human premolars with an A2 shade, extracted for orthodontic reasons from younger patients (20-28yrs) (younger teeth) and periodontal reasons from older patients (45-69yrs) (older teeth), were used in this study. Cylindrical shaped cavities (3.0mm depth; 2.0mm diameter) were prepared in the centre of the crowns on the buccal surface. One of four resin composites of A2 shade (Kalore, KA; Solare, SO; Clearfil Majesty, MJ; Beautifil II, BF) was placed in the cavity, and the colour was measured at four areas (0.4mm×0.4mm) on the restored teeth (area 1; tooth area 1.0mm away from the border of resin composite restoration: area 2; tooth border area 0.3mm away from margin of resin composite restoration: area 3; resin composite border area 0.3mm away from margin of resin composite restoration: area 4; resin composite area at the centre of resin composite restoration) using a spectrophotometer (Crystaleye). The colour of each area was determined according to the CIELAB colour scale. Colour differences (ΔE*) between the areas of 1 and 2, 2 and 3, 3 and 4 and 1 and 4 were calculated, and also the ratio of ΔE*area2-3 to ΔE*area1-4 (ΔE*area2-3/1-4), ΔE*area3-4 to ΔE*area1-4 (ΔE*area3-4/1-4) and ΔE*area1-2 to ΔE*area1-4 (ΔE*area1-2/1-4) as a parameter of the colour shift in resin composite restoration, were determined. Moreover, the light transmission characteristics of the resin materials and dentine discs from the younger and older teeth were measured using a goniophotometer. The data were statistically analyzed using two-way ANOVA, and Dunnett's T3 and t-test for the post hoc test. ΔE*area2-3 (colour difference between resin composite and tooth at the border) and ΔE*area1-4 (colour difference between resin composite and tooth) of the older teeth groups were significantly larger than those of younger

  7. Structure Property Relationships of Biobased Epoxy Resins

    Science.gov (United States)

    Maiorana, Anthony Surraht

    The thesis is about the synthesis, characterization, development, and application of epoxy resins derived from sustainable feedstocks such as lingo-cellulose, plant oils, and other non-food feedstocks. The thesis can be divided into two main topics 1) the synthesis and structure property relationship investigation of new biobased epoxy resin families and 2) mixing epoxy resins with reactive diluents, nanoparticles, toughening agents, and understanding co-curing reactions, filler/matrix interactions, and cured epoxy resin thermomechanical, viscoelastic, and dielectric properties. The thesis seeks to bridge the gap between new epoxy resin development, application for composites and advanced materials, processing and manufacturing, and end of life of thermoset polymers. The structures of uncured epoxy resins are characterized through traditional small molecule techniques such as nuclear magnetic resonance, high resolution mass spectrometry, and infrared spectroscopy. The structure of epoxy resin monomers are further understood through the process of curing the resins and cured resins' properties through rheology, chemorheology, dynamic mechanical analysis, tensile testing, fracture toughness, differential scanning calorimetry, scanning electron microscopy, thermogravimetric analysis, and notched izod impact testing. It was found that diphenolate esters are viable alternatives to bisphenol A and that the structure of the ester side chain can have signifi-cant effects on monomer viscosity. The structure of the cured diphenolate based epoxy resins also influence glass transition temperature and dielectric properties. Incorporation of reactive diluents and flexible resins can lower viscosity, extend gel time, and enable processing of high filler content composites and increase fracture toughness. Incorpora-tion of high elastic modulus nanoparticles such as graphene can provide increases in physical properties such as elastic modulus and fracture toughness. The synthesis

  8. Assessing the effects of adsorptive polymeric resin additions on fungal secondary metabolite chemical diversity

    Science.gov (United States)

    González-Menéndez, Víctor; Asensio, Francisco; Moreno, Catalina; de Pedro, Nuria; Monteiro, Maria Candida; de la Cruz, Mercedes; Vicente, Francisca; Bills, Gerald F.; Reyes, Fernando; Genilloud, Olga; Tormo, José R.

    2014-01-01

    Adsorptive polymeric resins have been occasionally described to enhance the production of specific secondary metabolites (SMs) of interest. Methods that induce the expression of new chemical entities in fungal fermentations may lead to the discovery of new bioactive molecules and should be addressed as possible tools for the creation of new microbial chemical libraries for drug lead discovery. Herein, we apply both biological activity and chemical evaluations to assess the use of adsorptive resins as tools for the differential expression of SMs in fungal strain sets. Data automation approaches were applied to ultra high performance liquid chromatography analysis of extracts to evaluate the general influence in generating new chemical entities or in changing the production of specific SMs by fungi grown in the presence of resins and different base media. PMID:25379340

  9. Separation and Purification of Total Phloroglucinols inDryopteris crassirhizoma with DM-130 Macroporous Adsorption Resin

    Institute of Scientific and Technical Information of China (English)

    Jin Zhe; Huang Jian-ping; Wang He-meng; Ju han-xun; Ren Si-rui; Chang Ying

    2015-01-01

    To improve the purity of the total phloroglucinols fromDryopteris crassirhizoma extracts, the separation and purification conditions of the total phloroglucinols fromDryopteris crassirhizoma were studied with DM-130 macroporous adsorption resin in this study. Adsorption rate, elution rate and purity of the total phloroglucinols were used as indexes to investigate the adsorption and desorption capacity of the total phloroglucinols with DM-130 macroporous adsorption resin. Through the study, the optimum sample concentration of the total phloroglucinols and maximum sample volume were 1.5 mg• mL-1 and 7 BV (210 mL), respectively. The optimum desorption conditions were achieved by using 80% ethanol as desorption solvent at elution flow rate of 1.0 mL• min-1. The result showed DM-130 macroporous adsorption resin performed effective adsorption and desorption. After purification, the purity of the total phloroglucinols increased by 11.5-fold.

  10. Waterborne hyperbranched alkyd-acrylic resin obtained by mini emulsion polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Murillo, Edwin, E-mail: edwinalbertomurillo@gmail.com [Grupo de Investigacion en Materiales Polimericos (GIMAPOL), Universidad Francisco de Paula Santander, San Jose de Cucuta (Colombia); Lopez, Betty [Grupo de Investigacion en Ciencia de los Materiales, Universidad de Antioquia, Calle, Medellin (Colombia)

    2016-10-15

    Four waterborne hyper branched alkyd-acrylic resins (HBRAA) were synthesized by mini emulsion polymerization from a hyper branched alkyd resin (HBR), methyl methacrylate (MMA), butyl acrylate (BA) and acrylic acid (AA), by using benzoyl peroxide (BPO) and ammonium persulfate (AP) as initiators. The reaction between HBR and acrylic monomers was evidenced by differential scanning calorimetric (DSC), nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The conversion percentage, glass transition temperature (T{sub g}), content of acrylic polymer (determined by soxhlet extraction) and molecular weight increased with the content of acrylic monomers used in the synthesis. The main structure formed during the synthesis was the HBRAA. The analysis by dynamic light scattering (DLS) showed that the particle size distribution of HBRAA2, HBRAA3 and HBRAA4 resins were mainly mono modal. The film properties (gloss, flexibility, adhesion and drying time) of the HBRAA were good. (author)

  11. Literature search on the use of resins for treatment of radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    AlMahamid, I.; Smith, B.M.

    1997-10-01

    Over 100 commercial providers with mixed-waste treatability capabilities exist in the US. The maturity level of these technologies varies from a bench scale to a pilot or a commercial scale. The techniques include deactivation, chemical oxidation, recovery of metals, stabilization, vitrification, incineration, biodegradation, and chemical extraction. This report focuses on the use of resins to remove actinides and heavy metals from aqueous waste streams. Only the literature that described resins with high removing efficiency are presented here. The majority of the literature reviewed are proceedings and national or international reports ordered through the Berkeley Lab Library. Some of the reports that the authors requested have not yet arrived. Only a few papers were found in the open literature (journals or magazines). Although this report does not include all existing references, it provides an accurate assessment of efficient resins to be considered for waste minimization procedures. 70 refs.

  12. Resin infiltration-taking the first steps to filling the holes in cheese molars.

    Science.gov (United States)

    Kumar, Harleen; Palamara, Joseph; Burrow, Michael F; Manton, David J

    2012-04-01

    Molar incisor hypomineralization (MIH) involves enamel hypomineralization of systemic origin affecting one or more first permanent molars (FPM) and is often associated with other teeth, particularly the incisors. A challenging condition for both the clinician and the patient, MIH affected teeth are often subjected to repeated treatments and frequently the decision to extract one or more FPM is made. At present, there are no clinical reports of available restorative materials that are able to provide consistently adequate restorations on hypomineralized teeth. The concept of resin infiltration, which involves occluding incipient enamel carious lesions with low viscosity resins to arrest or slow the development of caries has the potential to be applied to hypomineralized enamel. Successful penetration of resin infiltrant into MIH affected enamel may aid in improving its micromechanical properties.

  13. Phytochemical and anti-staphylococcal biofilm assessment of Dracaena draco L. Spp. draco resin

    Directory of Open Access Journals (Sweden)

    V. Di Stefano

    2014-01-01

    Full Text Available Background: Dracaena draco L. ssp. draco is known as the "dragon′s blood tree" and it is endemic from the Canary Islands and Morocco. Objective: Carry out phytochemical investigation of acetonic extracts of red resin obtained from the trunk of D. draco, to obtain to the isolation of the most abundant resin constituents, belonging to the class of flavonoids: flavans, along with homoisoflavans and homoisoflavanones. Materials and Methods: The structures of the isolated compounds were established by Nuclear Magnetic Resonance (NMR and mass spectrometry data and comparison with literature data. The acetonic extract was evaluated for its anti-staphylococcal properties against two reference strains. Results: The acetonic extracts resulted inactive at the maximum tested concentration of 1000 μg/ml against free living forms of tested staphylococci, but they showed a very interesting activity in the prevention of a biofilm formation at a concentration equal to 200 μg/ml against S. aureus ATCC 25923.

  14. ANALYSIS OF RESIN AND FATTY ACIDS ENRICHED IN PAPERMAKING PROCESS WATERS

    Directory of Open Access Journals (Sweden)

    Piia Valto

    2010-02-01

    Full Text Available The applicability of a special pilot-scale installation (Short Circulation Device was studied for demonstrating the enrichment of selected resin and fatty acids in process waters when increasing water reuse during the manufacture of paper. The traditional gas chromatography with flame ionization detection (GC-FID, turbidity, and online sample enrichment (solid phase extraction, SPE for atmospheric pressure chemical ionization-mass spectrometry (APCI-MS measurements were used for the analysis of the resin and fatty acids. The data from all the measurements with unbleached thermomechanical pulp (TMP process waters were in a good agreement, and correlation coefficients (R2 > 0.9 were obtained in each case. Rapid information about the levels of wood extractives in papermaking process waters is of great importance, and it offers a suitable way to predict oncoming pitch problems. It was concluded that the routine control of the extractives level in papermaking process waters is possible by all these methods.

  15. Evaluation of Resin-Resin Interface in Direct Composite Restoration Repair

    Science.gov (United States)

    Stoleriu, S.; Andrian, S.; Pancu, G.; Nica, I.; Iovan, G.

    2017-06-01

    The aim of this study was to evaluate the resin-resin interface when a universal bonding agent was used in two different strategies in direct restoration repair. Two composite resins (a micro-filled hybrid and a nano-filled hybrid) as old restorations that have to be repair, a universal bonding agent and a micro-filled hybrid composite resin (different then that aged) as new material for repair were chosen for the study. Non-aged samples were used as control and aged samples were used as study groups. The universal bonding agent was applied in etch-and-rinse and in self-etch strategies. The interface between old and new composite resins was evaluated by SEM and the microleakage was assessed by scoring the dye penetration. Very good adaptation of the two different composite resins placed in direct contact in non-aged samples was recorded. No gaps or defects were visible and strong resin-resin contact was observed. After aging, enlargement of resin-resin junction were observed in most of the samples and a increased dye penetration was recorded irrespective of the strategy (etch-and-rinse or self-etch) used for bonding agent application.

  16. Evaluation of novalak resins as a precursor for fabrication of carbon - carbon composites. Pt. 1. Optimization of curing states

    Energy Technology Data Exchange (ETDEWEB)

    Sedghi, A.; Golestani Fard, F. [Iran Univ. of Science and Technology, Narmak, Tehran (Iran, Islamic Republic of). Dept. of Material Engineering

    1997-09-01

    Curing of novalak resin has been investigated by applying different thermal analysis methods and solvent extraction technique. Results revealed that cure can be optimized by finding the critical steps in cure and hold resin in these steps for appropriate time. Best results were also achieved by using resins which contained lower free phenol and hexamine amount. Application of pressure is necessary in initial stages of cure but found to be harmful in the final stages. It was also found that due to the defects produced in the final stages of curing, this process cannot be completed and long time post cure should be applied on these resins. By applying a special curing regime, it was proved that defects during pyrolysis stage could be decreased profoundly and a carbon residue of more than 67 percent expected. The results are explained by emphasis on carbon - carbon applications. (orig.)

  17. Resinous plants as an economic alternative to bioenergy plantations

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, J.J.

    1985-10-01

    The resin-producing xerophytic species Grindelia camporum is an economical alternative for bioenergy plantations in arid lands. A hypothetical bioenergy farm consists of the land and agricultural facilities needed to grow, harvest and transport 272,100 Mg of biomass to the central processing plant, where the plant material is extracted and the bagasse is converted into electricity. A farm of this type could produce plant extractives that are equivalent to crude oil, with a net positive energy balance. Economic analyses of a series of scenarios based on a plantation of this size indicate that bioenergy production in arid lands must be integrated with the generation of higher-priced chemica commodities, such as naval stores rosin.

  18. Effects of flowable resin on bond strength and gap formation in Class I restorations.

    Science.gov (United States)

    Miguez, Patricia A; Pereira, Patricia N R; Foxton, Richard M; Walter, Ricardo; Nunes, Mauro F; Swift, Edward J

    2004-11-01

    This study measured resin/dentin bond strengths and evaluated gap formation at the pulpal floor of occlusal composite restorations using a flowable resin as a liner with either bulk or incremental placement of the restorative composite. Class I occlusal preparations were made in 16 extracted molars, and were randomly divided into two groups for restoration using either One-Step adhesive (OS, BISCO) and Renew composite (RW, BISCO) or OptiBond SOLO adhesive (SOLO, Kerr) and Herculite XRV composite (XRV, Kerr). A flowable resin [AEliteFlo (AE, BISCO) or Revolution (RV, Kerr)] was applied as a liner in half of the specimens of each group. The lined and unlined groups were restored with composite cured in bulk, or cured in 1.5 mm increments. After 24 h in water, the teeth were sectioned into 0.7-mm thick slabs and were examined with an optical microscope (400 x) to determine the presence of internal resin-dentin gaps. The gap-free specimens were trimmed and were subjected to microtensile bond strength testing. Specimens that contained gaps had Knoop hardness of the restorative material measured. All incrementally filled restorations were well adapted to the pulpal floor but nearly all bulk-cured specimens had gaps between the flowable and the hybrid composites. The use of a flowable resin increased the bond strength of OS, but not SOLO. The incremental technique prevented gap formation regardless of the use of a flowable resin. In contrast, the use of a flowable composite did not guarantee gap-free restorations or improved bond strength of resin to dentin in bulk-filled restorations.

  19. In vitro Evaluation of Stainless Steel Crowns cemented with Resin-modified Glass Ionomer and Two New Self-adhesive Resin Cements

    Science.gov (United States)

    Shashibhushan, KK; Poornima, P; Reddy, VV Subba

    2016-01-01

    Aims To assess and compare the retentive strength of two dual-polymerized self-adhesive resin cements (RelyX U200, 3M ESPE & SmartCem2, Dentsply Caulk) and a resin-modified glass ionomer cement (RMGIC; RelyX Luting 2, 3M ESPE) on stainless steel crown (SSC). Materials and methods Thirty extracted teeth were mounted on cold cured acrylic resin blocks exposing the crown till the cemento-enamel junction. Pretrimmed, precontoured SSC was selected for a particular tooth. Standardized tooth preparation for SSC was performed by single operator. The crowns were then luted with either RelyX U200 or SmartCem2 or RelyX Luting 2 cement. Retentive strength was tested using Instron universal testing machine. The retentive strength values were recorded and calculated by the formula: Load/Area. Statistical analysis One-way analysis of variance was used for multiple comparisons followed by post hoc Tukey’s test for groupwise comparisons. Unpaired t-test was used for intergroup comparisons. Results RelyX U200 showed significantly higher retentive strength than rest of the two cements (p 0.05). Conclusion The retentive strength of dual-polymerized self-adhesive resin cements was better than RMGIC, and RelyX U200 significantly improved crown retention when compared with SmartCem2 and RelyX Luting 2. How to cite this article Pathak S, Shashibhushan KK, Poornima P, Reddy VVS. In vitro Evaluation of Stainless Steel Crowns cemented with Resin-modified Glass Ionomer and Two New Self-adhesive Resin Cements. Int J Clin Pediatr Dent 2016;9(3):197-200. PMID:27843249

  20. Assessment of Tensile Bond Strength of Fiber-Reinforced Composite Resin to Enamel Using Two Types of Resin Cements and Three Surface Treatment Methods

    Directory of Open Access Journals (Sweden)

    Tahereh Ghaffari

    2015-10-01

    Full Text Available Background: Resin-bonded bridgework with a metal framework is one of the most conservative ways to replace a tooth with intact abutments. Visibility of metal substructure and debonding are the complications of these bridgeworks. Today, with the introduction of fiber-reinforced composite resins, it is possible to overcome these complications. The aim of this study was to evaluate the bond strength of fiber-reinforced composite resin materials (FRC to enamel. Methods: Seventy-two labial cross-sections were prepared from intact extracted teeth. Seventy-two rectangular samples of cured Vectris were prepared and their thickness was increased by adding Targis. The samples were divided into 3 groups for three different surface treatments: sandblasting, etching with 9% hydrofluoric acid, and roughening with a round tapered diamond bur. Each group was then divided into two subgroups for bonding to etched enamel by Enforce and Variolink II resin cements. Instron universal testing machine was used to apply a tensile force. The fracture force was recorded and the mode of failure was identified under a reflective microscope. Results: There were no significant differences in bond strength between the three surface treatment groups (P=0.53. The mean bond strength of Variolink II cement was greater than that of Enforce (P=0.04. There was no relationship between the failure modes (cohesive and adhesive and the two cement types. There was some association between surface treatment and failure mode. There were adhesive failures in sandblasted and diamond-roughened groups and the cohesive failure was dominant in the etched group. Conclusion: It is recommended that restorations made of fiber-reinforced composite resin be cemented with VariolinkII and surface-treated by hydrofluoric acid. Keywords: Tensile bond strength; surface treatment methods; fiber-reinforced composite resin

  1. Restorative resins: abrasion vs. mechanical properties.

    Science.gov (United States)

    Jørgensen, K D

    1980-12-01

    The purpose of the present work was to examine whether it is possible by simple and reliable laboratory tests to evaluate the abrasion by food of Class 1 restorative resins. The results point to the following main conclusions: for the smooth-surface resins, i.e. the micro-filled composite and the unfilled resins, the Wallace hardness test appears to be a valid parameter for abrasion; the greater the depth of penetration of the Vickers diamond of this apparatus, the more severe abrasion is to be expected. The mode of abrasion in this type of resin is scratching. Porosity in the resins strongly enhances the abrasion. For the rough-surface resins, i.e. the conventional composites, a dual effect of the filler particles was concluded. The filler particles on the one hand protect the matrix against abrasion, but cause, on the other hand, in time an increase of the surface roughness of the composite and thereby via increased friction an increase of the abrasion. Considerations on possible ways to improve the present-day restorative resins are presented. It is stressed that the results obtained refer only to abrasion of Class 1 fillings by food.

  2. 21 CFR 175.270 - Poly(vinyl fluoride) resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Poly(vinyl fluoride) resins. 175.270 Section 175... Substances for Use as Components of Coatings § 175.270 Poly(vinyl fluoride) resins. Poly(vinyl fluoride... the purpose of this section, poly(vinyl fluoride) resins consist of basic resins produced by the...

  3. Melamine-modified urea formaldehyde resin for bonding particleboards

    Science.gov (United States)

    Chung-Yun Hse; Feng Fu; Hui Pan

    2008-01-01

    For the development of a cost-effective melamine-modified urea formaldehyde resin (MUF), the study evaluated the effects of reaction pH and melamine content on resin properties and bond performance of the MUF resin adhesive systems. Eight resins, each with three replicates, were prepared in a factorial experiment that included two formulation variables: two reaction...

  4. 21 CFR 177.2260 - Filters, resin-bonded.

    Science.gov (United States)

    2010-04-01

    ... Components of Articles Intended for Repeated Use § 177.2260 Filters, resin-bonded. Resin-bonded filters may... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Filters, resin-bonded. 177.2260 Section 177.2260... of this section. (a) Resin-bonded filters are prepared from natural or synthetic fibers to which have...

  5. 21 CFR 177.2490 - Polyphenylene sulfide resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyphenylene sulfide resins. 177.2490 Section 177... Components of Articles Intended for Repeated Use § 177.2490 Polyphenylene sulfide resins. Polyphenylene sulfide resins (poly(1,4-phenylene sulfide) resins) may be safely used as coatings or components...

  6. 76 FR 4936 - Granular Polytetrafluoroethylene Resin From Italy

    Science.gov (United States)

    2011-01-27

    ... COMMISSION Granular Polytetrafluoroethylene Resin From Italy AGENCY: United States International Trade... antidumping duty order on granular polytetrafluoroethylene resin (``granular PTFE resin'') from Italy. DATES... on granular PTFE resin from Italy and Japan (75 FR 67082-67083 and 67105-67108, November 1,...

  7. Sorption Efficiency of a New Sorbent towards Cadmium(II: Methylphosphonic Acid Grafted Polystyrene Resin

    Directory of Open Access Journals (Sweden)

    Nacer Ferrah

    2013-01-01

    Full Text Available A new chelating polymeric sorbent has been developed using polystyrene resin grafted with phosphonic acid. After characterization by FTIR and elementary analysis, the new resin has been investigated in liquid-solid extraction of cadmium(II. The results indicated that phosphonic resin could adsorb Cd(II ion effectively from aqueous solution. The adsorption was strongly dependent on the pH of the medium and the optimum pH value level for better sorption was between 3.2 and 5.2. The influence of other analytical parameters including contact time, amount of resin, metal ion concentration, and the presence of some electrolytes was investigated. The maximum uptake capacity of Cd(II ions was 37,9 mg·g−1 grafted resin at ambient temperature, at an initial pH value of 5.0. The overall adsorption process was best described by pseudo second-order kinetic. When Freundlich and Langmuir isotherms were tested, the latter had a better fit with the experimental data. Furthermore, more than 92% of Cd(II could be eluted by using 1.0 mol·L−1 HCl in one cycle.

