Ultraviolet Spectrophotometer Research Articles

Antioxidant and Antibacterial Activities Evaluation, Phytochemical Characterisation of Rhizome from Angiopteris helferiana and Barks from Saurauia fasciculata in Nepal

Ethnomedicinally, more than 2000 plants were found to be used in Nepal. Among them, the red colored rhizome of Angiopteris helferiana and the bark of Saurauia fasciculata have been used widely to treat muscle fatigue, bone pain, fever, postpartum hemorrhage, and thirst by healers in Kaski and Tanahun districts, Nepal. However, scientific evidence towards their traditional uses is lacking till December, 2023. Therefore, we report the phytochemicals, total phenolic content (TPC), total flavonoid content (TFC), total carbohydrate content (TCC), antioxidant and antibacterial activities of A. helferiana and S. fasciculata extracts. Phytochemical analysis indicated that A. helferiana and S. fasciculata extracts were potential sources of chemicals such as phenols, flavonoids, tannins, terpenoids, saponins, and carbohydrates. The TPC, TFC, and TCC of extracts were determined by using an ultraviolet visible spectrophotometer. Among the extracts tested, A. helferiana extracts showed the highest phenolic and carbohydrate contents of 208.33 ± 12.96 mg of gallic acid equivalent/g and 564.16 ± 2.92 mg of D‐glucose equivalent/g of dry extract, respectively. Similarly, S. fasciculata revealed the highest flavonoid content of 30.35 ± 0.1 mg quercetin equivalent/g of dry extract. The extract of A. helferiana and S. fasciculata exhibited potent antioxidant activity by scavenging 2,2‐diphenyl‐1‐picrylhydrazyl radicals with an IC50 of 25.9 µg/ml and 31.07 µg/ml, respectively. The antibacterial activity of the A. helferiana and S. fasciculata extract against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli was determined using an agar‐well diffusion protocol that revealed the potential antibacterial activity of A. helferiana against E. coli. The present study will help validate the traditional uses of A. helferiana rhizomes and S. fasciculata barks as a healing medicine and inspire the researcher towards further research, development, and formulation.

Investigating the Effect of Ph Variation on the Optoelectronic and Structural Properties of Electrodeposited Copper Selenide Thin Films.

Copper Selenide (CuSe) thin film compound semiconductors have been deposited onto fluorine doped tin oxide (FTO) conducting substrates using electrodeposition technique through various electrolytic bath pH values of 2.00, 2.20, and 2.40. The deposition was carried out in potentiostatic mode using a 2-electrode system set-up at room temperature for 15 minutes at the cathodic voltage of 500 mV. The electrical and the optical properties of the thin films were carried out using photoelectrochemical (PEC) cells and ultraviolet visible spectrophotometer respectively. CuSe thin film possesses a p-type electrical conductivity and the sample grown at semiconductor and a pH of 2.2 was recorded to have the highest PEC signal and highest photo and dark currents that brings forth its maximum power. The energy band gap values of the electrodeposited CuSe thin films were observed to be 2.30 eV, 2.20 eV, and 2.00 eV at bath pH values of 2.0, 2.2, and 2.4 respectively. The optical band obtained at the various pH decreases as pH increases and these band gap values agree with the bulk band gap of CuSe. The preferred orientation peak of electrodeposited CuSe layers exists as klockmannite (CuSe) and the highest peak intensity for the preferred orientation peak occurred at pH of 2.20. At this pH value, the electrodeposited CuSe layers have the highest crystallite sizes.

Preconcentration and measurement of trace Amitriptyline hydrochloride in water samples using magnetic nanoparticles with dispersive solid‐phase extraction

