Children Second Language Acquisition Pre-elementary and Elementary Level

This article deals with child’s second language acquisition and learning within the scope of the very early stages of school system. Normally, children learn language through their everyday social environment. In other words, from everyday language use with parents at home and outside home. To teach a foreign language to children, however, takes a little more effort. If one is teaching a child between 4 and 10, one will need to collect kid-friendly materials and get in understanding to how children use languages in appropriate methodology which corresponds to children’s needs. Thus, our proposal takes into account some basic principles that allow the child and get him ready to learning process. We will also focus on the parents’ and teachers’ role for acquiring an efficient background in his preparatory stages. So, how soon can one begin before introducing L2 instruction at school and how can this be reached in the teaching / learning process

Some Principles on the Practice of the Receptive and Productive Skills in Teaching Translation

This current paper deals with some principles on the practice of the receptive and the productive skills in teaching translation. The integration of the four skills is based on two basic elements. The first is based on the language whereas the second covers the major points in the application of the skills. Thus, our interest in this paper takes, s into account the focus on the language. We try to outline the basic linguistic aspects such as grammar, function, vocabulary and pronunciation. Moreover, we focus on the integration of the receptive and the productive skills during translation process. So, to what extent can a successful methodology be fruitful and helpful in facilitating the task in the application of the four skills adequately

Commissioning of the Liquid Nitrogen Thermo-Siphon System for NASA-JSC Chamber-A

NASA's Space Environment Simulation Laboratory's (SESL) Chamber A, located at the Johnson Space Center in Houston Texas has recently implemented major enhancements of its cryogenic and vacuum systems. The new liquid nitrogen (LN2) thermo-siphon system was successfully commissioned in August of 2012. Chamber A, which has 20 K helium cryo-panels (or shrouds ) which are shielded by 80 K nitrogen shrouds, is capable of simulating a deep space environment necessary to perform ground testing of NASA s James Webb Space Telescope (JWST). Chamber A s previous system used forced flow LN2 cooling with centrifugal pumps, requiring 200,000 liters of LN2 to cool-down and consuming 180,000 liters per day of LN2 in steady operation. The LN2 system did not have the reliability required to meet the long duration test of the JWST, and the cost estimate provided in the initial approach to NASA-JSC by the sub-contractor for refurbishment of the system to meet the reliability goals was prohibitive. At NASA-JSC's request, the JLab Cryogenics Group provided alternative options in 2007, including a thermo-siphon, or natural flow system. This system, eliminated the need for pumps and used one tenth of the original control valves, relief valves, and burst disks. After the thermo-siphon approach was selected, JLab provided technical assistance in the process design, mechanical design, component specification development and commissioning oversight, while the installation and commissioning operations of the system was overseen by the Jacobs Technology/ESC group at JSC. The preliminary commissioning data indicate lower shroud temperatures, 70,000 liters to cool-down and less than 90,000 liters per day consumed in steady operation. All of the performance capabilities have exceeded the design goals. This paper will outline the comparison between the original system and the predicted results of the selected design option, and the commissioning results of thermo-siphon system

Study of MgO Under Pressure Structural and Electronic Properties

In this study, the Density Function Theory (DFT), Generalized Gradient Approximation (GGA) and Local Density Approximation (LDA) were used, based on the Siesta code, in order to study the magnesium oxide compound (MgO) and focus on the (B4) Wurtzite phase. This is to find the primary cell constants and energy gap at 0 pressure, which are consistent with previous results. The effect of pressure on the energy gap and the size of the primary cell as well as the dielectric constant were studied. The study also revealed that the (B4) phase can move to the (B2) phase at the pressure of 45.86 GPa and from the h-MgO phase to the (B2) phase at 70 GPa

Altered fronto-striatal functions in the Gdi1 -null mouse model of X-linked Intellectual Disability

RAB-GDP dissociation inhibitor 1 (GDI1) loss-of-function mutations are responsible for a form of non-specific X-linked Intellectual Disability (XLID) where the only clinical feature is cognitive impairment. GDI1 patients are impaired in specific aspects of executive functions and conditioned response, which are controlled by fronto-striatal circuitries. Previous molecular and behavioral characterization of the Gdi1-null mouse revealed alterations in the total number/distribution of hippocampal and cortical synaptic vesicles as well as hippocampal short-term synaptic plasticity, and memory deficits. In this study, we employed cognitive protocols with high translational validity to human condition that target the functionality of cortico-striatal circuitry such as attention and stimulus selection ability with progressive degree of complexity. We previously showed that Gdi1-null mice are impaired in some hippocampus-dependent forms of associative learning assessed by aversive procedures. Here, using appetitive-conditioning procedures we further investigated associative learning deficits sustained by the fronto-striatal system. We report that Gdi1-null mice are impaired in attention and associative learning processes, which are a key part of the cognitive impairment observed in XLID patients

Commissioning of a 20 K Helium Refrigeration System for NASA-JSC Chamber A

A new 20 K helium refrigerator installed at NASA Johnson Space Center s Space Environment Simulation Laboratory (SESL) was successfully commissioned and tested in 2012. The refrigerator is used to create a deep space environment within SESL s Chamber A to perform ground testing of the James Webb Space Telescope (JWST). The chamber previously and currently still has helium cryo-pumping panels (CPP) and liquid nitrogen shrouds used to create low earth orbit environments. Now with the new refrigerator and new helium shrouds the chamber can create a deep space environment. The process design, system analysis, specification development, and commissioning oversight were performed by the cryogenics department at Jefferson Lab, while the contracts and system installation was performed by the ESC group at JSC. Commissioning data indicate an inverse coefficient of performance better than 70 W/W for a 18 kW load at 20 K (accounting for liquid nitrogen pre-cooling power) that remains essentially constant down to one third of this load. Even at 10 percent of the maximum capacity, the performance is better than 150 W/W at 20 K. The refrigerator exceeded all design goals and demonstrated the ability to support a wide load range from 10 kW at 15 K to 100 kW at 100 K. The refrigerator is capable of operating at any load temperature from 15 K to ambient with tight temperature stability. The new shroud (36 tons of aluminum) can be cooled from room temperature to 20 K in 24 hours. This paper will outline the process design and commissioning results

Physicochemical Characteristics for Fen (n = 2–10) Cluster by Density Functional Theory

The In this work, we present a theoretical study on the equilibrium geometry and the energetic, electronic and magnetic properties of Fen (n = 2–10) based on the use of density functional theory (DFT). The results are obtained using Both Generalized Gradient Approximation according to the scheme described by Perdew-Burke-Ernzerhof (GGA-PBE). More stable structures obtained compared to other isomers have not been previously found. It is shown by the results calculated as the calculated fragmentation energy, and the second-order energy difference that Fen (n = 7,8,9) clusters are more stable than the other cluster sizes. The calculated magnetic properties of the most stable clusters display varying magnetic torque between values 3.00 μB and 3.35 μB, except for the Fe10 cluster, which takes the upper value 3.38 μB. These results are very important for experimental experts who are active in designing new nanocatalysis systems in the physical and chemical fields