  8. Factorial experimental design for recovering heavy metals from sludge with ion-exchange resin.

    Science.gov (United States)

    Lee, I Hsien; Kuan, Yu-Chung; Chern, Jia-Ming

    2006-12-01

    Wastewaters containing heavy metals are usually treated by chemical precipitation method in Taiwan. This method can remove heavy metals form wastewaters efficiently, but the resultant heavy metal sludge is classified as hazardous solid waste and becomes another environmental problem. If we can remove heavy metals from sludge, it becomes non-hazardous waste and the treatment cost can be greatly reduced. This study aims at using ion-exchange resin to remove heavy metals such as copper, zinc, cadmium, and chromium from sludge generated by a PCB manufacturing plant. Factorial experimental design methodology was used to study the heavy metal removal efficiency. The total metal concentrations in the sludge, resin, and solution phases were measured respectively after 30 min reaction with varying leaching agents (citric acid and nitric acid); ion-exchange resins (Amberlite IRC-718 and IR-120), and temperatures (50 and 70 degrees C). The experimental results and statistical analysis show that a stronger leaching acid and a higher temperature both favor lower heavy metal residues in the sludge. Two-factors and even three-factor interaction effects on the heavy metal sorption in the resin phase are not negligible. The ion-exchange resin plays an important role in the sludge extraction or metal recovery. Empirical regression models were also obtained and used to predict the heavy metal profiles with satisfactory results.

  9. The efficiency of different light sources to polymerize resin cement beneath porcelain laminate veneers.

    Science.gov (United States)

    Usumez, A; Ozturk, A N; Usumez, S; Ozturk, B

    2004-02-01

    Plasma arc light units for curing resin composites have been introduced with the claim of relatively short curing times. The purpose of this study was to evaluate the efficiency of two different light sources to polymerize dual curing resin cement beneath porcelain laminate veneers. Twenty extracted healthy human maxillary centrals were used. Teeth were sectioned 2 mm below the cemento-enamel junction and crown parts were embedded into self-cure acrylic resin, labial surface facing up. Cavity preparation was carried out on labial surfaces. These teeth were divided into two groups of 10 each. The resin cement/veneer combination was exposed to two different photo polymerization units. A conventional halogen light (Hilux 350, Express Dental Products) and a plasma arc light (Power PAC, ADT) were used to polymerize resin cement. Ten specimens were polymerized conventionally (40 s) and the other specimens by plasma arc curing (PAC) (6 s). Two samples from each tooth measuring 1.2 x 1.2 x 5 mm were prepared. These sections were subjected to microshear testing and failure values were recorded. Statistically significant differences were found between the bond strength of veneers exposed to conventional light and PAC unit (P < 0.001). Samples polymerized with halogen light showed better bond strength. The results of this study suggest that the curing efficiency of PAC through ceramic was lower compared with conventional polymerization for the exposure durations tested in this study.

  10. Long-term nano-mechanical properties of biomodified dentin-resin interface components.

    Science.gov (United States)

    Dos Santos, Paulo Henrique; Karol, Sachin; Bedran-Russo, Ana Karina

    2011-06-03

    Failures of dental composite restorative procedures are largely attributed to the degradation of dentin-resin interface components. Biomodification of dentin using bioactive agents may improve the quality and durability of the dentin-resin bonds. The aim of this study was to nanomechanically assess the reduced modulus of elasticity (Er) and nano-hardness (H) of major components of the dentin-resin interface (hybrid layer, adhesive layer and underlying dentin) biomodified by collagen cross-linkers at 24h, 3 and 6 months following restorative procedure. Demineralized dentin surfaces were biomodified with 5% glutaraldehyde (GD) or 6.5% grape seed extract (GSE) prior to placement of adhesive systems and composite resin. Nano-measurements of the interface components in a fluid cell showed that both agents increased the Er and H of underlying dentin after 3 and 6 months when compared to a control. The mechanical properties of the adhesive and hybrid layers decreased over time. Biomodification of the dentin-resin interface structures using GD and GSE can increase the mechanical properties of the interface over time and may contribute to the long-term quality of adhesive restorations.

  11. Degradation of Resin Restorative Materials by Streptococcus Mutans: A Pilot Study.

    Science.gov (United States)

    Gautam, Ankit K; Thakur, Ruchi; Shashikiran, N D; Shilpy, Singla; Agarwal, Nikita; Tiwari, Shilpi

    To evaluate the degradation of three resin based restorative materials by S Mutans. Class I cavity was prepared in extracted premolars and were randomly divided into 3 groups (Group I - Conventional composite (CC), Group II - Resin Modified GIC and Group III-Giomer). Teeth were then restored by respective restorative material and equally divided in two subgroups (Control and Experimental). Experiment subgroup samples were then incubated in 2 ml of BHI with 1:10 dilution of SM (MTCC-497) grown overnight in BHI whereas control subgroup samples were incubated in BHI without SM. The incubation solution was collected at 2,14 and 30 days interval, and the analysis for identification and quantification of Bis-HPPP was done by High performance Liquid Chromatography. Statistical analysis of the collected data revealed a statistically increased Bis HPPP production in the presence of SM in all the tested materials, with minimum in Resin Modified GIC and a maximum in Conventional Composite (CC). SM degrades the resin based restorative materials & among the tested materials Resin Modified GIC appears to be most Biostable.

  12. Epoxy resin synthesis using low molecular weight lignin separated from various lignocellulosic materials.

    Science.gov (United States)

    Asada, Chikako; Basnet, Sunita; Otsuka, Masaya; Sasaki, Chizuru; Nakamura, Yoshitoshi

    2015-03-01

    A low molecular weight lignin from various lignocellulosic materials was used for the synthesis of bio-based epoxy resins. The lignin extracted with methanol from steam-exploded samples (steaming time of 5 min at steam pressure of 3.5 MPa) from different biomasses (i.e., cedar, eucalyptus, and bamboo) were functionalized by the reaction with epichlorohydrin, catalyzed by a water-soluble phase transfer catalyst tetramethylammonium chloride, which was further reacted with 30 wt% aqueous NaOH for ring closure using methyl ethyl ketone as a solvent. The glycidylated products of the lignin with good yields were cured to epoxy polymer networks with bio-based curing agents i.e., lignin itself and a commercial curing agent TD2131. Relatively good thermal properties of the bio-based epoxy network was obtained and thermal decomposition temperature at 5% weight loss (Td5) of cedar-derived epoxy resin was higher than that derived from eucalyptus and bamboo. The bio-based resin satisfies the stability requirement of epoxy resin applicable for electric circuit boards. The methanol-insoluble residues were enzymatically hydrolyzed to produce glucose. This study indicated that the biomass-derived methanol-soluble lignin may be a promising candidate to be used as a substitute for petroleum-based epoxy resin derived from bisphenol A, while insoluble residues may be processed to give a bioethanol precursor i.e., glucose.

  13. Molecular composition and paleobotanical origin of Eocene resin from northeast India

    Indian Academy of Sciences (India)

    Arka Rudra; Suryendu Dutta; Srinivasan V Raju

    2014-07-01

    The molecular composition of fossil resins from early to middle Eocene coal from northeast India, has been analyzed for the first time to infer their paleobotanical source. The soluble component of fossil resin was analyzed using gas chromatography–mass spectrometry (GC–MS). The resin extracts are composed of cadalene-based C15 sesquiterpenoids and diagenetically altered triterpenoids. The macromolecular composition was investigated using pyrolysis gas chromatography-mass spectrometry (Py-GC–MS) and Fourier transform infrared (FTIR) spectroscopy. The major pyrolysis products are C15} bicyclic sesquiterpenoids, alkylated naphthalenes, benzenes and a series of C17–C34 -alkene--alkane pairs. Spectroscopic analysis revealed the dominance of aliphatic components. The presence of cadalene-based sequiterpenoids confirms the resin to be Class II or dammar resin, derived from angiosperms of Dipterocarpaceae family. These sesquiterpenoids are often detected in many SE Asian fluvio-deltaic oils. Dipterocarpaceae are characteristic of warm tropical climate suggesting the prevalence of such climate during early Eocene in northeast India.

  14. Cobalt Ions Improve the Strength of Epoxy Resins

    Science.gov (United States)

    Stoakley, D. M.; St. Clair, A. K.

    1986-01-01

    Technique developed for improving mechanical strength of epoxy resins by adding cobalt ions in form of tris(acetylacetonato)cobalt (III) complex. Solid cast disks prepared from cobalt ion-containing epoxy resins tested for flexural strength and stiffness. Incorporation of cobalt ions into epoxies increased flexural strength of resins by 10 to 95 percent. Suitable resins for this technique include any liquid or solid TGMDA resins. Improved epoxy formulation proves useful as composite matrix resin, adhesive, or casting resin for applications on commercial and advanced aircraft.

  15. Catalytic Graphitization of Phenolic Resin

    Institute of Scientific and Technical Information of China (English)

    Mu Zhao; Huaihe Song

    2011-01-01

    The catalytic graphitization of thermal plastic phenolic-formaldehyde resin with the aid of ferric nitrate (FN) was studied in detail. The morphologies and structural features of the products including onion-like carbon nanoparticles and bamboo-shaped carbon nanotubes were investigated by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction and Raman spectroscopy measurements. It was found that with the changes of loading content of FN and residence time at 1000℃, the products exhibited various morphologies. The TEM images showed that bamboo-shaped carbon nanotube consisted of tens of bamboo sticks and onion-like carbon nanoparticle was made up of quasi-spherically concentrically closed carbon nanocages.

  16. Accurate determination of ¹²⁹I concentrations and ¹²⁹I/¹³⁷Cs ratios in spent nuclear resins by Accelerator Mass Spectrometry.

    Science.gov (United States)

    Nottoli, Emmanuelle; Bienvenu, Philippe; Labet, Alexandre; Bourlès, Didier; Arnold, Maurice; Bertaux, Maité

    2014-04-01

    Determining long-lived radionuclide concentrations in radioactive waste has fundamental implications for the long-term management of storage sites. This paper focuses on the measurement of low (129)I contents in ion exchange resins used for primary fluid purification in Pressurised Water Reactors (PWR). Iodine-129 concentrations were successfully determined using Accelerator Mass Spectrometry (AMS) following a chemical procedure which included (1) acid digestion of resin samples in HNO3/HClO4, (2) radioactive decontamination by selective iodine extraction using a new chromatographic resin (CL Resin), and (3) AgI precipitation. Measured (129)I concentrations ranged from 4 to 12 ng/g, i.e. from 0.03 to 0.08 Bq/g. The calculation of (129)I/(137)Cs activity ratios used for routine waste management produced values in agreement with the few available data for PWR resin samples.

  17. Luminous Efficient Compositions Based on Epoxy Resin

    Directory of Open Access Journals (Sweden)

    R.S. Palaiah

    2006-07-01

    Full Text Available Magnesium/sodium nitrate illuminating compositions with epoxy resin - E 605 have beenstudied for luminosity and luminous efficiency by varying fuel oxidizer ratio and binder content.The compositions have been evaluated for impact and friction sensitivities, burn rate, thermalcharacteristics, and mechanical properties. Flame temperature and combustion products areevaluated theoretically by using REAL program. Experimental results show that, luminosity,burn rate, and calorimetric value are higher for polyester resin-based compositions. The highluminous efficiency composition is achieved with magnesium/sodium nitrate ratio of 70/30 with4 per cent epoxy resin.

  18. Advanced Fibre Reinforced Methyl Nadicimide Resins .

    Directory of Open Access Journals (Sweden)

    Sarfaraz Alam

    1996-07-01

    Full Text Available Glass/carbon/kevlar-reinforced composites were fabricated using two structurally different methl nadicimide resins. The resin content of the laminates was in the range of 32-39 per cent. Interlaminar shear strength (ILSSand flexual strength (FS depended on the structure of the methyl nadicimide resins. A significant decrease in the ILSS was observed on treatment with boiling water for 500 h and on isothermal ageing at 300 degree celsius for 100,250 and 500 h. The limiting oxygen index (LOI was the lowest for laminates based on Kevlar fabrics (i.e.54 whereas the laminates based on glass/carbon showed very high LOI(>90.

  19. The flexible resin transfer molding (FRTM) process

    Science.gov (United States)

    Foley, Michael F.

    1992-12-01

    An innovative composite manufacturing process, FRTM, which is based on detailed cost analysis intended to be 'cost effective by design', is described. FRTM is based on a combination of the technical characteristics and respective favorable economics of diaphragm forming, and resin transfer molding. The process control system determines the optimal time for compaction and forming using an empirical resin polymerization model, a fluid flow model, and dielectric sensing of in-situ resin properties. The modified FRTM process is capable of producing high-quality parts with low thickness variation, low void content, and high fiber volume.

  20. EP-toxicity test of saturated GT-73 resin and resin in grout

    Energy Technology Data Exchange (ETDEWEB)

    Bibler, J.P.

    1985-04-24

    The results of EP-toxicity tests on mercury saturated Duolite{reg_sign} GT-73 cation exchange resin clarify options for the ultimate disposal of spent resin. Samples of GT-73 saturated with mercury passed the EP-toxicity test, indicating that fully spent resin may be classifed as ``solid``-not``hazardous``-waste and stored or disposed-of as such. Samples of GT-73 resin saturated with mercury and then incorporated into Portland Type 1 cement did not pass the EP-toxicity test and fall into the ``hazardous waste`` category. Samples of GT-73 resin less-than-saturated with mercury which were in corporated in Portland Type 1 cement passed the EP-toxicity test and may be classified as ``solid waste.`` Other commercially available materials are being investigated for incorporating fully spent GT-73 resin in a solid waste form.

  1. 5-year clinical performance of resin composite versus resin modified glass ionomer restorative system in non-carious cervical lesions

    DEFF Research Database (Denmark)

    Franco, Eduardo Batista; Benetti, Ana Raquel; Ishikiriama, Sérgio Kiyoshi

    2006-01-01

    To comparatively assess the 5-year clinical performance of a 1-bottle adhesive and resin composite system with a resin-modified glass ionomer restorative in non-carious cervical lesions.......To comparatively assess the 5-year clinical performance of a 1-bottle adhesive and resin composite system with a resin-modified glass ionomer restorative in non-carious cervical lesions....

  2. Magnetic ion-exchange resin treatment: Impact of water type and resin use

    OpenAIRE

    Mergen, Maxime Rodolphe Denis; Jefferson, Bruce; Parsons, Simon A.; Jarvis, Peter

    2008-01-01

    Three raw waters of fundamentally different natural organic matter (NOM) character were treated by magnetic resin using a bench-scale method designed to mimic how the resin is used in continuous operation. Increasing water hydrophobicity resulted in reduced dissolved organic carbon (DOC) removal with removal of 56%, 33% and 25% for waters containing 21%, 50% and 75% hydrophobic NOM, respectively. Study of consecutive resin uses showed that the NOM in the hydrophobic water ha...

  3. Compaction and Cure of Resin Film Infusion Prepregs

    OpenAIRE

    Thompson, Joseph E.

    2004-01-01

    Gutowski et al.'s model has been employed to describe the cure and consolidation of prepregs used for resin film infusion. Resin kinetics, rheology, flow and fiber deformation are considered. Resin kinetics are simulated with an isothermal autocatalytic-1 type relation. The non-Newtonian viscosity of the Cytec™ 754 resin is represented with a gel type expression. The one dimensional flow of resin through a deformable, partially saturated porous medium is studied. A nonlinear partial...

  4. Determination of Trace Nickel in Bi-Based Superconductor Powder by Inductively Coupled Plasma Atomic Emission Spectroscopy after Separation with Anion Exchange Resin and Extraction with Methylbenzene%阴离子交换树脂分离甲苯萃取ICP-AES测定铋系超导粉中的痕量镍

    Institute of Scientific and Technical Information of China (English)

    范丽新; 李建强; 范慧俐; 孙建伶; 张霞; 包蕊; 陆青; 王杰

    2011-01-01

    A new method for the determination of trace nickel in superconductor powder by ICP-AES was proposed. The instrument parameters were optimized) and the matrix effects as well as the method of eliminating interferences were also studied sys-temically. The results showed that matrix interference in the superconductor powder was serious when the amount of matrix increased, and the repeatability as well as the accuracy was poor, so it was necessary to used separation and preconcentration to improve the accuracy and precision. In this experiment, Ni-diacetyl dioxime complexes were enriched by toluene extraction in alkaline condition after eliminating the interference of major element Bi and partial Pb, Sr, Ca and Cu by eluting with anion exchange resin, then the Ni-complexes were back extracted by diluted hydrochloric acid. The enrichment conditions were investigated in detail and the recovery rate of Ni was higher than 95%. Under the optimal condition, an artificial sample was analysed, the result showed that the found values were identical with reference values, and the RSD and detection limit were 1. 9% and 0.19 μg ? g-1, respectively. The method has been applied to the determination of trace nickel in Bi-based superconductor powder samples with satisfactory results.%建立了ICP-AES测定超导粉中痕量镍的新方法.优化了仪器工作参数,对超导前驱粉中痕量镍测定时的基体干扰及干扰消除方法进行了系统研究,结果表明:大量存在的基体元素产生严重基体效应,导致测定重现性及准确度变差,实验采用分离富集方法以提高测定结果的准确度和精密度.实验中首先用阴离子交换树脂,除去Bi3+及部分pb2+,Sr2+,Ca2+,Cu2十等基体元素;在碱性条件下再通过甲苯萃取镍与丁二酮肟的络合物、稀盐酸反萃取富集镍;对分离富集条件进行了优化.对模拟标准样品进行测定,分析结果与理论值一致,相对标准偏差为1.9%,方法检出限为0

  5. Dental repair material: a resin-modified glass-ionomer bioactive ionic resin-based composite.

    Science.gov (United States)

    Croll, Theodore P; Berg, Joel H; Donly, Kevin J

    2015-01-01

    This report documents treatment and repair of three carious teeth that were restored with a new dental repair material that features the characteristics of both resin-modified glass-ionomer restorative cement (RMGI) and resin-based composite (RBC). The restorative products presented are reported by the manufacturer to be the first bioactive dental materials with an ionic resin matrix, a shock-absorbing resin component, and bioactive fillers that mimic the physical and chemical properties of natural teeth. The restorative material and base/liner, which feature three hardening mechanisms, could prove to be a notable advancement in the adhesive dentistry restorative materials continuum.

  6. Antiectoparasitic activity of the gum resin, gum haggar, from the East African plant, Commiphora holtziana.

    Science.gov (United States)

    Birkett, Michael A; Abassi, Sate Al; Kröber, Thomas; Chamberlain, Keith; Hooper, Antony M; Guerin, Patrick M; Pettersson, Jan; Pickett, John A; Slade, Robin; Wadhams, Lester J

    2008-05-01

    The mechanism of ixodid tick (Acari: Ixodidae) repellency by gum haggar, a resin produced by Commiphora holtziana (Burseraceae), was investigated by evaluating activity against the cattle tick, Boophilus microplus. In an arena bioassay, a hexane extract of the resin of C. holtziana exhibited a repellent effect lasting up to 5h. The hydrocarbon fraction of the resin extract was shown to account for the repellent activity, and was analysed by coupled gas chromatography-mass spectrometry (GC-MS). Major sesquiterpene hydrocarbons were tentatively identified as germacrene-D, delta-elemene and beta-bourbonene. The identity and stereochemistry of the former compound was confirmed as the (+)-isomer by peak enhancement using enantioselective GC, whereas the latter 2 compounds, which are most likely degradation products of germacrene-type precursors, were identified through isolation by preparative gas chromatography followed by microprobe-NMR spectroscopy. GC comparison of gum haggar with another resin, C. myrrha, which was inactive in the tick bioassay, showed that the latter contained much lower levels of these hydrocarbons. To assess the suitability of the gum haggar resin as a general acarine repellent, further tests were made on a major acarine pest of European and US animal husbandry systems, the red poultry mite, Dermanyssus gallinae (Acari: Dermanyssidae). Gum haggar extract, and the isolated hydrocarbon fraction, showed strong repellent effects in an olfactometer assay, and again gum myrrh showed no effect. These findings provide a scientific basis for the observed anti-tick properties of gum haggar, and demonstrate the potential for its development as a general acarine repellent for use in animal husbandry systems.

  7. Cytotoxicity and cytokine expression induced by silorane and methacrylate-based composite resins

    Science.gov (United States)

    LONGO, Daniele Lucca; PAULA-SILVA, Francisco Wanderley Garcia; FACCIOLI, Lucia Helena; GATÓN-HERNÁNDEZ, Patrícia Maria; de QUEIROZ, Alexandra Mussolino; da SILVA, Léa Assed Bezerra

    2016-01-01

    ABSTRACT The successful use of composite resins in Dentistry depends on physicochemical properties, but also on the biological compatibility of resins, because of the close association between pulp and dentin. Objective The aim of this study was to evaluate cytotoxicity and cytokine production induced by light-cured or non-light-cured methacrylate-based and silorane composite resins in RAW 264.7 macrophages. Material and Methods Cells were stimulated with the extracts from light-cured or non-light-cured composite resins. After incubation for 24 h, cytotoxicity was assessed with the lactate dehydrogenase (LDH) and methyl thiazolyl tetrazolium (MTT) assays, and total protein was quantified using the Lowry method. TNF-α detection was examined with an enzyme-linked immunosorbent assay (ELISA) conducted with cell supernatants after cell stimulation for 6, 12, and 24 h. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey’s post hoc test (α=0.05). Results KaloreTM and FiltekTM Silorane were cytotoxic with or without light curing (p0.05). However, after 24 h FiltekTM Silorane inhibited the production of TNF-α (p<0.05). Conclusions KaloreTM and FiltekTM Silorane were cytotoxic regardless of light curing. The extract obtained from KaloreTM after 15 days of incubation stimulated the production of TNF-α, unlike that obtained from FiltekTM Silorane. PMID:27556204

  8. Zinc Chloride Influence on The Resins Furan Polymerization to Foundry Moulds

    Science.gov (United States)

    de Miranda, Leila Figueiredo; Vale, Marcus; Júnior, Antonio Hortêncio Munhoz; Masson, Terezinha Jocelen; de Andrade e Silva, Leonardo Gondin

    The resins used in foundry molds developed for the automotive market has led to major changes in the manufacturing method of foundry molds. The polymerization of these resins and a subsequent curing are used to connect to the foundry sand in a rigid structure capable of receiving and holding liquid metal. It is essential to know the process of polymerization of these resins and their impact on the final properties of the obtained molds, especially in the mechanical characteristics. In this work it was studied the influence of the addition of zinc chloride (in solution) in the sand-furan resin mixture, with the aim of reducing the relation between the extraction time intervals and time bench life. The results showed that addition of percentages of the order of 5.0wt% to 7.5wt% zinc chloride solution reduces this ratio between 10% and 17%; this means that the casting model may be extracted from the sand mass in a smaller time interval increasing the productivity of manufacturing molds. It was also observed that there was also an increase of 9% to 18% in bench life intervals.

  9. Purification of chlorogenic acid in Flos Lonicerae with system of polar ordered resins

    Institute of Scientific and Technical Information of China (English)

    XIANG Zhi-nan; ZHAN Yu; NING Zheng-xiang

    2007-01-01

    A system of polar ordered resins was established for purification of chlorogenic acid in Flos Lonicerae. It was composed of three reversed phase resins, AB-8, DM-130 and NKA-9, representative for their gradually increased polarity and selectivity. A method of RP-HPLC was used for determination of chlorogenic acid. And the performance of adsorption and desorption for chlorogenic acid with the system of polar ordered resins was studied. Furthermore, the effects of concentration, pH and flow rate of the adsorbate on adsorption ability were researched. It is indicated that the optimum parameters for chlorogenic acid are as follows:pH 3.5 with a flow rate of 2.5 BV/h, the concentration of extract solution at 0.50, 0.40, 0.30 g/L respectively for the adsorptive operation twice, and 6.93, 8.66, 10.39 mol/L ethanol used as gradient eluants. The purity of resulted product of chlorogenic acid arrives 70.20% with yield of 89.79%. With simple procedures, low costs and high purity product, the method of system of polar ordered resins followed by sequential reversed phase separations can be used to refine the chlorogenic acid in the extraction of Flos Lonicerae.

