Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Sci Rep ; 14(1): 11221, 2024 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-38755253

RESUMO

The underutilization of digestate-derived polymers presents a pressing environmental concern as these valuable materials, derived from anaerobic digestion processes, remain largely unused, contributing to pollution and environmental degradation when left unutilized. This study explores the recovery and utilization of biodegradable polymers from biomass anaerobic digestate to enhance the performance of solar photovoltaic (PV) cells while promoting environmental sustainability. The anaerobic digestion process generates organic residues rich in biodegradable materials, often considered waste. However, this research investigates the potential of repurposing these materials by recovering and transforming them into high-quality coatings or encapsulants for PV cells. The recovered biodegradable polymers not only improve the efficiency and lifespan of PV cells but also align with sustainability objectives by reducing the carbon footprint associated with PV cell production and mitigating environmental harm. The study involves a comprehensive experimental design, varying coating thickness, direct normal irradiance (DNI) (A), dry bulb temperature (DBT) (B), and relative humidity (C) levels to analyze how different types of recovered biodegradable polymers interact with diverse environmental conditions. Optimization showed that better result was achieved at A = 8 W/m2, B = 40 °C and C = 70% for both the coated material studied. Comparative study showed that for enhanced cell efficiency and cost effectiveness, EcoPolyBlend coated material is more suited however for improving durability and reducing environmental impact NanoBioCelluSynth coated material is preferable choice. Results show that these materials offer promising improvements in PV cell performance and significantly lower environmental impact, providing a sustainable solution for renewable energy production. This research contributes to advancing both the utilization of biomass waste and the development of eco-friendly PV cell technologies, with implications for a more sustainable and greener energy future. This study underscores the pivotal role of exploring anaerobic digestate-derived polymers in advancing the sustainability and performance of solar photovoltaic cells, addressing critical environmental and energy challenges of our time.Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 7 Given name: [Ashok] Last name [Kumar Yadav]. Also, kindly confirm the details in the metadata are correct.correct.


Assuntos
Biomassa , Polímeros , Energia Solar , Polímeros/química , Reciclagem , Anaerobiose
2.
ACS Omega ; 8(37): 33794-33801, 2023 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-37744822

RESUMO

In this work, new compositions of Sr0.8Mg0.2(Sn1-xZrx)O3 0.00 ≤ x ≤ 0.06 ceramics are designed and synthesized by the conventional solid-state route. The influence of Zr doping on the phase, microstructural, optical, and dielectric properties is thoroughly investigated. The peaks (0 0 4) and (1 1 0) are observed to shift toward lower 2θ values, due to the variation of the ionic radius between Zr4+ and Sn4+. X-ray diffraction patterns reveal the orthorhombic structure with the space group Pbnm. Scanning electron microscopy images reveal the presence of pores and particles with a high degree of agglomeration. The functional groups and modes of vibration are determined by Fourier transform infrared spectroscopy of the prepared metal oxide samples. The existence of green emission of all the synthesized samples around 554.91 nm is identified by photoluminescence spectroscopy. The dielectric properties of the fabricated samples are measured by using an impedance analyzer. The values of the tangent loss and relative permittivity are found to decrease with increasing frequency.

3.
Polymers (Basel) ; 15(5)2023 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-36904539

RESUMO

Infectious diseases remain inevitable factors for high mortality and morbidity rate in the modern world to date. Repurposing is a novel approach to drug development has become an intriguing research topic in the literature. Omeprazole is one of the top ten proton pump inhibitors prescribed in the USA. The literature suggests that no reports based on omeprazole anti-microbial actions have been discovered to date. This study entails the potential of omeprazole to treat skin and soft tissue infections based on the literature's evident anti-microbial effects. To get a skin-friendly formulation, a chitosan-coated omeprazole-loaded nanoemulgel formulation was fabricated using olive oil, carbopol 940, Tween 80, Span 80, and triethanolamine by high-speed homogenization technique. The optimized formulation was physicochemically characterized for zeta potential, size distribution, pH, drug content, entrapment efficiency, viscosity, spreadability, extrudability, in-vitro drug release, ex-vivo permeation analysis, and minimum inhibitory concentration determination. The FTIR analysis indicated that there was no incompatibility between the drug and formulation excipients. The optimized formulation exhibited particle size, PDI, zeta potential, drug content, and entrapment efficiency of 369.7 ± 8.77 nm, 0.316, -15.3 ± 6.7 mV, 90.92 ± 1.37% and 78.23 ± 3.76%, respectively. In-vitro release and ex-vivo permeation data of optimized formulation showed 82.16% and 72.21 ± 1.71 µg/cm2, respectively. The results of minimum inhibitory concentration (1.25 mg/mL) against selected bacterial strains were satisfactory, suggesting a successful treatment approach for the topical application of omeprazole to treat microbial infections. Furthermore, chitosan coating synergistically increases the antibacterial activity of the drug.

