Exploring The Relationships Among Social Benefits, Online Social Networks Dependency, Satisfaction and Youth's Habit Formation

Online social network is one of the biggest phenomenon of the Internet, which has attracted many marketers and psychologists to understand social network users' behavior. Recognizing lack of theoretical and empirical attention has been given to this field especially in Vietnam market, this study is conducted to examine the relationships among social benefits, online social network dependency, satisfaction and youth's habit formation in the context of Facebook. The findings of the study of 200 Facebook users indicate that the interrelationship among four factors of social benefits, online social network dependency, satisfaction and habit formation are affected each other. Indeed, online social network dependency among the youth whose age range from 16 to 24 years old is significantly affected by social benefits factor and also lead to the formation of habit. In addition, satisfaction plays a role in determining the habitual use of Facebook. This paper contains a discussion of theoretical and practical implication in marketing and psychology field

Free vibration of functionally graded sandwich plates with stiffeners based on the third-order shear deformation theory

In this paper, the free vibration of functionally  sandwich grades plates with stiffeners is investigated by using the finite  element method. The material properties are assumed to be graded in the  thickness direction by a power-law distribution. Based on the third-order  shear deformation theory, the governing equations of motion are derived from  the Hamilton's principle. A parametric study is carried out to highlight the  effect of material distribution, stiffener parameters on the free  vibration characteristics of the plates

Efficient and fast degradation of 4-nitrophenol and detection of Fe(III) ions by Poria cocos extract stabilized silver nanoparticles

In this study, a simple and environment-friendly method has been successfully applied for the production of silver nanoparticles (AgNPs) using Poria cocos extract. The reaction time of 60 min, the temperature of 90◦ C, and silver ion concentration of 2.0 mM were identified as the best condition for the PC-AgNPs fabrication. The XRD analysis confirmed a highly crystalline face-centered cubic structure of the biosynthesized material. The PCAgNPs were presented separately in a spherical shape with an average crystal size of 20 nm, as endorsed by the TEM and FE-SEM measurement

Chemical Components of Essential Oils From the Leaves of Seven Species Belonging to Rutaceae Family from Binh Chau-Phuoc Buu Nature Reserve, Vietnam

Several plant species of the Rutaceae family are medicinal plants, oil bearing and food crops. To provide more information for utilization of some species of this family in Binh Chau-Phuoc Buu Nature Reserve, we extracted essential oils from the leaves of seven species of the Rutaceae family: Acronychia pedunculata (L.) Miq., Atalantia citroides Pierre ex Guillaumin, Clausena excavata Burm.f., Glycosmis pentaphylla (Retz.) DC., Luvunga scandens (Roxb.) Buch.-Ham. ex Wight & Arn, Melicope pteleifolia (Champ. ex Benth.) T.G. Hartley, and Micromelum sp., via hydrodistillation, and identified their components using GC/MS analysis. A total of 60 compounds were identified from essential oils of seven species. The main components of the essential oils isolated from five species, including A. pedunculata, C. excavata, M. pteleifolia, G. pentaphylla, and Micromelum sp., were caryophyllene (57.63% and 55.41% in A. pedunculata and C. excavata, respectively), 1,9-decadiyne (32.59%, M. pteleifolia), β-ocimene (23.10%, G. pentaphylla), and 3-carene (58.03%, Micromelum sp.). Additionally, this study revealed the chemical composition of essential oils of L. scandens and A. citroides for the first time. The main constituent of A. citroides was 7-oxabicyclo[4.1.0] heptane, 3-oxiranyl- (53.91%) and that of L. scandens was caryophyllene (34.66%). These findings provide the basis for further application of these species in medicine

Nanomaterial for Adjuvants Vaccine: Practical Applications and Prospects

Vaccines contain adjuvants to strengthen the immune responses of the receiver against pathogen infection or malignancy. A new generation of adjuvants is being developed to give more robust antigen-specific responses, specific types of immune responses, and a high margin of safety. By changing the physical and chemical properties of nanomaterials, it is possible to make antigen-delivery systems with high bioavailability, controlled and sustained release patterns, and the ability to target and image. Nanomaterials can modulate the immune system so that cellular and humoral immune responses more closely resemble those desired. The use of nanoparticles as adjuvants is believed to significantly improve the immunological outcomes of vaccination because of the combination of their immunomodulatory and delivery effects. In this review, we discuss the recent developments in new adjuvants using nanomaterials. Based on three main vaccines, the subunit, DNA, and RNA vaccines, the possible ways that nanomaterials change the immune responses caused by vaccines, such as a charge on the surface or a change to the surface, and how they affect the immunological results have been studied. This study aims to provide succinct information on the use of nanomaterials for COVID-19 vaccines and possible new applications

Orange Peel Essential Oil Nanoemulsions Supported by Nanosilver for Antibacterial Application

