Green tea polyphenol-reduced graphene oxide: derivatisation, reduction efficiency, reduction mechanism and cytotoxicity

This paper reports on the derivatisation, reduction efficiency, reduction mechanism and cytotoxicity of green tea polyphenol-reduced graphene oxide (GTP-RGO). The reduction of graphene oxide (GO) at 90°C using a weight ratio (WR) of GTP/GO=1 resulted in the production of a stable GTP-RGO dispersion in aqueous media, as indicated by the results of ultravioletvisible (UV-Vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and the measurement of zeta potential and electrophoretic mobility. In addition, the results from UV-Vis spectroscopy and X-ray photoelectron spectroscopy (XPS) analysis indicated the comparable reduction ability of GTP relative to the standard reducing agent, hydrazine (N2H4). The removal mechanism of epoxy group from GO via reduction reaction with GTP was investigated by implementing hybrid functional method of Becke-3-parameters-Lee-Yang-Parr (B3LYP)using Gaussian 09 software. The energy and frequency calculations showed that the GO reduction using GTP was more spontaneous and relatively took place faster than the reduction using N2H4, as evidenced by higher entropy change (ΔS) (0.039 kcal/mol·K) and lower Gibbs free energy (ΔG) barrier (58.880 kcal/mol).The cytotoxicities of GO and GTP-RGO samples were evaluated against human colonic fibroblasts cells (CCD-18Co). The GO sample was determined to be toxic even at low concentration (6.25 μg/mL), while the GTP-RGO sample possesses notably low toxicity at the same concentration. The cell culture experiments revealed that the incorporation of GTP led to a decrease in the toxicity of GTP-RGO samples

Pengelolaan Perpustakaan Sekolah

The purpose of research is to describe the management of school\u27s library in Public Junior High School 01 of Pondok Kubang Middle Bengkulu Regency. This research is qualitative descriptive. Subjects in this research are head of library and staffs. The techniques of data collection use observation, structured interview and documentation. The technique of data analysis uses qualitative descriptive method. The results of the research show that this school has done arranging daily work programmes, short term, middle term and long term. For implementing all that work programmes, so the principal establishs the organizational structure of the library managers as the implementers of daily activities as well job description of each part/work function in there. The principal doing evalution with purpose to know the achievement of work from various work programmes have been set that will be as inputs to make improvements of the library management in the next school years

Moving Beyond on Home Country: Developing Global Citizenship Through International Learning in Japan

Globalization causes increasing competition in facing future challenges become more intense. Students as new generation the future need to improve their ability and talents in term of foreign language proficiency, knowledge, intercultural competency to remain viable. Students mobility to abroad as platform to build student's knowledge, skills and character and the experience become more reflective to the workforce needs of today. This paper examine the impact of study abroad program among Malaysian students (N=245) who studying in Japan. Quantitative analysis of the data revealed that strongest influenced study abroad participation that (a) enhanced their tolerance towards people who different culture, (b) enhanced their awareness about cultural difference, (c) influenced their awareness of the importance of diplomatic relations between Malaysia and Japan and (d) increased their desire to engage in employment sector organization or International company and enhanced their Japanese language skills. The result gives an insight that study abroad program will give them opportunity to get out from their own culture and society to explore new worlds, build their own identity and competencies, and challenge ourselves to work or living together with people who have different cultural background. Study abroad program will provide first-hand learning experience to students

