Power Equation Research Articles

Empirical relationships between compressive and flexural strength of concrete containing recycled asphalt material for pavement applications using different specimen configurations

The flexural strength of pavement concrete is generally deduced by testing beams or by applying empirical equations. In this investigation, concrete mixtures were manufactured, incorporating 0, 20, 50 and 100% Reclaimed Asphalt Pavement (RAP), by weight, as a replacement for natural aggregates. The compressive strength was measured using cubic specimens and the flexural strength was measured for three types of specimens; beam, semicircular (SCB) and modified beam. This study proposes logarithmic and power equations that allow the estimation of the flexural strength of a concrete mix that incorporates RAP as a function of its compressive strength. Linear or power models are proposed to predict beam flexural strength from SCB specimens and a logarithmic model for modified beam specimens. Statistical analyses show that the proposed prediction models can be considered sufficiently accurate and their use is justified.

Improving the Solder Joint Reliability Prediction Accuracy for Quad Flat No Lead Packages

This paper discusses the modeling approach used in improving the solder joint reliability prediction for Quad Flat No Lead (QFN) packages. A new power equation fatigue prediction model was developed based on the accumulated creep strain energy density from FEA (finite element analysis) simulation and the corresponding actual experimental result in terms of solder characteristic life of different QFN packages. The new curve fitted fatigue life correlation equation was then used in the solder joint reliability modeling together with the use of a hyperbolic sine constitutive model for lead-free solder. The model prediction using the new curve fitted equation was compared with the result from using the equation previously published. Based on the results, the new curve-fitted life prediction equation was able to improve the accuracy of solder life prediction. This study shows that solder joint reliability prediction could be improved by developing a prediction model based on actual data and consistent FEA modeling considerations in terms of methodology, material model and properties.

Mass and surface modelling of green plantain banana fruit based on physical characteristics

The physical characteristic such as dimensional, projected area, volume, mass, and sphericity are directly related to the quality of a fruit. The consumer generally prefers the uniform size, mass, and shape of the fruit. Thermal properties are important to predict the heat flux or the time required for drying, freezing, refrigeration processing. The knowledge of these properties is essential for the process designing and development of equipment involved in carrying out different tasks such as grading, sizing, peeling, storage, and packaging system in the green banana processing industry (banana powder, banana chips, banana starch, banana-based soup, baby foods).The objective of this study was to determine the physical and thermal properties of plantain banana fruit as well as to develop mathematical models based on physical properties so that the same may be used to design various related equipment. The average dimension of fruit was 15.42, 4.08, and 3.59 cm as length (L), width (W), and thickness (T), respectively. The geometric mean diameter (Dg) and arithmetic mean diameter (Da) were measured as 6.08 and 7.7 cm, respectively. The sphericity, aspect ratio, and radius of curvature were found to be 39.60%, 0.27, and 186.49, respectively. The elongation and flakiness ratio was found to be 3.77 and 0.88, respectively. From measured physical properties, it was concluded that banana fruit is curved, non-spherical, elongated in shape. Linear, quadratic, power, and S-curve equations were applied to analyze the mass, surface area, and projected area of green banana fruit. The measured physical properties of fruit were statistically found significant at p < 0.05. The mass of fruit was best predicted via length as dimensional characteristics in the quadratic model (M = 305.37–36.50L + 1.46L2; R2 = 0.95; χ2 = 20.24; RMSE = 4.50). Whereas, the surface area of fruit was best predicted in the quadratic model based on ellipsoid spheroid volume (Vellip) (S = 25.34 + 0.87Vellip – 8.99Vellip2; R2 = 0.99; χ2 = 0.01; RMSE = 0.12) and projected area of fruit was best predicted in a power model produced by projected area perpendicular to length (PL) (PA = 0.69 PL0.91; R2 = 0.99; χ2 = 0.0; RMSE = 0.05). The thermal conductivity and specific heat of banana fruit were found to be 0.58 W/m°C and 3.86 kJ/kg°C, respectively.

Proton Irradiation the DNA of Human Cells

Proton beam therapy provides favorable physical characteristics to kill cancer cells. It is known that all living organisms contain DNA, so we will simulate the bombardment of dry DNA of human’s body cells by protons. The knowledge of stopping powers is very important especially for ion beam cancer therapy. The simulations first-principles dynamics helps the mostly employed linear description of response theory. The study denotes that DNA has suffered ionization by proton bombarding, which leads to long–lasting harm to human or cancer DNA that empowers us to diagnose the latter and treat it with radiation. Through using Bethe and Ziegler’s equations, and also the SRIM programs, we determine the stopping power of the interaction of proton with human’s DNA at approximate energy of 1 to 2.5 MeV. The human’s DNA components are made of five main elements. All mathematical processes and analysis are achieved using Matlab program. The results are introduced in tables and figures. The researchers have formulated the power equation that denotes the values of stopping power according to the range of energy under investigation.

