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1.
Chemosphere ; 363: 142825, 2024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-38996982

RESUMEN

Electrochemical oxidation (EO), electro-Fenton (EF), and photoelectro-Fenton (PEF) with a BDD anode have been comparatively assessed to remediate solutions of Red CL and/or Red WB azo dyes from real raw water. For the EO process in 50 mM Na2SO4 at pH 3.0, the main oxidant was the heterogeneous •OH generated at the anode, whereas in EF and PEF, the cathodic production of H2O2 and the addition of 0.50 mM Fe2+ catalyst additionally originated homogeneous •OH that enhanced the oxidation of organics. In PEF, the solution was illuminated with a 6 W UVA light. An almost total discoloration was always found operating with a 1:1 mixture of 200 mg L-1 of both dyes in 60 min, whose efficiency increased in the order of EO < EF < PEF. The HPLC analysis of the dye mixture treated by PEF disclosed that its degradation process agreed with its discoloration. A high 74% of COD was reduced due to the oxidative action of hydroxyl radicals and the photolysis of final Fe(III)-carboxylate species with UVA irradiation. The process was accompanied by an energy consumption of 0.76 kWh (g COD)-1, a value similar to the energy consumed by the applied UVA light.

2.
Chemosphere ; 351: 141153, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38219991

RESUMEN

The widespread use of antibiotics for the treatment of bacteriological diseases causes their accumulation at low concentrations in natural waters. This gives health risks to animals and humans since it can increase the damage of the beneficial bacteria, the control of infectious diseases, and the resistance to bacterial infection. Potent oxidation methods are required to remove these pollutants from water because of their inefficient abatement in municipal wastewater treatment plants. Over the last three years in the period 2021-September 2023, powerful peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs) have been developed to guaranty the effective removal of antibiotics in synthetic and real waters and wastewater. This review presents a comprehensive analysis of the different procedures proposed to activate PMS-producing strong oxidizing agents like sulfate radical (SO4•-), hydroxyl radical (•OH, radical superoxide ion (O2•-), and non-radical singlet oxygen (1O2) at different proportions depending on the experimental conditions. Iron, non-iron transition metals, biochar, and carbonaceous materials catalytic, UVC, photocatalytic, thermal, electrochemical, and other processes for PMS activation are summarized. The fundamentals and characteristics of these procedures are detailed remarking on their oxidation power to remove antibiotics, the influence of operating variables, the production and detection of radical and non-radical oxidizing agents, the effect of added inorganic anions, natural organic matter, and aqueous matrix, and the identification of by-products formed. Finally, the theoretical and experimental analysis of the change of solution toxicity during the PMS-based AOPs are described.


Asunto(s)
Antibacterianos , Peróxidos , Humanos , Antibacterianos/farmacología , Oxidación-Reducción , Oxidantes , Agua
3.
Chemosphere ; 349: 140848, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38036228
4.
Heliyon ; 9(9): e20048, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37809571

RESUMEN

Encapsulation of photovoltaic cells was carried out using a transparent glass fiber reinforced composite with enhanced chemical recyclability based on a matrix of an epoxy resin containing cleavable functional groups. The current-voltage curves showed a decrease of 6.3% on the short-circuit current (Isc) after encapsulation of the cell, lower than the one observed for the reference non-recyclable standard epoxy composite. Its performance stability under thermal cycling, ultraviolet (UV), and damp-heat exposure was evaluated and compared with the one of the reference standard epoxy. Both resins showed good stability performance under UV exposure and thermal cycling accelerated aging. Moreover, a power loss below the 5% allowed by the photovoltaic standard was observed for the recyclable resin after 1000 h of damp-heat exposure, even the pronounced loss of 4.7% in power remains a concern. Regarding the recyclability, the composite was dissolved in acetic acid dissolution and glass fiber fabrics were successfully recovered. A new module was manufactured with these fabrics, showing this time a loss of 12% in Isc comparing with the non-encapsulated cell. Further work will consider improving the moisture barrier properties of the composite, and adjusting the recycling conditions to allow component recovery valid for new modules.

