bluuebunny/crossref_metadata_2025 huggingface dataset:
Petrogenesis and Tectonic Evolution of Huashigou Granitoids in the South Qilian Orogen, NW China: Constraints from Geochronology, Geochemistry, and Sr–Nd–Hf–O Isotopes
Authors: Wang Yuxi , Chen Wanfeng , Wang Jinrong , Jia Zhilei , Tang Qingyan , Di Pengfei
Published: January 2024

The origin of granitic rocks from the South Qilian orogenic belt is of great significance for understanding the continental tectonic framework of Western China. Currently, scholars have different opinions on the tectonic evolution of the South Qilian. Huashigou granite, which exhibits multiple intrusive episodes, is a suitable example for studying the tectonic evolution of the South Qilian. New zircon U–Pb ages and the whole-rock elemental and Sr–Nd–Hf–O isotopic compositions of Huashigou granitic rocks are presented here to investigate their petrogenesis and discuss the tectonic implications for the evolution of the South Qilian orogenic belt. LA-ICP-MS zircon U–Pb dating yielded crystallization ages of 368.7 ± 3.5 Ma, 261.5 ± 0.63 Ma, and 262.2 ± 1.4 Ma for granodiorites from the Hua1 pluton, quartz diorites from the Hua2 pluton, and porphyritic tonalites from the Hua4 pluton, respectively. Late Devonian granodiorites from the Hua1 pluton belonged to the metaluminous calc-alkaline series and were characterized by an enrichment in LREEs, a depletion in HREEs, negative Eu anomalies, and Sr/Y ratios of 9.17 to 11.67. They showed (87Sr/86Sr)i ratios of 0.712356 to 0.71195, εNd(t) values of −6.56 to −6.14, and an εHf(t) value of −2.06. Middle Permian granitic rocks mainly consisted of quartz diorites and porphyritic tonalites, which are part of the metaluminous tholeiitic series and weakly peraluminous tholeiitic series, respectively. Quartz diorites from the Hua2 pluton were characterized by an enrichment in LREEs, depletions in HREEs and HESEs, weak negative Eu anomalies, and Sr/Y ratios of 13.25 to 14.79. They showed (87Sr/86Sr)i ratios of 0.705905 to 0.705971, εNd(t) values of +0.78 to +0.82, and a δ18OV-SMOW value of 12.4‰. Porphyritic tonalites of the Hua4 pluton were characterized by an enrichment in LREEs, depletions in HREEs and HESEs, weak negative Eu anomalies, and Sr/Y ratios of 9.22 to 12.74. They showed (87Sr/86Sr)i ratios of 0.719528, εNd(t) values of −8.57, and a δ18OV-SMOW value of 11.8‰. We can conclude that Late Devonian granodiorites were derived from the partial melting of enriched and shallow-depth crustal materials, whereas Middle Permian granitic rocks were formed by the delamination of a thickened lower crust after the closure of the Paleo-Tethys Ocean, which caused the underplating of mantle-derived basaltic magma, inducing the partial melting of the lower crust at different depths. Our results show that there were at least two important stages of compressional and extensional tectonic switches in the South Qilian orogenic belt during the Late Paleozoic Era, and the evolution of Altyn Tagh–Qilian–North Qaidam had evident stages.
A Chronological Study of the Miocene Shanwang Diatomaceous Shale in Shandong Province, Eastern China
Authors: Wei Shuhao , Jiang Zongkai , Yu Jifeng , Jia Haibo , Liu Tianjiao , Jiang Zihao , Zhao Bo
Published: January 2024

The varve chronological approach has been applied to older ages (pre-Quaternary) in the Shanwang Basin for the first time. This study focuses on the analysis of diatom shale from the Shanwang Basin, which was formed in Maar Lake (a volcanic crater basin, often filled by a lake). The lacustrine sediments of the basin encapsulate comprehensive geological information. By identifying species and providing systematic paleontological descriptions of diatoms in the profile, two genera and seven species were recognized. A microscopic examination of the thin sections revealed five types of laminae and couplets. On this basis, the study adopted the artificial semi-automatic counting method of the laminae. The calculation results show that the age of the diatom shale section in the Shanwang Basin is 18.524–17.985 Myr B.P, the deposition time is 0.54 Myr, and the deposition rate is 4.06 cm/Kyr. Finally, through the comparative discussion of various dating methods, it can be concluded that the varve chronology is a more accurate and reliable dating method than other dating methods. The research findings contribute to our understanding of the geological history of the region.
Pharmacokinetic, Tissue Distribution, Metabolite, and Toxicity Evaluation of the Matrine Derivative, (6aS, 10S, 11aR, 11bR, 11cS)-10-Methylaminododecahydro-3a, 7a-Diaza-benzo (de) Anthracene-8-thione
Authors: Li Liuyan , Lu Fangfang , Ding Shuqin , Wang Xiaoying , Wang Weibiao , Zhang Wannian , Xu Weiheng , Zhuang Chunlin , Miao Zhenyuan , Ma Xueqin
Published: January 2024

