Ice Accretion and Performance Degradation Calculations with LEWICE/NS

The LEWICE ice accretion computer code has been extended to include the solution of the two-dimensional Navier-Stokes equations. The code is modular and contains separate stand-alone program elements that create a grid, calculate the flow field parameters, calculate the droplet trajectory paths, determine the amount of ice growth, calculate aeroperformance changes, and plot results. The new elements of the code are described. Calculated results are compared to experiment for several cases, including both ice shape and drag rise

The Chaotic Properties of the Shift Map and His Conjugacy of Horseshoe Map

في هذا العمل, درسنا بعض الخصائص الفوضوية المختلفة لفضاء الضرب على دالة التزحيف. اوجدنا ترافقا تبولوجيا بين دالة التزحيف ودالة حدوة الحصان لنقل الخواص الفوضوية المدروسة على فضاء   .In our study, we prove some chaotic properties of the shift map  on the symbol space  and apply the topological conjugacy property of the shift map on the horseshoe map

Fully symbolic-based technique for solving complex state-space control systems

Despite the superiority of symbolic approaches over the purely numerical approaches in many aspects, it does not receive the proper attention due to its significant complexity, high resources requirement and long drawn time which even grows significantly with the increase of model dimensions. However, its merits deserve every attempt to overcome the difficulties being faced. In this paper, a fully generic symbolic-based technique is proposed to deal with complex state space control problems. In this technique, depending on the model dimension if exceeds a predefined limit, the state space is solved using the partitioned matrices theory and block wise inversion formula. Experimental results demonstrate that the proposed technique overcomes all the previously mentioned barriers and gives the same results when compared to numerical methods (Simulink). Moreover, it can be used to gain useful information about the system itself, provides an indication of which parameters are more important and reveals the sensitivity of system model to single parameter variations

Assessment of Bond Strength between Metal Brackets and Non-Glazed Ceramic in Different Surface Treatment Methods

Objective: The aim of this study was to evaluate the bond strength between metal brackets and non-glazed ceramic with three different surface treatment methods.Materials and Methods: Forty-two non-glazed ceramic disks were assigned into three groups. Group I and II specimens were etched with 9.5% hydrofluoric acid. Subsequently in group I, silane and adhesive were applied and in group II, bonding agent was used only.In group III, specimens were treated with 35% phosphoric acid and then silane and adhesive were applied. Brackets were bonded with light-cured composites. The specimens were stored in water in room temperature for 24 hours and then thermocycled 500 times between 5°C and 55°C.Results: The difference of tensile bond strength between groups I and III was not significant(P=0.999). However, the tensile bond strength of group II was significantly lower than groups I, and III (P<0.001). The adhesive remnant index scores between the threegroups had statistically significant differences (P<0.001).Conclusion: With the application of scotch bond multi-purpose plus adhesive, we can use phosphoric acid instead of hydrofluoric acid for bonding brackets to non-glazed ceramic restorations

Factorization and Lie point symmetries of general Lienard-type equation in the complex plane

We present a variational approach to a general Lienard-type equation in order to linearize it and, as an example, the Van der Pol oscillator is discussed. The new equation which is almost linear is factorized. The point symmetries of the deformed equation are also discussed and the two-dimensional Lie algebraic generators are obtained

Performance management practices within emerging market multinational enterprises: the case of Brazilian multinationals

This study advances our understanding of HRM within EM-MNEs by examining the extent to, and mechanism by, which Brazilian MNEs standardize or localise their performance management (PM) policies and practices, and the factors that influence their design and implementation. We explored these issues through qualitative case studies of three Brazilian MNEs. The analysis of interview data reveals a strong tendency for Brazilian MNEs to centralise and standardise their PM policies and practices. The key finding of this paper is that PM practices within Brazilian MNEs are not based on indigenous Brazilian practices, but rather, are heavily influenced by global best practices. The findings are at odds with previous research, which suggests that EM-MNEs apply different HR practices in developed country subsidiaries and developing country subsidiaries. Also, contrary to expectations, our results indicate that institutional distance does not have a significant influence on the adaptation of PM practices at subsidiary level

New biomimetic sensors for the determination of tetracycline in biological samples: batch and flow mode operations

New potentiometric membrane sensors with cylindrical configuration for tetracycline (TC) are described based on the use of a newly designed molecularly imprinted polymer (MIP) material consisting of 2-vinylpyridine as a functional monomer in a plasticized PVC membrane. The sensor exhibited significantly enhanced response towards TC over the concentration range 1.59 10 5–1.0 10 3 mol L 1 at pH 3–5 with a lower detection limit of 1.29 10 5 mol L 1. The response was near-Nernstian, with average slopes of 63.9 mV decade 1. The effect of lipophilic salts and various foreign common ions were tested and were found to be negligible. The possibility of applying the proposed sensor to TC determination in spiked biological fluid samples was demonstrated