AbstractIn the separation and determination of trace amounts of drugs in aqueous samples, there is a major challenge in synthesizing highly efficient, cost‐effective, and easy‐to‐use adsorbents based on natural polymers, which are also biocompatible and biodegradable. In the proposed method, magnetite nanoparticles (Fe3O4) on chitosan (as the carrier) modified with β‐cyclodextrin (BCD) were used as a suitable adsorbent for the pre‐concentration and solid‐phase extraction of trace amounts of Amitriptyline HCl (hydrochloride). Ultraviolet spectrophotometer (λ = 236 nm) was the main instrument used for analyte detection and quantification. Moreover, X‐ray diffraction, Fourier transform infrared spectroscopy, Field Emission Scanning Electron Microscopy, and Energy‐Dispersive X‐ray were used for the identification and characterization of the structure and morphology of the adsorbent and to establish the formation of the synthesized magnetic nanosorbents, as well as to confirm the analyte binding to the adsorbent. Experimental variables affecting the extraction/pre‐concentration and determination of the analyte were investigated and optimized; pH of the sample solution, the amount of NaCl salt (in terms of ionic strength of the solution), the amount of adsorbent, temperature, adsorption time, and volume of the eluent (methanol) were the optimized parameters. Finally, the method was successfully applied for the determination of spiked Amitriptyline hydrochloride (HCl) in tap water and human urine samples. Also, High‐Performance Liquid Chromatography was performed on the aqueous samples to compare the proposed method with the USP (the United States Pharmacopeia) standard method of Amitriptyline HCl assay and after performing a t‐test (confidence level of 95%), no significant difference was observed between the two methods. High accuracy and precision (RSD = 3.91%), High analysis speed, few limitations, low expenses, pure extracted analyte, and low waste were the advantages of this method. This method was also compatible with many existing device methods. Under the optimized experimental conditions, the calibration graph was linear in the range of 0.183 to 50 mg.L−1 with a correlation coefficient of 0.996. RSD of the method was 3.91%, the limit of detection was 37.8 µg.L−1, the maximum sorption capacity of the adsorbent for Amitriptyline hydrochloride was 306.525 mg.g−1 and the preconcentration factor was 3.61. Eventually, the proposed method was compared to other methods that have been performed for the determination of Amitriptyline hydrochloride.

Enhanced Electrochemical and Safety Performance of Electrocatalytic Synthesis of NH3 with Walnut Shell-Derived Carbon by Introducing Sulfur

An efficient catalyst is key to achieving the synthesis of electrochemical ammonia and improving safety. In this work, using biomass walnut shell as a carbon source and sodium thiosulfate as a sulfur source, sulfur-modified walnut shell-derived carbon material was synthesized via a simple low-temperature impregnation method at room temperature and atmospheric pressure as an effective electrochemical ammonia synthesis catalyst with high thermal stability. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), nitrogen adsorption–desorption apparatus, thermogravimetry (TG), and other characterization methods were applied to analyze the micro-morphology and physicochemical structure of the electrocatalyst. The synthesized ammonia performance of the catalyst was measured using an ultraviolet (UV) spectrophotometer and electrochemical workstation. The catalyst design used the doping of sulfur atoms to create rich catalytic active sites, while the presence of elemental sulfur on the catalyst surface provided hydrophobicity, which was conducive to inhibiting competitive hydrogen evolution reaction (HER) and enhancing the electrocatalytic ammonia synthesis performance of the catalyst. Under normal temperature and pressure conditions, when a voltage of −0.45 V was applied, the ammonia yield in 0.05 M H2SO4 electrolyte was 10.39 μgNH3 mgcat.−1 h−1. The results showed that the introduction of sulfur effectively improved the electrocatalytic and thermal safety performance of bio-derived carbon materials, and the test presented that the performance of the catalyst was stable and reusable.

Portable visual and electrochemical detection of hydrogen peroxide release from living cells based on dual-functional Pt-Ni hydrogels

It is important to monitor the intra-/extracellular concentration of hydrogen peroxide (H2O2) in biological processes. However, miniaturized devices that enable portable and accurate H2O2 measurement are still in their infancy because of the difficulty of developing facile sensing strategies and highly integrated sensing devices. In this work, portable H2O2 sensors based on Pt-Ni hydrogels with excellent peroxidase-like and electrocatalytic activities are demonstrated. Thus, simple and sensitive H2O2 sensing is achieved through both colorimetric and electrochemical strategies. The as-fabricated H2O2 sensing chips exhibit favorable performance, with low detection limits (0.030 μM & 0.15 μM), wide linearity ranges (0.10 μM–10.0 mM & 0.50 μM–5.0 mM), outstanding long-term stability (up to 60 days), and excellent selectivity. With the aid of an M5stack development board, portable visual and electrochemical H2O2 sensors are successfully constructed without complicated and expensive equipment or professional operators. When applied to the detection of H2O2 released from HeLa cells, the results obtained by the developed sensors are in good agreement with those from an ultraviolet‒visible spectrophotometer (UV‒vis) (1.97 μM vs. 2.08 μM) and electrochemical station (1.77 μM vs. 1.84 μM).

