Plasma-activated water (PAW) is enriched with reactive oxygen and nitrogen species (RONS). Application of PAW in plant cultivation demonstrated that RONS promote seed germination and early plant growth, as well as stimulate plant defense mechanisms. The aim of this paper was to investigate the potential of reactive nitrogen species in PAW to partially replace urea fertilizer nitrogen in lettuce cultivation without resulting in a negative effect on growth and mineral composition. Lettuce was grown under two treatments: urea only and a combined treatment in which 10% of the urea-derived nitrogen was replaced by an equivalent amount of nitrogen supplied via plasma-activated water (PAW). Plant growth parameters of lettuce (number of leaves, head weight, rosette diameter and height, and dry matter weight) were measured. Concentrations of 21 elements in the plants were analyzed using inductively coupled plasma optical emission spectroscopy (ICP—OES). Results showed no significant difference in growth parameters between the two treatments, as well as no significant difference between treatments in the concentrations of most elements except magnesium, boron and sodium. The results demonstrate that PAW reactive nitrogen can partially substitute for nitrogen from synthetic fertilizer without negative effects on the growth and nutritional content of lettuce. The study contributes to the development of sustainable horticultural fertilization practices and the adoption of environmentally friendly technologies.
Characterizing both the radial (p) and azimuthal (ℓ) indices of Laguerre-Gaussian (LG) beams remains a challenge mainly due to their transverse amplitude profiles. We report a simple yet robust method for simultaneously identifying both mode indices using an off-axis parabolic mirror (OPM). The far-field diffraction pattern produced by an incident LG beam on OPM exhibits characteristic spot distributions, which can be analyzed to determine the magnitude and sign of the topological charge, as well as the radial index. Furthermore, we show that this technique exhibits excellent tolerance to beam misalignment. Experimental results show good agreement with numerical simulations.
In this study, the effect of Mg addition on the composition and aging of water samples treated with nitrogen plasma was analyzed. The study focused on the measurements of the pH of the samples and the comparison of chosen oxygen and nitrogen reactive species (RONS) concentrations formed as a result of the plasma reaction and their changes over time. The results showed that the addition of Mg increased the concentration of RONS compared to the control samples. The pH changes resulting from the reaction of magnesium with water were also observed. Stability studies of the resulting composition also showed that the addition of Mg improved the stability of H2O2, NO3⁻, and NO2⁻ ions in water samples. The results suggest that it may be useful in water purification processes, environmental decontamination, and in analytical techniques requiring accurate control of chemical components in solutions. Additionally, it can be used in medicine and agriculture, where accurate analysis and stabilization of the composition of solutions are crucial.
Raman spectroscopy has become an indispensable tool for in operando monitoring in preparative mechanochemistry due to its ability to provide real-time, non-invasive insight into solid-state reactions. While commercial systems based on fiber Raman probes offer ease of use and plug-and-play deployment, their relatively low spectral resolution and lower sensitivity make them less suitable for the specific demands of mechanochemical reaction monitoring. To address these challenges and make this valuable methodology widely available, we describe a high-sensitivity free-optics Raman system, termed mcRS (mechanochemical Raman System), constructed from the ground up using affordable off-the-shelf optical components. The mcRS includes a free-space Raman probe and a custom-designed dispersive spectrometer utilising only lenses, paired with a low-cost industrial-grade CMOS camera as the detector. By fine-tuning the optics to minimise photon loss and achieving tighter spot sizes on the detector, the mcRS provides a 30% improvement in spectral resolution compared to previous in-house fiber-based systems for half of the cost and offers a five-fold reduction in price compared to commercial systems. This is accompanied by a five-fold improvement in time resolution and a novel feature, the possibility to simultaneously collect Raman data and monitor the rheology of the sample, which often plays an important role in mechanochemical reactions. We validated the mcRS performance by monitoring the reaction between ZnO and imidazole under neat grinding (NG) and liquid-assisted grinding (LAG) conditions, using ethanol as the liquid additive. The enhanced capabilities of the mcRS offer significant advancements in the in situ studies of mechanochemical processes, allowing for differentiation between two zeolitic imidazolate framework products based on subtle differences in the high-frequency modes (3100-3200 cm-1).
