Single Gauge Research Articles

The One-loop Improved Lagrangian of the Grimus--Neufeld Model

Adding a single gauge singlet fermion and a second Higgs doublet to the original Standard Model allows an explanation for the observed smallness of the neutrino masses using the seesaw mechanism. This model predicts two neutral fermions with vanishing mass. The one-loop contribution to the neutral fermion masses due to the second Higgs doublet lifts this degeneracy and allows to fit the model parameters to the observed neutrino mass differences. We determine the values of the additional Yukawa couplings by requiring the correct prediction of the mass differences and mixings in the neutrino sector. We also discuss the ambiguities of the model parameters.

Abelian tensor hierarchy in 4D N $$ \mathcal{N} $$ = 1 conformal supergravity

We consider Abelian tensor hierarchy in four-dimensional ${\cal N}=1$ supergravity in the conformal superspace formalism, where the so-called covariant approach is used to antisymmetric tensor fields. We introduce $p$-form gauge superfields as superforms in the conformal superspace. We solve the Bianchi identities under the constraints for the superforms. As a result, each of form fields is expressed by a single gauge invariant superfield. The action of superforms is shown with the invariant superfields. We also show the relation between the superspace formalism and the superconformal tensor calculus.

A Spatial–Dynamical Framework for Evaluation of Satellite Rainfall Products for Flood Prediction

Abstract Rainfall maps that are derived from satellite observations provide hydrologists with an unprecedented opportunity to forecast floods globally. However, the limitations of using these precipitation estimates with respect to producing reliable flood forecasts at multiple scales are not well understood. To address the scientific and practical question of applicability of space-based rainfall products for global flood forecasting, a data evaluation framework is developed that allows tracking the rainfall effects in space and time across scales in the river network. This provides insights on the effects of rainfall product resolution and uncertainty. Obtaining such insights is not possible when the hydrologic evaluation is based on discharge observations from single gauges. The proposed framework also explores the ability of hydrologic model structure to answer questions pertaining to the utility of space-based rainfall observations for flood forecasting. To illustrate the framework, hydrometeorological data collected during the Iowa Flood Studies (IFloodS) campaign in Iowa are used to perform a hydrologic simulation using two different rainfall–runoff model structures and three rainfall products, two of which are radar based [stage IV and Iowa Flood Center (IFC)] and one satellite based [TMPA–Research Version (RV)]. This allows for exploring the differences in rainfall estimates at several spatial and temporal scales and provides improved understanding of how these differences affect flood predictions at multiple basin scales. The framework allows for exploring the differences in peak flow estimation due to nonlinearities in the hydrologic model structure and determining how these differences behave with an increase in the upstream area through the drainage network. The framework provides an alternative evaluation of precipitation estimates, based on the diagnostics of hydrological model results.

Single molecular force sensitivity and threshold for the activation of B cell receptors

Abstract B lymphocytes show remarkable mechanosensing capability by utilizing the surface expressed B cell receptors (BCRs) to sense antigens. However, the sensitivity and threshold for the activation of BCRs resulting from the stimulation by mechanical forces are unknown. Here we systemically addressed this question using a ds-DNA based tension gauge tether (TGT) system serving as a predefined single molecular force gauge ranging from 12 to 56 pN to restrict BCR and antigen tension. Utilizing total internal reflection fluorescence microscopy, we observed that IgM-BCR activation is sensitive to single molecular forces. We observed an obvious multi-threshold effect with a low-end 12–16 pN force which triggered a weak activation, whereas a 23–43 pN force initiated a medium-level activation, and a high-end 50–56 pN force produced a strong activation. Such patterned dependence on mechanical forces with multi-threshold effects did not strictly rely on myosin IIA, dynein and integrin. However, the break-through of the high-end but not the medium-level and low-end mechanical force threshold in IgM-BCR activation required myosin IIA and the inside-out activation of integrin. Surprisingly, we found that the activation of the isotype-switched IgG-BCR or IgE-BCR only requires an extremely low threshold of less than 12 pN, providing an explanation for their rapid activation in response to antigen stimulation. Mechanistically, we found that the cytoplasmic tail of the IgG-BCR heavy chain is both required and sufficient to account for the low mechanical force threshold to activate the IgG-BCR. These results defined the single molecular force sensitivity and threshold that are required to activate different isotyped BCRs.

