Average Dimensions Research Articles

Image simulation and realism evaluation for mammography and tomosynthesis based on the detailed breast phantom

The virtual image system is a key component of virtual clinical trials (VCTs) which can be utilized to evaluate and improve medical imaging devices. The main limitation of VCTs in the Chinese female breast is the lack of detailed structure in the breast model employed in the Chinese specification for testing of quality control in mammography. In this paper, based on Chinese female breast parameters, detailed breast phantoms with different glandularity (fatty, glandular, dense) and compressed breast thicknesses (CBT) (2–7 cm) were generated. Digital mammography (DM) and digital breast tomosynthesis (DBT) projections for these phantoms were simulated with clinical system configuration. Compressed breast volumes were reconstructed through DBT projections with different angles. Power spectrum analysis and fractal dimension measurement were applied for simulated and clinical images. The results show that the average power law exponents and standard deviation (DM, DBT) for clinical and simulated images were (3.26 ± 0.29, 3.33 ± 0.42) and (3.63 ± 0.25, 3.18 ±0.36) respectively. The average fractal dimensions and standard deviation (DM, DBT) for clinical and simulated images were (2.36 ± 0.03, 2.41 ± 0.05) and (2.10 ± 0.01, 2.26 ± 0.06) respectively. We constructed two virtual imaging systems for DM and DBT and obtained the imaging data based on the three-dimensional (3D) detailed breast phantoms. These results indicate that the texture indexes of simulated images are similar to that of the clinical images, and validate that these breast phantoms are suitable for imaging in VCTs requiring realistic anatomy with the Chinese female population. Results also show that the values of power law exponents for clinical and simulated images in DM and DBT are positively correlated with the value of breast glandularity, but the values of fractal dimensions keep steady for different glandularity.

Effect of incorporation of nano-graphene oxide on physicochemical, mechanical, and biological properties of tricalcium silicate cement

ObjectiveEvaluation of setting time, compressive strength, pH, calcium ion release, and antibacterial activity of mineral trioxide aggregate (MTA) after modification with three different concentrations of nano-graphene oxide (GO) powder compared to unmodified Biodentine as a commercial control. MethodsGO powder, unhydrated and hydrated cements were characterized using Environmental Scanning Electron Microscope (ESEM) with Energy Dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Raman Spectroscopy, and Fourier Transform Infrared spectroscopy (FTIR). GO was also analyzed using Scanning Transmission Electron Microscope (STEM) to determine average lateral dimensions. Specimens were prepared and grouped according to the concentration of GO added to Rootdent MTA (control, 1, 3, and 5 wt%) and the material used (MTA and unmodified Biodentine) into five groups. Setting time was evaluated using Gillmore penetrometer (n = 5). Compressive strength was evaluated using universal testing machine (n = 7). pH and calcium ion release were assessed using pH meter and Induced Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) at 1, 7, 14, and 28 days (n = 7). Antibacterial activity was evaluated against Streptococcus mutans using direct contact test (n = 7). One-way and repeated measures ANOVA followed by Tukey's post hoc test were used for data analysis with significance level set at p ≤ 0.05. ResultsAddition of GO to MTA reduced both initial and final setting time. GO modified MTA groups and unmodified Biodentine showed significantly increased calcium ion release at 14 and 28 days. All cements showed alkaline pH of the storage media at all tested time intervals. 1 wt% GO recorded the highest compressive strength values in MTA modified groups. The increased concentration of GO from 1 to 5 wt% successively increased antibacterial activity of MTA, with Biodentine showing the lowest significant value. ConclusionAddition of 1 wt% GO can significantly improve the tested properties of tricalcium silicate-based cements without compromising their compressive strength. Clinical significanceGO is a promising modification for tricalcium silicate cements to improve setting time, compressive strength, and antibacterial activity to provide a variety of materials for different clinical situations. This in turn can reduce the risk of reinfection and allow placement of the final restoration in a single visit.

