Irradiation Period Research Articles

Photoswitchable and reusable superhydrophobic/hydrophilic TiO2-coated stainless-steel mesh as oil–water separator

This study fabricated a superhydrophobic/hydrophilic stainless-steel mesh with a TiO2-coated surface for efficient oil–water separation. The mesh manifested both hydrophobic and hydrophilic properties upon incorporating fluorine- and amine-containing silanes, respectively. The photoswitching speed and recovery of surface properties were evaluated by adjusting the UV irradiation period. Additionally, the mesh was subjected to ultrasonic treatment to enhance the photoswitching speed. After alternating UV irradiation and ultrasonification treatments, the variations in contact angle confirmed the feasibility of reversible surface conversion: 158° → 15° → 149.4° → 9.1° → 146.8° → 8.4° → 147.3°. Furthermore, the oil–water separation efficiency of the fluorine-modified mesh was assessed using water and n-hexane solutions. Over eight cycles, the hydrophobic/hydrophilic mesh achieved an average separation efficiency of 95.3% and 96.7%, respectively. The separation process occurred within approximately 5 s. Thus, this study proposed a comprehensive approach for developing a single superhydrophobic mesh capable of facile and rapid photoswitching between hydrophilic and hydrophobic properties. The developed mesh offers precise filtration, durability, and reusability, contributing to sustainable oil–water separation processes.

Seasonality of reproduction in an ever-wet lowland tropical forest in Amazonian Ecuador.

Flowering and fruiting phenology have been little studied in the ever-wet hyperdiverse lowland forests of northwestern equatorial Amazonia. These Neotropical forests are typically called aseasonal with reference to climate because they are ever-wet, and it is often assumed they are also aseasonal with respect to phenology. The physiological limits to plant reproduction imposed by water and light availability are difficult to disentangle in seasonal forests because these variables are often temporally correlated, and both are rarely studied together, challenging our understanding of their relative importance as drivers of reproduction. Here we report on the first long-term study (18 years) of flowering and fruiting phenology in a diverse equatorial forest, Yasuní in eastern Ecuador, and the first to include a full suite of on-site monthly climate data. Using twice monthly censuses of 200 traps and > 1000 species, we determined whether reproduction at Yasuní is seasonal at the community- and species-levels and analyzed the relationships of environmental variables to phenology. We also tested the hypothesis that seasonality in phenology, if present, is driven primarily by irradiance. Both the community- and species-level measures demonstrated strong reproductive seasonality at Yasuní. Flowering peaked in September-November and fruiting peaked in March-April, with a strong annual signal for both phenophases. Irradiance and rainfall were also highly seasonal, even though no month on average experienced drought (a month with < 100 mm rainfall). Flowering was positively correlated with current or near-current irradiance, supporting our hypothesis that the extra energy available during the period of peak irradiance drives seasonality of flowering at Yasuní. As Yasuní is representative of lowland ever-wet equatorial forests of northwestern Amazonia, we expect that reproductive phenology will be strongly seasonal throughout this region. This article is protected by copyright. All rights reserved.

Effect of Additives on Decomposition of Methyl Orange and Congo Red Dyes Found in Industrial Wastewater

A number of textile industries are using different types of dyes which can be a threat to the environment when they are directly exposed without any treatment. The advanced oxidation process (AOP) has become one of the popular methods in which the dye molecules are degraded using microwave irradiation. This method has become popular due to its eco-friendly and cost-efficient characteristics. In this article, the author has reported the degradation of two azo dyes, named methyl orange (MO) and congo red (CR), in the presence of inorganic salts, some additives like charcoal, H2O2, CCl4, tert-butyl alcohol (TBA), glucose and sucrose. A comparative study was conducted to find out the relative degradation rate enhanced by various additives. For both of the dyes, it was found that charcoal was the most effective additive and significantly enhanced the degradation rate mainly due to its high adsorption capability. TBA was found to be the least enhancer. The order of effectiveness based on the irradiation period for MO was 0.01g charcoal &gt; 20 ml NaCl &gt; 20 ml Na2SO4 &gt; 20ml glucose&gt; 10 ml sucrose &gt; 100 μL CCl4 &gt; 200 μL H2O2 &gt; pure MO &gt; TBA. On the other hand, the order of effectiveness for CR for the same condition of irradiation was Combined additives&gt;0.01g charcoal &gt; TBA &gt; 100 μL CCl4&gt; pure CR.