5.
Chemosphere ; 339: 139666, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37532204

RESUMEN

Today, water shortage problems around the world have forced the search for new treatment alternatives, in this context, electrochemical oxidation technology is a hopeful process for wastewater treatment, although it is still needed exploration of new efficient and economically viable electrode materials. In this way, mixed metal oxide anodes look like promising alternatives but their preparation is still a significant point to study, searching for finding low-cost materials to improve electrocatalytic efficiencies. In an exploration of this kind of highly efficient materials, this work presents the results obtained using an MMO Ti/IrO2-SnO2-Sb2O5 anode. All the prepared anodes exhibited excellent physical and electrochemical properties. The electrochemical oxidation of 100 mL and 200 mg L-1 Reactive Orange 84 (RO 84) diazo dye was studied using 3 cm2 of such synthesized anodes by applying current densities of 25, 50, and 100 mA cm-2. Faster and more efficient electrochemical oxidation occurred at 100 mA cm-2 with 50 mM of Na2SO4 + 10 mM NaCl as supporting electrolyte at pH 3.0. The degradation and mineralization processes of the above solution were enhanced with the electro-Fenton process with 0.05 mM Fe2+ and upgraded using photoelectron-Fenton with UVA light. This process yielded 91% COD decay with a low energy consumption of 0.1137 kWh (g COD)-1 at 60 min. The evolution of a final carboxylic acid like oxalic was followed by HPLC analysis. The Ti/IrO2-SnO2-Sb2O5 is then an efficient and low-cost anode for the photoelectro-Fenton treatment of RO 84 in a chloride and sulfate media.


Asunto(s)
Rayos Ultravioleta , Contaminantes Químicos del Agua , Titanio/química , Peróxido de Hidrógeno/química , Oxidación-Reducción , Electrodos , Contaminantes Químicos del Agua/química , Técnicas Electroquímicas
6.
Chem Biodivers ; 20(3): e202200554, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36799136

RESUMEN

The optimized geometry of palbociclib, (PD 0332991) (8-cyclopentyl-6-ethanoyl-5-methyl-2-(5-(piperazin-1-yl)pyridin-2-ylamino)pyrido[2,3-d]pyrimidin-7(8H)-one), electrostatic potential map, molecular orbitals were calculated using the density functional theory. The geometry was used in a molecular docking study of palbociclib-kinase complexes, results could be explained by the charge of the nitrogen and oxygen atoms within the palbociclib. Energy gap of HOMO-LUMO surfaces, could help to explain the reactivity of the ligand and the hydrogen bonding with three different kinases, two of CDK6 and one of CDK4 type. Docking results are similar and complementary with literature reports using molecular dynamics, were hydrogen bonding was obtained and analyzed. The promiscuity of three kinases with palbociclib was detected by the docking results, thus, palbociclib could be used in other types of cancer besides myeloid leukemia. Some similarities are found with CDK4/CDK6 kinases which allow us to determine that palbociclib could be used to control other resistant inhibitor types of cancer.


Asunto(s)
Neoplasias , Humanos , Simulación del Acoplamiento Molecular , Piperazinas/farmacología , Piridinas/farmacología , Inhibidores de Proteínas Quinasas/farmacología
8.
Chemosphere ; 303(Pt 1): 134883, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35577132

RESUMEN

Paracetamol (PCT), also known as acetaminophen, is a drug used to treat fever and mild to moderate pain. After consumption by animals and humans, it is excreted through the urine to the sewer systems, wastewater treatment plants, and other aquatic/natural environments. It has been detected in trace amounts in effluents of wastewater plant treatments, sewage sludge, hospital wastewaters, surface waters, and drinking water. PCT can cause genetic code damage, oxidative degradation of lipids, and denaturation of protein in cells, and its toxicity has been well-proven in bacteria, algae, macrophytes, protozoan, and fishes. To avoid its harmful health problems over living beings, powerful Fenton and Fenton-based treatments as pre-eminent advanced oxidation processes (AOPs) have been developed because of the inefficient treatment by conventional treatments. This paper presents a comprehensive and critical review over the application of such Fenton technologies to remove PCT from natural waters, synthetic wastewaters, and real wastewaters. The characteristics and main results obtained using Fenton, photo-Fenton, electro-Fenton, and photoelectro-Fenton are described, making special emphasis in the oxidative action of the generated reactive oxygen species. Hybrid processes based on the coupling with ultrasounds, gamma radiation, photocatalysis, photoelectrocatalysis, zero-valent iron-activated persulfate, adsorption, and microbial fuel cells, are analyzed. Sequential treatments involving the initiation with plasma gliding arc discharge and post-biological process are detailed. Comparative results with other available AOPs are also described and discussed. Finally, 13 aromatic by-products and 9 short-linear aliphatic carboxylic acid detected during the PCT removal by Fenton and Fenton-based processes are reported, with the proposal of three parallel pathways for its initial degradation.


Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Acetaminofén , Animales , Peróxido de Hidrógeno/metabolismo , Oxidación-Reducción , Aguas Residuales , Agua , Purificación del Agua/métodos
9.
Environ Res ; 212(Pt C): 113362, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35525294

RESUMEN

The electrophoretic deposition of titanium dioxide (TiO2) nanoparticles (Degussa P25) onto a boron-doped diamond (BDD) substrate was carried out to produce a photoanode (TiO2/BDD) to apply in the degradation and mineralization of sodium diclofenac (DCF-Na) in an aqueous medium using photoelectrocatalysis (PEC). This study was divided into three stages: i) photoanode production through electrophoretic deposition using three suspensions (1.25%, 2.5%, 5.0% w/v) of TiO2 nanoparticles, applying 4.8 V for 15 and 20 s; ii) characterization of the TiO2/BDD photoanode using scanning electron microscopy and cyclic voltammetry response with the [Fe(CN)6]3-/4- redox system; iii) degradation of DCF-Na (25 mg L-1) through electrochemical oxidation (EO) on BDD and PEC on TiO2/BDD under dark and UVC-light conditions. The degradation of DCF-Na was evaluated using high-performance liquid chromatography and UV-Vis spectroscopy, and its mineralization measured using total organic carbon and chemical oxygen demand. The results showed that after 2 h, DCF-Na degradation and mineralization reached 98.5% and 80.1%, respectively, through PEC on the TiO2/BDD photoanode at 2.2 mA cm-2 under UVC illumination, while through EO on BDD applying 4.4 mA cm-2, degradation and mineralization reached 85.6% and 76.1%, respectively. This difference occurred because of the optimal electrophoretic formation of a TiO2 film with a 9.17 µm thickness on the BDD (2.5% w/v TiO2, time 15 s, 4.8 V), which improved the electrocatalysis and oxidative capacity of the TiO2/BDD photoanode. Additionally, PEC showed a lower specific energy consumption (1.55 kWh m-3). Thus, the use of nanostructured TiO2 films deposited on BDD is an innovative photoanode alternative for the photoelectrocatalytic degradation of DCF-Na, which substantially improves the degradation capacity of bare BDD.


Asunto(s)
Boro , Contaminantes Químicos del Agua , Diclofenaco , Electrodos , Oxidación-Reducción , Titanio/química , Contaminantes Químicos del Agua/química
10.
Neurosci Lett ; 782: 136684, 2022 06 21.
Artículo en Inglés | MEDLINE | ID: mdl-35595190

RESUMEN

Absence seizures are characterized as a generalized type of epilepsy that occurs during childhood. Importantly, absence seizures in children often discontinue after puberty. There is limited availability of animal models in which electroencephalography (EEG) can be performed in the long term; however, two absence seizure models, GAERS and WAG/Rij albino rats, are available. The taiep rat is a myelin mutant rat with tubulinopathy due to a tubulin ß 4A gene mutation and characteristic spike-wave discharges (SWDs) that mimic absence seizure epilepsy in humans and the above rat models. This study aimed to analyze spike-wave discharges after an orchiectomy was performed on postnatal day (PND) 2 or PND 90 in adult rats; and SWDs was recorded in both groups on PND 104. The results suggest that androgens play a critical role in susceptibility to SWDs. In fact, orchiectomy during the neonatal period significantly reduced the frequency of spike-wave discharges. However, if an orchiectomy was performed in adulthood, then SWDs were significantly increased. The mean duration of spike-wave discharges did not differ among the groups tested. Acute administration of testosterone (1 mg/kg) did not change the frequency or duration of spike-wave discharges in the control group or both orchiectomized groups. Overall, this study is the first to show a dichotomic influence of testicular androgens on spike-wave discharges. These findings will have implications in children with this type of generalized epilepsy and may explain the disappearance of absence epilepsy in two-thirds of patients after puberty.


