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This paper examines the current empirical accounting research paradigm. We ask: In general, do the estimated regressions support the promoted narratives? We focus on a regression model's main variable of interest and consider the extent to which it contributes to the explanation of the dependent variable. We replicate 10 recently published accounting studies, all of which rely on significant t-statistics, per conventional levels, to claim rejection of the null hypothesis. Our examination shows that in eight studies, the incremental explanatory power contributed by the main variable of interest is effectively zero. For the remaining two, the incremental contribution is at best marginal. These findings highlight the apparent overreliance on t-statistics as the primary evaluation metric. A closer examination of the data shows that the t-statistics produced reject the null hypothesis primarily due to a large number of observations (N). Empirical accounting studies often require N > 10,000 to reject the null hypothesis. To avoid the drawback of t-statistics' connection with N, we consider the implications of using Standardized Regressions (SR). The magnitude of SR coefficients indicates variables' relevance directly. Empirical analyses establish a strong correlation between a variable's estimated SR coefficient magnitude and its incremental explanatory power, without reference to N or t-statistics. [ABSTRACT FROM AUTHOR]

The wide distribution of tuff layers, locally named the "green bean rocks" (GBRs) in the Yangtze Block straddling the Early Middle Triassic marine sequence indicates intense volcanic eruption(s). Sr, Nd, and S isotope compositions and trace elements of marine sediments were analyzed spanning the tuff layers to elucidate their responses to the volcanic eruptions and related environmental changes. The Sr isotope compositions of marine sediments are comparable to those of open seawater during the time interval of ca. 245–248 Ma. Sr and Nd isotope compositions of the samples show synchronous increases in the 87Sr/86Sr ratios and εNd(t) values during the deposition of GBRs. The elevated 87Sr/86Sr ratios and εNd(t) values are proposed to be caused by the input of volcanic tephra and increased influx of weathering product of mafic rocks (most likely the Emeishan flood basalts). The S isotope compositions of sulfates exhibit a negative shift in the GBRs, which could possibly be attributed to greater input of lighter 32S from weathering products and volcanic eruptions. The variation of Th/U ratios indicate that the GBRs formed in an anoxic environment, resulting from high marine productivity as a consequence of more nutrients from weathering and volcanic materials. The responses of Sr, Nd, and S isotopes to volcanic eruptions during the Early Middle Triassic indicate this event resulted in adverse effects, namely enhanced eutrophication and low O2 levels, acidic precipitation, toxic components, etc., that could cause ecological destruction both on land and in the sea. Plain Language Summary: A large scale volcanic eruption occurred in South China during the Early Middle Triassic, which is a crucial period for the recovery of biosystems after the end‐Permian mass extinction. Volcanic ashes had fallen to the surface, forming tuff layers which were intercalated with marine sediments. We analyzed Sr, Nd, and S isotopes of marine sediments spanning the tuff layer to elucidate the possible influence on marine and land environments and related Sr, Nd, and S isotopic responses caused by volcanic eruptions. We found that the volcanic eruptions induced intensified weathering on land, deterioration of the environment due to toxic acidic precipitation and toxic components, and enhanced eutrophication and low O2 levels caused by increased nutrients from weathering products and volcanic ashes. Consequently, this volcanic eruption very likely imposed adverse impacts on the ecological recovery during the early Middle Triassic. Key Points: High‐resolution curves of Sr, Nd, and S isotope compositions of the Early to Middle Triassic marine sediments and intercalated tuff layersThe variations of Sr, Nd, and S isotopes show their responses to the volcanic eruptions and the implication of environmental changes [ABSTRACT FROM AUTHOR]

In this research, stir casting was used to create the aluminium alloy (AA7075) composite filled with 10wt.% zirconia (ZrO2) particles as reinforcement. Die sinking electric discharge machining (EDM) was used to examine the machining characteristics of the proposed composite. The machining experiments were executed in accordance with the L9 orthogonal layout. Here, the material removal rate (MRR) and surface roughness (SR) were taken into account as the output responses, and the discharge current (Ip), pulse on-time (Ton), and pulse off-time (Toff) were taken as the machining parameters. To determine the optimal parameter conditions for the output responses, the technique for order preference by similarity to ideal solution (TOPSIS) approach was applied. According to the experimental findings, the optimum settings of the parameters are determined at 15amps of ‘Ip’, 750μs of ‘Ton’ and 50μs of ‘Toff’. ANOVA results stated that ‘Ton’ has the most notable factor with a contribution of 90.85%. The interaction effect of parameters on the responses was shown by the contour plots. The confirmatory experiment was finally conducted at the optimum machining parameter settings, and it was found that the error only occurred in 8.4%. [ABSTRACT FROM AUTHOR]

