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This study was conducted to synthesize Gallium Oxide nanomaterials from its bulk form using a low-cost and repeatable method and investigate on its potential as sensing element for Ethanol (EtOH). Horizontal Vapor Phase Growth (HVPG) Technique was utilized to synthesize monoclinic Gallium Oxide (β-Ga2O3) nanowires. Images obtained from the Scanning Electron Microscope showed high density nanowires specifically in the area of highest temperature gradient. SEM also showed that the grown structures using HVPG Technique were at the nanoscale with diameters ranging from 51.60 to 908.38 nm. Higher surface-to-volume ratio was also noted in the area of highest temperature gradient which was subjected to an applied magnetics field. The Gallium to Oxygen ratio was verified via EDX to be approximately 2:3 which agrees with the atomic ratio of Ga2O3. The monoclinic structure of the grown nanomaterials was investigated using Raman Spectroscopy. Raman peaks of the samples were at 199 and 486 cm−1 which was accounted to the presence of two Raman-active modes of the b-polymorph of Ga2O3. The Raman spectrum of the grown nanowires confirmed that the material is monoclinic in structure and belongs to C2/m space group. The I-V Curve of the grown nanowires were also determined using two-point probe which illustrates a non-linear curve similar to that of a semiconductor material. Furthermore, additional fundamental properties such as resistivity and specific conductance of the materials were also determined via van der Pauw Technique. Results showed that the material has high specific conductance and low resistivity. The synthesized nanomaterial was responsive to Ethanol vapor. Exposure to the said compound increased its resistance. Graphs showed that there is a significant increase in the resistance after exposure to ethanol vapor.
H M B Dela Torre; G N C Santos. Synthesis and Characterization of Monoclinic Gallium Oxide Nanomaterials for High-Concentration Ethanol Vapor Detection. IOP Conference Series: Materials Science and Engineering 2020, 739, 012031 .
AMA StyleH M B Dela Torre, G N C Santos. Synthesis and Characterization of Monoclinic Gallium Oxide Nanomaterials for High-Concentration Ethanol Vapor Detection. IOP Conference Series: Materials Science and Engineering. 2020; 739 (1):012031.
Chicago/Turabian StyleH M B Dela Torre; G N C Santos. 2020. "Synthesis and Characterization of Monoclinic Gallium Oxide Nanomaterials for High-Concentration Ethanol Vapor Detection." IOP Conference Series: Materials Science and Engineering 739, no. 1: 012031.
Purpose The purpose of this paper is to explore the disparities in social awareness and use of the internet between urban and rural school children in the North of Vietnam. Design/methodology/approach A total of 525 pupils, aged 9-11 years old, randomly selected from seven urban and rural schools, who are internet users, participated in the study and consented to responding to a questionnaire adapted from an equivalent European Union study. A comparative statistical analysis of the responses was then carried out, using IBM SPSS v21, which consisted of a descriptive analysis, an identification of personal self-development opportunities, as well as issues related to pupils’ digital prowess and knowledge of internet use and internet safety, including parental engagement in their offspring’s online activities. Findings The study highlights the fact that children from both the urban and rural regions of the North of Vietnam mostly access the internet from home, but with more children in the urbanized areas accessing it at school than their rural counterparts. Although children from the rural areas scored lower on all the internet indicators, such as digital access and online personal experience and awareness, there was no disparity in awareness of internet risks between the two sub-samples. It is noteworthy that there was no statistically significant gender difference towards online activities that support self-development. In relation to safe internet usage, children are likely to seek advice from their parents, rather than through teachers or friends. However, they are not yet provided with an effective safety net while exposing themselves to the digital world. Originality/value Although the Vietnamese national curriculum on the computer science subject does not explicitly cover the use of the internet and its related aspects, the majority of children who took part in this study claimed to have used the internet in their learning activities. This emphasises the urgent need for the Ministry of Education and educators in the country to not only improve information and communication technology facilities in schools, but also to revise the computer science curriculum in order to provide a supportive environment for learning development and collectively advocate the dynamics of internet use in order to ensure safe access and use by the children.
