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A procedure for the rapid separation of Tc, Sr, Fe, Nb, and Ni in radioactive waste samples was developed for measuring their activity. After separating Tc on an anion-exchange resin column, Sr was separated as Sr(CaCO) co-precipitates, and Ni, Fe, and Nb were sequentially separated on an anion-exchange resin column in the presence of oxalate. The separated Sr and Ni were further purified on extraction chromatographic resin columns, respectively. The chemical yields of the separation procedure for Re, Sr, Fe, Nb, and Ni, which were added as chemical carriers, are 99.3 ± 0.3 %, 94.8 ± 0.6 %, 93.3 ± 1.2 %, 95.3 ± 1.9 %, and 92.6 ± 0.6 %, respectively. The separation of these radionuclides from sixteen radioactive waste samples required only seven person-days. [ABSTRACT FROM AUTHOR]

The effects of chloride concentration, creviced scaling factor and immersion time on the percentage area and maximum depth of attack for Type 304 stainless steel (SS304) in chloride solutions were investigated. The crevice assembly comprised of coupon (SS-304), polytetrafluoroethylene (crevice former) and fasteners (titanium bolt, nut and washers). The full immersion tests were based on ASTM G-78 using full factorial design to study the effects of chloride concentration (1.5, 3.0 and 4.5 w/w%), crevice scaling factor (8, 16 and 24) and immersion time (15, 30 and 45 days) on the percentage area of attack (Y1) and maximum depth of attack (Y2) of SS-304. Data obtained was used to develop and optimize the models of Y1 and Y2 in terms of the three factors using Response Surface Methodology (RSM). The R2 of Y1 and Y2 were 0.98 and 0.91, respectively. The minimum Y1 (5.63%) and Y2 (3.32×10−7 mm) were obtained at 4.5% chloride concentration, 20 scaling factor and 15 days immersion time. The predicted optimal conditions agreed with the experimental results for validation with a maximum absolute relative error of 5.75%. [ABSTRACT FROM AUTHOR]

Proportional- Integral (PI) like Fuzzy Logic Controllers (FLC) has been widely used for control of static power converters (SPC). The performance of these controllers is sensitive to controller rules, parameters of membership functions and input-output scaling factors. Among these parameters, scaling factor (SF) directly affects the controller performance in terms of transient response, steady state error and stability. Therefore, using an optimum SF value increases the performance of the FLC against using a constant value. Hence, in this paper optimizing the output scaling factor (OSF) of the PI-like fuzzy logic controller (PIFLC) by using Particle Swarm Optimization (PSO) algorithm is proposed. In order to optimize and analyze the effect of this parameter on the controller performance, first the output scaling factor of FLC is optimized with various PSO algorithms and one of these algorithms is selected for experimental test. Then optimized FLC is applied to a DC-DC Buck converter, and the performance of the controller is evaluated under nominal load and load disturbance. The controller design, the OSF optimization, and the controller performance analysis approaches are presented in detail. [ABSTRACT FROM AUTHOR]

The geomagnetic field is a major influence on in situ cosmogenic nuclide production rates at a given location (in addition to atmospheric pressure and, to a lesser extent, solar modulation effects). A better understanding of how past fluctuations in these influences affected production rates should allow more accurate application of cosmogenic nuclides. As such, this work explores the cosmogenic nuclide production rate scaling implications of two recent time-dependent spherical harmonic geomagnetic models spanning the Holocene. Korte and Constable (2011, Phys. Earth Planet. Inter. 188 , 247–259) and Korte et al. (2011, Earth Planet. Sci. Lett . 312 , 497–505) recently updated earlier spherical harmonic paleomagnetic models with new paleomagnetic data from sediment cores in addition to new archeomagnetic and volcanic data. These updated models offer improved resolution and accuracy over the previous versions, in part due to increased temporal and spatial data coverage. In addition, Pavón-Carrasco et al. (2014, Earth Planet. Sci. Lett . 388 , 98–109) developed another time-dependent spherical harmonic model of the Holocene geomagnetic field, based solely on archeomagnetic and volcanic paleomagnetic data from the same underlying paleomagnetic database as the Korte et al. models, but extending to 14 ka. With the new models as input, trajectory-traced estimates of effective vertical cutoff rigidity ( R C – the standard method for ordering cosmic ray data) yield significantly different time-integrated scaling predictions when compared to each other and to results using the earlier models. In addition, predictions of each new model using R C are tested empirically using recently published production rate calibration data for both 10 Be and 3 He, and compared to predictions using corresponding time-varying geocentric dipolar R C formulations and a static geocentric axial dipole (GAD) model. Results for the few calibration sites from geomagnetically sensitive regions suggest that the Pavón-Carrasco et al. (2014) time-varying dipolar model tends to predict sea level, high latitude production rates more in line with those from calibration sites not affected by geomagnetic variations. This suggests that uncertainties arising from hemispheric and temporal sampling biases in the Holocene spherical harmonic models considered here, combined with the currently limited spatial and temporal distribution of production rate calibration sites as empirical tests, limit the robustness of the non-dipole aspects of these models for production rate scaling. These analyses should be revisited as such models improve and additional calibration sites become available. [ABSTRACT FROM AUTHOR]