Photocatalytic Degradation of Losartan with Bismuth Oxychloride: Batch and Pilot Scale Demonstration

The solar-induced semiconductor photocatalytic process is one of the greenest and most promising technologies for the elimination of pharmaceuticals in aqueous media. In the context of this study, a bismuth oxychloride (BiOCl) photocatalyst was fabricated and characterized by its morphology, crystallographic structure, and optical properties. Its photocatalytic efficiency was tested towards the degradation of Losartan (LOS), a medication used to treat high blood pressure, in water using a solar simulator. The as-prepared BiOCl exhibited significant photocatalytic efficiency, achieving complete degradation of 0.3 mg/L LOS in short periods of irradiation (15–30 min). The examined system showed optimal efficiency using 500 mg/L of BiOCL (kapp = 0.21 min−1) and pH 3 (kapp = 0.32 min−1). However, LOS removal significantly decreased in environmentally relevant water matrices, including wastewater (kapp = 0.006 min−1) and bottled water (kapp = 0.023 min−1). Additional tests carried out in synthetic water matrices showed that the LOS degradation rate was reduced by more than 40% in the presence of humic acid (kapp = 0.016 min−1) and bicarbonates (kapp = 0.029 min−1), while chlorides did not affect the overall efficiency. Moreover, photogenerated holes and singlet oxygen were the dominant oxidative species. The efficiency of the BiOCl photocatalyst towards LOS degradation was further studied using a flat plate pilot-plant scale photoreactor. It was found that more than 75% of LOS was removed after 100 kJ/L of accumulated solar irradiation. The results obtained in the pilot-plant unit confirmed the suitability of BiOCl as a potential photocatalytic material.

Facile synthesis of visible-responsive photocatalytic Eu-doped layered double hydroxide for selective removal of NOx pollutant

Efficient nitrogen oxides (NOx) removal from the urban atmosphere is still a target for the researchers. Herein, a Zn2Al-CO3 based layered double hydroxide (LDH) was doped with increasing amounts of Eu3+ (0.01–0.04) and the photocatalytic oxidation of NOx gases was investigated. The LDHs were synthesized by a facile coprecipitation method at room temperature and ambient pressure. The successful Eu3+ substitution in the LDH layers induces a shift in the M−O bonds that modifies the electronic band structure of the doped photocatalysts. Compared to the undoped LDH, the NOx removal efficiency was enhanced by ∼ 17–25 % under UV–Vis light irradiation. Remarkably, a NOx removal efficiency of ∼ 47 % was attained by the optimally doped LDH under Visible irradiation (420 nm), surpassing raw LDH (∼ 9 %). Moreover, the Eu3+ doped LDHs retained its photocatalytic efficiency during long periods of irradiation during consecutive tests with high selectivity (>90 %). Photoluminescence studies indicated that Eu3+ was located in a non-centrosymmetric position, thereby producing structural disorder within the lattice. Eu doping promoted charge separation and a higher production of ⋅OH radicals as verified by time-resolved photoluminescence and electron paramagnetic resonance, respectively. We believe this work reports unprecedent results obtained by Eu-doping of Zn2Al-based LDHs under visible light for NOx photooxidation and serves as a new strategy to prepare functional LDHs for other photocatalytic applications.

Rapid Crystal Structural, Optical and Morphological Studies of Transition Metal Oxide Nanoparticles and their Photocatalytic Activity

In the present work, we report a green synthesis of cobalt oxide (Co3O4), bismuth oxide (Bi2O3) and cobalt-doped bismuth oxide (Co-doped BiO) nanoparticles using Bambusa seed extract. The green synthesized nanoparticles are characterized using various techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy and field emission scanning electron microscopy (FESEM). The phase purity of the synthesized nanoparticles is confirmed with the aid of XRD analysis, and the crystallite sizes are found to be 10.42 nm, 18.85 nm and 61.23 nm for Co3O4, Bi2O3 and Co-doped BiO nanoparticles, respectively. Bond length calculations and functional group analysis are done by FTIR technique. The UV–visible analysis depicts higher optical absorption and band gaps varying from 1.81, 2.65 and 1.87 eV for Co3O4, Bi2O3 and Co-doped BiO nanoparticles, respectively. Changes in the surface morphology are observed from FESEM analysis. In addition, the samples' catalytic efficiency in the breakdown of methylene blue (MB) dye was studied and the effects of various process parameters on the extent of dye removals such as photocatalyst amount, irradiation period, the concentration of dye and pH of the solution were also studied. The pseudo-first-order MB photocatalytic decomposition kinetic model has a high correlation coefficient value (R2 > 0.95). The findings support the use of a Co-doped BiO in the field of photocatalytic applications under natural sunlight.

