LARGE DEFLECTION OF CANTILEVER FUNCTIONALLY GRADED SANDWICH BEAM UNDER END FORCES BASED ON A TOTAL LAGRANGE FORMULATION

A two-node beam element for large deflection analysis of cantilever functionally graded sandwich (FGSW) beams subjected to end forces is formulated in the context of total Lagrange formulation. The beams consist of three layers, a homogeneous core and two functionally graded layers with material properties varying in the thickness direction by a power gradation law. Linear functions are adopted to interpolate the displacement field and reduced integral technique is applied to evaluate the element formulation. Newton-Raphson based iterative algorithm is employed in combination with arc-length control method to compute equilibrium paths of the beams. Numerical investigations are given for the beam under a transverse point load and a moment to show the accuracy of the element and to illustrate the effects of material inhomogeneity and the layer thickness ratio on the large deflection behavior of the FGSW beams

Quy trình gia công và phân tích hóa thạch Tảo vôi, áp dụng cho các trầm tích ven biển tỉnh Sóc Trăng

Calcareous nannofossils are very small microfossils composed of calcium carbonate. They are very good biostratigraphic markers within marine sediments by covering the Jurassic to present. The standard preparation of a sample for nannofossil analysis requires the collection of the largest quantity and the best fossils. Sample preparation accords to the following steps: i. Pounding sample; ii. Eliminating organic matter; iii. Washing sample; iv. Filter sample through the sieve; v. Eliminating clay; vi. Drying sample in an incubator; vii. Packing sample. Sample analysis accords to the following steps: i. Preparation of smear - slide; ii. Observation of morphology; iii. Determination; iv. Taking photo; v. Evaluating overall preservation and abundance of fossils; vi. Making analysis result sheet. This process is applied to study calcareous nannofossils within marine sediments in Soc Trang province. It makes much clear to understand middle Pleistocene-early Holocene ecosystem of calcareous nannofossil. In conclusion, this assemblage belongs to NN21 zone by the present of Emiliania huxleyi and Gephyrocapsa oceanica.Hóa thạch Tảo vôi có kích thước rất nhỏ, thành phần chính là canxi carbonat. Chúng là hóa thạch định tầng rất tốt cho các trầm tích biển có tuổi từ Jura đến nay. Để nghiên cứu hóa thạch Tảo vôi, cần tiến hành gia công và phân tích mẫu theo đúng quy trình để thu được lượng hóa thạch nhiều nhất và bảo tồn tốt nhất. Quy trình gia công gồm các bước sau: i. giã mẫu; ii. tẩy keo hữu cơ; iii. rửa mẫu; iv. lọc mẫu; v. tẩy sét; vi. sấy mẫu; vii. đóng gói. Quy trình phân tích tiến hành theo những bước sau: i. chuẩn bị tiêu bản; ii. nghiên cứu đặc điểm hình thái của hóa thạch; iii. xác định hóa thạch; iv. chụp ảnh hóa thạch; v. đánh giá mức độ bảo tồn và phong phú của hóa thạch; vi. lập phiếu kết quả phân tích. Kết quả áp dụng quy trình cho các trầm tích ven biển tỉnh Sóc Trăng đã góp phần làm sáng tỏ hệ sinh thái Tảo vôi ở khu vực nghiên cứu trong Pleistocen giữa - Holocen sớm. Tập hợp hóa thạch ở khu vực ven biển Sóc Trăng thuộc sinh đới NN21 với bằng chứng là sự xuất hiện của Emiliania huxleyi và Gephyrocapsa oceanica

THE ANALYSIS OF FLUID DYNAMICS OF WAVE POWER STATION WITH WELLS TURBIN BY CFD

Natural energy such as wind, wave and other natural vibrations is one of the high potential renewable energy sources. The Wells turbine is based on the use of bidirectional turbines, which act as axial-flow self-rectifying turbines that employs a symmetrical blade profile and rotating unidirectionally in reciprocating airflows generated by the air chamber to extract energy from vibrations. These topics have been extensively studied both numerically and experimentally such as research on the parameters of the effects of structure, angle of attack, blade shape, etc. In this paper, numerical simulation is carried out using commercially available tool Fluent for fluid dynamics analysis and focus on oscillating predictions, with particular attention to the behavior of the flow. Based on the Numerical Wave Tank (NWT) model is simulated in a two dimensional used in this model, which is constructed mainly based on the spatially averaged Navier Stokes equation with the k-ε model for simulating the turbulence and modeled with Volume of Fluid (VOF). Axial-flow turbines system and future development as well as the proposed limitations will be discussed in detail

SECURITY CAPABILITY ANALYSIS OF COGNITIVE RADIO NETWORK WITH SECONDARY USER CAPABLE OF JAMMING AND SELF-POWERING

This paper investigates a cognitive radio network where a secondary sender assists a primarytransmitter in relaying primary information to a primary receiver and also transmits its own information toa secondary recipient. This sender is capable of jamming to protect secondary and/or primary informationagainst an eavesdropper and self-powering by harvesting radio frequency energy of primary signals.Security capability of both secondary and primary networks are analyzed in terms of secrecy outageprobability. Numerous results corroborate the proposed analysis which serves as a design guidelineto quickly assess and optimize security performance. More importantly, security capability trade-offbetween secondary and primary networks can be totally controlled with appropriate selection of systemparameters

Detection of Luminescence Centers in Colloidal Cd0.3_{0.3}Zn0.7_{0.7}S Nanocrystals by Synchronous Luminescence Spectroscopy

