1,963 research outputs found
Auger Spectra and Different Ionic Charges Following 3s, 3p and 3d Sub-Shells Photoionization of Kr Atoms
The decay of inner-shell vacancy in an atom through radiative and
non-radiative transitions leads to final charged ions. The de-excitation decay
of 3s, 3p and 3d vacancies in Kr atoms are calculated using Monte-Carlo
simulation method. The vacancy cascade pathway resulted from the de-excitation
decay of deep core hole in 3s subshell in Kr atoms is discussed. The generation
of spectator vacancies during the vacancy cascade development gives rise to
Auger satellite spectra. The last transitions of the de-excitation decay of 3s,
3p and 3d holes lead to specific charged ions. Dirac-Fock-Slater wave functions
are adapted to calculate radiative and non-radiative transition probabilities.
The intensity of Kr^{4+} ions are high for 3s hole state, whereas Kr^{3+} and
Kr^{2+} ions have highest intensities for 3p and 3d hole states, respectively.
The present results of ion charge state distributions agree well with the
experimental data.Comment: Published in SIGMA (Symmetry, Integrability and Geometry: Methods and
Applications) at http://www.emis.de/journals/SIGMA
Dilemma of Vibrant City and Endless Urban Growth, Lessons from Alexandria, Egypt
Urban planners and visionary leaders always have dreams of designing and establishing new vibrant cities or making new history by regenerating old cities. When the city (new or revived) starts to be “vibrant”, it begun to attract more residents to work and live in it. The city will grow and expand as a natural result of that. This continuous urban growth may lead to dangerous environmental impacts. Some cities during growth may consume valuable cultivated lands to provide spaces for accelerated demands of urban development projects. This leads to “Urban desertification”. Moreover, future scenarios of these cities tell us that urban growth will continue and the city will expand consuming valuable resources. In this case, some important questions will arise; do we need this endless urban growth? Can we bear the consequences of this endless urban growth? Do we need to control this growth to keep the city vibrant? Or we just leave the city grow endlessly? This paper will try to address these questions on Alexandria of Egypt. Alexandria was a dream of Alexander III the Great. Alexander ordered that a city be designed and founded in his name at the mouth of river Nile, as trading and military Macedonian outpost, the first of many to come. He never lived to see it built, but Alexandria will become a major economic and cultural center in the Mediterranean world not only during the Macedonian rule in Egypt but centuries after. Alexandria witnessed a continuous urban growth from the beginning of the Mohammed Ali era (1805) up to the present time. In 1905, Alexandria's 370 thousand inhabitants lived in an area of about 4 km2 between the two harbors. Since that time the city has expanded rapidly, eastwards and westwards, beyond its medieval walls. It presently occupies a built-up area of about 300 km2 and has a ten-fold increase in population at 4 millions in 1996, and become 4.7 millions in 2014, with a density of 2,760 per km². The urban physical expansion and change were detected using Landsat satellite images of 1984 and 1993. The images were classified using a tailored classification scheme with accuracy of 93.82% and 95.27% for 1984 and 1993 images respectively. This high accuracy enabled detecting land use/cover changes with high confidence using a post-classification comparison method. One of the most important findings here is the loss of cultivated land in favour of urban expansion. If the current loss rates continued, 75% of green lands would be lost by year 2191. These hazardous rates call for an urban growth management policy that can preserve such valuable resources to achieve sustainable urban development. The starting point of any management programme will be based on the modelling of the future growth. Modelling techniques can help in defining the scenarios of urban growth in the future. In this study, the SLEUTH urban growth model was applied to predict future urban expansion in Alexandria until the year 2055. The application of this model in Alexandria of Egypt with its different environmental characteristics is the first application outside USA and Europe. The results revealed that future urban growth would continue in the edges of the current urban extent, which means the cultivated lands in the east and the southeast of the city will continue to lose more day by day from their area.To deal with such crisis, there is a serious need for a comprehensive urban growth management programme that can be based on the best practices in similar situations
Seating arrangement and cooperative learning activities: students\u27 on-task/off-task participation in EFL classrooms
Research has shown that student participation is affected by a number of factors that include students\u27 gender, personality differences as well as class environment. This class environment includes classroom seating arrangements which are believed to play an important role in fostering students\u27 on-task behavior. However, how a seating arrangement can encourage on-task or off-task behavior is found to depend on how far this seating arrangement agrees with the activity being done and the interaction pattern aimed at in class. On the other hand, some research linked teachers\u27 choice of different classroom seating arrangement and their beliefs in their role inside the class and the institution\u27s views and concepts concerning learning and teaching. Limited research has been done on classroom seating arrangements and its effect on students\u27 participation while working no cooperative learning activities. In addition, limited studies have also been done on students\u27 preferences in relation to different furniture arrangements while almost nothing is done in the Egyptian context. The idea of classroom seating arrangement is therefore of great importance since it can be one of the factors that either encourages or inhibits students\u27 on-task participation in language classes. The purpose of this study was to determine: (1) if classroom seating arrangements affect student on-task/off-task participation in CL activities, (2) in what ways seating arrangements affected student participation (3) students\u27 preferences of different classroom seating arrangements, namely rows and columns and circles (4) if students\u27 preferences to seating arrangements are affected by their personal views of their participation rate inside the class and the reasons for their choices