Photovoltaic (PV) systems are crucial to the production of electricity for a newly established community in Egypt, especially in grid-tied systems. Power quality (PQ) issues appear as a result of PV ...connection with the power grid (PG). PQ problems cause the PG to experience faults and harmonics, which affect consumers. A series compensator dynamic voltage restorer (DVR) is the most affordable option for resolving the abovementioned PQ problems. To address PQ difficulties, this paper describes a grid-tied PV combined with a DVR that uses a rotating dq reference frame (dqRF) controller. The main goal of this study is to apply and construct an effective PI controller for a DVR to mitigate PQ problems. The artificial rabbits optimization (ARO) is used to obtain the best tune of the PI controller. The obtained results are compared with five optimization techniques (L-SHADE, CMAES, WOA, PSO, and GWO) to show its impact and effectiveness. Additionally, Lyapunov’s function is used to analyze and evaluate the proposed controller stability. Also, a mathematical analysis of the investigated PV, boost converter, and rotating dqRF control is performed. Two fault test scenarios are examined to confirm the efficacy of the suggested control approach. The parameters’ (voltage, current, and power) waveforms for the suggested system are improved, and the system is kept running continuously under fault periods, which improves the performance of the system. Moreover, the findings demonstrate that the presented design successfully keeps the voltage at the required level with low THD% values at the load side according to the IEEE standards and displays a clear enhancement in voltage waveforms. The MATLAB/SIMULINK software is used to confirm the proposed system’s performance.
Solar energy, a prominent renewable resource, relies on photovoltaic systems (PVS) to capture energy efficiently. The challenge lies in maximizing power generation, which fluctuates due to changing ...environmental conditions like irradiance and temperature. Maximum Power Point Tracking (MPPT) techniques have been developed to optimize PVS output. Among these, the incremental conductance (INC) method is widely recognized. However, adapting INC to varying environmental conditions remains a challenge. This study introduces an innovative approach to adaptive MPPT for grid-connected PVS, enhancing classical INC by integrating a PID controller updated through a fuzzy self-tuning controller (INC-FST). INC-FST dynamically regulates the boost converter signal, connecting the PVS's DC output to the grid-connected inverter. A comprehensive evaluation, comparing the proposed adaptive MPPT technique (INC-FST) with conventional MPPT methods such as INC, Perturb & Observe (P&O), and INC Fuzzy Logic (INC-FL), was conducted. Metrics assessed include current, voltage, efficiency, power, and DC bus voltage under different climate scenarios. The proposed MPPT-INC-FST algorithm demonstrated superior efficiency, achieving 99.80%, 99.76%, and 99.73% for three distinct climate scenarios. Furthermore, the comparative analysis highlighted its precision in terms of control indices, minimizing overshoot, reducing rise time, and maximizing PVS power output.
Starting from the biopolymer chitosan, two new functionalized chitosan nanocomposities, (CTS-Cin) and (Fe3O4@CTS-Cin) were synthesised and explored for the removal of toxic chromium from aqueous ...solution. The two chitosan based adsorbents were prepared by co-precipitation method under N2 conditions and fully characterized by means of different analytical techniques, FT-IR, EDS, XRD, SEM, HR-TEM and VSM. Adsorption mechanism of toxic Cr (VI) was performed by batch experiments as a function of pH, adsorbent dosage, contact time and initial hexavalent chromium concentration.
The adsorption isotherm and kinetics were fitted well by Langmuir and pseudo-second–order model indicating that the adsorption process is monolayer adsorption. The maximum adsorption capacity for CTS-Cin adsorbent at 298 K is 61.35 mg/g at pH = 2 and it achieved adsorption equilibrium within 35 min. However, Fe3O4@CTS-Cin adsorbent achieved adsorption equilibrium within 80 min and its maximum adsorption capacity is 58.14 mg/g at pH = 3. These results indicate that the two modified adsorbents represent promising adsorbents that would have a practical impact on wastewater treatment applications.
•Two new modified chitosan adsorbents, CTS-Cin and Fe3O4@CTS-Cin has been prepared and fully characterized.•The prepared adsorbents were used to investigate the adsorption properties of Cr(VI) metal ion in an aqueous solution.•The sorption of Cr(VI) ion fit well the second order reaction and Langmuir isotherm model.•The maximum adsorption capacity of Cr(VI) onto the CTS-Cin and Fe3O4@CTS-Cin was 61.35 mg/g and 58.14 mg/g, respectively.•The two adsorbents represent promising adsorbents that would have a practical impact on water treatment applications.