Low-Constraint Toughness Testing of Two Single-Edge Notched Tension Methods in a Single Specimen

Single-edge notched tension (SE(T) or SENT) specimens have been increasingly proposed as a low-constraint toughness test to measure toughness of line pipe materials, as the crack tip constraint approximates a circumferential surface flaw in a pipe under loading. The clamped SE(T) single-specimen procedures recently developed by Shen and Tyson (2008, “Fracture Toughness Evaluation of High Strength Steel Pipe,” ASME Paper No. PVP2008-61100; 2008, “Development of Procedure for Low-Constraint Toughness Testing Using a Single-Specimen Technique,” CANMET Materials Technology Laboratory, Technical Report No. 2008-18 (TR)) and Tang et al. (2010, “Development of the SENT Test of Strain-Based Design of Welded Pipelines,” 8th International Pipeline Conference, IPC 2010, Calgary, AB, Canada) have both used in common the use of a clamped single-specimen of similar geometry and relied on the unloading compliance technique for crack size estimation. In the former case, a single clip gauge is attached to the integral knife edge and the crack-tip opening displacement (CTOD) is estimated by means of a J-integral-to-CTOD conversion, similar to the procedure of ASTM E1820-11. The latter uses a pair of clip gauges mounted on an attachable raised set of knife edges to estimate CTOD at the original crack tip position by a triangulation rule. Consolidating these two sets of clip gauges in a specimen makes direct comparisons of two SE(T) methods under identical test conditions: material, specimen geometry, equipment, test temperature, and operator (Weeks et al., 2013, “Fracture Toughness Instrumentation Techniques for Single-Specimen Clamped SE(T) Tests on X100 Linepipe Steel: Experimental Setup,” 6th Pipeline Technology Conference, Ostend, Belgium). In this study, SE(T) testing employing these two SE(T) methods on a single specimen was conducted on B × B shallow-cracked (a/W ∼ 0.35) specimens of two X70 pipeline girth welds. This paper discusses details of the two SE(T) methods and techniques on the same specimen.

On Conditioning of Resistive Strain Gage Channel Connected in Quarter Bridge Configuration in Measurement of Moderately Large Strains

In response to engineering needs of measuring moderate or large strains in metallic structures’ progress in resistance strain gages, technology resulted in widening the measurement range of this type of sensors to a range of 10–15%. For precision strain measurement applications, especially when a considerable number of measurement points are involved, single strain gage sensors are commonly used in quarter Wheatstone bridge configurations. Extension of measurement range to moderate strains requires taking into account inherent nonlinearities in signal transfer functions of the elements present in measurement chain. This work discusses in detail the most important ones, that is resistive gage sensor and quarter bridge measurement configuration nonlinearities to indicate that they are of the same order for moderate strains. Quite straightforward, shunt calibration procedure, taking into account these nonlinearities, is delivered or proposed enabling elimination of systematic errors. Thus, optimum accuracy of strain measurements matching the characteristics of components of strain measurement system can be conveniently achieved upon following simple steps. Inverse hyperbolic tangent—\( \epsilon \)Ln =tanh−1(2 ∙e0/Eex)—linking scalar logarithmic strain and bridge reduced output voltage is shown to be a transfer function of strain measurement system with gage sensor in quarter bridge configuration for moderate or large strains.