A Comparative Assessment of Homomorphic Encryption Algorithms Applied to Biometric Information

This paper provides preliminary research regarding the implementation and evaluation of a hybrid mechanism of authentication based on fingerprint recognition interconnected with RFID technology, using Arduino modules, that can be deployed in different scenarios, including secret classified networks. To improve security, increase efficiency, and enhance convenience in the process of authentication, we perform a comparative assessment between two homomorphic encryption algorithms, the Paillier partial homomorphic algorithm and the Brakerski–Gentry–Vaikuntanathan fully homomorphic encryption scheme, applied to biometric templates extracted from the device mentioned above, by analyzing factors such as a histogram analysis, mean squared error (MSE), peak signal-to-noise ratio (PSNR), the structural similarity index measure (SSIM), the number of pixel change rate (NPCR), the unified average changing intensity (UACI), the correlation coefficient, and average encryption time and dimension. From security and privacy perspectives, the present findings suggest that the designed mechanism represents a reliable and low-cost authentication alternative that can facilitate secure access to computer systems and networks and minimize the risk of unauthorized access.

Harnessing asymmetry to reprogram nonlinear metamaterials on-the-fly with no moving parts

Various two-dimensional fabrication methods, such as deposition, etching, milling, laser cutting, and water jetting, suffer from asymmetry between the top and the bottom surface of fabricated parts. Such asymmetry is usually undesirable and can compromise functionality, or at least add uncertainty to fabricated components. The common practice is to assume symmetry between the top and the bottom surfaces by using average dimensions. In this study, we harness such asymmetry to realize metamaterials with dynamically tunable (i.e., re-programmable) properties. Our metamaterial is composed of identical unit cells with two concentric Archimedean spiral cuts and a permanent magnet embedded in the unit cell's center. By utilizing external electromagnets, we further amplify the fabrication asymmetry, through the inherent asymmetry between a repulsive vs attractive state between the permanent magnets and the electromagnets. We demonstrate the utility of our metamaterials by programming its spatiotemporal response in both time and frequency even in the presence of high amplitude harmonic excitation. Our findings can be utilized for broad range of applications, from seismic sensing at low frequency to ultrasonic imaging at higher frequencies.

Nano Enabled Plasmonic Strips For Colorimetric Detection Of Food Adulterants

AbstractPaper‐based analytical devices constitute a remarkable platform for low‐cost and point‐of‐care application with minimal external resources. The present work aims at the development of gold nanoparticles (AuNPs) based plasmonic substrates for food sensor application. AuNPs were synthesized by using redox method with dual reducing agents (tannic acid and citrate ions). Physicochemical and sensing characteristics were determined by various spectroscopic and microscopic techniques. The sensing characteristic was evaluated using melamine (MA) as representative analyte (food adulterants). HR‐TEM images imply that the synthesized AuNPs was spherically‐shaped with an average dimension of 5 nm. After the interaction of MA with AuNPs, the size of the NPs changed from 5 to 8.9 nm due to aggregation. The interaction of MA with AuNPs has been carried out in the solution phase as well as in the strip phase by visual and spectroscopic techniques. The concentration dependent color variation was observed with a limit of detection 5×10−5 M in the solution phase. This sensor probe is highly specific for MA and did not show any visible color variation with other adulterants. The sensor system is simple, reproducible and highly promising for rapid and low‐cost sensing of MA in food samples.

Parametric Design and Prototyping of a Low-Power Planar Biped Robot.

This study proposes a design approach and the development of a low-power planar biped robot named YU-Bibot. The kinematic structure of the robot consists of six independently driven axes, and it weighs approximately 20 kg. Based on biomimetics, the robot dimensions were selected as the average anthropomorphic dimensions of the human lower extremities. The optimization of the mechanical design and actuator selection of the robot was based on the results of parametric simulations. The natural human walking gait was mimicked as a walking pattern in these simulations. As a result of the optimization, a low power-to-weight ratio of 30 W/kg was obtained. The drive system of the robot joints consists of servo-controlled brushless DC motors with reduction gears and additional bevel gears at the knee and ankle joints. The robot features spring-supported knee and ankle joints that counteract the robot's weight and compensate for the backlash present in these joints. The robot is constrained to move only in the sagittal plane by using a lateral support structure. The robot's feet are equipped with low-cost, force-sensitive resistor (FSR)-type sensors for monitoring ground contact and zero-moment point (ZMP) criterion. The experimental results indicate that the proposed robot mechanism can follow the posture commands accurately and demonstrate locomotion at moderate stability. The proposed parametric natural gait simulation-based design approach and the resulting biped robot design with a low power/weight ratio are the main contributions of this study.