DC-biased optical orthogonal frequency-division multiplexing (DCO-OFDM) is widely used in visible light communication (VLC) systems to provide high data rate transmission. As intensity modulation with direct detection (IM/DD) is employed to modulate the OFDM signal, scale up the amplitude of the signal can increase the effective transmitted electrical power whereas more signals are likely to be clipped due to the limited dynamic range of LEDs, resulting in severe clipping distortion. Thus, it is crucial to scale the signal to find a tradeoff between the effective electrical power and the clipping distortion. In this paper, an optimal scaling scheme is proposed to maximize the received signal-to-noise-plus-distortion ratio (SNDR) with the constraint of the radiated optical power in a practical scenario where DC bias is fixed for a desired dimming level. Simulation results show that the system with the optimal scaling factor outperforms that with fixed scaling factor under different equivalent noise power in terms of the bit error ratio (BER) performance. [ABSTRACT FROM AUTHOR]

A novel unconditionally stable split-step finite-difference time domain (SS-FDTD) method based on an isotropic dispersion finite-difference scheme is introduced. The proposed method reformed the weighting factor and scaling factor of the isotropic-dispersion FDTD for the SS-FDTD method with four substeps, which can generate nearly exact phase velocity for a single frequency. Compared with the conventional four-stage split-step FDTD method, the numerical dispersion error of the new method is significantly reduced even for a large stability factor. The new method is validated by numerical simulations. [ABSTRACT FROM AUTHOR]

Within the dynamics of structures, sensitivity analysis shows how to achieve the most effective modification to reach a change in the structural behaviour.Usually, the modal model is available, has a limited number of vibration modes; even so, it is possible to achieve a reasonable approximation to estimate the sensitivities of the natural frequencies and the eigenvectors. Throughout the exhibition of the work, we develop an experimental validation of both analytical expressions for determining estimates of modification of modal parameters, i.e., estimates of the variation of the frequency deviation Δωi, and the increase Δ{ψi } the components of each eigenvector, belonging to the mode i.

Physiological based pharmacokinetic (PBPK) modeling is now commonly used in drug development to integrate human or animal physiological data in order to predict pharmacokinetic profiles. The aim of this work was to construct and refine a PBPK model of irbesartan taking into account its active uptake via OATP1B1/B3 in order to predict more accurately its pharmacokinetic profile using Simcyp®. The activity and expression of the human hepatocyte transporters OATP1B1 and OATP1B3 were studied. The relative activity factors (RAFs) for OATP1B1 and OATP1B3 transporters were calculated from intrinsic clearances obtained by concentration dependent uptake experiments in human hepatocytes and HEK overexpressing cells: RAF1B1 using estrone-3-sulfate and pitavastatine clearances, and RAF1B3 using cholecystokinine octapeptide (CCK-8) clearances. The relative expression factor (REF) was calculated by comparing immunoblotting of hepatocytes (REFHH) or tissues (REFtissue) with those of overexpressing HEK cells for each transporter. These scaling factors were applied in a PBPK model of irbesartan using the Simcyp® simulator. Pharmacokinetic simulation using REFHH (1.82 for OATP1B1, 8.03 for OATP1B3) as an extrapolation factor was the closest to the human clinical pharmacokinetic profile of irbesartan. These investigations show the importance of integrating the contribution of the active uptake of a drug in the liver to improve PBPK modeling. [ABSTRACT FROM AUTHOR]