In this study, we present an analysis of deflections in a Morpho butterfly wing using digital holographic interferometry (DHI). Our methodology revolves around an off-axis lensless Fourier holographic setup, using laser excitation to induce deflections in the object. The implementation of a DHI setup, tailored for rapid monitoring of micro-deformation, is a central aspect of our research. We offer an overview of the theoretical foundations of this technique, complemented by both experimental and numerical results aimed at validating our findings. We designed an optical setup that enhanced both laser illumination and hologram reconstruction for the sample. The experimental findings decisively show that the proposed method is effective for rapid deformation analysis. The deformation of the wing can be measured with micro-meter accuracy thanks to numerical analysis.
Blue diode lasers are alternative curing devices for dental composites. The aim of this study was to investigate the influence of blue diode laser polymerization on shear bond strength of bulk fill composites to human dentin and temperature rise during two types of polymerization. Composite cylinders of SDR Plus(SDR) and Ever X Flow(EX) were bonded to dentin slabs using Adhese Universal and curing devices blue diode laser (449 nm, 1.6 W) and Power Cure LED. For each material and curing device there were two polymerization approaches: 1)conventional: separate curing of adhesive; 2)co-curing: simultaneous adhesive and composite curing. Polymerization modes for each material in conventional and co-curing(c) approach were: blue laser 2000 mW/cm2 for 5 s (L5 and L5c); blue laser 1000 mW/cm2 for 10 s (L10 and L10c); Power Cure 2000 mW/cm2 for 5 s (LED5 and LED5c); Power Cure 1000 mW/cm2 for 10 s (LED10 and LED10c). Temeperature was measured using thermal vision camera. For SDR, the highest bond strength was 24.3 MPa in L10c, and the lowest 9.2 MPa in LED5c. EX exhibited the highest bond strength(21.3 MPa) in LED5, and the lowest in L5(7.7 MPa). The highest temperature rise for SDR was in L10 and L5 (7.3 and 7.2 °C), and the lowest in LED5(0.8 °C). For EX, the highest temperature rise was in L5 (13.0 °C), and the lowest in LED5 (0.7 °C). Temperature rise was higher during blue laser polymerization, especially at high intensity and with conventional curing. Preferable blue laser curing mode is co-curing at 1000mW/cm2 for 10 s.
Directed by successfully manufacturing the computer-generated hologram (CGH) using the computer-to-film (CtF) process, we present, to the best of our knowledge, a new method for low-cost and fast hologram manufacturing. This new method allows for advances in the CtF process and manufacturing using new techniques in hologram production. These techniques include computer-to-plate, offset printing, and surface engraving utilizing the same CGH calculations and prepress. With an advantage in cost and the possibility to be mass manufactured, the aforementioned techniques combined with the presented method have a solid foundation to be implemented as security elements.
The objective of this study was to compare the polymerization kinetics of bulk-fill resin composites cured with a LED-curing device and a diode laser (449 nm). Three bulk-fill composites were light-cured with constant radiation exposure at 10 J/cm2 by varying radiant exitance and curing time. The following three light-curing protocols were used: (I) 3300 mW/cm2 for 3 s; (II) 2000 mW/cm2 for 5 s; and (III) 1000 mW/cm2 for 10 s. The degree of conversion (DC) was monitored in real time at a data acquisition rate of 2 spectra/s over a 5-min period and again after seven days using Fourier transform infrared spectroscopy. DC amounted to 30.9–61.7% at 4-mm depth after 5 min. DC values of two sculptable composites were significantly higher with the laser, regardless of the curing protocol used, but not for the flowable composite. The maximum polymerization rate (2.0–22.1%/s) was less affected by the type of curing device for one of the composites, while the other two composites achieved significantly higher values when cured with the laser. Laser curing generally increased the DC and the maximum polymerization rate while it shortened the onset of the maximum reaction rate. New handheld laser devices with adjustable power have the potential to be used as a photopolymerization light source for new generations of bulk-fill composites.
Signal detection and imaging in invisible spectral regions is interesting in both military and civil applications. This work examines the possibility of making a camera that would use the thermophoretic effect on certain biomimetic microstructures caused by radiation coming from the broad spectral range. The microstructures are inspired by the micron lamellae that we find in butterfly wings, and a proposed imaging device would not be limited to visible light but could be sensitive in other parts of the spectrum (ultraviolet and infrared). The microstructures are ordered in a pixelized focal point array (FPA). This device would not be based on bimaterial thermal expansion as some previous optomechanical imaging devices [1], but on thermophoresis aided by air molecules at normal pressure.
