Decay Function Research Articles

Gender Differences in the Journey to Suicide: Comparing distance decay functions of home and found locations in missing person reports to the police

To date, no research has examined the decay models that best describe male and female spatial behaviours whilst missing, particularly of those that demonstrate suicide intent. Such knowledge could help to inform investigative strategies. Three studies were conducted using missing persons data from two police forces. In study 1, ANOVA and Mann-Whitney U tests examined the distance travelled by male (n=158) and female (n=135) subgroups; with respect to the impact of gender, likely suicidal and vehicle possession. Study 2a considers which curve estimate best describes likely and non-likely suicidal males (n=180) and females (n=157) spatial movements whilst missing. Study 2b cross validated suicidal male curves identified in study 2a, using information taken from missing persons cases where the person had been found to have died through suicide (N=24). Vehicle possession increased the distance travelled across all groups. Females travelled further than suicidal males, however, no distance travelled differences were found between suicide and non-suicidal sub-groups. The most significant curve estimate for likely suicidal males and females were the inverse and quadratic models respectively, illustrating exclusive gender movements in journeys to suicide. There are meaningful gender differences in spatial movements when missing. Thus, gender specified search parameters can be generated, potentially aiding quicker detection, prevention and safeguarding of adults at risk of self-harm. KEY WORDS: Geographical profiling, distance decay, suicide, gender

An Analysis of Mobility Patterns in Sexual Homicide

This article—based on a national data set ( N = 173)—focuses on extrafamilial sexual homicides and their spatial mobility. The study combines the location of the crime scene and the offenders and victims’ residences in mobility crime triangles. The findings reveal that most of the homicides fall within the categories of offender mobility and total mobility. Our results show the validity of the distance decay function, with over 70% of homicides occurring within 10 km of the offender’s residence. It appears that under certain circumstances, sexual murderers perceive their surroundings as a safe place to commit a homicide. Finally, the study proposes a four-category spatial typology of sexual homicide.

Beyond mere pollution source identification: Determination of land covers emitting soil heavy metals by combining PCA/APCS, GeoDetector and GIS analysis

In this work, we propose a method that is not limited in the identification of the type of pollution source but it also suggests the land covers that emit heavy metals into the surrounding soils by introducing a three-stage procedure, as follows: (a) the Principal Component Analysis/Absolute Principal Component Scores technique is applied to the spatial distribution of soil heavy metal accumulations to identify the type of source that is responsible for soil heavy metal accumulation, (b) based on the spatial distribution of the principal component scores and on four selected driving factors (land cover, distance to mine or smelter, distance to road, and topographic elevation), the Geographical Detector model was used to identify the effect intensity of the driving factors on soil heavy metal accumulation and obtain the landscape type of pollutant sources, and (c) GIS analysis (buffer and overlap analysis) was performed on the principal component scores around the suspected land covers linked to the landscape type of pollutant sources to determine the land covers that, in fact, emit heavy metals into the surrounding soils. Based on the proposed approach, four mining and metallurgy land or land groups were determined to be the actual sources of soil heavy metal pollution in Daye city, Hubei Province, China. Lastly, a Multiple Linear Regression model with decay function was proposed to quantify the contributions of previously identified pollution sources to soil heavy metals accumulation. It was found that the HuangJin mountain quarry, the Tonglu mountain cooper mine (together with some related mineral processing and smelting enterprises), the Lion mountain mining and mineral processing base, and the large Oujia mountain mine are the four sources that contributed 3.2%, 34.3%, 8.3%, and 44% of the total soil heavy metal accumulations in the study area.

Preliminary test of ultrasonically disinfection efficacy towards selected aquaculture pathogens

