Towards the technological maturity of membrane distillation: the MD module performance curve

Membrane distillation (MD) is constantly acknowledged in the research literature as a promising technology for the future of desalination, with an increasing number of studies reported year after year. However, real MD applications still lag behind with only a few pilot-plant tests worldwide. The lack of technology transfer from academia to industry is caused by important gaps between its fundamental basis and the process design. Herein, we explore critical disconnections by conducting coupled mass and heat transfer modeling and MD simulations; we use well-known MD mass and heat transfer equations to model and simulate flux over a typical MD membrane for different geometries, areas, and operational conditions in direct contact configuration. From the analysis of the results, we propose research guidelines and process development strategies, and construct an MD module performance curve. From this graph, permeate flow rate, thermal energy consumption and outlet temperatures can be determined for given feed inlet conditions (temperature and concentration). Comprehensive tools such as this MD module curve and good communication between membrane developers and process engineers are required to accelerate the process of bringing the MD technology from a still-emerging status to a maturity level

Fracturas estallido de columna toracolumbar: Evaluación clinicoradiológica y terapéutica de 90 casos

Presentamos un estudio retrospectivo de 90 fracturas toracolumbares tipo estallido con un seguimiento mínimo de 12 meses. Se realizó tratamiento ortopédico en 43 casos y en 47 se indicó una artrodesis instrumentada. Realizamos una evaluación clínico-radiológica en base al dolor residual y evolución del ángulo de cifosis con el objetivo de valorar el tratamiento ortopédico como opción terapéutica y la necesidad de distinguir fracturas estallido con afectación de 2 ó 3 columnas. No apreciamos diferencias estables significativas en el dolor y la lesión de las tres columnas. El aumento de cifosis angular media en las fracturas estallido estable no operadas es de 4.7º y de 5.2º en las fracturas estallido inestables tratadas ortopédicamente. Observamos una alta incidencia de complicaciones relacionadas con la fijación (21%) cuando la fractura asentaba en la charnela y se instrumentaba a un solo nivel. El tratamiento ortopédico es una opción aceptable en las fracturas estallido en pacientes neurológicamente indemnes.Ninety burst fractures of the thoracolumbar spine were retrospectively assessed with a minum follow-up of 12 months. Conservative treatment was indicated in 43 cases, and reduction and surgical stabilization in 47. The aim was to compare the two treatment modalities according to fracture stability. Clinical and radiological evaluation included chronic pain and kyphotic angle progression. No statistical differences were found between stable and unstable fractures as to chronic pain. The kyphotic angle average progression for stable burst fractures was 4.7º and 5.2º for unstable fractures conservatively treated. There was a high rate of complications related to instrumentation (21%) particularly when the fracture was at the thoracolumbar junction and a single level was fixed. The orthopaedic treatment is an acceptable alternative treatment for stable burst fractures without neurological injury

Synthesis, molecular modelling and NLO properties of new ytterbium(iii) complexes with vildagliptin

Two nonlinear optical ytterbium(III) complexes with vildagliptin have been synthesized and their ground state geometries have been predicted by semi-empirical quantum chemistry methods: [Yb(vilda)3(acac)] and [Yb(vilda)2(acac)(bipy)], where vilda = vildagliptin, acac = acetylacetonate and bipy = 2,2'-bipyridine. ATR-Fourier transform infrared (ATR-FTIR) spectral studies have been carried out to identify the functional groups of the novel complexes. The third order nonlinear optical response has been experimentally studied using Z-scan and P-scan methods, and static and frequency dependent second hyperpolarizabilities have been theoretically investigated using the Sparkle/PM6 model. The novel materials in diluted solutions have nonlinear refractive indices comparable to that of carbon disulphide.J.A. Novoa-López would like to thank University of Vigo for its financial support under “Axudas predoutorais: Áreas de especial dificultade” PhD scholarship program. Support by Xunta de Galicia under projects K133131H64102 and K044131H64502 is gratefully acknowledged by P. Chamorro-Posada, H. Michinel and P. Martín-Ramos are grateful to Junta de Castilla y León for providing funds under project VA300A12-1

In-situ CO measurements at Izaña global GAW station: GC-RGA system, data processing, and 2008-2011 time series

Comunicación presentada en: 16th WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases, and Related Measurement Techniques celebrado del 25 al 28 de octubre de 2011 en Wellington, Nueva Zelanda

Activity of Ricinus communis (Euphorbiaceae) against Spodoptera frugiperda (Lepidoptera: Noctuidae)

One of the most studied plant species with insecticidal properties is the castor bean Ricinus communis. However, its activity against Spodoptera frugiperda is unclear. Therefore, to determinate the insecticidal and insectistatic activities of methanol, hexane and ethyl acetate extracts of the seeds and leaves of R. communis, castor oil and ricinine were tested at different concentrations against S. frugiperda. This study demonstrated for the first time, that the castor oil and ricinine are active ingredients of R. communis that acts against S. frugiperda and that each of the seed extracts exhibited better insecticidal and insectistatic activity than the leaf extracts. The half maximum larvae viability concentration (LVC50) were 0.38 × 103 ppm for the ricinine, 0.75 × 103 ppm for a methanol extract ofseeds, 1.97 × 103 ppm for an ethyl acetate seed extract, 2.69×103 ppm for the castor oil, 4.83 × 103 ppm for a methanol extract of leaves, 5.07 × 103 ppm for an ethyl acetate extract of leaves, 9.95 × 103 ppm fora hexane extract of seeds and 10.01 × 103 ppm for a hexane extract of leaves