Evaluation of antibacterial effect of a cationic porphyrin derivative on Pseudomonas aeruginosa in photodynamic therapy

BackgroundPseudomonas aeruginosa is a gram-negative bacterium without spores, and it is one of the pathogens that easily cause secondary infectious diseases when human immune function is low. The purpose of this study is to explore the inhibitory effect of photodynamic antibacterial chemotherapy-induced by cationic porphyrin derivative on clinical P. aeruginosa and its mechanism. MethodsThe uptake of photosensitizer by P. aeruginosa and L929 cells was measured by an ultraviolet spectrophotometer. Effect of laser energy density on the bacterial activity of P. aeruginosa and post antibiotic effect were measured by bacterial suspension and tenfold dilution method. Flow cytometry and scanning electron microscopy were used to observe the activity and morphological changes of P. aeruginosa after PACT treatment. ResultsThe uptake of Tetra-ATPP-Lys-by P. aeruginosa and L929 was shown as concentration-dependent and time-dependent. However the uptake of L929 cell had a clear difference with P. aeruginosa at the same time and concentration intervals(P < 0.05).The increasing laser energy density had a high inactivation effect of on P. aeruginosa at the same Tetra-ATPP-Lys-concentration(P < 0.05). Post-antibiotic effect of Tetra-ATPP-Lys -PACT was dose-dependent(P < 0.05). Bacterial viability which evaluated by the flow cytometry method demonstrated that the proportion of viable bacteria is decreased with the photosensitizer dose-dependent. The morphology and microstructure of P. aeruginosa after Tetra-ATPP-Lys -PACT was demonstrated by a scanning electron microscope(SEM). After PACT, the morphology of P. aeruginosa was rod-shaped, the outer membrane surface was rough, and the bacteria were dry flat, sunken, shrunk and deformed. ConclusionsCationic porphyrin photosensitizer had a great damage effect on P. aeruginosa under the PACT, which can effectively destroy the microstructure of bacteria and lead to bacterial inactivation and death.

Dual anticancer activity of Aspergillus nidulans pigment and Ionizing γ-Radiation on human larynx carcinoma cell line

BackgroundFungi are a readily available source of naturally generated colored compounds. These compounds might be used as radiosensitizers for treating cancer cells.MethodsAspergillus nidulans was examined for its color-producing ability in Potato dextrose agar (PDA) broth medium. The pigment was characterized by Ultraviolet (UV) spectrophotometer and Gas Chromatography Mass Spectrometry (GC/MS). Pigment extracts from A. nidulans were studied for their cytotoxic effects on the growth of human larynx carcinoma cell line (HEp-2) with or without exposure to γ-radiation at three different doses (5, 10, and 15 Gy). A. nidulans pigment cytotoxic activity was tested against normal Vero cells. Cell apoptosis was studied using flow cytometry. Gene expression of P53, Caspase 3 and Bcl-2 were quantified.ResultsUltraviolet spectrum and GC/MS revealed the ability of Aspergillus nidulans to produce Rhodopin pigment. HEp-2 cells treated with A. nidulans pigment only give IC50 about 208 µg/ml. In contrast, when treated with the pigment +10 Gy γ-radiation, it give about 115 µg/ml. However, for normal cells, lower cytotoxic activity was detected. Treatment with pigment (208 g/mL) caused about 50% ± 1.0 total apoptosis level and gene expression of P53: 2.3 fold and Caspase 3: 1.84 fold in respect to untreated HEp-2), while Bcl-2 was decreased (Bcl-2: 0.63 fold in respect to untreated HEp-2). Furthermore, treated with pigment (115 µg/mL) + 10Gy caused about 47.41% ± 1.7 total apoptosis level and P53: 2.53 fold and Caspase 3: 2.0 fold in respect to untreated HEp-2, while Bcl-2 was downregulated (Bcl-2: 0.61 fold in respect to untreated HEp-2).ConclusionThis study concluded that the anti-cancer activity of Aspergillus nidulans pigment was enhanced by ionizing radiation at 10 Gy, as well as its low cytotoxic activity against normal Vero cells.