MASM, a structurally modified derivative of matrine, exhibits superior efficacy in reducing inflammation and liver injury in rats when compared to matrine. This study aims to investigate the pharmacokinetic profile and acute toxicity of MASM. Pharmacokinetic results revealed that MASM exhibited rapid absorption, with a Tmax ranging from 0.21 ± 0.04 h to 1.31 ± 0.53 h, and was eliminated slowly, with a t1/2 of approximately 10 h regardless of the route of administration (intravenous, intraperitoneal, or intragastric). The absolute intragastric bioavailability of MASM in rats was determined to be 44.50%, which was significantly higher than that of matrine (18.5%). MASM was detected in all rat tissues including the brain, and through the utilization of stable isotope-labeled compounds and standard references, ten metabolites of MASM, namely sophocarpine, oxysophocarpine, and oxymatrine, were tentatively identified. The LD50 of MASM in mice was determined to be 94.25 mg/kg, surpassing that of matrine (83.21 mg/kg) based on acute toxicity results. Histopathological and biochemical analysis indicated no significant alterations in the primary organs of the low- to medium-dosage groups of MASM. These findings provide valuable insights into the efficacy and toxicity profile of MASM.
Fractionation and Lability of Phosphorus Species in Cottonseed Meal-Derived Biochars as Influenced by Pyrolysis Temperature
Authors: Guo Mingxin , He Zhongqi , Tian Jing
Published: January 2024

Defatted cottonseed meal (CSM), the residue of cottonseeds after oil extraction, is a major byproduct of the cotton industry. Converting CSM to biochar and utilizing the goods in agricultural and environmental applications may be a value-added, sustainable approach to recycling this byproduct. In this study, raw CSM was transformed into biochar via complete batch slow pyrolysis at 300, 350, 400, 450, 500, 550, and 600 °C. Thermochemical transformation of phosphorus (P) in CSM during pyrolysis was explored. Fractionation, lability, and potential bioavailability of total P (TP) in CSM-derived biochars were evaluated using sequential and batch chemical extraction techniques. The recovery of feed P in biochar was nearly 100% at ≤550 °C and was reduced to <88% at 600 °C. During pyrolysis, the organic P (OP) molecules predominant in CSM were transformed into inorganic P (IP) forms, first to polyphosphates and subsequently to orthophosphates as promoted by a higher pyrolysis temperature. Conversion to biochar greatly reduced the mobility, lability, and bioavailability of TP in CSM. The biochar TP consisted of 9.3–17.9% of readily labile (water-extractable) P, 10.3–24.1% of generally labile (sequentially NaHCO3-extractable) P, 0.5–2.8% of moderately labile (sequentially NaOH-extractable) P, 17.0–53.8% of low labile (sequentially HCl-extractable) P, and 17.8–47.5% of residual (unextractable) P. Mehlich-3 and 1 M HCl were effective batch extraction reagents for estimating the “readily to mid-term” available and the “overall” available P pools of CSM-derived biochars, respectively. The biochar generated at 450 °C exhibited the lowest proportions of readily labile P and residual P compounds, suggesting 450 °C as the optimal pyrolysis temperature to convert CSM to biochar with maximal P bioavailability and minimal runoff risk.
In Silico Design, Synthesis, and Evaluation of Novel Enantiopure Isoxazolidines as Promising Dual Inhibitors of α-Amylase and α-Glucosidase
Authors: Alhawday Fahad , Alminderej Fahad , Ghannay Siwar , Hammami Bechir , Albadri Abuzar E. A. E. , Kadri Adel , Aouadi Kaiss
Published: January 2024

Isoxazolidine derivatives were designed, synthesized, and characterized using different spectroscopic techniques and elemental analysis and then evaluated for their ability to inhibit both α-amylase and α-glucosidase enzymes to treat diabetes. All synthesized derivatives demonstrated a varying range of activity, with IC50 values ranging from 53.03 ± 0.106 to 232.8 ± 0.517 μM (α-amylase) and from 94.33 ± 0.282 to 258.7 ± 0.521 μM (α-glucosidase), revealing their high potency compared to the reference drug, acarbose (IC50 = 296.6 ± 0.825 µM and 780.4 ± 0.346 µM), respectively. Specifically, in vitro results revealed that compound 5d achieved the most inhibitory activity with IC50 values of 5.59-fold and 8.27-fold, respectively, toward both enzymes, followed by 5b. Kinetic studies revealed that compound 5d inhibits both enzymes in a competitive mode. Based on the structure–activity relationship (SAR) study, it was concluded that various substitution patterns of the substituent(s) influenced the inhibitory activities of both enzymes. The server pkCSM was used to predict the pharmacokinetics and drug-likeness properties for 5d, which afforded good oral bioavailability. Additionally, compound 5d was subjected to molecular docking to gain insights into its binding mode interactions with the target enzymes. Moreover, via molecular dynamics (MD) simulation analysis, it maintained stability throughout 100 ns. This suggests that 5d possesses the potential to simultaneously target both enzymes effectively, making it advantageous for the development of antidiabetic medications.
Synthesis of AZO-Coated ZnO Core–Shell Nanorods by Mist Chemical Vapor Deposition for Wastewater Treatment Applications
Authors: Wai Htet Su , Ikuta Tomoya , Li Chaoyang
Published: January 2024

AZO-coated ZnO core–shell nanorods were successfully fabricated using the mist chemical vapor deposition method. The influence of coating time on the structural, optical, and photocatalytic properties of zinc oxide nanorods was investigated. It was observed that the surface area of AZO-coated ZnO core–shell nanorods increased with an increase in coating time. The growth orientation along the (0001) crystal plane of the AZO thin film coating was the same as that of zinc oxide nanorods. The crystallinity of AZO-coated ZnO core–shell nanorods was significantly improved as well. The optical transmittance of AZO-coated ZnO core–shell nanorods was greater than 55% in the visible region. The degradation efficiency for methyl red dye solution increased with an increase in coating time. The highest degradation efficiency was achieved by AZO-coated ZnO core–shell nanorods with a coating duration of 20 min, exhibiting a degradation rate of 0.0053 min−1. The photodegradation mechanism of AZO-coated ZnO core–shell nanorods under ultraviolet irradiation was revealed.
Effects of Temperature, Axial Ligand, and Photoexcitation on the Structure and Spin-State of Nickel(II) Complexes with Water-Soluble 5,10,15,20-Tetrakis(1-methylpyridinium-4-yl)porphyrin
Authors: Major Máté Miklós , Valicsek Zsolt , Horváth Ottó
Published: January 2024