Electrical parameters are vital for electrical discharge machining (EDM) process performance. The study utilized the combination of Taguchi and grey relational analysis (GRA) to optimize sinking EDM. Optimization of peak current, pulse duration, duty ratio and electrode lifting time affecting material removal rate (MRR), relative electrode wear rate (REWR) and surface roughness (SR) in sinking EDM. Analysis of variance (ANOVA) shows that peak current and pulse duration significantly affect MRR and REWR, respectively. Peak current and pulse duration significantly affect SR. The optimized parameters were subjected to EDM experiments and the results are 8.54% increase in MRR, 11.11% decrease in REWR and 9.42% decrease in SR. It was found that at a peak current of 1A, the discharge pit not only depends on peak current and pulse duration but also on pulse off time. Compared to conventional optimization methods, this study analyzed the microstructure and recast layer of the workpieces. [ABSTRACT FROM AUTHOR]

Machining of AISI 304 enables the customization of parts to meet specific mechanical and aesthetic requirements, ensuring optimal performance and durability in various applications. In this study, electrical discharge machining (EDM) is introduced to machine AISI 304 stainless steel. To accomplish the desired machining characteristics (MRR, SR), different EDM factors are chosen, such as discharge current, pulse on time, and pulse off time. The experiment is planned using central composite design in response surface methodology (RSM). The impact of EDM variables on metal removal rate (MRR) and surface roughness (SR) is examined through surface plot. Regression coefficient values for MRR and SR are 92.37% and 83.28%, respectively, indicating an empirical relation between the factors and responses. The lack of fit values for MRR and SR were 3.87 and 1.49, respectively, which were lower than the average values. Thus, the developed model was sufficient. It was observed that MRR and SR increases with increase in all parameters, but decreases at higher range of parameters. As current and pulse on time increase, the ionization temperature generated in the machining zone which removed more quantity of materials from the workpiece. Due to ionization temperature, more craters and voids formed which made surface irregular and hard, resulted increased SR. At lower level of discharge current and pulse on time, insufficient spark intensity is developed which made cracks and globules on the surface. The estimated error of actual and expected values for MRR and SR are 7.07% and 5.12% respectively. The desirability of optimization was calculated to be 0.9710, indicating that parameters are within acceptable conditions. [ABSTRACT FROM AUTHOR]

This study investigated the effect of adding La–Ce mixed rare earths and Sr on the microstructure and mechanical properties of AlSi10MnMg alloy. The experiment utilized different combinations of modifiers, including single La–Ce rare earths, single Sr, and the combined addition of La–Ce mixed rare earths and Sr. This study compared their effects on grain refinement, the modification of the α-Al phase and eutectic silicon phase, and tensile properties and hardness. The results showed that the combined modification of Sr and mixed rare earth elements significantly refined the grains, optimized the morphology of the α-Al phase and eutectic silicon phase, and improved the overall mechanical properties of the aluminum alloy. Under the combined modification, the addition of 0.02 wt.% Sr and 0.1 wt.% RE (La–Ce mixed rare earths) exhibited the most pronounced refining effect. The secondary dendrite arm spacing (SDAS) was reduced by 59.18%. The eutectic silicon phase transformed from coarse needle-like shapes to fine fibrous or granular forms, with an aspect ratio reduction of 69.39%. Meanwhile, the alloy's tensile strength and hardness were significantly improved. The tensile strength increased to 240 MPa, achieving an increase of 23.08%; the yield strength increased to 111 MPa, achieving an increase of 18.09%; and the elongation reached 7.3%, achieving an increase of 73.81%. This indicates that the proper addition of Sr and mixed rare earths can significantly optimize the microstructure and enhance the mechanical properties of AlSi10MnMg alloy, providing an effective method for the preparation of high-performance heat-treatment-free aluminum alloys. [ABSTRACT FROM AUTHOR]

Copyright of Automobile Technology & Material is the property of Automobile Technology & Material Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The combination of silicone rubber (SR) and ethylene‐propylene‐diene monomer (EPDM) could have an aggregate of their properties. High temperature vulcanized (HTV) is one of the most widely used SR type. This study explores the impact of montmorillonite Cloisite® layered silicate nanoclay on the vulcanization characteristics, mechanical‐dynamical behavior, and thermal properties of the HTV/EPDM blend. For this purpose, varying ratios of the HTV/EPDM compounds were prepared in the range of 100/0, 50/50, and 0/100, with 0, 3, and 5 wt% of Cloisite® using an internal mixer. The X‐ray diffraction results indicate that the mixing time, Cloisite® content and base polymer significantly influence the distance between Cloisite® layers. Cloisite® was found to accelerate the curing system and reduce the difference between minimum and maximum torque. The mechanical analysis of the prepared HTV/EPDM/clay nanocomposites revealed an increase in hardness, tensile strength, and modulus for samples with applied Cloisite® content. The degradation temperature was raised in HTV base samples by the presence of Cloisite®. On the other hand, the degradation temperature was dropped in the EPDM base samples as the amount of Cloisite® increased. In the HTV/EPDM/clay compounds, the degradation temperature was between the degradation temperatures of pure HTV and EPDM rubbers. [ABSTRACT FROM AUTHOR]