Quynh Nguyen; Raouf N.G. Naguib; Ashish K. Das; Michail Papathomas; Edgar A. Vallar; Nilmini Wickramasinghe; Gil Nonato Santos; Maria Cecilia Galvez; Viet Anh Nguyen. Primary education in Vietnam and pupil online engagement. International Journal of Educational Management 2018, 32, 71 -83.
AMA StyleQuynh Nguyen, Raouf N.G. Naguib, Ashish K. Das, Michail Papathomas, Edgar A. Vallar, Nilmini Wickramasinghe, Gil Nonato Santos, Maria Cecilia Galvez, Viet Anh Nguyen. Primary education in Vietnam and pupil online engagement. International Journal of Educational Management. 2018; 32 (1):71-83.
Chicago/Turabian StyleQuynh Nguyen; Raouf N.G. Naguib; Ashish K. Das; Michail Papathomas; Edgar A. Vallar; Nilmini Wickramasinghe; Gil Nonato Santos; Maria Cecilia Galvez; Viet Anh Nguyen. 2018. "Primary education in Vietnam and pupil online engagement." International Journal of Educational Management 32, no. 1: 71-83.
In this study, nanosilver-graphene composites were successfully manufactured via the horizontal vapor phase growth (HVPG) technique. A quartz tube loaded with the starting material, equal masses silver (Ag) powder and multi-layer graphene (Ge), was evacuated to ~10-6 Torr, sealed, and then baked at 1200°C for 6 hours, with its orientation such that a horizontal temperature gradient was generated across the tube. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) analysis revealed variations in the structure and composition of the nanomaterials deposited on different regions of the tube, and the diameter of the nanomaterials was found to decrease with decreasing temperature.
Muhammad Akhsin Muflikhun; Gwen B. Castillon; Gil Nonato C. Santos; Alvin Y. Chua. Micro and Nano Silver-Graphene Composite Manufacturing via Horizontal Vapor Phase Growth (HVPG) Technique. Materials Science Forum 2017, 901, 3 -7.
AMA StyleMuhammad Akhsin Muflikhun, Gwen B. Castillon, Gil Nonato C. Santos, Alvin Y. Chua. Micro and Nano Silver-Graphene Composite Manufacturing via Horizontal Vapor Phase Growth (HVPG) Technique. Materials Science Forum. 2017; 901 ():3-7.
Chicago/Turabian StyleMuhammad Akhsin Muflikhun; Gwen B. Castillon; Gil Nonato C. Santos; Alvin Y. Chua. 2017. "Micro and Nano Silver-Graphene Composite Manufacturing via Horizontal Vapor Phase Growth (HVPG) Technique." Materials Science Forum 901, no. : 3-7.
We report on the fabrication of a graphene/titanium dioxide nanocomposite (TiO2-G) and its use as an effective electrode material in an amperometric hypoxanthine (Hx) sensor for meat freshness evaluation. The nanocomposite was characterized by TEM, XRD, FTIR, XPS, TGA, BET, and CV using the redox couples [Fe(CN)6]−3/−4 and [Ru(NH3)6]+3/+2 respectively. The TiO2/G nanocomposite offered a favorable microenvironment for direct electrochemistry of xanthine oxidase (XOD). The fabricated Nafion/XOD/TiO2-G/GCE sensor exhibited excellent electro catalytic activity towards Hx with linear range of 20 μM to 512 μM, limit of detection of 9.5 μM, and sensitivity of 4.1 nA/μM. In addition, the biosensor also demonstrated strong anti-interference properties in the presence of uric acid (UA), ascorbic acid (AA) and glucose. Minimal interference of xanthine (Xn) was observed at ~7%. Moreover, the biosensor showed good repeatability (4.3% RSD) and reproducibility (3.8% RSD). The reported biosensor was tested towards the detection of Hx in pork tenderloins stored at room temperature for seven days. There was a good correlation (r=0.9795) between biosensor response and measurements obtained by a standard enzymatic colorimetric method. The TiO2-G nanocomposite is therefore an effective electrode material to be used in electrochemical biosensors to assess the freshness of meat.