were and (5) whether their preferences changed after experiencing both seating arrangements. The study was mainly exploratory and qualitative using a convenience sample of two EFL classes, of a total of 43 students. Data were collected through students\u27 responses to a questionnaire and a reflective paper. In addition, video recordings of class sessions were also used to collect data about student on-task/off-task participation in both seating arrangements. Analysis of data shows seating arrangement is a priority to foster student on-task participation in class since the videos show that students in one class were keen to create their semi-circle shaped when seated in the rows and columns in order to work on group activities while students in the other were subversive to the rows and columns seating arrangement where two of the group members left their places and sat facing the group. Further, analysis of data also shows that students\u27 preferences of different seating arrangements are determined by their views of how shy/talkative they are inside the class. However, their preferences changed after experiencing both seating arrangements classroom using the teacher\u27s chairs
Size distribution of heavy mineral grains in some modern Nile Delta coastal sands, Egypt
This study includes determination and discussion of the texture and heavy mineral compositions of some modem Nile Delta coastal sands (river, coastal dune, beach-face, and nearshore marine) in order to delineate the process and factors that regulate the size distribution of heavy mineral grains comprising these coastal sands. Textural analysis of unseparated bulk samples indicate that the examined four types of sands differ in their mean grain sizes and degree of sorting. However, analysis of size distribution curves of 10 heavy mineral species or group of species in the four environments having the same general shape and nearly similar in that general order of arrangement. However, these curves vary both in median sizes and sorting. The size distribution of a heavy mineral in the Nile Delta coastal sands appear to depend on: (1) range of grain size fractions in each sample, (2) relative availability of heavy mineral in each size grade of the sample, (3) specific gravity of minerals comprising these sands, and (4) some other unknown factor or factors. Results of size measurement of heavy minerals indicated that increasing specific gravity is accompanied by increasing fineness of the heavy minerals. This study may be useful in search for marine placers and understanding the processes of grain-sorting on the sea beaches
The impact of politics on lexical coinage: A study of the morphological patterns in Egyptian printed media after January, 25th 2011
All living languages come across linguistic changes with time. It is important to mention that various linguistic phenomena that living languages encounter include sound change, phonological change, syntactic change, lexical change or semantic change. From 2011 to 2015, Egypt passed through a critical political situation; a result, media and press introduce new lexical items and revive lexical terminology from the past. During the Arab Spring media websites tried to offer the most accurate lexical terminologies that express people’s impatience for dignity, socio-political reforms, and human rights (Michel, 2013). This study aims to primarily investigate the impact of the political situation on the media lexical production, and the word formation strategies that has been frequently used to coin lexical items. Thus, this paper tries to answer the following research questions: 1. to what extent does political change influence the process of lexical creation. What are the common strategies used in lexical creation in modern written Arabic. The data is extracted by scanning opinion columns in al-Ahram and Al-Shorouq newspapers from 2009 to 2015. Preliminary results demonstrate that socio-political variables influence the lexical production in which the language used incorporates the social and political feelings. Moreover, from data analysis, the study gives an updated definition of compounding, as a word formation process, and highlights the grammatical structures and the linguistic functions of compounding in MSA which vary from that produced by Arabic Academies. The Results also illustrate that the most common strategies adopted to create lexical items are compounding, as most used strategy, followed by derivation. The paper ends with pedagogical implications for strategies of teaching vocabulary in classroom
The Pandemic and Media Discourse: Linguistic Framing of Covid-19 in Egyptian Advertisements
Since the outbreak of Covid-19 in late 2019, media discourse worldwide has attempted to frame the pandemic as an invisible enemy everyone needs to fight. The total lockdown that took place due to the pandemic has also had an impact on media discourse in its different forms, such as television commercials. Business companies have tried to address the theme of the pandemic and the urgency to abide by the lockdown and social distancing in their advertisements produced during the period of 2019-2020. This paper aimed to examine selected Egyptian commercials, either on television or YouTube, to analyze how they tackled the pandemic. Eight Egyptian commercials were analyzed, focusing on how the pandemic was framed verbally and visually. Analysis was carried out on two levels. The first level was concerned with examining the ideas/themes that were promoted in the selected commercials that would shape how the audience would regard the pandemic. The second level investigated how these themes were represented verbally and visually by analyzing the linguistic as well as the visual layout used in the selected commercials. Significant results showed that the pandemic was linguistically framed in metaphors related to war, enemy, family, and Lockdown/Stay Home. These linguistic frames were also supported by the visual representation that highlighted the themes of social distancing and the lockdown
Hand Commanded Machine Interface (Data Glove)
Human-Robot interface is a methodology that is heavily utilized in industrial and
commercial applications such as to fulfill user needs. Different types of robotic
frameworks are designed to fulfill those needs. The aim of the work presented in this
paper is to simulate a robotic movement that emulates the movement of a human
hand (i.e. arm and fingers section). The robotic hand comprises of three fingers. The
main objective of this robotic hand simulation is to design a link between the pre
designed data glove (FYPI) to a robotic hand and imitates the movement of a human
hand.