Water-soluble metalloporphyrins, depending on the metal center, possess special spectral, coordination, and photochemical features. In nickel(II) porphyrins, the Ni(II) center can occur with low-spin or high-spin electronic configuration. In aqueous solution, the cationic nickel(II) complex (Ni(II)TMPyP4+, where H2TMPyP4+ = 5,10,15,20-tetrakis(1-methylpyridinium-4-yl)porphyrin), exists in both forms in equilibrium. In this study, an equilibrium system involving the low-spin and high-spin forms of Ni(II)TMPyP4+ was investigated via application of irradiation, temperature change, and various potential axial ligands. Soret band excitation of this aqueous system, in the absence of additional axial ligands, resulted in a shift in the equilibrium toward the low-spin species due to the removal of axial solvent ligands. The kinetics and the thermodynamics of the processes were also studied via determination of the rate and equilibrium constants, as well as the ΔS, ΔH, and ΔG values. Temperature increase had a similar effect. The equilibrium of the spin isomers was also shifted by decreasing the solvent polarity (using n-propanol) as well as by the addition of a stronger coordinating axial ligand (such as ammonia). Since triethanolamine is an efficient electron donor in Ni(II)TMPyP4+-based photocatalytic systems, its interaction with this metalloporphyin was also studied. The results promote the development of efficient photocatalytic systems based on this complex.
Cu(II) Coordination Polymers Containing Mixed Ligands with Different Flexibilities: Structural Diversity and Iodine Adsorption
Authors: Lin Shu-Yu , Shen Yi-Lin , Chen Wei-Hao , Govindaraj Manivannan , Chen Jhy-Der
Published: January 2024

Reactions of N,N′-bis(3-methylpyridyl)oxalamide (L1), N,N’-bis(3-methylpyridyl)adipoamide (L2) and N,N’-bis(3-methylpyridyl)sebacoamide (L3) with tricarboxylic acids and Cu(II) salts afforded {[Cu(L1)(1,3,5-HBTC)]·H2O}n (1,3,5-H3BTC = 1,3,5-benzenetricarboxylic acid), 1, {[Cu1.5(L2)1.5(1,3,5-BTC)(H2O)2]·6.5H2O}n, 2, [Cu(L2)0.5(1,3,5-HBTB)]n (1,3,5-H3BTB = 1,3,5-tri(4-carboxyphenyl)benzene), 3, [Cu4(L3)(OH)2(1,3,5-BTC)2]n, 4, {[Cu3(L3)2(1,3,5-BTB)2]·2.5MeOH·2H2O}n, 5, and {[Cu3(L3)2(1,3,5-BTB)2 ]·DMF·2H2O}n, 6, which have been structurally characterized by using single crystal X-ray crystallography. Complexes 1–4 form a 2D layer with the {44.62}-sql topology, a 2D layer with the (4.62)2(42.62.82)-bex topology, a three-fold interpenetrated 3D net with the (412·63)-pcu topology and a 3D framework with the (410·632·83)(42·6)2(43·63) topology, respectively, whereas 5 and 6 are 3D frameworks with the (63)2(64·82)(68·85·102) topology. Complex 5 shows a better iodine adsorption factor of 290.0 mg g−1 at 60 °C for 360 min than the other ones, revealing that the flexibility of the spacer ligand governs the structural diversity and the adsorption capacity.
Molecular Dynamics Simulation Study on the Occurrence of Shale Oil in Hybrid Nanopores
Authors: Fang Yujia , Li Zhongxiao , Yang Erlong , Sha Mingyu , Song Shuling
Published: January 2024

The molecular dynamics simulation was used to simulate the influence of the composite wall stacking effect on shale oil occurrence. The kerogen-illite heterogeneous wall pore model was established to study the effects of temperature, pore size, and wall component ratio on the adsorption ratio and diffusion capacity of shale oil. The calculation results show that the fluid density distribution in the hybrid nanopore is not uniform. When the pore size increases, the proportion of the first adsorption layer to the total adsorption amount decreases rapidly, and the phenomenon of the “solid-like layer” of shale oil in small pores is more obvious. In addition, increases in temperature have little effect on the density peak of the first adsorption layer. With increases in organic matter content in the shale pore model, the diffusion coefficient of fluid decreases gradually, along with adsorption capacity. The influence of the irregular arrangement of kerogen molecules on the adsorption of shale oil is greater than the influence of surface roughness caused by illite on the adsorption.
Vitamin D Status among Patients Admitted to a Geriatric Ward—Are Recommendations for Preventing Its Deficiency Effective Enough?
Authors: Lech Maksymilian Adam , Warpechowski Marcin , Wojszel Aleksandra , Rentflejsz Justyna , Świętek Marta , Wojszel Zyta Beata
Published: January 2024

