Absolute Intensity Research Articles

Fuzzy subspace clustering noisy image segmentation algorithm with adaptive local variance & non-local information and mean membership linking

The Fuzzy C-means (FCM) clustering algorithm is an effective method for image segmentation. Non-local spatial information considers more redundant information of the image thus is more robust to noise. However, under-segmentation of non-local spatial information may exist with higher noise density. The number of iteration steps is also significant in FCM, and employing membership linking can effectively reduce the number of iteration steps. Nonetheless, when there are outliers in the membership degree, the membership linking can make the algorithm converge prematurely before reaching the optimum, affecting segmentation performance. This paper presents a fuzzy subspace clustering noisy image segmentation algorithm with adaptive local variance & non-local information and mean membership linking (FSC_LNML). Firstly, local variance templates are utilized to eliminate the under-segmentation of non-local information, and local variance & non-local information are integrated into the FCM objective function to improve robustness. Secondly, the mean membership linking is employed as the denominator of the objective function to reduce the number of iterations and solve the problem that the algorithm converges early before reaching the optimum when the membership has an outlier. Thirdly, the absolute intensity difference between the original image and the local variance & non-local information and its inverse are used to adaptively constrain the original image and the local variance & non-local information. Finally, the concept of the subspace is introduced to adaptively assign appropriate weights to each dimension of the image to improve the segmentation performance of color images. The simulation results on noisy grayscale images and noisy color images show that the efficiency of the proposed method FSC_LNML is better than other fuzzy-based clustering algorithms. The convergence proof of the algorithm is also presented.

Inferred Measurements of the Zodiacal Light Absolute Intensity through Fraunhofer Absorption Line Spectroscopy with CIBER

Abstract Scattered sunlight from the interplanetary dust (IPD) cloud in our solar system presents a serious foreground challenge for spectrophotometric measurements of the extragalactic background light (EBL). In this work, we report on inferred measurements of the absolute intensity of the zodiacal light (ZL) using the novel technique of Fraunhofer line spectroscopy on the deepest 8542 Å line of the near-infrared Ca ii absorption triplet. The measurements are performed with the narrow band spectrometer (NBS) on board the Cosmic Infrared Background Experiment sounding rocket instrument. We use the NBS data to test the accuracy of two ZL models widely cited in the literature, the Kelsall and Wright models, which have been used in foreground removal analyses that produce high and low EBL results respectively. We find a mean reduced χ 2 = 3.5 for the Kelsall model and χ 2 = 2.0 for the Wright model. The best description of our data is provided by a simple modification to the Kelsall model, which includes a free ZL offset parameter. This adjusted model describes the data with a reduced χ 2 = 1.5 and yields an inferred offset amplitude of 46 ± 19 nW m−2 sr−1 extrapolated to 12500 Å. These measurements elude to the potential existence of a dust cloud component in the inner solar system whose intensity does not strongly modulate with the Earth’s motion around the Sun.

Refining the absolute chronology of Teotihuacan (Mesoamerica): New archaeomagnetic datings of fire footprints

Teotihuacan is considered as the best planned and largest pre-Hispanic city in Mesoamerica. One of the causes, related to the decline of the Teotihuacan, is the so-called “Big Fire”. However, associated chronological constraints are still poorly defined. Here, we report new archaeomagnetic dates of three burned walls located in the Plaza de la Luna vicinity, considered as the last construction stage of Teotihuacan. Detailed rock-magnetic and absolute archaeointensity studies were performed on 24 samples allowing to determine both mean directions and absolute intensities. Magnetic dating using full geomagnetic vector provided a time interval between 327 and 441 CE as the best estimate of the last fire exposure of studied footprints. This new data, in combination with previous results, suggest that Teotihuacán experienced various fire episodes probably caused and controlled during public acts loaded with symbolic values, such as the rituals for the termination of a cycle or those related to the beginning of a new constructive stage.

Structured illumination-based transport-of-intensity phase imaging for quantitative diagnostics of high-speed flows.