This investigation explores the application of electrical discharge machining (EDM) to ceramic composites constructed from Si3N4–TiN (Syalon 501) by testing both square and cylindrical electrodes. Various experimental methods have been employed, including design-of-experiments (DoE), Grey relational analysis (GRA), analysis of variance (ANOVA), confirmation testing, and scanning electron microscopy (SEM), in an effort to optimize machining settings and comprehend their effect on performance. While ANOVA revealed crucial parameter levels influencing overall machining conditions as measured by the grey relational grade (GRG), the sophisticated method of GRA considerably improved the machining characteristics. Significant improvements in the EDM process were shown experimentally, resulting in outstanding results for material removal rate (MRR), surface roughness (SR), and electrode wear rate (EWR). In particular, numerous benefits of the square electrode layout over the more common cylindrical arrangement stood out. All of the aforementioned resulted in an impressively high MRR (measured at 0.0281gm/min), a low EWR (at 0.0020gm/min), and a significant improvement in SR (at 0.3150μm). The GRG value was 0.0163 for the square electrode design, which was excellent, and 0.0025 for the cylindrical electrode, which was significantly better. The optimized parameters were successfully used, especially with the square electrode arrangement, leading to significant improvements in MRR and decreases in EWR. On the other hand, surface quality was negatively affected by larger parameter values, which increased the development of microfractures, particularly when using the square electrode design. In any case, our study provides strong proof that adjusted settings can greatly improve EDM performance, allowing for accurate machining of Si3N4–TiN composites with increased MRR, great surface texture, and reduced electrode wear. In conclusion, our study provides useful information to improve EDM procedures for Si3N4–TiN ceramic composites, as well as practical insights into increasing the efficiency and quality of EDM operations in a variety of industrial sectors. [ABSTRACT FROM AUTHOR]

Copyright of GeSec: Revista de Gestao e Secretariado is the property of Sindicato das Secretarias e Secretarios do Estado de Sao Paulo (SINSESP) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract The wide distribution of tuff layers, locally named the “green bean rocks” (GBRs) in the Yangtze Block straddling the Early Middle Triassic marine sequence indicates intense volcanic eruption(s). Sr, Nd, and S isotope compositions and trace elements of marine sediments were analyzed spanning the tuff layers to elucidate their responses to the volcanic eruptions and related environmental changes. The Sr isotope compositions of marine sediments are comparable to those of open seawater during the time interval of ca. 245–248 Ma. Sr and Nd isotope compositions of the samples show synchronous increases in the 87Sr/86Sr ratios and εNd(t) values during the deposition of GBRs. The elevated 87Sr/86Sr ratios and εNd(t) values are proposed to be caused by the input of volcanic tephra and increased influx of weathering product of mafic rocks (most likely the Emeishan flood basalts). The S isotope compositions of sulfates exhibit a negative shift in the GBRs, which could possibly be attributed to greater input of lighter 32S from weathering products and volcanic eruptions. The variation of Th/U ratios indicate that the GBRs formed in an anoxic environment, resulting from high marine productivity as a consequence of more nutrients from weathering and volcanic materials. The responses of Sr, Nd, and S isotopes to volcanic eruptions during the Early Middle Triassic indicate this event resulted in adverse effects, namely enhanced eutrophication and low O2 levels, acidic precipitation, toxic components, etc., that could cause ecological destruction both on land and in the sea.

Datong Coalfield was intruded by igneous intrusions in both the Indosinian (Late Permian to the end of the Triassic) and the Yanshan (Late Jurassic to the Early Cretaceous) periods，which caused contact metamorphism of the coal seam. Previous studies have shown that Sr is significantly enriched in coal from the 5222 tunnel of the Tashan coal mine. The maximum concentration of Sr in thermally-altered and unaffected coal is 3067 μg/g and 2729 μg/g respectively, and the average concentration of Sr is 1165 μg/g, which is 10.6times of the world average level in hard coal. However, the modes of occurrence of Sr in the Tashan coal still remain unclear. Samples in the 5222 tunnel including coal and intrusive rock were systematically collected. Inductively coupled plasma mass spectrometry (ICP-MS) and X-ray fluorescence spectrometry (XRF) were applied to elucidate Sr concentration variations in the sample; correlation analysis, scanning electron microscope with energy spectrum (SEM-EDS), and sequential chemical extraction procedure (SCEP) were carried out to reveal the occurrence modes of Sr, as well as the characteristics of Sr-bearing minerals. The results demonstrated that Sr exhibits a strong correlation with P2O5 in coal; Sr mainly occurs in phosphate (apatite) and clay minerals that are intimately associated; apatite was distinguished as fluorapatite in the shape of hexagonal columns and hydroxyapatite in the shape of fine scattered particles embedded in the clay minerals.