  10. Color-Matching and Blending-Effect of Universal Shade Bulk-Fill-Resin-Composite in Resin-Composite-Models and Natural Teeth.

    Science.gov (United States)

    Abdelraouf, Rasha M; Habib, Nour A

    2016-01-01

    Objectives. To assess visually color-matching and blending-effect (BE) of a universal shade bulk-fill-resin-composite placed in resin-composite-models with different shades and cavity sizes and in natural teeth (extracted and patients' teeth). Materials and Methods. Resin-composite-discs (10 mm × 1 mm) were prepared of universal shade composite and resin-composite of shades: A1, A2, A3, A3.5, and A4. Spectrophotometric-color-measurement was performed to calculate color-difference (ΔE) between the universal shade and shaded-resin-composites discs and determine their translucency-parameter (TP). Visual assessment was performed by seven normal-color-vision-observers to determine the color-matching between the universal shade and each shade, under Illuminant D65. Color-matching visual scoring (VS) values were expressed numerically (1-5): 1: mismatch/totally unacceptable, 2: Poor-Match/hardly acceptable, 3: Good-Match/acceptable, 4: Close-Match/small-difference, and 5: Exact-Match/no-color-difference. Occlusal cavities of different sizes were prepared in teeth-like resin-composite-models with shades A1, A2, A3, A3.5, and A4. The cavities were filled by the universal shade composite. The same scale was used to score color-matching between the fillings and composite-models. BE was calculated as difference in mean-visual-scores in models and that of discs. Extracted teeth with two different class I-cavity sizes as well as ten patients' lower posterior molars with occlusal caries were prepared, filled by universal shade composite, and assessed similarly. Results. In models, the universal shade composite showed close matching in the different cavity sizes and surrounding shades (4 ≤ VS composite showed good-matching (VS = 3-3.3, BE = -0.9-2.1). Conclusions. Color-matching of universal shade resin-composite was satisfactory rather than perfect in patients' teeth.

  11. (GSA) resin for removal and recovery o

    African Journals Online (AJOL)

    2011-05-30

    May 30, 2011 ... The adsorption of different metal ions on GSA resin follows the order: Cu2+ > Fe2+ > Zn2+ ..... midazolylazo group and its use in the separation of heavy metals. .... cosmetics formulations, drug delivery vehicle and waste water.

  12. Amine chemistry. Update on impact on resin

    Energy Technology Data Exchange (ETDEWEB)

    Bachman, Gregory; Kellogg, Douglas [Siemens Industry, Inc., Rockford, IL (United States). Technology and Lab Services; Wilkes, Marty [Siemens Industry, Inc., Rockford, IL (United States). Water Technologies Div.

    2012-03-15

    Impurity removal in the steam cycle and the associated prevention of corrosion and/or fouling of system components are the goals of ion exchange resins. However, in many instances (such as a switch to amine chemistry or a change in product specifications), resins do not remove, and, in fact, contribute impurities to the steam cycle. This paper reviews recent data compiled to determine the direct and indirect effects of amines on ion exchange resins used in the power industry. Water chemistries have improved in recent years, in large part due to changes in chemistry and resins, but it is necessary to continue to develop products, processes and techniques to reduce impurities and improve overall water chemistry in power plant systems. (orig.)

  13. Indirect composite resin materials for posterior applications.

    Science.gov (United States)

    Shellard, E; Duke, E S

    1999-12-01

    Indirect composite resin restorations were introduced a number of years ago as possible alternatives to traditional metallic or ceramic-based indirect restorations. However, the earlier formulations did not provide evidence of improvement in mechanical and physical properties over chairside-placed direct composite resin materials. Because they required more tooth structure removal than direct restorations, their use became unpopular and was abandoned by most clinicians. Over the past few years, a new class of composite resin indirect materials has surfaced in the profession. Various technologies have been suggested as reinforcement mechanisms. Fibers, matrix modifications, and an assortment of innovations have been proposed for enhancing indirect composite resin restorations. Applications are from inlay restorations all the way to multi-unit fixed prostheses. This manuscript summarizes some of the progress made in this area. When available, data is presented to provide clinicians with guidelines and indications for the use of these materials.

  14. Light-cured resin for post patterns.

    Science.gov (United States)

    Waldmeier, M D; Grasso, J E

    1992-09-01

    A method of using light-cured acrylic resin as an alternative to the use of chemically-cured acrylic resins with elastomeric impressions for direct post patterns is presented. The GC Unifast LC acrylic resin is a powder/liquid type resin cured by exposure to visible light. The polymerization process has four stages before final curing: slurry, stringy, dough-like (plastic), and rubber-like (elastic). Advantages over current direct and indirect procedures include ease of manipulation of the material and no change in laboratory handling procedures. While in the dough-like state, the material can be contoured. In the rubber-like state, it is flexible to disengage from minor undercut areas.

  15. Phenolic Resin Sector Enters New Stage

    Institute of Scientific and Technical Information of China (English)

    Pu Zeshuang

    2007-01-01

    @@ Rapid output increase With the importation of new production technologies and the boom of large timber processing, insulation refractory material, composite material and foam plastics sectors in recent years, the phenolic resin production in China has developed rapidly.

  16. Separation and purification of amygdalin from thinned bayberry kernels by macroporous adsorption resins.

    Science.gov (United States)

    Wang, Tao; Lu, Shengmin; Xia, Qile; Fang, Zhongxiang; Johnson, Stuart

    2015-01-15

    To utilize the low-value thinned bayberry (Myrica rubra Sieb. et Zucc) kernels (TBKs) waste, an efficient method using macroporous adsorption resins (MARs) for separation and purification of amygdalin from TBKs crude extracts was developed. An aqueous crude sample was prepared from a methanol TBK extract, followed by resin separation. A series of MARs were initially screened for adsorption/desorption of amygdalin in the extract, and D101 was selected for characterization and method development. The static adsorption data of amygdalin on D101 was best fitted to the pseudo-second-order kinetics model. The solute affinity toward D101 at 30 °C was described and the equilibrium experimental data were well-fitted to Langmuir and Freundlich isotherms. Through one cycle of dynamic adsorption/desorption, the purity of amygdalin in the extract, determined by HPLC, increased about 17-fold from 4.8% to 82.0%, with 77.9% recovery. The results suggested that D101 resin effectively separate amygdalin from TBKs. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. 40 CFR 414.40 - Applicability; description of the thermoplastic resins subcategory.

    Science.gov (United States)

    2010-07-01

    ... AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS... (HDPE) Polyethylene Resin (LPDE) Polyethylene Resin, Scrap Polyethylene Resin, Wax (Low M.W...

  18. Resin composites : Sandwich restorations and curing techniques

    OpenAIRE

    Lindberg, Anders

    2005-01-01

    Since the mid-1990s resin composite has been used for Class II restorations in stress-bearing areas as an alternative to amalgam. Reasons for this were the patients’ fear of mercury in dental amalgam and a growing demand for aesthetic restorations. During the last decades, the use of new resin composites with more optimized filler loading have resulted in reduced clinical wear. Improved and simplified amphiphilic bonding systems have been introduced. However, one of the main problems with res...

  19. Biocompatibility of Resin-based Dental Materials

    OpenAIRE

    Keyvan Moharamzadeh; Ian M. Brook; Richard van Noort

    2009-01-01

    Oral and mucosal adverse reactions to resin-based dental materials have been reported. Numerous studies have examined thebiocompatibility of restorative dental materials and their components, and a wide range of test systems for the evaluation of the biological effects of these materials have been developed. This article reviews the biological aspects of resin-based dental materials and discusses the conventional as well as the new techniques used for biocompatibility assessment of dental mat...

  20. Contraction stresses of composite resin filling materials.

    Science.gov (United States)

    Hegdahl, T; Gjerdet, N R

    1977-01-01

    The polymerization shrinkage of composite resin filling materials and the tensile stresses developed when the shrinkage is restrained were measured in an in vitro experiment. This allows an estimation to be made of the forces exerted upon the enamel walls of cavities filled with the resin in the acid etch technique. The results indicate that the stresses acting on the enamel are low compared to the tensile strength of the enamel.

  1. Clinical applications of preheated hybrid resin composite.

    Science.gov (United States)

    Rickman, L J; Padipatvuthikul, P; Chee, B

    2011-07-22

    This clinical article describes and discusses the use of preheated nanohybrid resin composite for the placement of direct restorations and luting of porcelain laminate veneers. Two clinical cases are presented. Preheating hybrid composite decreases its viscosity and film thickness offering the clinician improved handling. Preheating also facilitates the use of nanohybrid composite as a veneer luting material with relatively low polymerisation shrinkage and coefficient of thermal expansion compared to currently available resin luting cements.

  2. Volumetric polymerization shrinkage of contemporary composite resins

    Directory of Open Access Journals (Sweden)

    Halim Nagem Filho

    2007-10-01

    Full Text Available The polymerization shrinkage of composite resins may affect negatively the clinical outcome of the restoration. Extensive research has been carried out to develop new formulations of composite resins in order to provide good handling characteristics and some dimensional stability during polymerization. The purpose of this study was to analyze, in vitro, the magnitude of the volumetric polymerization shrinkage of 7 contemporary composite resins (Definite, Suprafill, SureFil, Filtek Z250, Fill Magic, Alert, and Solitaire to determine whether there are differences among these materials. The tests were conducted with precision of 0.1 mg. The volumetric shrinkage was measured by hydrostatic weighing before and after polymerization and calculated by known mathematical equations. One-way ANOVA (a or = 0.05 was used to determine statistically significant differences in volumetric shrinkage among the tested composite resins. Suprafill (1.87±0.01 and Definite (1.89±0.01 shrank significantly less than the other composite resins. SureFil (2.01±0.06, Filtek Z250 (1.99±0.03, and Fill Magic (2.02±0.02 presented intermediate levels of polymerization shrinkage. Alert and Solitaire presented the highest degree of polymerization shrinkage. Knowing the polymerization shrinkage rates of the commercially available composite resins, the dentist would be able to choose between using composite resins with lower polymerization shrinkage rates or adopting technical or operational procedures to minimize the adverse effects deriving from resin contraction during light-activation.

  3. The influences of N-acetyl cysteine (NAC on the cytotoxicity and mechanical properties of Poly-methylmethacrylate (PMMA-based dental resin

    Directory of Open Access Journals (Sweden)

    Yang Jiao

    2015-04-01

    Full Text Available Objectives. This study aimed to investigate the influences of N-acetyl cysteine (NAC on cytotoxicity and mechanical properties of Poly-methylmethacrylate (PMMA dental resins.Methods. Experimental PMMA resin was prepared by incorporating various concentrations of NAC (0, 0.15, 0.3, 0.6 and 0.9 wt.%. MTT assay was performed to investigate viability of human dental pulp cells after exposure to extract of PMMA resin with or without NAC. Cell adhesion on resin specimens was examined with scanning electron microscopy. Degree of conversion was studied with Fourier Transform Infrared Spectroscopy (FTIR. Flexural strength, microhardness and surface roughness was evaluated using a universal testing machine, microhardness tester and optical profilometer, respectively.Results. Incorporation of NAC into PMMA resin significantly reduced its cytotoxicity and enhanced cell adhesion on its surface. NAC induced negative influences on the mechanical and physical properties of PMMA resin in a dose-dependent manner. The degree of conversion for all experimental PMMA resins reached as high as 72% after 24 h of polymerization. All the tested properties were maintained when the concentration of incorporated NAC was 0.15 wt.%.Conclusion. The addition of 0.15 wt.% NAC remarkably improved biocompatibility of PMMA resin without exerting significant negative influence on its mechanical and physical properties.

  4. The influences of N-acetyl cysteine (NAC) on the cytotoxicity and mechanical properties of Poly-methylmethacrylate (PMMA)-based dental resin.

    Science.gov (United States)

    Jiao, Yang; Ma, Sai; Li, Jing; Shan, Lequn; Yang, Yanwei; Li, Meng; Chen, Jihua

    2015-01-01

    Objectives. This study aimed to investigate the influences of N-acetyl cysteine (NAC) on cytotoxicity and mechanical properties of Poly-methylmethacrylate (PMMA) dental resins. Methods. Experimental PMMA resin was prepared by incorporating various concentrations of NAC (0, 0.15, 0.3, 0.6 and 0.9 wt.%). MTT assay was performed to investigate viability of human dental pulp cells after exposure to extract of PMMA resin with or without NAC. Cell adhesion on resin specimens was examined with scanning electron microscopy. Degree of conversion was studied with Fourier Transform Infrared Spectroscopy (FTIR). Flexural strength, microhardness and surface roughness was evaluated using a universal testing machine, microhardness tester and optical profilometer, respectively. Results. Incorporation of NAC into PMMA resin significantly reduced its cytotoxicity and enhanced cell adhesion on its surface. NAC induced negative influences on the mechanical and physical properties of PMMA resin in a dose-dependent manner. The degree of conversion for all experimental PMMA resins reached as high as 72% after 24 h of polymerization. All the tested properties were maintained when the concentration of incorporated NAC was 0.15 wt.%. Conclusion. The addition of 0.15 wt.% NAC remarkably improved biocompatibility of PMMA resin without exerting significant negative influence on its mechanical and physical properties.

  5. Sorption of Cr(VI) by Amberlite XAD-7 resin impregnated with brilliant green and its determination by quercetin as a selective spectrophotometric reagent.

    Science.gov (United States)

    Hosseini, Mohammad Saeid; Hosseini-Bandegharaei, Ahmad; Raissi, Haidar; Belador, Foroogh

    2009-09-30

    A new chelating polymeric sorbent as an extractant-impregnated resin (EIR) has been developed using brilliant green (BG) and Amberlite XAD-7 resin. The BG-impregnated resin showed superior binding affinity for Cr(VI) in the presence of many co-existing ions and no considerable interference was observed. The influence of various physicochemical parameters on the recovery of Cr(VI) were optimized by both static and dynamic methods. The Langmuir adsorption isotherm gave a satisfactory fit of the equilibrium data. The kinetic studies performed for Cr(VI) sorption revealed that 93%, which confirmed accuracy of the measurements.

  6. Extraction of extracellular polymeric substances (EPS) from anaerobic granular sludges: comparison of chemical and physical extraction protocols

    OpenAIRE

    2010-01-01

    The characteristics of the extracellular polymeric substances (EPS) extracted with nine different extraction protocols from four different types of anaerobic granular sludge were studied. The efficiency of four physical (sonication, heating, cationic exchange resin (CER), and CER associated with sonication) and four chemical (ethylenediaminetetraacetic acid, ethanol, formaldehyde combined with heating, or NaOH) EPS extraction methods was compared to a control extraction protocols (i.e., centr...

  7. EXTRACTION OF CITRIC ACID FROM FERMENTATION BROTH USING ION—EXCHANGE METHOD

    Institute of Scientific and Technical Information of China (English)

    LiuZuozhen; WangXiangyang; 等

    1998-01-01

    A number of ion-exchange resins were tested on their capacity to adsorb citric acid,among them resin 335,d315, Amberlite IRA-35 and IRA-68 exhibited higher adsorption capacity.We chose resin 335 and D315 to be used for extraction of citric acid from fermentation broth,followed by elution with 10% ammonia liquor,decoloration with K-15 carbon and removal of ammonia with resin 732,converting citrate of free citric acid with a concentration of 10% and an amount of readily carbonizable substance meeting the GB 8269-87 standard.

  8. [Classification and several mechanical properties of core composite resins].

    Science.gov (United States)

    Yamada, T; Hosoda, H; Tsurugai, T

    1990-03-01

    According to the classification proposed by Hosoda, six core resins could be divided into two categories on the basis of the elemental composition and size distribution of filler particles by SEM observation and EDX analysis. Furthermore, several mechanical properties of the resins were determined. The following facts were found: Bell Feel Core, Clearfil Core, Clearfil PhotoCore, Core Max, and Core Max II resins were classified as a semihybrid resin, and Microrest Core resin as a hybrid type resin. The elements detected in the resins by the EDX were Si, Zr, Al, Ba and La. The mechanical properties of the resins were shown to be highly stable at one day or one week after curing. The mechanical properties of the resins suggest that the subsequent crown preparation and impression taking should be postponed until the next appointment.

  9. Degradation and detoxification of softwood extractives by sapstain fungi

    NARCIS (Netherlands)

    Dorado, J.; Claassen, F.W.; Lenon, G.; Beek, van T.A.; Wijnberg, J.B.P.A.; Sierra-Alvarez, R.

    2000-01-01

    Wood extractives (resin) cause pitch deposition problems and effluent toxicity in pulp and papermaking. The ability of six sapstaining fungi to degrade and detoxify extractive constituents in Scots pine sapwood was examined, and the results were compared with those obtained with the commercial depit

  10. Clinical Evaluation of Indirect Composite Resin Restorations Cemented with Different Resin Cements.

    Science.gov (United States)

    Marcondes, Maurem; Souza, Niélli; Manfroi, Fernanda Borguetti; Burnett, Luiz Henrique; Spohr, Ana Maria

    2016-01-01

    To clinically evaluate the performance of indirect composite resin restorations cemented with conventional and self-adhesive resin cements over a 12-month period. Ten patients fulfilled all the inclusion criteria. Twenty-four composite resin restorations were performed using an indirect technique and cemented with a resin cement (RelyX ARC) or a self-adhesive resin cement (RelyX U100). Two independent evaluators analyzed the restorations using modified USPHS criteria after periods of two weeks and 6 and 12 months. Statistical significance between the cements at each timepoint was evaluated with the Wilcoxon test and between timepoints with the Mann-Whitney test, both at a significance level of 5%. Fisher's exact test was used to assess the occurrence of absolute failures. No statistically significant differences were found between the groups at the same timepoint nor between groups at different timepoints. The only significant difference was found for color match for both groups after 12 months. After 12 months, indirect composite resin restorations cemented with self-adhesive resin cement performed similarly to those cemented with conventional resin cement.

  11. Industrial application of Raman spectroscopy for control and optimization of vinyl acetate resin polymerization.

    Science.gov (United States)

    Frauendorfer, Eric; Hergeth, Wolf-Dieter

    2017-01-01

    Monitoring and control of resin polymerizations is essential for high process safety, high product quality, and competitive production costs. Vinyl acetate resins created by bulk and solution polymerization usually have a high molecular weight and viscosity, making sample extraction for analysis a cumbersome process. In-process analytical methods, like Raman spectroscopy, enable not only the measurement of monomer and polymer composition during the reaction without complex mathematical calibrations but also the determination of final product properties. The latter is also possible in conjunction with other process data like temperatures and feed rates and with a multivariate approach. An overview of challenges, necessary considerations, and results is given. Graphical abstract Prediction of product quality parameter viscosity using online-Raman spectroscopy data vs. reference data (Hoeppler viscosity measured in the lab after sample extraction) using partial least squares modelling.

  12. Imide modified epoxy matrix resins

    Science.gov (United States)

    Scola, D. A.

    1984-01-01

    The results of a program designed to develop tough imide modified epoxy resins cured by bisimide amine (BIA) hardeners are described. State-of-the-art epoxides MY720 and DER383 were used, and four bismide amines were evaluated. These were the BIA's derived from the 6F anhydride (4,4'-(hexafluoroisopropylidene) bis(phthalic anhydride) and the diamines 3,3'-diaminodiphynyl sulfone, 4,4'-oxygianiline, 4,4'-methylene dianiline, and 1,12-dodecane diamine. A key intermediate, designated 6F anhydride, is required for the synthesis of the bisimide amines. Reaction parameters to synthesize a precursor to the 6F anhydride (6FHC) in high yields were investigated. The catalyst trifluoromethane sulfonic acid was studied. Although small scale runs yielded the 6FHC in 50 percent yield, efforts to ranslate these results to a larger scale synthesis gave the 6FHC in only 9 percent yield. Results show that the concept of using bisimide amine as curing agents to improve the toughness properties of epoxies is valid.

  13. Ex vivo fracture resistance of direct resin composite complete crowns with and without posts on maxillary premolars.

    NARCIS (Netherlands)

    Fokkinga, W.A.; Bell, A.M. Le; Kreulen, C.M.; Lassila, L.V.; Vallittu, P.K.; Creugers, N.H.J.

    2005-01-01

    AIM: To investigate ex vivo the fracture resistance and failure mode of direct resin composite complete crowns with and without various root canal posts made on maxillary premolars. METHODOLOGY: The clinical crowns of 40 human extracted single-rooted maxillary premolars were sectioned at the cemento

  14. [Bonding compatibility between adhesive systems and composite resins].

    Science.gov (United States)

    Giachetti, L; Scaminaci Russo, D; Landi, D

    2003-04-01

    The purpose of the present study was to analyse bonding compatibility between photo- and self-polymerising composite resins ad two-step total-etch (one component) adhesive systems with a different activation method. Thirty healthy extracted molars were cut transversally to obtain sixty flat dentin surfaces. The acid conditioned surfaces were bonded with Scotchbond 1 (3M), Excite (Vivadent) or Excite DSC (Vivadent). A cylinder of composite resin (3 mm diameter and 4 mm height) was constructed on each adhesive layer using photopolymerised Tetric Ceram (Vivadend) and dual Luxacore (DMG) but activated only chemically. The samples were subjected to the shear bond test. The fracture surfaces obtained were classified by type and site in the stereomicroscope. Twelve samples representing each group were further prepared for the SEM. The data obtained from the test, the microscopic investigation and statistical analysis (ANOVA and Bonferroni) seem to confirm the presence of a reduced bonding compatibility between one-component adhesive systems and self-polymerising composites. This incompatibility is evident for the adhesive Scotchbond 1 and limited for Excite, while it seems to be overcome by Excite DSC which appears to bond well with both Tetric Ceram and Luxacore. Adhesive-composite incompatibility seems to depend on the activation method of the composite as well as on that of the adhesive system. The chemical compatibility bet-ween these two materials is influenced not only by the chemical composition of the adhesive, but also by that of the composite.

  15. Utilization of Methacrylates and Polymer Matrices for the Synthesis of Ion Specific Resins

    Energy Technology Data Exchange (ETDEWEB)

    Czerwinski, Kenneth [Univ. of Nevada, Las Vegas, NV (United States)

    2013-10-29

    Disposal, storage, and/or transmutation of actinides such as americium (Am) will require the development of specific separation schemes. Existing efforts focus on solvent extraction systems for achieving suitable separation of actinide from lanthanides. However, previous work has shown the feasibility of ion-imprinting polymer-based resins for use in ion-exchange-type separations with metal ion recognition. Phenolic-based resins have been shown to function well for Am-Eu separations, but these resins exhibited slow kinetics and difficulties in the imprinting process. This project addresses the need for new and innovative methods for the selective separation of actinides through novel ion-imprinted resins. The project team will explore incorporation of metals into extended frameworks, including the possibility of 3D polymerized matrices that can serve as a solid-state template for specific resin preparation. For example, an anhydrous trivalent f-element chain can be formed directly from a metal carbonate, and methacrylic acid from water. From these simple coordination complexes, molecules of discrete size or shape can be formed via the utilization of coordinating ligands or by use of an anionic multi-ligand system incorporating methacrylate. Additionally, alkyl methyl methacrylates have been used successfully to create template nanospaces, which underscores their potential utility as 3D polymerized matrices. This evidence provides a unique route for the preparation of a specific metal ion template for the basis of ion-exchange separations. Such separations may prove to be excellent discriminators of metal ions, even between f-elements. Resins were prepared and evaluated for sorption behavior, column properties, and proton exchange capacity.

