Time Distribution Research Articles

Manajemen Marketing Madrasah Melalui Teknologi Informasi Dan Komunikasi di MA Hidayatul Mubtadiin Jati Agung Lampung Selatan

The point of this examination is to decide and break down the preparation, execution and assessment of madrasa showcasing the executives through data and correspondence innovation at Madrasah Aliyah Hidayatul Mubtadiin Jati Agung South Lampung. This sort of exploration is subjective examination, the technique utilized in this exploration utilizes perception, meetings and documentation. The information sources in this examination are essential and optional exploration sources. The information investigation procedure utilized is an intuitive model and information triangulation to really look at the legitimacy of the information. The exploration results show that 1) Mama Hidayatul Mubtadiin's new understudy confirmations advertising arranging (PPDB) is the most vital phase in the understudy affirmations process. The initial step is vital, on the grounds that the initial step is important for the interaction that will prompt the eventual outcome. Figuring out a promoting program execution plan zeros in additional on tips, strategies, procedures or methodologies that are successful, effective and adaptable to carry out. Execution arranging should think about time distribution, accessibility of assets, HR, offices, etc. 2) Execution of Mama Hidayatul Muntadiin's showcasing through data and correspondence innovation by carrying out a blend, in particular item, value, spot and advancement. In the interim, the media utilized for madrasa advertising are handouts and the web like sites, WA, Instagram, Facebook, TV and papers. 3) Assess the advertising system or execution associated with showcasing, by taking a gander at the degree of promoting exercises that have been carried out, by proceeding with exercises that have been generally answered by the general population.

Epidemiological Profile of IBD in the Northern Region: "Pilot Study"

Inflammatory bowel disease (IBD) refers to three chronic inflammatory disorders, ulcerative colitis (UC), Crohn disease (CD) and indeterminate colitis. Classically IBD is described as a disease of rich countries, and historical data on the geographical distribution of IBD around the world have shown a high incidence and prevalence in high-income countries, like Northern Europe and the USA. More recently, IBD emerged with increasing frequency in many parts of the planet especially in developing countries [1], including Morocco, becoming a global infection. UC remains more frequent than CD except in certain countries including France [2]. Although progress has recently been made, particularly in the genetic field, in understanding their physiopathology, the cause(s) of these two diseases remains unknown to date. A better knowledge of the descriptive epidemiology of IBD, in particular the differences in incidence in relation to time, age or geographical distribution, can lead to etiological leads. Study the epidemiology of IBD is a challenge, in part because it is difficult to diagnose, but it is important because of its direct and indirect costs. Data from Moroccan studies remain rare. Our study on the epidemiology of inflammatory bowel disease (IBD) is the first in the northern region.

UNDERSTANDING THE TRADE-OFF IN TCP'S CUBIC WINDOWS CONGESTION: A COMPREHENSIVE ANALYSIS

This study investigates the difficulties of the CUBIC TCP algorithm, focusing on the trade-off between efficiency and fairness in window congestion control. The CUBIC approach, which was devised to optimize high-bandwidth and long-distance networks, is currently widely used as the default TCP congestion control algorithm in Linux and other systems. Our work investigates the dynamics of CUBIC's window expansion, specifically the interaction between the cubic function and the most recent congestion event. We look at how this interplay impacts the distribution of window widths, throughput, round-trip time (RTT), loss rate, and queue size under different network configurations. Keywords: TCP CUBIC, Window Congestion, Efficiency-Fairness Trade-Off, TCP’s Cubic Function.

