Enhancing Knee Osteoarthritis severity level classification using diffusion augmented images

This research paper explores the classification of knee osteoarthritis (OA) severity levels using advanced computer vision models and augmentation techniques. The study investigates the effectiveness of data preprocessing, including Contrast-Limited Adaptive Histogram Equalization (CLAHE), and data augmentation using diffusion models. Three experiments were conducted: training models on the original dataset, training models on the preprocessed dataset, and training models on the augmented dataset. The results show that data preprocessing and augmentation significantly improve the accuracy of the models. The EfficientNetB3 model achieved the highest accuracy of 84\% on the augmented dataset. Additionally, attention visualization techniques, such as Grad-CAM, are utilized to provide detailed attention maps, enhancing the understanding and trustworthiness of the models. These findings highlight the potential of combining advanced models with augmented data and attention visualization for accurate knee OA severity classification.Comment: Paper has been accepted to be presented at ICACECS 2023 and the final version will be published by Atlantis Highlights in Computer Science (AHCS) , Atlantis Press(part of Springer Nature

Chemical Design Rules for Non-Fullerene Acceptors in Organic Solar Cells

Efficiencies of organic solar cells have practically doubled since the development of non-fullerene acceptors (NFAs). However, generic chemical design rules for donor-NFA combinations are still needed. Such rules are proposed by analyzing inhomogeneous electrostatic fields at the donor-acceptor interface. It is shown that an acceptor-donor-acceptor molecular architecture, and molecular alignment parallel to the interface, results in energy level bending that destabilizes the charge transfer state, thus promoting its dissociation into free charges. By analyzing a series of PCE10:NFA solar cells, with NFAs including Y6, IEICO, and ITIC, as well as their halogenated derivatives, it is suggested that the molecular quadrupole moment of ca 75 Debye A balances the losses in the open circuit voltage and gains in charge generation efficiency

Remarkable conductivity enhancement in P-doped polythiophenes via rational engineering of polymer-dopant interactions

Molecular doping is an effective approach to tune the charge density and optimize electrical performance of conjugated polymers. However, the introduction of dopants, on the other hand, may disturb the polymer microstructure and disrupt the charge transport path, often leading to a decrease of charge carrier mobility and deterioration of electrical conductivity of the doped films. Here we show that dopant-induced disorder can be overcome by rational engineering of polymer-dopant interactions, resulting in remarkable enhancement of electrical conductivity. Benchmark poly(3-hexylthiophene) (P3HT) and its analogous random polymers of 3-hexylthiophene and thiophene P[(3HT)1-x-stat-(T)x] were synthesized and doped by 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ). Remarkably, random P[(3HT)1-x-stat-(T)x] was doped to a far superior electrical conductivity, that in the case of x ≥ 0.24, the conductivity of P[(3HT)1-x-stat-(T)x] is over 100 times higher than that of the doped P3HT, despite both P3HT and P[(3HT)1-x-stat-(T)x] exhibit comparable charge carrier mobility in their pristine state and in spite of their practically identical redox properties. This result can be traced back to the formation of π-stacked polymer-dopant-polymer co-crystals exhibiting extremely short packing distances of 3.13–3.15 \uc5. The mechanism behind these performances is based on a new role played by the dopant molecules that we name “bridging-gluing”. The results are coherently verified by the combination of optical absorption spectroscopy, X-ray diffraction, density functional theory calculations, and molecular dynamics simulations

Synthesis and characterization of spark plasma sintered FeAl and in situ FeAl–Al₂O₃ composite

In the present work, nanocrystalline FeAl and FeAl–Al2O3 composite were synthesized by high energy ball milling and subsequent compaction by spark plasma sintering. Microstructural changes during all stages of processing are studied using X-ray analysis. After 20 h of milling, the disordered FeAl and some amount of Fe rich solid solution was obtained in both of these compositions. Subsequent heat treatment results in formation of ordered FeAl. However, disordering of FeAl was observed in both compositions after spark plasma sintering. Nanocrystallinity is retained in both the compositions even after sintering at high temperature of 1,000°C. Very high hardness of ∼575 HV1 and ∼600 HV1 was exhibited by FeAl and FeAl–Al2O3 composite

Efficient Hybrid Amorphous Silicon Organic Tandem Solar Cells Enabled by Near Infrared Absorbing Nonfullerene Acceptors

Monolithically stacked tandem solar cells present opportunities to absorb more of the sun s radiation while reducing the degree of energetic loss through thermalization. In these applications, the bandgap of the tandem s constituent subcells must be carefully adjusted so as to avoid competition for photons. Organic photovoltaics based on nonfullerene acceptors NFAs have recently exploded in popularity owing to the ease with which their electrical and optical properties can be tuned through chemistry. Here, highly complementary and efficient 2 terminal tandem solar cells are reported based on a wide bandgap amorphous silicon absorber, and a narrow bandgap NFA bulk heterojunction with power conversion efficiencies PCEs exceeding 15 . Interface engineering of this tandem device allows for high PCEs across a wide range of light intensities both above and below 1 sun. Furthermore, the addition of an inorganic silicon subcell enhances the operational stability of the tandem by reducing the light stress experienced by the bulk heterojunction, resolving a long standing stumbling block in organic photovoltaic researc