Key role of surface plasmon polaritons in generation of periodic surface structures following single-pulse laser irradiation of a gold step edge

Understanding the mechanisms and controlling the possibilities of surface nanostructuring is of crucial interest for both fundamental science and application perspectives. Here, we report a direct experimental observation of laser-induced periodic surface structures (LIPSS) formed near a predesigned gold step edge following single-pulse femtosecond laser irradiation. Simulation results based on a hybrid atomistic-continuum model fully support the experimental observations. We experimentally detect nanosized surface features with a periodicity of ∼300 nm and heights of a few tens of nanometers. We identify two key components of single-pulse LIPSS formation: excitation of surface plasmon polaritons and material reorganization. Our results lay a solid foundation toward simple and efficient usage of light for innovative material processing technologies.

Making and Using AI in the Library: Creating a BERT Model at the National Library of Sweden

How can novel AI techniques be made and put to use in the library? Combining methods from data and library science, this article focuses on Natural Language Processing technologies in especially national libraries. It explains how the National Library of Sweden’s collections enabled the development of a new BERT language model for Swedish. It also outlines specific use cases for the model in the context of academic libraries, detailing strategies for how such a model could make digital collections available for new forms of research: from automated classification to enhanced searchability and improved OCR cohesion. Highlighting the potential for cross-fertilizing AI with libraries, the conclusion suggests that while AI may transform the workings of the library, libraries can also have a key role to play in the future development of AI.

Identifying optimal cycles in quantum thermal machines with reinforcement-learning

The optimal control of open quantum systems is a challenging task but has a key role in improving existing quantum information processing technologies. We introduce a general framework based on reinforcement learning to discover optimal thermodynamic cycles that maximize the power of out-of-equilibrium quantum heat engines and refrigerators. We apply our method, based on the soft actor-critic algorithm, to three systems: a benchmark two-level system heat engine, where we find the optimal known cycle; an experimentally realistic refrigerator based on a superconducting qubit that generates coherence, where we find a non-intuitive control sequence that outperforms previous cycles proposed in literature; a heat engine based on a quantum harmonic oscillator, where we find a cycle with an elaborate structure that outperforms the optimized Otto cycle. We then evaluate the corresponding efficiency at maximum power.

Silk Microlens Array

Optics that are capable of merging with biomaterials create a variety of opportunities for sensing disease, for therapeutics, and for augmenting brain-machine interface. The FDA has approved silk devices for sutures and reconstructive surgery. Recently, a silk product made from regenerated silk protein is FDA approved for orthopedic application, as the understanding of structure and processing technologies of silk fibroin has been improved. Here, we report a facile fabrication process to construct silk microlens array. The process includes preparation of regenerated silk solution and casting on a micropatterned poly(dimethylsiloxane) (PDMS) master. Due to the identical surface area of a unit patterned regime, the silk solution exhibits a partial wetting state in the vicinity of the silk solution–PDMS–vapor interface with same contact angle, and after drying, produces consistent radius of curvature within the microlens array. This in turn provides highly uniform focal length, focal spot diameter, and imaging performance of individual lens. Our results provide the foundation for biophotonic microlens adding new capabilities for implantable and degradable devices from regenerated silk protein.

Experimental Models of Glaucoma

Optic nerve pits are a mono- or bilateral congenital anomaly represented by optic disc depressions of various sizes. In half of the cases, the pits are complicated by edema, central retinal detachment and retinoschisis, and cause visual function decrease. Visual acuity losses can be either insignificant or pronounced. Optic discs pits have been investigated massively over the last century and a half, but their etiology is still underresearched. In recent years, however, due to the development of digital scanning and data processing technologies and the emergence of non-invasive highly informative diagnostic methods, it has become possible to reveal structural and functional changes of the optic disc in vivo, in addition to the traditional detection of histological changes in cadaveric eyes.Glaucomatous process modeling is one of the challenges in ophthalmology. And this is due primarily to the fact that, so far, the main reasons for the onset and progression of glaucoma. Numerous works on experimental research in its core model ocular. However, there are forms of glaucoma, which are independent of the level of intraocular pressure. Ideal model of glaucoma is considered a model with the development of the characteristic symptom in which a key symptom is a slowly progressive excavation of the optic nerve. But given the new knowledge in the pathogenesis of neurodegenerative changes in glaucoma in this model should be added and the opportunity to study the brain, vascular factors of progression, the level of neurotransmitters, trophic factors, etc. Therefore, we tried to make the analysis of models of glaucoma in various experimental animals and determine the most appropriate model for studying the pathogenesis of glaucoma.

