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1.
J Environ Manage ; 181: 515-521, 2016 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-27423100

RESUMEN

Conventional sanitary landfill leachate treatment has recently been complemented and, in some cases, completely replaced by reverse osmosis technology. Despite the good quality of treated water, the efficiency of the process is low and a large volume of reverse osmosis concentrate has to be either discharged or further treated. In this study, the use of anodic oxidation combined with electro-Fenton processes to treat the concentrate obtained in the reverse osmosis of sanitary landfill leachate was evaluated. The anodic oxidation pretreatment was performed in a pilot plant using an electrochemical cell with boron-doped diamond electrodes. In the electro-Fenton experiments, a boron-doped diamond anode and carbon-felt cathode were used, and the influence of the initial pH and iron concentration were studied. For the experimental conditions, the electro-Fenton assays performed at an initial pH of 3 had higher organic load removal levels, whereas the best nitrogen removal was attained when the electrochemical process was performed at the natural pH of 8.8. The increase in the iron concentration had an adverse impact on treatment under natural pH conditions, but it enhanced the nitrogen removal in the electro-Fenton assays performed at an initial pH of 3. The combined anodic oxidation and electro-Fenton process is useful for treating the reverse osmosis concentrate because it is effective at removing the organic load and nitrogen-containing species. Additionally, this process potentiates the increase in the biodegradability index of the treated effluent.


Asunto(s)
Técnicas Electroquímicas/métodos , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos , Biodegradación Ambiental , Análisis de la Demanda Biológica de Oxígeno , Boro , Carbono , Diamante , Técnicas Electroquímicas/instrumentación , Electrodos , Peróxido de Hidrógeno , Concentración de Iones de Hidrógeno , Hierro/química , Nitrógeno/química , Nitrógeno/aislamiento & purificación , Ósmosis , Oxidación-Reducción
2.
Bull Cancer ; 111(4): 371-383, 2024 Apr.
Artículo en Francés | MEDLINE | ID: mdl-38458928

RESUMEN

INTRODUCTION: Despite the undeniable benefits of physical activity during and beyond cancer treatments, patients do not always undertake and/or maintain it. The aim of the study is to identify, describe and understand the barriers and facilitators of physical activity practice among adults arriving at the end of treatment for solid cancer, in precarious situations, living in Seine-Saint-Denis. METHODS: The study was conducted using a descriptive qualitative phenomenological method involving semi-directed interviews with 23 participants during and beyond cancer. RESULTS: Multiple-level factors (micro, meso, macro) are involved in active behavior of patients. Three main facilitators were identified: perceived benefit, social support, and urban planning. Three barriers are identified: (1) physical and psychological disorders whether or not related to cancer and its treatment, (2) precariousness, organizational constraints, unfavorable social environment, (3) lack of coordination, lack of accurate and appropriate information, lack of realistic referral to physical activity offers. DISCUSSION: A diversity of representations, combinations of factors, and experiences are described. Getting people with cancer to engage in and maintain long-term physical activity is a complex task, requiring multidisciplinary action on all socio-ecological factors.


Asunto(s)
Ejercicio Físico , Trastornos Mentales , Adulto , Humanos , Ejercicio Físico/psicología , Investigación Cualitativa , Apoyo Social , Motivación
3.
Chemosphere ; 339: 139687, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37541439

RESUMEN

Arsenic (As) is a highly toxic heavy metal and has been widely concerned for its hazardous environmental impact. Aromatic organic arsenic (AOCs) has been frequently used as an animal supplement to enhance feed utilization and prevent dysentery. The majority of organic arsenic could be discharged from the body and evolve as highly toxic inorganic arsenic that is hazardous to the environment and human health via biological conversion, photodegradation, and photo-oxidation. Current environmental issues necessitate the development and application of multifunctional porous materials in environmental remediation. Compared to the conventional adsorbent, such as activated carbon and zeolite, metal-organic frameworks (MOFs) exhibit a number of advantages, including simple synthesis, wide variety, simple modulation of pore size, large specific surface area, excellent chemical stability, and easy modification. In recent years, numerous scientists have investigated MOFs related materials involved with organic arsenic. These studies can be divided into three categories: detection of organic arsenic by MOFs, adsorption to remove organic arsenic by MOFs, and catalytic removal of organic arsenic by MOFs. Here, we conduct a critical analysis of current research findings and knowledge pertaining to the structural characteristics, application methods, removal properties, interaction mechanisms, and spectral analysis of MOFs. We summarized the application of MOFs in organic arsenic detection, adsorption, and catalytic degradation. Other arsenic removal technologies and conventional substances are also being investigated. This review will provide relevant scientific researchers with references.