A method for quantitative estimation of density in a high-speed flow field is presented, which uses structured illumination to interrogate the region of interest (ROI). Wavefront distortion suffered by the interrogating beam as it passes through the shock-induced flow field is investigated. Customized camera optics is used to measure the cross-sectional intensities of the exiting wavefront at two different planes, concurrently. A technique is proposed that uses the displacement of the structured light pattern to estimate the axial intensity derivative, ∂I∂z, which is the input to the transport-of-intensity equation (TIE) for phase estimation. The proposed method allows the use of images with larger defocused distances, ∂z, as it does not follow the conventional recipe of finite-difference (FD) approximation for intensity derivative estimation. This flexes two requirements of conventional TIE imaging: first, it brings flexibility in imaging optics, not restricted to small f-number objectives; second, use of a sensitive camera is optional, as ∂I∂z estimation does not use absolute intensities but information from the distorted pattern of structured light. The recovered phase from the TIE is used as an input to the phase tomography algorithm to obtain the refractive index followed by density distributions in the flow field quantitatively. The proposed phase estimation technique is verified through simulations first and then is implemented in experiments conducted in a hypersonic shock tunnel for flow Mach No. of 8.8. Estimated cross-sectional densities of the flow field around the aerodynamic test model are presented and compared with the numerically estimated values, which shows good agreement.

Exploring Dissolved Organic Carbon Variations in a High Elevation Tropical Peatland Ecosystem: Cerro de la Muerte, Costa Rica

Tropical peatlands are distributed mainly in coastal lowlands; however high elevation regions exhibit a large prevalence of small and fragmented peatlands that are mostly understudied. Artificial drainage of peatlands to expand the area of cattle farming, horticulture, and urbanization is increasing carbon losses to the atmosphere and streams worldwide. Here, we present an exploratory characterization of dissolved carbon optical properties in ombrotrophic peat bogs of the Talamanca range of Costa Rica, across an altitudinal gradient (2,400–3,100 m a.s.l.) during the rainy season. Dissolved organic matter (DOM) sources and decomposition processes were evaluated in the light of dissolved organic and inorganic carbon (DOC and DIC), optical properties, and major water chemistry. DOC concentrations ranged from 0.2 up to 47.0 mg/L. DIC concentrations were below 2 mg/L and δ13CDIC values indicated a mixture between soil organic matter, CO2 in soil water, and to a lesser degree DIC derived from bacterial CO2. Absolute fluorescence intensity of humic-like peaks was 6–7 times greater than fresh-like peaks across all sites. Fluorescence peak ratios coupled with the biological and humification indexes point to a greater relative contribution of recalcitrant soil-derived DOM. Excitation/Emission matrices denoted a high prevalence of humic and fulvic acids in the peat bogs, with moderate intensities in soluble microbial by-products-like and aromatic protein regions at three sites. Our data provides a baseline to underpin tropical carbon dynamics across high elevation peatlands.

Small angle x-ray scattering to investigate the specific surface of hydrated alginate microbeads

Encapsulation of active substances in biopolymer beads becomes a widely developed approach to gain efficiency for many applications. However, the characterization of such aqueous materials in their early stage of production is very delicate regarding their textural properties. The classical tools such as gas adsorption and Hg porosimetry can hardly provide relevant information since they require the removal of water, which is yet a fundamental part of the sample that drives its structure. In this article, we used small angle x-ray scattering (SAXS) as a tool in order to determine the specific surface area (SSA) of alginate microbeads in solution. This has been made possible by a careful procedure of SAXS measurements, involving calibration samples, allowing writing intensities in absolute units. Therefore, the Porod limit theory was used to calculate the SSA from the scattering length contrast and the measured absolute intensity. In addition, we compared the SSA of microbeads obtained from pure water and from a widely used cell culture medium, and we followed the textural evolution of a water alginate sample during the first step of a gentle drying process. Our results show that SAXS should be considered as a valuable tool for physico-chemists and food formulators in order to extract in situ dimensional and textural information of hydrogels during the formulation. It enables them to figure out the real surface available for the sorption of additive or active molecules in the formulation of biopolymers such as alginates, empowering them to better control encapsulation processes.

Determination of the gamma emission intensities of 125Xe based on 125I radioactivity

The radionuclide 125Xe plays an important role in diagnosing deuterium-tritium (DT) fuel areal density in inertial confinement fusion (ICF). Accurate data for the gamma emission intensities of 125Xe are highly desired. In this paper, after the 125Xe and 125I samples were prepared, the activity of 125I was determined by the sum-peak method using a high resolution well-type HPGe (High Purity Germanium) detector, and the activity of 125Xe was obtained by the decay relationship between 125Xe and 125I. The full-energy peak efficiencies of gamma-rays of 125Xe were accurately calibrated using standard radioactive sources. As a result, the absolute emission intensities of 125Xe for 12 gamma-rays were determined experimentally for the first time.

