We present alternative methods to oxidize a graphene layer through ultraviolet (UV)/ozone (O3)-treatment, resulting in chemically homogeneous graphene oxide (GO), and then to reduce GO through UV-irradiation. Both UV/O3-treatment and UV-irradiation were performed at room temperature in atmospheric pressure for only several minutes and did not involve any wet chemical treatments. The quantity of doped oxygen, determined using X-ray photoelectron spectroscopy, increased after oxidation and decreased after reduction. The quantity of doped oxygen reached its maximum, which was around 20% (approximately one oxygen atom in every five or six carbon atoms) after performing UV/O3-treatment for 6 to 10 min. Conducting UV/O3-treatment for around 6 or 10 min resulted in a chemically homogeneous GO surface with only oxygen epoxide groups on the graphene surface. Performing UV/O3-treatment beyond 15 min as well as multiple turns of UV/O3-treatment could lead to the formation of defects and carbonyl groups on graphene lattice. The oxygen quantity gradually decreased after conducting 6 min UV-irradiation several times, indicating that the resulting GO was successfully reduced. How the doped oxygen atoms distributed on graphene surface was directly investigated using scanning tunneling microscopy. Moreover, changes in electrical properties of three identical single-layer graphene field-effect transistors (G-FETs) after being oxidized through UV/O3-treatment were investigated. The electron mobility of G-FETs decreased after oxidation; however, it recovered after irradiating the oxidized G-FETs with UV-lights, indicating that GO was successfully reduced nonthermally through UV-irradiation. The reversibility in electron mobility was confirmed even after conducting redox processes twice. Furthermore, the reversibility of oxidation was also verified from the graphene lattice disorder point of view using Raman spectroscopy. We concluded that UV/O3-treatment produced chemically homogeneous GO that is nonthermally reversible through UV-irradiation, and changes in the electron mobility were nonthermally reversible also.

An alternative way to construct a stable p-n junction on graphene-based field effect transistor (G-FET) through physical adsorption of ferritin (spherical protein shell) is presented. The produced p-n junction on G-FET could also operate through water-gate. Native ferritins are known to be negatively charged in wet condition; however, we found that native negatively charged ferritins became positively charged after performing electron beam (EB)-irradiation. We utilized this property to construct p-n junction on G-FET. We found also that EB-irradiation could remove the effect of charged impurity adsorbed on graphene layer, thus the Dirac point was adjusted to gate voltage Vg = 0.

Changes in electrical properties of a bilayer graphene-based field-effect transistor (G-FET) after being oxidized through ultraviolet (UV)/ozone (O3) treatment are presented. A decrease in conductivity and carrier mobility was observed after oxidation. However, electrical properties recovered after annealing oxidized G-FET with H2/Ar, indicating that oxidation with UV/O3 treatment was thermally reversible. Raman spectroscopy was conducted to verify that no defects were introduced after oxidation. The existence of chemical bonds between oxygen and graphene was confirmed from the X-ray photoelectron spectroscopy. Moreover, we found that graphene's sheet resistance increased after oxidation. Nevertheless, contact resistivity at graphene-Au/TiN electrode interface remained unchanged.

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Saat ini masyarakat banyak beralih berbelanja di pasar modern daripada di pasar tradisional, karena pasar modern cenderung lebih bersih, serta dikelola lebih profesional.  Selain pasar modern, pasar online menjadi salah satu ancaman keberadaan pasar tradisional.  Agar pasar tradisional tidak tenggelam dan tertinggal dengan pasar modern dan pasar online, maka pedagang pasar di pasar tradisional harus mengikuti perkembangan jaman terutama dengan  berkembangnya teknologi internet sekarang ini dengan  memasuki pasar di dunia maya yang disebut sebagai electronic commerce (e-commerce). Saat ini terdapat peluang yang besar untuk melakukan pemasaran dengan memanfaatkan teknologi internet yaitu melalui media sosial. Melalui media social, bisnis mendapatkan akses berkaitan dengan sumber daya yang lebih besar dan lebih luas bagi pemilik bisnis. Penelitian ini merupakan penelitian kausal. Obyek penelitian ini adalah seluruh pedagang yang ada di Pasar Tradisional, dengan pengambilan sampel menggunakan teknik random cluster sampling (random area sampling). Data dikumpulkan  menggunakan kuesioner. Pengujian hipotesis menggunakan analisis deskriptif, pengujian asumsi klasik, analisis regresi berganda, pengujian hipotesis dan analisis koefisien determinasi.  Berdasarkan analisis data dapat disimpulkan bahwa kemampuan e-commerce berpengaruh tidak signifikan terhadap kinerja pemasaran, promosi di media sosial berpengaruh signifikan terhadap kinerja pemasaran serta  kemampuan e-commerce dan promosi di media sosial secara simultan berpengaruh signifikan terhadap kinerja pemasaran