A Simplified Lattice Boltzmann Boundary Conditions for Gas Transport in Self-Affine Microchannels with an Inherent Roughness of in a Tight Reservoir

A simplified method of determining lattice Boltzmann boundary conditions based on self-affine microchannels with an inherent roughness in a tight reservoir is presented in this paper to address nonlinear efficiency problems in fluid simulation. This approach effectively combines the influence of rough surfaces in the simulation of the flow field, the description of L-fractal theory applied to rough surfaces, and a generalized lattice Boltzmann method with equivalent composite slip boundary conditions for inherent roughness. The numerical simulations of gas slippage in a two-dimensional plate model and rough surfaces to induce gas vortex reflux flow are also successfully carried out, and the results are in good agreement with the simulation results, which establishes the reliability and flexibility of the proposed simplified method of rough surfaces. The effects of relative average height and fractal dimensions of the rough surfaces under exact boundary conditions and equivalent coarsened ones are investigated from three perspectives, namely those of the average lattice velocity, the lattice velocity at average height position at the outlet, and the coefficient of variation for lattice velocity at average height position. It was found that the roughness effect on gas flow behavior was more obvious when it was associated with the enhanced rarefaction effect. In addition, the area of gas seepage was reduced, and the gas flow resistance was increased. When the fractal dimension of the wall was about 1.20, it has the greatest impact on the fluid flow law. In addition, excessive roughness of the wall surface tends to lead to vortex backflow of the gas in the region adjacent to the wall, which greatly reduces its flow velocity. For gas flow in the nanoscale seepage space, wall roughness hindered gas migration rate by 84.7%. For pores larger than 200 nm, the effects of wall roughness on gas flow are generally negligible.

Response of Anatomical Characteristics of Nile Flower Eichhornia crassipes to Environmental Changes and their Impact on Tigris Water Quality

The current study was conducted on the Tigris River in the distance between Qayyarah district of Nineveh province and Baiji district of Salahuddin province by five stations (Al-Gayyarah, Jisr Al-Shirgat, Asdeira, Al-Zuwia and Almsahag). Anatomical Characteristics of Nile flower Eichhornia crassipes were studied. Some qualitative properties of river water were studied. The results indicated that there were significant differences between the study stations in all anatomical characteristics of the plant, Significant differences were found in the different study stations in all the characteristics of the upper and lower skin of the leaves of the Nile flower plants, it is the dimensions of stomata and its index and the average dimensions of the cells of the upper and lower skin. For the stems of the Nile flower plants, anatomical characteristics showed significant differences with different study stations. Al- Mosahak station achieved the highest stomatal dimensions of 15 and 13 μm for length and width respectively. Al-Gayyarah station excelled in the highest averages of the stomata index and average length × width of normal cells with values of 14 and 32 × 15 μm respectively. The highest mean of the physical characteristics of the river water was 1407 mg / L of total dissolved solids at the Al-Zuwia station in December, 8.4 for pH at Al-Gayyarah and Jisr Al-Shirgat stations during January, and 1.4 mg / L for BOD5 in Al-Gayyarah station during March, 2.3 mg / L for total hardness at Asdira station in February, 1.02 mg / L of nitrate at Almsahag station in December, 1.231 mg / L for sulfate at Al-Gayyarah station in January, 2.38 mg / L for sodium at Al-Zauwia station in December, and 1.2 mg / L for potassium at Almsahag station in March.

First report of Neopestalotiopsis rosae causing leaf blight on Shatangju in southern China.