4.
Gels ; 9(2)2023 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-36826305

RESUMO

Retinoids are considered the mainstay treatment for moderate to severe acne. Adapalene, a third-generation retinoid, has physiochemical properties which hinder the effective delivery of the drug to the skin. Therefore, the current study aimed to develop and evaluate adapalene liposomal loaded gel (ADA-LP gel) for the effective management of acne to improve tolerability and delivery to targeted sites as compared to the conventional dosage form of the drug. A novel spontaneous phase transition method (SPT) was used to formulate liposomes. Liposomal formulation (ADA-LP) was prepared and optimized based on particle size, zeta potential, and PDI. Optimized formulation was further characterized by different techniques and loaded into Carbopol gel. In vitro drug release, ex vivo permeation, and in vivo studies were performed using the prepared adapalene-loaded liposomal-based gel. The in vivo study was done employing the testosterone-induced acne model in mice. The optimized formulation had a size of 181 nm, PDI 0.145, and a zeta potential of -35 mV, indicating that the formulation was stable. Encapsulation efficiency was 89.69 ± 0.5%. ADA-LPs were loaded into the gel. Prepared ADA-LP showed a 79 ± 0.02% release of drug in a sustained manner, within 24 h. The ex vivo permeability study showed a total of 43 ± 0.06 µg/cm2 of drug able to permeate through the skin within 24 h. Moreover, only 28.27 ± 0.04% was retained on the epidermis. The developed ADA-LP gel showed significant improvement in the acne lesions in mice with no visible scars and inflammation on the skin. Therefore, ADA-LP-based gel could be a promising carrier system for the safe and effective delivery of Adapalene.

5.
Sci Rep ; 13(1): 2022, 2023 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-36739452

RESUMO

Zinc (Zn) deficiency is a major health concern in developing countries due to dependency on cereal based diet. Cereals are inherently low in Zn and inevitable use of stressed land has further elevated the problem. The aim of current research was to improve wheat and rice grains grain Zn concentration grown in saline soils through zinc oxide nanoparticles (ZnO-NPs) due to their perspective high availability. The ZnO-NPs were prepared by co-precipitation method and characterized through X-ray diffraction (XRD) and Scanning Electron Microscope (SEM). Two separate pot experiments for wheat and rice were conducted to check the relative effectiveness of ZnO-NPs compared to other bulk Zn sources i.e., zinc sulphate heptahydrate (ZnSO4·7H2O) and ZnO. Results showed that salt stress negatively impacted the tested parameters. There was a significant (p ≤ 0.05) improvement in growth, salt tolerance, plant Zn uptake and grain Zn concentrations by Zn application through Zn sources. The ZnO-NPs showed maximum improvement in crops parameters as compared to other sources due to their higher uptake and translocation in plants under both normal and stressed soil conditions. Thus, ZnO nanoparticles proved to be more effective for grain Zn fortification in both tested wheat and rice crops under normal and saline conditions.