This study is devoted to the synthesis of King Orange peel essential oil in water nanoemulsions combined with nanosilver by ultrasonic method supported by mechanical stirring for antibacterial application. The samples were characterized by Gas chromatography-mass spectrometry (GC-MS), Ultraviolet–visible (UV-Vis), Transmission electron microscopy (TEM), and Dynamic light scattering (DLS) methods. According to the above-experimental results, it was found that the emulsions based on orange essential oil (without nanosilver) and the ones combined with nanosilver have the average particle size from 66.2 nm and 42.9 nm, respectively. The obtained nanoemulsions were also tested to examine their antibacterial ability against Escherichia coli (E. coli) by the disc diffusion method. It has been also found that nanoemulsions based on orange essential oil supported by nanosilver have the superior antibacterial ability, compared with individual components of the materials

Results of magnetotelluric survey for studying geothermal system in the Bang area, Quang Binh province

This paper presents the first results from the application of magnetotelluric method (MT) using the new equipment MTU 2000 (Canada) and analysis software to investigate the structure of geothermal area around the Bang hot water source (Quang Binh province). Results of data analysis by MT 1D and 2D models to a depth of 20 km show low resistivity zone in the southwest of Bang hot water (100°C) and allow for interpreting the structural elements of athehydro- geothermal system. This includes a very low resistivity layer at depth of 2 km suggesting a clay cap (heat resistive shield), a relatively low resistivity zone at depth ≥ 2 km reflecting  fractured rocks containing geothermal fluid and hot steam. A lower resistivity body at depth of 12-14 km located about 1.5 km from the hot water source indicates the existence of a heat source or a hot mass of intrusive magma., commonly thought to be sources of typical hydro- geothermal systems potential for energy exploitation. The obtained results not only provide new information for better understanding geothermal resource in the surveyed area, but also point out the methods and technology needed to improve the effectiveness for assessing potential of geothermal resources elsewhere in Vietnam.ReferencesBản đồ Địa chất và khoáng sản Việt Nam tỷ lệ 1:1.000.000. Cục Địa chất và Khoáng sản Việt Nam xuất bản 2004. Lưu trữ Địa chất. Cumming W., 2009: Geothermal resource conceptual models using surface exploration data. In: proceedings, 34th workshop on geothermal reservoir engineering, Stanford University. Data Processing User guide. Phoenix Geophysic Ltd. 2005, 201p. Di Pippo R., 2012: Geothermal Power plant. Principles, applications, case studies. 3rd edition. Elseverdirect, 579p. Doan Van Tuyen, Tran Anh Vu, Nguyen Thi Kim Thuong, 2014: Geochemical Characteristics of Geothermal Hot Water Sources on the Territory of Vietnam. Proceeding, Thirty-Eighth Workshop on Geothermal Reservoir Engineering Stanford University, Stanford, California, February 24-26, 2014 SGP-TR-202. Duchkov A.D., Nguyen Trong Yem, Dinh Van Toan, and Trinh Viet Bac, 1992: First estimations of heat flow in northern Vietnam. Soviet Geology and Geophysics, Vol. 33, No. 5, pp 92-96. Flynn T., Quy H. H., 1997: Assessment of the geothermal resources of Socialist Republic of Vietnam. Geothermal resources Council Transactions, vol.21, 341-345. IGA report, 2013: Geothermal Exploration best practices: A Guide to resource data collection, analysis, and presentation for Geothermal projects. He Lijuan, 1999: Analysis of heat flow along a transect across the South China Sea. Geothermal Training Programme, Reports 1999, Number 5, 125-140. Hoang Huu Quy, 1998: Overview of the Geothermal potential of Vietnam. Geothermics, Vol.27, n.1, 109-115. Koenig J. et al., 1981: Evaluation of the potential for Geothermal Energy Resources in the SR of Vietnam. Berkeley, CA. Kulinich G.G., Zabolotnikov A.A, Markov Yu., 1989: Cenozoic evalution of the Earth crust and orogeny in South- Eastern Asia (Tiếng Nga). MTU2000: User guide. Phoenix Geophysic Ltd. 2000, 36p. Munoz Gerard, 2014: Exploring for Geothermal Resources with Electromagnetic Methods. Surv Geophys (2014) 35:101-122, Springer, DOI 10.1007/s10712-013-9236-0. Pellerin et al., Johnston M, Hohmann W., 1996: A numerical evaluation of electromagnetic methods in geothermal exploration. Geophysics 61(1996):121-130. Thomas Mathews, et al., 2008: Study on the sozio-economic framework for the use Geothermal energy in Vietnam. Proceedings of the 8th Asian Geothermal Symposium, Hanoi. Trần Huyên, Trương Minh, Nguyễn Tiến Bào, 1999: Về chế độ địa nhiệt ở các bể trầm tích thềm lục địa Việt Nam. Tạp chí Kinh tế Địa chất và Nguyên liệu khoáng. Cục Địa chất và Khoáng sản Việt Nam. Số 18 tháng 2 năm 1999, tr.16-25. Võ Công Nghiệp (chủ biên), 1998: Danh bạ các nguồn nước khoáng và nước nóng Việt Nam. Cục Địa chất và Khoáng sản Việt Nam. Hà Nội, 300tr. Zhdanov M., 2009: Geophysical Electromagnetic Theory and Methods. Methods in Geochemistry and Geophysics, Volume 43. ISSN: 0076-6895 Elsevier, 831pp. WinGLink User guide. Geosystem 200, 182p. www.geosystem.net.