The aim of this work was to determine if PAW (Plasma Activated Water) seed treatment and growing conditions could have positive effects on lettuce seedlings and growth. The paper presents the results of a pot experiment on lettuce (Lactuca sativa L.) cultivation in greenhouse and field conditions after seed treatment with PAW. The experiment was conducted in two consecutive seasons in 2021 and 2022 and the following growth parameters were measured: head mass, rosette height, rosette width, number of leaves, root mass and root length. As a result of the study, it was found that lettuces grown in the greenhouse from PAW treated seeds had higher results in the first measurement for both cultivars (mass 32.26%, diameter 19.01%, number of leaves 13.49% and height 24.01%), while there were no statistically significant effects on the root system. The lowest results were obtained in untreated and field-grown plants. In addition, plant dry matter was measured and it was found that plants grown from PAW treated seeds had a higher percentage of dry matter (11.51% in 2021, and 11.58% in 2022). It was also found that cultivation in greenhouse resulted in a better quality of plants than the cultivation in the open field.
We demonstrate a method based on a unique sinusoidally shaped phased grating for efficient and nearly alignment free detection of both signs and modulus of the orbital angular momentum (OAM) of light. OAM detection efficiency is almost the same over the whole grating area. The capability and robustness of this method are demonstrated by detection of optical vortices with OAM topological charge up to 150 using a reflective phase-only liquid crystal on a silicon spatial light modulator.
In this study, the morphological, pomological, and nutritional values of wild and cultivated rosehip fruits grown in the Slavonia region of eastern Croatia were studied. The results revealed significant differences in several morphological and pomological characteristics among the rosehip genotypes in terms of fruit weight, flesh weight, seed weight, and fruit flesh ratio, with no significant differences in fruit width, fruit length, fruit shape index, seed number per fruit, or seed length. The evaluated rosehip fruit genotypes differed significantly from each other in terms of hectoliter weight (kg), fruit bulk (cm3), and bulk density (kg/m3). For water–soluble extracts, ash, and pH, no statistical difference was found between naturally grown genotypes, but there was a significant difference between naturally grown and cultivated genotypes. Twenty-three major and trace elements were analyzed. The most abundant elements were K, Ca, Mg, and P in both cultivated and naturally grown fruits. The highest concentrations of microelements were Fe, Al, Mn, and Sr. The conventionally cultivated genotype L1 had the highest concentration of Fe and Na as essential elements for humans but also had the highest concentrations of Al, Sr, Ti, V, Cr, Pb, Co, Li, and As of all the genotypes studied. The naturally grown genotype L4 had the highest concentrations of S, Zn, Rb, and Cd and the lowest concentrations of Mg, K, and Ca among all studied genotypes. The data showed that the analyzed genotypes from eastern Croatia had good nutritional quality and variability, making them suitable as genetic resources and possibly leading to the detection of rosehip genotypes as potential sources of beneficial ingredients for human health.
This study assessed the influence of rapid 3 s light curing on the new generation of bulk-fill resin composites under the simulated aging challenge and depths up to 4 mm. Four bulk-fill materials were tested: two materials designed for rapid curing (Tetric PowerFill—PFILL; Tetric PowerFlow—PFLW) and two regular materials (Filtek One Bulk Fill Restorative—FIL; SDR Plus Bulk Fill Flowable—SDR). Three-point bending (n = 10) was used to measure flexural strength (FS) and flexural modulus (FM). In the 3 s group, two 2 mm thick specimens were stacked to obtain 4 mm thickness, while 2 mm-thick specimens were used for ISO group. Specimens were aged for 1, 30, or 30 + 3 days in ethanol. The degree of conversion (DC) up to 4 mm was measured by Raman spectroscopy. There was no difference between curing protocols in FS after 1 day for all materials except PFLW. FM was higher for all materials for ISO curing protocol. Mechanical properties deteriorated by increasing depth (2–4 mm) and aging. ISO curing induced higher DC for PFLW and FIL, while 3 s curing was sufficient for PFILL and SDR. The 3 s curing negatively affected FM of all tested materials, whereas its influence on FS and DC was highly material-specific.
Femtosecond laser pulses were employed to make rectangular cavities in hard dental tissue by simultaneously monitoring the temperature rise in tooth. Following ‘gentle ablation’, the surface left after ablation was smooth with closed dental tubules.
