Morphological studies on trichomes of Brassicaceae in Egypt and taxonomic significance

Trichomes morphology, structure, and taxonomic significance of 82 species belonging to 9 tribes of Brassicaceae from Egypt were studied using light microscopy (LM) and scanning electron microscopy (SEM). This work was largely based on herbarium material in addition, fresh material of most of the taxa was studied. A total of twelve trichome types could be distinguished and classified into unicellular or multicellular based on the structure of the hair. The unicellular trichomes could be distinguished as simple, hooked, vasculate, clavate simple glandular, appressed medifixed, trifixed, Y-shaped, branched (3–4 fids), dendroid and stellate. The multicellualr trichomes were glandular. We found trichomes as being valuable characteristics for identification of tribes, genera, species, subspecies, and varieties in Brassicaceae. A key for the identification of the investigated taxa based on trichome characters is provided in this paper

Disparaging Trademarks: Who Matters

For more than a century, non-majority groups have protested the use of trademarks comprised of or containing terms referencing the group—albeit for various reasons. Under the 1946 Lanham Act, Congress added a prohibition against registering disparaging trademarks, which could offer protection to non-majority groups targeted by the use of trademarks offensive to members of the group. The prohibition remained relatively unclear, however, and rarely applied in that context until a group of Native Americans petitioned to cancel the Washington NFL team’s trademarks as either scandalous, offensive to the general population, or disparaging, offensive to the referenced group. In clarifying the appropriate test for disparaging, however, the decision makers have overly analogizing the two prohibitions, rendering the disparaging trademark prohibition less effective in protecting non-majority groups from offensive trademarks

Five-Phase Modular External Rotor PM Machines with Different Rotor Poles: A Comparative Simulation Study

The performance of fault-tolerant modular permanent magnet machines depends on the proper selection of the pole and slot numbers which result in negligible coupling between phases. The preferred slot and pole number combinations eliminate the effect of low-order harmonics in the stator magnetomotive force and thereby the vibration and stray loss are reduced. In this paper, three external rotor machines with identical machine dimensions are designed with different slots per phase per pole ratios. A simulation study is carried out using finite element analysis to compare the performance of the three machines in terms of machine torque density, ripple torque, core loss, and machine efficiency. A mathematical model based on the conventional-phase-model approach is also used for the comparative study. The simulation study is extended to depict machine performance under fault conditions

Biosystematic studies on Brassicaceae (Cruciferae) in Egypt

The present work deals with a systematic investigation of 45 taxa belonging to 23 genera of the tribes Arabideae, Euclidieae, Hesperideae, Lunarieae, Matthioleae and Sisymbrieae of the family Brassicaceae from Egypt. This work is largely based on herbarium material received on loan from B, BM, BR, E, HUJ, K, KSU, L, LY, NMGM, OXF & FHO and W, and collections kept in the following herbaria; B, CAI, CAIM, WAG and Sohag University Herbarium (SHG, proposed abbreviation). In addition, fresh material of most of the taxa was studied and field observations were made from several localities in Egypt.Chapter 1 describes the family as a whole, presenting a historical review, its phytogeography, uses and economic importance, an outline of the thesis, aims and general objectives.Chapter 2 deals with the materials and methods used in this chapter. A full discussion for all morphological characters is provided; systematic treatment, based on macro-characters such as habit, leaf, floral, fruit, embryo and seed and micro-characters of trichomes. An artificial key applies the most reliable characters for the distinction of the genera.In the systematic treatment 45 taxa are recognized, presenting up-to-date nomenclature, literature citations, type specimens and their locations, synonyms, specimens examined, and distribution maps.Some taxonomic and nomenclature problems in Rorippa, Neslia, Eremobium, Malcolmia, Matthiola, Arabidopsis and Neotorularia are discussed and changes proposed.Chapter 3 presents macro-morphological characters of the seeds such as seed shape, colour, size, radicle, and micro- morphological characters by (SEM examination) of the epidermal cell shape, anticlinal boundaries, the outer periclinal cell wall and relief of outer cell walls are presented. Three types of basic anticlinal cell wall boundaries are recognized and, six different shapes of the outer periclinal cell wall are described. A key for the identification of the investigated taxa based on seed characters is provided.Chapter 4 deals with morphological characters of the pollen grains using SEM. In general the pollen morphology varies within a narrow range. The pollen grains are tricolpate. The shape varies from prolate spheroidal, subprolate to prolate. Three pollen types can be distinguished based on the size of lumina. The exine ornamentation of pollen grains varies between genera within tribes and between species within the same genus. The exine ornamentation of pollen was found useful to distinguish between closely related genera.Chapter 5 deals with the systematics of the tribes of the Brassicaceae, by means of numerical analysis based on sixty-two morphological characters, including vegetative parts, pollen grains and seeds. Morphological characters have been analyzed using two types of analyses: firstly, we performed a cluster analysis using average taxonomic distance and UPGMA clustering (procedures SIMINT, SAHN, and TREE). Secondly, we performed a principal coordinates analysis (PCO), using the product-moment correlation as a coefficient. The procedures STAND and SIMINT were used to calculate the distance matrix, the procedures EIGEN, PROJ, and MXPLOT to perform the PCO. Four main groups are recognised: Lunarieae, Euclidieae, Matthioleae and a mixed group. Representatives of these groups cluster together based on characters with high factor loading in the PCO analysis. The tribe Euclidieae is the most homogeneous group, and the tribe Arabideae is the most heterogeneous and probably of polyphyletic origin.Chapter 6 deals with phylogenetic relationships of 83 species belonging to 39 genera of tribes Brassiceae, Alysseae, Arabideae, Euclidieae, Hesperideae, Lepidieae, Lunarieae, Matthioleae and Sisymbrieae. In total 44 species belonging to 28 genera from Egypt were investigated using nucleotide sequences variation of the chloroplast matK gene to assess relationships among genera within tribe and tribes within the family. The topology of Jackknife, parsimony analysis, and Maximum Likelihood trees are largely in agreement. The analysis indicates that tribes Arabideae, Sisymbrieae, Hesperideae, and Lepidieae are polyphyletic

Parameter Estimation of Asymmetrical Six-phase Induction Machines using Modified Standard Tests

In multiphase machine drives, accuracy of the estimated machine parameters is crucial for effective performance prediction and/or control. While a great amount of work has been done on parameter estimation for three-phase machines, corresponding discussions for six-phase machine remain scarce. It has been proven in the literature that the effect of mutual leakage inductance between different winding layers has a significant impact on the equivalent machine reactance, which challenges the standard separation method of stator and rotor leakage inductances from the measured locked-rotor impedance. In this paper, parameter identification of an asymmetrical six-phase induction machine using six-phase no-load and locked-rotor tests is discussed. A zero-sequence test using an improved equivalent circuit is proposed to improve the accuracy of the estimated parameters. The concept is verified using experimental results obtained from a low-power prototype asymmetrical six-phase machine

Studying the effect of over-modulation on the output voltage of three-phase single-stage grid-connected boost inverter

AbstractVoltage boosting is very essential issue in renewable-energy fed applications. The classical two-stage power conversion process is typically used to interface the renewable energy sources to the grid. For better efficiency, single-stage inverters are recommended. In this paper, the performance of single-stage three-phase grid-connected boost inverter is investigated when its gain is extended by employing over-modulation technique. Using of over-modulation is compared with the employment of third order harmonic injection. The latter method can increase the inverter gain by 15% without distorting the inverter output voltage. The performance of extended gain grid-connected boost inverter is also tested during normal operation as well as in the presence of grid side disturbances. Simulation and experimental results are satisfactory