Analysis of the upscaling problem – A case study for the barotropic dynamics in the North Sea and the German Bight

The upscaling problem is investigated using the barotropic dynamics of the North Sea and the German Bight as an example. The impact of small scale perturbations of bathymetry, bottom roughness, wind forcing, and boundary forcing is quantified using a two-dimensional linear barotropic model for the entire North Sea with 5 km resolution. The model is solved in the spectral domain for the dominant M2 tide. Comparisons with results from a fully nonlinear 3D circulation model show that the main circulation features are well captured by the spectral model. The impact of different types of perturbations is estimated by inversion of the model using the perturbation covariance matrix as input. Case studies with white noise and fully correlated noise are presented. It is shown that the German Bight area stands out in its sensitivity with respect to small scale uncertainties of bathymetry. Small scale changes of bottom roughness have a particularly strong effect in the English Channel. Small scale wind perturbations have a significant local effect only in very shallow near coastal areas. It is shown that uncorrelated noise introduced along an open boundary around the German Bight only has a very local effect. Perturbations with long correlation length are shown to lead to significant far field effects along the east coast of England. It is demonstrated that this effect is related to the boundary conditions used for the North Sea model. In a next step a German Bight grid with 1 km resolution is nested into the North Sea grid and the spectral model is solved in a two way nested configuration. It is shown that there are some significant local and far field effects caused by the change of resolution in this coastal area. Finally, the potential impact of observations taken in coastal areas is investigated by evaluating the Kalman a posteriori distribution of analysis vectors based on different assumptions about model errors. The area of influence of a single tide gauge is quantified for the case where the model errors are dominated by boundary forcing errors. The results show a strong dependence on spatial correlation properties of the errors.

Eguchi-Kawai reduction with one flavor of adjoint Möbius fermion

We study the single site lattice gauge theory of SU(N) coupled to one Dirac flavor of fermion in the adjoint representation. We utilize M\"obius fermions for this study, and accelerate the calculation with graphics processing units (GPUs). Our Monte Carlo simulations indicate that for sufficiently large inverse 't Hooft coupling b = 1/g^2 N, and for N \leq 10 the distribution of traced Polyakov loops has "fingers" that extend from the origin. However, in the massless case the distribution of eigenvalues of the untraced Polyakov loop becomes uniform at large N, indicating preservation of center symmetry in the thermodynamic limit. By contrast, for a large mass and large b, the distribution is highly nonuniform in the same limit, indicating spontaneous center symmetry breaking. These conclusions are confirmed by comparing to the quenched case, as well as by examining another observable based on the average value of the modulus of the traced Polyakov loop. The result of this investigation is that with massless adjoint fermions center symmetry is stabilized and the Eguchi-Kawai reduction should be successful; this is in agreement with most other studies.

What Really Happens at the End of the Rainbow? – Paying the Price for Reducing Uncertainty (Using Reverse Hydrology Models)

Modelling of environmental processes is subject to a high degree of uncertainty due to the incorporation of random errors and a lack of knowledge about how processes operate at the scale of interest. Use of uncertain data when identifying and calibrating a model can lead to disinformative data being included in the procedure, resulting in uncertain parameter estimation and ambiguity in the outcomes. Rainfall-runoff modelling where a single rain-gauge is often assumed to be representative of the potentially highly variable (in both space and time) rainfall field is a good example. The noisy pattern of rainfall inputs is transformed by the catchment into streamflow. The streamflow pattern is dependent on the spatio-temporal pattern of rainfall and of the dominant processes operating within the catchment. Inverse modelling of the catchment dynamics, that is, inferring catchment rainfall from streamflow, provides a possible means of improving the estimated rainfall input because all rain falling on the catchment becomes streamflow, and thus, providing improved forecasts of the streamflow output. A combination of inverse modelling, time series analysis, spatial analysis and spectral analysis may also help to provide an insight into the complex processes operating within the catchment system. This paper applies a novel method for inferring true catchment rainfall from streamflow highlighting that the streamflow is better estimated using inferred rainfall than observed rainfall (from a single gauge) because a single gauge only gives a partial description of the rainfall field. However reducing uncertainty in this way comes at a price, in this case, the reduction in time-resolution of the inferred rainfall series.

