1,824 research outputs found
Characterization 410 Stainless Steel by Vacuum Tempering Process
It has been reported that low-temperature vacuum tempering of 410 stainless steel hard layer improving wear resistance and hardness. Grade 410 stainless steel being a hardened material were modified by low temperature tempering process. By the process of tempering, brittleness on the stainless steel material will be reduced and ductility will be promoted. The microstructure, surface hardness and erosion-corrosion resistance were systematically evaluated. Vacuum tempering is done at low temperature of 430℃ can form a hardened layer, and with the treated time prolong, the thickness of the layer increased. The stainless specimens were vacuum tempered for 30 minutes, 60 minutes and 120 minutes. Wear tests were conducted with the help of pin on disc apparatus. The output results were determined with various metallographic tests like scanning electron microscope and optical microscope results
The Stability of the Gauge Hierarchy in
It has been shown that the Dimopoulos-Wilczek (or missing-VEV) mechanism for
doublet-triplet splitting can be implemented in models,
which requires no adjoint Higgs fields. This is an advantage from the point of
view of string theory construction. Here the stability of the gauge hierarchy
is examined in detail, and it is shown that it can be guaranteed much more
simply than in . In fact a symmetry ensures the stability of the
DW form of the expectation values to all orders in GUT-scale VEVs. It is also
shown that models based on have the advantages of while permitting complete quark-lepton unification as in
.Comment: 13 pages, LaTe
Constraining Proton Lifetime in SO(10) with Stabilized Doublet-Triplet Splitting
We present a class of realistic unified models based on supersymmetric SO(10)
wherein issues related to natural doublet-triplet (DT) splitting are fully
resolved. Using a minimal set of low dimensional Higgs fields which includes a
single adjoint, we show that the Dimopoulos--Wilzcek mechanism for DT splitting
can be made stable in the presence of all higher order operators without having
pseudo-Goldstone bosons and flat directions. The \mu term of order TeV is found
to be naturally induced. A Z_2-assisted anomalous U(1)_A gauge symmetry plays a
crucial role in achieving these results. The threshold corrections to
alpha_3(M_Z), somewhat surprisingly, are found to be controlled by only a few
effective parameters. This leads to a very predictive scenario for proton
decay. As a novel feature, we find an interesting correlation between the d=6
(p\to e^+\pi^0) and d=5 (p\to \nu-bar K+) decay amplitudes which allows us to
derive a constrained upper limit on the inverse rate of the e^+\pi^0 mode. Our
results show that both modes should be observed with an improvement in the
current sensitivity by about a factor of five to ten.Comment: 21 pages LaTeX, 2 figures, Few explanatory sentences and three new
references added, minor typos corrected
Bflier's: A Novel Butterfly Inspired Multi-robotic Model in Search of Signal Sources
The diversified ecology in nature had various forms of swarm behaviors in
many species. The butterfly species is one of the prominent and a bit
insightful in their random flights and converting that into an artificial
metaphor would lead to enormous possibilities. This paper considers one such
metaphor known as Butterfly Mating Optimization (BMO). In BMO, the Bfly follows
the patrolling mating phenomena and simultaneously captures all the local
optima of multimodal functions. To imitate this algorithm, a mobile robot
(Bflybot) was designed to meet the features of the Bfly in the BMO algorithm.