A phase II randomized clinical trial to assess toxicity and quality of life of breast cancer patients with hypofractionated versus conventional fractionation radiotherapy with regional nodal irradiation in the context of COVID-19 crisis.

This study, conducted during the COVID-19 crisis, primarily aimed to compare the acute toxicity between conventional fractionated radiation therapy (CF-RT) with hypofractionated radiation therapy (HF-RT) among patients who underwent breast-conserving surgery or mastectomy in whom breast or chest wall and regional nodal irradiation (RNI) were indicated. The secondary endpoints were both acute and subacute toxicity, cosmesis, quality of life, and lymphedema features. In this open and non-inferiority randomized trial, patients (n = 86) were randomly allocated 2:1 in the CF-RT arm (n = 33; 50 Gy/25 fractions ± sequential boost [10 Gy/5 fractions]) versus the HF-RT arm (n = 53; 40 Gy/15 fractions ± concomitant boost [8 Gy/15 fractions]). Toxic effects and cosmesis evaluation used the Common Terminology Criteria for Adverse Events, version 4.03 (CTCAE) and the Harvard/National Surgical Adjuvant Breast and Bowel Project (NSABP)/Radiation Therapy Oncology Group (RTOG) scale. For the patient-reported quality of life (QoL), the European Organisation for Research and Treatment of Cancer quality of life questionnaire (EORTC QLQ-C30) and the breast cancer-specific supplementary questionnaire (QLQ-BR23) were used. Lymphedema was assessed by comparing volume differences between the affected and contralateral arms using the Casley-Smith formula. Grade 2 and grade 3 dermatitis were lower with HF-RT than with CF-RT (28% vs. 52%, and 0% vs. 6%, respectively; p = 0.022). HF-RT had a lower rate of grade 2 hyperpigmentation (23% vs. 55%; p = 0.005), compared to CF-RT. No other differences in overall rates of physician-assessed grade 2 or higher and grade 3 or higher acute toxicity between HF-RT and CF-RT were registered. There was no statistical difference between groups regarding cosmesis, lymphedema rate (13% vs. 12% HF-RT vs. CF-RT; p = 1.000), and functional and symptom scales, during both the irradiation period and after 6 months of the end of treatment. The results revealed that the subset of patients up to 65 years or older did not show a statistical difference between both arm fractionation schedules (p > 0.05) regarding skin rash, fibrosis, and lymphedema. HF-RT was non-inferior to CF-RT, and moderate hypofractionation showed lower rates of acute toxicity, with no changes in quality-of-life outcomes. ClinicalTrials.gov, identifier NCT40155531.

Effect of Target Changes on Target Coverage and Dose to the Normal Brain in Fractionated Stereotactic Radiation Therapy for Metastatic Brain Tumors

We evaluated the dosimetric effect of tumor changes in patients with fractionated brain stereotactic radiation therapy (SRT) on the tumor and normal brain using repeat verification magnetic resonance imaging (MRI) in the middle of the treatment period. Fifteen large intracranial metastatic lesions with fractionated SRT were scanned employing standardized planning MRI (MRI-1). Repeat verification MRI (MRI-2) were performed during the middle of the irradiation period. Gross tumor volume (GTV) was defined as the volume of the contrast-enhancing lesion on T1-weighted MRI with gadolinium contrast agent. The doses to the tumor and normal brain were evaluated on the MRI-1 scan. Beam configuration and intensity on the initial volumetric modulated arc therapy plan were used to evaluate the dose to the tumor and the normal brain on MRI-2. We evaluated the effect of D98% (percent dose irradiating 98% of the volume) on the GTV using the plans on the MRI-1 and MRI-2 scans. For the normal brain, the V90%, V80%, and V50% (volume of the normal brain receiving >90%, 80%, and 50% of the prescribed dose, respectively) were investigated. Three (20% of the total) and 4 (26% of the total) tumors exhibited volume shrinkage or enlargement changes of >10%. Five (33% of the total) tumors exhibited volume shrinkage and enlargement changes of <10%. Three tumors (20% of the total) showed no volume changes. D98% of the GTV increased in patients with tumor shrinkage because of dose inhomogeneity and decreased in patients with tumor enlargement, with a coefficient of determination of 0.28. The V90%, V80%, and V50% increase with decreasing tumor volumes and were linearly related to the tumor volume difference with a coefficient of determination values of 0.97, 0.98, and 0.97, respectively. Repeat verification MRI for brain fractionated SRT during the treatment period should be considered to reduce the magnitude of target underdosing or normal brain overdosing.

