ABSTRACT
CONTEXT: Yebes 40m radio telescope is the main and largest observing instrument at Yebes Observatory and it is devoted to Very Long Baseline Interferometry (VLBI) and single dish observations since 2010. It has been covering frequency bands between 2 GHz and 90 GHz in discontinuous and narrow windows in most of the cases, to match the current needs of the European VLBI Network (EVN) and the Global Millimeter VLBI Array (GMVA). AIMS: Nanocosmos project, a European Union funded synergy grant, opened the possibility to increase the instantaneous frequency coverage to observe many molecular transitions with single tunnings in single dish mode. This reduces the observing time and maximises the output from the telescope. METHODS: We present the technical specifications of the recently installed 31.5 - 50GHz (Q band) and 72 - 90.5 GHz (W band) receivers along with the main characteristics of the telescope at these frequency ranges. We have observed IRC+10216, CRL 2688 and CRL 618, which harbour a rich molecular chemistry, to demonstrate the capabilities of the new instrumentation for spectral observations in single dish mode. RESULTS: The results show the high sensitivity of the telescope in the Q band. The spectrum of IRC+10126 offers a signal to noise ratio never seen before for this source in this band. On the other hand, the spectrum normalised by the continuum flux towards CRL 618 in the W band demonstrates that the 40 m radio telescope produces comparable results to those from the IRAM 30 m radio telescope, although with a smaller sensitivity. The new receivers fulfil one of the main goals of Nanocosmos and open the possibility to study the spectrum of different astrophysical media with unprecedented sensitivity.
ABSTRACT
La prescripción de medicamentos autorizados para su utilización en condiciones distintas a las autorizadas, coloquialmente conocida como prescripción "fuera de ficha técnica" es una práctica habitual en psiquiatría del niño y del adolescente. Dicha práctica tiene consecuencias clínicas y legales tanto para el paciente como para el prescriptor, por lo que es importante tener una información actualizada de las indicaciones aprobadas como del estatus jurídico derivado de esta modalidad de prescripción. Este artículo lleva a cabo una revisión exhaustiva y actualizada de las indicaciones específicas para niños y adolescentes de 112 psicofármacos empleados en psiquiatría, de acuerdo con la información que contienen las 177 fichas técnicas correspondientes de los medicamentos aprobados para su comercialización en España. La prescripción de psicofármacos con indicación fuera de ficha en menores de 18 años es la norma más que la excepción y, requeriría de forma sistemática la obtención del consentimiento informado, según la normativa actual
Prescription of medicines for use under conditions other than authorized, colloquially known as "off-label" prescription, is a common practice in child and adolescent psychiatry. This practice has clinical and legal consequences for both the patient and the prescriber, so it is important to have up-to-date information on the approved indications and the legal status derived from this type of prescription. This article carries out a comprehensive and up-to-date review of the specific indications for children and adolescents of 112 drugs used in psychiatry, according to the information contained in the 177 corresponding "summary of product information" approved for marketing in Spain. Off-label prescription Central Nervous System drugs in children under 18 years of age is the rule rather than the exception and therefore systematically would require obtaining informed consent, according to the current normative
Subject(s)
Humans , Child , Adolescent , Clinical Record , Psychotropic Drugs/therapeutic use , Off-Label Use , Nervous System/drug effects , Anticonvulsants/therapeutic use , Anti-Anxiety Agents/therapeutic use , Antidepressive Agents/therapeutic use , Mental Disorders/drug therapy , Mental Health ServicesABSTRACT
We present a new experimental setup devoted to the study of gas phase molecules and processes using broad band high spectral resolution rotational spectroscopy. A reactor chamber has been equipped with radio receivers similar to those used by radio astronomers to search for molecular emission in space. The whole Q (31.5-50 GHz) and W bands (72-116.5 GHz) are available for rotational spectroscopy observations. The receivers are equipped with 16×2.5 GHz Fast Fourier Transform spectrometers with a spectral resolution of 38.14 kHz allowing the simultaneous observation of the complete Q band and one third of the W band. The whole W band can be observed in three settings in which the Q band is always observed. Species such as CH3CN, OCS, and SO2 are detected, together with many of their isotopologues and vibrationally excited states, in very short observing times. The system permits automatic overnight observations and integration times as long as 2.4×105 seconds have been reached. The chamber is equipped with a radiofrequency source to produce cold plasmas and with four ultraviolet lamps to study photochemical processes. Plasmas of CH4, N2, CH3CN, NH3, O2, and H2, among other species, have been generated and the molecular products easily identified by their rotational spectrum, and mass spectrometry and optical spectroscopy. Finally, the rotational spectrum of the lowest energy conformer of CH3CH2NHCHO (N-Ethylformamide), a molecule previously characterized in microwave rotational spectroscopy, has been measured up to 116.5 GHz allowing the accurate determination of its rotational and distortion constants and its search in space.
