Glass Foils Research Articles

Studying the optical properties of assembled silver and gold nanoparticles for the purpose of creating SERS sensors

The optical properties of silver and gold sols with different sizes of nanoparticles and the method of their chemical deposition on the surface of silicon, silicon oxide, glass and aluminum foil were studied in order to obtain SERS substrates – promising platforms for the development of aptamer sensors and immunochemical analysis of various pathogens. It has been established that for operation on lasers with exciting radiation wavelengths of 532, 638 and 785 nm, it is possible to create universal SERS substrates based on colloidal solutions obtained by the liquid-phase chemical method with an average silver particle size of 40 nm and by the Leopold-Lendl method with an average size of 20 nm.

Burst pressure prediction of carbon/natural fiber and hybrid composite pressure vessels by theoretical and numerical analysis

This study utilized finite element modeling to assess the stress and burst strength of a composite pressure vessel (CPV). The fiber type and its sequences were considered while developing the best CPV. The stress produced inside the CPV may cause damage to the vessel as well as loss of life and property. Therefore, it is critical to guarantee that the CPV's stress output does not surpass the vessel material's maximum allowable stress value. The primary goal of this research is to investigate the stresses induced in composite pressure vessels and then examine the stress using three different solutions: von Mises, Tresca, and ASSY. The theoretical burst strength is first established, and then a numerical solution is developed using ABAQUS. To confirm the correctness of FEA, the outcomes of the theoretical technique and the finite element method are compared. The six-layer carbon fiber-reinforced CPV shows twelve times higher burst strength than four layers but an equal thickness of jute fiber-based CPV. On the other hand, the hybrid combination of CPV (jute and carbon) shows a strength improvement over jute fiber based CPV by almost four times. Other jute fiber-based hybrid CPVs with glass, banana, and aluminum foil show very comparable strength relative to only jute CPV. This study's primary goal is to examine the failure phenomena and burst strength of thin, cylindrical pressure vessels.

One-step hydrothermal synthesis of sulfur quantum dots for detection of Hg2+ ions and latent fingerprints

High blue-emitting sulfur quantum dots (SQDs) with quantum yields of up to 58.7% were prepared using elemental sulfur using a facile ethylenediamine-assisted hydrothermal acceleration method at 60 °C for 7 h. In the presence of ethylenediamine, bulk sublimated sulfur powder can be broken down into fine particles of sulfur-nitrogen compounds and then oxidized to produce SQDs. HRTEM analysis of the morphology of SQDs showed that SQDs had a quasi-spherical shape with a size of 3.2 nm. In this process, under the influence of ethylenediamine, sublimated sulfur is rapidly converted from zero-valent sulfur to polysulfide with simple heating, greatly improving manufacturing efficiency. Synthesized fluorescent sulfur quantum dots (SQDs) were used in this study as fluorescent probes for quantitative detection of Hg2+. The SQD served as an effective Hg2+ detection probe with a detection limit of 2.7 μM through an efficient on-off switching mechanism in response to Hg2+. In addition, latent fingerprints were recognized using SQD powder, and fingerprints were detected on the surfaces of various media, such as paper, glass, and aluminum foil. The synthesized SQDs have a high potential for sensing applications of various luminescent materials.

Влияние заполнения прослоек малотеплопроводными газами на тепловую защиту оконных блоков с экранами

ISPU scientists have developed energy-saving constructions of window units with heat-reflecting screens, have tested them in a climate chamber, and have carried out simulation modeling of the heat transfer process through these constructions. Despite a large number of scientific papers that consider experimental laboratory studies and numerical simulation of heat transfer processes through translucent constructions, there is no data on the effect of the application of low thermal conductivity gases in the gaps formed by glass and metal elements on increasing the thermal protection of window units with screens. The correct calculation of the reduced heat transfer resistance of window units with screens and low-thermal conductivity gases affects the correctness of the heat balance for premises and, consequently, the quality of the design of energy systems to ensure the indoor microclimate. Thus, the development of models of heat transfer process through a window unit with screens is an urgent task to ensure the indoor microclimate. Simulation numerical modeling is carried out using the finite element method based on the fundamental laws of heat transfer. The authors have developed a two-dimensional simulation model of heat transfer through a window unit with heat-reflecting screens, in which the gaps between the glass and aluminum foil are filled with argon and krypton. The distribution of resistance to heat transfer along the height of a translucent enclosing structure has been studied. The adequacy of the proposed simulation model is confirmed by comparison with data of other scientists and regulatory documentation. Filling the gaps between glass and metal foil with argon makes it possible to increase the zonal heat transfer resistance of a window unit with screens in relation to the base-case scenario (air) by 6–23 %, krypton by 8–58 % (depending on the measurement location and the number of screens). The application of the developed simulation model will make it possible to more accurately determine the potential to use heat-reflecting screens in windows for intermittent heating systems of buildings.