Экспериментальные интенсивности линий колебательно-вращательных переходов в полосах ν1+ ν2 и ν2+ ν3 молекулы D234S

The study of the absolute line intensities in the high-resolution spectrum of the D234S molecule in the range 2300-2900 cm-1 has been carried out for the first time. As a result of the analysis, about 800 experimental intensities of vibrational-rotational transitions were obtained for the v 1 + v 2 and v 2 + v 3 bands, and a set of 6 parameters of the effective dipole moment was calculated, which reproduces the initial experimental line intensities with drms = 9.7%. A list of transitions with frequencies and line intensities in the range under study has been compiled.

Социо-эколого-экономическая устойчивость северного региона на основе модели «окно устойчивости»

A review of the scientific literature and other materials related to sustainable development and the implementation of the Sustainable Development Goals at the national level shows that there is a need to take into account all aspects of sustainable development: environmental, social, economic. In this regard, monitoring and measuring the sustainability of the development of regional social, ecological and economic systems, the pace of change, determining the vector of development of the main components and their relationship are of high relevance. The analysis revealed the methodology of sustainable development window (SuWi) applied for an integral assessment of the social, ecological and economic sustainability of the northern region. This methodology takes into account the principles of sustainable development to the greatest extent. Methodology’s scope is to determine the parameters of minimum and maximum economic development, highlight the GDPmin – GDPmax interval (or a sustainability window), which helps economic development meet the criteria of social and environmental sustainability. The parameters of the window’s minimum level are determined by social criteria, while the window’s the maximum level – by environmental ones. The sustainability window scope is defined as follows: an analytical database (2007–2019) of the northern region (Komi Republic) is compiled in economic, social and environmental dimensions; assessment criteria (indicators) for the main components of sustainable development are reasoned; their index relative to the base year is assessed (in absolute value and intensity); the lower and upper limits of the stability window are defined by calculation and graphical methods, the window’s integral width is found taking into account all indicators. SuWi analysis of social sustainability showed that “wages” and “life expectancy at birth” out of the five indicators correspond to the minimum level of economic growth. At the same time, it should be noted that since 2017, economic performance decline has been a constraining factor for the region’s social development in terms of these indicators as well. The authors arrive at the conclusion that the situation in the development of the northern region is unfavorable, primarily in the social sphere due to the long-term decline in the gross regional product (which is below its baseline since 2014), which requires enhanced economic growth. The study gives valuable results in sustainability-window based social, ecological and economic sustainability analysis, which makes the study relevant. The methodology of the sustainable development window can be built into the management decisions system for the respective authorities. In the future, research should be focused on improving the economic stability of the region, conducting an in-depth analysis of the possibilities aimed to overcome the recession identified in this paper.

The short-term development of performance and aerobic endurance following prolonged low-intensity ski trekking in Svalbard: A case study

Abstract The purpose of this case study was to examine the short-term development of performance and aerobic endurance following prolonged low-intensity ski trekking (LIST) in an Arctic region. Two male recreational athletes (aged 24 and 26 years) with high aerobic fitness performed LIST 7 ± 2 h·day−1 for 23 consecutive days, while hauling sledges (∼80 kg initially) with supplies from the north to the south of Svalbard (∼640 km). Time to exhaustion, maximal oxygen uptake (V̇O2max), lactate threshold (LT) and work economy were evaluated at pre- and post-trek. The results showed that the absolute and relative exercise intensity during LIST were ∼3.9 km·h−1 and ∼60% of maximal heart rate, respectively. Time to exhaustion during a ∼4–6 min ramp walking test, and a >45 min stepwise walking test, while pulling 12.5 kg weights (simulation of ski trekking with loaded sledge), increased by 11–17% and 3–9%, respectively, following LIST. Body mass and V̇O2max relative to body mass (ml·kg−1·min−1) decreased by 5–8% and increased by 3–8%, respectively. Furthermore, the workload associated with LT and LT percentage of V̇O2max increased by 39–69% and 12–13%, respectively. No notable change in work economy was observed. The mean pace during LIST (∼3.9 km·h−1) corresponded to the treadmill walking speed (4 km·h−1) with the lowest oxygen cost (mL·kg−1·m−1) in both participants. It can be concluded that short-term prolonged LIST can improve ski trek-simulated performance and fractional utilisation of V̇O2max in recreational athletes with high aerobic fitness. Moreover, highly aerobically fit ski trekkers appear to instinctively choose the most energy-efficient pace during LIST.