Application of High-Intensity Ultrasound to Improve Food Processing Efficiency: A Review

The use of non-thermal processing technologies has grown in response to an ever-increasing demand for high-quality, convenient meals with natural taste and flavour that are free of chemical additions and preservatives. Food processing plays a crucial role in addressing food security issues by reducing loss and controlling spoilage. Among the several non-thermal processing methods, ultrasound technology has shown to be very beneficial. Ultrasound processing, whether used alone or in combination with other methods, improves food quality significantly and is thus considered beneficial. Cutting, freezing, drying, homogenization, foaming and defoaming, filtration, emulsification, and extraction are just a few of the applications for ultrasound in the food business. Ultrasounds can be used to destroy germs and inactivate enzymes without affecting the quality of the food. As a result, ultrasonography is being hailed as a game-changing processing technique for reducing organoleptic and nutritional waste. This review intends to investigate the underlying principles of ultrasonic generation and to improve understanding of their applications in food processing to make ultrasonic generation a safe, viable, and innovative food processing technology, as well as investigate the technology’s benefits and downsides. The breadth of ultrasound’s application in the industry has also been examined. This will also help researchers and the food sector develop more efficient strategies for frequency-controlled power ultrasound in food processing applications.

Microstructure and High-Temperature Performance of High K-Doped Tungsten Fibers Used as Reinforcement of Tungsten Matrix

Tungsten (W) fiber-reinforced tungsten (Wf/W) composite with ultra-high strength and high-temperature resistance is considered an attractive candidate material for plasma-facing materials (PFM) in future fusion reactors. The main component of Wf/W composite is tungsten wire, which is obtained through powder metallurgy and the drawing process. In this paper, high potassium (K)-doped tungsten wires with 98 ppm of K and 61 ppm of impurities are prepared using traditional and optimized processing technologies, respectively, and a comparative study with conventional K-doped tungsten wires with 83 ppm of K and 80 ppm of impurities is conducted. The high-temperature mechanical properties as well as the microstructure’s evolution of the prepared tungsten wires are investigated. The results show that the high-temperature performance of K-doped tungsten wires is improved by increasing the K content and by simultaneously reducing the impurities. By adopting small compression deformation and low-temperature processing technology, the high-temperature performance of high K-doped tungsten wires can be further improved. A microstructure analysis indicates that the excellent high-temperature performance is attributed to a combination of the small K bubble size, high K bubble number density, and long K bubble string, which are produced through optimization of the processing technology. A study on the processing technology and the performance of tungsten wires with a high K content and a high purity can provide important information regarding Wf/W composites.

Historical aspects and current views of the etiopathogenesis and clinical manifestations of optic nerve pits

Optic nerve pits are a mono- or bilateral congenital anomaly represented by optic disc depressions of various sizes. In half of the cases, the pits are complicated by edema, central retinal detachment and retinoschisis, and cause visual function decrease. Visual acuity losses can be either insignificant or pronounced. Optic discs pits have been investigated massively over the last century and a half, but their etiology is still underresearched. In recent years, however, due to the development of digital scanning and data processing technologies and the emergence of non-invasive highly informative diagnostic methods, it has become possible to reveal structural and functional changes of the optic disc in vivo, in addition to the traditional detection of histological changes in cadaveric eyes.

Quantitative Identification Cracks of Heritage Rock Based on Digital Image Technology

Digital image processing technologies are used to extract and evaluate the cracks of heritage rock in this paper. Firstly, the image needs to go through a series of image preprocessing operations such as graying, enhancement, filtering and binaryzation to filter out a large part of the noise. Then, in order to achieve the requirements of accurately extracting the crack area, the image is again divided into the crack area and morphological filtering. After evaluation, the obtained fracture area can provide data support for the restoration and protection of heritage rock. In this paper, the cracks of heritage rock are extracted in three different locations.The results show that the three groups of rock fractures have different effects on the rocks, but they all need to be repaired to maintain the appearance of the heritage rock.