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Sample records for preparation pharmaceutical compositions

  1. Unlicensed pharmaceutical preparations for clinical patient care: Ensuring safety.

    Science.gov (United States)

    de Wilde, Sofieke; de Jong, Maria G H; Le Brun, Paul P H; Guchelaar, Henk-Jan; Schimmel, Kirsten J M

    2018-01-01

    Most medicinal products dispensed to patients have marketing authorization (MA) to ensure high quality of the product, safety, and efficacy. However, in daily practice, to treat patients adequately, there is a medical need for drugs that do not hold MA. To meet this medical need, medicinal products are used in clinical care without MA (unlicensed), such as products prepared by (local) pharmacies: the pharmaceutical preparations. Three types of pharmaceutical preparations are distinguished: (i) reconstitution in excess of summary of product characteristics; (ii) adaptation of a licensed medicinal product (outside its official labeling); (iii) medicinal products from an active pharmaceutical ingredient. Although unlicensed, patients may expect the same quality for these unlicensed pharmaceutical preparations as for the licensed medicinal products. To assure this quality, a proper risk-benefit assessment and proper documentation in (centralized) patient registries and linking to a national pharmacovigilance database should be in place. Based on a risk assessment matrix, requirements for quality assurance can be determined, which has impact on the level of documentation of a pharmaceutical preparation. In this paper, the approach for good documentation including quality assurance and benefit-risk assessment will be discussed and possibilities for patient registries are described to make these crucial preparations available for regular patient care. KEY POINTS Ensuring pharmaceutical quality and performing a proper benefit-risk assessment will guarantee safe use of pharmaceutical preparations. Good documentation of (ultra-)orphan treatments can be collected in centralized patient registries and should be combined with existing information in (inter)national databases and self-reflection of patients. Linking patient registries to a centralized database for adverse drug events is highly recommended as it increases safety control of the (ultra) orphan pharmaceutical

  2. Novel HPLC Analysis of Hydrocortisone in Conventional and Controlled-Release Pharmaceutical Preparations

    OpenAIRE

    Adi-Dako, Ofosua; Oppong Bekoe, Samuel; Ofori-Kwakye, Kwabena; Appiah, Enoch; Peprah, Paul

    2017-01-01

    An isocratic sensitive and precise reverse phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for the determination and quantification of hydrocortisone in controlled-release and conventional (tablets and injections) pharmaceutical preparations. Chromatographic separation was achieved on an ODS (C18), 5??m, 4.6 ? 150?mm, with an isocratic elution using a freshly prepared mobile phase of composition methanol?:?water?:?acetic acid (60?:?30?:?10, v/v/v) at ...

  3. [Bioequivalence studies of pharmaceutical preparations].

    Science.gov (United States)

    Vetchý, D; Frýbortová, K; Rabisková, M; Danecková, H

    2007-01-01

    Bioequivalence studies are very important for the development of a pharmaceutical preparation in the pharmaceutical industry. Their rationale is the monitoring of pharmacokinetic and pharmacodynamic parameters after the administration of tested drugs. The target of such study is to evaluate the therapeutic compatibility of tested drugs (pharmaceutical equivalents or pharmaceutical alternatives). The importance of bioequivalence studies is increasing also due to the large growth of the production and consumption of generic products. Generic products represent approximately 50 % of the whole consumption in many European countries and USA. The search output of bioequivalence study is together with the pharmaceutical quality data of medical product one of the main part of the registration file submitted to a national regulatory authorities. The registration of generic products does not demand complicated and expensive clinical study contrary to original product. The comparison of the original and the generic product via bioequivalence study is suggested as sufficient. The aim of this article is to provide to a medical public a summary about the types of bioequivalence studies, their range, rules of their practise and let them gain their own attitude to this question.

  4. Structural characterization of pharmaceutical heparins prepared from different animal tissues.

    Science.gov (United States)

    Fu, Li; Li, Guoyun; Yang, Bo; Onishi, Akihiro; Li, Lingyun; Sun, Peilong; Zhang, Fuming; Linhardt, Robert J

    2013-05-01

    Although most pharmaceutical heparin used today is obtained from porcine intestine, heparin has historically been prepared from bovine lung and ovine intestine. There is some regulatory concern about establishing the species origin of heparin. This concern began with the outbreak of mad cow disease in the 1990s and was exacerbated during the heparin shortage in the 2000s and the heparin contamination crisis of 2007-2008. Three heparins from porcine, ovine, and bovine were characterized through state-of-the-art carbohydrate analysis methods with a view profiling their physicochemical properties. Differences in molecular weight, monosaccharide and disaccharide composition, oligosaccharide sequence, and antithrombin III-binding affinity were observed. These data provide some insight into the variability of heparins obtained from these three species and suggest some analytical approaches that may be useful in confirming the species origin of a heparin active pharmaceutical ingredient. Copyright © 2013 Wiley Periodicals, Inc.

  5. Radiation sterilization of some pharmaceutical preparations and medical products

    International Nuclear Information System (INIS)

    Tashmetov, M.Yu.; Makhkamov, Sh.M.; Urinov, Sh.S.; Turaev, A.S.; Sultanov, M.S.; Inagomov, Kh.S.

    2006-01-01

    Full text: In connection with intensive development of pharmacology and medical techniques, use of the products contacting to blood, with the internal environment of an organism, with wound surface, with mucous membranes and skin there were high requirements to sterility of pharmaceutical preparations and medical products. Traditional methods of sterilization (heat treatment, gas processing and processing the ferry) have some restrictions in application, and not insufficient degree of sterilization required for pharmaceutical preparations and medical products. Thermal processing can lead to degradation of structure (medicine), mechanical changes and loss of medical properties. Besides, it is impossible to carry out sterilization of many pharmaceutical preparations by a method of heat treatment. Sterilization of products in packing is very complicated, because sterilization temperature of packing and a product is different. Gas processing is basically applied to sterilization of medical products (syringes, bandage, cotton wools, etc.). However, the degree of sterility is low, because of rather low ability and heterogeneity of sterilizing substance. Sterilization in packing represents special difficulty and demands additional charges related with delivery of the purified gas from abroad. Last years alongside with known technological methods of sterilization of medical products and pharmaceutical preparations radiating methods of processing have found wide application. Use of electronic bunches with the moderate energy and various isotopes became a basis for formation and development of a new direction in the medicine, called by 'radiation sterilization'. The radiation technology is highly harmless and economic, not polluting substance and surrounding space. Unlike the specified traditional methods, radiating processing of products by the isotope 60 Co, radiating the gamma quantum, has unique opportunities - high penetrability in substance, providing uniformity of

  6. Novel HPLC Analysis of Hydrocortisone in Conventional and Controlled-Release Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    Ofosua Adi-Dako

    2017-01-01

    Full Text Available An isocratic sensitive and precise reverse phase high-performance liquid chromatography (RP-HPLC method was developed and validated for the determination and quantification of hydrocortisone in controlled-release and conventional (tablets and injections pharmaceutical preparations. Chromatographic separation was achieved on an ODS (C18, 5 μm, 4.6 × 150 mm, with an isocratic elution using a freshly prepared mobile phase of composition methanol : water : acetic acid (60 : 30 : 10, v/v/v at a flow rate of 1.0 ml/min. The detection of the drug was successfully achieved at a wavelength of 254 nm. The retention time obtained for the drug was 2.26 min. The proposed method produced linear detectable responses in the concentration range of 0.02 to 0.4 mg/ml of hydrocortisone. High recoveries of 98–101% were attained at concentration levels of 80%, 100%, and 120%. The intraday and interday precision (RSD were 0.19–0.55% and 0.33–0.71%, respectively. A comparison of hydrocortisone analyses data from the developed method and the official USP method showed no significant difference (p>0.05 at a 95% confidence interval. The method was successfully applied to the determination and quantification of hydrocortisone in six controlled-release and fifteen conventional release pharmaceutical preparations.

  7. 76 FR 65210 - Certain Products and Pharmaceutical Compositions Containing Recombinant Human Erythropoetin...

    Science.gov (United States)

    2011-10-20

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-568] Certain Products and Pharmaceutical Compositions Containing Recombinant Human Erythropoetin; Termination of Investigation on the Basis of... after importation of certain products and pharmaceutical compositions containing recombinant human...

  8. WHO expert committee on specifications for pharmaceutical preparations.

    Science.gov (United States)

    2013-01-01

    The Expert Committee on Specifications for Pharmaceutical Preparations works towards clear, independent and practical standards and guidelines for the quality assurance of medicines. Standards are developed by the Committee through worldwide consultation and an international consensus-building process. The following new guidelines were adopted and recommended for use: Release procedure for International Chemical Reference Substances; WHO guidelines on quality risk management; WHO guidelines on variations to a prequalified product; and the Collaborative procedure between the World Health Organization Prequalification of Medicines Programme and national medicines regulatory authorities in the assessment and accelerated national registration of WHO-prequalified pharmaceutical products.

  9. Pharmaceutical studies on and clinical application of olanzapine suppositories prepared as a hospital preparation

    OpenAIRE

    Matsumoto, Kazuaki; Kimura, Satoru; Takahashi, Kenichi; Yokoyama, Yuta; Miyazawa, Masayuki; Kushibiki, Satoko; Katamachi, Morio; Kizu, Junko

    2016-01-01

    Background A new formulation of olanzapine available for terminally ill patients is needed. Rectal administration using suppositories is an alternative for patients for whom administration via the oral route is not feasible. In the present study, we prepared olanzapine suppositories, and confirmed using pharmaceutical tests. Furthermore, we demonstrated the efficacy and safety of olanzapine suppositories in terminally ill patients. Methods We prepared olanzapine suppositories using bases cons...

  10. Infrared imaging spectroscopy and chemometric tools for in situ analysis of an imiquimod pharmaceutical preparation presented as cream

    Science.gov (United States)

    Carneiro, Renato Lajarim; Poppi, Ronei Jesus

    2014-01-01

    In the present work the homogeneity of a pharmaceutical formulation presented as a cream was studied using infrared imaging spectroscopy and chemometric methodologies such as principal component analysis (PCA) and multivariate curve resolution with alternating least squares (MCR-ALS). A cream formulation, presented as an emulsion, was prepared using imiquimod as the active pharmaceutical ingredient (API) and the excipients: water, vaseline, an emulsifier and a carboxylic acid in order to dissolve the API. After exposure at 45 °C during 3 months to perform accelerated stability test, the presence of some crystals was observed, indicating homogeneity problems in the formulation. PCA exploratory analysis showed that the crystal composition was different from the composition of the emulsion, since the score maps presented crystal structures in the emulsion. MCR-ALS estimated the spectra of the crystals and the emulsion. The crystals presented amine and C-H bands, suggesting that the precipitate was a salt formed by carboxylic acid and imiquimod. These results indicate the potential of infrared imaging spectroscopy in conjunction with chemometric methodologies as an analytical tool to ensure the quality of cream formulations in the pharmaceutical industry.

  11. WHO Expert Committee on Specifications for Pharmaceutical Preparations. Fiftieth report.

    Science.gov (United States)

    2016-01-01

    The Expert Committee on Specifications for Pharmaceutical Preparations works towards clear, independent and practical standards and guidelines for the quality assurance of medicines. Standards are developed by the Committee through worldwide consultation and an international consensus-building process. The following new guidelines were adopted and recommended for use. Good pharmacopoeial practices; FIP-WHO technical guidelines: points to consider in the provision by health-care professionals of children-specific preparations that are not available as authorized products; Guidance on good manufacturing practices for biological products; Guidance on good manufacturing practices: inspection report, including Appendix 1: Model inspection report; Guidance on good data and record management practices; Good trade and distribution practices for starting materials; Guidelines on the conduct of surveys of the quality of medicines; Collaborative procedure between the World Health Organization (WHO) prequalification team and national regulatory authorities in the assessment and accelerated national registration of WHO-prequalified pharmaceutical products and vaccines; Guidance for organizations performing in vivo bioequivalence studies; and World Health Organization (WHO) general guidance on variations to multisource pharmaceutical products.

  12. Sample preparation composite and replicate strategy case studies for assay of solid oral drug products.

    Science.gov (United States)

    Nickerson, Beverly; Harrington, Brent; Li, Fasheng; Guo, Michele Xuemei

    2017-11-30

    Drug product assay is one of several tests required for new drug products to ensure the quality of the product at release and throughout the life cycle of the product. Drug product assay testing is typically performed by preparing a composite sample of multiple dosage units to obtain an assay value representative of the batch. In some cases replicate composite samples may be prepared and the reportable assay value is the average value of all the replicates. In previously published work by Harrington et al. (2014) [5], a sample preparation composite and replicate strategy for assay was developed to provide a systematic approach which accounts for variability due to the analytical method and dosage form with a standard error of the potency assay criteria based on compendia and regulatory requirements. In this work, this sample preparation composite and replicate strategy for assay is applied to several case studies to demonstrate the utility of this approach and its application at various stages of pharmaceutical drug product development. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Evaluation of the pharmaceutical quality of some quinine preparations sold in Nigeria.

    Science.gov (United States)

    Nnamdi, Jolly A; Arhewoh, Ikhuoria M; Okhamafe, Augustine O; Enato, Ehijie F O

    2009-01-01

    The purpose of this study was to determine the pharmaceutical quality of quinine preparations sold in Nigerian markets. The organoleptic and physicochemical properties of quinine tablets, as well as oral liquids and parenteral quinine preparations, were assessed according to British Pharmacopoeia (BP) and unofficial standards as recommended by the manufacturers. Of the 6 brands of tablets assessed, 4 passed the uniformity of content test and 5 the disintegration test, but only 2 the dissolution test. The pH of 2 of the 6 brands of oral liquid preparations met BP standards, while only 1 oral liquid met the BP standard for percentage content. The assay further demonstrated that 4 brands of the parenteral preparations met BP standards for quinine content. All the parenteral preparations were found to be sterile. Quinine preparations sold in Nigeria varied considerably in their pharmaceutical quality. A strict check of the quality of brands of quinine by regulatory agencies and distributors before they are sold to the public is therefore recommended. Copyright 2009 S. Karger AG, Basel.

  14. Determination of ethamsylate in pharmaceutical preparations based on an auto-oxidation chemiluminescence reaction.

    Science.gov (United States)

    Yang, Fengzhen; Zhang, Chao; Baeyens, Willy R G; Zhang, Xinrong

    2002-10-15

    Strong chemiluminescence emission has been observed by mixing alkaline hydrolytic products of ethamsylate with Tween 80 in acidic rhodamine 6G solution. This phenomenon has been utilized to design a flow-injection chemiluminescence method for the determination of ethamsylate in a pharmaceutical preparation. Under the optimum conditions, the proposed procedure has a linear range between 0.05 and 2.0 microg ml(-1), with a detection limit of 0.02 microg ml(-1) for ethamsylate. The method was applied to the determination of ethamsylate in pharmaceutical preparations. The possible mechanism of this chemiluminescence reaction was proposed. Copyright 2002 Elsevier Science B.V.

  15. Pharmaceutical microparticle engineering with electrospraying

    DEFF Research Database (Denmark)

    Bohr, Adam; Wan, Feng; Kristensen, Jakob

    2015-01-01

    Microparticles of Celecoxib, dispersed in a matrix of poly(lactic-co-glycolic acid) (PLGA), were prepared by electrospraying using different solvent mixtures to investigate the influence upon particle formation and the resulting particle characteristics. Mixtures consisting of a good solvent, ace...... demonstrated by the increasingly higher drug release rates. The results demonstrate the importance of solvent composition in particle preparation and indicate potential for exploiting this dependence to improve pharmaceutical particle design and performance....

  16. Basic pharmaceutical technology

    OpenAIRE

    Angelovska, Bistra; Drakalska, Elena

    2017-01-01

    The lecture deals with basics of pharmaceutical technology as applied discipline of pharmaceutical science, whose main subject of study is formulation and manufacture of drugs. In a broad sense, pharmaceutical technology is science of formulation, preparation, stabilization and determination of the quality of medicines prepared in the pharmacy or in pharmaceutical industry

  17. A validated high performance thin layer chromatography method for determination of yohimbine hydrochloride in pharmaceutical preparations

    OpenAIRE

    Jihan M Badr

    2013-01-01

    Background: Yohimbine is an indole alkaloid used as a promising therapy for erectile dysfunction. A number of methods were reported for the analysis of yohimbine in the bark or in pharmaceutical preparations. Materials and Method: In the present work, a simple and sensitive high performance thin layer chromatographic method is developed for determination of yohimbine (occurring as yohimbine hydrochloride) in pharmaceutical preparations and validated according to International Conference of Ha...

  18. Voltammetric determination of copper in selected pharmaceutical preparations--validation of the method.

    Science.gov (United States)

    Lutka, Anna; Maruszewska, Małgorzata

    2011-01-01

    It were established and validated the conditions of voltammetric determination of copper in pharmaceutical preparations. The three selected preparations: Zincuprim (A), Wapń, cynk, miedź z wit. C (B), Vigor complete (V) contained different salts and different quantity of copper (II) and increasing number of accompanied ingredients. For the purpose to transfer copper into solution, the samples of powdered tablets of the first and second preparation were undergone extraction and of the third the mineralization procedures. The concentration of copper in solution was determined by differential pulse voltammetry (DP) using comparison with standard technique. In the validation process, the selectivity, accuracy, precision and linearity of DP determination of copper in three preparations were estimated. Copper was determined within the concentration range of 1-9 ppm (1-9 microg/mL): the mean recoveries approached 102% (A), 100% (B), 102% (V); the relative standard deviations of determinations (RSD) were 0.79-1.59% (A), 0.62-0.85% (B) and 1.68-2.28% (V), respectively. The mean recoveries and the RSDs of determination satisfied the requirements for the analyte concentration at the level 1-10 ppm. The statistical verification confirmed that the tested voltammetric method is suitable for determination of copper in pharmaceutical preparation.

  19. Colorimetric humidity sensor based on liquid composite materials for the monitoring of food and pharmaceuticals.

    Science.gov (United States)

    Bridgeman, Devon; Corral, Javier; Quach, Ashley; Xian, Xiaojun; Forzani, Erica

    2014-09-09

    Using supported ionic-liquid membrane (SILM)-inspired methodologies, we have synthesized, characterized, and developed a humidity sensor by coating a liquid composite material onto a hygroscopic, porous substrate. Similar to pH paper, the sensor responds to the environment's relative humidity and changes color accordingly. The humidity indicator is prepared by casting a few microliters of low-toxicity reagents on a nontoxic substrate. The sensing material is a newly synthesized liquid composite that comprises a hygroscopic medium for environmental humidity capture and a color indicator that translates the humidity level into a distinct color change. Sodium borohydride was used to form a liquid composite medium, and DenimBlu30 dye was used as a redox indicator. The liquid composite medium provides a hygroscopic response to the relative humidity, and DenimBlu30 translates the chemical changes into a visual change from yellow to blue. The borate-redox dye-based humidity sensor was prepared, and then Fourier transform infrared spectroscopy, differential scanning calorimetry, and image analysis methods were used to characterize the chemical composition, optimize synthesis, and gain insight into the sensor reactivity. Test results indicated that this new sensing material can detect relative humidity in the range of 5-100% in an irreversible manner with good reproducibility and high accuracy. The sensor is a low-cost, highly sensitive, easy-to-use humidity indicator. More importantly, it can be easily packaged with products to monitor humidity levels in pharmaceutical and food packaging.

  20. Spectrofluorimetric analysis of famotidine in pharmaceutical preparations and biological fluids by derivatization with benzoin.

    Science.gov (United States)

    Alamgir, Malik; Khuhawar, Muhammad Yar; Memon, Saima Q; Hayat, Amir; Zounr, Rizwan Ali

    2015-01-05

    A sensitive and simple spectrofluorimetric method has been developed for the analysis of famotidine, from pharmaceutical preparations and biological fluids after derivatization with benzoin. The reaction was carried out in alkaline medium with measurement of fluorescence intensity at 446 nm with excitation wavelength at 286 nm. Linear calibration was obtained with 0.5-15 μg/ml with coefficient of determination (r(2)) 0.997. The factors affecting the fluorescence intensity were optimized. The pharmaceutical additives and amino acid did not interfere in the determination. The mean percentage recovery (n=4) calculated by standard addition from pharmaceutical preparation was 94.8-98.2% with relative standard deviation (RSD) 1.56-3.34% and recovery from deproteinized spiked serum and urine of healthy volunteers was 98.6-98.9% and 98.0-98.4% with RSD 0.34-0.84% and 0.29-0.87% respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Developing a tool for the preparation of GMP audit of pharmaceutical contract manufacturer.

    Science.gov (United States)

    Linna, Anu; Korhonen, Mirka; Mannermaa, Jukka-Pekka; Airaksinen, Marja; Juppo, Anne Mari

    2008-06-01

    Outsourcing is rapidly growing in the pharmaceutical industry. When the manufacturing activities are outsourced, control of the product's quality has to be maintained. One way to confirm contract manufacturer's GMP (Good Manufacturing Practice) compliance is auditing. Audits can be supported for instance by using GMP questionnaires. The objective of this study was to develop a tool for the audit preparation of pharmaceutical contract manufacturers and to validate its contents by using Delphi method. At this phase of the study the tool was developed for non-sterile finished product contract manufacturers. A modified Delphi method was used with expert panel consisting of 14 experts from pharmaceutical industry, authorities and university. The content validity of the developed tool was assessed by a Delphi questionnaire round. The response rate in Delphi questionnaire round was 86%. The tool consisted of 103 quality items, from which 90 (87%) achieved the pre-defined agreement rate level (75%). Thirteen quality items which did not achieve the pre-defined agreement rate were excluded from the tool. The expert panel suggested only minor changes to the tool. The results show that the content validity of the developed audit preparation tool was good.

  2. Experiences of using the GMP audit preparation tool in pharmaceutical contract manufacturer audits.

    Science.gov (United States)

    Linna, Anu; Korhonen, Mirka; Airaksinen, Marja; Juppo, Anne Mari

    2010-06-01

    Use of external contractors is nowadays inevitable in the pharmaceutical industry. Therefore the amount of current good manufacturing practice audits has been increasing. During the audit, a large amount of items should be covered in a limited amount of time. Consequently, pharmaceutical companies should have systematic and effective ways to manage and prepare for the audits. This study is a continuation to the earlier study, where a tool for the preparation of cGMP audit was developed and its content was validated. The objective of this study was to evaluate the usefulness of the developed tool in audit preparation and during the actual cGMP audit. Three qualitative research methods were used in this study (observation, interviews, and opinion survey). First, the validity of the information given through the tool was examined by comparing the responses to the actual conditions observed during the contract manufacturer audits (n = 15). Additionally the opinions of the contract manufacturers of the tool were gathered (n = 10) and the auditors were interviewed (n = 2). The developed tool was proven to be useful in audit preparation phase from both the auditor's and the contract manufacturers' point of view. Furthermore, using the tool can also save some time when performing the audit. The results show that using the tool can give significant support in audit preparation phase and also during the actual audit.

  3. Determination of ascorbic acid in pharmaceutical preparation and fruit juice using modified carbon paste electrode

    Directory of Open Access Journals (Sweden)

    Simona Žabčíková

    2016-06-01

    Full Text Available Acrobic acid is key substance in the human metabolism and the rapid and accurate determination in food is of a great interest. Ascorbic acid is an electroactive compound, however poorly responded on the bare carbon paste electrodes. In this paper, brilliant cresyl blue and multi-walled carbon nanotubes were used for the modification of carbon paste electrode. Brilliant cresyl blue acts as a mediator improving the transition of electrons, whereas multiwalled carbon nanotubes increased the surface of the electrode. Both brilliant cresyl blue and multiwalled carbon nanotubes were added directly to the composite material. The electrochemical behavior of modified electode was determined in electrolyte at various pH, and the effect of the scan rate was also performed. It was shown that the electrochemical process on the surface of the modified carbon paste electrode was diffusion-controlled. The resulted modified carbon paste electrode showed a good electrocatalytic activity towards the oxidation of ascorbic acid at a reduced overpotential of +100 mV descreasing the risk of interferences. A linear response of the ascorbic acid oxidation current measured by the amperometry in the range of 0.1 - 350 µmol.L-1 was obtained applying the sensor for the standard solution. The limit of detection and limit of quantification was found to be 0.05 and 0.15 µmol.L-1, respectively. The novel method was applied for the determination of ascorbic acid in pharmaceutical vitamin preparation and fruit juice, and the results were in good agreement with the standard HPLC method. The presented modification of carbon paste electrode is suitable for the fast, sensitive and very accurate determination of ascorbic acid in fruit juices and pharmaceutical preparation.

  4. Aqueous degradation kinetics of pharmaceutical drug diclofenac by photo catalysis using nano structured titania–zirconia composite catalyst

    International Nuclear Information System (INIS)

    Das, L.; Barodia, S. K.; Sengupta, S.; Basu, J. K.

    2015-01-01

    Diclofenac is an anti-inflammatory pharmaceutical drug and its presence in a trace amount in waste water makes severe environmental pollution. The degradation of diclofenac was investigated by a photo catalytic process in presence of ultra violet irradiation at room temperature using titania and titania-zirconia nano composite catalysts in a batch reactor. The composite catalyst was prepared by sol-gel method and characterized by X-ray diffraction, transmission electron microscopy as well as BET surface area analyzer. The effect of various process parameters such as catalyst loading, initial concentration of diclofenac and p H of the experimental solution was observed on the degradation of diclofenac. The titania-zirconia nano composites exhibited reasonably higher photo catalytic activity than that of anatase form of titania without zirconia. The maximum removal of diclofenac of about 92.41% was achieved using Zr/Ti mass ratio of 11.8 wt% composite catalyst. A rate equation was proposed for the degradation of diclofenac using the composite catalyst. The values of rate constant (kc) and adsorption equilibrium constant (K1) were found to vary with the catalyst content in the reaction mixture.

  5. Spectrophotometric determination of metformin in pharmaceutical preparations, serum and urine using benzoin as derivatizing reagent

    International Nuclear Information System (INIS)

    Alamgir, M.; Hayat, A.

    2014-01-01

    A simple and selective spectrophotometric procedure is described for the determination of Metformin based on derivatization with benzoin. The Beers law was obeyed with 2.50-12.50 meu mol L-1 at 290 nm with coefficient of determination (r2) 0.997. The experimental conditions in term of pH, reaction time and temperature, and addition of derivatizing reagent were examined. The pure metformin-benzoin derivative was prepared and characterized by FT-IR and mass spectroscopic techniques. The method was applied for the determination of metformin from pharmaceutical preparations and serum and urine of volunteers after spiking with metformin. The results were checked by standard addition method. A number of pharmaceutical additives and serum or urine matrix did not affect the determination of metformin. (author)

  6. Identification of CJC-1295, a growth-hormone-releasing peptide, in an unknown pharmaceutical preparation.

    Science.gov (United States)

    Henninge, John; Pepaj, Milaim; Hullstein, Ingunn; Hemmersbach, Peter

    2010-01-01

    Several peptide drugs are being manufactured illicitly, and in some cases they are being made available to the public before entering or completing clinical trials. At the request of Norwegian police and customs authorities, unknown pharmaceutical preparations suspected to contain peptide drugs are regularly subjected to analysis. In 2009, an unknown pharmaceutical preparation was submitted for analysis by liquid chromatography-high resolution tandem mass spectrometry (LC-HRMS/MS). The preparation was found to contain a 29 amino acid peptide with a C-terminal amide function. Based on the interpretation of mass spectrometric data, an amino acid sequence was proposed. The sequence is consistent with a peptide currently marketed under the name CJC-1295. CJC-1295 is a releasing factor for growth hormone and is therefore considered a Prohibited Substance under Section S2 of the WADA Prohibited List. This substance has potential performance-enhancing effects, it is readily available, and there is reason to believe that it is being used within the bodybuilding community. Copyright © 2010 John Wiley & Sons, Ltd.

  7. Pharmaceutical Composition of Valsartan: β-Cyclodextrin: Physico–Chemical Characterization and Anti-Hypertensive Evaluation

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo de Matos Jensen

    2010-06-01

    Full Text Available Valsartan, a water-insoluble drug, is mainly used in the treatment of hypertension albeit with reduced oral bioavailability. The aim of work was to develop a valsartan:β-cyclodextrin (VAL:β-CD pharmaceutical composition in order to improve its water solubility and bioavailability. The VAL:β-CD complexes were prepared by the kneading, solid dispersion and freeze-drying methods, of which the freeze-drying method (FDY was found to be the best to prepare an inclusion complex. A physical mixtyure PM was also prepared. Complexes were characterized by thermal analysis, Fourier transformed- infrared (FTIR spectroscopy, Powder X-ray diffractometry, intrinsic dissolution and NMR (2D-ROESY. Phase-solubility analysis showed AL-type diagrams with β-cyclodextrin (β-CD. Microcalorimetric titrations suggested the formation of 1:1 inclusion complex between VAL and β-CD. The apparent stability constants K1:1 calculated from phase-solubility plots were 165.4 M-1 (298 K, 145.0 M-1 (303 K and 111.3 M-1 (310 K. In vivo experiments in rats showed that reduction in arterial pressure for the FDY complex is better than with valsartan used alone. The better activity of FDY can be attributed to the higher solubility of valsartan after inclusion in the cyclodextrin cavity, as suggest by the intrinsic dissolution studies.

  8. Pharmaceutical films made from the waste material from the preparation of propolis extracts: development and characterization

    Directory of Open Access Journals (Sweden)

    Lucas de Alcântara Sica de Toledo

    2015-12-01

    Full Text Available abstract This study investigated the development and characterized the physicochemical properties of films obtained from by-products (BP from the preparation of propolis extracts. Films were produced in the presence and absence of a polymeric adjuvant (gelatin or ethylcellulose and propylene glycol by a solvent casting method. Density, surface topography by scanning electron microscopy, mechanical properties (folding endurance, tensile strength and percentage elongation, water vapour permeability (WVP, moisture uptake capacity, thermogravimetry, differential scanning calorimetry and Fourier transform infrared spectroscopy (FTIR were determined. The films were a transparent, light greenish-yellow colour, with a uniform surface, and were flexible and easy to handle. The thickness and density of the preparations indicated that the compounds were homogeneously dispersed throughout the film. Mechanical properties were influenced by the film composition; films containing gelatin were more resistant to stress, while those containing ethylcellulose were more flexible. Increasing the adjuvant concentration decreased the elasticity and the rupture resistance, but increased the moisture uptake capacity and WVP of the formulations. BP was thermally stable as were the films. FTIR tests suggested interactions between BP and the adjuvants. This work could contribute to the utilization of BP to prepare films for food and pharmaceutical uses

  9. Preparation and characterization of water-absorbing composite ...

    African Journals Online (AJOL)

    The present work introduces a novel method for the formation of water absorbing composite membrane. The prepared composite is based on chitosan, carboxymethyl cellulose (CMC), and Montmorillonite. Prepared composite membrane exhibits high water absorbing and holding capacity with increasing clay content.

  10. Preparation and characterization of water-absorbing composite ...

    African Journals Online (AJOL)

    ABCO

    2012-08-16

    Aug 16, 2012 ... The present work introduces a novel method for the formation of water absorbing composite membrane. The prepared composite is based on chitosan, carboxymethyl cellulose (CMC), and. Montmorillonite. Prepared composite membrane exhibits high water absorbing and holding capacity with increasing ...

  11. Development and validation of microbial bioassay for quantification of Levofloxacin in pharmaceutical preparations

    Directory of Open Access Journals (Sweden)

    Nishant A. Dafale

    2015-02-01

    Full Text Available The aim of this study was to develop and validate a simple, sensitive, precise and cost-effective one-level agar diffusion (5+1 bioassay for estimation of potency and bioactivity of Levofloxacin in pharmaceutical preparation which has not yet been reported in any pharmacopoeia. Among 16 microbial strains, Bacillus pumilus ATCC-14884 was selected as the most significant strain against Levofloxacin. Bioassay was optimized by investigating several factors such as buffer pH, inoculums concentration and reference standard concentration. Identification of Levofloxacin in commercial sample Levoflox tablet was done by FTIR spectroscopy. Mean potency recovery value for Levofloxacin in Levoflox tablet was estimated as 100.90%. A validated bioassay method showed linearity (r2=0.988, precision (Interday RSD=1.05%, between analyst RSD=1.02% and accuracy (101.23%, RSD=0.72%. Bioassay was correlated with HPLC using same sample and estimated potencies were 100.90% and 99.37%, respectively. Results show that bioassay is a suitable method for estimation of potency and bioactivity of Levofloxacin pharmaceutical preparations. Keywords: Levofloxacin, Antibiotic resistance, Microbiological bioassay, HPLC, Pharmacopoeia

  12. A validated high performance thin layer chromatography method for determination of yohimbine hydrochloride in pharmaceutical preparations.

    Science.gov (United States)

    Badr, Jihan M

    2013-01-01

    Yohimbine is an indole alkaloid used as a promising therapy for erectile dysfunction. A number of methods were reported for the analysis of yohimbine in the bark or in pharmaceutical preparations. In the present work, a simple and sensitive high performance thin layer chromatographic method is developed for determination of yohimbine (occurring as yohimbine hydrochloride) in pharmaceutical preparations and validated according to International Conference of Harmonization (ICH) guidelines. The method employed thin layer chromatography aluminum sheets precoated with silica gel as the stationary phase and the mobile phase consisted of chloroform:methanol:ammonia (97:3:0.2), which gave compact bands of yohimbine hydrochloride. Linear regression data for the calibration curves of standard yohimbine hydrochloride showed a good linear relationship over a concentration range of 80-1000 ng/spot with respect to the area and correlation coefficient (R(2)) was 0.9965. The method was evaluated regarding accuracy, precision, selectivity, and robustness. Limits of detection and quantitation were recorded as 5 and 40 ng/spot, respectively. The proposed method efficiently separated yohimbine hydrochloride from other components even in complex mixture containing powdered plants. The amount of yohimbine hydrochloride ranged from 2.3 to 5.2 mg/tablet or capsule in preparations containing the pure alkaloid, while it varied from zero (0) to 1.5-1.8 mg/capsule in dietary supplements containing powdered yohimbe bark. We concluded that this method employing high performance thin layer chromatography (HPTLC) in quantitative determination of yohimbine hydrochloride in pharmaceutical preparations is efficient, simple, accurate, and validated.

  13. Preparation and characteristics of CNT-metal composites

    CSIR Research Space (South Africa)

    Pityana, SL

    2006-01-01

    Full Text Available The success in keeping carbon nanotubes (CNT) bonded to stainless steel provides a possible method for the preparation of CNT-metal composites. Alternative methods for the preparation of CNT-metal composites include hot pressing, sintering, etc...

  14. Preparation of polyester /Calcium sulfate/ composites using radiation

    International Nuclear Information System (INIS)

    Ajji, Z.

    2004-01-01

    Different composites have been prepared using various doses of gamma radiation. Two polyesters, Super Mastics and General, and calcium sulfate or natural gypsum have been used for preparing the composites. Some physical properties of the composites and the influence of Gamma rays on it has been studied as: compression, hardness, thermal decomposition temperature in nitrogen or oxygen, and change in weight in aqua solutions with different pH. Our results show that the glass transition temperature increases by increasing the absorbed dose up to a plateau. Further, the composites show a good thermal stability, and the absorbed dose does not affect the thermal decomposition temperature or the oxidation induction time for the prepared composites. Compression strength of the prepared composites decreases by increasing the filler ratios, and the absorbed does not seem to influence this property significantly. (author)

  15. Preparation of polyester /Calcium sulfate/ composites using radiation

    International Nuclear Information System (INIS)

    Ajji, Z.

    2003-04-01

    Different composites have been prepared using various doses of gamma radiation. Two polyesters, Super Mastics and General, and calcium sulfate or natural gypsum have been used for preparing the composites. Some physical properties of the composites and the influence of Gamma rays on it has been studied as: compression, hardness, thermal decomposition temperature in nitrogen or oxygen, and change in weight in aqua solutions with different pH. Our results show that the glass transition temperature increases by increasing the absorbed dose up to a plateau. Further, the composites show a good thermal stability, and the absorbed dose does not affect the thermal decomposition temperature or the oxidation induction time for the prepared composites. Compression strength of the prepared composites decreases by increasing the filler ratios, and the absorbed does not seem to influence this property significantly. (author)

  16. Sensitive kinetic spectrophotometric determination of captopril and ethamsylate in pharmaceutical preparations and biological fluids.

    Science.gov (United States)

    El-Shabrawy, Y; El-Enany, N; Salem, K

    2004-10-01

    A highly sensitive kinetic spectrophotometric method was developed for the determination of captopril (CPL) and ethamsylate (ESL) in pharmaceutical preparations and biological fluids. The method is based on a catalytic acceleration of the reaction between sodium azide and iodine in an aqueous solution. Concentration range of 0.1-1.5 microg ml(-1) for CPL and 0.3-3 microg ml(-1) for ESL was determined by measuring the decrease in the absorbance of iodine at 348 nm by a fixed time method. The decrease in absorbance after 5 min was markedly correlated to the concentration. The relative standard deviations obtained were 1.30 and 1.87 for CPL and ESL, respectively, in pure forms. Correlation coefficients were 0.9997 and 0.9999 for CPL and ESL, respectively. The detection limits were determined as (S/N = 3) were 20 ng ml(-1) for CPL and 50 ng ml(-1) for ESL. The proposed procedure was successively applied for the determination of both drugs in pharmaceutical preparations and in biological fluids.

  17. Sample preparation composite and replicate strategy for assay of solid oral drug products.

    Science.gov (United States)

    Harrington, Brent; Nickerson, Beverly; Guo, Michele Xuemei; Barber, Marc; Giamalva, David; Lee, Carlos; Scrivens, Garry

    2014-12-16

    In pharmaceutical analysis, the results of drug product assay testing are used to make decisions regarding the quality, efficacy, and stability of the drug product. In order to make sound risk-based decisions concerning drug product potency, an understanding of the uncertainty of the reportable assay value is required. Utilizing the most restrictive criteria in current regulatory documentation, a maximum variability attributed to method repeatability is defined for a drug product potency assay. A sampling strategy that reduces the repeatability component of the assay variability below this predefined maximum is demonstrated. The sampling strategy consists of determining the number of dosage units (k) to be prepared in a composite sample of which there may be a number of equivalent replicate (r) sample preparations. The variability, as measured by the standard error (SE), of a potency assay consists of several sources such as sample preparation and dosage unit variability. A sampling scheme that increases the number of sample preparations (r) and/or number of dosage units (k) per sample preparation will reduce the assay variability and thus decrease the uncertainty around decisions made concerning the potency of the drug product. A maximum allowable repeatability component of the standard error (SE) for the potency assay is derived using material in current regulatory documents. A table of solutions for the number of dosage units per sample preparation (r) and number of replicate sample preparations (k) is presented for any ratio of sample preparation and dosage unit variability.

  18. Gravimetric method for the determination of diclofenac in pharmaceutical preparations.

    Science.gov (United States)

    Tubino, Matthieu; De Souza, Rafael L

    2005-01-01

    A gravimetric method for the determination of diclofenac in pharmaceutical preparations was developed. Diclofenac is precipitated from aqueous solution with copper(II) acetate in pH 5.3 (acetic acid/acetate buffer). Sample aliquots had approximately the same quantity of the drug content in tablets (50 mg) or in ampules (75 mg). The observed standard deviation was about +/- 2 mg; therefore, the relative standard deviation (RSD) was approximately 4% for tablet and 3% for ampule preparations. The results were compared with those obtained with the liquid chromatography method recommended in the United States Pharmacopoeia using the statistical Student's t-test. Complete agreement was observed. It is possible to obtain more precise results using higher aliquots, for example 200 mg, in which case the RSD falls to 1%. This gravimetric method, contrary to what is expected for this kind of procedure, is relatively fast and simple to perform. The main advantage is the absolute character of the gravimetric analysis.

  19. Pharmaceutical composition and drug effect of synthetic Bacopa monnieri L. health promoting agent from the perspective of resistance fatigue.

    Science.gov (United States)

    Chen, Zhidan; Yan, Yanqin

    2017-09-01

    Bacopa monnieri has effect on the nervous system, digestive system and blood circulation systems. In this paper, the authors conducted pharmacological analysis on Bacopa monniera and its innovative pharmaceutical preparation of promote motor function. The extract of the drug has some effect on relieving the fatigue and providing the movement function. By analyzing the composition and efficacy of Chinese herbal extracts, it can be seen that these drugs have obvious effect on improving immunity. Experimental results show that the agent can increase the liver glycogen energy reserves, reduce Bla and BUN levels, balance and energy metabolism of muscle cells in the environment, it plays a positive role to improve the exercise capacity and exercise fatigue.

  20. The possibility of obtaining marketing authorization of orphan pharmaceutical compounding preparations: 3,4-DAP for Lambert-Eaton Myasthenic Syndrome.

    Science.gov (United States)

    de Wilde, Sofieke; de Jong, Maria G H; Lipka, Alexander F; Guchelaar, Henk-Jan; Schimmel, Kirsten J M

    2018-03-01

    Pharmaceutical compounding preparations, produced by (hospital) pharmacies, usually do not have marketing authorization. As a consequence, some of these pharmaceutical compounding preparations can be picked-up by a pharmaceutical company to obtain marketing authorization, often leading to price increases. An example is the 3,4-diaminopyridine slow release (3,4-DAP SR) tablets for Lambert-Eaton Myasthenic Syndrome (LEMS). In 2009 marketing authorization was given for the commercial immediate release phosphate salt of the drug, including a fifty-fold price increase compared to the pharmaceutical compounding preparation. Obtaining marketing authorization for 3,4-DAP SR by academia might have been a solution to prevent this price increase. To determine whether the available data of a pharmaceutical compounding preparation with long-term experience in regular care are adequate to obtain marketing authorization, 3,4-DAP SR is used as a case study. A retrospective qualitative case-study was performed. Initially, document analysis was executed by collecting the required data for marketing authorization in general and whether data of Firdapse® and 3,4-DAP SR met these requirements. Secondly, the (non-) available data of the two formulations were compared with each other to determine the differences in availability. At the time of approval, almost all data were available for both Firdapse® and 3,4-DAP SR. Conversely, much of the data used for the approval of Firdapse® originated from the 3,4-DAP immediate release (3,4-DAP IR) formulation. Only two bioequivalence studies and one pharmacology safety study was performed with Firdapse® before marketing authorization application. In conclusion, at time Firdapse® obtained approval, the data available did not differ substantially from 3,4-DAP SR, indicating that approval with 3,4-DAP SR would have been possible. We make a plea for approval of orphan medicinal products developed and manufactured by academic institutions as to

  1. Simultaneous spectrophotometric determination of overlapping spectra of paracetamol and caffeine in laboratory prepared mixtures and pharmaceutical preparations using continuous wavelet and derivative transform

    Directory of Open Access Journals (Sweden)

    Ahmed Ashour

    2015-03-01

    Full Text Available In the present paper, two spectrophotometric methods were used for the simultaneous analysis of paracetamol (PCT and caffeine (CAF in their laboratory prepared mixtures and pharmaceutical preparations. Simple spectrophotometric analysis of PCT and CAF is not possible due to their complete spectral overlap. The proposed methods are based on the application of continuous wavelet transform (CWT and derivative transform (using Savitsky–Golay filters on the ratio spectra to predict each of CAF and PCT. Several wavelet families were tested. Coif1 and Sym2 were found to give best results under optimum conditions. The transformed signals of ratio spectra were used to plot the calibration curves for both components. The predictability of the built calibrations was validated through their application on several synthetic mixtures of both drugs. The proposed methods were used for the prediction of CAF and PCT in pharmaceutical preparation. The obtained results were statistically compared to a reference HPLC method. No significant differences were found between the obtained results and those from the reference method. Being simple, rapid, cheap and sensitive, the proposed methods are recommended for the routine daily analysis of these two drugs in their mixtures in quality control laboratories.

  2. Desloratadine analysis: as a pharmaceutical preparation and after accelerating ageing

    Directory of Open Access Journals (Sweden)

    Bober Katarzyna

    2015-09-01

    Full Text Available Desloratadine is a biologically active compound that is not described in the Polish Pharmacopoeia IX, hence, its study is particular important. The aim of this work was to establish a procedure for desloratadine analysis by way of HPTLC in combination with densitometry, so as to be able to ascertain its presence and degree of presence within pharmaceutical preparations. In our work, a mixture of ethyl acetate, n-butanol, ammonia and methanol was used as the mobile phase. Moreover, HPTLC plates precoated with silica gel 60F254 were also employed. The proposed method was tested and subsequently validated. Spectrodensitometric analysis was then performed to determine the optimal wavelength for the quantitative determination (λ=276 nm, and following this, a quantitative analysis of desloratadine within certain pharmaceutical preparations was performed. Our research also took into consideration an analysis of the products of desloratadine decomposition that come about as a result of the accelerated aging of its solutions. The employed procedure for accelerating the aging of such desloratadine solutions consisted of heating these at 40℃ and then irradiating the solution surfaces with UV light. The changing color of these solutions after 2 hours of exposure served to indicate that degradation had occurred. Of note: as a result of irradiation with UV light, desloratadine content was seen to decrease with time, declining to almost zero after 30 hours. However, heating a solution of desloratadine alone did not induce a change in its content. Solutions of desloratadine that had previously undergone irradiation and heating were also analyzed to ascertain whether new substances were present. For this purpose, the GC-MS process was employed. As a result of this procedure, the spectrum of the solution after aging showed the presence of several new peaks that displayed retention several times larger and smaller than the normal desloratadine peak.

  3. Toxic element contamination of natural health products and pharmaceutical preparations.

    Directory of Open Access Journals (Sweden)

    Stephen J Genuis

    Full Text Available BACKGROUND: Concern has recently emerged regarding the safety of natural health products (NHPs-therapies that are increasingly recommended by various health providers, including conventional physicians. Recognizing that most individuals in the Western world now consume vitamins and many take herbal agents, this study endeavored to determine levels of toxic element contamination within a range of NHPs. METHODS: Toxic element testing was performed on 121 NHPs (including Ayurvedic, traditional Chinese, and various marine-source products as well as 49 routinely prescribed pharmaceutical preparations. Testing was also performed on several batches of one prenatal supplement, with multiple samples tested within each batch. Results were compared to existing toxicant regulatory limits. RESULTS: Toxic element contamination was found in many supplements and pharmaceuticals; levels exceeding established limits were only found in a small percentage of the NHPs tested and none of the drugs tested. Some NHPs demonstrated contamination levels above preferred daily endpoints for mercury, cadmium, lead, arsenic or aluminum. NHPs manufactured in China generally had higher levels of mercury and aluminum. CONCLUSIONS: Exposure to toxic elements is occurring regularly as a result of some contaminated NHPs. Best practices for quality control-developed and implemented by the NHP industry with government oversight-is recommended to guard the safety of unsuspecting consumers.

  4. Preparation of Calcined Zirconia-Carbon Composite from Metal Organic Frameworks and Its Application to Adsorption of Crystal Violet and Salicylic Acid

    Directory of Open Access Journals (Sweden)

    Zubair Hasan

    2016-03-01

    Full Text Available Zirconia-carbon (ZC composites were prepared via calcination of Zr-based metal organic frameworks, UiO-66 and amino-functionalized UiO-66, under N2 atmosphere. The prepared composites were characterized using a series of instrumental analyses. The surface area of the ZC composites increased with the increase of calcination temperature, with the formation of a graphite oxide phase observed at 900 °C. The composites were used for adsorptive removal of a dye (crystal violet, CV and a pharmaceutical and personal care product (salicylic acid, SA. The increase of the calcination temperature resulted in enhanced adsorption capability of the composites toward CV. The composite calcined at 900 °C exhibited a maximum uptake of 243 mg·g−1, which was much greater than that by a commercial activated carbon. The composite was also effective in SA adsorption (102 mg·g−1, and N-functionalization of the composite further enhanced its adsorption capability (109 mg·g−1. CV adsorption was weakly influenced by solution pH, but was more dependent on the surface area and pore volume of the ZC composite. Meanwhile, SA adsorption showed strong pH dependence, which implies an active role of electrostatic interactions in the adsorption process. Base-base repulsion and hydrogen bonding are also suggested to influence the adsorption of CV and SA, especially for the N-functionalized composite.

  5. Preparation and characterization of PVC /ENR/CNTs Nano composites

    International Nuclear Information System (INIS)

    Ratnam, C.T.; Nur Azrini Ramlee; Keong, C.C.

    2011-01-01

    Poly (vinyl chloride), PVC/ epoxidized natural rubber blend, ENR/ carbon nano tubes, CNTs were prepared by using melt and solution blending methods. Addition of 2 phr of CNTs found to cause a drop in the tensile strength, Ts of the 50/ 50 PVC/ ENR blend. The nano composites prepared by the melt blending method exhibited higher values of Ts compared to the nano composites prepared by solution blending. Melt blending found to be an efficient method to prepare PVC/ ENR/ CNTs nano composites. (author)

  6. New spectrofluorimetric method for the determination of nizatidine in bulk form and in pharmaceutical preparations

    Science.gov (United States)

    Karasakal, Ayça; Ulu, Sevgi Tatar

    2013-08-01

    A simple, accurate and highly sensitive spectrofluorimetric method has been developed for determination of nizatidine in pure form and in pharmaceutical dosage forms. The method is based on the reaction between nizatidine and 1-dimethylaminonaphthalene-5-sulphonyl chloride in carbonate buffer, pH 10.5, to yield a highly fluorescent derivative peaking at 513 nm after excitation at 367 nm. Various factors affecting the fluorescence intensity of nizatidin-dansyl derivative were studied and conditions were optimized. The method was validated as per ICH guidelines. The fluorescence concentration plot was rectilinear over the range of 25-300 ng/mL. Limit of detection and limit of quantification were calculated as 11.71 and 35.73 ng/mL, respectively. The proposed method was successfully applied to pharmaceutical preparations.

  7. Method for preparing ceramic composite

    Science.gov (United States)

    Alexander, K.B.; Tiegs, T.N.; Becher, P.F.; Waters, S.B.

    1996-01-09

    A process is disclosed for preparing ceramic composite comprising blending TiC particulates, Al{sub 2}O{sub 3} particulates and nickel aluminide and consolidating the mixture at a temperature and pressure sufficient to produce a densified ceramic composite having fracture toughness equal to or greater than 7 MPa m{sup 1/2}, a hardness equal to or greater than 18 GPa. 5 figs.

  8. Development and Validation of Spectrophotometric Methods for the Determination of Rasagiline in Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    Serife Evrim Kepekci Tekkeli

    2013-01-01

    Full Text Available This study presents three simple, rapid, and accurate spectrophotometric methods for the determination of Rasagiline (RSG in pharmaceutical preparations. The determination procedures depend on the reaction of RSG with chloranilic acid for method A, tetrachloro-1,4-benzoquinone for method B, and 7,7,8,8-tetracyanoquinodimethane for method C. The colored products were quantitated spectrophotometrically at 524, 535, and 843 nm for methods A, B, and C, respectively. Different variables affecting the reaction were optimized. Linearity ranges of the methods with good correlation coefficients (0.9988–0.9996 were observed as 25–300 µg mL−1, 25–350 µg mL−1, and 50–500 µg mL−1 for methods A, B, and C, respectively. The formation of products takes place through different mechanisms. The sites of interaction were confirmed by elemental analysis using IR and 1H-NMR spectroscopy. The validation of the methods was carried out in terms of specificity, linearity, accuracy, precision, robustness, limit of detection, and limit of quantitation. No interference was observed from concomitants usually present in dosage forms. The methods were applied successfully to the determination of RSG in pharmaceutical preparations.

  9. Assessing the Factors Associated With Iran's Intra-Industry Trade in Pharmaceuticals.

    Science.gov (United States)

    Yusefzadeh, Hassan; Hadian, Mohammad; Abolghasem Gorji, Hassan; Ghaderi, Hossein

    2015-03-30

    Pharmaceutical industry is a sensitive and profitable industry. If this industry wants to survive, it should be able to compete well in international markets. So, study of Iran's intra-industry trade (IIT) in pharmaceuticals is essential in order to identify competitiveness potential of country and boost export capability in the global arena. This study assessed the factors associated with Iran's intra-industry trade in pharmaceuticals with the rest of the world during the 2001-2012 periods using seasonal time series data at the four-digit SITC level. The data was collected from Iran's pharmaceutical Statistics, World Bank and International Trade Center. Finally, we discussed a number of important policy recommendations to increase Iran's IIT in pharmaceuticals. The findings indicated that economies of scale, market structure and degree of economic development had a significantly positive impact on Iran's intra-industry trade in pharmaceuticals and tariff trade barriers were negatively related to IIT. Product differentiation and technological advancement didn't have the expected signs. In addition, we found that Iran's IIT in pharmaceuticals have shown an increasing trend during the study period. Thus, the composition of Iran trade in pharmaceuticals has changed from inter-industry trade to intra-industry trade. In order to get more prepared for integration into the global economy, the development of Iran's IIT in pharmaceuticals should be given priority. Therefore, paying attention to IIT could have an important role in serving pharmaceutical companies in relation to pharmaceutical trade.

  10. Preparation of fullerene/glass composites

    Science.gov (United States)

    Mattes, Benjamin R.; McBranch, Duncan W.; Robinson, Jeanne M.; Koskelo, Aaron C.; Love, Steven P.

    1995-01-01

    Synthesis of fullerene/glass composites. A direct method for preparing solid solutions of C.sub.60 in silicon dioxide (SiO.sub.2) glass matrices by means of sol-gel chemistry is described. In order to produce highly concentrated fullerene-sol-gel-composites it is necessary to increase the solubility of these "guests" in a delivery solvent which is compatible with the starter sol (receiving solvent). Sonication results in aggregate disruption by treatment with high frequency sound waves, thereby accelerating the rate of hydrolysis of the alkoxide precursor, and the solution process for the C.sub.60. Depending upon the preparative procedure, C.sub.60 dispersed within the glass matrix as microcrystalline domains, or dispersed as true molecular solutions of C.sub.60 in a solid glass matrix, is generated by the present method.

  11. [Hospital pharmaceutical practice in prison].

    Science.gov (United States)

    Harcouët, L

    2010-09-01

    Since 1994, hospital pharmaceutical teams have been in charge of pharmaceutical tasks in "unités de consultation et de soins ambulatoires" (UCSA), which are hospital consulting care units in French prisons. In 2008, pharmaceutical team in Parisian prisons received 6500 prescriptions and prepared 85,000 nominative bags containing drugs. Prisoners were 1.3% to receive treatments against HIV, 8.2% cardiovascular drugs, 7.2% opioid substitution treatments, and 52.9% psychoactive drugs, including 39.3% hypnotics, 40.5% anxiolytics, 11.3% antidepressants and 12.2% neuroleptics. In prison, the dichotomy between somatic and mental care is marked, attitudes of prisoners about their medicines are complex (important claims, embezzlement, etc.) and it is difficult for law defendants to maintain treatment confidentiality and to prepare prison outing in terms of health. To attenuate the heterogeneity of drug distribution systems in French prisons, we propose pharmaceutical analysis of prescriptions and nominative dispensation, computerization in UCSA in coordination with hospitals, a better contribution of prison medical and pharmaceutical staff in hospital "drug committees" and the redaction of pharmaceutical guidelines. Acting in concert with multidisciplinary medical staff in UCSA, pharmaceutical teams have to develop epidemiological studies to improve knowledge in prisoner's health and also prevention and health care in prison. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  12. Importance of the rate of hydration of pharmaceutical preparations of guar gum; a new in vitro monitoring method.

    Science.gov (United States)

    Ellis, P R; Morris, E R

    1991-05-01

    Dietary supplements of guar gum are known to improve blood glucose control in diabetic patients. The efficacy of guar is probably dependent mainly upon its capacity to hydrate rapidly and thus to increase viscosity in the small intestine post-prandially. Measurement of the rate of hydration in vitro might therefore be a useful index of the effectiveness of guar formulations. A simple method for monitoring the hydration rate of guar gum has been developed, which involves measuring the changes in viscosity at discrete time intervals over a period of 5 h using a Brookfield RVT rotoviscometer. Six different samples of guar gum (four pharmaceutical preparations and two food grades of guar flour) were hydrated in sealed glass jars rotated at 6 rev min-1 in order to prevent particle aggregation. Marked differences in hydration rate and ultimate (maximum) viscosity between the different guar samples were observed. Three of the four pharmaceutical preparations were lower in viscosity than the food grades of guar flour during the first 60 min of hydration. Two of the preparations hydrated so slowly that even after 5 h they attained viscosity levels of only 60% of their ultimate viscosity. These results may explain why some guar gum preparations are clinically ineffective.

  13. The influence of complexing pharmaceutical compositions on alkaline phosphatase

    Science.gov (United States)

    Atyaksheva, L. F.; Chukhrai, E. S.; Stepina, N. D.; Novikova, N. N.; Yur'eva, E. A.

    2011-06-01

    It is established that the pharmaceutical compositions xydiphon, medifon, succimer, and EDTA, which are used as complexing agents for accelerating the excretion of heavy metals from human organism, at certain concentrations inhibit enzyme alkaline phosphatase (AP). It is concluded that xydiphon and EDTA have a noticeable effect on AP activity at concentrations over 0.01 mM; medifon and succimer, at concentrations of over 0.3-0.5 mM. The enzyme's inhibition constants and type of inhibition are determined. Xydiphon is found to manifest the highest affinity to AP ( K I = 0.35 mM). It is shown by kinetic analysis that dissociative chemoinactivation of the enzyme takes place under the action of complexing agents. The corresponding kinetic parameters are calculated.

  14. Study of dosimetric properties of acetylsalicylic acid in pharmaceutical preparations by EPR spectroscopy

    International Nuclear Information System (INIS)

    Juarez Calderon, J.M.; Negron Mendoza, A.; Ramos Bernal, S.; Gomez Vidales, V.

    2008-01-01

    Electron paramagnetic resonance (EPR) was used to investigate the dosimetric properties of two pharmaceutical preparations containing acetylsalicylic acid, Aspirin (trademark) and Cafiaspirin (trademark). The EPR spectra of the irradiated samples were found to have an asymmetric absorption characterized by a major resonance at g = 2.0033. Dose response was investigated between dose ranges of 2 to 40 kGy for 60 Co-gamma rays. Fading characteristics and dependence on temperature irradiation were also studied. We suggest that commercial Aspirin (trademark) and Cafiaspirin (trademark) tablets can be used as dosimeters for industrial processes. (author)

  15. [Pharmaceutical preparations in the hospital. Analysis and in-house development of an automated system of management.

    Science.gov (United States)

    Barberini, Cinzia; Lavezzini, Enrica; Zoboli, Daniela; Busani, Corrado

    2018-02-01

    In the past couple of years, the demand of galenic compounds has risen sharply. In order to plan the activity, our team designed and set up a database which stores all the necessary information related to drugs and ingredients. This allows our internal Galenic Laboratory to better manage the pharmaceutical prescriptions for the hospital and the outpatients, optimizing the use of raw materials. The application is based on the interconnection of prescription-related aspects (patients' and prescriber's details and prescription information). The prescription name is linked to the list of substances, which allows to monitor the stock levels. Inserting the daily dosage into the system, our personnel can calculate the monthly supply of the medicine. Each prescription contains specific warnings on printable labels. A printed sheet, inclusive of label and checks on the final preparation, is produced for each prescription. After a testing phase, the application gradually replaced our traditional process of pharmaceutical activity management, allowing for a more accurate scheduling of the medicine requests. The worksheet and its specific label are automatically generated. Then a prediction scheme is generated for the ordinary programmable galenic activity. The project successfully achieved the following goals: 1) automate the information flow related to preparations; 2) improve the response time in terms of drug preparation and delivery; 3) minimize the number of emergencies.

  16. Electrostaticspray preparation and properties of RDX/DOS composites

    Directory of Open Access Journals (Sweden)

    Jian Yao

    2017-08-01

    Full Text Available A composite explosive based on 1, 3, 5-trinitro-1, 3, 5-triazinane (RDX was prepared by electrostaticspray method with dioctyl sebacate (DOS as desensitizer. After preparation, the particle size and crystal structure were characterized and chemical features, such as chemical bonds, functional groups, thermal decomposition parameters and mechanical sensitivity were investigated as well. In terms of the morphologies of the composites, the particle sizes were in the range of 1–3 μm. Compared with RDX, the crystal types, chemical bonds and functional groups of the RDX/DOS composites were unchanged. The activation energy of the composites was lower than that of raw RDX, and the 3wt % DOS composites had the lowest activation energy. The impact sensitivity and friction sensitivity of the RDX/DOS composites were lower than those of raw RDX, and the 10wt% DOS composites had the highest H50 (125.9 cm and the lowest friction sensitivity (8%.

  17. Chitosan/waste coffee-grounds composite: An efficient and eco-friendly adsorbent for removal of pharmaceutical contaminants from water.

    Science.gov (United States)

    Lessa, Emanuele F; Nunes, Matheus L; Fajardo, André R

    2018-06-01

    Waste coffee-grounds (WCG), a poorly explored source of biocompounds, were combined with chitosan (Cs) and poly(vinyl alcohol) (PVA) in order to obtain composites. Overall, WCG showed a good interaction with the polymeric matrix and good dispersibility up to 10 wt-%. At 5 wt-% WCG, the composite exhibited a noticeable enhancement (from 10 to 44%) of the adsorption of pharmaceuticals (metamizol (MET), acetylsalicylic acid (ASA), acetaminophen (ACE), and caffeine (CAF)) as compared to the pristine sample. The highest removal efficiency was registered at pH 6 and the removal followed the order ASA > CAF > ACE > MET. For all pharmaceuticals, the adsorption kinetics was found to follow the pseudo-second order model, while the adsorption mechanism was explained by the Freundlich isotherm. Reuse experiments indicated that the WCG-containing composite has an attractive cost-effectiveness since it presented a remarkable reusability in at least five consecutive adsorption/desorption cycles. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Sensitive spectrofluorimetric determination of tizanidine in pharmaceutical preparations, human plasma and urine through derivatization with dansyl chloride.

    Science.gov (United States)

    Ulu, Sevgi Tatar

    2012-01-01

    A sensitive spectrofluorimetric method was developed for the determination of tizanidine in human plasma, urine and pharmaceutical preparations. The method is based on reaction of tizanidine with 1-dimethylaminonaphthalene-5-sulphonyl chloride (dansyl chloride) in an alkaline medium to form a highly fluorescent derivative that was measured at 511 nm after excitation at 383 nm. The different experimental parameters affecting the fluorescence intensity of tizanidine was carefully studied and optimized. The fluorescence-concentration plots were rectilinear over the ranges 50-500 and 20-300 ng/mL for plasma and urine, respectively, detection limits of 1.81 and 0.54 ng/mL and quantification limits of 5.43 and 1.62 ng/mL for plasma and urine, respectively. The method presents good performance in terms of linearity, detection and quantification limits, precision, accuracy and specificity. The proposed method was successfully applied for the determination of tizanidine in pharmaceutical preparations. The results obtained were compared with a reference method, using t- and F-tests. Copyright © 2011 John Wiley & Sons, Ltd.

  19. Ionic liquid-facilitated preparation of lignocellulosic composites

    Science.gov (United States)

    Lignocellulosic composites (LCs) were prepared by partially dissolving cotton along with steam exploded Aspen wood and burlap fabric reinforcements utilizing an ionic liquid (IL) solvent. Two methods of preparation were employed. In the first method, a controlled amount of IL was added to preassembl...

  20. New potentiometric and spectrophotometric methods for the determination of dextromethorphan in pharmaceutical preparations.

    Science.gov (United States)

    Elmosallamy, Mohamed A F; Amin, Alaa S

    2014-01-01

    New, simple and convenient potentiometric and spectrophotometric methods are described for the determination of dextromethorphan hydrobromide (DXM) in pharmaceutical preparations. The potentiometric technique is based on developing a potentiometric sensor incorporating the dextromethorphan tetrakis(p-chlorophenyl)borate ion-pair complex as an electroactive species in a plasticized PVC matrix membrane with o-nitophenyl octyl ether or dioctyl phthalate. The sensor shows a rapid near Nernstian response of over 1 × 10(-5) - 1 × 10(-2) mol L(-1) dextromethorphan in the pH range of 3.0 - 9.0. The detection limit is 2 × 10(-6) mol L(-1) DXM and the response time is instantaneous (2 s). The proposed spectrophotometric technique involves the reaction of DXM with eriochrom black T (EBT) to form an ion-associate complex. Solvent extraction is used to improve the selectivity of the method. The optimal extraction and reaction conditions have been studied, and the analytical characteristics of the method have been obtained. Linearity is obeyed in the range of 7.37 - 73.7 × 10(-5) mol L(-1) DXM, and the detection limit of the method is 1.29 × 10(-5) mol L(-1). The relative standard deviation (RSD) and relative error for six replicate measurements of 3.685 × 10(-4) mol L(-1) are 0.672 and 0.855%, respectively. The interference effect of some excepients has also been tested. The drug contents in pharmaceutical preparations were successfully determined by the proposed methods by applying the standard-addition technique.

  1. Study of dosimetric properties of acetylsalicylic acid in pharmaceutical preparations by EPR spectroscopy

    International Nuclear Information System (INIS)

    Juarez-Calderon, J.M.; Negron-Mendoza, A.; Ramos-Bernal, S.; Gomez-Vidales, V.

    2009-01-01

    Electron paramagnetic resonance (EPR) was used to investigate the dosimetric properties of two pharmaceutical preparations containing acetylsalicylic acid, Aspirin R and Cafiaspirin R . The EPR spectra of the irradiated samples were found to have an asymmetric absorption characterized by a major resonance at g = 2.0033. Dose response was investigated between dose ranges of 2 to 95 kGy for 60 Co-gamma rays. Fading characteristics and dependence on temperature irradiation were also studied. We suggest that commercial Aspirin R and Cafiaspirin R tablets can be used as dosimeters in the case of a short accident. (author)

  2. Preparation of fine powdered composite for latent heat storage

    Energy Technology Data Exchange (ETDEWEB)

    Fořt, Jan, E-mail: jan.fort.1@fsv.cvut.cz; Trník, Anton, E-mail: anton.trnik@fsv.cvut.cz; Pavlíková, Milena, E-mail: milena.pavlikova@fsv.cvut.cz; Pavlík, Zbyšek, E-mail: pavlikz@fsv.cvut.cz [Department of Materials Engineering and Chemistry, Faculty of Civil Engineering, Czech Technical University in Prague, Thákurova 7, 166 29 Prague (Czech Republic); Pomaleski, Marina, E-mail: marina-pomaleski@fsv.cvut.cz [Faculty of Civil Engineering, Architecture and Urbanism, University of Campinas, R. Saturnino de Brito 224, 13083-889 Campinas – SP (Brazil)

    2016-07-07

    Application of latent heat storage building envelope systems using phase-change materials represents an attractive method of storing thermal energy and has the advantages of high-energy storage density and the isothermal nature of the storage process. This study deals with a preparation of a new type of powdered phase change composite material for thermal energy storage. The idea of a composite is based upon the impregnation of a natural silicate material by a reasonably priced commercially produced pure phase change material and forming the homogenous composite powdered structure. For the preparation of the composite, vacuum impregnation method is used. The particle size distribution accessed by the laser diffraction apparatus proves that incorporation of the organic phase change material into the structure of inorganic siliceous pozzolana does not lead to the clustering of the particles. The compatibility of the prepared composite is characterized by the Fourier transformation infrared analysis (FTIR). Performed DSC analysis shows potential of the developed composite for thermal energy storage that can be easily incorporated into the cement-based matrix of building materials. Based on the obtained results, application of the developed phase change composite can be considered with a great promise.

  3. Assessing the Factors Associated With Iran’s Intra-Industry Trade in Pharmaceuticals

    Science.gov (United States)

    Yusefzadeh, Hassan; Hadian, Mohammad; Gorji, Hassan Abolghasem; Ghaderi, Hossein

    2015-01-01

    Background: Pharmaceutical industry is a sensitive and profitable industry. If this industry wants to survive, it should be able to compete well in international markets. So, study of Iran’s intra-industry trade (IIT) in pharmaceuticals is essential in order to identify competitiveness potential of country and boost export capability in the global arena. Methods: This study assessed the factors associated with Iran’s intra-industry trade in pharmaceuticals with the rest of the world during the 2001–2012 periods using seasonal time series data at the four-digit SITC level. The data was collected from Iran’s pharmaceutical Statistics, World Bank and International Trade Center. Finally, we discussed a number of important policy recommendations to increase Iran’s IIT in pharmaceuticals. Results: The findings indicated that economies of scale, market structure and degree of economic development had a significantly positive impact on Iran’s intra-industry trade in pharmaceuticals and tariff trade barriers were negatively related to IIT. Product differentiation and technological advancement didn’t have the expected signs. In addition, we found that Iran’s IIT in pharmaceuticals have shown an increasing trend during the study period. Thus, the composition of Iran trade in pharmaceuticals has changed from inter-industry trade to intra-industry trade. Conclusions: In order to get more prepared for integration into the global economy, the development of Iran’s IIT in pharmaceuticals should be given priority. Therefore, paying attention to IIT could have an important role in serving pharmaceutical companies in relation to pharmaceutical trade. PMID:26156931

  4. Information on the quality of substance for the preparation of pharmaceutical drugs in terms of hospital pharmacy

    Directory of Open Access Journals (Sweden)

    Jovović Marija Đ.

    2015-01-01

    Full Text Available Explanation the topic The pharmaceutical activity is the activity of public or social and special interest, because it is a direct function of health care. Topic positioning and discussion The aim of this paper is to highlight the importance of ensuring the quality of pharmaceutical substances that supplies hospitals, which are used for production of galenic and magistral drugs. Conclusion Compliance with national legislation, as well as establishing compliance prescribed by the European legislation in the field of drug development is binding. Therefore, all manufacturers of drugs and/or active pharmaceutical ingredients must apply quality standards prescribed by the European Pharmacopoeia in order to develop, manufacture and sales of medicines. When it comes to the quality of pharmaceutical ingredients for the production of drugs in the pharmacy, pharmacies especially in residential institutions in our country is permanently done by harmonizing national legislation in order to improve conditions for the preparation and production of galenic drugs in terms of inpatient health institutions performed in a manner that is prescribed by international regulations. This requires the adaptation of institutions, including fundamental changes in competence as national professional and administrative and regulatory rules that apply to state- and private sectors.

  5. The effect of processing and composition on the properties of polylactide–multiwall carbon nanotube composites prepared by solvent casting

    International Nuclear Information System (INIS)

    Rizvi, Reza; Naguib, Hani; Kim, Jae-Kyung

    2010-01-01

    This study investigates the effects of processing solvent and filler concentration on the thermal, electrical and mechanical properties of polylactide (PLA)–multiwall carbon nanotube (MWNT) composites. PLA–MWNT composites were prepared by a solvent casting method using two different solvents, chloroform and 1,4-dioxane, in compositions of 0, 0.5, 2 and 5 wt% MWNTs. The dispersion of the MWNTs in PLA was examined using a scanning electron microscope and was found to be improved when 1,4-dioxane was used as the solvent as compared with when chloroform was used. Owing to their better MWNT dispersion, composites prepared using 1,4-dioxane displayed a greater dependence on the MWNT concentration of the thermal, electrical and mechanical properties. Composites prepared using 1,4-dioxane had a greater effect on PLA's decomposition temperature and displayed faster crystallization kinetics than those prepared using chloroform. Not only was the conductivity of 1,4-dioxane prepared composites greater than that of chloroform prepared composites, but also the filler percolation point was observed to be reduced as well (less than 0.5 wt% MWNTs). At 5 wt% MWNT composition, a 31% increase in Young's modulus was observed in 1,4-dioxane prepared composites while a 14% improvement was observed in chloroform prepared composites, as compared with neat PLA. On the basis of the results, it is believed that the chemical interaction between the carboxylated MWNTs and 1,4-dioxane allows for a better dispersion of the MWNTs in PLA

  6. New Polymorphic Forms of Pemetrexed Diacid and Their Use for the Preparation of Pharmaceutically Pure Amorphous and Hemipentahydrate Forms of Pemetrexed Disodium

    Directory of Open Access Journals (Sweden)

    Olga Michalak

    2015-07-01

    Full Text Available The preparation of stable amorphous pemetrexed disodium of pharmaceutical purity as well as the process optimization for the preparation of the hemipentahydrate form of pemetrexed disodium are described. Analytical methods for the polymorphic and chemical purity studies of pemetrexed disodium and pemetrexed diacid forms were developed. The physicochemical properties of the amorphous and hydrate forms of pemetrexed disodium, as well as new forms of pemetrexed diacid (a key synthetic intermediate were studied by thermal analysis and powder X-ray diffraction. High-performance liquid chromatography and gas chromatography methods were used for the chemical purity and residual solvents determination. In order to study the polymorphic and chemical stability of the amorphous and hemipentahydrate forms, a hygroscopicity test (25 °C, 80% RH was performed. Powder diffraction and high-performance liquid chromatography analyses revealed that the amorphous character and high chemical purity were preserved after the hygroscopicity test. The hemipentahydrate form transformed completely to the heptahydrate form of pemetrexed disodium. Both pemetrexed disodium forms were produced with high efficiency and pharmaceutical purity in a small commercial scale. Amorphous pemetrexed disodium was selected for further pharmaceutical development. Two new polymorphs (forms 1 and 2 of pemetrexed diacid were used for the preparation of high purity amorphous pemetrexed disodium.