A study on setting standards for near-infrared fluorescence-image guided surgery (NIRFGS) time lapse monitoring based on preoperative liver function assessment.

BackgroundThis study aimed to explore the relationship between the fluorescence intensity of indocyanine green (ICG) in near-infrared fluorescence guided surgery (NIRFGS) and preoperative liver function indicators.MethodsA total of 12 4T1 tumor-bearing mice were used for model establishment. Intraperitoneal injection (i.p.) of 20% carbon tetrachloride (CCl4) corn oil solution (50 µL) was given to mice in the liver injury model group, 24 hours after injection, the model was established, while the control group received 0% CCl4 corn oil solution (50 µL) (n=6 for each group). Additionally, doses of 8 mg/kg and 1 mg/kg of free ICG were injected intravenously (i.v.) (n=3 in each group). Fluorescence was imaged in vivo using an NIR fluorescence imaging system at different time points (1, 2, 4, 8, 12, 24, 48, and 72 h) after injection.ResultsThe absolute fluorescence intensity of mice in the liver injury model group was stronger than that in the control group. Mice in the liver injury model group had the same clearance rate of ICG from the tumor as normal mice. However, the background clearance rate was slower than that of normal mice, which prolonged the optimal tumor to background ratio (TBR) time. Correlation analysis was also used to determine which preoperative liver function parameters were most correlated with hepatic ICG clearance.ConclusionsLiver injury does not significantly affect the maximum TBR, but prolongs the optimal TBR time, and at the same time, a wider and more stable surgical window will appear. This study showed that a prolonged surgical start time is feasible according to preoperative liver function testing using NIR fluorescence imaging technology.

The effectiveness of in-office dental bleaching with and without sonic activation: A randomized, split-mouth, double-blind clinical trial.

This study was aimed at comparing the bleaching efficacy and bleaching sensitivity (BS) of two higher-concentration in-office bleaching gels (37% carbamide peroxide [CP] and 38% hydrogen peroxide [HP]) applied under two conditions: alone or in association with sonic activation. Fifty-six volunteers were randomly assigned in the split-mouth design into the following groups: CP, CP with sonic activation (CPS), HP, and HP with sonic activation (HPS). Two in-office bleaching sessions were performed. Color was evaluated using Vita Classical, Vita Bleachedguide, and digital spectrophotometer at baseline and at 30 days post-bleaching. Absolute risk and intensity of BS were recorded using two pain scales. All data were evaluated statistically (color changes [t test], BS [Chi-square and McNemar test], and BS intensity [VAS; t test; NRS; Wilcoxon; α=0.05]). Significant and higher whitening was observed for HP when compared with CP (p < 0.04). However, higher BS intensity was observed in the former (p < 0.001). No significant difference was observed in whitening effect or BS when the HP or CP bleaching gels were agitated (sonic application) compared with when they were not (p > 0.05). The 37% CP gel demonstrated lower bleaching efficacy and lower BS compared with the 38% HP bleaching gel. The whitening effect was not influenced by the use of sonic activation. The use of 37% CP gel did not achieve the same whitening effect when compared to 38% HP gel used for in-office bleaching. The use of sonic activation offers no benefit for in-office bleaching.

Lung cancer incidence and mortality trends&#x0D; in the Republic of Belarus&#x0D; (1990-2019)