Despite a decade of available recommendations aimed at preventing vitamin D (VD) deficiency in Poland, the efficacy of these measures among community-dwelling older individuals remains inconsistent. The PolSenior2 study provided valuable insights into VD status among community-dwelling older individuals in Poland. However, it is important to note that this research did not include the elderly living in care institutions. Therefore, our study concentrates on evaluating VD status in older patients admitted to a geriatrics ward to indirectly assess their adherence to existing recommendations and preventive actions in this particular setting (whether they translate into health-promoting behaviors (i.e., taking vitamin D supplements) and whether the recommended, optimal 25(OH)D concentration values are achieved). This approach offers a comprehensive understanding of VD status in a previously understudied population. We aimed to evaluate VD status in patients aged 70 and above within the geriatrics ward, exploring its association with age, sex, BMI, and the use of VD supplements. The study involved the measurement of serum VD concentration in 240 individuals. Of these participants, 177 (73.8%) were women, and 193 (80.4%) were over 75 years old. The median 25(OH)D concentration was found to be 22.95 (IQR, 13.7–33.0) ng/mL. Notably, profound deficiency (<10 ng/mL) was noted in 15% of the participants, while 67.5% exhibited VD inadequacy (<30 ng/mL). It is worth mentioning that only 18.3% of individuals took VD supplements preadmission. Insufficiency was more prevalent in nonsupplemented individuals (70.9% vs. 52.3%, p = 0.02) and those with a BMI ≥30 kg/m2 (76.2% vs. 59.2%, p = 0.007). The logistic regression model demonstrated that obese patients had over two times higher odds of VD inadequacy (OR = 2.21, p = 0.0074), as did nonsupplemented individuals (OR = 2.23, p = 0.0187). The high prevalence of VD deficiency and inadequacy in geriatric ward admissions emphasizes the urgent need for targeted interventions and enhanced education for older adults, caregivers, and physicians to improve adherence to preventive supplementation practices.
Intestinal Morphology and Glucose Transporter Gene Expression under a Chronic Intake of High Sucrose
Authors: Yamamoto Kana , Harada Norio , Yasuda Takuma , Hatoko Tomonobu , Wada Naoki , Lu Xuejing , Seno Youhei , Kurihara Takashi , Yamane Shunsuke , Inagaki Nobuya
Published: January 2024

Sucrose is a disaccharide that is degraded into fructose and glucose in the small intestine. High-sucrose and high-fructose diets have been reported, using two-dimensional imaging, to alter the intestinal morphology and the expression of genes associated with sugar transport, such as sodium glucose co-transporter 1 (SGLT1), glucose transporter 2 (GLUT2), and glucose transporter 5 (GLUT5). However, it remains unclear how high-fructose and high-sucrose diets affect the expression of sugar transporters and the intestinal morphology in the whole intestine. We investigate the influence of a chronic high-sucrose diet on the expression of the genes associated with sugar transport as well as its effects on the intestinal morphology using 3D imaging. High sucrose was found to increase GLUT2 and GLUT5 mRNA levels without significant changes in the intestinal morphology using 3D imaging. On the other hand, the delay in sucrose absorption by an α-glucosidase inhibitor significantly improved the intestinal morphology and the expression levels of SGLT1, GLUT2, and GLUT5 mRNA in the distal small intestine to levels similar to those in the proximal small intestine, thereby improving glycemic control after both glucose and sucrose loading. These results reveal the effects of chronic high-sugar exposure on glucose absorption and changes in the intestinal morphology.
Food and Consumers’ Environment Inside and around Federal Public Schools in Bahia, Brazil
Authors: de França Fabiana Chagas Oliveira , Zandonadi Renata Puppin , da Silva Santana Ívenes Ariele , da Silva Izabel Cristina Rodrigues , Akutsu Rita de Cassia Coelho de Almeida
Published: January 2024

The food environment plays a crucial role in shaping people’s eating habits and, in and around schools, this influence becomes even more critical due to the time students spend daily in these spaces. This study aimed to analyze the food and consumer environments inside and around federal institutes in Bahia, Brazil. Ecological study and audit methodologies were combined, with all the 35 federal institutes in Bahia as the sample universe. To delimit the food environment around the school, the establishments were mapped in a 1000 m buffer, with the school as the centroid. The geographic coordinates of schools and food outlets were initially obtained using Google Maps and later confirmed on-site. The data were collected in WGS 84 and converted to UTM zone 23S SIRGAS 2000. To map the consumer environment, establishments found in a 250 m buffer and also canteens within schools were audited, using the ESAO-r instrument that considers the availability and prices of healthy and unhealthy foods; availability of nutritional information near the point of purchase or on the menu; and presence of internal marketing of healthy and unhealthy foods. The healthy meal–restaurant index (HMRI) was also measured. This index ranges from 0 to 8 points and positively scores items related to healthy consumption and fails to score those related to unhealthy consumption and behavior. The establishments were grouped into four categories (healthy, unhealthy, mixed, and supermarkets). The surrounding area with four or more unhealthy establishments within the 250 m buffer was considered a food swamp. Descriptive analyses were carried out with frequency measurements, measures of central tendency (mean and median), and dispersion (standard deviation). Around the analyzed schools, 732 food establishments were identified, 73.8% (n = 540) formal and 26.2% (n = 192) informal. Considering the characteristics of existing commerce, there was a predominance of snack bars (45%), grocery stores (23%), and bars (7.8%), with a smaller number of supermarkets identified (4.1%). School canteens were found in 20 schools analyzed and only 15% had a variety of healthy foods. When evaluating the availability of healthy foods, a median HMRI of 3 (1–7) was observed. When analyzing this index according to the type of establishment, it was found that fruit and vegetables presented higher values (HMRI = 7; P25–P75: 4–8) compared to large chain supermarkets (HMRI = 5; P25–P75: 2–6; p < 0.001) and local markets (HMRI = 4; P25–P75: 2–5; p < 0.001). From the analysis of the food and consumer environments, it was possible to make inferences about the quality of the food offered to students in these locations, as well as the potential health outcomes arising from this exposure and the need to carry out food education activities and nutritional activities.
Combined Role of Interleukin-15 Stimulated Natural Killer Cell-Derived Extracellular Vesicles and Carboplatin in Osimertinib-Resistant H1975 Lung Cancer Cells with EGFR Mutations
Authors: Nathani Aakash , Sun Li , Khan Islauddin , Aare Mounika , Bagde Arvind , Li Yan , Singh Mandip
Published: January 2024

