Analysis Of Limit Research Articles

Design and Simulation for Minimizing Non-Radiative Recombination Losses in CsGeI2Br Perovskite Solar Cells.

CsGeI2Br-based perovskites, with their favorable band gap and high absorption coefficient, are promising candidates for the development of efficient lead-free perovskite solar cells (PSCs). However, bulk and interfacial carrier non-radiative recombination losses hinder the further improvement of power conversion efficiency and stability in PSCs. To overcome this challenge, the photovoltaic potential of the device is unlocked by optimizing the optical and electronic parameters through rigorous numerical simulation, which include tuning perovskite thickness, bulk defect density, and series and shunt resistance. Additionally, to make the simulation data as realistic as possible, recombination processes, such as Auger recombination, must be considered. In this simulation, when the Auger capture coefficient is increased to 10-29 cm6 s-1, the efficiency drops from 31.62% (without taking Auger recombination into account) to 29.10%. Since Auger recombination is unavoidable in experiments, carrier losses due to Auger recombination should be included in the analysis of the efficiency limit to avoid significantly overestimating the simulated device performance. Therefore, this paper provides valuable insights for designing realistic and efficient lead-free PSCs.

Depth detection limit of a fluorescent object in tissue-like medium with background emission in continuous-wave measurements: a phantom study.

Although the depth detection limit of fluorescence objects in tissue has been studied, reports with a model including noise statistics for designing the optimum measurement configuration are missing. We demonstrate a variance analysis of the depth detection limit toward clinical applications such as noninvasively assessing the risk of aspiration. It is essential to analyze how the depth detection limit of the fluorescence object in a strong scattering medium depends on the measurement configuration to optimize the configuration. We aim to evaluate the depth detection limit from theoretical analysis and phantom experiments and discuss the source-detector distance that maximizes this limit. Experiments for detecting a fluorescent object in a biological tissue-mimicking phantom of ground beef with background emission were conducted using continuous wave fluorescence measurements with a point source-detector scheme. The results were analyzed using a model based on the photon diffusion equations. Then, variance analysis of the signal fluctuation was introduced. The model explained the measured fluorescence intensities and their fluctuations well. The variance analysis showed that the depth detection limit in the presence of ambient light increased with the decrease in the source-detector distance, and the optimum distance was in the range of 10 to 15mm. The depth detection limit was found to be with this optimum distance for the phantom. The presented analysis provides a guide for the optimum design of the measurement configuration for detecting fluorescence objects in clinical applications.

Analysis and Prediction of the Stability Limit for Centrifugal Compressors with Vaneless Diffusers

A numerical study was conducted to identify the mechanisms involved in the destabilisation of centrifugal compressors with vaneless diffusers. A stability analysis—carried out on the rotating and fixed parts of the studied machines—showed that the vaneless diffuser is a limiting component at a low mass flow rate. It was demonstrated that the reorganisation of stall patterns into recirculation in the inducer stabilises the impellers’ flow fields. As the destabilisation of vaneless diffusers has been a recurrent topic in the literature, many models have shown that it is the inlet-flow angle that drives the loss of stability. Models from the literature have estimated critical angle values using the geometry of the diffuser. Thus, for a given stage, expressing the diffuser inlet-flow angle as a function of the mass flow rate allows one to estimate its stability limit. However, this law needs to be calibrated to consider each compressor’s geometrical and aerodynamic specificities. This calibration can be achieved through single-passage steady simulations performed at stable operating points with high mass flow rates. With this methodology, a designer can estimate the stability limit of a centrifugal compressor with a vaneless diffuser from single-passage RANS calculations.

Enhancing the performance of integer models for addressing the long-term production planning problem in open pit mines by decision variable fixation based on parametric analysis of the final pit limit

Enhancing the performance of integer models for addressing the long-term production planning problem in open pit mines by decision variable fixation based on parametric analysis of the final pit limit

Exploring the effects of antimicrobial treatment on the gut and oral microbiomes and resistomes from elderly long-term care facility residents via shotgun DNA sequencing.