favorable malignant diseases globally. In the Republic of Belarus, it ranks third (8.2%) in the cancer incidence structure and&#x0D; first (21.5%) in the cancer mortality structure.&#x0D; The object of the study were the lung cancer incidence and&#x0D; mortality trends in the Republic of Kazakhstan in 1990-2019.&#x0D; Methods: The present study included all patients - residents of Belarus, registered in the national cancer registry from&#x0D; 1990 to 2019 with a diagnosis of lung cancer (ICD-10 code:&#x0D; C33-C34). Demographic variables included gender, age, and&#x0D; area of residence (urban or rural). The number of PD cases is&#x0D; presented as absolute values and rough intensity indicators&#x0D; per 100,000 population. Standardized morbidity and mortality&#x0D; rates are calculated using the world standard (World) and are&#x0D; indicated per 100,000 population.&#x0D; Results: In the study period, the standardized incidence&#x0D; rate decreased from 27.5 to 25.6 per 100 000 population&#x0D; (– 7.1%, p&lt;0.01). In males, it decreased from 62.1 to 54.6 per 100&#x0D; 000 males (– 12.1%, p&lt;0.001); in females, it increased from 5.3&#x0D; to 6.4 per 100 000 females (+20.7%, p&lt;0.05).&#x0D; The standardized lung cancer mortality rate has decreased&#x0D; over the study period from 23.0 to 18.3 per 100 000 population&#x0D; (– 20.4%, p&lt;0.001). In males, it went down from 53.6 to 40.7 (–&#x0D; 24.1%, p&lt;0.001), and in women it changed slightly from 3.6 to&#x0D; 3.7 (+2.8%, p&gt;0.05) per 100 000 of the relevant sex. The average annual increase in standardized mortality decreased eight&#x0D; times faster than the growth in standardized incidence.&#x0D; Conclusion: In the Republic of Belarus, lung cancer incidence is increasing in males and decreasing in females. At that,&#x0D; lung cancer mortality is decreasing. Quality specialized cancer&#x0D; care creates conditions for quicker negative growth of lung cancer standardized mortality vs. incidence

Methods to match high-intensity interval exercise intensity in hypoxia and normoxia – A pilot study

Background/ObjectivesThe aim of this study was to compare high-intensity interval exercise (HIIE) sessions prescribed on the basis of a maximal value (peak power output, PPO) and a submaximal value (lactate threshold, LT) derived from graded exercise tests (GXTs) in normoxia and hypoxia. MethodsA total of ten males (aged 18–37) volunteered to participate in this study. The experimental protocol consisted of a familiarization procedure, two GXTs under normoxia (FiO2 = 0.209) and two GXTs under normobaric hypoxia (FiO2 = 0.140), and three HIIE sessions performed in a random order. The HIIE sessions included one at hypoxia (HY) and two at normoxia (one matched for the absolute intensity in hypoxia, designated as NA, and one matched for the relative intensity in hypoxia, designated as NR). ResultsThe data demonstrated that there was significant lower peak oxygen uptake (V̇O2peak), peak heart rate (HRpeak), PPO, and LT derived from GXTs in hypoxia, with higher respiratory exchange ratio (RER), when compared to those from GXTs performed in normoxia (p < 0.001). Among the three HIIE sessions, the NA session resulted in lower percentage of HRpeak (85.0 ± 7.5% vs 94.4 ± 5.0%; p = 0.002) and V̇O2peak (74.1 ± 9.1% vs 88.7 ± 7.7%; p = 0.005), when compared to the NR session. HIIE sessions in HY and NR resulted in similar percentage of HRpeak and V̇O2peak, as well as similar rating of perceived exertion and RER. The blood lactate level increased immediately after all the three HIIE sessions (p < 0.001), while higher blood lactate concentrations were observed immediately after the HY (p = 0.0003) and NR (p = 0.014) sessions when compared with NA. ConclusionCombining of PPO and LT derived from GXTs can be used to prescribe exercise intensity of HIIE in hypoxia.

Relative Vigorous-Intensity Physical Activity Predicts Brain Microstructural Changes in Older Adults

Physical activity especially at moderate-to-vigorous intensity may preserve brain structure in old age. However, current findings are cross-sectional and rely on absolute intensity. This study aimed to examine whether relative or absolute vigorous-intensity physical activity (VPA) predicts brain microstructural changes. We analyzed 260 initially cognitively normal and well-functioning participants(age=70.5yrs) who had VPA data via ActiHeart and longitudinal brain microstructure by DTI(follow-up=3.7yrs). Associations of VPA with microstructural changes were examined using linear mixed-effects models, adjusted for demographics. Each SD higher relative VPA defined by heart rate reserve (i.e. 21 min/day) was significantly associated with less decline in memory-related microstructural integrity, including mean diffusivity of entorhinal cortex and parahippocampal gyrus and fractional anisotropy of uncinate fasciculus and cingulum-hippocampal part, and not executive/motor-related microstructure. Absolute VPA was not associated with microstructural markers. Among well-functioning older adults, participating in VPA defined by heart rate reserve may predict less brain microstructural decline in memory-related areas.

