Universal Parameter Research Articles

A fast method for trapped gas determination

Gas reservoirs are mainly produced by depletion with an aquifer rise; reservoir simulation requires two main SCAL inputs: the amount of trapped gas by the aquifer (residual gas saturation: Sgr) and the relative permeability to water due to aquifer flooding. As it is quasi impossible to predict aquifer strength, the primary SCAL input for reservoir simulation is the Sgr. The recovery factor is directly defined by initial and residual gas saturations. In fact, the residual gas saturation Sgr highly depends on the initial gas saturation Sgi and there is no universal petrophysical parameter governing the shape of this curve. This relationship can be described by several different models (Land, Aissaoui…). While Land’s model is widely used, the Aissaoui model better fits the experimental results (Suzanne et al. 2003), at least for homogeneous sandstones. For a given threshold of initial gas saturation Sg0, this relationship typically exhibits a plateau at high Sgi>Sg0 and an increasing linear trend at low Sgi<Sg0. The challenge here is to properly estimate the value of the Sg0 threshold. Classical laboratory method would require one experiment per point in the Sgr/Sgi plot, and therefore can be achieved in a matter of months. Here we propose a laboratory method allowing the acquisition of the Sgr/Sgi curve in a few days. The proposed method combines centrifugation and capillary rise under imaging. First, the centrifuge allows creating a saturation profile along a sample; measured by NMR. Then, capillary rise is used to capture Sgr under NMR monitoring. By adding NMR imaging, this technique allows combining the benefits of centrifugation to explore a wide range of Sgi; and the ease and cost effectiveness of capillary rise to measure the resulting Sgr. Therefore, at a timescale close to a traditional capillary rise, the proposed technique avoids Land extrapolation and provides a direct measurement of Sgr in a wide range of Sgi. As an additional benefit, the combination of NMR and centrifuge can provide at the same time a direct measurement of capillary pressure, providing information on the gas in place and potential imbibition process in the reservoir.

Stress transfer at the nanoscale on graphene ribbons of regular geometry.

The knowledge of the mechanism of stress transfer from a polymer matrix to a 2-dimensional nano-inclusion such as a graphene flake is of paramount importance for the design and the production of effective nanocomposites. For efficient reinforcement the shape of the inclusion must be accurately controlled since the axial stress transfer from matrix to the inclusion is affected by the axial-shear coupling observed upon loading of a flake of irregular geometry. Herein, we study true axial phenomena on regular- exfoliated-graphene micro-ribbons which are perfectly aligned to the loading direction. We exploit the strain sensitivity of vibrational wave numbers in order to map point-by-point the strain built up along the length of graphene. By considering the balance of shear-to-axial forces, we identify the shear stress at the interface and develop a universal inverse-length parameter that governs the stress transfer process at the nanoscale. An important parameter that has come out of this approach is the prediction and measurement of the transfer length that is required for efficient stress in these systems.

Mechanization of Root Crop Seed Production Technologies

Abstract.The sugar beet seed production is currently employing a non-planting-and-transplant technology with the use of steklings. Planting units of the machines available on the market feature a number of drawbacks: low productivity, possible injuring of root crops, and increased labor intensity of operators. (Research purpose) To develop a universal design and parameters of an increased-productivity unit for planting steklings of sugar beet and other root crops. (Materials and methods) The design scheme and type of a planting unit have been chosen according to the requirements of applicability and versatility. Its preferred design parameters have been calculated as well. A prototype machine with a universal planting unit in the form of a cellular disk has been developed and manufactured in test production. (Results and discussion) The conducted field experiments proved the versatility of a planting machine with a disc-type unit used for planting root crops, including dimensional characteristics corresponding to those of steklings. The authors have found that when replacing a disk with a different number of cells of different sizes, the machine is suitable for planting a number of similar crops. A removable disk with 12-16 cells has been installed, with its angular speed decreased to 0.393-1.180 radian per second, which is lower as compared to the existing machines. Satisfactory agrotechnical tolerances have been provided for carrot planting in the soil at a depth of 12 cm, a step of 30 cm, and a deviation from the vertical of 110. The intensity of root crop laying in the cells of a seeding disk has been increased to 1-3 pcs. per second. (Conclusions) It has been found that the machine and the planting unit can increase the working speed up to 1.0 meter per second and reduce the labor intensity of operators to the level of safety requirements. The use of universal machines in the breeding and seed production of root crops will reduce the range of the applied machines and operating costs of farm enterprises.