Joint r-process Enrichment by Supernovae with a Metallicity Threshold and Neutron Star Mergers

The enrichment history of r-process elements has been imprinted on the stellar abundances that change in accordance with increasing metallicity in galaxies. Close examination of the [Eu/Fe] feature caused by stars in nearby galaxies, including the Large Magellanic Cloud (LMC), shows its perplexity. The decreasing trend of the [Eu/Fe] feature is followed by a nearly constant value; this trend is generally attributed to an onset of the delayed Fe release from Type Ia supernovae (SNe Ia), which is the same interpretation of the [α/Fe] feature. However, this feature appears in the LMC at [Fe/H] of approximately −0.7, which is significantly higher than that for the [α/Fe] case (≈−2). This result potentially indicates the presence of an overlooked property of the r-process site that remains unseen in the study of the Milky Way. Here, we propose that this [Eu/Fe]-knee feature is created by a fade-out of core-collapse SNe producing r-process elements; these elements along with neutron star mergers (NSMs) promote the r-process enrichment under the condition for this specific SNe such that their occurrence is limited to a low-metallicity environment. This metallicity threshold for the occurrence rate of r-process SNe at a subsolar is nearly identical to that for long gamma-ray bursts whose origin may be connected to fast-rotating massive stars. Moreover, we reason that the contribution of Eu from NSMs is crucial to maintain a high [Eu/Fe] at an early stage in dwarf galaxies by a balance with Fe from SNe Ia; both enrichments via NSMs and SNe Ia proceed with similar delay time distributions.

The late positive event-related potential component is time locked to the decision in recognition memory tasks

Two event-related potential (ERP) components are commonly observed in recognition memory tasks: the Frontal Negativity (FN400) and the Late Positive Component (LPC). These components are widely interpreted as neural correlates of familiarity and recollection, respectively. However, the interpretation of LPC effects is complicated by inconsistent results regarding the timing of ERP amplitude differences. There are also mixed findings regarding how LPC amplitudes covary with decision confidence. Critically, LPC effects have almost always been measured using fixed time windows relative to memory probe stimulus onset, yet it has not been determined whether LPC effects are time locked to the stimulus or the recognition memory decision. To investigate this, we analysed a large (n = 132) existing dataset recorded during recognition memory tasks with old/new decisions followed by post-decisional confidence ratings. We used ERP deconvolution to disentangle contributions to LPC effects (defined as differences between hits and correct rejections) that were time locked to either the stimulus or the vocal old/new response. We identified a left-lateralised parietal LPC effect that was time locked to the vocal response rather than probe stimulus onset. We also isolated a response-locked, midline parietal ERP correlate of confidence that influenced measures of LPC amplitudes at left parietal electrodes. Our findings demonstrate that, contrary to widespread assumptions, the LPC effect is time locked to the recognition memory decision and is best measured using response-locked ERPs. By extension, differences in response time distributions across conditions of interest may lead to substantial measurement biases when analysing stimulus-locked ERPs. Our findings highlight important confounding factors that further complicate the interpretation of existing stimulus-locked LPC effects as neural correlates of recollection. We recommend that future studies adopt our analytic approach to better isolate LPC effects and their sensitivity to manipulations in recognition memory tasks.

Single-photon lidar depth imaging based on sparsity adaptive matching pursuit method

Photon counting lidar has the ability to detect weak echo photons. However, in imaging applications, a small number of echo signals obtained in a very short acquisition time cannot get an accurate image estimation through the photon arrival time distribution histogram. Therefore, high-precision and fast imaging of an object using a small amount of weak echo photon signals is urgent to be solved. In this work, a sparse adaptive matching pursuit (SAMP) algorithm is proposed to process the echo photons without prior information to obtain the effective photon interval, which improves the reconstruction quality and imaging speed. By constructing a non-coaxial scanning imaging system to detect the face model, it has been experimentally proven that the proposed algorithm can achieve depth and reflectance image estimation under the condition of low power and low acquisition time of 4µs per pixel on average, and the mean absolute error (MAE) value is reduced by about 10 times compared to conventional reconstruction algorithm.