Asunto(s)
Epilepsia Tipo Ausencia , Enfermedades Neurodegenerativas , Adulto , Andrógenos , Animales , Modelos Animales de Enfermedad , Electroencefalografía , Epilepsia Tipo Ausencia/genética , Humanos , Incidencia , Ratas , Ratas Wistar , Convulsiones
11.
Chaos Solitons Fractals ; 155: 111655, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34955615

RESUMEN

The spread of COVID-19 and ensuing containment measures have accentuated the profound interdependence among nations or regions. This has been particularly evident in tourism, one of the sectors most affected by uncoordinated mobility restrictions. The impact of this interdependence on the tendency to adopt less or more restrictive measures is hard to evaluate, more so if diversity in economic exposures to citizens' mobility are considered. Here, we address this problem by developing an analytical and computational game-theoretical model encompassing the conflicts arising from the need to control the economic effects of global risks, such as in the COVID-19 pandemic. The model includes the individual costs derived from severe restrictions imposed by governments, including the resulting economic interdependence among all the parties involved in the game. By using tourism-based data, the model is enriched with actual heterogeneous income losses, such that every player has a different economic cost when applying restrictions. We show that economic interdependence enhances cooperation because of the decline in the expected payoffs by free-riding parties (i.e., those neglecting the application of mobility restrictions). Furthermore, we show (analytically and through numerical simulations) that these cross-exposures can transform the nature of the cooperation dilemma each region or country faces, modifying the position of the fixed points and the size of the basins of attraction that characterize this class of games. Finally, our results suggest that heterogeneity among regions may be used to leverage the impact of intervention policies by ensuring an agreement among the most relevant initial set of cooperators.

12.
Chemosphere ; 281: 130821, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34000653

RESUMEN

Water pollution is an environmental problem in constant raising because of population growing, industrial development, agricultural frontier expansion, and principally because of the lack of wastewater treatment technology to remove organic recalcitrant and toxic pollutants from industrial and domestic wastewater. Recalcitrant compounds are a serious environmental and health problem mainly due to their toxicity and potential hazardous effects on living organisms, including human beings. Conventional wastewater treatments have not been able to remove efficiently pollutants from water; however, electrochemical advanced oxidation processes (EAOPs) are able to solve this environmental concern. One of the most recent EAOPs technology is photoelectrocatalysis (PEC), it consists in applying an external bias potential to a semiconductor film placed over a conductive substrate to avoid the recombination of photogenerated electron-hole (e-/h+) pairs, increasing h+ availability and hydroxyl radicals' formation, responsible for promoting the degradation/mineralization of organic pollutants in aqueous medium. This review summarizes the recent advances in PEC as a promising technology for wastewater treatment. It addresses the fundamentals and kinetic aspects of PEC. An analysis of photoanode materials and of the configuration of photoelectrochemical reactors is also presented, including an analysis of the influence of the main operational parameters on the treatment of contaminated water. Finally, the most recent applications of PEC are reviewed, and the challenges and perspectives of PEC in wastewater treatment are discussed.


Asunto(s)
Contaminantes Ambientales , Contaminantes Químicos del Agua , Purificación del Agua , Humanos , Oxidación-Reducción , Aguas Residuales/análisis , Agua , Contaminantes Químicos del Agua/análisis
13.
Sensors (Basel) ; 21(7)2021 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-33917275

RESUMEN

A moisture sensor based on a composite resonator is used to measure different honey samples, which include imitation honey. The sensor changes its frequency response in accordance with the dielectric permittivity that it detects in the measured samples. Although reflectometry sensors have been used to measure the percentage of moisture in honey for almost a century, counterfeiters have achieved that their apocryphal product is capable of deceiving these kinds of sensors. Metamaterial features of the composite resonators are expected to improve their response when detecting lossy samples such as organic samples. It is also sought that these sensors manage to detect small differences not only in the real parts of the dielectric permitivities of samples but also in their imaginary parts, and, thus, the sensors are able to discern between real honey and slightly altered honey. Effectively, not only was it possible to improve the response of the sensors by using lossy samples but it was also possible to identify counterfeit honey.