ABSTRACT
A graphene oxide-titania (GO/TiO2) composite was synthesized via sol-gel method, and studied in aqueous Primidone mineralization with ozone and LED visible light. The photocatalyst was characterized by different techniques (XRD, TEM, SBET, TGA, UV-vis diffuse reflectance spectroscopy). The band gap value decrease from 3.14 eV for bare TiO2 samples to 2.5 eV in GO/TiO2 composites clearly shows the interaction of GO with TiO2 structure. Approximately 20 mg L-1 of Primidone was removed in less than 20 min if ozone was applied, regardless of the presence or absence of light and catalyst. However, reactivity tests show a synergism effect between photocatalysis and ozonation for mineralization purposes. The combination of ozone and GO improved the activation of TiO2 under visible light. Process optimization led us to select a catalyst dosage of 0.25 g L-1, a light radiance of 359 W m-2 and a GO loading in the catalyst around 0.75%. At these conditions, with photocatalytic ozonation, the presence of GO in the catalyst improved mineralization up to 82% in 2 h compared to 70% reached with bare TiO2. Catalyst reusability shows no decrease of photocatalytic activity. Scavenger tests point to hydroxyl radicals as the main species responsible for Primidone removal.
ABSTRACT
Poly(lactic acid) (PLA) is a biobased polymer that represents one of the most interesting alternatives to fossil-fuel based polymers in food packaging applications. Most of the PLA used in food packaging is used only once and then discarded, even though the PLA types used in packaging have good properties and stability. Therefore, it seems reasonable to consider the possibility of recycling the used polymer through a mechanical recycling process. The main aims of this work are to study the effect of the mechanical recycling on the properties of PLA and the usefulness of different upgrading methods to obtain recycled PLA with improved properties. A commercial type of PLA was subjected to accelerated thermal, photochemical and hydrolytic aging and then reprocessed. During reprocessing, aged PLA was blended with virgin PLA and a commercial chain extender was added. Results point out that recycling causes the degradation of PLA, and negatively affects the thermal stability and mechanical properties. However, addition of virgin PLA, and the chain extender, led to an increase of up to 9% in the intrinsic viscosity and 8% in the Vickers hardness of the recycled material. These results suggest that mechanically recycled PLA with improved performance can be obtained, a fact which might improve the recyclability of PLA and thus the environmental impact of this material.
Subject(s)
Polyesters , Polymers , Food Packaging , RecyclingABSTRACT
La estrongiloidiosis es una infección cuyos agentes responsables son Strongyloides stercoralis y S. fuelleborni. Estos nematodos son de localización intestinal, el factor de riesgo principal es el andar descalzo en lugares contaminados con las larvas filariformes. El estudio presenta a un paciente varón de 23 años de edad, residente de San Juan de Lurigancho, presentó 14 meses de enfermedad con signos de meteorismo, náuseas, vómitos y permaneció afebril, se indica también que 28 días antes presentó dolor del epigastrio irradiado a la espalda de duración constante. Al examen físico se encontró un abdomen distendido, blando timpánico doloroso a la palpación, el informe de ecografía abdominal evidenció dilatación de las asas intestinales, meteorismo, con presencia abundante de líquido libre en la cavidad abdominal (ascitis) y en los exámenes parasitológicos del líquido se observó larvas rabditoides L1, L2 y filariformes L3 de Strongyloides stercoralis; por lo que recibió tratamiento con Ivermectina, obteniéndose la recuperación del paciente.
The strongyloidiasis is an infection whose responsible agents are Strongyloides stercoralis and S. fuelleborni. These nematodes have an intestinal location; the main risk factor is to be barefoot in places contaminated with filariform larvae. The study presents a male 23-year-old resident of San Juan de Lurigancho, with 14 months of illness with signs of bloating, nausea, vomiting and wasafebrile,also indicates that 28 days before he had epigastric pain irradiated to the back. On physical examination a distended abdomen was found, soft painful tympanic tenderness, the abdominal ultrasonography showed dilated bowel loops, bloat, with abundant presence of free fluid in the abdominal cavity (ascites) and parasitological examinations observed, rabditoides larvae L1 and L2 and filariform L3 of Strongyloides stercoralis. He received Ivermectin, obtaining the patient's recovery.