With the advantages of selectivity, spectral resolution and reduction of interference on account of light scattering, synchronous luminescence spectroscopy (SLS) is successfully applied to analyze complex mixtures with overlapped emission and/or excitation spectra. In fact, it is difficult to clearly distinguish the contributions of various luminescence centers to low-energy band of semiconductor nanocrystals (NCs). Herein, we report the application of SLS method to detect luminescence centers in colloidal Cdsub0.3/subZnsub0.7/subS NCs. Their conventional luminescence and synchronous luminescence spectra were comparatively investigated. Differently from conventional luminescence spectrum, the emission peaks at 460 and 515 nm were found using SLS method. They are attributed to the emission transitions related to sulfur and zinc/cadmium vacancies. The obtained results are useful to clarify the nature of luminescence centers as well as relaxation mechanism in Cdsubx/subZnsub1-x/subS NCs

Vitamin C inhibited FasL-induced apoptotic death of mouse dendritic cells through c-FLIP expression

Vitamin C (VitC) is a potent antioxidant and contributes as an apoptosis inhibitor by preventing death receptor-triggered caspase 8 activity. Fas ligand (FasL) induces the apoptotic cell death via activation of Fas signaling, which is dependent on the expression level of anti-apoptotic molecule c-FLIP (FADD-like IL-1beta-converting enzyme-inhibitory proteins). The present study addressed the effects of VitC on survival of dendritic cells (DCs), a regulator of innate and adaptive immunity. To this end, mouse bone marrow cells were isolated and cultured to attain bone marrow-derived DCs (BMDCs). The cells were treated with FasL in the presence or absence of VitC. Real time RT-PCR, Western blotting and FACS analysis were performed to determine different hallmarks of DC apoptosis. As a result, FasL treatment resulted in activation of caspase 8 and stimulation of cell membrane scrambling, the effects were supressed when VitC was present in the cell culture or the cells were transfected with FLIP siRNA. In conclusion, VitC prevented FasL-triggered DC apoptosis mediated through the expression of c-FLIP

FREE VIBRATION ANALYSIS OF POROUS NANOPLATES USING NURBS FORMULATIONS

This paper presents free vibration analysis of functionally graded (FG) porous nanoplates based on isogeometric approach. Material properties of the nanoplates are given by using a modified power-law function. The Eringen’s nonlocal elasticity is used to capture the size effects. Based on a combination of the Hamilton’s principle and the higher order shear deformation theory, the governing equations of the porous nanoplates are derived. The obtained results demonstrate the significance of nonlocal parameter, porosity volume fraction, porosity distributions and volume fraction exponent on free vibration analysis of the nanoplates with porosities

Threadfin bream (Nemipteridae) resources in the sea of Vietnam based on the bottom trawl surveys

The threadfin bream (Nemipteridae) resources in the sea of Vietnam were analysed using the results of  bottom trawl surveys conducted by the assessment of living marine resources project in Vietnam (ALMRV) in period 2000–2005 and comprehensive investigation of marine fisheries resources project in Vietnam sea during 2012–2013. Results showed that a total of 23 species belonging to 4 genera of Nemipterus, Parascolopsis, Pentapodus and Scolopsis were recorded. The Southeast region has the highest number of species encountered with 26 species, and the lowest number in Central waters with 16 species. The highest number of species was encountered at 50–100 m depth range with 25 species and the lowest number at the depth of less than 20 m with 9 species. Catch of threadfin bream comprised more than 1% of total catch of surveys. In threadfin bream family, genus Nemipterus was the most abundant, the catch of this genus contributed from 75.1% to 88.4% of the family catch. The catch per unit effort decreased from Northern region to Southern region, while the catch in the Northeast monsoon was higher than in the Southwest monsoon. The biomass of threadfin bream in Vietnamese water was estimated to be 7,534 to 12,229 tons depending on the monsoon patterns

Research on the stability of the 3D frame on coral foundation subjected to impact load

This article presents an application of the finite element method (FEM) for the stability analysis of 3D frame (space bar system) on the coral foundation impacted by collision impulse. One-way joints between the rod and the coral foundation are described by the contact element. Numerical analysis shows the effect of some factors on the stability of the bar system on coral foundation. The results of this study can be used for stability analysis of the bar system on coral foundation subjected to sea wave load

Stimulation of shoot regeneration through leaf thin cell layer culture of Passiflora edulis Sims.

Passiflora edulis Sims. belonged to the genus Passiflora, is one of the important economic crops of the world as well as Vietnam. Nowadays, the commercial P. edulis is mainly propagated by seeds, cuttings and grafting; however, these methods still have some limitations such as genetic degradation and heterogeneity and the spread of pathogenic viruses. Micro-propagation has been used for clonal breeding and disease-free plant breeding, as well as providing a source of materials for Passiflora breeding. In this study, leaf explants of P. edulis Sims. (2.0-month-old) excised from the in vitro culture of ex vitro axillary buds cut longitudinally and transversally into thin cell layers (lTCL and tTCL) were used as plant materials to evaluate the shoot regeneration. In addition, the effects of explant age and lighting condition on shoot regeneration were also investigated. After 8 weeks of culture, the results showed that shoot regeneration rate (100%) and shoot multiplication coefficient (13.33) of the in vitro leaf-tTCL-4 were higher than those of other treatments and control. The shoot regeneration rate of P. edulis Sims. also varied with the change of explant age. The highest shoot regeneration rate (100%) was obtained from leaf explants of 1.5-month-old shoots after 8 weeks of culture. Moreover, the light (fluorescent lamps with photoperiod of 16 hours/day and lighting intensity of 40 - 45 μmol.m-2.s-1) improved not only morphogenesis rate, but also shoot regeneration rate (100%) of leaf explants after 8 weeks of culture. This study provided a novel method for rapid micro-propagation of P. edulis Sims