Time distribution of stimulated transition probabilities

In recent years, an increasing number of experimental results have been published for a wide variety of systems in which high-precision, ultra-fast, and ultra-short laser pulses techniques have been used to study time-resolved dynamical processes. In the absence of a theoretical prediction of the time distribution of the transition probabilities, the lifetimes τ are generally extracted by fitting the decay time with an exponential, bi-exponential or three-exponential function. In fitting the data, the short-time behavior is generally neglected. The purpose of this study is to show that an explicit formula for the time distribution of the transition probability can be determined rigorously using time-dependent perturbation theory. A formula that perfectly fits an important subset of the experimental results from t = 0 to t=∞ . We show that by following a route different from the usual procedure for deriving transition amplitudes and Einstein coefficients in time-dependent perturbation theory, one ends up with a time-dependent factor, that is, a temporal distribution function of the transition probabilities, and for the Einstein coefficients. The time distribution reported here looks in the time domain similar to the Planck distribution in the frequency domain. In fact, the behavior of the time distribution, with a maximum at 2τln⁡2 , and with τ playing the role of temperature, resembles the behavior of the Planck frequency distribution. We present several examples to demonstrate that the theoretical formula allows for easier fitting of the experimental results reported in the literature. We also show that the time distribution explains the difference in resonance heights between the experimental and theoretical blue laser spectra.

An essay on semiclassical analysis for microlocal singularities, turbulence intensity and integration of singularities by Schrödinger equation in probabilistic behavior

The Schrödinger equation governs the probabilistic behavior of quantum particles through the wave function. Microlocal singularities denote regions with significantly high probability density or abrupt changes therein. By visualizing the probability distribution in time and space, we discern regions with higher probability density, indicative of potential microlocal singularities. These regions probably correspond to areas with a greater probability of particle presence. Such analysis aligns with Theorem 1, predicting characteristics of microlocal singularities of wave functions. Furthermore, Theorem 2 postulates that semiclassical path integrals along these singularities contribute significantly to solving the Schrödinger equation. Interpreting the temporal evolution of the probability density in the probability distribution visualization reveals the propagation of the particle over time. Regions of high density mean likely presence of particles at specific times, aligning with the predictions of Theorem 2. Consequently, the analysis of the contribution of high-density regions to the temporal evolution of the wave function resembles semi-classical path integral calculations. Thus, our findings demonstrate that visualization of probability distributions obtained from the numerical resolution of the Schrödinger equation allows a comprehensive interpretation of the behavior of quantum particles, consistent with the theorems.

The burden of working time lost to compensable occupational injury and disease in Australia, 2012-17: a retrospective population-based study.

To determine the national burden of working time lost to occupational injury and disease in Australia compensable by workers' compensation schemes; to characterise the distribution of time lost by age, sex, and injury and disease type. Retrospective population-based study; analysis of National Dataset for Compensation-based Statistics (NDS) data. Granted workers' compensation claims by people aged 15-100 years including payment of wage replacement benefits for time off work lodged in Australia, 1 July 2012 - 30 June 2017. Working years lost (WYL) per annum (total number of years of wage replacement benefits paid to injured and ill workers), overall and by sex, age, and injury and disease type; WYL per 10 000 fulltime equivalent (FTE) years worked. A total of 755 330 eligible claims with complete data for analysis variables by people aged 15-100 years were identified, for compensable injuries and disease that led to 41 194 (95% confidence interval [CI], 41 020-41 368) WYL/year. The annual WYL number and rate were each higher for men (25 367 [95% CI, 25 230-25 503] WYL/year; 42.6 [95% CI, 42.1-43.1] WYL/10 000 FTE years) than for women (15 827 [95% CI, 15 720-15 935] WYL/year; 38.8 [95% CI, 38.2-39.4] WYL/10 000 FTE years). Workers aged 45-100 years made 66 742 claims per year (44.1% of all claims) but incurred 21 763 WYL/year (52.8% of all WYL). Traumatic joint and muscle injuries led to 16 494 WYL/year (40.0% of all WYL), musculoskeletal disorders to 8547 WYL/year (20.7%), mental health conditions to 5361 WYL/year (13.0%), fractures to 4276 WYL/year (10.4%), and wounds and lacerations to 3449 WYL/year (8.4%). Occupational injury and disease covered by workers' compensation result in lost working time in Australia equivalent to more than 41 000 fulltime jobs. Distribution of the burden reflects the greater labour force participation of men, slower recovery of older workers, and the impact of common occupational injuries and diseases. Population-based monitoring of lost working time could support effective occupational health surveillance and allocation of resources for protecting the health of Australian workers.