DEM Calibration Approach: Random Forest

A lot of researchers are developing new DEM parameters calibration approaches based on an experiment plan or the use of learning algorithms. This research is aimed at improving iterative algorithms frequently used for calibration. The big time consumption as a main problem of iterative algorithms is questioned. It is proposed to use Random forest algorithm to determine DEM parameters impact on the measured bulk responses. Measured responses are the parameters obtained by image processing using a technical vision system. As a result of 200 experiments processing, DEM parameters impact values on each bulk response were generated and presented as histograms. Obtained results were interpreted on the basis of the bulk material behavior and its physical properties. There is a discussion on the possibility of developing a universal DEM parameters calibration method based on the iterative algorithm.

Teichmüller spaces and tame quasiconformal motions

The concept of “quasiconformal motion” was first introduced by Sullivan and Thurston (in [24]). Theorem 3 of that paper asserted that any quasiconformal motion of a set in the sphere over an interval can be extended to the sphere. In this paper, we give a counter-example to that assertion. We introduce a new concept called “tame quasiconformal motion” and show that their assertion is true for tame quasiconformal motions. We prove a much more general result that, any tame quasiconformal motion of a closed set in the sphere, over a simply connected Hausdorff space, can be extended as a quasiconformal motion of the sphere. Furthermore, we show that this extension can be done in a conformally natural way. The fundamental idea is to show that the Teichmüller space of a closed set in the sphere is a “universal parameter space” for tame quasiconformal motions of that set over a simply connected Hausdorff space.

Predict the rheological properties of aged asphalt binders using a universal kinetic model

In this study, universal models were proposed to predict the aging behaviors of five different asphalt binders, where the rheological properties were emphasized on. The carbonyl content and crossover modulus of binders during oxidative aging process were predicted using the proposed universal kinetic models. The carbonyl content test using the Fourier Transform infrared spectroscopy (FTIR) technique and the frequency sweep test using a Dynamic Shear Rheometer (DSR) were performed to obtain the optimum model parameters. From the testing results, the crossover modulus of binders under oxidative aging effect showed similar growth trend to the carbonyl content that follows the two-reaction kinetics of aging. An approximately linear relation was established between the log crossover frequency and the inverse of log crossover modulus. A sufficient good agreement was achieved between the measured and predicted results of carbonyl content and crossover modulus of asphalt binders at given aging temperature and duration. However, it lost a little prediction accuracy when using the universal model parameters, compared to the specific model parameters. Moreover, based on the calculated crossover modulus and crossover frequency, the complex shear modulus and phase angle were successfully predicted based on the Christensen-Anderson model. The proposed universal model provides an effective approach of predicting the rheological properties of aged asphalt binders.

Role of Chain Length in the Formation of Frank-Kasper Phases in Diblock Copolymers.

The phase behavior of poly(styrene)-b-poly(1,4-butadiene) diblock copolymers with a polymer block invariant degree of polymerization N[over ¯]_{b}≈800 shows no evidence of Frank-Kasper phases, in contrast to low molar mass diblock copolymers (N[over ¯]_{b}<100) with the same conformational asymmetry. A universal self-concentration crossover parameter N[over ¯]_{x}≈400 is identified, directly related to the crossover to entanglement dynamics in polymer melts. Mean-field behavior is recovered when N[over ¯]_{b}>N[over ¯]_{x}, while complex low symmetry phase formation is attributed to fluctuations and space-filling constraints, which dominate when N[over ¯]_{b}<N[over ¯]_{x}.

A compact multi‐frequency GNSS scintillation model

We present a scintillation model that generates complex scintillation realizations using two-dimensional phase-screen calculations. A compact parameter set simplifies the model. The parameters can be adjusted to reproduce statistically equivalent realizations of target multi-frequency GNSS intensity and phase scintillation time series or defaulted to representative values. Geometric range and TEC inputs can be incorporated to generate realizations of baseband GNSS signals for processor performance evaluation. Selecting model parameters is guided by an efficient encapsulation of the two-dimensional phase-screen theory. Motion of the propagation path through ionospheric structure generates temporal variation. The phase-screen theory incorporates space-to-time conversion via a ratio of the Fresnel scale to an effective scan velocity. A universal strength parameter adjusts the strength of the scintillation. The model is an encapsulation of results that have been used for GPS performance analysis work that is cited in the paper. A MATLAB implementation of the model with examples has been made available.