The disinfection potential of ultrasound was evaluated for fish production in aquaculture systems by investigating the sensitivity of a wide range of different model organisms representing different taxa of common fish pathogens such as bacteria or parasites and algae at a size range of a few micrometers to 1 mm. Therefore, dose-dependent inactivation rates depending on consumed energy (kJ/L) at low (20 kHz, LFUS) and high (850 kHz, HFUS) frequency ultrasound were determined in in-vitro tests using a laboratory-scaled set-up for three zooplankton and five algae species as well as for heterotrophic marine and fresh water bacteria separated from recirculating aquaculture system water. LFUS and HFUS were effective against most tested eukaryotic organisms even at low energy input and the dose-dependent inactivation could be well described by functions of an exponential decay. HFUS seemed to be more effective compared to LFUS regarding the inactivation of bigger-sized algae species (≥14 μm). Within the tested zooplankton species, no systematic correlation between the size of the organisms and the effect of ultrasound frequency on the inactivation efficiency became apparent, suggesting a strong species-dependency likely caused by additional relevant morphological and physiological factors. Our data also suggest ultrasound treatment alone to be insufficient for an efficient bacterial reduction as LFUS and HFUS did not significantly reduced total viable counts even at high energy inputs up to 144 kJ/L. Measurements of total residual oxidants (TRO) revealed a higher formation potential of sonochemically-produced oxidants for HFUS compared to LFUS as well as an increased TRO accumulation at saline waters most likely due to the formation of more persistent halogenated secondary oxidants. Hence, particularly when HFUS is applied in a marine process chain total residual oxidants should be monitored in order to avoid deleterious impacts on animal health.

The shift of the thermoluminescence peak maximum temperature versus heating rate, trap filling and trap emptying: Predictions, experimental verification and comparison

The peak maximum temperature (Tmax) at the maximum intensity (Imax) are basic characteristics of a thermoluminescence (TL) peak. It is theoretically predicted and experimentally verified that Tmax shifts to higher temperatures as the readout heating rate increases. It is also predicted theoretically that Tmax shifts to lower temperatures as the radiation dose increases. However, although, experiments of the TL as a function of dose are the most common in TL literature the predicted shift is never unambiguously verified. This discrepancy between theory and experiment is extensively investigated in the present work. The behavior of the Tmax as a function of (a) heating rate, (b) dose (trap filling) and (c) trap decay (trap emptying) was studied in CaSO4:Dy, CaSO4:Tm, LiB4O7:Cu,In, MgB4O7:Dy,Na, Al2O3:C, BeO, and a sample of natural salt un-annealed and annealed at 600 . The results showed that the shift of Tmax as a function of heating rate and trap emptying are experimentally verified. On the other hand the shift of Tmax as a function of radiation dose (trap filling) is not verified experimentally. The results are extensively discussed and the explanations of the three different sources of Tmax shift are attempted.

Breakdown on LDPE film due to partial discharge in air gap and its correlation with electrical properties and surface degradation

This paper describes the breakdown characteristic of the low density poly ethylene film caused by partial discharge in the air gap. The purpose of this paper is to clarify the effect number of discharge under repetition rectangular pulses with a needle-plane electrode system as a function of pulse frequency. The result performed, from 10 Hz up to 1000 Hz. From 10 Hz to 200 Hz, the pulse number up to breakdown did not change significantly with increasing the pulse frequency and the magnitude of partial discharge function of pulse number with varied frequency until breakdown were similar. By using both potential decay and surface degradation analysis function of number of pulse, the breakdown phenomena caused by partial discharge was shown to reveal a significant correlation between electrical properties and the transparency of its surface to change deposited on it by a partial discharge exposure.

Effects of number of freeze-thaw cycles and freezing temperature on mode I and mode II fracture toughness of cement mortar

Natural and artificial materials including rocks and cement-based materials such as concrete and cement mortar are affected both physically and chemically by various natural factors known as weathering factors. The freeze-thaw process, as a weathering factor, considerably affects the properties of rocks and concrete. Therefore, the effect of the freeze-thaw process on the physical and mechanical properties of materials should be taken into account in areas with the risk of this process. Given that few studies have been conducted on the effect of the freeze-thaw process on the fracture toughness, in this work, we aimed at investigating the effects of the freeze-thaw cycles and freezing temperature on the mode I and mode II fracture toughness of cement mortar. To this end, specimens were exposed to 0, 5, 10, 20, and 30 freeze-thaw cycles, and the mode I and mode II fracture toughness was determined in different cycles. The effect of freezing temperature in a freeze-thaw cycle on the mode I and mode II fracture toughness was also investigated. The damage factor was also defined based on the effective porosity of cement mortar, and its changes with the number of freeze-thaw cycles and mode I and mode II fracture toughness were studied. Finally, the decay function model provided by Mutluturk was investigated. According to the results obtained, the mode I and mode II fracture toughness of cement mortar decreased linearly with increase in the number of freeze-thaw cycles. The mode I and mode II fracture toughness decreased linearly with increase in the freezing temperature in a freeze-thaw cycle. The damage factor increased with increase in the number of freeze-thaw cycles, and, additionally, its relationship with mode I and mode II fracture toughness exhibited a linear behavior.

