138 research outputs found
Preliminary Study of New Electrolytes Based on [MPPyr][TFSI] for Lithium Ion Batteries
Financiado para publicaciĂłn en acceso aberto: Universidade da Coruña/CISUG[Abstract] The application of ionic liquids in lithium ion batteries has increased in recent years in order to find new electrolytes that improve both performance and safety. The gathering of experimental data in order to understand the behaviour of these systems will help us design electrolytes that can be optimized for a specific objective. Data on electrolytes made up of a ternary mixture with an ionic liquid are missing in the literature. In this work, we provide new data on physical properties and refractive indexes for the ternary mixtures 1-methyl-1-propylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([MPPyr][TFSI]) + acetonitrile (AN) or Îł butyrolactone (GBL) or dimethyl sulfoxide (DMSO) + lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) with different concentrations of salt, specifically, 10%, 15%, 20%, 30%, 35%. The measured properties were density (Ï), viscosity (η) and ionic conductivity (Îș) in the temperature range of 278.15 to 358.15 K except for the mixtures with acetonitrile whose temperature range was 278.15 K to 328.15 K and the refractive indexes (nD) that were measured at a single temperature of 298.15 K. In general, the addition of salt in the binary mixtures provokes an increase of density and viscosity and therefore a decrease of ionic conductivity. It is worth mentioning that some of the studied systems showed values of ionic conductivity even better than those obtained for electrolyte systems based on carbonate.This work was supported by Ministerio de Economia y Competitividad (MINECO) and FEDER Program through the projects MAT2017â89239-C2â1-P, MAT2017â89239-C2â2-P and D2018â102679-T; Xunta de Galicia. Funding for open access charge: Universidade da Coruña/CISU
PENGARUH MEDIA PEMBELAJARAN MIND MAPPING TERHADAP MINAT BELAJAR PESERTA DIDIK PADA PELAJARAN EKONOMI KELAS XI IPS 1 di SMA NEGERI 27 BANDUNG
Judul penelitian ini adalah pengaruh media pembelajaran mind
mapping terhadap minat belajar peserta didik pada pelajaran ekonomi kelas
XI IPS 1 di SMA Negeri 27 Bandung tahun ajaran 2016-2017. Berdasarkan
tinjauan langsung di SMA Negeri 27 Bandung kelas XI IPS 1, Pembelajaran
konvensional (ceramah) hanya membuat peserta didik kurang aktif dan malas
dalam menerima materi yang ada, karena pembelajaran hanya terpusat pada apa
yang disampaikan sehingga tidak dapat dimengerti secara maksimal. Tujuan dari
penelitian ini adalah: (1) Mengetahui penggunaan media mind mapping pada mata
pelajaran ekonomi kelas XI IPS 1 di SMA Negeri 27 Bandung. (2) Mengetahui
minat belajar peserta didik pada mata pelajaran ekonomi kelas XI IPS 1 di SMA
Negeri 27 Bandung. (3) Mengetahui seberapa besar pengaruh media mind
mapping terhadap minat belajar peserta didik pada mata pelajaran ekonomi kelas
XI IPS 1 di SMA Negeri 27 Bandung. Metode yang digunakan dalam penelitian
ini adalah survei. Teknik pengumpulan data yang digunakan yaitu observasi dan
angket dengan teknik pengolahan data uji validitas, uji reliabilitas, uji normalitas
data, analisis regresi linier sederhana dan koefisien determinasi, Hipotesis
penelitian berbunyi âTerdapat pengaruh antara media pembelajaran mind mapping
(X) terhadap minat belajar peserta didik (Y) pada mata pelajaran ekonomi. Hasil
penelitian ini adalah terdapat pengaruh antara variabel X dan Variabel Y sebesar
0,336 atau 33,60%. Untuk mengetahui hubungan fungsional antara variabel X dan
variabel Y maka digunakan analisis regresi linier sederhana dengan hasil
perhitungan sebagai berikut : Y = 9.915 + 0.537 X artinya bahwa setiap media
pembelajaran mind mapping bertambah 9,915 maka minat belajar meningkat
sebesar 0,537. Untuk mengetahui seberapa besar pengaruh variabel X (media
pembelajaran mind mapping) terhadap variabel Y (minat belajar), maka
digunakan koefisien determinasi dengan hasil perhitungan sebesar 33,60% maka
sebagian lainnya ditentukan oleh faktor lain yang tidak diteliti. Kesimpulan
hipotesis penelitian dapat diterima, sebagai akhir penelitian penulis
menyampaikan saran kepada guru agar sebaiknya guru menggunakan variasi
media pembelajaran yang menarik berkaitan dengan materi pelajaran yang akan
disampaikan, karena cara ini dapat membuat peserta didik aktif dan kreatif untuk
belajar. Kepada para praktisi atau peneliti lain di bidang pendidikan dapat
melakukan penelitian serupa dengan media pembelajaran dan metode yang
berbeda agar diperoleh berbagai alternatif untuk peningkatan pemahaman
pembelajaran pada pokok bahasan selanjutnya dan kepada pihak sekolah sebagai
bahan kajian bagi sekolah dan menyarankan guru untuk menggunakan media
pembelajaran yang mampu meningkatkan prestasi belajar peserta didik untuk
mendukung pendekatan saintifik dan media pembelajaran yang baik.