This study used a global hydrological model (GHM), PCR-GLOBWB, which simulates surface water storage changes, natural and human induced groundwater storage changes, and the interactions between surface water and subsurface water, to generate scaling factors by mimicking low-pass filtering of GRACE signals. Signal losses in GRACE data were subsequently restored by the scaling factors from PCR-GLOBWB. Results indicate greater spatial heterogeneity in scaling factor from PCR-GLOBWB and CLM4.0 than that from GLDAS-1 Noah due to comprehensive simulation of surface and subsurface water storage changes for PCR-GLOBWB and CLM4.0. Filtered GRACE total water storage (TWS) changes applied with PCR-GLOBWB scaling factors show closer agreement with water budget estimates of TWS changes than those with scaling factors from other land surface models (LSMs) in China's Yangtze River basin. Results of this study develop a further understanding of the behavior of scaling factors from different LSMs or GHMs over hydrologically complex basins, and could be valuable in providing more accurate TWS changes for hydrological applications (e.g., monitoring drought and groundwater storage depletion) over regions where human-induced interactions between surface water and subsurface water are intensive. [ABSTRACT FROM AUTHOR]

We confirmed how well the exchange–correlation functional vdW-DF2, with its non-local correlation part, describes the adsorption of CO on close-packed surfaces and clusters of Co, Ni, Cu, Ru, Rh, Pd, and Pt. The calculated adsorption energies are fairly close to the experimental values. The carbonyl vibrational frequencies, calculated within the harmonic approximation, systematically underestimate the experimental results. To amend this deficiency, we explored multiplicative and additive correction schemes. Scaling the calculated harmonic CO frequencies by a uniform factor of 1.030 yields results with a mean absolute deviation of ∼13 cm −1 from experiment. With this correction scheme we were able to clarify some controversial structures for CO adsorption on the surfaces Pd(1 1 1) and Co(0 0 0 1). [ABSTRACT FROM AUTHOR]

Some optimization problems in the field of nuclear engineering, as for example the incore nuclear fuel management and a nuclear reactor core design, are highly multimodal, requiring techniques that overcome local optima, exploring the search space and promoting the exploitation of its most promising areas. The differential evolution algorithm (DE) relies mainly on the mechanism of mutation, where an individual is perturbed using the weighted difference (with the so-called “scaling factor” F ) between two randomly chosen individuals. DE's canonical version employs a constant value of F . However, this parameter should be variable in order to balance the exploration and exploitation of the search space. In this work, we test some variable scaling factors from the literature and present the novel exponential scaling factor. These methods are applied to two problems: the aforementioned core design and the turbine balancing problem, which is an NP-hard (i.e. intrinsically harder than those that can be solved in nondeterministic polynomial time) combinatorial optimization problem that can be used to assess the potential of an algorithm to be applied to fuel management optimization. DE with variable scaling factors perform well in both problems, showing potential to be used in other nuclear science and engineering optimization problems. [ABSTRACT FROM AUTHOR]

Cuckoo search (CS), inspired by the obligate brood parasitic behavior of some cuckoo species, iteratively uses Lévy flights random walk (LFRW) and biased/selective random walk (BSRW) to search for new solutions. In this study, we seek a simple strategy to set the scaling factor in LFRW, which can vary the scaling factor to achieve better performance. However, choosing the best scaling factor for each problem is intractable. Thus, we propose a varied scaling factor (VSF) strategy that samples a value from the range [0,1] uniformly at random for each iteration. In addition, we integrate the VSF strategy into several advanced CS variants. Extensive experiments are conducted on three groups of benchmark functions including 18 common test functions, 25 functions proposed in CEC 2005, and 28 functions introduced in CEC 2013. Experimental results demonstrate the effectiveness of the VSF strategy. [ABSTRACT FROM AUTHOR]