Jasmine Angelie Albelda; Aytekin Uzunoglu; Gil Nonato C. Santos; Lia A. Stanciu. Graphene-titanium dioxide nanocomposite based hypoxanthine sensor for assessment of meat freshness. Biosensors and Bioelectronics 2016, 89, 518 -524.
AMA StyleJasmine Angelie Albelda, Aytekin Uzunoglu, Gil Nonato C. Santos, Lia A. Stanciu. Graphene-titanium dioxide nanocomposite based hypoxanthine sensor for assessment of meat freshness. Biosensors and Bioelectronics. 2016; 89 ():518-524.
Chicago/Turabian StyleJasmine Angelie Albelda; Aytekin Uzunoglu; Gil Nonato C. Santos; Lia A. Stanciu. 2016. "Graphene-titanium dioxide nanocomposite based hypoxanthine sensor for assessment of meat freshness." Biosensors and Bioelectronics 89, no. : 518-524.
Bangalore is one of India's fastest growing metropolises and, although benefiting economically due to its fast development, has a rapidly deteriorating environment. This paper provides a critical analysis of the air pollution trend in the city over the period 2006-2013 at six specific locations where measurements have been consistently recorded. It also discusses the potential health implications pertaining to exceeding levels of pollutants where these are applicable. In order to attain informed decisions on the protection of the health of populations from elevated levels of air pollution, an understanding of spatial-temporal variance of air pollutant patterns is necessary. The study highlights the fact that Bangalore and other similar developing cities do not have an adequate number of fixed monitoring stations that could provide a complete coverage of the air pollution levels for the entire city. It is suggested that this can be overcome by using geospatial interpolation techniques that provide a complete coverage of the levels of pollutants, as well as assist in mapping health characteristics of the population, in order to reach evidence-based decisions and target effective interventions.
Tuan Nghia Ton; Nilmini Wickramasinghe; Mohyi Shaker; Edgar A. Vallar; Gil Nonato C. Santos; Norlaily Yaacob; Ian M. Marshall; Raouf N.G. Naguib; Nigel Trodd; Hewa Balisane; Quynh T. Nguyen; Anitha Chinnaswamy; Maria Cecilia D. Galvez. Air pollution in Bangalore, India: an eight-year trend analysis. International Journal of Environmental Technology and Management 2016, 19, 177 .
AMA StyleTuan Nghia Ton, Nilmini Wickramasinghe, Mohyi Shaker, Edgar A. Vallar, Gil Nonato C. Santos, Norlaily Yaacob, Ian M. Marshall, Raouf N.G. Naguib, Nigel Trodd, Hewa Balisane, Quynh T. Nguyen, Anitha Chinnaswamy, Maria Cecilia D. Galvez. Air pollution in Bangalore, India: an eight-year trend analysis. International Journal of Environmental Technology and Management. 2016; 19 (3/4):177.
Chicago/Turabian StyleTuan Nghia Ton; Nilmini Wickramasinghe; Mohyi Shaker; Edgar A. Vallar; Gil Nonato C. Santos; Norlaily Yaacob; Ian M. Marshall; Raouf N.G. Naguib; Nigel Trodd; Hewa Balisane; Quynh T. Nguyen; Anitha Chinnaswamy; Maria Cecilia D. Galvez. 2016. "Air pollution in Bangalore, India: an eight-year trend analysis." International Journal of Environmental Technology and Management 19, no. 3/4: 177.