Asunto(s)
Intoxicación por Arsénico , Arsénico , Estructuras Metalorgánicas , Humanos , Estructuras Metalorgánicas/química , Intoxicación por Metales Pesados , Adsorción
4.
ChemSusChem ; 16(24): e202300845, 2023 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-37525963

RESUMEN

Solar-driven interfacial evaporation technology is regarded as an attracting sustainable strategy for obtaining portable water from seawater and wastewater, and the recycle of waste materials to fabricate efficient photothermal materials as evaporator to efficiently utilize solar energy is very critical, but still difficult. To this purpose, graphite recovered from spent lithium-ion batteries (SLIBs) was realized using a simple acid leaching method, and a reconstructed graphite-based porous hydrogel (RG-PH) was subsequently fabricated by crosslinking foaming method. The incorporation of reconstructed graphite (RG) improves the mechanical characteristics of hydrogels and the light absorption performance significantly. The evaporation rate of optimized RG-PH can constantly reach 3.4278 kg m-2 h-1 for desalination under a one solar irradiation, and it also showed the excellent salt resistance in various salty water. Moreover, RG-PH has a strong elimination of a variety of organic contaminants in wastewater, including the typical volatile organic compound of phenol. This research shows the potential application of flexible and durable solar evaporators made from waste materials in purifying seawater and wastewater, not only contributing to carbon neutrality by recycling graphite from SLIBs, but also ensuring the cost-effectiveness harvest of solar energy for constantly obtaining clean water.

5.
ChemSusChem ; 16(24): e202301772, 2023 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-38057131

RESUMEN

Invited for this month's cover, the researchers from Huaqiao University and Jilin Jianzhu University. The Cover image shows the use of spent graphite to prepare hydrogels for photothermal evaporation to produce clean water. The Research Article itself is available at 10.1002/cssc.202300845.

6.
Front Psychol ; 11: 611803, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33424723

RESUMEN

The aim of this present study is to investigate the influence of three learning contexts on the development of motor creativity of young footballers (8-9 years old). In team sport, creativity is a fundamental issue because it allows players to adapt in an environment of high social uncertainty. To carry out this work, we suggest a method for assessing motor creativity into ecological situations based on the analysis of praxical communications. Creativity originates from an interaction between divergence and convergence. In our case, the number of communications (fluidity) and the diversity of updated communications (flexibility) are our divergence indicators. Convergence, understood as the ability to make good decisions, is assessed by two expert judges (R > 0.90). Sixty boys' football players (M = 8.67; SD = 0.3) coming from three football clubs participated in this research. The study lasted 2 years. Each year, a team of 10 players from each club participated in the research twice a week for 32 weeks (8 months), these groups attended different training sessions: (a) the control group (n = 20) followed a classical learning; (b) the decoding group (n = 20) attended training focused on learning the praxemes of football; (c) the traditional sporting games group (n = 20) followed a training session that was jointly focused on praxemes and the practice of traditional sporting games. The motor creativity of players and groups was assessed both at the beginning and at the end of the year during football matches. Compared to the control group, in the post-test, the group with the highest fluidity is the decoding group (p < 0.001) and the one with the highest fluidity is the traditional sporting games group. The latter group is also the one with the best convergence (p < 0.001). The results showed that traditional games can help develop players' creative abilities. This research invites us to investigate the complementarity between the different offered training.