Temporal loudness weights in background noise: Data and models

Previous studies consistently showed that human listeners primarily consider the beginning of a time-varying sound when judging its overall loudness, and place less weight on subsequent temporal portions. However, all experiments studying this primacy effect in temporal loudness weights presented the target sound in quiet. Here, we compared temporal weights when the target sound was either presented in quiet or in a continuous background noise, and for a variation in the level of the target sound across a range of 60 dB. The target sound was a time-varying narrowband noise, the background noise was a continuous bandpass-filtered noise. In all conditions, we observed the expected primacy effect, well described by an exponential decay function using parameters based on previous studies. The patterns of temporal weights were very similar in conditions with and without background noise, and largely independent of the variation in target level. Simulations using a dynamical model for the partial loudness of time-varying sounds in background noise showed that the model does not predict the observed temporal loudness weights. Strongly depending on the loudness statistic extracted from the loudness model, the predicted loudness weights were either uniform, or showed an inverse U-shaped pattern with higher weights predicted for temporal portions in the middle of the sound compared to temporal portions near onset or offset.Previous studies consistently showed that human listeners primarily consider the beginning of a time-varying sound when judging its overall loudness, and place less weight on subsequent temporal portions. However, all experiments studying this primacy effect in temporal loudness weights presented the target sound in quiet. Here, we compared temporal weights when the target sound was either presented in quiet or in a continuous background noise, and for a variation in the level of the target sound across a range of 60 dB. The target sound was a time-varying narrowband noise, the background noise was a continuous bandpass-filtered noise. In all conditions, we observed the expected primacy effect, well described by an exponential decay function using parameters based on previous studies. The patterns of temporal weights were very similar in conditions with and without background noise, and largely independent of the variation in target level. Simulations using a dynamical model for the partial loudness of ti...

Long-term temperature evolution of neutron stars undergoing episodic accretion outbursts

Context. Transient neutron star low-mass X-ray binaries undergo episodes of accretion, alternated with quiescent periods. During an accretion outburst, the neutron star heats up due to exothermic accretion-induced processes taking place in the crust. Besides the long-known deep crustal heating of nuclear origin, a likely non-nuclear source of heat, dubbed “shallow heating”, is present at lower densities. Most of the accretion-induced heat slowly diffuses into the core on a timescale of years. Over many outburst cycles, a state of equilibrium is reached when the core temperature is high enough that the heating and cooling (photon and neutrino emission) processes are in balance.Aims. We investigate how stellar characteristics and outburst properties affect the long-term temperature evolution of a transiently accreting neutron star. For the first time the effects of crustal properties are considered, particularly that of shallow heating.Methods. Using our codeNSCool, we tracked the thermal evolution of a neutron star undergoing outbursts over a period of 105yr. The outburst sequence is based on the regular outbursts observed from the neutron star transient Aql X-1. For each model we calculated the timescale over which equilibrium was reached and we present these timescales along with the temperature and luminosity parameters of the equilibrium state.Results. We performed several simulations with scaled outburst accretion rates, to vary the amount of heating over the outburst cycles. The results of these models show that the equilibrium core temperature follows a logarithmic decay function with the equilibrium timescale. Secondly, we find that shallow heating significantly contributes to the equilibrium state. Increasing its strength raises the equilibrium core temperature. We find that if deep crustal heating is replaced by shallow heating alone, the core would still heat up, reaching only a 2% lower equilibrium core temperature. Deep crustal heating may therefore not be vital to the heating of the core. Additionally, shallow heating can increase the quiescent luminosity to values higher than previously expected. The thermal conductivity in the envelope and crust, including the potentially low-conductivity pasta layer at the bottom of the crust, is unable to significantly alter the long-term internal temperature evolution. Stellar compactness and nucleon pairing in the core change the specific heat and the total neutrino emission rate as a function of temperature, with the consequences for the properties of the equilibrium state depending on the exact details of the assumed pairing models. The presence of direct Urca emission leads to the lowest equilibrium core temperature and the shortest equilibrium timescale.