Subject(s)
Animals , Humans , Male , Young Adult , Strongyloidiasis/parasitology , Ascitic Fluid/parasitology , Strongyloides stercoralis/isolation & purification , Severity of Illness IndexABSTRACT
The strongyloidiasis is an infection whose responsible agents are Strongyloides stercoralis and S. fuelleborni. These nematodes have an intestinal location; the main risk factor is to be barefoot in places contaminated with filariform larvae. The study presents a male 23-year-old resident of San Juan de Lurigancho, with 14 months of illness with signs of bloating, nausea, vomiting and wasafebrile,also indicates that 28 days before he had epigastric pain irradiated to the back. On physical examination a distended abdomen was found, soft painful tympanic tenderness, the abdominal ultrasonography showed dilated bowel loops, bloat, with abundant presence of free fluid in the abdominal cavity (ascites) and parasitological examinations observed, rabditoides larvae L1 and L2 and filariform L3 of Strongyloides stercoralis. He received Ivermectin, obtaining the patient's recovery.
Subject(s)
Ascitic Fluid/parasitology , Strongyloides stercoralis/isolation & purification , Strongyloidiasis/parasitology , Animals , Humans , Male , Severity of Illness Index , Young AdultABSTRACT
The aim of this work is to study the effects of different simulated mechanical recycling processes on the structure and properties of PLA. A commercial grade of PLA was melt compounded and compression molded, then subjected to two different recycling processes. The first recycling process consisted of an accelerated ageing and a second melt processing step, while the other recycling process included an accelerated ageing, a demanding washing process and a second melt processing step. The intrinsic viscosity measurements indicate that both recycling processes produce a degradation in PLA, which is more pronounced in the sample subjected to the washing process. DSC results suggest an increase in the mobility of the polymer chains in the recycled materials; however the degree of crystallinity of PLA seems unchanged. The optical, mechanical and gas barrier properties of PLA do not seem to be largely affected by the degradation suffered during the different recycling processes. These results suggest that, despite the degradation of PLA, the impact of the different simulated mechanical recycling processes on the final properties is limited. Thus, the potential use of recycled PLA in packaging applications is not jeopardized.
Subject(s)
Polyesters , Recycling , Lactic Acid , PolymersABSTRACT
Atomic force acoustic microscopy is a dynamic technique where the resonances of a cantilever, that has its tip in contact with the sample, are used to quantify local elastic properties of surfaces. Since the contact resonance frequencies (CRFs) monotonically increase with the tip-sample contact stiffness, they are used to evaluate the local elastic properties of the surfaces through a suitable contact mechanical model. The CRFs depends on both, normal and lateral contact stiffness, kN and kS respectively, where the last one is taken either as constant (kS<1), or as zero, leading to uncertainty in the estimation of the elastic properties of composite materials. In this work, resonance spectra for free and contact vibration were used in a finite element analysis of cantilevers to show the influence of kS in the resonance curves due to changes in the kS/kN ratio. These curves have regions for the different vibrational modes that are both, strongly and weakly dependent on kS, and they can be used in a selective manner to obtain a precise mapping of elastic properties.
ABSTRACT
In this study, Ti-Zr and Ti-Zr-C coatings were deposited at room temperature via pulsed-DC magnetron sputtering. A 70Ti-30Zr at% target and a 99.99% graphite plate were used to deposit samples. In order to modify C content, coatings were deposited at different target powers such as 50, 75 and 100 W. Changes on the structure, microstructure and mechanical properties due to C addition were studied. Results indicate that the as-deposited coatings were partly crystalline and that an increment on C content stabilized α' phase and inhibited the appearance of ω precipitates. Therefore, Ti-Zr-C alloys with C>1.9 at% showed only α' phase whereas the others alloys exhibited α'+ω structures. Hardness values from 12.94 to 34.31 GPa were obtained, whereas the elastic modulus was found between 181.84 and 298 GPa. Finally, a high elastic recovery ratio (0.69-0.87) was observed as a function of composition. The overall properties of these coatings were improved due to C content increment, martensitic α' phase and nanocrystalline grain size (10-16 nm).