HSI combined with CNN model detection of heavy metal Cu stress levels in apple rootstocks

In recent years, the prolonged application of copper-based fungicides, ripening agents, and fertilizers in agricultural activities has resulted in copper (Cu) levels in the soil exceeding safe levels. Excess Cu has a negative impact on plant growth and crop yields. The practice of grafting horticultural crops onto appropriate rootstocks is frequently employed as a preventive measure against copper accumulation and its associated toxicity. Therefore, the selection of high-quality rootstocks that are not contaminated with heavy metal Cu is important for the growth of grafted crops and the breeding of grafted crops. This study proposed a technique based on convolutional neural network (CNN) and hyperspectral imaging (HSI) for the rapid, non-destructive, and accurate identification of copper contamination levels in apple rootstocks. The effect of different heavy metal Cu contamination levels on leaves was obtained by measuring chlorophyll content in leaves using the ultraviolet spectrophotometer method. A hybrid strategy for spectral variable selection was utilized, involving competitive adaptive reweighted sampling and successive projection algorithms. A traditional partial least squares discriminant analysis linear classification model, and least squares support vector machine, random forest, and extreme learning machine nonlinear models were developed. The results showed that the accuracy of the CNN model and Macro-F1 were 99.6% and 99.2%, respectively, which were better than the traditional linear and nonlinear models. Principal component analysis and t-distributed stochastic neighbor embedding were used for visual analysis to investigate the clustering patterns among sample classes. The results indicated that the combination of CNN and HSI techniques has great potential for classifying copper contamination levels in apple rootstocks.

Mechanism of sugar degradation product 5-hydroxymethylfurfural reducing the stability of anthocyanins.

The coexistence of anthocyanin with the sugar degradation product 5-hydroxymethylfurfural (5-HMF) is inevitable during the processing and storage of anthocyanin-rich juices. It was determined from our study that lower concentrations of 5-HMF have little effect on the stability of Cyanidin-3-O-glucoside (C3G), and even cause a slight increase for a short period of time. As the concentration of 5-HMF increased, the retention of C3G decreased and the color of the solution changed from orange-red to purple-red. The reaction sites of 5-HMF and C3G in its hemiketal form were predicted by quantum chemical calculations in order to investigate the pathways of action of the two. The degradation mechanism of 5-HMF on anthocyanin was verified by Ultraviolet and Visible spectrophotometer and Ultra performance liquid chromatography-mass spectrometry. Therefore, this article provides further theoretical support for the study of the effect of furfural compounds, which are sugar degradation products, on the stability of anthocyanins.

High efficient COVID-19 waste co-pyrolysis char/TiO2 nanocomposite for photocatalytic reduction of Cr(VI) under visible light.

Titanium dioxide (Titania) nanoparticle-coated biochar derived through co-pyrolysis of COVID-19 waste face mask (WFM) and Moringa oleifera seed cake (MO) provides an effective way to alleviate toxic metal in wastewater. This study investigates the effects of Biochar/titania photocatalyst preparation, characterization, and its photoreduction of Cr(VI). The morphological and functional modifications in the catalyst were identified using X-Ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, ultraviolet spectrophotometer, surface area analysis, and Raman spectrophotometer, respectively. The influencing parameters, namely, pH, photocatalyst dosage, initial pollutant concentration, and visible light irradiation time, have been investigated. The findings reveal that the Cr(VI) reduction by the photocatalyst was highly facilitated by photocatalytic process. The prepared photocatalyst shows higher and faster reduction rate of Cr(VI) and also improves the catalyst stability. The photoreduction of Cr(VI) ensembles well with pseudo-first order kinetics. At 180 min of reaction time, maximum Cr(VI) reduction of 98.65% was achieved at pH 2, 0.3 g/L catalyst dosage, and 10 ppm initial concentration, respectively. The synthesized photocatalyst shows excellent recycling performance up to 7 times, and these studies proved that the prepared catalyst is cost-effective and efficiently employed for removing pollutants.

In situ temperature-compensated ultraviolet spectrophotometry to estimate nitrate and chloride concentrations in estuarine seawater with different salinity and composition