Optimization of photocatalytic parameters for MB degradation by g-C3N4 nanoparticles using Response Surface Methodology (RSM)

In the present paper, graphitic carbon nitride (g-C3N4) was prepared using a conventional hydrothermal process. Several characterization methods were applied to analyze the resulting g-C3N4 sample, such as: X-ray diffraction (XRD), ultraviolet-visible (UV–Vis) spectrophotometry, attenuated total reflectance -Fourier-transform infrared (ATR-FTIR) spectroscopy and scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDS). The pollutant selected to measure the g-C3N4 photocatalytic performance was methylene blue (MB). Using Response Surface Methodology (RSM), the pH solution effects, photocatalyst dose (mg/L), and irradiation period (min) were examined and adjusted. The optimal conditions, which included 1.3 g/L of g-C3N4 photocatalyst, solution pH = 10.83, and irradiation time = 119.3 min, resulted in a degradation efficiency of 86.58 %. The principal active species involved in photocatalytic degradation have been identified and a potential mechanism has also been provided. Additionally, the degradation kinetics were monitored and obtained to follow pseudo-second order kinetics.

Determination of a New Performance Indicator for the Assessment of Stand-Alone PV System

The use of stand-alone PV systems (SAPV) must be efficient and profitable for a better integration of solar energy in the global energy mix. However, the performance indicators that allow the evaluation of SAPV systems do not clearly inform us about the actual level of use of their sized and installed capacity. This article aims to determine a new performance indicator, called the theoretical power factor (TPF) by an original method based on the modelling of the SAPV system in the form of a matrix equation. The resolution of this matrix equation, makes it possible to bring out the reactive energy of the system during operation. A case study is presented and scenario I represents the case where the main elements are all assumed to operate at their rated capacity. scenario II represents the case were the rated capacity of storage system is reduced of 40%, scenario III represents the case were the rated current capacity of charge controller is reduced of 40%, and finally scenario IV represents the case were the rated power capacity of inverter is also reduced of 40%. The results obtained after implementation in the Spyder environment (python 5.1) show the effectiveness of TPF in the performance evaluation of SAPV systems. And also show how the TPF is substantially related to the capacity of each main element of the system. This being proved by the results obtained after the simulation of the four scenarios mentioned above. One can observe an increase in TPF of 0.1% in Scenario II during the period of low irradiance, and no change in TPF for the other scenarios in the same period. During the period of high irradiance, an increase in TPF of 17.9% is observed in scenario II and a decrease in TPF of 15.4% and 1.2% respectively in scenarios III and IV.

Factors Affecting Prostate Displacement During Volumetric Modulated Arc Therapy in Prone Position After High-Dose-Rate Brachytherapy for Prostate Cancer