In this study, we evaluated IL-15 stimulated natural killer cell-derived EVs (NK-EVs) as therapeutic agents in vitro and in vivo in Osimertinib-resistant lung cancer (H1975R) with EGFR mutations (L858R) in combination with carboplatin (CBP). NK-EVs were isolated by ultracentrifugation and characterized by nanoparticle tracking analysis, and atomic force microscopy imaging revealed vesicles with a spherical form and sizes meeting the criteria of exosomal EVs. Further, Western blot studies demonstrated the presence of regular EV markers along with specific NK markers (perforin and granzyme). EVs were also characterized by proteomic analysis, which demonstrated that EVs had proteins for natural killer cell-mediated cytotoxicity (Granzyme B) and T cell activation (perforin and plastin-2). Gene oncology analysis showed that these differentially expressed proteins are involved in programmed cell death and positive regulation of cell death. Further, isolated NK-EVs were cytotoxic to H1975R cells in vitro in 2D and 3D cell cultures. CBP’s IC50 was reduced by approximately in 2D and 3D cell cultures when combined with NK-EVs. The EVs were then combined with CBP and administered by i.p. route to H1975R tumor xenografts, and a significant reduction in tumor volume in vivo was observed. Our findings show for the first time that NK-EVs target the PD-L1/PD-1 immunological checkpoint to induce apoptosis and anti-inflammatory response by downregulation of SOD2, PARP, BCL2, SET, NF-κB, and TGF-ß. The ability to isolate functional NK-EVs on a large scale and use them with platinum-based drugs may lead to new clinical applications. The results of the present study suggest the possibility of the combination of NK-cell-derived EVs and CBP as a viable immunochemotherapeutic strategy for resistant cancers.
Efficient Cherenkov-Type Optical-to-Terahertz Conversion of Femtosecond Oscillator Pulses
Authors: Kurnikov M. A. , Abramovsky N. A. , Shugurov A. I. , Bodrov S. B. , Bakunov M. I.
Published: January 2024

We demonstrate experimentally that a recently proposed structure comprising a tens of microns thick layer of LiNbO3 sandwiched between two totally reflecting Si prisms can serve as an efficient Cherenkov-type optical-to-terahertz converter of femtosecond laser pulses from an optical oscillator. Using Ti:sapphire laser pulses of 3.75 nJ energy as a pump, we achieved a conversion efficiency of 2.3 ×10−5, which exceeds the efficiency of the conventional collinear scheme with a ZnTe crystal by an order of magnitude. The converter can be used as a reliable radiation source for performing terahertz time-domain spectroscopy.
Optical Filter Design for Daylight Outdoor Electroluminescence Imaging of PV Modules
Authors: Dhimish Mahmoud , Tyrrell Andy M.
Published: January 2024

This paper presents an advanced outdoor electroluminescence (EL) imaging system for inspecting solar photovoltaic (PV) modules under varying daylight conditions. EL imaging, known for its effectiveness in non-destructively detecting PV module defects, is enhanced through specialized optical filters. These filters, including a bandpass filter targeting EL emissions and a neutral density filter to reduce background light, significantly improve the system’s signal-to-noise ratio (SNR). The experimental results demonstrate the system’s enhanced performance, with superior clarity and detail in EL emissions, enabling precise defect localization and characterization at the cellular level. Notably, the system achieves an SNR improvement, with values consistently above two, outperforming previous systems and confirming its suitability for efficient solar PV maintenance and diagnostics. This research offers a flexible approach to optimizing EL imaging quality across various solar irradiance levels and angles, essential for improved PV module performance and reliability. The system effectively handles different PV module configurations, orientations, and types, including monofacial and bifacial arrays. It showcases robust imaging capabilities under high solar irradiance and different sun illumination levels, maintaining high-quality imaging due to its optimized filter design. Additionally, the system’s adaptability in detecting EL emissions from series-connected PV modules is highlighted, demonstrating its comprehensive evaluation capabilities for PV array performance.
Does Preheating Influence the Cytotoxic Potential of Dental Resin Composites?
Authors: Dunavári Erika Katalin , Kőházy Anna , Vecsernyés Mónika , Szalma József , Lovász Bálint Viktor , Berta Gergely , Lempel Edina
Published: January 2024