Data-driven diagnosis of high temperature PEM fuel cells based on the electrochemical impedance spectroscopy: Robustness improvement and evaluation

Utilizing machine learning techniques for data-driven diagnosis of high temperature PEM fuel cells is beneficial and meaningful to the system durability. Nevertheless, ensuring the robustness of diagnosis remains a critical and challenging task in real application. To enhance the robustness of diagnosis and achieve a more thorough evaluation of diagnostic performance, a robust diagnostic procedure based on electrochemical impedance spectroscopy (EIS) and a new method for evaluation of the diagnosis robustness was proposed and investigated in this work. To improve the diagnosis robustness: (1) the degradation mechanism of different faults in the high temperature PEM fuel cell was first analyzed via the distribution of relaxation time of EIS to determine the equivalent circuit model (ECM) with better interpretability, simplicity and accuracy; (2) the feature extraction was implemented on the identified parameters of the ECM and extra attention was paid to distinguishing between the long-term normal degradation and other faults; (3) a Siamese Network was adopted to get features with higher robustness in a new embedding. The diagnosis was conducted using 6 classic classification algorithms—support vector machine (SVM), K-nearest neighbor (KNN), logistic regression (LR), decision tree (DT), random forest (RF), and Naive Bayes employing a dataset comprising a total of 1935 collected EIS. To evaluate the robustness of trained models: (1) different levels of errors were added to the features for performance evaluation; (2) a robustness coefficient (Roubust_C) was defined for a quantified and explicit evaluation of the diagnosis robustness. The diagnostic models employing the proposed feature extraction method can not only achieve the higher performance of around 100% but also higher robustness for diagnosis models. Despite the initial performance being similar, the KNN demonstrated a superior robustness after feature selection and re-embedding by triplet-loss method, which suggests the necessity of robustness evaluation for the machine learning models and the effectiveness of the defined robustness coefficient. This work hopes to give new insights to the robust diagnosis of high temperature PEM fuel cells and more comprehensive performance evaluation of the data-driven method for diagnostic application.

Crescent-shaped spatial distribution: radiation properties concerning beam waist from the cross collision of a tightly focused laser pulse and a relativistic electron

The radiation properties of the cross collision between a single electron and an intense laser pulse are researched by numerical simulation methods. Under the condition of tightly-focused laser, the electron trajectories, spatiotemporal distribution and spectrum are compared with that under non-tightly focused lasers. The results show that the torsion effect on the electron during the oscillation process is more notable after the tightly focused laser interacts with electron. The radiation it generates is asymmetric in space, and its time distribution is nearly unimodal and can be regarded as a single attosecond pulse. In frequency domain, the spectrum appears to be a supercontinuum. With the increase of beam waist radius, the symmetry of the spatial distribution enhances and time distribution also exhibits a three-peak structure that is symmetrical about the main peak. Furthermore, the spectrum changes from a supercontinuum to a multimodal distribution. The analysis turns out that tightly focused laser is more realistic compared to non-tightly focused laser or even plane wave, which benefits the design of high-quality x-rays in practical application.

Optimisation and effect of ionomer loading on porous Fe–N–C-based proton exchange membrane fuel cells probed by emerging electrochemical methods

The next generation of proton exchange membrane fuel cells (PEMFCs) require a substantial reduction or elimination of Pt-based electrocatalyst from the cathode, where O2 reduction takes place. The most promising alternative to Pt is atomic Fe embedded in N-doped C (Fe–N–C). Successful incorporation of Fe–N–C in PEMFCs relies on a thorough understanding of the catalyst layer properties, both ex situ and in situ, with tailored electrode interface engineering. To help resolve this conundrum, we provide a quantitative protocol on the optimisation of I/C for Fe–N–Cs. It is demonstrated that a high pore volume (3.33 cm3 g−1FeNC) Fe–N–C catalyst requires a sufficiently high ionomer to catalyst mass ratio (I/C, 2.8≤I/C ≤ 4.2) for optimum PEMFC activity under H2/O2. Emerging electrochemical techniques (distribution of relaxation times and Fourier transformed alternating current voltammetry) were used to deconvolute for the first time the trade-off between proton and electron resistance and accessible FeNx active site density with increasing ionomer loading. These findings highlight the significant impact of tuning the I/C ratio based on the catalyst layer properties and feature the power of evolving electrochemical tools for optimising performance in PEMFCs and other electrochemical devices.