К МЕТОДИКЕ ОПРЕДЕЛЕНИЯ ПЛОЩАДИ ЛИСТЬЕВ РАСТЕНИЙ СЕМЕЙСТВА NYMPHAEACEAE SALISB.

Leaf area is an important indicator that is closely related to the size of the assimilating surface, photosynthesis, respiration, transpiration, specific leaf area, and production.&#x0D; The purpose of this work is to obtain regression models for determining the leaf area of widespread hydrophytes – Nuphar lutea (L.) Smith and Nymphaea candida C. Presl. These plants have a high ecological valence and make a significant contribution to the overall productivity of reservoirs.&#x0D; Collection of floating leaves of water lilies was carried out in 2019 in the gulf of the Volga river in the Tver region (56°58'50.4", 37°27'45.2"). A total of 108 leaves of Nuphar lutea and 170 – Nymphaea candida were collected. Main parameters: the length of the leaf blade from the attachment point of the petiole to the tip (l1), the total length (l2) and width (w) of the leaf blade were measured with an accuracy of 0.1 cm. The actual leaf area was determined by a Planix 7 planimeter. Correlation and regression analyses were used to analyze the data.&#x0D; The growth of water lily leaves is uniform. Regression analysis revealed the dependence of the actual leaf area (LA) on morphometric indicators l1, l2, and w. For Nuphar lutea: LAN.l=2.12∙l11.81; LAN.l=0.64∙l21.95; LAN.l=0.93∙w2.05. For Nymphaea candida: LAN.c=3.88∙l11.79; LAN.c=0.85∙l21.94; LAN.c=0.93∙w1.96&#x0D; The received power equation is fair from a biological point of view and correct with mathematical. They can be used in the field without causing damage to plant communities. This is a fast, reliable and cost-effective method. It allows you to monitor, assess the degree of overgrowth of reservoirs, predict the further development of communities, and allows you to conduct research on specially protected natural areas.

Using Statistical and Experimental Methods to Investigate the Mixing of Dense Slurries with Coaxial Mixers: Effects of Design Parameters and Novel Equations for Power and Reynolds Numbers

A thorough literature review demonstrates that the correlations to determine the Reynolds number and the power number of a dense slurry system furnished with a coaxial mixer have not been reported....

Impact of Moisture on AC Breakdown Voltage of Crude, Refined and Transesterified Groundnut Oil-based Liquid Insulations

With the aim of analyzing the ability of vegetable oil-based liquid insulation as alternate medium under moisture-rich environment, this study presents an experimental analysis of impact on breakdown voltage characteristics vegetable oil-based insulating liquids for the moisture inclusion with oil sample. The study has been proposed to carry out with different categories of groundnut oil in crude form, refined form and transesterified form. The moisture inclusion range of 5 ppm to 25 ppm is considered based on the literature with the scope of having lower solubility level and less than 50% of water saturation level for avoiding wet transformer conditions. Experimental investigations have been done on AC breakdown voltage of three categories of groundnut oil for inclusion of proposed range of moisture. With an increased moisture level from 5 to 25 ppm, significant reduction in breakdown voltage of oil samples has been obtained with the average percentage of 53 to 67% which may be due to possible modification in the molecular component of oil with the influence of moisture's polarization characteristics. Based on the experimental observations, the empirical power equations developed based on the regression method to predict the approximate breakdown voltage at different moisture levels.

Newly Discovered Śaiva-Ascetic Icons from West Bengal

Abstract Koṭivarṣa, a sacred place and an administrative unit that is mentioned in early medieval Indian religious and epigraphic sources from 700 to 1200 ce, is the area of focus of this essay. As an administrative unit, it was almost coterminous with the old Dinajpur district of Bengal, which is now divided into the present Indian state of West Bengal and Bangladesh. At one point in time, its headquarters came to be known as Devīkoṭa, underscoring its rise as a prime place for Devī, the Mother goddess. Sculptural arrays of the Mother goddess from this place point to the domineering presence of her fearsome principles; they parallel textual descriptions about the sacred importance of a wrathful form of the Mother, normally referred to as Cāmuṇḍā. The religious texts, however, do not speak of the ascetics who might have performed the rituals to propitiate the Mother. We do not yet know if any new dimension was added to the corpus of rituals, and the Śiva-Śakti power equation after the Saiddhāntika Śaiva preceptors affiliated with Golagī great monastery of Durvāsas lineage entered Devīkoṭa at the end of the tenth century. This essay searches for answers in the visual elements on the lower registers of stone steles, such as the devotees/donors, other individuals in the service of the Mother Goddess, potfuls of offerings, and the environment of cremation grounds in which worship took place. The main deity and associated figures occupying the larger space in the middle of the steles have tantric content. Icons of Śaiva ascetics from West Bengal, including the three newly discovered examples, are important subjects for this essay, which concludes with the transformation of Devīkoṭa to Bangarh, where Śiva emerged as the chief god par excellence. The Devī had lost her koṭa, her bastion, forever.

