Theoretical and experimental analysis of the exact receptance function of a clamped-clamped beam with concentrated masses

This paper establishes the exact receptance function of a clamped-clamped beam carrying concentrated masses. The derivation of exact receptance and the numerical simulations are provided. The proposed receptance function can be used as a convenient tool for predicting the dynamic response at arbitrary point of the beam acted by a harmonic force applied at arbitrary point. The influence of the concentrated masses on the receptance is investigated. The numerical simulations show that peak in the receptance will decrease when there is a mass located close to that peak position. The numerical results have been compared to the experimental results to justify the theory

Numerical and experimental studies for crack detection of a beam-like structure using element stiffness index distribution method

In this paper, numerical and experimental studies for crack detection of structures using "element stiffness index distribution" are presented. The element stiffness index distribution is defined as a vector of norms of sub-matrices corresponding to element stiffness matrices calculated from the reconstructed global stiffness matrix of the beam. When there is a crack at an element, the element stiffness index of that element will be changed. By inspecting the change in the element stiffness index distribution, the crack can be detected. A significant peak in the element stiffness index distribution is the indicator of the crack existence. The crack location is determined by the location of the peak and the crack depth can be determined from the height of the peak. The global stiffness matrix is calculated from the measured frequency response functions instead of mode shapes to avoid limitations of the mode shape-based methods for crack detection. Numerical simulation results for the cases of beam-like structures are provided. The experiment is carried out to justify the efficiency of the proposed method

Growth and development of transgenic peanut (Arachis hypogaea) lines containing chitinase 42 kDa gene from Trichoderma asperellum SH16

Peanut (Arachis hypogaea L.) is vulnerable to many diseases. Vietnam and other regions where peanut is widely cultivated have a high threat of fungal and other plant diseases. Various fungicides are available to control the fungal disease but these have various harmful effects on the natural flora, fauna, and environment. Transgenic peanut lines which possess antifungal activity provide a possible solution in managing fungal diseases apart from the traditional resistance and fungicide usage. Therefore, this study evaluated the probable growth and development of chitinase transgenic peanut lines against Sclerotium rolfsii, a pathogen that causes “southern blight” in plants, under greenhouse conditions. This study provided evidence that through Agrobacterium itumefaciens mediated transformation, 42 kDa chitinase genes from Trichoderma asperellum, which is under the regulation of 35S promoter, were successfully incorporated into the peanut’s (A. hypogaea L.) genome and expressed in their plants. This evidence also demonstrated that transgenic peanut lines were suitable for growing and developing in the greenhouse. Further, it was reported that transgenic peanut lines took approximately 133 to 145 days from planting to maturity. These results also revealed that various growth characteristics of transgenic peanut lines having two synthetic genes (syncod Chi42-2 i.e. S2-2, S2-4, S2-6, and syncod Chi42-1 i.e. S1-1, S1-2, S1-3) were greater than that from the wild-type Chi42 (WT-1, WT-2, and WT-3). In addition, yield-related parameters including the number of mature pods, 100 pods weight and 100 seeds weight for all the transgenic peanut lines were higher than that of the non-transformed plant. Among the transgenic lines, line S2-4 exhibited significantly higher growth and yield than the other transgenic lines. These results demonstrated that 42 kDa chitinase genes overexpressing peanut lines could be a candidate for improvement against plants to phytopathogenic fungus S. rolfsii and high yield.

Antibacterial Nanocomposites Based on Fe 3

For the vulcanized natural rubber (NR), incorporation of silver nanoparticles (AgNPs) into the NR matrix did not exhibit the bactericidal property against Escherichia coli (E. coli). However, incorporation of AgNPs into polyethylene (PE) matrix showed good antibacterial activities to both Gram-negative and Gram-positive bacteria. In the present work, NR/PE (85/15) blends have been prepared by melt blending with presence of compatibilizer in an internal mixer. To possess antibacterial property, AgNPs (5–10 nm) or Fe3O4–Ag hybrid nanoparticles (FAgNPs, 8 nm/16 nm) were added into PE matrix before its blending with NR component. The tensile test indicated that the presence of compatibilizer in NR/PE blend significantly enhanced the tensile strength and elongation at break (up to 35% and 38% increases, resp.). The antibacterial activity test was performed by monitoring of the bacterial lag-log growth phases with the presence of nanocomposites in the E. coli cell culture reactor. The antibacterial test showed that the presence of FAgNPs in NR/PE blend had a better antibacterial activity than that obtained with the lone AgNPs. Two similar reasons were proposed: (i) the faster Ag+ release rate from the Fe3O4–Ag hybrid nanoparticles due to the electron transfer from AgNP to Fe3O4 nanoparticle and (ii) the fact that the ionization of AgNPs in hybrid nanostructure might be accelerated by Fe3+ ions

DETERMINATION THE PRIORITY OF FACTORS INFLUENCING OVERSEAS INVESTMENT DESTINATIONS OF BUSINESSES USING AN ANALYTIC HIERARCHY PROCESS METHOD