14.
Sci Rep ; 11(1): 5043, 2021 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-33658596

RESUMEN

The current COVID-19 pandemic has impacted millions of people and the global economy. Tourism has been one the most affected economic sectors because of the mobility restrictions established by governments and uncoordinated actions from origin and destination regions. The coordination of restrictions and reopening policies could help control the spread of virus and enhance economies, but this is not an easy endeavor since touristic companies, citizens, and local governments have conflicting interests. We propose an evolutionary game model that reflects a collective risk dilemma behind these decisions. To this aim, we represent regions as players, organized in groups; and consider the perceived risk as a strict lock-down and null economic activity. The costs for regions when restricting their mobility are heterogeneous, given that the dependence on tourism of each region is diverse. Our analysis shows that, for both large populations and the EU NUTS2 case study, the existence of heterogeneous costs enhances global agreements. Furthermore, the decision on how to group regions to maximize the regions' agreement of the population is a relevant issue for decision makers to consider. We find out that a layout of groups based on similar costs of cooperation boosts the regions' agreements and avoid the risk of having a total lock-down and a negligible tourism activity. These findings can guide policy makers to facilitate agreements among regions to maximize the tourism recovery.


Asunto(s)
COVID-19/economía , Control de Enfermedades Transmisibles/métodos , Transmisión de Enfermedad Infecciosa/prevención & control , Control de Enfermedades Transmisibles/economía , Transmisión de Enfermedad Infecciosa/economía , Humanos , Modelos Estadísticos , Pandemias/economía , Factores de Riesgo , SARS-CoV-2/patogenicidad , Turismo
15.
Home Healthc Now ; 39(1): 25-31, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33417359

RESUMEN

Frequent rehospitalizations among patients with heart failure (HF) result in patient burden and high cost. Homebound patients with HF qualify for home healthcare after hospital discharge. It is not known if nonhomebound patients with HF could also benefit from home healthcare nursing (HHN) visits to improve the transition from hospital to home. The purpose of this quality-improvement pilot study was to assess the impact of HHN visits provided to nonhomebound HF patients after hospital discharge on 30-day rehospitalization rates. We included patients with HF who were ineligible for home healthcare services due to their nonhomebound status. Home healthcare nurses followed a modified version of the discharge checklist from the American Heart Association's Rise Above Heart Failure materials, and provided education as appropriate based on patients' responses. We enrolled 68 patients in the study. The mean age was 60.2 years; 61.8% were male and 77.9% were White. Based on patient responses to the checklist, key areas addressed during HHN visits were medication management and HF self-care. In the HHN visit group, 15% of the patients experienced rehospitalization within 30 days, compared with 23% in the non-HHN visit group among 540 patients discharged in the same time frame who met the inclusion criteria but were not enrolled in the study (p = .12). Our pilot data show that HHN visits for nonhomebound patients are feasible and result in a numerically lower 30-day rehospitalization rate after discharge. Further study is needed to confirm the clinical efficacy of this approach.


Asunto(s)
Insuficiencia Cardíaca , Alta del Paciente , Atención a la Salud , Insuficiencia Cardíaca/terapia , Hospitales , Humanos , Masculino , Persona de Mediana Edad , Readmisión del Paciente , Proyectos Piloto
16.
Chemosphere ; 267: 129234, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33352363

RESUMEN

In this study, known combinations of Advanced Oxidation Processes (AOPs, namely Electro-Fenton (EF), Photo-Electro-Fenton (PEF), Electro-Oxidation (EO), and EO/Ozone (O3) were compared for the discoloration of tannery industry azo dye Brown HT (BHT). The different AOPs were tested in a 0.160 L batch electrochemical stirred thank reactor using Boron Doped Diamond (BDD) electrodes. The influence of parameters such as the current density (j) and the initial BHT concentration were to exanimated on the efficiency of all the tested processes. The oxidation tendency of EF, and PEF were compared with those of EO and O3, based on their efficiency for BHT discoloration, which resulted as PEF > EF > EO > O3. The AOPs showing the best oxidation performance was PEF which, using Na2SO4 (0.05 M) electrolyte solution and Fe2+ (0.5 mM), pH 3.0, j = 71 mA cm-2, and 500 rpm process, achieved 100% discoloration and 80% chemical oxygen demand (COD) abatement after 60 min of treatment for two initial BHT concentrations (50 and 80 mg L-1). The process accounted for a current efficiency of 30% and energy consumption 2.25 kWh (g COD)-1 through the discoloration test. The azo dye gradually degraded, yielding non-toxic oxalic, oxamic, and glyoxylic acid, whose Fe(III) complexes were quickly photolyzed.