Shatangju (CitrusreticulataBlancocv.Shatangju) belongs to genus Citrus and was cultivated extensively in southern China. In April 2022, a leaf blight-like symptom (firstly brown spots appeared on infecting leaves, then these brown spots extended, finally the whole leaves displayed blight-like symptom) was observed on 5%~10% of Shatangju seedlings (around five hundreds in total) in an orchard located in Wuhan city, Hubei, China. Diseased leaves from three seedlings were collected and cut into pieces (0.2 to 0.5 cm). These pieces were surface-sterilized using 75% ethanol for 3 min, rinsed with sterile distilled water for several times, then placed on potato dextrose agar (PDA) and incubated at 26°C with 12-h light/dark cycle. Over 20 pieces plated, wherein 30% were identified as Colletotrichum fructicola, 60% as Neopestalotiopsis spp., and 10% developed saprophytes. C. fructicola was a known pathogen on citrus, thus Neopestalotiopsis spp. was further investigated. Eight single-conidium colonies of the Neopestalotiopsis spp. were obtained, wherein STJ-8 was chosen as a representative for further study. The average growth rate of STJ-8 was 15.1±0.5 mm/day (n=5). Fungal colonies produced white cottony mycelium with abundant black acervuli distributed in concentric rings 6-8 days after planting, which ranged from 342.3 to 710.5 μm in diameter (n=100). Conidia were fusoid, five cells, four septa with average dimensions of 25.36×5.47 μm (n=100). Basal and apical cells were hyaline, wherein three middle cells were brown with darker septa. The apical cell was cylindrical with two to three transparent accessory filaments (13.7 to 30.5 µm in length, n=80). Basal cell was conic with an appendage (4.1 to 8.8 µm in length, n=40). Partial sequences of internal transcribed spacer (ITS), translation elongation factor 1-alpha (TEF-1α), and β-tubulin (TUB2) were amplified with reported primers (White et al. 1990; Lee et al. 2006; Maharachchikumbura et al. 2014), sequenced, and submitted to GenBank (accession nos. ITS: OP236541; TEF-1α: OP250124; TUB2:OP263094). BLASTn results showed 100% identity with the corresponding sequences of Neopestalotiopsis rosae. A multilocus phylogenetic analysis showed STJ-8 was closest to N. rosae. Thus, STJ-8 was identified as N. rosae. Pathogenicity tests were performed on one-year-old Shatangju seedlings and detached primary leaves by inoculating needle-wounded leaves with seven days old 5-mm mycelial plugs/acervuli (about 5000 spores) of STJ-8. Control seedlings/leaves were inoculated with 5-mm PDA plugs/sterile water drops. All inoculated detached leaves were cultured at same the place with STJ-8 cultured, while inoculated seedlings were put in a growth chamber at 26°C under a 16-h light/dark cycle (60% humidity). Symptoms developed on all inoculated leaves (except healthy control) 2 and 4 days post-inoculation by mycelial plugs and acervuli, respectively. N. rosae was re-isolated from the inoculated leaves, confirming Koch's postulates. N. rosae has been reported to cause diseases on various plants worldwide (Rebollar-Alviter et al. 2020; Xavier et al. 2021; Lawrence et al. 2022). In China, N. rosae has been reported to cause leaf spot/blight on pecan and strawberry (Wu et al. 2021; Gao et al. 2022), which caused great loss on these crops. To our knowledge, this is the first report of N. rosae causing leaf disease on citrus. Our study is important for developing control strategies against N. rosae in future.

Preoperative CT-Guided Coil Localization of Lung Nodule Resection: A Single-Center Experience.

The increased use of computed tomography (CT) for lung cancer screening has led to an increase in the incidence of lung nodules. However, accurately localizing small or deep-seated nodules remains challenging and often requires image-guided techniques. CT-guided coil localization has emerged as a popular method for precise localization. A retrospective analysis was conducted on a cohort of patients who underwent CT-guided coil localization followed by surgical resection of lung nodules at the National University Hospital, Singapore, between 2015 and 2021. The study examined the rates of successful localization, procedural complications, and postoperative length of stay. Descriptive statistics were employed for data analysis. This retrospective study included 55 patients with pulmonary nodules, of whom 76.4% had a history of previous malignancy. A total of 58 nodules were successfully localized using coil placement and distributed across various lung lobes. The average dimensions of the nodules were 8.4 ± 3.2 mm × 10.1 ± 4.0 mm, with an average distance of 10.9 ± 9.0 mm from the pleura. Surgical resection of the coiled nodules resulted in an average resected volume of 91.1 ± 76.0 cm3 and a resection margin of 9.5 ± 7.3 mm. Failed localization occurred in only 3.6% of cases. Procedural complications were observed in 21.8% of patients, including hemothorax, persistent air leaks, pneumothoraces, pleural effusion, pneumonia, and atelectasis, all of which were appropriately managed. The average length of postoperative hospital stay was 6.7 ± 15.9 days. Preoperative CT-guided coil localization is a reliable and safe technique for accurately localizing lung nodules before surgical resection. The high success rate of this approach enables precise intraoperative planning. Despite procedural complications, their manageable nature and the absence of major adverse events highlight the safety of this technique. Incorporating CT-guided coil localization into routine clinical practice can significantly enhance surgical planning, improve patient outcomes, and optimize resource utilization.

