Modeling anisotropic and rate-dependent plasticity in short-fiber reinforced thermoplastics

In this study, an anisotropic viscoelastic-viscoplastic macro-mechanical model is presented for short-fiber reinforced thermoplastics (SFRT). In injection molding of SFRT, the fiber orientation is influenced by the flow velocity profile which varies throughout the mold. The flow-induced orientation in the microstructure leads to anisotropy in the mechanical response. In addition to the mechanical anisotropy, SFRTs show time dependent behavior because of the thermoplastic matrix. The developed model captures the effects of both material orientation and loading rate on the yield behavior. In this study, uniaxial tests are performed at different strain rates and material orientations with samplescutfrominjectionmoldedplaques. Theexperimentalresultsshowthattheeffects of loading rate and material orientation on the yield are decoupled. The presented model takes advantage of this observation to simplify material characterization. An implicit integration scheme is used for the numerical implementation of the model as a UMAT in ABAQUS. Multiple relaxation times are used in order to capture the nonlinear pre-yield regime. An efficient method for obtaining the model parameters for different modes is proposed. Experimental results are used for validation of the model and a good agreement is observed for the prediction of viscoelastic and viscoplastic behavior

Application of synthetic oxidants for intensification of uranium in-situ leaching process

Эта работа посвящена изучению процесса скважинного подземного выщелачивания (СПВ) урана и применению искусственных окислителей для его интенсификации. В ходе выполнения работы была создана термодинамическая модель процесса СПВ. Показано, что двухвалентное железо может являться восстановителем для ионов шестивалентного урана на стадии закисления новых технологических блоков. Проведены лабораторные испытания применения нитрита натрия и бихромата натрия для интенсификации выщелачивания урана из руды. Установлено, что применение этих окислителей позволяет повысить концентрацию урана в продуктивных растворах на 20-30%.This study investigated the process of in situ leaching (ISL) method of uranium mining, and the application of synthetic oxidants for intensification of uranium in-situ leaching process. Thermodynamic model of the ISL was created. It was shown that iron (II) may be a reducing agent for hexavalent uranium ion at the stage of acidification of new technological cells. Sodium nitrite and potassium dichromate were used in experiments carried out in laboratory. It was established that application of these oxidizing agents enables to increase the concentration of uranium in productive solutions on 20-30%.Программа развития УрФУ на 2013 год (п.2.1.1.1

Tendencies of interaction between Russian universities and companies implementing innovative development programs

The main aim of this article is to analyze key indicators and trends of global innovative development and their role in development. Attention is given to the consideration of several mechanisms of interaction between universities and state companies, with concrete measures and steps that can be used in economic policy. The authors analyze the real experience of the Russian economy now. Based on collected data for the total volume of R&D, revenues and the number of patents, regression models were constructed to determine the relationship between the named indicators. Recommendations and innovative ideas to improve the economic policy are given to achieve the goals and to justify the use of mechanisms of "compulsion to innovate" in state companies for the implementation of more productive development programs.peer-reviewe

Digital Watermarking as an Image Protection Method

This article presents the classification of digital watermarks. The types of embedding algorithms are analyzed, their main advantages and disadvantages are highlighted

Developing a System for Hidden Information Using a Transposition Cipher

This article discusses: an algorithm for hiding data using a permutation cipher and the main functions of the developed software product

Methods of Modern Cryptoattacks

The article discusses typical types of attacks on modern cryptosystem as the way to protect all weak sides of current security