Kata Kunci : media pembelajaran mind mapping, minat Belajar
Identification and conservation of remnant genetic resources of brown trout in relict populations from Western Mediterranean streams
This is a post-peer-review, pre-copyedit version of an article published in Hydrobiologia. The final authenticated version is available online at: https://doi.org/10.1007/s10750-012-1402-8Brown trout is a cold-adapted freshwater species with restricted distribution to headwater streams in rivers of the South European peninsulas, where populations are highly vulnerable because Mediterranean regions are highly sensitive to the global climatic warming. Moreover, these populations are endangered due to the introgressive hybridization with cultured stocks. Individuals from six remnant populations in Western Mediterranean rivers were sequenced for the complete mitochondrial DNA control region and genotyped for 11 nuclear markers. Three different brown trout lineages were present in the studied region. Significant genetic divergence was observed among locations and a strong effect of genetic drift was suggested. An important stocking impact (close to 25%) was detected in the zone. Significant correlations between mitochondrial-based rates of hatchery introgression and water flow variation suggested a higher impact of stocked females in unstable habitats. In spite of hatchery introgression, all populations remained highly differentiated, suggesting that native genetic resources are still abundant. However, climatic predictions indicated that suitable habitats for the species in these rivers will be reduced and hence trout populations are highly endangered and vulnerable. Thus, management policies should take into account these predictions to design upstream refuge areas to protect remnant native trout in the regionThis study has been supported by the Generalitat Valenciana Autonomous Government (Spain) project (2008/CI446)S
Monolithic SiC supports with tailored hierarchical porosity for molecularly selective membranes and supported liquid-phase catalysis
Monolithic support materials with the mechanical resistance and thermal conductivity of SiC as well as tunable surface chemistry and textural properties were developed for their use in catalytic membrane reactors. After heat treatment, the extruded SiC monoliths have a monomodal distribution of macropores of a few ÎŒm in diameter depending on the particle size of the starting material. A macroporous, defect-free, smoother skin was applied onto the external wall using a solution of sub-micrometer SiC particles. These monoliths with skin could be coated successfully with molecularly selective membranes, and thus have application in membrane reactor processes. Finally, metal oxide nanoparticles were infiltrated into the macropores to modify the surface texture and chemistry, allowing the immobilization of liquid phase catalysts. The resulting multimodal distribution of pore sizes could be tuned by the choice of SiC and oxide particle sizes, number of wash-coats and calcination temperature. Mesopores created between nanoparticles had diameters of roughly 40 % of those of the nanoparticles. Small macropores, between 10â1000 nm, were also created, with bigger size and volume at higher calcination temperatures due to the metal oxide particles contraction. The developed materials were validated as support for PDMS membranes and for continuous gas-phase hydroformylation of 1-butene using Rh-diphosphite catalysts.The authors gratefully acknowledge financial support from the European Commissionwithin the Horizon2020-SPIRE project ROMEO (Grant Agreement Number 680395). Furthermore, the authors would like to thank Dr. Andreas Bösmann and M. Sc. Patrick Wolf (Universit Ìat Erlangen-NĂŒrnberg) for the XRF measurements, as well as Markus Wist (RWTH Aachen University) for his work in the membrane fabricatio
Long-Term outcomes and durability of the mitroflow aortic bioprosthesis
[Abstract] Background. This study aims to determine the incidence and causes of structural valve deterioration (SVD) among all models of Mitroflow bioprostheses (A12/LX/DL), as well as to define their long-term clinical and hemodynamic performance.