  7. Preparation and Characterization of Pure Organic Dielectric Composites for Capacitors

    Directory of Open Access Journals (Sweden)

    Mao Xin

    2018-01-01

    Full Text Available This work reports the excellent dielectric composites were prepared from polyimide (PI and poly(vinylidene fluoride (PVDF via solution blending and thermal imidization or chemical imidization. The dielectric and thermal properties of the composites were studied. Results indicated that the dielectric properties of the composites synthesized by these two methods were enhanced through the introduction of PVDF, and the composites exhibited excellent thermal stability. Compared to the thermal imidization, the composites prepared by chemical imidization exhibited superior dielectric properties. This study demonstrated that the PI/PVDF composites were potential dielectric materials in the field of electronics.

  8. Pharmacokinetics and pharmacodynamics of high doses of pharmaceutically prepared heroin, by intravenous or by inhalation route in opioid-dependent patients

    NARCIS (Netherlands)

    Rook, Elisabeth J.; van Ree, Jan M.; van den Brink, Wim; Hillebrand, Michel J. X.; Huitema, Alwin D. R.; Hendriks, Vincent M.; Beijnen, Jos H.

    2006-01-01

    A pharmacokinetic-pharmacodynamic study was performed in opioid-dependent patients in the Netherlands, who were currently treated with high doses of pharmaceutically prepared heroin on medical prescription. Besides intravenous heroin, heroin was prescribed for inhalation by "chasing the dragon"

  9. Comparison between properties of polyurethane nano composites prepared by two different methods

    International Nuclear Information System (INIS)

    Barmar, M.; Barikani, M.; Fereidoonnia, M.

    2009-01-01

    In this work, a thermoplastic polyurethane elastomer model based on polytetramethylene glycol. toluene diisocyanate and 1,4-butanediol was selected and synthesized. According to this model two types of polyurethane nano composites were prepared by in situ polymerization and melt intercalation procedures. The organo-modified nano clay was used in nano composites samples in 0.4 weight percent level. The prepared nano composites were studied by WAXD, tensile and thermal analysis. Thermal properties of the nano composites were higher than those of pure polyurethane elastomers. Nano composites prepared via melt intercalation method showed a lower tensile strength and hardness than those prepared through in situ polymerization method

  10. 1H NMR method for simultaneous identification and determination of caffeine and theophylline in human serum and pharmaceutical preparations

    International Nuclear Information System (INIS)

    Talebpour, Z.; Bijanzadeh, H.R.; Haghgoo, S.; Shamsipur, M.

    2004-01-01

    A 1 H NMR method for simultaneous identification and determination of caffeine and theophylline in pharmaceutical preparations and human serum has been developed. 1 H NMR spectrum of caffeine exhibits three sharp singlets at 2.75, 2.93 and 3.4 ppm, while that of theophyline shows two singlet peaks at 2.77 and 2.97 ppm. For the purpose of quantitative analyses of the mixtures of these two alkaloids 1 H NMR spectra of caffeine and theophylline was compared to that of maleic acid as an internal standard at the constant temperature. The suitable peaks were selected and standard deviation and reproducibility of the results were studied applying the full factorial design method. The obtained detection limits are 1.6 μgL - 1 and 1.43 μg L 1 for caffeine and theophylline, respectively. The average recoveries of the studied applying compounds in various samples, pharmaceutical preparations and human serum ranged from 90.2 to 107.5% (author)

  11. Preparation and characterization of single-crystal multiferroic nanofiber composites

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Zhaohui; Xiao, Zhen; Yin, Simin; Mai, Jiangquan; Liu, Zhenya; Xu, Gang; Li, Xiang; Shen, Ge [State Key Lab of Silicon Materials, Department of Material Science and Engineering, Cyrus Tang Center for Sensor Materials and Applications, Zhejiang University, Hangzhou 310027 (China); Han, Gaorong, E-mail: hgr@zju.edu.cn [State Key Lab of Silicon Materials, Department of Material Science and Engineering, Cyrus Tang Center for Sensor Materials and Applications, Zhejiang University, Hangzhou 310027 (China)

    2013-03-05

    Graphical abstract: One-dimensional single-crystal multiferroic composites composed of PbTiO{sub 3} nanofiber-CoFe{sub 2}O{sub 4} nanodot have been prepared for the first time by a facile in situ solid state sintering method. The composites demonstrate ferroelectricity and ferromagnetism as well as strong coupling between them. Highlights: ► 1D single-crystal multiferroic PTO-CFO was prepared via in situ solid state sintering method. ► A simple epitaxial growth relation has been found between the PTO–CFO composites. ► The composites reveal ferroelectricity and ferromagnetism as well as coupling between them. -- Abstract: One-dimensional single-crystal multiferroic composites consisting of PbTiO{sub 3} (PTO) nanofiber-CoFe{sub 2}O{sub 4} (CFO) nanodot were prepared using an in situ solid state sintering method, where pre-perovskite PTO nanofibers and CFO nanodots were used as precursors. Structural analyses by using transmission electron microscopy, scanning electron microscopy and X-ray diffraction determined a epitaxial growth relation between the PTO nanofiber and the CFO nanodot. Ferromagnetism and ferroelectricity of the nanofiber composites were investigated by using vibarting sample magnetometer (VSM) and piezoresponse force microscopy (PFM)

  12. Review on preparation techniques of particle reinforced metal matrix composites

    Directory of Open Access Journals (Sweden)

    HAO Bin

    2006-02-01

    Full Text Available This paper reviews the investigation status of the techniques for preparation of metal matrix composites and the research outcomes achieved recently. The mechanisms, characteristics, application ranges and levels of development of these preparation techniques are analyzed. The advantages and the disadvantages of each technique are synthetically evaluated. Lastly, the future directions of research and the prospects for the preparation techniques of metal matrix composites are forecasted.

  13. Functional polyaniline/multiwalled carbon nanotube composite as an efficient adsorbent material for removing pharmaceuticals from aqueous media.

    Science.gov (United States)

    Dutra, Flávia Viana Avelar; Pires, Bruna Carneiro; Nascimento, Tienne Aparecida; Borges, Keyller Bastos

    2018-09-01

    The composite polyaniline/multiwalled carbon nanotube (PAni/MWCNT, 1:0.1 w/w) was developed with the intention of binding the adsorbent properties of two materials and using it to adsorb pharmaceuticals from aqueous media. PAni/MWCNT was characterized by scanning electron microscopy, thermogravimetry, infrared spectroscopy, pH at the point of zero charge, and the effect on the surface wettability of the material. As proof of concept, adsorption studies were carried out using meloxicam (MLX) as the pharmaceutical and it was evaluated as a function of pH, temperature, ionic strength, contact time and variation in concentration. Kinetics and isothermal models were applied to evaluate the mechanism of the adsorption process. The best MLX adsorption result was at pH 2 with 6 min of contact with PAni/MWCNT. The kinetics models that fitted the experimental data were pseudo-second order and Elovich and the kinetics model was the dual-site Langmuir-Freundlich. Both models suggest that the adsorption occurs by the chemical nature of the surface and in the pores of the energetically heterogeneous composite. The PAni/MWCNT presented an adsorption capacity of 221.2 mg g -1 , a very good value when compared with the literature and can be used to remove pharmaceuticals from aqueous environments. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Preparation and characterization of bio-composite PEEK/nHA

    Science.gov (United States)

    Jin, Y. S.; Bian, C. C.; Zhang, Z. Q.; Zhao, Y.; Yang, L.

    2017-01-01

    PEEK/nHA composite material, with excellent mechanical property as polyetheretherketone (PEEK) and biological activity as hydroxyapatite (HA), has attracted wide attention of medical experts and materials science experts. The addition of hydroxyapatite was the decisive factor for biological activity in PEEK/nHA composite. In this paper, acicular nanohydroxyapatite was prepared by chemical precipitation method with Ca(NO3)2, (NH4)2HPO4 as raw material; PEEK/nHA composite was prepared by solution blending and vacuum sintering method. The composite was characterized with FT-IR, XRD, DSC, TG and mechanical property test. Results showed that the composite has good thermal stability and compressive property when the mass ratio of PEEK to nHA is 10:3; and high nHA content can improve the biological activity of the composite, which can meet the basic requirements for bone tissue engineering scaffold.

  15. Utilization of Lavandula angustifolia Miller extracts as naturalrepellents, pharmaceutical and industrial auxiliaries

    Directory of Open Access Journals (Sweden)

    AYOE YUSUFOGLU

    2004-01-01

    Full Text Available Essential oils, absolutes and concretes were prepared from the flowers and leaves of the plant Lavandula angustifolia Miller cultivated in the Bosphorus region of Istanbul, Turkey. The difference in the chemical composition of the mentioned extracts was investigated and compared by using a combination of capillary GC-MS with the aim of offering them as repellent, pharmaceutical and industrial auxiliaries. The IR-spectra, the yields and the physico-chemical data of the extracts were also analysed.

  16. Sulphur cement pre-composition and process for preparing such sulphur cement pre-composition

    NARCIS (Netherlands)

    2013-01-01

    The invention provides a process for the preparation of a sulphur cement pre-composition comprising reacting sulphur modifier with polysulphide-containing organosilane to obtain in the presence of sulphur the sulphur cement pre-composition, wherein the organosilane has the general molecular formula:

  17. Lipids in pharmaceutical and cosmetic preparations

    Directory of Open Access Journals (Sweden)

    González Rodríguez, María Luisa

    2000-04-01

    Full Text Available In this paper, a review of the applications of lipids in the pharmaceutical field has been reported. In a first stage, different lipids used as excipients in cosmetics and medicines have been described. Many vegetable oils are used in this sense: almond oil, apricot oil, avocado oil, borage oil, coffee oil, safflower oil, etc.; from de animal source, fish oil and bird oil can be employed as excipients in cosmetical formulations. Fats and waxes may be also used for this purpose. A broad range of phospholipids are suitable for use in cosmetics, pharmaceuticals and diagnosis. These substances are used as vehicle for therapeutic substances, such as liposomes. Finally, a study of lipids, as a function of their biological activity, as active substances for the elaboration of pharmaceuticals, cosmetics or nutritional supplements, was carried out. Carotenoids, retinoids, tocopherols are used for their antioxidant properties, that are important to health and diagnostic medicine.En el presente trabajo se ha llevado a cabo una revisión sobre las aplicaciones de los lípidos en el campo famacéutico. En un primer apartado, se describieron los diferentes lípidos utilizados como excipientes en cosmética y medicina. En este sentido, se utilizan muchos aceites vegetales, como el aceite de almendra, albaricoque, aguacate, borraja, café, cártamo, etc.; a partir de fuente animal, pueden emplearse como excipientes en formulaciones cosméticas los aceites de pescados y de aves. También se utilizan con este propósito las grasas y las ceras. Así mismo se revisan los fosfolípidos empleados en cosmética y en diagnosis, que actúan como vehículos transportadores de sustancias activas, como los liposomas. Finalmente, se llevó a cabo un estudio de los lípidos, en función de su actividad biológica, como sustancias activas que forman parte de la elaboración de formulaciones cosméticas, farmacéuticas o suplementos nutricionales. Los carotenoides, retinoides

  18. Preparation and characterization of photoactive composite kaolinite/TiO2

    International Nuclear Information System (INIS)

    Mamulova Kutlakova, K.; Tokarsky, J.; Kovar, P.; Vojteskova, S.; Kovarova, A.; Smetana, B.; Kukutschova, J.; Capkova, P.; Matejka, V.

    2011-01-01

    Preparation of nanocomposite kaolinite/TiO 2 , using hydrolysis of titanyl sulfate in the presence of kaolin was addressed. A variable (kaolin)/(titanyl sulfate) ratio has been used in order to achieve the desired TiO 2 content in prepared nanocomposites. Calcination of the composites at 600 deg, C led to the transformation of the kaolinite to metakaolinite and to origination of metakaolinite/TiO 2 composites. The prepared samples were investigated using X-ray fluorescence spectroscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetry and diffuse reflectance spectroscopy in the UV-VIS region. Structural ordering of TiO 2 on the kaolinite particle surface was modeled using empirical force field atomistic simulations in the Material Studio modeling environment. Photodegradation activity of the composites prepared was evaluated by the discoloration of Acid Orange 7 aqueous solution.

  19. Pharmaceutical care in Kuwait: hospital pharmacists' perspectives.

    Science.gov (United States)

    Katoue, Maram G; Awad, Abdelmoneim I; Schwinghammer, Terry L; Kombian, Samuel B

    2014-12-01

    Pharmaceutical care practice has been championed as the primary mission of the pharmacy profession, but its implementation has been suboptimal in many developing countries including Kuwait. Pharmacists must have sufficient knowledge, skills, and positive attitudes to practise pharmaceutical care, and barriers in the pharmacy practice model must be overcome before pharmaceutical care can be broadly implemented in a given healthcare system. To investigate hospital pharmacists' attitudes towards pharmaceutical care, perceptions of their preparedness to provide pharmaceutical care, and the barriers to its implementation in Kuwait. Six general hospitals, eight specialized hospitals and seven specialized health centers in Kuwait. A descriptive, cross-sectional survey was distributed to all pharmacists working in the governmental hospitals in Kuwait (385 pharmacists). Data were collected via a pre-tested self-administered questionnaire. Descriptive statistics including percentages, medians and means Likert scale rating (standard deviations) were calculated and compared using statistical package for social sciences, version 20. Statistical significance was accepted at a p value of Kuwait. Completed surveys were received from 250 (64.9%) of the 385 pharmacists. Pharmacists expressed overall positive attitudes towards pharmaceutical care. They felt well prepared to implement the various aspects of pharmaceutical care, with the least preparedness in the administrative/management aspects. Pharmacists with more practice experience expressed significantly more positive attitudes towards pharmaceutical care (p = 0.001) and they felt better prepared to provide pharmaceutical care competencies (p Kuwait advocate implementation of pharmaceutical care while also appreciating the organizational, technical and professional barriers to its widespread adoption. Collaborative efforts between health authorities and educational institutions, and the integration of innovative approaches in

  20. Novel hard compositions and methods of preparation

    Science.gov (United States)

    Sheinberg, H.

    1983-08-23

    Novel very hard compositions of matter are prepared by using in all embodiments only a minor amount of a particular carbide (or materials which can form the carbide in situ when subjected to heat and pressure); and no strategic cobalt is needed. Under a particular range of conditions, densified compositions of matter of the invention are prepared having hardnesses on the Rockwell A test substantially equal to the hardness of pure tungsten carbide and to two of the hardest commercial cobalt-bonded tungsten carbides. Alternately, other compositions of the invention which have slightly lower hardnesses than those described above in one embodiment also possess the advantage of requiring no tungsten and in another embodiment possess the advantage of having a good fracture toughness value. Photomicrographs show that the shapes of the grains of the alloy mixture with which the minor amount of carbide (or carbide-formers) is mixed are radically altered from large, rounded to small, very angular by the addition of the carbide. Superiority of one of these hard compositions of matter over cobalt-bonded tungsten carbide for ultra-high pressure anvil applications was demonstrated. 3 figs.

  1. Optical characterization of composite layers prepared by plasma polymerization

    International Nuclear Information System (INIS)

    Radeva, E; Hikov, T; Mitev, D; Pramatarova, L; Stroescu, H; Nicolescu, M; Gartner, M; Presker, R

    2016-01-01

    Thin composite layers from polymer/nanoparticles (Ag-nanoparticles and detonation nanodiamonds) were prepared by plasma polymerization process on the base of hexamethyldisiloxane. The variation of the layer composition was achieved by changing the type of nanoparticles. The optical measurement techniques used were UV-VIS-NIR ellipsometry (SE), Fourier-transformed infrared spectroscopy (FTIR) and Raman spectroscopy. The values of the refractive index determined are in the range 1.30 to 1.42. All samples are transparent with transmission between 85-95% and very smooth. The change in Raman and FTIR spectra of the composites verify the expected bonding between polymer and diamond nanoparticles due to the penetration of the fillers in the polymer matrix. The comparison of the spectra of the corresponding NH3 plasma treated composites revealed that the composite surface becomes more hydrophilic. The obtained results indicate that preparation of layers with desired compositions is possible at a precise control of the detonation nanodiamond materials. (paper)

  2. Application of radioisotopes in pharmaceutical research

    International Nuclear Information System (INIS)

    Khujaev, S.

    2004-01-01

    Full text: To use of radioisotopes in the processes of receiving radiopharmaceutical diagnostic means it is widely know [1]. Radioactivity labeled chemical compounds, pharmacological kinetics of which allows one solving a concrete diagnostic problem in an organism are used in radio pharmaceutics. In spite of this choice of the radioisotope, possessing the most favorable nuclei-physical characteristics for it to be detected and minimization of beam loadings, be of great importance. Development of a method of introduction of a radioisotope also has important value, as it is included into chemical structure of a radiopharmaceutical preparation. One more way of use of radioisotopes in pharmaceutics is their use as a radioactive mark at a stage of creation of a new medical product. And in this case, all those moments, which are listed above, take place. Preparations labeling by radioisotopes are used basically for their studying pharmacological kinetics. In Institute of nuclear physics AS RU, in recent years, works are done on studying pharmacological kinetics of some new medical products, which have been synthesized in the Tashkent pharmaceutical institute. These preparations are on the basis of microelements with a complex set of properties possessing expressed biological activity and have great value in pharmaceutical science of Republic of Uzbekistan. Reception of labeled compounds of all preparations was carried out by a method of introduction of a radioisotope at a stage of their synthesis. The work presents the results of researches on synthesis and study of pharmacological kinetics of radioactively labeled preparations - PIRACIN, labeled by radioisotope 69m Zn; FERAMED, labeled by radioisotope 59 Fe; COBAVIT, labeled by radioisotope 57 Co; VUC, labeled by radioisotope 57 Co

  3. Palladium nanoparticles in electrochemical sensing of trace terazosin in human serum and pharmaceutical preparations

    Energy Technology Data Exchange (ETDEWEB)

    Sefid-sefidehkhan, Yasaman [Department of Chemistry, University of Mohaghegh Ardabili, Ardabil (Iran, Islamic Republic of); Nekoueian, Khadijeh [Laboratory of Green Chemistry, Faculty of Technology, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli (Finland); Amiri, Mandana, E-mail: mandanaamiri@uma.ac.ir [Department of Chemistry, University of Mohaghegh Ardabili, Ardabil (Iran, Islamic Republic of); Sillanpaa, Mika [Laboratory of Green Chemistry, Faculty of Technology, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli (Finland); Eskandari, Habibollah [Department of Chemistry, University of Mohaghegh Ardabili, Ardabil (Iran, Islamic Republic of)

    2017-06-01

    In this approach, palladium nanoparticle film was simply fabricated on the surface of carbon paste electrode by electrochemical deposition method. The film was characterized using scanning electron microscopy, electrochemical impedance spectroscopy and cyclic voltammetry. The prepared electrode exhibited an excellent electrocatalytic activity toward detection of trace amounts of terazosin, which is an antihypertensive drug. Under the optimum experimental conditions, a linear range of 1.0 × 10{sup −8}–1.0 × 10{sup −3} mol L{sup −1} with a detection limit of 1.9 × 10{sup −9} mol L{sup −1} was obtained for determination of terazosin using differential pulse voltammetry as a sensitive method. The efficiency of palladium nanoparticle film on the surface of carbon paste electrode successfully proved for determination of terazosin in pharmaceutical sample and human serum sample with promising recovery results. The effect of some foreign species has been studied. - Highlights: • PdNPs were simply fabricated by electrochemical deposition. • PdNPs exhibited an excellent electrocatalytic activity toward oxidation of terazosin. • Terazosin has been determined in pharmaceutical sample and human serum sample.

  4. Biocatalytic Synthesis of Chiral Pharmaceutical Intermediates

    Directory of Open Access Journals (Sweden)

    Ramesh N. Patel

    2004-01-01

    Full Text Available The production of single enantiomers of drug intermediates has become increasingly important in the pharmaceutical industry. Chiral intermediates and fine chemicals are in high demand from both the pharmaceutical and agrochemical industries for the preparation of bulk drug substances and agricultural products. The enormous potential of microorganisms and enzymes for the transformation of synthetic chemicals with high chemo-, regio- and enantioselectivities has been demonstrated. In this article, biocatalytic processes are described for the synthesis of chiral pharmaceutical intermediates.

  5. A novel strategy for pharmaceutical cocrystal generation without knowledge of stoichiometric ratio: myricetin cocrystals and a ternary phase diagram.

    Science.gov (United States)

    Hong, Chao; Xie, Yan; Yao, Yashu; Li, Guowen; Yuan, Xiurong; Shen, Hongyi

    2015-01-01

    To develop a streamlined strategy for pharmaceutical cocrystal preparation without knowledge of the stoichiometric ratio by preparing and characterizing the cocrystals of myricetin (MYR) with four cocrystal coformers (CCF). An approach based on the phase solubility diagram (PSD) was used for MYR cocrystals preparation and the solid-state properties were characterized by differential scanning calorimetry (DSC), fourier transform-infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD), and scanning electron microscopy (SEM). The ternary phase diagram (TPD) was constructed by combining the PSD and nuclear magnetic resonance (NMR) data. After that, the TPD was verified by traditional methods. The dissolution of MYR in the four cocrystals and pure MYR within three different media were also evaluated. A simple research method for MYR cocrystal preparation was obtained as follows: first, the PSD of MYR and CCF was constructed and analyzed; second, by transforming the curve in the PSD to a TPD, a region of pure cocrystals formation was exhibited, and then MYR cocrystals were prepared and identified by DSC, FT-IR, PXRD, and SEM; third, with the composition of the prepared cocrystal from NMR, the TPD of the MYR-CCF-Solvent system was constructed. The powder dissolution data showed that the solubility and dissolution rate of MYR was significantly enhanced by the cocrystals. A novel strategy for pharmaceutical cocrystals preparation without knowledge of the stoichiometric ratio based on the TPD was established and MYR cocrystals were successfully prepared. The present study provides a systematic approach for pharmaceutical cocrystal generation, which benefits the development and application of cocrystal technology in drug delivery.

  6. Development and validation of a sensitive spectrofluorimetric method for the determination of cilazapril of human plasma, urine, in pure and pharmaceutical preparations

    Science.gov (United States)

    Karasakal, A.

    2015-08-01

    A selective and sensitive spectrofluorimetric method was developed and validated for the determination of cilazapril in human plasma urine, in pure and pharmaceutical preparations. The proposed method is based on derivatization using 1-dimethylaminonaphthalene-5-sulphonyl chloride (dansyl chloride) as fluorogenic agent and measuring the fluorescence of the products at emission wavelengths of 503 nm after excitation at 374 nm. The method was validated for linearity, limit of detection, limit of quantification, precision, accuracy, recovery. The calibration curves were linear over a concentration range of 100-500 and 50-250 ng/mL for plasma and urine, respectively. The limits of detection were calculated to be 0.26 and 31.59 ng/mL for plasma and urine, respectively. The proposed method was applied to study of cilazapril in pure, human plasma, urine, and pharmaceutical preparations.

  7. Preparation and thermal properties of polyacrylonitrile/hexagonal boron nitride composites

    International Nuclear Information System (INIS)

    Madakbaş, Seyfullah; Çakmakçı, Emrah; Kahraman, Memet Vezir

    2013-01-01

    Highlights: ► PAN/h-BN composites with improved thermal stability were prepared. ► Thermal properties of composites were analysed by TGA and DSC. ► Flame retardancy of the composites increased up to 27%. - Abstract: Polyacrylonitrile is a thermoplastic polymer with unique properties and it has several uses. However its flammability is a major drawback for certain applications. In this study it was aimed to prepare polyacrylonitrile (PAN)/hexagonal boron nitride (h-BN) composites with improved flame retardancy and thermal stability. Chemical structures of the composites were characterized by FTIR analysis. Thermal properties of these novel composites were analysed by TGA and DSC measurements. Glass transition temperatures and char yields increased with increasing h-BN percentage. Flame retardancy of the PAN composite materials improved with the addition of h-BN and the LOI value reached to 27% from 18%. Furthermore, the surface morphology of the composites was investigated by SEM analysis.

  8. Preparation of Novel Thin-Film Composite Nanofiltration Membranes for Separation of Amoxicillin

    Directory of Open Access Journals (Sweden)

    A. Akbari

    2014-04-01

    Full Text Available Several novel composite membranes were prepared to separate and recycle amoxicillin from pharmaceutical wastewater via nanofiltration process. The synthesis of these membranes included three stages: 1- preparation of polysulfone ultrafiltration membranes as a support via phase separation process, 2- modification of its surface by interfacial polymerization as a selective layer (polyamide, and 3- self-assembly of TiO2 nanoparticles on the selective layer as an anti-fouling agent. The rejection of all nanofiltration membranes was more than 99% and only its flux was changed proportional to different conditions. In the presence and absence of TiO2 nanoparticles, the pure water flux of polyamide thin-film membrane also obtained 44.4 and 38.4 L/h.m2 at 4 bar pressure, respectively. These were equal to 34 L/h.m2 for amoxicillin solutions. The results showed that TiO2 nanoparticles increased hydrophilicity of polyamide selective layer and therefore, nanoparticles decreased the fouling level. SEM images illustrated the excellent establishment of polyamide layer and distribution of TiO2 nanoparticles on the selective layer. The properties of membrane surface were taken into consideration by using AFM, indicating the increment of surface roughness with interfacial polymerization and TiO2 nanoparticles self-assembly. The pore size of membranes was in the nanoscale (2.653 and 2.604 nm without and with TiO2 nanoparticles self-assembly, respectively

  9. New Polymorphic Forms of Pemetrexed Diacid and Their Use for the Preparation of Pharmaceutically Pure Amorphous and Hemipentahydrate Forms of Pemetrexed Disodium

    OpenAIRE

    Michalak, Olga; Łaszcz, Marta; Jatczak, Kamil; Witkowska, Anna; Bujak, Iwona; Groman, Aleksandra; Cybulski, Marcin

    2015-01-01

    The preparation of stable amorphous pemetrexed disodium of pharmaceutical purity as well as the process optimization for the preparation of the hemipentahydrate form of pemetrexed disodium are described. Analytical methods for the polymorphic and chemical purity studies of pemetrexed disodium and pemetrexed diacid forms were developed. The physicochemical properties of the amorphous and hydrate forms of pemetrexed disodium, as well as new forms of pemetrexed diacid (a key synthetic intermedia...

  10. Preparation and characterization of collagen-hydroxyapatite/pectin composite.

    Science.gov (United States)

    Wenpo, Feng; Gaofeng, Liang; Shuying, Feng; Yuanming, Qi; Keyong, Tang

    2015-03-01

    Pectin, a kind of plant polysaccharide, was introduced into collagen-hydroxyapatite composite system, and prepared collagen-hydroxyapatite/pectin (Col-HA/pectin) composite in situ. The structure of the composite was investigated by XRD, SEM, and FT-IR. The mechanical properties, water absorption, enzyme degradation, and cytotoxicity of the composite were investigated as well. The results show that the inorganic substance in the composite materials is hydroxyapatite in relatively low crystallinity. A new interface appeared by the interaction among hydroxyapatite and collagen-pectin, and formed smooth fine particles. The mechanical properties, water absorption, enzyme degradation, and cytotoxicity indicate a potential use in bone replacement for the new composite. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Preparation and characterization of antimony barium composite oxide photocatalysts

    Science.gov (United States)

    Han, X. P.; Yao, B. H.; Pan, Q. H.; Pen, C.; Zhang, C. L.

    2018-01-01

    In this paper, two kinds of antimony barium composite oxide photocatalysts have been prepared by two methods and characterized by XRD and SEM. The photocatalytic activity was evaluated by a photocatalytic reactor and an ultraviolet spectrophotometer. The results showed that-BaSb2O5•4H2O, BaSb2O6 two kinds of antimony barium composite oxide photocatalysts were successfully prepared in this experiment and they showed good photocatalytic properties. In addition, BaSb2O6 morphology showed more regular, microstructure and better catalytic performance.

  12. Cannabinoids concentration variability in cannabis olive oil galenic preparations.

    Science.gov (United States)

    Carcieri, Chiara; Tomasello, Cristina; Simiele, Marco; De Nicolò, Amedeo; Avataneo, Valeria; Canzoneri, Luca; Cusato, Jessica; Di Perri, Giovanni; D'Avolio, Antonio

    2018-01-01

    Knowledge of the exact concentration of active compounds in galenic preparations is crucial to be able to ensure their quality and to properly administer the prescribed dose. Currently, the need for titration of extracts is still debated. Considering this, together with the absence of a standard preparation method, the aim of this study was to evaluate cannabinoids concentrations variability in galenic olive oil extracts, to evaluate the interlot and interlaboratory variability in the extraction yield and in the preparation composition. Two hundred and one extracts (123 (61.2%) from Bedrocan ® , 54 (26.9%) from Bediol ® , 11 (5.5%) from Bedrolite ® , and 13 (6.5%) from mixed preparations) were analysed by liquid chromatography coupled with tandem mass spectrometry, quantifying cannabinoids (THC, CBD, THCA, CBDA and CBN) concentrations. The RSD% of THC and CBD concentrations resulted higher than 50%. Specifically for Bedrocan ® , Bediol ® , Bedrolite ® (5 g/50 ml), these were THC 82%, THC 53% and CBD 91%, THC 58% and CBD 59%, respectively. The median extraction yields were greater than 75% for all preparations. Our results highlighted a wide variability in THC and CBD concentrations that justify the need for titration and opens further questions about other pharmaceutical preparations without regulatory indication for this procedure. © 2017 Royal Pharmaceutical Society.

  13. Nickel/Diamond Composite Coating Prepared by High Speed Electrodeposition

    Directory of Open Access Journals (Sweden)

    ZHANG Yan

    2016-10-01

    Full Text Available Nickel/diamond composite coatings were prepared on the basis of a new high speed electroplating bath. The influence of additives, plating parameters and diamond concentration on internal stress was investigated in order to find the solution to decrease the stress introduced by high current density; the micro morphology of the coatings were observed by SEM. The bath and depositing parameters were optimized that thick nickel/diamond composite coatings with low internal stress can be high speed electroplated with a high cathode current density of 30A/dm2. The results show that when plated with bath composition and parameters as follows: sodium dodecyl sulfate 0.5g/L, ammonium acetate 3g/L, sodium citrate 1.5g/L, diamond particles 30g/L; pH value 3-4, temperature 50℃, the composite coatings prepared in high speed have the lowest internal stress.

  14. Parafac and PLS Applied to Determination of Captopril in Pharmaceutical Preparation and Biological Fluids by Ultraviolet Spectrophotometry

    International Nuclear Information System (INIS)

    Niazi, A.; Ghasemi, N.

    2007-01-01

    A new ultraviolet spectrophotometric method has been developed for the direct qualitative determination of captopril in pharmaceutical preparation and biological fluids such as human plasma and urine samples. The method was accomplished based on parallel factor analysis (PARAFAC) and partial least squares (PLS). The study was carried out in the pH range from 2.0 to 12.8 and with a concentration from 0.70 to 61.50 μg ml -1 of captopril. Multivariate calibration models PLS at various pH and PARAFAC were elaborated from ultraviolet spectra deconvolution and captopril determination. The best models for this system were obtained with PARAFAC and PLS at pH = 2.04 (PLS-PH2). The applications of the method for the determination of real samples were evaluated by analysis of captopril in pharmaceutical preparations and biological (human plasma and urine) fluids with satisfactory results. The accuracy of the method, evaluated through the root mean square error of prediction (RMSEP), was 0.58 for captopril with PARAFAC and 0.67 for captopril with PLS-PH2 model. Acidity constant of captopril at 25 0 C and ionic strength of 0.1 M have also been determined spectrophotometrically. The obtained pK a values of captopril are 3.90 ± 0.05 and 10.03 ± 0.08 for pK a1 and pK a2 , respectively

  15. Variations in polyethylene glycol brands and their influence on the preparation process of hydrogel microspheres

    DEFF Research Database (Denmark)

    Wöhl-Bruhn, Stefanie; Bertz, Andreas; Kuntsche, Judith

    2013-01-01

    differences in the salt composition and molecular weight distribution of the polymers which can explain the results from the production process. The results illustrate that the range of product specifications may not always be tight enough to avoid variability in pharmaceutical processes like the preparation...

  16. Composition and production rate of pharmaceutical and chemical waste from Xanthi General Hospital in Greece.

    Science.gov (United States)

    Voudrias, Evangelos; Goudakou, Lambrini; Kermenidou, Marianthi; Softa, Aikaterini

    2012-07-01

    The objective of this work was to determine the composition and production rates of pharmaceutical and chemical waste produced by Xanthi General Hospital in Greece (XGH). This information is important to design and cost management systems for pharmaceutical and chemical waste, for safety and health considerations and for assessing environmental impact. A total of 233 kg pharmaceutical and 110 kg chemical waste was collected, manually separated and weighed over a period of five working weeks. The total production of pharmaceutical waste comprised 3.9% w/w of the total hazardous medical waste produced by the hospital. Total pharmaceutical waste was classified in three categories, vial waste comprising 51.1%, syringe waste with 11.4% and intravenous therapy (IV) waste with 37.5% w/w of the total. Vial pharmaceutical waste only was further classified in six major categories: antibiotics, digestive system drugs, analgesics, hormones, circulatory system drugs and "other". Production data below are presented as average (standard deviation in parenthesis). The unit production rates for total pharmaceutical waste for the hospital were 12.4 (3.90) g/patient/d and 24.6 (7.48) g/bed/d. The respective unit production rates were: (1) for vial waste 6.4 (1.6) g/patient/d and 13 (2.6) g/bed/d, (2) for syringe waste 1.4 (0.4) g/patient/d and 2.8 (0.8) g/bed/d and (3) for IV waste 4.6 (3.0) g/patient/d and 9.2 (5.9) g/bed/d. Total chemical waste was classified in four categories, chemical reagents comprising 18.2%, solvents with 52.3%, dyes and tracers with 18.2% and solid waste with 11.4% w/w of the total. The total production of chemical waste comprised 1.8% w/w of the total hazardous medical waste produced by the hospital. Thus, the sum of pharmaceutical and chemical waste was 5.7% w/w of the total hazardous medical waste produced by the hospital. The unit production rates for total chemical waste for the hospital were 5.8 (2.2) g/patient/d and 1.1 (0.4) g/exam/d. The respective

  17. Preparation and performance of ZnO/Polyaniline nano-composite for supercapacitor

    Energy Technology Data Exchange (ETDEWEB)

    Yu, S.P.; Chang, X.C.; Wang, Z.M.; Han, K.F.; Zhu, H. [Beijing Univ. of Chemical Technology, Beijing (China). School of Science

    2010-07-01

    Supercapacitors combine the advantages of traditional capacitors and batteries. In this study, a zinc oxide (ZnO-PANI) nano-composite material was fabricated in order to investigate its behaviour in a supercapacitor application. The ZnO nano-powder was synthesized using the sol-gel method. An inverted emulsion polymerization method was then used to prepare the ZnO/PANI nanocomposite. X-ray diffraction (XRD) analyses demonstrated that the prepared ZnO had a hexagonal structure. The ZnO/PANI composite electrode was prepared. Electrochemical impedance spectroscopy (EIS) analyses indicated that the nano-composite material functioned well as an electrode. The highest capacitance rating achieved by the electrode was 31.82 F per g. 6 refs., 4 figs.

  18. Composition and production rate of pharmaceutical and chemical waste from Xanthi General Hospital in Greece

    International Nuclear Information System (INIS)

    Voudrias, Evangelos; Goudakou, Lambrini; Kermenidou, Marianthi; Softa, Aikaterini

    2012-01-01

    Highlights: ► We studied pharmaceutical and chemical waste production in a Greek hospital. ► Pharmaceutical waste comprised 3.9% w/w of total hazardous medical waste. ► Unit production rate for total pharmaceutical waste was 12.4 ± 3.90 g/patient/d. ► Chemical waste comprised 1.8% w/w of total hazardous medical waste. ► Unit production rate for total chemical waste was 5.8 ± 2.2 g/patient/d. - Abstract: The objective of this work was to determine the composition and production rates of pharmaceutical and chemical waste produced by Xanthi General Hospital in Greece (XGH). This information is important to design and cost management systems for pharmaceutical and chemical waste, for safety and health considerations and for assessing environmental impact. A total of 233 kg pharmaceutical and 110 kg chemical waste was collected, manually separated and weighed over a period of five working weeks. The total production of pharmaceutical waste comprised 3.9% w/w of the total hazardous medical waste produced by the hospital. Total pharmaceutical waste was classified in three categories, vial waste comprising 51.1%, syringe waste with 11.4% and intravenous therapy (IV) waste with 37.5% w/w of the total. Vial pharmaceutical waste only was further classified in six major categories: antibiotics, digestive system drugs, analgesics, hormones, circulatory system drugs and “other”. Production data below are presented as average (standard deviation in parenthesis). The unit production rates for total pharmaceutical waste for the hospital were 12.4 (3.90) g/patient/d and 24.6 (7.48) g/bed/d. The respective unit production rates were: (1) for vial waste 6.4 (1.6) g/patient/d and 13 (2.6) g/bed/d, (2) for syringe waste 1.4 (0.4) g/patient/d and 2.8 (0.8) g/bed/d and (3) for IV waste 4.6 (3.0) g/patient/d and 9.2 (5.9) g/bed/d. Total chemical waste was classified in four categories, chemical reagents comprising 18.2%, solvents with 52.3%, dyes and tracers with 18.2% and

  19. Spectrophotometric determination of dopaminergic drugs used for Parkinson's disease, cabergoline and ropinirole, in pharmaceutical preparations.

    Science.gov (United States)

    Onal, Armağan; Cağlar, Sena

    2007-04-01

    Simple and reproducible spectrophotometric methods have been developed for determination of dopaminergic drugs used for Parkinson's disease, cabergoline (CAB) and ropinirole hydrochloride (ROP), in pharmaceutical preparations. The methods are based on the reactions between the studied drug substances and ion-pair agents [methyl orange (MO), bromocresol green (BCG) and bromophenol blue (BPB)] producing yellow colored ion-pair complexes in acidic buffers, after extracting in dichloromethane, which are spectrophotometrically determined at the appropriate wavelength of ion-pair complexes. Beer's law was obeyed within the concentration range from 1.0 to 35 microg ml(-1). The developed methods were applied successfully for the determination of these drugs in tablets.

  20. A new generation of starch products as excipient in pharmaceutical tablets .1. Preparation and binding properties of high surface area potato starch products

    NARCIS (Netherlands)

    Wierik, GHPT; ArendsScholte, AW; Eissens, AC; Lerk, CF

    1996-01-01

    A new pharmaceutical excipient with a high binding capacity was prepared from potato starch by enzymatic degradation, followed by suitable dehydration of the precipitated and filtered retrograded starch to produce high specific surface area products. Thermal dehydration methods like drying at room

  1. Multiwall carbon nanotubes chemically modified carbon paste electrodes for determination of gentamicin sulfate in pharmaceutical preparations and biological fluids

    Energy Technology Data Exchange (ETDEWEB)

    Khalil, M.M., E-mail: magdy_mmagdy@yahoo.com; Abed El-aziz, G.M., E-mail: Gamal_abedelaziz@yahoo.com

    2016-02-01

    This article focused on the construction and characteristics of novel and sensitive gentamicin carbon paste electrodes which are based on the incorporation of multiwall carbon nanotubes (MWCNTs) which improve the characteristics of the electrodes. The electrodes were constructed based on gentamicin-phosphotungstate (GNS-PTA) called CPE{sub 1}, gentamicin-phosphomolybdate (GNS-PMA) called CPE{sub 2}, GNS-PTA + MWMCNTs called MWCPE{sub 1}, and GNS-PMA + MWMCNTs called MWCPE{sub 2}. The constructed electrodes, at optimum paste composition, exhibited good Nernstian response for determination of gentamicin sulfate (GNS) over a linear concentration range from 2.5 × 10{sup −6} to 1 × 10{sup −2}, 3.0 × 10{sup −6} to 1 × 10{sup −2}, 4.9 × 10{sup −7} to 1 × 10{sup −2} and 5.0 × 10{sup −7} to 1 × 10{sup −2} mol L{sup −1}, with lower detection limit 1 × 10{sup −6}, 1 × 10{sup −6}, 1.9 × 10{sup −7} and 2.2 × 10{sup −7} mol L{sup −1}, and with slope values of 29.0 ± 0.4, 29.2 ± 0.7, 31.2 ± 0.5 and 31.0 ± 0.6 mV/decade for CPE{sub 1}, CPE{sub 2}, MWCPE{sub 1} and MWCPE{sub 2}, respectively. The response of electrodes is not affected by pH in the range 3–8 for CPE{sub 1} and CPE{sub 2} and in the range 2.5–8.5 for MWCPE{sub 1} and MWCPE{sub 2}. The results showed fast dynamic response time (about 8–5 s) and long lifetime (more than 2 months) for all electrodes. The sensors showed high selectivity for gentamicin sulfate (GNS) with respect to a large number of interfering species. The constructed electrodes were successfully applied for determination of GNS in pure form, its pharmaceutical preparations and biological fluids using standard addition and potentiometric titration methods with high accuracy and precision. - Graphical abstract: The incorporation of MWCNTs in paste composition improves the characteristics of the MWCPE electrodes which show better responses in terms of sensitivity, Nernstian slope, linear range, faster

  2. The preparation of dental glass-ceramic composites with controlled fraction of leucite crystals

    Directory of Open Access Journals (Sweden)

    Martina Mrázová

    2008-06-01

    Full Text Available This work is dealing with synthesis of leucite powder, which can be used for the preparation of dental glassceramic composites by subsequent thermal treatment. Newly developed procedure is based on preparation of dental raw material as a mixture of two separate compounds: the crystalline leucite powder prepared at relatively low temperature and a commercial matrix powder.Hydrothermal synthesis of tetragonal leucite particles (KAlSi2O6 with the average size of about 3 μm was developed in our laboratory. The leucite dental raw material was prepared by mixing of 20 wt.% of synthetic tetragonal leucite with commercial matrix. Dental composites were prepared from the dental raw material by uniaxial pressing and firing up to 960°C. Dilatometric measurements confirmed that the coefficient of thermal expansion increased by 32% when 20 wt.% of the tetragonal leucite was added into the basic matrix. In addition, it was showed that the synthesized leucite powder was suitable for the preparation of leucite composites with controlled coefficient of thermal expansion. High value of the thermal expansion coefficient enables application of prepared composite in metal-ceramics restorations.

  3. Preparation of gypsum/polymer composites using radiation

    International Nuclear Information System (INIS)

    Aji, Z.

    2007-05-01

    Gypsum composites have been prepared with different monomers using Gamma radiation: acrylamide, butyl acrylate, butyl methacrylate, methyl methacrylate, and methyl acrylate. The conversion of polymerization was determined as a function of absorbed dose. The data show that conversion of polymerization increases by increasing the dose.(author)

  4. Composite Materials with Magnetically Aligned Carbon Nanoparticles and Methods of Preparation

    Science.gov (United States)

    Hong, Haiping (Inventor); Peterson, G.P. (Bud) (Inventor); Salem, David R. (Inventor)

    2018-01-01

    The present invention relates to magnetically aligned carbon nanoparticle composites and methods of preparing the same. The composites comprise carbon nanoparticles, host material, magnetically sensitive nanoparticles and surfactant. The composites may have enhanced mechanical, thermal, and/or electrical properties.

  5. Preparation and Photocatalytic Performance of Bamboo-Charcoal-Supported Nano-ZnO Composites

    Directory of Open Access Journals (Sweden)

    Yunlong ZHOU

    2018-02-01

    Full Text Available Nano-ZnO/bamboo charcoal composites were prepared by precipitation with bamboo charcoal as support. Nano-ZnO/bamboo charcoal composites were characterized by XRD, SEM and EDS. Photocatalytic degradation processes of methyl orange were studied. The results indicate that the structure of nano-ZnO is of the wurtzite type and the grain size is about 19-54 nm. The best preparation temperature for these composites is 500℃. The composites have better photocatalytic degradation ability than pure ZnO under UV irradiation. Photocatalytic degradation of methyl orange with the composites obeys first-order kinetics, and the composites can be recycled.DOI: http://dx.doi.org/10.5755/j01.ms.24.1.17397

  6. Spectrophotometric Determination of Lamotrigine in Pharmaceutical Preparations and Urine Samples Using Bromothymol Blue and Bromophenol Blue

    International Nuclear Information System (INIS)

    Najib, F.M.; Aziz, K.H.H.

    2013-01-01

    Two simple and sensitive spectrophotometric methods have been developed for the determination of the antiepileptic drug lamotrigine (LMT) in pharmaceutical preparations and urine samples. The methods are based on the interaction of LMT with two sulphonphthalein dyes, namely, bromothymol blue (BTB) and bromophenol blue (BPB) in dichloromethane (DCM) medium to form stable and yellow-colored ion-pairs with λ max 410 and 413 nm respectively. The ion-pair LMT-BPB has been extracted from aqueous solutions at pH 3.25±0.25 using DCM; while LMT-BTB ion-pair was directly prepared in DCM. Interferences from the compounds of the urine samples, in case of LMT-BPB were removed using a suppressing solution (S.S.) prepared from the salts of the interfering ions. In LMT-BTB method, the urine of normal person not taking LMT, was used as a blank to remove the effect of interferences. Under optimum conditions, the calibration curve of LMT-BTB was linear over the range of 1-12 μg.ml -1 , ε=1.97x10 4 L.mole -1 .cm -1 , r 2 = 0.9983, and D.L of 0.13 μg.ml -1 . The corresponding values for (LMT-BPB) ion-pair were 0.5-12 μg.ml -1 linear range, ε=1.92x10 4 , r 2 = 0.9980, and D.L= 0.24 μg.ml -1 . The stoichiometry of the ion-pairs were found to be 1:1, based on Jobs, mole ratio and slope ratio methods. The recoveries (%R) for both methods were in the range of 97-101.8 % and 95-97.1 % with RSD≤1.68 and 3.1 % respectively. For LMT- spiked urine samples, the recoveries were 98.5-106.6 % with RSD≤1.66 %. Interferences from phenobarbital and carbamazepine were in the range of 25-40 folds. Statistical comparison of the results with a published method using F and t-tests showed no significant differences between each of the two methods and the reported one at 95 % confidence level. A standard addition method, gave high accuracy with LMT-BPB method. The proposed methods were successfully applied for the determination of LMT in pharmaceutical preparation and urine samples. (author)

  7. Method of preparing composite superconducting wire

    International Nuclear Information System (INIS)

    Verhoeven, J. D.; Finnemore, D. K.; Gibson, E. D.; Ostenson, J. E.; Schmidt, F. A.

    1985-01-01

    An improved method of preparing composite multifilament superconducting wire of Nb 3 Sn in a copper matrix which eliminates the necessity of coating the drawn wire with tin. A generalized cylindrical billet of an alloy of copper containing at least 15 weight percent niobium, present in the copper as discrete, randomly distributed and oriented dendritic-shaped particles, is provided with at least one longitudinal opening which is filled with tin to form a composite drawing rod. The drawing rod is then drawn to form a ductile composite multifilament wire containing a filament of tin. The ductile wire containing the tin can then be wound into magnet coils or other devices before heating to diffuse the tin through the wire to react with the niobium forming Nb 3 Sn. Also described is an improved method for making large billets of the copper-niobium alloy by consumable-arc casting

  8. Nano-structured polymer composites and process for preparing same

    Science.gov (United States)

    Hillmyer, Marc; Chen, Liang

    2013-04-16

    A process for preparing a polymer composite that includes reacting (a) a multi-functional monomer and (b) a block copolymer comprising (i) a first block and (ii) a second block that includes a functional group capable of reacting with the multi-functional monomer, to form a crosslinked, nano-structured, bi-continuous composite. The composite includes a continuous matrix phase and a second continuous phase comprising the first block of the block copolymer.

  9. Microstructure of Pharmaceutical Semicrystalline Dispersions: The Significance of Polymer Conformation.

    Science.gov (United States)

    Van Duong, Tu; Goderis, Bart; Van Humbeeck, Jan; Van den Mooter, Guy

    2018-02-05

    The microstructure of pharmaceutical semicrystalline solid dispersions has attracted extensive attention due to its complexity that might result in the diversity in physical stability, dissolution behavior, and pharmaceutical performance of the systems. Numerous factors have been reported that dictate the microstructure of semicrystalline dispersions. Nevertheless, the importance of the complicated conformation of the polymer has never been elucidated. In this study, we investigate the microstructure of dispersions of polyethylene glycol and active pharmaceutical ingredients by small-angle X-ray scattering and high performance differential scanning calorimetry. Polyethylene glycol with molecular weight of 2000 g/mol (PEG2000) and 6000 g/mol (PEG6000) exhibited remarkable discrepancy in the lamellar periodicity in dispersions with APIs which was attributed to the differences in their folding behavior. The long period of PEG2000 always decreased upon aging-induced exclusion of APIs from the interlamellar region of extended chain crystals whereas the periodicity of PEG6000 may decrease or increase during storage as a consequence of the competition between the drug segregation and the lamellar thickening from nonintegral-folded into integral-folded chain crystals. These processes were in turn significantly influenced by the crystallization tendency of the pharmaceutical compounds, drug-polymer interactions, as well as the dispersion composition and crystallization temperature. This study highlights the significance of the polymer conformation on the microstructure of semicrystalline systems that is critical for the preparation of solid dispersions with consistent and reproducible quality.

  10. Manganese(III Porphyrin-based Potentiometric Sensors for Diclofenac Assay in Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    Eugenia Fagadar-Cosma

    2010-09-01

    Full Text Available Two manganese(III porphyrins: manganese(III tetraphenylporphyrin chloride and manganese(III-tetrakis(3-hydroxyphenylporphyrin chloride were tested as ionophores for the construction of new diclofenac−selective electrodes. The electroactive material was incorporated either in PVC or a sol−gel matrix. The effect of different plasticizers and additives (anionic and cationic on the potentiometric response was studied. The best results were obtained for the PVC membrane plasticized with dioctylphtalate and having sodium tetraphenylborate as a lipophilic anionic additive incorporated. The sensor response was linear in the concentration range 3 × 10−6 – 1 × 10−2 M with a slope of −59.7 mV/dec diclofenac, a detection limit of 1.5 × 10−6 M and very good selectivity coefficients. It was used for the determination of diclofenac in pharmaceutical preparations, by direct potentiometry. The results were compared with those obtained by the HPLC reference method and a good agreement was found between the two methods.

  11. A water soluble fraction capable of regulating the immunity reactions of a host against allogenic cells or tissues, the pharmaceutical preparations which contain this fraction and a procedure for the preparation of the latter

    International Nuclear Information System (INIS)

    1980-01-01

    The preparation is described of non-toxic bone marrow cell suspensions containing a marrow-regulating factor, which are suitable for intravenous injection in patients with serious hematopoietic disturbances or radiation syndrome. The marrow-regulating factor conditions the bone marrow in a manner which enhances the success of bone marrow transplantation in donor-incompatible or semicompatible hosts. The extensive testing of this pharmaceutical preparation in irradiated mice is described and a toxicity study reported. (Auth.)

  12. Composite nanoparticles containing rare earth metal and methods of preparation thereof

    Science.gov (United States)

    Kandapallil, Binil Itty Ipe; Krishnan, Lakshmi; Johnson, Francis

    2018-04-10

    The present invention is directed to composite nanoparticles comprising a metal, a rare earth element, and, optionally, a complexing ligand. The invention is also directed to composite nanoparticles having a core-shell structure and to processes for preparation of composite nanoparticles of the invention.

  13. Composite Preparation of Wood Dust-Polyester-Coconut Choir Fiber Mixture for Particle Board

    International Nuclear Information System (INIS)

    Danu, Sugiarto; Darsono; Padmono; Betty, Angesti

    2002-01-01

    Experiment on the use of γ-ray of Co 60 radiation has been used for curing of composite which made of wood dust, unsaturated polyester resin and coconut coir mixture. Composite was prepared by mixing of wood dust, polyester and coconut coir at a various mixture composition. Concentration of polyesters were 50, 55 and 60 % by weight based on saw dust and polyester mixture. Irradiation was conducted using 27,6 kCi acti vity Co 60 at a dose rate of 5 kGy/hrs and dose of 8, 10 and 12 kGy. Composite was also prepared conventionally by using peroxide catalyst. Parameters observed were density, pencil hardness and compression strength Experimental results showed that optimum condition wus achieved at irradiation dose of 12 kGy, polyester concentration of 60 % and coconut coir fiber of 4 %. In this condition, the density, hardness and compression strength were 1,115 g/cm 3, 5 Hand 6,815 kN/cm2 respectively. Density, hardness of composite prepared by radiation were almost the same whereas the compression strength was higher than that of composite prepared by conventional method

  14. Nanocrystals Technology for Pharmaceutical Science.

    Science.gov (United States)

    Cheng, Zhongyao; Lian, Yumei; Kamal, Zul; Ma, Xin; Chen, Jianjun; Zhou, Xinbo; Su, Jing; Qiu, Mingfeng

    2018-05-17

    Nanocrystals technology is a promising method for improving the dissolution rate and enhancing the bioavailability of poorly soluble drugs. In recent years, it has been developing rapidly and applied to drug research and engineering. Nanocrystal drugs can be formulated into various dosage forms. This review mainly focused on the nanocrystals technology and its application in pharmaceutical science. Firstly, different preparation methods of nanocrystal technology and the characterization of nanocrystal drugs are briefly described. Secondly, the application of nanocrystals technology in pharmaceutical science is mainly discussed followed by the introduction of sustained release formulations. Then, the scaling up process, marketed nanocrystal drug products and regulatory aspects about nanodrugs are summarized. Finally, the specific challenges and opportunities of nanocrystals technology for pharmaceutical science are summarized and discussed. This review will provide a comprehensive guide for scientists and engineers in the field of pharmaceutical science and biochemical engineering. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  15. Negatively charged silver nanoparticles with potent antibacterial activity and reduced toxicity for pharmaceutical preparations

    Directory of Open Access Journals (Sweden)

    Salvioni L

    2017-03-01

    Full Text Available Lucia Salvioni,1 Elisabetta Galbiati,1 Veronica Collico,1 Giulia Alessio,1 Svetlana Avvakumova,1 Fabio Corsi,2,3 Paolo Tortora,1 Davide Prosperi,1 Miriam Colombo1 1Nanobiolab, Department of Biotechnology and Bioscience, University of Milano-Bicocca, 2Biological and Clinical Science Department, University of Milan, Milano, 3Surgery Department, Breast Unit, IRCCS S Maugeri Foundation, Pavia, Italy Background: The discovery of new solutions with antibacterial activity as efficient and safe alternatives to common preservatives (such as parabens and to combat emerging infections and drug-resistant bacterial pathogens is highly expected in cosmetics and pharmaceutics. Colloidal silver nanoparticles (NPs are attracting interest as novel effective antimicrobial agents for the prevention of several infectious diseases.Methods: Water-soluble, negatively charged silver nanoparticles (AgNPs were synthesized by reduction with citric and tannic acid and characterized by transmission electron microscopy, dynamic light scattering, zeta potential, differential centrifuge sedimentation, and ultraviolet–visible spectroscopy. AgNPs were tested with model Gram-negative and Gram-positive bacteria in comparison to two different kinds of commercially available AgNPs.Results: In this work, AgNPs with higher antibacterial activity compared to the commercially available colloidal silver solutions were prepared and investigated. Bacteria were plated and the antibacterial activity was tested at the same concentration of silver ions in all samples. The AgNPs did not show any significant reduction in the antibacterial activity for an acceptable time period. In addition, AgNPs were transferred to organic phase and retained their antibacterial efficacy in both aqueous and nonaqueous media and exhibited no toxicity in eukaryotic cells.Conclusion: We developed AgNPs with a 20 nm diameter and negative zeta potential with powerful antibacterial activity and low toxicity compared

  16. Kinetics of oil saponification by lead salts in ancient preparations of pharmaceutical lead plasters and painting lead mediums.

    Science.gov (United States)

    Cotte, M; Checroun, E; Susini, J; Dumas, P; Tchoreloff, P; Besnard, M; Walter, Ph

    2006-12-15

    Lead soaps can be found in archaeological cosmetics as well as in oil paintings, as product of interactions of lead salts with oil. In this context, a better understanding of the formation of lead soaps allows a follow-up of the historical evolution of preparation recipes and provides new insights into conservation conditions. First, ancient recipes of both pharmaceutical lead plasters and painting lead mediums, mixtures of oil and lead salts, were reconstructed. The ester saponification by lead salts is determined by the preparation parameters which were quantified by FT-IR spectrometry. In particular, ATR/FT-IR spectrometer was calibrated by the standard addition method to quantitatively follow the kinetics of this reaction. The influence of different parameters such as temperature, presence of water and choice of lead salts was assessed: the saponification is clearly accelerated by water and heating. This analysis provides chemical explanations to the historical evolution of cosmetic and painting preparation recipes.

  17. A sensitive determination of terbutaline in pharmaceuticals and urine samples using a composite electrode based on zirconium oxide nanoparticles

    International Nuclear Information System (INIS)

    Baytak, Aysegul Kutluay; Teker, Tugce; Duzmen, Sehriban; Aslanoglu, Mehmet

    2016-01-01

    An accurate and precise determination of terbutaline has been carried out using a glassy carbon electrode (GCE) modified with a composite of multi-walled carbon nanotubes (MWCNTs) and nanoparticles of zirconium oxide (ZrO_2NPs). Energy dispersive X-ray and scanning electron microscopic techniques were utilized for the characterization of the composite layer. Terbutaline exhibited a broad oxidation peak at 770 mV on a GCE. However, MWCNTs/GCE presented an electrocatalytic effect toward the oxidation of terbutaline with a better anodic peak at 660 mV. Furthermore, the electrochemical behavior of terbutaline has greatly been improved at a GCE modified with a composite of MWCNTs and nanoparticles of ZrO_2. The ZrO_2NPs/MWCNTs/GCE exhibited a sharp anodic wave at 645 mV with a large enhancement of the current response for terbutaline. Square wave voltammetry (SWV) was performed for the determination of terbutaline at ZrO_2NPs/MWCNTs/GCE. A linear plot was obtained for the current responses of terbutaline against concentrations in the range of 10–160 nM yielding a detection limit of 2.25 nM (based on 3S_b/m). Improved voltammetric behavior, long-time stability and good reproducibility were obtained for terbutaline at the proposed electrode. A mean recovery of 101.2% with an RSD% of 1.9 was obtained for the analysis of the drug formulation. The accurate and precise quantification of terbutaline makes the ZrO_2NPs/MWCNTs/GCE system of great interest for monitoring its therapeutic use. - Graphical abstract: A sensitive determination of terbutaline in pharmaceuticals and urine samples using a composite electrode based on zirconium oxide nanoparticles. Display Omitted - Highlights: • A composite electrode was prepared using nanoparticles of ZrO_2 and MWCNTs. • The ZrO_2NPs/MWCNTs/GCE has greatly improved the voltammetry of terbutaline • The proposed electrode enabled a detection limit of 2.25 nM. • The proposed electrode exhibited good reproducibility and long

  18. Preparation of electrodes on cfrp composites with low contact resistance comprising laser-based surface pre-treatment

    KAUST Repository

    Almuhammadi, Khaled Hamdan

    2016-12-29

    Various examples are provided related to the preparation of electrodes on carbon fiber reinforced polymer (CFRP) composites with low contact resistance. Laser-based surface preparation can be used for bonding to CFRP composites. In one example, a method includes preparing a pretreated target area on a CFRP composite surface using laser pulsed irradiation and bonding an electrode to exposed fibers in the pretreated target area. The surface preparation can allow the electrode to have a low contact resistance with the CFRP composite.

  19. Preparation and characterization of nano hydroxyapatite/polymeric composites materials. Part I

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, Khaled R., E-mail: kh_rezk1966@yahoo.com [Biomaterials Dept., National Research Centre, Dokki, Cairo (Egypt); El-Rashidy, Zenab M. [Biomaterials Dept., National Research Centre, Dokki, Cairo (Egypt); Salama, Aida A. [Biophysics Dept., Faulty of Science, El-Azhar Univ., Cairo (Egypt)

    2011-10-17

    Highlights: {yields} The formation and coating of CHA increased by increasing polymer content. {yields} The size of the prepared CHA was within nano-range scale. {yields} The composites had homogeneity and CHA formed within the polymeric matrix. - Abstract: The present study is focused on preparation of nano composite materials and the effect of citric acid on their different properties. The formation of nano HA and its interaction with chitosan (C), gelatin (G) polymers and citric acid (CA) materials were studied. The Fourier Transformed Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), transmission electron microscope (TEM), and scanning electron microscope (SEM) were used to characterize these composite materials. The compressive strength (CS) was also measured to know the reinforcement of the prepared composites. The results show that carboxylic and amino groups play crucial role for HA formation on chitosan-gelatin polymeric matrix in the presence of citric acid (CA). The formation of nano HA particles and its average size of crystallite is increased with increase of CG content and decreased with addition of CA. Also, the HA formation and binding strength between its particles are improved into the composites especially with CA. The nano-composites containing the best ratio of nHA (70%) with CA (0.2 M) are promising for medical applications in the future.

  20. Wear Behavior of Aluminium Metal Matrix Composite Prepared from Industrial Waste

    Directory of Open Access Journals (Sweden)

    L. Francis Xavier

    2016-01-01

    Full Text Available With an increase in the population and industrialization, a lot of valuable natural resources are depleted to prepare and manufacture products. However industrialization on the other hand has waste disposal issues, causing dust and environmental pollution. In this work, Aluminium Metal Matrix Composite is prepared by reinforcing 10 wt% and 20 wt% of wet grinder stone dust particles an industrial waste obtained during processing of quarry rocks which are available in nature. In the composite materials design wear is a very important criterion requiring consideration which ensures the materials reliability in applications where they come in contact with the environment and other surfaces. Dry sliding wear test was carried out using pin-on-disc apparatus on the prepared composites. The results reveal that increasing the reinforcement content from 10 wt% to 20 wt% increases the resistance to wear rate.

  1. Gamma Radiation -Induced Preparation of Polymeric Composite Resins and their Structure Assignments

    International Nuclear Information System (INIS)

    El-Zahhar, A.A.; Abdel-Aziz, H.M.; Siyam, T.

    2005-01-01

    Poly(acrylamide-acrylic acid). ethylenediamine tetra acetic acid disodium salt P(AM-AA). EDTANa2, Poly(acrylamide-acrylic acid)montmorillonite P(AM-AA). montmorillonite, and Poly(acrylamide acrylic acid)-potassium nickel hexacyanoferrate P(AM-AA)-KNiHCF were prepared by gamma radiation- induced template polymerization of (AA) on P(AM) as a template polymer in the presence of EDTANa2, Clay(montmorillonite), KNiHCF and KZnHCF, respectively. The capacity of the prepared P (AM-AA)-EDTANa2 and P (AM-AA)-montmorillonite composites increases with increasing of EDTANa2 and montmorillonite concentration then decreases. While the capacity of P(AM- AA). KNiHCF composites increases with increasing of KNiHCF content. The characteristic properties of prepared polymeric composites resins were studied by using FTIR spectroscopy

  2. [Biomimetic nanohydroxyapatite/gelatin composite material preparation and in vitro study].

    Science.gov (United States)

    Li, Siriguleng; Hu, Xiaowen

    2014-09-01

    To prepare nHA/gelatin porous scaffold and to evaluate its physical and chemical properties and biocompatibility. We used nano-powders of HA and gelatin to prepare 3D porous composite scaffold by freeze-drying technique, and used scanning electron microscope, fourier transform infrared spectroscopy and universal testing machine to characterize the composite material. Osteoblasts were primarily cultured, and the third-passage osteoblasts were co-cultured with the composite material. The cell adhesion and morphology were examined under scanning electron microscope. The cell viability analysis was performed by MTT assay, and the alkaline phosphatase activity was measured with alkaline phosphatase kit. Scanning electron microscope showed that the scaffold possessed a 3-dimensional interconnected homogenous porous structure with pore sizes ranging from 150 to 400 μm. Fourier transform infrared spectroscopy showed that the composite material had a strong chemical bond between the inorganic phase and organic phase. The scaffold presented the compressive strength of (3.28 ± 0.51) MPa and porosities of (80.6 ± 4.1)%. Composite materials showed features of had good biocompatibility. Mouse osteoblasts were well adhered and spread on the materials. The grade of the cell toxicity ranged from I to II. On the 5th and 7th day the proliferative rate of osteoblasts on scaffolds in the composite materials was significantly higher than that in the control group. The activity of alkaline phosphatase was obviously higher than that in the control group on Day 1 and 3. Nano-hydroxyapatite and gelatin in certain proportions and under certain conditions can be prepared into a composite biomimetic porous scaffolds with high porosity and three-dimensional structure using freeze-drying method. The scaffold shows good biocompatibility with mouse osteoblasts and may be a novel scaffolds for bone tissue engineering.

  3. Systematic approach to preparing ceramic-glass composites with high translucency for dental restorations.

    Science.gov (United States)

    Yoshimura, Humberto N; Chimanski, Afonso; Cesar, Paulo F

    2015-10-01

    Ceramic composites are promising materials for dental restorations. However, it is difficult to prepare highly translucent composites due to the light scattering that occurs in multiphase ceramics. The objective of this work was to verify the effectiveness of a systematic approach in designing specific glass compositions with target properties in order to prepare glass infiltrated ceramic composites with high translucency. First it was necessary to calculate from literature data the viscosity of glass at the infiltration temperature using the SciGlass software. Then, a glass composition was designed for targeted viscosity and refractive index. The glass of the system SiO2-B2O3-Al2O3-La2O3-TiO2 prepared by melting the oxide raw materials was spontaneously infiltrated into porous alumina preforms at 1200°C. The optical properties were evaluated using a refractometer and a spectrophotometer. The absorption and scattering coefficients were calculated using the Kubelka-Munk model. The light transmittance of prepared composite was significantly higher than a commercial ceramic-glass composite, due to the matching of glass and preform refractive indexes which decreased the scattering, and also to the decrease in absorption coefficient. The proposed systematic approach was efficient for development of glass infiltrated ceramic composites with high translucency, which benefits include the better aesthetic performance of the final prosthesis. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  4. Preparation and Mechanical Properties of Aligned Discontinuous Carbon Fiber Composites

    OpenAIRE

    DENG Hua; GAO Junpeng; BAO Jianwen

    2018-01-01

    Aligned discontinuous carbon fiber composites were fabricated from aligned discontinuous carbon fiber prepreg, which was prepared from continuous carbon fiber prepreg via mechanical high-frequency cutting. The internal quality and mechanical properties were characterized and compared with continuous carbon fiber composites. The results show that the internal quality of the aligned discontinuous carbon fiber composites is fine and the mechanical properties have high retention rate after the fi...

  5. Preparation and mechanical properties of photo-crosslinked poly(trimethylene carbonate) and nano-hydroxyapatite composites

    NARCIS (Netherlands)

    Geven, Mike Alexander; Barbieri, D.; Yuan, Huipin; de Bruijn, Joost Dick; Grijpma, Dirk W.

    2015-01-01

    Composite materials of photo-crosslinked poly(trimethylene carbonate) and nanoscale hydroxyapatite were prepared and their mechanical characteristics for application as orbital floor implants were assessed. The composites were prepared by solvent casting poly(trimethylene carbonate) macromers with

  6. Hydrothermal Preparation of Apatite Composite with Magnetite or Anatase

    International Nuclear Information System (INIS)

    Murakami, Setsuaki; Ishida, Emile H.; Ioku, Koji

    2006-01-01

    Microstructure designed porous hydroxyapatite (Ca10(PO4)6(OH)2) composites with magnetite (Fe3O4) particles or anatase (TiO2) dispersion were prepared by hydrothermal treatment. These composites had micro-pores of about 0.1-0.5 μm in size. Magnetite / Hydroxyapatite composites should be suitable for medical treatment of cancer, especially in bones, because HA can bond to bones directly and magnetite can generate heat. They must be used for hyperthermia therapies of cancer in bones. Meanwhile, anatase / Hydroxyapatite composite should be suitable for environmental purification, because HA rod-shape particles expose the specific crystal face, which adsorbs organic contaminants and so on

  7. A novel approach in preparing polymer/nano-CaCO3 composites

    Institute of Scientific and Technical Information of China (English)

    Zhengying LIU; Runze YU; Mingbo YANG; Jianmin FENG; Wei YANG; Bo YIN

    2008-01-01

    An novel compounding process using nano-CaCO3 aqueous suspension for preparing polymer/ nano-CaCO3 composites with nanoparticles dispersed at the nanoscale is reported. The process is called the mild mixing method. In this method, the pre-dispersed nano-particle suspensions are blended with melting polymers in a weak shearing field using an extruder, followed by removing the water from the vent. The four typical poly-meric nanocomposites were prepared by mild mixing method. The dispersion of nano-CaCO3 in the matrix of the polymer at the nanoscale was confirmed by scanning electron microscopy (SEM). The molecular weights of polycarbonate (PC) and its nanocomposite showed that the degradation had not occurred during the mild mixing processing. The mechanical properties of the composite with 1.5 wt-% nano-CaCO3 improve slightly. It proved that this approach is suitable for the preparation of nano-composites based on both polar and non-polar polymers.

  8. Ion Association Methods for the Determination of Fexofenadine in Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    L. D. Srinivas

    2005-01-01

    Full Text Available Two simple and sensitive Visible spectrophotometric methods (A and B for the determination of Fexofenadine (FEX in bulk sample and pharmaceutical formulations are described. Methods A and B are based on the formation of ion-association complex involving carboxylic acid group of FEX and the basic dyes, Safranin-O (SFN-O, method A, methylene blue (MB, method B. The results obtained in the above two methods are reproducible and are statistically validated and found to be suitable for the assay of Fexofenadine in bulk and its pharmaceutical formulations.

  9. Preparation of new composite ceramics based on gadolinium-doped ceria and magnesia nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Jingying; Schelter, Matthias; Zosel, Jens; Oelssner, Wolfram [Kurt-Schwabe-Institut fuer Mess- und Sensortechnik e.V. Meinsberg, Waldheim (Germany); Mertig, Michael [Kurt-Schwabe-Institut fuer Mess- und Sensortechnik e.V. Meinsberg, Waldheim (Germany); Physikalische Chemie, Mess- und Sensortechnik, Technische Universitaet Dresden (Germany)

    2017-09-15

    To achieve solid electrolyte materials for electrochemical energy storage devices with very high oxygen ion conductivity, composites of gadolinium-doped ceria (GDC) and magnesia (MgO) are developed in this study. Three different preparation methods are used to prepare nanoparticles from these two components. According to the characterization results, the self-propagating high-temperature synthesis is best suited for the preparation of both nanometer-sized GDC powder as solid electrolyte and MgO powder as insulator. The structures of the prepared nanometer-sized powders have been characterized by X-ray diffraction and transmission electron microscopy. They show narrow size distributions in the lower nanometer range. Then, dense composite ceramics are prepared from a MgO-GDC mixture by sintering. The size of the crystallite domains in the sintered ceramic is in the upper nanometer range. TEM and TEM-EDX images of a new composite ceramic based on gadolinium-doped ceria and magnesia nanoparticles. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Preparation of new composite ceramics based on gadolinium-doped ceria and magnesia nanoparticles

    International Nuclear Information System (INIS)

    Yao, Jingying; Schelter, Matthias; Zosel, Jens; Oelssner, Wolfram; Mertig, Michael

    2017-01-01

    To achieve solid electrolyte materials for electrochemical energy storage devices with very high oxygen ion conductivity, composites of gadolinium-doped ceria (GDC) and magnesia (MgO) are developed in this study. Three different preparation methods are used to prepare nanoparticles from these two components. According to the characterization results, the self-propagating high-temperature synthesis is best suited for the preparation of both nanometer-sized GDC powder as solid electrolyte and MgO powder as insulator. The structures of the prepared nanometer-sized powders have been characterized by X-ray diffraction and transmission electron microscopy. They show narrow size distributions in the lower nanometer range. Then, dense composite ceramics are prepared from a MgO-GDC mixture by sintering. The size of the crystallite domains in the sintered ceramic is in the upper nanometer range. TEM and TEM-EDX images of a new composite ceramic based on gadolinium-doped ceria and magnesia nanoparticles. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Preparation and characterization of aluminium-silica metal matrix composite

    Science.gov (United States)

    Mallikarjuna, G. B.; Basavaraj, E.

    2018-04-01

    Aluminum alloys are widely used in aerospace and automobile industries due to their low density and good mechanical properties, better corrosion resistance and wear, low thermal coefficient of expansion as compared to conventional metals and alloys. The excellent properties of these materials and relatively low production cost make them a very attractive for a variety of applications. In this present work, Al alloy LM13-SiO2 composites were produced by stir casting method. The reinforcement SiO2 particle size used for preparation of composites are 106 µm, 150 µm, 250 µm and 355 µm with varying amount of 3 to 12 wt% in steps of 3. The prepared composite specimens were machined as per test standards. Effects of weight percentage of SiO2 particles on wear, tensile strength of Al alloy LM13-SiO2 composites have been investigated. The microstructures of the composites were studied to know the dispersion of the SiO2 particles in matrix. Experimental results shows that there is enhanced mechanical properties, when silica weighing 9% was added to the base aluminium alloy and also similar trend exists in all four different micron size of silica and also it has been observed that addition of SiO2 particles significantly improves wear resistance properties as compared with that of unreinforced matrix.