Concrete with ferrous tailings displacing natural sand is called ferrous tailings concrete. Cubic specimens of ferrous tailings concrete (strength grade C25-C50) with standard size(150mm side length) and with non-standard size(100mm side length) are tested for measuring compressive strength in this paper. The varied factors are the concrete strength grades with C25 to C50, and the ratio of W/(C+P) with the range of 0.75 to 0.3. Based on analyses of test data, it was concluded that the compressive strength of the standard size specimens are related closely with that of nonstandard size specimens, The ferrous tailings concrete compressive strength size correlation degree is linearly lowering with water-binder ratio (W/(C+P)), and the size scaling factor of standard size specimens to nonstandard size specimens is 0.88. [ABSTRACT FROM AUTHOR]

To broaden the use of an adaptive resistive algorithm (ARA), we present a 3-D model able to reproduce the experimental magnetic moment loop for a finite-size superconducting strip in a perpendicular field. We also develop the same model by using H-formulation, to strengthen the ARA results. We find that 2-D models computed with the two different approaches, i.e., ARA and H-formulation, provide similar results, and both well compare to approximate analytical solutions. Then, we verify that the computed magnetic moment loop by using either 3-D numerical approaches reproduces the experimental curve, i.e., the magnetic loops of a commercial YBCO-coated conductor sample measured at 5 K. Instead, the 2-D numerical data need a scaling factor to match the experimental ones. The 3-D computations provide support to the hypotheses on the current surface profile that has been used to find the scaling factor. [ABSTRACT FROM PUBLISHER]

Radioactive waste characterization is one of the constituent parts of the NPP radioactive waste management. Nuclear equipment is dismantled and placed in appropriate containers that firstly are transferred to the temporary storage area and then are distributed to the final waste repositories. In order to control whether the acceptance criteria are fulfilled or not, it is important to assess the radionuclide specific activity accumulated in the waste before transportation of the filled waste packages. One of the most effective methods for the determination of the most important radionuclide concentrations in the package is the scaling factor method (or nuclide vector). Using gamma spectroscopy or data on the surface dose rate, for each waste package, the activity of the key radionuclide is estimated. The remaining difficult to measure radionuclide concentrations are calculated using pre-determined scaling factors for different radionuclides. This article gives an overview of the most common methods for the assessment of the most important key radionuclide concentrations in radioactive waste packages paying more attention to the scaling factor method. [ABSTRACT FROM AUTHOR]

As a new material type for pavement, pervious concrete should be designed to maintain both porosity and the structural strength. The actual mix proportions for pervious concrete depend on the application, the mechanical properties required and the materials used. Actually, the mix proportions of pervious concrete were determined for locally available materials based frequently on trial batching and experience. Another analytical method should be developed to facilitate the concrete producers. Based on the assumption that the cement paste only plays a role of coating, it does not fulfill the void among the grains of gravel; this paper focuses on one modified method for the design of the pervious concrete. The volume cement paste is divided by the surface area of the aggregates to determine the thickness of the excess paste. A scaling factor has been defined to evenly distribute the cement paste toward the size of gravel. Moreover, a binder drainage test is proposed to determine the critical w / c ratio towards to prevent the flow of cement paste to the lower layers of concrete under the action of vibration or compaction. The pervious concrete has been formulated according to this method to validate it. The mechanical and hydraulic tests are performed to characterize the pervious concrete. The obtained pervious concrete presents a large sufficient permeability (1 mm s −1 ) for draining rainwater and good mechanical resistance ( R c = 28.6 MPa) with regard to typical pervious concrete applications such as parking lots, walkways and low-traffic roadways. In addition, the mechanical strength of pervious concrete in this research is found higher than that generally reported by other authors. The results indicate that the theoretical mix design method is a successful theory for an optimizing composition of pervious concrete. [ABSTRACT FROM AUTHOR]

In fuzzy controllers, the adjusting of scale factors, both input and output, is critical to the performance of the plant being controlled. The adjustment of scale factors in Fuzzy PD+I controllers (FPD+I) is well documented; however, in systems that have control signal saturation, FPD+I requires anti-windup systems (AW) that limit the controller's integral action. The adjustment procedure for FPD+I controllers cannot be used in Fuzzy PD+I controllers with anti-windup system (FPD+I AW), as it increases the overall gain system, which causes oscillatory behaviour and even critical stability in the controlled variable. The main motivation of this research was to have an approach for adjusting Fuzzy PD+I controllers with anti-windup system (FPD+I AW) without having oscillatory behaviour. In order to verify the proposed approach, both the input and output scale factors of a FPD+I AW controller were adjusted and used to control speed in a direct current motor with control signal saturation and were compared with the responses of conventional PID, Adaptive Neuro Fuzzy Inference System (ANFIS) and Fuzzy sliding controllers, all with AWs based on tracking back calculation, thereby demonstrating the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