Development of a Small Hydropower Plant (SHP); A Review Study of Erin-Ijesa Water Fall, Erin-ijesa, Osun State, Nigeria

Energy demand has been on the increase globally due to the increase in population, urbanization and industrialization. In developing countries, while the rate of energy consumption is increasing, supply which is usually produced from fossil fuels is depleting resulting in energy shortage and pollution. Hence the need to explore alternative or renewable sources of energy to meet current and future energy demand. This paper examines the potential of Erin-Ijesa waterfall as a possible source of power supply to Erin-Ijesa community. The erratic supply of electricity in Nigeria, Erin-Ijesa community inclusive makes it paramount to consider generating electricity from the waterfall. Towards achieving this, the waterfalls data were obtained from Osun State Water Corporation Board Secretariat in Osogbo and a survey was conducted on site at Erin-Ijesa water falls where the flow and the head parameters were collected. The falls gives gross head of 200m with water flow rate of 0.85m3/s. These two parameters were used in the standard hydroelectric power (SHP) equations. The results obtained gave a theoretical power of 1.4MW, compared with the required power consumption of 1MW by the inhabitants of Erin-Ijesa community. A deviation of +0.4 from the required power consumption. It was also observed that the generated power from the falls will be sufficient to supply the entire community. The viability of small hydropower plant and the reduction in design time were established. Small hydropower plant will perform well if explored and executed in Erin-Ijesa, and in Nigeria at large.

Effects of Fe-Doped Electrolyte and Feed Flow Rate Evaluation in Home Made Solid Oxide Fuel Cell

Solid Oxide Fuel Cell (SOFC) is one type of fuel cell that has several advantages over other types of fuel cells. To achieve low cost SOFC, the materials used are nickel oxide (NiO) for the anode, Calcia Stabilized Zirconia (SCZ) for the electrolyte and Calcia Cobalt Oxide Zinc Oxide (CCZO) as cathode. Fe2O3 is a doping agent to form a denser electrolyte. The cell with and without Fe doping was tested using hydrogen and ambient air. Additionally, the effect of the amount of fuel flow rate is also investigated using Aspen Plus Modelling. Based on physical characterization, it is determined that 3%-mole Fe doping on the electrolyte increases the electrolyte density from 83% to 90%. Using electrochemical impedance spectroscopy, it can be concluded that SOFC with Fe doped electrolyte has a lower resistance than SOFC without Fe doping. On the other hand, using a correction factor, an equation of power correlated to fuel flow for the SOFC is generated to show increasing fuel flow enhanced SOFC performance.

Transient Stability Analysis of Grid-Connected Converter Driven by Imbalance Power under Non-Severe Remote Voltage Sag

In the transient process of the grid-connected converter (GCC), the existing research mainly focuses on the impact of the control loops. Little attention is paid to the transient stability issues driven by the imbalance between the input power and output power of GCC. This paper shows that the transient stability issues will still exist even if ignoring the dynamics of phase-locked loop (PLL) and current loop. In this paper, the models of the AC grid and the GCC are built under the assumption that the dynamics of the PLL and current loop are ignored. Then, by analyzing the transient process of GCC under non-severe remote voltage sag, the effects of the imbalance power on the transient stability of GCC are discussed. Moreover, for the GCC to operate stably after the transient process, there should be a maximum input power limit (MIPL) for GCC, and the imbalance power equation is applied in this paper to determine the transient stability of GCC. Furthermore, the effects of the current limitation on the transient stability of the GCC are also discussed. Finally, the theoretical analysis has been verified by means of simulations.

Real Time Load Assessment and Economic Analysis of RES System

Renewable resources are complementary in nature so the weaknesses of one can be overcome with the strength of other. The factors such as climate condition and weather are unpredictable, more for wind than compared to solar sources. The complementary nature of wind and solar sources motivates us to hybrid wind-solar power plant concept. The major problems like environment hazards, depletion of fossil fuels can be overcome by using hybrid power station. With the help of grid interconnection, the energy can be supplied to the remote rural areas and the emission of carbon and other harmful gases can be reduced up to 80% to 90%. This paper focuses on the optimal combination of renewable energy resources that could electrify the area under study. This paper also highlights the village details, energy resources available in region under study and the predicted load assessment. The various power output equations of wind power and solar power has also been discussed. The overview of the Homer software that was used for simulation purposes has also been discussed in this work.