Methods and Results. We retrospectively reviewed a series of 1023 patients who underwent aortic valve replacement with Mitroflow bioprostheses between 2001 and 2014. A small aortic root was found in 22.4% of patients. There were two cases of severe patient-prosthesis mismatch. Only 31 patients developed SVD. The rate of incidence was 8.1 cases per 1000 patient-years. Cumulative incidence of SVD was 1.4% and 3% at five and 10 years, respectively. Freedom from SVD was 97.4% and 88.2% at five and 10 years, respectively. Anticalcification phospholipid reduction treatment (PRT) for model DL was a protective factor for SVD. Multivariable analysis confirmed age <70 years and use of 19âmm valve as independent predictors of SVD. Cumulative survival was 76.6% at five years and 42.3% at 10 years (mean follow-up 3.8â±â3.1 years). In multivariable analysis, neither the use of small aortic prosthesis (pâ=â0.18) nor the occurrence of SVD (pâ=â0.85) was found to be independent predictors of long-term survival.
Conclusions. Mitroflow valves demonstrate an acceptable rate of SVD and satisfactory long-term hemodynamic performance, particularly in patients with small aortic roots, age >70 years, and cases with severe left ventricular hypertrophy. PRT might contribute to improved long-term durability
A new wavelets image fusion strategy
The aim of image fusion is to combine information from multiple images of the same scene. The result of image fusion is a new image,,which is more suitable for human and machine perception or further image-processing tasks such as segmentation, feature extraction and object recognition. Different fusion methods have been proposed in the literature. This paper presents new methods based on the computation of local and global gradient. A comparative analysis is carried out against other existing strategies. The results are encouraging
Innovative Strategies for Ozone Treatment of Industrial Wastes: Hydrothermal Liquefaction of Surfactant Wastewater and Leacheate Evaporation
In this paper, ozonation is used as a pre-treatment for two different kinds of wastewaters. The first purpose is the study of the effect of ozonation on a landfill leachate treated by a reverse osmosis process prior a concentration step in an atmospheric evaporator. At first sight, an ozone treatment can supply three effects: Defoaming capacity, biocide effect, and pH acidifier to avoid the ammonia striping in the evaporation process. The second purpose of this paper is regarding hydrothermal liquefaction (HTL) of wastewaters. HTL can produce a liquid fuel, normally called crude-oil, alternative to fossil fuels, as well as other products of industrial interest (phenols, furfurals, etc.). The second objective is the study of the possible positive effect that a pre-treatment with ozone can have on the performance of the subsequent HTL. In this work, HTL is applied to liquid surfactant wastes obtaining up to 7% crude-oil yield, with a High Heating Value (HHV) higher than 8.000 cal/g. These results are compared with those obtained when an ozonation pre-treatment is applied before the HTL process. Ozone treatment shows a slight defoaming capacity for the leachate feed but donât seem to show a significant difference in the HHV of the crude-oils obtained from liquid surfactant. However, there is a noticeable difference in the solid residue generated for this later. Less aggregates of solid particles and a weight reduction of 20% in the filtering step were obtained from ozonated liquid surfactants. The reduction of solid by-products is of great interest for dimensioning an industrial-scale HTL plant due to the problems that these solids can generate in pipes and valves
Aprendizaje virtual de las matemĂĄticas utilizando distintas TICs
Proyecto para ayudar al estudiantado en el aprendizaje de las MatemĂĄticas y promover su aprendizaje autĂłnomo. Todo ello, con materiales mĂĄs visuales como vĂdeos, pĂldoras educativas, clases en modo sĂncrono, ejemplos con GeoGebra y cuestionarios
AnĂĄlisis de los contenidos docentes de matemĂĄticas en el doble grado ADE-InformĂĄtica
Depto. de EconomĂa Financiera y Actuarial y EstadĂsticaFac. de Ciencias EconĂłmicas y EmpresarialesFALSEsubmitte
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