Perceived Exertion in Physical Activity Measurement Across the Lifecourse: Results from SWAN

Physical activity (PA) guidelines recommend 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity PA, in addition to muscle strengthening activities, each week. Many questionnaires ascertain PA frequency, duration, and intensity to benchmark achievement of PA recommendations. However, most scoring algorithms utilize absolute intensity estimates when exertion may be influenced by age or other sociodemographic or health characteristics. This study compared PA estimates with and without adjustments for perceived exertion and determined if that difference was associated with individual characteristics. Women (n=2,711) from the longitudinal Study of Women’s Health Across the Nation who completed ≥3 Kaiser Physical Activity Surveys (KPAS) across 8 biennial visits were included (baseline age: 46.4±2.7 years). KPAS responses were converted to metabolic equivalent of a task (METs) using the Compendium of Physical Activities to estimate absolute and perceived intensity-adjusted MET values. Latent class growth modeling identified subgroups of participants following similar patterns of change in the difference between absolute intensity-based and perceived intensity-adjusted estimates across time. Four major trajectory classes emerged with patterns reflecting: (1) lessening high-intensity exercise (2.2%); (2) increasingly high-intensity exercise (3.1%); (3) consistently moderate-intensity exercise (92.0%); and (4) consistently low-intensity exercise (2.8%). Consistently low-intensity exercisers, for whom absolute intensity-based estimates exceeded perceived intensity-adjusted estimates, were more likely to be Japanese or Chinese (p<0.001) and have lower BMI (p=0.05). However, for most participants, absolute intensity-based estimates approximated perceived intensity-adjusted estimates over time, suggesting that traditional PA scoring techniques may provide sufficient estimates for PA in longitudinal cohort studies of mid-life and older adult women.

Impact of instrumental settings in electrospray ionization ion trap mass spectrometry on the analysis of multi-CH3-/CD3-isotopologs in cellulose ether analysis: a quantitative evaluation

Exact quantification of the molar ratios of isotopologous mixed O-methyl-O-methyl-d3-cellooligosaccharides (COS) comprising all combinations from fully methylated to fully deuteromethylated constituents within an individual degree of polymerization (DP) is the key step in the analysis of the substituent distribution over the polymer chains in methyl celluloses (MC). Deuteromethylation of MC is performed to level chemical differences, but due to a m/z range of 3 DP·ΔMe/Me-d3, bias during MS measurement cannot certainly be excluded. Therefore, ionization, ion transportation, and ion storage were studied with an electrospray ionization ion trap mass spectrometer (ESI-IT-MS) using binary equimolar mixtures of per-O-Me- and per-O-Me-d3-COS, defining the border cases of a particular Me/Me-d3-profile. Reference data of their molar ratio were determined after reductive amination with m-amino benzoic acid by HPLC-UV. COS of DP2–6 were measured as their sodium adducts at c = 10−6 M by syringe pump infusion. The impact of the RF voltage of the ion trap (TD), the octopole RF and DC voltages, and the Cap Exit potential on absolute and relative ion intensities were studied. Adapting the Cap Exit voltage was essential for correct quantification of DP2, while all COS of higher DP behaved insensitive with respect to bias. To check whether any bias occurs in the electrospray ionization process of the isotopologs, concentration-dependent measurements were performed with optimized instrumental settings for each DP. Intensity ratios IR = I (Me-d3)/I (Me) did not show any concentration-dependent trend and no selective ion suppression. Its decrease with DP observed under usually applied standard conditions (smart mode) is a consequence of discrimination according to m/z and can be overcome by appropriate instrumental settings of Oct 2 DC and TD. IR between 0.971 ± 0.008 and 1.040 ± 0.009 with no trend for DP (2-6) were obtained by averaging all measurements in the range 2 · 10−7 to 2 · 10−5 M total concentration. The DP-related optimized settings were applied to two MCs and compared with the results obtained under so far applied standard conditions.Graphical abstract

Temperature dependence of electrical and optical properties in Eu3+ doped Pb(Mg1/3Nb2/3)O3-PbZrO3-PbTiO3 ferroelectric ceramics