Analysis of MNF and FAVAD Model for Leakage Characterization by Exploiting Smart-Metered Data: The Case of the Gorino Ferrarese (FE-Italy) District

Leakages in water distribution systems have great economic and environmental impacts and are a major issue for water utilities. In this work, the water balance and the Minimum Night Flow (MNF) method for evaluating the amount of water loss, as well as the power and Fixed and Variable Area Discharge (FAVAD) equations for analyzing the relationship between leakage and pressure, were applied to a fully monitored District Metered Area (DMA) located in Gorino Ferrarese (FE, Italy). Time series of (a) the water consumption of each user, (b) the DMA inflow, and (c) the pressure at the DMA inlet point were monitored with a 5 min time step. The results of an analysis carried out by exploiting the collected time series highlighted that: (a) The application of the MNF method based on literature values can lead to significant inaccuracies in the presence of users with irregular consumption, and (b) the estimation of the parameters of the power and FAVAD equations is highly affected by the amounts and types of observed data used.

Sampling plan designs for gluten estimation in oat flour by discrete and composite sampling

Heterogeneous gluten distribution in certain food commodities, such as oat flour, warrants a sound sampling plan to reduce measurement variability and the risk associated with lot misclassification. Ten lots of oat flour, 45 kg each, with varying gluten content were produced in a pilot-scale hammer mill to evaluate various sampling plans for gluten in oat flour. Thirty-two samples from each lot were collected during milling to study the effect of discrete (individual samples taken from the lot) and composite (samples taken from a bulk sample prepared by compositing several individual samples) sampling methods. A 5 g test sample was manually taken from each of the 32 samples, extracted with a cocktail extraction buffer, and gluten content was estimated using ELISA by analyzing duplicate aliquots of the extract. The total variance (Vt) from gluten measurements was partitioned into variance between samples (Vs) and aliquots analyzed (Va). Regression analysis revealed a linear relationship between the log of all three variances and the log of gluten concentration, which can be explained by the power equation for discrete and composite sampling methods. The Vt and Vs for discrete sampling tended to be higher than those for composite sampling at a given gluten concentration. A log-normal distribution was found suitable to characterize the distribution of measured gluten in oat flour samples from a test procedure. Operating characteristic (OC) curves plotted to evaluate various sampling plans for gluten in oat flour showed reduced risk of misclassification for composite sampling, as compared to the discrete sampling method for a given sampling plan. Examples are shown for the change in OC curves depending on the sampling method, sample size, number of samples analyzed, and accept/reject limit.

Validation of estimating left ventricular ejection fraction by mitral annular displacement derived from speckle-tracking echocardiography: A neglected method for evaluating left ventricular systolic function.

The echocardiographic measurement of left ventricular (LV) ejection fraction (EF) is dependent on professional experience and adequate visualization. Tissue motion of mitral annular displacement (TMAD) can be easily assessed using speckle-tracking echocardiography (STE), even in patients with poor acoustic windows. Therefore, this study aimed to assess whether left ventricular ejection fraction (LVEF) can be estimated using STE-derived TMAD when LVEF is not available. Four-hundred fifty-six outpatients were enrolled after excluding the patients whose LVEF measurements remained challenging or TMAD value could be confounded. An optimized regression model for LVEF-TMAD was developed in the derivation set (n=287), and its reliability was verified in the validation set (n=123) and regional wall motion abnormalities (RWMA) set (n=46). In the derivation set, the power models had the highest F-value. Therefore, the power equations were chosen to estimate LVEF by TMAD in the validation set. There was a near-zero bias and a narrow range between the observed and estimated LVEF. The highest intra-class correlation coefficient was found between the observed and the estimated LVEF by normalized TMAD at the midpoint of mitral annular (nTMADmid). Moreover, there were no significant differences between the observed and the estimated LVEF in the RWMA set. The LVEF can be estimated with STE-derived TMAD, even for patients with RWMA, and nTMADmid may be the optimal parameter.

