124 research outputs found

    Study on the effect of processing methods on the total polyphenol, 2,3,5,4’-tetrahydroxystilben-2-O-β-D-glucoside, and physcion contents in Fallopia multiflora Thunb. Haraldson root

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    This study investigated the changes in the ingredients in Fallopia multiflora Thunb. Haraldson (FMT) root after processing it with different methods such as soaking, stewing, and steaming or combined methods. The total polyphenol, 2,3,5,4′-tetrahydroxystilben-2-O-β-D-glucoside (THSG), and physcion contents in FMT products after processing were determined using high-performance liquid chromatography (HPLC) and ultraviolet-visible (UV-VIS) methods. The results demonstrated that the processing method and time significantly affected the contents of polyphenol, THSG, and physcion. The physcion and total polyphenol content increased or decreased during processing depending upon the processing time, while the THSG content gradually decreased with an increase in the processing time. The content of physcion (a substance that can cause liver toxicity) was analysed, and the suitable conditions for processing of the FMT products were determined as initial soaking in rice swill for 24 h and subsequent stewing with black beans and water for 12 h

    Activities of the practice teaching organization and vocational teaching facilities in collaboration between the vocational school and units employing

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    The aim of this research is to evaluate the current level of preparation in the organization of practical training as well as the facilities that are available for practical vocational training. The collaboration in education between businesses and vocational schools is an effective strategy. As a result of the rapid transformation that has taken place in the socioeconomic context for professional skills and practical training among employees, a new educational strategy is required to address these demands in order to meet the needs of the workforce. A quantitative method was applied in this research. There were 570 individuals who were chosen at random. According to the findings, the majority of instructors and technicians possessed regulations for conducting practical teaching activities as well as suitable facilities and equipment for the purpose of vocational training. This study presents a number of suggestions for improving the standard of educational institutions as well as the professional growth opportunities available to teachers and lecturers. In addition, facility management and maintenance as well as optimize the instructional facilities and equipment are required

    Some Characteristics And Allopurinol Release Of Carrageenan/ Allopurinol Films Using Polyethylene Oxide As A Dispersion Aid Agent

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    This paper presents the effect of carrageenan (CG) on some characteristics and drug release of allopurinol in the presence of polyethylene oxide (PEO) as a dispersion aid agent. The samples were prepared in film shape by solution method, in which, the content of PEO was changed from 1 wt.% to 5 wt.% and the content of allopurinol was fixed at 10 wt.% in comparison with carrageenan weight. FTIR , FESEM, UV-Vis methods were used to evaluate characterizations and morphology of CG/PEO/allopurinol films

    Evaluating model teacher education and training at Vietnam's universities of technology and education

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    The traditional educational paradigm has become outdated as a result of changes in both the cultural and socioeconomic setting. A more sustainable and acceptable teacher is needed in education. A quantitative study was conducted. 95 administrators and teachers at the University of Technology and Education participated in this study with the aim of analyzing the current status of the teacher education model at the institution. According to the findings of the study, the model for educator preparation has been put into practice primarily through the processes of planning, organizing and directing activities related to educator preparation as well as inspecting and assessing the quality of education. The outcomes of the study indicate that it is essential to design educational programs that are appropriate for the present context. In particular, the study suggests that one of the most important steps towards achieving success is to incorporate technology into teaching methods. The process of educating teachers with the right degree of expertise and skills should be emphasized by educators and policymakers by developing relationships with other educational institutions and allowing teachers to participate in internships

    Using fly ash treated by NaOH and H2SO4 solutions for Hg2+ and Cd2+ ion adsorption.

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    This paper presents the results of adsorption ability of heavy metal ions (Hg2+ and Cd2+) by fly ash (FA) before and after treatment using NaOH and H2SO4 solutions.  Original- and treated FA were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Scanning Electron Microscope (SEM). Specific surface area of FA before and after treatment was calculated by Brunauer – Emmett – Teller (BET) isotherm equation. The obtained results indicated that the morphology and specific surface area of FA changed clearly after treatment by acid or alkaline solutions. Adsorption capacity the Hg2+ and Cd2+ ion by FA was determined from data of UV-Vis spectra. After treatment, the adsorption capacity of ions by FA increased remarkably in comparison with non-treated FA. The FA treated by NaOH solution has the adsorption capacity higher than FA treated by H2SO4 solution. The maximum adsorption capacity of the FA treated by NaOH solution for Cd2+ and Hg2+ ions at room temperature is 28.97 and 14.60 mg/g, respectively. The equilibrium adsorption data were described by the Langmuir and Freundlich isotherm models. The results showed that equilibrium data were fitted well to the Langmuir isotherm. Keywords. Fly ash, treatment, adsorption capacity, heavy metal, Langmuir isotherm

    EFFECTS OF pH OF TEOS SOLUTION ON MORPHOLOGY, THERMAL STABILITY AND MECHANICAL PROPERTIES OF EVA/SILICA NANOCOMPOSITES PREPARED BY SOL-GEL METHOD