New Media Interactive Design Visualization System Based on Artificial Intelligence Technology

The experimental results show that the average cumulative contribution rate of this algorithm was 92.78%, while that of the traditional algorithm was 88.88%. In contrast, the average cumulative contribution rate of this algorithm was improved by 3.9%. In terms of classification accuracy, the average classification accuracy of this algorithm was 94.99%, while the traditional algorithm was 90.98%. In contrast, the average classification accuracy of this algorithm was improved by 4.01%. In terms of dimension reduction time, the average dimension reduction time of this algorithm was 3.46s, while that of the traditional algorithm was 6.43s. In contrast, the average dimension reduction time of this algorithm was shortened by 2.97s. It can be seen from the data that the improved PCA algorithm can effectively improve the classification accuracy and cumulative contribution rate of the visualization system, shorten the dimension reduction time, and improve the system's ability to process data.

Evaluating Individual Involvement in Shaping Information Security Culture

In the increasingly advanced digital era, information security has become a crucial aspect for various organizations worldwide. In facing these challenges, organizations rely not only on sophisticated security technologies but also on active participation and involvement of individuals in shaping a strong information security culture. Information security culture encompasses the attitudes, values, and behaviors of individuals when it comes to addressing information security risks. This research aims to evaluate the individual involvement in shaping the information security culture within an organization. The study will involve measuring the level of individual awareness of information security, individual knowledge of information security, compliance with security policies and procedures, as well as individual behaviors in maintaining information security. Data collection will be done using a questionnaire that has been tested for validity and reliability. Awareness has an average total score of 13.20833333 and an average dimension score of 4.40277778. Meanwhile, knowledge has the same value as compliance and behavior, with an average total score of 13.27083333 and an average dimension score of 4.42361111. The results of this research reveal that the research subject has the lowest awareness value compared to other dimensions, while knowledge, compliance, and behavior have the same values. Overall, the research subject exhibits a relatively good information security culture, although it is not perfect.

Establishing an anthropometric database: A case for the Portuguese working population

Up-to-date anthropometric databases can help design appropriate workstations and equipment, reducing occupational accidents and disorders. The primary aim of this study was to create a company database to support the hypothesis that the latest anthropometric database for the Portuguese working population was outdated. Through the traditional manual measurement method, this work collected data on 27 dimensions from 343 workers in an industry in Northern Portugal. The interclass correlation coefficient showed high agreeability intra- and inter-evaluators with average values of 0.940 and 0.950, respectively. Socioeconomic aspects of the sample population, including gender, immigration, and age, were evaluated. Statistical analysis included correlations between the 27 anthropometric dimensions, age, and Body Mass Index (BMI). Among the main findings, men displayed larger average dimensions than women except for hip breadth, and female body measures decreased more with age than males. Men were 1.6 times more likely to be overweight than women, whereas women were twice more likely to be obese. Concerning working shifts, individuals on the night shift showed an increased tendency to be overweight or obese (BMI>25). Since the previous database employed a different method (photogrammetric), it was possible to compare only five dimensions (stature, knee height, elbow height, hip breadth, and abdominal depth) through mean absolute differences. Variations in the population stature and knee and elbow heights support this work's hypothesis and underscore the need to establish and update the Portuguese anthropometric database with a reliable and reproducible method.

Comparison of Hexaco 'S Personality Model in Clinical Depressed and Normal People in Isfahan

Background: Depression is one of the mood diseases characterized by symptoms of low mood, decreased energy and interest, feelings of guilt, problems in concentration, anorexia, thoughts of death and suicide, insomnia or hypersomnia, significant weight loss, and functional impairment. The purpose of the research was to compare the Hexagon personality model and self-compassion in clinically depressed people and normal people in Isfahan. Method: The research method is causal-comparative. The statistical population studied in this research were people with clinical depression disorder and normal people of Isfahan city. Sampling was done in a targeted way. In total, after the process, 50 people were selected in the clinically depressed group and 80 people were selected in the normal group. The research tool was Hexagon (2004) personality questionnaire. SPSS-22 software was used to analyze the data. Findings: The results of multivariate analysis of variance showed the difference between two groups of normal and clinically depressed people in Hexagon personality dimensions (p<0.05). The value of Eta is 0.989. The results showed that there was a significant difference between the average Hexagon personality dimensions between the two groups of normal and clinically depressed people (p<0.05). Conclusion: According to the results, it was found that clinically depressed people and normal people are different in terms of Hexagon personality dimensions, and by strengthening positive personality dimensions in the Hexagon model, the severity of depression of these people can be reduced.

