117 research outputs found
SPATIAL PREDICTION OF HEAVY METAL POLLUTION FOR SOILS IN COIMBATORE, INDIA BASED ON ANN AND KRIGING MODEL
The concentration of five soil heavy metals (Cr, Pb, and As) was measured in 121 sampling sites in Coimbatore, Tamil Nadu, India regions known as centres of pollution due to the chemical and metallurgical activities. The soil samples were collected from locations where the ground is not sliding and the probability of alluvial deposits is small. The concentration of heavy metals was measured by using Atomic Absorption spectrometer. Kriging and ANN techniques were used to develop the model to predict the constituents of the heavy metal in the soils. In some locations, the concentration for the investigated heavy metals exceeds the concentration admitted by the guideline. The highest concentration of lead (8.9 ppm) was found in Ukkadam Lake. The highest concentration of chromium was found in Ganapathi (3.6 ppm). The highest concentration of Arsenic (5.4 ppm) was found in Sidco Industrial Estate. The maximum admitted concentrations in the sensitive areas revealed to be exceed from five to twenty times
Cu-BTC Functional Microdevices as Smart Tools for Capture and Preconcentration of Nerve Agents
Cu-based metal-organic framework (MOF) microdevices are applied in sampling and preconcentration of nerve agents (NAs) diluted in gaseous streams. An in situ electrochemical-assisted synthesis of a Cu-benzene-1, 3, 5-tricarboxylate (BTC) thick film is carried out to functionalize a Cu-modified glass substrate. This simple, rapid, reproducible, and easy-to-integrate MOF synthesis approach enables the microfabrication of functional micro-preconcentrators with a large Brunauer-Emmett-Teller (BET) surface area (above 2000 cm2) and an active pore volume (above 90 nL) for the efficient adsorption of nerve agent molecules along the microfluidic channel 2.5 cm in length. The equilibrium adsorption capacity of the bulk material has been characterized through thermogravimetric analysis after exposure to controlled atmospheres of a sarin gas surrogate, dimethyl methylphosphonate (DMMP), in both dry and humid conditions (30% RH at 293 K). Breakthrough tests at the ppm level (162 mg/m3) reveal equilibrium adsorption capacities up to 691 mg/g. The preconcentration performance of such µ-devices when dealing with highly diluted surrogate atmosphere, i.e., 520 ppbV (2.6 mg/m3) at 298 K, leads to preconcentration coefficients up to 171 for sample volume up to 600 STP cm3. We demonstrate the potentialities of Cu-BTC micro-preconcentrators as smart first responder tools for "on-field" detection of nerve agents in the gas phase at relevant conditions
Cation ordering and crystallinity of dolomites in the geological record
Despite the fact that dolomite is an ubiquitous rock-forming carbonate in the geological record, the mechanism (or mechanisms) of its formation in nature remain elusive. The solution of such a mineralogical problem does not only require further experimental work but also a more detailed crystallochemical characterization of dolomites formed in different environments during the Earth’s history
As lesões por esforços repetitivos (LERS) como síndrome emblemática das novas relações e processos de trabalho
Bio- and magnetostratigraphic correlation of the Miocene primate bearing site of Castell de Barber a to the earliest Vallesian
Castell de Barberà, located in the Vallès-Penedès Basin (NE Iberian Peninsula), is one of the few European sites where pliopithecoids (Barberapithecus) and hominoids (cf. Dryopithecus) co-occur. The dating of this Miocene site has proven controversial. A latest Aragonian (MN7+8, ca. 11.88-11.18 Ma) age was long accepted by most authors, despite subsequent reports of hipparionin remains that signaled a Vallesian age. On the latter basis, Castell de Barberà was recently correlated to the early Vallesian (MN9, ca. 11.18-10.3 Ma) on tentative grounds. Uncertainties about the provenance of the Hippotherium material and the lack of magnetostratigraphic data precluded more accurate dating. After decades of inactivity, fieldwork was resumed in 2014-2015 at Castell de Barberà, including the original layer (CB-D) that in the past delivered most of the fossils. Here we report magnetostratigraphic results for the original outcrop and another nearby section. Our results indicate that CB-D is located in a normal polarity magnetozone at about midheight of a short (~20 m-thick) stratigraphic section. The composite magnetostratigraphic section (~50 m) has as many as four to six magnetozones. These multiple reversals, coupled with the in situ recovery of a Hippotherium humerus from CB-D in 2015, make it very unlikely the correlation of any of the sampled normal polarity magnetozones with the long normal polarity subchron C5n.2n (11.056-9.984 Ma), which is characteristic of the early Vallesian. Our results support instead a correlation of CB-D with C5r.1n (11.188-11.146 Ma), where the Aragonian/Vallesian boundary is situated, and therefore indicate an earliest Vallesian age of ~11.2 Ma for Castell de Barberà. Our results settle the longstanding debate about the Aragonian vs. Vallesian age of this site, which appears roughly coeval with the Creu de Conill 20 locality (11.18 Ma), where hipparionins are first recorded in the Vallès- Penedès Basi