How do high-voltage cathode and PEO electrolyte get along well? EIS analysis mechanism & potentiometric control strategy

PEO-based all-solid-state electrolytes are extensively utilized and researched owing to their exceptional safety, low-mass-density, and cost-effectiveness. However, the low oxidation potential of PEO makes the interface problem with the high-voltage cathode extremely severe. In this work, the impedance of PEO-based all-solid-state batteries with high-voltage cathode (NCM811) was studied at different potentials. The Nyquist plots displayed a gyrate arc at low-frequencies for NCM811/PEO interface. Based on the kinetic modeling, it was deduced that there is a decomposition reaction of PEO-matrix in addition to de-embedded reaction of NCM811, and the PEO intermediate product (dehydra-PEO) adsorbed on the electrode surface leading to low-frequency inductive arcs. Furthermore, the distribution of relaxation time shows the dehydra-PEO results in the kinetic tardiness of the charge transfer process in the temporal dimension. Hence, an artificial interface layer (CEIx) was modified on the surface of NCM811 to regulate the potential of cathode/electrolyte interface to prevent the high-voltage deterioration of PEO. NCM/CEIx/PEO batteries exhibit capacity retentions of 96.0%, 84.6%, and 76.8% after undergoing 100 cycles at cut-off voltages of 4.1, 4.2, and 4.3 V, respectively. Therefore, here the failure mechanism of high-voltage PEO electrolyte is investigated by EIS and a proposed solving strategy is presented.

Transient analysis of a bulk stream queue with arbitrarily distributed arrival intervals

We study the classical infinite buffer single server queueing model with renewal input of customers in batches of random size, having arbitrarily distributed arrival intervals and exponentially distributed service times. Using the technique of supplementary variable and shift operator we derive closed form expression of the time dependent system content distribution in terms of its Laplace transform. The analysis is mainly based on the root-finding technique of the non-linear characteristic equation in terms of the Laplace transform variable. Additionally, using asymptotic properties of Laplace transform, we deduce the corresponding steady-state distribution. We discuss some special cases of the model, thus providing an alternative approach in deriving the transient distribution. We further evaluate certain performance measures and present extensive numerical examples in tabular and graphical form to illustrate the applicability of our theoretical work. The effect of system parameters, interarrival time distribution and traffic intensity on the system behavior is also demonstrated.

Mesoscopic model of cycling trip energy expenditure based on operating modes

Cyclist physical exertion is largely ignored in quantitative travel analysis, partly due to a lack of appropriate tools. Microscopic models of second-by-second energy expenditure based on equations of motion are data intensive and cannot be applied to hypothetical routes (such as needed for route choice modelling). Macroscopic models of aggregate energy expenditure based on a fixed assumed energy intensity are insensitive to traveller, trip, and contextual factors that are relevant for behavioural research and policy analysis (such as bicycle type or trip purpose). Building on concepts from motor vehicle emissions analysis, this paper proposes a mesoscopic approach to model cycling trip energy expenditure based on the distribution of travel time across discrete states of motion (“operating modes”) for different classes of traveller and trip (“model segments”). We aim to answer two key questions for model implementation: 1) which variables most effectively classify trips into model segments and 2) what operating mode definition most consistently characterizes cycling energy expenditure within model segments? We also evaluate the precision of the mesoscopic model relative to cycling energy estimates from microscopic and macroscopic models. Applied to a dataset of naturalistic cycling trips in Vancouver, Canada, the proposed mesoscopic model with six model segments based on 3 segmenting variables (rider gender, electric-assist bicycle, and high or low speed tier) explains up to 28 % of the variance in trip-level energy estimates from the microscopic model (within around 35 W of the microscopic estimates, on average). Further research to develop cycling trip energy models for general application is discussed.