Various methods have been proposed for in situ measurement of nitrate concentrations from the ultraviolet (UV) absorbance spectrum of seawater with stable salinity and constituents. However, salinity and temperature affect the UV absorption spectrum of seawater. In sea areas with large variability in salinity and water temperature, accurate nitrate ion concentration measurements remain challenging. We performed in situ measurements of nitrate, chloride, and bromide in estuarine seawater with different salinity compositions and applied water temperature compensation. First, the impact of water temperature on the UV absorbance of chloride, bromide, and nitrate was experimentally investigated and represented in a mathematical model. Next, chloride, bromide, and nitrate concentrations were estimated by suppressing the impact of residual components from the UV absorbance spectra of seawater using principal component regression (PCR). Hence, the chloride, bromide, and nitrate concentrations were determined by measuring the UV absorbance spectrum of seawater alone, without measuring water temperature and electrical conductivity. The proposed method was more accurate (±1.39 μM below 100 μM and ±0.90 μM below 20 μM) than the conventional method (±2.35 μM below 100 μM and ±1.88 μM below 20 μM) and PCR without water temperature compensation (±3.67 μM). In a field study, an in situ UV spectrophotometer with water temperature compensation was used to measure depth profiles of nitrate concentrations in estuarine seawater. We successfully measured the depth profiles of low chloride and high nitrate concentrations in the surface layer as well as high chloride and low nitrate concentrations in the lower layer. The proposed method enables in situ measurements of nitrate concentrations in waters with either stable or highly variable salinity and composition. Unlike conventional chemical analysis, our method can describe detailed spatiotemporal variations in nitrate concentrations.

Rosa damascena flower mediated phytofabrication of palladium nanoparticles, in-vitro and in-vivo applications

The formation of palladium nanoparticles is described in this research work as being simple, affordable, and non-toxic. This study employed Rosa damascena flower extract to effectively reduce ions to palladium nanoparticles. Biogenic formation of palladium nanoparticles (PdNPs) is characterized using Ultraviolet spectrophotometers, FTIR, XRD spectrophotometers, and TEM. The SPR peak was recorded at 360 nm in UV–visible analysis of biologically formed palladium nanoparticles. The diameter of the synthesized palladium nanoparticles was around approx 50 nm with a spherical shape. These biologically formed palladium nanoparticles demonstrated notable antibacterial activities. After antibacterial testing of palladium nanoparticles further check for anti-inflammatory and analgesic activity on rat model. These finding indicate that the flower extract of R.damascena is an excellent bio-reductant for the formation of palladium nanoparticles and has promise for employment in several fields in biomedical application.

Updated temperature correction for computing seawater nitrate with in situ ultraviolet spectrophotometer and submersible ultraviolet nitrate analyzer nitrate sensors

AbstractSensors that use ultraviolet (UV) light absorption to measure nitrate in seawater at in situ temperatures require a correction to the calibration coefficients if the calibration and sample temperatures are not identical. This is mostly due to the bromide molecule, which absorbs more UV light as temperature increases. The current correction applied to in situ ultraviolet spectrophotometer (ISUS) and submersible ultraviolet nitrate analyzer (SUNA) nitrate sensors generally follows Sakamoto et al. (2009, Limnol. Oceanogr. Methods 7, 132–143). For waters warmer than the calibration temperature, this correction model can lead to a 1–2 μmol kg−1 positive bias in nitrate concentration. Here we present an updated correction model, which reduces this small but noticeable bias by at least 50%. This improved model is based on additional laboratory data and describes the temperature correction as an exponential function of wavelength and temperature difference from the calibration temperature. It is a better fit to the experimental data than the current model and the improvement is validated using two populations of nitrate profiles from Biogeochemical Argo floats navigating through tropical waters. One population is from floats equipped with ISUS sensors while the other arises from floats with SUNA sensors on board. Although this model can be applied to both ISUS and SUNA nitrate sensors, it should not be used for OPUS UV nitrate sensors at this time. This new approach is similar to that used for OPUS sensors (Nehir et al., 2021, Front. Mar. Sci. 8, 663800) with differing model coefficients. This difference suggests that there is an instrumental component to the temperature correction or that there are slight differences in experimental methodologies.

Effects of different pH, temperature, and pressurisation time on the stability of chlorophylls treated with Zn2+ and high hydrostatic pressure

SummaryThis study provides an effective method to improve the stability of chlorophylls. The effects of different pH, temperature, and pressurisation time on the colour, antioxidant activity, Zn2+ replacement ratio, structure, and thermal stability of chlorophylls treated with Zn2+ (10 mg 100 mL−1) and high hydrostatic pressure (500 MPa) were investigated. The electronic eye, ultraviolet spectrophotometer, high‐performance liquid chromatography, Fourier transform infrared, and high hydrostatic pressure (HHP) online monitor cooperated with fluorescence spectrophotometer were used to investigate the effects of different pH values, water bath temperatures, and pressurisation time on the colour, antioxidant activity, Zn2+ replacement ratio, and structure of chlorophylls. The highest −a* (6.92), antioxidant activity (ABTS 41.01 g ACE 100 g−1, DPPH 52.86 g ACE 100 g−1, FRAP 35.72 g TE 100 g−1 DW), and Zn2+ replacement ratio (47.32%) were obtained at 50 °C, pH = 7.0, and 20 min. It is hoped that this study will provide a new idea for the protection of natural pigments.