Subject(s)
Alloys/chemistry , Biocompatible Materials/chemistry , Carbon/chemistry , Mechanical Phenomena , Titanium/chemistry , Zirconium/chemistry , Materials Testing , Structure-Activity RelationshipABSTRACT
Common vampire bat populations distributed from Mexico to Argentina are important rabies reservoir hosts in Latin America. The aim of this work was to analyse the population structure of the rabies virus (RABV) variants associated with vampire bats in the Americas and to study their phylodynamic pattern within Argentina. The phylogenetic analysis based on all available vampire bat-related N gene sequences showed both a geographical and a temporal structure. The two largest groups of RABV variants from Argentina were isolated from northwestern Argentina and from the central western zone of northeastern Argentina, corresponding to livestock areas with different climatic, topographic and biogeographical conditions, which determined their dissemination and evolutionary patterns. In addition, multiple introductions of the infection into Argentina, possibly from Brazil, were detected. The phylodynamic analysis suggests that RABV transmission dynamics is characterized by initial epizootic waves followed by local enzootic cycles with variable persistence. Anthropogenic interventions in the ecosystem should be assessed taking into account not only the environmental impact but also the potential risk of disease spreading through dissemination of current RABV lineages or the emergence of novel ones associated with vampire bats.
Subject(s)
Chiroptera/virology , Genetics, Population , Phylogeny , Rabies virus/genetics , Rabies/epidemiology , Animals , Argentina/epidemiology , Cattle , Likelihood Functions , Molecular Sequence Data , RNA, Viral/genetics , Rabies/transmissionABSTRACT
In early October 2010, adult goats (no.=22, 3.5 yr old, 7/8 Sannen-Alpine, 26° N, 103° W, at 1117 m), were randomly assigned to: i) beta-carotene group (BC) [no.=10; live weight (LW)=45.9±1.97 kg, body condition score (BCS) =3.04±0.08; orally supplemented with 50 mg of BC per goat per day]; ii) control group (CONT) (no.=12; LW=46.2±2.04 kg, BCS=3.0±0.08). Animals received a basal diet of alfalfa hay, corn silage, and corn grain, having free access to water, shade, and mineral salts. During the second half of October, estrus was synchronized by using intravaginal sponges. Thereafter, by mid-follicular phase, an intensive blood sampling (6 h × 60 min) was performed to evaluate serum insulin concentrations (INS) by radioimmunoassay. By the end of the luteal phase, an ultrasonographic scanning was performed to evaluate total ovarian activity (TOA) [TOA=total follicles (TF) + total corpus luteum (TCL)]. The whole experimental period consisted of 34 days pre- and 17 days post-ovulation, for a total of 52 days. Average LW and BCS did not differ (p>0.05) during the experimental period. Nonetheless, increases in TF no. (5.0 vs 3.4±0.6 units; p=0.05), TCL no. (3.4 vs 2.8±0.2 units; p=0.05), TOA (8.1 vs 6.2±0.6 units; p=0.05) and INS (4.6 vs 3.9±0.4 ng ml-1; p=0.05) favored to the BC-supplemented group. A positive correlation between LW (r(2)=0.42; p=0.04) and BCS (r(2)=0.47; p=0.02) with respect to ovulation rate, was detected. BC-supplementation increased ovarian activity in the female goat while positively affected the release pattern of insulin, suggesting a potential role of BC as a central and/or pancreas-activating molecule in adult goats; such results may hold not only physiologic but also clinical significance.
Subject(s)
Dietary Supplements , Insulin/blood , Ovary/drug effects , beta Carotene/administration & dosage , Animal Feed , Animals , Drug Administration Schedule , Drug Evaluation, Preclinical , Female , Goats , Models, Animal , Osmolar Concentration , Ovary/diagnostic imaging , Ovary/physiology , Random Allocation , Time Factors , Ultrasonography , beta Carotene/pharmacologyABSTRACT
A new resonance-tracking (RT) method using fast frequency sweeping excitation was developed for quantitative scanning probe microscopy (SPM) imaging. This method allows quantitative imaging of elastic properties and ferroelectrical domains with nanoscale resolution at high data acquisition rates. It consists of a commercial AFM system combined with a high-frequency lock-in amplifier, a programmed function generator and a fast data acquisition card. The resonance-tracking method was applied to the atomic force acoustic microscopy (AFAM) and to the piezoresponse force microscopy (PFM) modes. Plots of amplitude versus time and phase versus time for resonant spectra working with different sweeping frequencies were obtained to evaluate the response speed of the lock-in amplifier. It was proved that this resonance-tracking method allows suitable spectral acquisition at a rate of about 5 ms/pixel, which is useful for SPM imaging in a practical scanning time. In order to demonstrate the system performance, images of RT-AFAM for TiN films and RT-PFM for GeTe are shown.