Assuntos
Oryza , Poluentes do Solo , Óxido de Zinco , Zinco/análise , Triticum , Sulfato de Zinco , Grão Comestível/química , Produtos Agrícolas , Estresse Salino , Solo , Poluentes do Solo/análise
6.
Front Chem ; 10: 969698, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36569963

RESUMO

Pristine lanthanum nickelate (LaNiO3), silver phosphate (Ag3PO4) and perovskite lanthanum nickelate silver phosphate composites (LaNiO3/Ag3PO4) were prepared using the facile hydrothermal method. Three composites were synthesized by varying the percentage of LaNiO3 in Ag3PO4. The physical properties of as-prepared samples were studied by powder X-ray diffraction (pXRD), Fourier-transform infrared (FT-IR), Scanning electron microscopy (SEM) and Energy-dispersive X-ray (EDX). Among all synthesized photocatalysts, 5%LaNiO3/Ag3PO4 composite has been proved to be an excellent visible light photocatalyst for the degradation of dyes i.e., rhodamine B (RhB) and methyl orange (MO). The photocatalytic activity and stability of Ag3PO4 were also enhanced by introducing LaNiO3 in Ag3PO4 heterojunction formation. Complete photodegradation of 50 mg/L of RhB and MO solutions using 25 mg of 5%LaNiO3/Ag3PO4 photocatalyst was observed in just 20 min. Photodegradation of RhB and MO using 5%LaNiO3/Ag3PO4 catalyst follows first-order kinetics with rate constants of 0.213 and 0.1804 min-1, respectively. Perovskite LaNiO3/Ag3PO4 photocatalyst showed the highest stability up to five cycles. The photodegradation mechanism suggests that the holes ( h +) and superoxide anion radicals O 2 • - plays a main role in the dye degradation of RhB and MO.

7.
Micromachines (Basel) ; 13(11)2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36363845

RESUMO

Low loss Ruddlesden-Popper (RP) series, i.e., (Sr1-xCax)5Ti4O13, 0.0 ≤ x ≤ 0.06, has been synthesized by a mixed oxide route. In this work, the substitution of Ca2+ cation in Sr5Ti4O13 sintered ceramics was chosen to enhance the structural, optical, and dielectric properties of the product. It was found that the Ca2+ content has significant effects on enhancing the dielectric properties as compared to Mn and glass additions. It was observed that the relative density, band gap energy, and dielectric loss (tangent loss) increase while relative permittivity decreases along with Ca2+ content. High relative density (96.7%), low porosity, and high band gap energy (2.241 eV) values were obtained in (Sr1-xCax)5Ti4O13, 0.0 ≤ x ≤ 0.06 sintered ceramics. These results will play a key role in the application of dielectric resonators.

8.
Gels ; 8(11)2022 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-36354616

RESUMO

A transdermal delivery approach may circumvent the limitations associated with the oral use of risperidone (RIS), an atypical antipsychotic drug. The current study focuses on the utilization of poloxamer (pluronic) lecithin organogel (PLO), a suitable transdermal vehicle, and a biodegradable nanoparticulate system of PLGA with the potential to deliver RIS in an efficient way. PLGA nanoparticles were fabricated using different ratios of the polymer and surfactant. The optimization was performed principally on the basis of particle size and entrapment efficiency (EE). The developed PLGA nanoparticles were spherical, sized around 109 nm with negative charge (−9.3 mv) and enhanced drug entrapment efficiency (58%). The in vitro drug release study of lyophilized nanoparticles showed a sustained pattern. Statistical analysis confirmed that there was a significant difference (p < 0.05) between the nanoparticle-loaded PLO gel and conventional drug formulations in terms of drug release and ex vivo permeation across rat skin (three-fold). The results confirm enhanced drug release and permeation through the skin at 72 h. Hence, the investigated formulation could be a better alternative to the conventional route for improving patient compliance.

9.
RSC Adv ; 12(42): 27508-27516, 2022 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-36276036

RESUMO

In this work, the structural, electronic, magnetic and elastic properties of the xenon-based fluoroperovskites XeMF3 (M = Ti, V, Zr, Nb) have been studied using density functional theory. The structural study reveals that all the perovskites have stable structures. A half-metallic nature is observed due to the presence of a band gap in only the spin-down channel. The result indicates that the considered compounds are ferromagnetic materials with integer magnetic moments. The elastic parameters were studied to obtain their elastic properties. It is noted that all compounds have an anisotropic nature and show ductility. The optical characteristics show that these compounds are good optical absorbers at high energy. Furthermore, we suggest that these compounds could be good candidates for spintronic and optoelectronic devices.