The universalities of a single-component Fermi gas at a p-wave resonant point

We investigate the universalities of a single-component Fermi gas at a p-wave resonant point where the scattering volume is infinite with the lowest-order constrained variational (LOCV) method. We calculate the energy per particle for different effective ranges with different interaction configuration, our result confirms the universality assumption at the p-wave resonant point and we also find the universal parameter which is the counterpart of the Bertsch parameter for the p-wave case. We then examine the density dependence of the energy per particle at the p-wave resonant point and find n2/3 density dependence which is the same as in the s-wave case.

Revisiting flavor and CP violation in supersymmetric SU(5) with right-handed neutrinos

We revisit the minimal supersymmetric SU(5) grand unified theory with three right-handed neutrinos in which universality conditions for soft-supersymmetry breaking parameters are imposed at an input scale above the unification scale. If the Majorana masses for the neutrinos are around $10^{15}$ GeV, large mixing angles and phases in the neutrino sector lead to flavor-violation and CP-violation in the right-handed down squark and left-handed slepton sectors. Since the observed Higgs boson mass and the proton decay constraints indicate sfermions have masses larger than a few TeV, flavor and CP constraints are less restrictive. We explore the constraints on models with a universal soft-supersymmetry breaking input parameters coming from proton stability, electric dipole moments, $\mu\to e\gamma$ decays, and the Higgs mass observed at the LHC. Regions compatible with all constraints can be found if non-zero A-terms are taken.

Concrete pump working capacity determination in the composition of small-sized technological set equipment for the wet method gunite work

The small-sized technological set equipment with a universal, non-porous hose concrete pump is shown, that is verified during the execution of wet method gunite work. Dependencies for determination of basic universal hose concrete pump work parameters are proposed. The stand surface concreted with wet-cracking method, by the using of the concrete mixture composition, which has been checked during the gunite work execution on the construction site. A check of the resulting rubber-concrete coating strength has been carried out. The stability of the offered technological package operating conditions is confirmed.

Scaling the phase-planes of social dilemma strengths shows game-class changes in the five rules governing the evolution of cooperation.

Game theory has been extensively applied to help explain how cooperative behaviour is promoted in human and animal societies. How do humans and animals establish reciprocity when confronting a social dilemma? In 2006, Nowak theoretically proved that numerous mechanisms and models for evolving cooperative behaviour reported over the last few decades can be distilled into five reciprocity mechanisms (rules). Additionally, universal scaling parameters were proposed to measure two different types of dilemmas, namely, the gamble-intending dilemma (GID) and risk-averting dilemma (RAD). In this work, by drawing a RAD–GID phase-plane diagram for pair-wise games, we prove that these five rules are indeed quite different for the resolution (relaxation) of the two dilemmas. These diagrams also demonstrate whether and when game-class change (resolution of a dilemma) occurs, thus implying how defectors can be eliminated.

Acoustothermal Atomization of Water Nanofilms.

We report nonequilibrium molecular simulations of the vibration-induced heating of nanoscale-thick water layers on a metal substrate. In addition to experimentally confirmed acoustothermal evaporation, we observe hitherto unmapped nucleate and film boiling regimes, accompanied by the generation of unprecedented heat fluxes [∼O(10^{9}) W/m^{2}]. We develop a universal scaling parameter to classify the heat-transfer regimes and to predict the thickness of the residual nonevaporating liquid layer. The results find broad application to systems involving drying, coatings, and sprays.

Potential Cost-Effectiveness of a Universal Influenza Vaccine in Older Adults.

Background and Objectives“Universal” vaccines that could have multistrain and multiyear effectiveness are being developed. Their potential cost-effectiveness in geriatric populations is unknown.Research Design and MethodsA Markov model estimated effects of a theoretical universal influenza vaccine compared with available seasonal vaccines in hypothetical cohorts of U.S. 65+-year olds followed over a 5-year time horizon to capture potential multiyear protection. Outcomes included costs per quality-adjusted life-year gained and influenza cases avoided.ResultsUsing hypothetical universal vaccine parameter values (cost $100, vaccine effectiveness 39%, uptake 64%, effectiveness duration 5 years), universal vaccine was less costly than seasonal influenza vaccination strategies. High-dose trivalent influenza vaccine, compared with universal vaccine, gained 0.0028 quality-adjusted life-years and cost $82 more, or $28,700 per quality-adjusted life-year gained. Other seasonal vaccines were not favorable economically. Five-year influenza risk with universal vaccination was 32.3% under base case assumptions, compared with <30% with adjuvanted or high-dose vaccine use. In sensitivity analyses, universal vaccine was favored when uptake or vaccine effectiveness was greater than standard-dose influenza vaccine. If absolute universal vaccine effectiveness was 10% less than standard-dose vaccine, universal vaccine could be cost-saving but not more effective than other strategies. Universal vaccine was not favored if its effectiveness duration was <3 years.Discussion and ImplicationsUniversal vaccine use in older persons could be either cost effective or cost saving when universal vaccine parameters are within plausible ranges. However, if its effectiveness is substantially less than current vaccines, its use would probably not be favored in geriatric populations.