The purpose of this study is to investigate the therapeutic efficacy of individual or combined doses of dehydro-epiandrosterone (DHEA) and quercetin in ameliorating some biochemical indices in liver ...of CuO-NPs intoxicated-rats. CuO-NPs (50 nm) was administered as a daily oral dose 100 mg/kg for 2 weeks to rats followed by the fore-mentioned antioxidants for 1 month. We highlighted the therapeutic effect of DHEA and quercetin against CuO-NPs toxicity through monitoring the alteration of liver enzyme activity, antioxidant defense mechanism, necrosis, apoptosis, histopathological alterations, and DNA damage. The rats given CuO-NPs only showed marked significant elevation in liver enzymes, alteration in oxidant-antioxidant balance and an elevation in the hepatic inflammatory marker; tumor necrosis factor-α. Additionally, over expression of both caspase-3 and Bax proteins were detected. Whereas, Bcl2 was down regulated and DNA fragmentation was elevated. Moreover, Histopathological examination of hepatic tissue reinforced the previous biochemical results. Co-treatment with either DHEA, quercetin alone or in combination ameliorated the deviated parameters with variable degrees against CuO-NPs toxicity in rat. In conclusion, our findings suggested that the aforementioned treatments exert therapeutic effect in CuO-NPs toxicity by diminishing oxidative stress, mRNA gene expression and hepatic tissues DNA damage.
Modified biopolymer chitosan namely 2-hydroxy-1-naphthaldehyde chitosan (CTS-Nap) has been synthesized for the removal of toxic chromium from aqueous solutions. In an attempt to enhance the ...adsorption capacity of toxic chromium on the prepared modified biopolymer, magnetic Fe3O4 nanoparticles have been loaded on the modified adsorbent to form the magnetite adsorbent (Fe3O4@CTS-Nap). The adsorption mechanism of both adsorbents is explored by batch experiments, FT-IR, SEM, TEM, XRD, VSM, and EDS. The optimum adsorption is achieved at pH 1.5 for CTS-Nap and 1.0 for Fe3O4@CTS-Nap. Pseudo second order illustrated the best description for the adsorption process with correlation coefficient R2 = 0.999 and the film diffusion or chemisorption is the rate-limiting step. The equilibrium data is analyzed using five isotherm models, the experimental data agreed well with the Freundlich model with a maximum adsorption capacity of 78.12 mg g-1 and 57.14 mg g-1 for CTS-Nap and Fe3O4@CTS-Nap, respectively. However, this unexpected result revealed that the presence of magnetic nanoparticles does not always enhance the adsorption process and many other factors could control the adsorption process. Generally, these outcomes revealed that the unmagnetite modified adsorbent CTS-Nap have practical greater influence on wastewater treatment management rather than the magnetic modified chitosan Fe3O4@CTS-Nap.
3-nitropropionic acid (3-NP) is a potent mitochondrial inhibitor mycotoxin. Systemic administration of 3-NP can induce Huntington's disease (HD)-like symptoms in experimental animals. Safranal (Safr) ...that is found in saffron essential oil has antioxidant, anti-inflammatory and anti-apoptotic actions. Candesartan (Cands) is an angiotensin receptor blocker that has the potential to prevent cognitive deficits. The present study aims to investigate the potential neuroprotective efficacy of Safr or Cands in 3-NP-induced rat model of HD. The experiments continued for nine consecutive days. Rats were randomly assigned into seven groups. The first group (Safr-control) was daily intraperitoneally injected with paraffin oil. The second group (Cands- and 3-NP-control) daily received an oral dose of 0.5% carboxymethylcellulose followed by an intraperitoneal injection of 0.9% saline. The third and fourth groups received a single daily dose of 50 mg/kg Safr (intraperitoneal) and 1 mg/kg Cands (oral), respectively. The sixth group was daily treated with 50 mg Safr kg/day (intraperitoneal) and was intraperitoneally injected with 20 mg 3-NP/ kg, from the 3.sup.rd till the 9.sup.th day. The seventh group was daily treated with 1 mg Cands /kg/day (oral) and was intraperitoneally injected with 20 mg 3-NP/ kg, from the 3.sup.rd till the 9.sup.th day. The present results revealed that 3-NP injection induced a considerable body weight loss, impaired memory and locomotor activity, reduced striatal monoamine levels. Furthermore, 3-NP administration remarkably increased striatal malondialdehyde and nitric oxide levels, whereas markedly decreased the total antioxidant capacity. Moreover, 3-NP significantly upregulated the activities of inducible nitric oxide synthase and caspase-3 as well as the Fas ligand, in striatum. On the contrary, Safr and Cands remarkably alleviated the above-mentioned 3-NP-induced alterations. In conclusion, Safr and Cands may prevent or delay the progression of HD and its associated impairments through their antioxidant, anti-inflammatory, anti-apoptotic and neuromodulator effects.