Monitoring antibiotic-resistant bacteria (ARB) and understanding the effects of antimicrobial drugs on the human microbiome and resistome are crucial for public health. However, no study has investigated the association between antimicrobial treatment and the microbiome-resistome relationship in long-term care facilities, where residents act as reservoirs of ARB but are not included in the national surveillance for ARB. We conducted shotgun metagenome sequencing of oral and stool samples from long-term care facility residents and explored the effects of antimicrobial treatment on the human microbiome and resistome using two types of comparisons: cross-sectional comparisons based on antimicrobial treatment history in the past 6 months and within-subject comparisons between stool samples before, during and 2-4 weeks after treatment using a single antimicrobial drug. Cross-sectional analysis revealed two characteristics in the group with a history of antimicrobial treatment: the archaeon Methanobrevibacter was the only taxon that significantly increased in abundance, and the total abundance of antimicrobial resistance genes (ARGs) was also significantly higher. Within-subject comparisons showed that taxonomic diversity did not decrease during treatment, suggesting that the effect of the prescription of a single antimicrobial drug in usual clinical treatment on the gut microbiota is likely to be smaller than previously thought, even among very elderly people. Additional analysis of the detection limit of ARGs revealed that they could not be detected when contig coverage was <2.0. This study is the first to report the effects of usual antimicrobial treatments on the microbiome and resistome of long-term care facility residents.

Bright and dark solitons in a photonic nonlinear quantum walk: lessons from the continuum

Abstract We propose a nonlinear quantum walk model inspired in a photonic implementation in which the polarization state of the light field plays the role of the coin-qubit. In particular, we take profit of the nonlinear polarization rotation occurring in optical media with Kerr nonlinearity, which allows to implement a nonlinear coin operator, one that depends on the state of the coin-qubit. We consider the space-time continuum limit of the evolution equation, which takes the form of a nonlinear Dirac equation. The analysis of this continuum limit allows us to gain some insight into the existence of different solitonic structures, such as bright and dark solitons. We illustrate several properties of these solitons with numerical calculations, including the effect on them of an additional phase simulating an external electric field.

Correction to: Number of Passes of Endovascular Therapy for Stroke With a Large Ischemic Core: Secondary Analysis of RESCUE-Japan LIMIT.

Correction to: Number of Passes of Endovascular Therapy for Stroke With a Large Ischemic Core: Secondary Analysis of RESCUE-Japan LIMIT.

Fracture mechanics-based analysis of the fatigue limit of Ti6Al4V alloy specimens manufactured by SLM in as-built surface conditions by means of areal measurements

The fatigue limit of additively manufactured Ti6Al4V alloy specimens in as-built surface conditions is estimated using a fracture mechanics analysis involving different definitions of an effective crack size related to the areal parameter, Sv, of the surface texture, on which the fatigue limit is made to depend. The approach adopts the Extreme Value Statistics (EVS) to determine the largest Sv of the individual as well as the entire batch of specimens and is validated by comparison with the experimental results. Finally, the applicability of the approach by using the 1D roughness profile parameter, Rv, is discussed using the EVS with appropriate hypotheses.

Analysis of speed limit and energy consumption in electric vehicles

This paper presents an analysis of the mileage energy consumption for an electric passenger vehicle in terms of the introduction of numerous speed limits. Regulations concerning the limiting of vehicle speed to 30 km/h in cities or residential areas are particularly common. This restriction is intended to increase traffic safety, but at the same time introduces increased mileage fuel or energy consumption in electric drivetrain. Regardless of the energy carrier, any increase in energy causes negative effects for the environment. The analysis was focused on the mileage energy consumption of electric passenger cars for a constant speed under real traffic conditions. During the tests, the tested vehicles’ speed on a specially designated road section was changed gradually by 10 km/h, with simultaneous recording of the car’s traction parameters and mileage energy consumption. An analysis of the mileage energy consumption was then carried out for the assumed fleet of cars travelling one after another (in a so-called traffic jam), while maintaining a safe distance. This allowed for the calculation of the environment’s energy burden caused by a fleet of vehicles travelling on a given road section, indicating that a reduction in vehicle speed causes an increase in the vehicles’ energy consumption. Both total and mileage energy consumption of electric vehicles were analysed during the tests.

