311 research outputs found

    On the Supersymplectic Homogeneous Superspace Underlying the OSp(1/2) Coherent States

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    In this work we extend Onofri and Perelomov's coherent states methods to the recently introduced OSp(1/2)OSp(1/2) coherent states. These latter are shown to be parametrized by points of a supersymplectic supermanifold, namely the homogeneous superspace OSp(1/2)/U(1)OSp(1/2)/U(1), which is clearly identified with a supercoadjoint orbit of OSp(1/2)OSp(1/2) by exhibiting the corresponding equivariant supermoment map. Moreover, this supermanifold is shown to be a nontrivial example of Rothstein's supersymplectic supermanifolds. More precisely, we show that its supersymplectic structure is completely determined in terms of SU(1,1)SU(1,1)-invariant (but unrelated) K\"ahler 22-form and K\"ahler metric on the unit disc. This result allows us to define the notions of a superK\"ahler supermanifold and a superK\"ahler superpotential, the geometric structure of the former being encoded into the latter.Comment: 19 pgs, PlainTeX, Preprint CRM-185

    Co-oligomers Based on 2-Methoxy, 5-(2’-ethylhexyloxy) phenylene and Thienylenevinylene for Organic Solar Cells

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    Thanks to their optoelectronic properties and specific applications such as organic solar cells, the research on the lower band gap of organic p-conjugated materials encompassing both polymers and oligomers have been widely studied over the last years. The control of the band gap of these materials is a research issue of ongoing interest. In this study, theoretical study using the DFT method on four oligomers based on 2-methoxy, 5-(2’-ethylhexyloxy) phenylene and thienylenevinylene is reported. The theoretical ground-state geometry and electronic structure of the studied molecules were obtained by the DFT method at the B3LYP level with a 6–31G (d) basis set. Theoretical knowledge of the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) energy levels the gap energy (Eg) and the open-circuit voltage (Voc) of the studied compounds are calculated and discussed. The results of this work suggest these materials as a good candidate for organic solar cells. DOI: http://dx.doi.org/10.17807/orbital.v8i3.80

    Phenolic characterization and antioxidant activity of two endemic wormwood species of Morocco: Artemisia ifranensis J. Didier and Artemisia mesatlantica

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    Artemisia ifranensis and Artemisia mesatlantica are two endemic species in Morocco belonging to the Asteraceae family. Located in the region of Moroccan Atlas, they are very much sought after by the local population for their therapeutic properties.However, given the limited studies conducted on these species and in order to contribute to their valorization, we selected them in full bloom in the region of Timahdite for a phytochemical study and an evaluation of their antioxidant properties. The results of phytochemical screening revealed their richness in polyphenols, sterols, triterpenes and mucilages. The extraction yields of the total polyphenols by maceration in a methanol-water mixture (80/20) were 10.10% for A. mesatlantica and 16.66% for A. ifranensis. The determination of the total phenols by the Folin-Ciocalteu method after fractionation of the polyphenolic extracts showed the abundance of these compounds in the butanolic fraction of A. Mesatlantica and the methanolic extract of A. Ifranensis. For the total flavonoids dosed with aluminum trichloride, the ethyl acetate fractions of A. Mesatlantica and butanolic acid. Ifranensis were the richest. In addition, the crude extract of A. Mesatlantica was particularly rich in condensed tannins.Evaluation of the antioxidant activity by reduction of iron (FRAP) and trapping of the free radical DPPH * showed that all the extracts have a moderate antioxidant power.These early studies on A. mesatlantica and A. ifranensis of Timahdite reveal their abundance of important chemical compounds. Also, due to the ability of these plants to trap radicals, they can be considered as sources of natural antioxidants

    Co-oligomers Based on 2-Methoxy, 5-(2’-ethylhexyloxy) phenylene and Thienylenevinylene for Organic Solar Cells