A novel approach for quantitative characterization of aqueous in-situ foam dynamic structure based on fractal theory

In this study, a quantitative characterization method of in-situ foam microstructure is proposed based on fractal theory and the captured two dimension(2D) microstructure image for the study of its fractal characteristic, evolution law, sensitivity of temperature and concentration, as well as the relationship between average particle size and fractal dimension of in-situ foam. The results demonstrate that in-situ aqueous foam in the bulk phase exhibits fractal characteristics with a box-counting fractal dimension ranging from 1.4 to 2.0. Distinct from the “exponential” evolution law of conventional foam, in-situ foam displays the “check mark” evolution law, which can be precisely described by two items with clear physical meaning in our proposed fitting model. Additionally, the in-situ foam's evolutionary characteristic exhibits high adaptability towards temperature and foaming agent concentration. Elevated temperatures accelerate coalescence, resulting in shorter effective times, while higher concentrations of foaming agents prolong the overall stability of in-situ foam. Besides, the variation of average particle size of in-situ foam correspond closely with the evolution of fractal dimension under different temperatures and foaming agent concentrations, providing the potential for predicting changes in microstructure of in-situ foam by fractal dimension.

Ultrasound findings to predict failure of conservative treatment in the appendix testis torsion

BackgroundTorsion of the appendix testis (TAT) is considered the most common cause of acute scrotum in childhood. When clinical and ultrasound (US) findings agree with the diagnosis, after testicular torsion has been excluded, conservative therapy is attempted whereas scrotal exploration and removal of the hydatid are required when medical therapy has failed. We hypothesized there are US features that can predict the failure of conservative therapy.MethodsWe conducted a retrospective analysis on pediatric patients treated for TAT. The age of patients, number of days spent with symptoms before the start of treatment, presence of epididymitis and/or hydrocele, and dimension of the twisted hydatid were analyzed. A search for a correlation between these variables and failure of conservative treatment was conducted.ResultsPatients were divided into 2 groups based on the efficacy of conservative management: responders (group I) and non-responders subjected to surgical treatment (group II). No statistically significant differences were registered in regard to age (p = 0.25), average dimension of hydatid (p = 0.09), and time gap between symptoms and the start of therapy (p = 0.92) between the 2 groups. An associated epididymitis was described in 27.5% of patients in group I and 41.7% in group II (p = 0.03; OR 1.89), and associated hydrocele was described in 33.4% of patients in group I and 45.8% in group II (p = 0.03; OR 1.83). Considering the odds ratios, the probability of surgical intervention when presenting only epididymitis without hydrocele is estimated to be 15%, when presenting only hydrocele without epididymitis: 9%, with both epididymitis and hydrocele: 74%, and without epididymitis nor hydrocele: 2%.ConclusionsThe presence of both epididymitis and hydrocele at first US evaluation is associated with a high probability of conservative treatment failure, thus predicting the need for surgical intervention.

On the low cycle fatigue behaviour of an Al-Zn-Mg-Cu alloy processed via non-isothermal ageing

The low cycle fatigue behaviour of an Al-Zn-Mg-Cu alloy processed via non-isothermal ageing (NIA) was examined at different strain amplitudes. We showed that NIA improved the low cycle fatigue life (more than 7000 cycles) by optimising the precipitate configuration within 5.5 h while maintaining comparable mechanical properties (570 MPa for tensile strength) and conductivity (nearly 39% IACS) to conventional isothermal ageing, simultaneously. Experimental observation combined with molecular dynamic simulation revealed that precipitation configuration manipulated by NIA had a crucial effect on fatigue resistance. A great number of repeatedly sheared and locally destructed GP zones enhanced co-planar slip and slip localisation in the under-aged alloy during the early stage of NIA, responsible for the dramatic displacement steps on the surface and resultant poor fatigue performance. As the NIA further proceeded, moderately coarsened precipitates with an average dimension of 6.0 nm and elevated number density effectively impeded the dislocation movement and weaken the slip localisation to a great extent, improving the fatigue performance within a few hours.

Exciton Fine Structure of CsPbCl3 Nanocrystals: An Interplay of Electron-Hole Exchange Interaction, Crystal Structure, Shape Anisotropy, and Dielectric Mismatch.