Experimental investigation on the explosion limits of diethyl ether spray near boiling point temperatures

Assessing explosion danger for flammable liquids with low boiling points that may form the spray due to leakage during production, storage, and transportation requires further refinement. The present study aims to investigate the explosion limits of diethyl ether (DEE) in a 20-L spherical vessel at various material and air temperatures ranging from 298.15 K to 323.15 K. The influence of material and air temperatures on the explosion limits of DEE was examined separately as individual factors and in combination. The results showed that the effect of material or air temperature on the upper explosion limit (UEL) was significant over the altered temperature range, while the impact on the lower explosion limit (LEL) was relatively minor. Upon combining the effects of material and air temperatures, the UEL was more significantly influenced by the air temperature, particularly at high air temperatures. However, the impact of material temperatures on the UEL was more pronounced at low air temperatures. Overall, the explosion limits exhibited a linear relationship with the initial temperature (general term for temperatures at which the material temperature equals the air temperature), except for the vicinity of the boiling point. Meanwhile, a quantitative analysis of the explosion limit and its range was conducted to assess the spray explosion hazard. The explosion hazard of DEE spray was found to be relatively higher near the boiling point of DEE.

Simulasi Pinjaman Daerah sebagai alternatif pilihan Pembiayaan Pembangunan Infrastruktur di Kabupaten Batang Hari

Regional Loans are one of the alternative sources of financing in the Regional Revenue and Expenditure Budget to fund activities that are initiatives of the Regional Government in the framework of Local Government affairs based on the provisions of laws and regulations. Regional loans can be used to finance infrastructure and/or investment in regional infrastructure and facilities in the framework of public services. In addition, Regional Loans can also be used to cover regional cash flow. This study aims to determine the financial capability of the Batang Hari Regency Government and determine the number of feasible loans if the Batang Hari Regency Government makes regional loans as an alternative to financing infrastructure development. The data used in this study is secondary time series data derived from the Batang Hari Regency Government Budget Realization Report for the 2017-2021 period. The analysis tools used are the ratio of regional financial ability to repay loans with the Debt Service Coverage Ratio (DSCR), the Maximum Loan Limit (BMP) and to determine the amount of loans that can be made by regions in 2017-2021 by calculating regional revenue plans and regional spending plans, which are carried out using the Trend analysis method. Based on the simulation result conducted, the Batang Hari Regency Government has a Debt Service Coverage Ratio (DSCR) value of 4.81 which exceeds the minimum standard set at 2.5. The results of the analysis also show a Maximum Loan Limit of Rp. 740,070,216,978. Based on data obtained in fiscal year 2021. When viewed from the projection results, the loan that can be obtained by the Regional Government of Batang Hari Regency according to the analysis of the BMP Maximum Loan Limit in 2022 is IDR 706,263,200,215. Net funds are obtained from the projected results for 2022 of Rp. 503,718,603,808 and the maximum installments that can be prepared are Rp. 201,487,441,523.

Compressive frequency-difference direction-of-arrival estimation

Direction-of-arrival estimation is difficult for signals spatially undersampled by more than half the wavelength. Frequency-difference beamforming [Abadi, Song, and Dowling (2012). J. Acoust. Soc. Am. 132, 3018–3029] offers an alternative approach to avoid such spatial aliasing by using multifrequency signals and processing them at a lower frequency, the difference-frequency. As with the conventional beamforming method, lowering the processing frequency sacrifices spatial resolution due to a beam broadening. Thus, unconventional beamforming is detrimental to the ability to distinguish between closely spaced targets. To overcome spatial resolution deterioration, we propose a simple yet effective method by formulating the frequency-difference beamforming as a sparse signal reconstruction problem. Similar to compressive beamforming, the improvement (compressive frequency-difference beamforming) promotes sparse nonzero elements to obtain a sharp estimate of the spatial direction-of-arrival spectrum. Analysis of the resolution limit demonstrates that the proposed method outperforms the conventional frequency-difference beamforming in terms of separation if the signal-to-noise ratio exceeds 4 dB. Ocean data from the FAF06 experiment support the validity.

Filtering Methods for Coupled Inverse Problems

In many applications it is required to determine a parameters set which is suitable for competing models. To this end, we are interested in ensemble methods to solve multiobjective optimization problems. Here, the ensemble Kalman Filter method is applied and adapted in order to solve coupled inverse nonlinear problems using a weighted function approach. An analysis of the mean field limit of the ensemble method yields an explicit update formula for the weights. Numerical examples show the improved performance of the proposed method.