7.
Eur J Sport Sci ; 18(9): 1208-1216, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29869946

RESUMEN

The aims of this study were to (1) propose a method for evaluating shot-putters mechanical power, (2) investigate the relationship between mechanical work of hand action force (WHAF), peak power output (PPO) of different limbs and shot-put performance and (3) show which of these two parameters (WHAF, PPO) were the most appropriate to characterize the explosive abilities of the shot-putter. Twelve junior right-handed shot-putters, practised glide technique shot-put throwers (personal best = 13.57 ± 1.72 m), participated in this study. Arm and leg force-velocity tests were performed to measure PPO. Kinematic analysis was conducted during a shot-putting event in regular conditions to quantify the WHAF at the release moment and shot-put performance. Significant correlations were found between absolute arm and leg PPO with upper and lower muscle volumes (r = .67; p = .03; r = .76; p = .01; r = .74, p = .01; r = .65, p = .04). Positive relationships were recorded between absolute arm and leg PPO and shot-put performance (r = .67, p = .02; r = .81, p = .004, respectively). Shot-put performance was also closely related to the WHAF (r = .93, p = .0001) and release velocity parameter (r = .86, p = .001). The present results confirm that force-velocity test and WHAF constitute useful tools for assessing mechanical power in throwing. The WHAF could be considered as more suitable than force-velocity test.


Asunto(s)
Mano/fisiología , Músculo Esquelético/fisiología , Atletismo/fisiología , Adolescente , Brazo , Rendimiento Atlético/fisiología , Fenómenos Biomecánicos , Humanos , Pierna , Fuerza Muscular
8.
Chemosphere ; 184: 1223-1229, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28672722

RESUMEN

The electro-Fenton oxidation of a concentrate from reverse osmosis of a sanitary landfill leachate, with an initial chemical oxygen demand (COD) of 42 g L-1, was carried out using a carbon-felt cathode and a boron doped diamond anode. The influence of the applied current intensity, initial pH and dissolved iron initial concentration on the electro-Fenton process was assessed. For the experimental conditions used, results showed that the initial pH is the parameter that more strongly influences the current efficiency of the electro-Fenton process, being this influence more pronounced on the oxidation rate than on the mineralization rate of the organic matter. The increase in iron initial concentration was found to be detrimental, since the natural amount of iron present in the effluent, 73 mg L-1 of total iron and 61 mg L-1 of dissolved iron, was sufficient to ensure the electro-Fenton process at the applied intensities - 0.2-1.4 A. For the more favourable conditions studied, initial pH of 3 and natural iron concentration, it was found an increase in the organic load and nitrogen removals with the applied current intensity. For the highest current intensity applied, a COD removal of 16.7 g L-1 was achieved after 8-h experiments.


Asunto(s)
Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/química , Análisis de la Demanda Biológica de Oxígeno , Boro/química , Carbono , Diamante , Electrodos , Filtración , Peróxido de Hidrógeno/química , Hierro , Nitrógeno , Ósmosis , Oxidación-Reducción , Instalaciones de Eliminación de Residuos
9.
J Hazard Mater ; 297: 34-41, 2015 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-25935408

RESUMEN

The mineralization of a new azo dye - the (4-amino-3-hydroxy-2-p-tolylazo-naphthalene-1-sulfonic acid) (AHPS) - has been studied by a novel electrochemical advanced oxidation process (EAOP), consisting in electro-Fenton (EF) oxidation, catalyzed by pyrite as the heterogeneous catalyst - the so-called 'pyrite-EF'. This solid pyrite used as heterogeneous catalyst instead of a soluble iron salt, is the catalyst the system needs for production of hydroxyl radicals. Experiments were performed in an undivided cell equipped with a BDD anode and a commercial carbon felt cathode to electrogenerate in situ H2O2 and regenerate ferrous ions as catalyst. The effects on operating parameters, such as applied current, pyrite concentration and initial dye content, were investigated. AHPS decay and mineralization efficiencies were monitored by HPLC analyses and TOC measurements, respectively. Experimental results showed that AHPS was quickly oxidized by hydroxyl radicals (OH) produced simultaneously both on BDD surface by water discharge and in solution bulk from electrochemically assisted Fenton's reaction with a pseudo-first-order reaction. AHPS solutions with 175 mg L(-1) (100 mg L(-1) initial TOC) content were then almost completely mineralized in 8h. Moreover, the results demonstrated that, under the same conditions, AHPS degradation by pyrite electro-Fenton process was more powerful than the conventional electro-Fenton process.