Resin-based dental composites (RBC) release cytotoxic components, however the extent of the elution from preheated RBCs is barely investigated. The aim was therefore to determine the cytotoxic effect of preheated conventional, bulk, and thermoviscous RBCs of clinically relevant sizes using different cell viability methods in a contact-free model. Samples (6 × 4 mm) were prepared from conventional [Estelite Sigma Quick (ESQ), Filtek Z250 (FZ)] and bulk-filled [Filtek One BulkFill Restorative (FOB), SDR Plus Bulk Flow (SDR), VisCalor Bulk (VCB)] RBCs. The pre-polymerization temperature was set to room temperature (RT) and 55/65 °C. Pulp cells were cultured, followed by a 2-day exposure to monomers released from solid RBC specimens suspended in the culture medium. Cytotoxicity was assessed using a WST-1, MTT, and LDH colorimetric viability assays. Data were analyzed using one-way ANOVA, Tukey’s post hoc test, multivariate analysis, and independent t-test. The effect size (ƞp2) of material and temperature factors was also assessed. All the RBCs demonstrated cytotoxic effect upon exposure to pulp cells, but to a varying extent (ESQ >> VCB > FZ = FOB = SDR). The effect of pre-polymerization temperature was insignificant (ƞp2 < 0.03), except for the thermoviscous RBC, which showed inconsistent findings when subjected to distinct viability tests. Cell viability was predominantly dependent on the type of material used (p < 0.001) which showed a large effect size (ƞp2 > 0.90). Irrespective of the pre-polymerization temperature, RBC samples in a clinically relevant size can release monomers to such an extent, which can substantially decrease the cytocompatibility.
Assessment of Clayey Freshwater Sediments as Suitable Precursors for Alkaline Activation
Authors: Fořt Jan , Afolayan Ayodele , Mildner Martin , Hotěk Petr , Keppert Martin , Černý Robert
Published: January 2024

One of the biggest challenges in the construction industry in recent times is the mitigation of the environmental impact of this sector, the reduction in dependence on primary raw materials, and the reduction in CO2 production while maintaining functional properties. Alkaline activation of a number of waste products represents a promising way to achieve the above-mentioned goals, but the availability of a number of waste products changes over time, especially in Europe. While freshwater sediments were in the past widely utilized as an agricultural fertilizer, recent precautions have significantly decreased such application, and thus new destinations must be delivered. To explore the potential of freshwater sediments, select samples from various locations were subjected to detailed characterization to verify the applicability of the material for alkali activation. As recognized, the selected sediments contain a substantial volume of desired mineralogical compounds that can serve, after 900 °C curing, as suitable precursors. Such samples have consequently activated the mixture of alkaline activators to obtain dense structures and were subjected to detailed investigation aimed at understanding the mechanical parameters. The obtained mechanical results ranging between 14.9 MPa and 36.8 MPa reveal the engineering potential of sediments for valorization through alkali activation and outline new research challenges in this area.
Development of Antibacterial Thermoplastic Starch with Natural Oils and Extracts: Structural, Mechanical and Thermal Properties
Authors: López Terán Jorge Luis , Cabrera Maldonado Elvia Victoria , Araque Rangel Judith del Carmen , Poveda Otazo José , Beltrán Rico María Isabel
Published: January 2024

In this study, the influence of the incorporation of eucalyptus (EO), tea tree (TT) and rosemary (RO) essential oils and Chiriyuyo extract (CE) on the structure and properties of thermoplastic starch (TPS) obtained from potato starch, glycerin and water was evaluated. All oils and the extract were used at a concentration of 0.5 g/100 g of TPS, while for TT, the effect of the concentration was also studied. The mixtures obtained were processed by extrusion and thermocompression molding. The sheets were characterized by XRD, FTIR, TGA, SEM and analyses of their mechanical properties, antimicrobial characteristics and biodegradability. The results show that the use of small concentrations of the oils in 70TPS does not induce changes in the TPS structure according to the results of XRD, FTIR and TGA, with each essential oil and CE affecting the mechanical properties unevenly, although in all cases, antimicrobial activity was obtained, and the biodegradability of TPS in soil was not modified. An increase in the concentration of TT in 60TPS causes marked changes in the crystallinity of TPS, providing a greater modulus with a higher concentration of TT. Regardless of the amount of TT, all sheets maintain antimicrobial characteristics, and their biodegradation in soil is delayed with a higher oil content.
Application and Properties of Polyglycolic Acid as a Degradation Agent in MPU/HNBR Degradable Elastomer Composites for Dissolvable Frac Plugs
Authors: Cheng Kai , Yuan Mingyang , Zhang Yupeng , Sun Ningjing , Peng Bo
Published: January 2024

In this research, fully degradable elastomeric sealing materials were developed to enhance the environmental sustainability of oil and gas extraction. The modification of millable polyurethane rubber (MPU) with polyglycolic acid/hydrogenated nitrile butadiene rubber (PGA/HNBR) led to the synthesis of PGA@MPU/HNBR composite materials. The impact of varying monomer quantities on the mechanical properties, degradation behavior, degradation mechanisms, and thermal stability of these materials was investigated. Our findings illustrate that an increasing proportion of HNBR in the PGA@MPU/HNBR composite materials resulted in a decreased degradation rate. Simultaneously, higher HNBR content improved the thermal stability of the materials, while the inclusion of PGA reduced material hardness, rendering the composites more susceptible to swelling. At an HNBR content of 40 phr, MPU at 60 phr, and PGA at 6 phr, the composite material demonstrated the highest retention of mechanical properties at 31.3% following 168 h of hydrolysis at 100 °C. The degradation of the composite materials in 100 °C water primarily resulted from the hydrolysis of MPU’s ester groups, with HNBR remaining unaffected.
The Influence of a Manifold Structure on the Measurement Results of a PIV Flowmeter
Authors: Chen Huiyu , Qiu Yilong , Wang Hui , Gao Mengjie
Published: January 2024

