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Silk is a filament obtained from animal sources and is advantageous over plant-based fibres for its high uniformity, toughness, crystallinity, and tensile strength. The real source of silk waste is cocoons, which is obtained from the silk industry while reeling and processing. A large volume of fibres discarded as waste even at the later stage of silk fabric manufacturing are termed industrial wastes, which can be utilised for technical applications. This could be achieved through a nonwoven structure, as this engineering fabric would satisfy many technical requirements. This study focuses on the conversion of silk waste into needle-punched nonwoven material at various needle penetration depths to investigate the best penetration depth for an effective engineering structure. This investigation for different properties of nonwoven fabrics was carried out by varying the needle penetration depths, namely 5 mm, 10 mm, and 15 mm because the penetration of needle influences the fabric property. These were assessed for various aspects, namely fabric weight, thickness, stiffness, bulk density, tensile strength, elongation, air permeability, thermal resistance, and scanning electron microscope appearance. The strength of needle-punched fabric structures was noted to be better in machine direction and elongation in cross direction in the prepared fabrics. The sample with the deepest needle penetration of 15 mm exhibited the highest values of 235.6 GSM and 2.45 mm for weight and thickness, respectively. Also the maximum value of 14.7 N for strength in the machine direction, with the maximum elongation over other samples in the cross direction was exhibited by this sample at 15mm depth. Fabric stiffness was noticed to be the highest in the sample, with minimum needle penetration depth of 5 mm in both the directions. The lowest air permeability of 114 ft3/ft2/min and maximum thermal resistance of 46.24 percent in sample at 15-mm needle penetration depth depicts more compactness due to best interlocking of fibres in the structure which is also evident in the scanning electron microscopic appearance. This study aids in inducing an idea for utilizing the fabric as nonwoven structure itself or in converting them into composites using suitable polymers. The significance of the study is the conversion of waste into a potential material through fabrication for serving various fields of engineering in future.

Unconventional superconductivity often emerges in close proximity to a magnetic instability. Upon suppressing the magnetic transition down to zero temperature by tuning the carrier concentration, pressure, or disorder, the superconducting transition temperature Tc acquires its maximum value. A major challenge is the elucidation of the relationship between the superconducting phase and the strong quantum fluctuations expected near a quantum phase transition (QPT) that is either second order (i.e. a quantum critical point) or weakly first order. While unusual normal state properties, such as non-Fermi liquid behavior of the resistivity, are commonly associated with strong quantum fluctuations, evidence for its presence inside the superconducting dome are much scarcer. In this paper, we use sensitive and minimally invasive optical magnetometry based on NV-centers in diamond to probe the doping evolution of the T = 0 penetration depth in the electron-doped iron-based superconductor Ba(Fe1−xCox)2As2. A non-monotonic evolution with a pronounced peak in the vicinity of the putative magnetic QPT is found. This behavior is reminiscent to that previously seen in isovalently-substituted BaFe2(As1−xPx)2 compounds, despite the notable differences between these two systems. Whereas the latter is a very clean system that displays nodal superconductivity and a single simultaneous first-order nematic-magnetic transition, the former is a charge-doped and significantly dirtier system with fully gapped superconductivity and split second-order nematic and magnetic transitions. Thus, our observation of a sharp peak in λ(x) near optimal doping, combined with the theoretical result that a QPT alone does not mandate the appearance of such peak, unveils a puzzling and seemingly universal manifestation of magnetic quantum fluctuations in iron-based superconductors and unusually robust quantum phase transition under the dome of superconductivity.

In past years, lithium-ion batteries (LIBs) can be found in every aspect of life, and batteries, as energy storage systems (ESSs), need to offer electric vehicles (EVs) more competition to be accepted in markets for automobiles. Thick electrode design can reduce the use of non-active materials in batteries to improve the energy density of the batteries and reduce the cost of the batteries. However, thick electrodes are limited by their weak mechanical stability and poor electrochemical performance; these limitations could be classified as the critical cracking thickness (CCT) and the limited penetration depth (LPD). The understanding of the CCT and the LPD have been proposed and the recent works on breaking the CCT and improving the LPD are listed in this article. By comprising these attempts, some thick electrodes could not offer higher mass loading or higher accessible areal capacity that would defeat the purpose.

An ultrashort pulse laser, capable of varying the pulse duration from 0.2 ps up to 10 ps, is used to study the ablation characteristics of stainless steel and cemented tungsten carbide. In addition to the influence of pulse duration, the number of pulses and the wavelength are examined for their influence on the ablation process. By determining the ablation diameter of generated cavities, the ablation threshold of the materials is calculated as a function of the number of pulses, the pulse duration, and the wavelength. The experimentally determined ablation thresholds tend to agree with calculated values. Due to the incubation effect, the ablation threshold decreases with increasing the number of pulses. In this context, the incubation factor (0.81@1030 nm and 0.80@515 nm for stainless steel, 0.90@1030 nm and 0.77@515 nm for cemented tungsten carbide) for the investigated materials is determined. On the basis of the measured ablated volume, the effective penetration depth (a reduction in a range from about 12 nm and 15 nm to 6 nm for stainless steel and in a range from 22 nm and 32 nm to 11 nm and 13 nm for cemented tungsten carbide by increasing the pulse duration from 0.2 ps to 10 ps) of the energy is calculated and it is proven that in the femtosecond regime the penetration depth increases compared with the picosecond regime. In consequence, the efficiency of the ablation process is increased by using shorter laser pulses.