Antioxidant Potential of Different Parts of Three Pineapple Varieties N36, Madu and MD2

Pineapple (Ananas comosus) is widely consumed and appreciated not only due to its taste and aroma and to its nutritional and antioxidant properties, including its vitamin C and phenolic contents. In an attempt to explore new antioxidant leads, pineapple waste is often neglected in the pineapple industry. Fruit processing has considerably higher ratios of by-products and pineapple by-products are not exceptions as they consist basically of the residual pulp, peels, stem, and leaves. Pineapple waste is a by-product resulting from canning processing of pineapple that produces about 35% of fruit waste and leads to serious environmental pollution. The objective of this study is to determine whether different varieties and parts of pineapple waste (peel, core, crown, and stalk) can affect and give the highest amount of natural antioxidant activity. In this study, the antioxidant activities of different parts of three pineapples (N36, Madu, and MD2 were measured using the DPPH method. Methanol solvent has been used for extraction and various parts of pineapple were used to determine the effect of different plants on antioxidants. The samples were determined by using an ultraviolet (UV) spectrophotometer. The result for scavenging activity (DPPH) indicates Madu variety displayed high scavenging activity compared to MD2 and N36 varieties. Madu varieties demonstrated a significant free radical scavenging ability where their crown has IC50 and cores are merely IC50 at 175 ppm and 500ppm. The MD2 crown also demonstrates IC50 at 275 ppm. The results suggest that Madu varieties comprised of the crown of pineapple studied may be useful as potential sources of natural antioxidants.

Tin Oxide-Graphene Oxide (SnO2/GO) Nanocomposite: A Promising Photocatalyst for Rhodamine-B Dye Degradation

Appropriate wastewater treatment methods for effectual and practical decontamination of wastewater bodies is the prime goal of today’s environmentalists and industrialists. Herein, sunlight driven photocatalytic degradation of rhodamine-B (RhB) has been investigated by employing hydrothermally synthesized tin oxide-graphene oxide (SnO2/GO) nanocomposite. Physiochemical characterization of composite has been accomplished via X-ray diffraction (XRD) analysis, ultraviolet (UV) spectroscopy, diffused reflectance spectroscopy (DRS) and photoluminescence (PL). Photocatalytic degradation of RhB is studied using UV light and spectrophotometer. SnO2-GO nanocomposite degraded the RhB dye in 120 min comparatively in quite lesser time than separate SnO2 and GO degradation performances. The incorporation of GO into SnO2 decreases the rate of electron–hole recombination, increases the oxidation of carriers as well as the rate of carrier separation owing to the synergistic impact of GO and SnO2. Therefore, an affordable graphene oxide supported SnO2 nanocomposite can be implicated as efficacious real wastewater treatment method at industrial scale.

The Design, Synthesis and Application of Nitrogen Heteropolycyclic Compounds with UV Resistance Properties.

Exposure to ultraviolet (UV) light is known to cause skin aging, skin damage, cancer, and eye diseases, as well as polymer material aging. Therefore, significant attention has been devoted to the research and development of UV absorbers. Considering the robust hydrogen bonding and conjugated structure present in nitrogen-containing polycyclic compounds, these compounds have been selected as potential candidates for exploring ultraviolet absorption properties. After structural optimization and the simulation of ultraviolet absorption spectra, four tris-[1,2,4]-triazolo-[1,3,5]-triazine (TTTs) derivatives, namely TTTB, TTTD, TTTJ, and TTTL, were selected as the preferred compounds and synthesized. The structure of the compound was determined using various analytical techniques, including FTIR, 1HNMR, 13CNMR, HRMS, and XRD. Subsequently, composite films of polyvinyl chloride (PVC) and TTTs were produced using a simple solvent casting technique. The PVC films were subjected to UV age testing by exposing them to an ultraviolet aging chamber. The age-resistant performance of the fabricated films was evaluated using an ultraviolet spectrophotometer and Fourier infrared spectrum instrument. The findings suggest that TTTs exhibit a noteworthy capacity for absorbing ultraviolet radiation. The TTTL compound exhibits a superior UV absorption performance compared to commercially available UV absorbers such as UV-0 and UV-327 in the market.