The expanding use of photovoltaics (PV) as a green energy resource has been rising in these years, mostly due to the possibility of being incorporated with traditional power systems, to meet the ...world's energy needs and reduce carbon emissions. However, providing green electricity from this renewable generator is frequently vulnerable to power quality (PQ) disruptions resulting from the PV's intermittent nature and other factors associated with the electric grid, power converters, and linked loads. These disruptions need to be reduced to keep the investigated system's PQ from deteriorating. The investigated system includes PV, DC-DC, and DC-AC converters, filter, power grid, and control schemes. If the DC-DC converter is not managed, a deviation from the maximum power point (MPP) extrapolated from the PV system will take place. In order to maximize the energy harvested from the PV system by managing the DC-DC converter, this research developed two MPP tracking (MPPT) algorithms: artificial neural networks (ANN) and cuckoo search (CS). Additionally, a design and implementation for a shunt active power filter (LCL) using genetic algorithm and GRG is provided to lower the injected total harmonic distortion (THD) and thereby enhance the PQ. To achieve the smallest size of the LCL components, the generalized reduced gradient (GRG) was the best compared to genetic algorithms GA. The results of the simulation showed that ANN performed better at tracking maximum power than CS. With the designed LCL, the THD is reduced by 99.78% compared to without a filter. To verify the simulation's findings, a practical configuration is implemented.
The influences of intrinsic decoherence, tunnelling rates, and Coulomb coupling interaction on the behaviour of negativity, quantum coherence and the measurement-induced disturbance of two coupled ...quantum dot molecules are discussed. The aforementioned is implemented by obtaining the exact solution of the Milburn equation, where the initial setting state is prepared in an entangled Werner state. Various phenomena are illustrated for three physical measures, namely entanglement, coherence, and quantum correlations. It showed that the intrinsic decoherence strength plays a destructive role for the maximum bounds of all these physical quantities, in which they are decayed to a non-zero fixed point. Altering the tunnelling rates strength increases/ decreases the maximum and minimum bounds of the three physical measurements, whereby increasing the tunnelling rate lessens the entanglement and denigrates the maximum and minimum values of coherence and quantumness. Otherwise, the Coulomb coupling enhances the stability of all physical quantities.
Diabetic nephropathy (DN) is a major leading cause of kidney failure. So, early detection of DN by assessing urinary microRNAs (miRNAs) expression may be of clinical value. In this study, the ...diagnostic value of two urinary miRNAs (miR-210 & miR-34a) as biomarkers for diagnosis of DN was assessed using a simple colorimetric gold nanoparticle (AuNP) assay and real-time PCR. MiR-(210 & 34a) were markedly up-regulated in DN groups (micro-albuminuric and macro-albuminuric groups) compared to the non-albuminuric group and healthy controls. The sensitivity and specificity for the qualitative detection of urinary miR-(210 & 34a) using the AuNP assay were (78% and 72%) & (81% and 69%), respectively, which were consistent with the results of real-time PCR. There was a highly significant correlation between urinary miR-(210 & 34a) detected by either qRT-PCR or qualitative AuNP assay. Accordingly, this simple AuNP assay may be considered a valid test for the detection of these two urinary miRNAs as potential biomarkers that can aid in the noninvasive diagnosis of DN.
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•Urinary miRNAs-(210 & 34a) are promising biomarkers for diabetic nephropathy (DN).•A simple colorimetric gold nanoassay for clinical miRNA detection was validated.•Sensitivity and specificity of this nanoassay were consistent with qRT-PCR results.•This gold nanoassay may be valuable for detection of urinary miRNAs-(210 & 34a).•The nanoassay can also aid quick noninvasive diagnosis of DN in clinical samples.
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