  12. Properties of natural rubber/attapulgite composites prepared by latex compounding method: Effect of filler loading

    International Nuclear Information System (INIS)

    Muttalib, Siti Nadzirah Abdul; Othman, Nadras; Ismail, Hanafi

    2015-01-01

    This paper reports on the effect of filler loading on properties of natural rubber (NR)/attapulgite (ATP) composites. The NR/ATP composites were prepared by latex compounding method. It is called as masterbatch. The masterbatch was subsequently added to the NR through melt mixing process. The vulcanized NR/ATP composites were subjected to mechanical, swelling and morphological tests. All the results were compared with NR/ATP composites prepared by conventional system. The composites from masterbatch method showed better results compared to composites prepared by conventional method. They have higher tensile properties, elongation at break and tear strength. The images captured through scanning electron microscopy test revealed the improvement of tensile strength in masterbatch NR/ATP composites. It can be seen clearly that masterbatch NR/ATP have better filler dispersion compared to conventional method NR/ATP composites

  13. Properties of natural rubber/attapulgite composites prepared by latex compounding method: Effect of filler loading

    Energy Technology Data Exchange (ETDEWEB)

    Muttalib, Siti Nadzirah Abdul, E-mail: sitinadzirah.amn@gmail.com; Othman, Nadras, E-mail: srnadras@usm.my; Ismail, Hanafi, E-mail: ihanafi@usm.my [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, Seri Ampangan, 14300 Nibong Tebal, Pulau Pinang (Malaysia)

    2015-07-22

    This paper reports on the effect of filler loading on properties of natural rubber (NR)/attapulgite (ATP) composites. The NR/ATP composites were prepared by latex compounding method. It is called as masterbatch. The masterbatch was subsequently added to the NR through melt mixing process. The vulcanized NR/ATP composites were subjected to mechanical, swelling and morphological tests. All the results were compared with NR/ATP composites prepared by conventional system. The composites from masterbatch method showed better results compared to composites prepared by conventional method. They have higher tensile properties, elongation at break and tear strength. The images captured through scanning electron microscopy test revealed the improvement of tensile strength in masterbatch NR/ATP composites. It can be seen clearly that masterbatch NR/ATP have better filler dispersion compared to conventional method NR/ATP composites.

  14. The role of herbometallic preparations in traditional medicine--a review on mica drug processing and pharmaceutical applications.

    Science.gov (United States)

    Wijenayake, Apsara; Pitawala, Amarasooriya; Bandara, Ratnayake; Abayasekara, Charmalie

    2014-09-11

    Biotite mica enriched with Fe(2+) ions are widely used as a major mineral ingredient in traditional pharmaceutical science of alchemy (Rasashastra). Abhrak bhasma (mica ash), a pharmaceutical product containing treated mica, is utilized, for example, in Ayurvedic treatments for ailments such as gastritis, renal disease, skin disease and mainly in rejuvenation formulations. However, the untreated mica minerals may be harmful when used directly, as they carry considerably high amounts of trace-elements that can cause undesirable effects in the human body. In order to remove toxic factors and produce readily absorbable materials having high nutrient capacity, specific thermal and chemical treatments (purification, detoxification, particle size reduction and incineration) are performed during the preparation of Rasashastra. This review evaluates the chemical and pharmacological aspects of mica ash as well as the technological aspects of mica ash production. The detailed literature review on the chemistry and scientific basis of mica ash, its preparation techniques, mica alterations and pharmaceutical applications was carried out by using published Ayurvedic text books and research articles, available from Science Direct, on mica minerals, mica ash and their physico-chemical alteration processes and pharmacological applications. During the purification and detoxification procedures, heating followed by quenching (in ionic medium) influences the structural distortion and the development of stress-induced cracks and spallations of the micaceous plates. Thus, the efficient diffusion of the external medium takes place at successive heating and quenching steps. Acidic organic liquids and animal byproducts can enhance the cation exchange capacity and solubility of mica. Further, these natural compounds facilitate the removal of toxic-elements in the structure. When treated-mica and paddy husks are tied up in a cloth and squeezed, particle size reduction and further

  15. Preparation of raspberry-like polypyrrole composites with applications in catalysis.

    Science.gov (United States)

    Yao, Tongjie; Wang, Chuanxi; Wu, Jie; Lin, Quan; Lv, Hui; Zhang, Kai; Yu, Kui; Yang, Bai

    2009-10-15

    Raspberry-like composites were prepared by coating the silver/polypyrrole core/shell composites onto the surface of silica spheres via oxidation polymerization of pyrrole monomer with [Ag(NH3)2]+ ions as oxidants. The whole process allowed the absence of stabilizers, which greatly improved the quality of the conducting polymer composites. The morphology of the resulting composites was investigated, which can be described as raspberry-like; also, the structure and composition of the composites were characterized in detail. A possible formation mechanism was proposed. The present synthetic strategy substantially extended the scope of metal/conducting polymer composite synthesis. The raspberry-like composites exhibited excellent catalytic properties in the reduction of methylene blue dye with the reducing agent of sodium borohydride.

  16. Preparation and temperature dependence of electrostriction properties for PMN-based composite ceramics

    International Nuclear Information System (INIS)

    Zhao Jingbo; Qu Shaobo; Du Hongliang; Zheng Yanju; Xu Zhuo

    2009-01-01

    Both low- and high-temperature units were prepared by columbite precursor method, and Pb(Mg 1/3 Nb 2/3 )O 3 (PMN)-based ferroelectric composite ceramics were prepared by conventional method, baking-block method and coating method, respectively. The effects of preparation methods on dielectric and electrostriction properties as well as the temperature-dependence property of the obtained composite ceramics were studied. The results show that compared with the samples prepared by traditional blend sintering method, of the samples prepared by baking-block and coating methods have much better dielectric and electrostriction properties. For those prepared by baking-block method, the electrostriction temperature-dependence properties are good in the range of 20-60 deg. C. For those prepared by coating method, the dielectric temperature-dependence properties are also good in the broad range of -30 to 70 deg. C, and the electrostriction temperature properties are better than those prepared by blending-block. Compared with the traditional blending sintering method, the dielectric and electrostriction temperature-dependence properties are much better, which effectively solves the problem of temperature properties existing in present engineering applications.

  17. Spectrophotometric and spectrofluorimetric methods for the determination of saxagliptin and vildagliptin in bulk and pharmaceutical preparations

    Directory of Open Access Journals (Sweden)

    Marwa S. Moneeb

    2013-12-01

    Full Text Available New simple and sensitive spectrophotometric and spectrofluorimetric methods have been developed and validated for the determination of saxagliptin (SAX and vildagliptin (VDG in bulk and pharmaceutical preparations. The spectrophotometric methods were based on derivatization of the investigated drugs with two reagents: 1,2-naphthoquinone-4-sulfonic acid sodium salt (NQS and 4-chloro-7-nitrobenzofurazan (NBD-Cl. For further increase in the sensitivity, the D1 spectra of the reactions products were also recorded. For NQS reaction, Beer’s law was obeyed over the ranges of 5–30 and 7–45 μg mL−1 for the absorbance readings; and 3–32 and 5–50 μg mL−1 for the derivative readings of SAX and VDG, respectively. For NBD-Cl reaction, Beer’s law was obeyed over the ranges of 3–20 and 4.5–35 μg mL−1 for the absorbance readings; and 1.5–25 and 2.5–40 μg mL−1 for the derivative readings of SAX and VDG, respectively. Spectrofluorimetric methods were developed based on the fact that the derivatized investigated drugs with NBD-Cl reagent are highly fluorescent products. The fluorescence concentration plots were linear over the ranges of 0.02–0.25 and 0.03–0.37 μg mL−1 for SAX and VDG, respectively. The fluorescence measurement enabled the detection of SAX and VDG at concentrations of about 3 and 7 ng mL−1, respectively. The proposed methods have been validated and successfully applied to the determination of the investigated drugs in their pharmaceutical preparations. The results obtained were statistically compared to those obtained from reference methods.

  18. Preparation and characterization of bioglass/polyvinyl alcohol composite hydrogel

    International Nuclear Information System (INIS)

    Xu Hong; Wang Yingjun; Zheng Yudong; Chen Xiaofeng; Ren Li; Wu Gang; Huang Xiaoshan

    2007-01-01

    In order to form firm active fixation with the adjacent bone, a new kind of bioactive composite hydrogel was prepared with polyvinyl alcohol (PVA) and bioglass (BG) through ultrasonic dispersion, heat-high-pressure and freeze/thawed technique. A digital speckle correlation method (DSCM) was utilized to characterize the mechanical properties of the series of BG/PVA composites. Results showed that at different load pressures, the composite hydrogel displayed different displacement and deformation in the V field. Results also showed that an increase of PVA percentage (15-30 wt%) or of bioglass percentage (2-10 wt%) in composite hydrogel could lead to an increase in the elastic compression modulus. Scanning electron microscope results indicated that bioglass was uniformly dispersed in the BG/PVA composite hydrogel. The BG/PVA composite hydrogel shows a promising prospect as a new bionic cartilage implantation material

  19. Structural and compositional gradients: basic idea, preparation, applications

    International Nuclear Information System (INIS)

    Ilschner, B.

    1993-01-01

    The term gradient materials refers to gradients of chemical composition and/or microstructural parameters which are intentionally introduced into components of any kind of homogeneous or heterogeneous materials, including metallic alloys, ceramics, glasses, polymers, and composites. After a short review of the development of the gradient materials technology since 1972, some fundamental aspects concerning the effects of such gradients on physical or mechanical properties are discussed. A selection of technical applications which have been discussed recently is presented. Finally, different methods for the preparation of gradients from gaseous, liquid or powder precursors are reviewed. (orig.)

  20. Innovative Fly Ash Geopolymer-Epoxy Composites: Preparation, Microstructure and Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Giuseppina Roviello

    2016-06-01

    Full Text Available The preparation and characterization of composite materials based on geopolymers obtained from fly ash and epoxy resins are reported for the first time. These materials have been prepared through a synthetic method based on the concurrent reticulation of the organic and inorganic components that allows the formation of hydrogen bonding between the phases, ensuring a very high compatibility between them. These new composites show significantly improved mechanical properties if compared to neat geopolymers with the same composition and comparable performances in respect to analogous geopolymer-based composites obtained starting from more expensive raw material such as metakaolin. The positive combination of an easy synthetic approach with the use of industrial by-products has allowed producing novel low cost aluminosilicate binders that, thanks to their thixotropicity and good adhesion against materials commonly used in building constructions, could be used within the field of sustainable building.

  1. Simple fluorimetric liquid chromatographic method for the analysis of undecylenic acid and zinc undecylenate in pharmaceutical preparations.

    Science.gov (United States)

    Lin, Ming-Chun; Wu, Hsin-Lung; Kou, Hwang-Shang; Wu, Shou-Mei

    2006-06-30

    A simple and selective liquid chromatographic method is described for the analysis of undecylenic acid (UA) and zinc undecylenate (ZnUA) in pharmaceutical preparations. The method is based on the derivatization of the analytes extracted from various samples with 2-(2-naphthoxy)ethyl 2-(piperidino)ethanesulfonate. The resulting derivative was analyzed by liquid chromatography with fluorimetric detection. The quantitation of the method is in the range of 3.0-50.0 microM UA with a detection limit of about 0.3 microM (S/N = 3 with 10 microl injection). We found that acetonitrile is a selective solvent for differentially dissolving UA from coexisted ZnUA in compound formulation. This results in the specific analysis of UA in the presence of ZnUA and simply analyzing the coexisted ZnUA by the value of total UA (UA+ZnUA) minus that of UA. Application of the method to the analysis of undecylenic acid and zinc undecylenate in ointment, powder and solution preparations proved feasible.

  2. Thermodynamics parameters of nano-Ni/PS composites prepared by in situ polymerization method

    International Nuclear Information System (INIS)

    Liao Qilong; Xiong Jie; Ning Haixia

    2011-01-01

    Spherical nickel nanoparticles with about 75∼200 nm in size were obtained by a liquid reduction method. The nickel nanoparticles/PS composites were synthesized via in situ polymerization method. XRD, FTIR, SEM and TG-DSC were respectively used to measure the properties of nickel nanoparticles, the microstructure of as-prepared composites samples, the distribution of nickel nanoparticles in PS and the thermodynamic parameters of as-prepared composites. The results show that the nickel nanoparticles will enhance the glass transition temperature of nano-Ni/PS composites. The enthalpy of composites is heightened by increasing of doping dose, and it reaches the top when the doping dose is from 1% to 2%. The specific heat of the composites will reduce with the doping dose of nickel nanoparticles increasing. (authors)

  3. Preparation and thermal energy storage properties of paraffin/calcined diatomite composites as form-stable phase change materials

    International Nuclear Information System (INIS)

    Sun, Zhiming; Zhang, Yuzhong; Zheng, Shuilin; Park, Yuri; Frost, Ray L.

    2013-01-01

    Highlights: ► Composite phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite. ► The optimum mixed proportion was obtained through differential scanning calorimetry. ► Thermal energy storage properties of the composite PCMs were determined by DSC. ► Thermal cycling test showed that the prepared PCMs are thermally reliable and chemically stable. - Abstract: A composite paraffin-based phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite through the fusion adsorption method. In this study, raw diatomite was purified by thermal treatment in order to improve the adsorption capacity of diatomite, which acted as a carrier material to prepare shape-stabilized PCMs. Two forms of paraffin (paraffin waxes and liquid paraffin) with different melting points were blended together by the fusion method, and the optimum mixed proportion with a suitable phase-transition temperature was obtained through differential scanning calorimetry (DSC) analysis. Then the prepared composite paraffin was adsorbed in calcined diatomite. The prepared paraffin/calcined diatomite composites were characterized by the scanning electron microscope (SEM) and Fourier transformation infrared (FT-IR) analysis techniques. Thermal energy storage properties of the composite PCMs were determined by DSC method. DSC results showed that there was an optimum adsorption ratio between composite paraffin and calcined diatomite and the phase-transition temperature and the latent heat of the composite PCMs were 33.04 °C and 89.54 J/g, respectively. Thermal cycling test of composite PCMs showed that the prepared material is thermally reliable and chemically stable. The obtained paraffin/calcined diatomite composites have proper latent heat and melting temperatures, and show practical significance and good potential application value

  4. Preparation and thermal energy storage properties of paraffin/calcined diatomite composites as form-stable phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Zhiming [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia); Zhang, Yuzhong [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Zheng, Shuilin, E-mail: shuilinzh@yahoo.com.cn [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Park, Yuri [Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia); Frost, Ray L., E-mail: r.frost@qut.edu.au [Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia)

    2013-04-20

    Highlights: ► Composite phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite. ► The optimum mixed proportion was obtained through differential scanning calorimetry. ► Thermal energy storage properties of the composite PCMs were determined by DSC. ► Thermal cycling test showed that the prepared PCMs are thermally reliable and chemically stable. - Abstract: A composite paraffin-based phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite through the fusion adsorption method. In this study, raw diatomite was purified by thermal treatment in order to improve the adsorption capacity of diatomite, which acted as a carrier material to prepare shape-stabilized PCMs. Two forms of paraffin (paraffin waxes and liquid paraffin) with different melting points were blended together by the fusion method, and the optimum mixed proportion with a suitable phase-transition temperature was obtained through differential scanning calorimetry (DSC) analysis. Then the prepared composite paraffin was adsorbed in calcined diatomite. The prepared paraffin/calcined diatomite composites were characterized by the scanning electron microscope (SEM) and Fourier transformation infrared (FT-IR) analysis techniques. Thermal energy storage properties of the composite PCMs were determined by DSC method. DSC results showed that there was an optimum adsorption ratio between composite paraffin and calcined diatomite and the phase-transition temperature and the latent heat of the composite PCMs were 33.04 °C and 89.54 J/g, respectively. Thermal cycling test of composite PCMs showed that the prepared material is thermally reliable and chemically stable. The obtained paraffin/calcined diatomite composites have proper latent heat and melting temperatures, and show practical significance and good potential application value.

  5. Review on Physicochemical, Chemical, and Biological Processes for Pharmaceutical Wastewater

    Science.gov (United States)

    Li, Zhenchen; Yang, Ping

    2018-02-01

    Due to the needs of human life and health, pharmaceutical industry has made great progress in recent years, but it has also brought about severe environmental problems. The presence of pharmaceuticals in natural waters which might pose potential harm to the ecosystems and humans raised increasing concern worldwide. Pharmaceuticals cannot be effectively removed by conventional wastewater treatment plants (WWTPs) owing to the complex composition, high concentration of organic contaminants, high salinity and biological toxicity of pharmaceutical wastewater. Therefore, the development of efficient methods is needed to improve the removal effect of pharmaceuticals. This review provides an overview on three types of treatment technologies including physicochemical, chemical and biological processes and their advantages and disadvantages respectively. In addition, the future perspectives of pharmaceutical wastewater treatment are given.

  6. Chapter 5. Essential equipment, pharmaceuticals and supplies. Recommendations and standard operating procedures for intensive care unit and hospital preparations for an influenza epidemic or mass disaster

    NARCIS (Netherlands)

    Sprung, Charles L.; Kesecioglu, Jozef; Christian, Michael D.; Camargo, Ruben; Ceraso, Daniel; Azoulay, Elie; Duguet, Alexandre; Guery, Benoit; Reinhart, Konrad; Adini, Bruria; Barlavie, Yaron; Benin-Goren, Odeda; Cohen, Robert; Klein, Motti; Leoniv, Yuval; Margalit, Gila; Rubinovitch, Bina; Sonnenblick, Moshe; Steinberg, Avraham; Weissman, Charles; Wolff, Donna; de Jong, Menno; Moreno, Rui; An, Youzhong; Du, Bin; Joynt, Gavin M.; Colvin, John; Loo, Shi; Richards, Guy; Artigas, Antonio; Pugin, Jerome; Amundson, Dennis; Devereaux, Asha; Beigel, John; Danis, Marion; Farmer, Chris; Hick, John L.; Maki, Dennis; Masur, Henry; Rubinson, Lewis; Sandrock, Christian; Talmor, Daniel; Truog, Robert; Zimmerman, Janice; Brett, Steve; Montgomery, Hugh; Rhodes, Andrew; Sanderson, Frances; Taylor, Bruce

    2010-01-01

    To provide recommendations and standard operating procedures for intensive care unit and hospital preparations for an influenza pandemic or mass disaster with a specific focus on essential equipment, pharmaceuticals and supplies. Based on a literature review and expert opinion, a Delphi process was

  7. A fast ultra high pressure liquid chromatographic method for qualification and quantification of pharmaceutical combination preparations containing paracetamol, acetyl salicylic acid and/or antihistaminics.

    Science.gov (United States)

    Deconinck, E; Sacré, P Y; Baudewyns, S; Courselle, P; De Beer, J

    2011-09-10

    A fully validated UHPLC method for the identification and quantification of pharmaceutical preparations, containing paracetamol and/or acetyl salicylic acid, combined with anti-histaminics (phenylephrine, pheniramine maleate, diphenhydramine, promethazine) and/or other additives as quinine sulphate, caffeine or codeine phosphate, was developed. The proposed method uses a Waters Acquity BEH C18 column (2 mm × 100 mm, 1.7 μm) with a gradient using an ammonium acetate buffer pH 4.0 as aqueous phase and methanol as organic modifier. The obtained method was fully validated based on its measurement uncertainty (accuracy profile) and robustness tests. Calibration lines for all components were linear within the studied ranges. The relative bias and the relative standard deviations for all components were respectively smaller than 1.5% and 2%, the β-expectation tolerance limits did not exceed the acceptance limits of 10% and the relative expanded uncertainties were smaller than 5% for all of the considered components. A UHPLC method was obtained for the identification and quantification of these kind of pharmaceutical preparations, which will significantly reduce analysis times and workload for the laboratories charged with the quality control of these preparations. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Preparation technology of 103Pd-110Agm composite alloy membranes

    International Nuclear Information System (INIS)

    Liu Zhuo; Chen Daming; Jin Xiaohai; Li Zhongyong; Guo Feihu; Qin Hongbin

    2012-01-01

    The preparation of 103 Pd- 110 Ag m alloy membranes was the basis for the production of 103 Pd- 125 I composite sources. Taking 103 Pd and 110 Ag m as trace elements, the method of non-electrolytical plating was chosen to prepare the alloy membrane. A γ-detector and electron microscope (SEM) were used for quantitative and qualitative analysis, respectively. The pre-treatment of the support before the preparation of Palladium-silver composite membranes was discussed in detail. It was found that when the concentration of PdCl 2 was between 0.5 and 2.0 mmol/L the result was good. The effects of various factors were investigated, including the proportion of Pd and Ag, the concentrations of the total metal, ammonium hydroxide hydrazine and ethylenediaminetetraacetic acid, temperature, the time, and the rotation speed. By improving the reaction conditions the alloy membrane with metallic luster was obtained. Besides, the presence of Pd and Ag was observed in the alloy membranes by qualitative analysis. (authors)

  9. Preparation, characterization and optical properties of Lanthanum-(nanometer MCM-41) composite materials

    International Nuclear Information System (INIS)

    Zhai, Q. Z.; Wang, P.

    2008-01-01

    Nanometer MCM-41 molecular sieve was prepared under a base condition by using cetyltrimethylammonium bromide as template and tetraethyl orthosilicate as silica source by means of hydrothermal method. Lanthanum(III) was incorporated into the nanometer MCM-41 by a liquid phase grafting method. The prepared nano composite materials were characterized by means of powder X-ray diffraction, spectrophotometric analysis, Fourier transform infrared spectroscopy, low temperature nitrogen adsorption-desorption technique, solid diffuse reflectance absorption spectra and luminescence. The powder X-ray diffraction studies show that the nanometer MCM-41 molecular sieve is successfully prepared. The highly ordered meso porous two-dimensional hexagonal channel structure and framework of the support MCM-41 is retained intact in the prepared composite material La-(nanometer MCM-41). The spectrophotometric analysis indicates that lanthanum exists in the prepared nano composite materials. The Fourier transform infrared spectra indicate that the framework of the MCM-41 molecular sieve still remains in the prepared nano composite materials and some framework vibration peaks show blue shifts relative to those of the MCM-41 molecular sieve. The low temperature nitrogen adsorption-desorption indicates that the guest locales in the channel of the molecular sieve. Compared with bulk lanthanum oxide, the guest in the channel of the molecular sieve has smaller particle size and shows a significant blue shift of optical absorption band in solid diffuse reflectance absorption spectra. The observed blue shift in the solid state diffuse reflectance absorption spectra of the lanthanum-(nanometer MCM-41) sample show the obvious stereoscopic confinement effect of the channel of the host on the guest, which further indicates the successful encapsulation of the guest in the host. The La-(nanometer MCM-41) sample shows luminescence

  10. Preparation and characterization of aluminum based alloy - mica composites

    International Nuclear Information System (INIS)

    Rashid, M.A.; Shamim, A.

    1999-01-01

    In this work, six pallets each of 2.0 cm dia and 0.5 cm thickness were prepared by powder metallurgy; half of them also contained 1% mica-powder to form a composite. Inclusion of mica resulted in a decreased density and an increased porosity of the sample. Brinell hardness was found to be 21% less for the composite than for the pure alloy. Micro-graphs of different areas of the sample show uniform distribution of mica particles and avoids around them. (author)

  11. Strong composite films with layered structures prepared by casting silk fibroin-graphene oxide hydrogels

    Science.gov (United States)

    Huang, Liang; Li, Chun; Yuan, Wenjing; Shi, Gaoquan

    2013-04-01

    Composite films of graphene oxide (GO) sheets and silk fibroin (SF) with layered structures have been prepared by facile solution casting of SF-GO hydrogels. The as-prepared composite film containing 15% (by weight, wt%) of SF shows a high tensile strength of 221 +/- 16 MPa and a failure strain of 1.8 +/- 0.4%, which partially surpass those of natural nacre. Particularly, this composite film also has a high modulus of 17.2 +/- 1.9 GPa. The high mechanical properties of this composite film can be attributed to its high content of GO (85 wt%), compact layered structure and the strong hydrogen bonding interaction between SF chains and GO sheets.Composite films of graphene oxide (GO) sheets and silk fibroin (SF) with layered structures have been prepared by facile solution casting of SF-GO hydrogels. The as-prepared composite film containing 15% (by weight, wt%) of SF shows a high tensile strength of 221 +/- 16 MPa and a failure strain of 1.8 +/- 0.4%, which partially surpass those of natural nacre. Particularly, this composite film also has a high modulus of 17.2 +/- 1.9 GPa. The high mechanical properties of this composite film can be attributed to its high content of GO (85 wt%), compact layered structure and the strong hydrogen bonding interaction between SF chains and GO sheets. Electronic supplementary information (ESI) available: XPS spectrum of the SF-GO hybrid film, SEM images of lyophilized GO dispersion and the failure surface of GO film. See DOI: 10.1039/c3nr00196b

  12. Preparation of zeolite-A/chitosan hybrid composites and their bioactivities and antimicrobial activities

    International Nuclear Information System (INIS)

    Yu, Liang; Gong, Jie; Zeng, Changfeng; Zhang, Lixiong

    2013-01-01

    Zeolite-A/chitosan hybrid composites with zeolite contents of 20–55 wt.% were prepared by in situ transformation of silica/chitosan mixtures in a sodium aluminate alkaline solution through impregnation–gelation–hydrothermal synthesis. The products were characterized by X-ray diffraction, diffuse reflectance infrared Fourier transform spectroscopy, scanning electron microscopy, thermogravimetric analysis, and mercury penetration porosimetry. Their in vitro bioactivities were examined using as-synthesized and Ca 2+ -exchanged hybrid composites in simulated body fluid (SBF) for hydroxyapatite (HAP) growth. Their antimicrobial activities for Escherichia coli (E. coli) in trypticase soy broth (TSB) were evaluated using Ag + -exchanged hybrid composites. The zeolite-A/chitosan hybrid composites could be prepared as various shapes, including cylinders, plates and thin films. They possessed macropores with pore sizes ranging from 100 to 300 μm and showed compressive mechanical strength as high as 3.2 MPa when the zeolite content was 35 wt.%. Fast growth on the Ca 2+ -exchanged hybrid composites was observed with the highest weight gain of 51.4% in 30 days. The 35 wt.% Ag + -exchanged hybrid composite showed the highest antimicrobial activity, which could reduce the 9 × 10 6 CFU mL −1 E. coli concentration to zero within 4 h of incubation time with the Ag + -exchanged hybrid composite amount of 0.4 g L −1 . The bioactivity and antimicrobial activity could be combined by ion-exchanging the composites first with Ca 2+ and then with Ag + . These zeolite-A/chitosan hybrid composites have potential applications on tissue engineering and antimicrobial food packaging. - Graphical abstract: Zeolite A/chitosan hybrid composites were prepared by in situ transformation of precursors in the chitosan matrix, which possess macroporous structures and exhibit superior bioactivity and antimicrobial activity and potential biomedical application. Highlights: • Zeolite A

  13. Preparation of zeolite-A/chitosan hybrid composites and their bioactivities and antimicrobial activities

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Liang; Gong, Jie [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009 (China); Zeng, Changfeng [College of Mechanic and Power Engineering, Nanjing University of Technology, Nanjing 210009 (China); Zhang, Lixiong, E-mail: lixiongzhang@yahoo.com [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009 (China)

    2013-10-15

    Zeolite-A/chitosan hybrid composites with zeolite contents of 20–55 wt.% were prepared by in situ transformation of silica/chitosan mixtures in a sodium aluminate alkaline solution through impregnation–gelation–hydrothermal synthesis. The products were characterized by X-ray diffraction, diffuse reflectance infrared Fourier transform spectroscopy, scanning electron microscopy, thermogravimetric analysis, and mercury penetration porosimetry. Their in vitro bioactivities were examined using as-synthesized and Ca{sup 2+}-exchanged hybrid composites in simulated body fluid (SBF) for hydroxyapatite (HAP) growth. Their antimicrobial activities for Escherichia coli (E. coli) in trypticase soy broth (TSB) were evaluated using Ag{sup +}-exchanged hybrid composites. The zeolite-A/chitosan hybrid composites could be prepared as various shapes, including cylinders, plates and thin films. They possessed macropores with pore sizes ranging from 100 to 300 μm and showed compressive mechanical strength as high as 3.2 MPa when the zeolite content was 35 wt.%. Fast growth on the Ca{sup 2+}-exchanged hybrid composites was observed with the highest weight gain of 51.4% in 30 days. The 35 wt.% Ag{sup +}-exchanged hybrid composite showed the highest antimicrobial activity, which could reduce the 9 × 10{sup 6} CFU mL{sup −1}E. coli concentration to zero within 4 h of incubation time with the Ag{sup +}-exchanged hybrid composite amount of 0.4 g L{sup −1}. The bioactivity and antimicrobial activity could be combined by ion-exchanging the composites first with Ca{sup 2+} and then with Ag{sup +}. These zeolite-A/chitosan hybrid composites have potential applications on tissue engineering and antimicrobial food packaging. - Graphical abstract: Zeolite A/chitosan hybrid composites were prepared by in situ transformation of precursors in the chitosan matrix, which possess macroporous structures and exhibit superior bioactivity and antimicrobial activity and potential biomedical

  14. Preparation of gelatin-assisted polypyrrole-poly(3,4-ethylenedioxythiophene) composites

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Eun Jin; Male, Umashankar; Huh, Do Sung [Dept.of Chemistry and Nanosystem Engineering, Center for Nano Manufacturing, Inje University, Kimhae (Korea, Republic of)

    2016-11-15

    Conductive polymer composite was synthesized by the polymerization of pyrrole with 3,4-ethylenedioxythiophene using ammonium persulfate as an oxidant with different concentrations of gelatin dispersed in aqueous medium along with the polymerization. Differently from pure polypyrrole–poly(3,4-ethylenedioxythiophene) (PPy–PEDOT) copolymer, the gelatin-assisted composites showed good solubility in aqueous media. The prepared PPy–PEDOT/gelatin composites were identified with Fourier-transform infrared, UV–visible spectroscopy, and X-ray diffraction. Morphological analysis and temperature-dependent direct current conductivity of PPy–PEDOT/gelatin composites were carried out. Obtained results revealed that added gelatin greatly increased conductivity due to the improved mobility of charge carriers.

  15. Study on Preparation and Property of Poly-Aminosilicone-Rare Earth Composite

    Institute of Scientific and Technical Information of China (English)

    Zhang Ming(张明); Qiu Guanming(邱关明); Chen Haiyan(陈海燕); Zhou Lanxiang(周兰香); Inoue Shinich; Okamoto Hiroshi

    2003-01-01

    The poly-aminosilicone-rare earth composite was prepared by poly-aminosilicone cross-linked with rare earth and active silanol. The thermal stability of the composites was studied by thermogravimetric analysis (TG). Force condition of the composites in electric field was analyzed and relative polarizability was derived. It is found that the composites containing different rare earth ions have different relative polarizability. The experiment results reveal that organosilicon materials with different electrical performance can be obtained by this way. Meanwhile, the absorption and flourescene spectrum of composites were also investigated. Compared to rare earth chloride, the spectrum properties of the composite are changed obviously. The possible reasons for these phenomena were discussed.

  16. Preparation of novel functional Mg/O/PCL/ZnO composite biomaterials and their corrosion resistance

    International Nuclear Information System (INIS)

    Xi, Zhongxian; Tan, Cui; Xu, Lan; Yang, Na; Li, Qing

    2015-01-01

    Highlights: • Novel functional Mg/O/PCL/ZnO composite biomaterials were prepared. • The biomaterials were prepared by anodization treatment and dip-coating technique. • The composite biomaterials were smooth and with low porosity. • The prepared biomaterials have good corrosion resistance in SBF. • The composite biomaterials can release zinc ion to promote bone formation. - Abstract: In this study, novel and functional Mg/O/PCL/ZnO (magnesium/anodic film/poly(ε-caprolactone)/zinc oxide) composite biomaterials for enhancing the bioactivity and biocompatibility of the implant was prepared by using anodization treatment and dip-coating technique. The surface morphology, microstructure, adhesion strength and corrosion resistance of the composite biomaterials were investigated using scanning electron microscopy (SEM), adhesion measurements, electrochemical tests and immersion tests respectively. In addition, the biocompatible properties of Mg (magnesium), Mg/PCL (magnesium/poly(ε-caprolactone)) and Mg/O/PCL (magnesium/anodic film/poly(ε-caprolactone)) samples were also investigated. The results show that the Mg/O/PCL/ZnO composite biomaterials were with low porosity and with the ZnO powders dispersed in PCL uniformly. The adhesion tests suggested that Mg/O/PCL/ZnO composite biomaterials had better adhesion strength than that of Mg/PCL composite biomaterials obviously. Besides, an in vitro test for corrosion demonstrated that the Mg/O/PCL/ZnO composite biomaterials had good corrosion resistance and zinc ion was released obviously in SBF

  17. Effect of preparation conditions on the characteristics and photocatalytic activity of TiO2/purified diatomite composite photocatalysts

    International Nuclear Information System (INIS)

    Sun, Zhiming; Hu, Zhibo; Yan, Yang; Zheng, Shuilin

    2014-01-01

    Highlights: • TiO 2 /purified diatomite composites were synthesized under different conditions. • The optimum preparation conditions of composites were obtained. • The obtained photocatalyst showed good photocatalytic activity. • The dispersity and grain size of loaded TiO 2 NPs are the critical factors. - Abstract: TiO 2 /purified diatomite composite materials were prepared through a modified hydrolysis-deposition method under low temperature using titanium tetrachloride as precursor combined with a calcination crystallization process. The microstructure and crystalline phases of the obtained composites prepared under different preparation conditions were characterized by high resolution scanning electron microscope (SEM) and X-ray diffraction (XRD), respectively. The photocatalytic performance of TiO 2 /purified diatomite composites was evaluated by Rhodamine B as the target pollutant under UV irradiation, and the optimum preparation conditions of composites were obtained. The TiO 2 crystal form in composites prepared under optimum conditions was anatase, the grain size of which was 34.12 nm. The relationships between structure and property of composite materials were analyzed and discussed. It is indicated that the TiO 2 nanoparticles uniformly dispersed on the surface of diatoms, and the photocatalytic performance of the composite materials was mainly determined by the dispersity and grain size of loaded TiO 2 nanoparticles

  18. Preparation and Characterization of Chitosan—Agarose Composite Films

    Directory of Open Access Journals (Sweden)

    Zhang Hu

    2016-09-01

    Full Text Available Nowadays, there is a growing interest to develop biodegradable functional composite materials for food packaging and biomedicine applications from renewable sources. Some composite films were prepared by the casting method using chitosan (CS and agarose (AG in different mass ratios. The composite films were analyzed for physical-chemical-mechanical properties including tensile strength (TS, elongation-at-break (EB, water vapor transmission rate (WVTR, swelling ratio, Fourier-transform infrared spectroscopy, and morphology observations. The antibacterial properties of the composite films were also evaluated. The obtained results reveal that an addition of AG in varied proportions to a CS solution leads to an enhancement of the composite film’s tensile strength, elongation-at-break, and water vapor transmission rate. The composite film with an agarose mass concentration of 60% was of the highest water uptake capacity. These improvements can be explained by the chemical structures of the new composite films, which contain hydrogen bonding interactions between the chitosan and agarose as shown by Fourier-transform infrared spectroscopy (FTIR analysis and the micro-pore structures as observed with optical microscopes and scanning electron microscopy (SEM. The antibacterial results demonstrated that the films with agarose mass concentrations ranging from 0% to 60% possessed antibacterial properties. These results indicate that these composite films, especially the composite film with an agarose mass concentration of 60%, exhibit excellent potential to be used in food packaging and biomedical materials.

  19. High performance liquid chromatographic determination of vanadium in crude oils and cobalt and iron in pharmaceutical preparations

    International Nuclear Information System (INIS)

    Khuhawar, M.Y.; Lanjwani, S.N.; Khaskhely, G.Q.

    1993-01-01

    High performance liquid Chromatographic (HPLC) method has ben developed for the determination of vanadium in crude oils, based on acid decomposition of oils, followed by complexation with bis (salicylaldehyde) tetramethyl ethylenediamine (H2SA2Ten). The complex is extracted in organic phase and is separated from copper and nickel using normal phase HPLC column. Detection is achieved using spectrophtmetric detector. The vanadium in oil is obtained at sub microgram/g level. Similarly cobalt(II), cobalt(III) and iron(II) are separated on reversed phase HPLC column. Pre column derivatization is used to develop HPLC method for the determination of cobalt and iron in pharmaceutical preparations. Finally results are compared using atomic absorption spectrometer. (author)

  20. Effect of preparation conditions on the characteristics and photocatalytic activity of TiO2/purified diatomite composite photocatalysts

    Science.gov (United States)

    Sun, Zhiming; Hu, Zhibo; Yan, Yang; Zheng, Shuilin

    2014-09-01

    TiO2/purified diatomite composite materials were prepared through a modified hydrolysis-deposition method under low temperature using titanium tetrachloride as precursor combined with a calcination crystallization process. The microstructure and crystalline phases of the obtained composites prepared under different preparation conditions were characterized by high resolution scanning electron microscope (SEM) and X-ray diffraction (XRD), respectively. The photocatalytic performance of TiO2/purified diatomite composites was evaluated by Rhodamine B as the target pollutant under UV irradiation, and the optimum preparation conditions of composites were obtained. The TiO2 crystal form in composites prepared under optimum conditions was anatase, the grain size of which was 34.12 nm. The relationships between structure and property of composite materials were analyzed and discussed. It is indicated that the TiO2 nanoparticles uniformly dispersed on the surface of diatoms, and the photocatalytic performance of the composite materials was mainly determined by the dispersity and grain size of loaded TiO2 nanoparticles.

  1. Validated stability-indicating spectrofluorimetric methods for the determination of ebastine in pharmaceutical preparations

    Directory of Open Access Journals (Sweden)

    Eid Manal

    2011-03-01

    Full Text Available Abstract Two sensitive, selective, economic, and validated spectrofluorimetric methods were developed for the determination of ebastine (EBS in pharmaceutical preparations depending on reaction with its tertiary amino group. Method I involves condensation of the drug with mixed anhydrides (citric and acetic anhydrides producing a product with intense fluorescence, which was measured at 496 nm after excitation at 388 nm. Method (IIA describes quantitative fluorescence quenching of eosin upon addition of the studied drug where the decrease in the fluorescence intensity was directly proportional to the concentration of ebastine; the fluorescence quenching was measured at 553 nm after excitation at 457 nm. This method was extended to (Method IIB to apply first and second derivative synchronous spectrofluorimetric method (FDSFS & SDSFS for the simultaneous analysis of EBS in presence of its alkaline, acidic, and UV degradation products. The proposed methods were successfully applied for the determination of the studied compound in its dosage forms. The results obtained were in good agreement with those obtained by a comparison method. Both methods were utilized to investigate the kinetics of the degradation of the drug.

  2. Thinking Outside the 'Block': Alternative Polymer Compositions for Micellar Drug Delivery.

    Science.gov (United States)

    Jones, Marie-Christine

    2015-01-01

    With a number of formulations currently in clinical trials, the interest in polymer micelles as drug carriers in unlikely to subside. Historically, linear diblock copolymers have been used as the building blocks for micelle preparation. Yet, recent advances in polymer chemistry have meant that a wider variety of polymer architectures and compositions have become available and been trialed for pharmaceutical applications. This mini-review aims to provide an overview of recent, exciting developments in triblock, graft and hyperbranched polymer chemistries that may change the way polymeric micelles drug formulations are prepared.

  3. Preparation of Sandy Soil Stabilizer for Roads Based on Radiation Modified Polymer Composite

    International Nuclear Information System (INIS)

    Elnahas, H.H.

    2016-01-01

    Radiation modified polymer composite (RMPC) was studied to build an extremely durable sandy road, construct a trail or bath, or control dust and erosion. A dilute solution of composite binds sandy soil fines through a coagulation bonding process. The result is a dense soil structure that has superior resistance to cracks and water penetration and can also solve erosion control problems. In erosion control applications, diluted composite is merely sprayed into sandy soil without compaction, effectively sealing the surface to prevent air-born dust or deterioration from erosion. The prepared composite has an elastic and melt-able film formation that imparts thermal compacting to the stabilized sandy soil after full dryness for sandy road leveling, repairing and restoration processes. The prepared composite is environmentally economical when compared with traditional sandy soil stabilizing (SSS) or sealing methods.

  4. Preparation and thermal energy storage properties of paraffin/expanded graphite composite phase change material

    International Nuclear Information System (INIS)

    Zhang, Zhengguo; Zhang, Ni; Peng, Jing; Fang, Xiaoming; Gao, Xuenong; Fang, Yutang

    2012-01-01

    Highlights: ► EG was obtained by microwave irradiation to prepare the paraffin/EG composite PCM. ► Composite PCM was characterized by XRD to investigate the chemical compatibility. ► Temperature profiles of the composite PCM were obtained during thermal energy storage. -- Abstract: The paraffin/expanded graphite (EG) composite phase change material (PCM) was prepared by absorbing liquid paraffin into EG, in which paraffin was chosen as the PCM. EG was produced by microwave irradiation performed at room temperature. It was found that the EG prepared at 800 W irradiation power for 10 s exhibited the maximum sorption capacity of 92 wt% for paraffin. Scanning electron microscopy images showed that paraffin was uniformly dispersed in the pores of EG. Differential scanning calorimeter analysis indicated that the melting temperature of the composite PCM was close to that of paraffin, and its latent heat was equivalent to the calculated value based on the mass fraction of paraffin in the composite. X-ray diffraction analysis showed that the composite PCM was just a combination of paraffin with EG, and no new substance was produced. Thermal energy storage performance of the composite PCM was tested in a latent thermal energy storage (LTES) system. Transients of axial and radial temperature profiles were obtained in the LTES for the composite PCM and paraffin. The thermal energy storage charging duration for the composite PCM was reduced obviously compared to paraffin.

  5. Preparation of the Jaws Damaged Parts from Composite Biopolymers Materials

    Directory of Open Access Journals (Sweden)

    Riyam A. Al-husseini

    2017-10-01

    Full Text Available Composite materials composing of fusing two materials or more are disaccorded in mechanical and physical characteristics, The studied the effect of changing in the reinforcement percentage by Hydroxyapatite Prepared nano world via the size of the nanoscale powder manufacturing manner chemical precipitation and microwave powders were two types their preparations have been from natural sources: the first type of eggshells and the other from the bones of fish in mechanical Properties which include the tensile strength, elastic modulus, elongation, hardness and tear for composite material consisting of Silicone rubber (SIR reinforced by (µ-n-HA, after strengthening silicone rubber Protect proportions (5,10,15,20 wt% of Article achieved results that increase the additive lead to increased hardness while tougher and modulus of elasticity decreases with added as shown in the diagrams.

  6. Preparation and Properties of Nano-Hydroxyapatite/Gelatin/Poly(vinyl alcohol) Composite Membrane.

    Science.gov (United States)

    Liao, Haotian; Shi, Kun; Peng, Jinrong; Qu, Ying; Liao, Jinfeng; Qian, Zhiyong

    2015-06-01

    In this study, the bone-like composite membrane based on blends of gelatin (Gel), nano-hydroxyapatite (n-HA) and poly(vinyl alcohol) (PVA) was fabricated by solvent casting and evaporation methods. The effect of n-HA content and the ratio of Gel/PVA on the properties of the composite was investigated. The Gel/PVA and n-HA/Gel/PVA composite membranes were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), water contact angle measurement and scanning electron microscopy (SEM). The mechanical properties of the composites were determined by tensile tests. The as prepared composite membranes exhibited hydrophobility, the water contact angle of composite membrane was 126.6 when its mass ratio of n-HA/Gel/PVA was 10/50/40. The tensile strength of composite membranes was greatly increased due to the introduction of n-HA, and the tensile strength was increased to 74.92 MPa when the mass ratio of n-HA/Gel/PVA was 10/50/40. SEM observation indicated that n-HA was dispersed in the membranes and a sea-island structure was formed in the n-HA/Gel/PVA composite membranes, resulting in a significant increase in tensile strength. The as-prepared n-HA/Gel/PVA composite membranes may be applied in the field of bone tissue engineering.

  7. Graphene-reinforced aluminum matrix composites prepared by spark plasma sintering

    Institute of Scientific and Technical Information of China (English)

    Wen-ming Tian; Song-mei Li; Bo Wang; Xin Chen; Jian-hua Liu; Mei Yu

    2016-01-01

    Graphene-reinforced 7055 aluminum alloy composites with different contents of graphene were prepared by spark plasma sinter-ing (SPS). The structure and mechanical properties of the composites were investigated. Testing results show that the hardness, compressive strength, and yield strength of the composites are improved with the addition of 1wt% graphene. A clean, strong interface is formed between the metal matrix and graphene via metallurgical bonding on atomic scale. Harmful aluminum carbide (Al4C3) is not formed during SPS processing. Further addition of graphene (above 1wt%) results in the deterioration in mechanical properties of the composites. The agglomeration of graphene plates is exacerbated with increasing graphene content, which is the main reason for this deterioration.

  8. Preparation of electrodes on cfrp composites with low contact resistance comprising laser-based surface pre-treatment

    KAUST Repository

    Almuhammadi, Khaled Hamdan; Lubineau, Gilles; Alfano, Marco Francesco; Buttner, Ulrich

    2016-01-01

    Various examples are provided related to the preparation of electrodes on carbon fiber reinforced polymer (CFRP) composites with low contact resistance. Laser-based surface preparation can be used for bonding to CFRP composites. In one example, a

  9. A novel approach for analyzing glass-transition temperature vs. composition patterns: application to pharmaceutical compound+polymer systems.

    Science.gov (United States)

    Kalogeras, Ioannis M

    2011-04-18

    In medicine, polymer-based materials are commonly used as excipients of poorly water-soluble drugs. The success of the encapsulation, as well as the physicochemical stability of the products, is often reflected on their glass transition temperature (T(g)) vs. composition (w) dependencies. The shape of the T(g)(w) patterns is critically influenced by polymer's molecular mass, drug molecule's shape and molecular volume, the type and degree of shielding of hydrogen-bonding capable functional groups, as well as aspects of the preparation process. By altering mixture's T(g) the amorphous solid form of the active ingredient may be retained at ambient or body temperatures, with concomitant improvements in handling, solubility, dissolution rate and oral bioavailability. Given the importance of the problem, the glass transitions observed in pharmaceutical mixtures have been extensively analyzed, aiming to appraise the state of mixing and intermolecular interactions. Here, accumulated experimental information on related systems is re-evaluated and comparably discussed under the light of a more effective and system-inclusive T(g)(w) equation. The present analysis indicates that free volume modifications and conformational changes of the macromolecular chains dominate, over enthalpic effects of mixing, in determining thermal characteristics and crystallization inhibition/retardation. Moreover, hydrogen-bonding and ion-dipole heterocontacts--although favorable of a higher degree of mixing--appear less significant compared to the steric hindrances and the antiplasticization proffered by the higher viscosity component. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. ANALYSIS OF THE PERSONNEL POTENTIAL EFFICIENCY OF THE PHARMACEUTICAL INSTITUTION

    Directory of Open Access Journals (Sweden)

    Марина Юрьевна Клищенко

    2017-03-01

    The study revealed common patterns of the personnel potential efficiency of the pharmaceutical institution. It was found that pharmaceutical institutions need qualified professionals with a high level of practical training, ready to immediately join the working process. It was noted that only 47 % of graduates are prepared to work in the specialty chosen. We studied the length of employment with one employer. The analysis of the main problems making pharmaceutical professionals to change their work is performed. During the questioning of pharmaceutical students it was noted that a large number of students (32,89 % feel uncertainty about their further employment and 47 % of respondents are going to work in the profession.

  11. Thermoplastic starch composites with TiO2 particles: Preparation, morphology, rheology and mechanical properties.

    Science.gov (United States)

    Ostafińska, A; Mikešová, J; Krejčíková, S; Nevoralová, M; Šturcová, A; Zhigunov, A; Michálková, D; Šlouf, M

    2017-08-01

    Composites of thermoplastic starch (TPS) with titanium dioxide particles (mTiO 2 ; average size 0.1μm) with very homogeneous matrix and well-dispersed filler were prepared by a two-step method, including solution casting (SC) followed by melt mixing (MM). Light and scanning electron microscopy confirmed that only the two-step procedure (SC+MM) resulted in ideally homogeneous TPS/mTiO 2 systems. The composites prepared by single-step MM contained non-plasticized starch granules and the composites prepared by single-step SC suffered from mTiO 2 agglomeration. Dynamic mechanical measurements showed an increase modulus with increasing filler concentration. In TPS containing 3wt.% of mTiO 2 the stiffness was enhanced by >40%. Further experiments revealed that the recommended addition of chitosan or the exchange of mTiO 2 for anisometric titanate nanotubes with high aspect ratio did not improve the properties of the composites. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Methods of preparing and using intravenous nutrient compositions

    International Nuclear Information System (INIS)

    Beigler, M.A.; Koury, A.J.

    1983-01-01

    A method for preparing a stable, dry-packaged, sterile, nutrient composition which upon addition of sterile, pyrogen-free water is suitable for intravenous administration to a mammal, including a human, is described. The method comprises providing the nutrients in a specific dry form and state of physical purity acceptable for intravenous administration, sealing the nutrients in a particular type of container adapted to receive and dispense sterile fluids and subjecting the container and its sealed contents to a sterilizing, nondestructive dose of ionizing radiation. The method results in a packaged, sterile nutrient composition which may be dissolved by the addition of sterile pyrogen-free water. The resulting aqueous intravenous solution may be safely administered to a mammal in need of nutrient therapy. The packaged nutrient compositions of the invention exhibit greatly extended storage life and provide an economical method of providing intravenous solutions which are safe and efficacious for use. (author)

  13. Solvent exfoliated graphene for reinforcement of PMMA composites prepared by in situ polymerization

    International Nuclear Information System (INIS)

    Wang, Jialiang; Shi, Zixing; Ge, Yu; Wang, Yan; Fan, Jinchen; Yin, Jie

    2012-01-01

    Graphene (GP)-based polymer nanocomposites have attracted considerable scientific attention due to its pronounced improvement in mechanical, thermal and electrical properties compared with pure polymers. However, the preparation of well-dispersed and high-quality GP reinforced polymer composites remains a challenge. In this paper, a simple and facile approach for preparation of poly(methyl methacrylate) (PMMA) functionalized GP (GPMMA) via in situ free radical polymerization is reported. Fourier transform infrared (FTIR), X-ray photoelectron spectra (XPS), Raman, transmission electron microscope (TEM) and thermogravimetric analysis (TGA) are used to confirm the successful grafting of PMMA chains onto the GP sheets. Composite films are prepared by incorporating different amounts of GPMMA into the PMMA matrix through solution-casting method. Compared with pure PMMA, PMMA/GPMMA composites show simultaneously improved Young's modulus, tensile stress, elongation at break and thermal stability by addition of only 0.5 wt% GPMMA. The excellent reinforcement is attributed to good dispersion of high-quality GPMMA and strong interfacial adhesion between GPMMA and PMMA matrix as evidenced by scanning electron microscope (SEM) images of the fracture surfaces. Consequently, this simple protocol has great potential in the preparation of various high-performance polymer composites. Highlights: ► Functionalization of solvent exfoliated graphene by in situ polymerization. ► A simple and scalable method for preparing high-quality graphene. ► Functionalized graphene can be well-dispersed and have a strong interfacial adhesion with the polymer matrix. ► The nanocomposites exhibit a remarkable improvement of thermal and mechanical properties.

  14. Preparation and characterization of UV-curable cationic composite adhesive

    International Nuclear Information System (INIS)

    Shen Yan; Yang Wenbin; Li Yintao; Xie Changqiong; Li Yingjun; Cheng Yafei; Zhou Yuanlin; Lu Zhongyuan

    2011-01-01

    UV-curable cationic composite adhesives containing TiO 2 nanostructures were prepared by using 3, 4-epoxycyclohexylmethyl-3, 4-epoxycyclohexanecarboxylate(CE) as monomer, triphenylsulfonium hexafluorophosphate salt (PI-432) as photoinitiator and titanium isopropoxide (TIP) as inorganic precursor. The morphology of the composite adhesives was characterized by atom force microscopy (AFM). The effect of TIP content on refractive index and transmittance of adhesives were studied. The results show that TiO 2 nanostructures, the average diameter of which is 20 nm or so, can be uniformly dispersed in polymers of composite adhesives. The refractive index of adhesives can be adjusted from 1.501 9 to 1.544 9 with the change of TIP content. The transmittance of adhesives has a slight reduce with the increase of TIP content. When TIP content is up to 40%, the transmittance of composite adhesives remains around 90% or so. (authors)

  15. Preparation of graphite dispersed copper composite on copper plate with CO2 laser

    Science.gov (United States)

    Yokoyama, S.; Ishikawa, Y.; Muizz, M. N. A.; Hisyamudin, M. N. N.; Nishiyama, K.; Sasano, J.; Izaki, M.

    2018-01-01

    It was tried in this work to prepare the graphite dispersed copper composite locally on a copper plate with a CO2 laser. The objectives of this study were to clear whether copper graphite composite was prepared on a copper plate and how the composite was prepared. The carbon content at the laser spot decreased with the laser irradiation time. This mainly resulted from the elimination by the laser trapping. The carbon content at the outside of the laser spot increased with time. Both the laser ablation and the laser trapping did not act on the graphite particles at the outside of the laser spot. Because the copper at the outside of the laser spot melted by the heat conduction from the laser spot, the particles were fixed by the wetting. However, the graphite particles were half-floated on the copper plate. The Vickers hardness decreased with an increase with laser irradiation time because of annealing.

  16. International Conference on Harmonisation; guidance on Q10 Pharmaceutical Quality System; availability. Notice.

    Science.gov (United States)

    2009-04-08

    The Food and Drug Administration (FDA) is announcing the availability of a guidance entitled "Q10 Pharmaceutical Quality System." The guidance was prepared under the auspices of the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH). The guidance describes a model for an effective quality management system for the pharmaceutical industry, referred to as the Pharmaceutical Quality System. The guidance is intended to provide a comprehensive approach to an effective pharmaceutical quality system that is based on International Organization for Standardization (ISO) concepts, includes applicable good manufacturing practice (GMP) regulations and complements ICH guidances on "Q8 Pharmaceutical Development" and "Q9 Quality Risk Management."

  17. Code of Ethics for Pharmacists – Pharmaceutical Chamber of Macedonia

    OpenAIRE

    Angelovska, Bistra

    2015-01-01

    Code of ethics represents the principles that form the fundamental basis of the roles and responsibilities of pharmacists in pharmaceutical practice. According to pharmacy practice, pharmacists are confirmed as healthcare professionals with unique knowledge, skills and responsibilities for safe and efficient medication therapy management in order to optimize therapeutic outcomes. The scope of pharmacy practice includes technical aspects of pharmaceutical services, the preparation of p...

  18. Optimising concentrations of antimicrobial agents in pharmaceutical preparations: Case of an oral solution of glycerol and an ophthalmic solution containing cysteamine.

    Science.gov (United States)

    Chan Hew Wai, A; Becasse, P; Tworski, S; Pradeau, D; Planas, V

    2014-11-01

    In the context of current distrust of antimicrobial preservatives, the quantities of these substances in two pharmaceutical formulas were studied: an ophthalmic solution of cysteamine preserved benzalkonium chloride at 1mg/5mL and Glycerotone(®) preserved with sorbic acid at 0.1g/100g. The purpose of this work was to verify that a reduction of the quantities of preservative continues to fulfil the requirements for antimicrobial preservation. The Test of efficacy of antimicrobial preservation, section 5.1.3 of the 8th edition of the European Pharmacopoeia, was carried out on each formulation prepared with decreasing quantities of preservative. The results show that formulations whose preservative concentration was reduced by a factor of four remained compliant with standards. It is to be noted that in formulas without preservative, fungal growth was observed in both the solution of Glycerotone(®) and the ophthalmic solution containing cysteamine. Although there is no question that an antimicrobial preservative is necessary, the quantity of preservative can be reduced without deteriorating the quality of the pharmaceutical product but the minimal effective concentration remains to be determined. The formulations of many pharmaceutical products should therefore be examined in order to limit the quantities of preservative while continuing to guarantee patient's safety. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  19. Development and Validation of RP-HPLC Method for Simultaneous Estimation of Ramipril, Aspirin and Atorvastatin in Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    Rajesh Sharma

    2012-01-01

    Full Text Available A simple, sensitive, accurate and rapid reverse phase high performance liquid chromatographic method is developed for the simultaneous estimation of ramipril, aspirin and atorvastatin in pharmaceutical preparations. Chromatography was performed on a 25cm×4.6 mm i.d, 5µm particle, C18 column with Mixture of (A acetonitrile methanol (65:35 and (B 10 mM sodium dihydrogen phosphate monohydrate (NaH2PO4.H2O buffer and mixture of A:B (60:40 v/v adjusted to pH 3.0 with o-phosphoric acid (5%v/v was used as a mobile phase at a flow rate of 1.5 ml min-1. UV detection was performed at 230 nm. Total run time was less then 12 min; retention time for Ramipril, aspirin and Atorvastatin were 3.620, 4.920 min and 11.710 min respectively. The method was validated for accuracy, precision, linearity, specificity and sensitivity in accordance with ICH guidelines. Validation revealed that the method is specific, rapid, accurate, precise, reliable, and reproducible. Calibration plots were linear over the concentration ranges 05-50 µg mL-1 for Ramipril, 05-100 µgmL-1 for aspirin and 02-20 µg mL-1 for atorvastatin. Limits of detection were 0.014, 0.10 and 0.0095 ng mL-1 limits of quantification were 0.043, 0.329 and 0.029 ng mL-1 for ramipril aspirin and atorvastatin respectively. The high recovery and low coefficients of variation confirm the suitability of the method for simultaneous analysis of the all three drugs in the dosage forms. The validated method was successfully used for quantitative analysis of marketed pharmaceutical preparations.

  20. The merit of medicinal mushrooms from a pharmaceutical point of view.

    Science.gov (United States)

    Lindequist, Ulrike

    2013-01-01

    Whereas pharmaceuticals prepared by extraction of medicinal plants constitute an important part of evidence-based medicine also in the Western Hemisphere, medicinal mushrooms are mainly used as dietary supplements without declaration of a medical indication. Scientific investigations and case studies from Asian medicine show that fungi have very promising pharmacological potential. This article provides an overview of the principles of authorization and market access of herbal drugs in Europe, with special reference to Germany. The current status regarding mushrooms is reported, with an aim toward supporting the development of legalized pharmaceutical preparations of medicinal mushrooms in Europe.

  1. Chemical stability of insulin. 2. Formation of higher molecular weight transformation products during storage of pharmaceutical preparations.

    Science.gov (United States)

    Brange, J; Havelund, S; Hougaard, P

    1992-06-01

    Formation of covalent, higher molecular weight transformation (HMWT) products during storage of insulin preparations at 4-45 degrees C was studied by size exclusion chromatography. The main products are covalent insulin dimers (CID), but in protamine-containing preparations the concurrent formation of covalent insulin-protamine (CIP) products takes place. At temperatures greater than or equal to 25 degrees C parallel or consecutive formation of covalent oligo- and polymers can also be observed. Rate of HMWT is only slightly influenced by species of insulin but varies with composition and formulation, and for isophane (NPH) preparations, also with the strength of preparation. Temperature has a pronounced effect on CID, CIP, and, especially, covalent oligo- and polymer formation. The CIDs are apparently formed between molecules within the hexameric unit common for all types of preparations and rate of formation is generally faster in glycerol-containing preparations. Compared with insulin hydrolysis reactions (see the preceding paper), HMWT is one order of magnitude slower, except for NPH preparations.

  2. Characterization of Three-Dimensional Printed Composite Scaffolds Prepared with Different Fabrication Methods

    Directory of Open Access Journals (Sweden)

    Szlązak K.

    2016-06-01

    Full Text Available An optimal method for composites preparation as an input to rapid prototyping fabrication of scaffolds with potential application in osteochondral tissue engineering is still needed. Scaffolds in tissue engineering applications play a role of constructs providing appropriate mechanical support with defined porosity to assist regeneration of tissue. The aim of the presented study was to analyze the influence of composite fabrication methods on scaffolds mechanical properties. The evaluation was performed on polycaprolactone (PCL with 5 wt% beta-tricalcium phosphate (TCP scaffolds fabricated using fused deposition modeling (FDM. Three different methods of PCL-TCP composite preparation: solution casting, particles milling, extrusion and injection were used to provide material for scaffold fabrication. The obtained scaffolds were investigated by means of scanning electron microscope, x-ray micro computed tomography, thermal gravimetric analysis and static material testing machine. All of the scaffolds had the same geometry (cylinder, 4×6 mm and fiber orientation (0/60/120°. There were some differences in the TCP distribution and formation of the ceramic agglomerates in the scaffolds. They depended on fabrication method. The use of composites prepared by solution casting method resulted in scaffolds with the best combination of compressive strength (5.7±0.2 MPa and porosity (48.5±2.7 %, both within the range of trabecular bone.

  3. Graphite fiber/copper composites prepared by spontaneous infiltration

    Science.gov (United States)

    Wang, Hongbao; Tao, Zechao; Li, Xiangfen; Yan, Xi; Liu, Zhanjun; Guo, Quangui

    2018-05-01

    The major bottleneck in developing graphite fiber reinforced copper (GF/Cu) composites is the poor wettability of Cu/graphite system. Alloying element of chromium (Cr) is introduced to improve the wettability of liquid copper on graphite. Sessile drop method experiments illustrate that the contact angle of liquid Cu-Cr (1.0 wt.%) alloy on graphite substrate decreases to 43° at 1300 °C. The improvement of wettability is related to the formation of chromium carbide layer at interface zone. Based on the wetting experiment, a spontaneous infiltration method for preparing GF/Cu composites is proposed. Unidirectional GF preforms are infiltrated by Cu-Cr alloys without external pressure in a tubular furnace. Results reveal that the GF preform can be fully infiltrated by Cu-Cr alloy (8 wt.%) spontaneously when fiber volume fraction is 40%. The coefficient of thermal expansion (CTE) of GF/Cu-Cr (8.0 wt.%) composites is 4.68 × 10-6/K along the longitudinal direction.

  4. Thiomers: A Blessing to Evaluating Era of Pharmaceuticals

    Directory of Open Access Journals (Sweden)

    Muhammad Hanif

    2015-01-01

    Full Text Available Thiomers are the polymers modified for the mucoadhesive properties and other additive properties by incorporating thiol moieties in the backbone of the unmodified polymeric chain by substitution reactions or simple oxidation reactions. Drugs that are less soluble and permeable can be complexed with thiomers for their increased absorption through the mucosal membranes by increase in contact time and prolonged stay in body due to mucoadhesion. Immobilization of thiol group therefore increases the mucoadhesive properties of the modified polymer by 2–140-folds. The prepared thiomers are characterized and made stable by different techniques. Thiomers also give the controlled delivery of the active pharmaceutical ingredients in the body. Different polymers that are modified by thiolation are chitosan, polyacrylic acid, sodium alginate, sodium carboxy methyl cellulose, guar gum, and so forth. Thiomeric formulations are a challenge to deliver drugs with low therapeutic compatibility. Micro- and nanopreparations containing thiomers can be prepared by different techniques such as covalent crosslinking, in situ gelation, radical emulsion polymerization, and emulsification. Nowadays thiomers have wide range of applications as a promising pharmaceutical excipient in the evaluating era of pharmaceutical technology.

  5. Preparation of polymers suitable for radiation shielding and studying its properties (polyester composites with heavy metals salts)

    International Nuclear Information System (INIS)

    Kharita, M. H.; Al-Ajji, Z.; Yousef, S.

    2010-12-01

    Four composites were prepared in this work, based on polyester and heavy metals oxides and salts. The attenuation properties, as well as mechanical properties were studied, and the chemical stability was evaluated. It has been shown, that these composites can be used in radiation shielding for X-rays successfully, and the exact composition of these composites can be optimized according to the radiation energy to prepare the lightest possible shield. (author)

  6. Preparation and electrochemical characterization of polyaniline/activated carbon composites as an electrode material for supercapacitors.

    Science.gov (United States)

    Oh, Misoon; Kim, Seok

    2012-01-01

    Polyaniline (PANI)/activated carbon (AC) composites were prepared by a chemical oxidation polymerization. To find an optimum ratio between PANI and AC which shows superior electrochemical properties, the preparation was carried out in changing the amount of added aniline monomers. The morphology of prepared composites was investigated by scanning electron microscopy (SEM) and transmission electron microscope (TEM). The structural and thermal properties were investigated by Fourier transform infrared spectra (FT-IR) and thermal gravimetric analysis (TGA), respectively. The electrochemical properties were characterized by cyclic voltammetry (CV). Composites showed a summation of capacitances that consisted of two origins. One is double-layer capacitance by ACs and the other is faradic capacitance by redox reaction of PANI. Fiber-like PANIs are coated on the surface of ACs and they contribute to the large surface for redox reaction. The vacancy among fibers provided the better diffusion and accessibility of ion. High capacitances of composites were originated from the network structure having vacancy made by PANI fibers. It was found that the composite prepared with 5 ml of aniline monomer and 0.25 g of AC showed the highest capacitance. Capacitance of 771 F/g was obtained at a scan rate of 5 mV/s.

  7. Preparation and performance of novel polyvinylpyrrolidone/polyethylene glycol phase change materials composite fibers by centrifugal spinning

    Science.gov (United States)

    Zhang, Xiaoguang; Qiao, Jiaxin; Zhao, Hang; Huang, Zhaohui; Liu, Yangai; Fang, Minghao; Wu, Xiaowen; Min, Xin

    2018-01-01

    Currently, phase change materials (PCMs) composite fibers are typically prepared by electrospinning. However, electrospinning exhibits safety concerns and a low production rate, which limit its practical applications as a cost-effective fiber fabrication approach. Therefore, a novel, and simple centrifugal spinning technology is employed to extrude fibers from composite solutions using a high-speed rotary and perforated spinneret. The composite fibers based on polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG) were prepared by centrifugal spinning. The SEM of PVP/PEG composite fibers indicated that the fibrous morphology is well preserved. The DSC and TGA indicated that PVP/PEG composite fibers exhibit good thermal properties.

  8. Composite phase change materials prepared by encapsuling paraffin in PVC macrocapsules

    International Nuclear Information System (INIS)

    Chen, Yingbo; Zhang, Shifeng; Zhang, Qi; Chen, Yusheng; Zhang, Yufeng

    2014-01-01

    Highlights: • PVC macrocapsules coated with SiO 2 were synthesized. • Paraffin was encapsuled in the capsules. • The composite PCM has high heat capacity. • The composite PCM has no surpercooling. - Abstract: A novel phase change material capsules with SiO 2 in their surface was prepared by absorbing paraffin into PVC hollow capsules and by the polycondensation reaction of TEOS in different conditions. X-ray photoelectron spectroscopy (XPS) analysis and scanning electronic microscope (SEM) were used to determine chemical composition and microstructure of the composite capsules, respectively. Enthalpy capacity and thermal stability of the composite capsules are systematically characterized by using differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA) and thermocycling tests. The composite has high heat capacity with good stability and absence of supercooling phenomena

  9. Process for the preparation of a vinylidene chloride polymer composite

    NARCIS (Netherlands)

    2013-01-01

    Process for the preparation of a vinylidene chloride polymer composite comprising a solid particulate encapsulated in the vinylidene chloride polymer. The process comprises providing a dispersion of a solid particulate material in a liquid phase, said dispersion comprising a RAFT/MADIX agent;

  10. Effect of preparation conditions on the characteristics and photocatalytic activity of TiO{sub 2}/purified diatomite composite photocatalysts

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Zhiming, E-mail: szmcumtb@hotmail.com; Hu, Zhibo; Yan, Yang; Zheng, Shuilin, E-mail: shuilinzh@sina.com

    2014-09-30

    Highlights: • TiO{sub 2}/purified diatomite composites were synthesized under different conditions. • The optimum preparation conditions of composites were obtained. • The obtained photocatalyst showed good photocatalytic activity. • The dispersity and grain size of loaded TiO{sub 2} NPs are the critical factors. - Abstract: TiO{sub 2}/purified diatomite composite materials were prepared through a modified hydrolysis-deposition method under low temperature using titanium tetrachloride as precursor combined with a calcination crystallization process. The microstructure and crystalline phases of the obtained composites prepared under different preparation conditions were characterized by high resolution scanning electron microscope (SEM) and X-ray diffraction (XRD), respectively. The photocatalytic performance of TiO{sub 2}/purified diatomite composites was evaluated by Rhodamine B as the target pollutant under UV irradiation, and the optimum preparation conditions of composites were obtained. The TiO{sub 2} crystal form in composites prepared under optimum conditions was anatase, the grain size of which was 34.12 nm. The relationships between structure and property of composite materials were analyzed and discussed. It is indicated that the TiO{sub 2} nanoparticles uniformly dispersed on the surface of diatoms, and the photocatalytic performance of the composite materials was mainly determined by the dispersity and grain size of loaded TiO{sub 2} nanoparticles.

  11. Pharmaceutical care education in Kuwait: pharmacy students' perspectives.

    Science.gov (United States)

    Katoue, Maram G; Awad, Abdelmoneim I; Schwinghammer, Terry L; Kombian, Samuel B

    2014-07-01

    Pharmaceutical care is defined as the responsible provision of medication therapy to achieve definite outcomes that improve patients' quality of life. Pharmacy education should equip students with the knowledge, skills, and attitudes they need to practise pharmaceutical care competently. To investigate pharmacy students' attitudes towards pharmaceutical care, perceptions of their preparedness to perform pharmaceutical care competencies, opinions about the importance of the various pharmaceutical care activities, and the barriers to its implementation in Kuwait. A descriptive, cross-sectional survey of pharmacy students (n=126) was conducted at Faculty of Pharmacy, Kuwait University. Data were collected via a pre-tested self-administered questionnaire. Descriptive statistics including percentages, medians and means Likert scale rating (SD) were calculated and compared using SPSS, version 19. Statistical significance was accepted at a p value of 0.05 or lower. The response rate was 99.2%. Pharmacy students expressed overall positive attitudes towards pharmaceutical care. They felt prepared to implement the various aspects of pharmaceutical care, with the least preparedness in the administrative/management aspects. Perceived pharmaceutical care competencies grew as students progressed through the curriculum. The students also appreciated the importance of the various pharmaceutical care competencies. They agreed/strongly agreed that the major barriers to the integration of pharmaceutical care into practice were lack of private counseling areas or inappropriate pharmacy layout (95.2%), lack of pharmacist time (83.3%), organizational obstacles (82.6%), and pharmacists' physical separation from patient care areas (82.6%). Pharmacy students' attitudes and perceived preparedness can serve as needs assessment tools to guide curricular change and improvement. Student pharmacists at Kuwait University understand and advocate implementation of pharmaceutical care while also

  12. Preparation and characterization of antibacterial Au/C core-shell composite

    Energy Technology Data Exchange (ETDEWEB)

    Gao Yanhong [Department of Chemistry and Institute of Nanochemistry, Jinan University, 601 Huangpudadaoxi Road, Guangzhou 510632, Guangdong (China); Centers for Disease Control and Prevention of Guangdong Province, Guangzhou 510300, Guangdong (China); Zhang Nianchun [Department of Chemistry and Institute of Nanochemistry, Jinan University, 601 Huangpudadaoxi Road, Guangzhou 510632, Guangdong (China); Zhong Yuwen [Centers for Disease Control and Prevention of Guangdong Province, Guangzhou 510300, Guangdong (China); Cai Huaihong [Department of Chemistry and Institute of Nanochemistry, Jinan University, 601 Huangpudadaoxi Road, Guangzhou 510632, Guangdong (China); Liu Yingliang, E-mail: tliuyl@jnu.edu.cn [Department of Chemistry and Institute of Nanochemistry, Jinan University, 601 Huangpudadaoxi Road, Guangzhou 510632, Guangdong (China)

    2010-09-01

    An environment-friendly oxidation-reduction method was used to prepare Au/C core-shell composite using carbon as core and gold as shell. The chemical structures and morphologies of Au/C core-shell composite and carbon sphere were characterized by X-ray diffraction, transmission electron microscope, energy dispersion X-ray spectrometry (EDS) and X-ray photoelectron spectroscopy (XPS). The antibacterial properties of the Au/C core-shell composite against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Candida albicans (C. albicans) were examined by the disk diffusion assay and minimal inhibition concentration (MIC) methods. In addition, antibacterial ability of Au/C core-shell composite was observed by atomic force microscope. Results demonstrated that gold homogeneously supported on the surface of carbon spheres without aggregation and showed efficient antibacterial abilities.

  13. Preparation of magnesium metal matrix composites by powder metallurgy process

    Science.gov (United States)

    Satish, J.; Satish, K. G., Dr.