10.
ACS Omega ; 7(29): 25573-25579, 2022 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-35910166

RESUMO

Solid solutions of Sr-doped barium nonatitanate (Ba2Ti9O20) ceramics were synthesized by a mixed oxide route, studied their structural, microstructural, optical, and microwave dielectric properties were studied. X-ray diffraction (XRD) has been used to reveal the structure and crystallite size of doped Ba2Ti9O20 ceramics. Rietveld refinements of XRD patterns revealed that all of the ceramics have a tetragonal structure with space group I4/m. The surface morphologies of all the samples were characterized by using scanning electron microscopy (SEM). Fourier transform infrared (FT-IR) studies gave the O-H and Ti-O modes of vibrations. The stretching modes of Ti-O and O-H were noted at 1400, 2960, 3700, and near to 440 cm-1, respectively. The band gap energy decreases with increasing Sr2+ contents, and a high value (2.12 eV) was observed in the base sample. The microwave dielectric properties of the ceramic samples were studied at different frequencies ranging from 1 to 2 GHz by using impedance spectroscopy. The obtained results showed the suitability of these samples for microwave dielectric resonator (antenna) applications.

11.
Plants (Basel) ; 11(12)2022 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-35736676

RESUMO

Green synthesis of metal nanoparticles is of great importance in the modern health care system. In this study, zinc nanoparticles (ZnONPs) were synthesized using leaf and root extracts of Withania somnifera using four different solvents. ZnONPs were characterized by UV-vis spectrophotometer with a range between 350-400 nm. Scanning electron microscope revealed spherical morphology with an overall size of 70-90 nm and XRD pattern confirmed the crystalline structure. The total flavonoids, phenolic, and alkaloid contents were significantly greater in the crude extracts as compared to ZnONPs. The highest scavenging activity was observed in ZnONPs from n-hexane and ethyl-acetate extracts of roots with IC50 values of 27.36 µg/mL and 39.44 µg/mL, respectively. ZnONPs from methanol and aqueous extracts showed significant antibacterial activity against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis while none of the extracts were found to have significant antifungal activity. Maximum cytotoxic activity was observed in ZnONPs synthesized from aqueous and n-hexane root extracts with LC50 values of 9.36 µg/mL and 18.84 µg/mL, respectively. The highest antidiabetic potential was exhibited by ZnONPs from n-hexane leaf extracts, i.e., 47.67 ± 0.25%. Maximum protein kinase inhibitory potential was observed in ZnONPs of ethyl-acetate extract of roots with a bald zone of 12 mm. These results indicated that Withania somnifera-based ZnONPs showed significant biological activities compared to crude extracts. These findings can further be utilized for in-vivo analysis of nano-directed drug delivery systems.

12.
Sci Rep ; 12(1): 10024, 2022 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-35705691

RESUMO

The use of the green approach for nanoparticle synthesis yielded noticeable concern due to its eco-friendliness, cost-effectiveness, and reduced production of toxic chemicals. The current study was designed to formulate Zinc oxide nanoparticles (ZnO NPs) by using Fagonia cretica extracts, evaluating its phytochemical content, and different biological activities. Four different solvents; methanol (MeOH), n-Hexane (n-H), aqueous (Aq), and ethyl acetate (EA), had been utilized in the extracting method. ZnO NPs were successfully synthesized and characterized by UV-vis spectroscopy and scanning electron microscopy (SEM). The UV-vis spectra showed absorbance peaks between 350-400 nm range and SEM analysis revealed spherical morphology with particle sizes ranging from 65-80 nm. In phytochemical analysis, crude extracts exhibited the highest phytochemical content as they contain enriched secondary metabolites. n-hexane extract showed the highest phenolic contents while aqueous extracts showed the highest flavonoid content. Maximum free radicle scavenging activity was observed in NPs synthesized from ethyl-acetate extract with an IC50 value of 35.10 µg/ml. Significant antibacterial activity was exhibited by NPs polar solvents against K. pneumonae, E. coli, and B. subtilis. Polar solvents showed considerable antifungal potential against A. flavus and F. solani. NPs synthesized from nH extract showed potential cytotoxic activity with an LC50 value of 42.41 µg/ml against brine shrimps. A noteworthy antidiabetic activity was exhibited by nanoparticles synthesized from methanol extract i.e., 52.61 ± 0.36%. Significant bald zones were observed in nanoparticles synthesized from methanol extract rendering protein kinase inhibition. The present study highlights the significance of F. indica as a natural source for synthesizing functional nanoparticles with substantial antioxidant, antimicrobial, cytotoxic, protein kinase inhibitory, and antidiabetic properties.