We studied the absorption spectrum of dense rubidium vapor generated in a T-type sapphire cell with a special emphasis on the structured photoionization continuum observed in the 200-300nm spectral region. The photoionization spectrum has a continuous atomic contribution with a pronounced Seaton-Cooper minimum at about 250nm and a molecular photoionization contribution with many broad bands. We discuss the possible origin of the photoionization bands as stemming from the absorption from the ground state of the Rb-2 molecule to excited states of Rb-2+* and to doubly excited autoionizing states of Rb-2** molecule. All these photoionization bands are located above the Rb+ and Rb-2(+) ionization limits. (C) 2018 Elsevier Ltd. All rights reserved.
We used the superheating of the dense alkali vapor in order to separate atomic from the molecular photoionization spectrum. Homonuclear and heteronuclear alkali molecules are essentially two electron systems and therefore simultaneous excitation of two atoms above the ionization limit will form autoionizing potential curves which will bring about new bands in the photoionization spectrum. We present a satisfactory comparison between experimental and theoretical emission coefficient function of diffuse bands (cesium dimer excimer) at temperatures up to 1000 °C, where the metal vapor was heavily superheated. New results for Rb2 photoionization process reveal similar structured photoionization continuum but with reduced number of photoionization bands.
We report on the observation of three RbCs satellite bands in the blue and green ranges of the visible spectrum. Absorption measurements are performed using all-sapphire cell filled with a mixture of Rb and Cs. We compare high resolution absorption spectrum of Rb-Cs vapor mixture with pure Rb and Cs vapor spectra from the literature. After detailed analysis, the new satellite bands of RbCs molecule at 418.3 nm, 468.3, and 527.5 nm are identified. The origin of these bands is discussed by direct comparison with difference potentials derived from quantum chemistry calculations of RbCs potential energy curves. These bands originate from the lower Rydberg states of the RbCs molecule. This study thus provides further insight into photoassociation of lower Rydberg molecular states, approximately between Cs(7s) + Rb(5s) and Cs(6s) + Rb(6p) asymptotes, in ultracold gases.
To investigate the effects of bleaching agent on microhardness, color and light transmission of different restorative materials. Specimens (n=20) of Tetric EvoCeram (TEC), Tetric EvoCeram Bulk Fill (TECBF) and Equia Fill (EQUIA) were treated with either 40% hydrogen peroxide Opalesence Boost or destilled water for 45 min. Specimens were stained in tea solution or stored in deionized water for one and two weeks. Color, microhardness and light transmission were monitored at the baseline, after the bleaching and after the tea immersion or storage in deionized water. After the bleaching a significant reduction in surface microhardness (p<0.001) was recorded for all materials. Clinically visible color change (ΔE>3) was observed after the bleaching and after treatment in tea solution, but only in EQUIA samples. The absorption coefficient was the largest for the samples stained in tea solution. Bleaching can affect the microhardness and color of fillings; therefore, they should be sometimes replaced.
OBJECTIVESTo evaluate 1) the influence of five bleaching agents (with additional light activation) on enamel and dentin surface microhardness and chemical composition and 2) the remineralizing potential of artificial saliva and amorphous calcium phosphate (ACP).METHODS AND MATERIALSThe study was conducted on 125 human third molars dissected into quarters for separate enamel and dentin measurements. The bleaching process was performed with 38% and 25% hydrogen peroxide (HP) and 30%, 16%, and 10% carbamide peroxide (CP) gels two times for 15 minutes each time. All bleaching gels were tested alone and in combination with ZOOM2, light-emitting diode (LED), organic LED, and femtosecond laser. A total of 25 bleaching combinations (n=10) were evaluated. Microhardness was measured by a Vickers diamond. Chemical analysis was performed using energy-dispersive X-ray spectroscopy.RESULTSBleaching agents used in the absence of light activation caused a significant reduction in enamel and dentin surface microhardness (p<0.001), ranging from 8% for 16% CP to 40% for 25% HP. The effects of different light activations were negligible. After two-week treatment with ACP and artificial saliva, maximum deviation from baseline microhardness was just 3%. Such treatment increased the concentrations of calcium, phosphorus, and fluorine.CONCLUSIONSAn increase in peroxide concentration and gel acidity negatively affected microhardness and concentrations of calcium and phosphorus in enamel and dentin. ACP and artificial saliva stimulated the remineralization of hard tissues.