AlxIn1−xN on Si (100) Solar Cells (x = 0–0.56) Deposited by RF Sputtering

We investigate the photovoltaic performance of solar cells based on n-AlxIn1−xN (x = 0–0.56) on p-Si (100) hetero-junctions deposited by radio frequency sputtering. The AlxIn1−xN layers own an optical bandgap absorption edge tuneable from 1.73 eV to 2.56 eV within the Al content range. This increase of Al content results in more resistive layers (≈10−4–1 Ω·cm) while the residual carrier concentration drops from ~1021 to ~1019 cm−3 . As a result, the top n-contact resistance varies from ≈10−1 to 1 MΩ for InN to Al0.56In0.44N-based devices, respectively. Best results are obtained for devices with 28% Al that exhibit a broad external quantum efficiency covering the full solar spectrum with a maximum of 80% at 750 nm, an open-circuit voltage of 0.39 V, a short-circuit current density of 17.1 mA/cm2 and a conversion efficiency of 2.12% under air mass 1.5 global (AM1.5G) illumination (1 sun), rendering them promising for novel low-cost III-nitride on Si photovoltaic devices. For Al contents above 28%, the electrical performance of the structures lessens due to the high top-contact resistivityThis research was funded by the national projects from the Ministry of Research and Innovation TEC2017-84378-R and NERA (RTI2018-101037-B-I00); the projects from the Comunidad de Madrid SINFOTON2-CM (P2018/NMT-4326), MADRID-PV2 (P-2018/EMT-4308) and SOLA (CM/JIN/2019-013); the projects from the University of Alcalá ANIS (CCG2018/EXP-042) and PISA (CCG19/IA-005); and by the FEDER program. R. Blasco acknowledges the financial support of his contract associated with the Ramon y Cajal Fellowship RYC-2013-1408

Method for Planning Graduate Programs in Construction Management

University programs in Western countries must be accredited, and although several detailed conceptual methods have aimed to design new programs, no specific quantitative tools are currently available. The purpose of this paper is to describe a method to plan, design, or improve graduate degree programs based on selected requirements and market demands. This method involves two metrics, which are later combined into a final index. The first metric is the completeness index that evaluates the extent to which certain programs cover a discipline, in this case, construction management, according to a model using two variables: infrastructure life cycle and organizational breakdown. The second metric is the adequacy index, which measures how a program addresses the previously identified market demands. The final indicator (summary index) relates both indexes in a plot chart. In this study, the applicability of the method is illustrated by a sample of 21 construction management programs from prestigious universities and a survey of the Spanish construction industry. It can be applied in practice, not only in the construction management field, but also in other fields with an appropriate theoretical model that maps each field of knowledge and exploratory data that highlight the demands of each specific market.Pellicer Armiñana, E.; Yepes Piqueras, V.; Ortega Llarena, AJ. (2013). Method for Planning Graduate Programs in Construction Management. Journal of Professional Issues in Engineering Education and Practice. 139(1):33-41. doi:10.1061/(ASCE)EI.1943-5541.0000120S3341139

Comparison of the material quality of AlxIn1-xN (x ~ 0-0.50) films deposited on Si (100) and (111) by reactive RF sputtering

Here, we compare the material quality of AlxIn1-xN layers deposited on Si with different crystallographic orientations, (100) and (111), via radio-frequency (RF) sputtering. To modulate their Al content, the Al RF power was varied from 0 to 225 W, whereas the In RF power and deposition temperature were fixed at 30 W and 300oC, respectively. X-ray diffraction measurements reveal a c-axis-oriented wurtzite structure with no phase separation regardless of the Al content (x = 0-0.50), which increases with the Al power supply. The surface morphology of the AlxIn1-xN layers improves with increasing Al content and it is similar for samples grown on both Si substrates (the root-mean-square roughness decreases from 12 nm to 2.5 nm). Furthermore, from TEM images we notice a similar grain-like columnar morphology and defect density on samples deposited on both Si substrates under the same conditions. Simultaneously grown AlxIn1-xN-on-sapphire samples point to a residual n-type carrier concentration in the 1020-1021 cm-3 range. The optical band gap energy of these layers evolves from 1.75 eV to 2.56 eV with increasing Al content, consistent with the blue shift of their low-temperature photoluminescence. In general, the material quality of the AlxIn1-xN films on Si is similar for both crystallographic orientations. Nonetheless, samples deposited on sapphire show an improved structural and morphological characteristic likely due to the lower difference in lattice constants between the nitride and the sapphire substrate

A cross-cultural comparison of the link between modernization, anthropomorphism and attitude to wildlife

Anthropogenic pressure has significantly increased in the last decades, often enhancing conflicts at the humanndash;wildlife interface. Therefore, understanding peoplesrsquo; value orientations, attitudes and behavioural intentions towards wildlife is a crucial endeavour to reduce the occurrence of conflicts between humans and wildlife. Previous research in the USA has shown a consistent link between modernization and increased anthropomorphism (i.e., the tendency to attribute human mental or physical characteristics to other entities), leading to positive changes in value orientations, attitudes, and behavioural intentions towards wildlife. In this paper, we aimed to address whether this link is also present in other cultures, by testing participants (N = 741) in five different countries (Brazil, Indonesia, Malaysia, Mexico, and Spain). Our study shows that while the positive link between anthropomorphism, positive attitudes and behavioural intentions towards wildlife is universal, the link between modernization and anthropomorphism is culturally mediated. In some countries (Indonesia, Malaysia, Spain), modernization increased anthropomorphism, while in others modernization predicted no differences (Brazil) or even a decrease in anthropomorphism (Mexico), ultimately deteriorating individualsrsquo; attitude and behavioural intentions towards wildlife. These results call for caution when generalizing findings from western industrialized countries to inform conservation policies worldwide

The motion of the 2D hydrodynamic Chaplygin sleigh in the presence of circulation

We consider the motion of a planar rigid body in a potential flow with circulation and subject to a certain nonholonomic constraint. This model is related to the design of underwater vehicles. The equations of motion admit a reduction to a 2-dimensional nonlinear system, which is integrated explicitly. We show that the reduced system comprises both asymptotic and periodic dynamics separated by a critical value of the energy, and give a complete classification of types of the motion. Then we describe the whole variety of the trajectories of the body on the plane.Comment: 25 pages, 7 figures. This article uses some introductory material from arXiv:1109.321

Cytomolecular identification of individual wheat-wheat chromosome arm associations in wheat-rye hybrids

Chromosome pairing in the meiotic metaphase I of wheatrye hybrids has been characterized by sequential genomic and fluorescent in situ hybridization allowing not only the discrimination of wheat and rye chromosomes, but also the identification of the individual wheat and rye chromosome arms involved in the chromosome associations. The majority of associations (93.8%) were observed between the wheat chromosomes. The largest number of wheat-wheat chromosome associations (53%) was detected between the A and D genomes, while the frequency of B-D and A-B associations was significantly lower (32 and 8%, respectively). Among the A-D chromosome associations, pairing between the 3AL and 3DL arms was observed with the highest frequency, while the most frequent of all the chromosome associations (0.113/ cell) was found to be the 3DS-3BS. Differences in the pairing frequency of the individual chromosome arms of wheat-rye hybrids have been discussed in relation to the homoeologous relationships between the constituent genomes of hexaploid wheat