Assuntos
Nanopartículas Metálicas , Óxido de Zinco , Zygophyllaceae , Antibacterianos/farmacologia , Escherichia coli , Hipoglicemiantes/farmacologia , Nanopartículas Metálicas/química , Metanol , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Proteínas Quinases , Solventes , Zinco , Óxido de Zinco/química , Óxido de Zinco/farmacologia
13.
Polymers (Basel) ; 14(9)2022 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-35566808

RESUMO

The aim of the current study is extraction and isolation of bergenin from Bergenia ciliata and fabrication of pH-sensitive Eudragit® L100 (EL100) polymeric nanoparticles (NP) to tackle limitations of solubility. Bergenin-loaded EL100 nanoparticles (BN-NP) were fabricated via nanoprecipitation and an experimental design was conducted for optimization. A reverse phase-high performance liquid chromatography (RP-HPLC) method was developed for the quantitation of bergenin. The optimized nanoformulation was characterized by its particle size, morphology, loading capacity, entrapment efficiency, drug-excipient interaction and crystallinity. An in vitro assay was executed to gauge the release potential of pH-sensitive nanoformulation. The mean particle size, zeta potential and polydispersity index (PDI) of the optimized nanoparticles were observed to be 86.17 ± 2.1 nm, -32.33 ± 5.53 mV and 0.30 ± 0.03, respectively. The morphological analysis confirmed the spherical nature of the nanoparticles. Drug loading capacity and entrapment efficiency were calculated to be 16 ± 0.34% and 84 ± 1.3%, respectively. Fourier transform infrared spectroscopy (FTIR) studies unfolded that no interaction was present between the drug and the excipients in the nanoformulation. Crystallography studies revealed that the crystalline nature of bergenin was changed to amorphous and the nanoformulation was stable for up to 3 months at 40 °C. The present study confirms that bergenin isolation can be scaled up from abundantly growing B. ciliata. Moreover, it could also be delivered by entrapment in stimuli-responsive polymer, preventing the loss of drug in healthy tissues.

14.
Gels ; 8(5)2022 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-35621575

RESUMO

Transdermal hydrogels have the potential to improve therapeutic outcomes via enhancing bioavailability and reducing toxicity associated with oral delivery. The goal of the present study was to formulate and optimise argan oil loaded transdermal hydrogel containing lipid nanoparticles. The high pressure homogenization (HPH) method was utilised to fabricate Simvastatin loaded solid lipid nanoparticles (SIM-SLNs) with precirol ATO 5 as a lipid core and Poloxamer 407 (P407) to stabilise the core. The optimised nanoformulation was characterised for its particle diameter, zeta potential, surface morphology, entrapment efficiency, crystallinity and molecular interaction. Furthermore, transdermal hydrogel was characterised for physical appearance, rheology, pH, bio adhesion, extrudability, spreadability and safety profile. In vitro and ex vivo assays were executed to gauge the potential of SLNs and argan oil for transdermal delivery. The mean particle size, zeta potential and polydispersity index (PDI) of the optimised nanoparticles were 205 nm, -16.6 mV and 0.127, respectively. Crystallinity studies and Fourier transform infrared (FTIR) analysis revealed no molecular interaction. The in vitro release model explains anomalous non-Fickian release of drug from matrix system. Ex vivo skin penetration studies conducted through a fluorescence microscope confirmed penetration of the formulation across the stratum corneum. Hydrogel plays a crucial role in controlling the burst release and imparting the effect of argan oil as hypolipidemic agent and permeation enhancer.