    2018-02-01

    Magnesium is the lightest metal used as the source for constructional alloys. Today Magnesium based metal matrix composites are widely used in aerospace, structural, oceanic and automobile applications for its light weight, low density(two thirds that of aluminium), good high temperature mechanical properties and good to excellent corrosion resistance. The reason of designing metal matrix composite is to put in the attractive attributes of metals and ceramics to the base metal. In this study magnesium metal matrix hybrid composite are developed by reinforcing pure magnesium with silicon carbide (SiC) and aluminium oxide by method of powder metallurgy. This method is less expensive and very efficient. The Hardness test was performed on the specimens prepared by powder metallurgy method. The results revealed that the micro hardness of composites was increased with the addition of silicon carbide and alumina particles in magnesium metal matrix composites.

  14. Conductive ceramic composition and method of preparation

    Science.gov (United States)

    Smith, J.L.; Kucera, E.H.

    1991-04-16

    A ceramic anode composition is formed of a multivalent metal oxide or oxygenate such as an alkali metal, transition metal oxygenate. The anode is prepared as a non-stoichiometric crystalline structure by reaction and conditioning in a hydrogen gas cover containing minor proportions of carbon dioxide and water vapor. The structure exhibits a single phase and substantially enhanced electrical conductivity over that of the corresponding stoichiometric structure. Unexpectedly, such oxides and oxygenates are found to be stable in the reducing anode fuel gas of a molten carbonate fuel cell. 4 figures.

  15. Pharmaceutical regulation in 15 European countries review.

    Science.gov (United States)

    Panteli, Dimitra; Arickx, Francis; Cleemput, Irina; Dedet, Guillaume; Eckhardt, Helen; Fogarty, Emer; Gerkens, Sophie; Henschke, Cornelia; Hislop, Jennifer; Jommi, Claudio; Kaitelidou, Daphne; Kawalec, Pawel; Keskimaki, Ilmo; Kroneman, Madelon; Lopez Bastida, Julio; Pita Barros, Pedro; Ramsberg, Joakim; Schneider, Peter; Spillane, Susan; Vogler, Sabine; Vuorenkoski, Lauri; Wallach Kildemoes, Helle; Wouters, Olivier; Busse, Reinhard

    2016-10-01

    In the context of pharmaceutical care, policy-makers repeatedly face the challenge of balancing patient access to effective medicines with affordability and rising costs. With the aim of guiding the health policy discourse towards questions that are important to actual and potential patients, this study investigates a broad range of regulatory measures, spanning marketing authorization to generic substitution and resulting price levels in a sample of 16 European health systems (Austria, Belgium, Denmark, England, Finland, France, Germany, Greece, Ireland, Italy, the Netherlands, Poland, Portugal, Scotland, Spain and Sweden). All countries employ a mix of regulatory mechanisms to contain pharmaceutical expenditure and ensure quality and efficiency in pharmaceutical care, albeit with varying configurations and rigour. This variation also influences the extent of publicly financed pharmaceutical costs. Overall, observed differences in pharmaceutical expenditure should be interpreted in conjunction with the differing volume and composition of consumption and price levels, as well as dispensation practices and their impact on measurement of pharmaceutical costs. No definitive evidence has yet been produced on the effects of different cost-containment measures on patient outcomes. Depending on the foremost policy concerns in each country, different levers will have to be used to enable the delivery of appropriate care at affordable prices. World Health Organization 2016 (acting as the host organization for, and secretariat of, the European Observatory on Health Systems and Policies).

  16. Plasma preparation and low-temperature sintering of spherical TiC-Fe composite powder

    Institute of Scientific and Technical Information of China (English)

    Jian-jun Wang; Jun-jie Hao; Zhi-meng Guo; Song Wang

    2015-01-01

    A spherical Fe matrix composite powder containing a high volume fraction (82vol%) of fine TiC reinforcement was produced us-ing a novel process combining in situ synthesis and plasma techniques. The composite powder exhibited good sphericity and a dense struc-ture, and the fine sub-micron TiC particles were homogeneously distributed in theα-Fe matrix. A TiC–Fe cermet was prepared from the as-prepared spherical composite powder using powder metallurgy at a low sintering temperature;the product exhibited a hardness of HRA 88.5 and a flexural strength of 1360 MPa. The grain size of the fine-grained TiC and special surface structure of the spherical powder played the key roles in the fabrication process.

  17. Microbiological testing of pharmaceuticals and cosmetics in Egypt.

    Science.gov (United States)

    Zeitoun, Hend; Kassem, Mervat; Raafat, Dina; AbouShlieb, Hamida; Fanaki, Nourhan

    2015-12-09

    Microbial contamination of pharmaceuticals poses a great problem to the pharmaceutical manufacturing process, especially from a medical as well as an economic point of view. Depending upon the product and its intended use, the identification of isolates should not merely be limited to the United States Pharmacopeia (USP) indicator organisms. Eighty-five pre-used non-sterile pharmaceuticals collected from random consumers in Egypt were examined for the eventual presence of bacterial contaminants. Forty-one bacterial contaminants were isolated from 31 of the tested preparations. These isolates were subjected to biochemical identification by both conventional tests as well as API kits, which were sufficient for the accurate identification of only 11 out of the 41 bacterial contaminants (26.8%) to the species level. The remaining isolates were inconclusively identified or showed contradictory results after using both biochemical methods. Using molecular methods, 24 isolates (58.5%) were successfully identified to the species level. Moreover, polymerase chain reaction (PCR) assays were compared to standard biochemical methods in the detection of pharmacopoeial bacterial indicators in artificially-contaminated pharmaceutical samples. PCR-based methods proved to be superior regarding speed, cost-effectiveness and sensitivity. Therefore, pharmaceutical manufacturers would be advised to adopt PCR-based methods in the microbiological quality testing of pharmaceuticals in the future.

  18. Preparation of graphene oxide/polypyrrole/multi-walled carbon nanotube composite and its application in supercapacitors

    International Nuclear Information System (INIS)

    Wang, Bin; Qiu, Jianhui; Feng, Huixia; Sakai, Eiichi

    2015-01-01

    Highlights: • A novel method for synthesizing graphene oxide/polypyrrole/multi-walled nanotube composites. • Investigation of the effects of the mass ratio of GO, CM and Py on the capacitance of prepared composites. • Excellent electrochemical performance of PCMG composites. - Abstract: We report a novel method for preparing graphene oxide/polypyrrole/multi-walled carbon nanotubes (MWCNTs) composites (PCMG). The MWCNTs are treated by sulfuric acid, nitric acid and thionyl chloride, and then composite with graphene oxide and PPy by in suit polymerization. Transition electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) results show that in 3-D structure of PCMG composites, PPy chains act as the “bridge” between graphene oxide and chlorinated-MWCNTs. Electrochemical tests reveal that the PCMG1-1 composite has high capacitance of 406.7 F g −1 at current density of 0.5 A g −1 , and the capacitance retention of PCMG1-1 composite is 92% after 1000 cycles

  19. Chitosan-cellulose composite materials: Preparation, Characterization and application for removal of microcystin

    Energy Technology Data Exchange (ETDEWEB)

    Tran, Chieu D., E-mail: chieu.tran@marquette.edu [Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, WI 53201 (United States); Duri, Simon [Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, WI 53201 (United States); Delneri, Ambra; Franko, Mladen [Laboratory for Environmental Research, University of Nova Gorica, Vipavska 13, 5001 Nova Gorica (Slovenia)

    2013-05-15

    Highlights: •A novel and recyclable synthetic method using an ionic liquid, a Green Solvent. •Ecocomposite materials were synthesized from cellulose (CEL) and chitosan (CS). •Adding CEL into CS substantially increases tensile strength of the composite. •The composite is much better adsorbent for cyanotoxins than other materials. •The composite can be reused because adsorbed microcystin can be desorbed. -- Abstract: We developed a simple and one-step method to prepare biocompatible composites from cellulose (CEL) and chitosan (CS). [BMIm{sup +}Cl{sup −}], an ionic liquid (IL), was used as a green solvent to dissolve and prepare the [CEL + CS] composites. Since majority (>88%) of IL used was recovered for reuse by distilling the aqueous washings of [CEL + CS], the method is recyclable. XRD, FTIR, NIR, {sup 13}C CP-MAS-NMR and SEM were used to monitor the dissolution and to characterize the composites. The composite was found to have combined advantages of their components: superior mechanical strength (from CEL) and excellent adsorption capability for microcystin-LR, a deadly toxin produced by cyanobacteria (from CS). Specifically, the mechanical strength of the composites increased with CEL loading; e.g., up to 5× increase in tensile strength was achieved by adding 80% of CEL into CS. Kinetic results of adsorption confirm that unique properties of CS remain intact in the composite, i.e., it is not only a very good adsorbent for microcystin but also is better than all other available adsorbents. For example, it can adsorb 4× times more microcystin than the best reported adsorbent. Importantly, the microcystin adsorbed can be quantitatively desorbed to enable the composite to be reused with similar adsorption efficiency.

  20. Chitosan-cellulose composite materials: Preparation, Characterization and application for removal of microcystin

    International Nuclear Information System (INIS)

    Tran, Chieu D.; Duri, Simon; Delneri, Ambra; Franko, Mladen

    2013-01-01

    Highlights: •A novel and recyclable synthetic method using an ionic liquid, a Green Solvent. •Ecocomposite materials were synthesized from cellulose (CEL) and chitosan (CS). •Adding CEL into CS substantially increases tensile strength of the composite. •The composite is much better adsorbent for cyanotoxins than other materials. •The composite can be reused because adsorbed microcystin can be desorbed. -- Abstract: We developed a simple and one-step method to prepare biocompatible composites from cellulose (CEL) and chitosan (CS). [BMIm + Cl − ], an ionic liquid (IL), was used as a green solvent to dissolve and prepare the [CEL + CS] composites. Since majority (>88%) of IL used was recovered for reuse by distilling the aqueous washings of [CEL + CS], the method is recyclable. XRD, FTIR, NIR, 13 C CP-MAS-NMR and SEM were used to monitor the dissolution and to characterize the composites. The composite was found to have combined advantages of their components: superior mechanical strength (from CEL) and excellent adsorption capability for microcystin-LR, a deadly toxin produced by cyanobacteria (from CS). Specifically, the mechanical strength of the composites increased with CEL loading; e.g., up to 5× increase in tensile strength was achieved by adding 80% of CEL into CS. Kinetic results of adsorption confirm that unique properties of CS remain intact in the composite, i.e., it is not only a very good adsorbent for microcystin but also is better than all other available adsorbents. For example, it can adsorb 4× times more microcystin than the best reported adsorbent. Importantly, the microcystin adsorbed can be quantitatively desorbed to enable the composite to be reused with similar adsorption efficiency

  1. Quantitative morphological and compositional evaluation of laboratory prepared aluminoborosilicate glass surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Yuxuan, E-mail: yg4@alfred.edu; Wren, Anthony W.; Mellott, Nathan P.

    2015-01-01

    Graphical abstract: - Highlights: • Aluminoborosilicate glass surfaces were prepared through both melting and polishing/etching and the surface composition and morphology were quantified as a function of processing method. • Glass surface morphology was quantified using PSD analysis, followed by both fractal and ABC model fitting, resulting in a comprehensive description of the spatial distribution of roughness. • All melt surfaces showed a depletion in Na, Ca, and B with respect to the bulk composition. Polished/etched surfaces showed a depletion in Na, B, and Al with respect to the bulk composition. • It was found that increasing heat treatment temperature of melt surfaces lead to a decrease in equivalent roughness and an increased spatial homogeneity of roughness while etching of polished ISG glass surfaces decreases the roughness and spatial distribution homogeneity of roughness. - Abstract: Surface finishing techniques including polishing, etching and heat treatment can modify the topography and the surface chemical composition of glasses. It is widely acknowledged that atomic force microscopy (AFM) can be used to quantify the morphology of surfaces, providing various parameters including average, peak-to-valley, and apparent root-mean-square roughness. Furthermore advanced power spectral density (PSD) analysis of AFM-derived surface profiles offers quantification of the spatial homogeneity of roughness values along different wavelengths, resulting in parameters including equivalent RMS, Hurst exponent, and fractal dimension. Outermost surface (∼8 nm) chemical composition can be quantitatively measured by X-ray photoelectron spectroscopy. In this paper, we first developed a series of surface finishing methods for an aluminoborosilicate glass system by polishing, etching or heat treatment. The chemical composition and environment of prepared glass surfaces were quantified by XPS and topographical analysis was carried out by fractal and k

  2. Spray-coating process in preparing PTFE-PPS composite super-hydrophobic coating

    Directory of Open Access Journals (Sweden)

    Rui Weng

    2014-03-01

    Full Text Available In order to improve the performance of a liquid-floated rotor micro-gyroscope, the resistance of the moving interface between the rotor and the floating liquid must be reduced. Hydrophobic treatment can reduce the frictional resistance between such interfaces, therefore we proposed a method to prepare a poly-tetrafluoroethylene (PTFE-poly-phenylene sulphide (PPS composite super-hydrophobic coating, based on a spraying process. This method can quickly prepare a continuous, uniform PTFE-PPS composite super-hydrophobic surface on a 2J85 material. This method can be divided into three steps, namely: pre-treatment; chemical etching; and spraying. The total time for this is around three hours. When the PTFE concentration is 4%, the average contact angle of the hydrophobic coating surface is 158°. If silicon dioxide nanoparticles are added, this can further improve the adhesion and mechanical strength of the super-hydrophobic composite coating. The maximum average contact angle can reach as high as 164° when the mass fraction of PTFE, PPS and silicon dioxide is 1:1:1.

  3. Spray-coating process in preparing PTFE-PPS composite super-hydrophobic coating

    Science.gov (United States)

    Weng, Rui; Zhang, Haifeng; Liu, Xiaowei

    2014-03-01

    In order to improve the performance of a liquid-floated rotor micro-gyroscope, the resistance of the moving interface between the rotor and the floating liquid must be reduced. Hydrophobic treatment can reduce the frictional resistance between such interfaces, therefore we proposed a method to prepare a poly-tetrafluoroethylene (PTFE)-poly-phenylene sulphide (PPS) composite super-hydrophobic coating, based on a spraying process. This method can quickly prepare a continuous, uniform PTFE-PPS composite super-hydrophobic surface on a 2J85 material. This method can be divided into three steps, namely: pre-treatment; chemical etching; and spraying. The total time for this is around three hours. When the PTFE concentration is 4%, the average contact angle of the hydrophobic coating surface is 158°. If silicon dioxide nanoparticles are added, this can further improve the adhesion and mechanical strength of the super-hydrophobic composite coating. The maximum average contact angle can reach as high as 164° when the mass fraction of PTFE, PPS and silicon dioxide is 1:1:1.

  4. Preparation of conductive paper composites based on natural cellulosic fibers for packaging applications.

    Science.gov (United States)

    Youssef, Ahmed M; El-Samahy, Magda Ali; Abdel Rehim, Mona H

    2012-08-01

    Conducting paper based on natural cellulosic fibers and conductive polymers was prepared using unbleached bagasse and/or rice straw fibers (as cellulosic raw materials) and polyaniline (PANi) as conducting polymer. These composites were synthesized by in situ emulsion polymerization using ammonium persulfate (APS) as oxidant in the presence of dodecylbenzene sulfonic acid (DBSA) as emulsifier. The prepared composites were characterized using Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA), differential scanning calorimeter (DSC), and their morphology was investigated using scanning electron microscope (SEM). Electrical conductivity measurements showed that the conductivity of the paper sheets increases by increasing the ratio of PANi in the composite. Mechanical properties of the paper sheets were also investigated, the results revealed that the values of breaking length, burst factor, and tear factor are decreased with increasing ratio of added PANi, and this effect is more pronounced in bagasse-based composites. The new conductive composites can have potential use as anti-static packaging material or anti-bacterial paper for packaging applications. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Preparation and characterization of dense nanohydroxyapatite/PLLA composites

    International Nuclear Information System (INIS)

    Gay, Sandrine; Arostegui, Saioa; Lemaitre, Jacques

    2009-01-01

    Synthetic bone graft substitutes based on PLLA have been largely studied during the past decade. PLLA/hydroxyapatite composites appear as promising materials for large bone defect healing. In this study dense PLLA/nano-hydroxyapatite composites were prepared by hot pressing. Dense samples were investigated rather than porous scaffolds, in order to shed light on possible correlations between intrinsic mechanical properties and nano-hydroxyapatite concentration. Hydroxyapatite deagglomerated by wet attrition milling, and further dispersed into chloroform was used (median diameter = 80 nm). Particle size distribution measurements and transmission electron microscopy show evidence that particle size and dispersion are maintained throughout the successive steps of composite processing. Mechanical properties were tested (uni-axial and diametral compression tests) as a function of nano-hydroxyapatite content. Increasing concentrations of nano-hydroxyapatite (0, 25 and 50 wt.%) increase the Young's modulus and the mechanical strength of the composite; at the same time, the failure mechanism of the material changes from plastic to brittle. Young's modulus over 6 GPa and uniaxial compressive strength over 100 MPa have been achieved. These values expressed in terms of intrinsic tensile and shear strengths indicate that 50 wt.% nano-hydroxyapatite containing samples develop properties comparable to those of cortical bone. PLLA/nano-hydroxyapatite composites are thus promising candidates to develop bioresorbable porous bone substitutes showing superior mechanical performance

  6. Preparation and controlled release of mesoporous MCM-41/propranolol hydrochloride composite drug.

    Science.gov (United States)

    Zhai, Qing-Zhou

    2013-01-01

    This article used MCM-41 as a carrier for the assembly of propranolol hydrochloride by the impregnation method. By means of chemical analysis, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy and low-temperature N(2) adsorption-desorption at 77 K, the characterization was made for the prepared materials. The propranolol hydrochloride guest assembly capacity was 316.20 ± 0.31 mg/g (drug/MCM-41). Powder XRD test results indicated that during the process of incorporation, the frameworks of the MCM-41 were not destroyed and the crystalline degrees of the host-guest nanocomposite materials prepared still remained highly ordered. Characterization by SEM and TEM showed that the composite material presented spherical particle and the average particle size of composite material was 186 nm. FT-IR spectra showed that the MCM-41 framework existed well in the (MCM-41)-propranolol hydrochloride composite. Low-temperature nitrogen adsorption-desorption results at 77 K showed that the guest partially occupied the channels of the molecular sieves. Results of the release of the prepared composite drug in simulated body fluid indicated that the drug can release up to 32 h and its maximum released amount was 99.20 ± 0.11%. In the simulated gastric juice release pattern of drug, the maximum time for the drug release was discovered to be 6 h and the maximum cumulative released amount of propranolol hydrochloride was 45.13 ± 0.23%. The drug sustained-release time was 10 h in simulated intestinal fluid and the maximum cumulative released amount was 62.05 ± 0.13%. The prepared MCM-41 is a well-controlled drug delivery carrier.

  7. Preparation, Characterization and Properties of Alginate/Poly(γ-glutamic acid) Composite Microparticles.

    Science.gov (United States)

    Tong, Zongrui; Chen, Yu; Liu, Yang; Tong, Li; Chu, Jiamian; Xiao, Kecen; Zhou, Zhiyu; Dong, Wenbo; Chu, Xingwu

    2017-04-11

    Alginate (Alg) is a renewable polymer with excellent hemostatic properties and biocapability and is widely used for hemostatic wound dressing. However, the swelling properties of alginate-based wound dressings need to be promoted to meet the requirements of wider application. Poly( γ -glutamic acid) (PGA) is a natural polymer with high hydrophility. In the current study, novel Alg/PGA composite microparticles with double network structure were prepared by the emulsification/internal gelation method. It was found from the structure characterization that a double network structure was formed in the composite microparticles due to the ion chelation interaction between Ca 2+ and the carboxylate groups of Alg and PGA and the electrostatic interaction between the secondary amine group of PGA and the carboxylate groups of Alg and PGA. The swelling behavior of the composite microparticles was significantly improved due to the high hydrophility of PGA. Influences of the preparing conditions on the swelling behavior of the composites were investigated. The porous microparticles could be formed while compositing of PGA. Thermal stability was studied by thermogravimetric analysis method. Moreover, in vitro cytocompatibility test of microparticles exhibited good biocompatibility with L929 cells. All results indicated that such Alg/PGA composite microparticles are a promising candidate in the field of wound dressing for hemostasis or rapid removal of exudates.

  8. Preparation and characterization of flower-like gold nanomaterials and iron oxide/gold composite nanomaterials

    International Nuclear Information System (INIS)

    Yang Zusing; Lin, Z H; Tang, C-Y; Chang, H-T

    2007-01-01

    We have successfully synthesized flower-like gold nanomaterials and Fe 3 O 4 /Au composite nanomaterials through the use of wet chemical methods in aqueous solution. In the presence of 0.5 mM citrate, 0.313 mM poly(ethylene glycol), and 109.72 mM sodium acetate (NaOAc), we prepared Au nanoflowers (NFs) having diameters ranging from 300 to 400 nm in aqueous solution after the reduction of Au ions at room temperature for 10 min. In the presence of spherical Fe 3 O 4 nanomaterials, we applied a similar synthetic method to prepare Fe 3 O 4 /Au composite nanomaterials, including nanowires (NWs) that have a length of 1.58 μm and a width of 28.3 nm. We conducted energy-dispersive x-ray analysis, scanning electron microscopy, transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) absorption, and x-ray powder diffraction measurements to characterize the as-prepared flower-like Au nanomaterials and Fe 3 O 4 /Au composite nanomaterials. From time-evolution TEM measurements, we suggested that Au atoms that were bound to the Fe 3 O 4 nanomaterials grew to form Fe 3 O 4 /Au composite nanomaterials. The as-prepared Au NFs absorbed light strongly in the visible-near-infrared (Vis-NIR) region (500-1200 nm). The Fe 3 O 4 /Au composite nanomaterials had electronic conductivities greater than 100 nA at an applied voltage of 20 mV, which induced a temperature increase of 20.5 ± 0.5 deg. C under an alternating magnetic field (62 μT)

  9. Preparation and characterization of a novel bone graft composite ...

    Indian Academy of Sciences (India)

    MS received 28 July 2009; revised 14 September 2009 ... The mechanical studies indicate that the composite having a stoichiometric ratio of BA (3 g) ... also synthesized by several authors using egg shell as the ... 2.1d Preparation of ESP with G (ESP–G): To 6 ml of ... 2.2c Infrared spectroscopy (FT–IR): The IR spectra of the.

  10. Pharmaceuticals as indictors of sewage-influenced groundwater

    Science.gov (United States)

    Müller, Beate; Scheytt, Traugott; Asbrand, Martin; de Casas, Andrea Mross

    2012-09-01

    A set of human pharmaceuticals enables identification of groundwater that is influenced by sewage and provides information on the time of recharge. As the consumption rates of the investigated pharmaceuticals have changed over time, so too has the composition of the sewage. At the study area, south of Berlin (Germany), irrigation was performed as a method of wastewater clean-up at sewage irrigation farms until the early 1990s. Today, treated wastewater is discharged into the surface-water-stream Nuthegraben. Groundwater and surface-water samples were analyzed for the pharmaceutical substances clofibric acid, bezafibrate, diclofenac, carbamazepine and primidone, the main ions and organic carbon. The pharmaceutical substances were detected at concentrations up to microgram-per-liter level in groundwater and surface-water samples from the Nuthegraben Lowland area and from the former irrigation farms. Concentrations detected in groundwater are generally much lower than in surface water and there is significant variation in the distribution of pharmaceutical concentrations in groundwater. Groundwater influenced by the irrigation of sewage water shows higher primidone and clofibric-acid concentrations. Groundwater influenced by recent discharge of treated sewage water into the surface water shows high carbamazepine concentrations while concentrations of primidone and clofibric acid are low.

  11. Bioactive carbon-PEEK composites prepared by chemical surface treatment.

    Science.gov (United States)

    Miyazaki, Toshiki; Matsunami, Chisato; Shirosaki, Yuki

    2017-01-01

    Polyetheretherketone (PEEK) has attracted much attention as an artificial intervertebral spacer for spinal reconstruction. Furthermore, PEEK plastic reinforced with carbon fiber has twice the bending strength of pure PEEK. However, the PEEK-based materials do not show ability for direct bone bonding, i.e., bioactivity. Although several trials have been conducted for enabling PEEK with bioactivity, few studies have reported on bioactive surface modification of carbon-PEEK composites. In the present study, we attempted the preparation of bioactive carbon-PEEK composites by chemical treatments with H 2 SO 4 and CaCl 2 . Bioactivity was evaluated by in vitro apatite formation in simulated body fluid (SBF). The apatite formation on the carbon-PEEK composite was compared with that of pure PEEK. Both pure PEEK and carbon-PEEK composite formed the apatite in SBF when they were treated with H 2 SO 4 and CaCl 2 ; the latter showed higher apatite-forming ability than the former. It is conjectured that many functional groups able to induce the apatite nucleation, such as sulfo and carboxyl groups, are incorporated into the dispersed carbon phase in the carbon-PEEK composites. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. [Preparation of sodium alginate-nanohydroxyapatite composite material for bone repair and its biocompatibility].

    Science.gov (United States)

    Wang, Yanmei; He, Jiacai; Li, Quanli; Shen, Jijia

    2014-02-01

    To prepare sodium alginate-nanohydroxyapatite composite material and to explore its feasibility as a bone repair material. Sodium alginate-nanohydroxyapatite composite material was prepared using chemical cross-linking and freeze-drying technology. The composite was characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) and its porosity was measured by liquid displacement method. The fifth passage of bone marrow stromal stem cells (BMSCs) were incubated on the composite material and then growth was observed by inverted microscope and SEM. BMSCs were cultured with liquid extracts of the material, methyl thiazolyl tetrazolium (MTT) assay was used to calculate the relative growth rate (RGR) on 1, 3, 5 d and to evaluate the cytotoxicity. Fresh dog blood was added into the liquid extracts to conduct hemolysis test, the spectrophotometer was used to determine the optical density (OD) and to calculate the hemolysis rate. Sodium alginate-nanohydroxyapatite composite material displayed porosity, the porous pore rate was (88.6 +/- 4.5)%. BMSCs showed full stretching and vigorous growth under inverted microscope and SEM. BMSCs cultured with liquid extracts of the material had good activities. The toxicity of composite material was graded as 1. Hemolysis test results showed that the hemolysis rate of the composite material was 1.28%, thus meeting the requirement of medical biomaterials. The composite material fabricated in this study has high porosity and good biocompatibility.

  13. Nacre biomimetic design—A possible approach to prepare low infrared emissivity composite coatings

    International Nuclear Information System (INIS)

    Zhang, Weigang; Xu, Guoyue; Ding, Ruya; Duan, Kaige; Qiao, Jialiang

    2013-01-01

    Mimicking the highly organized brick-and-mortar structure of nacre, a kind of nacre-like organic–inorganic composite material of polyurethane (PU)/flaky bronze composite coatings with low infrared emissivity was successfully designed and prepared by using PU and flaky bronze powders as adhesives and pigments, respectively. The infrared emissivity and microstructure of the coatings were systematically investigated by infrared emissometer and scanning electron microscopy, respectively, and the cause of low infrared emissivity of the coatings was discussed by using the theories of one-dimensional photonic structure. The results show that the infrared emissivity of the nacre-like PU/flaky bronze composite coatings can be as low as 0.206 at the bronze content of 60 wt. %, and it is significantly lower than the value of PU/sphere bronze composite coatings. Microstructure observation illustrated that the nacre-like PU/flaky bronze composite coatings have similar one-dimensional photonic structural characteristics. The low infrared emissivity of PU/flaky bronze composite coatings is derived from the similar one-dimensional photonic structure in the coatings. Highlights: ► Nacre-like composite coatings with low infrared emissivity were prepared. ► Infrared emissivity of PU/flaky bronze composite coatings can be as low as 0.206. ► One-dimensional photonic structure is the cause for low emissivity of the coatings.

  14. Preparation and electromagnetic properties of low-temperature sintered ferroelectric-ferrite composite ceramics

    International Nuclear Information System (INIS)

    Yue Zhenxing; Chen Shaofeng; Qi Xiwei; Gui Zhilun; Li Longtu

    2004-01-01

    For the purpose of multilayer chip EMI filters, the new ferroelectric-ferrite composite ceramics were prepared by mixing PMZNT relaxor ferroelectric powder with composition of 0.85Pb(Mg 1/3 Nb 2/3 )O 3 -0.1Pb(Ni 1/3 Nb 2/3 )O 3 -0.05PbTiO 3 and NiCuZn ferrite powder with composition of (Ni 0.20 Cu 0.20 Zn 0.60 )O(Fe 2 O 3 ) 0.97 at low sintering temperatures. A small amount of Bi 2 O 3 was added to low sintering temperature. Consequently, the dense composite ceramics were obtained at relative low sintering temperatures, which were lower than 940 deg. C. The X-ray diffractometer (XRD) identifications showed that the sintered ceramics retained the presence of distinct ferroelectric and ferrite phases. The sintering studies and scanning electron microscope (SEM) observations revealed that the co-existed two phases affect the sintering behavior and grain growth of components. The electromagnetic properties, such as dielectric constant and initial permeability, change continuously between those of two components. Thus, the low-temperature sintered ferroelectric-ferrite composite ceramics with tunable electromagnetic properties were prepared by adjusting the relative content of two components. These materials can be used for multilayer chip EMI filters with various properties

  15. Preparation of pinewood/polymer/composites using gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ajji, Zaki [Polymer Technology Division, Department of Radiation Technology, Atomic Energy Commission, P.O. Box 6091, Damascus (Syrian Arab Republic)]. E-mail: atomic@aec.org.sy

    2006-09-15

    Wood/polymer composites (WPC) have been prepared from pinewood with different compounds using gamma irradiation: butyl acrylate, butyl methacrylate, styrene, acrylamide, acrylonitrile, and unsaturated polyester styrene resin. The polymer loading was determined with respect to the compound concentration and the irradiation dose. The polymer loading increases generally with increase in the monomer or polymer concentration. Tensile and compression strength have been improved in the four cases, but no improvement was observed using unsaturated polyester styrene resin or acrylamide.

  16. [New research on the significance of polymers in pharmaceutical formulations].

    Science.gov (United States)

    Amighi, K

    2001-01-01

    During these last few decades, a lot of work has been made in pharmaceutical area in order to control the drug delivery from various pharmaceutical dosage forms. The use of polymers in pharmaceutical technology have led to the development of the first drug delivery systems proposed in order to prolong or to delay the drug delivery, or to enhance drug release for drugs showing bioavailability shortcomings. The wide range of polymers available for pharmaceutical use, their low reactivity towards drugs and other formulation ingredients and their safe nature, have permitted a widespread use of polymers to improve manufacturing processes or for the formulation of pharmaceutical dosage forms for various administration routes. More over, the preparation of new polymeric materials by the synthesis of new polymers with unique properties or by the modification of available natural or synthetic polymers, offer to the formulator a wide range of applications in order to optimise the drug delivery for each specific case.

  17. Preparation and characterization of the PVDF-based composite membrane for direct methanol fuel cells

    OpenAIRE

    Qian Liu, Laizhou Song, Zhihui Zhang, Xiaowei Liu

    2010-01-01

    The polyvinylidene fluoride-sulfonated polystyrene composite membrane with proton exchange performance, denoted as PVDF-SPS, was prepared using a thermally induced polymerization technique. The thermal stability of the PVDF-SPS composite membrane was investigated using thermogravimetric (TG) analysis. The complex formation of the composite membrane was ascertained by Fourier transform infrared spectroscopy (FTIR). The surface compositions of the PVDF-SPS membrane were analyzed using X-ray pho...

  18. Al/ B4C Composites with 5 and 10 wt% Reinforcement Content Prepared by Powder Metallurgy

    International Nuclear Information System (INIS)

    Yusof Abdullah; Mohd Reusmaazran Yusof; Azali Muhammad; Nadira Kamarudin; Wilfred Sylvester Paulus; Roslinda Shamsudin; Nasrat Hannah Shudin; Nurazila Mat Zali

    2012-01-01

    The preparation, physical and mechanical properties of Al/ B 4 C composites with 5 and 10 wt.% reinforcement content were investigated. In order to obtain the feedstock with a low powder loading, B 4 C mixtures containing fine powders were investigated to obtain the optimal particle packing. The experimental results indicated that the fine containing 5 and 10 wt.% particles are able to prepare the feedstock with a good flowability. The composites fabricated by powder metallurgy have low densities and homogeneous microstructures. Additionally there is no interface reaction observed between the reinforcement and matrix by XRD analysis. The hardness of Al/ B 4 C composites prepared by powder metallurgy was high. (Author)

  19. High-performance liquid chromatographic method for the determination of nicardipine in pure, pharmaceutical preparations and plasma and its application to pharmacokinetics in humans

    Directory of Open Access Journals (Sweden)

    Sheikha M. Al-Ghannam

    2009-01-01

    Full Text Available A simple, sensitive and reproducible reversed-phase liquid chromatographic method has been developed and validated for the determination of nicardipine hydrochloride (NC in pure, pharmaceutical preparations, human plasma and the study of the pharmacokinetics of the drug in human body. Nicardipine in plasma were extracted with hexane-butanol (12:1,v/v after addition of borate buffer (0.5 M, pH=9.0, and then measured by HPLC-UV using a Waters Symmetry C18 column as stationary phase and methanol– triethylamine buffer (0.01M pH 4 with acetic acid (70:30 as mobile phase. Nicardipine was quantified by ultraviolet absorbance at 353 nm. The method proved to be linear in the pure drug in the ranges of 15-200 ng/mL (r=0.9989 and 5-40 ?g/mL (r=0.9995, and for the pharmaceutical preparations and plasma for drug concentrations in the range of 5-40 ?g/mL (r =0.9992 and 25-150 ng/mL (r=0.9991, respectively. The lower limit of detection and the lower quantitation limit of NC in plasma were 11.74 and 35.57 ng/mL, respectively. The method is sensitive and reliable for harmacokineticstudies of nicardipine in humans after the oral administration of immediate-release capsules to healthy subjects.

  20. High-performance liquid chromatographic method for the determination of nicardipine in pure, pharmaceutical preparations and plasma and its application to pharmacokinetics in humans

    Directory of Open Access Journals (Sweden)

    Sheikha Mohammed Al-Ghannam

    2008-12-01

    Full Text Available A simple, sensitive and reproducible reversed-phase liquid chromatographic method has been developed and validated for the determination of nicardipine hydrochloride (NC in pure, pharmaceutical preparations, human plasma and the study of the pharmacokinetics of the drug in human body. Nicardipine in plasma were extracted with hexane-butanol (12:1,v/v after addition of borate buffer (0.5 M, pH=9.0, and then measured by HPLC-UV using a Waters Symmetry C18 column as stationary phase and methanol– triethylamine buffer (0.01M pH 4 with acetic acid (70:30 as mobile phase. Nicardipine was quantified by ultraviolet absorbance at 353 nm. The method proved to be linear in the pure drug in the ranges of 15-200 ng/mL (r=0.9989 and 5-40 µg/mL (r=0.9995, and for the pharmaceutical preparations and plasma for drug concentrations in the range of 5-40 µg/mL (r =0.9992 and 25-150 ng/mL (r=0.9991, respectively. The lower limit of detection and the lower quantitation limit of NC in plasma were 11.74 and 35.57 ng/mL, respectively. The method is sensitive and reliable for pharmacokinetic studies of nicardipine in humans after the oral administration of immediate-release capsules to healthy subjects.

  1. Clay based polymeric composites: Preparation and quality characterization

    International Nuclear Information System (INIS)

    Aloisi, G.G.; Elisei, F.; Nocchetti, M.; Camino, G.; Frache, A.; Costantino, U.; Latterini, L.

    2010-01-01

    Commercial clays Cloisites Na + , 30B and 20A were labelled with the fluorescent dye Rhodamine B and used as fillers of polypropylene in order to prepare composites to be studied with confocal fluorescence microscopy. The dye uptake by clays was monitored by X-ray powder diffraction and spectroscopic analyses and clear evidences of intercalated dye in the organically modified montmorillonites Clo30B and Clo20A were obtained. Clay-Rhodamine B hybrids were investigated by steady-state absorption and emission spectroscopy to explore the effect of dye arrangement on the optical properties. The obtained information was used to rationalize fluorescence behaviour of composites. Confocal fluorescence imaging gave rise to bright fluorescent images of Cloisite aggregated labelled with the dye allowing to easily and directly visualize the 3-D dispersion of the labelled fillers in the polymer matrix in a non-invasive manner. The images were analyzed in terms of size distribution of the fluorescence grains to quantify the dispersion degree. The data indicate that Clo20A is able to homogeneously distribute in the polymer matrix forming a composite material.

  2. Aqueous preparation of polyethylene glycol/sulfonated graphene phase change composite with enhanced thermal performance

    International Nuclear Information System (INIS)

    Li, Hairong; Jiang, Ming; Li, Qi; Li, Denian; Chen, Zongyi; Hu, Waping; Huang, Jing; Xu, Xizhe; Dong, Lijie; Xie, Haian; Xiong, Chuanxi

    2013-01-01

    Highlights: • We report an aqueous preparation technique of PEG/graphene phase change composite. • Hydrophilic sulfonated graphene (SG) nanosheets were synthesized. • Large increase in thermal conductivity is attained at low SG loading. • High latent heat is retained due to the low filler loading. • Affinity between SG and PEG contributes to the enhanced thermal performance. - Abstract: A polyethylene glycol (PEG)/sulfonated graphene (SG) phase change composite with enhanced thermal performance was prepared by solution processing in aqueous medium. It is remarkable that the addition of only 4 wt.% of SG to PEG could lead to a four times higher increase in thermal conductivity and a slight decrease in the phase change enthalpy, which is attributed to the formation of efficient thermal conductive network within the PEG matrix relevant to the excellent thermal property and unique 2-dimensional morphology of graphene as well as strong interface affinity between PEG matrix and SG nanosheets. The aqueous preparation technique is expected to pioneer a new way to prepare environment friendly organic phase change materials, and the production of PEG/SG composites is potentially scalable due to the facile fabricating process

  3. Effective executive management in the pharmaceutical industry.

    Science.gov (United States)

    Tran, Hoang; Kleiner, Brian H

    2005-01-01

    Along with the boom in information technology and vast development in genomic and proteomic discoveries, the pharmaceutical and biotech industries have been provided the means and tools to create a new page in medicinal history. They are now able to alter the classic ways to cure complex diseases thanks to the completion of the human genome project. To be able to compete in this industry, pharmaceutical management has to be effective not only internally but also externally in socially acceptable conduct. The first department that requires focus is marketing and sales. As the main driving force to increase revenues and profits, marketing and sales employees should be highly motivated by compensation. Also, customer relationships should be maintained for long-term gain. As important as marketing, research and development requires the financial support as well as the critical decision making to further expand the product pipeline. Similarly, finance and technologies should be adequately monitored and invested to provide support as well as prepare for future expansion. On top of that, manufacturing processes and operations are operated per quality systems and FDA guidelines to ensure high quality. Human Resources, on the other hand, should carry the managing and motivation from upper management through systematic recruitment, adequate training, and fair compensation. Moreover, effective management in a pharmaceutical would also require the social welfare and charity to help patients who cannot afford the treatment as well as improving the organization's image. Last but not least, the management should also prepare for the globalization of the industry. Inevitably, large pharmaceutical companies are merging with each other or acquiring smaller companies to enhance the competitive advantages as well as expand their product mix. For effectiveness in a pharmaceutical industry, management should focus more than just the daily routine tasks and short-term goals. Rather, they

  4. Preparation and application of conducting polymer/Ag/clay composite nanoparticles formed by in situ UV-induced dispersion polymerization

    Science.gov (United States)

    Zang, Limin; Qiu, Jianhui; Yang, Chao; Sakai, Eiichi

    2016-02-01

    In this work, composite nanoparticles containing polypyrrole, silver and attapulgite (PPy/Ag/ATP) were prepared via UV-induced dispersion polymerization of pyrrole using ATP clay as a templet and silver nitrate as photoinitiator. The effects of ATP concentration on morphology, structure and electrical conductivity were studied. The obtained composite nanoparticles with an interesting beads-on-a-string morphology can be obtained in a short time (10 min), which indicates the preparation method is facile and feasible. To explore the potential applications of the prepared PPy/Ag/ATP composite nanoparticles, they were served as multifunctional filler and blended with poly(butylene succinate) (PBS) matrix to prepare biodegradable composite material. The distribution of fillers in polymer matrix and the interfacial interaction between fillers and PBS were confirmed by scanning electron microscope, elemental mapping and dynamic mechanical analysis. The well dispersed fillers in PBS matrix impart outstanding antibacterial property to the biodegradable composite material as well as enhanced storage modulus due to Ag nanoparticles and ATP clay. The biodegradable composite material also possesses modest surface resistivity (106 ~ 109 Ω/◻).

  5. Preparation and application of conducting polymer/Ag/clay composite nanoparticles formed by in situ UV-induced dispersion polymerization.

    Science.gov (United States)

    Zang, Limin; Qiu, Jianhui; Yang, Chao; Sakai, Eiichi

    2016-02-03

    In this work, composite nanoparticles containing polypyrrole, silver and attapulgite (PPy/Ag/ATP) were prepared via UV-induced dispersion polymerization of pyrrole using ATP clay as a templet and silver nitrate as photoinitiator. The effects of ATP concentration on morphology, structure and electrical conductivity were studied. The obtained composite nanoparticles with an interesting beads-on-a-string morphology can be obtained in a short time (10 min), which indicates the preparation method is facile and feasible. To explore the potential applications of the prepared PPy/Ag/ATP composite nanoparticles, they were served as multifunctional filler and blended with poly(butylene succinate) (PBS) matrix to prepare biodegradable composite material. The distribution of fillers in polymer matrix and the interfacial interaction between fillers and PBS were confirmed by scanning electron microscope, elemental mapping and dynamic mechanical analysis. The well dispersed fillers in PBS matrix impart outstanding antibacterial property to the biodegradable composite material as well as enhanced storage modulus due to Ag nanoparticles and ATP clay. The biodegradable composite material also possesses modest surface resistivity (10(6)~ 10(9) Ω/◻).

  6. Structure and Properties of Multiwall Carbon Nanotubes/Polystyrene Composites Prepared via Coagulation Precipitation Technique

    Directory of Open Access Journals (Sweden)

    I. N. Mazov

    2011-01-01

    Full Text Available Coagulation technique was applied for preparation of multiwall carbon nanotube- (MWNT-containing polystyrene (PSt composite materials with different MWNT loading (0.5–10 wt.%. Scanning and transmission electron microscopies were used for investigation of the morphology and structure of produced composites. It was shown that synthesis of MWNT/PSt composites using coagulation technique allows one to obtain high dispersion degree of MWNT in the polymer matrix. According to microscopy data, composite powder consists of the polystyrene matrix forming spherical particles with diameter ca. 100–200 nm, and the surface of MWNT is strongly wetted by the polymer forming thin layer with 5–10 nm thickness. Electrical conductivity of MWNT/PSt composites was investigated using a four-probe technique. Observed electrical percolation threshold of composite materials is near to 10 wt.%, mainly due to the insulating polymer layer deposited on the surface of nanotubes. Electromagnetic response of prepared materials was investigated in broadband region (0.01–4 and 26–36 GHz. It was found that MWNT/PSt composites are almost radiotransparent for low frequency region and possess high absorbance of EM radiation at higher frequencies.

  7. Preparation of nickel-coated titanium carbide particulates and their use in the production of reinforced iron matrix composites

    International Nuclear Information System (INIS)

    Yi, Danqing; Yu, Pengchao; Hu, Bin; Liu, Huiqun; Wang, Bin; Jiang, Yong

    2013-01-01

    Highlights: • Ni-coated TiC composite powders were prepared by electroless plating. • Iron-based composites reinforced by TiC particles was prepared by HIP. • Mechanical and wear properties were improved with the addition of Ni-coated TiC. • The nickel coating promotes the formation and growth of sintering neck. - Abstract: Ni-coated titanium carbide (TiC) composite powders were prepared by electroless plating (EP). Further, using hot isostatic pressing (HIP), iron matrix composites reinforced with 4 wt% Ni-coated TiC particulates with relative density close to 100% were prepared. The microstructure and phase composition of the Ni-coated powders and the composites were analyzed using X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The results showed that the TiC particles were distributed uniformly in the matrix and were free of segregation or coarsening. Compared to the TiC particles without Ni coating, the reinforced iron-based composites containing the Ni-coated particles showed higher relative densities and better mechanical properties. The density, hardness, tensile strength, and elongation were enhanced to 99.98%, 243 HV, 565 MPa, and 11.7%, respectively in composites containing Ni-coated TiC particles from 99.70%, 210 HV, 514 MPa, and 10.3%, respectively in composites that were prepared using particles without Ni coating. In addition, the mass losses in the composites containing the Ni-coated particles were reduced by 32–75% in the abrasive wear test with various vertical loads. We propose that the nickel coatings on the particulates had a beneficial effect on the microstructure and properties of the reinforced iron-based composites is due to promotion of neck formation and growth between TiC and iron powders during sintering, which enhanced the density of the sintered compact and the bonding strength between the TiC particles and the iron matrix

  8. Chitosan Modification and Pharmaceutical/Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Jiali Zhang

    2010-06-01

    Full Text Available Chitosan has received much attention as a functional biopolymer for diverse applications, especially in pharmaceutics and medicine. Our recent efforts focused on the chemical and biological modification of chitosan in order to increase its solubility in aqueous solutions and absorbability in the in vivo system, thus for a better use of chitosan. This review summarizes chitosan modification and its pharmaceutical/biomedical applications based on our achievements as well as the domestic and overseas developments: (1 enzymatic preparation of low molecular weight chitosans/chitooligosaccharides with their hypocholesterolemic and immuno-modulating effects; (2 the effects of chitin, chitosan and their derivatives on blood hemostasis; and (3 synthesis of a non-toxic ion ligand—D-Glucosaminic acid from Oxidation of D-Glucosamine for cancer and diabetes therapy.

  9. Pharmaceutical care education in Kuwait: pharmacy students’ perspectives

    Directory of Open Access Journals (Sweden)

    Katoue MG

    2014-09-01

    Full Text Available Background: Pharmaceutical care is defined as the responsible provision of medication therapy to achieve definite outcomes that improve patients’ quality of life. Pharmacy education should equip students with the knowledge, skills, and attitudes they need to practise pharmaceutical care competently. Objective: To investigate pharmacy students’ attitudes towards pharmaceutical care, perceptions of their preparedness to perform pharmaceutical care competencies, opinions about the importance of the various pharmaceutical care activities, and the barriers to its implementation in Kuwait. Methods: A descriptive, cross-sectional survey of pharmacy students (n=126 was conducted at Faculty of Pharmacy, Kuwait University. Data were collected via a pre-tested self-administered questionnaire. Descriptive statistics including percentages, medians and means Likert scale rating (SD were calculated and compared using SPSS, version 19. Statistical significance was accepted at a p value of 0.05 or lower. Results: The response rate was 99.2%. Pharmacy students expressed overall positive attitudes towards pharmaceutical care. They felt prepared to implement the various aspects of pharmaceutical care, with the least preparedness in the administrative/management aspects. Perceived pharmaceutical care competencies grew as students progressed through the curriculum. The students also appreciated the importance of the various pharmaceutical care competencies. They agreed/strongly agreed that the major barriers to the integration of pharmaceutical care into practice were lack of private counseling areas or inappropriate pharmacy layout (95.2%, lack of pharmacist time (83.3%, organizational obstacles (82.6%, and pharmacists’ physical separation from patient care areas (82.6%. Conclusion: Pharmacy students’ attitudes and perceived preparedness can serve as needs assessment tools to guide curricular change and improvement. Student pharmacists at Kuwait University

  10. Preparation and characterization of titanate nanotubes/carbon composites

    International Nuclear Information System (INIS)

    Wang Xiaodong; Pan Hui; Xue Xiaoxiao; Qian Junjie; Yu Laigui; Yang Jianjun; Zhang Zhijun

    2011-01-01

    Highlights: → Titanate nanotubes/carbon composites were synthesized from TiO 2 -carbon composites. → The carbon shell of TiO 2 particles obstructed the reaction between TiO 2 and NaOH. → TEM, XRD, and Raman spectra reveal the formation processes of the TNT/CCs. - Abstract: Titanate nanotubes/carbon composites(TNT/CCs) were synthesized by allowing carbon-coated TiO 2 (CCT) powder to react with a dense aqueous solution of NaOH at 120 deg. C for a proper period of time. As-prepared CCT and TNT/CCs were characterized by means of transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectrometry. The processes for formation of titanate nanotubes/carbon composites were discussed. It was found that the TiO 2 particles in TiO 2 -carbon composite were enwrapped by a fine layer of carbon with a thickness of about 4 nm. This carbon layer functioned to inhibit the transformation from anatase TiO 2 to orthorhombic titanate. As a result, the anatase TiO 2 in CCT was incompletely transformed into orthorhombic titanate nanotubes upon 24 h of reaction in the dense and hot NaOH solution. When the carbon layers were gradually peeled off along with the formation of more orthorhombic titanate nanotubes at extended reaction durations (e.g., 72 h), anatase TiO 2 particles in CCT were completely transformed into orthorhombic titanate nanotubes, yielding TNT/CCs whose morphology was highly dependent on the reaction time and temperature.

  11. Preparation and photocatalytic activity of immobilized composite photocatalyst (titania nanoparticle/activated carbon)

    International Nuclear Information System (INIS)

    Mahmoodi, Niyaz Mohammad; Arami, Mokhtar; Zhang, Jason

    2011-01-01

    Research highlights: → Dyes were decolorized and degraded using novel immobilized composite photocatalyst. → Formate, acetate and oxalate anions were detected as dominant aliphatic intermediates where, they were further oxidized slowly to CO 2 . → Nitrate, chloride and sulfate anions were detected as the photocatalytic mineralization products of dyes. → Novel immobilized composite photocatalyst is the most effective novel immobilized composite photocatalyst to degrade of textile dyes. - Abstract: An immobilized composite photocatalyst, titania (TiO 2 ) nanoparticle/activated carbon (AC), was prepared and its photocatalytic activity on the degradation of textile dyes was tested. AC was prepared using Canola hull. Basic Red 18 (BR18) and Basic Red 46 (BR46) were used as model dyes. Fourier transform infrared (FTIR), wavelength dispersive X-ray spectroscopy (WDX), scanning electron microscopy (SEM), UV-vis spectrophotometry, chemical oxygen demand (COD) and ion chromatography (IC) analyses were employed. The effects of reaction parameters such as weight percent (wt.%) of activated carbon, pH, dye concentration and anions (NO 3 - , Cl - , SO 4 2- , HCO 3 - and CO 3 2- ) were investigated on dye degradation. Data showed that dyes were decolorized and degraded using novel immobilized composite photocatalyst. Formate, acetate and oxalate anions were detected as dominant aliphatic intermediates where, they were further oxidized slowly to CO 2 . Nitrate, chloride and sulfate anions were detected as the photocatalytic mineralization products of dyes. Results show that novel immobilized composite photocatalyst with 2 wt.% of AC is the most effective novel immobilized composite photocatalyst to degrade of textile dyes.

  12. Preparation and characterization of form-stable paraffin/polyurethane composites as phase change materials for thermal energy storage

    International Nuclear Information System (INIS)

    Chen, Keping; Yu, Xuejiang; Tian, Chunrong; Wang, Jianhua

    2014-01-01

    Highlights: • Paraffin/polyurethane composite as form-stable phase change material was prepared by bulk polymerization. • Paraffin/polyurethane composite possesses typical character of dual phase transition. • Total latent heat of n-eicosane/PUPCM is as high as 141.2 J/g. • Maximum encapsulation ratio for n-octadecane/PUPCM composites is 25% w/w. - Abstract: Polyurethane phase change material (PUPCM) has been demonstrated to be effective solid–solid phase change material for thermal energy storage. However, the high cost and complex process on preparation of PUPCMs with high enthalpy and broad phase transition temperature range can prohibit industrial-scale applications. In this work, a series of novel form-stable paraffin/PUPCMs composites (n-octadecane/PUPCM, n-eicosane/PUPCM and paraffin wax/PUPCM) with high enthalpy and broad phase transition temperature range (20–65 °C) were directly synthesized via bulk polymerization. The composites were prepared at different mass fractions of n-octadecane (10, 20, 25, 30% w/w). The results indicated that the maximum encapsulation ratio for n-octadecane/PUPCM10000 composites was around 25% w/w. The chemical structure and crystalline properties of these composites were characterized by Fourier transform infrared spectroscopy (FT-IR), polarizing optical microscopy (POM), wide-angle X-ray diffraction (WAXD). Thermal properties and thermal reliability of the composites were determined using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). From DSC analysis, the composites showed a typical dual phase change temperature. The enthalpy for the composite with 25% w/w n-eicosane was as high as 141.2 J/g. TGA analysis indicated that the composites degraded at considerably high temperatures. The process of preparation of PUPCMs and their composites was very simple, inexpensive, environmental friendly and easy to process into desired shapes, which could find the promising applications in solar

  13. Preparation of dexamethasone-loaded biphasic calcium phosphate nanoparticles/collagen porous composite scaffolds for bone tissue engineering.

    Science.gov (United States)

    Chen, Ying; Kawazoe, Naoki; Chen, Guoping

    2018-02-01

    Although bone is regenerative, its regeneration capacity is limited. For bone defects beyond a critical size, further intervention is required. As an attractive strategy, bone tissue engineering (bone TE) has been widely investigated to repair bone defects. However, the rapid and effective bone regeneration of large non-healing defects is still a great challenge. Multifunctional scaffolds having osteoinductivity and osteoconductivity are desirable to fasten functional bone tissue regeneration. In the present study, biomimetic composite scaffolds of collagen and biphasic calcium phosphate nanoparticles (BCP NPs) with a controlled release of dexamethasone (DEX) and the controlled pore structures were prepared for bone TE. DEX was introduced in the BCP NPs during preparation of the BCP NPs and hybridized with collagen scaffolds, which pore structures were controlled by using pre-prepared ice particulates as a porogen material. The composite scaffolds had well controlled and interconnected pore structures, high mechanical strength and a sustained release of DEX. The composite scaffolds showed good biocompatibility and promoted osteogenic differentiation of hMSCs when used for three-dimensional culture of human bone marrow-derived mesenchymal stem cells. Subcutaneous implantation of the composite scaffolds at the dorsa of athymic nude mice demonstrated that they facilitated the ectopic bone tissue regeneration. The results indicated the DEX-loaded BCP NPs/collagen composite scaffolds had high potential for bone TE. Scaffolds play a crucial role for regeneration of large bone defects. Biomimetic scaffolds having the same composition of natural bone and a controlled release of osteoinductive factors are desirable for promotion of bone regeneration. In this study, composite scaffolds of collagen and biphasic CaP nanoparticles (BCP NPs) with a controlled release nature of dexamethasone (DEX) were prepared and their porous structures were controlled by using ice particulates

  14. Radiation protection in the pharmaceutical-chemical industry

    International Nuclear Information System (INIS)

    Griesser, R.

    1992-01-01

    Some aspects of the use of ionizing radiation in research in the pharmaceutical and chemical industries will be discussed, the emphasis being placed on the handling of open radioactive materials in research laboratories. The compliance with official regulations and the preparation of company internal radiation protection regulations are described. 1 tab., 9 refs

  15. Utilization of a Green Brominating Agent for the Spectrophotometric Determination of Pipazethate HCl in Pure Form and Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    Ayman A. Gouda

    2013-01-01

    Full Text Available Five simple, accurate, and sensitive spectrophotometric methods (A–E have been described for the indirect assay of pipazethate HCl (PZT either in pure form or in pharmaceutical preparations. The proposed methods are based on the bromination of pipazethate HCl with a solution of excess bromate-bromide mixture in hydrochloric acid medium and subsequent estimation of the residual bromine by different reaction schemes. In the first three methods (A–C, the determination of the residual bromine is based on its ability to bleach the color of methyl orange, indigo carmine, or thymol blue dyes and measuring the absorbance at 520, 610, and 550 nm for methods A, B, and C, respectively. Methods D and E involves treating the unreacted bromine with a measured excess of iron(II, and the remaining iron(II is complexed with 1,10-phenanthroline, and the increase in absorbance is measured at 510 nm for method D and the resulting iron(III is complexed with thiocyanate and the absorbance is measured at 480 nm for method E. The different experimental parameters affecting the development and stability of the color are carefully studied and optimized. Regression analysis of the Beer-Lambert plots showed good correlation in the concentration ranges of 0.5–8.0 μg . The apparent molar absorptivity, Sandell's sensitivity, detection and quantitation limits were evaluated. The proposed methods have been applied and validated successfully for the analysis of the drug in its pure form and pharmaceutical formulations with mean recoveries of 99.94%–100.15% and relative standard deviation ≤1.53. No interference was observed from a common pharmaceutical adjuvant. Statistical comparison of the results with the reference method shows excellent agreement and indicates no significant difference in accuracy and precision.

  16. Microwave Irradiation Assisted Preparation of Chitosan Composite Microsphere for Dye Adsorption

    Directory of Open Access Journals (Sweden)

    Xiaoyu Chen

    2017-01-01

    Full Text Available Chitosan-activated carbon composite microspheres were prepared by emulsion cross-linking method and its adsorption properties for methyl orange were studied. Chitosan solution was mixed with activated carbon powder and then chitosan was cross-linked by epichlorohydrin under microwave irradiation. SEM photos show that the composite microspheres have diameters of 200–400 μm and activated carbon powder dispersed on the surface of composite microsphere. FTIR spectrum indicates chitosan is successfully cross-linked. Microwave irradiation can effectively shorten the cross-linking time. Composite microspheres have enhanced dye adsorption capacity for methyl orange compared to chitosan microspheres. Kinetic studies showed that the adsorption followed a pseudo-second-order model. Isotherm studies show that the isotherm adsorption equilibrium is better described by Freundlich isotherm. Regeneration results show that adsorption capacity of composite microsphere decreased about 5.51% after being reused for three times. These results indicated that chitosan-activated carbon composite microsphere has potential application in the removal of dye from wastewaters.

  17. Influence of preparation conditions of hollow silica–nickel composite spheres on their catalytic activity for hydrolytic dehydrogenation of ammonia borane

    Energy Technology Data Exchange (ETDEWEB)

    Umegaki, Tetsuo, E-mail: umegaki.tetsuo@nihon-u.ac.jp [Department of Materials and Applied Chemistry, College of Science and Engineering, Nihon University, 1-8-14, Kanda-Surugadai, Chiyoda-Ku, Tokyo 101-8308 (Japan); Seki, Ayano [Department of Materials and Applied Chemistry, College of Science and Engineering, Nihon University, 1-8-14, Kanda-Surugadai, Chiyoda-Ku, Tokyo 101-8308 (Japan); Xu, Qiang [National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan); Kojima, Yoshiyuki [Department of Materials and Applied Chemistry, College of Science and Engineering, Nihon University, 1-8-14, Kanda-Surugadai, Chiyoda-Ku, Tokyo 101-8308 (Japan)

    2014-03-05

    Highlights: • We study influence of preparation conditions on activity of hollow silica–nickel composite spheres. • The activity for hydrolytic dehydrogenation of NH{sub 3}BH{sub 3} increases with increase of Si+Ni content. • The particle size distribution affects the activity and reducibility of active nickel species. • The amount of PS residue in the hollow spheres decreases by treatment of as-prepared sample in toluene. -- Abstract: In this paper, we investigated influence of preparation conditions of hollow silica–nickel composite spheres on their morphology and catalytic activity for hydrolytic dehydrogenation of ammonia borane. In the preparation method of this study, when silica–nickel composite shells were coated on polystyrene templates by the sol–gel method using L(+)-arginine as the promoter for the reaction to form silica–nickel composite shell, the polystyrene templates were dissolved subsequently, even synchronously, in the same medium to form hollow spheres. The as-prepared silica–nickel composite spheres were characterized by transmission electron microscopy and scanning electron microscopy. The effects of Si+Ni content on the morphology were systematically evaluated. All the as-prepared hollow silica–nickel composite spheres have the similar morphology as identified by SEM and TEM measurement. Homogeneity of the hollow silica–nickel composite spheres increases with the increase in the Si+Ni content as shown by the laser diffraction particle size analysis. The catalytic activities of the hollow silica–nickel composite spheres for hydrolytic dehydrogenation of ammonia borane prepared with different Si+Ni contents were compared. The catalytic activity for the hydrogen evolution in the presence of the hollow spheres increases with the increase of Si+Ni content. The results of FTIR spectra of the hollow silica–nickel composite spheres indicate that a certain amount of residual PS templates exists in hollow silica

  18. High Dehumidification Performance of Amorphous Cellulose Composite Membranes prepared from Trimethylsilyl Cellulose

    KAUST Repository

    Puspasari, Tiara; Akhtar, Faheem Hassan; Ogieglo, Wojciech; Alharbi, Ohoud; Peinemann, Klaus-Viktor

    2018-01-01

    Cellulose is widely regarded as an environmentally friendly, natural and low cost material which can significantly contribute the sustainable economic growth. In this study, cellulose composite membranes were prepared via regeneration

  19. Preparation and analysis of multilayer composites based on polyelectrolyte complexes

    Energy Technology Data Exchange (ETDEWEB)

    Petrova, V. A. [Russian Academy of Sciences, Institute of Macromolecular Compounds (Russian Federation); Orekhov, A. S. [Russian Academy of Sciences, Shubnikov Institute of Crystallography, Federal Scientific Research Centre “Crystallography and Photonics” (Russian Federation); Chernyakov, D. D. [St. Petersburg State Chemical Pharmaceutical Academy (Russian Federation); Baklagina, Yu. G. [Russian Academy of Sciences, Institute of Macromolecular Compounds (Russian Federation); Romanov, D. P. [Russian Academy of Sciences, Grebenshchikov Institute of Silicate Chemistry (Russian Federation); Kononova, S. V. [Russian Academy of Sciences, Institute of Macromolecular Compounds (Russian Federation); Volod’ko, A. V.; Ermak, I. M. [Russian Academy of Sciences, Elyakov Pacific Institute of Bioorganic Chemistry, Far-Eastern Branch (Russian Federation); Klechkovskaya, V. V., E-mail: klechvv@ns.crys.ras.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography, Federal Scientific Research Centre “Crystallography and Photonics” (Russian Federation); Skorik, Yu. A., E-mail: yury-skorik@mail.ru [Russian Academy of Sciences, Institute of Macromolecular Compounds (Russian Federation)

    2016-11-15

    A method for preparing multilayer film composites based on chitosan has been developed by the example of polymer pairs: chitosan–hyaluronic acid, chitosan–alginic acid, and chitosan–carrageenan. The structure of the composite films is characterized by X-ray diffractometry and scanning electron microscopy. It is shown that the deposition of a solution of hyaluronic acid, alginic acid, or carrageenan on a chitosan gel film leads to the formation of a polyelectrolyte complex layer at the interface, which is accompanied by the ordering of chitosan chains in the surface region; the microstructure of this layer depends on the nature of contacting polymer pairs.

  20. Preparation and Characterization of K-Carrageenan/Nanosilica Biocomposite Film

    Directory of Open Access Journals (Sweden)

    Lokesh R. Rane

    2014-01-01

    Full Text Available The purpose of this study is to improve the performance properties of K-carrageenan (K-CRG by utilizing nanosilica (NSI as the reinforcing agent. The composite films were prepared by solution casting method. NSI was added up to 1.5% in the K-CRG matrix. The prepared films were characterized for mechanical (tensile strength, tensile modulus, and elongation at break, thermal (differential scanning calorimetry, thermogravimetric analysis, barrier (water vapour transmission rate, morphological (scanning electron microscopy, contact angle, and crystallinity properties. Tensile strength, tensile modulus, and crystallinity were found to have increased by 13.8, 15, and 48% whereas water vapour transmission rate was found to have decreased by 48% for 0.5% NSI loaded K-CRG composite films. NSI was found to have formed aggregates for concentrations above 0.5% as confirmed by scanning electron microscopy. Melting temperature, enthalpy of melting, and degradation temperature of K-CRG increased with increase in concentration of NSI in K-CRG. Contact angle also increased with increase in concentration of NSI in K-CRG, indicating the decrease in hydrophilicity of the films improving its water resistance properties. This knowledge of the composite film could make beneficial contributions to the food and pharmaceutical packaging applications.

  1. Gas sensing properties of graphene–WO3 composites prepared by hydrothermal method

    International Nuclear Information System (INIS)

    Chu, Xiangfeng; Hu, Tao; Gao, Feng; Dong, Yongping; Sun, Wenqi; Bai, Linshan

    2015-01-01

    Graphical abstract: - Highlights: • The amount of graphene had an effect on the morphology of graphene–WO 3 composites. • The optimum temperature of 0.1 wt% graphene–WO 3 sensor to acetaldehyde was 100 °C. • 0.1 wt% graphene–WO 3 sensor exhibited good selectivity to acetaldehyde at 100 °C. - Abstract: Graphene–WO 3 composites mixed with different amounts of graphene (0, 0.1, 0.5, 1 and 3 wt%) were prepared by hydrothermal method at 180 °C for 24 h. The as-prepared graphite oxide, graphene and graphene–WO 3 composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectra (FT-IR) and Raman spectroscopy, respectively. The effect of the amount of graphene in the composites on the gas-sensing responses and the gas-sensing selectivity of the materials was investigated. The experimental results revealed that the sensor based on 0.1 wt% graphene–WO 3 composite exhibited high response and good selectivity to acetaldehyde vapor at 100 °C, the optimum operating temperature of this sensor to 1000 ppm acetaldehyde vapor decreased from 180 °C to 100 °C comparing with that of pure WO 3 . The response time and the recovery time for 100 ppm acetaldehyde vapor were 250 s and 225 s, respectively

  2. Potassium diperiodatocuprate-mediated preparation of poly(methyl methacrylate/organo-montmorillonite composites via in situ grafting copolymerization

    Directory of Open Access Journals (Sweden)

    2008-09-01

    Full Text Available In this study, potassium diperiodatocuprate (Cu3+ was selected as an initiator to prepare poly(methyl methacrylate/organo-montmorillonite composites (OMMT-g-PMMA by in situ graft copolymerization. Three synthetic parameters were systematically evaluated as a function of the temperature, the concentration of initiator, pH and the ratio of MMA to OMMT. It was found that Cu3+ was a highly efficient initiator for the preparation of OMMT-g-PMMA i.e., monomer conversion and grafting efficiency were as higher as 95%. The X-ray diffraction measurement showed the intercalation of PMMA chains into OMMT layers on base of an increasing basal spacing after polymerization. FTIR analysis also suggested that the PMMA chains were effectively grafted onto OMMT substrate. The enhanced thermal stabilities of OMMT-g-PMMA composites were confirmed by the thermal gravimetric analysis (TGA. Finally, a single-electron-transfer mechanism was proposed to illustrate the formation of radicals and the preparation process of OMMT-g-PMMA composites. Cu3+ can be used as an effective and practical initiator in preparing the organic/inorganic composite due to its high grafting efficiency and the milder reaction condition.

  3. Flame retardancy of polyaniline-deposited paper composites prepared via in situ polymerization.

    Science.gov (United States)

    Wu, Xianna; Qian, Xueren; An, Xianhui

    2013-01-30

    Polyaniline-deposited paper composites doped with three inorganic acids were prepared via in situ polymerization, and their flame-retardant properties were investigated. Both the conductivity and flame retardancy of the composite increased with the increase of the amount of the polyaniline deposited. The doping acid played a very key role in both the conductivity and flame retardancy of the composite. The comprehensive properties of the composite could be improved when codoped with an equimolar mixture of H(3)PO(4) and H(2)SO(4) or H(3)PO(4) and HCl. The decay of the flame retardancy of the composite in atmosphere was due to the dedoping of the polyaniline deposited on cellulose fibers. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Monitoring and removal of residual phthalate esters and pharmaceuticals in the drinking water of Kaohsiung City, Taiwan.

    Science.gov (United States)

    Yang, Gordon C C; Yen, Chia-Heng; Wang, Chih-Lung

    2014-07-30

    This study monitored the occurrence and removal efficiencies of 8 phthalate esters (PAEs) and 13 pharmaceuticals present in the drinking water of Kaohsiung City, Taiwan. The simultaneous electrocoagulation and electrofiltration (EC/EF) process was used to remove the contaminants. To this end, a monitoring program was conducted and a novel laboratory-prepared tubular carbon nanofiber/carbon/alumina composite membrane (TCCACM) was incorporated into the EC/EF treatment module (collectively designated as "TCCACM-EC/EF treatment module") to remove the abovementioned compounds from water samples. The monitoring results showed that the concentrations of PAEs were lower in water samples from drinking fountains as compared with tap water samples. No significant differences were found between the concentrations of pharmaceuticals in the two types of water samples. Under optimal operating conditions, the TCCACM-EC/EF treatment module yielded the lowest residual concentrations, ranging from not detected (ND) to 52ng/L for PAEs and pharmaceuticals of concern in the tap water samples. Moreover, the performance of the TCCACM-EC/EF treatment module is comparable with a series of treatment units employed for the drinking fountain water treatment system. The relevant removal mechanisms involved in the TCCACM-EC/EF treatment module were also discussed in this work. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Preparation and physical properties of vapour-deposited carbon-carbon composites

    International Nuclear Information System (INIS)

    Loll, Philippe

    1976-01-01

    In its first part, this research thesis reports a bibliographical study on methods of preparation of various types of vapour-deposited (CVD) carbons, and the author notices that only structure and texture properties of these macroscopically homogeneous pyro-carbons have been studied in detail. For a better understanding of the behaviour of carbon-carbon composites, this thesis thus reports the study of the relationships between physical properties, macroscopic texture and microscopic structure. A densification installation and methods of characterisation have been developed. The fabrication process and its installation are presented (oven with its temperature and gas rate controls, study of its thermal gradient, substrate, heat treatments), and the study and characterisation of carbon-carbon composites are reported: structure and texture properties (studied by optic and scanning electronic microscopy, density measurements, and X-ray diffraction), physical properties (electronic paramagnetic resonance, static magnetism, electric and thermal conductivity). In the last part, the author comments and discusses the obtained results: conditions of preparation, existence, physical properties of the different observed microstructures [fr

  6. Activated carbon/ZnO composites prepared using hydrochars as intermediate and their electrochemical performance in supercapacitor

    International Nuclear Information System (INIS)

    Li, Yueming; Liu, Xi

    2014-01-01

    We report a new methodology to prepare activated carbon and activated carbons/ZnO composites from walnut shell-derived hydrothermal carbons (hydrochars), which were prepared under hydrothermal condition in presence of ZnCl 2 . For this method, activated carbon/ZnO composites were prepared via heat treatment of hydrochars under inert environment and activated carbons were prepared by removing the ZnO in activated carbon/ZnO composites. The chemical structure of walnut shell, hydrochars, activated carbon/ZnO and activated carbon was investigated by Fourier transform infrared spectroscopy, Raman, X-ray powder diffraction, thermogravimetric analysis and N 2 adsorption/desorption measurements. It is found ZnCl 2 plays multiple roles, i.e., helping to remove the oxygen-containing groups during hydrothermal stage, improving the surface area of activated carbon and acting as the precursor of ZnO in heat-treatment stage. The specific surface areas up to 818.9 and 1072.7 m 2  g −1 have been achieved for activated carbon/ZnO composites and activated carbon, respectively. The activated carbon/ZnO as electrode materials for supercapacitors showed that specific capacitance of up to 117.4 F g −1 at a current density of 0.5 A g −1 in KOH aqueous solution can be achieved and keeps stable in 1000 cycles. - Highlights: • Hydrochars as intermediate to prepare activated carbon/ZnO composites. • Activated carbon/ZnO showed excellent electrochemical performance in supercapacitors. • Activated carbon with large surface area can be obtained by removing ZnO

  7. Preparation and Properties of Silver Nanowire-Based Transparent Conductive Composite Films

    Science.gov (United States)

    Tian, Ji-Li; Zhang, Hua-Yu; Wang, Hai-Jun

    2016-06-01

    Silver nanowire-based transparent conductive composite films with different structures were successfully prepared using various methods, including liquid polyol, magnetron sputtering and spin coating. The experimental results revealed that the optical transmittance of all different structural composite films decreased slightly (1-3%) compared to pure films. However, the electrical conductivity of all composite films had a great improvement. Under the condition that the optical transmittance was greater than 78% over the wavelength range of 400-800 nm, the AgNW/PVA/AgNW film became a conductor, while the AZO/AgNW/AZO film and the ITO/AgNW/ITO film showed 88.9% and 94% reductions, respectively, for the sheet resistance compared with pure films. In addition, applying a suitable mechanical pressure can improve the conductivity of AgNW-based composite films.