Bangalore is one of India's fastest growing metropolises and, although benefiting economically due to its fast development, has a rapidly deteriorating environment. This paper provides a critical analysis of the air pollution trend in the city over the period 2006-2013 at six specific locations where measurements have been consistently recorded. It also discusses the potential health implications pertaining to exceeding levels of pollutants where these are applicable. In order to attain informed decisions on the protection of the health of populations from elevated levels of air pollution, an understanding of spatial-temporal variance of air pollutant patterns is necessary. The study highlights the fact that Bangalore and other similar developing cities do not have an adequate number of fixed monitoring stations that could provide a complete coverage of the air pollution levels for the entire city. It is suggested that this can be overcome by using geospatial interpolation techniques that provide a complete coverage of the levels of pollutants, as well as assist in mapping health characteristics of the population, in order to reach evidence-based decisions and target effective interventions.
Anitha K. Chinnaswamy; Maria Cecilia D. Galvez; Hewa Balisane; Quynh Nguyen; Raouf Naguib; Nigel Trodd; Ian M. Marshall; Norlaily Yaacob; Gil Nonato C. Santos; Edgar A. Vallar; Mohyi Shaker; Nilmini Wickramasinghe; Tuan Nghia Ton. Air pollution in Bangalore, India: an eight-year trend analysis. International Journal of Environmental Technology and Management 2016, 19, 177 .
AMA StyleAnitha K. Chinnaswamy, Maria Cecilia D. Galvez, Hewa Balisane, Quynh Nguyen, Raouf Naguib, Nigel Trodd, Ian M. Marshall, Norlaily Yaacob, Gil Nonato C. Santos, Edgar A. Vallar, Mohyi Shaker, Nilmini Wickramasinghe, Tuan Nghia Ton. Air pollution in Bangalore, India: an eight-year trend analysis. International Journal of Environmental Technology and Management. 2016; 19 (3/4):177.
Chicago/Turabian StyleAnitha K. Chinnaswamy; Maria Cecilia D. Galvez; Hewa Balisane; Quynh Nguyen; Raouf Naguib; Nigel Trodd; Ian M. Marshall; Norlaily Yaacob; Gil Nonato C. Santos; Edgar A. Vallar; Mohyi Shaker; Nilmini Wickramasinghe; Tuan Nghia Ton. 2016. "Air pollution in Bangalore, India: an eight-year trend analysis." International Journal of Environmental Technology and Management 19, no. 3/4: 177.
SnO2-Ag composite nanomaterials of mass ratio 1:4, 2:3, 3:2 and 4:1 were fabricated and tested for toxicity to E. coli using the pour-plate technique. The said nanomaterials were mixed with laminating fluid and then coated on glass slides. The intensity of UVA transmitted through the coated glass slides was measured. Results revealed that the 1:4 ratios of SnO2-Ag composite nanomaterials have the optimum toxicity to E. coli. Furthermore, the glass slides coated with SnO2 nanomaterial showed the lowest intensity of transmitted UVA.
Gil Nonato C. Santos; Eduardo B. Tibayan; Gwen B. Castillon; Elmer Estacio; Takashi Furuya; Atsushi Iwamae; Kohji Yamamoto; Masahiko Tani. Tin Oxide-Silver Composite Nanomaterial Coating for UV Protection and Its Bactericidal Effect on Escherichia coli (E. coli). Coatings 2014, 4, 320 -328.
AMA StyleGil Nonato C. Santos, Eduardo B. Tibayan, Gwen B. Castillon, Elmer Estacio, Takashi Furuya, Atsushi Iwamae, Kohji Yamamoto, Masahiko Tani. Tin Oxide-Silver Composite Nanomaterial Coating for UV Protection and Its Bactericidal Effect on Escherichia coli (E. coli). Coatings. 2014; 4 (2):320-328.
Chicago/Turabian StyleGil Nonato C. Santos; Eduardo B. Tibayan; Gwen B. Castillon; Elmer Estacio; Takashi Furuya; Atsushi Iwamae; Kohji Yamamoto; Masahiko Tani. 2014. "Tin Oxide-Silver Composite Nanomaterial Coating for UV Protection and Its Bactericidal Effect on Escherichia coli (E. coli)." Coatings 4, no. 2: 320-328.