Subject(s)
Image Enhancement/instrumentation , Micro-Electrical-Mechanical Systems/instrumentation , Microscopy, Acoustic/instrumentation , Microscopy, Atomic Force/instrumentation , Microscopy, Scanning Probe/instrumentation , Equipment Design , Equipment Failure AnalysisABSTRACT
We empirically applied the GrooFiWorld agent-based model (Puga-Gonzalez et al. 2009) in a group of captive redcapped mangabeys (Cercocebus torquatus). We analysed several measurements related to aggression and affiliative patterns. The group adopted a combination of despotic and egalitarian behaviours resulting from the behavioural flexibility observed in the Cercopithecinae subfamily. Our study also demonstrates that the GrooFiWorld agent-based model can be extended to other members of the Cercopithecinae subfamily generating parsimonious hypotheses related to the social organization.
Subject(s)
Aggression , Cercocebus/psychology , Feeding Behavior , Grooming , Social Behavior , Animals , Social Networking , Social Participation , Social SupportABSTRACT
When a rodent licks a sweet-tasting solution, taste circuits in the central nervous system that facilitate stimulus identification, motivate intake, and prepare the body for digestion are activated. Here, we asked whether taste also determines daily intake of sugar solutions in C57BL/6 mice. We tested several dilute concentrations of glucose (167, 250, and 333 mM) and fructose (167, 250, and 333 mM). In addition, we tested saccharin (38 mM), alone and in binary mixture with each of the sugar concentrations, to manipulate sweet taste intensity while holding caloric value constant. In experiment 1, we measured taste responsiveness to the sweetener solutions in two ways: chorda tympani nerve responses and short-term lick tests. For both measures, the mice exhibited the following relative magnitude of responsiveness: binary mixtures > saccharin > individual sugars. In experiment 2, we asked whether the taste measures reliably predicted daily intake of the sweetener solutions. No such relationship was observed. The glucose solutions elicited weak taste responses but high daily intakes, whereas the fructose solutions elicited weak taste responses and low daily intakes. On the other hand, the saccharin + glucose solutions elicited strong taste responses and high daily intakes, while the saccharin + fructose solutions elicited strong taste responses but low daily intakes. Overall, we found that 1) daily intake of the sweetener solutions varied independently of the magnitude of the taste responses and 2) the solutions containing glucose stimulated substantially higher daily intakes than did the solutions containing isomolar concentrations of fructose. Given prior work demonstrating greater postoral stimulation of feeding by glucose than fructose, we propose that the magnitude of postoral nutritive stimulation plays a more important role than does taste in determining daily intake of dilute sugar solutions.
Subject(s)
Behavior, Animal , Chorda Tympani Nerve/physiology , Dietary Carbohydrates/administration & dosage , Feeding Behavior , Fructose/administration & dosage , Glucose/administration & dosage , Taste , Animals , Behavior, Animal/drug effects , Chorda Tympani Nerve/drug effects , Feeding Behavior/drug effects , Mice , Mice, Inbred C57BL , Saccharin/administration & dosage , Solutions , Sweetening Agents/administration & dosage , Taste/drug effectsABSTRACT
The photodegradation of the endocrine disrupting chemical Bisphenol A (BPA) under UVA irradiation in the presence of Fe(III) or Fe(III)-polycarboxylate systems was studied. The effect of Fe(III) concentration, aqueous pH and the presence of four carboxylic acids (oxalic, malic, tartaric and citric) were investigated. The Fe(III)/UVA system was able to effectively degrade BPA at pH 3 but failed at pH > 4. At any rate, no mineralization of BPA was achieved with the Fe(III)/UVA system. The presence of carboxylic acids greatly enhanced the BPA degradation rate because of the formation of photoactive Fe(III)-polycarboxylate complexes. Aqueous pH in the 3-7 range exerted a negative effect on the BPA degradation rate and TOC conversion in the presence of oxalic, malic and tartaric acids. Only slight effect of pH was observed in the presence of citric acid, being the BPA degradation rate significant even at pH 7.