Asunto(s)
Compuestos Azo/aislamiento & purificación , Técnicas Electroquímicas/métodos , Peróxido de Hidrógeno/química , Hierro/química , Naftalenosulfonatos/aislamiento & purificación , Sulfuros/química , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del Agua/métodos , Catálisis , Técnicas Electroquímicas/instrumentación , Electrodos , Estructura Molecular , Oxidación-Reducción , Purificación del Agua/instrumentación
10.
Chemosphere ; 141: 250-7, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26291910

RESUMEN

Levofloxacin is a large spectrum antibiotic from fluoroquinolones family, widely used and detected in natural waters. Here, this drug was degraded by a novel heterogeneous electro-Fenton (EF) process, so-called EF-pyrite, in which pyrite powder in suspension regulates the solution pH to 3.0 and supplies 0.2mM Fe(2+) as catalyst to the solution. Trials were performed with a stirred boron-doped diamond (BDD)/carbon-felt cell under O2 bubbling for cathodic H2O2 generation. Hydroxyl radicals formed from water oxidation at the BDD anode and in the bulk from Fenton's reaction between Fe(2+) and H2O2 were the main oxidizing agents. The effect of applied current and antibiotic concentration over the mineralization rate and degree, mineralization current efficiency and specific energy consumption was studied. An almost total mineralization was achieved for a 0.23mM drug solution operating at 300mA for 8h. The kinetic decay of the drug was followed by reversed-phase HPLC and obeyed a pseudo-first-order reaction. Ion-exclusion HPLC analysis of treated solutions revealed that oxalic and oxamic acids, the most persistent final products, were the predominant pollutants remaining in solution at long electrolysis time. Ion chromatography analysis confirmed the release of F(-), NO3(-) and NH4(+) ions during levofloxacin mineralization.


Asunto(s)
Antibacterianos/análisis , Técnicas Electroquímicas/métodos , Peróxido de Hidrógeno/química , Hierro/química , Levofloxacino/análisis , Sulfuros/química , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos , Antibacterianos/química , Boro/química , Diamante/química , Técnicas Electroquímicas/instrumentación , Radical Hidroxilo/química , Cinética , Levofloxacino/química , Modelos Teóricos , Oxidación-Reducción , Contaminantes Químicos del Agua/química , Purificación del Agua/instrumentación
11.
Water Res ; 74: 77-87, 2015 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-25720669

RESUMEN

Tyrosol (TY) is one of the most abundant phenolic components of olive oil mill wastewaters. Here, the degradation of synthetic aqueous solutions of 0.30 mM TY was studied by a novel heterogeneous electro-Fenton (EF) process, so-called EF-pyrite, in which pyrite powder was the source of Fe(2+) catalyst instead of a soluble iron salt used in classical EF. Experiments were performed with a cell equipped with a boron-doped diamond anode and a carbon-felt cathode, where TY and its products were destroyed by hydroxyl radicals formed at the anode surface from water oxidation and in the bulk from Fenton's reaction between Fe(2+) and H2O2 generated at the cathode. Addition of 1.0 g L(-1) pyrite provided an easily adjustable pH to 3.0 and an appropriate 0.20 mM Fe(2+) to optimize the EF-pyrite treatment. The effect of current on mineralization rate, mineralization current efficiency and specific energy consumption was examined under comparable EF and EF-pyrite conditions. The performance of EF-pyrite was 8.6% superior at 50 mA due to self-regulation of soluble Fe(2+) by pyrite. The TY decay in this process followed a pseudo-first-order kinetics. The absolute rate constant for TY hydroxylation was 3.57 × 10(9) M(-1) s(-1), as determined by the competition kinetics method. Aromatic products like 3,4-dihydroxyphenylethanol, 4-hydroxyphenylacetic acid, 4-hydroxybenzoic acid, 3,4-dihydroxybenzoic acid and catechol, as well as o-benzoquinone, were identified by GC-MS and reversed-phase HPLC. Short-chain aliphatic carboxylic acids like maleic, glycolic, acetic, oxalic and formic were quantified by ion-exclusion HPLC. Oxalic acid was the major and most persistent product found. Based on detected intermediates, a plausible mineralization pathway for TY by EF-pyrite was proposed.