  8. Preparation of Fe–Si–Ni soft magnetic composites with excellent high-frequency properties

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Wei; Wu, Chen, E-mail: chen_wu@zju.edu.cn; Yan, Mi, E-mail: mse_yanmi@zju.edu.cn

    2015-05-01

    Fe–Si–Ni powders were firstly prepared into soft magnetic composites (SMCs) by ball milling, surface passivation and subsequent compaction. The morphology, phase composition, and magnetic properties of the Fe–Si–Ni powders and their high-frequency performance as SMCs were investigated. The Fe–Si–Ni powders, with saturation magnetization (M{sub s}) of 254.40 emu/g after annealing, were milled down to particle sizes ranging from 40 μm to 150 μm. Surface passivation of the powders was carried out with 0.2–1.0 wt% phosphoric acid solution prior to compaction. Evolution of the high-frequency properties for the Fe–Si–Ni SMCs with the passivator concentration and the molding pressure was studied. With optimized preparation parameters, high saturation flux density (B{sub s}) of 1.23 T, stable permeability, and superior dc-bias property with a percentage permeability above 70% while H=50 Oe were achieved for the Fe–Si–Ni SMC. Minimum core loss (285 mW/cm{sup 3}) was also measured at 50 kHz for B{sub m}=50 mT. - Highlights: • Fe–Si–Ni as a new type of magnetic powder has been prepared into soft magnetic composites. • Effective surface passivation of the Fe–Si–Ni powders can be achieved by phosphate treatment. • Influence of the passivator concentration and molding pressure has been investigated. • The obtained Fe–Si–Ni soft magnetic composites exhibit excellent high-frequency performance.

  9. Pharmaceutical Cocrystals: New Solid Phase Modification Approaches for the Formulation of APIs

    Directory of Open Access Journals (Sweden)

    Anna Karagianni

    2018-01-01

    Full Text Available Cocrystals can be used as an alternative approach based on crystal engineering to enhance specific physicochemical and biopharmaceutical properties of active pharmaceutical ingredients (APIs when the approaches to salt or polymorph formation do not meet the expected targets. In this article, an overview of pharmaceutical cocrystals will be presented, with an emphasis on the intermolecular interactions in cocrystals and the methods for their preparation. Furthermore, cocrystals of direct pharmaceutical interest, along with their in vitro properties and available in vivo data and characterization techniques are discussed, highlighting the potential of cocrystals as an attractive route for drug development.

  10. Pharmaceutical Cocrystals: New Solid Phase Modification Approaches for the Formulation of APIs.

    Science.gov (United States)

    Karagianni, Anna; Malamatari, Maria; Kachrimanis, Kyriakos

    2018-01-25

    Cocrystals can be used as an alternative approach based on crystal engineering to enhance specific physicochemical and biopharmaceutical properties of active pharmaceutical ingredients (APIs) when the approaches to salt or polymorph formation do not meet the expected targets. In this article, an overview of pharmaceutical cocrystals will be presented, with an emphasis on the intermolecular interactions in cocrystals and the methods for their preparation. Furthermore, cocrystals of direct pharmaceutical interest, along with their in vitro properties and available in vivo data and characterization techniques are discussed, highlighting the potential of cocrystals as an attractive route for drug development.

  11. Preparation and characterization of bagasse/HDPE composites using multi-walled carbon nanotubes.

    Science.gov (United States)

    Ashori, Alireza; Sheshmani, Shabnam; Farhani, Foad

    2013-01-30

    This article presents the preparation and characterization of bagasse/high density polyethylene (HDPE) composites. The effects of multi-walled carbon nanotubes (MWCNTs), as reinforcing agent, on the mechanical and physical properties were also investigated. In order to increase the interphase adhesion, maleic anhydride grafted polyethylene (MAPE) was added as a coupling agent to all the composites studied. In the sample preparation, MWCNTs and MAPE contents were used as variable factors. The morphology of the specimens was characterized using scanning electron microscopy (SEM) technique. The results of strength measurement indicated that when 1.5 wt% MWCNTs were added, tensile and flexural properties reached their maximum values. At high level of MWCNTs loading (3 or 4 wt%), increased population of MWCNTs lead to agglomeration and stress transfer gets blocked. The addition of MWCNTs filler slightly decreased the impact strength of composites. Both mechanical and physical properties were improved when 4 wt% MAPE was applied. SEM micrographs also showed that the surface roughness improved with increasing MAPE loading from 0 to 4 wt%. The improvement of physicomechanical properties of composites confirmed that MWCNTs have good reinforcement and the optimum synergistic effect of MWCNTs and MAPE was achieved at the combination of 1.5 and 4 wt%, respectively. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Pharmaceutical cocrystals: along the path to improved medicines.

    Science.gov (United States)

    Duggirala, Naga K; Perry, Miranda L; Almarsson, Örn; Zaworotko, Michael J

    2016-01-14

    Cocrystals, a long known but understudied class of crystalline solids, have attracted interest from crystal engineers and pharmaceutical scientists in the past decade and are now an integral part of the preformulation stage of drug development. This is largely because cocrystals that contain a drug molecule, pharmaceutical cocrystals, can modify physicochemical properties without the need for covalent modification of the drug molecule. This review presents a brief history of cocrystals before addressing recent advances in design, discovery and development of pharmaceutical cocrystals that have occurred since an earlier review published in 2004. We address four aspects of cocrystals: nomenclature; design using hydrogen-bonded supramolecular synthons; methods of discovery and synthesis; development of pharmaceutical cocrystals as drug products. Cocrystals can be classified into molecular cocrystals (MCCs) that contain only neutral components (coformers) and ionic cocrystals (ICCs), which are comprised of at least one ionic coformer that is a salt. That cocrystals, especially ICCs, offer much greater diversity in terms of composition and properties than single component crystal forms and are amenable to design makes them of continuing interest. Seven recent case studies that illustrate how pharmaceutical cocrystals can improve physicochemical properties and clinical performance of drug substances, including a recently approved drug product based upon an ICC, are presented.

  13. Preparation of SnO 2 /Carbon Composite Hollow Spheres and Their Lithium Storage Properties

    KAUST Repository

    Lou, Xiong Wen; Deng, Da; Lee, Jim Yang; Archer, Lynden A.

    2008-01-01

    In this work, we present a novel concept of structural design for preparing functional composite hollow spheres and derived double-shelled hollow spheres. The approach involves two main steps: preparation of porous hollow spheres of one component and deposition of the other component onto both the interior and exterior surfaces of the shell as well as in the pores. We demonstrate the concept by preparing SnO2/carbon composite hollow spheres and evaluate them as potential anode materials for lithium-ion batteries. These SnO2/carbon hollow spheres are able to deliver a reversible Li storage capacity of 473 mA h g-1 after 50 cycles. Unusual double-shelled carbon hollow spheres are obtained by selective removal of the sandwiched porous SnO2 shells. © 2008 American Chemical Society.

  14. Preparation of SnO 2 /Carbon Composite Hollow Spheres and Their Lithium Storage Properties

    KAUST Repository

    Lou, Xiong Wen

    2008-10-28

    In this work, we present a novel concept of structural design for preparing functional composite hollow spheres and derived double-shelled hollow spheres. The approach involves two main steps: preparation of porous hollow spheres of one component and deposition of the other component onto both the interior and exterior surfaces of the shell as well as in the pores. We demonstrate the concept by preparing SnO2/carbon composite hollow spheres and evaluate them as potential anode materials for lithium-ion batteries. These SnO2/carbon hollow spheres are able to deliver a reversible Li storage capacity of 473 mA h g-1 after 50 cycles. Unusual double-shelled carbon hollow spheres are obtained by selective removal of the sandwiched porous SnO2 shells. © 2008 American Chemical Society.

  15. Preparation and characterization of poly(lactic acid)/ zinc-aluminium layered double hydroxide nano composites

    International Nuclear Information System (INIS)

    Eili Mahboobeh; Wan Mohd Zin Wan Yunus; Zobir Hossein; Mansor Ahmad; Norazowa Ibrahim

    2009-01-01

    Full text: Poly (lactic acid)/ stearate - zinc aluminum layered double hydroxide/ (PLA/ SZnAl LDH) nano composites were prepared via solution intercalation process using a modified ZnAl LDH. The anionic clay Zn 3 Al-NO 3 -LDH was prepared by a co-precipitation method and then modified with stearate ions by ion exchange process. Stearate-ZnAl LDH particles were then homogeneously dispersed in PLA matrix by a solution casting method. The pristine and modified ZnAl LDH was characterized by X-ray diffraction (XRD) and Fourier transforms infrared (FTIR) spectroscopy which suggested that the modification was successful. The XRD analysis showed that during modification of LDH, the basal spacing increased from 8.83 Angstrom to 40.1 Angstrom. The PLA/ ZnAl LDH nano composites were characterized by tensile testing and XRD. The obtained nano composites showed dramatic enhancements in elongation at break as compared to those of the pure PLA. XRD results indicated that the materials formed are nano composites. (author)

  16. Preparation of chitosan-collagen-alginate composite dressing and its promoting effects on wound healing.

    Science.gov (United States)

    Xie, Haixia; Chen, Xiuli; Shen, Xianrong; He, Ying; Chen, Wei; Luo, Qun; Ge, Weihong; Yuan, Weihong; Tang, Xue; Hou, Dengyong; Jiang, Dingwen; Wang, Qingrong; Liu, Yuming; Liu, Qiong; Li, Kexian

    2018-02-01

    The present study aimed to prepare a composite dressing composed of collagen, chitosan, and alginate, which may promote wound healing and prevent from seawater immersion. Chitosan-collagen-alginate (CCA) cushion was prepared by paintcoat and freeze-drying, and it was attached to a polyurethane to compose CCA composite dressing. The swelling, porosity, degradation, and mechanical properties of CCA cushion were evaluated. The effects on wound healing and seawater prevention of CCA composite dressing were tested by rat wound model. Preliminary biosecurity was tested by cytotoxicity and hemocompatibility. The results revealed that CCA cushion had good water absorption and mechanical properties. A higher wound healing ratio was observed in CCA composite dressing treated rats than in gauze or chitosan treated ones. On the fifth day, the healing rates of CCA composite dressing, gauze, and chitosan were 48.49%±1.07%, 28.02%±6.4%, and 38.97%±8.53%, respectively. More fibroblast and intact re-epithelialization were observed in histological images of CCA composite dressing treated rats, and the expressions of EGF, bFGF, TGF-β, and CD31 increased significantly. CCA composite dressing showed no significant cytotoxicity, and favorable hemocompatibility. These results suggested that CCA composite dressing could prevent against seawater immersion and promote wound healing while having a good biosecurity. Copyright © 2017. Published by Elsevier B.V.

  17. Preparation of Ti-aluminide reinforced in situ aluminium matrix composites by reactive hot pressing

    International Nuclear Information System (INIS)

    Roy, D.; Ghosh, S.; Basumallick, A.; Basu, B.

    2007-01-01

    Aluminium based metal matrix composites reinforced with in situ Ti-aluminide and alumina particles were prepared by reactive hot pressing a powder mix of aluminium and nanosized TiO 2 powders. The reinforcements were formed in situ by exothermal reaction between the TiO 2 nano crystalline powder and aluminium. The thermal characteristics of the in situ reaction were studied with the aid of Differential scanning calorimetry (DSC). X-ray diffraction (XRD), Energy dispersive spectroscopy (EDS) and Scanning electron microscopy (SEM) techniques were employed to study the microstructural architecture of the composites as a function of hot pressing temperature and volume percent reinforcement. Microhardness measurements on the as prepared in situ aluminium matrix composites exhibit significant increase in hardness with increase in hot pressing temperature and volume fraction of reinforcement

  18. Preparation of organophilic clays and polypropylene nano composites

    International Nuclear Information System (INIS)

    Lima, Martha Fogliato S.; Nascimento, Vinicius G. do; Lenz, Denise M.; Schenato, Flavia

    2011-01-01

    Polypropylene/montmorillonite nano composites were prepared by the melt intercalation technique. The clay was organically modified with different quaternary ammonium salts to obtain the organo clay. The modified clays with the quaternary ammonium salts were introduced in a polypropylene matrix with 3 wt. % of clay. The interlayer distance (d001) of the clay particles were obtained by X- ray diffraction and the thermal stability of the systems were investigated by thermogravimetry. The organo clay presence in the polymer matrix increased the degradation temperature in relation to the pure polymer. (author)

  19. Preparation and characterization of poly(vinylidene fluoride) based composite electrolytes for electrochemical devices

    International Nuclear Information System (INIS)

    Karabelli, D.; Leprêtre, J.-C.; Cointeaux, L.; Sanchez, J.-Y.

    2013-01-01

    Highlights: • Macroporous PVdF based membranes for electrochemical applications were prepared with support materials. • Woven PET and PA fabrics and non-woven cellulose paper are used as support materials. • Porous structure of PVdF was obtained on the support material. • Interaction between the electrolyte solvent and the composite material played an important role on the mechanical properties. • Compared to the pure PVdF separators, enhanced mechanical strength was obtained for composite separators, without decreasing the ionic conductivity. -- Abstract: PVdF-based separators are very promising materials in electrochemical energy storage systems but they suffer from fairly poor mechanical properties. To overcome this drawback, composite PVdF separators were fabricated and characterized in electrolytes of Li-ion batteries and supercapacitors. Macroporous PVdF composite separators were prepared by phase inversion method using PA and PET, and non-woven cellulose as support layers. Ionic conductivity and thermomechanical analyses were performed using electrolytes of Li-ion batteries and supercapacitors. The composite approach allowed a tremendous increase of the mechanical performances of the separator (between 340 and 750 MPa) compared to the unreinforced PVdF separator (56 MPa), without compromising the ionic conductivities (up to 15.6 mS cm −1 )

  20. Experimental Optimization In Polymer BLEND Composite Preparation Based On Mix Level of Taguchi Robust Design

    International Nuclear Information System (INIS)

    Abdul Aziz Mohamed; Jaafar Abdullah; Dahlan Mohd; Rozaidi Rasid; Megat Harun AlRashid Megat Ahmad; Mahathir Mohamad; Mohd Hamzah Harun

    2012-01-01

    L 18 orthogonal array in mix level of Taguchi robust design method was carried out to optimize experimental conditions for the preparation of polymer blend composite. Tensile strength and neutron absorption of the composite were the properties of interest. Filler size, filler loading, ball mixing time and dispersion agent concentration were selected as parameters or factors which are expected to affect the composite properties. As a result of Taguchi analysis, filler loading was the most influencing parameter on the tensile strength and neutron absorption. The least influencing was ball-mixing time. The optimal conditions were determined by using mix-level Taguchi robust design method and a polymer composite with tensile strength of 6.33 MPa was successfully prepared. The composite was found to fully absorb thermal neutron flux of 1.04 x 10 5 n/ cm 2 / s with only 2 mm in thickness. In addition, the filler was also characterized by scanning electron microscopy (SEM) and elemental analysis (EDX). (Author)

  1. Preparation of Pt Ag alloy nanoisland/graphene hybrid composites and its high stability and catalytic activity in methanol electro-oxidation

    Directory of Open Access Journals (Sweden)

    Feng Lili

    2011-01-01

    Full Text Available Abstract In this article, PtAg alloy nanoislands/graphene hybrid composites were prepared based on the self-organization of Au@PtAg nanorods on graphene sheets. Graphite oxides (GO were prepared and separated to individual sheets using Hummer's method. Graphene nano-sheets were prepared by chemical reduction with hydrazine. The prepared PtAg alloy nanomaterial and the hybrid composites with graphene were characterized by SEM, TEM, and zeta potential measurements. It is confirmed that the prepared Au@PtAg alloy nanorods/graphene hybrid composites own good catalytic function for methanol electro-oxidation by cyclic voltammograms measurements, and exhibited higher catalytic activity and more stability than pure Au@Pt nanorods and Au@AgPt alloy nanorods. In conclusion, the prepared PtAg alloy nanoislands/graphene hybrid composites own high stability and catalytic activity in methanol electro-oxidation, so that it is one kind of high-performance catalyst, and has great potential in applications such as methanol fuel cells in near future.

  2. Preparation of zeolite-A/chitosan hybrid composites and their bioactivities and antimicrobial activities.

    Science.gov (United States)

    Yu, Liang; Gong, Jie; Zeng, Changfeng; Zhang, Lixiong

    2013-10-01

    Zeolite-A/chitosan hybrid composites with zeolite contents of 20-55 wt.% were prepared by in situ transformation of silica/chitosan mixtures in a sodium aluminate alkaline solution through impregnation-gelation-hydrothermal synthesis. The products were characterized by X-ray diffraction, diffuse reflectance infrared Fourier transform spectroscopy, scanning electron microscopy, thermogravimetric analysis, and mercury penetration porosimetry. Their in vitro bioactivities were examined using as-synthesized and Ca(2+)-exchanged hybrid composites in simulated body fluid (SBF) for hydroxyapatite (HAP) growth. Their antimicrobial activities for Escherichia coli (E. coli) in trypticase soy broth (TSB) were evaluated using Ag(+)-exchanged hybrid composites. The zeolite-A/chitosan hybrid composites could be prepared as various shapes, including cylinders, plates and thin films. They possessed macropores with pore sizes ranging from 100 to 300 μm and showed compressive mechanical strength as high as 3.2 MPa when the zeolite content was 35 wt.%. Fast growth on the Ca(2+)-exchanged hybrid composites was observed with the highest weight gain of 51.4% in 30 days. The 35 wt.% Ag(+)-exchanged hybrid composite showed the highest antimicrobial activity, which could reduce the 9×10(6) CFU mL(-1)E. coli concentration to zero within 4h of incubation time with the Ag(+)-exchanged hybrid composite amount of 0.4 g L(-1). The bioactivity and antimicrobial activity could be combined by ion-exchanging the composites first with Ca(2+) and then with Ag(+). These zeolite-A/chitosan hybrid composites have potential applications on tissue engineering and antimicrobial food packaging. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Pharmaceutical Cocrystals: New Solid Phase Modification Approaches for the Formulation of APIs

    OpenAIRE

    Anna Karagianni; Maria Malamatari; Kyriakos Kachrimanis

    2018-01-01

    Cocrystals can be used as an alternative approach based on crystal engineering to enhance specific physicochemical and biopharmaceutical properties of active pharmaceutical ingredients (APIs) when the approaches to salt or polymorph formation do not meet the expected targets. In this article, an overview of pharmaceutical cocrystals will be presented, with an emphasis on the intermolecular interactions in cocrystals and the methods for their preparation. Furthermore, cocrystals of direct phar...

  4. submitter Preparation and luminescence properties of ZnO:Ga – polystyrene composite scintillator

    CERN Document Server

    Burešová, Hana; Turtos, Rosana Martinez; Jarý, Vítězslav; Mihóková, Eva; Beitlerová, Alena; Pjatkan, Radek; Gundacker, Stefan; Auffray, Etiennette; Lecoq, Paul; Nikl, Martin; Čuba, Václav

    2016-01-01

    Highly luminescent ZnO:Ga-polystyrene composite (ZnO:Ga-PS) with ultrafast subnanosecond decay was prepared by homogeneous embedding the ZnO:Ga scintillating powder into the scintillating organic matrix. The powder was prepared by photo-induced precipitation with subsequent calcination in air and Ar/H2 atmospheres. The composite was subsequently prepared by mixing the ZnO:Ga powder into the polystyrene (10 wt% fraction of ZnO:Ga) and press compacted to the 1 mm thick pellet. Luminescent spectral and kinetic characteristics of ZnO:Ga were preserved. Radioluminescence spectra corresponded purely to the ZnO:Ga scintillating phase and emission of polystyrene at 300-350 nm was absent. These features suggest the presence of non-radiative energy transfer from polystyrene host towards the ZnO:Ga scintillating phase which is confirmed by the measurement of X-ray excited scintillation decay with picosecond time resolution. It shows an ultrafast rise time below the time resolution of the experiment (18 ps) and a single-...

  5. Activated carbon/ZnO composites prepared using hydrochars as intermediate and their electrochemical performance in supercapacitor

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yueming, E-mail: liyueming@ysu.edu.cn; Liu, Xi

    2014-11-14

    We report a new methodology to prepare activated carbon and activated carbons/ZnO composites from walnut shell-derived hydrothermal carbons (hydrochars), which were prepared under hydrothermal condition in presence of ZnCl{sub 2}. For this method, activated carbon/ZnO composites were prepared via heat treatment of hydrochars under inert environment and activated carbons were prepared by removing the ZnO in activated carbon/ZnO composites. The chemical structure of walnut shell, hydrochars, activated carbon/ZnO and activated carbon was investigated by Fourier transform infrared spectroscopy, Raman, X-ray powder diffraction, thermogravimetric analysis and N{sub 2} adsorption/desorption measurements. It is found ZnCl{sub 2} plays multiple roles, i.e., helping to remove the oxygen-containing groups during hydrothermal stage, improving the surface area of activated carbon and acting as the precursor of ZnO in heat-treatment stage. The specific surface areas up to 818.9 and 1072.7 m{sup 2} g{sup −1} have been achieved for activated carbon/ZnO composites and activated carbon, respectively. The activated carbon/ZnO as electrode materials for supercapacitors showed that specific capacitance of up to 117.4 F g{sup −1} at a current density of 0.5 A g{sup −1} in KOH aqueous solution can be achieved and keeps stable in 1000 cycles. - Highlights: • Hydrochars as intermediate to prepare activated carbon/ZnO composites. • Activated carbon/ZnO showed excellent electrochemical performance in supercapacitors. • Activated carbon with large surface area can be obtained by removing ZnO.

  6. Preparation and Anodizing of SiCp/Al Composites with Relatively High Fraction of SiCp.

    Science.gov (United States)

    Wang, Bin; Qu, Shengguan; Li, Xiaoqiang

    2018-01-01

    By properly proportioned SiC particles with different sizes and using squeeze infiltration process, SiCp/Al composites with high volume fraction of SiC content (Vp = 60.0%, 61.2%, 63.5%, 67.4%, and 68.0%) were achieved for optical application. The flexural strength of the prepared SiC p /Al composites was higher than 483 MPa and the elastic modulus was increased from 174.2 to 206.2 GPa. With an increase in SiC volume fraction, the flexural strength and Poisson's ratio decreased with the increase in elastic modulus. After the anodic oxidation treatment, an oxidation film with porous structure was prepared on the surface of the composite and the oxidation film was uniformly distributed. The anodic oxide growth rate of composite decreased with SiC content increased and linearly increased with anodizing time.

  7. Preparation and Anodizing of SiCp/Al Composites with Relatively High Fraction of SiCp

    Directory of Open Access Journals (Sweden)

    Bin Wang

    2018-01-01

    Full Text Available By properly proportioned SiC particles with different sizes and using squeeze infiltration process, SiCp/Al composites with high volume fraction of SiC content (Vp = 60.0%, 61.2%, 63.5%, 67.4%, and 68.0% were achieved for optical application. The flexural strength of the prepared SiCp/Al composites was higher than 483 MPa and the elastic modulus was increased from 174.2 to 206.2 GPa. With an increase in SiC volume fraction, the flexural strength and Poisson’s ratio decreased with the increase in elastic modulus. After the anodic oxidation treatment, an oxidation film with porous structure was prepared on the surface of the composite and the oxidation film was uniformly distributed. The anodic oxide growth rate of composite decreased with SiC content increased and linearly increased with anodizing time.

  8. Preparation and Anodizing of SiCp/Al Composites with Relatively High Fraction of SiCp

    Science.gov (United States)

    2018-01-01

    By properly proportioned SiC particles with different sizes and using squeeze infiltration process, SiCp/Al composites with high volume fraction of SiC content (Vp = 60.0%, 61.2%, 63.5%, 67.4%, and 68.0%) were achieved for optical application. The flexural strength of the prepared SiCp/Al composites was higher than 483 MPa and the elastic modulus was increased from 174.2 to 206.2 GPa. With an increase in SiC volume fraction, the flexural strength and Poisson's ratio decreased with the increase in elastic modulus. After the anodic oxidation treatment, an oxidation film with porous structure was prepared on the surface of the composite and the oxidation film was uniformly distributed. The anodic oxide growth rate of composite decreased with SiC content increased and linearly increased with anodizing time. PMID:29682145

  9. PETI-298 Prepared by Microwave Synthesis: Neat Resin and Composite Properties

    Science.gov (United States)

    Smith, Joseph G.; Connell, John W.; Li, Chao-Jun; Wu, Wei; Criss, Jim M., Jr.

    2004-01-01

    PETI-298 is a high temperature/high performance matrix resin that is processable into composites by resin transfer molding (RTM), resin infusion and vacuum assisted RTM techniques. It is typically synthesized in a polar aprotic solvent from the reaction of an aromatic anhydride and a combination of diamines and endcapped with phenylethynylphthalic anhydride. Microwave synthesis of PETI-298 was investigated as a means to eliminate solvent and decrease reaction time. The monomers were manually mixed and placed in a microwave oven for various times to determine optimum reaction conditions. The synthetic process was subsequently scaled-up to 330g. Three batches were synthesized and combined to give 1 kg of material that was characterized for thermal and rheological properties and compared to PETI-298 prepared by the classic solution based synthetic method. The microwave synthesized PETI-298 was subsequently used to fabricate flat laminates on T650 carbon fabric by RTM. The composite panels were analyzed and mechanical properties determined and compared with those fabricated from PETI-298 prepared by the classic solution method. The microwave synthesis process and characterization of neat resin and carbon fiber reinforced composites fabricated by RTM will be presented. KEY WORDS: Resin Transfer Molding, High Temperature Polymers, Phenylethynyl Terminated Imides, Microwave Synthesis

  10. Nano spray drying for encapsulation of pharmaceuticals.

    Science.gov (United States)

    Arpagaus, Cordin; Collenberg, Andreas; Rütti, David; Assadpour, Elham; Jafari, Seid Mahdi

    2018-05-17

    Many pharmaceuticals such as pills, capsules, or tablets are prepared in a dried and powdered form. In this field, spray drying plays a critical role to convert liquid pharmaceutical formulations into powders. In addition, in many cases it is necessary to encapsulate bioactive drugs into wall materials to protect them against harsh process and environmental conditions, as well as to deliver the drug to the right place and at the correct time within the body. Thus, spray drying is a common process used for encapsulation of pharmaceuticals. In view of the rapid progress of nanoencapsulation techniques in pharmaceutics, nano spray drying is used to improve drug formulation and delivery. The nano spray dryer developed in the recent years provides ultrafine powders at nanoscale and high product yields. In this paper, after explaining the concept of nano spray drying and understanding the key elements of the equipment, the influence of the process parameters on the final powders properties, like particle size, morphology, encapsulation efficiency, drug loading and release, will be discussed. Then, numerous application examples are reviewed for nano spray drying and encapsulation of various drugs in the early stages of product development along with a brief overview of the obtained results and characterization techniques. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Preparation and Properties of Microarc Oxidation Self-Lubricating Composite Coatings on Aluminum Alloy

    Directory of Open Access Journals (Sweden)

    Zhenwei Li

    2017-04-01

    Full Text Available Microarc oxidation (MAO coatings were prepared on 2024-T4 aluminum alloy using pulsed bipolar power supply at different cathode current densities. The MAO ceramic coatings contained many crater-like micropores and a small number of microcracks. After the MAO coatings were formed, the coated samples were immersed into a water-based Polytetrafluoroethylene (PTFE dispersion. The micropores and microcracks on the surface of the MAO coatings were filled with PTFE dispersion for preparing MAO self-lubricating composite coatings. The microstructure and properties of MAO coatings and the wear resistance of microarc oxidation self-lubricating composite coatings were analyzed by SEM, laser confocal microscope, X-ray diffractometry (XRD, Vickers hardness test, scratch test and ball-on-disc abrasive tests, respectively. The results revealed that the wear rates of the MAO coatings decreased significantly with an increase in cathode current density. Compared to the MAO coatings, the microarc oxidation self-lubricating composite coatings exhibited a lower friction coefficient and lower wear rates.

  12. Multidrug analysis of pharmaceutical and urine matrices by on-line coupled capillary electrophoresis and triple quadrupole mass spectrometry.

    Science.gov (United States)

    Maráková, Katarína; Piešt'anský, Juraj; Veizerová, Lucia; Galba, Jaroslav; Dokupilová, Svetlana; Havránek, Emil; Mikuš, Peter

    2013-06-01

    The present work illustrates potentialities of CE hyphenated with MS/MS for the simultaneous determination and identification of a mixture of simultaneously acting drugs in pharmaceutical and biological matrices. Here, the hyphenation was provided by ESI interface, while the MS/MS technique was based on the triple quadrupole configuration. Three drugs, namely pheniramine, phenylephrine, and paracetamol were determined and identified with high reliability due to their characterization in three different dimensions, i.e. electrophoresis and MS/MS, that prevented practically any interference. Appropriately selected transitions of the analytes (parent ion-quantifier product ion-qualifier product ion) provided their selective determination at maximum S/N. The proposed CE-MS/MS method was validated (LOD/LOQ, linearity, precision, recovery, accuracy) and applied for (i) the multidrug composition pharmaceuticals, namely Theraflu®, and (ii) human urine taken after per-oral administration of the same pharmaceutical preparation. The method was applied also for the investigation of potential weak associates of the drugs and monitoring of predicted (bio)degradation products of the drugs. Successful validation and application of the proposed method suggest its routine use in highly effective and reliable advanced drug control and biomedical research. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Synthesis and electrochemical analysis of polyaniline/TiO2 composites prepared with various molar ratios between aniline monomer and para-toluenesulfonic acid

    International Nuclear Information System (INIS)

    Oh, Misoon; Kim, Seok

    2012-01-01

    Graphical abstract: Polyaniline (PANI)/TiO 2 composites were prepared by in situ polymerization using para-toluenesulfonic acid (p-TSA). The composites showed different morphology and specific capacitances as a function of aniline concentration, which are related to the morphology (shape or size) of particles. Scheme of the formation of composites consisting of PANI film and the micelle structures is shown. Highlights: ► PANI/TiO 2 composite were prepared with a different concentration of monomer and dopant. ► Aniline/acid ratio influenced the morphological and electrochemical properties. ► The composites showed different capacitances as a function of aniline concentrations. ► Aniline/acid ratio could influence on the dispersion and surface roughness of particles. - Abstract: Polyaniline (PANI)/titanium dioxide (TiO 2 ) composites were prepared with a chemical oxidation polymerization of aniline monomer (ANI) with various molar ratios between ANI and para toluenesulfonic acid (p-TSA). To find an effect of the [ANI]:[p-TSA] molar ratio on the electrochemical properties of the prepared PANI/TiO 2 composites, the composites were synthesized under same conditions except the p-TSA concentrations. The prepared composite films had more homogeneous TiO 2 dispersion with changing [ANI]:[p-TSA] molar ratios from 6:1 to 1:1. p-TSA surfactant-like doping acid helped the dispersion of TiO 2 particles in the PANI matrix. PANI covering the TiO 2 surfaces was confirmed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Prepared PANI films on the TiO 2 particles had the smoothest surface when the ANI and p-TSA had 1:1 molar ratio in the reaction solution. The composite prepared with molar ratio [ANI]:[p-TSA] of 3:1 had the highest capacitance (800 F g −1 ) among the prepared composites.

  14. Preparates for the production of sup(99m)technetium radiodiagnostics specimens

    International Nuclear Information System (INIS)

    Schmidt-Dunker, M.; Greb, W.

    1977-01-01

    The preparations serve to produce sup(99m) Tc radiodiagnostics specimens to be used for scintigraphy of bones and calcereous deposits in tumors or muscle tissue. They consists of a mixture of the trisodium salt of the cyclohexane-hexacarbon acid and SnCl 2 , Cr(II) chloride, or Sn(II) Cl 2 and Fe(II) sulfate. The admixture of Sn(II), Fe(II), or Cr(II) salts serve for reduction of the eluted sup(99m) pertechnate. They amount to a fraction of 1-5 W/O of the total composition of the preparation. Their pH lies between 5 and 9. The pharmacologically harmless water-soluble salts of the cyclo hexane-hexacarbon acid may also be pharmaceutically applied. As filters glucose and/or NCl may be used. (DG) 891 HP [de

  15. Preparation and characterization of high density polyethylene and residual fibre of Attalea funifera Mart (piacava) composites

    International Nuclear Information System (INIS)

    Agrela, Sara P.; Guimaraes, Danilo H.; Jose, Nadia M.; Carvalho, Gleidson G.P.; Carvalho, Ricardo F.

    2009-01-01

    The use of natural fiber reinforcement thermoplastic polymer is continuously increasing. This fact is manly due to its advantages as low cost, availability, recyclability, low energy demand and then environmental appeal if compared to synthetics fibers. The composites were prepared in different fiber volume ratios (5%, 10% and 20%) mixed with high density polyethylene (HDPE) and heated at 190 deg C. Thermogravimetric analysis and differential scanning calorimetry were used to investigate thermal stability. The composites structure was characterized by Fourier Transform Infrared spectroscopy, X-ray diffractometry. Fiber and residue of piassava (Attalea funifera Mart) chemical composition were determined by Van Soest Method. The results indicate that thermo stability of the composites of HDPE prepared with fiber volume ratios up to 20% is only slightly lowered. (author)

  16. Preparation of Ni-C Ultrafine Composite from Waste Material

    Directory of Open Access Journals (Sweden)

    Mahmoud A. Rabah

    2017-06-01

    Full Text Available This work depicts the preparation of Ni-C ultrafine composite from used engine oil. The used oil was emulsified with detergent loaded with Ni (OH2. The loaded emulsion was sprayed on electric plasma generated between two C electrodes to a DC main 28 V and 70-80 A. The purged Ni-doped carbon fume was trapped on a polymer film moistened with synthetic adhesive to fix the trapped smoke. Characterization of the deposit was made using SEM. XRD examined the crystal morphology. Carbon density in the cloud was calculated. The average size and thickness of the deposited composite is 120-160 nm. Aliphatic hydrocarbons readily decompose to gaseous products. Solid carbon smoke originates from aromatic compounds. Plasma heat blasts the oil in short time to decompose in one step.

  17. Thermophysical properties of starch and whey protein composite prepared in presence of organic acid and esters

    Science.gov (United States)

    Previously, we prepared starch and protein composite by reactive mixing in presence of various organic acids and found that use of these acid esters resulted in composites with good mechanical properties. In this study, concentration (% w/w) of acid citrates in the starch-protein composites were var...

  18. Composite perfluorohydrocarbon membranes, their preparation and use

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Yong; Bikson, Benjamin

    2017-04-04

    Composite porous hydrophobic membranes are prepared by forming a perfluorohydrocarbon layer on the surface of a preformed porous polymeric substrate. The substrate can be formed from poly (aryl ether ketone) and a perfluorohydrocarbon layer can be chemically grafted to the surface of the substrate. The membranes can be utilized for a broad range of fluid separations, such as microfiltration, nanofiltration, ultrafiltration as membrane contactors for membrane distillation and for degassing and dewatering of fluids. The membranes can further contain a dense ultra-thin perfluorohydrocarbon layer superimposed on the porous poly (aryl ether ketone) substrate and can be utilized as membrane contactors or as gas separation. membranes for natural gas treatment and gas dehydration.

  19. Code of ethics for the national pharmaceutical system: Codifying and compilation.

    Science.gov (United States)

    Salari, Pooneh; Namazi, Hamidreza; Abdollahi, Mohammad; Khansari, Fatemeh; Nikfar, Shekoufeh; Larijani, Bagher; Araminia, Behin

    2013-05-01

    Pharmacists as one of health-care providers face ethical issues in terms of pharmaceutical care, relationship with patients and cooperation with the health-care team. Other than pharmacy, there are pharmaceutical companies in various fields of manufacturing, importing or distributing that have their own ethical issues. Therefore, pharmacy practice is vulnerable to ethical challenges and needs special code of conducts. On feeling the need, based on a shared project between experts of the ethics from relevant research centers, all the needs were fully recognized and then specified code of conduct for each was written. The code of conduct was subject to comments of all experts involved in the pharmaceutical sector and thus criticized in several meetings. The prepared code of conduct is comprised of professional code of ethics for pharmacists, ethics guideline for pharmaceutical manufacturers, ethics guideline for pharmaceutical importers, ethics guideline for pharmaceutical distributors, and ethics guideline for policy makers. The document was compiled based on the principles of bioethics and professionalism. The compiling the code of ethics for the national pharmaceutical system is the first step in implementing ethics in pharmacy practice and further attempts into teaching the professionalism and the ethical code as the necessary and complementary effort are highly recommended.

  20. Research on the preparation, biocompatibility and bioactivity of magnesium matrix hydroxyapatite composite material.

    Science.gov (United States)

    Linsheng, Li; Guoxiang, Lin; Lihui, Li

    2016-08-12

    In this paper, magnesium matrix hydroxyapatite composite material was prepared by electrophoretic deposition method. The optimal process parameters of electrophoretic deposition were HA suspension concentration of 0.02 kg/L, aging time of 10 days and voltage of 60 V. Animal experiment and SBF immersion experiment were used to test the biocompatibility and bioactivity of this material respectively. The SD rats were divided into control group and implant group. The implant surrounding tissue was taken to do tissue biopsy, HE dyed and organizational analysis after a certain amount of time in the SD rat body. The biological composite material was soaked in SBF solution under homeothermic condition. After 40 days, the bioactivity of the biological composite material was evaluated by testing the growth ability of apatite on composite material. The experiment results showed that magnesium matrix hydroxyapatite biological composite material was successfully prepared by electrophoretic deposition method. Tissue hyperplasia, connective tissue and new blood vessels appeared in the implant surrounding soft tissue. No infiltration of inflammatory cells of lymphocytes and megakaryocytes around the implant was found. After soaked in SBF solution, a layer bone-like apatite was found on the surface of magnesium matrix hydroxyapatite biological composite material. The magnesium matrix hydroxyapatite biological composite material could promot calcium deposition and induce bone-like apatite formation with no cytotoxicity and good biocompatibility and bioactivity.

  1. The Pharmaceutical Industry Beamline of Pharmaceutical Consortium for Protein Structure Analysis

    International Nuclear Information System (INIS)

    Nishijima, Kazumi; Katsuya, Yoshio

    2002-01-01

    The Pharmaceutical Industry Beamline was constructed by the Pharmaceutical Consortium for Protein Structure Analysis which was established in April 2001. The consortium is composed of 22 pharmaceutical companies affiliating with the Japan Pharmaceutical Manufacturers Association. The beamline is the first exclusive on that is owned by pharmaceutical enterprises at SPring-8. The specification and equipments of the Pharmaceutical Industry Beamline is almost same as that of RIKEN Structural Genomics Beamline I and II. (author)

  2. Preparation and electrocatalytic property of WC/carbon nanotube composite

    International Nuclear Information System (INIS)

    Li Guohua; Ma Chunan; Tang Junyan; Sheng Jiangfeng

    2007-01-01

    Tungsten carbide/carbon nanotube composite was prepared by surface decoration and in situ reduction-carbonization. The samples were characterized by XRD, SEM, EDS, TEM, HRTEM and BET, respectively. The XRD results show that the sample is composed of carbon nanotube, tungsten carbide and tungsten oxide. The EDS results show that the distribution of tungsten oxide is consistent with that of tungsten carbide. SEM, TEM and HRTEM results show that the tungsten carbide nanoparticle with irregular granule grows on the outside surface of carbon nanotube homogenously. The electrocatalytic activity of the sample for p-nitrophenol reduction was tested by a powder microelectrode in a basic solution. The results show that the electrocatalytic activity of the sample is higher than that of granular tungsten carbide, hollow globe tungsten carbide with mesoporosity and carbon nanotube purified. The improvement of the electrocatalytic activity of the sample can be attributed to its components and composite structure. These results indicate that tungsten carbide/carbon nanotube composite is one of the effective ways to improve the electrocatalytic activity of tungsten carbide

  3. Preparation and characterization of RuO2/polyaniline/polymer binder composite electrodes for supercapacitor applications

    Directory of Open Access Journals (Sweden)

    SUZANA SOPČIĆ

    2012-03-01

    Full Text Available The composite electrodes consisting of amorphous and hydrous RuO2, polyaniline and polymeric binder, Nafion® or poly(vinilydene fluoride were prepared. The electro¬chem-ical and pseudocapacitive properties of the prepared electrodes were investigated by cyclic voltammetry and electrochemical impedance spectroscopy. The results show that the responses of composite electrodes are very sensitive to the presence of individual components and their respective ratio in the mixture. The difference in the electro-chemical behavior was explained by the different physico-chemical properties of the polymeric binders.

  4. Preparation and characterization of nanocrystalline porous TiO2/WO3 composite thin films

    International Nuclear Information System (INIS)

    Hsu, C.-S.; Lin, C.-K.; Chan, C.-C.; Chang, C.-C.; Tsay, C.-Y.

    2006-01-01

    TiO 2 materials possessing not only photocatalytic but also electrochromic properties have attracted many research and development interests. Though WO 3 exhibits excellent electrochromic properties, the much higher cost and water-sensitivity of WO 3 as compared with the TiO 2 may restrict the practical application of WO 3 materials. In the present study, the feasibility of preparing nanocrystalline porous TiO 2 /WO 3 composite thin films was investigated. Precursors of sols TiO 2 and/or WO 3 and polystyrene microspheres were used to prepare nanocrystalline pure TiO 2 , WO 3 , and composite TiO 2 /WO 3 thin films by spin coating. The spin-coated thin films were amorphous and, after heat treating at a temperature of 500 o C, nanocrystalline TiO 2 , TiO 2 /WO 3 , and WO 3 thin films with or without pores were prepared successfully. The heat-treated thin films were colorless and coloration-bleaching phenomena can be observed during cyclic voltammetry tests. The heat-treated thin films exhibited good reversible electrochromic behavior while the porous TiO 2 /WO 3 composite film exhibited improved electrochromic properties

  5. Who's cooking? Time spent preparing food by gender, income and household composition

    OpenAIRE

    Mancino, Lisa; Newman, Constance

    2006-01-01

    We use the American Time Use Survey data and multivariate analysis to explore how time allocated to food preparation differs across income groups, household composition (number of adults and presence of children), and employment status of adults in the household.

  6. Preparation of Polyaniline/Filter-paper Composite for Removal of Coomassie Brilliant Blue

    DEFF Research Database (Denmark)

    Liu, Wanwan; Li, Xiaoqiang; Li, Mengjuan

    2015-01-01

    Polyaniline/filter-paper (PANI/FP) composite was prepared by in-situ polymerization of polyaniline onto filter-paper and subsequently evaluated for the removal of Coomassie brilliant blue (CBB) from aqueous solution. Scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and Fourier...

  7. Development of an HPLC-UV Method for the Analysis of Drugs Used for Combined Hypertension Therapy in Pharmaceutical Preparations and Human Plasma

    Directory of Open Access Journals (Sweden)

    Serife Evrim Kepekci Tekkeli

    2013-01-01

    Full Text Available A simple, rapid, and selective HPLC-UV method was developed for the determination of antihypertensive drug substances: amlodipine besilat (AML, olmesartan medoxomil (OLM, valsartan (VAL, and hydrochlorothiazide (HCT in pharmaceuticals and plasma. These substances are mostly used as combinations. The combinations are found in various forms, especially in current pharmaceuticals as threesome components: OLM, AML, and HCT (combination I and AML, VAL, and HCT (combination II. The separation was achieved by using an RP-CN column, and acetonitrile-methanol-10 mmol orthophosphoric acid pH 2.5 (7 : 13 : 80, v/v/v was used as a mobile phase; the detector wavelength was set at 235 nm. The linear ranges were found as 0.1–18.5 μg/mL, 0.4–25.6 μg/mL, 0.3–15.5 μg/mL, and 0.3–22 μg/mL for AML, OLM, VAL, and HCT, respectively. In order to check the selectivity of the method for pharmaceutical preparations, forced degradation studies were carried out. According to the validation studies, the developed method was found to be reproducible and accurate as shown by RSD ≤6.1%, 5.7%, 6.9%, and 4.6% and relative mean error (RME ≤10.6%, 5.8%, 6.5%, and 6.8% for AML, OLM, VAL, and HCT, respectively. Consequently, the method was applied to the analysis of tablets and plasma of the patients using drugs including those substances.

  8. Preparation of shape-stabilized co-crystallized poly (ethylene glycol) composites as thermal energy storage materials

    International Nuclear Information System (INIS)

    Qian, Yong; Wei, Ping; Jiang, Pingkai; Li, Zhi; Yan, Yonggang; Ji, Kejian; Deng, Weihua

    2013-01-01

    Highlights: • Shape-stabilized PEG composites were prepared by sol–gel process. • The increased energy storage ability of composite was from cocrystallization effect. • Diammonium phosphate improved flame retardancy properties of PEG composite. • PEG composites had potential to be used as thermal energy storage materials. - Abstract: Shape-stabilized co-crystallized poly (ethylene glycol) (PEG) composites were prepared by sol–gel process. Tetraethoxysilane was utilized as supporting matrix precursor. The crystallization property as well as thermal energy storage properties of PEG was influenced by silica network. The combination of PEG 2k and PEG 10k with suitable ratio (3:1 by weight) led to synergistically increased fusion enthalpy attributed to cocrystallization effect. Furthermore, halogen-free flame retarded PEG composites were obtained using diammonium phosphate as flame retardant. With suitable composition, the latent heat value of flame retarded PEG composite was 96.7 kJ/kg accompanied with good thermal stability and improved flame retardancy properties. Fourier transform infrared spectrum (FT-IR), X-ray diffraction (XRD), polarized optical microscope (POM) and scanning electron microscope (SEM) were used to characterize the structure of PEG composites. Thermal stability properties of PEG composites were investigated by thermogravimetric analyzer (TGA). Char residue obtained from muffle furnace of PEG composites was analyzed by SEM and FT-IR. Flame retardancy properties of PEG composites were estimated by pyrolysis combustion flow calorimeter. Results showed that it was potential for shape-stabilized halogen-free flame retarded PEG composite to be applied in thermal energy storage field

  9. Preparation, Characterization and Thermal Degradation of Polyimide (4-APS/BTDA/SiO2 Composite Films

    Directory of Open Access Journals (Sweden)

    Arash Dehzangi

    2012-04-01

    Full Text Available Polyimide/SiO2 composite films were prepared from tetraethoxysilane (TEOS and poly(amic acid (PAA based on aromatic diamine (4-aminophenyl sulfone (4-APS and aromatic dianhydride (3,3,4,4-benzophenonetetracarboxylic dianhydride (BTDA via a sol-gel process in N-methyl-2-pyrrolidinone (NMP. The prepared polyimide/SiO2 composite films were characterized using X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, scanning electron microscope (SEM and thermogravimetric analysis (TGA. The FTIR results confirmed the synthesis of polyimide (4-APS/BTDA and the formation of SiO2 particles in the polyimide matrix. Meanwhile, the SEM images showed that the SiO2 particles were well dispersed in the polyimide matrix. Thermal stability and kinetic parameters of the degradation processes for the prepared polyimide/SiO2 composite films were investigated using TGA in N2 atmosphere. The activation energy of the solid-state process was calculated using Flynn–Wall–Ozawa’s method without the knowledge of the reaction mechanism. The results indicated that thermal stability and the values of the calculated activation energies increased with the increase of the TEOS loading and the activation energy also varied with the percentage of weight loss for all compositions.

  10. Electrospinning preparation and luminescence properties of Eu(TTA)_3phen/polystyrene composite nanofibers

    Institute of Scientific and Technical Information of China (English)

    张小萍; 温世鹏; 胡水; 张立群; 刘力

    2010-01-01

    Efficient luminescent composite nanofibers,composed of polystyrene(PS,Mw=250000) and europium complex Eu(TTA)3phen(TTA=2-thenoyltrifluoroacetone,phen=1,10-phenanthroline) with diameters ranging from 350 nm to 700 nm,were prepared by electrospinning and characterized by scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FT-IR),fluorescence spectroscopy,and thermogravimetric analysis(TG).The room-temperature fluorescence spectra of the composite nanofibers were composed of the typical E...

  11. Preparation of polymer-organo clay nano composites through the spray drying process

    International Nuclear Information System (INIS)

    Bernardo, Paulo R.A.; Pessan, Luiz A.; Carvalho, Antonio J.F. de; Vidotti, Suel E.

    2011-01-01

    The objective of the work was the study and preparation of polymer nano composites with montmorillonite organo clays (MMT) through the spray drying process. A new technique was proposed and tested to obtaining polymer nano composites, based on the use of the spray drying process to produce a nano composite with high clay content. The process consisted of the following stages: clay intercalation in water solution, with after addition of polyvinyl alcohol (PVOH) and a hydro soluble polyester ionomer (GEROLPS20) as exfoliation agents; spray drying the mixture obtained; incorporation powder in EVOH, PET e PP matrix. The effects of exfoliation agent on morphological and thermal properties of the nano composites were studied by XRD, transmission electron microscopy (TEM) and TGA. The results demonstrate that the process of spray drying is an innovative way to obtain a nano composite with high clay content. (author)

  12. TCLP Preparation and Analysis of K East Basin Composite Sludge Samples

    International Nuclear Information System (INIS)

    Silvers, K.L.; Wagner, J.J.; Steele, R.T.

    2000-01-01

    Sludge samples from the Hanford K East Basin were analyzed by the Toxicity Characterization Leaching Procedure (TCLP) to assist in the appropriate Resource Conservation and Recovery Act (RCIL4) designation of this material. Sludge samples were collected by Fluor Hanford, Inc. using the consolidated sludge sampling system (system that allows collection of a single sample from multiple sample locations). These samples were shipped to the Postirradiation Testing Laboratory (PTL, 327 Building) and then transferred to the Pacific Northwest National Laboratory (PNNL) Radiochemical Processing Laboratory (RPL, 325 Building) for recovery and testing. Two sludge composites were prepared, using the consolidated sludge samples, to represent K East canister sludge (sample KC Can Comp) and K East floor sludge (sample KC Floor Comp). Each composite was extracted in duplicate and analyzed in duplicate following pre-approved(a) TCLP extraction and analyses procedures. In addition, these samples and duplicates were analyzed for total RCRA metals (via acid digestion preparation). The work was conducted in accordance with the requirements of the Hanford Analytical Quality Assurance Requirements Document (HASQARD). A PNNL Quality Assurance Program compliant with J HASQARD was implemented for this effort. The results from the TCLP analyses showed that all RCRA metal concentrations were less than the TCLP limits for both the canister and floor composite samples and their respective duplicates

  13. The A to Z of pharmaceutical cocrystals: a decade of fast-moving new science and patents.

    Science.gov (United States)

    Almarsson, Örn; Peterson, Matthew L; Zaworotko, Michael

    2012-07-01

    From aspirin to zoledronic acid, pharmaceutical cocrystals emerged in the past decade as a promising new weapon in the arsenal of drug development. Resurgence of interest in multicomponent crystal compositions has led to significant advances in the science of cocrystal design and discovery. These advances have built upon crystal engineering, which provides a deep understanding of supramolecular interactions between molecules that govern crystal packing and physicochemical properties of crystalline materials. Concomitantly, the patent landscape of pharmaceutical cocrystals developed rapidly in the last decade. This review presents a broad survey of patents issued in the area of pharmaceutical cocrystals. In addition, the review contains analyses of key patents in the area involving compositions and methodologies. Along the way, the main events of the past decade representing a renaissance of cocrystals of pharmaceutical materials are chronicled. Future directions in the area are discussed in light of key pending patent applications and recent publications of seminal interest.

  14. Preparation and characterization of highly transparent Nd:YAG/YAG composite ceramics

    Science.gov (United States)

    Ma, Benyuan; Zhang, Wei; Shen, Bizhou; Wang, Yuezhong; Song, Haizhi; Li, Feng; Xie, Xiumin; Zhang, Zhibin; Yang, Yongqiang; Guan, Zhouguo

    2018-05-01

    Using the co-precipitated Nd:YAG and YAG powders as raw materials, the Nd:YAG/YAG composite ceramics (Ф 50 mm × 5 mm) were prepared by vacuum sintering (1790 °C 50 h), followed by hot isostatic pressing (HIP) post treatment (1700 °C 2 h, 200 MPa Ar atmosphere) and air annealing (1250 °C 100 h). The optical properties of Nd:YAG/YAG samples were improved markedly by HIP post-treatment, mainly due to the elimination of residual pores in the samples. The composite sample showed a perfect bonding interface from Nd:YAG to YAG regions without obvious grain size difference, pores or other defects. This structure should be responsible for the thermal conductivity larger than that of non-composite sample. The composite sample revealed good optical properties with transmittance up to 83.9% at 1064 nm and 80.8% at 400 nm, and a maximum laser output power of 1.38 KW with the slope efficiency of 36.7% was obtained.

  15. Multiwall carbon nanotubes chemically modified carbon paste electrodes for determination of gentamicin sulfate in pharmaceutical preparations and biological fluids.

    Science.gov (United States)

    Khalil, M M; Abed El-Aziz, G M

    2016-02-01

    This article focused on the construction and characteristics of novel and sensitive gentamicin carbon paste electrodes which are based on the incorporation of multiwall carbon nanotubes (MWCNTs) which improve the characteristics of the electrodes. The electrodes were constructed based on gentamicin-phosphotungstate (GNS-PTA) called CPE1, gentamicin-phosphomolybdate (GNS-PMA) called CPE2, GNS-PTA+ MWMCNTs called MWCPE1, and GNS-PMA+ MWMCNTs called MWCPE2. The constructed electrodes, at optimum paste composition, exhibited good Nernstian response for determination of gentamicin sulfate (GNS) over a linear concentration range from 2.5×10(-6) to 1×10(-2), 3.0×10(-6) to 1×10(-2), 4.9×10(-7) to 1×10(-2) and 5.0×10(-7) to 1×10(-2)molL(-1), with lower detection limit 1×10(-6), 1×10(-6), 1.9×10(-7) and 2.2×10(-7)molL(-1), and with slope values of 29.0±0.4, 29.2±0.7, 31.2±0.5 and 31.0±0.6mV/decade for CPE1, CPE2, MWCPE1 and MWCPE2, respectively. The response of electrodes is not affected by pH in the range 3-8 for CPE1 and CPE2 and in the range 2.5-8.5 for MWCPE1 and MWCPE2. The results showed fast dynamic response time (about 8-5s) and long lifetime (more than 2months) for all electrodes. The sensors showed high selectivity for gentamicin sulfate (GNS) with respect to a large number of interfering species. The constructed electrodes were successfully applied for determination of GNS in pure form, its pharmaceutical preparations and biological fluids using standard addition and potentiometric titration methods with high accuracy and precision. Published by Elsevier B.V.

  16. Preparation and evaluation of cerium oxide-bovine hydroxyapatite composites for biomedical engineering applications.

    Science.gov (United States)

    Gunduz, O; Gode, C; Ahmad, Z; Gökçe, H; Yetmez, M; Kalkandelen, C; Sahin, Y M; Oktar, F N

    2014-07-01

    The fabrication and characterization of bovine hydroxyapatite (BHA) and cerium oxide (CeO2) composites are presented. CeO2 (at varying concentrations 1, 5 and 10wt%) were added to calcinated BHA powder. The resulting mixtures were shaped into green cylindrical samples by powder pressing (350MPa) followed by sintering in air (1000-1300°C for 4h). Density, Vickers microhardness (HV), compression strength, scanning electron microscopy (SEM) and X-ray diffraction (XRD) studies were performed on the products. The sintering behavior, microstructural characteristics and mechanical properties were evaluated. Differences in the sintering temperature (for 1wt% CeO2 composites) between 1200 and 1300°C, show a 3.3% increase in the microhardness (564 and 582.75HV, respectively). Composites prepared at 1300°C demonstrate the greatest compression strength with comparable results for 5 and 10wt% CeO2 content (106 and 107MPa) which are significantly better than those for 1wt% and those that do not include any CeO2 (90 and below 60MPa, respectively). The results obtained suggest optimal parameters to be used in preparation of BHA and CeO2 composites, while also highlighting the potential of such materials in several biomedical engineering applications. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Ultrasound-assisted preparation of electrospun carbon nanofiber/graphene composite electrode for supercapacitors

    Science.gov (United States)

    Dong, Qiang; Wang, Gang; Hu, Han; Yang, Juan; Qian, Bingqing; Ling, Zheng; Qiu, Jieshan

    2013-12-01

    Electrospun carbon nanofiber/graphene (CNF/G) composites are prepared by in situ electrospinning polymeric nanofibers with simultaneous spraying graphene oxide, followed by heat treatment. The freestanding carbon nanofiber web acts as a framework for sustaining graphene, which helps to prevent the agglomeration of graphene and to provide a high conductivity for the efficient charge transfer to the pores. The as-obtained CNF/G composite exhibits a specific capacitance of 183 F g-1, which is approximately 1.6 times higher than that of the pristine CNF. The results have demonstrated that the high performance of the CNF/G composite is due to the novel structure and the synergic effect of graphene and the carbon nanofibers.

  18. Pharmaceutical policies for the Third World--whose responsibility?

    Science.gov (United States)

    1983-07-16

    Several developing countries, such as Bangladesh, Cuba, India, and Mozambique, are currently formulating national pharmaceutical policies to reduce expenditures on drugs while increasing their availability to those in greatest need. 5 components of such national policies have been identified: 1) elimination of ineffective and inappropriate preparations through concentrating on a selection such as the World Health Organization's 200 "basic and essential drugs", coupled with national drug pricing policies that discriminate between essential drugs and non-essential or luxury drugs; 2) public systems of drug distribution which would reduce costs to the consumer; 3) importation of the limited number of drugs distributed through the public system in bulk, which might reduce costs by 20-25%; 4) use of generic rather than brand name drugs; and 5) establishment of domestic pharmaceutical industries within developing countries to encourage research into drugs for local health problems, reduce use of foreign exchange to import drugs, and increase local self-reliance in dealing with disease. In November 1982, Health Action International, a coordinating body for more than 50 publish interest groups seeking to promote rational use of pharmaceuticals, presented a draft internationl code on pharmaceuticals to the UN Conference on Trade and Development. A voluntary code produced in 1981 by the International Federation of Pharmaceutical Manufacturers' Associations paid little attention to monitoring and enforcement. Little progress has been made, and the need for sensible policy making at the international and national levels has long been apparent.

  19. Preparation, optimization and property of PVA-HA/PAA composite hydrogel.

    Science.gov (United States)

    Chen, Kai; Liu, Jinlong; Yang, Xuehui; Zhang, Dekun

    2017-09-01

    PVA-HA/PAA composite hydrogel is prepared by freezing-thawing, PEG dehydration and annealing method. Orthogonal design method is used to choose the optimization combination. Results showed that HA and PVA have the maximum effect on water content. PVA and freezing-thawing cycles have the maximum effect on creep resistance and stress relaxation rate of hydrogel. Annealing temperature and freezing-thawing cycles have the maximum effect on compressive elastic modulus of hydrogel. Comparing with the water content and mechanical properties of 16 kinds of combination, PVA-HA/PAA composite hydrogel with freezing-thawing cycles of 3, annealing temperature of 120°C, PVA of 16%, HA of 2%, PAA of 4% has the optimization comprehensive properties. PVA-HA/PAA composite hydrogel has a porous network structure. There are some interactions between PVA, HA and PAA in hydrogel and the properties of hydrogel are strengthened. The annealing treatment improves the crystalline and crosslinking of hydrogel. Therefore, the annealing PVA-HA/PAA composite hydrogel has good thermostability, strength and mechanical properties. It also has good lubrication property and its friction coefficient is relative low. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Preparation and hygrothermal properties of composite phase change humidity control materials

    International Nuclear Information System (INIS)

    Chen, Zhi; Qin, Menghao

    2016-01-01

    Highlights: • A new kind of phase change humidity control material (PCHCM) was prepared. • The PCHCM can moderate both the indoor temperature and humidity. • The silicon dioxide shell can improve the thermal properties of the composite. • The PCM microcapsules can improve the moisture buffer ability of the composite. • The CPCM/vesuvianite composite has a better hygrothermal performance than pure hygroscopic material. - Abstract: A novel phase change humidity control material (PCHCM) was prepared by using PCM microcapsules and different hygroscopic porous materials. The PCHCM composite can regulate the indoor hygrothermal environment by absorbing or releasing both heat and moisture. The PCM microcapsules were synthesized with methyl triethoxysilane by the sol–gel method. The vesuvianite, sepiolite and zeolite were used as hygroscopic materials. The scanning electron microscopy (SEM) was used to measure the morphology profiles of the microcapsules and PCHCM. The differential scanning calorimetry (DSC) and the thermal gravimetric analysis (TGA) were used to determine the thermal properties and thermal stability. Both the moisture transfer coefficient and moisture buffer value (MBV) of different PCHCMs were measured by the improved cup method. The DSC results showed that the SiO 2 shell can reduce the super-cooling degree of PCM. The super-cooling degrees of microcapsules and PCHCM are lower than that of the pure PCM. The onset temperature of thermal degradation of the microcapsules and PCHCMs is higher than that of pure PCM. Both the moisture transfer coefficient and MBV of PCHCMs are higher than that of the pure hygroscopic materials. The results indicated the PCHCMs have better thermal properties and moisture buffer ability.

  1. Composite wheat-plantain starch salted noodles: Preparation, proximal composition and in vitro starch digestibility

    OpenAIRE

    Rendón-Villalobos, Rodolfo; Osorio-Díaz, Perla; Agama-Acevedo, Edith; Tovar, Juscelino; Bello-Pérez, Luis A

    2008-01-01

    Salted noodles were prepared with different contents of wheat grits and plantain starch (PS). The blends were hydrated with 2% NaCl (w/v), homogenized, and the resulting doughs were sheeted through a pasta machine, cut into strips ~30cm in length, cooked, and their composition and in vitro starch digestibility was assessed. Moisture (6.43-7.60%) and ash contents (2.08-3.12%) increased by the addition of PS. Fat level decreased from 0.41 to 0.31% as the substitution of wheat grits increased. R...

  2. Preparation and characterization of rubbery epoxy/multiwall carbon nanotubes composites using amino acid salt assisted dispersion technique

    Directory of Open Access Journals (Sweden)

    S. B. Jagtap

    2013-04-01

    Full Text Available Epoxy/multiwall carbon nanotubes (MWCNT composites were prepared using sodium salt of 6-aminohexanoic acid (SAHA modified MWCNT and its effect properties of related composites were investigated. The composite prepared using a polar solvent, tetrahydrofuran exhibits better mechanical properties compared to those prepared using less polar solvent and without using solvent. The tensile properties and dynamic storage modulus was found to be increased as a result of modification of MWCNT with SAHA. This improvement in the tensile properties and dynamic mechanical properties of epoxy/MWCNT composite is a combined effect of cation-π interaction and chemical bonding. Fourier transform infrared spectroscopy (FTIR and Raman spectroscopy were used to explain cation-π interaction between SAHA with MWCNT and chemical bonding of SAHA with epoxy resin. The effect of modification of MWCNT on morphology of a nanocomposite was confirmed by using scanning electron microscopy (SEM and transmission electron microscopy (TEM. The present approach does not disturb the ! electron clouds of MWCNT as opposed to chemical functionalization strategy.

  3. Preparation and characterization of an aromatic polyester/polyaniline composite and its improved counterpart

    Directory of Open Access Journals (Sweden)

    C. S. Wu

    2012-06-01

    Full Text Available Poly(butylene terephthalate (PBT composites containing polyaniline (PANI were prepared using a melt-blending process. Maleic anhydride-grafted PBT (PBT-g-MA and PANI were used to improve the compatibility of PANI within the PBT matrix. PBT-g-MA/PANI composites exhibited noticeably superior mechanical properties compared with those of PBT/PANI due to greater compatibility with the added PANI. The antibacterial and antistatic properties of the composites were also evaluated. Escherichia coli were chosen as the standard bacteria for determining the antibacterial properties of the composite materials. The PBT-g-MA/PANI composites showed markedly enhanced antibacterial and antistatic properties compared to PBT/PANI composites due to the formation of imide bonds from condensation of the anhydride carboxyl acid groups of PBT-g-MA with the amino groups of PANI. The optimal level of PANI in the composites was 9 wt%, as excess PANI led to separation of the two organic phases, lowering their compatibility.

  4. Electrostatics of Pharmaceutical Aerosols for Pulmonary Delivery.

    Science.gov (United States)

    Lip Kwok, Philip Chi

    2015-01-01

    This paper provides a review on key research findings in the rapidly developing area of pharmaceutical aerosol electrostatics. Solids and liquids can become charged without electric fields, the former by contact or friction and the latter by flowing or spraying. Therefore, charged particles and droplets carrying net charges are produced from pharmaceutical inhalers (e.g. dry powder inhalers, metered dose inhalers, and nebulisers) due to the mechanical processes involved in aerosolisation. The charging depends on many physicochemical factors, such as formulation composition, solid state properties, inhaler material and design, and relative humidity. In silico, in vitro, and limited in vivo studies have shown that electrostatic charges may potentially influence particle deposition in the airways. However, the evidence is not yet conclusive. Furthermore, there are currently no regulatory requirements on the characterisation and control of the electrostatic properties of inhaled formulations. Besides the need for further investigations on the relationship between physicochemical factors and charging characteristics of the aerosols, controlled and detailed in vivo studies are also required to confirm whether charges can affect particle deposition in the airways. Since pharmaceutical aerosol electrostatics is a relatively new research area, much remains to be explored. Thus there is certainly potential for development. New findings in the future may contribute to the advancement of pharmaceutical aerosol formulations and respiratory drug delivery.

  5. Preparation of Chitin-PLA laminated composite for implantable application

    Directory of Open Access Journals (Sweden)

    Romana Nasrin

    2017-12-01

    Full Text Available The present study explores the possibilities of using locally available inexpensive waste prawn shell derived chitin reinforced and bioabsorbable polylactic acid (PLA laminated composites to develop new materials with excellent mechanical and thermal properties for implantable application such as in bone or dental implant. Chitin at different concentration (1–20% of PLA reinforced PLA films (CTP were fabricated by solvent casting process and laminated chitin-PLA composites (LCTP were prepared by laminating PLA film (obtained by hot press method with CTP also by hot press method at 160 °C. The effect of variation of chitin concentration on the resulting laminated composite's behavior was investigated. The detailed physico-mechanical, surface morphology and thermal were assessed with different characterization technique such as FT-IR, XRD, SEM and TGA. The FTIR spectra showed the characteristic peaks for chitin and PLA in the composites. SEM images showed an excellent dispersion of chitin in the films and composites. Thermogravimetric analysis (TGA showed that the complete degradation of chitin, PLA film, 5% chitin reinforced PLA film (CTP2 and LCTP are 98%, 95%, 87% and 98% respectively at temperature of 500 °C. The tensile strength of the LCTP was found 25.09 MPa which is significantly higher than pure PLA film (18.55 MPa and CTP2 film (8.83 MPa. After lamination of pure PLA and CTP2 film, the composite (LCTP yielded 0.265–1.061% water absorption from 30 min to 24 h immerse in water that is much lower than PLA and CTP. The increased mechanical properties of the laminated films with the increase of chitin content indicated good dispersion of chitin into PLA and strong interfacial actions between the polymer and chitin. The improvement of mechanical properties and the results of antimicrobial and cytotoxicity of the composites also evaluated and revealed the composite would be a suitable candidate for implant application in biomedical

  6. Preparation of Chitin-PLA laminated composite for implantable application.

    Science.gov (United States)

    Nasrin, Romana; Biswas, Shanta; Rashid, Taslim Ur; Afrin, Sanjida; Jahan, Rumana Akhter; Haque, Papia; Rahman, Mohammed Mizanur

    2017-12-01

    The present study explores the possibilities of using locally available inexpensive waste prawn shell derived chitin reinforced and bioabsorbable polylactic acid (PLA) laminated composites to develop new materials with excellent mechanical and thermal properties for implantable application such as in bone or dental implant. Chitin at different concentration (1-20% of PLA) reinforced PLA films (CTP) were fabricated by solvent casting process and laminated chitin-PLA composites (LCTP) were prepared by laminating PLA film (obtained by hot press method) with CTP also by hot press method at 160 °C. The effect of variation of chitin concentration on the resulting laminated composite's behavior was investigated. The detailed physico-mechanical, surface morphology and thermal were assessed with different characterization technique such as FT-IR, XRD, SEM and TGA. The FTIR spectra showed the characteristic peaks for chitin and PLA in the composites. SEM images showed an excellent dispersion of chitin in the films and composites. Thermogravimetric analysis (TGA) showed that the complete degradation of chitin, PLA film, 5% chitin reinforced PLA film (CTP2) and LCTP are 98%, 95%, 87% and 98% respectively at temperature of 500 °C. The tensile strength of the LCTP was found 25.09 MPa which is significantly higher than pure PLA film (18.55 MPa) and CTP2 film (8.83 MPa). After lamination of pure PLA and CTP2 film, the composite (LCTP) yielded 0.265-1.061% water absorption from 30 min to 24 h immerse in water that is much lower than PLA and CTP. The increased mechanical properties of the laminated films with the increase of chitin content indicated good dispersion of chitin into PLA and strong interfacial actions between the polymer and chitin. The improvement of mechanical properties and the results of antimicrobial and cytotoxicity of the composites also evaluated and revealed the composite would be a suitable candidate for implant application in biomedical sector.

  7. Preparation of electromechanically active silicone composites and some evaluations of their suitability for biomedical applications

    International Nuclear Information System (INIS)

    Iacob, Mihail; Bele, Adrian; Patras, Xenia; Pasca, Sorin; Butnaru, Maria; Alexandru, Mihaela; Ovezea, Dragos; Cazacu, Maria

    2014-01-01

    Some films based on electromechanically active polymer composites have been prepared. Polydimethylsiloxane-α,ω-diols (PDMSs) having different molecular masses (Mv = 60 700 and Mv = 44 200) were used as matrix in which two different active fillers were incorporated: titanium dioxide in situ generated from its titanium isopropoxide precursor and silica particles functionalized with polar aminopropyl groups on surface. A reference sample based on simple crosslinked PDMS was also prepared. The composites processed as films were investigated to evaluate their ability to act as efficient electromechanical actuators for potential biomedical application. Thus, the surface morphology of interest for electrodes compliance was analysed by atomic force microscopy. Mechanical and dielectric characteristics were evaluated by tensile tests and dielectric spectroscopy, respectively. Electromechanical actuation responses were measured by interferometry. The biocompatibility of the obtained materials has been verified through tests in vitro and, for valuable films, in vivo. The experimental, clinical and anatomopathological evaluation of the in vivo tested samples did not reveal significant pathological modifications. - Highlights: • Silicone composites differing by the filler and matrix characteristics were prepared. • Stress–strain curves were registered in normal and cyclic modes for composite films. • The dielectric permittivity, dielectric loss, and conductivity were determined. • Electromechanical response of the films was measured at an applied voltage. • Some biocompatibility tests, both in vitro and in vivo, were performed

  8. Preparation of electromechanically active silicone composites and some evaluations of their suitability for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Iacob, Mihail; Bele, Adrian [“Petru Poni” Institute of Macromolecular Chemistry, Aleea Gr. Ghica Voda 41A, Iasi 700487 (Romania); Patras, Xenia [“Apollonia” University, 2 Muzicii Street, 700511 Iasi (Romania); Pasca, Sorin [“Ion Ionescu de la Brad” University of Agricultural Sciences and Veterinary Medicine Iaşi, Aleea Mihail Sadoveanu nr. 3, Iasi 700490 (Romania); Butnaru, Maria [“Gr. T. Popa” University of Medicine and Pharmacy, Faculty of Medical Bioengineering, 16 University Street, 700115 Iasi (Romania); Alexandru, Mihaela [“Petru Poni” Institute of Macromolecular Chemistry, Aleea Gr. Ghica Voda 41A, Iasi 700487 (Romania); Ovezea, Dragos [National Institute for Research and Development in Electrical Engineering ICPE-CA, 313 Splaiul Unirii, Bucharest 030138 (Romania); Cazacu, Maria, E-mail: mcazacu@icmpp.ro [“Petru Poni” Institute of Macromolecular Chemistry, Aleea Gr. Ghica Voda 41A, Iasi 700487 (Romania)

    2014-10-01

    Some films based on electromechanically active polymer composites have been prepared. Polydimethylsiloxane-α,ω-diols (PDMSs) having different molecular masses (Mv = 60 700 and Mv = 44 200) were used as matrix in which two different active fillers were incorporated: titanium dioxide in situ generated from its titanium isopropoxide precursor and silica particles functionalized with polar aminopropyl groups on surface. A reference sample based on simple crosslinked PDMS was also prepared. The composites processed as films were investigated to evaluate their ability to act as efficient electromechanical actuators for potential biomedical application. Thus, the surface morphology of interest for electrodes compliance was analysed by atomic force microscopy. Mechanical and dielectric characteristics were evaluated by tensile tests and dielectric spectroscopy, respectively. Electromechanical actuation responses were measured by interferometry. The biocompatibility of the obtained materials has been verified through tests in vitro and, for valuable films, in vivo. The experimental, clinical and anatomopathological evaluation of the in vivo tested samples did not reveal significant pathological modifications. - Highlights: • Silicone composites differing by the filler and matrix characteristics were prepared. • Stress–strain curves were registered in normal and cyclic modes for composite films. • The dielectric permittivity, dielectric loss, and conductivity were determined. • Electromechanical response of the films was measured at an applied voltage. • Some biocompatibility tests, both in vitro and in vivo, were performed.