In irradiating the prostate and pelvic lymph node regions, registration based on bony structures matches the pelvic lymph node regions but not necessarily the prostate position, and it is important to identify factors that influence prostate displacement. Therefore, we investigated factors influencing prostate displacement during volumetric modulated arc therapy after single-fraction high-dose-rate brachytherapy (HDR-BT) for prostate cancer and the trends in displacement for each fraction. Seventy patients who underwent pelvic volumetric modulated arc therapy of 46 Gy in the prone position 15 days after 13 Gy HDR-BT were included. Prostate displacement relative to bony structures was calculated using cone beam computed tomography. Systematic error (SE) and random error (RE) were evaluated in the right-left (RL), craniocaudal (CC), and anteroposterior (AP) directions. The association with clinical and anatomic factors on the planning computed tomography or magneticresonanceimaging was analyzed. Prostate volume change (PVC) was defined as the volume change at 2 days after HDR-BT. Displacement trends were individually examined from the first to 23rd fractions. The mean SE in the RL, CC, and AP directions was -0.01 mm, -2.34 mm, and -0.47 mm, respectively. The root mean square of the RE in the RL, CC, and AP directions was 0.44 mm, 1.14 mm, and 1.10 mm, respectively. SE in the CC direction was independently associated with bladder volume (P=.021, t statistic=2.352) and PVC (P < .001, t statistic=-8.526). SE in the AP direction was independently associated with bladder volume (P=.013, t statistic=-2.553), PVC (P < .001, t statistic=5.477), and rectal mean area (P=.008, t statistic=2.743). RE in the CC direction was independently associated with smoking (P=.035). RE in the AP direction was associated with PVC (P=.043). Gradual displacement caudally and posteriorly occurred during the irradiation period. Anatomic characteristics of the bladder, rectum, and prostate predict SE. Smoking and PVC predict RE. In particular, whether PVC is ≥140% affects setting internal margins.

Plasmon-Enhanced Photocatalytic CO2 Reduction for Higher-Order Hydrocarbon Generation Using Plasmonic Nano-Finger Arrays.

The carbon dioxide reduction reaction (CO2RR) is a promising method to both reduce greenhouse gas carbon dioxide (CO2) concentrations and provide an alternative to fossil fuel by converting water and CO2 into high-energy-density chemicals. Nevertheless, the CO2RR suffers from high chemical reaction barriers and low selectivity. Here we demonstrate that 4 nm gap plasmonic nano-finger arrays provide a reliable and repeatable plasmon-resonant photocatalyst for multiple-electrons reactions: the CO2RR to generate higher-order hydrocarbons. Electromagnetics simulation shows that hot spots with 10,000 light intensity enhancement can be achieved using nano-gap fingers under a resonant wavelength of 638 nm. From cryogenic 1H-NMR spectra, formic acid and acetic acid productions are observed with a nano-fingers array sample. After 1 h laser irradiation, we only observe the generation of formic acid in the liquid solution. While increasing the laser irradiation period, we observe both formic and acetic acid in the liquid solution. We also observe that laser irradiation at different wavelengths significantly affected the generation of formic acid and acetic acid. The ratio, 2.29, of the product concentration generated at the resonant wavelength 638 nm and the non-resonant wavelength 405 nm is close to the ratio, 4.93, of the generated hot electrons inside the TiO2 layer at different wavelengths from the electromagnetics simulation. This shows that product generation is related to the strength of localized electric fields.

The behavior of microplastics and nanoplastics release from UV-aged masks in the water

In this study, three types of disposable masks were exposed to ultraviolet (UV) irradiation to determine the effect of UV irradiation on the release of microplastics (MPs) and nanoplastic (NPs) from the masks. A kinetic model was used to investigate the mechanisms of M/NP release from the masks under UV irradiation. Results showed that UV irradiation exacerbated the damage to the structure of the mask over time. As the irradiation time increased, the middle layer of the mask was damaged first (15 d) and subsequently all layers of the mask were damaged (30 d). There was no significant difference in the quantity of M/NPs released from the treatment groups at different irradiance during a 5-d irradiation period. When the UV time reached 15 and 30 d, the highest quantity of M/NPs was released at 8.5 W/m2 followed by 4.9 W/m2, 15.4 W/m2, and 17.1 W/m2. Exponential equations fitted the release curve of M/NPs. The release quantity of M/NPs increases exponentially with increasing UV irradiation time, and the longer the irradiation time, the faster the rate of increase. Estimated release of 1.78 × 1017–3.66 × 1019 particles/piece of MPs and 8.23 × 1019–2.18 × 1022 particles/piece of NPs into the water when the masks are exposed to the real environment for 1–3 years.