Observation and suppression of metallic and metallic-like plating on hard carbon for high-performance sodium-ion batteries

Increasing the lifespan of Na-ion batteries (NIBs) is one of the primary requirements for stationary energy storage. Metallic and metallic-like Na plating on hard carbon (HC) could be one of the main causes for degraded performance during cycling, but the mechanism remains unclear. Here, we systematically investigate the plating phenomenon on HC under various cycling conditions in NIBs. We reveal that underpotential deposition (UPD) could potentially trigger the metallic-like plating on the surface of HC electrodes. In-situ distribution of relaxation times (DRT) analysis provides an effective indictor to identify the occurring of metallic and metallic-like Na plating on HC electrode by probing the time constant for charge transfer process. Based on the understanding, we apply a uniform nano porous coating layer on HC electrode to restrict potential UPD on the HC electrode surface but allow uniform Na+ transport across interface, which greatly suppress the plating phenomenon, leading to significantly improved cycling stability of NIBs.

Prompt gamma timing for proton range verification with TlBr and TlCl as pure Cherenkov emitters

Objective. Prompt gamma timing (PGT) uses the detection time of prompt gammas emitted along the range of protons in proton radiotherapy to verify the position of the Bragg peak (BP). Cherenkov detectors offer the possibility of enhanced signal-to-noise ratio (SNR) due to the inherent physics of Cherenkov emission which enhances detection of high energy prompt gamma rays relative to other induced uncorrelated signals. In this work, the PGT technique was applied to 3 semiconductor material slabs that emit only Cherenkov light for use in a full scale system: a 3 × 3 × 20 mm3 TlBr, a 12 × 12 × 12 mm3 TlBr, and a 5 × 5 × 5 mm3 TlCl. Approach. A polymethyl methacrylate (PMMA) target was exposed to a 67.5 MeV, 0.5 nA proton beam and shifted in 3 mm increments at the Crocker nuclear laboratory (CNL) in Davis, CA, USA. A fast plastic scintillator coupled to a photomultiplier tube (PMT) provided the start reference for the proton time of flight. Time of flight (TOF) distributions were generated using this reference and the gamma-ray timestamp in the Cherenkov detector. Main results. The SNR of the proton correlated peaks relative to the background was 20, 29, and 30 for each of the three samples, respectively. The upper limit of the position resolutions with the TlCl sample were 2 mm, 3 mm, and 5 mm for 30k, 10k, and 5k detected events, respectively. The time distribution of events with respect to the reference reproduced with clarity the periodicity of the beam, implying a very high SNR of the Cherenkov crystals to detect prompt gammas. Background presence from the neutron-induced continuum, prompt gammas from deuterium, or positron activation were not observed. Material choice and crystal dimensions did not seem to affect significantly the outcome of the results. Significance. These results show the high SNR of the pure Cherenkov emitters TlBr and TlCl for the detection of prompt gammas in a proton beam with current of clinical significance and their potential for verifying the proton range. The accuracy in determining shifts of the BP was highly dependent on the number of events acquired, therefore, the performance of these detectors are expected to vary with different beam conditions such as current, pulse repetition, and proton bunch width.