  9. Application of halloysite clay nanotubes as a pharmaceutical excipient.

    Science.gov (United States)

    Yendluri, Raghuvara; Otto, Daniel P; De Villiers, Melgardt M; Vinokurov, Vladimir; Lvov, Yuri M

    2017-04-15

    Halloysite nanotubes, a biocompatible nanomaterial of 50-60nm diameter and ca. 15nm lumen, can be used for loading, storage and sustained release of drugs either in its pristine form or with additional polymer complexation for extended release time. This study reports the development composite tablets based on 50wt.% of the drug loaded halloysite mixed with 45wt.% of microcrystalline cellulose. Powder flow and compressibility properties of halloysite (angle of repose, Carr's index, Hausner ratio, Brittle Fracture Index, tensile strength) indicate that halloysite is an excellent tablet excipient. Halloysite tubes can also be filled with nifedipine with ca. 6wt.% loading efficiency and sustained release from the nanotubes. Tablets prepared with drug loaded halloysite allowed for almost zero order nifedipine release for up to 20h. Nifedipine trapped in the nanotubes also protect the drug against light and significantly increased the photostability of the drug. All of these demonstrate that halloysite has the potential to be an excellent pharmaceutical excipient that is also an inexpensive, natural and abundantly available material. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Preparation and Characterization of PLA-Starch Biodegradable Composites Via Radiation Processing

    Energy Technology Data Exchange (ETDEWEB)

    Hemvichian, K.; Suwanmala, P. [Thailand Institute of Nuclear Technology (TINT) (Thailand); Kungsumrith, W. [Department of Industrial Engineering, Faculty of Engineering, Thammasat University (TU) (Thailand); Pongprayoon, T. [Department of Chemical Engineering, Faculty of Engineering, King Mongkut’s University of Technology North Bangkok (KMUTNB), Bangkok (Thailand)

    2011-07-01

    This research project aims to apply the use of radiation processing to prepare biodegradable composites from poly(lactic acid) or polylactide (PLA) and cassava starch. Cassava starch, a natural polymer that is inexpensive and abundant, especially in Thailand, will be used as starting material. Functional group of cassava starch will be modified first in order to render starch more compatible with PLA. The monomer with desired functional groups will be grafted onto the backbone of starch via radiation-induced grafting polymerization. Different parameters will be examined to determine the optimum conditions for the grafting polymerization. The modified starch will subsequently be blended with PLA, with and without clay, to form biodegradable composites. In order to further improve the thermal properties, the blends and their composites will be subjected to radiation to induce crosslinking between the molecules of PLA and starch derivatives. (author)

  11. Preparation and Characterization of PLA-Starch Biodegradable Composites Via Radiation Processing

    International Nuclear Information System (INIS)

    Hemvichian, K.; Suwanmala, P.; Kungsumrith, W.; Pongprayoon, T.

    2011-01-01

    This research project aims to apply the use of radiation processing to prepare biodegradable composites from poly(lactic acid) or polylactide (PLA) and cassava starch. Cassava starch, a natural polymer that is inexpensive and abundant, especially in Thailand, will be used as starting material. Functional group of cassava starch will be modified first in order to render starch more compatible with PLA. The monomer with desired functional groups will be grafted onto the backbone of starch via radiation-induced grafting polymerization. Different parameters will be examined to determine the optimum conditions for the grafting polymerization. The modified starch will subsequently be blended with PLA, with and without clay, to form biodegradable composites. In order to further improve the thermal properties, the blends and their composites will be subjected to radiation to induce crosslinking between the molecules of PLA and starch derivatives. (author)

  12. Preparation and mechanical properties of photo-crosslinked poly(trimethylene carbonate) and nano-hydroxyapatite composites.

    Science.gov (United States)

    Geven, Mike A; Barbieri, Davide; Yuan, Huipin; de Bruijn, Joost D; Grijpma, Dirk W

    2015-01-01

    Composite materials of photo-crosslinked poly(trimethylene carbonate) and nanoscale hydroxyapatite were prepared and their mechanical characteristics for application as orbital floor implants were assessed. The composites were prepared by solvent casting poly(trimethylene carbonate) macromers with varying amounts of nano-hydroxyapatite and subsequent photo-crosslinking. The incorporation of the nano-hydroxyapatite into the composites was examined by thermogravimetric analysis, scanning electron microscopy and gel content measurements. The mechanical properties were investigated by tensile testing and trouser tearing experiments. Our results show that nano-hydroxyapatite particles can readily be incorporated into photo-crosslinked poly(trimethylene carbonate) networks. Compared to the networks without nano-hydroxyapatite, incorporation of 36.3 wt.% of the apatite resulted in an increase of the E modulus, yield strength and tensile strength from 2.2 MPa to 51 MPa, 0.5 to 1.4 N/mm2 and from 1.3 to 3.9 N/mm2, respectively. We found that composites containing 12.4 wt.% nano-hydroxyapatite had the highest values of strain at break, toughness and average tear propagation strength (376% , 777 N/mm2 and 3.1 N/mm2, respectively).

  13. Preparation and properties of yttria doped tetragonal zirconia polycrystal/Sr-doped barium hexaferrite ceramic composites

    International Nuclear Information System (INIS)

    Wang, Shanshan; Zhang, Chao; Guo, Ruisong; Liu, Lan; Yang, Yuexia; Li, Kehang

    2015-01-01

    Highlights: • The 3Y-TZP/Sr-doped barium ferrite composites were prepared. • The saturation magnetization was improved by 15% with Sr-doping. • The dispersion coefficient p could reflect the microscopic lattice variation. • The composite with x = 0.5 had the maximum fracture toughness of 8.3 MPa m 1/2 . - Abstract: The effects of substitution of Ba 2+ by Sr 2+ on the magnetic property of barium ferrite and addition barium ferrite secondary phase to the 3 mol% yttria-doped tetragonal zirconia polycrystal (3Y-TZP) matrix on the mechanical property of composites were investigated. The Sr-doped barium ferrite (Ba 1−x Sr x Fe 12 O 19 , x = 0, 0.25, 0.50 and 0.75) was synthesized by solid-state reaction in advance. Then 3Y-TZP/20 wt% Sr-doped barium ferrite composites were prepared by means of conventional ceramic method. It was found that a moderate amount of Sr added to barium ferrite could boost the saturation magnetization by 15% compared with the composites without Sr-doping. Besides, the composite with x = 0.50 possessed the best mechanical properties, such as 11.5 GPa for Vickers hardness and 8.3 MPa m 1/2 for fracture toughness, respectively. It was demonstrated that magnetic and mechanical properties of the composites could be harmonized by the incorporation of barium ferrite secondary phase

  14. Preparation and characterization of functionalized cellulose nano crystals with methyl adipoyl chloride used to prepare chitosan grafting nano composite

    International Nuclear Information System (INIS)

    Mesquita, Joao Paulo de; Teixeira, Ivo F.; Donnici, Claudio L.; Pereira, Fabiano V.

    2011-01-01

    Cellulose nano crystals (CNCs) were prepared from eucalyptus pulp and functionalized with methyl adipoyl chloride. The nano materials were characterized by different techniques including FTIR, 1H NMR and XRD which showed that the functionalization occurs only on the surface of the nano structures without change in crystalline structure of the nanoparticles. The new-functionalized CNCs were used as reinforcement in the preparation of a nano composite with chitosan, through the formation of a covalent bond between the nano filler and matrix. Preliminary results of mechanical tests indicate an improvement in tensile strength and increase in deformation of chitosan. (author)

  15. Preparation and characterization of nanostructured MWCNT-TiO2 composite materials for photocatalytic water treatment applications

    International Nuclear Information System (INIS)

    Wang Wendong; Serp, Philippe; Kalck, Philippe; Silva, Claudia Gomes; Faria, Joaquim Luis

    2008-01-01

    Nanoscale composite materials containing multi-walled carbon nanotubes (MWCNT) and titania were prepared by using a modified sol-gel method. The composites were comprehensively characterized by thermogravimetric analysis, nitrogen adsorption-desorption isotherm, powder X-ray diffraction, scanning electron microscopy with energy dispersive X-ray analysis, transmission electron microscopy, X-ray photoelectron spectroscopy and UV-vis absorption spectroscopy. The analysis revealed the presence of titania crystallites of about 7.5 nm aggregated together with MWCNT in particles of 15-20 nm of diameter. The photoactivity of the prepared materials, under UV or visible irradiation, was tested using the conversion of phenol from model aqueous solutions as probe reaction. A synergy effect on the photocatalytic activities observed for the composite catalysts was discussed in terms of a strong interphase interaction between carbon and TiO 2 phases by comparing the different roles of MWCNT in the composite materials

  16. Facile preparation and enhanced microwave absorption properties of flake carbonyl iron/Fe3O4 composite

    International Nuclear Information System (INIS)

    Min, Dandan; Zhou, Wancheng; Luo, Fa; Zhu, Dongmei

    2017-01-01

    Highlights: • Flake carbonyl iron/Fe 3 O 4 composites were prepared by surface oxidation technique. • Lower permittivity and modest permeability was obtained by the FCI/Fe 3 O 4 composites. • Enhanced absorption efficiency and broader absorption band were obtained. - Abstract: Flake carbonyl iron/Fe 3 O 4 (FCI/Fe 3 O 4 ) composites with enhanced microwave absorption properties were prepared by a direct and flexible surface oxidation technique. The phase structures, morphology, magnetic properties, frequency-dependent electromagnetic and microwave absorption properties of the composites were investigated. The measurement results showed that lower permittivity as well as modest permeability was obtained by the FCI/Fe 3 O 4 composites. The calculated microwave absorption properties indicated that enhanced absorption efficiency and broader absorption band were obtained by the FCI/Fe 3 O 4 composite comparing with the FCI composite. The absorption frequency range with reflection loss (RL) below −5 dB of FCI/Fe 3 O 4 composites at reaction time of 90 min at thickness of 1.5 mm is 13.3 GHz from 4.7 to 18 GHz, while the bandwidth of the FCI composite is only 5.9 GHz from 2.6 to 8.5 GHz at the same thickness. Thus, such absorbers could act as effective and wide broadband microwave absorbers in the GHz range.

  17. Preparation of Reduced Graphene Oxide/MnO Composite and Its Electromagnetic Wave Absorption Performance

    Science.gov (United States)

    Yuan, Jiangtao; Li, Kunzhen; Liu, Zhongfei; Jin, Shaowei; Li, Shikuo; Zhang, Hui

    2018-02-01

    The composite containing reduced graphene oxide and MnO nanoparticles (RGO/MnO) has been prepared via a one step pyrolysis method. The MnO nanoparticles were uniformly dispersed on the surface of RGO nanosheets forming MnO/RGO composite. The composite displays a maximum absorption of ‒38.9 dB at 13.5 GHz and the bandwidth of reflection loss corresponding to -10 dB can reach 4.9 GHz (from 11.5 to 16.4 GHz) with a coating layer thickness of only 2 mm. Therefore, the obtained RGO/MnO composite a perfect lightweight and high-performance electromagnetic wave absorbent.

  18. Preparation and Thermoelectric Properties of Graphite/Bi0.5Sb1.5Te3 Composites

    Science.gov (United States)

    Hu, Wenhua; Zhou, Hongyu; Mu, Xin; He, Danqi; Ji, Pengxia; Hou, Weikang; Wei, Ping; Zhu, Wanting; Nie, Xiaolei; Zhao, Wenyu

    2018-06-01

    Bismuth telluride zone-melting alloys are the most commercially used thermoelectric materials. However, the zone-melting ingots have weak machinability due to the strong preferred orientation. Here, non-textured graphite/Bi0.5Sb1.5Te3 (G/BST) composites were prepared by a powder metallurgy method combined with cold-pressing and annealing treatments. The composition, microstructure, and thermoelectric properties of the G/BST composites with different mass percentages of G were investigated. It was found that G addition could effectively reduce the thermal conductivity and slightly improve the electrical properties of the BST, which resulted in a large enhancement in the figure-of-merit, ZT. The largest ZT for the xG/BST composites with x = 0.05% reached 1.05 at 320 K, which is increased by 35% as compared with that of the G-free BST materials. This work provided an effective method for preparing non-textured Bi2Te3-based TE materials with a simple process, low cost, and large potential in scale production.

  19. Preparation and characterization of morph-genetic aluminum nitride/carbon composites from filter paper

    International Nuclear Information System (INIS)

    Wang Wei; Xue Tao; Jin Zhihao; Qiao Guanjun

    2008-01-01

    Morph-genetic aluminum nitride/carbon composites with cablelike structure were prepared from filter paper template through the surface sol-gel process and carbothermal nitridation reaction. The resulting materials have a hierarchical structure originating from the morphology of cellulose paper. The aluminum nitride/carbon composites have the core-shell microstructure, the core is graphitic carbon, and the shell is aluminum nitride nanocoating formed by carbothermal nitridation reduction of alumina with the interfacial carbon in nitrogen atmosphere. Scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and transmission electron microscope were employed to characterize the structural morphology and phase compositions of the final products

  20. Preparation and properties of carboxylated styrene-butadiene rubber/cellulose nanocrystals composites.

    Science.gov (United States)

    Cao, Xiaodong; Xu, Chuanhui; Liu, Yuhong; Chen, Yukun

    2013-01-30

    A series of carboxylated styrene-butadiene rubber (XSBR)/cellulose nanocrystals (CNs) latex composites were successfully prepared. The vulcanization process, morphology, dynamic viscoelastic behavior, dynamic mechanical property, thermal and mechanical performance of the XSBR/CNs composites were investigated in detail. The results revealed that CNs were dispersed uniformly in the XSBR matrix and formed a strong filler-filler network. The dynamic mechanical analysis (DMA) showed that the glass transition temperature (T(g)) of XSBR matrix was shifted from 48.45 to 50.64 °C with 3 phr CNs, but decreased from 50.64 to 46.28 °C when further increasing CNs content up to 15 phr. The composites exhibited a significant enhancement in tensile strength (from 16.9 to 24.1 MPa) and tear strength (from 43.5 to 65.2 MPa) with loading CNs from 0 to 15 phr. In addition, the thermo-gravimetric analysis (TGA) showed that the temperature at 5% weight loss of the XSBR/CNs composites decreased slightly with an increase of the CNs content. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  1. SANS studies of solutions and molecular composites prepared from cellulose tricarbanilate

    CERN Document Server

    Alava, C; Cameron, J D; Cowie, J M G; Vaqueiro, P; Möller, A; Triolo, A

    2002-01-01

    We report on SANS measurements carried out on the instrument SANS1 (V4) at the BENSC facility on solutions and composites of cellulose tricarbanilate (CTC). This cellulose derivative exhibits lyotropic behaviour in methylacrylate (MA). The SANS data indicate that in the isotropic liquid state (up to 25% wt CTC in MA) the CTC chains behave like rods of mass per unit length (M/L). In the liquid crystalline (LC) phase (at and above 35% wt CTC in MA), the Q dependence varies from Q sup - sup 1 to Q sup - sup 4 , probably as a result of self-assembling of the CTC chains. The general aim of our work is to prepare molecular composites, i.e. miscible blends of rigid-rod and flexible-coil polymers, from CTC solutions in polymerizable media. To establish the degree of homogeneity of the composites, we performed SANS measurements on UV-cured CTC/MA solutions. Here, we compare the SANS data of CTC/monomer solutions with those of the corresponding composites. (orig.)

  2. Preparation and properties of electrodeposited Ni-TiO2 composite coating

    Directory of Open Access Journals (Sweden)

    Sukhdev Singh Bhogal

    2015-03-01

    Full Text Available Mechanical properties of cutting tool like microhardness, coating adhesiveness & corrosion resistance are some important parameters, which affects the tool life and further indirectly affects the component cost. In this paper Ni-TiO2 composite coating was prepared through electrocodeposition in order to improve the mechanical properties of tungsten carbide cutting tools. Microhardness of Ni-TiO2 composite layer have been studied by varying input current density (mA, pH vale of electrolyte & particle concentration of TiO2 in electrolyte bath. Microstructure and phase structure of composite layer were investigated using atomic force microscope (AFM, scanning electronic microscope (SEM and X-ray diffraction (XRD. Surface morphology of Ni-TiO2 coated layer shows fine grained structures is obtained at low currents with higher microhardness of composite coating. Maximum microhardness 1483 HV of coated layer is found at 15mA of current and at 4.5 pH of watt’s solution. It has also been seen that with the increase of Ti, microhardness of the layer is also increases.  

  3. Effect of Minor Titanium Addition on Copper/Diamond Composites Prepared by Hot Forging

    Science.gov (United States)

    Yang, Fei; Sun, Wei; Singh, Ajit; Bolzoni, Leandro

    2018-03-01

    Copper/diamond composites have great potential to lead the next generation of advanced heat sink materials for use in high-power electronic devices and high-density integrated circuits because of their potential excellent properties of high thermal conductivity and close thermal expansion to the chip materials (e.g., Si, InP, GaAs). However, the poor wettability between copper and diamond presents a challenge for synthesizing copper/diamond composites with effective metallurgical bonding and satisfied thermal performance. In this article, copper/diamond composites were successfully prepared by hot forging of elemental copper and artificial diamond powders with small amounts (0 vol.%, 3 vol.% and 5 vol.%) of titanium additives. Microstructure observation and mechanical tests showed that adding minor titanium additions in the copper/diamond composite resulted in fewer cracks in the composites' microstructure and significantly improved the bonding between the copper and diamond. The strongest bonding strength was achieved for the copper/diamond composite with 3 vol.% titanium addition, and the possible reasons were discussed.

  4. Extractive spectrophotometric determination of five selected drugs by ion-pair complex formation with bromothymol blue in pure form and pharmaceutical preparations

    Directory of Open Access Journals (Sweden)

    Sneha G. Nair

    2015-12-01

    Full Text Available Simple, precise, selective, and expeditious spectrophotometric methods have been developed for the determination of itopride (ITO, midodrine (MID, diclofenac (DIC, mesalamine (MES, and sumatriptan (SUM in their pure form as well as in pharmaceutical preparations. The method was based on ion-pair complex formation between the drugs and anionic dye, bromothymol blue in an acidic medium (pH 2.0–4.0. The yellow colored complexes formed were quantitatively extracted into chloroform and measured at 411, 410, 413, 412, and 414 nm wavelength for ITO, MID, DIC, MES, and SUM, respectively. Beer’s law was obeyed in the concentration range of 3.0–30 µg/mL for ITO, 1.0–20 µg/mL for MID, 1.5–40 µg/mL for DIC, 1.2–12 µg/mL for MES, and 0.5–15 µg/mL for SUM. The stoichiometry of the complexes formed between the drugs and the dye was 1:1 as determined by Job’s method of continuous variation. The association constant (KIP of the ion-pair complexes formed was evaluated using Benesi–Hildebrand equation. Limit of detection, limit of quantification, and Sandell’s sensitivity of the methods were also estimated. The proposed methods were successfully employed for the determination of these drugs in their pharmaceutical dosage forms.

  5. Preparation of Composite Hydrogel Based on Polyacrylamide and the Effect of Kaolinite on Its Properties in the Reservoir Conditions

    Directory of Open Access Journals (Sweden)

    Farhad Salimi

    2013-01-01

    Full Text Available A gel composite (based on polyacrylamide and crosslinker Cr(III acetate was prepared by solvent method (distillate and water formation and nanoclay particle (kaolinite. Using XRD tests, d001 was evaluated for kaolinite nanoparticles in gel composite. Kaolinite modification using dimethyl-sulfoxide led to increase interlamellar spacing from 7.21 to 10.82 o A. Based on the results obtained for samples prepared from unmodified clay besides the pure clay, there is a wide peak at 2θ = 8o; which is a representative of polymer diffusion between the clay layers. For the sample prepared from modified clay, no increase in interlamellar space was observed. Addition of 15% clay (modified and unmodified caused the syneresis to reduce by 20%. The gelation time for composites prepared from both types of clays increased due to increases in clay concentration, which this increase for the sample prepared from unmodified clay was greater. The viscosity of gel for samples prepared from modified clay increased due to increased clay concentration, which reached its maximum for 15% clay concentration. However for unmodified clay the maximum value of viscosity was observed for 30% clay concentration.

  6. Inherent Anticipation in the Pharmaceutical and Biotechnology Industries.

    Science.gov (United States)

    Goldman, Michael; Evans, Georgia; Zappia, Andrew

    2015-04-15

    Pharmaceutical and biotech research often involves discovering new properties of, or new methods to use, existing compositions. The doctrine of inherent anticipation, however, prevents the issuance and/or validity of a patent for discoveries deemed to have been implicitly disclosed in the prior art. This can be a barrier to patent rights in these technologies. Inherent anticipation therefore creates uncertainty for patent protection in the pharmaceutical and biotech sciences. Despite this uncertainty, Federal Circuit jurisprudence provides guidance on the boundaries of the inherent anticipation doctrine. In view of the case law, certain strategies may be employed to protect inventions that may potentially be viewed as inherent in the prior art. Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.

  7. Nano-sized particles, processes of making, compositions and uses thereof

    Science.gov (United States)

    O'Brien, Stephen [New York, NY; Yin, Ming [Los Alamos, NM

    2012-05-22

    The present invention describes methods for preparing high quality nanoparticles, i.e., metal oxide based nanoparticles of uniform size and monodispersity. The nanoparticles advantageously comprise organic alkyl chain capping groups and are stable in air and in nonpolar solvents. The methods of the invention provide a simple and reproducible procedure for forming transition metal oxide nanocrystals, with yields over 80%. The highly crystalline and monodisperse nanocrystals are obtained directly without further size selection; particle size can be easily and fractionally increased by the methods. The resulting nanoparticles can exhibit magnetic and/or optical properties. These properties result from the methods used to prepare them. Also advantageously, the nanoparticles of this invention are well suited for use in a variety of industrial applications, including cosmetic and pharmaceutical formulations and compositions.

  8. Preparation and in vitro evaluation of nanostructured TiO2/TCP composite coating by plasma electrolytic oxidation

    International Nuclear Information System (INIS)

    Hu, Hongjie; Liu, Xuanyong; Ding, Chuanxian

    2010-01-01

    Porous and nanostructured TiO 2 /tricalcium phosphate (TCP) composite coating on titanium substrate was prepared by plasma electrolytic oxidation (PEO). The microstructure and phase composition of the coating were characterized using scanning electron microscopy and X-ray diffraction. Its bioactivity was evaluated by simulated body fluid (SBF) immersion tests. MG63 cells were cultured on the surface of the coating to investigate its cytocompatibility. Potentiodynamic polarization tests were applied to measure its corrosion resistance. The results revealed that rough and hydrophilic TiO 2 /TCP composite coating with pores of several micrometers and grains of 50-200 nm was prepared by one-step PEO treatment. The TiO 2 /TCP composite coating showed good apatite-forming ability in SBF, and the TCP phase in the coating played an important role in inducing apatite formation. MG63 cells could adhere and proliferate on the surface of the coating, indicating its good cytocompatibility. The composite coating also exhibited good corrosion resistance in 0.9% NaCl solution.

  9. Preparation and characterization of flake graphite/silicon/carbon spherical composite as anode materials for lithium-ion batteries

    International Nuclear Information System (INIS)

    Lai Jun; Guo Huajun; Wang Zhixing; Li Xinhai; Zhang Xiaoping; Wu Feixiang; Yue Peng

    2012-01-01

    Highlights: ► Flake graphite/silicon/carbon composite is synthesized via spray drying. ► Flake graphite of ∼0.5 μm and glucose are used to prepare the composite. ► The as-prepared composite shows spherical and porous appearance. ► The composite shows nearly the same cycleability as commercial graphite in 20 cycles. ► The composite shows a reversible capacity of 552 mAh/g at the 20th cycle. - Abstract: Using nano-Si, glucose and flake graphite of ∼0.5 μm as raw materials, flake graphite/silicon/carbon composite is successfully synthesized via spray drying and subsequent pyrolysis. The samples are characterized by XRD, SEM, TEM and electrochemical measurements. The composite is composed of flake graphite, nano-Si and amorphous glucose-pyrolyzed carbon and presents good spherical appearance. Some micron pores arising from the decomposition of glucose exist on the surface of the composite particles. The composite has a high reversible capacity of 602.7 mAh/g with an initial coulombic efficiency of 69.71%, and shows nearly the same cycleability as the commercial graphite in 20 cycles. Both the glucose-pyrolyzed carbon and the micron pores play important roles in improving the cycleability of the composite. The flake graphite/silicon/carbon composite electrode is a potential alternative to graphite for high energy-density lithium ion batteries.

  10. Blending Problem-Based Learning and Peer-Led Team Learning, in an Open Ended "Home-Grown" Pharmaceutical Chemistry Case Study

    Science.gov (United States)

    Veale, Clinton G. L.; Krause, Rui W. M.; Sewry, Joyce D.

    2018-01-01

    Pharmaceutical chemistry, medicinal chemistry and the drug discovery process require experienced practitioners to employ reasoned speculation in generating creative ideas, which can be used to evolve promising molecules into drugs. The ever-evolving world of pharmaceutical chemistry requires university curricula that prepare graduates for their…

  11. A novel visible spectrophotometric method for the determination of ethamsylate in pharmaceutical preparations and biological samples

    Science.gov (United States)

    Zhang, Meiyun; Zhang, Yan; Li, Quanmin

    2010-03-01

    A highly sensitive visible spectrophotometric method has been developed to determine ethamsylate in this paper, which is based on using Cu(II) as spectroscopic probe reagent. The study indicates that in the presence of SCN - and KNO 3, Cu(II) is reduced to Cu(I) by ethamsylate at pH 5.0, and the in situ formed Cu(I) reacts with SCN - to form into the white emulsion CuSCN that could be stayed upon the surface of water. According to the amount of residual Cu(II), the amount of ethamsylate can be indirectly determined. Under the optimal conditions, Beer's law is applicable in the range of 0.2-9.0 μg/mL (7.60 × 10 -7-3.42 × 10 -5 mol/L) for aqueous standard solution of ethamsylate with linear correlation coefficient of 0.9998. The detection limit and relative standard deviation are 0.12 μg/mL and 1.5%, respectively. And the molar absorption coefficient of the indirect determination of ethamsylate is 1.0 × 10 5 L/mol cm. The method is successfully applied to determine ethamsylate in pharmaceutical preparations and biological samples.

  12. Identification of an exposure risk to heavy metals from pharmaceutical-grade rubber stoppers.

    Science.gov (United States)

    Li, Xianghui; Qian, Pingping

    2017-07-01

    Exposure to low concentrations of heavy metals and metalloids represents a well-documented risk to animal and human health. However, current standards (European Pharmacopeia [EP], United States Pharmacopoeia [USP], International Organization for Standardization [ISO], YBB concerned with rubber closures) only require testing for Zn in pharmaceutical-grade rubber stoppers and then using only pure water as a solvent. We extracted and quantified heavy metals and trace elements from pharmaceutical-grade rubber stoppers under conditions that might occur during the preparation of drugs. Pure water, saline, 10% glucose, 3% acetic acid (w/v), 0.1 mol/L hydrochloric acid, and diethylenetriaminepentaacetic acid (4 mg/mL, 0.4 mg/mL, and 0.04 mg/mL) were used as extraction agents. We quantified the extracted arsenic, lead, antimony, iron, magnesium, aluminum, and zinc using inductively coupled plasma mass spectrometry. The concentration of extracted metals varied depending on the different extraction solutions used and between the different rubber stopper manufacturers. Rubber stoppers are ubiquitously used in the pharmaceutical industry for the storage and preparation of drugs. Extraction of heavy metals during the manufacturing and preparation of drugs represents a significant risk, suggesting a need for industry standards to focus on heavy metal migration from rubber stoppers. Copyright © 2016. Published by Elsevier B.V.

  13. Preparation and properties of highly conductive palmitic acid/graphene oxide composites as thermal energy storage materials

    International Nuclear Information System (INIS)

    Mehrali, Mohammad; Latibari, Sara Tahan; Mehrali, Mehdi; Indra Mahlia, Teuku Meurah; Cornelis Metselaar, Hendrik Simon

    2013-01-01

    PA/GO (palmitic acid/graphene oxide) as PCMs (phase change materials) prepared by vacuum impregnation method, have high thermal conductivity. The GO (graphene oxide) composite was used as supporting material to improve thermal conductivity and shape stabilization of composite PCM (phase change material). SEM (Scanning electronic microscope), FT-IR (Fourier transformation infrared spectroscope) and XRD (X-ray diffractometer) were applied to determine microstructure, chemical structure and crystalloid phase of palmitic acid/GO composites, respectively. DSC (Differential scanning calorimeter) test was done to investigate thermal properties which include melting and solidifying temperatures and latent heat. FT-IR analysis represented that the composite instruction of porous palmitic acid and GO were physical. The temperatures of melting, freezing and latent heats of the composite measured through DSC analysis were 60.45, 60.05 °C, 101.23 and 101.49 kJ/kg, respectively. Thermal cycling test showed that the form-stable composite PCM has good thermal reliability and chemical stability. Thermal conductivity of the composite PCM was improved by more than three times from 0.21 to 1.02. As a result, due to their acceptable thermal properties, good thermal reliability, chemical stability and great thermal conductivities, we can consider the prepared form-stable composites as highly conductive PCMs for thermal energy storage applications. - Highlights: • Novel composite PCM with high thermal conductivity and latent heat storage. • New thermal cycling test for thermal reliability of composite PCMs. • Increasing thermal conductivity of composite PCM with graphene oxide. • Increasing thermal stability of phase change material by adding graphene oxide

  14. Preparation and characterization of copper-graphite composites by electrical explosion of wire in liquid.

    Science.gov (United States)

    Bien, T N; Gul, W H; Bac, L H; Kim, J C

    2014-11-01

    Copper-graphite nanocomposites containing 5 vol.% graphite were prepared by a powder metallurgy route using an electrical wire explosion (EEW) in liquid method and spark plasma sintering (SPS) process. Graphite rods with a 0.3 mm diameter and copper wire with a 0.2 mm diameter were used as raw materials for EEWin liquid. To compare, a pure copper and copper-graphite mixture was also prepared. The fabricated graphite was in the form of a nanosheet, onto which copper particles were coated. Sintering was performed at 900 degrees C at a heating rate of 30 degrees C/min for 10 min and under a pressure of 70 MPa. The density of the sintered composite samples was measured by the Archimedes method. A wear test was performed by a ball-on-disc tribometer under dry conditions at room temperature in air. The presence of graphite effectively reduced the wear of composites. The copper-graphite nanocomposites prepared by EEW had lower wear rates than pure copper material and simple mixed copper-graphite.

  15. Critical evaluation of methodology commonly used in sample collection, storage and preparation for the analysis of pharmaceuticals and illicit drugs in surface water and wastewater by solid phase extraction and liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Baker, David R; Kasprzyk-Hordern, Barbara

    2011-11-04

    The main aim of this manuscript is to provide a comprehensive and critical verification of methodology commonly used for sample collection, storage and preparation in studies concerning the analysis of pharmaceuticals and illicit drugs in aqueous environmental samples with the usage of SPE-LC/MS techniques. This manuscript reports the results of investigations into several sample preparation parameters that to the authors' knowledge have not been reported or have received very little attention. This includes: (i) effect of evaporation temperature and (ii) solvent with regards to solid phase extraction (SPE) extracts; (iii) effect of silanising glassware; (iv) recovery of analytes during vacuum filtration through glass fibre filters and (v) pre LC-MS filter membranes. All of these parameters are vital to develop efficient and reliable extraction techniques; an essential factor given that target drug residues are often present in the aqueous environment at ng L(-1) levels. Presented is also the first comprehensive review of the stability of illicit drugs and pharmaceuticals in wastewater. Among the parameters studied are: time of storage, temperature and pH. Over 60 analytes were targeted including stimulants, opioid and morphine derivatives, benzodiazepines, antidepressants, dissociative anaesthetics, drug precursors, human urine indicators and their metabolites. The lack of stability of analytes in raw wastewater was found to be significant for many compounds. For instance, 34% of compounds studied reported a stability change >15% after only 12 h in raw wastewater stored at 2 °C; a very important finding given that wastewater is typically collected with the use of 24 h composite samplers. The stability of these compounds is also critical given the recent development of so-called 'sewage forensics' or 'sewage epidemiology' in which concentrations of target drug residues in wastewater are used to back-calculate drug consumption. Without an understanding of stability

  16. One-step preparation of silver–polyaniline nanotube composite for non-enzymatic hydrogen peroxide detection

    Energy Technology Data Exchange (ETDEWEB)

    Lorestani, Farnaz, E-mail: Farnaz.lorestani@siswa.um.edu.my; Shahnavaz, Zohreh; Nia, Pooria Moozarm; Alias, Y.; Manan, Ninie S.A., E-mail: niniemanan@um.edu.my

    2015-08-30

    Graphical abstract: - Highlights: • Silver nanoparticle-decorated polyaniline nanotube composites (AgNPs–PANINTs) have been fabricated through a one step modified method without adding any extra acids, template and surface modifier. • The sensor showed excellent selectivity, reproducibility, and stability properties. • The AgNPs–PANINTs composite that prepared with silver ammonia solution (Ag(NH{sub 3}){sub 2}OH) exhibits better electrochemical performance than the AgNPs–PANINTs composite that was prepared with silver nitrite (AgNO{sub 3}) due to smaller size and higher surface area of silver nanoparticle (AgNPs) in the composite. • The electrocatalytic activity for the reduction was strongly affected by the concentration of silver ammonia solution in the nanocomposites, with the best electrocatalytic activity observed for the composite of 6:1 volume ratios of PANI to Ag(NH{sub 3}){sub 2}OH (0.04 M). - Abstract: A modified glassy carbon electrode with silver nanoparticles–polyaniline nanotubes (AgNPs–PANINTs) composite is used as a non-enzymatic nanobiosensor for detecting hydrogen peroxide (H{sub 2}O{sub 2}). The electrocatalytic activity for the reduction was strongly affected by the concentration of silver ammonia solution in the nanocomposites, with the best electrocatalytic activity observed for the composite of 6:1 volume ratios of PANI to Ag(NH{sub 3}){sub 2}OH (0.04 M). Field emission scanning electron microscope images and their size distribution diagrams indicated that using the silver ammonia complex instead of silver nitrate caused uniform distribution of nanometer-sized silver nanoparticles with a narrow size distribution in the composite. The corresponding calibration curve for the current response showed a linear detection range of 0.1–90 mM (R{sup 2} = 0.9986), while the limit of detection was estimated to be 0.2 μM at the signal to noise ratio of 3.

  17. Preparation and characterization of Fe3O4@Au-C225 composite targeted nanoparticles for MRI of human glioma.

    Science.gov (United States)

    Ge, Yaoqi; Zhong, Yuejiao; Ji, Guozhong; Lu, Qianling; Dai, Xinyu; Guo, Zhirui; Zhang, Peng; Peng, Gang; Zhang, Kangzhen; Li, Yuntao

    2018-01-01

    To study the characterization of Fe3O4@Au-C225 composite targeted MNPs. Fe3O4@Au-C225 was prepared by the absorption method. The immunosorbent assay was used to evaluate its absorption efficiency at C225 Fc. ZETA SIZER3000 laser particle size analyzer, ultraviolet photometer and its characteristics were analyzed by VSM. the targeting effect of Fe3O4@Au-C225 composite targeted MNPs on U251 cells in vitro were detected by 7.0 Tesla Micro-MR; and subcutaneous transplanted human glioma in nude mice were performed the targeting effect in vivo after tail vein injection of Fe3O4@Au-C225 composite targeted MNPs by MRI. The self-prepared Fe3O4@Au composite MNPs can adsorb C225 with high efficiency of adsorption so that Fe3O4@Au-C225 composite targeted MNPs were prepared successfully. Fe3O4@Au-C225 composite targeted MNPs favorably targeted human glioma cell line U251 in vitro; Fe3O4@Au-C225 composite targeted MNPs have good targeting ability to xenografted glioma on nude mice in vivo, and can be traced by MRI. The Fe3O4@Au-C225 composite targeted MNPs have the potential to be used as a tracer for glioma in vivo.

  18. Preparation of intravenous cytostatic mixtures: one-year work experience at the Pharmaceutical Service of the Nacional Institute of Oncology and Radiobiology

    International Nuclear Information System (INIS)

    Arbesu Michelena, Antonieta; Jimenez Rodriguez, Deise; Guzman Descondido, Anisley; Masso Maulin, Kenia

    2008-01-01

    From October 2006 to September 2007, which marked the beginning of the preparation of intravenous cytostatic mixtures by the Pharmaceutical Service of the National Institute of Oncology and Radiobiology, a number of results were achieved and then considered for analysis in this paper. The selected indicators included the number of detected and/or avoided medication errors, cytostatics consumption, therapies recovered through centralized preparation and the implementation of Good Practices of Preparation and Pharmacy. The results were compared with those of similar periods of time in previous years. It was observed that the involvement of the pharmacist in the oncological chemotherapy team contributed to recovering costly therapies such as 80 mg Docetaxel, 300 mg Paclitaxel and 150 mg Transtuzomab ampules. One hundred and twenty one patients could potentially benefit from these therapies, mainly those suffering breast cancer. The consumption of cytostatic drugs such as 1 mg Vincristine and 15 mg Bleomycin ampules decreased; the application of technical and economic control evidenced an increased use of 200 mg Cyclophosphamide and 10 mg Cisplatine ampules. Besides, 1,3% medication errors in prescription was detected and avoided, although this is still a high figure. It was concluded that the involvement of a pharmacist in the medical team improves the quality of service in those hospitals that care for oncological patients. It was suggested that a pharmacist should be incorporated into the medical teams of other hospital centers throughout the country since this encourages the implementation of Good Practices of Preparation and contributes to minimizing medication errors. (Author)

  19. Food interactions with sustained-release theophylline preparations. A review.

    Science.gov (United States)

    Jonkman, J H

    1989-03-01

    Currently, theophylline is being used predominantly as sustained-release capsules or tablets. In the mid-seventies the first preparations for use with a dosage interval of 12 hours (twice-daily preparations) were introduced. Since 1983, theophylline preparations that can be given with an interval of 24 hours (once-daily preparations) have become available. The release of theophylline from some of these products can be influenced (either increased or decreased) by concomitant intake of food. With some preparations the composition of the meal (especially the fat content) has an influence on the degree of effect. The consequence may be an effect on the rate of absorption or on the amount absorbed, or both simultaneously. This could result in an unexpected shift of the plasma theophylline concentration. Such a shift is therapeutically undesirable, because theophylline has a fairly narrow therapeutic range. A review is given of those food interactions with the sustained-release theophylline preparations, both twice-daily and once-daily products, that are currently on the world market. Special attention is paid to the specific (bio)pharmaceutical characteristics of the different products, and to the influence of the composition and timing of the meals. For each preparation the effect of food on the following pharmacokinetic parameters is discussed: area under the plasma concentration-time curve, peak plasma drug concentration and time to reach this peak. Where possible, the results for both adults and children are discussed. There are indications that children are more susceptible to food-effects than adults. The regulatory aspects are mentioned briefly. Clinically important effects of food have been observed with the following twice-daily products: 'Theo-Dur Sprinkle', 'Theolair SR' (= 'Nuelin SR') and 'Theograd'. Pronounced effects could have an even greater impact with once-daily preparations, as the total daily dose will be given at a single time. A particularly

  20. Preparation and antibacterial activities of Ag/Ag+/Ag3+ nanoparticle composites made by pomegranate (Punica granatum rind extract

    Directory of Open Access Journals (Sweden)

    Hui Yang

    Full Text Available Nano-silver and its composite materials are widely used in medicine, food and other industries due to their strong conductivity, size effect and other special performances. So far, more microbial researches have been applied, but a plant method is rarely reported. In order to open up a new way to prepare AgNP composites, pomegranate peel extract was used in this work to reduce Ag+ to prepare Ag/Ag+/Ag3+ nanoparticle composites. UV–Vis was employed to detect and track the reduction of Ag+ and the forming process of AgNPs. The composition, structure and size of the crystal were analyzed by XRD and TEM. Results showed that, under mild conditions, pomegranate peel extract reacted with dilute AgNO3 solution to produce Ag/Ag+/Ag3+ nanoparticle composites. At pH = 8 and 10 mmol/L of AgNO3 concentration, the size of the achieved composites ranged between 15 and 35 nm with spherical shapes and good crystallinity. The bactericidal experiment indicated that the prepared Ag/Ag+/Ag3+ nanoparticles had strong antibacterial activity against gram positive bacteria and gram negative bacteria. FTIR analysis revealed that biological macromolecules with groups of NH2, OH, and others were distributed on the surface of the newly synthesized Ag/Ag+/Ag3+ nanoparticles. This provided a useful clue to further study the AgNP biosynthesis mechanism. Keywords: Pomegranate rind, Biosynthesis, Ag/Ag+/Ag3+ nanoparticle composites, Antibacterial activity

  1. Comparative study of six sequential spectrophotometric methods for quantification and separation of ribavirin, sofosbuvir and daclatasvir: An application on Laboratory prepared mixture, pharmaceutical preparations, spiked human urine, spiked human plasma, and dissolution test.

    Science.gov (United States)

    Hassan, Wafaa S; Elmasry, Manal S; Elsayed, Heba M; Zidan, Dalia W

    2018-05-18

    In accordance with International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) guidelines, six novel, simple and precise sequential spectrophotometric methods were developed and validated for the simultaneous analysis of Ribavirin (RIB), Sofosbuvir (SOF), and Daclatasvir (DAC) in their mixture without prior separation steps. These drugs are described as co-administered for treatment of Hepatitis C virus (HCV). HCV is the cause of hepatitis C and some cancers such as liver cancer (hepatocellular carcinoma) and lymphomas in humans. These techniques consisted of several sequential steps using zero, ratio and/or derivative spectra. DAC was first determined through direct spectrophotometry at 313.7 nm without any interference of the other two drugs while RIB and SOF can be determined after ratio subtraction through five methods; Ratio difference spectrophotometric method, successive derivative ratio method, constant center, isoabsorptive method at 238.8 nm, and mean centering of the ratio spectra (MCR) at 224 nm and 258 nm for RIB and SOF, respectively. The calibration curve is linear over the concentration ranges of (6-42), (10-70) and (4-16) μg/mL for RIB, SOF, and DAC, respectively. This method was successfully applied to commercial pharmaceutical preparation of the drugs, spiked human urine, and spiked human plasma. The above methods are very simple methods that were developed for the simultaneous determination of binary and ternary mixtures and so enhance signal-to-noise ratio. The method has been successfully applied to the simultaneous analysis of RIB, SOF, and DAC in laboratory prepared mixtures. The obtained results are statistically compared with those obtained by the official or reported methods, showing no significant difference with respect to accuracy and precision at p = 0.05. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. An export-marketing model for pharmaceutical firms (the case of iran).

    Science.gov (United States)

    Mohammadzadeh, Mehdi; Aryanpour, Narges

    2013-01-01

    Internationalization is a matter of committed decision-making that starts with export marketing, in which an organization tries to diagnose and use opportunities in target markets based on realistic evaluation of internal strengths and weaknesses with analysis of macro and microenvironments in order to gain presence in other countries. A developed model for export and international marketing of pharmaceutical companies is introduced. The paper reviews common theories of the internationalization process, followed by examining different methods and models for assessing preparation for export activities and examining conceptual model based on a single case study method on a basket of seven leading domestic firms by using mainly questionares as the data gathering tool along with interviews for bias reduction. Finally, in keeping with the study objectives, the special aspects of the pharmaceutical marketing environment have been covered, revealing special dimensions of pharmaceutical marketing that have been embedded within the appropriate base model. The new model for international activities of pharmaceutical companies was refined by expert opinions extracted from result of questionnaires.

  3. An Export-Marketing Model for Pharmaceutical Firms (The Case of Iran)

    Science.gov (United States)

    Mohammadzadeh, Mehdi; Aryanpour, Narges

    2013-01-01

    Internationalization is a matter of committed decision-making that starts with export marketing, in which an organization tries to diagnose and use opportunities in target markets based on realistic evaluation of internal strengths and weaknesses with analysis of macro and microenvironments in order to gain presence in other countries. A developed model for export and international marketing of pharmaceutical companies is introduced. The paper reviews common theories of the internationalization process, followed by examining different methods and models for assessing preparation for export activities and examining conceptual model based on a single case study method on a basket of seven leading domestic firms by using mainly questionares as the data gathering tool along with interviews for bias reduction. Finally, in keeping with the study objectives, the special aspects of the pharmaceutical marketing environment have been covered, revealing special dimensions of pharmaceutical marketing that have been embedded within the appropriate base model. The new model for international activities of pharmaceutical companies was refined by expert opinions extracted from result of questionnaires. PMID:24250597

  4. Preparation and Properties of Paraffin/TiO2/Active-carbon Composite Phase Change Materials

    Directory of Open Access Journals (Sweden)

    HAO Yong-gan

    2016-11-01

    Full Text Available A novel composite phase change materials (PCMs of paraffin/TiO2/active-carbon was prepared by a microemulsion method, where paraffin acted as a PCM and titanium dioxide (TiO2 as matrix material, and a small amount of active carbon was added to improve the thermal conductivity. The compositions, morphology and thermal properties of the paraffin/TiO2/active-carbon composite PCMs were characterized by XRD, SEM, TGA and DSC respectively. The shape stability during phase change process of this composite was also tested. The results show that paraffin is well encapsulated by TiO2 matrix, and thus exhibiting excellent shape-stabilized phase change feature. Besides, this composite PCM also presents superhydrophobic property. Therefore, these multifunctional features will endow PCMs with important application potential in energy efficient buildings.

  5. Preparation and Characterization of Carbon Nanotubes-Based Composite Electrodes for Electric Double Layer Capacitors

    International Nuclear Information System (INIS)

    Seo, Min Kang; Park, Soo Jin

    2012-01-01

    In this work, we prepared activated multi-walled carbon nanotubes/polyacrylonitrile (A-MWCNTs/C) composites by film casting and activation method. Electrochemical properties of the composites were investigated in terms of serving as MWCNTs-based electrode materials for electric double layer capacitors (EDLCs). As a result, the A-MWCNTs/C composites had much higher BET specific surface area, and pore volume, and lower volume ratio of micropores than those of pristine MWCNTs/PAN ones. Furthermore, some functional groups were added on the surface of the A-MWCNTs/C composites. The specific capacitance of the A-MWCNTs/C composites was more than 4.5 times that of the pristine ones at 0.1 V discharging voltage owing to the changes of the structure and surface characteristics of the MWCNTs by activation process

  6. Preparation and antibacterial activities of Ag/Ag+/Ag3+ nanoparticle composites made by pomegranate (Punica granatum) rind extract

    Science.gov (United States)

    Yang, Hui; Ren, Yan-yu; Wang, Tao; Wang, Chuang

    Nano-silver and its composite materials are widely used in medicine, food and other industries due to their strong conductivity, size effect and other special performances. So far, more microbial researches have been applied, but a plant method is rarely reported. In order to open up a new way to prepare AgNP composites, pomegranate peel extract was used in this work to reduce Ag+ to prepare Ag/Ag+/Ag3+ nanoparticle composites. UV-Vis was employed to detect and track the reduction of Ag+ and the forming process of AgNPs. The composition, structure and size of the crystal were analyzed by XRD and TEM. Results showed that, under mild conditions, pomegranate peel extract reacted with dilute AgNO3 solution to produce Ag/Ag+/Ag3+ nanoparticle composites. At pH = 8 and 10 mmol/L of AgNO3 concentration, the size of the achieved composites ranged between 15 and 35 nm with spherical shapes and good crystallinity. The bactericidal experiment indicated that the prepared Ag/Ag+/Ag3+ nanoparticles had strong antibacterial activity against gram positive bacteria and gram negative bacteria. FTIR analysis revealed that biological macromolecules with groups of sbnd NH2, sbnd OH, and others were distributed on the surface of the newly synthesized Ag/Ag+/Ag3+ nanoparticles. This provided a useful clue to further study the AgNP biosynthesis mechanism.

  7. In situ preparation of composite from conjugated polyschiff bases and multiwalled carbon nanotube: Synthesis, electrochromic, acidochromic properties

    International Nuclear Information System (INIS)

    Ma Lina; Cai Jiwei; Zhao Ping; Niu Haijun; Wang Cheng; Bai Xuduo; Wang Wen

    2012-01-01

    Graphical abstract: The introduction of carbon nanotubes greatly improves the photochromic property of the composites. Highlights: ► MWNTs/PSB composite was prepared by in situ polymerization with a new type of PSB. ► The introduction of carbon nanotubes greatly improves the photochromic property of the composites. ► The composites exhibited excellent thermal stability and reversible electrochemical behavior. - Abstract: Polyschiff base (PSB) which has the structure of C=N double bond is well known as conducting material with high thermal resistance, chemical and electrical properties. Recently, it was used as hole transporting material in organic light emitting diode (OLED), chemical sensor and electrochromic materials. Carbon nanotubes (CNTs) with excellent properties such as unique electrical, mechanical, optical and chemical properties are promising reinforcing materials for polymer composites which improve the comprehensive properties of polymers. In this paper, conjugated PSB-grafted multiwalled carbon nanotubes (MWNTs) composite was prepared by in situ polymerization. The resultant composites were characterized by thermogravimetric (TGA), scanning electron microscopy (SEM), UV–vis absorption, photoluminescence (PL), cyclic voltammograms (CV), infrared spectroscopy (IR) and Raman spectroscopy. The composites exhibited high thermal stability and excellent reversibilities of electrochromic, photochromic, acidochromic characteristics, with the color change from the light yellow to blue.

  8. Confused ionic liquid ions--a "liquification" and dosage strategy for pharmaceutically active salts.

    Science.gov (United States)

    Bica, Katharina; Rogers, Robin D

    2010-02-28

    We present a strategy to expand the liquid and compositional ranges of ionic liquids, specifically pharmaceutically active ionic liquids, by simple mixing with a solid acid or base to form oligomeric ions.

  9. New Diazo Coupling Reactions for Visible Spectrophotometric Determination of Alfuzosin in Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    M. Vamsi Krishna

    2007-01-01

    Full Text Available Simple, rapid and sensitive spectrophotometric procedures were developed for the analysis of Alfuzosin hydrochloride (AFZ in pure form as well as in pharmaceutical formulations. The methods are based on the reaction of AFZ with nitrite in acid medium to form diazonium ion, which is coupled with ethoxyethylenemaleic ester (Method A or ethylcyanoacetate (Method B or acetyl acetone (method C in basic medium to form azo dyes, showing absorption maxima at 440, 465 and 490 nm respectively. Beer’s law is obeyed in the concentration of 4-20 μg/mL of AFZ for methods A, B and 3-15 μg/mL of AFZ for method C. The molar absorptivity and sandell’s sensitivity of AFZ- ethoxyethylenemaleic ester, AFZ- ethylcyanoacetate and AFZ-acetyl acetone are1.90 × 104, 0.022; 1.93 × 104, 0.021 and 2.67 × 104 L mole-1 cm-1, 0.015 μg cm-2 respectively. The optimum reaction conditions and other analytical parameters were evaluated. The methods were successfully applied to the determination of AFZ in pharmaceutical formulations.

  10. Preparation and properties of in situ amino-functionalized graphene oxide/polyimide composite films

    Science.gov (United States)

    Lu, Yunhua; Hao, Jican; Xiao, Guoyong; Chen, Lin; Wang, Tonghua; Hu, Zhizhi

    2017-11-01

    The pure light-colored and transparent polyimide (PI) film was prepared from aromatic dianhydride 4,4‧-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and diamine 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene (6FAPB) in the solvent of DMAc via two-step method. Graphene oxide (GO) was in situ grafted with 6FAPB and directly used as a functional inorganic nanofiller to further synthesize poly(amic acid) (PAA)/GO solution. Then, PI/GO composite films with different loadings of GO were prepared by the thermal imidization. The mechanical, thermal, optical, electrical, surface properties, and electrochemical behavior were characterized. The FTIR and XPS results indicate that amino groups can be successfully grafted on the surface of GO. The tensile strength and Young's modulus of the PI-1.0%GO composite film were increased to 118.4 MPa and 2.91 GPa, respectively, which was an approximate improvement of 30.8% and 39.9% compared with pure PI film. These PI/GO composites showed around 256 °C for the glass transition temperature, and around 535 °C for the 5% thermal decomposition temperature, respectively. However, the optical transmittance was significantly decreased from 81.5% (pure PI) to 0.8% (PI-1.0%GO). Besides, the electrical conductivity increased from 1.6 × 10-13 S/m (pure PI) to 2.5 × 10-9 S/m (PI-1.0%GO). Furthermore, when the incorporation of GO was 1.0 wt%, an obvious reduction from 1.08% (pure PI) to 0.65% in the water uptake was observed for the PI/GO composite films, and the water surface contact angle raised from 72.5° (pure PI) to 83.5°. The electrochemical behavior showed that the ability of oxygen atom on the imide ring to gain and loss electron was increased due to incorporation of GO. These results indicated that the strong interfacial interaction between GO and PAA as well as uniform dispersion of GO in PI matrix were benefit to improve the mechanical, thermal, electrical properties and so on. The in situ amino-functionalized approach

  11. Design and Preparation of Carbon Based Composite Phase Change Material for Energy Piles.

    Science.gov (United States)

    Yang, Haibin; Memon, Shazim Ali; Bao, Xiaohua; Cui, Hongzhi; Li, Dongxu

    2017-04-07

    Energy piles-A fairly new renewable energy concept-Use a ground heat exchanger (GHE) in the foundation piles to supply heating and cooling loads to the supported building. Applying phase change materials (PCMs) to piles can help in maintaining a stable temperature within the piles and can then influence the axial load acting on the piles. In this study, two kinds of carbon-based composite PCMs (expanded graphite-based PCM and graphite nanoplatelet-based PCM) were prepared by vacuum impregnation for potential application in energy piles. Thereafter, a systematic study was performed and different characterization tests were carried out on two composite PCMs. The composite PCMs retained up to 93.1% of paraffin and were chemically compatible, thermally stable and reliable. The latent heat of the composite PCM was up to 152.8 J/g while the compressive strength of cement paste containing 10 wt % GNP-PCM was found to be 37 MPa. Hence, the developed composite PCM has potential for thermal energy storage applications.

  12. Preparation and characterization of 304 stainless steel/Q235 carbon steel composite material

    Science.gov (United States)

    Shen, Wenning; Feng, Lajun; Feng, Hui; Cao, Ying; Liu, Lei; Cao, Mo; Ge, Yanfeng

    The composite material of 304 stainless steel reinforced Q235 carbon steel has been prepared by modified hot-rolling process. The resulted material was characterized by scanning electron microscope, three-electrode method, fault current impact method, electrochemical potentiodynamic polarization curve measurement and electrochemical impedance spectroscopy. The results showed that metallurgical bond between the stainless steel layer and carbon steel substrate has been formed. The composite material exhibited good electrical conductivity and thermal stability. The average grounding resistance of the composite material was about 13/20 of dip galvanized steel. There has no surface crack and bubbling formed after fault current impact. The composite material led to a significant decrease in the corrosion current density in soil solution, compared with that of hot dip galvanized steel and bare carbon steel. On the basis polarization curve and EIS analyses, it can be concluded that the composite material showed improved anti-corrosion property than hot-dip galvanized steel.

  13. Design and Preparation of Carbon Based Composite Phase Change Material for Energy Piles

    Science.gov (United States)

    Yang, Haibin; Memon, Shazim Ali; Bao, Xiaohua; Cui, Hongzhi; Li, Dongxu

    2017-01-01

    Energy piles—A fairly new renewable energy concept—Use a ground heat exchanger (GHE) in the foundation piles to supply heating and cooling loads to the supported building. Applying phase change materials (PCMs) to piles can help in maintaining a stable temperature within the piles and can then influence the axial load acting on the piles. In this study, two kinds of carbon-based composite PCMs (expanded graphite-based PCM and graphite nanoplatelet-based PCM) were prepared by vacuum impregnation for potential application in energy piles. Thereafter, a systematic study was performed and different characterization tests were carried out on two composite PCMs. The composite PCMs retained up to 93.1% of paraffin and were chemically compatible, thermally stable and reliable. The latent heat of the composite PCM was up to 152.8 J/g while the compressive strength of cement paste containing 10 wt % GNP-PCM was found to be 37 MPa. Hence, the developed composite PCM has potential for thermal energy storage applications. PMID:28772752

  14. Preparation and characterization of flake graphite/silicon/carbon spherical composite as anode materials for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Lai Jun [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Guo Huajun, E-mail: Lai_jun_@126.com [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Wang Zhixing; Li Xinhai; Zhang Xiaoping; Wu Feixiang; Yue Peng [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China)

    2012-07-25

    Highlights: Black-Right-Pointing-Pointer Flake graphite/silicon/carbon composite is synthesized via spray drying. Black-Right-Pointing-Pointer Flake graphite of {approx}0.5 {mu}m and glucose are used to prepare the composite. Black-Right-Pointing-Pointer The as-prepared composite shows spherical and porous appearance. Black-Right-Pointing-Pointer The composite shows nearly the same cycleability as commercial graphite in 20 cycles. Black-Right-Pointing-Pointer The composite shows a reversible capacity of 552 mAh/g at the 20th cycle. - Abstract: Using nano-Si, glucose and flake graphite of {approx}0.5 {mu}m as raw materials, flake graphite/silicon/carbon composite is successfully synthesized via spray drying and subsequent pyrolysis. The samples are characterized by XRD, SEM, TEM and electrochemical measurements. The composite is composed of flake graphite, nano-Si and amorphous glucose-pyrolyzed carbon and presents good spherical appearance. Some micron pores arising from the decomposition of glucose exist on the surface of the composite particles. The composite has a high reversible capacity of 602.7 mAh/g with an initial coulombic efficiency of 69.71%, and shows nearly the same cycleability as the commercial graphite in 20 cycles. Both the glucose-pyrolyzed carbon and the micron pores play important roles in improving the cycleability of the composite. The flake graphite/silicon/carbon composite electrode is a potential alternative to graphite for high energy-density lithium ion batteries.

  15. Pharmacy preparations : Back in the limelight? Pharmacists make up your mind!

    NARCIS (Netherlands)

    Crommelin, Daan J A; Bouwman-Boer, Yvonne

    2016-01-01

    In this contribution to the theme issue recognizing prof. Florence's achievements as editor -in-chief of the Int. J. Pharmaceutics, we analyze the future of pharmacy preparations (also known as extemporaneous preparations or compounded products). Pharmacy preparations, long considered as an

  16. Alloy composition dependence of formation of porous Ni prepared by rapid solidification and chemical dealloying

    Energy Technology Data Exchange (ETDEWEB)

    Qi Zhen [Key Laboratory of Liquid Structure and Heredity of Materials, Shandong University, Jingshi Road 73, Jinan 250061 (China); Zhang Zhonghua [Key Laboratory of Liquid Structure and Heredity of Materials, Shandong University, Jingshi Road 73, Jinan 250061 (China)], E-mail: zh_zhang@sdu.edu.cn; Jia Haoling [Key Laboratory of Liquid Structure and Heredity of Materials, Shandong University, Jingshi Road 73, Jinan 250061 (China); Qu Yingjie [Shandong Labor Occupational Technology College, Jingshi Road 388, Jinan 250022 (China); Liu Guodong; Bian Xiufang [Key Laboratory of Liquid Structure and Heredity of Materials, Shandong University, Jingshi Road 73, Jinan 250061 (China)

    2009-03-20

    In this paper, the effect of alloy composition on the formation of porous Ni catalysts prepared by chemical dealloying of rapidly solidified Al-Ni alloys has been investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis and N{sub 2} adsorption experiments. The experimental results show that rapid solidification and alloy composition have a significant effect on the phase constituent and microstructure of Al-Ni alloys. The melt spun Al-20 at.% Ni alloy consists of {alpha}-Al, NiAl{sub 3} and Ni{sub 2}Al{sub 3}, while the melt spun Al-25 and 31.5 at.% Ni alloys comprise NiAl{sub 3} and Ni{sub 2}Al{sub 3}. Moreover, the formation and microstructure of the porous Ni catalysts are dependent upon the composition of the melt spun Al-Ni alloys. The morphology and size of Ni particles in the Ni catalysts inherit from those of grains in the melt spun Al-Ni alloys. Rapid solidification can extend the alloy composition of Al-Ni alloys suitable for preparation of the Ni catalysts, and obviously accelerate the dealloying process of the Al-Ni alloys.

  17. Composite nanofibers prepared from metallic iron nanoparticles and polyaniline: high performance for water treatment applications.

    Science.gov (United States)

    Bhaumik, Madhumita; Choi, Hyoung J; McCrindle, Rob I; Maity, Arjun

    2014-07-01

    Presented here is a simple preparation of metallic iron nanoparticles, supported on polyaniline nanofibers at room temperature. The preparation is based on polymerization of interconnected nanofibers by rapid mixing of the aniline monomer with Fe(III) chloride as the oxidant, followed by reductive deposition of Fe(0) nanoparticles, using the polymerization by-products as the Fe precursor. The morphology and other physico-chemical properties of the resulting composite were characterized by scanning and transmission electron microscopy, Brunauer-Emmett-Teller method, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and vibrating-sample magnetometry. The composite fibers were 80-150 nm in diameter and exhibited the expected ferromagnetic behavior. The composite rapidly and efficiently removed As(V), Cr(VI), and also Congo red dye, from aqueous solutions suggesting their usefulness for removal of toxic materials from wastewater. The composite fibers have high capacity for toxin removal: 42.37 mg/g of As(V), 434.78 mg/g of Cr(VI), and 243.9 mg/g of Congo red. The fibers are easily recovered from fluids by exploiting their ferromagnetic properties. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Studies of beneficial interactions between active medicaments and excipients in pharmaceutical formulations.

    Science.gov (United States)

    Kalinkova, G N

    1999-09-30

    A review of "up to date" research findings leading to new concepts of the pharmaceutical formulations and their interactions has been presented. The rational approaches to the excipients choice as well as to their interactions with medicaments have been shown as a basis for modern modelling of pharmaceutical formulations. The importance of complexation, hydrogen bonding, ion-dipole, dipole-dipole and van der Waals attractions as the tools which can modify the physicochemical, pharmacological or pharmacokinetical behaviour of the medicaments has been emphasised. In vivo studies (carried out in healthy human subjects-volunteers, in beagle dogs, in rats etc.) and in vitro studies (on excised human skin, hairless mouse skin etc.) as well as studies of chemical stability and bioavailability serve also as a proof of these interactions. Therefore, excipients are important components of pharmaceutical formulations and they can take an active part in the improvement of the characteristics of formulations (but they may also reduce the effectiveness of some preparations). In this context, the so called active and inactive ingredients in pharmaceutical formulations are inexact, old and "out-of date". Their further use is only conventional. In conclusion, among the various modern techniques applied the combination of infrared spectroscopy and X-ray diffraction has been estimated as the most successful in proving the interactions between drugs and excipients. Finally, pharmaceutical formulations and their interactions have constituted a diverse and rapidly expanding field of Pharmacy (Pharmaceutical Technology, Pharmaceutical Industry and Pharmaceutical Sciences) which covers a wide range of numerical topics within an unified framework.

  19. In-Situ Preparation and Magnetic Properties of Fe3O4/WOOD Composite

    Science.gov (United States)

    Gao, Honglin; Zhang, Genlin; Wu, Guoyuan; Guan, Hongtao

    2011-06-01

    Fe3O4/wood composite, a magnetic material, was prepared by In-situ chemosynthesis method at room temperature. The X-ray diffraction (XRD) shows that the average partical size of Fe3O4 was about 14 nm. The magnetic properties of the resulting composites were investigated by vibrating sample magnetometer (VSM). The composites have saturation magnetization (Ms) values from 4.7 to 25.3 emu/g with the increase of weight percent gains (WPG) of the wood for the composites, but coercive forces (Hc) are invariable, which is different from the magnetic materials reported before. It may be due to the fact that the interaction between wood and Fe3O4 becomes stronger when less of Fe3O4 particles are introduced in the composition, and this also changes the surface anisotropy (Ks) of the magnetism. A structural characterization by Fourier transform infrared (FTIR) proved the interaction between Fe3O4 particles and wood matrix, and it also illustrates that this interaction influences the coercive force of the composite.

  20. Development and validation of NIR-chemometric methods for chemical and pharmaceutical characterization of meloxicam tablets.

    Science.gov (United States)

    Tomuta, Ioan; Iovanov, Rares; Bodoki, Ede; Vonica, Loredana

    2014-04-01

    Near-Infrared (NIR) spectroscopy is an important component of a Process Analytical Technology (PAT) toolbox and is a key technology for enabling the rapid analysis of pharmaceutical tablets. The aim of this research work was to develop and validate NIR-chemometric methods not only for the determination of active pharmaceutical ingredients content but also pharmaceutical properties (crushing strength, disintegration time) of meloxicam tablets. The development of the method for active content assay was performed on samples corresponding to 80%, 90%, 100%, 110% and 120% of meloxicam content and the development of the methods for pharmaceutical characterization was performed on samples prepared at seven different compression forces (ranging from 7 to 45 kN) using NIR transmission spectra of intact tablets and PLS as a regression method. The results show that the developed methods have good trueness, precision and accuracy and are appropriate for direct active content assay in tablets (ranging from 12 to 18 mg/tablet) and also for predicting crushing strength and disintegration time of intact meloxicam tablets. The comparative data show that the proposed methods are in good agreement with the reference methods currently used for the characterization of meloxicam tablets (HPLC-UV methods for the assay and European Pharmacopeia methods for determining the crushing strength and disintegration time). The results show the possibility to predict both chemical properties (active content) and physical/pharmaceutical properties (crushing strength and disintegration time) directly, without any sample preparation, from the same NIR transmission spectrum of meloxicam tablets.

  1. Radiosterilization of medical products, pharmaceuticals and bioproducts

    International Nuclear Information System (INIS)

    1967-01-01

    A Panel on the Radiosterilization of Medical Products, Pharmaceuticals and Bioproducts was convened by the International Atomic Energy Agency on 17-19 January 1966 at its headquarters in Vienna. The purpose of the meeting was to survey the activities of the Member States in this field with a view to preparing the way for an international code of practice for the radiosterilization of medical products, in conformity with existing legal international rules. Refs, figs and tabs

  2. Preparation of Superconductor YBCO-123/Ag Composite Through Urea Molten Salt

    International Nuclear Information System (INIS)

    Yustinus, P.; Indra-Gunawan; Wuryanto

    1996-01-01

    Superconductor YBCO-123/Ag composite has been prepared through Urea molten salt by mixing salt nitrate of Yttrium, Barium, Copper and Silver. The weight of Silver content varied from 0 % - 50 %. After pyrolysis process the powder was subjected to calcination at 300, 500 and 700 o C subsequently for 1 hour. The calcined powders was pelletized into a disk of 1.0 cm in diameter and thickness of 2-3 mm. Sintering of pellet samples was done at 900 o C for 16 hours. Meissner effect on all samples displayed superconductivity phenomena. Samples were examined by XRD, SEM, measurement of critical temperature by using susceptibility magnet vs temperature, and critical current density measurement by using four point probe. Based on orthorhombic structure of YBCO-123 the result of the lattice crystal calculation were is a = 3.8167 - 3.8241 A o ; b = 3.8561 - 3.8895 A o and c = 11.6518 - 11.7104 A o , this showed that silver did not influence the structure of YBCO. Superconductor YBCO-123/Ag composite was prepared. This was proved by critical current density. Jc data which showed increased with increasing of silver content and the highest result was 9.71 x 10 5 Amp/m 2

  3. Preparation of regenerable granular carbon nanotubes by a simple heating-filtration method for efficient removal of typical pharmaceuticals

    Science.gov (United States)

    Shan, Danna; Deng, Shubo; Zhao, Tianning; Yu, Gang; Winglee, Judith; Wiesner, Mark R.

    2017-04-01

    A simple and convenient method was used to prepare novel granular carbon nanotubes (CNTs) for enhanced adsorption of pharmaceuticals. By heating CNTs powder at 450 degree centigrade in air, followed by filtration, the obtained granular adsorbent exhibited high surface area and pore volume since the heating process produced some oxygen-containing functional groups on CNT surface, making CNTs more dispersible in the formation of granular cake. The porous granular CNTs not only had more available surfaces for adsorption but also were more easily separated from solution than pristine CNTs (p-CNTs) powder. This adsorbent exhibited relatively fast adsorption for carbamazepine (CBZ), tetracycline (TC) and diclofe- nac sodium (DS), and the maximum adsorption capacity on the granular CNTs was 369.5 μmol/g for CBZ, 284.2 μmol/g for TC and 203.1 μmol/g for DS according to the Langmuir fitting, increasing by 42.4%, 37.8% and 38.0% in comparison with the pristine CNTs powder. Moreover, the spent granular CNTs were successfully regenerated at 400 degree centigrade in air without decreasing the adsorption capacity in five regeneration cycles. The adsorbed CBZ and DS were completely degraded, while the adsorbed TC was partially oxidized and the residual was favorable for the subsequent adsorption. This research develops an easy method to prepare and regenerate granular CNT adsorbent for the enhanced removal of organic pollutants from water or wastewater.

  4. Investigation of Tribological Behavior of a Novel Hybrid Composite Prepared with Al-Coconut Shell Ash Mixed with Graphite

    Science.gov (United States)

    Siva Sankara Raju, R.; Panigrahi, M. K.; Ganguly, R. I.; Srinivasa Rao, G.

    2017-08-01

    The present investigation develops a next-generation hybrid Al metal matrix composite using coconut shell ash (CSA) and graphite (Gr) reinforcement. Stir-casting is adapted to prepare an Al-1100-based composite. Three other composites of Al-Al2O3, Al-Al2O3-Gr, and Al-CSA are prepared that contain equivalent volume fractions of Al2O3, CSA, and Gr. These assist in comparisons among the three composites and the developed hybrid Al-CSA-Gr composite. The study reveals that the addition of 3 pct Gr improves the specific strength, toughness, and tribological properties. The Al-CSA composite shows better mechanical properties, such as tensile strength and hardness, than the other three composites. Gr addition helps the hybrid Al-CSA-Gr composite to attain better tribological properties with a slightly lower specific strength. Scanning electron microscopy studies of the worn material surfaces corroborate the findings of the abrasion testing. Elemental analyses by energy-dispersive X-ray spectroscopy of the debris from the counter-face of the tribo surface confirm the presence of Al, O, Si, Fe, Mn, and C.

  5. Preparation, Characterization and Thermal Properties of Paraffin Wax – Expanded Perlite Form-Stable Composites for Latent Heat Storage

    Directory of Open Access Journals (Sweden)

    Tugba GURMEN OZCELIK

    2017-02-01

    Full Text Available In this study, form-stable composite phase change materials (PCM for latent heat storage were prepared by impregnating paraffin wax into the pores of the expanded perlite (EP. The characterization of the composite PCMs was performed by FTIR, TGA, SEM and DSC analysis. The melting point and heat of fusion were determined for 25 % paraffin included composite, as 54.3 °C and 94.71 J/g and for 45 % paraffin included composite as 53.6 °C and 106.69 J/g, respectively. The FTIR results showed that there were no chemical reaction between the perlite and paraffin. TGA analysis indicated that both composite PCMs had good thermal stability. SEM images showed that the paraffin was dispersed uniformly into the pores and on the EP surface. There was no leakage and degradation at the composite PCMs after heating and cooling cycles. According to the results, both prepared composites showed good thermal energy storage properties, reliability and stability. All results suggested that the presented form- stable composite PCMs has great potential for thermal energy storage applications.DOI: http://dx.doi.org/10.5755/j01.ms.23.1.13661

  6. Implementing Concepts of Pharmaceutical Engineering into High School Science Classrooms

    Science.gov (United States)

    Kimmel, Howard; Hirsch, Linda S.; Simon, Laurent; Burr-Alexander, Levelle; Dave, Rajesh

    2009-01-01

    The Research Experience for Teachers was designed to help high school science teachers develop skills and knowledge in research, science and engineering with a focus on the area of pharmaceutical particulate and composite systems. The experience included time for the development of instructional modules for classroom teaching. Results of the…

  7. Preparation of TiC/Ni3Al Composites by Upward Melt Infiltration

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    TiC/Ni3Al composites have been prepared using upward infiltration method. The densificstion was performed by both Ni3Al melt filling and TiC sintering during the infiltration. The dissolution of TiC in liquid Ni3Al has been evidenced by finding Ni3(Al,Ti)C after fast cooling in the TiC/Ni3Al composites. The dissolution may be responsible for the infiltration and sintering. Compared with downward infiltration, the upward infiltration brought about higher strength and fracture toughness and shorter infiltration time. TiC/20 vol. pct Ni3Al composite processed by upward infiltration had a flexural strength of 1476 Mpa with a statistic Weibull modulus of 20.2 and a fracture toughness of 20.4 Mpa(m). Better mechanical properties may be attributed to melt unidirectional movement in upward infiltration.

  8. Pharmaceutical aerosols. Study of their gamma radiation sterilization

    International Nuclear Information System (INIS)

    Sebert, P.

    1984-10-01

    The gamma radiation sterilization of pharmaceutical aerosols was studied. The following topics were investigated: radiosterilization of nitrogen protoxide used as a propellant; radiosterilization of packaging materials (aluminium containers, plastics valves); radio-sterilization of excipients and active ingredients. Most of the investigated materials proved to be stable to irradiation (2,5 Mrads) from pharmacopoeial aspect. Stability tests of the preparations packaged showed no change in the parameters investigated [fr

  9. Thermal behavior of La2O3/Nio composite prepared by sol-gel method

    International Nuclear Information System (INIS)

    Sakallioglu, M.

