The attitude of Egyptian Nubian university students towards Arabic and Nubian languages

This research investigates the attitude of Egyptian Nubian university students towards the Arabic and the two Nubian languages, Nobiin and Kenuzi-Dongola. The Nubian languages are called by Egyptian Nubians, Fadijja/Fadicca and Kenzi, respectively. Nubians are people who live in the Nubia area which lies between Egypt\u27s southern borders with the northern part of Sudan. Nubia is divided into two parts - one under the Egyptian regime, and the other under the Sudanese regime. The number of participants used in the study was forty - half male and half female. Twenty of these participants live in the Nubian region and are enrolled at the South Valley University in Aswan, Egypt. This number was compared with an additional twenty Egyptian-Nubian university students who live outside the Nubian region and attend various Egyptian universities located in Alexandria and Cairo. The hypothesis of this study is that Egyptian Nubian university students tend to have positive attitudes toward Arabic and also the Nubian languages. This research is a qualitative and partially quantitative one. Observations, questionnaires, and interviews were used to collect data in order to explore the following: (1) the language students prefer to speak at home and in public and if language preferences are gender-related, (2) the factors that influence the Egyptian Nubian university students\u27 attitudes towards Arabic and Nubian languages, and (3) a look at the future of these ethnic Nubian languages. Results that answered the main question on the attitude of Egyptian Nubian university students toward Arabic and Nubian languages revealed that students who live inside and outside the Nubian region tend to have positive attitudes towards both the Arabic and the Nubian languages

The impact of twinning on the local texture of chalcopyrite-type thin films

Twinning in a CuInS2 layer in a completed thin film solar cell was analyzed by means of electron backscatter diffraction. This technique revealed the microstructure of the CuInS2 thin films and local orientation relationships between the grains. At various locations within the layer it was possible to retrace how twinning occurred comparing the local orientations with the theoretically possible changes in orientation by twinnin

Correlative microscopy analyses of thin film solar cells at multiple scales

In the present work, a brief overview is given on how to apply transmission TEM as well as scanning electron microscopy SEM and their related techniques electron diffraction, energy dispersive X ray spectrometry, electron energy loss spectroscopy, electron holography; electron backscatter diffraction, electron beam induced current, cathodoluminescence for the analysis of interfaces between individual layers or extended structural defects in a thin amp; 64257;lm stack. All examples given in the present work were recorded on Cu In, Ga Se2 thin amp; 64257;lm solar cells, however, the shown experimental approaches may be used on any similar thin amp; 64257;lm semiconductor device. A particular aspect is the application of various techniques on the same identical specimen area, in order to enhance the insight into structural, com positional, and electrical properties. For aberration corrected TEM, the spatial resolutions of such measurements can be as low as on the subnanometer scale. However, when dealing with semiconductor devices, it is often necessary to characterize electrical and optoelectronic properties at larger scales, of few 10 nm up to even mm, for which SEM is more appropriate. At the same time, these larger scales provide also enhanced statistics of the analysis. In the present review, it is also outlined how to apply SEM techniques in combination with scanning probe and optical microscopy, on the same identical positions. Altogether, a multiscale toolbox is provided for the thorough analysis of structure property relationships in thin amp; 64257;lm solar cells using correlative microscopy approache

Grain boundaries in polycrystalline materials for energy applications: First principles modeling and electron microscopy

\ua9 2024 Author(s). Polycrystalline materials are ubiquitous in technology, and grain boundaries have long been known to affect materials properties and performance. First principles materials modeling and electron microscopy methods are powerful and highly complementary for investigating the atomic scale structure and properties of grain boundaries. In this review, we provide an introduction to key concepts and approaches for investigating grain boundaries using these methods. We also provide a number of case studies providing examples of their application to understand the impact of grain boundaries for a range of energy materials. Most of the materials presented are of interest for photovoltaic and photoelectrochemical applications and so we include a more in depth discussion of how modeling and electron microscopy can be employed to understand the impact of grain boundaries on the behavior of photoexcited electrons and holes (including carrier transport and recombination). However, we also include discussion of materials relevant to rechargeable batteries as another important class of materials for energy applications. We conclude the review with a discussion of outstanding challenges in the field and the exciting prospects for progress in the coming years

Electrostatic potentials at Cu In,Ga Se2 grain boundaries Experiment and simulations

In the present Letter, we report on a combined ab initio density functional theory calculation, multislice simulation, and electron holography study, performed on a amp; 931;9 grain boundary GB in a CuGaSe2 bicrystal, which exhibits a lower symmetry compared with highly symmetric amp; 931; 3 GBs. We find an electrostatic potential well at the amp; 931;9 GB of 0.8 V in depth and 1.3 nm in width, which in comparison with results from amp; 931;3 and random GBs exhibits the trend of increasing potential well depths with lower symmetry. The presence of this potential well at the amp; 931; 9 GB can be explained conclusively by a reduced density of atoms at the GB. Considering experimental limitations in resolution, we demonstrate quantitative agreement of experiment and theor

Comprehensive Comparison of Various Techniques for the Analysis of Elemental Distributions in Thin Films: Additional Techniques

In a recent publication by Abou-Ras et al., various techniques for the analysis of elemental distribution in thin films were compared, using the example of a 2-µm thick Cu(In,Ga)Se2 thin film applied as an absorber material in a solar cell. The authors of this work found that similar relative Ga distributions perpendicular to the substrate across the Cu(In,Ga)Se2 thin film were determined by 18 different techniques, applied on samples from the same identical deposition run. Their spatial and depth resolutions, their measuring speeds, their availabilities, as well as their detection limits were discussed. The present work adds two further techniques to this comparison: laser-induced breakdown spectroscopy and grazing-incidence X-ray fluorescence analysisThe work was supported in part by National Research Foundation of Korea (NRF) grant funded by Korea government (MEST, No. 2013- 064113), by the Spanish MINECO within the Ramón y Cajal programme (RYC-2011- 08521), and by the European Metrology Research Program (EMRP) within the projects IND07 Thin Films and ENG53 ThinErg

Synthesis of Cu2ZnxSnySe1+x+2y nanocrystals with wurtzite-derived structure

The most reported stable crystal structure of Cu2ZnSnS4 and Cu2ZnSnSe4 (CZTSe) is kesterite, which is derived from the ternary chalcopyrite structure. However, by controlling the reaction conditions, we found that the structure and composition of the CZTSe nanocrystals (NCs) can be tuned. This can be achieved by using a simple hot injection approach. The structural properties of the CZTSe NCs were characterized by powder X-ray diffraction (PXRD), Raman spectroscopy and transmission electron microscopy. The energy dispersive X-ray spectroscopy confirms the stoichiometry of CZTSe NCs. The optical band gap of the NCs is found to be around 1.38 eV, as estimated from UV-Vis absorption spectroscopy. PXRD studies show that the obtained CZTSe NCs occurring in three structurally different phases (tetragonal kesterite type, hexagonal wurtzite type and orthorhombic wurtz-stannite type) are converted to the kesterite structure by annealing at 540 °C for 30 min under an Se-vapour atmosphere

CdS/Cu(In,Ga)S2 based solar cells with efficiencies reaching 12.9% prepared by a rapid thermal process

In this letter, we report externally confirmed total area efficiencies reaching up to 12.9% for CdS/Cu(In,Ga)S2 based solar cells. These are the highest externally confirmed efficiencies for such cells. The absorbers were prepared from sputtered metals subsequently sulfurized using rapid thermal processing in sulfur vapor. Structural, compositional, and electrical properties of one of these champion cells are presented. The correlation between the Ga distribution profile and solar cell properties is discussed