Effects of the Larch–Ashtree Mixed Forest on Contents of Secondary Metabolites in Larix olgensis

To understand the insect resistance mechanism of the larch, Larix olgensis, in a mixed forest, larch (Larix olgensis) seedlings and ashtree (Fraxinus mandshurica) seedlings were planted with mixed banding forests in the proportion of 1:1 (BMF1:1), 3:3 (BMF3:3) and 5:5 (BMF5:5), in pots and in the field. One year later, the content of secondary metabolites in the needles of each larch treatment were tested with an ultraviolet spectrophotometer. The results showed that the allelopathic effect of F. mandshuricas (ashtree) on L. olgensis (larch) could increase the content of secondary metabolites in larch needles. It was found that the flavonoid content in the needles of BMF5:5 was higher than that in the needles of BMF1:1 and BMF3:3 (p &lt; 0.05). The tannin content in the needles of FBMF3:3 and FBMF5:5 was significantly higher than that of FBMF1:1, whereas the tannin content in the needles of PBMF3:3 reached 1.27 mg/g, which was the highest (p &lt; 0.05). The lignin content in the needles of FBMF3:3 reached 2.27 mg/g, which was significantly more increased than that in the control group in a dose-dependent manner, while that in the needles of PBMF3:3 and PBMF5:5 was higher than that in the needles of PBMF1:1 (p &lt; 0.05). The tannin and lignin content in the needles of FBMF was higher than that of PBMF. However, there was no difference in the content of flavonoids in the needles of FBMF and PBMF. These results suggest that banding mixed larches and ashtrees can significantly increase the content of secondary metabolites (phenolic compounds) in the needles of L. olgensis and improve its chemical defense, and the allelopathic effect of ashtrees on larches is related to the mixed proportion. Thus, the effect of mixed banding forests in the proportion of 3:3 and 5:5 is better.

Sol-Gel Synthesis and Optical Characterization of Zno Nanoparticles

The zinc oxide nanoparticles were synthesized to investigate the ultraviolet light absorbance and transmittance for applications of UV protection. Zinc oxide nanoparticles were characterized by photon cross-correlation and ultra-violet spectrophotometers. The results show that the synthesized zinc oxide nanoparticles have the mean diameter of ~35 nm of main particles with particle size distribution range from ~11 nm to ~80 nm.The use of synthesized nanoparticles achieved transmission levels of over 95 % in the UVA regions at the wavelength range of 320-400 nm.

Effects of ultra-low emission air pollution control devices on the evolution of PM and its associated water-soluble ions in a 1000 MW coal-fired power plant

PM (Particulate matter) is a major air pollutant from CFPPs (coal-fired power plants). APCDs (Air pollutant control devices) work in concert to achieve ultra-low emission requirements. Large-scale and higher parameters CFPPs have become a future trend. This work investigated the PM evolution of the APCDs in a 1000 MW ultra-low emission CFPP. The PM1, PM2.5, and PM10 (particulate matter with an aerodynamic diameter less than 1, 2.5, and 10 μm) and WSIs (water-soluble ions) characteristics at the inlet and outlet of selective catalytic reduction (SCR), low-low temperature electrostatic precipitators (LLT-ESP), wet flue gas desulfurization (WFGD), and wet electrostatic precipitator (WESP) were investigated. PM samples were collected by a Dekati low-pressure impactor. The WSIs in PM (K+, Ca2+, Na+, Mg2+, NH4+, Cl-, SO42-, NO3–) were also detected by inductively coupled plasma optical emission spectrometer, ion chromatography, and ultraviolet spectrophotometer, respectively. The results show that PM1, PM2.5, and PM10 generally decrease along with flue gas steam, while PM1 increases by 16.36% and 17.47% at SCR outlet and GGH outlet. The percentages of WSIs in PM show an increasing trend along with flue gas steam. SO42- and Ca2+ are the main components of WSIs. ESP had high efficiencies of 98.18%, 98.54%, and 99.31% for PM1, PM2.5, and PM10, respectively. PM reduces by more than 50% after WFGD and WESP. About 1.00% of PM1, 0.29% of PM2.5, and 0.08% of PM10 are emitted at Stack. PM emissions meet ultra-low emission requirements. The emission factors of PM1, PM2.5, and PM10 are 8.73, 15.90, and 21.04 g/t_fuel on average.