Nuevos recursos audiovisuales para la enseñanza de la cristalografía: cristales y difracción
Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasFALSEsubmitte
Microfluidic devices as gas – Ionic liquid membrane contactors for CO2 removal from anaesthesia gases
This work proposes a microfluidic gas – ionic liquid contactor for CO2 removal from anaesthesia gas, containing Xe. The working principle involves the transport of CO2 through a polymer flat membrane followed by its capture and enzymatic bioconversion in the ionic liquid solvent. Microfluidic devices enable a rapid and inexpensive screening of potential CO2 absorbers. The alveolar – type design of the ionic liquid chamber was adopted to reduce mass transfer limitations of CO2 through the liquid phase. Polydimethylsiloxane (PDMS) was the chosen polymer for dense membrane, as well as for the microfluidic device fabrication, mainly due to the high permeability of gases, O2 and CO2, and low cost. The selected ionic liquid was cholinium propionate (CP) with a water activity of 0.753, due to its high affinity towards CO2 and biocompatibility with the enzyme used for CO2 conversion to bicarbonate, carbonic anhydrase (CA). The CO2 and Xe permeability and CO2/Xe selectivity were determined in the microfluidic devices developed and compared to those exhibited by free standing PDMS membranes mounted on a standard permeation cell. The performance of the microfluidic devices as gas – ionic liquid contactors was evaluated for a given solvent flow rate with pure gas streams of CO2 and Xe. The obtained results show that cholinium propionate with or without the enzyme has no effect on the Xe transport, but remarkably enhances the affinity towards carbon dioxide leading to enhancement factor up to 1.9 in the presence of 0.1 mg CA/gIL
Protein crystallization in a microfluidic contactor with nafion®117 membranes
UIDB/50006/2020 UIDP/50006/2020 “Erasmus Mundus Doctorate in Membrane Engineering”–EUDIME (FPA 2011–2014, http://www.eudime.unical.itProtein crystallization still remains mostly an empirical science, as the production of crystals with the required quality for X-ray analysis is dependent on the intensive screening of the best protein crystallization and crystal’s derivatization conditions. Herein, this demanding step was addressed by the development of a high-throughput and low-budget microfluidic platform consisting of an ion exchange membrane (117 Nafion® membrane) sandwiched between a channel layer (stripping phase compartment) and a wells layer (feed phase compartment) forming 75 independent microcontactors. This microfluidic device allows for a simultaneous and independent screening of multiple protein crystallization and crystal derivatization conditions, using Hen EggWhite Lysozyme (HEWL) as the model protein and Hg2+ as the derivatizing agent. This microdevice offers well-regulated crystallization and subsequent crystal derivatization processes based on the controlled transport of water and ions provided by the 117 Nafion® membrane. Diffusion coefficients of water and the derivatizing agent (Hg2+) were evaluated, showing the positive influence of the protein drop volume on the number of crystals and crystal size. This microfluidic system allowed for crystals with good structural stability and high X-ray diffraction quality and, thus, it is regarded as an efficient tool that may contribute to the enhancement of the proteins’ crystals structural resolution.publishersversionpublishe
Implementation of a project-based learning to the coordination of subjects in the Agrifood and Rural Engineering Bachelor
The Bachelor’s Degree in Agrifood and
Rural Engineering at Universitat Jaume
I of Castelló has implemented in the
second academic year a multidisciplinary project using a Project-Based Learning as
the teaching method. Its final purpose is
the acquisition of skills that should help
the students to cope with their future
career. This teaching-learning system has
been used for three consecutive years
since the degree was firstly implemented.