15.
Sci Rep ; 12(1): 7362, 2022 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-35513408

RESUMO

The present study encompasses the application of cost effective, organo-modified bentonite material for efficient desulfurization of model oil and real fuel. For the adsorptive desulfurization of oil, dibenzothiophene (DBT) was used as model compound. Various experimental parameters (time, temperature, adsorbent-amount and DBT concentration) were thoroughly investigated. The synthesized material was characterized via X-ray diffraction (XRD), X-ray Fluorescence (XRF), Scanning electron microscopy (SEM), Energy dispersive x-ray (EDX), Thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR). The modification exhibits the increase in interlayer spacing of clay as confirmed from XRD and modified material shows interesting morphology as compared to unmodified bentonite. The results showed that > 90% of DBT removal was achieved under optimized conditions for B-BTC, B-BTB and B-DSS and > 80% for B-BEHA, for model fuel oil which are greater than unmodified clay (< 45%). Additionally, the findings from desulfurization of real fuel oil declare that 96.76% and 95.83% removal efficiency was achieved for kerosene and diesel oil respectively, at optimized conditions and fuel properties follow ASTM specifications. The obtained findings well fitted with thermodynamic, isothermal (Langmuir) with adsorption capacity (70.8 (B-BTC), 66 (B-BTB), 61.2 (B-DSS) and 55.2 (B-BEHA) in mg/g) and pseudo-second-order kinetics. In thermodynamic studies, negative sign ([Formula: see text] specifies the spontaneity whereas, [Formula: see text] endothermic and positive sign [Formula: see text] show randomness after DBT adsorption onto organoclay.

16.
RSC Adv ; 12(16): 9556-9566, 2022 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-35424907

RESUMO

Microplastics (MPs) have been reported as an emerging xenobiotic organic pollutant in freshwater ecosystems and a universal hazard for ecosystems because of the rapid increase in global demand. The present study was conducted to explore MPs' occurrence, abundance and spatial distribution in sediment, water and Schizothorax plagiostomus samples, collected from the Swat River. ATR-FTIR spectroscopy was used for chemical characterization of visually identified MPs by using standard protocols such as digestion using H2O2, density separation using ZnCl2, vacuum filtration with borosilicate glass micro filter papers and digital microscopy using a stereomicroscope connected with a camera. Range of mass abundance of identified MPs in river sediments, river water, tributaries sediment and tributary water was found to be 0.6-2.5 mg kg-1, 0.7-3.8 mg L-1, 0.9-4.5 mg kg-1 and 0.6-1.1 mg L-1 respectively. Meanwhile, in Schizothorax plagiostomus digestive tracts samples, it was 0.6-1.9 mg per fish. Numeric abundance of MPs in all matrices was found to be tributary sediment (202 items per kg) > river water (192 items per L) > river sediment (182 items per kg) > fish (153 items per fish) > tributary water (92 items per L). MPs identified on the basis of morphology in all matrices were found to be fragments > fibers > pellets > films > foams. MPs were dominant in all urban stations while their spatial distribution along with the study site was heterogeneous due to the surroundings such as tourist spots, hydrodynamic conditions, and proximity to urban areas, plastic industries and due to recharge by the highly contaminated tributaries. The MPs identified on the basis of size dimensions show that S1 (0.5-1 mm) in all matrices was highest while S2 (1-5 mm) was the lowest. Primary source MPs identified were fibers, films, fragments and foams particles while secondary sources were pellets. Results of ATR-FTIR showed that PE was the most common plastic type identified in all samples followed by PVC, PET, PP and PS. This is the first study exploring the MPs' occurrence, numeric and mass abundance and spatial distribution in the SR ecosystem. The present study may be a valuable reference for better understanding the MPs' pollution in Pakistan. The findings of the present study can help to identify the potential sources (i.e., primary and secondary) of MPs to improve waste management in the Swat District and model the transport fluxes of these microplastics in other rivers using water quality parameters and basin characteristics.