This study examined the effect of the Sr concentration in SrK/CaO catalysts based on oyster shells for the transesterification of canola oil. The CaO support was obtained by mixing 800 °C calcined oyster shell and limestone. Then, K and Sr were impregnated simultaneously at three different Sr/(Sr + K) molar ratios, 0.2, 0.3, and 0.4, and calcined at 800 °C. XRD, SEM, and Hammett indicators were used to characterize the catalysts. The reaction conditions were 60 °C, 1 h, met/oil = 12.5, and a catalyst loading of 7 wt%. The results showed that a Sr/(Sr + K) = 0.3 produces larger K2Sr(CO3)2 crystals that contribute synergistically to the catalytic activity. At Sr/(Sr + K) > 0.3, the K and Sr are segregated, decreasing the alkaline character and activity. Also, the optimization of WCO transesterification conditions was carried out by Box–Behnken response surface design with SrK/CaO-0.3 catalyst. The theoretical optimal conditions were 70 °C, 1.5 h, and a met/oil = 10, which achieved 79 % of biodiesel yield. Nonetheless, the produced WCO biodiesel did not present acceptable quality, and this reactive system increased the lixiviation of the active phases. [ABSTRACT FROM AUTHOR]

Nowadays, advanced engineering materials are gradually becoming more attractive to the industries because of their high fatigue strength, hardness, thermal shock resistance, attractive strength to weight ratio, etc. Aluminium metal matrix composites (MMCs) have such properties and good electrical conductivity. Therefore, wire electrical discharge machining (WEDM) was found to be a suitable process for machining of such materials. The open gap voltage, pulse-on-time, pulse-off-time, peak current, wire feed rate and wire tension were considered as input process parameters, and experiments were carried out on fabricated hybrid Al/(SiC+ZrO2+ NiTi)-MMC. Taguchi method-based L18 (21x37) mixed orthogonal array was employed for planning of experiments. The process parameters were optimised for material removal rate (MRR) and surface roughness (SR) heights. Confirmation results reveals 61.88%, −28.75% and −20.25% improvement in MRR, Ra and Rt respectively, over initial setting. From analysis of variance (ANOVA), open gap voltage and pulse-on-time were found significant parameters for MRR and SR. The mathematical models for MRR and SR were developed and confirmation test reveals good agreement of it with experimental results. Scanning electron microscopy images reveal that the recast layer thickness was 8.569 µm at optimal MRR setting and 6.113 µm at optimal surface roughness (Ra) setting. [ABSTRACT FROM AUTHOR]

In this present study, stir cast AA7075 composite containing 5 wt.% quantity of rice husk ash was machined through electrical discharge machining process. The effects of variation of different process variables including peak current, pulse on time, and gap voltage along with constant duty cycle on performance attributes such as material removal rate (MRR), tool wear rate (TWR), and surface roughness (SR) were evaluated by differing one parameter at a time. Analysis of results revealed that MRR showed directly proportional relationship with current and decreased with increasing gap voltages. MRR also varied directly with pulse on time upto 300 µs and decreased afterwards. TWR enhanced with increasing peak current and pulse duration whereas insignificant variation of TWR with changing gap voltages was observed. SR was found to be significantly exhibiting increasing trend with increasing current and pulse duration. However, SR exhibited a fluctuating trend with increase in gap voltage. EDM surface was also characterised through SEM. [ABSTRACT FROM AUTHOR]

Powder-Mixed Electrical Discharge Machining (PM-EDM) is one of the latest advancements in EDM process capability augmentation. This procedure involves effectively mixing a suitable material in fine powder form with the dielectric fluid. The dielectric fluid's breakdown properties are enhanced by the additional powder. The objective of the present research is to machine the Ti-35Nb-7Zr-5Ta alloy prepared by powder metallurgy and study the influence of process parameters, such as peak current, pulse-on time, pulse-off time, powder type (Ag, Si, Ag+Si), and powder concentration. The metal removal rate and SR represent the response parameters. The Taguchi approach was followed to design the experiments. The five-factor three-level design was chosen to use the Taguchi L27 orthogonal array. It was found that the addition of Ag, Si, or Ag+Si powders to the dielectric fluid enhanced the metal removal rate and the surface finish for this alloy. The addition of Ag powder to the dielectric fluid gave a higher Material Removal Rate (MRR) and a lower SR compared to Si or Ag+Si powders. Powder concentration and pulse current are the most effective parameters on MRR and SR followed by powder type, pulse-on, and pulse-off. The maximum Grey Relational Grade (GRG) exists at (I=5 A, Ton=9 µs, Toff=37 µs, PT=Ag, PC=20 g/L). These are the optimal conditions for PM-EDM of the Ti-35Nb-7Zr-5Ta alloy that give maximum MRR with minimum SR. [ABSTRACT FROM AUTHOR]