Soil air permeability ( k a ) is an important factor that controls subsurface gas transport and exchange of gas across the soil–atmosphere interface. It is thus crucial to evaluate the spatial distribution of k a for both application and modeling purposes. However, relevant studies are still very limited, partly due to the fact that the dependence of k a on soil moisture levels cannot be directly included in the methods such as geostatistical techniques for analyzing the spatial distribution of k a . To tackle this problem, the scaling scheme based on the similar media concept, which has been widely used in soil hydrology for characterizing spatial variability of soil hydraulic properties, was employed for scaling k a in this study. Four air permeability models, including Millington and Quirk (1960)—MQ, Hunt (2005)—HT, Brooks and Corey (1964)—BC, and Kawamoto et al. (2006)—KA, were selected to test this method using two independent datasets. For the first dataset that included k a measured for river sediments, all of the four models were able to delineate the spatial distribution of k a with a reference curve of k a and a set of scaling factors. Specifically, the MQ model gave the least satisfactory results due to the less flexibility of its form; whereas, there were no significant differences in the performances for the HT, BC, and KA models. For the second dataset that contained k a measured for agricultural soils, the overall performance of the four models for scaling k a deteriorated, largely due to the alterations in the microscopic structures of soil samples caused by repacking and compression of soil samples. Nonetheless, as the first attempt, this study shows the viability of using the similar media concept for scaling k a . The merit of this method resides in the fact that the spatial variations of moisture conditions and soil properties can be simultaneously included for analyzing the spatial distribution of k a . With a reference curve of k a and the distribution of scaling factors, this method would be particularly suitable for modeling subsurface gas transport. [ABSTRACT FROM AUTHOR]

To keep the global search capability and robustness for unmanned surface vessel (USV) path planning, an improved differential evolution particle swarm optimization algorithm (DePSO) is proposed in this paper. In the optimization process, approach to optimal value in particle swarm optimization algorithm (PSO) and mutation, hybridization, selection operation in differential evolution algorithm (DE) are combined, and the mutation factor is self-adjusted. First, the particle population is initialized and the optimization objective is determined, the individual and global optimal values are updated. Then differential variation is conducted to produces new variables and cross over with the current individual, the scaling factor is adjusted adaptively with the number of iterations in the mutation process, particle population is updated according to the hybridization results. Finally, the convergence of the algorithm is determined according to the decision standard. Numerical simulation results show that, compared with conventional PSO and DE, the proposed algorithm can effectively reduce the path intersection points, and thus greatly shorten the overall path length., Competing Interests: Author SM was employed by Zhejiang Jialan Ocean Electronics Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Gong, Zhang, Luo and Ma.)

The wind energy industry is moving to offshore installations allowing for larger wind turbines to be deployed in deep-water regions with higher and steadier wind speeds. Floating offshore wind turbines consist of two main subsystems: a wind turbine itself and a floating substructure that supports it and provides stability. While the wind turbine technology is mature, the floating support structures for offshore wind turbines are still evolving and have not been deployed at a commercial scale. Due to a significant increase in the size of wind turbines over the last decade, it is important to understand how to design the floating platform to support larger wind turbines, and how the dynamics of the entire system change with increasing scale. Firstly, this article provides an overview of the trends in wind energy systems for offshore applications. Secondly, a review of existing semi-submersible platforms designed to support 5–15 MW wind turbines is provided. In addition, this article provides a comparative analysis of the techniques proposed to upscale floating support structures for larger wind energy systems with a particular focus on the system dynamics. The results demonstrate that the wind turbine mass, rated power and rotor thrust force scale with close to square rotor diameter. Towers designed for floating wind applications are usually significantly stiffer and heavier as compared to their fixed-bottom counterparts to place the tower's natural frequencies outside the wave excitation region. The analysis of semi-submersible platforms revealed a strong correlation between the wind turbine rotor diameter and the product of the distance to the offset columns and their diameter. Also, it has been found that design practices adapted by the platform developers roughly follow the theoretical square–cube (or 'mass') scaling law when designing platforms for larger wind turbines. • Identified scaling laws for offshore wind turbines up to 20 MW. • Towers for floating wind turbines are stiffer than for bottom-fixed foundations. • Waterplane area does not govern the design of a semisubmersible platform. • Fixed-draught scaling law leads to the platform's highest motion amplitudes. • Platform scaling laws proposed in literature do not reflect industry practices. [ABSTRACT FROM AUTHOR]