Neutron gamma analysis of soil carbon: Post-irradiation physicochemical effects

In-situ soil carbon measurements would be beneficial when assessing carbon (C) sequestration practices and associated C credits. Neutron gamma analysis, which registers gamma rays that appear due to neutron irradiation, is a tool that can be used for such assessments. However, questions regarding post-effects of neutron irradiation on soil remain unexplored. Temporal post-irradiation effects (neutron flux 2⋅107 neutron/s, neutron energy 14 MeV) on soil chemical and physical attributes were investigated using a previously constructed pulsed fast-thermal neutron-gamma analysis system. Neutron and gamma dose rate distributions during stationary irradiation using this system and Monte-Carlo computer simulations were found to be in agreement; a stationary 1 h irradiation period (conservative or worse-case scenario) was utilized in these scenarios. Physical effects of activating new radioactive isotopes were experimentally determined by assessing changes in the post-irradiated soil gamma spectra (“hot background”) over time; additional soil radioactivity decreased to natural background levels within ∼1 h. Radiolytic decomposition estimates of soil water and soil organic material (primarily cellulosic residue), based on received dose loads and known radiation-chemical yields of water and organic material, were practically negligible. Results indicate that adsorbed radiation doses in scanning mode would be 500 to 1000 times less than in static mode. Thus, neutron gamma analysis does not impact physicochemical aspects of soil health and can be used for soil elemental content determinations without additional radiation safety concerns.

Liquid Sn corrosion behaviors to high-flux hydrogen plasmas irradiated Mo capillary-pore systems

This paper studied the effects of hydrogen plasma irradiation on the corrosion resistance of Mo capillary porous systems (CPSs) in high temperature liquid Sn. Initial Mo CPSs showed a significant morphology change and mass loss rate (1.107 × 10–3 mg/(mm2·h)) after corrosion in liquid Sn at 1,023 K for 100 h. A brief period of irradiation enhanced the corrosion resistance of Mo wires, resulting in a dramatic decrease to 1.23 × 10–4 mg/(mm2·h) in mass loss rate under the same corrosion conditions. To determine whether temperature was the main factor leading to above phenomenon, Mo CPSs were pre-annealed at the same temperature (843 K) as irradiation. The mass loss rate of annealed Mo CPSs (3.09 × 10–4 mg/(mm2·h)), which was lower than that of the initial sample, was still higher than that of the plasma-treated samples. Difference between plasma irradiation and heat treatment was the incident of various particles in hydrogen plasma. Therefore, the suppressed corrosion phenomenon caused by plasma could not only be attributed to the function of high temperature but its synergistic effect with hydrogen isotope retention.

Radioiodine-131 Therapy Used for Differentiated Thyroid Cancer Can Impair Titanium Dental Implants: An In Vitro Analysis.

The aim was to assess, in vitro, the effects of radioiodine-131 (I-131) on the structure of titanium implants. A total of 28 titanium implants were divided into 7 groups (n = 4) and irradiated at 0, 6, 12, 24, 48, 192 and 384 hours. At the end of the experiment, each sample was investigated via scanning electron microscopy (SEM) and electrochemical measures. The control sample revealed a smooth and compact surface. The small micro-sized porosity is slightly visible at the macroscopic level, but the precise details cannot be observed. A mild exposure to the radioactive solution for 6 to 24 h showed a good preservation of the macro-structural aspects such as thread details and surface quality. Significant changes occurred after 48 h of exposure. It was noticed that the open-circuit potential (OCP) value of the non-irradiated implants move toward more noble potentials during the first 40 min of exposure to the artificial saliva and then stabilizes at a constant value of -143 mV. A displacement of the OCP values toward more negative values was observed for all irradiated implants; these potential shifts are decreasing, as the irradiation period of the tested implants increased. After exposure to I-131, the structure of titanium implants is well preserved up to 12 h. The eroded particles start to appear in the microstructural details after 24 h of exposure and their numbers progressively increase up to 384 h after exposure.

Optimization of an isolated photovoltaic water pumping system with technical–economic criteria in a water users association