Copyright of Hungarian Medical Journal / Orvosi Hetilap is the property of Akademiai Kiado and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bányászati és Kohászati Lapok - Kohászat is the property of Hungarian Mining & Metallurgical Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The adoption of Stereo Imaging technology within endoscopic procedures represents a transformative advancement in medical imaging, providing surgeons with depth perception and detailed views of internal anatomy for enhanced diagnostic accuracy and surgical precision. However, the practical application of stereo imaging in endoscopy faces challenges, including the generation of low-resolution and blurred images, which can hinder the effectiveness of medical diagnoses and interventions. Our research introduces an endoscopic image SR model in response to these specific. This model features an innovative feature extraction module and an advanced cross-view feature interaction module tailored for the intricacies of endoscopic imagery. Initially trained on the SCARED dataset, our model was rigorously tested across four additional publicly available endoscopic image datasets at scales 2, 4, and 8, demonstrating unparalleled performance improvements in endoscopic SR. Our results are compelling. They show that our model not only substantially enhances the quality of endoscopic images but also consistently surpasses other existing methods like E-SEVSR, DCSSRNet, and CCSBESR in all tested datasets, in quantitative measures such as PSNR and SSIM, and in qualitative evaluations. The successful application of our SR model in endoscopic imaging has the potential to revolutionize medical diagnostics and surgery, significantly increasing the precision and effectiveness of endoscopic procedures. The code will be released on GitHub and can be accessed at https://github.com/cu-vtrg-lab/Saliency-Aware-Deep-Learning-Approach-for-Enhanced-Endoscopic-Image-SR.

Hepatitis B is a major global challenge, but there is a lack of epidemiological research on hepatitis B incidence from a change point perspective. This study aimed to fill this gap by identifying significant change points and trends in hepatitis time series in Xinjiang, China. The datasets were obtained from the Xinjiang Information System for Disease Control and Prevention. The Mann-Kendall-Sneyers (MKS) test was used to detect change points and trend changes on the hepatitis B time series of 14 regions in Xinjiang, and the effectiveness of this method was validated by comparing it with the binary segmentation (BS) and segment regression (SR) methods. Based on the results of change point analysis, the prevention and control policies and measures of hepatitis in Xinjiang were discussed. The results showed that 8 regions (57.1%) with at least one change fell within the 95% confidence interval (CI) in all 14 regions by the MKS test, where five regions (Turpan (TP), Hami (HM), Bayingolin (BG), Kyzylsu Kirgiz (KK), Altai (AT)) were identified at one change point, two change points existed for two regions (Aksu (AK), Hotan (HT)) and three change points was detected in 1 region (Bortala (BT)). Most of the change points occurred at both ends of the sequence. More change points indicated an upward trend in the front half of the sequence, while in the latter half, many change points indicated a downward trend prominently. Finally, in comparing the results of the three change point tests, the MKS test showed a 61.5% agreement (8/13) with the BS and SR.

The influence of wire electrical discharge machining (WEDM) factors on the WE43 magnesium alloy is experimentally investigated in this work. Voltage, peak current, pulse-on time, and pulse-off time, are some of the factors taken into consideration in the study. The goal of the study is to understand how the output responses like material removal rate (MRR), surface roughness (SR), and development of recast layers are affected by the factors like voltage, peak current, pulse-on time and pulse-off time. The experimental set-up used a wire electrical discharge machine with a brass wire electrode and a workpiece made of the WE43 magnesium alloy. The L27 orthogonal array was used to alter the selected parameters through a series of experiments. The findings of the experimental investigation showed a strong link between the output responses and the electrical discharge machining (EDM) parameters. Peak current was discovered to have a direct correlation with the rate of material removal, with greater currents resulting in faster machining. SR and MRR were affected by pulse-on time and pulse-off time. Voltage had a direct impact on the development and thickness of the recast layer, with higher voltages favoring thinner recast layers. [ABSTRACT FROM AUTHOR]

