553 research outputs found
Photodetachment of H near a partial reflecting surface
Theoretical and interpretative study on the subject of photodetachment of
H near a partial reflecting surface is presented, and the absorption
effect of the surface is investigated on the total and differential cross
sections using a theoretical imaging method. To understand the absorption
effect, a reflection parameter is introduced as a multiplicative factor to
the outgoing detached-electron wave of H propagating toward the wall. The
reflection parameter measures, how much electron wave would reflect from the
surface; K=0 corresponds to no reflection and K=1 corresponds to the total
reflection.Comment: 8 pages, 4 figure
Stack-run adaptive wavelet image compression
We report on the development of an adaptive wavelet image coder based on stack-run representation of the quantized coefficients. The coder works by selecting an optimal wavelet packet basis for the given image and encoding the quantization indices for significant coefficients and zero runs between coefficients using a 4-ary arithmetic coder. Due to the fact that our coder exploits the redundancies present within individual subbands, its addressing complexity is much lower than that of the wavelet zerotree coding algorithms. Experimental results show coding gains of up to 1:4dB over the benchmark wavelet coding algorithm
Transmuted Inverse Rayleigh Distribution: A Generalization of the Inverse Rayleigh Distribution.
In this article, we generalize the Inverse Rayleigh distribution using the quadratic rank transmutation map studied by Shaw et al. (2007) to develop a transmuted inverse Rayleigh distribution. The properties of this distribution are derived and the estimation of the model parameters is performed by maximum likelihood method. Keywords: Inverse Rayleigh Distribution, Transmutation Map, Hazard Rate Function, Reliability Function, Order Statistics, Parameter Estimation
Synthesis and Characterization of Some New Dianiline Oxide Derivatives
Multifunctional dianiline oxide ligands from 1,3-indanedione with aniline derivatives in ethanol (abs.) then with hydrogen peroxide in gl acial acetic acid (Scheme 1) were synthesized. These dianiline oxide compounds have been characterized by C, H, N elemental analysis, FT-IR, and 1H NMR spectroscopy. Keywords: aniline oxide , indanedione, nitron
Synthesis, Characterization and Antibacterial Activity of Some New 5,5'-diphenyl-4,4',5,5'-tetrahydro-1H,1'H-3,3'-bipyrazole Derivatives
An efficient and practical synthesis of five compounds of pyrazoline derivatives structures was achieved through cyclization of hydrazine hydrate with 1,6-diphenylhexa-1,5-diene-3,4-dione using glacial acetic acid as catalyst under thermal conditions. These compounds have been characterized by FT-IR, elemental analysis (C.H.N.) and 1H NMR spectroscopy. Keywords:pyrazoline, chalcone, heterocycli
Crop-based irrigation operations in the North West Frontier Province of Pakistan. Vol.II: Research approach and interpretation. Final Report
Irrigation management / Crop-based irrigation / Research / Irrigation canals / Water demand / Performance evaluation / Agricultural production / Pakistan / North West Frontier Province
Prevalence and patterns of physical activity among school aged adolescents in Pakistan: A systematic review and meta-analysis
Less than one fifth of Pakistani adolescents, aged 13–15, years achieve recommended activity levels. This systematic review and meta-analysis was conducted to determine a pooled estimate of the prevalence of PA, and to systematically evaluate the literature available on PA among adolescents in Pakistan. A systemic search of databases was conducted. In addition, hand search of references of all the included relevant publications was performed. Random effects meta-analysis was used to get weighted prevalence of PA among adolescents. Quality of undertaken studies was assessed using New-Castle Ottawa Scale. After removing duplicates, reviewing titles and abstracts and screening full texts, 15 articles were included for analysis. All studies were conducted in school setting, with a total sample size of 10,651. Weighted pooled prevalence of PA among adolescents was 36.0% with high heterogeneity (99.28%). Most of the studies met study quality assessment criteria except for comparability of subjects in different outcome groups and assessment of outcome. Prevalence of PA among adolescents is low in Pakistan. Formal strategies are needed for promoting PA among adolescents for their improved health and for reducing future burden of NCDs
A young boy with abdominal pain
At times, acute diffuse abdominal pain can be a diagnostic dilemma, especially when the symptoms appear to be out of proportion to the findings on physical examination. The case of a young boy with abdominal pain is presented
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