As a new type of optoelectronic integration multifunctional material, rare earth doped lead-based ferroelectrics have great potential in sensing, detection and information transmission. In order to obtained multifunctional ferroelectric ceramics with high electrical properties, the ternary ferroelectric 0.38Pb(Mg1/3Nb2/3)O3-xPbZrO3-(0.62 − x)PbTiO3 ceramics doped with rare earth Eu ions were sintered by traditional two-step niobate precursor method. Their electrical and optical properties were investigated. It was found that the ceramics exhibited good temperature stability and the morphotropic phase boundary is near x = 0.27, wherein the piezoelectric coefficient d33 and dielectric constant εr reach the desirable values of 574 pC/N and 3740, respectively. Furthermore, the absolute intensity of 5D0 – 7F2 transition of Eu3+ in x = 0.27 ceramics varies with temperature, in which abnormities of the uplifted peaks contained the information of ceramic phase transition. This work provides a new direction for improving the performance of rare earth doped ferroelectrics and expanding their application range.

Block-Greedy and CNN Based Underwater Image Dehazing for Novel Depth Estimation and Optimal Ambient Light

A lack of adequate consideration of underwater image enhancement gives room for more research into the field. The global background light has not been adequately addressed amid the presence of backscattering. This paper presents a technique based on pixel differences between global and local patches in scene depth estimation. The pixel variance is based on green and red, green and blue, and red and blue channels besides the absolute mean intensity functions. The global background light is extracted based on a moving average of the impact of suspended light and the brightest pixels within the image color channels. We introduce the block-greedy algorithm in a novel Convolutional Neural Network (CNN) proposed to normalize different color channels’ attenuation ratios and select regions with the lowest variance. We address the discontinuity associated with underwater images by transforming both local and global pixel values. We minimize energy in the proposed CNN via a novel Markov random field to smooth edges and improve the final underwater image features. A comparison of the performance of the proposed technique against existing state-of-the-art algorithms using entropy, Underwater Color Image Quality Evaluation (UCIQE), Underwater Image Quality Measure (UIQM), Underwater Image Colorfulness Measure (UICM), and Underwater Image Sharpness Measure (UISM) indicate better performance of the proposed approach in terms of average and consistency. As it concerns to averagely, UICM has higher values in the technique than the reference methods, which explainsits higher color balance. The μ values of UCIQE, UISM, and UICM of the proposed method supersede those of the existing techniques. The proposed noted a percent improvement of 0.4%, 4.8%, 9.7%, 5.1% and 7.2% in entropy, UCIQE, UIQM, UICM and UISM respectively compared to the best existing techniques. Consequently, dehazed images have sharp, colorful, and clear features in most images when compared to those resulting from the existing state-of-the-art methods. Stable σ values explain the consistency in visual analysis in terms of sharpness of color and clarity of features in most of the proposed image results when compared with reference methods. Our own assessment shows that only weakness of the proposed technique is that it only applies to underwater images. Future research could seek to establish edge strengthening without color saturation enhancement.

The PINT database: a definitive compilation of absolute palaeomagnetic intensity determinations since 4 billion years ago

SUMMARY Palaeomagnetic field intensity measurements, derived from rocks with ages that span geological time, provide a crucial constraint on the evolution of Earth’s deep interior and its magnetic environment. The palaeointensity database PINT has been updated to version v.8.0.0 and includes palaeointensity site-mean records spanning an interval from 50 ka to 4.2 Ga, compiling efforts from the palaeomagnetic community spanning from 1959 to the end of 2019. Nearly all site-mean palaeointensity records have been assessed using the qualitative reliability of palaeointensity (quality of palaeointensity, QPI) framework. This updated database brings together and harmonizes prior QPI and PINT compilation efforts into a unified database referred to as the PINT database, incorporating recent efforts since 2014 to assess QPI. The spatio-temporal distribution of the PINT database is analysed, revealing substantial biases towards young records (from the Brunhes chron) in the Northern hemisphere, and intervals with little to no palaeointensity data with a duration of 10s to 100s of millions of years in the Palaeozoic and Precambrian. General QPI compliance is characterized for the PINT database, which shows that the median QPI scores range from 2 to 3 (out of a total possible score of 10), with a positive trend towards increasing QPI scores in studies published after the year 2000. This illustrates an increasing community awareness of what is required to establish confidence in palaeointensity data and an increasing robustness of the large scale interpretations that can be made with these data. We additionally present a description of the long-term average dipole field strength with descriptive statistics for distinct intervals of Earth history.