The application of particle image velocimetry (PIV) technology for monitoring natural gas flow is a new method of flow measurement. Since the principle of this technology was proposed, there are still some potential issues. This article investigates the influence of a manifold structure on the measurement results of a PIV flowmeter. A comparison is performed between concentric and eccentric manifold structures, using a circular straight pipe as reference, in terms of the measurement error of the PIV flowmeter and the internal flow state of the natural gas. The results demonstrate that the manifold structure significantly affects the measurement reliability of the PIV flowmeter, especially the eccentric manifold structure. Under flow conditions ranging from 100 to 600 m3/h, the maximum measurement errors caused by the concentric and eccentric manifold structures are 2.49% and 3.05%, respectively, which show a noticeable increase compared to the maximum measurement error of 2.08% observed for the circular straight pipe. Additionally, the influence of the manifold structure on the downstream flow field is also evident, as the eccentric manifold structure increases the turbulence intensity of the downstream fluid by nearly twofold. The addition of a rectifier can effectively improve the flow state and enhance the measurement reliability of the PIV flowmeter. For the concentric manifold structure under the condition of a 600 m3/h flow rate, the inclusion of a rectifier produces highly accurate measurement results, similar to those obtained by an ultrasonic flowmeter, with an error value close to zero. This study provides technical support for further promoting the practical application of PIV flowmeters.
Surface Chemistry of Cherry Stone-Derived Activated Carbon Prepared by H3PO4 Activation
Authors: González-Domínguez Jose M. , Fernández-González Carmen , Alexandre-Franco María , Gómez-Serrano Vicente
Published: January 2024

The preparation of activated carbons (ACs) from cherry stones and chemical activation with H3PO4 can be controlled by the experimental variables during the impregnation step in order to obtain a tailored porous structure of the as-prepared ACs. This control not only extends to the ACs’ texture and porosity development, but also to the chemical nature of their surface. The spectroscopic and elemental characterization of different series of ACs is presented in this study. The spectroscopic band features and assignments strongly depend on the H3PO4 concentration and/or the semi-carbonization treatments applied to the feedstock before impregnation, which ultimately influence different characteristics such as the AC hydrophilicity. Different surface chemistries arise from the different tailored impregnation solutions, showing a practical outcome for future applications of the as-prepared ACs.
An Emergency Decision-Making Method for Coal Spontaneous Combustion Based on Improved Prospect Theory
Authors: Zeng Jingwei , Jing Guoxun , Zhu Qifeng
Published: January 2024

In response to the limited available information during the initial stages of coal spontaneous combustion and the influence of decision makers’ risk preferences on decision-making, this paper proposes an emergency decision-making method for coal spontaneous combustion that integrates grey correlation degree and TOPSIS with an enhanced prospect theory. Firstly, a normalized weighted evaluation matrix is established for the emergency response plan of coal spontaneous combustion, and the entropy method is utilized to determine the weights of various indexes. Then, considering the imperfect rationality of decision makers and their diverse individual risk preferences, they are categorized into three types: risk-seeking type, risk-neutral type, and risk-averse type. The corresponding risk coefficients are determined based on these different types. Positive and negative ideal solutions are taken as reference points, and matrices representing gains and losses are constructed. The grey correlation degree is introduced to calculate both positive and negative prospect values based on these matrices. Moreover, the prospect value for each emergency response plan is calculated, respectively, based on different types of decision makers, and the entropy method is used to assign weights to decision makers according to their respective risk preferences. Consequently, based on these prospect values and the weights, comprehensive prospect values for each emergency response plan are obtained and ranked to identify the optimal one. Finally, in order to validate the effectiveness of our proposed approach, a case study is conducted, and the results obtained from this case study are discussed and compared with those from other methods.
Determining the Level of Structural and Mechanical Degradation of Steel in the Supporting Structure of Mining Excavation Machinery
Authors: Radu Sorin Mihai , Vîlceanu Florin , Toderas Mihaela , Lihoacă Alexandra , Dinescu Stela
Published: January 2024

The steels from which the components of mining machinery are constructed must be based primarily on knowledge of their behaviour under environmental conditions and of the excavation technology. Secondly, the structural changes undergone by the materials due to mechanical and thermal processing and the stresses generated by the action of excavation forces that can induce internal stresses at a level that is difficult to determine must be taken into account. Determining the level of structural and mechanical degradation involves sampling the load-bearing structure elements of the excavation and storage machinery for analysis of the mechanical and chemical properties of the component materials. The paper focuses on issues related to the structural and mechanical degradation of steel as a material for parts of mining machinery. In this paper, a methodology for evaluating the degree of structural degradation of three types of bucket wheel excavators with different operating hours (ERc 1400-30/7-07 with 50,400 h, ERc 1400-30/7-08 with 69,264 h, and SRs 1300-26/3.5 with 112,000 h) is proposed. The methodology aims to provide a quantitative assessment of the structural degradation by considering the specific elastic limit of the material used in the machines and the number of hours of operation. This method uses a minimum set of destructive mechanical tests, such as tensile, resilience for three working temperatures, chemical analysis, and durometry on resistance elements taken from the machine, as well as the use of Weibull analysis. By combining this information with the number of hours of operation, a comprehensive evaluation can be made to determine the extent of degradation and potential maintenance requirements. The use of a minimum set of mechanical tests ensures an efficient and cost-effective approach to assessing the structural integrity of these machines. The metallographic analysis highlighted a predominant and defined form of grain rearrangement in the E14-07 machine after only 50,400 h. The constituents identified in the samples taken from the three machines are ferrite and pearlite. The highest hardness of the samples was recorded for the E14-08 machine, with values between 162–165 HV10. For bucket wheel excavators E14-07 and E14-08, the material structure showed elongated grains in the direction of deformation, compared to the material structure of E13-04, which has finely equiaxed grains. As a result of the research, final conclusions were formulated.
On the Brinks of Language: Benjamin’s Approach to a Tragic Dialogue
Authors: Hansen Bjarke Mørkøre Stigel
Published: January 2024