The need for innovative materials has increased in the current era of research and technology. Advanced materials such as shape memory alloys are in great supply in the industrial and commercial sectors. It is a unique and very uncommon metal alloy that can regain its original shape after being subjected to extremely low temperatures. SMAs may be classified as NiTi-based, Cu-based, or Fe-based depending on the metal-combination. Alloys based on copper have excellent elasticity and damping properties that allow them to withstand a broad variety of temperatures. Using the EDM method, this research investigates the effects of Ton, Toff, Ip, and GV on SR and dimensional deviation. 8.87 mm and 4.79 mm are the greatest and lowest values of SR that can be found, respectively. The dimensional deviation ranges from 0.03 mm to 0.28 mm, with a minimum value of 0.03 mm. Ton and Ip have a greater influence on surface roughness than Toff and GV. Images from SEM of workpiece samples show the production of micro-cracks as-well-as macro-ridges on the surface of the sample during EDM operations. SEM micrographs depicted the deviation in the dimensions of the workpiece samples after EDM operations on Cu-based SMA samples. [ABSTRACT FROM AUTHOR]

A geochronological and isotope–geochemical study of alkaline basalts from three areas of young magmatism within the northeastern part of the Arabian Plate (Southeastern Turkey), Batman, Kurtalan and Alemdağ, was carried out. The obtained isotope data have indicated that the volcanism in the studied region developed over a 5-Ma period from the end of Miocene to the middle Pleistocene during four pulses separated by breaks in magmatic activity: 6.1–4.9 Ma (Batman area, hawaiites), ~3.0 Ma (Alemdağ plateau, phase I, basalts), 2.0–1.9 Ma (Alemdağ plateau, phase II, tephrites), and 1.5–1.3 Ma (Alemdağ plateau, phase III, basalts; Kurtalan area, basalts). A comparison of spatial–temporal changes of magmatic activity evolution in the studied part of the Arabian Plate and within the largest basalt plateau of Arabian foreland, Karacadağ Plateau, located to the west, was carried out. The results of Sr–Nd–Pb isotope–geochemical studies show that the development of young basalt volcanism in the Arabian Plate was characterized at different time by the contribution of various mantle sources in magma generation under this region. Initial pulses of magmatic activity are associated with melting of Arabian subcontinental lithospheric mantle (SCLM). The processes of fractional crystallization combined with crustal assimilation (AFC) have played an important role in the petrogenesis of lavas as well. Later, a deep mantle source (PREMA) with a depleted isotopic composition played a leading role in the formation of basaltic magmas of increased alkalinity. The melts generated by this source were mixed with the SCLM material in various proportions at different stages of magmatism with a limited participation of AFC processes in the petrogenesis of the rocks. It was concluded that young basalt volcanism of increased alkalinity in the northeast of the Arabian Plate is not related to the collision of the Eurasian and Arabian plates genetically, but presumably manifested here as a result of the migration of the initial rift geodynamic setting from the Red Sea basin to the north along Levantine and East Anatolian transform faults due to directed convection flows in the lower part of mantle under this part of the Earth. [ABSTRACT FROM AUTHOR]

The primary objective of this study is to investigate and develop a rapid and effective method for the immobilization of Sr in the event of a nuclear leakage incident. Coal gangue, an underutilized form of solid waste from the coal industry, can be used as a raw material for curing Sr due to its high content of silica–alumina oxides. In the present study, Sr was successfully solidified in cancrinite synthesized using a hydrothermal method with coal gangue as raw material. A stable cancrinite phase was formed at a relative alkali concentration of more than 6 M. When the Sr/Al(Si) ratio was <1/6, cancrinite was the only stable phase that varied with the hydrothermal temperature and time. When the Sr/Al(Si) ratio increased to 1/2, the cancrinite phase completely disappeared, and a new strontium feldspar phase (SrAl2Si2O8) appeared. PCT leaching experiments showed that when Sr/Al(Si) < 1/6, the Sr leaching rate of Sr-cancrinite samples obtained by hydrothermal synthesis at 180 °C for 24 h was very low. [ABSTRACT FROM AUTHOR]

Improving the accuracy of monitoring cropland CO2 exchange at heterogeneous spatial scales is of high importance to limit spatial and temporal uncertainty of terrestrial carbon (C) dynamic estimates. A combination of field scale eddy covariance EC) CO2 flux data and spatially matched Sentinel-2 derived vegetation indices (VIs) was tested as an approach to upscale agricultural C flux. The ability of different VIs to estimate daily net ecosystem exchange (NEE) and gross primary productivity GPP) based on linear regression models was assessed. Most VIs showed high (>0.9) and statistically significant (p<0.001) correlations with GPP and NEE although some VIs deviated from the seasonal pattern of CO2 exchange. In contrast, correlations between ecosystem respiration (Reco) and VIs were weak and statistically not significant, and no attempt was made to estimate Reco from VIs. Linear regression models explained generally more than 80% and 70% of the variability of NEE and GPP, respectively, with high variability amongst the individual VIs. The performance in estimating daily C fluxes varied amongst VIs depending on C flux component (NEE or GPP) and observation period. RMSE values ranged from 1.35 g C m-2 d-1 using the Green Normilized Difference Vegetation Index (GNDVI) for NEE to 5 g C m-2 d-1 using the Simple Ratio SR) for GPP. This equated to an underestimated net C uptake of only 41 g C m-2 (18%) and an overestimation of gross C uptake of 854 g C m-2 (73%). Differences between measured and estimated C fluxes were mainly explained by the diversion of the C flux and VI signal during winter, when C uptake stayed low while VI values indicated an increased C uptake due to relatively high crop leaf area. Overall, results exhibited similar error margins as mechanistic crop models. Thus, they indicated suitability and developability of the proposed approach to monitor cropland C exchange with satellite derived VIs. [ABSTRACT FROM AUTHOR]

