Geometrically nonlinear isogeometric analysis of laminated composite plates based on higher-order shear deformation theory

In this paper, we present an effectively numerical approach based on isogeometric analysis (IGA) and higher-order shear deformation theory (HSDT) for geometrically nonlinear analysis of laminated composite plates. The HSDT allows us to approximate displacement field that ensures by itself the realistic shear strain energy part without shear correction factors. IGA utilizing basis functions namely B-splines or non-uniform rational B-splines (NURBS) enables to satisfy easily the stringent continuity requirement of the HSDT model without any additional variables. The nonlinearity of the plates is formed in the total Lagrange approach based on the von-Karman strain assumptions. Numerous numerical validations for the isotropic, orthotropic, cross-ply and angle-ply laminated plates are provided to demonstrate the effectiveness of the proposed method

Characterization of carboxymethyl cellulase produced by Trichoderma asperellum

Background: The present study characterized extracellular carboxymethyl cellulase (CMCase), an enzyme catalyzes the hydrolysis of the cellulose, from Trichoderma asperellum PQ34 that was isolated from agricultural cultivation soil in Thua Thien Hue, Vietnam.Methods: CMCase was produced by culturing T. asperellum PQ34 on Czapek-Dox medium supplemented with carboxymethyl cellulose (CMC) at 28ºC for 96 h at a shaking speed of 150 rpm. Enzyme activity was spectrophotometerically determined with CMC used as a substrate and the absorbance was measured at 540 nm. The molecular weight of CMCase was determined by zymogram based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with 0.2% CMC.Results: CMCase achieved the highest activity after 4 days of culture with the optimal pH and temperature at 4 and 55°C. The enzyme maintains pH and thermal stability in the range of 4-5 and 10-40°C and the relative activity of both is more than 90%. The presence of metal ions at 5 mM such as Ca2+, Al3+, or Co2+ increased the enzyme activity up to 133%, 124%, and 217%, respectively. CMCase was stable with 1 mM ethylenediaminetetraacetic acid and 1 M urea, but inhibited by 5% sodium dodecyl sulfate (SDS) and 5% Triton-X100. Zymographic analysis showed that CMCase from T. asperellum PQ34 consists of two enzymes with a molecular weight of about 31 and 66 kDa.Conclusion: CMCases from T. asperellum PQ34 exhibited characteristics of an acidic and thermostable enzyme. The interaction of Co2+ and CMCase resulted in a significant increase in enzyme activity, however they were strongly inhibited by 5% SDS.Keywords: Carboxymethyl cellulase; Cellulase; Endo-β-1,4-glucanase, Trichoderma asperellu

State Regulation of Forest Industrial Complex in Vietnam

This article discusses the development of the forest industrial complex - one of the key sectors of the economy of the Socialist Republic of Vietnam which, to a great extent, defines the status and outlook of the Vietnamese economy in general. Development of the forest industrial complex is discussed in the context of fundamental socioeconomic reforms being implemented in Vietnam. Among other things they are aimed to attain one of the key backbone goals, i.e. defining the optimum balance between the state regulation and the initiative of economic subjects. The author touches endogenic and endogenic factors of the Vietnamese forest industrial complex development, including the natural-and-geographic factor, ethno-cultural traditions in economic activities, attraction of foreign investments. The author emphasizes both the achievements in the process of reforming the Vietnamese economy and unattained goals

Influence on the World Market on the Features of Development of Forestry Complex of the Asia-Pacific Region

The estimation of the development of the main trends of the global timber marketisgiven,there are characterized relative labor productivity indices in the forestry sector of the world economy in various regions of the world over 20 year. There is carried an analysis of the key implications of the spread of the modern model of consumption in the Asia-Pacific region for the wood and furniture industry

Whole-genome sequencing of three local rice varieties (Oryza sativa L.) in Vietnam

Recently, a new technology, Next-generation sequencing (NGS) has been launched and providing whole-genome sequences that helps identify molecular markers across the genome. DNA markers such as single nucleotides and insertion – deletion (InDel) polymorphisms were widely used for plant breeding particularly to distinguish important traits in rice. These PCR-based markers can be used for the precision detection of polymorphisms. Moreover, PCR-based approaches are simple and effective methods for dealing with the issue of fraudulent labeling and adulteration in the global rice industry. In this study, three local varieties of Oryza sativa L. in Vietnam were sequenced with up to ten times genome depth and at least four times coverage (~83%) using the Illumina HiSeq2000™ system, with an average of 6.5 GB clean data per sample, generated after filtering low-quality data. The data was approximately mapped up to 95% to the reference genome IRGSP 1.0. The results obtained from this study will contribute to a wide range of valuable information for further investigation into this germplasm

Parameter optimization of tuned mass damper for three-degree-of-freedom vibration systems

There are problems in mechanical, structural and aerospace engineering that can be formulated as Nonlinear Programming. In this paper, the problem of parameters optimization of tuned mass damper for three-degree-of-freedom vibration systems is investigated using sequential quadratic programming method. The objective is to minimize the extreme vibration amplitude of vibration models. It is shown that the constrained formulation, that includes lower and upper bounds on the updating parameters in the form of inequality constraints, is important for obtaining a correct updated model