Radial electron fluence around ion tracks as a new physical parameter for the detection threshold of PADC using Geant4-DNA toolkit

The detection threshold of poly(allyl dyglycol carbonate), PADC, for C ions is determined as 55 eV/nm in stopping power, which is significantly higher than that for proton and He ions. The stopping power is not a universal parameter for expressing the detection threshold of PADC. A new physical parameter of Radial Electron Fluence around Ion Tracks, REFIT, is proposed to describe the detection threshold of PADC. It is defined as the number density of electrons passing through the surface of a cylinder of a certain radius that is co-axial with the trajectory. Furthermore, preliminary calculations are presently being performed using the Monte Carlo simulation code of Geant4-DNA. The values of the REFIT at the detection thresholds for each ion are of the same order. Several issues affecting implementation of the REFIT paramter are discussed. These include the effects of impact parameter relating to the initial locations of secondary electrons, the effects of electron attachment below the cut off energy of 7.4 eV and the necessity of a more physically realistic medium than water for Monte Carlo simultaions.

Analysis of the effects of pharyngeal flap surgery on reducing hypernasality in patients with velopharyngeal insufficiency

Background and Objectives:Velopharyngeal insufficiency (VPI) occurs in 25 to 43% of patients that undergo cleft palate repair. This disorder has a variety of signs including variations in nasal resonance (hypernasality), misarticulating, turmoil in nasal emissions, and grimacing. VPI can considerably affect social relations and the mental health of patients. Numerous methods have been developed for the treatment of VPI such as speech therapy, continuous positive airway pressure (CPAP), prosthetic treatment, and surgical interventions. The most common method, especially in the past three decades, has been the pharyngeal flap method. The objective of this study was to study the effects of the pharyngeal flap surgical method on the treatment of hypernasality which is a measureable sign of velopharyngeal insufficiency.Methods & Materials:In this cross-sectional study, a total of 112 patients with pharyngeal sphincter insufficiency who aged between 3 and 25 and had visited the otorhinolaryngology clinic of Imam Hospital of Ahvaz were studied from 2008 to 2015. The severity of hypernasality was measured by three speech therapists based on a universal parameter before the superior based pharyngeal flap surgery and 3 to 12 months after the surgery. The significance level for the aforementioned statistical tests was 0.05. Data was also analyzed using SPSS 16.Results:Following the superior based pharyngeal flap surgery, improved hypernasality, mild hypernasaliy, severe hypernasality, and hyponasality were observed in 42%, 6.44%, 6.11% and 8.1% of the patients, respectively. None of the 19-year old or older patients showed improvement of hyponasality and only patients aged between 3 and 6 years showed hyponasality. However, statistical analyses revealed that there was no significant difference between the responses of patients with different ages to treatment with superior based pharyngeal flap surgery (p=671).Conclusion:Results of the present study suggest that 12 months after pharyngeal flap surgery almost 87% of patients experience a complete or relative improvement of hypernasality. This finding complies with the findings of numerous previous studies.

X-ray binaries with neutron stars at different accretion stages

Abstract. Different accretion regimes onto magnetized NSs in HMXBs are considered: wind-fed supersonic (Bondi) regime at high accretion rates &lt;math/&gt; g s-1, subsonic settling regime at lower &lt;math/&gt; and supercritical disc accretion during Roche lobe overflow. In wind-fed stage, NSs in HMXBs reach equilibrium spin periods P* proportional to binary orbital period Pb. At supercritical accretion stage, the system may appear as a pulsating ULX. Population synthesis of Galactic HMXBs using standard assumptions on the binary evolution and NS formation is presented. Comparison of the model P* – Pb (the Corbet diagram), P* – Lx and Pb – Lx distributions with those for the observed HMXBs (including Be X-ray binaries) and pulsating ULXs suggests the importance of the reduction of P* in non-circular orbits, explaining the location of Be X-ray binaries in the model Corbet diagram, and the universal parameters of pulsating ULXs depending only on the NS magnetic fields.