Numerical study on Rayleigh-Taylor effect on cylindrically converging Richtmyer-Meshkov instability

Evolution of a two-dimensional air/SF6 single-mode interface is numerically investigated by an upwind CE/SE method under a cylindrically converging circumstance. The Rayleigh-Taylor effect caused by the flow deceleration on the phase inversion (RTPI) is highlighted. The RTPI was firstly observed in our previous experiment, but the related mechanism remains unclear. By isolating the three-dimensional effect, it is found here that the initial amplitude (a0), the azimuthal mode number (k0) and the re-shocking moment are the three major parameters which determine the RTPI occurrence. In the variable space of (k0, a0), a critical a0 for the RTPI occurrence is solved for each k0, and there exists a threshold value of k0 below which the RTPI will not occur no matter what a0 is. There exists a special k0 corresponding to the largest critical a0, and the reduction rule of critical a0 with k0 can be well described by an exponential decay function. The results show that the occurrence of the RTPI requires a small a0 which should be less than a critical value, a large k0 which should exceed a threshold, and a right impinging moment of the re-shock which should be later than the RTPI occurrence. Finally, the effects of the incident shock strength, the density ratio and the initial position of the interface on the threshold value of k0 and on the maximum critical a0 are examined. These new findings would facilitate the understanding of the converging Richtmyer-Meshkov instability and would be helpful for designing an optimal structure of the inertia confinement fusion capsule.

Fast fluorescence lifetime imaging techniques: A review on challenge and development

Fluorescence lifetime imaging microscopy (FLIM) is increasingly used in biomedicine, material science, chemistry, and other related research fields, because of its advantages of high specificity and sensitivity in monitoring cellular microenvironments, studying interaction between proteins, metabolic state, screening drugs and analyzing their efficacy, characterizing novel materials, and diagnosing early cancers. Understandably, there is a large interest in obtaining FLIM data within an acquisition time as short as possible. Consequently, there is currently a technology that advances towards faster and faster FLIM recording. However, the maximum speed of a recording technique is only part of the problem. The acquisition time of a FLIM image is a complex function of many factors. These include the photon rate that can be obtained from the sample, the amount of information a technique extracts from the decay functions, the efficiency at which it determines fluorescence decay parameters from the recorded photons, the demands for the accuracy of these parameters, the number of pixels, and the lateral and axial resolutions that are obtained in biological materials. Starting from a discussion of the parameters which determine the acquisition time, this review will describe existing and emerging FLIM techniques and data analysis algorithms, and analyze their performance and recording speed in biological and biomedical applications.

A Two Time Scale Relaxation Model and Its Application to Enthalpy Relaxation of Glassy Polystyrene

The enthalpy relaxation of polystyrene (PS) is studied by assuming a two time scale relaxation process. Kohlrausch–Williams–Watts and exponential decay functions are used to describe the isothermal relaxation behavior of the two time scale processes and three cases are considered. The relaxation time of the fast and slow relaxation processes are calculated using Tool–Narayanaswamy–Moynihan, Adam–Gibbs–Vogel, Free Volume or Macedo model and their corresponding linear forms, respectively. The assumption that the slow relaxation has an exponential character gives better fitting quality to the experimental results than that of assuming the fast relaxation has an exponential character. When Macedo model and its linear form were used, the fitting quality of both normalized heat capacity data and limit fictive temperatures improved greatly. This result shows that combining of two time scale and Macedo models may help to describe the enthalpy relaxation mechanism more properly.

Bayesian decay time estimation in a reverberation chamber for absorption measurements.

This work investigates the use of the initial decay time to obtain the Sabine absorption coefficient from measurements conducted in a reverberation chamber. Due to non-uniform distribution of sound absorption in the test chamber, measured energy decay functions exhibit multiple slopes, which cannot be evaluated unambiguously using linear regression as prescribed in the current standard (ISO 354, International Organization for Standardization, Geneva, Switzerland, 2003). As an alternative, this study proposes a Bayesian framework that allows estimating multiple decay parameters, hence capturing more accurately the energy decay features. Measurements are carried out in a reverberation chamber with and without diffusing elements to investigate the influence of diffusers on the absorption coefficient and on the decay process. Measured absorption coefficients of a porous sample are compared to theoretical values estimated with a transfer matrix model. The results show that the Sabine absorption coefficient calculated using the shortest decay time agrees well with the size-corrected theoretical absorption coefficient.

