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

Kajian Pelaksanaan Penyuluhan dan Partisipasi Perempuan pada Kegiatan Pertanian Tanaman Palawija di Desa Suka Damai, Kecamatan Dramaga, Kabupaten Bogor

The study of the implementation studies of extension and women\u27s participation in Agricultural Crops Activity in Sukadamai Village, District Dramaga, Bogor Regency aimed to analyze the level of women participation in agricultural crops activity; to analyze the level of women participation in agricultural crops extension activities; to identify the institusional of agricultural extension; to analyze the influence factor in the ability of the extension worker to improve women\u27s participation in agricultural crops extension activities. Sampling was done randomly respondents. Number of study sample as many as 30 people. Primary data obtained through the use of closed questionnaires, interviews with the use of an open questionnaire, focus group discussion (FGD), and observations. Stages of data analysis is divided into stages of data description and hypothesis testing phase. Results showed that the women participation in agricultural crops extension activities in high category is 53,3%; the women participation in agricultural extension activities in the low category is 50%; the existence of agricultural extension workers is recognized by women are civil servants extension workers and independent extension workers; the method of agricultural extension and the attidude of extension workers affect significantly (p < 0,05) to women\u27s participation in agricultural extension activities

Pengaruh Penilaian Kinerja Perusahaan terhadap Return Saham

Penelitian ini bertujuan untuk melihat apakah terdapat pengaruh Penilaian kinerjaPerusahaan yang diukur dengan rasio PER terhadap return saham. Metode penelitian inimenggunakan metode kuantitatif. Pengujian hipotesis dilakukan menggunakan modelregresi. Sampel menggunakan Perusahaan terbaik menurut OJK pada tahun 2013 danmengambil data Perusahaan tersebut dalam kurun waktu selama 2009-2013. Hasilpenelitian ini memberikan bukti empiris bahwa kinerja Perusahaan yang diproksi denganrasio PER berpengaruh positif dan signifikan terhadap Return Saham

Informal institutions and managers’ earnings management choices: evidence from IFRS-adopting countries

In this study, we investigate the role of informal institutions (religiosity and culture) in determining managers’ choices of earnings management methods (accruals vs. real activities), after controlling for formal institutions (investor protection, enforcement quality and equity market development). Using an ethical perspective, we find that managers tend to choose an earnings management strategy that meets the prevailing social (informal) norms of the environment where the firm is headquartered. Specifically, our analysis shows that firms domiciled in countries with strong religious adherence and highpower- distance cultures prefer to manage their earnings ‘upwards’ through real activities rather than accruals. Overall, our results suggest that informal institutions determine managers’ earnings management choices at least as strongly as formal institutions do. It would therefore be misleading to analyze managers’ choices in managing earnings solely from the formal rules perspective without considering the role of informal constraints or vice versa

Editorial message

Handheld computing is an emerging mobile computing paradigm that promotes using handheld wireless devices (or mobile devices) such as cellular phones and Personal Digital Assistants (PDAs) to accomplish various computing tasks. As handheld devices continue to appear in many forms with diverse functionalities, handheld computing will become the dominant computing paradigm in many fields including education, enterprises, and healthcare

Engineering Wireless Mobile Applications

Conventional desktop software applications are usually designed, built, and tested on a platform similar to the one on which they will be deployed and run. Wireless mobile application development, on the other hand, is more challenging because applications are developed on one platform (like UNIX or Windows) and deployed on a totally different platform like a cellular phone. While wireless applications can be much smaller than conventional desktop applications, developers should think in small terms of the devices on which the applications will run and the environment in which they will operate instead of the amount of code to be written. This paper presents a systematic approach to engineering wireless application and offers practical guidelines for testing them. What is unique about this approach is that it takes into account the special features of the new medium (mobile devices and wireless networks), the operational environment, and the multiplicity of user backgrounds; all of which pose new challenges to wireless application development

Special track on handheld computing

Handheld computing is an emerging mobile computing paradigm that promotes using handheld wireless devices (or mobile devices) such as cellular phones and Personal Digital Assistants (PDAs) to accomplish various computing tasks. As handheld devices continue to appear in many forms with diverse functionalities, handheld computing will become the dominant computing paradigm in many fields including education, enterprises, and healthcare