Sky-canopy border length, exposure and thresholding influence accuracy of hemispherical photography for complex plant canopies

BackgroundHemispherical photography (HP) is a popular method to estimate canopy structure and understorey light environment, which analyses photographs acquired with wide view-angle lens (i.e. fisheye lens). To increase HP accuracy, the approaches of most previous studies were to increase the preciseness of exposure and thresholding of photographs, while ours quantified effects of canopy properties (gap fraction and length of sky-canopy border (SCB)) and errors of exposure and thresholding on the accuracy of HP.ResultsThrough analysing photographs of real and model canopies, it was showed that HP inaccuracy resulted from the mismatch between exposure and thresholding rather than exposure or thresholding errors alone. HP inaccuracy was a function of the SCB length and the extent of exposure and thresholding errors, but independent of gap fraction.DiscussionIn photographs, SCBs are recorded as grey pixels which greyness is in between that of sky and canopy pixels. When there are exposure and thresholding errors, grey pixels are those prone to be misclassified in image analysis. Longer (vegetation with taller canopies) and wider (lower image sharpness) SCBs in photographs can both result in a higher amount of grey pixels and ultimately higher HP inaccuracy for a given extent of exposure and threshold errors.ConclusionsUsing lenses with view angle narrower rather than that of fisheye lens can shorten the SCB length in photographs and in turn reduce HP estimation inaccuracy for canopy structure and understorey light environment. Since short SCBs and low levels of exposure and thresholding errors can both result in low HP inaccuracy, to identify the true performance of new exposure and thresholding methods for HP, photographs recording canopies with long SCBs and acquired with fisheye lenses should be used. Because HP inaccuracy in a function of the amount of grey pixels resulting from SCBs, the amount of these pixels in photographs can be used as a universal parameter to quantify canopy properties influential to HP estimation and in turn make cross-study comparisons feasible.

CORRELAÇÃO ENTRE FACETAS DE DESGASTE E A OCORRÊNCIA DE LESÕES CERVICAIS NÃO CARIOSAS: UMA REVISÃO DE LITERATURA

A elevada prevalência de facetas de desgaste na população jovem é um alerta para que estas alterações sejam observadas e ferramentas sejam criadas para agilizar o processo de diagnóstico. Objetivou-se revisar a literatura sobre a influência das facetas de desgaste no surgimento de lesões cervicais não cariosas. Pesquisou-se sobre facetas de desgaste e lesões cervicais não cariosas, nas bases de dados Bireme, Lilacs, Pubmed e Bibliotecas Virtuais, em estudos in vitro, in silico (elementos finitos), ensaios clínicos e revisões sistemáticas com metanálise. Incluindo artigos em português, inglês e espanhol, sendo excluídos os de revisão de literatura, caso clínico, carta ao editor, e os estudos que não abordarem as variáveis em questão. A literatura apresenta-se escassa, assim são necessários novos estudos longitudinais para melhor entendimento dessa associação, bem como, para definir os parâmetros universais para a avaliação de desgaste dental e estabelecimento do seu diagnóstico, com a finalidade de obter a melhor forma de tratamento desses problemas cada vez mais frequentes na clínica diária.

A Load-Forecasting-Based Adaptive Parameter Optimization Strategy of STATCOM Using ANNs for Enhancement of LFOD in Power Systems

This paper proposes a load-oriented control parameter optimization strategy for static synchronous compensator (STATCOM) to enhance low-frequency oscillation damping (LFOD) and improve stability of overall complex power systems. Frequency deviations of generators of interest are employed as the input signals of the designed supplementary damping controller of STATCOM. In order to obtain the optimal load-oriented control parameters, a day-ahead load-forecasting scheme is devised, using artificial neural network (ANN) learning techniques. The ANN is trained by a set of data over a 4-year period, and then the control parameters are optimized using Particle Swarm Optimization technique by minimizing the critical damping index. The proposed control strategy is implemented in the IEEE standard complex power system, and the numerical results demonstrate that the low-frequency oscillations (LFOs) of the power system can be effectively mitigated using the proposed controller. Compared to conventional robust controller with universal parameters, this novel load-oriented optimal control strategy shows its superiority in alleviating LFOs and enhancing the overall stability of the power system. Since the proposed control scheme aims to adaptively adjust the controller parameters in correspondence to load variations, this study is envisaged to have practical utilizations in industrial applications.