Petrogeochemical data on basalts (lithophile elements and Sr–Nd–Pb isotopes, liquidus olivine and spinel compositions) from the transition zone of the Southwest Indian Ridge (SWIR) in the Du Toit–Andrew Bain fault zone indicate significant differences in their composition. Tholeiites enriched in Na and depleted in Fe (Na-TOR genetic type) are developed within the rift valley adjacent to the faults. Deep-type basalts (TOR-1) are present in the western wall of the Andrew Bain Fault. The outpouring of these magma types reflects a possible change in geodynamic setting during formation of this zone: from deep and high temperature to shallower magma generation conditions (Sushchevskaya et al., 2022). Differences in the primary melts of tholeiites from the rift valley and the Andrew Bain Transform Fault are also traced in the composition of liquidus olivine. The olivines from rift valley are similar to the typical Na-TOR olivines with Mg number of Fo88-87, low Ni and elevated Mn contents. On the contrary, olivines in tholeiite from the Andrew Bain Fault Zone are enriched in Ni and depleted in Mn, which may indicate the involvement of pyroxenite in melt generation. This component is either oceanic lithosphere recycled through the deep mantle or fragments of previously formed oceanic crust, which were subsequently involved in melting during the spreading axes jumping. A similar process is typical of the Bouvet Triple Junction, where the trace-element composition of olivine shows significant heterogeneity. The radiogenic composition of Pb and Sr of the Andrew Bain Fault tholeiites are similar to those of enriched magmas from such Indian Ocean rises as Crozet, Marion and Bouvet, but differ from those of the Conrad and Af. Nikitin rises. The source of such tholeiite melts is close in composition to the model HIMU type (with high U/Pb), which likely contains an admixture of EM-II component (with elevated Rb/Sr). [ABSTRACT FROM AUTHOR]

The occurrence of bone disorders is steadily increasing worldwide. Bone tissue engineering (BTE) has emerged as a promising alternative to conventional treatments of bone defects, developing bone scaffolds capable of promoting bone regeneration. In this research, biomimetic scaffolds based on ion-substituted calcium phosphates, derived from cuttlefish bone, were prepared using a hydrothermal method. To synthesize Mn2+-substituted scaffolds, three different manganese concentrations (corresponding to 1, 2.5, and 5 mol% Mn substitutions for Ca into hydroxyapatite) were used. Also, syntheses with the simultaneous addition of an equimolar amount (1 mol%) of two (Mg2+ and Sr2+) or three ions (Mn2+, Mg2+, and Sr2+) were performed. A chemical, structural, and morphological characterization was carried out using X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. The effects of the ion substitutions on the lattice parameters, crystallite sizes, and fractions of the detected phases were discussed. Multi-substituted (Mn2+, Mg2+, and Sr2+) scaffolds were coated with polycaprolactone (PCL) using simple vacuum impregnation. The differentiation of human mesenchymal stem cells (hMSCs), cultured on the PCL-coated scaffold, was evaluated using histology, immunohistochemistry, and reverse transcription–quantitative polymerase chain reaction analyses. The expression of collagen I, alkaline phosphatase, and dentin matrix protein 1 was detected. The influence of PCL coating on hMSCs behavior is discussed. [ABSTRACT FROM AUTHOR]

The method of cooling aqueous solution and the Sankaranarayanan–Ramasamy technique were used for the preparation of urea doped KDP single crystals with additive concentrations of 0.1, 0.5, and 1 mol%. The single crystals were grown unidirectionally from seeds that were inclined to type I phase-matching angle, the requirement for maximal second harmonic generation (SHG) efficiency. The analysis employed to study the chemical composition, crystal structure, bonding vibrations, and optical properties of the crystal samples was energy-dispersive X-ray spectroscopy, X-ray diffraction patterns, Raman spectroscopy, ultraviolet-visible spectroscopy, and SHG measurement respectively. The differences in chemical composition, crystal structure, optical transmittance, and SHG efficiency of the parts on each urea doped KDP single crystal rod were explained by the variation in the growth sector boundary. This work aims to improve the second-order nonlinear optical coefficient of KDP crystals and suggests which part of the urea doped KDP crystal rod grown by the SR technique is most acceptable for frequency-doubling applications. [ABSTRACT FROM AUTHOR]