Classification of crankshaft remanufacturing using Mahalanobis-Taguchi system

Remanufacturing is a process of returning a used product to at least its original performance with a warranty that is equivalent or better than that of a newly manufactured product. During a preliminary inspection on remanufacturing companies, it was found that there is no end life for crankshafts in terms of classifying it either to remanufacture, repair or reject due to limited information provided by the original equipment manufacturer. The manufacturer did not provide any information on the annual quantity produced and their specifications to the remanufacturing company for the purpose of referencing. Eventually, the distinctiveness of the remanufactured crankshaft from the original cannot be measured. Thus, the aim of this work is to classify crankshafts' end life into recovery operations based on the Mahalanobis-Taguchi System. The crankpin diameter of six engine models were measured in order to develop a scale that represents their population in a scatter diagram. It was found that on the diagram of each engine model, the left distributions from the center point belong to rejected crankshafts, the right distributions belong to re-manufacturable crankshafts, and the upper distributions belong to the repairable crankshafts. The developed scale is believed to be able to help remanufacturers instantaneously identify and match any unknown model crankshafts to its right category. The Ministry of International Trade & Industry (MITI) has established a remanufacturing policy under RMK11 and put in efforts to encourage Malaysians to venture into the remanufacturing business. Thus, this model will help the industry to understand and formulate their decision-making to sustain the end of life of their products

Karyological study of the medicinal plant Papaver rhoeas from northwest of Iran

Karyotype and morphology of mitotic chromosomes in six populations of the medicinal plant Papaver rhoeas collected from various geographical locations of the northwest of Iran were studied. Chromosome characteristics were measured from 10 complete metaphase cells using micromeasure software. The results showed that P. rhoeas is a diploid species with 2n=2x=14 chromosomes. The karyotype consisted of seven pairs of submetacentric chromosomes with one pairs of SAT chromosome (chromosome 2) having a secondary constriction at the end of its short arm. Karyological characteristics of all the materials studied were similar to each other; however, there were some variations on chromosome arm ratios and relative lengths among the different populations. All of the populations are placed on 4A class of Stebbin’s asymmetry categories.Key words: Biodiversity, chromosome analysis, medicinal plants, Papaveraceae

Analisis Perhitungan Daya Dukung Pondasi Footplate Dengan Menggunakan PHP Script

Foundation as we know is part of construction. A purpose of this construction is to continue astructure load to the ground which can endure the load without settlement effect. In order toguarantee the building is on stable condition concerning from structure load or outer force like awind pressure, earthquake, etc and settlement which is more than permission limit unallowed. Toavoid unfunctional foundation structure, foundation must placed on the solid ground which canendure sttructure load without causing excessive settlement. In this era computer technologydevelop quickly. Part of that is programming using PHP script. Programming using script canmake some application to help us in our analyzing dan calculating proccess with interestingdesign , so we can operate it easily. And this program is using PHP script method . Basicallyanalyzing and calculating footplate manually can used up our time. Because on calculating thiswe use a complex method, we need program to analyze and calculate footplate foundation. Tomake a calculation simpler and quicker. Some of manual test result which are found by us ishaving 1% difference with the program. So we consider this program is able to calculate thefootplate foundatio

Antimicrobial activity of fingerroot [Boesenbergia rotunda (L.) Mansf. A.] extract against streptococcus mutans and streptococcus sobrinus

The extract of medicinal plants fingerroot [Boesenbergia rotunda (L.) Mansf. A.] obtained using 100% methanol was tested for antibacterial activity against two major pathogen of dental carries namely Streptococcus mutans KCCM 3309 and Streptococcus sobrinus KCCM 3207. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time-kill curve on S. mutans and S. sobrinus were analyzed using Clinical and Laboratory Standard Institutes (CLSI) methods. Preliminary antimicrobial screening showed the mean zones of inhibition for S. mutans (9.0 mm) and S. sobrinus (8.0 mm). MIC value obtained for S. sobrinus and S. mutans was 313 μg/ml while the MBC values were 313 μg/ml (S.mutans) and 625 μg/ml (S. sobrinus). Time-kill curve were obtained at concentrations of 0xMIC, 1/2xMIC, 1xMIC, 2xMIC, 4xMIC and 8xMIC. S. mutans was found to be more susceptible to the fingerroot extract than S. sobrinus. Time - kill curve showed that the concentration of 8xMIC was able to kill 99.9% of S. mutans after 4 hours treatment. These results may be useful for developing fingerroot B. rotunda as natural anticariogenic agent in toothpaste or any oral care products such as mouthwash in treatment of dental carries, sore throat and flaming gums