  16. Bulk-filled posterior resin restorations based on stress-decreasing resin technology

    DEFF Research Database (Denmark)

    van Dijken, Jan W.V.; Pallesen, Ulla

    2017-01-01

    This randomized study evaluated a flowable resin composite bulk-fill technique in posterior restorations and compared it intraindividually with a conventional 2-mm resin composite layering technique over a 6-yr follow-up period. Thirty-eight pairs of Class II restorations and 15 pairs of Class I...... restorations were placed in 38 adults. In all cavities a single-step self-etch adhesive (Xeno V) was applied. In the first cavity of each pair, the flowable resin composite (SDR) was placed, in bulk increments of up to 4 mm. The occlusal part was completed with a layer of nanohybrid resin composite (Ceram X...... mono). In the second cavity of each pair, the hybrid resin composite was placed in 2-mm increments. The restorations were evaluated using slightly modified US Public Health Service (USPHS) criteria at baseline and then annually for a time period of 6 yr. After 6 yr, 72 Class II restorations and 26...

  17. [Studies on purgative activity of rhubarb extracts by different technologies].

    Science.gov (United States)

    Zheng, Zhihua; Zhu, Chenchen; Gui, Shuhua; Lin, Chaozhan

    2002-08-01

    To study on purgative activity of rhubarb extracts by solvent extraction, SFE-CO2 and SFE-CO2 & residue resin purification. The effects of the extracts by the three technologies on creepage of mouse small intestine and rat large intestine were studied by injecting charcoal ink into the intestines. And the volume of the mouse small intestine was observed. The effects of the extracts were also studied on water absorption of mouse small intestine and large intestine by weighing the intestines. The purgative activity of the extracts by the three technologies was SFE-CO2 & residue resin purification > solvent extraction > SFE-CO2. Extracting different polar components separately might get a good result.

  18. Thermal rearrangement of novolak resins used in microlithography

    Science.gov (United States)

    Hardy, Ricky; Zampini, Anthony; Monaghan, Michael J.; O'Leary, Michael J.; Cardin, William J.; Eugster, Timothy J.

    1995-06-01

    Changes in phenolic-formaldehyde resin properties are described in terms of thermal exposure. At high temperature, resin molecular weight, dissolution properties and chemical composition change depending on the presence or absence of monomers. Without monomer in the resin melt at 220 degree(s)C, resin molecular weight increases with a corresponding decrease in dissolution rate. In the presence of monomer, molecular weight generally decreases. Dissolution rate may fluctuate depending on the monomer mixture. Three,five- Xylenol and 2,3,5-trimethylphenol co-monomers induced the most extreme changes in resin properties with thermal treatment. Resin degradation-recombination processes suggest a classical Friedel-Craft rearrangement mechanism.

  19. Tc-99 Ion Exchange Resin Testing

    Energy Technology Data Exchange (ETDEWEB)

    Valenta, Michelle M.; Parker, Kent E.; Pierce, Eric M.

    2010-08-01

    Pacific Northwest National Laboratory was contracted by CHPRC to evaluate the release of 99Tc from spent resin used to treat water from well 299-W15-765 and stored for several years. The key questions to be answered are: 1) does 99Tc readily release from the spent ion exchange resin after being in storage for several years; 2) if hot water stripping is used to remove the co-contaminant carbon tetrachloride, will 99Tc that has been sequestered by the resin be released; and 3) can spent resin be encapsulated into a cementitious waste form; if so, how much 99Tc would be released from the weathering of the monolith waste form? The results from the long term stability leach test results confirm that the resin is not releasing a significant amount of the sequestered 99Tc, evident by the less than 0.02% of the total 99Tc loaded being identified in the solution. Furthermore, it is possible that the measured 99Tc concentration is the result of 99Tc contained in the pore spaces of the resin. In addition to these results, analyses conducted to examine the impact of hot water on the release of 99Tc suggest that only a small percentage of the total is being released. This suggest that hot water stripping to remove carbon tetrachloride will not have a significant affect on the resin’s ability to hold-on to sequestered 99Tc. Finally, encapsulation of spent resin in a cementitious material may be a viable disposal option, but additional tests are needed to examine the extent of physical degradation caused by moisture loss and the effect this degradation process can have on the release of 99Tc.

  20. Enrichment of antioxidants in black garlic juice using macroporous resins and their protective effects on oxidation-damaged human erythrocytes.

    Science.gov (United States)

    Zou, Ying; Zhao, Mouming; Yang, Kun; Lin, Lianzhu; Wang, Yong

    2017-08-15

    The black garlic juice is popular for its nutritive value. Enrichment of antioxidants is needed to make black garlic extract an effective functional ingredient. Five macroporous resins were evaluated for their capacity in adsorbing antioxidants in black garlic juice. XAD-16 resin was chosen for further study due to its high adsorption and desorption ratios. Pseudo-second-order kinetics (qe=625μmol Trolox equiv/g dry resin, k2=0.0001463) and Freundlich isotherm models (ΔH=-10.1547kJ/mol) were suitable for describing the whole exothermic and physical adsorption processes of the antioxidants from black garlic juice on XAD-16 resin. The antioxidants and phenolics were mostly enriched in 40% ethanol fraction by XAD-16 resin column chromatography. The black garlic extract and its fractions could protect erythrocytes against AAPH-induced hemolysis in dose-dependent manners. The pretreatment of AAPH-damaged erythrocytes with 40% ethanol fractions (2.5mg/mL) significantly decreased the hemolysis ratios from 53.58% to 3.79%. The 40% ethanol fraction possessing strong intracellular antioxidant activity could be used as a functional food ingredient. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Effects of Different Light Curing Units/Modes on the Microleakage of Flowable Composite Resins

    OpenAIRE

    Yazici, A. Ruya; Celik, Cigdem; Dayangac, Berrin; Ozgunaltay, Gul

    2008-01-01

    Objectives The aim of this in vitro study was to evaluate the influence of different light curing units and modes on microleakage of flowable composite resins. Methods Eighty Class V cavities were prepared in buccal and lingual surfaces of 40 extracted human premolars with cervical wall located in dentin and the occlusal wall in enamel. These teeth were randomly assigned into two groups (n=20) and restored with different flowable composites; Group I: Esthet-X Flow, Group II: Grandio Flow. Eac...

  2. Thermal cycling effects on adhesion of resin-bovine enamel junction among different composite resins.

    Science.gov (United States)

    Chen, Wen-Cheng; Ko, Chia-Ling; Wu, Hui-Yu; Lai, Pei-Ling; Shih, Chi-Jen

    2014-10-01

    Thermal cycling is used to mimic the changes in oral cavity temperature experienced by composite resins when used clinically. The purpose of this study is to assess the thermal cycling effects of in-house produced composite resin on bonding strength. The dicalcium phosphate anhydrous filler surfaces are modified using nanocrystals and silanization (w/NP/Si). The resin is compared with commercially available composite resins Filtek Z250, Z350, and glass ionomer restorative material GIC Fuji-II LC (control). Different composite resins were filled into the dental enamel of bovine teeth. The bond force and resin-enamel junction graphical structures of the samples were determined after thermal cycling between 5 and 55°C in deionized water for 600 cycles. After thermal cycling, the w/NP/Si 30wt%, 50wt% and Filtek Z250, Z350 groups showed higher shear forces than glass ionomer GIC, and w/NP/Si 50wt% had the highest shear force. Through SEM observations, more of the fillings with w/NP/Si 30wt% and w/NP/Si 50wt% groups flowed into the enamel tubule, forming closed tubules with the composite resins. The push-out force is proportional to the resin flow depth and uniformity. The push-out tubule pore and resin shear pattern is the most uniform and consistent in the w/NP/Si 50wt% group. Accordingly, this developed composite resin maintains great mechanical properties after thermal cycling. Thus, it has the potential to be used in a clinical setting when restoring non-carious cervical lesions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Clinical evaluation of a flowable resin composite and flowable compomer for preventive resin restorations.

    Science.gov (United States)

    Qin, Man; Liu, HongSheng

    2005-01-01

    This clinical study evaluated the retention and caries protection of a flowable resin composite (Flow Line) and a flowable compomer (Dyract Flow) used in preventive resin restorations as compared to the conventional preventive resin technique which uses a resin composite (Brilliant) and a sealant (Concise). This study observed 205 permanent molars with small carious cavities less than 1.5 mm in width, which were obtained from 165 children aged 7 to 15 years. Flowable resin composite was used to treat 75 teeth, and 71 teeth were treated with flowable compomer in both cavities and caries-free fissures. For the control group, 59 teeth were treated with resin composite in cavities and sealant in caries-free fissures. The teeth were evaluated at 3, 6, 12, 18 and 24-month intervals. After three months, all 205 treated teeth were completely intact. After six months, 66 of the 71 teeth treated with flowable resin composite and 65 of the 70 teeth treated with flowable compomer were complete, compared to 57 of the 58 teeth treated with the conventional preventive resin technique. After 12 months, 60 of the 67 teeth treated with flowable resin composite and 61 of the 67 teeth treated with flowable compomer were complete, compared to 51 of the 55 teeth treated with the conventional preventive resin technique. After 18 months, 53 of the 61 teeth treated with flowable resin composite and 54 of the 62 teeth treated with flowable compomer were complete, compared to 47 of the 53 teeth treated with the conventional preventive resin technique. After 24 months, 49 of the 58 teeth treated with flowable resin composite and 45 of the 57 teeth treated with flowable compomer were complete, compared to 42 of the 52 teeth treated with the conventional preventive resin technique. There were no statistically significant differences in retention rates among all groups after 3, 6, 12, 18 or 24-months (p>0.05). One tooth treated with flowable resin composite and one tooth treated with flowable

  4. Ponderosa pine resin defenses and growth: metrics matter.

    Science.gov (United States)

    Hood, Sharon; Sala, Anna

    2015-11-01

    Bark beetles (Coleoptera: Curculionidae, Scolytinae) cause widespread tree mortality in coniferous forests worldwide. Constitutive and induced host defenses are important factors in an individual tree's ability to survive an attack and in bottom-up regulation of bark beetle population dynamics, yet quantifying defense levels is often difficult. For example, in Pinus spp., resin flow is important for resistance to bark beetles but is extremely variable among individuals and within a season. While resin is produced and stored in resin ducts, the specific resin duct metrics that best correlate with resin flow remain unclear. The ability and timing of some pine species to produce induced resin is also not well understood. We investigated (i) the relationships between ponderosa pine (Pinus ponderosa Lawson & C. Lawson) resin flow and axial resin duct characteristics, tree growth and physiological variables, and (ii) if mechanical wounding induces ponderosa pine resin flow and resin ducts in the absence of bark beetles. Resin flow increased later in the growing season under moderate water stress and was highest in faster growing trees. The best predictors of resin flow were nonstandardized measures of resin ducts, resin duct size and total resin duct area, both of which increased with tree growth. However, while faster growing trees tended to produce more resin, models of resin flow using only tree growth were not statistically significant. Further, the standardized measures of resin ducts, density and duct area relative to xylem area, decreased with tree growth rate, indicating that slower growing trees invested more in resin duct defenses per unit area of radial growth, despite a tendency to produce less resin overall. We also found that mechanical wounding induced ponderosa pine defenses, but this response was slow. Resin flow increased after 28 days, and resin duct production did not increase until the following year. These slow induced responses may allow

  5. Biocompatibility of polymethylmethacrylate resins used in dentistry.

    Science.gov (United States)

    Gautam, Rupali; Singh, Raghuwar D; Sharma, Vinod P; Siddhartha, Ramashanker; Chand, Pooran; Kumar, Rakesh

    2012-07-01

    Biocompatibility or tissue compatibility describes the ability of a material to perform with an appropriate host response when applied as intended. Poly-methylmethacrylate (PMMA) based resins are most widely used resins in dentistry, especially in fabrication of dentures and orthodontic appliances. They are considered cytotoxic on account of leaching of various potential toxic substances, most common being residual monomer. Various in vitro and in vivo experiments and cell based studies conducted on acrylic based resins or their leached components have shown them to have cytotoxic effects. They can cause mucosal irritation and tissue sensitization. These studies are not only important to evaluate the long term clinical effect of these materials, but also help in further development of alternate resins. This article reviews information from scientific full articles, reviews, or abstracts published in dental literature, associated with biocompatibility of PMMA resins and it is leached out components. Published materials were searched in dental literature using general and specialist databases, like the PubMED database.

  6. Eco-friendly Crosslinking Agent for Acid Functional Acrylic Resin

    Directory of Open Access Journals (Sweden)

    Archana Shah

    2009-01-01

    Full Text Available Oil from J. multifida was extracted and it was first converted into N,N-bis(2-hydroxyethyl Jatropha fatty amide (HEJFA. HEJFA has been synthesized by reaction between Jatropha oil and diethanol amine in presence of zinc oxide as a catalyst. The reaction is relatively rapid and proceeded to high yield at 200±5 OC. The resulting HEJFA was used to formulate thermosetting coating compositions. Films were cured at ambient (air drying and elevated (stove drying temperatures using N, N-bis(2-hydroxyethyl Jatropha fatty amide (HEJFA as eco-friendly crosslinking agent for acrylic resin. The coating performance of the various compositions was tested by measurement of scratch hardness, impact strength and chemical resistance. The results show better performance of the HEJFA based compositions compared to butylated melamine formaldehyde (MF based compositions.

  7. 40 CFR 414.50 - Applicability; description of the thermosetting resins subcategory.

    Science.gov (United States)

    2010-07-01

    ... thermosetting resins subcategory. 414.50 Section 414.50 Protection of Environment ENVIRONMENTAL PROTECTION... Thermosetting Resins § 414.50 Applicability; description of the thermosetting resins subcategory. The provisions... the products classified under SIC 28214 thermosetting resins including those resins and resin...

  8. The influence of resin flexural modulus on the magnitude of ceramic strengthening.

    LENUS (Irish Health Repository)

    Fleming, Garry J P

    2012-07-01

    The aim was to determine the magnitude of ceramic resin-strengthening with resin-based materials with varying flexural moduli using a regression technique to assess the theoretical strengthening at a \\'zero\\' resin-coating thickness. The hypothesis tested was that experimentally, increasing resin flexural modulus results in increased resin-strengthening observed at a theoretical \\'zero\\' resin-coating thickness.

  9. Structural Evaluation of High Strain Fiber and Resin Composite Material Systems

    Science.gov (United States)

    1986-04-01

    6 2. Resin Properties Necessary to Improve Laminate Properties ......................................... 6 3. Neat Resin Stress...Ratio, E/Eo OPSop 14Sl R Figure 2. Resin Properties Necessary to Improve Laminate Properties I 6 failure and normalized resin modulus. These...normalized resin-related parameters bound the resin properties which result in improvements in laminate transverse strength, transverse modulus, strain energy

  10. Determination and Correlation of Depth of Cure of a New Composite Resin Delivery System.

    Science.gov (United States)

    Owens, Barry M; Slaven; Phebus, Jeffrey G; Ragain, James C

    2015-01-01

    To quantify the depth of cure (DOC) of a composite resin system using two different testing criteria. The DOC testing employed two different experimental protocol: 1) Forty-eight previously extracted human molars were randomly assigned to four groups of twelve each (n = 12): Group 1 SonicFill composite resin system, shade A1; Group 2 SonicFill, shade A3; Group 3 Herculite Ultra composite resin, shade A1; Group 4 Herculite Ultra, shade A3. Cylindrical cavities (4.0 mm diameter and 10 mm depth) were prepared at the tooth CEJ, in a mesiodistal direction. The preparations were filled with each composite resin material in one bulk increment and polymerized with a LED light for 20 seconds. After 5 minutes, the occlusal surfaces of the teeth (specimens) were ground flat until the composite was exposed in a transverse plane. The uncured (soft) composite was scraped away, using a "modified" ISO 4049 DOC specification, and the remaining cured (hard) material was measured. Three measurements, at different positions of the specimen, were performed, for a total of thirty-six measurements per specimen group. The measurements were averaged and divided by fifty percent, arriving at the final DOC for each specimen. 2) A DOC testing protocol was performed using a two-piece (4.0 mm x 10.0 mm) custom-made Teflon device (mold). The groupings duplicated the previous experimental protocol. The mold was filled with each composite resin material in one bulk increment to a 10 mm length (depth). Excess composite material was removed, followed by placement of a Mylar strip over the external orifice. The composite resin specimen was light-polymerized for 20 seconds. Again, the uncured (soft) composite was scraped away, with the same measurement protocol followed as in method 1. Statistical analyses were conducted using ANOVA tests at a p composite revealed significantly greater DOC compared to the Herculite Ultra composite resin. Also, significant differences were displayed between the Al

  11. Effect of resin cement, aging process and root level on the bond strength of the resin-fiber posts

    Science.gov (United States)

    Almuhim, Khalid Salman

    Background. Little is known about the long-term clinical bonding effectiveness of the Fiber-reinforced composite (FRC) posts cemented with self-etch adhesive systems. Bond stability and longevity of the cemented post are adversely affected by physical and chemical factors over time, such as expansion and contraction stresses caused by thermal changes and occlusal load. This clinical condition can be simulated in vitro by thermocyclic loading; and bonding effectiveness can be evaluated by applying the micropush out test. Therefore, more in vitro studies are needed to evaluate the bond strength of the fiber posts cemented with different resin cement systems after simulating the artificial aging induced by thermocycling. The aim of this study was to compare the microtensile bond strength of two different resin cement systems (total etch, and self-etch resin cement system) used for cementation of fiber reinforced composite posts in three different aging periods using thermocycling. Methods. Following IRB approval, sixty freshly extracted bicuspid single rooted natural teeth were endodontically treated, and the post-spaces were prepared to receive a fiber-post cemented with either a total etch resin cement (Rely-X Ultimate) or with a self-etch resin cement (Rely-X Unicem). No thermocycling, 20,000 and 40,000 cycles was used to age the specimens. Teeth were randomly allocated into six different groups: G1 - Control: Rely-X Ultimate cement with no thermocycling. G2: Rely-X Ultimate cement with 20,000 thermocycling. G3: Rely-X Ultimate cement with 40,000 thermocycling. G4: Rely-X Unicem cement. G5: Rely-X Unicem cement. G6: Rely-X Unicem cement. Microtensile bond strength determined using a micropush out test on a universal testing machine (MTS). Additionally, the failure mode of each specimen was observed under a stereomicroscope (Olympus) at 40x magnification. Finally, one representative sample was randomly selected from each of the five failure modes for scanning

  12. Vitrification of spent ion exchange resin from Korean NPPs

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, Jiawei [Kyoto University, Osaka (Japan); Choi, Kwan Sik; Yang, Kyung Hwa; Lee, Myung Chan; Song, Myung Jae [Nuclear Environment Technology Institute, Taejon (Korea, Republic of)

    1999-07-01

    Spent resin is the main wet waste generated by nuclear power plants (NPPs). Vitrification is conceptually attractive because of the potential durability of the final product and the large volume reduction. The vitrification of spent resin from NPPs is examined. There is a large amount of sulfate in spent resin ash. However, the limited solubility of sulfate in glass resulted in the low waste loading of spent resin. High sulfate in glass led to the phase separation. Some well-developed glasses frits have been used to vitrify spent resin from Korean NPPs. The waste loading is less than 5 wt percent of resin ash. Spent resin also was added to the borate waste glasses, 20 g of dry resin could be vitrified in 100 g of borate waste glass without phase separation and final waste from has good durability. (author). 12 refs., 6 tabs.

  13. 76 FR 8774 - Granular Polytetrafluoroethylene Resin From Japan

    Science.gov (United States)

    2011-02-15

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Granular Polytetrafluoroethylene Resin From Japan AGENCY: United States International Trade... polytetrafluoroethylene resin from Japan would be likely to lead to continuation or recurrence of material injury....

  14. Composite resin fillings and inlays: An 11-year evaluation

    DEFF Research Database (Denmark)

    Pallesen, U.; Qvist, V.

    2003-01-01

    Clinical trial, composite resin, direct restorations, indirect restorations, long-term behaviour, posterior teeth......Clinical trial, composite resin, direct restorations, indirect restorations, long-term behaviour, posterior teeth...

  15. Fluorinated Alkyl Ether Epoxy Resin Compositions and Applications Thereof

    Science.gov (United States)

    Wohl, Christopher J. (Inventor); Connell, John W. (Inventor); Smith, Joseph G. (Inventor); Siochi, Emilie J. (Inventor); Gardner, John M. (Inventor); Palmieri, Frank M. (Inventor)

    2017-01-01

    Epoxy resin compositions prepared using amino terminated fluoro alkyl ethers. The epoxy resin compositions exhibit low surface adhesion properties making them useful as coatings, paints, moldings, adhesives, and fiber reinforced composites.

  16. Development of Polymer Resins using Neural Networks

    Directory of Open Access Journals (Sweden)

    Fabiano A. N. Fernandes

    2002-01-01

    Full Text Available The development of polymer resins can benefit from the application of neural networks, using its great ability to correlate inputs and outputs. In this work we have developed a procedure that uses neural networks to correlate the end-user properties of a polymer with the polymerization reactor's operational condition that will produce that desired polymer. This procedure is aimed at speeding up the development of new resins and help finding the appropriate operational conditions to produce a given polymer resin; reducing experimentation, pilot plant tests and therefore time and money spent on development. The procedure shown in this paper can predict the reactor's operational condition with an error lower than 5%.

  17. Cycloaliphatic epoxy resin coating for capillary electrophoresis.

    Science.gov (United States)

    Shah, Roopa S; Wang, Qinggang; Lee, Milton L

    2002-04-05

    Coating the interior surface of a fused-silica capillary with a polymeric material has long been used in capillary electrophoresis (CE) to reduce or eliminate electroosmotic flow and suppress adsorption. A cycloaliphatic epoxide-based resin was bonded to silane treated capillaries and crosslinked with a curing agent. The epoxy resin coating significantly reduced electroosmotic flow over a pH range of 3-10. This coating was sufficiently hydrophilic to suppress protein adsorption. The epoxy resin coated capillary was used to separate several acidic and basic proteins and peptides. Separation efficiencies greater than 400,000 theoretical plates were achieved. The relative standard deviations in migration times for proteins were methods.

  18. Investigations of toughening mechanisms of epoxy resins

    Science.gov (United States)

    Koenig, T.