Optimal strain gage location for determination of mode I stress intensity factor for orthotropic laminates using a single strain gage

Optimal strain gage location for determination of mode I stress intensity factor for orthotropic laminates using a single strain gage

IR-improved DGLAP-CS QCD parton showers in Pythia8

We introduce the recently developed IR-improved DGLAP-CS theory into the showers in Pythia8, as this Monte Carlo event generator is in wide use at LHC. We show that, just as it was true in the IR-improved shower Monte Carlo Herwiri, which realizes the IR-improved DGLAP-CS theory in the Herwig6.5 environment, the soft limit in processes such as single heavy gauge boson production is now more physical in the IR-improved DGLAP-CS theory version of Pythia8. This opens the way to one’s getting a comparison between the actual detector simulations for some of the LHC experiments between IR-improved and unimproved showers as Pythia8 is used in detector simulations at LHC whereas Herwig6.5, the environment of the only other IR-improved DGLAP-CS QCD MC in the literature, Herwiri1.031, is not any longer so used. Our achieving the availability of the IR-improved DGLAP-CS Pythia8 then is an important step in the further development of the LHC precision theory program under development by the author and his collaborators.

Determination of KI in orthotropic laminates with double ended cracks using a single strain gage technique

Experimental determination of mode I stress intensity factor (SIF) KI in orthotropic composites is of significant importance. In this direction, single strain gage techniques that are developed for measurement of KI are based on the solutions of the single ended crack theories and those have also been tested only for single ended cracked orthotropic configurations. Although, certain limitations prevent straight forward application of these single ended crack solutions to the double ended configurations, the present investigation aims at demonstrating the use of such a single strain gage technique recently proposed by the authors to the configurations containing double ended cracks or internal cracks in orthotropic materials for the accurate measurement of KI. Importantly, the present investigation also proposes existence and determination of optimal strain gage locations in double ended cracked orthotropic plates for the accurate measurement of KI. Studies have also been carried out to understand the effect of change in geometry of the configuration on the optimal gage locations. The results of the present investigation have been observed to substantiate the theoretical formulations in terms of accurate determination of KI. Numerical results clearly show that the proposed single strain gage technique yields accurate values of KI when the gage is placed at an optimal gage location. On the contrary, highly erroneous values of KI are obtained when the gage is placed at non-optimal locations.

Method for model scale blasting

Rock breakage by chemical explosive is a complex process involving the physicalproperties of the rock mass, the detonation properties of the explosive and blastparameters. A method for model scale blasting in cement mortar blocks with dimensions 90 x80 x55 cm has been studied and the results from a single shot experiment instrumentedwith accelerometers, strain gages and pressure gages are given. Results from staticand dynamic materials testing of the cement mortar are also given. The stress time and strain time determined by the different methods are compared.

Light composite scalar boson from a see-saw mechanism in two-scale TC models

We consider the possibility of a light composite scalar boson arising from mass mixing between a relatively light and heavy scalar singlets in a see-saw mechanism expected to occur in two-scale Technicolor (TC) models. A light composite scalar boson can be generated when the TC theory features two technifermions species in different representations, R1 and R2, under a single technicolor gauge group, with characteristic scales Λ1 and Λ2. We determine the final composite scalar fields, Φ1 and Φ2, effective theory using the effective potential for composite operators approach. To generate a light composite scalar it is enough to have a walking (or quasi-conformal) behavior just for one of the technifermions representations.

4D topological mass by gauging spin

We propose a spin gauge field theory in which the curl of a Dirac fermion current density plays the role of the pseudovector charge density. In this field-theoretic model, spin interactions are mediated by a single scalar gauge boson in its antisymmetric tensor formulation. We show that these long range spin interactions induce a gauge invariant photon mass in the one-loop effective action. The fermion loop generates a coupling between photons and the spin gauge boson, which acquires thus charge. This coupling represents also an induced, gauge invariant, topological mass for the photons, leading to the Meissner effect. The one-loop effective equations of motion for the charged spin gauge boson are the London equations. We propose thus spin gauge interactions as an alternative, topological mechanism for superconductivity in which no spontaneous symmetry breaking is involved.