Once a particular farm is assigned, the
students are organized in groups and
must fulfill their assigned tasks in a
collaborative manner with the final goal
of developing a project on that farm
including viable improvements of the
exploitation, taking into account the
issues related to the different subjects
involved. This work presents the results
obtained along the three years, analyzed
from two different points of view: student
satisfaction and learning outcomes.
Besides, the proposals for improvement
of the weaknesses identified during
the process are presented. The
results show that the used method
has promoted the acquisition of the
competences proposed. Moreover the
multidisciplinary approach has led to
better results in the student performance
than those obtained by students enrolled
in an unidisciplinary project. Although
improvement actions have solved some
of the problems detected, there are still
some weaknesses, mainly related to
team working and tutorials that should
be addressed in the future.El grado de Ingeniería Agroalimentaria y
del Medio Rural de la Universitat Jaume I
de Castelló viene aplicando en su segundo
curso un proyecto multidisciplinar usando el Aprendizaje Basado en
Proyectos como recurso docente en el
que se pretende que los estudiantes
adquieran competencias que les ayuden
a enfrentarse a su futuro profesional. Este
sistema de enseñanza-aprendizaje se ha
llevado a cabo durante los tres cursos que
está implantado el grado. Una vez asignado
un tipo de explotación agrícola concreta y
utilizando las herramientas del trabajo en
equipo, los estudiantes deben ser capaces
de desarrollar un proyecto sobre la
explotación con propuestas de mejora que
sean factibles y que abarquen aspectos
relacionados con las diferentes disciplinas
implicadas, aplicando los conocimientos
adquiridos en éstas. El presente trabajo
incluye los resultados obtenidos durante
los tres años del proyecto desde dos
puntos de vista importantes: la satisfacción
del estudiante y los resultados de
aprendizaje. Además se presentan las
propuestas de mejora aplicadas en cada
curso como respuesta a las debilidades
detectadas durante el proceso. Los
resultados demuestran que el método
utilizado ha favorecido la adquisición de
las competencias propuestas. Además,
el enfoque multidisciplinar ha propiciado
mejores resultados que los alcanzados
por los estudiantes que realizaron trabajos
unidisciplinares. Por otro lado, aunque
las acciones de mejora han permitido
solventar algunos de los problemas
detectados, siguen persistiendo carencias,
sobre todo a nivel de trabajo en equipo y
de tutorización, que se proponen como
mejoras para el futuro
Water and otolith chemistry: implications for discerning estuarine nursery habitat use of a juvenile flatfish
Variations in otolith elemental composition are widely used to reconstruct fish movements. However, reconstructing habitat use and environmental histories of fishes within estuaries is still a major challenge due to the dynamic nature of these coastal environments. In this study, we performed a laboratory experiment to investigate the effects of variations in salinity (three levels; 5, 18, 30) and temperature (two levels; 16,
21 C) on the otolith elemental composition (Mg:Ca, Mn:Ca, Sr:Ca, Ba:Ca) of juvenile Senegalese sole Solea senegalensis. Temperature and salinity treatments mirrored the natural conditions of the estuarine habitats occupied by juvenile Senegalese sole, thereby providing information on the applicability of otolith microchemistry to reconstruct habitat use patterns within estuarine nurseries, where individual fish move across
complex salinity and temperature gradients. While Sr:Ca and Ba:Ca in otoliths were both positively related to salinity, no temperature effect was observed. Partition coefficients, proxies for element incorporation rates increased with increasing salinity for Sr (DSr) and Ba (DBa). In contrast, salinity and temperature had little influence on otolith Mn:Ca and Mg:Ca, supporting physiological control on the incorporation of these elements. Our results are a stepping stone for the interpretation of otolith chemical profiles for fish collected in their natural habitats and contribute to better understanding the processes involved in otolith element incorporation.info:eu-repo/semantics/publishedVersio
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