    1986-01-01

    Composite material technology was applied to the solid rocket booster by the development of a carbon filament-epoxy resin case which yields a net increase of 4000 lbs. in payload in the shuttle. The question of reusability of the new composite tanks has not yet been answered and will depend on the toughness of the matrix resin. The present study was aimed at providing conditions whereby test specimens of the epoxy resin (EPON/85) and curing agents of systematically varied structures could be produced in a controlled manner. Three sets of conditions were found that might allow the isolation of the structural effects on toughness from the cure effects. The kinetic methods leading to the determination of these conditions are described.

  19. Composite resin in medicine and dentistry.

    Science.gov (United States)

    Stein, Pamela S; Sullivan, Jennifer; Haubenreich, James E; Osborne, Paul B

    2005-01-01

    Composite resin has been used for nearly 50 years as a restorative material in dentistry. Use of this material has recently increased as a result of consumer demands for esthetic restorations, coupled with the public's concern with mercury-containing dental amalgam. Composite is now used in over 95% of all anterior teeth direct restorations and in 50% of all posterior teeth direct restorations. Carbon fiber reinforced composites have been developed for use as dental implants. In medicine, fiber-reinforced composites have been used in orthopedics as implants, osseous screws, and bearing surfaces. In addition, hydroxyapatite composite resin has become a promising alternative to acrylic cement in stabilizing fractures and cancellous screw fixation in elderly and osteoporotic patients. The use of composite resin in dentistry and medicine will be the focus of this review, with particular attention paid to its physical properties, chemical composition, clinical applications, and biocompatibility.

  20. Resin injection in clays with high plasticity

    Science.gov (United States)

    Nowamooz, Hossein

    2016-11-01

    Regarding the injection process of polyurethane resins in clays with high plasticity, this paper presents the experimental results of the pressuremeter and cone penetration tests before and after injection. A very important increase in pressure limit or in soil resistance can be observed for all the studied depths close to the injection points. An analytical analysis for cylindrical pore cavity expansion in cohesive frictional soils obeying the Mohr-Coulomb criterion was then used to reproduce the pressuremeter tests before and after injection. The model parameters were calibrated by maintaining constant the elasticity parameters as well as the friction angel before and after injection. A significant increase in cohesion was observed because of soil densification after resin expansion. The estimated undrained cohesions, derived from the parameters of the Mohr-Coulomb criterion, were also compared with the cone penetration tests. Globally, the model predictions show the efficiency of resin injection in clay soils with high plasticity.

  1. [Allergic contact eczema from epoxy resin].

    Science.gov (United States)

    Calzado, Leticia; Ortiz-de Frutos, Francisco J; del Prado Sánchez-Caminero, María; Galera, Carmen María; Valverde, Ricardo; Vanaclocha, Francisco

    2005-11-01

    Epoxy resins are plastics that are widely used as electrical insulation, in coatings, and as adhesives and paints. They have strong sensitizing power and are one of the main causes of allergic contact eczema, both in the workplace and elsewhere. We present the case of a worker at a plastics/chemical plant, who handled aeronautical components in the process of manufacturing fuselage parts. He consulted his physician because of eczematous lesions on his fingers, hands and forearms which had developed over a two-year period and were clearly related to his work. The standard battery of skin tests was performed, along with the plastics and adhesives series and tests using the products from his workplace. Positivity was shown to epoxy resins (standard battery) and to the products from his workplace, which included different fiberglass and carbon fiber sheets impregnated with epoxy resins and epoxy adhesives.

  2. The Creep of Laminated Synthetic Resin Plastics

    Science.gov (United States)

    Perkuhn, H

    1941-01-01

    The long-time loading strength of a number of laminated synthetic resin plastics was ascertained and the effect of molding pressure and resin content determined. The best value was observed with a 30 to 40 percent resin content. The long-time loading strength also increases with increasing molding pressure up to 250 kg/cm(exp 2); a further rise in pressure affords no further substantial improvement. The creep strength is defined as the load which in the hundredth hour of loading produces a rate of elongation of 5 X 10(exp -4) percent per hour. The creep strength values of different materials were determined and tabulated. The effect of humidity during long-term tests is pointed out.

  3. Smooth coronal surface, resin restoration and microleakage.

    Science.gov (United States)

    Yanikoğlu, F; Türkmen, C; Kartal, N; Başaran, B

    1997-09-01

    The space between the resin and the cavity walls has always become interesting to search. The aim of this study was to evaluate any differences on leakage values of Class 5 type resin restorations prepared on surrounding surfaces of the tooth crown. Ninety human teeth were prepared as Class 5 cavities on buccal, lingual, mesial and distal surfaces and were randomly divided into groups for bevelling, groove preparation and as control. The subgroups were arranged as fluoride gel and/or sealant applications. Fluoride gel was applied following the cavity preparations. Sealant was applied over composite resin restorations. Treated teeth were thermocycled and immersed into dye solution for 96 hours. The restorations were evaluated in a stereo-microscope following the sectioning. Bevelling of the cavosurfaces and/or preparation of a groove addition to cavity procedures did not make any difference on the microleakage scores of the restorations done on either surfaces statistically.

  4. Sorption kinetics of ethanol/water solution by dimethacrylate-based dental resins and resin composites.

    Science.gov (United States)

    Sideridou, Irini D; Achilias, Dimitris S; Karabela, Maria M

    2007-04-01

    In the present investigation the sorption-desorption kinetics of 75 vol % ethanol/water solution by dimethacrylate-based dental resins and resin composites was studied in detail. The resins examined were made by light-curing of bisphenol A glycol dimethacrylate (Bis-GMA), triethylene glycol dimethacrylate (TEGDMA), urethane dimethacrylate (UDMA), bisphenol A ethoxylated dimethacrylate (Bis-EMA), and mixtures of these monomers. The resin composites were prepared from two commercial light-cured restorative materials (Z100 MP and Filtek Z250), the resin matrix of which is based on copolymers of the above-mentioned monomers. Ethanol/water sorption/desorption was examined in both equilibrium and dynamic conditions in two adjacent sorption-desorption cycles. For all the materials studied, it was found that the amount of ethanol/water sorbed or desorbed was always larger than the corresponding one reported in literature in case of water immersion. It was also observed that the chemical structure of the monomers used for the preparation of the resins directly affects the amount of solvent sorbed or desorbed, as well as sorption kinetics, while desorption rate was nearly unaffected. In the case of composites studied, it seems that the sorption/desorption process is not influenced much by the presence of filler. Furthermore, diffusion coefficients calculated for the resins were larger than those of the composites and were always higher during desorption than during sorption. Finally, an interesting finding concerning the rate of ethanol/water sorption was that all resins and composites followed Fickian diffusion kinetics during almost the whole sorption curve; however, during desorption the experimental data were overestimated by the theoretical model. Instead, it was found that a dual diffusion-relaxation model was able to accurately predict experimental data during the whole desorption curve. Kinetic relaxation parameters, together with diffusion coefficients, are reported

  5. Biphenyl liquid crystalline epoxy resin as a low-shrinkage resin-based dental restorative nanocomposite.

    Science.gov (United States)

    Hsu, Sheng-Hao; Chen, Rung-Shu; Chang, Yuan-Ling; Chen, Min-Huey; Cheng, Kuo-Chung; Su, Wei-Fang

    2012-11-01

    Low-shrinkage resin-based photocurable liquid crystalline epoxy nanocomposite has been investigated with regard to its application as a dental restoration material. The nanocomposite consists of an organic matrix and an inorganic reinforcing filler. The organic matrix is made of liquid crystalline biphenyl epoxy resin (BP), an epoxy resin consisting of cyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (ECH), the photoinitiator 4-octylphenyl phenyliodonium hexafluoroantimonate and the photosensitizer champhorquinone. The inorganic filler is silica nanoparticles (∼70-100 nm). The nanoparticles were modified by an epoxy silane of γ-glycidoxypropyltrimethoxysilane to be compatible with the organic matrix and to chemically bond with the organic matrix after photo curing. By incorporating the BP liquid crystalline (LC) epoxy resin into conventional ECH epoxy resin, the nanocomposite has improved hardness, flexural modulus, water absorption and coefficient of thermal expansion. Although the incorporation of silica filler may dilute the reinforcing effect of crystalline BP, a high silica filler content (∼42 vol.%) was found to increase the physical and chemical properties of the nanocomposite due to the formation of unique microstructures. The microstructure of nanoparticle embedded layers was observed in the nanocomposite using scanning and transmission electron microscopy. This unique microstructure indicates that the crystalline BP and nanoparticles support each other and result in outstanding mechanical properties. The crystalline BP in the LC epoxy resin-based nanocomposite was partially melted during exothermic photopolymerization, and the resin expanded via an order-to-disorder transition. Thus, the post-gelation shrinkage of the LC epoxy resin-based nanocomposite is greatly reduced, ∼50.6% less than in commercialized methacrylate resin-based composites. This LC epoxy nanocomposite demonstrates good physical and chemical properties and good biocompatibility

  6. Absorption and desorption behaviour of the flavonoids from Glycyrrhiza glabra L. leaf on macroporous adsorption resins.

    Science.gov (United States)

    Dong, Yi; Zhao, Mouming; Sun-Waterhouse, Dongxiao; Zhuang, Mingzhu; Chen, Huiping; Feng, Mengying; Lin, Lianzhu

    2015-02-01

    The kinetics of adsorption and desorption behaviours of five macroporous resins for enriching flavonoids from Glycyrrhizaglabra L. leaf were investigated. All five resins showed similar and effective adsorption and desorption properties. A pseudo-second-order kinetics model was suitable for evaluating the whole adsorption process. Additionally, two representative resins (XAD-16 and SP825) were chosen for adsorption thermodynamics study. The adsorption of the representative resins was an exothermic and physical adsorption process. Further column chromatography of XAD-16 and SP825 showed that the total flavonoids (from 16.8% to 55.6% by XAD-16 and to 53.9% by SP825) and pinocembrin (from 5.49% to 15.2% by XAD-16 and to 19.8% by SP825) were enriched in 90% ethanol fractions. Meanwhile, the antioxidant capacities and nitrite-scavenging capacities were 2-3times higher than those of the crude extract. The fractions with high flavonoid and pinocembrin contents could be used as biologically active ingredients in functional food.

  7. Fluorinated Epoxy Resins-based Sorbent Coating Materials for Quartz Piezoelectric Crystal Detector

    Directory of Open Access Journals (Sweden)

    D. C Gupta

    2004-04-01

    Full Text Available Fluorinated epoxy resins were synthesised and evaluated as sorbent coating materials for the detection of organophosphorus compounds using quartz piezoelectric crystal detector. These resins were prepared by reacting excess of epichlorohydrin with each of or in combination of fluorinated diols, ie, a, a, a', a' tetrakis (trifluoromethyl 1,3 benzene dimethanol (TTFMBD, 4,4'bis-2-hydroxy hexafluoro isopropyl biphenyl (BHHFIBP, 4,4'dihydroxyocta fluorodiphenyl (DHOFDP and 2,2,3,3,4,4 hexafluoro 1,5 pentanediol (HFPD in the presence of sodium hydroxide at reflux temperature. These polymers were extracted in organic solvents and dried. Each of these fluoroepoxy resins were coated over quartz piezoelectric crystal by solution-casting method and tested using dimethylmethyl phosphonate (DMMP as model compound. Change in the  frequency (AF of quartz piezoelectric crystal oscillator was recorded. Sensitive and potential fluorinated epoxy resins, ie, diglycidylethers (DGE of HFPD-TTFMBD (in the molar ratio 6:4 and DGE (HFPD-BHHFIBP in the molar ratio 4:6 were characterised by viscosity, number average molecular weight (Mn, epoxy equivalent, infrared spectroscopy, and thermal stability.

  8. Restorasi Resin Komposit Menggunakan Pasak Tapered Self Threading Pada Molar Ketiga Kiri Mandibula

    Directory of Open Access Journals (Sweden)

    Ellen Krisanti

    2013-06-01

    Composite Resin Restoration Using Tapered Self Threading Poston Left Mandibular Third Molar. Root canal morphology of mandibular third molar has more complex variation than the other molars. In third molar, the extraction teeth are often executed; however, the third molar can be maintained in other conditions. One visit root canal treatment is a therapy option for this case. The purpose of this case report is to show the success of one visit root canal treatment in third molar with pulp necrosis by restoring the composite resin through tapered self-treading post. A 20 year-old female patient who came to the Prof Soedomo RSGM, FKG UGM complained about the pain when chewing food on her third molar and positive in percussion. The radiographs showed that there was an incomplete restoration. There was a gap between cavities with restoration. The treatment plan for this case was one visit root canal treatment and composite resin with tapered self-threading post as final restoration. From the case, it can concluded that one visit root canal treatment results in a smaller chance for microorganism recontamination than the multi-visit in order to ensure the success of the treatment. Direct composite resin restoration with tapered self-threading dowel is an alternative restoration after endodontic treatment because it works out faster and more retentive.

  9. Fracture strength of root filled premolar teeth restored with silorane and methacrylate-based resin composite.

    Science.gov (United States)

    Taha, N A; Maghaireh, G A; Bagheri, R; Abu Holy, A

    2015-06-01

    To compare fracture characteristics of root-filled teeth with variable cavity design restored with a low shrinkage silorane and methacrylate-based resin composite. 77 extracted maxillary premolars were divided randomly into seven groups: (Group 1) intact teeth; (Groups 2-4) MOD plus endodontic access with the buccopalatal width of the occlusal isthmus equals one third of the intercuspal width; (Groups 5-7) MOD plus endodontic access with the buccopalatal width of the occlusal isthmus equals one half of the intercuspal width. Groups 2 and 5 were left unrestored, Groups 3 and 6 were restored with a silorane-based resin composite (Filtek P90) and Groups 4 and 7 with a methacrylate-based resin composite (Z250). Teeth were loaded in a universal testing machine; load and fracture patterns were recorded and compared statistically using 2-way ANOVA and t-test for pairwise comparisons and 1-way ANOVA with Dunnett test for multiple comparisons. Unrestored teeth became progressively weaker with more extensive preparations, Group 5 (unfilled ½) showed the lowest fracture load among the groups (71±22N, Presin composite have no superior strengthening effect over the conventional methacrylate-based resin composite in restoration of root filled teeth. Both materials showed similar fracture patterns. Root filled teeth are considerably weakened via restorative and endodontic procedures. A direct adhesive restoration will aid in preserving tooth structure as far as it provides enough strength. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Resins and asphaltenes: evolution as a function of organic-matter type and burial

    Energy Technology Data Exchange (ETDEWEB)

    Castex, H. (Institut Francais du Petrole, 92 - Rueil-Malmaison (France))

    Elemental analysis was used to investigate 151 resins and 175 asphaltenes extracted from rocks from several basins. It was shown that: resins have higher mean carbon and hydrogen values as well as a lower C/H ratio than asphaltenes. Resins thus have a more aliphatic and or more alicyclic structure. On the other hand, asphaltenes contain more sulfur, oxygen and nitrogen. Different types of organic matter are revealed by an H/C, O/C diagram. Their chemical evolution with burial is characterized by a decrease in hydrogen, oxygen and sulfur contents. Proton nuclear magnetic resonance (NMR) and infrared spectroscopy (IRS) were used to follow the structural evolution of resins and asphaltenes coming from different types of organic matter (algal, marine and terrestrial) buried at increasing depths. NMR can be used to compute several structural parameters such as Fsub(A) aromaticity and the degree of sigma substitution of the aromatic system. These data were completed by infrared spectroscopy. Variations in the intensity of bands: decrease of aliphatic C-H and of C = O fonctions; increase of aromatic C-H and C = C are related to both the type of organic matter and its catagenesis.

  11. Preparative Purification of Liriodendrin from Sargentodoxa cuneata by Macroporous Resin

    OpenAIRE

    Di-Hua Li; Yan Wang; Yuan-Shan Lv; Jun-Hong Liu; Lei Yang; Shu-Kun Zhang; Yu-Zhen Zhuo

    2015-01-01

    The preparative purification of liriodendrin from Sargentodoxa cuneata using macroporous resin combined with crystallization process was evaluated. The properties of adsorption/desorption of liriodendrin on eight macroporous resins were investigated systematically. X-5 resin was selected as the most suitable medium for liriodendrin purification. The adsorption of liriodendrin on X-5 resin fitted well with the pseudo-second-order kinetic model and Langmuir isotherm model. Dynamic adsorption/de...

  12. Study on the Novel Dicyanate Ester Resin Containing Naphthalene Unit

    Institute of Scientific and Technical Information of China (English)

    Hong Qiang YAN; Hong Yun PENG; Li JI; Guo Rong QI

    2004-01-01

    The novel dicyanate ester resin containing naphthalene unit (DNCY) was synthesized, and characterized by FT-IR, 1H-NMR, 13C-NMR and elemental analysis (EA).The thermal properties of DNCY resin was studied by thermal degradation analysis at a heating rate of 10 (C /min-1 in N2 and air. The DNCY resin exhibited better thermal and thermal-oxidative stability than bisphenol A dicyanate (BACY) resin.

  13. Adsorption of D113 Resin for Dysprosium(Ⅲ)

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The adsorption behavior and mechanism of D113 resin for Dy(Ⅲ) was investigated by using the method of resin adsorption. Experimental results show that the optimum medium pH of adsorption of D113 resin for Dy3+ is pH=6.00 in the HAc-NaAc medium. The static adsorption capacity of D113 resin for Dy3+chemical analysis and IR spectra.

  14. Investigation of Resin Systems for Improved Ablative Materials

    Science.gov (United States)

    2010-02-25

    and synthe- sized in Task I. " Commercial Sources: Monsanto - Skybond 700 (polyimide), and Narmco - Polybenzimidazole. Optimization of the resins will...tested in Contract NAS3-4188 (DuPont SP-I and SP-2), a new polyimide resin produced by Monsanto (Skybond 700) has recently been added to those resins...laminates from the improved modified polyimides being synthesized in Task I. The new resin selected for evaluation was Monsanto Chemical Company’s Skybond 700

  15. Improved Graphite Fiber/Acetylene Terminated Matrix Resin Prepreg Products

    Science.gov (United States)

    1988-03-01

    Neat Resin Properties Cured by Different Cure Cycles .............. 22 2.5 Effect of Cure Cycles on Water Absorption in m-ATS Neat Resins...Characterization of ATB Laminates ...... 81 3.4 Effect of Intermediate Temperature Hold on Neat Resin Properties for m-ATB Formulations ......... 86 3.5...using procedures described in Appendix A, are shown in Table 2.1. For comparison, the resin properties of a first generation epoxy, a state-of-the

  16. Separation of indium(Ⅲ),gallium(Ⅲ),and zinc(Ⅱ) with Levextrel resin containing di(2-ethylhexyl) phosphoric acid (CL-P204):Part Ⅱ.Mechanism and kinetics of adsorbing indium(Ⅲ)

    Institute of Scientific and Technical Information of China (English)

    LIU Junshen; ZHOU Baoxue; CAI Chunguang; CAI Jun; CAI Weimin

    2004-01-01

    The mechanism of adsorbing indium(Ⅲ) from sulfate solutions with CL-P204 Levextrel resin containing di(-2-ethylhexyl) phosphoric acid was examined by batch operation and infrared spectra. The results showed that the P204 adsorbed on the resin behaved in the similar way to solvent extraction except that it was as a monomer in resin adsorbing but in dimeric form in solvent extraction. Three factors including temperature, indium(Ⅲ) concentration of solution, and the size of resin particles which influence the In3+/H+ exchange on CL-P204 Levextrel resin were investigated by the modified limited batch technique in order to determine the kinetics of In3+/H+ exchange. It was found that the rate of ion exchange increased with the temperature and the concentration of solution increasing and with the size of the resin particles decreasing.According to the expression developed by Boyd et al., the controlling factor of In3+/H+ exchange on CL-P204 Levextrel resin was the diffusion through the resin particles. The effective diffusion coefficient, activation energy, and entropy of activation in the particle-diffusion were determined as 1.57 x l0-10 m2/s, 11.9 KJ/mol, -84.1 J/(mol. K), respectively.

  17. Benzonorbornadiene end caps for PMR resins

    Science.gov (United States)

    Panigot, Michael J.; Waters, John F.; Varde, Uday; Sutter, James K.; Sukenik, Chaim N.

    1992-01-01

    Several ortho-disubstituted benzonorbornadiene derivatives are described. These molecules contain acid, ester, or anhydride functionality permitting their use as end caps in PMR (polymerization of monomer reactants) polyimide systems. The replacement of the currently used norbornenyl end caps with benzonorbornadienyl end caps affords resins of increased aromatic content. It also allows evaluation of some mechanistic aspects of PMR cross-linking. Initial testing of N-phenylimide model compounds and of actual resin formulations using the benzonorbornadienyl end cap reveals that they undergo efficient thermal crosslinking to give oligomers with physical properties and thermal stability comparable to commercial norbornene-end-capped PMR systems.

  18. PMR Resin Compositions For High Temperatures

    Science.gov (United States)

    Vannucci, Raymond D.

    1989-01-01

    Report describes experiments to identify polymer matrix resins suitable for making graphite-fiber laminates used at 700 degree F (371 degree C) in such applications as aircraft engines to achieve higher thrust-to-weight ratios. Two particular high-molecular-weight formulations of PMR (polymerization of monomer reactants) resins most promising. PMR compositions of higher FMW exhibit enhanced thermo-oxidative stability. Formation of high-quality laminates with these compositions requires use of curing pressures higher than those suitable for compositions of lower FMW.

  19. Clinical guidelines for indirect resin restorations.

    Science.gov (United States)

    Shannon, A

    1997-06-01

    Ongoing advances in adhesive dentistry have made it possible to successfully and predictably bond tooth-supporting restorations using conservative preparation techniques. Improvements in the durability and esthetic properties of tooth-colored restorative materials have also increased the range of available treatment options. However, dentists have been slow to accept both direct and indirect posterior esthetics. This article provides a step-by-step technique for practitioners who choose to treat their patients with indirect resin esthetic restorations. It will not discuss other posterior restorative treatment techniques or materials (i.e. gold, porcelain, amalgam, bonded amalgam, or direct resin).

  20. Advances in the history of composite resins.

    Science.gov (United States)

    Minguez, Nieves; Ellacuria, Joseba; Soler, José Ignacio; Triana, Rodrigo; Ibaseta, Guillermo

    2003-11-01

    The use of composite resins as direct restoration material in posterior teeth has demonstrated a great increase, due to esthetic requirements and the controversy regarding the mercury content in silver amalgams. In this article, we have reviewed the composition modifications which have occurred in materials based on resins since their introduction over a half a century ago which have enabled great improvements in their physical and mechanical properties. Likewise, we have highlighted current lines of research, centered on finding the ideal material for replacing silver amalgam as a direct filling material.