Analysis of stream flow and its impact on thermal performance in shell-side of heat exchangers based on flow dead zone

The performance of shell-and-tube heat exchanger (STHE) is primarily determined by different flow paths on the shell-side. The flow path and its impact on the shell-side flow in segmental baffle shell-and-tube heat exchanger with clearance (SC-STHE) is investigated qualitatively and quantitatively, by adopting stream classification and dead zone analysis method. By utilizing Residence Time Distribution (RTD) curves, the influence of different streams on fluid flow and heat transfer is discussed to reveal the intricate interconnections within the shell-side of SC-STHE. Then the cases with baffle-tube clearance (0.2–1.0 mm) and baffle-shell clearance (1.0–5.0 mm) ranges are studied. The study identifies that optimal comprehensive performance is achieved with a baffle-tube clearance of 0.6 mm, resulting in a 3.5 % improvement compared to a clearance of 0.2 mm. An increase of baffle-shell clearance results in a reduction in comprehensive performance by 8.23–19.54 %. The interactions among stream flows and potential mechanisms are discussed by analyzing the influence of each flow path on the flow dead zone volume. It is revealed that the presence of baffle-tube and baffle-shell clearances reduces the volume fraction of flow dead zones compared to structures without clearances. A-stream and E-stream are identified as pivotal, mutually influencing B-stream and C-stream while maintaining relative independence. The result indicates that an increase in baffle-tube clearance results in a 7.60 % expansion of the volume of the dead zone within the B-stream, while in the C-stream, it decreases by 2.58 %. Conversely, an increase in baffle-shell clearance reduces the volume of the dead zone in the B-stream by 5.04 % but increases it in the C-stream by 31.95 %. The flow dead zones are mainly distributed in the B-stream and C-stream regions, and the diversion effect of leakage flows improves the fluid stagnation but also leads to a decrease in turbulence intensity and flow velocity. This study reveals the complex interaction mechanisms among the stream flows, facilitating further analysis and optimization in STHE design.

A grasp of police research: characteristics of empirical research on police careers based on multiple scoping reviews

PurposeThis article provides an overview of the literature characteristics of empirical research on topics related to police careers from 2000 to 2021. Methodology, distribution in time and space and types of publication are presented. Recommendations for new research avenues are given.Design/methodology/approachEight scoping reviews on specific topics were carried out by criminology students under the close guidance and supervision of the first author, an academic researcher. The reviews followed the same procedure, enabling an overarching reflection.FindingsThe scoping reviews resulted in 179 unique publications for analysis. It appears that the topic of police professional competencies is studied more often in the field of police careers (n = 55), in contrast to informal learning in police training (n = 4) which was studied the least frequently. Since 2012, there has been a noticeable increase in the number of publications. Publications in scientific journals are by far the most common (n = 153), as is a quantitative research design (n = 123). All topics have been studied in Europe and North America.Research limitations/implicationsMore qualitative research and international dissemination of empirical results are recommended to gain a deeper understanding of police careers. As for the limitations, specific topics were selected, which limits the scope of the findings. Working with students for data collection has its benefits in terms of workload, but comes with potential limitations in terms of quality. It is recommended to conduct a screening using the four-eyed principle, as was done here by the first and second authors. Additionally, the review protocol (e.g. keywords and databases) has an influence on the outcome. Different choices may lead to different results.Originality/valueA comprehensive analysis of police career literature is made based on eight scoping reviews that followed the same procedure. It allows to study the literature in a broad sense rather than studying one topic in depth.

Comparison of Fluid Flow and Tracer Dispersion in Four-Strand Tundish under Fewer Strand Casting and Sudden Blockage of Strand Conditions

The study focuses on the four-strand tundish as the research object, aiming at the phenomenon of fewer strand casting (stable blockage) and sudden blockage of the tundish in industrial production. Numerical simulation methods are employed to compare the velocity vectors, flow fields, residence time distribution (RTD) curves, and outflow percentage curves under stable blockage and sudden blockage of the tundishes with a double-weir structure, U-shaped weir structure, and U-shaped weir structure with holes in the front. The results indicate that, after sudden blockage of the tundish strands, the flow field transitions from an unstable four-strand flow field to a stable three-strand flow field. Both the double-weir tundish and the U-shaped weir tundish reach a stable state after 200 s, while the U-shaped weir tundish with holes in the front reaches stability after 150 s. Additionally, compared to other structures, the tundish strands of the U-shaped weir with holes in the front are less affected by blockage, showing better consistency among strands and better adaptability under non-standard casting conditions.