17.
ACS Omega ; 7(14): 12212-12221, 2022 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-35449949

RESUMO

Adsorption is one of the most common and most robust techniques for the decontamination approach of effluents, owing to its design flexibility, simplicity, cost effectiveness, and high efficiency. However, its application is limited on a large scale due to its cost. The current study investigates the use of low-cost, ecofriendly, and ubiquitous thermally activated clay material. Thermally treated clay was used for the adsorption of crystal violet (CV), Congo red (CR), and malachite green (MG) organic dyes from aqueous solutions. Characterization of slate was carried out with Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy, X-ray diffraction, N2 physisorption, and XRF spectrometry. The adsorption process was studied as a function of concentration, time, pH, and temperature. Using the batch adsorption technique, the experimentally obtained adsorption data were fitted to both Langmuir and Freundlich isotherms. The adsorption data followed the pseudo-second-order kinetics, and the adsorption capacity was recorded as 360.12 mg/g for CV, 409.23 mg/g for CR, and 390.14 mg/g for MG. The good uptake is the outcome of a greater surface area (24.751 m2/g) for the slate activated at 873 K. The thermodynamic studies showed that the adsorption process remained endothermic and spontaneous. Thermally activated slate proved itself to be an efficient adsorbent and can effectively be used for the removal of textile dyes from the contaminated water, and it is evident from the good uptake of the adsorbate by the adsorbent.

18.
Materials (Basel) ; 15(5)2022 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-35269010

RESUMO

The electronic, mechanical and transport properties of the In substitution in GaAs are investigated by the TB-mBJ potential, BoltzTraP code and Charpin tensor matrix analysis using Wien2k code. The formation energies of the alloys Ga1-xInxAs (x = 0.0, 0.25, 0.50, 0.75 and 1.0) confirm that they are thermodynamically favorable. The directional symmetry changes when increasing the In concentration and reduces the bandgap from 1.55 eV (GaAs) to 0.57 eV (InAs), as well as reducing the electrical conductivity and increasing the Seebeck coefficient. The thermoelectric performance is depicted by the power factor without including lattice vibration. The elastic properties' analysis shows mechanical stability, and elastic moduli decrease with an increasing In in GaAs, which converts the brittle nature to ductile. The Debye temperature, hardness and thermal conductivity decrease, thus, increasing their importance for device fabrications.

19.
Materials (Basel) ; 14(19)2021 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-34640004

RESUMO

There is considerable attention devoted to the use of agricultural waste as a raw material substitute for commercial silica in the development of borosilicate glasses doped with rare earth oxides. Here, we present a novel structure for borosilicate glasses made from rice husk ash with a 25% molar ratio of extracted SiO2 and doped with neodymium (GRN) or dysprosium (GRD). Adding rare earth oxides to borosilicate glasses by the melt quenching method enhanced optical transmission due to the presence of their tetrahedral geometries. GRN samples showed few bands near zero, which constitutes good utility for band rejection filters in image devices, and the samples exhibited energy values ranging from 3.03 to 3.00 eV before and after gamma irradiation. Optical transmissions of GRD samples showed peaks at 25,974, 22,172, 13,333, 11,273, 9302, 7987, and 6042 cm-1. Deterioration in transmittance was observed when the investigated samples were exposed to irradiation doses of 20 and 50 kGy in the wavenumber range of 12,500 to 50,000 cm-1; however, different behaviors after irradiation with 50 kGy caused an increase in transparency in comparison to 20 kGy irradiation, which was pronounced for higher wavenumbers (greater than 12,500 cm-1). Photoluminescence emission and excitation spectra of the glass-doped Nd3+ (GRN) and glass-doped Dy3+ (GRD) samples were determined. GRD exhibited emission in the blue and yellow regions of the visible spectrum, which gave a white flash of light. Chromaticity coordinate (CIE) measurements of GRD samples indicated the origin of its luminous color relative to the standard white light region.

20.
Nano Lett ; 18(1): 235-240, 2018 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-29191016

RESUMO

There is considerable interest in the development of InAsSb-based nanowires for infrared photonics due to their high tunability across the infrared spectral range, high mobility, and integration with silicon electronics. However, optical emission is currently limited to low temperatures due to strong nonradiative Auger and surface recombination. Here, we present a new structure based on conical type II InAsSb/InAs multiquantum wells within InAs nanowires which exhibit bright mid-infrared photoluminescence up to room temperature. The nanowires are grown by catalyst-free selective area epitaxy on silicon. This unique geometry confines the electron-hole recombination to within the quantum wells which alleviates the problems associated with recombination via surface states, while the quantum confinement of carriers increases the radiative recombination rate and suppresses Auger recombination. This demonstration will pave the way for the development of new integrated quantum light sources operating in the technologically important mid-infrared spectral range.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...