  1. Synthesis of a boron modified phenolic resin

    Directory of Open Access Journals (Sweden)

    Aparecida M. Kawamoto

    2010-08-01

    Full Text Available Phenolic resin has long been used as matrix for composites mainly because of its flame retardant behavior and high char yield after pyrolysis, which results in a self supporting structure. The addition of ceramic powders, such as SiC and B4C, as fillers to the phenolic resin, results in better thermo-oxidative stability, but as drawbacks, it has poor homogeneity, adhesion and processing difficulties during molding of the composites. The addition of single elements, such as boron, silicon and phosphorus in the main backbone of the thermo-set resin is a new strategy to obtain special high performance resins, which results in higher mechanical properties, avoiding the drawbacks of simply adding fillers, which results in enhanced thermo-oxidative stability compared to conventional phenol-formaldehyde resins. Therefore, the product can have several applications, including the use as ablative thermal protection for thermo-structural composites. This work describes the preparation of a boron-modified phenolic resin (BPR using salicyl alcohol and boric acid. The reaction was performed in refluxing toluene for a period of four hours, which produced a very high viscosity amber resin in 90% yield.The final structure of the compound, the boric acid double, substituted at the hydroxyl group of the aromatic ring, was determined with the help of the Infrared Spectroscopy, ¹H-NMR, TGA-DSC and boron elemental analysis. The absorption band of the group B-O at 1349 cm ˉ¹ can be visualized at the FT-IR spectrum. ¹H-NMR spectra showed peaks at 4.97-5.04 ppm and 3.60-3.90 ppm assigned to belong to CH2OH groups from the alcohol. The elemental analysis was also performed for boron determination.The product has also been tested in carbon and silicon fibers composite for the use in thermal structure. The results of the tests showed composites with superior mechanical properties when compared with the conventional phenolic resin.

  2. 21 CFR 177.2510 - Polyvinylidene fluoride resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyvinylidene fluoride resins. 177.2510 Section... as Components of Articles Intended for Repeated Use § 177.2510 Polyvinylidene fluoride resins. Polyvinylidene fluoride resins may be safely used as articles or components of articles intended for repeated use...

  3. TRIMETHYLSILYLATED SILICA AS RHEOLOGY MODIFIER FOR SILICONE RESINS

    Institute of Scientific and Technical Information of China (English)

    Wei Huang; Ying Huang; Yunzhao Yu

    2000-01-01

    Trimethylsilylated silica was synthesized through hydrolytic condensation of tetraethoxysilane followed by trimethylsilylation. Rheological properties of the silicone resin with trimethylsilylated silica as modifier were studied. It turned out that the particle size of silica was important to the rheological behavior of the modified resin. Trimethylsilylated silica of medium particle size shows the strongest tendency of forming physical network in the resin.

  4. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylamide-acrylic acid resins. 176.110 Section 176... Substances for Use Only as Components of Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely used as components of articles intended for use in producing...

  5. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid resin... acrylamide with partial hydrolysis, or by copolymerization of acrylamide and acrylic acid with the greater...

  6. 21 CFR 177.2355 - Mineral reinforced nylon resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Mineral reinforced nylon resins. 177.2355 Section... as Components of Articles Intended for Repeated Use § 177.2355 Mineral reinforced nylon resins. Mineral reinforced nylon resins identified in paragraph (a) of this section may be safely used as...

  7. 40 CFR 721.9499 - Modified silicone resin.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified silicone resin. 721.9499... Substances § 721.9499 Modified silicone resin. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified silicone resin (PMN P-96-1649)...

  8. 75 FR 67105 - Granular Polytetrafluoroethylene Resin From Italy and Japan

    Science.gov (United States)

    2010-11-01

    ... COMMISSION Granular Polytetrafluoroethylene Resin From Italy and Japan AGENCY: United States International... granular polytetrafluoroethylene resin from Italy and Japan. SUMMARY: The Commission hereby gives notice... polytetrafluoroethylene resin from Italy and Japan would be likely to lead to continuation or recurrence of...

  9. 40 CFR 721.5908 - Modified phenolic resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified phenolic resin (generic). 721... Substances § 721.5908 Modified phenolic resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as modified phenolic resin (PMN...

  10. 21 CFR 872.3300 - Hydrophilic resin coating for dentures.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hydrophilic resin coating for dentures. 872.3300... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3300 Hydrophilic resin coating for dentures. (a) Identification. A hydrophilic resin coating for dentures is a device that consists of a...

  11. 40 CFR 721.2673 - Aromatic epoxide resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aromatic epoxide resin (generic). 721... Substances § 721.2673 Aromatic epoxide resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as aromatic epoxide resin (PMN...

  12. 21 CFR 177.2410 - Phenolic resins in molded articles.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Phenolic resins in molded articles. 177.2410... as Components of Articles Intended for Repeated Use § 177.2410 Phenolic resins in molded articles. Phenolic resins identified in this section may be safely used as the food-contact surface of...

  13. 21 CFR 177.2415 - Poly(aryletherketone) resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Poly(aryletherketone) resins. 177.2415 Section 177... Components of Articles Intended for Repeated Use § 177.2415 Poly(aryletherketone) resins. Poly(aryletherketone) resins identified in paragraph (a) of this section may be safely used as articles or...

  14. 40 CFR 721.5762 - Aromatic aldehyde phenolic resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aromatic aldehyde phenolic resin... Specific Chemical Substances § 721.5762 Aromatic aldehyde phenolic resin (generic). (a) Chemical substance... aromatic aldehyde phenolic resin (PMN P-01-573) is subject to reporting under this section for...

  15. 21 CFR 172.215 - Coumarone-indene resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Coumarone-indene resin. 172.215 Section 172.215... CONSUMPTION Coatings, Films and Related Substances § 172.215 Coumarone-indene resin. The food additive coumarone-indene resin may be safely used on grapefruit, lemons, limes, oranges, tangelos, and tangerines...

  16. 21 CFR 177.2500 - Polyphenylene sulfone resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyphenylene sulfone resins. 177.2500 Section 177... Components of Articles Intended for Repeated Use § 177.2500 Polyphenylene sulfone resins. The polyphenylene sulfone resins (CAS Reg. No. 31833-61-1) identified in paragraph (a) of this section may be safely used...

  17. 21 CFR 872.3770 - Temporary crown and bridge resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Temporary crown and bridge resin. 872.3770 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device composed of a material, such...

  18. 40 CFR 721.5905 - Modified phenolic resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified phenolic resin (generic). 721... Substances § 721.5905 Modified phenolic resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified phenolic resin...

  19. 21 CFR 173.10 - Modified polyacrylamide resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Modified polyacrylamide resin. 173.10 Section 173... CONSUMPTION Polymer Substances and Polymer Adjuvants for Food Treatment § 173.10 Modified polyacrylamide resin. Modified polyacrylamide resin may be safely used in food in accordance with the following...

  20. 21 CFR 173.40 - Molecular sieve resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Molecular sieve resins. 173.40 Section 173.40 Food... Polymer Substances and Polymer Adjuvants for Food Treatment § 173.40 Molecular sieve resins. Molecular sieve resins may be safely used in the processing of food under the following prescribed conditions:...

  1. 76 FR 39896 - Granular Polytetrafluoroethylene Resin From Italy

    Science.gov (United States)

    2011-07-07

    ... COMMISSION Granular Polytetrafluoroethylene Resin From Italy Determination On the basis of the record \\1... antidumping duty order on granular polytetrafluoroethylene resin from Italy would be likely to lead to... Granular Polytetrafluoroethylene Resin from Italy: Investigation No. 731-TA-385 (Third Review). By order...

  2. 40 CFR 721.3135 - Phosphorous modified epoxy resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Phosphorous modified epoxy resin... Specific Chemical Substances § 721.3135 Phosphorous modified epoxy resin (generic). (a) Chemical substance... phosphorous modified epoxy resin (PMNs P-00-992 and P-01-471) is subject to reporting under this section...

  3. 40 CFR 721.2752 - Epoxy resin containing phosphorus (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Epoxy resin containing phosphorus... Specific Chemical Substances § 721.2752 Epoxy resin containing phosphorus (generic). (a) Chemical substance... epoxy resin containing phosphorus (PMN P-00-912) is subject to reporting under this section for...

  4. Solid-State Microwave Synthesis of Melamine-Formaldehyde Resin

    OpenAIRE

    Subhash Bajia; Rashmi Sharma; Birbal Bajia

    2009-01-01

    An efficient synthesis of melamine-formaldehyde resin has been achieved using conventional as well as microwave irradiations (without and with solid support) in different molar ratio. Resin samples were tested for their chemical as well as physical properties. The structure of all the resin has been supported by their spectral data

  5. Color change of composite resins subjected to accelerated artificial aging

    Directory of Open Access Journals (Sweden)

    Denise Cremonezzi Tornavoi

    2013-01-01

    Conclusions: All composite resins presented unacceptable color changes after 382 h of aging and different composite resins with same hue, presented different colors before being subjected to the aging process (B2 and C2 and after (B2. It was also observed color difference within a group of the same composite resin and same hue.

  6. Solid-State Microwave Synthesis of Melamine-Formaldehyde Resin

    Directory of Open Access Journals (Sweden)

    Subhash Bajia

    2009-01-01

    Full Text Available An efficient synthesis of melamine-formaldehyde resin has been achieved using conventional as well as microwave irradiations (without and with solid support in different molar ratio. Resin samples were tested for their chemical as well as physical properties. The structure of all the resin has been supported by their spectral data

  7. 21 CFR 872.3690 - Tooth shade resin material.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3690 Tooth shade resin material. (a) Identification. Tooth shade resin material is a device composed of materials such as bisphenol-A glycidyl... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tooth shade resin material. 872.3690 Section...

  8. 21 CFR 872.3670 - Resin impression tray material.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3670 Resin impression tray material. (a) Identification. Resin impression tray material is a device intended for use in a two-step dental mold fabricating... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Resin impression tray material. 872.3670...

  9. 21 CFR 872.3310 - Coating material for resin fillings.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3310 Coating material for resin fillings. (a) Identification. A coating material for resin fillings is a device intended to be applied to the... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Coating material for resin fillings....

  10. Flavylium chromophores as species markers for dragon's blood resins from Dracaena and Daemonorops trees.

    Science.gov (United States)

    Sousa, Micaela M; Melo, Maria J; Parola, A Jorge; Seixas de Melo, J Sérgio; Catarino, Fernando; Pina, Fernando; Cook, Frances E M; Simmonds, Monique S J; Lopes, João A

    2008-10-31

    A simple and rapid liquid chromatographic method with diode-array UV-vis spectrophotometric detection has been developed for the authentication of dragon's blood resins from Dracaena and Daemonorops trees. Using this method it was discovered that the flavylium chromophores, which contribute to the red colour of these resins, differ among the species and could be used as markers to differentiate among species. A study of parameters, such as time of extraction, proportion of MeOH and pH, was undertaken to optimise the extraction of the flavyliums. This method was then used to make extracts from samples of dragon's blood resin obtained from material of known provenance. From the samples analysed 7,6-dihydroxy-5-methoxyflavylium (dracorhodin), 7,4'-dihydroxy-5-methoxyflavylium (dracoflavylium) and 7,4'-dihydroxyflavylium were selected as species markers for Daemonorops spp., Dracaena draco and Dracaena cinnabari, respectively. The chromatograms from these samples were used to build an HPLC-DAD database. The ability to discriminate among species of dragon's blood using the single marker compounds was compared with a principal components analysis of the chromatograms in the HPLC-DAD database. The results from the HPLC-DAD method based on the presence of these flavylium markers was unequivocal. The HPLC-DAD method was subsequently applied to 37 samples of dragon blood resins from the historical samples in the Economic Botany Collection, Royal Botanic Gardens, Kew. The method identified anomalies in how samples in this collection had been labelled. It is clear that the method can be used to evaluate the provenance of samples used in different areas of cultural heritage. It also could be used to monitor the trade of endangered species of dragon's blood and the species being used in complex formulations of traditional Chinese medicine.

  11. Characterization and disposal of ion exchange resins used in nuclear installations; Caracterizacion y disposicion de resinas de intercambio ionico utilizadas en instalaciones nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Flores E, R.M.; Ortiz O, H.B.; Olguin G, M.T.; Emeterio H, M.; Garcia M, H. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2006-07-01

    To dispose of an appropriate way the used ion exchange resins so much in the pool water purification systems of the TRIGA Mark III reactor like in the JS6500 gamma irradiator, of the National Institute of Nuclear Research, were carried out a series of analytic nuclear techniques and complementary conventional to those recommended by the ASTM, with the object of to control and to manage 14 lots of worn out resins appropriately. For its were identified the radioactive isotopes, the resins type, the grade of chemical pollution and the physicochemical degradation of the same ones. The lots of resins that didn't contain radioactive isotopes its were regenerated in an usual way, as long as those that if they controlled them they selected options for its final disposition. The first selected option was the extraction method of ion radioactive isotopes, concentrating the elution product by evaporation. As second option it was carried out the resins stabilization damaged by micro-encapsulation by forged to ambient temperature, using an organic polymer. Previous to the immobilization the resins were pretreated by vacuum drying, pulverization and thermal drying, however before carrying out this last, it was carried out a thermal gravimetric analysis to determine the drying conditions of the resins avoiding its chemical decomposition. (Author)

  12. Effect of chlorhexidine incorporation into dental adhesive resin on durability of resin-dentin bond.

    Science.gov (United States)

    Yiu, Cynthia K; Hiraishi, Noriko; Tay, Franklin R; King, Nigel M

    2012-08-01

    This study evaluated the effect of chlorhexidine (CHX) incorporation into experimental dentin adhesives with different hydrophilicities on the microtensile bond strength (µTBS) to dentin. Flat, deep dentin surfaces were prepared from 60 extracted human third molars. Three ethanol-solvated (50 wt% ethanol/50 wt% comonomers) experimental adhesives with varying degrees of hydrophilicity were prepared for the CHX-free groups. For the CHX-containing groups, chlorhexidine diacetate was further added to the ethanol-solvated adhesives to form a concentration of 2.0 wt% CHX. Dentin surfaces were etched with 37% phosphoric acid for 15 s, rinsed and blot dried before bonding. The adhesives were generously applied to dentin with a microbrush for 15 s. A second application of fresh adhesive was made and light cured for 20 s (600 mW/cm2) after solvent evaporation. Composite buildups were made using Filtek Z250 (3M ESPE). The bonded teeth were sectioned into 0.9 mm x 0.9 mm beams and stressed to failure at a crosshead speed of 1 mm/min. Testing was performed 24 h after specimen preparation and 12 months after storage in artificial saliva. The µTBS data were analyzed using three-way ANOVA and Tukey's multiple comparison tests. Fractographic analysis was performed by SEM. Significant differences were observed for the three factors "adhesive hydrophilicity" (p adhesives (p > 0.05). After storage in artificial saliva, significant reduction in bond strength was observed in all adhesive groups, except for CHX-containing adhesive I (p adhesive III was significantly higher than the corresponding CHX-free adhesive (p dental adhesives, chlorhexidine can partially reduce the degradation of the resin-dentin bonds.

  13. Effect of epoxy resin properties on the mechanical properties of carbon fiber/epoxy resin composites

    Energy Technology Data Exchange (ETDEWEB)

    He, Hong-Wei; Gao, Feng [Taiyuan Univ. of Technology (China). College of Materials Science and Engineering; Taiyuan Univ. of Technology (China). Key Laboratory of Interface Science and Engineering in Advanced Materials; Li, Kai-Xi [Chinese Academy of Sciences, Taiyuan, Shanxi (China). Key Laboratory of Carbon Materials

    2013-09-15

    Three kinds of epoxy resins, i.e. tetraglycidyl diaminodiphenyl methane (AG80), difunctional diglycidyl ether of bisphenol-A (E51) and novolac type epoxy resin (F46) were selected as matrices for carbon fiber/epoxy composites. The objective of this work is to study the mechanical properties of fiber/epoxy composites by using these three kinds of epoxy resins with different physical and chemical performance. The results show that the composites fabricated with AG80 present the best stiffness and the composites prepared with E5 1have the best toughness. The stiffness and toughness of the composites prepared with F46 are middle values located between those for AG80/epoxy and E51/epoxy composites. Thus, the mixed epoxy resin is a promising approach for industrial production. (orig.)

  14. 含氨基膦酸螯合树脂的合成及其在铀提取中的性能研究%Synthesis of a chelate resin with amido and phosphoric acid and its character in uranium extraction

    Institute of Scientific and Technical Information of China (English)

    仇月双; 张建国; 封宇; 赵潮娅

    2013-01-01

    A chelate resin(D814) with amido and phosphoric acid functional group was synthetized by means of the reactions of stytene-divinyl benzene chloromethylated sphere with ethylenedianmine and orth-phosphorous acid and formaldehyde. This resin can be used to adsorb uranium from leaching solution with high chloride ion in the rang of pH 1. 33-9. 05,and the adsorption rate of uranium was above 95%. D814 resin had a good ability resistant to high chloride ion. The loading capacity for uranium was not apparently effected when chlorid ion concentration in solution was 60 g/L. The results of the adsorption experiment show that when the ratio of saturation volume to breakthrough volume was 1. 82, the uranium saturation capacity of D814 was 40. 5 mg/g dry resin. NaCl+NaHCO3 was used for elu-ting agent,and the eluting rate of uranium was 96. 7%. Adsorption uranium mechanism by D814 was also discussed.%苯乙烯-二乙烯苯氯球与乙二胺、亚磷酸、甲醛反应合成了一种带有氨基膦酸螯合基团的大孔树脂(D814),此树脂适用范围宽,能够从pH为1.33~9.05的高氯根浸出液中有效吸附铀,铀吸附率大于94%.树脂耐氯性能好,当原液中ρ(Cl-)达到60 g/L时,对树脂铀的吸附性能仍无明显影响.动态吸附表明,树脂吸附饱和体积与穿透树脂体积之比为1.82,每g干树脂铀吸附饱和容量为40.5 mg.选用NaCl+ NaHCO3混合淋洗剂,铀的淋洗率达到96.7%.对D814树脂的铀吸附机制进行了初步分析.

  15. A UV resonance Raman (UVRR) spectroscopic study on the extractable compounds of Scots pine ( Pinus sylvestris) wood . Part I: Lipophilic compounds

    Science.gov (United States)

    Nuopponen, M.; Willför, S.; Jääskeläinen, A.-S.; Sundberg, A.; Vuorinen, T.

    2004-11-01

    The wood resin in Scots pine ( Pinus sylvestris) stemwood and branch wood were studied using UV resonance Raman (UVRR) spectroscopy. UVRR spectra of the sapwood and heartwood hexane extracts, solid wood samples and model compounds (six resin acids, three fatty acids, a fatty acid ester, sitosterol and sitosterol acetate) were collected using excitation wavelengths of 229, 244 and 257 nm. In addition, visible Raman spectra of the fatty and resin acids were recorded. Resin compositions of heartwood and sapwood hexane extracts were determined using gas chromatography. Raman signals of both conjugated and isolated double bonds of all the model compounds were resonance enhanced by UV excitation. The oleophilic structures showed strong bands in the region of 1660-1630 cm -1. Distinct structures were enhanced depending on the excitation wavelength. The UVRR spectra of the hexane extracts showed characteristic bands for resin and fatty acids. It was possible to identify certain resin acids from the spectra. UV Raman spectra collected from the solid wood samples containing wood resin showed a band at ˜1650 cm -1 due to unsaturated resin components. The Raman signals from extractives in the resin rich branch wood sample gave even more strongly enhanced signals than the aromatic lignin.

  16. Guaianolides and a seco-Eudesmane from the Resinous Exudates of Cushion Bush (Leucophyta brownii) and Evaluation of Their Cytostatic and Anti-inflammatory Activity

    DEFF Research Database (Denmark)

    Hyldgaard, Mette G; Purup, Stig; Bond, Andrew D

    2015-01-01

    A detailed phytochemical investigation of a dichloromethane extract of the resinous exudates of the cushion bush plant (Leucophyta brownii) resulted in the isolation of the new 8,12-guaianolides leucophytalins A (5) and B (6), the new 1,10-seco-eudesmane leucophytalin C (10), six rare 8,12-guaian......A detailed phytochemical investigation of a dichloromethane extract of the resinous exudates of the cushion bush plant (Leucophyta brownii) resulted in the isolation of the new 8,12-guaianolides leucophytalins A (5) and B (6), the new 1,10-seco-eudesmane leucophytalin C (10), six rare 8...

  17. A temporary space maintainer using acrylic resin teeth and a composite resin.

    Science.gov (United States)

    Kochavi, D; Stern, N; Grajower, R

    1977-05-01

    A one-session technique for preparing a temporary space maintainer has been described. The technique consists of attaching an acrylic resin pontic to etched surfaces of natural adjacent teeth by means of a composite resin. The main advantages of this technique are elimination of premature tooth preparation, good esthetics, fair strength, low cost, and rapid completion of the restoration without the need of a dental laboratory.

  18. Thermal expansion characteristics of light-cured dental resins and resin composites.

    Science.gov (United States)

    Sideridou, Irini; Achilias, Dimitris S; Kyrikou, Eleni

    2004-07-01

    The thermal expansion characteristics of dental resins prepared by light-curing of Bis-GMA, TEGDMA, UDMA, Bis-EMA(4) or PCDMA dimethacrylate monomers and of commercial light-cured resin composites (Z-100 MP, Filtek Z-250, Sculpt-It and Alert), the organic matrix resin of which is based on different combinations of the above monomers, were studied by thermomechanical analysis (TMA). This study showed the existence of a glass transition temperature at around 35-47 degrees C for the resins and 40-45 degrees C for the composites; then the coefficient of linear thermal expansion (CLTE) was calculated at the temperature intervals 0-60 degrees C, 0-T(g) and T(g)-60 degrees C. The CLTE values of Bis-GMA, TEGDMA and UDMA resins are similar and lower than those of Bis-EMA (4) and PCDMA resins. The CLTE values of the composites indicated that the major factor that affects the CLTE of a composite is the filler content, but it also seems to be affected by the chemical structure of the matrix resin. TMA on water-saturated samples showed that water desorption takes place during the measurement and that the residual water acts as a plasticizer decreasing the T(g) and increasing the CLTE values. Furthermore, TMA on post-heated samples for 1, 3 or 6h showed, only for the resins, an initial decrease of CLTE and increase of the T(g) after 1h that was not significantly changed after 6h of heating.

  19. [Studies of dental methacrylic resin. (Part 8) Flexural and impact adhesive strength of self-curing methacrylic resin to cross-linked polymethyl methacrylate resins (author's transl)].

    Science.gov (United States)

    Hirasawa, T; Hirabayashi, S; Harashima, I

    1981-10-01

    Heat-curing methacylic resins cross-linked with three kinds of dimethacrylates, i.e. EDMA, tri-EDMA and nona-EDMA, were prepared, and the flexural and the impact adhesive strength of the dough moulding type and the pour type self-curing methacrylic resins to them were examined. The results obtained were as follows. (1) The flexural and the impact adhesive strength of the pour type self-curing resin were higher and more stable than those of the dough moulding type one. (2) The flexural and the impact adhesive strength of self-curing resins to cross-linked adherent resins rised in order of nona-EDMA greater than tri-EDMA greater than EDMA in the range of higher concentration of cross-linking agents. This tendency was marked for the pour type resin. (3) When the dough moulding type resin was used as adhesive resin, to adherent resin cross-linked with EDMA or tri-EDMA which had relatively short chain, the respective adhesive strength of that decreased with increasing the concentration of cross-linking agent. While, to adherent resin cross-linked with nona-EDMA, which had relatively long and more flexible chain, the respective adhesive strength of the dough moulding type resin increased with increasing the concentration of cross-linking agent. (4) When the pour type resin was used as adhesive resin, to adherent resin cross-linked with EDMA or tri-EDMA, the respective adhesive strength of that showed the maximum at the concentration near 2 to 5 mole% and decreased with increasing the concentration. While, to adherent resin cross-linked with nona-EDMA, the flexural adhesive strength of the pour type resin was approximately constant without the effect of the concentration, but the impact adhesive strength of that increased with increasing the concentration. (5) The flexural adhesive strength of the dough moulding and the pour type resin under the wet condition decreased about 30 to 60% compared with under the dry condition, but the percentage of the falling for the impact

  20. Integrating Porous Resins In Enzymatic Processes

    DEFF Research Database (Denmark)

    Al-Haque, Naweed

    synthesis of 1-phenylethylamine using Ȧ-transaminse, the asymmetric synthesis of 1-methyl-3-phenylpropylamine using Ȧ-transaminse and enantioselective synthesis of 2-octanol using alcohol dehydrogenase were selected. VI of resin stability and cost also have to be taken into account in the screening...