Numerical Modeling of Kevlar/Jute Fiber and Hybrid Composite Pressure Vessels

In this study, nine composite overwrapped pressure vessel (COPV) models (type IV) have been developed to analyze their burst pressure performance using the ultimate tensile strength (UTS) from experiment and the von Mises stress profile from finite element ABAQUS simulation. The four-layer jute-reinforced PV shows almost five times lower burst pressure than Kevlar-based PV, indicating the inherent vulnerability of using pure jute. However, for the hybrid jute/Kevlar alternate combination, JKJK shows strength improvement over a jute PV by almost two times. Other jute hybrids with glass and aluminum foil show very comparable performance when compared to jute PV. Both yarn and braided-type jute fiber exhibit similar operating conditions, indicating that the preparation type of jute fiber is invariant to pressure performance. However, COPVs woven with 90° cross-oriented jute fibers are found to have the most degraded strength, highlighting that fiber orientation remains an important optimization factor in designing PVs with hybrid composite wraps.

Multiphysics model for assessing photoelectrochemical phenomena under concentrated irradiation

A multiphysics model was developed for a photoelectrochemical (PEC) cell at the device level to simulate water splitting operating under concentrated irradiation (between 50 to 600 kW m−2). The 2D model couples charge, heat, mass, photon, and momentum transfer to predict local current densities, potential distributions, temperature profiles, volumetric gas fractions, pressure, and velocities profiles in the electrolyte. Electrode kinetics and electrolyte resistance were considered for the electrochemical processes, and two-phase bubbly-flow under laminar conditions for momentum transfer. The effects of bubbles on the incident photon flux and the thermal and electrical conductivities of the electrolyte were also considered. Photocurrent densities were estimated using a semiempirical correlations dependent on potential, charge transfer efficiencies, and temperature. The model was applied to a custom-made cell utilising a spray pyrolysed Sn-doped Fe2O3 photoanode, a material with well-known photoelectrochemical behaviour and stability. Transparent conductive glass and titanium foil were investigated as two possible photoanode substrates. Predictions indicate that commercial conductive glasses are not suitable substrates due to a significant ohmic drop caused by high current densities. The model illustrates that thermal and bubble management are critical to improving the overall performance of a PEC cell subjected to high photon flux. Furthermore, the model can be used to decouple the phenomena that occur under such conditions and could assist in the study of photoelectrode materials under high irradiance.

Houttuynia cordata Thunb. crude extract inactivates Cronobacter sakazakii: Antibacterial components, antibacterial mechanism, and application as a natural disinfectant

The purpose of this study was to reveal the antibacterial components of Houttuynia cordata Thunb. crude extract (HCCE), analyze the antibacterial activity and mechanism of HCCE against Cronobacter sakazakii, and evaluate the bactericidal effect of HCCE as a natural disinfectant. Using an ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-QE-MS) non-target metabolomics technology, 15 kinds oforganic acids (18.65%), 14 kinds of phenols (16.17%), 10 kinds of flavonoids (12.32%), 5 kinds of terpenoids (5.87%), 3 kinds of alkaloids (1.62%), and 3 kinds of aldehydes (1.28%) were detected from HCCE. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of HCCE against C. sakazakii were 7.5 mg/mL and 15 mg/mL, respectively, and when the concentration was 2 MIC, C. sakazakii stagnated in sluggish phase. C. sakazakii exposed to HCCE showed hyperpolarization of cell membrane, increased intracellular ROS content, decreased protein and DNA content, impaired cell membrane integrity, improved cell membrane permeability, cell fluid leakage, and partial cell fragmentation. After treatments with 1 MIC and 2 MIC of HCCE for 5 min, C. sakazakii strains on 8 contact surfaces including stainless steel, tinplate, glass, polystyrene, bamboo, plank, ceramic, and tin foil paper were significantly inhibited (P < 0.05), and the reduction amounts ranged from 3.00 to 3.68 log CFU/100 cm2 and 3.97 to 4.53 log CFU/100 cm2, respectively. These findings demonstrate the potential of HCCE as a natural disinfectant and provide a new idea to reduce the C. sakazakii contamination caused by surface contact.

Characterization of Magnetron Sputtered BiTe-Based Thermoelectric Thin Films.

