458 research outputs found
Absolute neutrino masses
We discuss the possibility of using experiments timing the propagation of
neutrino beams over large distances to help determine the absolute masses of
the three neutrinos.Comment: 3 pages, 2 figure
Neutrinos with velocities greater than c ?
A possible explanation of the results of the OPERA experiment is presented.
Assuming that the usual value of c should be interpreted as the velocity of
light in dark matter, we call the "true" velocity of light in vacuum, .
Then the OPERA neutrinos can be faster than c but slower than . We also
discuss the relationship between and neutrino masses.Comment: 5 pages, 1 figure, additional references adde
Perturbed S3 neutrinos
We study the effects of the perturbation which violates the permutation
symmetry of three Majorana neutrinos but preserves the well known (23)
interchange symmetry. This is done in the presence of an arbitrary Majorana
phase which serves to insure the degeneracy of the three neutrinos at the
unperturbed level.Comment: 11 pages, 2 figures, with some correction
Effect of Saline and Non-Specific Insulin Binding on the Phase Behavior of Poly (Ethylene Glycol)-Grafted Phosphoethanolamine-Succinyl Model Membranes
Poly (ethylene glycol)-grafted membrane-mimetic surfaces bearing negatively charged phospholipid headgroups have gained significant attention due to their promising contributions in numerous biomedical applications. The conformational properties of PEG chains have been mainly studied at the air/water interface, which does not elucidate much about its behavior at the physiological pH ~ 7.4. In this contribution, binary mixtures of a phosphoethanolamine-Succinyl bearing C16 aliphatic chains, DPPE-Succinyl, and a PEG-phospholipid conjugate bearing a PEG chain of 2000 Da, DPPE-PEG2000, have been used as ideal models of bio-nonfouling membrane-mimetic surfaces. The effect of PBS with pH ~7.4 as well as each of its individual constituents including Na2HPO4, KCl, KH2PO4, and NaCl on the biophysical properties of model membrane was examined. Our findings suggest that saline and each of its individual constituents play a pivotal role in the phase and conformational behavior of PEG-grafted membrane models. Insulin as a model protein was then selected to further investigate the effect of phase and conformation behavior of PEG-grafted membrane models on protein/membrane interactions. The insulin/membrane interactions were quantified in terms of monolayer area expansion, ΔA, penetration area, Ap, as well as protein binding degree, χp. To the best of our knowledge, this study provides the first insight into mechanistic aspects of protein interactions with model negatively charged PEG-grafted membranes. This knowledge, may aid in understanding the in-vivo performance of advanced targeted therapeutic carriers
Linear Sigma Models in QCD and S3 Symmetry for Neutrinos
This thesis has two parts with different topics in particle physics. In part I, we consider various linear sigma models and their applications to scalar mesons. It is shown that the tree amplitude for ππ scattering in the minimal linear sigma model has an exact expression which induces an infinite geometric series in which the pattern for both the I = 0 and I = 2 s-wave scattering lengths to orders , and seems to agree with chiral perturbation theory predictions. The model is then gauged to study the mass differences between the vector meson and the axial vector meson as a possibly useful template for the role of a light scalar in QCD as well as for (at a different scale) an effective Higgs sector for some recently proposed walking technicolor models. The model is applied to the s-wave pion-pion scattering in QCD. Both the near threshold region and (with an assumed unitarization) the global region up to about 800 MeV are considered. It is noted that there is a little tension between the choice of bare sigma mass parameter for describing these two regions.
By including the parity reversed partner we study a simple two Higgs dou-blet model which reflects, in a phenomenological way, the idea of compositeness for the Higgs sector. It is relatively predictive. In one scenario, it allows for a hidden usual Higgs particle in the 100 GeV region and a possible dark matter candidate.
Poles in unitarized [pi pi] scattering amplitude are studied in a generalized linear sigma model which contains two scalar nonets (one of quark-antiquark type and the other of diquark-antidiquark type) and two corresponding pseu- doscalar nonets. It is shown that a reasonable agreement with experimental data is obtained up to about 1 GeV. Some comparison is made to the situation in the usual SU(3) linear sigma model with a single scalar nonet.
We show that the mixing of two bare nonets, one of which is of quark- antiquark type and the other of two quark- two antiquark type is, before chiral symmetry breaking terms are included, only possible for three flavors. Specif ically, our criterion would lead one to believe that scalar and pseudoscalar states containing charm would not have four quark admixtures. We also discuss some aspects associated with the possibility of getting new experi- mental information about scalars from semileptonic decays of heavy charged mesons into an isosinglet scalar or pseudoscalar plus leptons.
In part II we explore a predictive model based on permutation symmetry S3 for the masses and mixing matrix of three Majorana neutrinos. At zeroth order the model yielded degenerate neutrinos and a generalized tribimaximal mixing matrix. We first study the effects of the perturbation which violates S3 but preserves the well known (23) interchange symmetry. This is done in the presence of an arbitrary Majorana phase ψ which serves to insure the degeneracy of the three neutrinos at the unperturbed level. At this order the mass splitting was incorporated and the tribimaximal mixing matrix emerged with very small corrections but with a zero value for the parameter s13. Next a different, assumed weaker, perturbation is included which gives a non zero value for s13 and further corrections to other quantities. These corrections are worked out and their consequences discussed under the simplifying assumption that the conventional CP violation phase vanishes. It is shown that the existing measurements of the parameter s23 provide strong bounds on s13 in this model
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Efficient energy management for the internet of things in smart cities
The drastic increase in urbanization over the past few years requires sustainable, efficient, and smart solutions for transportation, governance, environment, quality of life, and so on. The Internet of Things offers many sophisticated and ubiquitous applications for smart cities. The energy demand of IoT applications is increased, while IoT devices continue to grow in both numbers and requirements. Therefore, smart city solutions must have the ability to efficiently utilize energy and handle the associated challenges. Energy management is considered as a key paradigm for the realization of complex energy systems in smart cities. In this article, we present a brief overview of energy management and challenges in smart cities. We then provide a unifying framework for energy-efficient optimization and scheduling of IoT-based smart cities. We also discuss the energy harvesting in smart cities, which is a promising solution for extending the lifetime of low-power devices and its related challenges. We detail two case studies. The first one targets energy-efficient scheduling in smart homes, and the second covers wireless power transfer for IoT devices in smart cities. Simulation results for the case studies demonstrate the tremendous impact of energy-efficient scheduling optimization and wireless power transfer on the performance of IoT in smart cities
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