The strong coupling, unification, and recent data

The prediction of the strong coupling assuming (supersymmetric) coupling constant unification is reexamined. We find, using the new electroweak data, $\alpha_{s}(M_{Z}) \approx 0.129 \pm 0.010$. The implications of the large $\alpha_{s}$ value are discussed. The role played by the $Z$ beauty width is stressed. It is also emphasized that high-energy (but not low-energy) corrections could significantly diminish the prediction. However, unless higher-dimension operators are assumed to be suppressed, at present one cannot place strong constraints on the super-heavy spectrum. Non-leading electroweak threshold corrections are also discussed.Comment: 12 pages, LaTex + RevTex, uuencoded postscript file (including 13 figures) is attached. Also available at ftp://dept.physics.upenn.edu/pub/Ni

Two-Fluid RANS-RSTM-PDF Model for Turbulent Particulate Flows

A novel three-dimensional (3D) model based on Reynolds turbulence stress model (RSTM) closure of equations of carrier and particulate phases was elaborated for channel turbulent flows. The essence of the model is the direct calculation of normal and shear components of the Reynolds stresses for the particulate phase similar to the carrier fluid. The model is based on the Eulerian approach, which is applied for the 3D RANS modeling of the carrier flow and the particulate phase and the statistical probability dense function (PDF) approach focusing on the mathematical description of the second moments of the particulate phase

A life cycle stakeholder management framework for enhanced collaboration between stakeholders with competing interests

This is a postprint version of the Book Chapter. Information regarding the official publication is available from the link below - Copyright @ 2011 SpringerImplementation of a Life Cycle Sustainability Management (LCSM) strategy can involve significant challenges because of competing or conflicting objectives between stakeholders. These differences may, if not identified and managed, hinder successful adoption of sustainability initiatives. This article proposes a conceptual framework for stakeholder management in a LCSM context. The framework identifies the key sustainability stakeholder groups and suggests strategic ambiguity as a management tool to harness dysfunctional conflict into constructive collaboration. The framework is of practical value as it can be used as a guideline by managers who wish to improve collaboration with stakeholders along the supply chain. The article also fills a gap in the academic literature where there is only limited research on sustainability stakeholder management through strategic ambiguity

Single flux quantum circuits with damping based on dissipative transmission lines

We propose and demonstrate the functioning of a special Rapid Single Flux Quantum (RSFQ) circuit with frequency-dependent damping. This damping is achieved by shunting individual Josephson junctions by pieces of open-ended RC transmission lines. Our circuit includes a toggle flip-flop cell, Josephson transmission lines transferring single flux quantum pulses to and from this cell, as well as DC/SFQ and SFQ/DC converters. Due to the desired frequency-dispersion in the RC line shunts which ensures sufficiently low noise at low frequencies, such circuits are well-suited for integrating with the flux/phase Josephson qubit and enable its efficient control.Comment: 6 pages incl. 6 figure

Higher stability of oat, barley and wheat accessions in their 1000 grain weight is not associated with a smaller grain size

Background. It is important and relevant to know whether the selection among cultivars for increased stability in the weight of 1000 grains involves a significant change in grain size.   The aim of the study was to analyze the relationship between the 1000 grain weight in oat, barley and wheat accessions, on the one hand, and their adaptability indicators for this trait, on the other.   Material and methods. The studied material included 10 cultivars of oat, 12 of barley, and 11 of wheat from the VIR collection. Plants were grown in 2021 at five different sites over Eastern Siberia (Krasnoyarsk Territory, and the Republic of Khakassia and Tyva). After harvesting, the weight of 1000 grains was measured for each cultivar. The coefficient of environmental variation (Cv), stress tolerance index (d), homeostasis parameter (Hom), stability level index (CSL), and breeding value index (Cs) were determined to assess the cultivars for the analyzed character.   Results. Oat cultivars exhibited significantly lower plasticity and higher stability in their 1000 grain weight. The best adaptability characteristics were recorded for oat cvs. ‘Argument’ and ‘Kross’, barley cvs. ‘Krasnoyarsky 91’ and ‘Biom’, and wheat cvs. ‘Novosibirskaya 49’ and ‘Novosibirskaya 75’. Cvs. ‘Kross’ and ‘Argument’ (oat). and ‘Biom’ (barley) had the largest grain size and maximum values of the character’s stability parameters. Correlations of oat and wheat grain size with both plasticity indices were negative, and positive with all stability parameters, being significant for CSL and Cs. In the case of barley cultivars, the correlation between the weight of 1000 grains and the plasticity index was negative and statistically significant.   Conclusion. The results demonstrate that when selecting oat, barley and wheat for increased stability of their 1000 grain weight, the grain size will not decrease. Moreover, it may have a tendency to increase