Thermoelectric (TE) technology attracts much attention due to the fact it can convert thermal energy into electricity and vice versa. Thin-film TE materials can be synthesized on different kinds of substrates, which offer the possibility of the control of microstructure and composition to higher TE power, as well as the development of novel TE devices meeting flexible and miniature requirements. In this work, we use magnetron sputtering to deposit N-type and P-type BiTe-based thin films on silicon, glass, and Kapton HN polyimide foil. Their morphology, microstructure, and phase constituents are studied by SEM/EDX, XRD, and TEM. The electrical conductivity, thermal conductivity, and Seebeck coefficient of the thin film are measured by a special in-plane advanced test system. The output of electrical power (open-circuit voltage and electric current) of the thin film is measured by an in-house apparatus at different temperature gradient. The impact of deposition parameters and the thickness, width, and length of the thin film on the power output are also investigated for optimizing the thin-film flexible TE device to harvest thermal energy.

A survey of toxic elements in ready to eat baby foods in the US market 2021

ABSTRACT A non-targeted convenience survey was conducted in 2021 to estimate the range of total arsenic (As), cadmium (Cd), total mercury (Hg) and lead (Pb) concentrations in ready-to-eat baby foods. Four hundred samples were purchased both online and in brick-and-mortar retail. Samples included both organic and non-organic products, packaged in glass or plastic jars and foil or plastic pouches. Samples were analysed by acid assisted microwave digestion and ICP-MS with an emphasis on ultra-low detection limits. Limits of quantification were 2.26, 1.31, 0.72, and 3.14 µg/kg (ppb) for As, Cd, Hg and Pb, respectively. The median concentrations of As, Cd, Hg, and Pb in tested products were 2.60, 1.81, 0.09, and 1.38 µg/kg, respectively. Foods containing rice were more likely to contain arsenic. Foods with leafy greens, such as spinach and kale, were more likely to contain cadmium and foods with root vegetables had the highest concentrations of lead.

Antibacterial effect of surface-modified Zr50Cu50 metallic glass

Zr-based metallic glasses generally have an amorphous zirconium oxide film that strongly inhibits further oxidation. However, surface defects may deteriorate the glass stability of the amorphous oxide film, leading to the formation of a thick natural oxide layer. In this study, we demonstrated that the change in the oxidation behavior of a melt-spun Zr50Cu50 metallic glass foil caused by the surface casting defects on its wheel side can lead to a dramatic improvement in antibacterial properties. The superior antibacterial properties of the wheel side was attributed to the metallic Cu islands exposed on the surface.

Micro-mechanism for nanocrystallization of laminated Fe-based metallic glass foil side-milled

Although various achievements were made in past years to improve the mechanism of cystallization of metallic glass using annealing or deformation processes, the relationship between the micromechanisms of nanocrystalline formation in metallic glass while milling has not been thoroughly investigated. To elaborate on the connection between plastic deformation, stress, temperature, and nanocrystallization, the laminated Fe-based metallic glass foil (FMGF) was machined by side-milling with and without ultrasonic vibration. Plastic deformation can accelerate nucleation and therefore nanocrystallization with respect to phase separation in FMGF at high temperatures. The nanocrystal distributions in the FMGF milled with ultrasonic vibration is cyclical along the milling direction. The temperature of the nucleation and growth mechanism associated with phase separation is higher than that of the nucleation mechanism based on the linked-flus model. The results provide insights on the effects of plastic deformation and high temperature in the crystallization of FMGF.

Ultra-thin glass seals for protection against unauthorized tampering by permanent monitoring of optical integrity parameters

The advancement of high technology manipulation tools to gain unauthorized access to security eminent hardware in mobile devices demands more sophisticated tamper protection solutions. We developed sensory seal envelopes of ultra-thin glass with individual optical spectra used as signature for tamper protection of electronic controls or cryptographic communication units. A miniaturized autonomic read-out system detects and analyzes the state of the seal. The read-out system is located in the protected area under the seal, together with the secret, in order to protect against attacks via electronic interfaces, such as the mimicry of signature data and the deceptive simulation of the seal's integrity. We introduced a single optical waveguide Bragg grating element via femtosecond laser processing into ultra-thin glass slides. This single Bragg grating combines different functions: It is a sensor element which diffracts the light out-of-plane and doing this in a dispersing manner to create a unique spectral signature. This combination allows a miniaturization of the optical analysis of the dispersed light. We demonstrated that a single waveguide Bragg grating element, inscribed into a monolithic ultra-thin glass foil of 10 cm x 10 cm size, is sufficient for the registration of marginal local mechanical forces onto the glass foil, causing vertical deformations of less than 50 µm at any position. In case of manipulation attempts, such as drilling, cutting, and lasing through the glass foil, the seal's monitoring system recognizes the change or complete loss of the individual spectral signature immediately. We present all elements needed for an optical tamper protection system, based on the sensory seal envelopes of ultra-thin glass in a miniaturized setup, thus reflecting the high potential for future commercial solutions.