Non-Higgsable clusters for 4D F-theory models

We analyze non-Higgsable clusters of gauge groups and matter that can arise at the level of geometry in 4D F-theory models. Non-Higgsable clusters seem to be generic features of F-theory compactifications, and give rise naturally to structures that include the nonabelian part of the standard model gauge group and certain specific types of potential dark matter candidates. In particular, there are nine distinct single nonabelian gauge group factors, and only five distinct products of two nonabelian gauge group factors with matter, including $SU(3) \times SU(2)$, that can be realized through 4D non-Higgsable clusters. There are also more complicated configurations involving more than two gauge factors; in particular, the collection of gauge group factors with jointly charged matter can exhibit branchings, loops, and long linear chains.

Open-hole tension capacity of pultruded GFRP having staggered hole arrangement

The technique of using staggered bolt holes for connections is common practice in steel design since the method allows for greater design strengths from more compact connections. Steel however is a ductile isotropic material. Pultruded glass fiber reinforced polymer (GFRP), on the other hand, is a relatively brittle, often highly anisotropic material requiring different design formulations to assess its open-hole tension capacity. This study considers the development of open-hole capacity provisions and experimentally investigates the net section rupture limit state of GFRP plates having both a single gage line and staggered-hole arrangements in order to assess the open-hole capacity of pultruded GFRP plates. Tension testing of GFRP plates, having varying thickness, number of holes and hole-spacing arrangements (both staggered and non-staggered) were conducted. A significant strength reduction (beyond the net cross section area) results from the presence of a circular hole in the material, although additional holes do not compound this effect. The test results demonstrate that, unlike in isotropic materials, there is no capacity benefit from using staggered hole arrangements in GFRP plates.

Strain Analysis of Crust at the Stabilization Stage Using and Applied Statistical Analysis

A strainmeter goes through a period of instability immediately after installation. To determine the stability of strainmeters installed around the Andong fault zone, South Korea, an x-MR control chart analysis and a T2 control chart analysis were conducted. The x-MR control chart analysis used an empirically determined 3σ control limit line to identify abnormal data in recently installed strain gauges. In the T2 control chart analysis, the control limit line was set at a confidence of 95%. A comparison of the early stage of measurement with the terminal stage of measurement for three months after installation indicates that stabilization depends on the location and direction of each strain gauge in x-MR control chart analysis. In the T2 control chart analysis, the number of values exceeding the control limit line decreased as the terminal stage was approached. Based on these results, it is suggested that the 3σ control limit line of an x-MR control chart can be used as a standard for single gauge stability, and that the 95% confidence limit of a T2 control chart analysis could be used as the standard for the stability of multi-gauge strainmeters.

Review of physics results from the Tevatron: Electroweak physics

We summarize an extensive Tevatron (1984–2011) electroweak physics program that involves a variety of W and Z boson precision measurements. The relevance of these studies using single and associated gauge boson production to our understanding of the electroweak sector, quantum chromodynamics and searches for new physics is emphasized. We discuss the importance of the W boson mass measurement, the W/Z boson distributions and asymmetries, and diboson studies. We highlight the recent Tevatron measurements and prospects for the final Tevatron measurements.

Thin film sensors for measuring small forces

Abstract. Especially in the case of measuring small forces, the use of conventional foil strain gauges is limited. The measurement uncertainty rises by force shunts and is due to the polymer foils used, as they are susceptible to moisture. Strain gauges in thin film technology present a potential solution to overcome these effects because of their direct and atomic contact with the measuring body, omitting an adhesive layer and the polymer foil. For force measurements up to 1 N, a suitable deformation element was developed by finite element (FE) analysis. This element is designed for an approximate strain of 1000 μm m−1 at the designated nominal load. The thin film system was applied by magnetron sputtering. The strain gauge structure is fabricated by distinct photolithographic steps. The developed sensors were tested with different load increments. The functional capability of the single resistance strain gauges could be proven. Moreover, a developed sensor in a full bridge circuit showed a linear characteristic with low deviation and good stability.