Force-induced fluorescence spectrum shift of spiropyran-based polymer for mechano-response sensing

As spiropyran exhibits mechanophore response, i.e., becomes vibrantly fluorescent under an applied force, its change has been measured primarily by fluorescence intensity. However, fluorescence intensity, which is an extensive property, is strongly affected by specimen and set-up parameters, and the corresponding measurements therefore require laborious and assumptive corrections. Herein, spiropyran is covalently linked to poly(dimethylsiloxane) and an in-situ opto-mechanical set-up is developed to monitor fluorescence spectrum evolution under deformation. Peak wavelength, which is an intensive property, is shown to be a superior mechano-response indicator that offers high accuracy/reliability, allows one to establish a 1:1 correspondence to strain (or stress) without corrections, and is independent of size. To the best of our knowledge, this is the first report of peak wavelength as mechano-response indicator for SP and its first systematic in-situ study. In summary, peak wavelength is shown to successfully reflect the force applied to polymer specimens without the need for corrections and exhibit considerable resistance to cycling-induced fatigue, while analysis of the finite extensibility limit reveals that the change of peak wavelength is closely related to the forces exerted directly on the polymer chain.

Unravelling the nonlinear ideal density response of many-body systems

Nonlinear density response theory is revisited focusing on the harmonically perturbed finite temperature uniform electron gas. Within the non-interacting limit, brute force quantum kinetic theory calculations for the quadratic, cubic, quartic and quintic responses reveal a deep connection with the linear response. Careful analysis of the static long wavelength limit led us to conjecture a canonical non-interacting form that expresses arbitrary order nonlinear responses as the weighted sum of the linear responses evaluated at all multiple harmonics. This harmonic expansion is successfully validated against ab initio path integral Monte Carlo simulations.

Cooperative Localization for Passive RFID Backscatter Networks and Theoretical Analysis of Performance Limit

In fully-connected passive RFID backscatter networks, it is challenging to provide accurate range estimations due to complex channels. Facing this problem, we propose a differential analysis based anti-multipath technique by introducing a reference tag. Through the linear difference between target tag received power measurements with the reference tag activated and not, the power with respect to the reader-reference-target link is separated out from the mixed measurements, achieving the mitigation of multipath and accurately ranging. Under distributed localization schemes, after breaking down the full network into a series of fragments, it is vital but challenging to determine how to assemble them satisfactorily. VIABLE, virtual-actual assembling algorithm, is proposed to achieve distributed and cooperative localization. The virtual assembling phase rectifies the fragments over and over until their errors converge, which enables the mining of a satisfactory and adaptive assembling order. Subsequently, the actual phase assembles the rectified fragments together with that order and accomplishes the overall localization accurately. The theoretical analysis of performance limit is presented via the derivation of Cramér-Rao lower bound approximated by a particle approach. Extensive simulations demonstrate that our proposed framework outperforms existing algorithms for cooperative localization.

Analysis of the Speed Limit of Transrapid Maglev Train Explored From the Perspective of Its Suspension and Guidance Systems

In recent years, research on high-speed or ultra-high-speed maglev systems has become increasingly popular, and different countries or teams have been committing to several different suspension technologies. Among them, due to the profound accumulation of research on the normal-conducting electromagnetic suspension technology, China is actively adopting this suspension technology to develop a new high-speed maglev train faster than <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$600~km/h$ </tex-math></inline-formula> , and this work is mainly on the basis of Transrapid (TR) trains and Shanghai Maglev Line (SHML). To evaluate the feasibility of this project, the speed limit of the TR maglev system was explored from the perspective of its suspension and guidance systems. The analysis process was carried out from two aspects of aerodynamic interference and track irregularity. As for aerodynamic interference, the aerodynamic and electromagnetic simulation models were established based on the actual maglev train. The anti-interference abilities of the suspension and guidance systems were analyzed from two aspects of steady-state and transient-state respectively. The results verified that the train could operate safely when its speed below <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$800~km/h$ </tex-math></inline-formula> and the cross-wind speed below <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$26~m/s$ </tex-math></inline-formula> . As for track irregularity, based on the actual track construction indicators of the SHML, the relationship between suspension gap fluctuation and the train speed was studied through a dynamic calculation model of the suspension control system. The results showed that the suspension system had a risk of track collision when the train speed was greater than <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$717~km/h$ </tex-math></inline-formula> . In summary, from the perspective of its suspension and guidance systems, the current TR maglev system on the SHML has an upper speed limit. The conclusion would be valuable for the development of ultra-high-speed maglev systems in the future.