Influence of 3D printing process parameters on the mechanical properties and mass of PLA parts and predictive models

Purpose This paper aims to evaluate the influence of the parameters of the Fused Filament Fabrication (FFF) process on the mechanical properties and on the mass of parts printed in Polylactic Acid (PLA). In addition, the authors developed predictive models for the analysed responses. Design/methodology/approach A full Factorial type of experimental planning method was used to define the conditions for manufacturing parts according to the variation of the construction parameters, extrusion temperature and print speed. Samples were printed for tensile, flexion and compression tests. Their mass was measured. Multiple regression methods, based on power equations, were used to build the forecasting models. Findings It was found that the extrusion temperature was the parameter of greatest influence in the variation of the analysed responses, mainly because it generates behaviour patterns and indirectly demonstrates thermal/rheological characteristics of the material used. Print speed affects responses, however, with variations dependent on part geometry and printer hardware/software. It was possible to establish prediction models with low error rates in relation to the experimental values. Originality/value The study demonstrates a good relation between the use of a structured experimental planning method as the basis for the development of predictive models based on mathematical equations, the same structure of which can be used to describe different responses.

Optimal Operation of Soft Open Points-Based Energy Storage in Active Distribution Networks by Considering the Battery Lifetime

Soft open point-based energy storage (SOP-based ES) can transfer power in time and space and also regulate reactive power. These characteristics help promote the integration of distributed generations (DGs) and reduce the operating cost of active distribution networks (ADNs). Therefore, this work proposed an optimal operation model for SOP-based ES in ADNs by considering the battery lifetime. First, the active and reactive power equations of SOP-based ES and battery degradation cost were modeled. Then, the optimal operation model that includes the operation cost of ADNs, loss cost, and battery degradation cost was established. The mixed integer nonlinear programming model was transformed to a mixed integer linear programming model derived through linearization treatment. Finally, the feasibility and effectiveness of the proposed optimization model are verified by the IEEE33 node system.

EMG Based Gesture Recognition Using the Unbiased Difference Power

In this paper, we propose an unbiased difference power that is robust against noise as a feature for electromyography (EMG)-based gesture recognition. The proposed unbiased difference power is obtained by subtracting the noise-biased part from the difference power. We derive the difference power equation and discover that the difference power is biased by twice the noise power. For noise power estimation, we utilized the characteristics of the EMG signal and estimated the noise power from the resting period. For performance evaluation, we used EMG signals provided by the open source Ninapro project database. We used the recognition accuracy as an evaluation index. We compare the recognition accuracy of the case using the proposed unbiased feature with those of two conventional cases. Experimental results show that the proposed unbiased difference power improves the accuracy compared with conventional ones. As the noise level increases, cases where the proposed unbiased difference power is used show a clear improvement in accuracy compared with the two conventional cases. For the signal-to-noise ratio (SNR) of 0 dB, the proposed unbiased difference power improves the average accuracy by more than 12%.

Tie-line Power Adjustment Method Based on Proximal Policy Optimization Algorithm

The tie-line power adjustment is an essential part of the power system operation state calculation. Various existing algorithms to solve the tie-line power adjustment problem are mainly implemented by introducing tie-line power equation constraints into conventional power flow calculations. Such methods have low calculation efficiency, not enough automation, and are prone to non-convergence in the power flow calculation. In this paper, the tie-line power adjustment problem is formulated as a Markov decision process, and the proximal policy optimization algorithm is introduced to optimize the decision policy. In order to enhance the effectiveness of the proposed method, a new deep neural network structure suitable for the proximal policy optimization algorithm is designed. The proposed method is verified with the IEEE 39-bus system.

Is Allometric Variation in the Cephalic Horn on Male Rhinoceros Beetles Discontinuously Dimorphic?

I used linear and nonlinear regression to re-examine the allometric relationship between length of the cephalic horn and width of the pronotum (a measure of body size) for males of 28 species of rhinoceros beetle (Coleoptera, Scarabaeidae, Dynastinae). An earlier investigation reported that variation in relative size of the horn conforms in most of the 28 species to a pattern of discontinuous, loglinear allometry, which implies, in turn, that two different power equations are needed to describe the full range in untransformed data. My analyses indicate, however, that allometric variation is continuous in all 28 species and that pattern in each of the original bivariate distributions is well described by a single mathematical function. Allometric variation on the original, arithmetic scale is linear for some species; either linear or slightly sigmoidal for other species; and decidedly sigmoidal in still other species. So-called major and minor morphs merely represent the extremes in absolute and relative size for the horn on animals drawn from the same, continuous distribution. The different findings reported in the earlier investigation resulted from insidious problems introduced by logarithmic transformation of the original bivariate data coupled with an overly complex statistical protocol for classifying individual males as either “major” or “minor.” Attempts at classification lead inevitably to oversimplification and misrepresentation of the pattern of allometric variation. Focus needs to return to describing and interpreting pattern in untransformed observations because the relationship between the original variables is the relationship of interest.