Environmental DNA size sorting and degradation experiment indicates the state of Daphnia magna mitochondrial and nuclear eDNA is subcellular

Environmental DNA analysis has emerged as a key component of biodiversity and environmental monitoring. However, the state and fate of eDNA in natural environments is still poorly understood for many ecological systems. Here we assess the state and fate of eDNA derived from the water flea, Daphnia magna, using a full factorial mesocosm experiment. We measured the quantity and degradation of eDNA over a two month period across a range of filters differing in pore size (0, 0.2, 1 and 10 µm), which spans the range of eDNA source material including subcellular, cellular and tissue. We also used two primer sets targeting mitochondrial (COI) and nuclear (18S) genomic regions. Our findings demonstrated that eDNA was most prevalent in the effluent water, but also reliably detected on the 0.2 μm filter, suggesting subcellular material is the predominate state of eDNA. Temporal eDNA quantity dynamics followed an exponential decay function over the course of 6-17 days, demonstrating a predictable decline in eDNA concentration. Nuclear eDNA was more abundant than mitochondrial eDNA, which may be a result of greater primer affinity, or indicate greater availability of nuclear eDNA gene targets in the environment. In contrast to two previous size-sorting experiments, which utilizing fish eDNA, our findings suggest that the state of invertebrate eDNA is much smaller than previously suspected. Overall, our data suggest that the detection of eDNA greatly depends on our knowledge of the state and fate of eDNA, which differ among species, and likely across environmental conditions.

Modelling Strategies for Discontinuous Distance Decay in Willingness to Pay for Ecosystem Services

Distance decay is a well-known phenomenon affecting welfare measures of localized improvements in environmental quality. We focus on an often overlooked issue in the distance decay literature, namely the modeling of jump discontinuities, i.e. when the willingness to pay distance decay function makes a vertical jump up or down. In an empirical stated choice experiment concerning localized water quality improvements where a toll bridge presents a barrier in the landscape that causes a sudden jump in travel costs, we first estimate individual-specific willingness to pay. We then investigate distance decay in these obtained estimates. We find that the degree of distance decay depends on which type of ecosystem services respondents are primarily motivated by. Besides modelling distance decay with a range of commonly used parametric functional forms, we also test a nonparametric generalized additive model specification. We find only minor differences between the different distance decay specifications, with no generally superior model specification. The nonparametric approach tends to capture distance decay in WTP just as well as any of the parametric specifications, but without requiring the analyst to make assumptions concerning the functional form of the distance decay relationship.

Crystal structure, thermal studies, vibrational properties, atomic Hirshfeld surface, and electrical and dielectric studies of [C9H14N]3BiCl6 single crystal

The present research under study makes in attention the synthesis of a new organic inorganic hybrid material of formula [C9H14N]3BiCl6 by slow evaporation at room temperature. It is characterized by the following techniques: X-ray diffraction (XRD), IR absorption, Raman scattering, UV–Vis spectrum, Hirschfield surface analysis, thermal analysis, AC conductivity and dielectric measurements. The studied compound belongs to the centrosymmetric Pī space group of the triclinic system. The crystal structure is built up of one octahedral anion [BiCl6]3- and three monoprotonated cations [C9H14N]+. They give between them alternating anionic layers and cationic ones. The DSC revealed a phase transition at the temperature 380 K and the decomposition of the compound at 400 k. Raman and infrared spectra were recorded in the 50–400 and 400-4000 cm−1 frequency regions respectively. The optical properties were investigated by optical absorption and show three bands at 211, 266 and 321 nm. Hirshfeld surface analysis of close intermolecular interactions in this compound enables the identification and the examination of molecular shapes. The AC electrical conductivity and the dielectric relaxation properties of the [C9H14N]3BiCl6 material have been carefully studied by means of impedance spectroscopy measurements over 200 Hz–5 MHz frequencies and 330–400 K temperatures ranges. Nyquist plots (-Z″ versus Z′) results is well explained by an equivalent circuit which is modeled by a combination of a parallel Rp//CPE. Besides, the Arrhenius law is followed by temperature dependence of the electrical conductivity in the different phases and the Jonscher's universal dynamic law is also followed by the frequency dependence of σ (ω). Moreover, it is clear that the activation energy responsible for relaxation has been depicted and shown to be close to the DC conductivity. Finally, the modulus plots can be characterized by the non-experiential decay function ∅(t)=exp(−tτσ)β.