Asunto(s)
Peróxido de Hidrógeno/química , Hierro/química , Alcohol Feniletílico/análogos & derivados , Sulfuros/química , Boro/química , Carbono/química , Catálisis , Diamante/química , Técnicas Electroquímicas , Electrodos , Concentración de Iones de Hidrógeno , Radical Hidroxilo/química , Cinética , Alcohol Feniletílico/química , Contaminantes Químicos del Agua/química
12.
Hum Mov Sci ; 32(3): 425-35, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23639615

RESUMEN

Imitation is commonly considered as a hierarchical process. The current study explored the reproduction of a multi-task course in deferred imitation. Eighty-five children between 3.5 and 7.5 years old were divided into five groups and instructed to watch a live human adult demonstrator who performed simple successive actions, such as walking, jumping, grasping, carrying objects from one location to another through six sessions. After a five-minute delay, the children were individually instructed to reproduce the course. Their responses were videotaped and coded in dichotomous data at two hierarchical levels, namely goals and their spatial location. The main findings showed no improvement in the replication of goals due either to age or trials. However, there was an improvement in the integration of the goals' spatial location over trials. This signifies that imitation is an active reconstruction mechanism hierarchically organized.


Asunto(s)
Conducta Imitativa , Memoria a Corto Plazo , Destreza Motora , Desempeño Psicomotor , Percepción Visual , Factores de Edad , Atención , Niño , Preescolar , Femenino , Humanos , Masculino , Orientación , Aprendizaje Seriado
13.
J Electromyogr Kinesiol ; 22(4): 513-9, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22391341

RESUMEN

The present study examined the development of bimanual interaction during the imitation of a live demonstration. To this end, children of five different age groups observed an adult model performing in an object manipulation task consisting to open a box with one hand, taking out an object with the other hand, and closing the box again, before they were asked to imitate this motor task under different imitation conditions. The children's responses were videotaped, coded in dichotomous data, and then transformed in percentage scores. The main results showed that all children were able to imitate/attain the goal of the task. However, differences were observed for the different imitation conditions, which were also reflected in some age effects, while hand dominance was a strong constraint on imitation. Also, practice did not seem to increase the likelihood of model imitation. These findings confirm that imitation is a reconstruction mechanism hierarchically organized.


Asunto(s)
Cognición/fisiología , Lateralidad Funcional/fisiología , Conducta Imitativa/fisiología , Aprendizaje/fisiología , Movimiento/fisiología , Desempeño Psicomotor/fisiología , Niño , Preescolar , Femenino , Humanos , Masculino
14.
J Electromyogr Kinesiol ; 20(2): 322-9, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19625196

RESUMEN

Imitative behavior underlaid by perception and action links during children's development in complex locomotor skills has been the object of relatively few studies. In order to explore children's motor coordination modes, 130 children divided into five age groups from 3.5 to 7.5 years were instructed to imitate jumping tasks in spontaneous motor situation and in various imitative contexts by an adult providing verbal orders and gestural demonstrations. Their conformity to the model, stability and variability scores were coded from a video analysis when they performed jumps with obstacles. To evaluate their postural-motor control level, the durations of the preparatory phase and jumping flights were also timed. Results showed that all age groups generated the demonstrator's goal but not necessarily the same coordination modes of jumping. In imitation with temporal proximity, the model helped the youngest age groups to adopt his coordination modes and stabilized only the oldest age groups' performances starting from 5.5 years old, without effect on learning imitation. Differences between the youngest and oldest children in the jump duration suggested that the reproduction of a complex motor activity such as jumping with a one foot take-off would require resolution and adjustment of main postural stability.


Asunto(s)
Conducta Imitativa/fisiología , Aprendizaje/fisiología , Locomoción/fisiología , Destreza Motora/fisiología , Análisis y Desempeño de Tareas , Niño , Preescolar , Femenino , Humanos , Masculino
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