    2005-01-01

    The La 2 O 3 /NiO composite was prepared by sol-gel method by using transition metal oxides (La 2 O 3 /NiO). The variation of specific heat capacity Cp with temperature for La2O3/NiO composite was investigated by DSC. The heat capacity curve was taken with a heating rate of 20 degrees/min between 0-100 degrees. The variation of specific heat capacity was found by PKI Muse Standard Analysis Program. The thermal stability of the La 2 O 3 /NiO composite was investigated by thermogravimetric analysis (TG) in air atmosphere at a heating rate of 20 degrees/min. The weight loss of La 2 O 3 /NiO composite was determined by the variation of temperature

  10. Preparation and characterization of biodegradable composites based on brazilian cassava starch, corn starch and green coconut fibers

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, Maria Guadalupe Lomeli; Muniz, Graciela I. Bolzon de.; Satyanarayana, Kestur G.; Tanobe, Valcineide; Iwakiri, Setsuo, E-mail: glomeli12@hotmail.com [Universidade Federal do Parana (UFPR), Curitiba, Parana (Brazil). Centro de Ciencias Florestais e da Madeira

    2010-07-01

    Increasing search for new materials with high premium on eco-friendliness, new trend is emerging in materials development such as composites, which are well established for a wide variety of applications. With growing interest and importance of renewable bioresources has led to more stress on the use of locally available materials. This paper presents preliminary results on the preparation and characterization of composites based on Brazilian coconut fibers and starches of cassava and corn. The raw materials were characterized for their morphology, chemical composition, and thermal properties and X-ray diffraction studies. Coir fibers were also tested for their tensile properties showing increasing strength and Young's modulus with decreasing diameter, while the % elongation remaining constant. Lignin content of coir was found to be 35%. Structure and properties of composites containing 0, 5 10, 15% fibers in both the matrices and prepared by compression molding would be compared. For the 2 types of starch, there was an increase in the tensile strength by the increasing proportion of fiber. The effect of moisture in the composite stress affects the strength and percentage elongation. The water absorption was higher in the composites made from cassava starch. (author)

  11. Preparation and characterization of biodegradable composites based on brazilian cassava starch, corn starch and green coconut fibers

    International Nuclear Information System (INIS)

    Ramirez, Maria Guadalupe Lomeli; Muniz, Graciela I. Bolzon de.; Satyanarayana, Kestur G.; Tanobe, Valcineide; Iwakiri, Setsuo

    2010-01-01

    Increasing search for new materials with high premium on eco-friendliness, new trend is emerging in materials development such as composites, which are well established for a wide variety of applications. With growing interest and importance of renewable bioresources has led to more stress on the use of locally available materials. This paper presents preliminary results on the preparation and characterization of composites based on Brazilian coconut fibers and starches of cassava and corn. The raw materials were characterized for their morphology, chemical composition, and thermal properties and X-ray diffraction studies. Coir fibers were also tested for their tensile properties showing increasing strength and Young's modulus with decreasing diameter, while the % elongation remaining constant. Lignin content of coir was found to be 35%. Structure and properties of composites containing 0, 5 10, 15% fibers in both the matrices and prepared by compression molding would be compared. For the 2 types of starch, there was an increase in the tensile strength by the increasing proportion of fiber. The effect of moisture in the composite stress affects the strength and percentage elongation. The water absorption was higher in the composites made from cassava starch. (author)

  12. Pharmaceutical characterization of novel tenofovir liposomal formulations for enhanced oral drug delivery: in vitro pharmaceutics and Caco-2 permeability investigations

    Directory of Open Access Journals (Sweden)

    Spinks CB

    2017-02-01

    Full Text Available Crystal B Spinks,1 Ahmed S Zidan,2,3 Mansoor A Khan,4 Muhammad J Habib,1 Patrick J Faustino2 1Department of Pharmaceutical Sciences, School of Pharmacy, Howard University, Washington, DC, 2Division of Product Quality Research, Office of Pharmaceutical Quality, Food and Drug Administration, Silver Spring, MD, USA; 3Faculty of Pharmacy, Zagazig University, Zagazig, Egypt; 4Irma Lerma Rangel College of Pharmacy, Texas A&M Health Science Center, College Station, TX, USA Abstract: Tenofovir, currently marketed as the prodrug tenofovir disoproxil fumarate, is used clinically to treat patients with HIV/AIDS. The oral bioavailability of tenofovir is relatively low, limiting its clinical effectiveness. Encapsulation of tenofovir within modified long-circulating liposomes would deliver this hydrophilic anti-HIV drug to the reticuloendothelial system for better therapeutic efficacy. The objectives of the current study were to prepare and pharmaceutically characterize model liposomal tenofovir formulations in an attempt to improve their bioavailability. The entrapment process was performed using film hydration method, and the formulations were characterized in terms of encapsulation efficiency and Caco-2 permeability. An efficient reverse-phase high-performance liquid chromatography method was developed and validated for tenofovir quantitation in both in vitro liposomal formulations and Caco-2 permeability samples. Separation was achieved isocratically on a Waters Symmetry C8 column using 10 mM Na2PO4/acetonitrile pH 7.4 (95:5 v/v. The flow rate was 1 mL/min with a 12 min elution time. Injection volume was 10 µL with ultraviolet detection at 270 nm. The method was validated according to United States Pharmacopeial Convention category I requirements. The obtained result showed that tenofovir encapsulation within the prepared liposomes was dependent on the employed amount of the positive charge-imparting agent. The obtained results indicated that

  13. Neutron activation analysis method to determination vitamine B_1_2 (sianokobalamin) in pharmaceutical product

    International Nuclear Information System (INIS)

    Titiek Martati; June Mellawati

    2010-01-01

    Analysis of vita mine 812 in pharmaceutical preparations can be done by neutron activation method, because one molecule of vita mine 812 contains one atom of Co (4.35 %). The aim of research to know the ability of neutron activation method to analyze pharmaceutical preparations of vitamine 812 by test the precision and accuracy methods. It is expected that the method of neutron activation analysis can be an alternative method in the determination of vitamine 812 in pharmaceutical preparations. Samples were irradiated using thermal neutrons in the reactor during 30 minutes Siwabessy GA, and based on n, gamma reaction, the "6"0CO isotope formed then be identified using Gamma Spectrometer at 1173.5 and 1332.4 keV energy. Vitamine 812 concentration was obtained by calculating the ratio of vitamine 812 molecule to molecule Co. The results showed that the neutron activation method is good for determining 8_1_2 vitamin in low concentration (≥ 200 mg), but not for high concentrations ( ≥ 5000 mg). This method has a 99.11 to 99.52 % accuracy, and 96.52 to 104.95 % precision with a detection limit measures of vita mine 812184.36 mg. Recovery test obtained ranged between 98.19 to 101.07 % of vitamine 812 compared to levels specified in the label, so that still recommend the requirements of British Pharmacopoeia 2009 and the United States Pharmacopoeia 29. (author)

  14. Preparation of Lignin/Sodium Dodecyl Sulfate Composite Nanoparticles and Their Application in Pickering Emulsion Template-Based Microencapsulation.

    Science.gov (United States)

    Pang, Yuxia; Wang, Shengwen; Qiu, Xueqing; Luo, Yanling; Lou, Hongming; Huang, Jinhao

    2017-12-20

    Lignin is a vastly underutilized biomass resource. The preparation of water-dispersed lignin nanoparticles is an effective way to realize the high-value utilization of lignin. However, the currently reported preparation methods of lignin nanoparticles still have some drawbacks, such as the requirement for toxic organic solvent or chemical modification, complicated operation process, and poor dispersibility. Here, lignin/sodium dodecyl sulfate (SDS) composite nanoparticles (LSNPs) with outstanding water dispersibility and a size range of 70-200 nm were facilely prepared via acidifying the mixed basic solution of alkaline lignin and SDS. No harsh chemical was needed. The formation mechanism was systematically studied. Results indicated that the LSNPs were obtained by acid precipitation of the mixed micelles formed by the self-assembly of lignin and SDS. In addition, on the basis of the LSNP-stabilized Pickering emulsions, lignin/polyurea composite microcapsules combining the excellent chemical stability of a synthetic polyurea shell with the fantastic antiphotolysis and antioxidant properties of lignin were successfully prepared.

  15. Synthesis and characterization of polyaniline/activated carbon composites and preparation of conductive films

    International Nuclear Information System (INIS)

    Zengin, Huseyin; Kalayci, Guellue

    2010-01-01

    Polyaniline was synthesized via polyaniline/activated carbon (PANI/AC) composites by in situ polymerization and ex situ solution mixing. PANI and PANI/AC composite films were prepared by drop-by-drop and spin coating methods. The electrical conductivities of HCl doped PANI film and PANI/AC composite films were measured according to the standard four-point-probe technique. The composite films exhibited an increase in electrical conductivity over neat PANI. PANI and PANI/AC composites were investigated by spectroscopic methods including UV-vis, FTIR and photoluminescence. UV-vis and FTIR studies showed that AC particles affect the quinoid units along the polymer backbone and indicate strong interactions between AC particles and quinoidal sites of PANI. The photoluminescence properties of PANI and PANI/AC composites were studied and the photoluminescence intensity of PANI/AC composites was higher than that of neat PANI. The increase of conductivity of PANI/AC composites may be partially due to the doping or impurity effect of AC, where the AC competes with chloride ions. The amount of weight loss and the thermostability of PANI and PANI/AC composites were determined from thermogravimetric analysis. The morphology of particles and films were examined by a scanning electron microscope (SEM). SEM measurements indicated that the AC particles were well dispersed and isolated in composite films.

  16. Shear-bond-strength of orthodontic brackets to aged nano-hybrid composite-resin surfaces using different surface preparation.

    Science.gov (United States)

    Demirtas, Hatice Kubra; Akin, Mehmet; Ileri, Zehra; Basciftci, Faruk Ayhan

    2015-01-01

    The aim of this study was to evaluate the effects of different surface preparation methods on the shear bond strength (SBS) of orthodontic metal brackets to aged nano-hybrid resin composite surfaces in vitro. A total of 100 restorative composite resin discs, 6 mm in diameter and 3 mm thick, were obtained and treated with an ageing procedure. After ageing, the samples were randomly divided as follows according to surface preparation methods: (1)Control, (2)37% phosphoric acid gel, (3)Sandblasting, (4)Diamond bur, (5)Air-flow and 20 central incisor teeth were used for the control etched group. SBS test were applied on bonded metal brackets to all samples. SBS values and residual adhesives were evaluated. Analysis of variance showed a significant difference (porthodontic metal brackets to nano-hybrid composite resin surfaces.

  17. Effect of applied voltage on phase components of composite coatings prepared by micro-arc oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Wenjun [Department of Prosthodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou 510055 (China); Fang, Yu-Jing [Department of Colorectal Surgery, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou 510060 (China); Zheng, Huade [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); Tan, Guoxin [Guangdong University of Technology, Guangdong Province 510006 (China); Cheng, Haimei [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); Ning, Chengyun, E-mail: imcyning@scut.edu.cn [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China)

    2013-10-01

    In this report, we present results from our experiments on composite coatings formed on biomedical titanium substrates by micro-arc oxidation (MAO) in constant-voltage mode. The coatings were prepared on the substrates in an aqueous electrolyte containing calcium acetate and β-glycerol phosphate disodium salt pentahydrate (β-GP). We analyzed the element distribution and phase components of the coatings prepared at different voltages by X-ray diffraction, thin-coating X-ray diffraction, electron-probe microanalysis, and Fourier-transform infrared spectroscopy. The results show that the composite coatings formed at 500 V consist of titania (TiO{sub 2}), hydroxylapatite (HA), and calcium carbonate (CaCO{sub 3}). Furthermore, the concentration of Ca, P, and Ti gradually changes with increasing applied voltage, and the phase components of the composite coatings gradually change from the bottom of the coating to the top: the bottom layer consists of TiO{sub 2}, the middle layer consists of TiO{sub 2} and HA, and the top layer consists of HA and a small amount of CaCO{sub 3}. The formation of HA directly on the coating surface by MAO technique can greatly enhance the surface bioactivity. - Highlights: • Coatings prepared on biomedical titanium substrate by micro-arc oxidation • Coatings composed of titania, hydroxyapatite and calcium carbonate • Hydroxyapatite on the coating surface can enhance the surface bioactivity.

  18. Preparation and Dynamic Mechanical Properties at Elevated Temperatures of a Tungsten/Glass Composite

    Science.gov (United States)

    Gao, Chong; Wang, Yingchun; Ma, Xueya; Liu, Keyi; Wang, Yubing; Li, Shukui; Cheng, Xingwang

    2018-03-01

    Experiments were conducted to prepare a borosilicate glass matrix composite containing 50 vol.% tungsten and examine its dynamic compressive behavior at elevated temperatures in the range of 450-775 °C. The results show that the homogenous microstructure of the tungsten/glass composite with relative density of 97% can be obtained by hot-pressing sintering at 800 °C for 1 h under pressure of 30 MPa. Dynamic compressive testing was carried out by a separate Hopkinson pressure bar system with a synchronous device. The results show that the peak stress decreases and the composite transforms from brittle to ductile in nature with testing temperature increasing from 450 to 750 °C. The brittle-ductile transition temperature is about 500 °C. Over 775 °C, the composite loses load-bearing capacity totally because of the excessive softening of the glass phase. In addition, the deformation and failure mechanism were analyzed.

  19. Properties of form-stable paraffin/silicon dioxide/expanded graphite phase change composites prepared by sol–gel method

    International Nuclear Information System (INIS)

    Li, Min; Wu, Zhishen; Tan, Jinmiao

    2012-01-01

    Highlights: ► Paraffin/SiO 2 /EG composite PCM was prepared with sol–gel method. ► The thermal conductivity of SiO 2 /paraffin/EG is 94.7% higher than paraffin. ► The latent heat of paraffin/SiO 2 /EG composite is 104.4 J/g. -- Abstract: A form-stable paraffin/silicon dioxide (SiO 2 )/expanded graphite (EG) composite phase change material (PCM) was prepared by sol–gel method. Silica gel acts as the supporting material and EG is used to increase the thermal conductivity. The mass fractions of silicon oxide and graphite are 20.8% and 7.2%, respectively. The composite PCM was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transformation infrared spectroscopy (FTIR) method. Thermal properties and thermal stability of the composite PCM were studied using differential scanning calorimetry (DSC). The result shows that paraffin was well dispersed in the network of silica gel and there is no chemical reaction between them. The phase change temperature of the paraffin/SiO 2 composite and the paraffin/SiO 2 /EG composite are 27.53 °C and 27.72 °C, respectively. The latent heat of the paraffin/SiO 2 composite and the paraffin/SiO 2 /EG composite are 112.8 J/g and 104.4 J/g, respectively. The thermal conductivity of the SiO 2 /paraffin composite and the SiO 2 /paraffin/EG composite are 28.2% and 94.7% higher than that of paraffin.

  20. Characterization of polymethyl methacrylate/polyethylene glycol/aluminum nitride composite as form-stable phase change material prepared by in situ polymerization method

    International Nuclear Information System (INIS)

    Zhang, Lei; Zhu, Jiaoqun; Zhou, Weibin; Wang, Jun; Wang, Yan

    2011-01-01

    Highlights: → Form-stable PMMA/PEG/AlN PCMs were prepared by in situ polymerization method. → AlN additive effectively enhanced the heat transfer property of composite PCMs. → The composites exhibited desirable thermal performance and electric insulativity. → The composites were available for the thermal management of electronic device. - Abstract: This work was focused on the preparation and characterization of a new type of form-stable phase change material (PCM) employed in thermal management. Using the method of in situ polymerization, polyethylene glycol (PEG) acting as the PCM and aluminum nitride (AlN) serving as the thermal conductivity promoter were uniformly encapsulated and embedded inside the three-dimensional network structure of PMMA matrix. When the mass fraction of PEG was below 70%, the prepared composite PCMs remained solid without leakage above the melting point of the PEG. XRD and FT-IR results indicated that the PEG was physically combined with PMMA matrix and AlN additive and did not participate in the polymerization. Thermal analysis results showed that the prepared composite PCMs possess available latent heat capacity and thermal stability, and the AlN additive was able to effectively enhance the heat transfer property of organic PCM. Moreover, the volume resistivity of composite achieved (5.92 ± 0.16) x 10 10 Ω cm when the mass ratio of AlN was 30%. To sum up, the prepared form-stable PCMs were competent for the thermal management of electronic device due to their acceptable thermal performance and electric insulativity.

  1. Preparation and properties of Starch-g-PLA/poly(vinyl alcohol) composite film.

    Science.gov (United States)

    Hu, Yingmo; Wang, Qingling; Tang, Mingru

    2013-07-25

    Starch/lactic acid graft copolymer (Starch-g-PLA) was prepared by the in situ copolymerization of starch grafted with lactic acid catalyzed with sodium hydroxide, and then mixed with poly(vinyl alcohol) (PVA) to get composite films. The structures of the graft copolymer and composite films were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The mechanical properties, water resistance, and thermal stability were also investigated. It was found that the compatibility of Starch-g-PLA and PVA was better than that of starch and PVA in the composite films. The tensile strength and elongation at break of the Starch-g-PLA/PVA composite film increased by 69.15% and 84.22%, respectively, while the water absorption decreased by 50.39%, which overcame the shortcomings of hydrophilicity and poor mechanical properties of Starch/PVA film. Thermogravimetric analysis (TGA) also showed that the thermal stability of Starch-g-PLA/PVA film was improved compared with Starch/PVA film. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Process for preparing radiopharmaceuticals

    International Nuclear Information System (INIS)

    Barak, M.; Winchell, H.S.

    1977-01-01

    A process for the preparation of technetium-99m labeled pharmaceuticals is disclosed. The process comprises initially isolating technetium-99m pertechnetate by adsorption upon an adsorbent packing in a chromatographic column. The technetium-99m is then eluted from the packing with a biological compound to form a radiopharmaceutical

  3. Preparation and Characterization of Highly Aligned Carbon Nanotubes/Polyacrylonitrile Composite Nanofibers

    Directory of Open Access Journals (Sweden)

    Yanhua Song

    2017-01-01

    Full Text Available In the electrospinning process, a modified parallel electrode method (MPEM, conducted by placing a positively charged ring between the needle and the parallel electrode collector, was used to fabricate highly aligned carbon nanotubes/polyacrylonitrile (CNTs/PAN composite nanofibers. Characterizations of the samples—such as morphology, the degree of alignment, and mechanical and conductive properties—were investigated by a combination of scanning electron microscopy (SEM, transmission electron microscopy (TEM, universal testing machine, high-resistance meter, and other methods. The results showed the MPEM could improve the alignment and uniformity of electrospun CNTs/PAN composite nanofibers, and enhance their mechanical and conductive properties. This meant the successful preparation of highly aligned CNT-reinforced PAN nanofibers with enhanced physical properties, suggesting their potential application in appliances and communication areas.

  4. ASEAN GMP and pharmaceutical industries in Indonesia.

    Science.gov (United States)

    Soesilo, S; Sitorus, U

    1995-01-01

    Indonesia was appointed by the ASEAN Technical Cooperation in Pharmaceutical as a focal point and to coordinate the development of practical guidelines for the implementation of GMP. The ASEAN GMP Guidelines were endorsed by the ASEAN Technical Cooperation in Pharmaceutical in 1988, which among others required separation of Beta-Lactam dedicated facilities and three degrees of cleanliness for production areas. As it was realised that drug manufacturers in developing countries need more detailed guidelines to be able to implement the GMP, an Operational Manual for GMP was also prepared for providing examples of SOPs lay-outs, documentation etc. It was agreed by the technical cooperation group to leave the implementation of GMP to each member country. However, the ASEAN Manual for Inspection of GMP was drafted and endorsed by the group and training of ASEAN Drug Inspectors was organized to support the implementation. The ASEAN GMP is being implemented in Indonesia through a five-year, stepwise implementation plan, starting in 1989.

  5. Spherical nanostructured Si/C composite prepared by spray drying technique for lithium ion batteries anode

    Energy Technology Data Exchange (ETDEWEB)

    Chen Libao [Energy Science and Technology Laboratory, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Xie Xiaohua [Energy Science and Technology Laboratory, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Wang Baofeng [Department of Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Wang Ke [Energy Science and Technology Laboratory, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Xie Jingying [Energy Science and Technology Laboratory, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China) and Graduate School of Chinese Academy of Sciences, Beijing 100049 (China)]. E-mail: jyxie@mail.sim.ac.cn

    2006-07-15

    Spherical nanostructured Si/C composite was prepared by spray drying technique, followed by heat treatment, in which nanosized silicon and fine graphite particles were homogeneously embedded in carbon matrix pyrolyzed by phenol formaldehyde resin. Cyclic voltammetry tests showed two pairs of redox peaks corresponding to lithiation and delithiation of Si/C composite. The Si/C composite exhibited a reversible capacity of 635 mAh g{sup -1} and good cycle performance used in lithium ion batteries. To improve cycle performance of this Si/C composite further, the carbon-coated Si/C composite was synthesized by the second spray drying and heat treatment processing. The cycle performance of carbon-coated Si/C composite was improved significantly, which was attributed to the formation of stable SEI passivation layers on the outer surface of carbon shell which protected the bared silicon from exposing to electrolyte directly.

  6. Spherical nanostructured Si/C composite prepared by spray drying technique for lithium ion batteries anode

    International Nuclear Information System (INIS)

    Chen Libao; Xie Xiaohua; Wang Baofeng; Wang Ke; Xie Jingying

    2006-01-01

    Spherical nanostructured Si/C composite was prepared by spray drying technique, followed by heat treatment, in which nanosized silicon and fine graphite particles were homogeneously embedded in carbon matrix pyrolyzed by phenol formaldehyde resin. Cyclic voltammetry tests showed two pairs of redox peaks corresponding to lithiation and delithiation of Si/C composite. The Si/C composite exhibited a reversible capacity of 635 mAh g -1 and good cycle performance used in lithium ion batteries. To improve cycle performance of this Si/C composite further, the carbon-coated Si/C composite was synthesized by the second spray drying and heat treatment processing. The cycle performance of carbon-coated Si/C composite was improved significantly, which was attributed to the formation of stable SEI passivation layers on the outer surface of carbon shell which protected the bared silicon from exposing to electrolyte directly

  7. Preparation, characterization and thermal properties of binary nitrate salts/expanded graphite as composite phase change material

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Junbing [School of Materials and Energy, Guangdong University of Technology, 510006 Guangzhou (China); Huang, Jin, E-mail: huangjiner@126.com [School of Materials and Energy, Guangdong University of Technology, 510006 Guangzhou (China); Zhu, Panpan; Wang, Changhong [School of Materials and Energy, Guangdong University of Technology, 510006 Guangzhou (China); Li, Xinxi [School of Materials and Energy, Guangdong University of Technology, 510006 Guangzhou (China); Center for Nanochemistry, Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing (China)

    2014-07-01

    Highlights: • The expanded graphite enhanced thermal conductivity coefficient greatly. • The aqueous solution method adopting ultrasonic was utilized to disperse EG. • The combination of composite was physical without chemical reaction. • The reduction on total latent heat was slight after the adding EG. - Abstract: The binary nitrate salts/expanded graphite (EG) composite phase change material (PCM) were prepared via adding different mass rate of EG to binary nitrate salts consisting of NaNO{sub 3} and KNO{sub 3} (6:4) by aqueous solution method adopting ultrasonic. The morphology and chemical composition of EG and the composite PCM were characterized and investigated by X-ray diffraction (XRD), scan electron microscope (SEM), energy dispersive spectrometer (EDS), transmission electron microscope (TEM), respectively. Laser thermal conductivity instrument and differential scanning calorimeter (DSC) were employed to measure thermo physical properties. Drawing the conclusion from investigation, that EG had enhanced thermal conductivity coefficient which largely increased to 4.884 W/(m K) and reduced total latent heat by mostly 11.0%. The morphology and phase structure results indicated that EG were well dispersed into and physically combined with molten salts. In general, the prepared composite PCM could be a suitable phase change material for thermal energy storage.

  8. A Universal Strategy To Prepare Sulfur-Containing Polymer Composites with Desired Morphologies for Lithium-Sulfur Batteries.

    Science.gov (United States)

    Zeng, Shao-Zhong; Zeng, Xierong; Tu, Wenxuan; Huang, Haitao; Yu, Liang; Yao, Yuechao; Jin, Nengzhi; Zhang, Qi; Zou, Jizhao

    2018-06-19

    Lithium-sulfur (Li-S) batteries are probably the most promising candidates for the next-generation batteries owing to their high energy density. However, Li-S batteries face severe technical problems where the dissolution of intermediate polysulfides is the biggest problem because it leads to the degradation of the cathode and the lithium anode, and finally the fast capacity decay. Compared with the composites of elemental sulfur and other matrices, sulfur-containing polymers (SCPs) have strong chemical bonds to sulfur and therefore show low dissolution of polysulfides. Unfortunately, most SCPs have very low electron conductivity and their morphologies can hardly be controlled, which undoubtedly depress the battery performances of SCPs. To overcome these two weaknesses of SCPs, a new strategy was developed for preparing SCP composites with enhanced conductivity and desired morphologies. With this strategy, macroporous SCP composites were successfully prepared from hierarchical porous carbon. The composites displayed discharge/charge capacities up to 1218/1139, 949/922, and 796/785 mA h g -1 at the current rates of 5, 10, and 15 C, respectively. Considering the universality of this strategy and the numerous morphologies of carbon materials, this strategy opens many opportunities for making carbon/SCP composites with novel morphologies.

  9. Preparation, characterization and thermal properties of binary nitrate salts/expanded graphite as composite phase change material

    International Nuclear Information System (INIS)

    Xiao, Junbing; Huang, Jin; Zhu, Panpan; Wang, Changhong; Li, Xinxi

    2014-01-01

    Highlights: • The expanded graphite enhanced thermal conductivity coefficient greatly. • The aqueous solution method adopting ultrasonic was utilized to disperse EG. • The combination of composite was physical without chemical reaction. • The reduction on total latent heat was slight after the adding EG. - Abstract: The binary nitrate salts/expanded graphite (EG) composite phase change material (PCM) were prepared via adding different mass rate of EG to binary nitrate salts consisting of NaNO 3 and KNO 3 (6:4) by aqueous solution method adopting ultrasonic. The morphology and chemical composition of EG and the composite PCM were characterized and investigated by X-ray diffraction (XRD), scan electron microscope (SEM), energy dispersive spectrometer (EDS), transmission electron microscope (TEM), respectively. Laser thermal conductivity instrument and differential scanning calorimeter (DSC) were employed to measure thermo physical properties. Drawing the conclusion from investigation, that EG had enhanced thermal conductivity coefficient which largely increased to 4.884 W/(m K) and reduced total latent heat by mostly 11.0%. The morphology and phase structure results indicated that EG were well dispersed into and physically combined with molten salts. In general, the prepared composite PCM could be a suitable phase change material for thermal energy storage

  10. Preparation of Photocrosslinked Fish Elastin Polypeptide/Microfibrillated Cellulose Composite Gels with Elastic Properties for Biomaterial Applications

    Directory of Open Access Journals (Sweden)

    Shinya Yano

    2015-01-01

    Full Text Available Photocrosslinked hydrogels reinforced by microfibrillated cellulose (MFC were prepared from a methacrylate-functionalized fish elastin polypeptide and MFC dispersed in dimethylsulfoxide (DMSO. First, a water-soluble elastin peptide with a molecular weight of ca. 500 g/mol from the fish bulbus arteriosus was polymerized by N,N′-dicyclohexylcarbodiimide (DCC, a condensation reagent, and then modified with 2-isocyanatoethyl methacrylate (MOI to yield a photocrosslinkable fish elastin polypeptide. The product was dissolved in DMSO and irradiated with UV light in the presence of a radical photoinitiator. We obtained hydrogels successfully by substitution of DMSO with water. The composite gel with MFC was prepared by UV irradiation of the photocrosslinkable elastin polypeptide mixed with dispersed MFC in DMSO, followed by substitution of DMSO with water. The tensile test of the composite gels revealed that the addition of MFC improved the tensile properties, and the shape of the stress–strain curve of the composite gel became more similar to the typical shape of an elastic material with an increase of MFC content. The rheology measurement showed that the elastic modulus of the composite gel increased with an increase of MFC content. The cell proliferation test on the composite gel showed no toxicity.

  11. New type of chitosan/2-hydroxypropyl-β-cyclodextrin composite membrane for gallic acid encapsulation and controlled release.

    Science.gov (United States)

    Paun, Gabriela; Neagu, Elena; Tache, Andreia; Radu, G L

    2014-01-01

    A new type of chitosan/2-hydroxypropyl-β-cyclodextrin composite membrane have been developed for the encapsulation and controlled release of gallic acid. The morphology of the composite membrane was investigated by infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM), whereas swelling gallic acid and release properties were investigated by UV-visible spectroscopy. The release behavior with pH changes was also explored. The composite membrane based on chitosan/2-hydroxypropyl-β-cyclodextrin with gallic acid included showed improved antioxidant capacities compared to plain chitosan membrane. The information obtained in this study will facilitate the design and preparation of composite membrane based on chitosan and could open a wide range of applications, particularly its use as an antioxidant in food, food packaging, biomedical (biodegradable soft porous scaffolds for enhance the surrounding tissue regeneration), pharmaceutical and cosmetics industries.

  12. Manufacture of high-strength composite materials from prepregs prepared by radiation processing

    International Nuclear Information System (INIS)

    Laricheva, V.P.; Korotkij, A.F.

    2008-01-01

    Scientific principles of the manufacture of high-strength heat-resistant polymer composite materials with the successive ionizing-radiation and heat treatment (via the step of long-lived prepregs) were developed. Methods for the selection of components for the preparation of long-lived prepregs, as well as for the determination of the optimal curing conditions, were proposed. The mechanical properties of the materials were studied [ru

  13. Preparation and mechanical properties of rubber composites reinforced with carbon nanohorns.

    Science.gov (United States)

    Isshiki, Tetsuya; Hashimoto, Mikiko; Morii, Masato; Ota, Yuki; Kaneda, Kazuo; Takahashi, Hidetaka; Yudasaka, Masako; Iijima, Sumio; Okino, Fujio

    2010-06-01

    Nitrile butadiene rubber (NBR) composites with single-wall carbon nanohorns (SWNHs, or simply NHs), hole-opened NHs (h-NHs), and carbon black (CB), the most commonly used nanocarbon rubber filler, were prepared, and their mechanical properties were compared. The NBR composites with h-NHs (NBR/h-NH) showed higher tensile strength than those with NHs (NBR/NH), and the tensile strength of NBR/h-NH or NBR/NH was much greater than those of the NBR composites with CB (NBR/CB). At 5 parts per hundred of rubber (phr), the tensile stresses at break of NBR/h-NH was about 1.8 times larger than those of NBR/CB, and the strain at the break, 1.2 times larger. Similarly, at 20 phr, both the tensile strength and strain at the break of NBR/h-NH were 1.4 times larger than those of NBR/CB. NBR/NH showed the highest hardness while having the smallest specific gravity. The present results indicate that NHs and h-NHs have much superior reinforcement effects to CB for NBR rubber matrix.

  14. Amylose–halloysite–TiO{sub 2} composites: Preparation, characterization and photodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Pengwu; Du, Yuanyuan [School of Pharmacy, Jiangxi Science and Technology Normal University, 330013 Nanchang, Jiangxi (China); Chang, Peter R. [Bioproducts and Bioprocesses National Science Program, Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK S7N 0X2 Canada (Canada); Department of Chemical and Biological Engineering, University of Saskatchewan, Saskatoon, SK S7N 5A9 (Canada); Ma, Xiaofei, E-mail: maxiaofei@tju.edu.cn [Chemistry Department, School of Science, Tianjin University, Tianjin 300072 (China)

    2015-02-28

    Highlights: • The amylose–HNT–TiO{sub 2} with high dispersion of TiO{sub 2} was fabricated. • The amylose–HNT–TiO{sub 2} was characterized. • The photodegradation of MB and 4-NP was investigated. - Abstract: A supramolecular structure was initially formed between amylose and halloysite (HNT) simply by using a mechanical force. Subsequently, amylose acted as a template for the growth of TiO{sub 2} nanoparticles. The thus-prepared amylose–HNT–TiO{sub 2} composite was characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analyses, and transmission electron microscopy (TEM). In comparison to its counterpart HNT-TiO{sub 2} composite, the amylose–HNT–TiO{sub 2} composite exhibited better dispersion, a larger specific surface area, and photocatalytic activity that was more effective for the photodegradation/removal of methylene blue (MB) and the persistent organic pollutant 4-nitrophenol (4-NP) under UV irradiation. After four successive UV irradiation treatments, amylose–HNT–TiO{sub 2} removed about 90% of 4-NP or MB.

  15. Does brand differentiate pharmaceuticals?

    Science.gov (United States)

    Bednarik, Josef

    2005-12-01

    Role of marketing in pharmaceutical industry is increasing and inspiration by successful brands known from consumer goods market influenced pharmaceutical companies enough to switch their attention to branding initiatives. Still there is little evidence that pharmaceutical brands represent anything more than product only. This study aims to explore the area of branding in pharmaceutical industry. Central hypothesis of the research has been that brand and its emotional content differentiate pharmaceuticals as well as rational data derived from clinical studies. It has been tested by extensive review of available literature as well as by primary research focused on drivers of physicians' attitudes towards products and their influence on prescribing behavior. The research has been conducted in the sample of psychiatrists in the Czech Republic. No evidence about pharmaceutical brand exceeding value of product has been found in reviewed literature. Nevertheless, the primary research conducted in the sample of Czech psychiatrists indicates that emotional brand in pharmaceutical industry exists and enables author to draw a model of Customer/product life cycle that describes likely impact of functional, emotional and self-expressive benefits throughout pharmaceutical product's market presence. Pharmaceutical brand is likely to develop differently than the same of consumer goods products--it seems to be built predominantly on long-term positive experience. Marketing role in this process should lie in finding relevant product position and building brand identity compliant with real product capabilities.

  16. Pharmaceutical manufacturing facility discharges can substantially increase the pharmaceutical load to U.S. wastewaters

    Science.gov (United States)

    Scott, Tia-Marie; Phillips, Patrick J.; Kolpin, Dana W.; Colella, Kaitlyn M.; Furlong, Edward T.; Foreman, William T.; Gray, James L.

    2018-01-01

    Discharges from pharmaceutical manufacturing facilities (PMFs) previously have been identified as important sources of pharmaceuticals to the environment. Yet few studies are available to establish the influence of PMFs on the pharmaceutical source contribution to wastewater treatment plants (WWTPs) and waterways at the national scale. Consequently, a national network of 13 WWTPs receiving PMF discharges, six WWTPs with no PMF input, and one WWTP that transitioned through a PMF closure were selected from across the United States to assess the influence of PMF inputs on pharmaceutical loading to WWTPs. Effluent samples were analyzed for 120 pharmaceuticals and pharmaceutical degradates. Of these, 33 pharmaceuticals had concentrations substantially higher in PMF-influenced effluent (maximum 555,000 ng/L) compared to effluent from control sites (maximum 175 ng/L). Concentrations in WWTP receiving PMF input are variable, as discharges from PMFs are episodic, indicating that production activities can vary substantially over relatively short (several months) periods and have the potential to rapidly transition to other pharmaceutical products. Results show that PMFs are an important, national-scale source of pharmaceuticals to the environment.

  17. Preparation and characterization of 304 stainless steel/Q235 carbon steel composite material

    Directory of Open Access Journals (Sweden)

    Wenning Shen

    Full Text Available The composite material of 304 stainless steel reinforced Q235 carbon steel has been prepared by modified hot-rolling process. The resulted material was characterized by scanning electron microscope, three-electrode method, fault current impact method, electrochemical potentiodynamic polarization curve measurement and electrochemical impedance spectroscopy. The results showed that metallurgical bond between the stainless steel layer and carbon steel substrate has been formed. The composite material exhibited good electrical conductivity and thermal stability. The average grounding resistance of the composite material was about 13/20 of dip galvanized steel. There has no surface crack and bubbling formed after fault current impact. The composite material led to a significant decrease in the corrosion current density in soil solution, compared with that of hot dip galvanized steel and bare carbon steel. On the basis polarization curve and EIS analyses, it can be concluded that the composite material showed improved anti-corrosion property than hot-dip galvanized steel. Keywords: Stainless steel, Carbon steel, Anti-corrosion, Conductivity, Electrochemical, EIS

  18. Design and Preparation of Carbon Based Composite Phase Change Material for Energy Piles

    Directory of Open Access Journals (Sweden)

    Haibin Yang

    2017-04-01

    Full Text Available Energy piles—A fairly new renewable energy concept—Use a ground heat exchanger (GHE in the foundation piles to supply heating and cooling loads to the supported building. Applying phase change materials (PCMs to piles can help in maintaining a stable temperature within the piles and can then influence the axial load acting on the piles. In this study, two kinds of carbon-based composite PCMs (expanded graphite-based PCM and graphite nanoplatelet-based PCM were prepared by vacuum impregnation for potential application in energy piles. Thereafter, a systematic study was performed and different characterization tests were carried out on two composite PCMs. The composite PCMs retained up to 93.1% of paraffin and were chemically compatible, thermally stable and reliable. The latent heat of the composite PCM was up to 152.8 J/g while the compressive strength of cement paste containing 10 wt % GNP-PCM was found to be 37 MPa. Hence, the developed composite PCM has potential for thermal energy storage applications.

  19. Application of polymeric macroporous supports for temperature-responsive chromatography of pharmaceuticals.

    Science.gov (United States)

    Lamprou, Alexandros; Gavriilidou, Agni-Faviola-Mika; Storti, Giuseppe; Soos, Miroslav; Morbidelli, Massimo

    2015-08-14

    A macroporous particulate support prepared previously by reactive gelation under shear and functionalized with poly(N-isopropylacrylamide), PNIPAM, brushes of variable length is applied for temperature-responsive chromatography, whereby temperature modulates hydrophobic interactions. Several different analytes, including small pharmaceuticals, peptides, proteins and monoclonal antibodies are employed. Contrary to the most commonly observed behavior in conventional chromatography, increasing retention is observed at elevated temperatures. Peak broadening is quantified using the peak standard deviation, which depends on both the polymer chain conformation and analyte adsorptivity. The favorable effect of grafted polymer thickness on retention becomes progressively less pronounced for thicker grafted PNIPAM layers. The effect of eluent composition on solute-sorbent interactions was investigated by introducing NaCl, methanol, dioxane and by varying the pH. Salt or organic solvent addition affects apart from the analytes solution properties, the hydrophobicity of the stationary phase itself. Frontal analyses performed at different temperatures to determine dynamic binding capacities, indicate small mass transfer resistances imposed by this novel packing material. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Compositions, antibodies, asthma diagnosis methods, and methods for preparing antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Hongjun; Zangar, Richard C.

    2017-01-17

    Methods for preparing an antibody are provided with the method including incorporating 3-bromo-4-hydroxy-benzoic acid into a protein to form an antigen, immunizing a mammalian host with the antigen, and recovering an antibody having an affinity for the antigen from the host. Antibodies having a binding affinity for a monohalotyrosine are provided as well as composition comprising an antibody bound with monohalotyrosine. Compositions comprising a protein having a 3-bromo-4-hydroxy-benzoic acid moiety are also provided. Methods for evaluating the severity of asthma are provide with the methods including analyzing sputum of a patient using an antibody having a binding affinity for monohalotyrosine, and measuring the amount of antibody bound to protein. Methods for determining eosinophil activity in bodily fluid are also provided with the methods including exposing bodily fluid to an antibody having a binding affinity for monohalotyrosine, and measuring the amount of bound antibody to determine the eosinophil activity.

  1. Preparation and characterization of hydroxyapatite/chondroitin sulfate composites by biomimetic synthesis

    International Nuclear Information System (INIS)

    Xiao Xiufeng; He Dan; Liu Fang; Liu Rongfang

    2008-01-01

    Based on the principles of biomineralization, flakelike hydroxyapatite/chondroitin sulfate composites were synthesized through biomimetic method using Ca(NO 3 ) 2 .4H 2 O and (NH 4 ) 3 PO 4 .3H 2 O as reagents and chondroitin sulfate as template. The crystalline phase, microstructure, chemical composition, morphology and thermal behavior of the composites obtained in the experiment were characterized by means of X-ray diffraction (XRD), Fourier transform infrared spectroscope (FTIR), transmission electron microscope (TEM), Thermogravimetry-Differential thermal analyzer (TG-DTA) and Elemental analyzer, respectively. The interaction between the functional groups of ChS and HA was investigated by electrical conductivity and UV-vis spectrum. The results demonstrate that the as-prepared powders with small amount of carbonate have the component similar to human bone. It can be concluded that the nucleation and growth of HA crystals occurred through the chemical interactions between the HA crystals and preorganized functional groups of the ChS template. Furthermore, the concentration of ChS significantly affects the morphology of the composites. Short fiberlike crystals could be obtained at a low concentration of ChS, but flakelike crystals could be synthesized using a high concentration (≥0.5 wt%) of ChS as template

  2. Preparation and characterization of hydroxyapatite/chondroitin sulfate composites by biomimetic synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Xiao Xiufeng; He Dan; Liu Fang [College of Chemistry and Materials Science, Fujian Normal University, Fujian, Fuzhou 350007 (China); Liu Rongfang [College of Chemistry and Materials Science, Fujian Normal University, Fujian, Fuzhou 350007 (China)], E-mail: rfliu@vip.sina.com

    2008-12-20

    Based on the principles of biomineralization, flakelike hydroxyapatite/chondroitin sulfate composites were synthesized through biomimetic method using Ca(NO{sub 3}){sub 2}.4H{sub 2}O and (NH{sub 4}){sub 3}PO{sub 4}.3H{sub 2}O as reagents and chondroitin sulfate as template. The crystalline phase, microstructure, chemical composition, morphology and thermal behavior of the composites obtained in the experiment were characterized by means of X-ray diffraction (XRD), Fourier transform infrared spectroscope (FTIR), transmission electron microscope (TEM), Thermogravimetry-Differential thermal analyzer (TG-DTA) and Elemental analyzer, respectively. The interaction between the functional groups of ChS and HA was investigated by electrical conductivity and UV-vis spectrum. The results demonstrate that the as-prepared powders with small amount of carbonate have the component similar to human bone. It can be concluded that the nucleation and growth of HA crystals occurred through the chemical interactions between the HA crystals and preorganized functional groups of the ChS template. Furthermore, the concentration of ChS significantly affects the morphology of the composites. Short fiberlike crystals could be obtained at a low concentration of ChS, but flakelike crystals could be synthesized using a high concentration ({>=}0.5 wt%) of ChS as template.

  3. Evaluation of Alternative Peel Ply Surface Preparation Methods of SC-15 Epoxy / Fiberglass Composite Surfaces for Secondary Bonding

    Science.gov (United States)

    2014-01-01

    prepared composite surfaces. Examination of the surface compositions will show differences in makeup and identify any transfer of contaminants...by carefully brushing the specimen with a lint-free cloth followed by a high-pressure nitrogen gas stream. 3.2 X-ray Photospectroscopy (XPS

  4. Application of the PEE Model to essay composition in an IELTS preparation class

    Directory of Open Access Journals (Sweden)

    Ender Orlando Velasco Tovar

    2015-01-01

    Full Text Available Based on two case studies, this study investigates the application of the Point, Explanation, Example (PEE model to essay composition in a multi-lingual IELTS preparation class. This model was incorporated into an eight-week programme of instruction to ESL adults in London, England. Students preparing for the IELTS exam were asked to write pre and post instruction essays on a given topic within 40 minutes. Employing the IELTS band descriptors (IELTS, 2013b and analyses of coherence and cohesion in line with Systemic Functional Linguistic concepts (Halliday and Matthiessen, 2004; McCarthy, 1991, samples of students’ writing were analysed. Data from students’ pre and post instruction interviews was also gathered and analysed. The findings of this study suggest that the PEE model is to some extent effective in improving the essay composition performance of IELTS students, in particular in the area of cohesion and coherence. Students find the PEE model useful in regard to the clarity and structure that the model seems to add to their essays.

  5. Preparation and properties of carbohydrate-based composite films incorporated with CuO nanoparticles.

    Science.gov (United States)

    Shankar, Shiv; Wang, Long-Feng; Rhim, Jong-Whan

    2017-08-01

    The present study aimed to develop the carbohydrate biopolymer based antimicrobial films for food packaging application. The nanocomposite films of various biopolymers and copper oxide nanoparticles (CuONPs) were prepared by solvent casting method. The nanocomposite films were characterized using SEM, FTIR, XRD, and UV-vis spectroscopy. The thermal stability, UV barrier, water vapor permeability, and antibacterial activity of the composite films were also evaluated. The surface morphology of the films was dependent on the types of polymers used. The XRD revealed the crystallinity of CuONPs in the composite films. The addition of CuONPs increased the thickness, tensile strength, UV barrier property, relative humidity, and water vapor barrier property. The CuONPs incorporated composite films exhibited strong antibacterial activity against Escherichia coli and Listeria monocytogenes. The developed composite films could be used as a UV-light barrier antibacterial films for active food packaging. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Proposed changes to the reimbursement of pharmaceuticals and medical devices in Poland and their impact on market access and the pharmaceutical industry

    Science.gov (United States)

    Badora, Karolina; Caban, Aleksandra; Rémuzat, Cécile; Dussart, Claude; Toumi, Mondher

    2017-01-01

    ABSTRACT In Poland, two proposed amendments to the reimbursement act are currently in preparation; these are likely to substantially change the pricing and reimbursement landscape for both drugs and medical devices. Proposed changes include: alignment of medical device reimbursement with that of pharmaceuticals; relaxing the strict reimbursement criteria for ultra-orphan drugs; establishment of an additional funding category for vaccines; introduction of compassionate use, and a simplified reimbursement pathway for well-established off-label indications; appreciation of manufacturers’ innovation and research and development efforts by creating a dedicated innovation budget; introduction of a mechanism preventing excessive parallel import; prolonged duration of reimbursement decisions and reimbursement lists; and increased flexibility in defining drug programmes. Both amendments are still at a draft stage and many aspects of the new regulations remain unclear. Nonetheless, the overall direction of some of the changes is already evident and warrants discussion due to their high expected impact on pharmaceutical and device manufacturers. Here we evaluate the main changes proposed to the reimbursement of drugs, vaccines, and medical devices, and examine the impact they are likely to have on market access and pharmaceutical industry in Poland. PMID:29081924

  7. [Pharmaceutical logistic in turnover of pharmaceutical products of Azerbaijan].

    Science.gov (United States)

    Dzhalilova, K I

    2009-11-01

    Development of pharmaceutical logistic system model promotes optimal strategy for pharmaceutical functioning. The goal of such systems is organization of pharmaceutical product's turnover in required quantity and assortment, at preset time and place, at a highest possible degree of consumption readiness with minimal expenses and qualitative service. Organization of the optimal turnover chain in the region is offered to start from approximate classification of medicaments by logistic characteristics. Supplier selection was performed by evaluation of timeliness of delivery, quality of delivered products (according to the minimum acceptable level of quality) and time-keeping of time spending for orders delivery.

  8. Preparation of Nanofibrous Silver/Poly(vinylidene fluoride) Composite Membrane with Enhanced Infrared Extinction and Controllable Wetting Property.

    Science.gov (United States)

    Ren, Da-Ming; Huang, Hua-Kun; Yu, Yun; Li, Zeng-Tian; Jiang, Li-Wang; Chen, Shui-Mei; Lam, Kwok-Ho; Lin, Bo; Shi, Bo; He, Fu-An; Wu, Hui-Jun

    2018-05-01

    Nanofibrous silver (Ag)/poly(vinylidene fluoride) (PVDF) composite membranes were obtained from a two-step preparation method. In the first step, the electrospun silver nitrate (AgNO3)/PVDF membranes were prepared and the influence of the AgNO3 content on the electrospinning process was studied. According to scanning electron microscopy (SEM) results, when the electrospinning solution contained AgNO3 in the range between 3 to 7 wt.%, the nanofiber morphologies can be obtained. In the second step, the electrospun AgNO3/PVDF membranes were reduced by sodium borohydride to form the nanofibrous Ag/PVDF composite membranes. The resultant composite membranes were characterized by SEM, X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), differential scanning calorimetry, X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared. The XRD, XPS, and EDS characterizations proved the existence of Ag in the nanofibrous Ag/PVDF composite membranes. The crystallinity degree of PVDF for composite membranes declined with the increase in Ag content. More importantly, the nanofibrous Ag/PVDF composite membranes had obviously higher Rosseland extinction coefficients and lower thermal radiative conductivities in comparison with electrospun PVDF membrane, which demonstrates that such composite membranes with high porosity, low density, and good water vapor permeability are promising thermal insulating materials to block the heat transfer resulting from thermal radiation. In addition, three different methods for surface modification have been used to successfully improve the hydrophobicity of nanofibrous Ag/PVDF composite membranes.

  9. Sliding wear resistance of metal matrix composite layers prepared by high power laser

    NARCIS (Netherlands)

    Ocelik, Vaclav; Matthews, D; de Hosson, Jeff

    2005-01-01

    Two laser surface engineering techniques, Laser Cladding and Laser Melt Injection (LMI), were used to prepare three different metal matrix composite layers with a thickness of about 1 mm and approximately 25-30% volume fraction of ceramic particles. SiC/Al-8Si, WC/Ti-6Al-4V and TiB2/Ti-6Al-4V layers

  10. Preparation of 2-acrylamido-2 methyl propane-1-sulfonic acid/bentonite composite by radiation polymerization for adsorption of basic violet dye from aqueous solution

    International Nuclear Information System (INIS)

    Sokker, H.H.; Younes, M.M.; Abdel-Kareem, M.; Zohdy, K.

    2010-01-01

    Water uptake and the sorption properties of composite made by radiation polymerization of 2-acrylamido-2- methyl propane -1-sulfonic acid (AMPS) and a clay such as bentonite were investigated as a function of composition (2,6 and 10% w.t %) of bentonite and radiation dose. The prepared composite was characterized by FTIR and SEM. Swelling experiments were performed in water at 25 degree C. The prepared composite was applied for adsorption of basic violet dye at different ph values and the results showed that the prepared composite of composition (10% wt % of bentonite) showed the highest removal percent of basic violet dye at ph=9 compared with other compositions. Also, the adsorption capacity of basic violet at ph 3,7 and 9 were 3.5, 9 and 50 mg/g, respectively. The adsorption process of basic violet follows both Freundlich and Langmuir models and followed pseudo second order kinetic model

  11. Optimization of the pharmaceutical care system for diabetes patients using modern pharmaceutical informatics methodology

    Directory of Open Access Journals (Sweden)

    Андрій Ігорович Бойко

    2016-04-01

    Full Text Available Aim. Implementation of pharmaceutical informatics methods in the system of pharmaceutical care for diabetes patients in Ukraine.Methods. System method was used for the analysis of status and reforming the pharmaceutical care for patients with diabetes; program-oriented management at informatization project realization; pharmaceutical informatics in the creation of computer pharmaceutical knowledge bases; methods of data synthesis and summarizing.Results. System analysis of the basic directions of reforming the pharmaceutical care for patients with diabetes in Ukraine was carried out. Ways of it’s of optimization were processed: establishment of specialized pharmacies with implementation of modern information technologies and special postgraduate education for pharmacists. Structure and information providing of computer knowledge base “Pharmaceutical care for patients with diabetes” was substantiated.Conclusion. Based on the regional project “Informatization of prescription antidiabetic drugs circulation in Ukraine” realization, the necessity of establishment of specialized pharmacies providing pharmaceutical care for patients with diabetes was substantiated. Ways for optimization of postgraduate education for pharmacists of the specialized pharmacies by implementation of special thematic improvement cycles were proceed. Computer knowledge base as an effective tool for optimization of pharmaceutical care for patients with diabetes was realized

  12. Preparation of Composite Hydrogel Based on Polyacrylamide and the Effect of Kaolinite on Its Properties in the Reservoir Conditions

    OpenAIRE

    Farhad Salimi; Mohsen Vafaie; Mehdi Razzaghi Kashani; Majid Rafipoor

    2013-01-01

    A gel composite (based on polyacrylamide and crosslinker Cr(III) acetate) was prepared by solvent method (distillate and water formation) and nanoclay particle (kaolinite). Using XRD tests, d001 was evaluated for kaolinite nanoparticles in gel composite. Kaolinite modification using dimethyl-sulfoxide led to increase interlamellar spacing from 7.21 to 10.82 o A. Based on the results obtained for samples prepared from unmodified clay besides the pure clay, there is a wide peak at 2θ = 8o; whic...

  13. [Application of microwave irradiation technology to the field of pharmaceutics].

    Science.gov (United States)

    Zhang, Xue-Bing; Shi, Nian-Qiu; Yang, Zhi-Qiang; Wang, Xing-Lin

    2014-03-01

    Microwaves can be directly transformed into heat inside materials because of their ability of penetrating into any substance. The degree that materials are heated depends on their dielectric properties. Materials with high dielectric loss are more easily to reach a resonant state by microwaves field, then microwaves can be absorbed efficiently. Microwave irradiation technique with the unique heating mechanisms could induce drug-polymer interaction and change the properties of dissolution. Many benefits such as improving product quality, increasing energy efficiency and reducing times can be obtained by microwaves. This paper summarized characteristics of the microwave irradiation technique, new preparation techniques and formulation process in pharmaceutical industry by microwave irradiation technology. The microwave technology provides a new clue for heating and drying in the field of pharmaceutics.

  14. Investigating Micro-Tensile Bond Strength of Silorane Based Composite in Enamel Surfaces Prepared by Er:YAG Laser vs. Bur-Cut

    Directory of Open Access Journals (Sweden)

    AR Daneshkazemi

    2014-10-01

    Full Text Available Introduction: Recently, Er:YAG laser has been used for tooth preparations and silorane-based composites have been introduced to dentistry, though investigating this type of composites has received scant attention. Therefore, the aim of this study was to compare microtensile bond strength (MTBS of silorane- based composite (Filtek P90 3M/USA to enamel sufaces, prepared by Er:YAG laser irradiation versus bur cut. Methods:Same sized cavities were prepared by ER:YAG laser and bur on the enamel of 20 extracted teeth which were randomly divided into 4 groups:E1 laser + acid etching, E2: laser, E3: bur + acid etching, E4: bur. Then primer, adhesive and P60 resin composite were utilized according to the manufacturer instructions. After thermocycling, 20 samples were created in the form of an hour glass model with 1 mm2 slices in each group, and were tested by SD Mechatronic MTD 500 (Germany machine with cross head speed of 1mm/min to create the fracture. The failure mode was assessed under stereomicroscope (ZTX-3E, Zhejiang/China, and the study data were analysed by ANOVA test. Results: The study results revealed that highest and lowest microtensile bond strength belonged to E3 and E2 group respectively. No significant differences were observed between the tested groups(p= 0.213. Highest and lowest modes of failure were adhesive and cohesive respectively. ANOVA results did not demonstrate any significant differences between groups(p=0.845. Conclusion: Laser-prepared or bur-prepared cavities with or without etching and silorane based composite could not significantly affect MTBS in order to enamel.

  15. Mordenite/Nafion and analcime/Nafion composite membranes prepared by spray method for improved direct methanol fuel cell performance

    Science.gov (United States)

    Prapainainar, Paweena; Du, Zehui; Kongkachuichay, Paisan; Holmes, Stuart M.; Prapainainar, Chaiwat

    2017-11-01

    The aim of this work was to improve proton exchange membranes (PEMs) used in direct methanol fuel cells (DMFCs). A membrane with a high proton conductivity and low methanol permeability was required. Zeolite filler in Nafion (NF matrix) composite membranes were prepared using two types of zeolite, mordenite (MOR) and analcime (ANA). Spray method was used to prepare the composite membranes, and properties of the membranes were investigated: mechanical properties, solubility, water and methanol uptake, ion-exchange capacity (IEC), proton conductivity, methanol permeability, and DMFC performance. It was found that MOR filler showed higher performance than ANA. The MOR/Nafion composite membrane gave better properties than ANA/Nafion composite membrane, including a higher proton conductivity and a methanol permeability that was 2-3 times lower. The highest DMFC performance (10.75 mW cm-2) was obtained at 70 °C and with 2 M methanol, with a value 1.5 times higher than that of ANA/Nafion composite membrane and two times higher than that of commercial Nafion 117 (NF 117).

  16. Mechanical Properties of TC4 Matrix Composites Prepared by Laser Cladding

    Directory of Open Access Journals (Sweden)

    WANG Lin

    2017-06-01

    Full Text Available In order to improve the penetration performance of TC4, the direct laser deposition technology was used to prepare TC4 composite material. TA15+30% TiC powder, TA15+20%Cr3C2 powder and TA15+15%B4C powder were used as deposited materials for TC4 matrix. The micromorphology, change of hardness of the deposited coating and mechanical properties of the three composites were studied. The experimental results demonstrate that the TC4 matrix with the three kinds of materials can form a complete metallurgical bonding, and the strength of TC4-(TA15+TiC, TC4-(TA15+Cr3C2 and TC4-(TA15+B4C are higher than that of TC4 matrix materials, while the plasticity is slightly worse.

  17. THz spectroscopy: An emerging technology for pharmaceutical development and pharmaceutical Process Analytical Technology (PAT) applications

    Science.gov (United States)

    Wu, Huiquan; Khan, Mansoor

    2012-08-01

    As an emerging technology, THz spectroscopy has gained increasing attention in the pharmaceutical area during the last decade. This attention is due to the fact that (1) it provides a promising alternative approach for in-depth understanding of both intermolecular interaction among pharmaceutical molecules and pharmaceutical product quality attributes; (2) it provides a promising alternative approach for enhanced process understanding of certain pharmaceutical manufacturing processes; and (3) the FDA pharmaceutical quality initiatives, most noticeably, the Process Analytical Technology (PAT) initiative. In this work, the current status and progress made so far on using THz spectroscopy for pharmaceutical development and pharmaceutical PAT applications are reviewed. In the spirit of demonstrating the utility of first principles modeling approach for addressing model validation challenge and reducing unnecessary model validation "burden" for facilitating THz pharmaceutical PAT applications, two scientific case studies based on published THz spectroscopy measurement results are created and discussed. Furthermore, other technical challenges and opportunities associated with adapting THz spectroscopy as a pharmaceutical PAT tool are highlighted.

  18. Electrochemical Properties of Graphene-vanadium Oxide Composite Prepared by Electro-deposition for Electrochemical Capacitors

    International Nuclear Information System (INIS)

    Jeong, Heeyoung; Jeong, Sang Mun

    2015-01-01

    The nanostructural graphene/vanadium oxide (graphene/V 2 O 5 ) composite with enhanced capacitance was synthesized by the electro-deposition in 0.5 M VOSO 4 solution. The morphology of composites was characterized using scanning electron microscopy (SEM), x-ray diffraction pattern (XRD), and x-ray photoelectron spectroscopy (XPS). The oxidation states of the electro-deposited vanadium oxide was found to be V 5+ and V 4+ . The morphology of the prepared graphene/V 2 O 5 composite exhibits a netlike nano-structure with V 2 O 5 nanorods in about 100 nm diameter, which could lead a better contact between electrolyte an electrode. The composite with a deposition time of 4,000 s exhibits the specific capacitance of 854 mF/cm 2 at a scan rate of 20 mV/s and the capacitance retention of 53% after 1000 CV cycles

  19. Preparation and microwave-absorbing property of EP/BaFe{sub 12}O{sub 19}/PANI composites

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Huixia, E-mail: fenghx@lut.cn [State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou 730050 (China); College of Petrochemical Technology, Lanzhou University of Technology, Lanzhou 730050 (China); Bai, Dezhong [College of Petrochemical Technology, Lanzhou University of Technology, Lanzhou 730050 (China); Tan, Lin; Chen, Nali [State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou 730050 (China); College of Petrochemical Technology, Lanzhou University of Technology, Lanzhou 730050 (China); Wang, Yueyi [College of Petrochemical Technology, Lanzhou University of Technology, Lanzhou 730050 (China)

    2017-07-01

    In this paper, we introduced expanded perlite (EP) into the system of ferrite composites for the first time. By sol-gel self-propagating combustion method, expanded perlite/barium ferrite (EP/BaFe{sub 12}O{sub 19}) was prepared, and then ternary composites of expanded perlite/barium ferrite/polyaniline (EP/BaFe{sub 12}O{sub 19}/PANI) were obtained by in-situ oxidative polymerization of aniline on EP/BaFe{sub 12}O{sub 19} mixture. Although, as is well known, the values of saturation magnetization (Ms), remnant magnetization (Mr) and coercivity (Hc) of composites are all lower than the pure BaFe{sub 12}O{sub 19} particles owing to the existence of the nonmagnetic EP and PANI, the EP/BaFe{sub 12}O{sub 19}/PANI composites exhibit absorption characteristics at the range of 2–18 GHz, the effective absorption bandwidth (less than −4 dB) reached 12.12 GHz and the minimum reflection loss of −5.66 dB at 8.48 GHz with only 2 mm thickness of absorbing layer. So the composites could resist urban electromagnetic pollution, such as wireless network, communication and so on, effectively. - Highlights: • The expanded perlite (EP) was introduced into the system of ferrite composites at the first time. • Novel ternary nanocomposite of EP/BaFe{sub 12}O{sub 19}/PANI is prepared by in-situ oxidative polymerization. • Composite absorber exhibit a minimum reflection loss of -5.66 dB at 8.48 GHz with a matching thickness of 2 mm. • Composite absorber possess the features like low-cost, lightweight and wide bandwidth absorption of civil EM radiation.

  20. Preparation process and properties of LiCoO2/PANI/dodecylbenzenesulfonate composite electrode materials

    International Nuclear Information System (INIS)

    Ferchichi, Karima; Hbaieb, Souhaira; Amdouni, Noureddine; Kalfat, Rafik; Chevalier, Yves

    2013-01-01

    Composite materials that combine the lithium exchanging material LiCoO 2 and the conductive polymer poly(aniline) (PANI) have been investigated regarding their possible application to electrode materials of lithium batteries. Such composite materials have been prepared by means of polymerization of aniline in acidic suspensions of LiCoO 2 particles. PANI was synthesized by oxidative polymerization of aniline by ammonium persulfate in the presence of sodium dodecylbenzenesulfonate (SDBS) as a micellar template and dopant. The composite material consisted in LiCoO 2 particles dispersed in a continuous matrix of PANI. The ribbon-like morphology of the powdered material was distinctly different of the morphologies of the parent materials. The conductive material had conductivity close to that of PANI because the LiCoO 2 content of the composite material was low. The presence of the poorly conductive inorganic phase caused a significant loss of conductivity, showing that LiCoO 2 blocked electronic transfers between PANI crystallites. Ammonium persulfate caused the loss of lithium from LiCoO 2 when it was used at high concentration in the polymerization recipe. In this case a new phase made of Co 3 O 4 formed by chemical decomposition of Li x CoO 2 . Thin films prepared from stable suspensions of composite materials in water show comparable electrical performance to that measured for bulk materials. - Highlights: • LiCoO 2 was incorporated in a conductive polymer matrix made of PANI. • The hybrid material retained the high conductive properties of PANI. • Loss of lithium by persulfate oxidation caused conversion of LiCoO 2 into Co 3 O 4

  1. Fire retardancy assessment of polypropylene composite filed with nano clay prepared from Iraqi bentonite

    Science.gov (United States)

    Kareem Salih, Watheq

    2018-05-01

    Fire retardants have an extraordinary importance because of their role in saving the people, property and reducing the damages and minimizing the dangers resulting from fires and burning of polymeric composites which are used in different civil and industrial fields. The work in this paper can be divided into two main stages. In first one nano-clay was manufactured from Iraqi bentonite and it was characterized using AFM, XRD, XRF, SEM, and BET. The AFM test showed the particle size of prepared nano clay was about 99.25 nm. In the second stage, polypropylene/nano clay composites at three low loading percents (0%,2%,4%,6%) were formulated via twin screw extruder. The fire retardancy tests included burning rate according to ASTM:D-635 and maximum flame height of flame according to ASTM:D-3014. Besides, the mechanical tests and thermal behavior of prepared samples were investigated. The results showed that (4%) of nano-clay had the maximum fire retardancy and while at (2%) loading, the maximum value of tensile strength and Yong modulus were obtained. The maximum heat of fusion was recorded for 6% nano clay sample. The final results assessment confirmed on the possibility of using low loadings of prepared nano clay to improve the fire retardancy, mechanical and thermal properties successfully.

  2. Preparation of composite micro/nano structure on the silicon surface by reactive ion etching: Enhanced anti-reflective and hydrophobic properties

    Science.gov (United States)

    Zeng, Yu; Fan, Xiaoli; Chen, Jiajia; He, Siyu; Yi, Zao; Ye, Xin; Yi, Yougen

    2018-05-01

    A silicon substrate with micro-pyramid structure (black silicon) is prepared by wet chemical etching and then subjected to reactive ion etching (RIE) in the mixed gas condition of SF6, CHF3 and He. We systematically study the impacts of flow rates of SF6, CHF3 and He, the etching pressure and the etching time on the surface morphology and reflectivity through various characterizations. Meanwhile, we explore and obtain the optimal combination of parameters for the preparation of composite structure that match the RIE process based on the basis of micro-pyramid silicon substrate. The composite sample prepared under the optimum parameters exhibits excellent anti-reflective performance, hydrophobic, self-cleaning and anti-corrosive properties. Based on the above characteristics, the composite micro/nano structure can be applied to solar cells, photodetectors, LEDs, outdoor devices and other important fields.

  3. Novel method to prepare multiwalled carbon nanotube/poly(dimethyl siloxane) (MWCNT/PDMS) non-conducting composites

    DEFF Research Database (Denmark)

    Goswami, Kaustav; Daugaard, Anders Egede; Skov, Anne Ladegaard

    In this study a new method of carbon nanotube (CNT) incorporation was employed for the preparation of ultraviolet (UV) curable CNT filled poly (dimethyl siloxane) (PDMS) composites. The composites were designed to contain loadings of CNT above the percolation threshold without becoming conductive...... due to a localized distribution of CNT. Ultrasonicated and dispersed multiwalled CNTs were mixed with short chain ,- vinyl terminated PDMS. When the whole mixture containing dispersed CNT and short chain PDMS was irradiated with UV radiation in presence of deficient amount of hexa functional thiol...... PDMS crosslinker and a photoinitiator, hyperbranced PDMS layer was formed over the CNTs. The prepared hyperbranched CNTs were mixed in different weight ratios (0.33%, 0.66%, 1%) with long chain ,- vinyl terminated PDMS and crosslinked subsequently with the same hexa functional thiol PDMS via UV...

  4. High Performance Liquid Chromatographic Method for the Determination of Piroxicam, Naproxen, Diclofenac Sodium, and Mefenamic Acid in Bulk Drug and Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    Sarmad Bahjat Dikran

    2018-03-01

    Full Text Available A simple accurate and rapid reversed phase high performance liquid chromatographic method has been developed and validated for the determination of four nonsteroidal anti-inflammatory drugs;  Piroxicam(PX,  Naproxen(NAP,  Diclofenac sodium(DCL and Mefenamic acid(MFNC in their pure form and different commercial pharmaceutical formulation. The separation was performed on a NUCLEODUR® 100-5 C18ec (250 × 4.6 mm i.d.; particle size 5 μm column as stationary phase with a mobile phase comprising of acetonitrile: deionized water acidified with 1% acetic acid in gradient mode. The flow rate was 1.5 mL.min-1 at the temperature 35 ºC and detection was carried out at 264 nm. Separation has been completed within 8 min. The retention times of Piroxicam, Naproxen, Diclofenac sodium, and Mefenamic acid were 4.267 min, 4.785 min, 6.555 min, and 7.683 min respectively. The linearity for Piroxicam was in the range of 3–200 μg.mL-1 and for Naproxen and Mefenamic acid was in the range 1-200 μg.mL-1, while for Diclofenac sodium was in the range 1.5–200 μg.mL-1. The proposed method was successfully applied for the determination of these drugs in their pure form and different pharmaceutical preparations (tablets, capsules, and ampoule and there is no interference with additives.

  5. [The introduction of generic pharmaceutical products into Galicia].

    Science.gov (United States)

    Verdejo González, A; López-Lázaro, L; Rodríguez Moreno, C; Piñeiro Lago, B; Pereira Martínez, M L

    1999-11-30

    To know the evolution of the introduction of generic drugs (GDs) in Galicia. Secondarily, to evaluate its potential impact on pharmaceutical expenditure. Descriptive study of GDs utilization. Cost-minimization analysis. Galician autonomous region, year 1998. Using data from the prescription billing registry of Social Security we have selected the active ingredients corresponding to GDs with prescriptions in Galicia in 1997. We have analyzed the data for their oral single substance preparations by quarters. Consumption in DHDs of allopurinol, atenolol, captopril, naproxen and ranitidine remained stable during 1998. The market share for their GDs in quantitative terms relative to both total consumption of the active ingredients and to their pharmaceutical equivalents, showed an overall growing trend. The maximum observed value was seen for ranitidine at last quarter. Total expenditure (in final customer prices) during 1998 on the selected active substances was higher than 1864 million pesetas. Potential savings afforded by substitution for the lowest price GD prescribed in Galicia would reach 427 million pesetas. GDs market penetration in Galicia during 1998 was limited but increasing. Its utilization may afford estimated savings of 21-28% of the cost for the selected drugs. However, the expenditure on the above drugs was just 2.7% of total pharmaceutical expenditure.

  6. Preparation and Characterization of UPR/ LNR/ Glass Fiber Composite by using Unsaturated Polyester Resin (PET) from PET Wastes

    International Nuclear Information System (INIS)

    Siti Farhana Hisham; Ishak Ahmad; Rusli Daik

    2011-01-01

    UPR/ LNR/ glass fibre composite had been prepared by using unsaturated polyester resin (UPR) based from recycled PET product. PET waste was recycled by glycolysis process and the glycides product was then reacted with maleic anhydride to produce unsaturated polyester resin. The preparation of UPR/ LNR blends were conducted by varying the amount of LNR addition to the resin ranging from 0-7.5 % (wt). The composition of UPR/LNR blend with good mechanical properties had been selected as a matrix of the glass fiber reinforced composite. Glass fibre was also treated by (3-Amino propil)triethoxysilane as a coupling agent. From the result, the addition of 2.5 % LNR in UPR had showed the optimum mechanical and morphological properties where the elastomer particle's were well dispersed in the matrix with smaller size. The silane treatment on the glass fiber increased the tensile and impact strength values of the UPR/ LNR/ GF composite compared to untreated fiber reinforcement. (author)

  7. Marginal microleakage evaluation in class V composite restorations of deciduous teeth prepared conventionally and using Er:YAG laser

    International Nuclear Information System (INIS)

    Pulga, Neusa Vieira Galvao

    2001-01-01

    The evaluation of marginal microleakage in class V restorations of deciduous teeth prepared using Er:laser and comparison to the ones observed when conventionally prepared, using two photopolimerizable materials, composite resin and glass ionomer cement, was the subject of this study. Twenty eight complete deciduous teeth were divided into four groups Group 1 (G1) prepared with high speed drill + composite resin; Group 2 (G2) prepared with high speed drill + glass ionomer cement; Group 3 (G3) prepared using Er:YAG laser (2.94 μm), 300 mJ, 3 Hz, handpiece 2051, energy density 86 mJ/cm 2 + composite resin; Group 4 (G4) prepared using Er:YAG laser (2.94 μm), 300 mJ, 3 Hz, handpiece 2051, energy density 86 J / cm 2 + glass ionomer cement. After the preparation and restoration the specimens where stored at 37 deg C for 24 hours, thermally stressed, immersed in 50% aqueous solution of silver nitrate for 24 hours while kept in the dark. The specimens were rinsed in water, soaked in photodeveloping solution and exposed to fluorescent light for 6 hours. After this process the samples were sectioned and observed by stereomicroscopy. For comparison the groups were divided into occlusive and cervical microleakage. The results were analysed under the Kruskal-Wallis test. For the occlusive microleakage the statistical significance was 5% among the groups and the average comparison showed higher microleakage for G1 (M=35.1) than for G2 (M=24.0) as well as compared to G3 (M=22.3). The other groups did not present statistical differences among them. For the cervical microleakage the Kruskal-Wallis test did not present any statistical difference. Comparing the occlusive and cervical microleakage data, for every group, using the Wilcoxon test, no statistical differences were observed. Concluding, this study showed the Er:YAG laser to be effective for class V restorations and to result in a smaller microleakage degree using the composite resin. These results indicate the viability

  8. Preparation of Gold Nanoparticles for Biomedical Applications Using ...

    African Journals Online (AJOL)

    HP

    Tropical Journal of Pharmaceutical Research June 2013; 12 (3): 295-298 ... Applications Using Chemometric Technique. Soheila Honary. 1* ... approach for optimizing and testing the robustness of gold nanoparticle preparation method.

