1,237 research outputs found
Genetical studies on the interrelationships of certain viruses causing necrosis in the potato
This paper is concerned with a study of the
inheritance of a type of reaction in the potato plants
following infection -by certain viruses.The evidence presented herein seems to offer
a sound basis from which further incursions into potato
genetics may be made with some measure of confidence.
The majority of characters in the cultivated potato
such as leaf shape, pubescence, tuber shape, time of
maturity are quantitative in their expression and
unsuitable for straightforward genetical analysis.
With the simplified biochemical methods now available,
however, it should be possible to analyse the inheritance of tuber colour and most probably other discontinuous characters are to be looked for among the
wild South American potatoes. The possibilities of
the present material are by no means exhausted and
many aspects remain to be worked out. Additionally
it is hoped that an examination of the distribution
of the lethal necrotic genes among the South American
material may lead to interesting results
Sensory properties of menthol and smoking topography
Although there is a great deal known about menthol as a flavoring agent in foods and confections, less is known about the particular sensory properties of menthol cigarette smoke. Similarly, although smoking topography (the unique way an individual smokes a cigarette) has been well studied using non-menthol cigarettes, there is relatively less known about how menthol affects smoking behavior. The objective of this review is to assess the sensory properties of menthol tobacco smoke, and smoking topography associated with menthol cigarettes. The cooling, analgesic, taste, and respiratory effects of menthol are well established, and studies have indicated that menthol’s sensory attributes can have an influence on the positive, or rewarding, properties associated smoking, including ratings of satisfaction, taste, perceived smoothness, and perceived irritation. Despite these sensory properties, the data regarding menthol’s effect on smoking topography are inconsistent. Many of the topography studies have limitations due to various methodological issues
Open orbifold Gromov-Witten invariants of [C^3/Z_n]: localization and mirror symmetry
We develop a mathematical framework for the computation of open orbifold
Gromov-Witten invariants of [C^3/Z_n], and provide extensive checks with
predictions from open string mirror symmetry. To this aim we set up a
computation of open string invariants in the spirit of Katz-Liu, defining them
by localization. The orbifold is viewed as an open chart of a global quotient
of the resolved conifold, and the Lagrangian as the fixed locus of an
appropriate anti-holomorphic involution. We consider two main applications of
the formalism. After warming up with the simpler example of [C^3/Z_3], where we
verify physical predictions of Bouchard, Klemm, Marino and Pasquetti, the main
object of our study is the richer case of [C^3/Z_4], where two different
choices are allowed for the Lagrangian. For one choice, we make numerical
checks to confirm the B-model predictions; for the other, we prove a mirror
theorem for orbifold disc invariants, match a large number of annulus
invariants, and give mirror symmetry predictions for open string invariants of
genus \leq 2.Comment: 44 pages + appendices; v2: exposition improved, misprints corrected,
version to appear on Selecta Mathematica; v3: last minute mistake found and
fixed for the symmetric brane setup of [C^3/Z_4]; in pres
Braid graphs in simply-laced triangle-free Coxeter systems are partial cubes
Any two reduced expressions for the same Coxeter group element are related by
a sequence of commutation and braid moves. We say that two reduced expressions
are braid equivalent if they are related via a sequence of braid moves, and the
corresponding equivalence classes are called braid classes. Each braid class
can be encoded in terms of a braid graph in a natural way. In this paper, we
study the structure of braid graphs in simply-laced Coxeter systems. We prove
that every reduced expression has a unique factorization as a product of
so-called links, which in turn induces a decomposition of the braid graph into
a box product of the braid graphs for each link factor. When the Coxeter graph
has no three-cycles, we use the decomposition to prove that braid graphs are
partial cubes, i.e., can be isometrically embedded into a hypercube. For a
special class of links, called Fibonacci links, we prove that the corresponding
braid graphs are Fibonacci cubes.Comment: 24 page, 11 figure
Rapid prototyping of waveguide and horn antennas
In this paper we review how fused deposition
modelling (FDM) can be deployed for the rapid prototyping of microwave waveguide componentry and antennas. Additive
manufacture of such objects allows new, novel and complex structures to be fabricated with lower impact on the environment relative to current manufacturing processes, plus the fast turnaround of design to manufacture and test. Additionally while the resulting physical antenna properties may not be perfect compared to the design or what can be
machined, their RF/microwave performance can be quite forgiving thereby allowing the antenna design engineer to fully exploit the rapid prototyping concept
Additively manufactured profiled conical horn antenna with dielectric loading
The world's first additively manufactured dielectric loaded profiled conical horn antenna is presented in this letter. With a smooth profiled flare and two loaded dielectric core materials, this horn offers symmetrical patterns, wideband gain, low sidelobe level, and low cross polarization. Additive manufacturing, including electroplating, has been employed to address the fabrication challenges. The measurement results show that the fabrication process produces a horn antenna with reduced mass and volume (<;200 g with three-dimensional-printed flange) and high antenna performance with realized gain 16-20 dBi, sidelobe level -22 to -19 dB across the frequency range from 9 to 15 GHz
Fused deposition modelling for microwave circuits & antennas
Additive Manufacturing, or 3D printing, is
moving from the research labs and into both consumer and commercial manufacturing markets. As the systems, processes and materials available are becoming more mature we are seeing them being tested for new application areas such as electronics. In this paper we review how fused deposition
modelling (FDM) is being explored for creating microwave circuits and componentry, their RF performance and the materials challenges faced. In recent years such microwave circuits and components have included antennas, lenses, antireflective
coatings, transmission lines and planar circuits, waveguide terminations, performing at frequencies ranging from low GHz up to tens of GHz. Additive manufacture of such objects allows new, novel and complex structures to be fabricated with lower impact on the environment relative to current manufacturing processes, plus the rapid prototyping of circuits. Additionally it currently offers reasonable RF performance that can be competitive through further
advances in manufacturing processes and materials
The orbifold cohomology of moduli of genus 3 curves
In this work we study the additive orbifold cohomology of the moduli stack of
smooth genus g curves. We show that this problem reduces to investigating the
rational cohomology of moduli spaces of cyclic covers of curves where the genus
of the covering curve is g. Then we work out the case of genus g=3.
Furthermore, we determine the part of the orbifold cohomology of the
Deligne-Mumford compactification of the moduli space of genus 3 curves that
comes from the Zariski closure of the inertia stack of M_3.Comment: 29 pages, 2 figures. Minor changes, to appear in Manuscripta Mat
Wearable and meshed wideband monopole antennas and their interactions with the human body
This study considers a wideband monopole antenna and its interactions with different separations from the human body phantom over a wide frequency. A meshed alternative version has also been developed which has similar performance to the circular wideband monopole antenna but requires less material. The specific absorption rate and efficiency of this antenna have been analysed as a function of separation distance and frequency. The mesh design has been fabricated by using embroidery and 3D printing techniques
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