In this paper a numerical method for solving generalized three-dimensional magnetohydrodynamic (MHD) flow of an incompressible viscous fluid over a porous stretching sheet is proposed. This approach is based on Legendre pseudo-spectral method with a positive scaling factor and extrapolation. The present method solves the problem on the semi-infinite domain without truncating it to a finite domain. In addition, this method reduces the solution of the problem to solution of a system of algebraic equations. The obtained numerical results are compared with some well-known results to confirm the accuracy and efficiency of the proposed scheme. [ABSTRACT FROM AUTHOR]

Surface wetting is an important phenomenon in many industrial processes including micro- and nanofluidics. The wetting characteristics depend on the surface tension forces at the three-phase contact line and can be altered by introducing patterned groove structures. This study investigates the effect of the grooves on the transition in the wetting behavior between the Cassie to Wenzel regimes. The experiments demonstrate that the wettability on a patterned surface depends on the spacing factor ( S = channel depth/channel width). The spacing factor influences the contact angle, contact angle hysteresis, and the transition characteristics between the Cassie and Wenzel states. It was noted that under certain conditions ( S > 1) the droplet behaved as a Cassie droplet, while exhibiting Wenzel wetting the rest of the time on the silicon microchannels tested. This criterion was used to design the groove structures on the sidewall of the proton exchange membrane fuel cell gas channel to remove the water effectively. The water coming from the land region into the gas channel is pulled by the grooves to the top wall where the airflow aided in its removal. Also, the contact angles measured on the surfaces were compared with the classical models that use wetted area, and the contact line model that uses the three-phase contact line length. It was found in our experiments that the contact line model predicts the contact angle on the patterned groove surfaces more accurately than the classical models. [ABSTRACT FROM AUTHOR]

Physiologically based pharmacokinetic (PBPK) models provide a framework useful for generating credible human pharmacokinetic predictions from data available at the earliest, preclinical stages of pharmaceutical research. With this approach, the pharmacokinetic implications of in vitro data are contextualized via scaling according to independent physiological information. However, in many cases these models also require model-based estimation of additional empirical scaling factors (SFs) in order to accurately recapitulate known human pharmacokinetic behavior. While this practice clearly improves data characterization, the introduction of empirically derived SFs may belie the extrapolative power commonly attributed to PBPK. This is particularly true when such SFs are compound dependent and/or when there are issues with regard to identifiability. As such, when empirically-derived SFs are necessary, a critical evaluation of parameter estimation and model structure are prudent. In this study, we applied a global optimization method to support model-based estimation of a single set of empirical SFs from intravenous clinical data on seven OATP substrates within the context of a previously published PBPK model as well as a revised PBPK model. The revised model with experimentally measured unbound fraction in liver, permeability between liver compartments, and permeability limited distribution to selected tissues improved data characterization. We utilized large-sample approximation and resampling approaches to estimate confidence intervals for the revised model in support of forward predictions that reflect the derived uncertainty. This work illustrates an objective approach to estimating empirically-derived SFs, systematically refining PBPK model performance and conveying the associated confidence in subsequent forward predictions. [ABSTRACT FROM AUTHOR]

The gas phase vibrational spectroscopy of cryogenically cooled C2 n + 1N− anions with n = 1 − 5 is investigated in the spectral range of the C≡C and C≡N stretching modes (1850-2400 cm -1) by way of infrared photodissociation (IRPD) spectroscopy of messenger-tagged C2 n+1N -· mD2 complexes. The IRPD spectra are assigned based on a comparison to previously reported anharmonic and harmonic CCSD(T) vibrational frequencies and intensities. Experimentally determined and predicted anharmonic vibrational transition energies lie within ± 21 cm -1. For the harmonic CCSD(T)/vqz+ vibrational frequencies a scaling factor of 0.9808 is determined, resulting in comparable absolute deviations. The influence of the D2-messenger molecules on the structure and the IRPD spectrum is found to be small. Compared to the results of previous IR matrix isolation studies additional, in particular weaker, IR-active transitions are identified. [ABSTRACT FROM AUTHOR]