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    Thanks to their optoelectronic properties and specific applications such as organic solar cells, the research on the lower band gap of organic p-conjugated materials encompassing both polymers and oligomers have been widely studied over the last years. The control of the band gap of these materials is a research issue of ongoing interest. In this study, theoretical study using the DFT method on four oligomers based on 2-methoxy, 5-(2’-ethylhexyloxy) phenylene and thienylenevinylene is reported. The theoretical ground-state geometry and electronic structure of the studied molecules were obtained by the DFT method at the B3LYP level with a 6–31G (d) basis set. Theoretical knowledge of the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) energy levels the gap energy (Eg) and the open-circuit voltage (Voc) of the studied compounds are calculated and discussed. The results of this work suggest these materials as a good candidate for organic solar cells. DOI: http://dx.doi.org/10.17807/orbital.v8i3.80

    Development of specific primers for the detection of HVA1 from barley in transgenic durum wheat by polymerase chain reaction (PCR) technology

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    Genetic transformation is a widely employed tool in both basic research and commercial plant breeding programs. Its application requires that transgenes be stably integrated and expressed in the plant genome. When transgenic plants are developed, it is essential to determine which plants contain the transgene. Detection methods are usually based on amplification of the target transgene. This paper describes a development of detection method based on conventional and real time polymerase chain reaction (PCR) for simultaneous detection of barley HVA1 transgene and its transcript in transformed durum wheat. Since there exist a high homology between the barley HVA1 gene and the wheat gene, development of a specific sets of primers is needed for PCR-based characterizations, and the study of the transgene. Based on the alignment of the two genes sequences obtained from public databases, several primers were designed to detect and distinguish between the transformed and non-transformed plants. Real time PCR has been employed because of its inherent sensitivity and quantitative nature. It has been possible to design the following primers pairs F2/MMR, F2/R10 and F14/R10 as highly specific and suitable for the detection of HVA1 DNA by conventional and real-time PCR. Nonetheless, the primers used were allowed to reach high efficiencies and did not show any cross-reactivity with DNAs extracted from various plants. The sensitivity achieved was 6.4 pg. The primer pair F2/R10 was considered as highly specific for the detection of both DNA and mRNA of the HVA1 by real-time PCR. The assays proved to be accurate, specific, sensitive and sufficiently reproducible for further application in high-throughput molecular characterization of transgenic lines.Keywords: HVA1, durum wheat, transgenic plant, real time polymerase chain reaction (PCR), droughtAfrican Journal of Biotechnology, Vol. 13(4), pp. 581-592, 22 January, 201

    TRIZ effect exploitation on engineering students thinking skills in product design

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    Product design is a creative and multidisciplinary activity that often necessitates the application of analytical and innovative support tools to enhance the concept research phase and solutions development. The TRIZ theory, a highly effective innovation method, has demonstrated its efficacy in supporting innovation across various fields. In this context, our focus has been on integrating TRIZ into the product design process involving engineering designers. This article provides a descriptive and critically assessed evaluation of the operational impact of TRIZ on the design activity, specifically in the development of a "Wastewater Screening and Filtration System" during the preliminary design phases. The objective of this research is to assess the influence of TRIZ utilization on the engineering designers' ability to address a design problem. The ultimate goal is to establish an innovative design support approach based on the use of TRIZ tools that is easily comprehensible and applicable to future designers. Within this article, we present both quantitative and qualitative results of the exploitation of TRIZ tools combined with an energy analysis of the requirement in the product design field

    Canted antiferromagnetic order in the kagome material Sr-vesignieite

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    We report 51 V NMR, muon spin rotation, and zero-applied-field 63 , 65 Cu NMR measurements on powder samples of Sr-vesignieite, SrCu 3 V 2 O 8 ( OH ) 2 , a S = 1 / 2 nearly kagome Heisenberg antiferromagnet. Our results demonstrate that the ground state is a q = 0 magnetic structure with spins canting either in or out of the kagome plane, giving rise to weak ferromagnetism. We determine the size of ordered moments and the angle of canting for different possible q = 0 structures and orbital scenarios, thereby providing insight into the role of the Dzyaloshinskii-Moriya interaction in this material

    Advancements in tetronic acid chemistry. Part 1: Synthesis and reactions

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    AbstractThe preparation and the properties of the elusive tetronic acid are reviewed, including its synthesis, chemical reactivity and reactions
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