In the semiconducting perovskite materials family, the cesium-lead-chloride compound (CsPbCl3) supports robust excitons characterized by a blue-shifted transition and the largest binding energy, thus presenting a high potential to achieve demanding solid-state room-temperature photonic or quantum devices. Here we study the fundamental emission properties of cubic-shaped colloidal CsPbCl3 nanocrystals (NCs), examining in particular individual NC responses using micro-photoluminescence in order to unveil the exciton fine structure (EFS) features. Within this work, NCs with average dimensions ⟨Lα⟩ ≈ 8 nm (α = x, y, z) are studied with a level of dispersity in their dimensions that allows disentangling the effects of size and shape anisotropy in the analysis. We find that most of the NCs exhibit an optical response under the form of a doublet with crossed polarized peaks and an average inter-bright-state splitting, ΔBB ≈ 1.53 meV, but triplets are also observed though being a minority. The origin of the EFS patterns is discussed in the frame of the electron-hole exchange model by taking into account the dielectric mismatch at the NC interface. The different features (large dispersity in the ΔBB values and occasional occurrence of triplets) are reconciled by incorporating a moderate degree of shape anisotropy, observed in the structural characterization, by preserving the relatively high degree of the NC lattice symmetry. The energy distance between the optically inactive state and the bright manifold, ΔBD, is also extracted from time-resolved photoluminescence measurements (ΔBD ≈ 10.7 meV), in good agreement with our theoretical predictions.

Efficient degradation of 4-nitrophenol and colorimetric detection of Fe (III) by biogenic silver nanoparticles of Papiliotrema laurentii

In this study, novel biogenic silver nanoparticles have been developed involving a green method by a yeast strain, Papiliotrema laurentii (Y24) cell resuspension exudate. Synthesis conditions have been optimized and the produced nanomaterials have been characterized by DLS, Zeta Potential, FTIR, XRD, SEM, TEM to predict and analyse the particles. High crystallinity, irregular to cubical shape, and an average dimension of 20 nM of AgNPs were obtained from the characterization. Biogenic Y24-NPs were applied to reduce 4-Nitrophenol to 4-Aminophenol by catalytic activity (within 8 min). After 5 recycles, high reusability of Y24-NPs was observed (≥ 94%). Y24-NPs were further demonstrated for high selectivity and sensitivity towards Fe3＋ by colorimetric detection with the limit of 1.8 μM in the linear range of 5–150 μM. Additionally, the developed nanosensor has been tested for Fe3＋ ions in tap water samples. Therefore, Y24-NPs can be used for bioremediation with significant catalytic activity and reusability.

Synthesis of diaryl dithiocarbamate complexes of zinc and their uses as single source precursors for nanoscale ZnS

Diaryldithiocarbamate complexes, [Zn(S2CNAr2)2], have been prepared with a view to comparing their structures, reactivity and thermally-promoted degradation with respect to the well-studied dialkyl-derivatives. In the solid-state both [Zn{S2CN(p-tol)2}2] and [Zn{S2CN(p-anisyl)2}2] are monomeric with a distorted tetrahedral Zn(II) centre, but somewhat unexpectedly, the bulkier naphthyl-derivative [Zn{S2CN(2-nap)2}2]2 forms dimeric pairs with five-coordinate Zn(II) centres. Preliminary reactivity studies on [Zn{S2CN(p-tol)2}2] suggests that it binds amines and cyclic amines in a similar fashion to the dialkyl complexes and can achieve six-coordination as shown in the molecular structure of [Zn{S2CN(p-tol)2}2(2,2′-bipy)]. The thermal decomposition of [Zn{S2CN(p-tol)2}2] was studied in oleylamine solution by both heat-up and hot-injection methods. Nanorods of ZnS were produced in both cases with average dimensions of 17 × 2.1 nm and 11 × 3.5 nm respectively, being significantly shorter than those produced from [Zn(S2CNiBu2)2] under similar conditions. This is tentatively attributed to the differing rates of amine-exchange between diaryl- and dialkyl dithiocarbamate (DTC) complexes and/or their differing rates of DTC loss following amine-exchange. The solid-state decomposition of [Zn{S2CN(p-tol)2}2] has also been studied at 450 °C under argon affording irregular and large (10–300 µm) sheet-like particles of wurtzite.