  1. Evaluation of resins for use in brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Luiz Claudio F.M. Garcia; Ferraz, Wilmar Barbosa; Chrcanovic, Bruno Ramos; Santos, Ana Maria M., E-mail: ferrazw@cdtn.b, E-mail: amms@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    Brachytherapy is an advanced cancer treatment where radioactive seeds or sources are placed near or directly into the tumor thus reducing the radiation exposure in the surrounding healthy tissues. Prostate cancer can be treated with interstitial brachytherapy in initial stage of the disease in which tiny radioactive seeds with cylindrical geometry are used. Several kinds of seeds have been developed in order to obtain a better dose distribution around them and with a lower cost manufacturing. These seeds consist of an encapsulation, a radionuclide carrier, and X-ray marker. Among the materials that have potential for innovation in the construction of seeds, biocompatible resins appear as an important option. In this paper, we present some characterization results with Fourier transform infrared spectroscopic (FTIR) and ultraviolet-visible spectroscopy (UV-vis) performed on two types of resins in which curing temperatures for each one were varied as also the results of coatings with these resins under titanium substrates. Interactions of these resins in contact with the simulated body fluid were evaluated by atomic force microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. (author)

  2. Resin diffusion through demineralized dentin matrix

    Directory of Open Access Journals (Sweden)

    CARVALHO Ricardo M.

    1999-01-01

    Full Text Available This paper has focused on the factors that may affect the permeability of adhesive resins into the demineralized dentin matrix during the development of the bonding process. The effects of surface moisture are discussed respectively to the adhesive systems, and the problems related to incomplete hybrid layer formation presented.

  3. Pharmaceutical Applications of Ion-Exchange Resins

    Science.gov (United States)

    Elder, David

    2005-01-01

    The historical uses of ion-exchanged resins and a summary of the basic chemical principles involved in the ion-exchanged process are discussed. Specific applications of ion-exchange are provided that include drug stabilization, pharmaceutical excipients, taste-masking agents, oral sustained-release products, topical products for local application…

  4. Crack propagation directions in unfilled resins.

    Science.gov (United States)

    Baran, G; Sadeghipour, K; Jayaraman, S; Silage, D; Paul, D; Boberick, K

    1998-11-01

    Posterior composite restorative materials undergo accelerated wear in the occlusal contact area, primarily through a fatigue mechanism. To facilitate the timely development of new and improved materials, a predictive wear model is desirable. The objective of this study was to develop a finite element model enabling investigators to predict crack propagation directions in resins used as the matrix material in composites, and to verify these predictions by observing cracks formed during the pin-on-disc wear of a 60:40 BISGMA:TEGDMA resin and an EBPADMA resin. Laser confocal scanning microscopy was used to measure crack locations. Finite element studies were done by means of ABAQUS software, modeling a cylinder sliding on a material with pre-existing surface-breaking cracks. Variables included modulus, cylinder/material friction coefficient, crack face friction, and yield behavior. Experimental results were surprising, since most crack directions were opposite previously published observations. The majority of surface cracks, though initially orthogonal to the surface, changed direction to run 20 to 30 degrees from the horizontal in the direction of indenter movement. Finite element modeling established the importance of subsurface shear stresses, since calculations provided evidence that cracks propagate in the direction of maximum K(II)(theta), in the same direction as the motion of the indenter, and at an angle of approximately 20 degrees. These findings provide the foundation for a predictive model of sliding wear in unfilled glassy resins.

  5. 21 CFR 177.1580 - Polycarbonate resins.

    Science.gov (United States)

    2010-04-01

    ... FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic..., manufacturing, packing, processing, preparing, treating, packaging, transporting, or holding food, in accordance... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polycarbonate resins. 177.1580 Section...

  6. Restoration of traumatized teeth with resin composites

    DEFF Research Database (Denmark)

    Pallesen, Ulla; van Dijken, Jan WV

    2017-01-01

    For a long time, the primary choice for initial restoration of a crown-fractured front tooth has been resin composite material. The restoration can in most cases be performed immediately after injury if there is no sign of periodontal injury. The method’s adhesive character is conservative to tooth...

  7. Carbohydrate modified phenol-formaldehyde resins

    Science.gov (United States)

    Anthony H. Conner; Linda F. Lorenz

    1986-01-01

    For adhesive self-sufficiency, the wood industry needs new adhesive systems in which all or part of the petroleum-derived phenolic component is replaced by a renewable material without sacrificing high durability or ease of bonding. We tested the bonding of wood veneers, using phenolic resins in which part of the phenol-formaldehyde was replaced with carbohydrates. Our...

  8. Extended Resin Composite Restorations: Techniques and Procedures

    NARCIS (Netherlands)

    Loomans, B.A.C.; Hilton, T.

    2016-01-01

    This article gives an overview of the state of the art of different restorative treatment procedures and techniques needed for placing extended posterior resin composite restorations. Clinical aspects related to the procedure are discussed and reviewed based on the current literature, such as the

  9. Resin phantoms as skin simulating layers

    CSIR Research Space (South Africa)

    Karsten, AE

    2011-07-01

    Full Text Available on the efficiency of Photodynamic Therapy (PDT) treatment. Two resin based solid phantoms were prepared to simulate two different skin types. Cells were prepared and PDT treatment were done on cells with and without the phantoms, by keeping the total dose delivered...

  10. Microbial treatment of ion exchange resins

    Energy Technology Data Exchange (ETDEWEB)

    Kouznetsov, A.; Kniazev, O. [D. Mendeleyev University of Chemical Technology of Russia, Dept. Biotechnology, Mocow (Russian Federation)

    2001-07-01

    A bioavailability of ion exchange resins to a microbial destruction as one of the alternative methods of compacting used ionites from the nuclear fuel manufacturing cycle enterprises has been investigated. The bio-destruction was studied after a preliminary chemical treatment or without it. A sensitivity of the ion exchange resins (including highly acidic cationite KU-2-8) to the microbial destruction by heterotrophic and chemo-litho-trophic microorganisms under aerobic conditions was shown in principle. The biodegradation of the original polymer is possible in the presence of the water soluble fraction of the resin obtained after its treatment by Fenton reagent and accelerated in the presence of Mn-ions in optimal concentration 1-2 g of Mn per liter of medium. Thus, the process of bio-destruction of ionite polymer by heterotrophic microorganisms can be compared with the bio-destruction of lignin or humic substances. The optimum parameters of bio-destruction and microorganisms used must be different for resins with different functional groups. (authors)

  11. Hyperbranched Polymers for Resin Transfer Molding

    Science.gov (United States)

    2005-03-01

    refereed journals and referencing AFOSR support: 6 H. Qin, P.T. Mather, J.-B. Baek, and L.-S. Tan, "Modification of bisphenol-A based bismaleimide resin...Burstone, "Shape Memory Polymer Orthodontics ," SPE ANTEC Medical Plastics Division, May 9, 2006. b. Consultation and Advisory Functions with other

  12. 21 CFR 177.1380 - Fluorocarbon resins.

    Science.gov (United States)

    2010-04-01

    ... HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components...) Chlorotrifluoroethylene-1,1-difluoroethylene-tetrafluoroethylene co-polymer resins produced by copolymerization of..., Extrusion, and Coating Materials,” which is incorporated by reference in accordance with 5 U.S.C. 552(a)...

  13. Effect of dentin dehydration and composite resin polymerization mode on bond strength of two self-etch adhesives

    Directory of Open Access Journals (Sweden)

    Pooran Samimi

    2016-01-01

    Full Text Available Background: Dual-cured composite resins are similar to self-cured composite resins in some of their clinical applications due to inadequate irradiation, lack of irradiation, or delayed irradiation. Therefore, incompatibility with self-etch adhesives (SEAs should be taken into account with their use. On the other, the extent of dentin dehydration has a great role in the quality of adhesion of these resin materials to dentin. The aim of this study was to investigate the effect of dentin dehydration and composite resin polymerization mode on bond strength of two SEAs. Materials and Methods: A total of 120 dentinal specimens were prepared from extracted intact third molars. Half of the samples were dehydrated in ethanol with increasing concentrations. Then Clearfil SE Bond (CSEB and Prompt L-Pop (PLP adhesives were applied in the two groups. Cylindrical composite resin specimens were cured using three polymerization modes: (1 Immediate light-curing, (2 delayed light-curing after 20 min, and (3 self-curing. Bond strength was measured using universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed with two-way ANOVA and Duncan post hoc tests. Statistical significance was defined at P 0.05. PLP showed significant differences between subgroups with the lowest bond strength in hydrated dentin with delayed light-curing and self-cured mode of polymerization. Conclusion: Within the limitations of this study, a delay in composite resin light-curing or using chemically cured composite resin had a deleterious effect on dentin bond strength of single-step SEAs used in the study.

  14. Effect of dentin dehydration and composite resin polymerization mode on bond strength of two self-etch adhesives.

    Science.gov (United States)

    Samimi, Pooran; Alizadeh, Mehdi; Shirban, Farinaz; Davoodi, Amin; Khoroushi, Maryam

    2016-01-01

    Dual-cured composite resins are similar to self-cured composite resins in some of their clinical applications due to inadequate irradiation, lack of irradiation, or delayed irradiation. Therefore, incompatibility with self-etch adhesives (SEAs) should be taken into account with their use. On the other, the extent of dentin dehydration has a great role in the quality of adhesion of these resin materials to dentin. The aim of this study was to investigate the effect of dentin dehydration and composite resin polymerization mode on bond strength of two SEAs. A total of 120 dentinal specimens were prepared from extracted intact third molars. Half of the samples were dehydrated in ethanol with increasing concentrations. Then Clearfil SE Bond (CSEB) and Prompt L-Pop (PLP) adhesives were applied in the two groups. Cylindrical composite resin specimens were cured using three polymerization modes: (1) Immediate light-curing, (2) delayed light-curing after 20 min, and (3) self-curing. Bond strength was measured using universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed with two-way ANOVA and Duncan post hoc tests. Statistical significance was defined at P 0.05). PLP showed significant differences between subgroups with the lowest bond strength in hydrated dentin with delayed light-curing and self-cured mode of polymerization. Within the limitations of this study, a delay in composite resin light-curing or using chemically cured composite resin had a deleterious effect on dentin bond strength of single-step SEAs used in the study.

  15. NITRATE CONVERSION OF HB-LINE REILLEXTM HPQ RESIN

    Energy Technology Data Exchange (ETDEWEB)

    Steimke, J.; Williams, M.; Steeper, T.; Leishear, R.

    2012-05-29

    Reillex{trademark} HPQ ion exchange resin is used by HB Line to remove plutonium from aqueous streams. Reillex{trademark} HPQ resin currently available from Vertellus Specialties LLC is a chloride ionic form, which can cause stress corrosion cracking in stainless steels. Therefore, HB Line Engineering requested that Savannah River National Laboratory (SRNL) convert resin from chloride form to nitrate form in the Engineering Development Laboratory (EDL). To perform this task, SRNL treated two batches of resin in 2012. The first batch of resin from Reilly Industries Batch 80302MA was initially treated at SRNL in 2001 to remove chloride. This batch of resin, nominally 30 liters, has been stored wet in carboys since that time until being retreated in 2012. The second batch of resin from Batch 23408 consisted of 50 kg of new resin purchased from Vertellus Specialties in 2012. Both batches were treated in a column designed to convert resin using downflow of 1.0 M sodium nitrate solution through the resin bed followed by rinsing with deionized water. Both batches were analyzed for chloride concentration, before and after treatment, using Neutron Activation Analysis (NAA). The resin specification [Werling, 2003] states the total chlorine and chloride concentration shall be less than 250 ppm. The resin condition for measuring this concentration is not specified; however, in service the resin would always be fully wet. Measurements in SRNL showed that changing from oven dry resin to fully wet resin, with liquid in the particle interstices but no supernatant, increases the total weight by a factor of at least three. Therefore, concentration of chlorine or chloride expressed as parts per million (ppm) decreases by a factor of three. Therefore, SRNL recommends measuring chlorine concentration on an oven dry basis, then dividing by three to estimate chloride concentration in the fully wet condition. Chloride concentration in the first batch (No.80302MA) was nearly the same

  16. Preparation of montmorillonite modified phenolic resin for shell process

    Institute of Scientific and Technical Information of China (English)

    Xiong Jianmin; Li Yuancai; Wang Wenqing; Xia Chun

    2009-01-01

    The development of montmodllonite modified phenolic resin under microwave irradiation heating was investigated. The effect of montmorillonite content and stirring time on the structure and morphology of synthetic resin was analyzed. The optimum processing procedure was found to be 45 rain stirring time with 5.4% montmorillonite addition. Further, the platelet spacing increases with stirring time till montmorillonite exfoliated to nanoscales platelet. When montmorillonite is exfoliated, layered structure at nanoscale can be uniformly distributed in the resin. The overall performance of montmorillonite modified phenolic resin is improved remarkably, such as flow ability, tensile strength and toughness property of resin coated sand. However, the gelation speed decreased slightly by adding montmorillonite.

  17. The influence of a packable resin composite, conventional resin composite and amalgam on molar cuspal stiffness.

    Science.gov (United States)

    Molinaro, J D; Diefenderfer, K E; Strother, J M

    2002-01-01

    Packable resin composites may offer improved properties and clinical performance over conventional resin composites or dental amalgam. This in vitro study examined the cuspal stiffness of molars restored with a packable resin composite, a conventional posterior microfilled resin composite and amalgam. Forty-eight intact caries-free human third molars were distributed into four treatment groups (n=12) so that the mean cross-sectional areas of all groups were equal. Standardized MOD cavity preparations were made and specimens restored using one of four restorative materials: (1) a spherical particle amalgam (Tytin); (2) Tytin amalgam with a dentin adhesive liner (OptiBond Solo); (3) a conventional microfilled posterior resin composite (Heliomolar); (4) a packable posterior resin composite (Prodigy Posterior). Cuspal stiffness was measured using a Bionix 200 biomaterials testing machine (MTS). Specimens were loaded vertically to 300 N at a crosshead speed of 1.0 mm/minute. Stiffness was measured at 10 intervals: (1) prior to cavity preparation (intact); (2) following cavity preparation, but before restoration; (3) seven days after restoration; then (4) 1, 2, 3, 4, 5, 6 and 12 months after restoration. All specimens were stored at 37 degrees C in deionized water throughout the study and thermocycled (5 degrees/55 degrees C; 2000 cycles) monthly for 12 months. Repeated Measures ANOVA revealed significant differences among treatment groups over time (presin composite increased cuspal stiffness over that of amalgam.

  18. Curing depth of a resin-modified glass ionomer and two resin-based luting agents.

    Science.gov (United States)

    Sigemori, Ricardo Massao; Reis, André Figueiredo; Giannini, Marcelo; Paulillo, Luís Alexandre M S

    2005-01-01

    The degree of conversion of resin-based luting agents used for retention of prefabricated posts has been questioned due to the difficulty of light penetration into the resin-filled root canal. This study evaluated the depth of cure of a resin-modified glass ionomer cement (Rely X--3M ESPE) and two resin-based luting agents (Rely X ARC--3M ESPE and Enforce-Dentsply). Twenty-four 14x2x2mm3 specimens were prepared in a Teflon split mold with the three luting agents (n=8). After preparation, the specimens were stored at 37 degrees C in a dark box for 24 hours prior to microhardness testing. Measurements of Knoop hardness were performed at three different depths: superficial, medium and deep thirds. The results (KHN) were statistically analyzed by repeated measures ANOVA and Tukey test (0.05), which showed that resin-based luting agents presented the highest Knoop hardness values within the superficial third. Within the medium third, there were no significant differences among luting materials. However, within the deep third, Rely X presented the highest values. KHN values of resin-based luting agents decreased remarkably as depth increased.

  19. Bisphenol-A epoxy resin reinforced and toughened by hyperbranched epoxy resin

    Institute of Scientific and Technical Information of China (English)

    ZHANG Daohong; JIA Demin; HUANG Xianbo

    2007-01-01

    The study on toughening and reinforcing of bisphenol-A epoxy resin is one of important developmental direction in the field.This paper reports a one-pot synthesis of aromatic polyester hyperbranched epoxy resin HTDE-2,an effect of HTDE-2 content on the mechanical and thermal performance of the bisphenol-A (E51)/HTDE-2 hybrid resin in detail.Fourier transform infrared (FT-IR) spectrometer,scanning electronic microscopy (SEM),differential scanning calorimetry (DSC),thermogravimetric analysis (TGA),dynamic mechanical thermal analysis (DMA) and molecular simulation technology are used to study the structure of HTDE-2,performance and toughening and reinforcing mechanism of the HTDE-2/E51 hybrid resin.It has been shown that the content of HTDE-2 has an important effect on the performance of the hybrid resin,and the performance of the HTDE-2/E51 blends has maximum with the increase in HTDE-2 content.The impact strength and fracture toughness of the hybrid resin with 9 wt-% HTDE-2 are almost 3.088 and 1.749 times of E51 performance respectively,furthermore,the tensile and flexural strength can also be enhanced about 20.7% and 14.2%,respectively.The glass transition temperature and thermal degradation temperature,however,are found to decrease to some extent.

  20. Histological assessment of pulpal responses to resin modified glass ionomer cements in human teeth

    Directory of Open Access Journals (Sweden)

    Ali Eskandarizadeh

    2015-01-01

    Full Text Available Background: The biocompatibility of resin-modified glass ionomers (RMGIs as a lining material is still under question. The present study evaluated the response of the pulp-dentin complex following application of resin-modified glass-ionomer cement, calcium hydroxide and conventional glass-ionomer in deep cavities prepared in human teeth. Materials and Methods: In this controlled clinical trial, 30 deep class V buccal cavities (3 mm × 2 mm × 2 mm were prepared in human premolars treatment planned to be extracted for orthodontic reasons and divided into 3 groups. Groups were lined by a RMGI (Vivaglass, conventional glass Ionomer (Ionocid and calcium hydroxide respectively. The cavities were subsequently filled with amalgam. Each group was then divided into two sub-groups according to time intervals 5 and 30 days. The patients were referred to Kerman Dental School and in accordance with orthodontic treatment plan; premolars were extracted and then prepared for histological assessment. The sections were stained with hematoxylin and eosin and periodic acid Schiff techniques. All of the samples were examined using a number of criteria including odontoblastic changes, inflammatory cells response, reactionary dentin formation and presence of microorganisms. The data were analyzed by Kruskal-Wallis and Mann-Whitney tests. P 0.05. Conclusion: Ionocid and Vivaglass resin-modified glass ionomers can be used as lining materials in human teeth.

  1. On the heterogeneous structure of thermally cured bis-GMA/TEGDMA resins.

    Science.gov (United States)

    Jancar, J; Wang, W; DiBenedetto, A T

    2000-11-01

    In this paper we report on the morphogenesis of dental resins formed by a thermally initiated radical cross-linking copolymerization of model dental resins. These systems were considered reasonable model simplifications of the actual resins used in commercial filling composites, veneers, etc. Effect of bis-GMA content varying from 0 to 100% on the degree of conversion and morphology of the cured resin was investigated. Dynamic scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), dynamic mechanical thermal analysis (DMTA) and high temperature solvent extraction experiments were performed in order to determine the nature and location of unreacted unsaturations in relation to bis-GMA concentration. The interval of cure temperatures, ranging from 23 to 250 degrees C, may seem irrelevant from the clinical point of view but is instrumental for an understanding of the processes involved. Single glass transition temperature (Tg) found in DMTA experiments showed that the copolymerization process between bis-GMA and TEGDMA is random in nature, however, the overall cure reaction is inhomogeneous and this inhomogeneity is increasing with increasing bis-GMA molar fraction. Heterogeneous character of the cure was reflected into the network morphogenesis characterized by microgellation preceded by cyclization and, following connection of microgels. These cure kinetics resulted in a heterogeneous morphology of the cured resin. Moreover, it was shown that the cure kinetics controls to a great extent the degree of conversion of the reactive vinylidene C=C bonds in a fully cured resin. A decrease in bis-GMA concentration in the resin mixture led to a higher degree of conversion, however, even a neat TEGDMA homopolymer did not exhibit C=C conversion greater than 65-70% under the cure conditions used. Leaching out tests, consisting of an extraction of unreacted monomer from a finely ground cured resin in boiling cyclohexanone at 160 degrees C over a period of 5 d

  2. Separation and determination of arsenic species in water by selective exchange and hybrid resins

    Energy Technology Data Exchange (ETDEWEB)

    Issa, Nureddin Ben [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, Belgrade (Serbia); Rajakovic-Ognjanovic, Vladana N. [Faculty of Civil Engineering, University of Belgrade, Bulevar Kralja Aleksandra 73, Belgrade (Serbia); Marinkovic, Aleksandar D. [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, Belgrade (Serbia); Rajakovic, Ljubinka V., E-mail: ljubinka@tmf.bg.ac.rs [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, Belgrade (Serbia)

    2011-11-07

    Highlights: {yields} A simple and efficient method for separation and determination of arsenic species. {yields} A new hybrid resin HY-AgCl is effective for iAs and oAs analytical separation. {yields} SBAE resin was convenient for the separation of As(III) from As(V) and oAs species. {yields} HY-Fe resin was convenient for the separation of DMAs(V). - Abstract: A simple and efficient method for separation and determination of inorganic arsenic (iAs) and organic arsenic (oAs) in drinking, natural and wastewater was developed. If arsenic is present in water prevailing forms are inorganic acids of As(III) and As(V). oAs can be found in traces as monomethylarsenic acid, MMA(V), and dimethylarsenic acid, DMAs(V). Three types of resins: a strong base anion exchange (SBAE) and two hybrid (HY) resins: HY-Fe and HY-AgCl, based on the activity of hydrated iron oxides and a silver chloride were investigated. It was found that the sorption processes (ion exchange, adsorption and chemisorptions) of arsenic species on SBAE (ion exchange) and HY resins depend on pH values of water. The quantitative separation of molecular and ionic forms of iAs and oAs was achieved by SBAE and pH adjustment, the molecular form of As(III) that exists in the water at pH <8.0 was not bonded with SBAE, which was convenient for direct determination of As(III) concentration in the effluent. HY-Fe resin retained all arsenic species except DMAs(V), which makes possible direct measurements of this specie in the effluent. HY-AgCl resin retained all iAs which was convenient for direct determination of oAs species concentration in the effluent. The selective bonding of arsenic species on three types of resins makes possible the development of the procedure for measuring and calculation of all arsenic species in water. In order to determine capacity of resins the preliminary investigations were performed in batch system and fixed bed flow system. Resin capacities were calculated according to breakthrough

  3. Synthesis and Characterizations of Melamine-Based Epoxy Resins

    Directory of Open Access Journals (Sweden)

    Raffaele Cioffi

    2013-09-01

    Full Text Available A new, easy and cost-effective synthetic procedure for the preparation of thermosetting melamine-based epoxy resins is reported. By this innovative synthetic method, different kinds of resins can be obtained just by mixing the reagents in the presence of a catalyst without solvent and with mild curing conditions. Two types of resins were synthesized using melamine and a glycidyl derivative (resins I or by adding a silane derivative (resin II. The resins were characterized by means of chemical-physical and thermal techniques. Experimental results show that all the prepared resins have a good thermal stability, but differ for their mechanical properties: resin I exhibits remarkable stiffness with a storage modulus value up to 830 MPa at room temperature, while lower storage moduli were found for resin II, indicating that the presence of silane groups could enhance the flexibility of these materials. The resins show a pot life higher than 30 min, which makes these resins good candidates for practical applications. The functionalization with silane terminations can be exploited in the formulation of hybrid organic-inorganic composite materials.