Microcontainers for oral insulin delivery – In vitro studies of permeation enhancement

Oral delivery of peptides is challenging due to their low uptake through the small intestinal epithelium. Tight junctions, connecting the enterocytes, impede permeability, often necessitating the use of permeation enhancers in the formulation. Loading of peptide and permeation enhancer into micro-scale devices, such as microcontainers, can potentially confine the effective absorptive area through unidirectional release and thereby enhance absorption. This concept is investigated by in vitro permeation studies of insulin across Caco-2 cell and Caco-2/HT29-MTX-E12 co-culture monolayers mimicking the intestinal absorption barrier. The importance of proximity between the microcontainers and the barrier is assessed, by keeping the amounts of insulin and sodium caprate fixed throughout all experiments, while collectively orienting the unidirectional release towards the cell monolayers. Increasing the distance is observed to have a negative effect on insulin permeation matching a one-phase exponential decay function, while no difference in insulin transport is observed between Caco-2 and co-culture monolayers. Although there are no signs of cytotoxicity caused by the microcontainer material, reversible cell deterioration, as a consequence of high local concentrations of sodium caprate, becomes evident upon qualitative assessment of the cell monolayers. These results both suggest a potential of increasing oral bioavailability of peptides by the use of microcontainers, while simultaneously visualising the ability of regaining monolayer integrity upon local permeation enhancer induced toxicity.

Influence Area of Transit-Oriented Development for Individual Delhi Metro Stations Considering Multimodal Accessibility

Understanding the influence areas for transit stations in Indian cities is a prerequisite for adopting transit-oriented development (TOD). This study provides insights into the last mile patterns for selected Delhi Metro Rail (DMR) stations, specifically, Karkardooma, Dwarka Mor, Lajpat Nagar, and Vaishali, and the extent of the influence area based on different access modes. The variation in the extent of the influence areas based on various modes and the locational characteristics of stations have been considered in this study. The last mile distances reported in the conducted survey involved the problems of rounding and heaping, and they were subjected to multiple imputation to remove the bias. The spatial extent of the influence areas for various modes was estimated based on the compound power exponential distance decay function. Further, the threshold walking distances were calculated using the receiver operating characteristic (ROC) curves. The variations were noted in the last mile distances among stations. The walking distances (mean and 85th percentile) among stations did not vary considerably; however, large variations were noted when comparing other modes. These differences in accessibility must be taken into account when considering multimodal accessibility and multimode-based TOD. The study can provide useful inputs for planning and implementing TOD in New Delhi.

Settling dynamics of two identical vertically aligned spheres in a thixotropic fluid

Despite the great relevance of particle dynamics in non-Newtonian fluids, particles settling in non-Newtonian fluids has received limited scientific attention. The simple case of two vertically aligned spheres settling in a thixotropic xanthan fluid is considered using solutions of xanthan + glycerol + water and 0.75 mm radius stainless steel spheres. Chaining phenomenon is observed where the trailing sphere velocity is increased due to a corridor of reduced viscosity created by the leading sphere. Our experimental methods are first validated against a Newtonian fluid of glycerol + water in which the sphere velocities remained equal. Using the fluid velocity induced by a single sphere, the two sphere velocities are approximated by Faxén's first law. In a non-Newtonian (thixotropic) xanthan fluid, a viscosity ratio is introduced to account for the reduced fluid viscosity encountered by the trailing sphere due to the slow structure recovery of the fluid after shear thinning. The viscosity ratio is an exponential decay function dependent on the time between spheres normalised by the fluid recovery time, a parameter which is experimentally determined. When the sphere-sphere separation is large, the viscosity ratio tends towards unity. The predicted settling velocities show good agreement with experimental data.

High Dynamic Range Imaging with TDC-Based CMOS SPAD Arrays

This paper investigates the use of image sensors based on complementary metal–oxide–semiconductor (CMOS) single-photon avalanche diodes (SPADs) in high dynamic range (HDR) imaging by combining photon counts and timestamps. The proposed method is validated experimentally with an SPAD detector based on a per-pixel time-to-digital converter (TDC) architecture. The detector, featuring 32 × 32 pixels with 44.64-µm pitch, 19.48% fill factor, and time-resolving capability of ~295-ps, was fabricated in a 150-nm CMOS standard technology. At high photon flux densities, the pixel output is saturated when operating in photon-counting mode, thus limiting the DR of this imager. This limitation can be overcome by exploiting the distribution of photon arrival times in each pixel, which shows an exponential behavior with a decay rate dependent on the photon flux level. By fitting the histogram curve with the exponential decay function, the extracted time constant is used to estimate the photon count. This approach achieves 138.7-dB dynamic range within 30-ms of integration time, and can be further extended by using a timestamping mechanism with a higher resolution.