AbstractWith proper management, the modernization of irrigation systems makes it possible to improve the efficiency of application and use of water at the cost of an increase in pumping needs and, therefore, an increment of the energy consumed. The recent drastic price increase for energy put the viability of many farms at risk. In this context, using photovoltaic solar energy to power pumping stations has become an increasingly attractive alternative and a cheap and reliable option. The dimensioning of pumping systems powered by photovoltaic solar energy must be done considering the variability of solar radiation to take advantage of the available photovoltaic energy, especially during periods of less irradiation. By investigating a particular case, this paper studies the effect of increasing the number of pumps in parallel while maintaining the total power, as well as the relationship between the installed photovoltaic capacity and the power of the pumping system, to meet pumping requirements throughout the year. The pumped volume increased as the number of pumps installed in parallel increased for the same photovoltaic power generator. Although this increment has a limit, beyond which no greater significant rise in volume is achieved, installation costs increase. In addition, for the same pumping power installed, the required photovoltaic generator power decreases as the number of pumps in parallel increases. In the case studied, a 27% increase in the annual pumped volume was achieved by incrementing the number of pumps in parallel from one to five, thus leading to a 44.1% reduction in the size of the photovoltaic generator and a 13.3% reduction in the cost of installation compared with a system with only one pump. The procedure used to determine the most appropriate number of pumps to install in parallel when pumping water between two tanks, which minimizes the photovoltaic generator's size while guaranteeing pumping requirements, is easily generalizable for sizing isolated photovoltaic water pumping systems.

Microwave Supported Extraction and Optimization of Flavonoid Mangiferin from Mangifera indica L. Stem Bark using Orthogonal Array Design

A modest and swift microwave-backed extraction process has been established for the abstraction of a flavonoid mangiferin from the Shoot bark of Mangifera indica L. The content in the extracts was quantified by planar chromatography. An orthogonal array strategy was employed to conclude the effects of variables that affect the efficiency of MAE, namely temperature, irradiation period, the clout of irradiation, and particle size of drug powder. Under optimal conditions, MAE showed expressively higher recovery of mangiferin and markdown in the extraction period as well as solvent intake in comparison to the conventional method.

The Effect of Photobiostimulation by Light Waves in the Blue Range of the Spectrum on Microcirculation Parameters and the Activity of Oxidative Homeostasis Enzymes in the Skin

The study employs laser doppler flowmetry and laser fluorescence spectroscopy to reveal the changes in microcirculation and activity of coenzymes of oxidative metabolism in the finger skin under the influence of photobiostimulation by monochrome incoherent low-intensity electromagnetic radiation with a wavelength of 470 nm. Photobiostimulation with light waves in the blue range has contributed to an increase in hemomicrocirculation during and 15 min after the termination of exposure, while the indicator lymph outflow, on the contrary, decreased during the irradiation period and recovered after its termination. The dynamics of changes within the parameters of blood microcirculation, the lymph flow in microvessels and the indicators of oxidative metabolism showed that the skin microcirculation system is an important acceptor of the photobiostimulating effect of light in the blue range of the spectrum. Photobiostimulation triggers the mechanism of activation of hemomicrocirculation by reducing myogenic vasomotion, thereby increasing the conductivity of cardiogenic biorhythm in the vessels of the microcirculatory bed. With an increase in the level of hemomicrocirculation, photobiostimulation is directly associated with the activation of tissue oxidative metabolism.

Iron oxide nanoparticles derived from Chlorella vulgaris extract: Characterization and crystal violet photodegradation studies

Nanoparticles were first used a century ago, but have recently gained popularity due to their ease of use, eco-friendliness, pollution-free nature, nontoxicity and low cost for wastewater treatment applications. In terms of nanoparticles preparation, green synthesis is a more convenient, economical, quick, and environmentally friendly process than traditional synthesis (i.e. chemical and mechanical) methods. The objective of this study was to synthesise iron oxide nanoparticles from iron (III) chloride using microalgae (Chlorella vulgaris) extract for photodegradation of crystal violet (CV) dye. Various characterization methods such as X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and Fourier-transform infrared spectroscopy (FTIR) were used to examine properties of the nanoparticles including its crystallinity, morphologies and sizes, and functional groups, respectively. The CV photodegradation process was carried out under different process conditions included initial CV concentration (10 mg/L – 25 mg/L), CV solution pH (5.39 – 8.98), and irradiation period (30 – 90 mins) to investigate the optimum operating conditions for the CV removal. The analysis using FESEM demonstrated that the nanoparticles exhibited irregularities and cylindrical shapes, measuring 109 nm in size. Meanwhile, the XRD analysis indicated that the iron oxide nanoparticles possessed a tetragonal crystal structure. The presence of Fe-O stretching vibrations at 486 cm-1 was confirmed by the FTIR spectrum. In terms of CV photodegradation studies, the optimum operating conditions for CV removal using iron oxide nanoparticles were determined to be at initial CV concentration of 10 mg/L, solution pH of 8.98, and an irradiation period of 90 mins, with a percentage removal of 96.21 %.