The area of metallurgy has witnessed many advancements in the development of novel electrically conductive materials that shows exceptional mechanical as well as thermal properties. Nonetheless, traditional machining techniques encounter difficulties while machining hard materials. In order to address this limitation, electrical discharge machining (EDM) has emerged as a widely utilised method for machining of intricate geometries and the hard materials. EDM is a category of thermo-electric process that employs rapid recurring sparks between the electrode and work material, eroding the material without direct contact. As there is no contact between the electrode and work material, the issues related to machining defects such as mechanical stresses, clattering, and vibration eliminates. However, EDM have some limitations like poor surface finish and low volumetric material removal. To overcome these kind of limitations, the introduction of metallic powder into the dielectric fluid has been explored in powder-mixed electric discharge machining (PMEDM). This introduction of powder during the process leads to enhance the conductive strength of the fluid and increases the spark gap distance between the electrode and counter material. The inclusion of powder has a significant impact on the performance of the EDM process. Hence, this review aims to facilitate researchers in comprehending the concept of PMEDM and to examine the process parameters required to achieve improved levels of quality. [ABSTRACT FROM AUTHOR]

This study fills an important gap in the literature by providing causal evidence of the impact of relaxing financial constraints on corporate social responsibility (CSR). To isolate this causal link, we examine the enactment of anti-recharacterization laws in some U.S. states, an exogenous shock that has strengthened creditor rights and eased financial constraints of the treated firms. Our difference-in-difference analysis suggests that relaxing financial constraints leads to higher CSR. This evidence is more pronounced in financially constrained firms, firms with more analyst dispersion and increased volatility of cash flows. We also find that the most impacted firms are those with increased post-shock debt financing. In sum, our evidence suggests that easing access to external finance drives corporate goodness, in particular in firms that value external financing. [ABSTRACT FROM AUTHOR]

This study investigated the effect of adding La–Ce mixed rare earths and Sr on the microstructure and mechanical properties of AlSi10MnMg alloy. The experiment utilized different combinations of modifiers, including single La–Ce rare earths, single Sr, and the combined addition of La–Ce mixed rare earths and Sr. This study compared their effects on grain refinement, the modification of the α-Al phase and eutectic silicon phase, and tensile properties and hardness. The results showed that the combined modification of Sr and mixed rare earth elements significantly refined the grains, optimized the morphology of the α-Al phase and eutectic silicon phase, and improved the overall mechanical properties of the aluminum alloy. Under the combined modification, the addition of 0.02 wt.% Sr and 0.1 wt.% RE (La–Ce mixed rare earths) exhibited the most pronounced refining effect. The secondary dendrite arm spacing (SDAS) was reduced by 59.18%. The eutectic silicon phase transformed from coarse needle-like shapes to fine fibrous or granular forms, with an aspect ratio reduction of 69.39%. Meanwhile, the alloy’s tensile strength and hardness were significantly improved. The tensile strength increased to 240 MPa, achieving an increase of 23.08%; the yield strength increased to 111 MPa, achieving an increase of 18.09%; and the elongation reached 7.3%, achieving an increase of 73.81%. This indicates that the proper addition of Sr and mixed rare earths can significantly optimize the microstructure and enhance the mechanical properties of AlSi10MnMg alloy, providing an effective method for the preparation of high-performance heat-treatment-free aluminum alloys.

Tumors in the brain and pancreas are formed by abnormal cells accumulating in a tissue mass in the human body. The standard technique for MRI tumor detection and categorization would be to investigate them utilizing MR medical images. Due to a discrepancy among many brain and image characteristics, an MR picture is segmented at the early stage of diagnosis. The tumor identification framework is processed in the following order: The initial pre-processing (or) filtering is carried out using a Modified Decision-Based Coupled Windows Median Filter (MDBCWMF) technique. This stage's output is transmitted to a unique Distance Metric-based variant of the Fuzzy C-Means algorithm for segmenting MDM-FCM. This method results in a lower segmentation error. The image is then feature extracted using a Gray-Level Co-Occurrence Matrix (GLCM) algorithm and classified using a parameterized combination of Back Propagation Neural Network (BPNN) and Sparse Representation (SR) approaches known as Dynamic Score Level Integration (DSLI). Compared to other state-of-the-art methodologies, MDM-FCM segmented yields 0.9674 and 0.9481 in classification yield 97.84% and 95.62% accuracy for brain and pancreas images, experimental valuation being done with Datasets from TCIA. [ABSTRACT FROM AUTHOR]