This project presents a new simulation methodology for the human-machine
interface of robotic frameworks and control systems. The interface uses dynamic
hand gestures, relative arm position estimation in order to have control of the
Humanoid Robot used (NAO) and provides a control and visualization interface
between a human and NAO.
All the Important aspects to develop such an interface; image processing techniques,
object tracking, colour tracking, motion detection and software filters; contrast,
brightness and saturation have been explored. Seeking high ratio of faster and correct
tracking have been achieved from the experiments.
Using "Python" and some other programming IDEs (integrated developing
environments), Software simulation and hardware implementation to show the
behavior of the Data Glove will be carried
Neuroglial Mechanisms Involved In The Anti-Inflammatory Effect Of Acetate Supplementation
Acetate supplementation increases brain acetyl-CoA and attenuates lipopolysaccharide (LPS)-induced neuroinflammation in vivo. To explain the anti-inflammatory effect of acetate treatment, we proposed that acetate treatment disrupts inflammatory signaling in microglia and astrocytes, and induces histone hyperacetylation known to be correlated with anti-inflammatory properties. To test this hypothesis, we measured the effects that LPS and acetate treatment had on histone acetylation, mitogen-activated protein kinase (MAPK), nuclear factor-kappa B (NF-κB), and eicosanoid signaling. A single oral dose of acetate treatment (6 g/kg) in normal animals induced a time- and site-specific pattern of histone hyperacetylation, associated with reduction of histone deacetylase (HDAC) activity and expression. Long-term acetate treatment over 28 days induced the same site-specific pattern of histone hyperacetylation, and reversed LPS-induced histone H3 at lysine 9 (H3K9) hypoacetylation and interleukin (IL)-1β expression. In LPS-stimulated BV-2 microglia, acetate treatment reversed LPS-induced H3K9 hypoacetylation, IL-1β, IL-6, tumor necrosis factor (TNF)-α, cyclooxygenase (Cox)-1 and 2 protein levels, and NF-κB p65 protein level and phosphorylation at serine 468. Further, acetate treatment increased IL-4 and transforming growth factor (TGF)-β1 expression, and NF-κB p65 acetylation at lysine 310. Conversely, acetate treatment did not alter LPS-induced
cytosolic (c) phospholipase A2 (PLA2), transiently reduced MAPK p38 and JNK phosphorylation, and increased MAPK ERK1/2 phosphorylation. In LPS-stimulated astrocyte, acetate treatment induced H3K9 hyperacetylation, reversed LPS-induced increases in IL-1β, TNF-α, NF-κB p65, and Cox-1 protein levels, MAPK p38 and cPLA2 phosphorylation and PGE2 release, and reversed LPS-induced decreases in TGF-β1 and IL-4. Moreover, acetate treatment reduced basal levels of IL-6, phosphorylated ERK1/2 and NF-κB p65 at serine 536, sPLA2 IIA and PLCβ1. Acetate treatment also increased acetylated H3K9 bound to the promoters of the genes of Cox-1, Cox-2, IL-1β and NF-κB p65, but not IL-4 in BV-2 microglia, which suggests that acetate treatment-induced H3K9 hyperacetylation can potentially be involved in the alteration of the expression of these genes. These data suggest that acetate treatment has net anti-inflammatory effects in vivo and in vitro both in LPS-stimulated microglia and astrocyte cultures through neuroglial cell type-distinct mechanisms
Indoor Localisation and Mapping using Laser Range Finder
Simultaneous localization and mapping (SLAM) is one of the uprising and evolving branches in the field of robotics. SLAM gives a robot the capability of drawing a consistent map of the surrounding area while simultaneously localizing itself within the map without the need of having prior data about the surrounding like a pre-encoded map or localization aids like the Global Positioning System (GPS)
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