Material Characteristics and Comparison of Silver Foil Glass Beads Excavated from the Tomb of King Muryeong in Korea

This study investigated the comprehensive characteristics of silver foil beads excavated from the Tomb of King Muryeong, based on composition analysis of the foil and glass and morphological characterization. The major element components of metal foil and glass were investigated using a scanning electron microscope (SEM) equipped with an Energy Dispersive X-ray spectrometer (EDS). Trace elements were determined using LA-ICP-MS to constrain the source of the raw material. The morphological characteristics of the beads were recognized through an optical microscope. As a result of the analysis, the metal foil was detected as pure in both gold- and silver-colored glass beads. The chemical composition of the glass was determined as a soda glass, with Na+ acting as a flux and CaO added as a stabilizer to improve durability. It was confirmed that plant ash was used because MgO and K2O were found to contain more than 1.5%. Through trace element analysis, it was confirmed that the gold and silver-colored silver foil glass beads were made of plant ash glass using different materials. The content of Fe2O3 was significantly higher in the gold-colored silver foil glass beads than in the silver-colored silver foil glass beads. Therefore, it can be interpreted that the gold-colored silver foil glass beads excavated from the tomb of King Muryeong intentionally achieved the appearance of gold foil glass beads by controlling the color of the outer glass. The silver foil glass beads showed morphological differences according to the color of the outer glass. The gold-colored silver foil glass beads were manufactured as single or segment types, but the silver-colored silver foil glass beads were manufactured as segment types.

Effect of Bacteriocin (ALC102) of Enterococcus faecium GRD AA on Biofilm Forming Listeria monocytogenes MTCC 657

Antilisterial bacteriocin producing strain were isolated from milk samples and were subjected to 16S rRNA sequencing and found to be of genus Enterococcus faecium. The bacteriocin ALC102 were partially purified by Amberlite XAD-16 adsorption followed by column chromatography. The biofilm formation capacity of Listeria monocytogenes MTCC 657 were evaluated by tube method and CV binding assay. Biofilm formation on different abiotic substrates were also evaluated. Among three substrates stainless steel had a strong biofilm formation followed by glass and aluminum foil. From the results of biofilm eradication studies, the bacteriocin ALC102 showed almost similar activity of commercial bacteriocin nisin on all the substrates at 45°C, 30°C, 4°C and -20°C. Based on CBD® biofilm eradication assay, the eradication potential of ALC102 and nisin were found to be similar on high (45°C) and freezing (-20°C) temperatures. From the study, antilisterial bacteriocin ALC102 found to be able to inhibit the biofilm formed Listeria monocytogenes MTCC 657 at different temperatures and different incubation periods (24h, 48h and 72h). The biofilm eradication potential of antilisterial bacteriocin ALC102 was similar to nisin. Neither incubation temperature nor incubation period doesn’t altered the activity of the bacteriocin. So this bacteriocin can be considered as a potential competitor in food industry and we strongly recommend the use of this bacteriocin from Enterococcus faecium GRD AA in the food preservation industry to a higher temperature (45°C) to freezing temperature (-20°C).

Strength of 444 Stainless Steel Single-Lap Joints Brazed with Ni-Based Metallic Glass Foils for Corrosive Environments

Strength of 444 Stainless Steel Single-Lap Joints Brazed with Ni-Based Metallic Glass Foils for Corrosive Environments

An experimental investigation of ZnO nanostructures on various substrates using electrodeposition method

In this study, zinc oxide (ZnO) nanostructures were fabricated on the fluorine doped tin-oxide (FTO) glass and zinc (Zn) foil substrates by the electrodeposition method. After the preparation, ZnO nanostructures were characterized by Fourier transform infra-red (FTIR), fluorescence (FL) spectroscopy, field emission scanning electron microscopy (FESEM) and energy dispersive x-ray (EDX) spectroscopy, respectively. FTIR spectra confirmed the presence of Zn-O stretching vibrational modes at 445 cm−1 and the FL emission spectrum of both samples revealed the highest quenching fluorescence emission at ∼650 nm with the excitation wavelength of 320 nm. Further, the FESEM morphological images showed the well-defined and uniformly grown nanostructures (nanorod, nanowire and cauliflower-like structures) on the substrates. It was shown the diameter of the ZnO nanorods on FTO and ZnO cauliflower-like on Zn foil varies at 19.56–60.89 nm and 50.41–76.4 nm. Finally, EDX spectra endorsed the presence of ‘Zn’ and ‘O’ elements on the samples.