Because of the great benefits overseas investment brings, countries and businesses are increasingly concerned with the question of an ideal investment destination. Many studies have shown that, factors of the consumption market, the infrastructure and resources, economic and political environment have a significant impact on the decision to choose an investment location, however the priority order of these factors are different for various research spaces. By studying the specific case of Viettel Group - one of the largest telecommunications groups in Vietnam that is having many international investment activities in recent years, the study has been verified the priority order of factors influencing the decision to choose an overseas investment location of this corporation. The research outcomes show that the group of factors that have the most influence on investment decisions is the group "Consumption market", more specifically, the sub-factor "Market Size" is considered more than the others.    Keywords: Investment Destinations, Foreign Investment Decision, Analytic Hierarchy Process

ẢNH HƯỞNG CỦA DỊCH CHIẾT VI KHUẨN LAM ĐẾN NHÂN GIỐNG IN VITRO CÂY LAN HOÀNG THẢO GIẢ HẠC (Dendrobium anosmum Lindl.)

Protocorms of 4-week-old Dendrobium anosmum Lindl. were used as initial material for in vitro propagation. The stock extract of Arthrospira sp. was prepared by grinding 1 g of fresh biomass in 100 mL of distilled water. The in vitro propagation results show that the cyanobacterial extract has the effect of enhancing shoot multiplication and rooting of Dendrobium anosmum. An MS basal medium supplemented with 6 g·L–1 agar, 30 g·L–1 saccharose, and 1.5 mg·L–1 BAP in combination with 20 mL·L–1 cyanobacteria extract was suitable for protocorm multiplication with a protocorm cluster diameters of 2.43 cm. An MS medium supplemented with 6 g·L–1 agar, 30 g·L–1 sucrose, and 1.0 mg·L–1 BAP combined with 20 mL·L–1 cyanobacterial extract was optimal for shoot multiplication. The number of shoots/explant reached 4.7 and a shoot height of 1.37 cm. An MS medium supplemented with 6 g·L–1 agar, 30 g·L–1 sucrose, and 1.5 mg·L–1 NAA in combination with 30 mL·L–1 cyanobacteria extract was the most suitable for rooting with 4.87 roots/bud; the root length was 0.74 cm, and the shoot height was 2.76 cm. These results would open up the application of cyanobacterial extract to reduce costs in plant tissue culture technology.Protocorm của cây lan Hoàng thảo Giả hạc (Dendrobium anosmum Lindl.) bốn tuần tuổi được sử dụng để làm vật liệu khởi đầu cho nhân giống in vitro. Dịch chiết gốc vi khuẩn lam Arthrospira sp. được tạo thành bằng cách nghiền 1 g sinh khối tươi trong 100 mL nước cất. Kết quả cho thấy dịch chiết vi khuẩn lam có tác dụng tăng cường sự nhân chồi và ra rễ của cây lan Hoàng thảo Giả hạc nuôi cấy in vitro. Môi trường MS cơ bản bổ sung 6 g·L–1 agar, 30 g·L–1 saccharose và 1,5 mg·L–1 BAP kết hợp với 20 mL·L–1 dịch chiết vi khuẩn lam thích hợp cho sự nhân protocorm và môi trường tối ưu cho nhân chồi. Đường kính cụm protocorm thu được là 2,43 cm. Môi trường MS cơ bản bổ sung 6 g·L–1 agar, 30 g·L–1 saccharose và 1,0 mg·L–1 BAP kết hợp với 20 mL·L–1 dịch chiết vi khuẩn lam là môi trường tối ưu cho nhân chồi, số chồi/mẫu đạt 4,7; chồi cao 1,37 cm. Môi trường MS cơ bản bổ sung 6 g·L–1 agar, 30 g·L–1 saccharose và 1,5 mg·L–1 NAA kết hợp với 30 mL·L–1 dịch chiết vi khuẩn lam thích hợp nhất cho tạo rễ từ chồi in vitro với 4,87 rễ/chồi; chiều dài rễ là 0,74 cm và chiều cao chồi là 2,76 cm. Kết quả này sẽ mở ra triển vọng ứng dụng dịch chiết vi khuẩn lam giúp giảm chi phí trong công nghệ nuôi cấy mô tế bào thực vật

Premnaodoroside A and 10-o-trans-p-methoxycinnamoylcatalpol, two iridoid glycoside derivatives from the leaves of Premna integrifolia L

From the leaves of Premna integrifolia L. two iridoid glycoside derivatives premnaodoroside A (1) and 10-O-trans-p-methoxycinnamoylcatalpol (2) were isolated. Their chemical structures were elucidated by means of ESI-mass MS, 1H-NMR, 13C-NMR (CPD and DEPT), HSQC, and HMBC spectra in comparison with the literature. This is the first report of 1 and 2 from P. integrifolia species