A sequence stratigraphic based geological model for constraining hydrogeological modeling in the urbanized area of the Quaternary Besòs delta (NW Mediterranean coast, Spain)

The Quaternary Besòs delta is located on the Mediterranean coast in NE Spain. The Besòs Delta Complex includes 3 aquifers constituted by 3 sandy and gravelly bodies, separated by lutitic units. These aquifers supply water for domestic and industrial use in this area. Management of groundwater has been problematic in the Besòs delta since the 1960s, and continues to pose major problems for subsurface engineering works in this highly urbanized region. This study seeks to demonstrate the advantages of detailed geological characterization and modeling for designing and constructing a hydrogeological model. Available information of the subsurface was compiled, integrated and homogenized in a geospatial database. The interpretation of these data enabled us to delimit geological units by means of a sequence stratigraphic subdivision. A three-dimensional facies belt-based model of the Besòs delta was built on the basis of this geological characterization. This model was used to constrain the distribution of hydraulic parameters and thus to obtain a consistent hydrogeological model of the delta, which was calibrated by data of water management and production over the last hundred years. The resulting hydrogeological model yielded new insights into water front displacements in the aquifer during the time-span considered, improving predictions in an attempt to optimize aquifer management

Response to sequential treatment schedules in childhood epilepsy Risk for development of refractory epilepsy

AbstractPurposeTo investigate response to sequential treatment schedules and risk of development of refractory epilepsy in childhood.MethodsAll children younger than 14 years with two or more unprovoked seizures seen at our hospital between 1994 and 2004 were included and prospectively followed. “Seizure control” was defined as a 2-year seizure-free interval without further recurrences except those related to attempts of medication withdrawal and “refractory epilepsy” as failure of >2 drugs plus >1 seizure/month for ≥18 months.Results343 Patients were included, 191 males and 152 females. Mean age at diagnosis was 4y 10 mo (SD 3 year 10 month). Mean follow-up period was 76.2 mo (SD 35.2). The probability of achieving “seizure control” was 70% and 86% at 5 and 10 years. 59% of patients were “controlled” with the first drug used. Among patients failing the first, second and third therapeutic regimen due to lack of efficacy, 39%, 23% and 12% respectively were finally “controlled” with subsequent treatment schedules Risk of development of refractory epilepsy was 8% and 12% at 6 and 10 years.ConclusionAfter failing a first drug, a significant proportion of children can still be controlled with subsequent therapeutic schedules. Only a small proportion develops refractory epilepsy

A study of the far infrared Spectrum of N -Acetyl-D-Glucosamine using THz-TDS, FTIR, and semiempirical quantum chemistry methods

The far infrared spectrum of N-acetyl-D-glucosamine has been studied by combining THz-TDS and FTIR characterization techniques with theoretical studies based on semiempirical quantum chemistry methods. A strong spectral peak at 60 cm-1 has been identified, which constitutes the main signature of the material in the terahertz band. Calculated molecular vibrations are in good qualitative and semiquantitative agreement with both the THz-TDS and FTIR experiments. In comparison to previous DFT-based studies, the semiempirical approach chosen herein, suitable for parallel multi-core and GPU acceleration, allows for a full study using periodic boundary conditions and no further approximations within a constrained computing time

Overview of progress in European medium sized tokamaks towards an integrated plasma-edge/wall solution

Integrating the plasma core performance with an edge and scrape-off layer (SOL) that leads to tolerable heat and particle loads on the wall is a major challenge. The new European medium size tokamak task force (EU-MST) coordinates research on ASDEX Upgrade (AUG), MAST and TCV. This multi-machine approach within EU-MST, covering a wide parameter range, is instrumental to progress in the field, as ITER and DEMO core/pedestal and SOL parameters are not achievable simultaneously in present day devices. A two prong approach is adopted. On the one hand, scenarios with tolerable transient heat and particle loads, including active edge localised mode (ELM) control are developed. On the other hand, divertor solutions including advanced magnetic configurations are studied. Considerable progress has been made on both approaches, in particular in the fields of: ELM control with resonant magnetic perturbations (RMP), small ELM regimes, detachment onset and control, as well as filamentary scrape-off-layer transport. For example full ELM suppression has now been achieved on AUG at low collisionality with n = 2 RMP maintaining good confinement HH(98,y2) 0.95. Advances have been made with respect to detachment onset and control. Studies in advanced divertor configurations (Snowflake, Super-X and X-point target divertor) shed new light on SOL physics. Cross field filamentary transport has been characterised in a wide parameter regime on AUG, MAST and TCV progressing the theoretical and experimental understanding crucial for predicting first wall loads in ITER and DEMO. Conditions in the SOL also play a crucial role for ELM stability and access to small ELM regimes.European Commission (EUROfusion 633053

Experimental and theoretical investigations on a CVD grown thin film of polymeric carbon nitride and its structure

A polymeric carbon nitride thin film has been grown using chemical vapor deposition. The characterization of the material shows that it has the same molecular composition as a formerly synthesized graphitic carbon nitride powder but both substances differ widely in their structural organization. In particular, our analyses reveal a paradoxical character in which the thin film sample exhibits simultaneously a high degree of organization in the stacking of the polymer sheets with strong inter-layer interactions, as expected from the growth technique, and a complete lack of crystallinity. A comprehensive theoretical study based on massive semi-empirical quantum chemistry computations has permitted to explain the properties of the material and to elucidate fundamental issues regarding the structural conformation of graphitic carbon nitride