Fast Simulators for Satellite Cloud Optical Centroid Pressure Retrievals, 1. Evaluation of OMI Cloud Retrievals

The cloud Optical Centroid Pressure (OCP), also known as the effective cloud pressure, is a satellite-derived parameter that is commonly used in trace-gas retrievals to account for the effects of clouds on near-infrared through ultraviolet radiance measurements. Fast simulators are desirable to further expand the use of cloud OCP retrievals into the operational and climate communities for applications such as data assimilation and evaluation of cloud vertical structure in general circulation models. In this paper, we develop and validate fast simulators that provide estimates of the cloud OCP given a vertical profile of optical extinction. We use a pressure-weighting scheme where the weights depend upon optical parameters of clouds and/or aerosol. A cloud weighting function is easily extracted using this formulation. We then use fast simulators to compare two different satellite cloud OCP retrievals from the Ozone Monitoring Instrument (OMI) with estimates based on collocated cloud extinction profiles from a combination of CloudS at radar and MODIS visible radiance data. These comparisons are made over a wide range of conditions to provide a comprehensive validation of the OMI cloud OCP retrievals. We find generally good agreement between OMI cloud OCPs and those predicted by CloudSat. However, the OMI cloud OCPs from the two independent algorithms agree better with each other than either does with the estimates from CloudSat/MODIS. Differences between OMI cloud OCPs and those based on CloudSat/MODIS may result from undetected snow/ice at the surface, cloud 3-D effects, low altitude clouds missed by CloudSat, and the fact that CloudSat only observes a relatively small fraction of an OMI field-of-view

An Exact Approach to the Oscillator Radiation Process in an Arbitrarily Large Cavity

Starting from a solution of the problem of a mechanical oscillator coupled to a scalar field inside a reflecting sphere of radius $R$, we study the behaviour of the system in free space as the limit of an arbitrarily large radius in the confined solution. From a mathematical point of view we show that this way of facing the problem is not equivalent to consider the system {\it a} {\it priori} embedded in infinite space. In particular, the matrix elements of the transformation turning the system to principal axis, do not tend to distributions in the limit of an arbitrarily large sphere as it should be the case if the two procedures were mathematically equivalent. Also, we introduce "dressed" coordinates which allow an exact description of the oscillator radiation process for any value of the coupling, strong or weak. In the case of weak coupling, we recover from our exact expressions the well known decay formulas from perturbation theory.Comment: 27 page

Extra Families, Higgs Spectrum and Oblique Corrections

The standard model accommodates, but does not explain, three families of leptons and quarks, while various extensions suggest extra matter families. The oblique corrections from extra chiral families with relatively light (weak-scale) masses, $M_{f} \sim$, are analyzed and used to constrain the number of extra families and their spectrum. The analysis is motivated, in part, by recent N = 2 supersymmetry constructions, but is performed in a model-independent way. It is shown that the correlations among the contributions to the three oblique parameters, rather than the contribution to a particular one, provide the most significant bound. Nevertheless, a single extra chiral family with a constrained spectrum is found to be consistent with precision data without requiring any other new physics source. Models with three additional families may also be accommodated but only by invoking additional new physics, most notably, a two-Higgs-doublet extension. The interplay between the spectra of the extra fermions and the Higgs boson(s) is analyzed in the case of either one or two Higgs doublets, and its implications are explored. In particular, the precision bound on the SM-like Higgs boson mass is shown to be significantly relaxed in the presence of an extra relatively light chiral family.Comment: 20 pages, 8 figures, version for PR

Seesaw mechanism in the sneutrino sector and its consequences

The seesaw-extended MSSM provides a framework in which the observed light neutrino masses and mixing angles can be generated in the context of a natural theory for the TeV-scale. Sneutrino-mixing phenomena provide valuable tools for connecting the physics of neutrinos and supersymmetry. We examine the theoretical structure of the seesaw-extended MSSM, retaining the full complexity of three generations of neutrinos and sneutrinos. In this general framework, new flavor-changing and CP-violating sneutrino processes are allowed, and are parameterized in terms of two $3\times 3$ matrices that respectively preserve and violate lepton number. The elements of these matrices can be bounded by analyzing the rate for rare flavor-changing decays of charged leptons and the one-loop contribution to neutrino masses. In the former case, new contributions arise in the seesaw extended model which are not present in the ordinary MSSM. In the latter case, sneutrino--antisneutrino mixing generates the leading correction at one-loop to neutrino masses, and could provide the origin of the observed texture of the light neutrino mass matrix. Finally, we derive general formulae for sneutrino--antisneutrino oscillations and sneutrino flavor-oscillations. Unfortunately, neither oscillation phenomena is likely to be observable at future colliders.Comment: 69 pages, 5 figures, uses axodraw.sty. Version accepted for publication in JHEP: some comments and one more Appendix with additional discussion added, references update