Transverse momentum correlations of quarks in recursive jet models

In the symmetric string fragmentation recipe adopted by PYTHIA for jet simulations, the transverse momenta of successive quarks are uncorrelated. This is a simplification but has no theoretical reason. Transverse momentum correlations are naturally expected, for instance, in a covariant multiperipheral model of quark hadronization. We propose a simple recipe of string fragmentation which lead to such correlations. The definition of the jet axis and its relation with the primordial transverse momentum of the quark is also discussed.Comment: 7 pages, 3 figures, 1 tabl

Collision frequencies and electron temperatures in the lower ionosphere

Collision frequencies and electron temperatures in lower ionospher

An exponential Diophantine equation related to the difference between powers of two consecutive Balancing numbers

In this paper, we find all solutions of the exponential Diophantine equation $B_{n+1}^x-B_n^x=B_m$ in positive integer variables $(m, n, x)$, where $B_k$ is the $k$-th term of the Balancing sequence.Comment: Comments are welcom

Soot mass estimation from electrical capacitance tomography imaging for a diesel particulate filter

Indiana University-Purdue University Indianapolis (IUPUI)The Electrical capacitance tomography (ECT) method has recently been adapted to obtain tomographic images of the cross section of a diesel particulate filter (DPF). However, a soot mass estimation algorithm is still needed to translate the ECT image pixel data to obtain soot load in the DPF. In this research, we propose an estimation method to quantify the soot load in a DPF through an inverse algorithm that uses the ECT images commonly generated by a back-projection algorithm. The grayscale pixel data generated from ECT is used in a matrix equation to estimate the permittivity distribution of the cross section of the DPF. Since these permittivity data has direct correlation with the soot mass present inside the DPF, a permittivity to soot mass distribution relationship is established first. A numerical estimation algorithm is then developed to compute the soot mass accounting for the mass distribution across the cross-section of the DPF as well as the dimension of the DPF along the exhaust flow direction. Firstly, ANSYS Electronic Desktop software is used to compute the capacitance matrix for different amounts of soot filled in the DPF, furthermore it also analyzed different soot distribution types applied to the DPF. The Analysis helped in constructing the sensitivity matrix which was used in the numerical estimation algorithm. Experimental data have been further used to verify the proposed soot estimation algorithm which compares the estimated values with the actual measured soot mass to validate the performance of the proposed algorithm

Molecular investigations in date palm genetic structure and diversity among commercially important date palm cultivars (Phoenix dactylifera L.)

2019 Fall.Includes bibliographical references.The date palm, Phoenix dactylifera L. is the notable palm which produces a nutrient-rich edible fruit (the date), well known for its unique attributes of medicine and healthy energy. It is a species that has been cultivated since early civilizations in the fertile crescent and later in the Middle East. It is typically cloned with many cultivars (over 3000). A means of accurately identifying specific clones and an understanding of the relationships among major commercial cultivars would provide valuable information for the maintenance, potentially an improvement and continued conservation of superior genotypes. Phylogenetic relationships amid commercial date cultivars are poorly understood, despite their importance. This research aimed at providing applicable knowledge through an expedient technique, by developing an exclusively tailored Simple Sequence Repeat (SSR) panel, custom-made for date palm fingerprinting and molecular identification also named as 'Dates PalmàPrinting'. This assembled modified genotyping by microsatellite markers provides a standardized approach to cultivar identification and a quality control application in date palm micropropagation production. A deeper understanding and relationship of today's major commercial cultivars is incomplete. Improving the development and productivity of this tree species is restricted due to few genetic resources. Only regionally narrowed studies have been conducted but it is more important to have a broader base of such knowledge. The present research reports on 20 selected, commercially important date palm cultivars, consisting of 18 females and 2 males, which are grown throughout the world. The knowledge of relationships among these cultivars is needed, although the date palm genome has been mostly sequenced (90.2 %) with 41,660 gene models representing an 82,354 scaffold. The relationships among the major cultivars remain unclear. Presently, the information on the characterization of these cultivars requires an assessment to better understand the relationships among the superior genotypes. The use of microsatellites, due to their accuracy and high polymorphic capability, have led to fine scaled phylogenies. The phylogenetic relationships were determined using neighbor joining un-rooted trees correlated with genetic structure clustering. Primer selections were achieved from evaluation of 14 nuclear SSR loci isolated from P. dactylifera. Results revealed a high degree of polymorphism observed in the 20 cultivars with fewer common alleles than anticipated. Within the cultivars studied, a broad heterozygosity across base pair (bp) amplification data has led to an understanding of limited inbreeding, accounting for possible adaptation to environmental changes and revealing conserved extensive array of genomic structure. Population structure analysis suggests a large genetic boundary between Northwest African and Middle Eastern cultivars with 6 subpopulations that represent divergences and fragments of admixture in cultivars present in these regions. The possible selection of potential and good quality parents is achievable for improving cultivars by generating population and structure maps. This analysis documents patterns of relationship and provides genetic structure and diversity of gene pool specificity complexes of date palm cultivars. This study provides insights about the relationships that exist among cultivars of interest through genetic sequence analysis using SSRs, facilitating the development of a standard approach to identification and enhancements to the micropropagation process. Keywords: Microsatellites, Phoenix dactylifera L., Simple sequence repeats, Phylogenetics, Genetic structure, Date palm, Genetic diversit

Cross-Layer Design for Green Power Control

In this work, we propose a new energy efficiency metric which allows one to optimize the performance of a wireless system through a novel power control mechanism. The proposed metric possesses two important features. First, it considers the whole power of the terminal and not just the radiated power. Second, it can account for the limited buffer memory of transmitters which store arriving packets as a queue and transmit them with a success rate that is determined by the transmit power and channel conditions. Remarkably, this metric is shown to have attractive properties such as quasi-concavity with respect to the transmit power and a unique maximum, allowing to derive an optimal power control scheme. Based on analytical and numerical results, the influence of the packet arrival rate, the size of the queue, and the constraints in terms of quality of service are studied. Simulations show that the proposed cross-layer approach of power control may lead to significant gains in terms of transmit power compared to a physical layer approach of green communications.Comment: Presented in ICC 201