Optical properties and bipolar resistive switching of ZnO thin films deposited via DC magnetron sputtering

This work presents a study of the resistive switching behavior of ZnO thin films deposited via DC magnetron sputtering. Thin films were deposited on soda-lime glass and Ti foils, varying ZnO target power, between 80 W and 120 W, and substrate temperature, between 293 K and 423 K. All samples were submitted to annealing processes in situ at 473 K for 2 h. XRD measurements allowed identifying the ZnO wurtzite phase, while AFM micrographs showed the surface formation characterized by small, elongated grains of approximately 80 nm wide. Optical properties were determined by the Swanepoel method using transmittance spectra in the range of 300 nm to 1100 nm. The band-gap obtained was about 3.28 eV for the ZnO thin film, and the refractive index and extinction coefficient were calculated. Modification of the transport mechanism was associated with high defect concentration in the samples and contributed to resistive changes. I-V curves were performed in the -1 V–1 V range and showed a bipolar switching behavior in all samples. A correlation between the variation of synthesis parameters, structural characterization, and shape of bipolar switching effect was evidenced through a change in the resistance states and thickness of thin films. This research provides an insight into the fabrication and control of the resistive switching behavior for resistive random access memories.

Potassium-silicate glass foil irradiated with electrons – Asymmetry in migration and space distribution given by the elastic scattering of electrons on potassium atoms

Binary potassium silicate glass 15K2O·85SiO2 was prepared in the form of a thin foil and was irradiated with electrons in the transmission mode. A defocused beam of 10, 20, 30, and 50 keV energy was used to prevent a significant temperature increase. Both, the front and back surfaces were depleted of potassium by the irradiation, but not to the same extent; the front surface was quickly fully depleted of potassium, but the backside only partially. The potassium depth distribution was not consistent with the assumed shape of the electric field established in the solid, but was significantly shifted from the middle of the foil. The found asymmetry is due to the momentum transfer from the elastic scattering of the incident electron to the potassium ion, which acts as an additional effective force.

Strength of 316L Stainless Steel Single-Lap Joints Brazed with Ni-Based Metallic Glass Foils for Corrosive Environments

In brazing, the choice of base metal, brazing filler metal (BFM), and braze process conditions involves complex tradeoffs among cost, mechanical strength, corrosion resistance, and others. In this work, the tradeoff between strength and corrosion resistance of 316L stainless steel joints brazed with a newer “very corrosion-resistant” Ni-Cr-P-Mo-Si BFM and a more established “corrosion-resistant” Ni-Cr-Si-B BFM is quantitatively analyzed. Corrosion tests and microstructural analyses were performed using common practices. Joint strength was evaluated by testing brazed single-lap joints (SLJs) in tension following standardized procedures. However, conventional interpretations were found to be inadequate for quantitative comparisons. Therefore, the SLJ stress state was analyzed in detail and a complete interpretation was developed. Joint strength is shown to be determined by the SLJ geometry, base metal properties, and braze microstructure. This analysis was used to explain the occurrence of different failure modes (fast fracture, peeling, and base metal failure) and to make suggestions for improved methods for conducting and analyzing brazed SLJ tensile tests. The newer BFM is shown to provide significantly better corrosion resistance for a moderate reduction in mechanical strength.

Optical Index Matching, Flexible Electrospun Substrates for Seamless Organic Photocapacitive Sensors

Recent advances in optoelectronics are often based on thin‐film organic semiconductors. Interesting organic semiconductors are given by squaraines, small molecules that show excitonic coupling with visible light and are thus suitable for applications in solar cells and light sensors. While such squaraine thin films have already been proven to be suitable for stimulation of neuronal model cells, the integration into, e.g., the human eye to support blind people necessitates forming thin layers on seamless substrates. Herein, squaraine films are spin‐coated on electrospun nanofiber mats and nanomembranes, prepared from polyacrylonitrile, and made conductive by spin coating with poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). The fibrous non‐woven texture of the nanofiber mats and membranes alters the thin film formation of the squaraine compound considerably compared with preparation on planar, nonsoaking substrates such as glass and polyethylene terephthalate (PET) foil demanding further engineering regarding material's choice and processing conditions.