The London penetration depth λ is the basic length scale for electromagnetic behavior in a superconductor. Precise measurements of λ as a function of temperature, field and impurity scattering have been instrumental in revealing the nature of the order parameter and pairing interactions in a variety of superconductors discovered over the past decades. Here we recount our development of the tunnel-diode resonator technique to measure λ as function of temperature and field in small single crystal samples. We discuss the principles and applications of this technique to study unconventional superconductivity in the copper oxides and other materials such as iron-based superconductors. The technique has now been employed by several groups world-wide as a precision measurement tool for the exploration of new superconductors.

In this study, the effect of internal pores formed by a superabsorbent polymer (SAP) was analyzed by evaluating the compressive strength, chloride penetration depth, drying shrinkage, and pore size distribution of SAP-containing concrete, while securing workability using a water-reducing agent (WRA). The experimental results showed that the amount of WRA necessary increased as the amount of SAP added increased, and that the compressive strength was the highest when the SAP content was 1.5% of the concrete mix. Drying shrinkage tended to decrease as the SAP content increased, and it decreased by approximately 31–41% when the SAP content was 2.0% compared to that of the reference mix. The SAP expanded by approximately three times inside concrete, and it was distributed within the internal pores of air-entrained concrete. The optimal SAP content in concrete mix was 1.5%, and an SAP content of 2.0% or higher adversely affected the workability and compressive strength.

Penetration depth is a critical factor determining joint strength in butt welding; however, it is difficult to monitor in keyhole-mode laser welding due to the dynamic nature of the keyhole. Recently, optical coherence tomography (OCT) has been introduced for real-time keyhole depth measurement, though accurate results require meticulous calibration. In this study, deep learning-based models were developed to estimate penetration depth in laser welding of 780 dual-phase (DP) steel. The models utilized coaxial weld pool images and spectrometer signals as inputs, with OCT signals serving as the output reference. Both uni-sensor models (based on coaxial pool images) and multi-sensor models (incorporating spectrometer data) were developed using transfer learning techniques based on pre-trained convolutional neural network (CNN) architectures including MobileNetV2, ResNet50V2, EfficientNetB3, and Xception. The coefficients of determination values (R2) of the uni-sensor CNN transfer learning models without fine-tuning ranged from 0.502 to 0.681, and the mean absolute errors (MAEs) ranged from 0.152 mm to 0.196 mm. In the fine-tuning models, R2 decreased by more than 17%, and MAE increased by more than 11% compared to the previous models without fine-tuning. In addition, in the multi-sensor model, R2 ranged from 0.900 to 0.956, and MAE ranged from 0.058 mm to 0.086 mm, showing better performance than uni-sensor CNN transfer learning models. This study demonstrated the potential of using CNN transfer learning models for predicting penetration depth in laser welding of 780DP steel.

The growing demand for watertight concrete structures is conducive to the development of research in this area, but their results are rarely published. In order to partially fill this gap, the authors of the publication present the results of research into the effect of fly ash addition on the watertightness of concrete. Prior to the tests, a recipe for a concrete mix with the addition of a sealing admixture modified with fly ash was developed. The following properties were analyzed: consistency of the concrete mix, air content in the concrete mix, compressive strength of concrete, depth of penetration of water under pressure, and frost resistance of concrete for F150 level. The work meets the expectations of the construction industry with respect to the production of concrete structures resistant not only to the penetration of water into concrete but also resistant to aggressive substances dissolved in water that accelerate the destruction of concrete and corrosion of reinforcement bars. Based on the test results, it was found that the addition of fly ash to the concrete mix enhances the positive impact of the applied sealing admixture, increasing the tightness of the concrete. It reduces the depth of penetration of water under pressure and therefore increases the frost resistance of concrete.

The structural organization and dynamic nature of the biomembrane components are important determinants for numerous cellular functions. Particularly, membrane proteins are critically important for various physiological functions and are important drug targets. The mechanistic insights on the complex functionality of membrane lipids and proteins can be elucidated by understanding the interplay between structure and dynamics. In this regard, membrane penetration depth represents an important parameter to obtain the precise depth of membrane-embedded molecules that often define the conformation and topology of membrane probes and proteins. In this review, we discuss about the widely used fluorescence quenching-based methods (parallax method, distribution analysis, and dual-quencher analysis) to accurately determine the membrane penetration depths of fluorescent probes that are either membrane-embedded or attached to lipids and proteins. Further, we also discuss a relatively novel fluorescence quenching method that utilizes tryptophan residue as the quencher, namely the tryptophan-induced quenching, which is sensitive to monitor small-scale conformational changes (short distances of < 15 Å) and useful in mapping distances in proteins. We have provided numerous examples for the benefit of readers to appreciate the importance and applicability of these simple yet powerful methods to study membrane proteins.Graphic abstract

Weld quality monitoring and assessment in industrial robotic arc welding processes is key to ensure suitability of a component for the intended application. In particular, weld penetration depth is as a major fabrication requirement that has to be addressed. Several alternatives have been proposed based on the use of individual monitoring techniques, but, due to the physical challenges of the welding process and accessibility restrictions to the weld root, multi-sensor approaches have been recently developed. These methods require the adoption of complex setups or calibration strategies. In this work, a multi-sensor approach is proposed to create a calibration tool for weld penetration depth assessment, overcoming physical accessibility restrictions and enabling depth evaluation instantaneously, opening the gate for online usage.