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Barchan dunes of the Kharga Depression, Western Desert, Egypt, have been assessed in terms of their morphometry, grain size, and migration rate using remote sensing and GIS techniques and field and laboratory work. Thirty-seven sites were chosen along the Kharga dune belt and subdivided into northern, central, and southern sectors. At each site, several barchans were subjected to morphometric measurements (length, width, height, length of eastern and western horns, and length of windward and leeward sides). The rate and direction of 160 barchans were also measured for the period between 2002 and 2018. Grain size analysis was carried out on sand samples taken from the crest of these dunes. Statistically, significant relationships have been found between the morphometric parameters, dune migration, and grain size attributes. The analysis of the morphology of the barchan dunes, their movement, and the nature of sedimentary materials provide essential information for assessing and evaluating their environmental hazards.

The current study deals with textural, mineralogical, and geochemical characteristics of the barchan dune sands of Abu Muharak dune belts in the Kharga Depression. Abu Muharak is the longest dune belt in the Western Desert of Egypt. Sand samples from 37 sites were texturally, petrologically, and chemically analyzed. Our goals were to interpret the provenance of the sands in terms of grain size, petrology, and geochemistry and correlate these data with the proposed source such as Nubian sandstone, Pleistocene alluvial, and Holocene lacustrine sediments as well as ancient aeolian deposits exposed at the Kharga Depression. The present study concludes that the Moghra sandstone is the main source of the Abu Muharak dune belt with local contributions from Pleistocene alluvial and dune deposits as well as weathered Nubian sandstone in the Kharga Depression.

Background Attention-deficit/hyperactivity disorder (ADHD) is a brain disorder marked by an ongoing pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning or development. Although children with ADHD made much more spelling errors, they had a distinct pattern of letter insertions, replacements, transpositions, and omissions. This mistake type is sometimes referred to as graphemic buffer errors, and it is caused by a lack of attention required for motor planning. The aim of study was to assess the incidence of dysgraphia in Arabic language in children with ADHD for better helping, diagnosis and management of those children. Results Ten percent of ADHD children had normal handwriting with no disability, 40% had excellent handwriting with a minimum of disability and 50% of ADHD children showed mild to moderate disability. There were significant differences between ADHD children and control children regarding results of each item on the subtest of handwriting of dysgraphia disability scale (DDS), respecting lines, spacing between words, letter direction, spelling a sentence, and punctuation. Drawing affected in ADHD children. The finger tapping speed was affected in almost ADHD children. Conclusions Dysgraphia highly presents in our sample of ADHD children with poor fine motor skills in ADHD children than normal children. ADHD children have illegible handwriting, not respecting lines, insufficient space between and within words, multiple spelling errors, and omissions of letters or words. Graphesthesia and stereognosis are affected more in ADHD children than in control children drawing and finger tapping speed affected in ADHD children.

N-(3-Chlorophenyl)hydrazinecarbothioamide (2) was prepared by reacting 1-chloro-3-isothiocyanatobenzene (1) with hydrazine hydrate in 2-propanol, whose 1H-NMR spectrum showed its existence in a Zwitter ionic betain form. A number of 2-arylidene-N-(3-chlorophenyl)hydrazinecarbothioamides (3a–e) were synthesized by the condensation of 2 with aromatic aldehydes in absolute ethanol and in the presence of a catalytic amount of glacial acetic acid. They were reacted with 2-bromo-1-(4-bromophenyl)ethanone (4) in 2-propanol/DMF in the presence of anhydrous potassium carbonate to produce the respective 2-(arylidenehydrazono)-4-(4-bromophenyl)-3-(3-chlorophenyl)-2,3-dihydrothiazoles (5a–e) in excellent yields. The synthesized compounds were characterized by spectroscopic methods as well as mass spectrometry. The molecular modeling and atomic charges of heteroatoms in all compounds were performed using Chem3D Pro 12.0.2 software and provided an excellent tool to investigate the fragmentation pathways. The nitrogen rule was also found to be good predictors of molecular ions and their fragmentation patterns.