The aim of this article is to explore the potential tension that according to Walter Benjamin is at stake in the opposition between the bourgeois conception of language and an inquiry into the essence of language, taking into account important texts written in 1916, in order to shed light on language that moves in the direction of a dialogical situation premised on a tragic approach. More specifically, beginning with an outline of Benjamin’s notion of the relationship between language and action, with particular attention to his 1916 letter to Martin Buber and the role of language, it then goes on to discuss the structure of language in the 1916 essay on language, at the end of which Benjamin asserts that there is a “tragic relationship between the languages of human speakers”. Drawing on a posthumously published essay from 1916, entitled The Role of Language in Tragedy and Trauerspiel, it finally seeks to show how this tragic relationship is essential to a dialogical situation.
Mapping Cones on Mars in High-Resolution Planetary Images with Deep Learning-Based Instance Segmentation
Authors: Yang Chen , Zhang Nan , Guan Renchu , Zhao Haishi
Published: January 2024

Cones are among the significant and controversial landforms on Mars. Martian cones exhibit various morphological characteristics owing to their complex origin, and their precise origin remains an active research topic. A limited number of cones have been manually mapped from high-resolution images in local areas, and existing detection methods are only applicable to a single type of cone that has a similar morphology and spatial distribution, leading to the vast majority remaining unidentified. In this paper, a novel cone identification approach is proposed that is specially designed for adequately recognizing cones from different regions in high-resolution planetary images. First, due to the lack of a publicly available cone database for reference, we annotated 3681 cones according to the literature on manual interpretation and the cone information provided by the Lunar and Planetary Laboratory (IRL) in HiRISE images. Then, the cone identification problem was converted into an instance segmentation task, i.e., a cone identification approach was designed based on deep neural networks. The Feature Pyramid Network-equipped Mask R-CNN was utilized as the detection and segmentation model. Extensive experiments were conducted for fine recognition of Martian cones with HiRISE. The results show that the proposed approach achieves high performance; it especially efficiently detects multiple types of cones while generating accurate segmentation to describe the geometry contour of cones. Finally, a Martian cone dataset with deep learning-based instance segmentation (DL-MCD) was built, containing 3861 cones for exploring geological processes on the surface of Mars.
Absolute Calibration of a UAV-Mounted Ultra-Wideband Software-Defined Radar Using an External Target in the Near-Field
Authors: Melebari Asem , Nergis Piril , Eskandari Sepehr , Ramos Costa Pedro , Moghaddam Mahta
Published: January 2024

We describe a method to calibrate a Software-Defined Radar (SDRadar) system mounted on an uncrewed aerial vehicle (UAV) with an ultra-wideband (UWB) waveform operated in the near-field region. Radar calibration is a prerequisite for using the full capabilities of the radar system to retrieve geophysical parameters accurately. We introduce a framework and process to calibrate the SDRadar with the UWB waveform in the 675 MHz–3 GHz range in the near-field region. Furthermore, we present the framework for computing the near-field radar cross section (RCS) of an external passive calibration target, a trihedral corner reflector (CR), using HFSS software and with consideration for specific antennas. The calibration performance was evaluated with various distances between the calibration target and radar antennas. The necessity for the knowledge of the near-field RCS to calibrate SDRadar was demonstrated, which sets this work apart from the standard method of using a trihedral CR for backscatter radar calibration. We were able to achieve approximately 0.5 dB accuracy when calibrating the SDRadar in the anechoic chamber using a trihedral CR. In outdoor field conditions, where the ground rough surface scattering effects are present, the calibration performance was lower, approximately 1.5 dB. A solution is proposed to overcome the ground effect by elevating the CR above the ground level, which enables applying time-gating around the CR echo, excluding the reflection from the ground.
Monte Carlo Full-Waveform Inversion of Cross-Hole Ground-Penetrating Radar Data Based on Improved Residual Network
Authors: Wang Shengchao , Gong Xiangbo , Han Liguo
Published: January 2024

A full-waveform inversion (FWI) of ground-penetrating radar (GPR) data can be used to effectively obtain the parameters of a shallow subsurface. Introducing the Markov chain Monte Carlo (MCMC) algorithm into the FWI can reduce the dependence on the initial model and obtain the global optimal solution, but it requires a large number of computations. In order to better detect underground targets based on ground-penetrating radar data, this paper proposes a joint scheme of an improved ResNet and an MCMC full-waveform inversion. This scheme combines the Bayesian MCMC algorithm and an improved ResNet to accurately invert the target dielectric permittivity. The introduction of deep learning networks into the forward calculation part of the MCMC inversion algorithm replaced the complex forward simulation process, greatly improving the inversion speed. It is worth noting that the neural network model was an approximation of complex forward modeling, and, therefore, it contained modeling errors. The MCMC method could quantify and explain modeling errors during the inversion process, reducing the impact of modeling errors on the inversion results. Finally, a simulation dataset was constructed for training and testing, and the errors were statistically analyzed. The results showed that this method can accurately reconstruct underground medium targets, and it has strong robustness and efficiency.