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    Ethylene-vinyl acetate copolymer/silica nanocomposites (EVA/silica) were prepared by mixing EVA solutions and tetraethylorthosilicate (TEOS) solutions. Silica particles were formed through sol-gel mechanism with the aid of hydrochloric acid catalyst and dispersed in EVA matrix. The pH of TEOS solutions was controlled from 1 to 6. The influence of pH on formation of silica in EVA matrix, as well as morphology, thermal stability of the nanocomposites were characterized by using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and field emission scanning electron microscopy (FESEM). The FTIR spectra of the nanocomposites clearly indicated the presence of silica in EVA matrix, the shifts of Si-O stretching vibration in the nanocomposites in comparison with pure silica were also observed. This can be explained by hydrogen bonding between SiOH groups of the silica and carbonyl groups of vinyl acetate units in EVA. The TGA results of the nanocomposites showed that silica could improve thermal stability of EVA. Comparing preparation conditions at pH from 1 to 4, it is clear that at the lower pH the higher content of silica was formed in EVA matrix, 3.78; 3.70; 2.50 and 2.09 wt.% respectively. The FESEM images of the nanocomposites showed that nanoscale dispersion of silica was observed obviously at pH of 4 - 6, whereas during their preparation at pH of 1 - 3, the obtained silica particles formed mainly in microscale. The pH also affected on the mechanical properties (tensile strength, elongation at break) of EVA/silica nanocomposites. At pH of 1 - 3, the silica particles formed mainly in larger size, thereby they reduced the mechanical properties of EVA. At pH of 4 - 6, the nanosilica particles had significantly improved mechanical properties of EVA, particularly at pH of 4. The improvement of shear modulus of EVA/silica was also discussed

    EFFECT OF SOME ADDITIVES ON PROCESSBILITY, MECHANICAL PROPERTIES AND MORPHOLOGY OF POLYOXYMETHYLENE/SILICA NANOCOMPOSITES

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    Using additives for polyoxymethylene/silica (POM/SiO2) nanocomposite system is one of suitable solutions to improve processbility, mechanical properties, especially, elongation at break of the material. In this paper, the effect of some additives on the processbility, mechanical properties and morphology of polyoxymethylene/silica (POM/SiO2) nanocomposite was investigated. Zinc stearate (under the commercial name ultraflow – UTF), ethylene-vinyl acetate copolymer (EVA), linear low density polyethylene (LLDPE) and polylactic acid grafted 5 wt.% of polyethylene glycol (PELA) were used as additives for the nanocomposites. The obtained results showed that the preparing process of the POM/SiO2 nanocomposite becam more easily in the presence of PELA, UTF and EVA, corresponding to a lower torque and mixing energy. The PELA caused decrease in the E-modulus or hardness and increase in elongation at break as well as tensile strength of the POM/SiO2 nanocomposites. The SEM images showed that POM and  nanosilica were less compatible in the  nanocomposite using EVA, LLDPE and UTF and they were more compatible with using PELA

    Effect of Graphene-Gold Nanocomposites on the Photocatalytic Activity Of TiO2_2

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    The synthesis of graphene (Gr) - gold (Au) nanoparticle (NP) composite was achieved using continuous ultraviolet wave exposure. The functional groups were investigated with FT-IR spectra. From the Raman spectra, D-band and G-band of graphene were identified. As a result, the uniform deposition of nanometer-sized Au NPs on the graphene sheets was observed from the field emission scanning electron microscope (FE-SEM) images. The photodegradation of methylene blue in aqueous solutions is studied using various photocatalysts, including neat TiO2, Gr/TiO2 and Gr-Au/TiO2 composites. The Gr weight ratio in this research is 2%. The Gr2%-Au0.1%/TiO2 composite had the highest photoactivity

    PREPARATION AND FTIR STUDIES OF PMMA/PVC POLYMER BLENDS, PVC-g-PMMA GRAFT COPOLYMERS AND EVALUATING GRAFT CONTENT

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    This study presents the qualitative and quantitative analyses of Fourier Transform Infrared (FTIR) spectra of poly(methyl methacrylate)/poly(vinyl chloride) blends (PMMA/PVC), as well as PVC-g-PMMA graft copolymers. Graft copolymerizations of methyl mathacrylate (MMA) onto PVC macromolecules were carried out mixture of cyclohexanone/N,N-dimethylformamide as solvents, dibenzoyl peroxide as initiator and nitrogen medium. FTIR spectra of PMMA/PVC blends showed that there were molecular interactions between C=O groups of PMMA and C-Cl groups of PVC. Assignments of infrared absorption bands for specific groups of PMMA/PVC blends have been contributed. Using regression method, linear calibration curve between PMMA mole content and peak areas of C=O groups in FTIR spectra of the blends has been found when C=O peak areas were multiplied by an appropriate factor. PMMA grafted content and total PMMA formed content in PVC-g-PMMA graft copolymers have been evaluated. The results showed that grafted PMMA content was increased since PVC was initiatly dechlorinated by NaOH solution. The grafted PMMA content and total formed PMMA content were 5.05 wt.% and 11.25 wt.% respectively when MMA monomers were grafted onto neat PVC and modified PVC molecules
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