  4. Synthesis and characterizations of melamine-based epoxy resins.

    Science.gov (United States)

    Ricciotti, Laura; Roviello, Giuseppina; Tarallo, Oreste; Borbone, Fabio; Ferone, Claudio; Colangelo, Francesco; Catauro, Michelina; Cioffi, Raffaele

    2013-09-05

    A new, easy and cost-effective synthetic procedure for the preparation of thermosetting melamine-based epoxy resins is reported. By this innovative synthetic method, different kinds of resins can be obtained just by mixing the reagents in the presence of a catalyst without solvent and with mild curing conditions. Two types of resins were synthesized using melamine and a glycidyl derivative (resins I) or by adding a silane derivative (resin II). The resins were characterized by means of chemical-physical and thermal techniques. Experimental results show that all the prepared resins have a good thermal stability, but differ for their mechanical properties: resin I exhibits remarkable stiffness with a storage modulus value up to 830 MPa at room temperature, while lower storage moduli were found for resin II, indicating that the presence of silane groups could enhance the flexibility of these materials. The resins show a pot life higher than 30 min, which makes these resins good candidates for practical applications. The functionalization with silane terminations can be exploited in the formulation of hybrid organic-inorganic composite materials.

  5. [Antibacterial actions of denture base resin on oral bacteria].

    Science.gov (United States)

    Yamauchi, M; Nigauri, A; Yamamoto, K; Nakazato, G; Kawano, J; Kimura, K

    1989-06-01

    Antibacterial action of various denture base resins on thirteen species of bacteria were studied in vitro. Antibacterial effect of 5% tannin-fluoride preparation, 5% tannic acid and 5% chlorhexidine added to resins on these thirteen bacterial species were also investigated using heat-curing denture base resins. Fresh microwave-curing resin and pour-type resin each showed an antibacterial action on one bacterial strain. Fresh self-curing resins had antibacterial actions on several bacterial strains. However, after storage in water at 37 degrees C for one week, antibacterial action of microwave-curing and pour-type resin were diminished and self-curing resins partially lost their antibacterial actions. Denture base resin containing tannin-fluoride preparation or tannic acid showed an antibacterial effect on one bacterial strain. On the other hand, denture base resin containing chlorhexidine had an antibacterial action on eleven bacterial strains. However, color and mechanical properties of the drug-containing resins were not satisfactory.

  6. Resin-based preparation of HTGR fuels: operation of an engineering-scale uranium loading system

    Energy Technology Data Exchange (ETDEWEB)

    Haas, P.A.

    1977-10-01

    The fuel particles for recycle of /sup 233/U to High-Temperature Gas-Cooled Reactors are prepared from uranium-loaded carboxylic acid ion exchange resins which are subsequently carbonized, converted, and refabricated. The development and operation of individual items of equipment and of an integrated system are described for the resin-loading part of the process. This engineering-scale system was full scale with respect to a hot demonstration facility, but was operated with natural uranium. The feed uranium, which consisted of uranyl nitrate solution containing excess nitric acid, was loaded by exchange with resin in the hydrogen form. In order to obtain high loadings, the uranyl nitrate must be acid deficient; therefore, nitric acid was extracted by a liquid organic amine which was regenerated to discharge a NaNO/sub 3/ or NH/sub 4/NO/sub 3/ solution waste. Water was removed from the uranyl nitrate solution by an evaporator that yielded condensate containing less than 0.5 ppM of uranium. The uranium-loaded resin was washed with condensate and dried to a controlled water content via microwave heating. The loading process was controlled via in-line measurements of the pH and density of the uranyl nitrate. The demonstrated capacity was 1 kg of uranium per hour for either batch loading contractors or a continuous column as the resin loading contractor. Fifty-four batch loading runs were made without a single failure of the process outlined in the chemical flowsheet or any evidence of inability to control the conditions dictated by the flowsheet.

  7. Effect of adhesive layers on microshear bond strength of nanocomposite resin to dentin

    Science.gov (United States)

    Ebrahim, Mohamed I.

    2017-01-01

    Background Bond strength of adhesive layer can absorb unwanted stresses of polymerization shrinkage in composite resin restorations; increased microshear bond strength can prevent failure of restoration materials, the purpose of this study was to evaluate the effect of adhesive layers on microshear bond strength of nanocomposite resin to dentin. Material and Methods Two different types of adhesive systems: universal adhesive (ExciTE) and newly developed adhesive (Nano-Bond), and one type of light-cured resin restorative material (Nanocomposite resin) were used in this study. The occlusal surfaces of extracted human molar teeth were ground perpendicular to the long axis of each tooth to expose a flat dentin surface. The adhesives were applied on dentin surfaces (single application or double application). Nanocomposite resin was then placed and light cured for 40 seconds. After 24 hours of immersion in water at 37°C, then subjected to thermocycling before testing, a microshear bond test was carried out. The data were analyzed by a two-way ANOVA. For comparison between groups, Tukey’s post-hoc test was used. Results The mean bond strengths of ExciTE and Nano-Bond adhesives with a single application were 8.8 and 16.6 MPa, respectively. The mean bond strengths of ExciTE and Nano-Bond adhesives with double application were 13.2 and 21.8MPa, respectively. There were no statistically significant differences in microshear bond strengths between the single application of Nano-Bond and the double application of ExciTE adhesives. Conclusions Microshear bond strength increased significantly as the applied adhesive layer was doubled. Key words:Adhesive, microshear, bond, strength, nanocomposite. PMID:28210433

  8. In Vitro Fatigue Resistance of Teeth Restored With Bulk Fill versus Conventional Composite Resin.

    Science.gov (United States)

    Rauber, Gabrielle Branco; Bernardon, Jussara Karina; Vieira, Luiz Clovis Cardoso; Maia, Hamilton Pires; Horn, Françoá; Roesler, Carlos Rodrigo de Mello

    2016-01-01

    The aim of this study was to compare the fatigue resistance of restored teeth with bulk fill composite resin, conventional composite resin with incremental insertion and unprepared sound teeth. Twenty-eight extracted maxillary premolars were selected and divided into 4 groups based on composite resin and insertion technique: control (C), conventional composite resin with incremental insertion (I) and bulk fill composite resin with three (BF3) or single increment (BF1). The restored specimens were submitted to fatigue resistance test with a 5 Hz frequency. An initial application of 5,000 sinusoidal load cycles with a minimum force of 50 N and a maximum force of 200 N was used. Next, were applied stages of 30,000 load cycles with the maximum force increasing gradually: 400, 600, 800, 1000, 1200 and 1400 N. The test was concluded when 185,000 load cycles were achieved or the specimen failed. The fatigue resistance data were recorded for comparison, using the Kaplan-Meier survival curve and analyzed by log-rank test at 0.05 significance. Fractures were classified based on the position of the failure - above or below the cementoenamel junction (CEJ). Statistical analysis of the Kaplan-Meier survival curve and log-rank test showed a significant difference between groups (p=0.001). The fracture analysis demonstrated that only 28.58% of failures were below the CEJ in group C, while for groups I, BF1 and BF3 they were 42.85%, 85.71% and 85.71%, respectively. Teeth restored with composite bulk fill in both techniques present similar fatigue resistance values compared with those restored with a conventional incremental insertion of composite, while the fatigue strength values of unprepared sound teeth were higher. Furthermore, unprepared sound teeth showed a lower percentage of fractures below the CEJ.

  9. Effect of light-curing units on microleakage under dental composite resins

    Science.gov (United States)

    Queiroz, R. S.; Bandéca, M. C.; Calixto, L. R.; Saade, E. G.; Nadalin, M. R.; Andrade, M. F.; Porto-Neto, S. T.

    2009-09-01

    The aim of this study was to determine the effect of two light-curing units (QTH and LED) on microleakage of Class II composite resin restorations with dentin cavosurface margins. Twenty extracted mandibular first premolars, free of caries and fractures were prepared two vertical “slot” cavities in the occluso-mesial and -destal surfaces (2 mm buccal-lingually, 2 mm proximal-axially and cervical limit in enamel) and divided into 4 equal groups ( n = 8): GI and GII: packable posterior composite light-activated with LED and QTH, respectively; GIII and GIV: micro-hybrid composite resin light-activated with LED and QTH, respectively. The composite resins were applied following the manufacturer’s instructions. After 24 h of water storage specimens were subjected to thermocycling for a total of 500 cycles at 5 and 55°C and the teeth were then sealed with impermeable material. Teeth were immersed in 0.5% Basic fuchsin during 24 h at room temperature, and zero to three levels of penetration score were attributed. The Mann-Whitney and Kruskal-Wallis tests showed significant statistically similar ( P > 0.05) from GI to GII and GIII to GIV, which the GII (2.750) had the highest mean scores and the GIII and GIV (0.875) had lowest mean scores. The use of different light-curing units has no influence on marginal integrity of Class II composite resin restorations and the proprieties of composite resins are important to reduce the microleakage.

  10. ANALYSIS OF VENTING OF A RESIN SLURRY

    Energy Technology Data Exchange (ETDEWEB)

    Laurinat, J.; Hensel, S.

    2012-03-27

    A resin slurry venting analysis was conducted to address safety issues associated with overpressurization of ion exchange columns used in the Purex process at the Savannah River Site (SRS). If flow to these columns were inadvertently interrupted, an exothermic runaway reaction could occur between the ion exchange resin and the nitric acid used in the feed stream. The nitric acid-resin reaction generates significant quantities of noncondensable gases, which would pressurize the column. To prevent the column from rupturing during such events, rupture disks are installed on the column vent lines. The venting analysis models accelerating rate calorimeter (ARC) tests and data from tests that were performed in a vented test vessel with a rupture disk. The tests showed that the pressure inside the test vessel continued to increase after the rupture disk opened, though at a slower rate than prior to the rupture. Calculated maximum discharge rates for the resin venting tests exceeded the measured rates of gas generation, so the vent size was sufficient to relieve the pressure in the test vessel if the vent flow rate was constant. The increase in the vessel pressure is modeled as a transient phenomenon associated with expansion of the resin slurry/gas mixture upon rupture of the disk. It is postulated that the maximum pressure at the end of this expansion is limited by energy minimization to approximately 1.5 times the rupture disk burst pressure. The magnitude of this pressure increase is consistent with the measured pressure transients. The results of this analysis demonstrate the need to allow for a margin between the design pressure and the rupture disk burst pressure in similar applications.

  11. ANALYSIS OF VENTING OF A RESIN SLURRY

    Energy Technology Data Exchange (ETDEWEB)

    Laurinat, J.; Hensel, S.

    2012-03-27

    A resin slurry venting analysis was conducted to address safety issues associated with overpressurization of ion exchange columns used in the Purex process at the Savannah River Site (SRS). If flow to these columns were inadvertently interrupted, an exothermic runaway reaction could occur between the ion exchange resin and the nitric acid used in the feed stream. The nitric acid-resin reaction generates significant quantities of noncondensable gases, which would pressurize the column. To prevent the column from rupturing during such events, rupture disks are installed on the column vent lines. The venting analysis models accelerating rate calorimeter (ARC) tests and data from tests that were performed in a vented test vessel with a rupture disk. The tests showed that the pressure inside the test vessel continued to increase after the rupture disk opened, though at a slower rate than prior to the rupture. Calculated maximum discharge rates for the resin venting tests exceeded the measured rates of gas generation, so the vent size was sufficient to relieve the pressure in the test vessel if the vent flow rate was constant. The increase in the vessel pressure is modeled as a transient phenomenon associated with expansion of the resin slurry/gas mixture upon rupture of the disk. It is postulated that the maximum pressure at the end of this expansion is limited by energy minimization to approximately 1.5 times the rupture disk burst pressure. The magnitude of this pressure increase is consistent with the measured pressure transients. The results of this analysis demonstrate the need to allow for a margin between the design pressure and the rupture disk burst pressure in similar applications.

  12. FDI report on adverse reactions to resin-based materials.

    Science.gov (United States)

    Fan, P L; Meyer, D M

    2007-02-01

    Resin-based restorative materials are considered safe for the vast majority of dental patients. Although constituent chemicals such as monomers, accelerators and initiators can potentially leach out of cured resin-based materials after placement, adverse reactions to these chemicals are rare and reaction symptoms commonly subside after removal of the materials. Dentists should be aware of the rare possibility that patients could have adverse reactions to constituents of resin-based materials and be vigilant in observing any adverse reactions after restoration placement. Dentists should also be cognisant of patient complaints about adverse reactions that may result from components of resin-based materials. To minimise monomer leaching and any potential risk of dermatological reactions, resin-based materials should be adequately cured. Dental health care workers should avoid direct skin contact with uncured resin-based materials. Latex and vinyl gloves do not provide adequate barrier protection to the monomers in resin-based materials.

  13. Resin Material Dependence of Pit Shape in Thermal Direct Mastering

    Science.gov (United States)

    Sakai, Toshihiko; Shimo, Masanori; Takamori, Nobuyuki; Murakami, Yoshiteru; Takahashi, Akira

    2007-06-01

    We report the resin material dependence of the shape of pits obtained by thermal direct mastering (TDM), which is a heat-mode mastering method utilizing the thermal decomposition of resins. By applying suitable resins, both circular and crescent pits can be obtained by TDM. This difference in shape was considered to originate from the temperature difference between the glass transition temperature and the thermal decomposition temperature of the resins. The resin with a relatively small temperature difference was suitable for the fabrication of the circular pits and random patterns, and the resin with a large temperature difference was suitable for the fabrication of the crescent pits and monotone patterns with high linear density. By using a deep ultraviolet (DUV) laser mastering system with a wavelength of 257 nm and a numerical aperture of 0.90, a monotone pattern of 40-nm-length pits was fabricated by applying a novolak-type resin with a relatively large temperature difference.

  14. Commercial Ion Exchange Resin Vitrification in Borosilicate Glass

    Energy Technology Data Exchange (ETDEWEB)

    Cicero-Herman, C.A.; Workman, P. [Westinghouse Savannah River Co., Aiken, SC (United States); Poole, K.; Erich, D.; Harden, J. [Clemson Environmental Technologies Laboratory, Anderson, SC (United States)

    1998-05-01

    Bench-scale studies were performed to determine the feasibility of vitrification treatment of six resins representative of those used in the commercial nuclear industry. Each resin was successfully immobilized using the same proprietary borosilicate glass formulation. Waste loadings varied from 38 to 70 g of resin/100 g of glass produced depending on the particular resin, with volume reductions of 28 percent to 68 percent. The bench-scale results were used to perform a melter demonstration with one of the resins at the Clemson Environmental Technologies Laboratory (CETL). The resin used was a weakly acidic meth acrylic cation exchange resin. The vitrification process utilized represented a approximately 64 percent volume reduction. Glass characterization, radionuclide retention, offgas analyses, and system compatibility results will be discussed in this paper.

  15. Complexation of labile aluminium species by chelating resins Iontosorb--a new method for Al environmental risk assessment.

    Science.gov (United States)

    Matús, Peter; Kubová, Jana

    2005-09-01

    The utilization of chelating ion-exchange by the method based on binding strength and kinetic discrimination for aluminium fractionation was studied. Two chelating cellulose resins, Iontosorb Oxin (IO) and Iontosorb Salicyl (IS), were used for the determination of quickly reacting labile aluminium species. The possibilities of aluminium fractionation on these chelating resins were investigated by a solid phase extraction technique. The study of the pH (2.5-6.0) influence on the Al complexation by both resins indicates that at low pH the IS has lower sorption capacity but better adsorptive kinetic properties than IO. The optimal resin complexation time for reactive Al species was experimentally found after aluminium sorption study at pH 4.0 in synthetic solutions containing some inorganic and organic ligands, which simulate the composition of analysed acid soil and water samples. The negative influence of sulphate and iron on the Al complexation by IS resin was found and investigated. The flame atomic absorption spectrometry was used for the aluminium quantification.

  16. Affinity purification of the voltage-sensitive sodium channel from electroplax with resins selective for sialic acid

    Energy Technology Data Exchange (ETDEWEB)

    James, W.M.; Emerick, M.C.; Agnew, W.S. (Yale Univ. School of medicine, New Haven, CT (USA))

    1989-07-11

    The voltage-sensitive sodium channel present in the eel (Electrophorus electricus) has an unusually high content of sialic acid, including {alpha}-(2{yields}8)-linked polysialic acid, not found in other electroplax membrane glycopeptides. Lectins from Limax flavus (LFA) and wheat germ (WGA) proved the most effective of 11 lectin resins tried. The most selective resin was prepared from IgM antibodies against Neisseria meningitidis {alpha}-(2{yields}8)-polysialic acid which were affinity purified and coupled to Sepharose 4B. The sodium channel was found to bind to WGA, LFA, and IgM resins and was readily eluted with the appropriate soluble carbohydrates. Experiments with LFA and IgM resins demonstrated binding and unbinding rates and displacement kinetics, which suggest highly specific binding at multiple sites on the sodium channel protein. In preparative-scale purification of protein previously fractionated by anion-exchange chromatography, without stabilizing TTX, high yields were reproducibly obtained. Further, when detergent extracts were prepared from electroplax membranes fractionated by low-speed sedimentation, a single step over the IgM resin provided a 70-fold purification, yielding specific activities of 3,200 pmol of ({sup 3}H)TTX-binding sites/mg of protein and a single polypeptide of {approximately}285,000 Da on SDS-acrylamide gels. No small peptides were observed after this 5-h isolation. The authors describe a cation-dependent stabilization with millimolar levels of monovalent and micromolar levels of divalent species.

  17. Effects of curing mode of resin cements on the bond strength of a titanium post: An intraradicular study

    Directory of Open Access Journals (Sweden)

    Fazal Reza

    2012-01-01

    Full Text Available Aim: To compare push-out bond strength between self-cured and dual-cured resin cement using a titanium post. Background: Dual-cured resin cements have been found to be less polymerized in the absence of light; thus the bond strength of cements would be compromised due to the absence of light with a metallic post. Materials and Methods: Ten extracted teeth were prepared for cement titanium PARAPOST, of five specimens each, with Panavia F [dual-cured (PF] and Rely×Luting 2 [self-cured resin-modified glass ionomer luting cement (RL]; the push-out bond strength (PBS at three different levels of the sectioned roots was measured. The failure modes were observed and the significance of the differences in bond strength of the two types of cement at each level and at different levels of the same type was analyzed with non-parametric tests. Results: The push-out bond strength of the RL group was greater at all the three levels; with significant differences at the coronal and middle levels (P<0.05. No significant differences in PBS at different levels of the same group were observed. Cement material around the post was obvious in the PF group. The failure mode was mostly adhesive between the post and resin cement in the RL group. Conclusion: Bond strength was greater with self-cured, resin-modified glass ionomer luting cement, using titanium post.

  18. Determination of molybdate in environmental water by ion chromatography coupled with a preconcentration method employing a selective chelating resin.

    Science.gov (United States)

    Nakashima, Yasuo; Inoue, Yoshinori; Yamamoto, Takahisa; Kamichatani, Waka; Kagaya, Sigehiro; Yamamoto, Atsushi

    2012-01-01

    A simple and sensitive suppressed ion chromatography (IC) method with conductivity detection for the determination of molybdate in environmental water is proposed. Molybdate in highly saline water was extracted and preconcentrated. Preconcentration was accomplished by using a chelating resin using a chelating resin immobilized with carboxymethylated polyethylenimine (Presep(®) PolyChelate). This resin is able to trap a variety of metal elements without any interference of alkali and alkaline-earth metals. A 30-mL volume of brackish water was adjusted for appropriate pH and then flushed through 100 mg of the chelating resin. Molybdate concentrated on the resin could be easily eluted with 6 mL of 0.1 M NaOH. A large volume injection method for IC was achieved with in-line neutralization of the effluent. The determination of 0.6 μg L(-1) molybdate in highly saline water was made possible with a 500-μL injection. Samples of brackish water were taken at various distances from the river mouth. The determined concentrations of molybdate correlated closely with concentrations of chloride.

  19. [In vitro study of marginal microleakage of Clearfil S3 BOND adhesive systems and Majesty composite resin].

    Science.gov (United States)

    Wang, Bei; Zhu, Ya-qin

    2009-08-01

    To evaluate the microleakage of standard box-type cavity filled with Clearfil S3 BOND self-etch adhesive systems and Majesty composite resin. 40 permanent molars were randomly divided into experimental and control groups, 20 of each . The box-type cavities, 3mm in length and width and 2mm in depth, were prepared at the cemento-enamel junction on buccal surface of forty permanent extracted teeth. According to grouping, the experimental group was filled with Clearfil S(3) BOND self-adhesive systems and Majesty composite resin, and the control group was filled with 3M Adper Prompt self-adhesive and Filtek Z350 composite resin. After thermal circulation(2000 times, 5 degrees centigrade-55 degrees centigrade) and soaked for 24 hours in 2% methyl blue solution, the samples were cut through the midline of the restoration and the leakage depth was measured with vernier caliper. The microleakage degrees and microleakage depth of 2 groups were analyzed with SPSS 17.0 software package for Mann-Whitney U test and independent-samples t test. Microleakage was observed in both groups. But the microleakage degrees and microleakage depth of 2 groups had no significant difference (P>0.05). The marginal sealibility of Clearfil S(3) BOND self-adhesive systems and Majesty composite resin is as good as Adper Prompt self-adhesive and Filtek Z350 composite resin,it may be an ideal clinical restoration material.

  20. Quantitative characterization of interdiffusion at the resin-resin and resin-prepreg interphases of epoxy systems processed by model SQ-RTM

    OpenAIRE

    Ballout, Wael; Coulon, B.; Janssens, Y.-A.; Van Velthem, Pascal; Sclavons, Michel; Magnin, Delphine; Pardoen, Thomas; Bailly, Christian

    2016-01-01

    The interdiffusion between a low and a high viscosity epoxy resin was studied on model systems representing the novel composite manufacturing process called “Same Qualified-Resin Transfer Molding” (SQ-RTM). Neat resin model systems were first characterized after curing by Raman spectroscopy, energy dispersive X-ray microscopy, and nano-indentation, all methods reveal an interdiffusion distance of about 700–900 mm. Transmission electron microscopy further revealed a complex morphological gradi...