Subject(s)
Ferric Compounds/chemistry , Phenols/chemistry , Photolysis , Ultraviolet Rays , Water Pollution, Chemical/analysis , Water/chemistry , Benzhydryl Compounds , CatalysisABSTRACT
This study determined the presence of the rabies virus in salivary glands, as well as its titre and antigenic characterisation and the level of exposure to the virus from contact between domestic animals and humans. Twenty-six positive brain samples were selected, 80% of which were from the Brazilian free-tailed bat, Tadarida brasiliensis, corresponding to the period 1999-2005. Antigenic characterisation was conducted on a panel of 19 monoclonal antibodies targeting the rabies virus nucleoprotein supplied by the Centers for Disease Control and Prevention in Atlanta in the United States of America. The results revealed a high percentage of isolations in salivary glands (76.9%). Their average titres were compared in a batch of positive samples of brain and salivary glands, giving values of 4.75 and 3.81 respectively (expressed as log LD50/0.03 ml). The isolated viruses corresponded principally to variant 4 associated with T brasiliensis and variant 6 associated with the hoary bat, Lasiurus cinereus, and the red bat, L. borealis, and their respective subvariants. The level of exposure in domestic animals and humans was 50% during the period under study.
Subject(s)
Chiroptera/virology , Rabies virus/isolation & purification , Rabies/veterinary , Salivary Glands/virology , Animals , Chiroptera/classification , Disease Reservoirs/veterinary , Rabies/epidemiology , Species SpecificityABSTRACT
The efficacy of the oxidation systems: O3, UV radiation, O3/UV radiation, O3/perovskite, UV radiation/perovskite, O3/UV radiation/perovskite, H2O2/UV radiation, H2O2/UV radiation/perovskite, has been investigated by using pyruvic acid as probe compound. Under the operating conditions used, the combination of UV radiation and hydrogen peroxide (with or without perovskites) leads to the fastest pyruvic acid removal while the best results in terms of mineralization degree are obtained when combining O3/UV radiation/perovskite. The effect of the variables: inlet ozone (15-75 mg L(-1)) and initial pyruvic acid (10(-3) to 10(-2)M) concentrations, catalyst load (0.01-1.5 g L(-1)) and pH (2-9) was investigated for the photocatalytic ozonation. The most influencing parameter was the ozone concentration fed to the photoreactor. A zero order was observed for pyruvic acid concentration and close to zero for catalyst load. Some deactivation is observed after reusing the catalyst, likely due to leaching of the active phase.
Subject(s)
Calcium Compounds/chemistry , Oxides/chemistry , Titanium/chemistry , Hydrogen-Ion Concentration , Oxidation-Reduction , Ozone/chemistry , Ultraviolet RaysABSTRACT
The adsorption of fluorene onto TiO2 has been investigated by conducting equilibrium and kinetic experiments. Adsorption isotherms have been evaluated at two different pHs in the range of temperatures 296-325 K. The type III isotherm shapes obtained were modelled by considering several expressions taken from the literature. Temperature exerted a positive influence in fluorene uptake. Addition of phosphates involved a negative effect when computing the final equilibrium fluorene removal. The kinetic experiments carried out at 296 K corroborated the competitiveness of phosphates to occupy the active sites on the titania surface. Nevertheless, equilibrium conditions are faster achieved at pH 2 than at pH 5. The photocatalysis of fluorene at different initial concentrations of the parent compound revealed a slight improvement of the process at pH 5 if compared to the results obtained at pH 2. A Langmuir-Hinselwood representation of the data confirms the previous statement. Catalyst load shows an optimum, concentration values of the photocatalyst above the optimum provoke a decrease in the fluorene abatement rate. Reutilisation of the catalyst indicates that fluorene is completely eliminated from the solid, i.e. it is suggested that fluorene and intermediates are surface oxidised.
Subject(s)
Fluorenes/chemistry , Fluorenes/radiation effects , Titanium/chemistry , Ultraviolet Rays , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/radiation effects , Adsorption , Catalysis , Hydrogen-Ion Concentration , Kinetics , Photolysis , TemperatureABSTRACT
The adsorption of stabilized leachates generated in a municipal landfill onto three commercial activated carbons has been investigated. Norit 0.8, Chemviron AQ40 and Picacarb 1240 have been used as adsorbents. Equilibrium experiments have been conducted to obtain the experimental isotherm profiles. Isotherms have been plotted based on the adsorption of general parameters, for instance chemical oxygen demand, total carbon, absorption at 410 nm and absorption at 254 nm. Different literature models and error functions have been used to adequately fit the experimental data. As a rule of thumb, three-parameter models do adjust experimental results better than two-parameter models. Norit 0.8 shows better adsorption characteristics than the rest of activated carbons, both in terms of contaminant level reduction of per unit mass of absorbent and in terms of the process kinetics.