Asunto(s)
Compuestos Férricos , Contaminantes Químicos del Agua , Compuestos Azo , Diamante , Electrodos , Peróxido de Hidrógeno , Oxidación-Reducción
17.
Chemosphere ; 264(Pt 2): 128491, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33045507

RESUMEN

The removal of highly concentrated pollutants, presented in a wastewater mixture from industrial tannery effluents by electrocoagulation, was examined. All experiments were carried out in a rotating cylinder electrode reactor with six aluminum anodes and two sedimentation tanks. The influence of the applied current density and rotational speed on the removal efficiency of an electrocoagulation reactor was studied. Chemical oxygen demand was diminished at 70%, while total suspended solids, chromium (III) and turbidity were almost eliminated (>90%) with 6 mA cm-2 of the applied current density. Additionally, a homogeneous cathodic deposit was obtained at the end of each test. Those cathodic deposits and flocs were analyzed by SEM-EDS. Calculations of the cell energy consumption and the produced aluminum cost were estimated for 6 mA cm-2 and 100 rpm, obtaining 1.98 kWh m-3 and $0.7 USD m-3, respectively.


Asunto(s)
Aguas Residuales , Contaminantes Químicos del Agua , Aluminio , Análisis de la Demanda Biológica de Oxígeno , Electrocoagulación , Electrodos , Concentración de Iones de Hidrógeno , Residuos Industriales , Eliminación de Residuos Líquidos , Contaminantes Químicos del Agua/análisis
18.
Sensors (Basel) ; 20(11)2020 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-32517275

RESUMEN

In this paper, a gas sensing system based on a conventional absorption technique using a single-mode-fiber supercontinuum source (SMF-SC) is presented. The SC source was implemented by channeling pulses from a microchip laser into a one kilometer long single-mode fiber (SMF), obtaining a flat high-spectrum with a bandwidth of up to 350 nm in the region from 1350 to 1700 nm, and high stability in power and wavelength. The supercontinuum radiation was used for simultaneously sensing water vapor and acetylene gas in the regions from 1350 to 1420 nm and 1510 to 1540 nm, respectively. The experimental results show that the absorption peaks of acetylene have a maximum depth of approximately 30 dB and contain about 60 strong lines in the R and P branches, demonstrating a high sensitivity of the sensing setup to acetylene. Finally, to verify the experimental results, the experimental spectra are compared to simulations obtained from the Hitran database. This shows that the implemented system can be used to develop sensors for applications in broadband absorption spectroscopy and as a low-cost absorption spectrophotometer of multiple gases.

19.
Inorg Chem ; 59(2): 1315-1322, 2020 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-31880434

RESUMEN

Gallium (Ga) ion-doped TiO2 (Ga-TiO2) nanocomposite with small particle size (9-10 nm) and high surface area (104 m2/g) has been easily synthesized via sol-gel method at low temperature by using low-valent GaI as a doping precursor. The structural and morphological characterization of Ga-TiO2 was carried out with standard analytical and spectroscopic techniques. Ga doping into the TiO2 matrix inhibited a phase transformation from anatase to rutile (photocatalytically inactive) form, even at a higher temperature of 750 °C. Finally, Ga-TiO2 nanocomposite showed high photocatalytic activity and exhibited 97% degradation of acid violet 63 dye within 60 min. The dye degradation rate constant was calculated as 1.6 × 10-1 and 1.4 × 10-1 min-1 under UV and white light irradiation, respectively, which is higher, as compared to the previously reported Ga-TiO2 composites to date.

20.
Sensors (Basel) ; 19(20)2019 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-31635201

RESUMEN

The present work experimentally demonstrates a multimode fiber optic sensing setup for total fat detection in raw milk samples. The optical fiber arrangement incorporates a low-coherence Fabry-Perot cavity operating in dual response. The system provides a phase modulation for a total fat range from 0.97% to 4.36%. Here, the protein remains constant at 3%. The data indicate that maximum sensitivity close to 616 pm/%fat could be achieved at optimal wavelength operation (500 nm). In addition, the system presented a minimal repeatability error measurement of 0.08%, cross-sensitivity between protein and fat of 0.134, and a regression coefficient of r2=0.9763. A thermal analysis was also performed, which indicate the temperature immunity of the system. The proposed method represents a low-cost alternative to detect minimal fat variations in raw cow milk.


Asunto(s)
Ácidos Grasos/análisis , Interferometría/métodos , Leche/química , Animales , Bovinos , Interferometría/instrumentación , Refractometría , Temperatura
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