Within the dynamics of structures, sensitivity analysis shows how to achieve the most effective modification to reach a change in the structural behaviour. Usually, the modal model is available, has a limited number of vibration modes; even so, it is possible to achieve a reasonable approximation to estimate the sensitivities of the natural frequencies and the eigenvectors. Throughout the exhibition of the work, we develop an experimental validation of both analytical expressions for determining estimates of modification of modal parameters, i.e., estimates of the variation of the frequency deviation Δωi, and the increase Δ{ψi } the components of each eigenvector, belonging to the mode i. [ABSTRACT FROM AUTHOR]

Accurate determination of technetium-99 (Tc-99) is very important because any overestimation will cause the examined radioactive wastes to be categorized into super C class, which dramatically increases the cost of waste management. Herein, we demonstrated that by adopting the analytical method comprising TEVA resin pretreatment and ICP-MS measurement, the determined Tc-99 concentrations in representative waste stream samples from the Lan-Yu low-level radioactive waste temporary storage site in Taiwan were approximately two orders of magnitude lower than those determined from the beta radiation measurement using a low background liquid scintillation counter. Two important concerns emerged from our results. First, severe interferences from other nuclides residing in the matrix considerably affect the determination of Tc-99, even when a low background liquid scintillation counter was used. Second, the currently used Tc-99/Cs-137 scaling factor should be carefully revised, or it might lead to a considerable overestimation of the Tc-99 concentration. [ABSTRACT FROM AUTHOR]

The widely performed Bayesian synthesis inversion method (BSIM) utilizes prior carbon flux and atmospheric carbon dioxide observations to optimize the unknown flux. The prior flux is usually computed from ecological models with large biases. The BSIM is useful in solving the problem of insufficient data, but it will increase the inaccuracies in the estimates caused by the biased prior flux. In this study, we propose a dual optimization method (DOM) to introduce a set of scaling factors as new state variables to correct for the prior flux according to information on plant functional types. The DOM estimates the scaling factors and carbon flux simultaneously by minimizing the cost function. The statistical properties of the DOM, which compare favorably with the BSIM, are provided in this article. We tested the DOM through simulation experiments which represent a true ecosystem. The results, according to the root mean squared error, show that the DOM has a higher accuracy than the BSIM in flux estimates. [ABSTRACT FROM AUTHOR]

Highlights: [•] Scaling factors are calculated for the beginning of cycle (BOC) of VVER-1000 reactor using the direct and adjoint methods. [•] Space and energy dependent power density in core region is obtained from MCNP code. [•] Linearity assumption of relative detector response for small CBM is investigated. [•] It is shown that the direct method result is reliable for determining the CBM. [Copyright &y& Elsevier]

Abstract: When dealing with small and light structures, difficulties occur when measuring the modal parameters. The resonant frequencies are usually relatively high and therefore a wide frequency range is needed for the measurement. Furthermore, the mass that is added to the structure by the sensors causes structural modifications. To overcome these difficulties, an improved method using an operational modal analysis instead of an experimental modal analysis is proposed in this study. It is derived from the sensitivity-based operational mode-shape normalisation with a consideration of the mode-shape variation. The measurement of the excitation force is not needed, because the operational modal analysis is used and only two simultaneous response measurements at an unknown excitation are required. The proposed method includes the cancellation of the added mass, resulting in mode shapes and resonant frequencies of the unmodified structure. The numerical and experimental results on small and light structures are compared with the results of the experimental modal analysis. The comparison shows that the proposed approach allows measurements over a wide frequency range and increases the accuracy of the results compared to the sensitivity-based operational mode-shape normalisation and also compared to the particular experimental modal analysis method that was used in this study. The advantages of the proposed method can be seen whenever the mass that is added to the structure by the accelerometer is not negligible and therefore a variation of the mode shapes occurs. [Copyright &y& Elsevier]