Also, the multi-Bflybot swarm is designed to act like butterflies in nature and
follow the algorithm's rules. The real-time experiments were performed on the
BMO algorithm in the multi-robotic arena and considered the signal source as
the light source. The experimental results show that the BMO algorithm is
applicable to detect multiple signal sources with significant variations in
their movements i.e., static and dynamic. In the case of static signal sources,
with varying initial locations of Bflybots, the convergence is affected in
terms of time and smoothness. Whereas the experiments with varying step-size
leads to their variation in the execution time and speed of the bots. In this
work, experiments were performed in a dynamic environment where the movement of
the signal source in both maneuvering and non-maneuvering scenarios. The
Bflybot swarm is able to detect the single and multi-signal sources, moving
linearly in between two fixed points, in circular, up and down movements.To
evaluate the BMO phenomenon, various ongoing and prospective works such as
mid-sea ship detection, aerial search applications, and earthquake prediction
were discussed.Comment: 12 pages, 17 figure
SU(16) grandunification: breaking scales, proton decay and neutrino magnetic moment
We give a detailed renormalization group analysis for the SU(16) grandunified
group with general breaking chains in which quarks and leptons transform
separately at intermediate energies. Our analysis includes the effects of Higgs
bosons. We show that the grandunification scale could be as low as GeV and give examples where new physics could exist at relatively low
energy ( GeV). We consider proton decay in this model and show that
it is consistent with a low grandunification scale. We also discuss the
possible generation of a neutrino magnetic moment in the range of to
with a very small mass by the breaking of the embedded
SU(2) symmetry at a low energy.Comment: (16 pages in REVTEX + 6 figures not included) OITS-49
Primary Adenosquamous Carcinoma of Ascending Colon – A Rare Entity
Colorectal cancers (CRC) are on the rise globally with increased incidence rate 5.7/100000 cases in developing countries like India. 1 Majority (90%) of CRC are adenocarcinoma. The primary adenosquamous carcinoma (ASC) of the colon is exceedingly rare variant of adenocarcinoma with incidence of 0.025% and accounts for 0.1% of colonic epithelial malignancies. 2 The squamous differentiation accounts for its aggressiveness and poor prognosis. Here we report a rare case of primary ASC in 80year old male who presented with large bowel obstruction and peritonitis. A 80-year-old male brought to causality with history of fever, vomiting, pain in abdomen, altered sensorium since three days. The clinical examination revealed intestinal obstruction and peritonitis. Patient was immediately subjected for radiological and hematology investigations which showed signs of bowel obstruction and perforation. On emergency exploratory laparotomy, colonic perforation was identified along with an ulcer proliferative mass in ascending colon. Gross examination of right hemicolectomy revealed 9x6x3cm ulcero proliferative mass in ascending colon. The microscopic examination showed an infiltrating tumor composed of adenocarcinoma component and areas of squamous differentiation (60%) noted. Tumor was invading through muscularis propria and serosa. Final diagnosis of primary ASC was made. Colonic ASC is rare and associated with poorer prognosis. The squamous cell differentiation has greater metastatic potential than adenocarcinoma. Compared to adenocarcinoma, ASC is more likely to manifest with advanced disease and complications. Keywords: Adenosquamous, Carcinoma, Colo
Supersymmetric SO(10) Simplified
In the context of supersymmetric grand unified models, it is shown
that the gauge symmetry breaking as well as a natural doublet--triplet
splitting can be achieved with a minimal Higgs system consisting of a single
adjoint and a pair of vector and spinor multiplets. Such a Higgs spectrum has
been shown to arise in the free fermionic formulation of superstrings. Since
the symmetry breaking mechanism relies on non--renormalizable operators, some
of the Higgs particles of the model turn out to have masses somewhat below the
GUT scale. As a consequence, the unification scale is raised to about and sin is predicted to be slightly larger than the
minimal SUSY-- value. Including threshold uncertainties, which turn out
to be surprisingly small in the model, we show that sin prediction
is consistent with experiments.Comment: 23 pages, BA-94-4
b-physics signals of the lightest CP-odd Higgs in the NMSSM at large tan beta
We investigate the low energy phenomenology of the lighter pseudoscalar
in the NMSSM. The mass can naturally be small due to a global
symmetry of the Higgs potential, which is only broken by trilinear
soft terms. The mass is further protected from renormalization group
effects in the large limit. We calculate the
amplitude at leading order in and work out the contributions to
rare , and radiative -decays and mixing. We obtain
constraints on the mass and couplings and show that masses down to
MeV are allowed. The -physics phenomenology of the NMSSM
differs from the MSSM in the appearance of sizeable renormalization effects
from neutral Higgses to the photon and gluon dipole operators and the breakdown
of the MSSM correlation between the branching ratio and
mixing. For masses above the tau threshold the
can be searched for in processes with branching ratios
\lsim 10^{-3}.Comment: 18 pages, 3 figures; references adde
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