Legal and psychological aspects of determining age of criminal responsibility

The article presents a comparativist analysis of the age limit of the subject of criminal responsibility. The age as a characteristic of the subject of crime is considered in the context of determining the criteria on which the legislator should rely when setting the minimum age limit. These should include both legal and psychological indicators. Among the psychological indicators, the sufficiency of mental development is important, as well as the ability of the person to consciously selective behavior. The arguments of supporters and opponents of lowering the age limit of criminal liability from 16 and 14 years to 14 and 12 years respectively are evaluated. The authors conclude that today there is no need to adjust the age of criminal responsibility downwards.

A novel clean hydrogen production system combining cascading solar spectral radiation and copper-chlorine cycle: Modeling and analysis

In this work, a novel integrated hydrogen production system was proposed. A detailed analysis of the efficiency limit, energy requirement, and parametric impact was theoretically performed. The system combined cascading solar spectral radiation with a copper-chlorine thermochemical cycle, which effectively converted different grades of solar energy to clean hydrogen. The process of a four-step copper-chlorine cycle was simulated to obtain the energy demands using Aspen Plus software. A model for cascading utilization of solar spectral radiation was developed to select the optimal segmented wavelengths and investigate the effects of parameters on the system efficiency. The system designs integrated with other solar cells were also optimized using this model. Among the parameters, the segmented wavelengths were the key parameters that determined the amount of solar energy converted to heat and electricity. The theoretical calculations and simulations were used to determine the performance of this new hydrogen production system. Efficiency analysis demonstrated that the proposed system achieved an ideal efficiency of 68.20%, exceeding the theoretical limit of the single-junction photovoltaic-electrolysis water system. The efficiency of the actual design was 43.44%, higher than the systems without a spectrum splitting module. This study provides an efficient method for realizing high efficiency and high-grade solar energy cascading utilization for producing clean hydrogen energy.

Spatial ecology, optimal control and game theoretical fishing problems.

Of paramount importance in both ecological systems and economic policies are the problems of harvesting of natural resources. A paradigmatic situation where this question is raised is that of fishing strategies. Indeed, overfishing is a well-known problem in the management of live-stocks, as being too greedy may lead to an overall dramatic depletion of the population we are harvesting. A closely related topic is that of Nash equilibria in the context of fishing policies. Namely, two players being in competition for the same pool of resources, is it possible for them to find an equilibrium situation? The goal of this paper is to provide a detailed analysis of these two queries (i.e optimal fishing strategies for single-player models and study of Nash equilibria for multiple players games) by using a basic yet instructive mathematical model, the logistic-diffusive equation. In this framework, the underlying model simply reads [Formula: see text] where K accounts for natural resources, [Formula: see text] for the density of the population that is being harvested and [Formula: see text] encodes either the single player fishing strategy or, when dealing with Nash equilibria, a combination of the fishing strategies of both players. This article consists of two main parts. The first one gives a very fine characterisation of the optimisers for the single-player game where one aims at solving [Formula: see text], under [Formula: see text] and [Formula: see text] constraints on the fishing strategies [Formula: see text]. In particular, we show that, depending on the value of these constraints, this optimal control problem may behave like a convex or, conversely, concave problem. We also provide a detailed analysis of the large diffusivity limit of this problem. In the case where two players are involved, we rather write [Formula: see text] as [Formula: see text] where [Formula: see text], the fishing strategy of the i-th player, also satisfies [Formula: see text] and [Formula: see text] constraints. Defining [Formula: see text] we aim at finding a Nash equilibrium. We prove the existence of Nash equilibria in several different regimes and investigate several related qualitative queries, for instance providing examples of the well-known tragedy of commons. Our study is completed by a variety of numerical simulations that illustrate our results and allow us to formulate open questions and conjectures.