  9. Preparation and Performance of Amphiphilic Random Copolymer Noncovalently Modified MWCNTs/Epoxy Composite

    Directory of Open Access Journals (Sweden)

    MA Qiang

    2016-09-01

    Full Text Available An amphiphilic random copolymer of polyglycidyl methacrylate-co-N-vinyl carbazole P(GMA-co-NVC was synthesized by free radical polymerization and was used to noncovalently modify multi-walled carbon nanotubes (MWCNTs. The obtained P(GMA-co-NVC/MWCNTs was mixed with epoxy resin and used to reinforce epoxy resin. Polymer modified carbon nanotubes/epoxy resin composites were prepared by a casting molding method. Tensile test, electrical resistivity test and differential scanning calorimeter(DSC analysis were used to study the effect of polymer modified carbon nanotubes on the mechanical, electrical, and thermal properties of epoxy resin. The results show that the epoxy composite reinforced with P(GMA-co-NVC/MWCNTs shows a remarkable enhancement in both tensile strength and elongation at break compared to either the pure epoxy or the pristine MWCNTs/epoxy composites. In addition, the electrical conductivity of epoxy is significantly improved and the volume resistivity decreases from 1014Ω·m to 106Ω·m with 0.25% mass fraction loading of P(GMA-co-NVC/MWCNTs. Moreover, glass transition temperature of the epoxy composite also increases from 144℃ to 149℃.

  10. Novel Montmorillonite/TiO₂/MnAl-Mixed Oxide Composites Prepared from Inverse Microemulsions as Combustion Catalysts.

    Science.gov (United States)

    Napruszewska, Bogna D; Michalik-Zym, Alicja; Rogowska, Melania; Bielańska, Elżbieta; Rojek, Wojciech; Gaweł, Adam; Wójcik-Bania, Monika; Bahranowski, Krzysztof; Serwicka, Ewa M

    2017-11-19

    A novel design of combustion catalysts is proposed, in which clay/TiO₂/MnAl-mixed oxide composites are formed by intermixing exfoliated organo-montmorillonite with oxide precursors (hydrotalcite-like in the case of Mn-Al oxide) obtained by an inverse microemulsion method. In order to assess the catalysts' thermal stability, two calcination temperatures were employed: 450 and 600 °C. The composites were characterized with XRF (X-ray fluorescence), XRD (X-ray diffraction), HR SEM (high resolution scanning electron microscopy, N₂ adsorption/desorption at -196 °C, and H₂ TPR (temperature programmed reduction). Profound differences in structural, textural and redox properties of the materials were observed, depending on the presence of the TiO₂ component, the type of neutralization agent used in the titania nanoparticles preparation (NaOH or NH₃ (aq)), and the temperature of calcination. Catalytic tests of toluene combustion revealed that the clay/TiO₂/MnAl-mixed oxide composites prepared with the use of ammonia showed excellent activity, the composites obtained from MnAl hydrotalcite nanoparticles trapped between the organoclay layers were less active, but displayed spectacular thermal stability, while the clay/TiO₂/MnAl-mixed oxide materials obtained with the aid of NaOH were least active. The observed patterns of catalytic activity bear a direct relation to the materials' composition and their structural, textural, and redox properties.

  11. Evaluation of P-Listed Pharmaceutical Residues in Empty Pharmaceutical Containers

    Science.gov (United States)

    Under the Resource Conservation and Recovery Act (RCRA), some pharmaceuticals are considered acute hazardous wastes because their sole active pharmaceutical ingredients are P-listed commercial chemical products (40 CFR 261.33). Hospitals and other healthcare facilities have stru...

  12. 76 FR 20690 - Preparation for International Conference on Harmonization Steering Committee and Expert Working...

    Science.gov (United States)

    2011-04-13

    ... ICH sponsors are the European Commission; the European Federation of Pharmaceutical Industries... Pharmaceutical Research and Manufacturers of America. The ICH Secretariat, which coordinates the preparation of.../industry project to improve, through harmonization, the efficiency of the process for developing and...

  13. 75 FR 57803 - Preparation for International Conference on Harmonisation Steering Committee and Expert Working...

    Science.gov (United States)

    2010-09-22

    ... the European Commission; the European Federation of Pharmaceutical Industries Associations; the... Pharmaceutical Research and Manufacturers of America. The ICH Secretariat, which coordinates the preparation of... ICH was established in 1990 as a joint regulatory/industry project to improve, through harmonization...

  14. Preparation and mechanical properties of unidirectional boron nitride fibre reinforced silica matrix composites

    International Nuclear Information System (INIS)

    Li, Duan; Zhang, Chang-Rui; Li, Bin; Cao, Feng; Wang, Si-Qing

    2012-01-01

    Highlights: → BN fibres hardly degrade when exposed at elevated temperatures. → Few researches have related to BN f /SiO 2 composites. → BN f /SiO 2 composites have fine high-temperature mechanical properties. → Self-healing properties of fused SiO 2 and B 2 O 3 may contribute to the properties. -- Abstract: The unidirectional BN f /SiO 2 composites were prepared via sol-gel method, and the structure, composition and mechanical properties were studied. The results show that the composites consist of BN fibres and α-cristobalite matrix probably as well as the interface phases of Si 3 N 4 and B 2 O 3 . The composites have a density of 1.70 g cm -3 and an open porosity of 20.8%. The average flexural strength, elastic modulus and fracture toughness at room temperature are 51.2 MPa, 23.2 GPa and 1.46 MPa m 1/2 , respectively. The composites show a very plane fracture surface with practically no pulled-out fibres. The mechanical properties of BN f /SiO 2 composites at 300-1000 o C are desirable, with the maximum flexural strength and residual ratio being 80.2 MPa and 156.8% at 500 o C, respectively, while it is a sharply reduced trend as for SiO 2f /SiO 2 composites. The high thermal stability of BN fibres and self-healing properties caused by the fused SiO 2 and B 2 O 3 enable the composites fine high-temperature mechanical properties.

  15. Evaluation of pharmaceuticals removal by sewage sludge-derived adsorbents with rapid small-scale column tests

    Science.gov (United States)

    Zhang, P.; Ding, R.; Wallace, R.; Bandosz, T.

    2015-12-01

    New composite adsorbents were developed by pyrolyzing sewage sludge and fish waste (75:25 or 90:10 dry mass ratio) at 650 oC and 950 oC. Batch adsorption experiments demonstrated that the composite adsorbents were able to adsorb a wide range of organic contaminants (volatile organic compounds, pharmaceuticals and endocrine disrupting compounds (EDCs), and nitrosamine disinfection byproducts) with high capacities. Here we further examine the performance of the adsorbents for the simultaneous removal of 8 pharmaceuticals and EDCs with rapid small-scale column tests (RSSCT). Results show that the order of breakthrough in RSSCT is in general consistent with the affinity determined via batch tests. As expected, the maximum amount of adsorption for each compound obtained from RSSCT is identical to or less than that obtained from batch tests (with only one exception), due to adsorption kinetics. However, despite the very different input concentration (1 mg/L vs. 100 mg/L) and contact time (2 min empty bed contact time vs. 16 hour equilibrium time) used in RSSCT and batch tests, the maximum amount of pharmaceuticals and EDCs adsorbed under RSSCT is still about one half of that under equilibrium batch tests, validating the approach of using batch tests with much higher input concentrations to determine adsorption capacities. Results of a pilot-scale column test in a drinking water treatment plant for pharmaceuticals removal will also be presented.

  16. The Effect of Nylon and Polyester Peel Ply Surface Preparation on the Bond Quality of Composite Laminates

    Science.gov (United States)

    Moench, Molly K.

    The preparation of the surfaces to be bonded is critical to the success of composite bonds. Peel ply surface preparation is attractive from a manufacturing and quality assurance standpoint, but is a well known example of the extremely system-specific nature of composite bonds. This study examined the role of the surface energy, morphology, and chemistry left by peel ply removal in resulting bond quality. It also evaluated the use of contact angle surface energy measurement techniques for predicting the resulting bond quality of a prepared surface. The surfaces created by preparing three aerospace fiber-reinforced composite prepregs were compared when prepared with a nylon vs a polyester peel ply. The prepared surfaces were characterized with contact angle measurements with multiple fluids, scanning electron microscopy (SEM), and x-ray electron spectroscopy. The laminates were bonded with aerospace grade film adhesives. Bond quality was assessed via double cantilever beam testing followed by optical and scanning electron microscopy of the fracture surfaces.The division was clear between strong bonds (GIC of 600- 1000J/m2 and failure in cohesion) and weak bonds (GIC of 80-400J/m2 and failure in adhesion). All prepared laminates showed the imprint of the peel ply texture and evidence of peel ply remnants after fabric removal, either through SEM or XPS. Within an adhesive system, large amounts of SEM-visible peel ply material transfer correlated with poor bond quality and cleaner surfaces with higher bond quality. The both sides of failed weak bonds showed evidence of peel ply remnants under XPS, showing that at least some failure is occurring through the remnants. The choice of adhesive was found to be significant. AF 555 adhesive was more tolerant of peel ply contamination than MB 1515-3. Although the bond quality results varied substantially between tested combinations, the total surface energies of all prepared surfaces were very similar. Single fluid contact angle

  17. HPLC-APCI-MS analysis of triacylglycerols (TAGs) in historical pharmaceutical ointments from the eighteenth century.

    Science.gov (United States)

    Saliu, Francesco; Modugno, Francesca; Orlandi, Marco; Colombini, Maria Perla

    2011-10-01

    The lipid fractions of residues from historical pharmaceutical ointments were analysed by reversed-phase liquid chromatography coupled with atmospheric pressure chemical ionization and mass spectrometer detection. The residues were contained in a series of historical apothecary jars, dating from the eighteenth century and conserved at the "Aboca Museum" in Sansepolcro (Arezzo, Italy) and at the pharmacy of the "Real Cartuja de Valldemossa" in Palma de Majorca (Spain). The analytical protocol was set up using a comparative study based on the evaluation of triacylglycerol (TAG) compositions in raw natural lipid materials and in laboratory-reproduced ointments. These ointments were prepared following pharmaceutical recipes reported in historical treatises and used as reference materials. The reference materials were also subjected to stress treatments in order to evaluate the modification occurring in the TAG profiles as an effect of ageing. TAGs were successfully detected in the reproduced formulations even in mixtures of up to ten ingredients and after harsh degradative treatments, and also in real historical samples. No particular interferences were detected from other non-lipid ingredients of the formulations. The TAG compositions detected in the historical ointments indicated a predominant use of olive oil and pig adipose material as lipid ingredients. The detection of a high level of tristearine and myristyl-palmitoyl-stearyl glycerol in two of the samples suggested the presence of a fatty material of a different origin (maybe a ruminant). On the basis of the positional isomer ratio, sn-PPO/sn-POP, it was possible to hypothesize an exclusive use of pig fat in one sample. We also evaluated the application of principal component analysis of TAG profiles as an approach for the multivariate statistical comparison of the reference and historical ointments.

  18. Facile preparation and enhanced microwave absorption properties of flake carbonyl iron/Fe{sub 3}O{sub 4} composite

    Energy Technology Data Exchange (ETDEWEB)

    Min, Dandan, E-mail: mdd4776@126.com; Zhou, Wancheng; Luo, Fa; Zhu, Dongmei

    2017-08-01

    Highlights: • Flake carbonyl iron/Fe{sub 3}O{sub 4} composites were prepared by surface oxidation technique. • Lower permittivity and modest permeability was obtained by the FCI/Fe{sub 3}O{sub 4} composites. • Enhanced absorption efficiency and broader absorption band were obtained. - Abstract: Flake carbonyl iron/Fe{sub 3}O{sub 4} (FCI/Fe{sub 3}O{sub 4}) composites with enhanced microwave absorption properties were prepared by a direct and flexible surface oxidation technique. The phase structures, morphology, magnetic properties, frequency-dependent electromagnetic and microwave absorption properties of the composites were investigated. The measurement results showed that lower permittivity as well as modest permeability was obtained by the FCI/Fe{sub 3}O{sub 4} composites. The calculated microwave absorption properties indicated that enhanced absorption efficiency and broader absorption band were obtained by the FCI/Fe{sub 3}O{sub 4} composite comparing with the FCI composite. The absorption frequency range with reflection loss (RL) below −5 dB of FCI/Fe{sub 3}O{sub 4} composites at reaction time of 90 min at thickness of 1.5 mm is 13.3 GHz from 4.7 to 18 GHz, while the bandwidth of the FCI composite is only 5.9 GHz from 2.6 to 8.5 GHz at the same thickness. Thus, such absorbers could act as effective and wide broadband microwave absorbers in the GHz range.

  19. Composite films based on biorelated agro-industrial waste and poly(vinyl alcohol). Preparation and mechanical properties characterization.

    Science.gov (United States)

    Chiellini, E; Cinelli, P; Imam, S H; Mao, L

    2001-01-01

    As a part of an ongoing project on the production of composite materials based on poly(vinyl alcohol) (PVA) and polymeric materials from renewable resources, the present paper reports on the incorporation of agricultural waste materials as organic fillers in a film matrix based on PVA as continuous phase. In this study lignocellulosic fibers byproducts, derived from sugar cane (SC) and apple (AP) and orange (OR) fruit juice extraction, were cast from PVA aqueous solutions. The effect of fiber type and composition on the relative properties of cast films was evaluated and compared. OR resulted to be suitable for blending in higher amounts by weight than SC and AP. Glycerol and urea were added as plasticizing agents and were observed to be effective in giving flexible films. Additionally, cornstarch was added to further increase the composition of polymers from renewable resources in cost-effective and ecoefficient composite film formulations. The prepared films resulted sensitive to moisture and water. To reduce water sensitivity, hexamethoxymethylmelamine (HMMM) was tested as a cross-linking agent for the present composite formulations. Cross-linked films exhibited significant improvement in water-resistance that can be taken as a tuneable structural feature for customized applications. The mechanical properties of the prepared composite films (elongation at break, tensile strength, Young modulus) were found to be dependent upon the nature and content of the filler and on environmental conditions.

  20. Nutritional composition of Annona crassiflora pulp and acceptability of bakery products prepared with its flour

    OpenAIRE

    Villela,Paula; Batista,Ângela Giovana; Dessimoni-Pinto,Nísia Andrade Villela

    2013-01-01

    Annona crassiflora offers an edible fruit native to the Savanna. This study aimed to develop a flour meal from Annona crassiflora pulp; analyze the chemical composition of the fresh pulp and its flour; develop and verify the acceptance of formulations with different concentrations of the flour of Annona crassiflora pulp. Fruit used were selected and processed. The pulp was dried in an oven at 60-65 ºC/48h. We analyzed the chemical composition, and two formulations of breads were prepared with...

  1. Preparation of Nafion 117™-SnO2 Composite Membranes using an Ion-Exchange Method

    DEFF Research Database (Denmark)

    Nørgaard, Casper Frydendal; Nielsen, Ulla Gro; Skou, Eivind Morten

    2012-01-01

    Nafion 117™-SnO2 composite membranes were prepared by in-situ particle formation using an ion-exchange method. SnO2 was incorporated into Nafion 117ä membranes by ion-exchange in solutions of SnCl2 ∙2 H2O in methanol, followed by oxidation to SnO2 in air. By adjustment of the concentration of SnCl2...... ∙ 2 H2O used in the ion-exchange step, compositions ranging from 2 to 8 wt% SnO2 with SnO2 homogeneously distributed as nanoparticles were obtained. The prepared nanocomposite membranes were characterized by powder XRD, 119Sn MAS NMR spectroscopy, electrochemical impedance spectroscopy, water uptake...

  2. Pharmaceutical, cosmeceutical, and traditional applications of marine carbohydrates.

    Science.gov (United States)

    Ahmed, Abdul Bakrudeen Ali; Adel, Mohaddeseh; Karimi, Pegah; Peidayesh, Mahvash

    2014-01-01

    Marine carbohydrates are most important organic molecules made by photosynthetic organisms. It is very essential for humankind: the role in being an energy source for the organism and they are considered as an important dissolve organic compound (DOC) in marine environment's sediments. Carbohydrates found in different marine environments in different concentrations. Polysaccharides of carbohydrates play an important role in various fields such as pharmaceutical, food production, cosmeceutical, and so on. Marine organisms are good resources of nutrients, and they are rich carbohydrate in sulfated polysaccharide. Seaweeds (marine microalgae) are used in different pharmaceutical industries, especially in pharmaceutical compound production. Seaweeds have a significant amount of sulfated polysaccharides, which are used in cosmeceutical industry, besides based on the biological applications. Since then, traditional people, cosmetics products, and pharmaceutical applications consider many types of seaweed as an important organism used in food process. Sulfated polysaccharides containing seaweed have potential uses in the blood coagulation system, antiviral activity, antioxidant activity, anticancer activity, immunomodulating activity, antilipidepic activity, etc. Some species of marine organisms are rich in polysaccharides such as sulfated galactans. Various polysaccharides such as agar and alginates, which are extracted from marine organisms, have several applications in food production and cosmeceutical industries. Due to their high health benefits, compound-derived extracts of marine polysaccharides have various applications and traditional people were using them since long time ago. In the future, much attention is supposed to be paid to unraveling the structural, compositional, and sequential properties of marine carbohydrate as well. © 2014 Elsevier Inc. All rights reserved.

  3. Preparation and Characterization of Liquid Crystalline Polyurethane/Al2O3/Epoxy Resin Composites for Electronic Packaging

    Directory of Open Access Journals (Sweden)

    Shaorong Lu

    2012-01-01

    Full Text Available Liquid crystalline polyurethane (LCPU/Al2O3/epoxy resin composites were prepared by using LCPU as modifier. The mechanical properties, thermal stability, and electrical properties of the LCPU/Al2O3/epoxy resin composites were investigated systematically. The thermal oxidation analysis indicated that LCPU/Al2O3/epoxy resin composites can sustain higher thermal decomposition temperature. Meanwhile, coefficient of thermal expansion (CTE was also found to decrease with addition of LCPU and nano-Al2O3.

  4. Composition and microstructure of beryllium carbide films prepared by thermal MOCVD

    Energy Technology Data Exchange (ETDEWEB)

    He, Yu-dan; Luo, Jiang-shan; Li, Jia; Meng, Ling-biao; Luo, Bing-chi; Zhang, Ji-qiang; Zeng, Yong; Wu, Wei-dong, E-mail: wuweidongding@163.com

    2016-02-15

    Highlights: • Non-columnar-crystal Be{sub 2}C films were firstly prepared by thermal MOCVD. • Beryllium carbide was always the dominant phase in the films. • α-Be and carbon existed in films deposited below and beyond 400 °C, respectively. • Morphology evolved with temperatures and no columnar grains were characterized. • The preferred substrate temperature for depositing high quality Be{sub 2}C films was 400 °C. - Abstract: Beryllium carbide films without columnar-crystal microstructures were prepared on the Si (1 0 0) substrate by thermal metal organic chemical vapor deposition using diethylberyllium as precursor. The influence of the substrate temperature on composition and microstructure of beryllium carbide films was systematically studied. Crystalline beryllium carbide is always the dominant phase according to XRD analysis. Meanwhile, a small amount of α-Be phase exists in films when the substrate temperature is below 400 °C, and hydrocarbon or amorphous carbon exists when the temperature is beyond 400 °C. Surfaces morphology shows transition from domes to cylinders, to humps, and to tetraquetrous crystalline needles with the increase of substrate temperature. No columnar grains are characterized throughout the thickness as revealed from the cross-section views. The average densities of these films are determined to be 2.04–2.17 g/cm{sup 3}. The findings indicate the substrate temperature has great influences on the composition and microstructure of the Be{sub 2}C films grown by thermal MOCVD.

  5. Ductile alloy and process for preparing composite superconducting wire

    Science.gov (United States)

    Verhoeven, J.D.; Finnemore, D.K.; Gibson, E.D.; Ostenson, J.E.

    An alloy for the commercial production of ductile superconducting wire is prepared by melting together copper and at least 15 weight percent niobium under non-oxygen-contaminating conditions, and rapidly cooling the melt to form a ductile composite consisting of discrete, randomly distributed and oriented dendritic-shaped particles of niobium in a copper matrix. As the wire is worked, the dendritic particles are realigned parallel to the longitudinal axis and when drawn form a plurality of very fine ductile superconductors in a ductile copper matrix. The drawn wire may be tin coated and wound into magnets or the like before diffusing the tin into the wire to react with the niobium. Impurities such as aluminum or gallium may be added to improve upper critical field characteristics.

  6. Lignocellulose nanofibers prepared by ionic liquid pretreatment and subsequent mechanical nanofibrillation of bagasse powder: Application to esterified bagasse/polypropylene composites.

    Science.gov (United States)

    Ninomiya, Kazuaki; Abe, Megumi; Tsukegi, Takayuki; Kuroda, Kosuke; Tsuge, Yota; Ogino, Chiaki; Taki, Kentaro; Taima, Tetsuya; Saito, Joji; Kimizu, Mitsugu; Uzawa, Kiyoshi; Takahashi, Kenji

    2018-02-15

    In the present study, we examined the efficacy of choline acetate (ChOAc, a cholinium ionic liquid))-assisted pretreatment of bagasse powder for subsequent mechanical nanofibrillation to produce lignocellulose nanofibers. Bagasse sample with ChOAc pretreatment and subsequent nanofibrillation (ChOAc/NF-bagasse) was prepared and compared to untreated control bagasse sample (control bagasse), bagasse sample with nanofibrillation only (NF-bagasse) and with ChOAc pretreatment only (ChOAc-bagasse). The specific surface area was 0.83m 2 /g, 3.1m 2 /g, 6.3m 2 /g, and 32m 2 /g for the control bagasse, ChOAc-bagasse, NF-bagasse, and the ChOAc/NF-bagasse, respectively. Esterified bagasse/polypropylene composites were prepared using the bagasse samples. ChOAc/NF-bagasse exhibited the best dispersion in the composites. The tensile toughness of the composites was 0.52J/cm 3 , 0.73J/cm 3 , 0.92J/cm 3 , and 1.29J/cm 3 for the composites prepared using control bagasse, ChOAc-bagasse, NF-bagasse, and ChOAc/NF-bagasse, respectively. Therefore, ChOAc pretreatment and subsequent nanofibrillation of bagasse powder resulted in enhanced tensile toughness of esterified bagasse/polypropylene composites. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. A systematic investigation of the preparation and properties of composite carbon molecular sieves containing inorganic oxides

    Science.gov (United States)

    Foley, Henry C.

    1990-01-01

    The objective of this research is to define the methodology for the preparation and characterization of new carbon-based molecular sieves with composite structures. Carbon molecular sieves have found increasing application in the field of separation and purification of gases. These materials are relatively easy to prepare and their surfaces can be modified to some extent. It is expected that by combining inorganic oxides with the carbonaceous structure one can begin to design composite materials with a wider range of possible chemical and physical properties. In this way, the IOM-CMS materials may confer distinct advantages over pure carbon molecular sieves, not just for separation, but also for catalysis. The most recent results in the design and characterization of these IOM-CMS materials are reviewed and summarized. Directions for further research are also presented.

  8. Preparation and thermal properties characterization of carbonate salt/carbon nanomaterial composite phase change material

    International Nuclear Information System (INIS)

    Tao, Y.B.; Lin, C.H.; He, Y.L.

    2015-01-01

    Highlights: • Nanocomposite phase change materials were prepared and characterized. • Larger specific surface area is more efficient to enhance specific heat. • Columnar structure is more efficient to enhance thermal conductivity. • Thermal conductivity enhancement is the key. • Single walled carbon nanotube is the optimal nanomaterial additive. - Abstract: To enhance the performance of high temperature salt phase change material, four kinds of carbon nanomaterials with different microstructures were mixed into binary carbonate eutectic salts to prepare carbonate salt/nanomaterial composite phase change material. The microstructures of the nanomaterial and composite phase change material were characterized by scanning electron microscope. The thermal properties such as melting point, melting enthalpy, specific heat, thermal conductivity and total thermal energy storage capacity were characterized. The results show that the nanomaterial microstructure has great effects on composite phase change material thermal properties. The sheet structure Graphene is the best additive to enhance specific heat, which could be enhanced up to 18.57%. The single walled carbon nanotube with columnar structure is the best additive to enhance thermal conductivity, which could be enhanced up to 56.98%. Melting point increases but melting enthalpy decreases with nanomaterial specific surface area increase. Although the additives decrease the melting enthalpy of composite phase change material, they also enhance the specific heat. As a combined result, the additives have little effects on thermal energy storage capacity. So, for phase change material performance enhancement, more emphasis should be placed on thermal conductivity enhancement and single walled carbon nanotube is the optimal nanomaterial additive

  9. A novel method for preparing microfibrillated cellulose from bamboo fibers

    International Nuclear Information System (INIS)

    Nguyen, Huu Dat; Nguyen, Ngoc Bich; Dang, Thanh Duy; Thuy Mai, Thi Thanh; Phung Le, My Loan; Tran, Van Man; Dang, Tan Tai

    2013-01-01

    The bamboo fiber is a potential candidate for biomass and power source application. In this study, microfibrillated cellulose (MFC) is prepared from raw fibers of bamboo tree (Bambusa Blumeana J A and J H Schultes) by an alkali treatment at room temperature in association with a bleaching treatment followed by a sulfuric acid hydrolysis. Field-emission scanning electron microscopy (FESEM) images indicated that final products ranged from 20 to 40 nm in diameter. The chemical composition measurement and Fourier transform infrared (FTIR) spectroscopy showed that both hemicellulose and lignin are mostly removed in the MFC. The x-ray diffraction (XRD) results also show that MFC has crystallinity of more than 70%. The thermogravimetric analysis (TGA) curves revealed that cellulose microfibers have a two-step thermal decomposition behavior owing to the attachment of sulfated groups onto the cellulose surface in the hydrolysis process with sulfuric acid. The obtained MFCs may have potential applications in alternative power sources as biomass, in pharmaceutical and optical industries as additives, as well as in composite fields as a reinforcement phase. (paper)

  10. Determination of losartan potassium, quinapril hydrochloride and hydrochlorothiazide in pharmaceutical preparations using derivative spectrophotometry and chromatographic-densitometric method.

    Science.gov (United States)

    Stolarczyk, Mariusz; Maślanka, Anna; Apola, Anna; Krzek, Jan

    2013-01-01

    Two methods, spectrophotometric and chromatographic-densitometric ones, were developed for determination of losartan potassium, quinapril hydrochloride and hydrochlorothiazide in pharmaceutical preparations. Spectrophotometric method involved derivative spectrophotometry and zero order spectrophotometry. The measurements were carried out at lambda = 224.0 nm for quinapril, lambda = 261.0 nm for hydrochlorothiazide and lambda = 270.0 nm for losartan when the derivative spectrophotometry was applied and lambda = 317.0 nm when zero order spectrophotometry was applied for the determination of hydrochlorothiazide. In chromatographic-densitometric studies high performance thin layer chromatography (HPTLC) plates were used as stationary phase and a mixture of solvents n-butanol : acetic acid : water (15 : 5 : 1, v/v/v) as mobile phase. Under the established conditions good resolution of examined constituents was obtained. Retardation factor for quinapril hydrochloride was R(f) - 0.70, for losartan potassium R(f) - 0.85 and for hydrochlorothiazide R(f) - 0.78. The developed methods are characterized by high sensitivity and accuracy. For quantitative analysis, densitometric measurements were carried out at lambda = 218.0 nm for quinapril, lambda = 275.0 nm for hydrochlorothiazide and = 232.0 nm for losartan.

  11. [On the preparation and mechanical properties of PVA hydrogel bionic cartilage/bone composite artificial articular implants].

    Science.gov (United States)

    Meng, Haoye; Zheng, Yudong; Huang, Xiaoshan; Yue, Bingqing; Xu, Hong; Wang, Yingjun; Chen, Xiaofeng

    2010-10-01

    In view of the problems that conventional artificial cartilages have no bioactivity and are prone to peel off in repeated uses as a result of insufficient strength to bond with subchondral bone, we have designed and prepared a novel kind of PVA-BG composite hydrogel as bionic artificial articular cartilage/bone composite implants. The effects of processes and conditions of preparation on the mechanical properties of implant were explored. In addition, the relationships between compression strain rate, BG content, PVA hydrogels thickness and compressive tangent modulus were also explicated. We also analyzed the effects of cancellous bone aperture, BG and PVA content on the shear strength of bonding interface of artificial articular cartilage with cancellous bone. Meanwhile, the bonding interface of artificial articular cartilage and cancellous bone was characterized by scanning electron microscopy. It was revealed that the compressive modulus of composite implants was correspondingly increased with the adding of BG content and the augments of PVA hydrogel thickness. The compressive modulus and bonding interface were both related to the apertures of cancellous bone. The compressive modulus of composite implants was 1.6-2.23 MPa and the shear strength of bonding interface was 0.63-1.21 MPa. These results demonstrated that the connection between artificial articular cartilage and cancellous bone was adequately firm.

  12. CoFe2O4-SiO2 Composites: Preparation and Magnetodielectric Properties

    Directory of Open Access Journals (Sweden)

    T. Ramesh

    2016-01-01

    Full Text Available Cobalt ferrite (CoFe2O4 and silica (SiO2 nanopowders have been prepared by the microwave hydrothermal (M-H method using metal nitrates as precursors of CoFe2O4 and tetraethyl orthosilicate as a precursor of SiO2. The synthesized powders were characterized by XRD and FESEM. The (100-x (CoFe2O4 + xSiO2 (where x = 0%, 10%, 20%, and 30% composites with different weight percentages have been prepared using ball mill method. The composite samples were sintered at 800°C/60 min using the microwave sintering method and then their structural and morphological studies were investigated using X-ray diffraction (XRD, Fourier transformation infrared (FTIR spectra, and scanning electron microscopy (SEM, respectively. The effect of SiO2 content on the magnetic and electrical properties of CoFe2O4/SiO2 nanocomposites has been studied via the magnetic hysteresis loops, complex permeability, permittivity spectra, and DC resistivity measurements. The synthesized nanocomposites with adjustable grain sizes and controllable magnetic properties make the applicability of cobalt ferrite even more versatile.

  13. Preparation of graphene-enhanced nickel-phosphorus composite films by ultrasonic-assisted electroless plating

    Science.gov (United States)

    Yu, Qian; Zhou, Tianfeng; Jiang, Yonggang; Yan, Xing; An, Zhonglie; Wang, Xibin; Zhang, Deyuan; Ono, Takahito

    2018-03-01

    To improve the mechanical properties of nickel-phosphorus (Ni-P) mold material for glass molding, an ultrasonic-assisted electroless plating method is proposed for the synthesis of graphene-enhanced nickel-phosphorus (G-Ni-P) composite films on heat-resistant stainless steel (06Cr25Ni20). Graphene flakes are prepared by an electrochemical exfoliation method. The surface roughness of the as-plated G-Ni-P composite plating is Ra 2.84 μm, which is higher than that of the Ni-P plating deposited using the same method. After annealing at 400 ºC for 2 h, the main phase of the G-Ni-P composite is transformed to crystalline Ni3P with an average grain size of 32.8 nm. The Vickers hardness and Young's modulus of the G-Ni-P composite are increased by 8.0% and 8.2% compared with the values of Ni-P, respectively. The detailed plating process is of great significance for the fabrication of G-Ni-P mold materials with enhanced mechanical properties.

  14. Preparation of carbon nanotube-neodymium oxide composite and research on its catalytic performance

    International Nuclear Information System (INIS)

    Zhao Lei; Wang Zhihua; Han Dongmei; Tao Dongliang; Guo Guangsheng

    2009-01-01

    Carbon Nanotube-Neodymium Oxide (CNT-Nd 2 O 3 ) composite was prepared by using acid treated carbon nanotubes (CNTs) and neodymium nitrate in the presence of sodium dodecyl sulfate and ammonia liquid. Techniques of transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and differential thermal analysis (DTA) are used to characterize the morphology, structure, composition and catalytic property of the CNT-Nd 2 O 3 composite. The experimental results show that the Nd 2 O 3 nanoparticles, which have an average diameter of about 30-40 nm, are loaded on the surface of carbon nanotube. Compared with pure Nd 2 O 3 nanorods, the CNT-Nd 2 O 3 composite can catalyze the thermal decomposition of ammonium perchlorate more effectively. The sampling methods of the experimental samples made a difference on the catalytic experiment results, and the best catalytic result was obtained when de-ionized water served as the solvent of ammonium perchlorate

  15. Preparation and dielectric properties of Ba0.95Ca0.05Ti0.8Zr0.2O3-polyethersulfone composites

    International Nuclear Information System (INIS)

    Wang Fajun; Li Wen; Jiang Hongliu; Xue Mingshan; Lu Jinshan; Yao Junping

    2010-01-01

    We report the preparation and dielectric properties of ceramic-polymer composites using Ba 0.95 Ca 0.05 Ti 0.8 Zr 0.2 O 3 (BCTZ) as a ceramic filler and polyethersulfone (PES) as a polymer matrix. The BCTZ powders were synthesized by a sol-gel method to fabricate BCZT-PES composites. The composites with various BCTZ volume fractions were prepared by a solution mixing and hot-pressing method. The composite with 50 vol % BCTZ showed high dielectric constant (ε=48.80) and low loss (tan δ=0.042) at 1 kHz and room temperature. Such excellent dielectric properties of the composites displayed an acceptable stability within a wide range of temperature (from 20 to 150 deg. C) and frequency (from 100 Hz to 100 kHz). The present work indicates that the BCTZ-PES composite can be a candidate for embedded capacitors.

  16. High performance nano-titania photocatalytic paper composite. Part II: Preparation and characterization of natural zeolite-based nano-titania composite sheets and study of their photocatalytic activity

    International Nuclear Information System (INIS)

    Ko, Seonghyuk; Fleming, Paul D.; Joyce, Margaret; Ari-Gur, Pnina

    2009-01-01

    A novel paper composite with high photocatalytic performance was fabricated using natural zeolite (clinoptilolite)-based nanosized TiO 2 . Photocatalytic materials, from sol-gel derived TiO 2 colloids to its coupling with zeolite, have been designed, prepared and characterized. As-prepared anatase TiO 2 on zeolite particles were readily used in photocatalytic paper, which revealed zeolite-TiO 2 particles dispersed on a dense network of fibers with microvoids. Natural zeolite-based TiO 2 composite sheets described here decomposed gaseous toluene very effectively after UV irradiation and its removal efficiency was higher than that accomplished by photocatalytic paper made with Degussa P25 TiO 2 or Ahlstrom commercial photocatalytic non-woven paper.

  17. Application of ion chromatography in clinical studies and pharmaceutical industry.

    Science.gov (United States)

    Michalski, Rajmund

    2014-01-01

    Ion chromatography is a well-established regulatory method for analyzing anions and cations in environmental, food and many other samples. It offers an enormous range of possibilities for selecting stationary and mobile phases. Additionally, it usually helps to solve various separation problems, particularly when it is combined with different detection techniques. Ion chromatography can also be used to determine many ions and substances in clinical and pharmaceutical samples. It provides: availability of high capacity stationary phases and sensitive detectors; simple sample preparation; avoidance of hazardous chemicals; decreased sample volumes; flexible reaction options on a changing sample matrix to be analyzed; or the option to operate a fully-automated system. This paper provides a short review of the ion chromatography applications for determining different inorganic and organic substances in clinical and pharmaceutical samples.

  18. Inductively coupled plasma mass spectrometry in the analysis of biological samples and pharmaceutical drugs

    Science.gov (United States)

    Ossipov, K.; Seregina, I. F.; Bolshov, M. A.

    2016-04-01

    Inductively coupled plasma mass spectrometry (ICP-MS) is widely used in the analysis of biological samples (whole blood, serum, blood plasma, urine, tissues, etc.) and pharmaceutical drugs. The shortcomings of this method related to spectral and non-spectral interferences are manifested in full measure in determination of the target analytes in these complex samples strongly differing in composition. The spectral interferences are caused by similarity of masses of the target component and sample matrix components. Non-spectral interferences are related to the influence of sample matrix components on the physicochemical processes taking place during formation and transportation of liquid sample aerosols into the plasma, on the value and spatial distribution of plasma temperature and on the transmission of the ion beam from the interface to mass spectrometer detector. The review is devoted to analysis of different mechanisms of appearance of non-spectral interferences and to ways for their minimization or elimination. Special attention is paid to the techniques of biological sample preparation, which largely determine the mechanisms of the influence of sample composition on the results of element determination. The ways of lowering non-spectral interferences by instrumental parameter tuning and application of internal standards are considered. The bibliography includes 189 references.

  19. Fracture resistance of prepared premolars restored with bonded new lab composite and all-ceramic inlay/onlay restorations: Laboratory study.

    Science.gov (United States)

    Wafaie, Ramy Ahmed; Ibrahim Ali, Ashraf; Mahmoud, Salah Hasab

    2018-01-25

    To assess the influence of new light curing lab composite, lithium-disilicate glass-ceramic and yttrium-stabilized zirconia-based ceramic on the fracture resistance of maxillary premolars with class II inlay and onlay preparations. Seventy sound maxillary premolars were divided randomly into seven main groups. The first group was left intact (control group). The remaining six groups were prepared with inlay and onlay cavities and restored with lab composite (SR Nexco), lithium-disilicate glass-ceramic (IPS e.max Press) and yttrium-stabilized zirconia-based ceramic (ICE Zirkon). The restorations were cemented with luting resin composite (Variolink N). All specimens were thermocycled 5000 cycles between 5°C ± 2°C and 55°C ± 2°C and were then cyclic loaded for 500 000 cycles. The specimens were subjected to a compressive load in a universal testing machine using a metal sphere until fracture occurred. The results were analyzed by 2-way ANOVA and Tukey HSD post hoc tests. The level of significance was set at P  .05). However, statistically significant differences were found among the means of control group and the groups restored with lab composite inlays, lab composite onlays, pressable glass ceramic inlays and pressable glass ceramic onlays (P lab composite is used. Conversely, when a ceramic material being used, the prepared teeth for inlay and onlay restorations showed a comparable strength to the intact teeth especially zirconia ceramic. Premolar teeth restored with zirconia ceramic inlays and onlays exhibited fracture resistance comparable to intact teeth. © 2018 Wiley Periodicals, Inc.

  20. Microstructures and mechanical properties of Cu/Ti{sub 3}SiC{sub 2}/C/MWCNTs composites prepared by vacuum hot-pressing sintering

    Energy Technology Data Exchange (ETDEWEB)

    Xiaosong, Jiang, E-mail: xsjiang@yeah.net [School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Liu, Wanxia; Li, Jingrui [School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Shao, Zhenyi [Department of Mechanical Engineering, Chengdu Technological University, Chengdu, Sichuan 610031 (China); Zhu, Degui [School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China)

    2015-01-05

    Highlights: • Cu/Ti{sub 3}SiC{sub 2}/C/MWCNTs composites were prepared using vacuum hot-pressing sintering. • Dispersions of MWCNTs were prepared using 10 μg/ml gallic acid aqueous solution. • MWCNTs content has no effect on generation of TiC and Cu{sub 9}Si to effect matrix’s performance. - Abstract: Cu/Ti{sub 3}SiC{sub 2}/C/MWCNTs composites were prepared by vacuum hot-pressing sintering. Microstructures and mechanical properties of Cu/Ti{sub 3}SiC{sub 2}/C/MWCNTs composites with different multi-walled carbon nanotubes contents have been systematically investigated. The microstructures of the composites were examined by optical microscopy, X-ray diffraction, back scattered electron imaging, scanning electron microscope and energy dispersive spectrometer. The mechanical properties were determined from Brinell hardness and tensile tests. The results demonstrated that there was an optimum value of MWCNTs content which has an impact on microstructures and mechanical properties of Cu/Ti{sub 3}SiC{sub 2}/C/MWCNTs composites. Based on MWCNTs content on properties and microstructure of Cu/Ti{sub 3}SiC{sub 2}/C/MWCNTs composites, effects of MWCNTs on improvement of the composites and strengthening mechanism have been analyzed.

  1. Hydroxyapatite/MCM-41 and SBA-15 Nano-Composites: Preparation, Characterization and Applications

    Science.gov (United States)

    Anunziata, Oscar A.; Martínez, Maria L.; Beltramone, Andrea R.

    2009-01-01

    Composites of hydroxyapatite (HaP) and highly ordered large pore mesoporous silica molecular sieves such as, Al-SBA-15 and Al-MCM-41 (denoted as SBA-15 and MCM-41, respectively) were developed, characterized by XRD, BET, FTIR, HRTEM and NMR-MAS, and applied to fluoride retention from contaminated water. The proposed procedure by a new route to prepare the HaP/SBA-15 and HaP/MCM-41, composites generates materials with aluminum only in tetrahedral coordination, according to the 27Al NMR-MAS results. Free OH- groups of HaP nanocrystals, within the hosts, allowed high capacity fluoride retention. The activity of fluoride retention using HaP/MCM-41 or HaP/SBA-15 was 1-2 orders of magnitude greater, respectively, than with pure HaP.

  2. Preparation and characterization of stearic acid/expanded graphite composites as thermal energy storage materials

    International Nuclear Information System (INIS)

    Fang, Guiyin; Li, Hui; Chen, Zhi; Liu, Xu

    2010-01-01

    Stearic acid/expanded graphite composites with different mass ratios were prepared by absorbing liquid stearic acid into the expanded graphite. In the composite materials, the stearic acid was used as the phase change material for thermal energy storage, and the expanded graphite acted as the supporting material. Fourier transformation infrared spectroscopy, X-ray diffraction, scanning electron microscopy and thermal diffusivity measurement were used to determine the chemical structure, crystalline phase, microstructure and thermal diffusivity of the composites, respectively. The thermal properties and thermal stability were investigated by differential scanning calorimetry and thermogravimetric analysis. The thermal analysis results indicated that the materials exhibited the same phase transition characteristics as the stearic acid and their latent heats were approximately the same as the values calculated based on the weight fraction of the stearic acid in the composites. The microstructural analysis results showed that the stearic acid was well absorbed in the porous network of the expanded graphite, and there was no leakage of the stearic acid from the composites even when it was in the molten state.

  3. The argument for pharmaceutical policy.

    Science.gov (United States)

    Traulsen, Janine Morgall; Almarsdóttir, Anna Birna

    2005-02-01

    Pharmaceutical policy is a global concern. It has become a hot political topic in most countries--developed as well as developing--and can be found on the agenda of international organizations such as WHO, OECD, EU, WTO and even the World Bank. Pharmaceutical policy affects everyone in the world of pharmacy and it is therefore imperative that it be understood, discussed and debated within the pharmacy profession and included in the curriculum of schools of pharmacy. This, the first article in a series, argues for the importance of the academic discipline of pharmaceutical policy analysis and the involvement of pharmacists in this endeavour. The aim of the authors is to stimulate an informed and critical appreciation of this field. The authors begin with an introduction to the field of pharmaceutical policy, introducing several important concepts and current trends including: medicines regulation; how pharmaceutical policy is made; pharmaceutical policy as a dynamic process; and the new public health as a global issue. The article ends with a short description of the remaining five articles in the series which will deal with important aspects of pharmaceutical policy. The topics include: economic pressures on health care systems; drug utilization from the clinical viewpoint (rational use of medicines); the impact of pharmaceutical policy on patients and the patient impact on pharmaceutical policy; the professional perspective; and finally the last article which deals with studying and evaluating pharmaceutical policy.

  4. Use and practice of achiral and chiral supercritical fluid chromatography in pharmaceutical analysis and purification.

    Science.gov (United States)

    Lemasson, Elise; Bertin, Sophie; West, Caroline

    2016-01-01

    The interest of pharmaceutical companies for complementary high-performance chromatographic tools to assess a product's purity or enhance this purity is on the rise. The high-throughput capability and economic benefits of supercritical fluid chromatography, but also the "green" aspect of CO2 as the principal solvent, render supercritical fluid chromatography very attractive for a wide range of pharmaceutical applications. The recent reintroduction of new robust instruments dedicated to supercritical fluid chromatography and the progress in stationary phase technology have also greatly benefited supercritical fluid chromatography. Additionally, it was shown several times that supercritical fluid chromatography could be orthogonal to reversed-phase high-performance liquid chromatography and could efficiently compete with it. Supercritical fluid chromatography is an adequate tool for small molecules of pharmaceutical interest: synthetic intermediates, active pharmaceutical ingredients, impurities, or degradation products. In this review, we first discuss about general chromatographic conditions for supercritical fluid chromatography analysis to better suit compounds of pharmaceutical interest. We also discuss about the use of achiral and chiral supercritical fluid chromatography for analytical purposes and the recent applications in these areas. The use of preparative supercritical fluid chromatography by pharmaceutical companies is also covered. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Preparation and bioactive properties of nano bioactive glass and segmented polyurethane composites.

    Science.gov (United States)

    Aguilar-Pérez, Fernando J; Vargas-Coronado, Rossana F; Cervantes-Uc, Jose M; Cauich-Rodríguez, Juan V; Covarrubias, Cristian; Pedram-Yazdani, Merhdad

    2016-04-01

    Composites of glutamine-based segmented polyurethanes with 5 to 25 wt.% bioactive glass nanoparticles were prepared, characterized, and their mineralization potential was evaluated in simulated body fluid. Biocompatibility with dental pulp stem cells was assessed by MTS to an extended range of compositions (1 to 25 wt.% of bioactive glass nanoparticles). Physicochemical characterization showed that composites retained many of the matrix properties, i.e. those corresponding to semicrystalline elastomeric polymers as they exhibited a glass transition temperature (Tg) between -41 and -36℃ and a melting temperature (Tm) between 46 and 49℃ in agreement with X-ray reflections at 23.6° and 21.3°. However, with bioactive glass nanoparticles addition, tensile strength and strain were reduced from 22.2 to 12.2 MPa and 667.2 to 457.8%, respectively with 25 wt.% of bioactive glass nanoparticles. Although Fourier transform infrared spectroscopy did not show evidence of mineralization after conditioning of these composites in simulated body fluid, X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray microanalysis showed the formation of an apatite layer on the surface which increased with higher bioactive glass concentrations and longer conditioning time. Dental pulp stem cells proliferation at day 5 was improved in bioactive glass nanoparticles composites containing lower amounts of the filler (1-2.5 wt.%) but it was compromised at day 9 in composites containing high contents of nBG (5, 15, 25 wt.%). However, Runx2 gene expression was particularly upregulated for the dental pulp stem cells cultured with composites loaded with 15 and 25 wt.% of bioactive glass nanoparticles. In conclusion, low content bioactive glass nanoparticles and segmented polyurethanes composites deserve further investigation for applications such as guided bone regeneration membranes, where osteoconductivity is desirable but not a demanding mechanical performance. © The

  6. [Quality process control system of Chinese medicine preparation based on "holistic view"].

    Science.gov (United States)

    Wang, Ya-Qi; Jiao, Jiao-Jiao; Wu, Zhen-Feng; Zheng, Qin; Yang, Ming

    2018-01-01

    "High quality, safety and effectiveness" are the primary principles for the pharmaceutical research and development process in China. The quality of products relies not only on the inspection method, but also on the design and development, process control and standardized management. The quality depends on the process control level. In this paper, the history and current development of quality control of traditional Chinese medicine (TCM) preparations are reviewed systematically. Based on the development model of international drug quality control and the misunderstanding of quality control of TCM preparations, the reasons for impacting the homogeneity of TCM preparations are analyzed and summarized. According to TCM characteristics, efforts were made to control the diversity of TCM, make "unstable" TCM into "stable" Chinese patent medicines, put forward the concepts of "holistic view" and "QbD (quality by design)", so as to create the "holistic, modular, data, standardized" model as the core of TCM preparation quality process control model. Scientific studies shall conform to the actual production of TCM preparations, and be conducive to supporting advanced equipment and technology upgrade, thoroughly applying the scientific research achievements in Chinese patent medicines, and promoting the cluster application and transformation application of TCM pharmaceutical technology, so as to improve the quality and effectiveness of the TCM industry and realize the green development. Copyright© by the Chinese Pharmaceutical Association.

  7. Preparation of SiO2-KCoFC composite ion-exchanger for removal of Cs in the soil decontamination waste solution

    International Nuclear Information System (INIS)

    Lee, Jung Joon; Moon, Jei kwon; Lee, Kune Woo

    2009-01-01

    The soil decontamination process has been developed for remediate the soil wastes excavated from the TRIGA research reactor sites. Even though the process was proven to be very effective for decontaminate the radioactive nuclides such as cesium and cobalt, the secondary spent solution should be treated with an appropriate method to minimize the waste volume. There are mainly two components in the spent decontamination solution of Cs and Co. The Co in the waste solution can be removed easily by precipitation under a basic condition. However, since the Cs is hardly removed by precipitation, an appropriate selective removal method should be employed. In this study, an inorganic composite ion exchanger of SiO 2 -KCoFC was prepared by sol-gel method for a removal of Cs in the decontamination waste solution. An optimum condition for a preparation of the composite ion exchanger and the adsorption performances of the prepared composite ion exchangers were evaluated

  8. Preparation and Photocatalytic Property of TiO2/Diatomite-Based Porous Ceramics Composite Materials

    Directory of Open Access Journals (Sweden)

    Shuilin Zheng

    2012-01-01

    Full Text Available The diatomite-based porous ceramics was made by low-temperature sintering. Then the nano-TiO2/diatomite-based porous ceramics composite materials were prepared by hydrolysis deposition method with titanium tetrachloride as the precursor of TiO2 and diatomite-based porous as the supporting body of the nano-TiO2. The structure and microscopic appearance of nano-TiO2/diatomite-based porous ceramics composite materials was characterized by XRD and SEM. The photocatalytic property of the composite was investigated by the degradation of malachite green. Results showed that, after calcination at 550°C, TiO2 thin film loaded on the diatomite-based porous ceramics is anatase TiO2 and average grain size of TiO2 is about 10 nm. The degradation ratio of the composite for 5 mg/L malachite green solution reached 86.2% after irradiation for 6 h under ultraviolet.

  9. Preparation and characterization of carbon nanotube-hybridized carbon fiber to reinforce epoxy composite

    International Nuclear Information System (INIS)

    An, Feng; Lu, Chunxiang; Li, Yonghong; Guo, Jinhai; Lu, Xiaoxuan; Lu, Huibin; He, Shuqing; Yang, Yu

    2012-01-01

    Highlights: → CNTs were uniformly grown onto the carbon fibers. → No obvious mechanical properties of carbon fiber were observed after CNT growth. → The IFSS of multiscale epoxy composite was measured by single fiber pull-out tests. → Observing fractography of composite, the fracture modes of CNTs were discussed. -- Abstract: The multiscale carbon nanotube-hybridized carbon fiber was prepared by a newly developed aerosol-assisted chemical vapour deposition. Scanning electron microscopy and transmission electron microscope were carried out to characterize this multiscale material. Compared with the original carbon fibers, the fabrication of this hybrid fiber resulted in an almost threefold increase of BET surface area to reach 2.22 m 2 /g. Meanwhile, there was a slight degradation of fiber tensile strength within 10%, while the fiber modulus was not significantly affected. The interfacial shearing strength of a carbon fiber-reinforced polymer composite with carbon nanotube-hybridized carbon fiber and an epoxy matrix was determined from the single fiber pull-out tests of microdroplet composite. Due to an efficient increase of load transfer at the fiber/matrix interfaces, the interracial shear strength of composite reinforced by carbon nanotube-hybridized carbon fiber is almost 94% higher than that of one reinforced by the original carbon fiber. Based on the fractured morphologies of the composites, the interfacial reinforcing mechanisms were discussed through proposing different types of carbon nanotube fracture modes along with fiber pulling out from epoxy composites.

  10. Field emission characteristics of SnO2/CNT composite prepared by microwave assisted wet impregnation

    CSIR Research Space (South Africa)

    Kesavan Pillai, Sreejarani

    2012-01-01

    Full Text Available SnO2/CNT composites were prepared by microwave assisted wet impregnation at 60 °C. The process was optimized by varying the microwave power and reaction time. Raman analysis showed the typical features of the rutile phase of as-synthesized SnO2...

  11. Preparation and Characterization of Extruded Composites Based on Polypropylene and Chitosan Compatibilized with Polypropylene-Graft-Maleic Anhydride

    Science.gov (United States)

    Carrasco-Guigón, Fernando Javier; Rodríguez-Félix, Dora Evelia; Castillo-Ortega, María Mónica; Santacruz-Ortega, Hisila C.; Burruel-Ibarra, Silvia E.; Encinas-Encinas, Jose Carmelo; Plascencia-Jatomea, Maribel; Herrera-Franco, Pedro Jesus; Madera-Santana, Tomas Jesus

    2017-01-01

    The preparation of composites of synthetic and natural polymers represent an interesting option to combine properties; in this manner, polypropylene and chitosan extruded films using a different proportion of components and polypropylene-graft-maleic anhydride (PPgMA) as compatibilizer were prepared. The effect of the content of the biopolymer in the polypropylene (PP) matrix, the addition of compatibilizer, and the particle size on the properties of the composites was analyzed using characterization by fourier transform-infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), tensile strength, and contact angle, finding that in general, the addition of the compatibilizer and reducing the particle size of the chitosan, favored the physicochemical and morphological properties of the films. PMID:28772464

  12. Removal of Heavy Metal Ions by Using Composite of Cement Kiln Dust/Ethylene Glycol co Acrylic Acid Prepared by y-Irradiation

    International Nuclear Information System (INIS)

    Sokker, H.H.; Abdel-Rahman, H.A.; Khattab, M.M.; Ismail, M.R.

    2010-01-01

    Various composites of cement kiln dust (CKD) and poly(ethylene glycol co acrylic acid) using y-irradiation was investigated. The samples were prepared using three percentages of cement kiln dust namely, 20, 50 and 75 by wt % and mixed with an equimolar ratio (1:1) of ethylene glycol and acrylic acid then irradiated at doses; 10,20 and 30 kGy of gamma-irradiation. The results showed that (CKD) and poly(ethylene glycol co acrylic acid) composites were formed only at 30 kGy. In addition, CKD alone has the lowest degree of removal of heavy metal ions compared with the prepared composites. A composite containing 75% cement kiln dust by weight percentage, showed the highest degree of removal of cobalt ions, whereas, a composite of 20% CKD showed the highest degree for cadmium ion removal. While the composite of 75% CKD showed a higher selectivity of cobalt ion than cadmium ion in their mixed solution.

  13. The preparation and performance of calcium carbide-derived carbon/polyaniline composite electrode material for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Liping; Wang, Xianyou; Li, Na; An, Hongfang; Chen, Huajie [School of Chemistry, Key Laboratory of Environmentally Friendly Chemistry and Applications of Minister of Education, Xiangtan University, Hunan 411105 (China); Wang, Ying; Guo, Jia [School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Hubei 430073 (China)

    2010-03-15

    Calcium carbide (CaC{sub 2})-derived carbon (CCDC)/polyaniline (PANI) composite materials are prepared by in situ chemical oxidation polymerization of an aniline solution containing well-dispersed CCDC. The structure and morphology of CCDC/PANI composite are characterized by Fourier infrared spectroscopy (FTIR), scanning electron microscope (SEM), transmission electron microscopy (TEM) and N{sub 2} sorption isotherms. It has been found that PANI was uniformly deposited on the surface and the inner pores of CCDC. The supercapacitive behaviors of the CCDC/PANI composite materials are investigated with cyclic voltammetry (CV), galvanostatic charge/discharge and cycle life measurements. The results show that the CCDC/PANI composite electrodes have higher specific capacitances than the as grown CCDC electrodes and higher stability than the conducting polymers. The capacitance of CCDC/PANI composite electrode is as high as 713.4 F g{sup -1} measured by cyclic voltammetry at 1 mV s{sup -1}. Besides, the capacitance retention of coin supercapacitor remained 80.1% after 1000 cycles. (author)

  14. Determination of preservatives in cosmetics, cleaning agents and pharmaceuticals using fast liquid chromatography.

    Science.gov (United States)

    Baranowska, Irena; Wojciechowska, Iwona; Solarz, Natalia; Krutysza, Ewa

    2014-01-01

    This paper reports the development of a method for simultaneously determining five preservatives in cosmetics, cleaning agents and pharmaceuticals by fast liquid chromatography. Methylisothiazolinone, methylchloroisothiazolinone, benzyl alcohol, sodium benzoate and methylparaben were separated on a Chromolith Fast Gradient reversed-phase 18e column using gradient elution with acetonitrile and a 0.1% aqueous solution of formic acid, with a run time of 3 min. The preparation of solid and liquid samples included ultrasonic extraction with methanol with recoveries ranging from 69 to 119%. The developed method was used to analyze samples of cosmetics (66 samples), cleaning agents (five samples) and pharmaceutical industry products (17 samples).

  15. [Logistics in the pharmaceutical service].

    Science.gov (United States)

    Stanko, P; Fulmeková, M

    2005-11-01

    The conception of the field of pharmaceutical service defines pharmaceutical service as the basic part of pharmacy, the principal task of which is to provide pharmaceutical care as an inseparable part of providing health care. It represents a set of professional activities of the pharmacist oriented to securing human and veterinary pharmaceutical products and health care products and to optimising effective, safe and quality pharmacotherapy. Technically, pharmaceutical service is an applied discipline, as it makes use of knowledge gained in other pharmaceutical, medical, psychological, social, and economic sciences. Because of its interdisciplinary character it is necessary to extend the theory of pharmaceutical service in such a way so that it may reflect all aspects of its sphere of activity. One of the possibilities is to define the pharmacy premises as an independent functional unit which operates on the basis of valid legal standards in such a way that on the one hand it secures the provision of health (pharmaceutical) care, and on the other hand it maintains its cost-effectiveness. To keep the quality of care of the patient and the economic aspect in balance, it is necessary to define the term pharmaceutical logistics also under the conditions of Slovak (Czech) pharmacy as early satisfaction of the requirements of the patient (client) in the pharmacy premises, which means that the appropriate pharmaceutical product or health care product and the appropriate information must be at the right time in the required amount and required quality in the right place.

  16. Preparation, characterization and enhanced visible-light photocatalytic activities of BiPO4/BiVO4 composites

    International Nuclear Information System (INIS)

    Wu, Siyuan; Zheng, Hong; Lian, Youwei; Wu, Yiying

    2013-01-01

    Graphical abstract: - Highlights: • BiPO 4 /BiVO 4 composites were successfully prepared by the hydrothermal method. • BiPO 4 /BiVO 4 composites exhibited broad absorption in the visible region. • Visible-light photocatalytic activities of BiPO 4 /BiVO 4 composites were enhanced. • P/V molar ratio and pH value of the reaction affect photocatalytic activity. • The mechanism of enhanced visible-light photocatalytic activities was discussed. - Abstract: BiPO 4 /BiVO 4 composites with different P/V molar ratios were prepared by the hydrothermal method and the effect of pH values of hydrothermal reaction on photocatalytic activity of BiPO 4 /BiVO 4 composite was investigated. The photocatalysts were characterized by X-ray diffraction, field emission scanning electron microscopy, energy-dispersive spectroscopy, X-ray photoelectron spectroscopy and UV–vis diffuse reflectance spectroscopy. The photocatalytic property of BiPO 4 /BiVO 4 was evaluated by photocatalytic degradation of Methylene blue under visible light irradiation. The results showed that the photocatalytic activity of the composites was much higher than that of pure BiPO 4 and BiVO 4 . The rate constant of Methylene blue degradation over BiPO 4 /BiVO 4 (P/V molar ratio of 5:1 and hydrothermal reaction pH value of 1.5) is 1.7 times that of pure BiVO 4 . The photocatalytic activity enhancement of BiPO 4 /BiVO 4 composite is closely related to the BiVO 4 functioning as a sensitizer to adsorb visible light and the heterojunction of BiPO 4 /BiVO 4 acting as an active center for hindering the rapid recombination of electron–hole pairs during the photocatalytic reaction

  17. ZnO nanoparticles obtained by pulsed laser ablation and their composite with cotton fabric: Preparation and study of antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Svetlichnyi, Valery; Shabalina, Anastasiia, E-mail: shabalinaav@gmail.com; Lapin, Ivan; Goncharova, Daria; Nemoykina, Anna

    2016-05-30

    Highlights: • ZnO nanoparticles obtained by pulsed laser ablation exhibit antibacterial activity. • H{sub 2}O{sub 2} and Zn{sup 2+} are not responsible for antibacterial activity of obtained zinc oxide. • Nano-ZnO/cotton fabric composite is a promising material for antibacterial bandage. - Abstract: A simple deposition method was used to prepare a ZnO/cotton fabric composite from water and ethanol dispersions of ZnO nanoparticles obtained by the pulsed laser ablation method. The structure and composition of the nanoparticles from dispersions and as-prepared composites were studied using electron microscopy, X-ray diffraction, and spectroscopy. The nanoparticles and composite obtained exhibited antibacterial activity to three different pathogenic microorganisms—Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. An attempt to understand a mechanism of bactericidal effect of ZnO nanoparticles was made. It was shown that zinc ions and hydrogen peroxide were not responsible for antibacterial activity of the particles and the composite, and surface properties of nanoparticles played an important role in antibacterial activity of zinc oxide. The proposed composite is a promising material for use as an antibacterial bandage.

  18. Preparation and characterization of ABS/anhydrous cobalt chloride composites

    Science.gov (United States)

    Shao, Chengli; Shang, Peng; Mao, Yapeng; Li, Qiuying; Wu, Chifei

    2018-01-01

    Anhydrous cobalt chloride (CoCl2) particles filled acrylonitrile-butadiene-styrene (ABS) composites were successfully prepared and investigated. A strong interfacial interaction between CoCl2 particles and ABS matrix was generated by heat pressing at 190 °C for 15 min. SEM results demonstrated that the particles were dispersed uniformly in the matrix. Fourier transform infrared, x-ray photoelectron spectroscopy and electron spin resonance were used for the investigation of the coordination reaction. The interfacial interaction resulted from a solid-state coordination reaction between nitrile groups (-CN) and cobalt ions (Co2+), leading to an increase in mechanical properties and glass transition temperature. Moreover, heat deflection temperatures were measured and proved to achieve an improvement of 30.6 °C when the CoCl2 content was 7 wt%.

  19. Preparation and characterization of the micro-arc oxidation composite coatings on magnesium alloys

    OpenAIRE

    Yanfeng Ge; Bailing Jiang; Ming Liu; Congjie Wang; Wenning Shen

    2014-01-01

    The magnesium alloys attract the light-weight manufacture due to its high strength to weight ratio, however the poor corrosion resistance limits the application in automobile industry. The Micro-arc Composite Ceramic (MCC) coatings on AZ91D magnesium alloys were prepared by Micro-arc Oxidation (MAO) and electrophoresis technologies. The microstructure, corrosion resistance, abrasion resistance, stone impact resistance and adhesion of MCC coatings were studied respectively. The cross section m...

  20. Pharmaceutical powder compaction technology

    National Research Council Canada - National Science Library

    Çelik, Metin

    2011-01-01

    "Revised to reflect modern pharmaceutical compacting techniques, this Second Edition guides pharmaceutical engineers, formulation scientists, and product development and quality assurance personnel...

  1. Liquid separation techniques coupled with mass spectrometry for chiral analysis of pharmaceuticals compounds and their metabolites in biological fluids.

    OpenAIRE

    Erny, Guillaume L.; Cifuentes, Alejandro

    2006-01-01

    Determination of the chiral composition of drugs is nowadays a key step in order to determine purity, activity, bioavailability, biodegradation, etc, of pharmaceuticals. In this manuscript, works published for the last 5 years on the analysis of chiral drugs by liquid separation techniques coupled with mass spectrometry are reviewed. Namely, chiral analysis of pharmaceuticals including e.g., antiinflammatories, antihypertensives, relaxants, etc, by liquid chromatography-mass spectrometry and ...

  2. Optical and structural properties of ZnO/ZnMgO composite thin films prepared by sol–gel technique

    International Nuclear Information System (INIS)

    Xu, Linhua; Su, Jing; Chen, Yulin; Zheng, Gaige; Pei, Shixin; Sun, Tingting; Wang, Junfeng; Lai, Min

    2013-01-01

    Highlights: ► ZnMgO thin film and ZnO/ZnMgO composite thin film have been prepared by sol–gel method. ► The intensity of ultraviolet emission of ZnMgO thin film is enhanced two times compared with that of pure ZnO thin film. ► Compared with ZnMgO thin film, ZnO/ZnMgO composite thin film shows better crystallization and optical properties. ► ZnO/ZnMgO composite thin films prepared by sol–gel method have potential applications in many optoelectronic devices. - Abstract: In this study, pure ZnO thin film, Mg-doped ZnO (ZnMgO) thin film, ZnO/ZnMgO and ZnMgO/ZnO composite thin films were prepared by sol–gel technique. The structural and optical properties of the samples were analyzed by X-ray diffraction, scanning electron microscopy, UV–visible spectrophotometer, ellipsometer and photoluminescence spectra, respectively. The results showed that the incorporation of Mg increased the strain, broadened the optical bandgap, and improved the intensity of ultraviolet emission of ZnO thin film. The full width at half maximum (FWHM) of the ultraviolet emission peak was also increased due to Mg-doping at the same time. Compared with pure ZnO and ZnMgO thin films, the ZnO/ZnMgO thin film showed better crystalline quality and ultraviolet emission performance, smaller strains and higher transmittance in the visible range.

  3. Simple preparation of fluorescent composite films based on cerium and europium doped LaF3 nanoparticles

    Science.gov (United States)

    Secco, Henrique de L.; Ferreira, Fabio F.; Péres, Laura O.

    2018-03-01

    The combination of materials to form hybrids with unique properties, different from those of the isolated components, is a strategy used to prepare functional materials with improved properties aiming to allow their application in specific fields. The doping of lanthanum fluoride with other rare earth elements is used to obtain luminescent particles, which may be useful to the manufacturing of electronic devices' displays and biological markers, for instance. The application of the powder of nanoparticles has limitations in some fields; to overcome this, the powder may be incorporated in a suitable polymeric matrix. In this work, lanthanum fluoride nanoparticles, undoped and doped with cerium and europium, were synthesized through the co-precipitation method in aqueous solution. Aiming the formation of solid state films, composites of nanoparticles in an elastomeric matrix, the nitrile rubber (NBR), were prepared. The flexibility and the transparency of the matrix in the regions of interest are advantages for the application of the luminescent composites. The composites were applied as films using the casting and the spin coating techniques and luminescent materials were obtained in the samples doped with europium and cerium. Scanning electron microscopy images showed an adequate dispersion of the particles in the matrix in both film formation techniques. Aggregates of the particles were detected in the samples which may affect the uniformity of the emission of the composites.

  4. Crosslinked cellulose thin film composite nanofiltration membranes with zero salt rejection

    KAUST Repository

    Puspasari, Tiara

    2015-05-14

    We report a new synthetic route of fabricating regenerated cellulose nanofiltration membranes. The membranes are composite membranes with a thin selective layer of cellulose, which was prepared by regeneration of trimethylsilyl cellulose (a hydrophobic cellulose derivative) film followed by crosslinking. Filtration experiments using mixtures of sugar and sodium chloride showed that solutes above 300 Da were highly rejected whereas practically no rejection was observed for NaCl. This is a big advantage for a complete desalination as the existing commercial nanofiltration membranes typically exhibit NaCl rejection in the range of 30–60%. Membranes with zero NaCl rejection are required for recovery and purification applications in food, chemical and pharmaceutical industry.

  5. Pharmaceutical advertising in emergency departments.

    Science.gov (United States)

    Marco, Catherine A

    2004-04-01

    Promotion of prescription drugs represents a growing source of pharmaceutical marketing expenditures. This study was undertaken to identify the frequency of items containing pharmaceutical advertising in clinical emergency departments (EDs). In this observational study, emergency physician on-site investigators quantified a variety of items containing pharmaceutical advertising present at specified representative times and days, in clinical EDs. Measurements were obtained by 65 on-site investigators, representing 22 states. Most EDs in this study were community EDs (87% community and 14% university or university affiliate), and most were in urban settings (50% urban, 38% suburban, and 13% rural). Investigators measured 42 items per ED (mean = 42; median = 31; interquartile range of 14-55) containing pharmaceutical advertising in the clinical area. The most commonly observed items included pens (mean 15 per ED; median 10), product brochures (mean 5; median 3), stethoscope labels (mean 4; median 2), drug samples (mean 3; median 0), books (mean 3.4), mugs (mean 2.4), and published literature (mean 3.1). EDs with a policy restricting pharmaceutical representatives in the ED had significantly fewer items containing pharmaceutical advertising (median 7.5; 95% CI = 0 to 27) than EDs without such a policy (median 35; 95% CI = 27 to 47, p = 0.005, nonparametric Wilcoxon two-sample test). There were no differences in quantities of pharmaceutical advertising for EDs in community compared with university settings (p = 0.5), rural compared with urban settings (p = 0.3), or annual ED volumes (p = 0.9). Numerous items containing pharmaceutical advertising are frequently observed in EDs. Policies restricting pharmaceutical representatives in the ED are associated with reduced pharmaceutical advertising.

  6. Matrix-assisted cocrystallization (MAC) simultaneous production and formulation of pharmaceutical cocrystals by hot-melt extrusion.

    Science.gov (United States)

    Boksa, Kevin; Otte, Andrew; Pinal, Rodolfo

    2014-09-01

    A novel method for the simultaneous production and formulation of pharmaceutical cocrystals, matrix-assisted cocrystallization (MAC), is presented. Hot-melt extrusion (HME) is used to create cocrystals by coprocessing the drug and coformer in the presence of a matrix material. Carbamazepine (CBZ), nicotinamide (NCT), and Soluplus were used as a model drug, coformer, and matrix, respectively. The MAC product containing 80:20 (w/w) cocrystal:matrix was characterized by differential scanning calorimetry, Fourier transform infrared spectroscopy, and powder X-ray diffraction. A partial least squares (PLS) regression model was developed for quantifying the efficiency of cocrystal formation. The MAC product was estimated to be 78% (w/w) cocrystal (theoretical 80%), with approximately 0.3% mixture of free (unreacted) CBZ and NCT, and 21.6% Soluplus (theoretical 20%) with the PLS model. A physical mixture (PM) of a reference cocrystal (RCC), prepared by precipitation from solution, and Soluplus resulted in faster dissolution relative to the pure RCC. However, the MAC product with the exact same composition resulted in considerably faster dissolution and higher maximum concentration (∼five-fold) than those of the PM. The MAC product consists of high-quality cocrystals embedded in a matrix. The processing aspect of MAC plays a major role on the faster dissolution observed. The MAC approach offers a scalable process, suitable for the continuous manufacturing and formulation of pharmaceutical cocrystals. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  7. Characteristics of porous polymer composite columns prepared by radiation cast-polymerization

    International Nuclear Information System (INIS)

    Kumakura, Minoru; Kaetsu, Isao; Asami, Kazuhiro; Suzuki, Shuichi

    1989-01-01

    Porous polymer composite columns having porous structure were prepared by radiation cast-polymerization of hydrophilic monomers at low temperature and their characteristics were studied. The porosity of the polymer increased with decreasing monomer concentration. The elution time of water in the polymer column increased with increasing monomer concentration and with decreasing irradiation temperature. The elution time was dependent on the degree of hydration of the polymer. The polymer with a degree of hydration of 0.2 to 0.4 gave the minimum elution time. The elution time decreased with the addition of porous inorganic substances. (author)

  8. Preparation of polymer composites using nanostructured carbon produced at large scale by catalytic decomposition of methane

    International Nuclear Information System (INIS)

    Suelves, I.; Utrilla, R.; Torres, D.; Llobet, S. de; Pinilla, J.L.; Lázaro, M.J.; Moliner, R.

    2013-01-01

    Polymer-based composites were prepared using different concentrations of nanostructured carbons (NCs), produced by catalytic decomposition of methane (CDM). Four carbonaceous nanostructures were produced using different catalysts (with Ni and Fe as active phases) in a rotary bed reactor capable of producing up to 20 g of carbon per hour. The effect of nanostructured carbon on the thermal and electrical behaviour of epoxy-based composites is studied. An increase in the thermal stability and the decrease of electrical resistivity were observed for the composites at carbon contents as low as 1 wt%. The highest reduction of the electrical resistivity was obtained using multi-walled carbon nanotubes obtained with the Fe based catalysts. This effect could be related to the high degree of structural order of these materials. The results were compared with those obtained using a commercial carbon nanofibre, showing that the use of carbon nanostructures from CDM can be a valid alternative to the commercial nanofibres. -- Highlights: ► Preparation of polymer nanocomposites with enhanced thermal and electrical properties. ► Formation of nanostructured carbon materials with different textural and structural properties at large scale. ► Catalytic decomposition of methane to simultaneously produce hydrogen and carbon materials.

  9. The Use of Ionizing Radiation to Prepare Polymeric Agro-waste Composite for Sandy Soil Application

    International Nuclear Information System (INIS)

    Elhady, M.A.; Elnahas, H.H.; Meligi, G.A.; Ammar, A.H.

    2015-01-01

    Super absorbent hydrogel composite (SHC) by radiation induced crosslinking of polyacrylamide (PAAM)/ rice straw (RS) composite and hydrophilic membrane system based on polyvinyl alcohol (PVA) for possible applications in agricultural field of sandy soil was studied. The factors affecting the quick and capacity for retaining irrigated water of swelling behaviour of prepared hydrogel composite through hydrophilic membrane system and increasing foaming/ porosity of the SHC were studied. The mechanism for this is most likely a prevention of irrigated water to pass through sandy particles for a time ranged from 20 to 40 min for the fluid uptake capacity and swelling of the SHC to take and swelling place without almost