Monitoring and modeling infiltration–recharge dynamics of managed aquifer recharge with desalinated seawater

We study the relation between surface infiltration and groundwater recharge during managed aquifer recharge (MAR) with desalinated seawater in an infiltration pond, at the Menashe site that overlies the northern part of the Israeli Coastal Aquifer. We monitor infiltration dynamics at multiple scales (up to the scale of the entire pond) by measuring the ponding depth, sediment water content and groundwater levels, using pressure sensors, single-ring infiltrometers, soil sensors, and observation wells. During a month (January 2015) of continuous intensive MAR (2.45  ×  10⁶ m³ discharged to a 10.7 ha area), groundwater level has risen by 17 m attaining full connection with the pond, while average infiltration rates declined by almost 2 orders of magnitude (from  ∼  11 to  ∼  0.4 m d⁻¹). This reduction can be explained solely by the lithology of the unsaturated zone that includes relatively low-permeability sediments. Clogging processes at the pond-surface – abundant in many MAR operations – are negated by the high-quality desalinated seawater (turbidity  ∼  0.2 NTU, total dissolved solids  ∼  120 mg L⁻¹) or negligible compared to the low-permeability layers. Recharge during infiltration was estimated reasonably well by simple analytical models, whereas a numerical model was used for estimating groundwater recharge after the end of infiltration. It was found that a calibrated numerical model with a one-dimensional representative sediment profile is able to capture MAR dynamics, including temporal reduction of infiltration rates, drainage and groundwater recharge. Measured infiltration rates of an independent MAR event (January 2016) fitted well to those calculated by the calibrated numerical model, showing the model validity. The successful quantification methodologies of the temporal groundwater recharge are useful for MAR practitioners and can serve as an input for groundwater flow models

Managed aquifer recharge with reverse-osmosis desalinated seawater: modeling the spreading in groundwater using stable water isotopes

The spreading of reverse-osmosis desalinated seawater (DSW) in the Israeli coastal aquifer was studied using groundwater modeling and stable water isotopes as tracers. The DSW produced at the Hadera seawater reverse-osmosis (SWRO) desalination plant is recharged into the aquifer through an infiltration pond at the managed aquifer recharge (MAR) site of Menashe, Israel. The distinct difference in isotope composition between DSW (δ18O&thinsp; = &thinsp;1.41&thinsp;‰; δ2H&thinsp; = &thinsp;11.34&thinsp;‰) and the natural groundwater (δ18O&thinsp; = &thinsp;−4.48&thinsp;‰ to −5.43&thinsp;‰; δ2H&thinsp; = &thinsp;−18.41&thinsp;‰ to −22.68&thinsp;‰) makes the water isotopes preferable for use as a tracer compared to widely used chemical tracers, such as chloride. Moreover, this distinct difference can be used to simplify the system to a binary mixture of two end-members: desalinated seawater and groundwater. This approach is validated through a sensitivity analysis, and it is especially robust when spatial data of stable water isotopes in the aquifer are scarce. A calibrated groundwater flow and transport model was used to predict the DSW plume distribution in the aquifer after 50 years of MAR with DSW. The results suggest that after 50 years, 94&thinsp;% of the recharged DSW was recovered by the production wells at the Menashe MAR site. The presented methodology is useful for predicting the distribution of reverse-osmosis desalinated seawater in various downstream groundwater systems.</p

Laser Crystallization of Silicon Thin Films for Three-Dimensional Integrated Circuits

The three-dimensional integration of microelectronics is a standard that has been actively pursued by numerous researchers in a variety of technical ways over the years. The primary aim of three-dimensional integration is to alleviate the well-known issues associated with device shrinking in conjunction with Moore's Law. In this thesis, we utilize laser-based and other melt-mediated crystallization techniques to create Si thin films that may be of sufficient microstructural quality for use in monolithic thin-film-based three-dimensional integrated circuits (3D-ICs). Beam-induced solidification of initially amorphous or polycrystalline Si films has been actively investigated over the years as an unconventional, yet often-effective, technical means to generate Si films with suitable microstructures for fabricating high-performance electronic devices. Two specific melt-mediated methods that are aimed at crystallizing Si thin films for 3D-ICs are presented. One is referred to as "advanced sequential lateral solidification (SLS)" while the other is referred to as "advanced mixed-phase solidification (MPS)" and we show that these approaches can provide a more 3D-IC-optimal microstructure than can be generated using previous deposition and/or crystallization-based techniques. Advanced SLS, as presented in this thesis, is a novel implementation of the previously-developed directional-SLS method, and is specifically aimed at addressing the microstructural non-uniformity issue that can be encountered in the directional solidification processing of continuous Si films. Films crystallized via the directional-SLS method, for instance, can contain physically distinct regions with varying densities of planar defects and/or crystallographic orientations. As a result, transistors fabricated within such films can potentially exhibit relatively poor device uniformity. To address this issue, we employ advanced SLS whereby Si films are prepatterned into closely-spaced, long, narrow stripes that are then crystallized via directional-SLS in the long-axis-direction of the stripe length. By doing so, one can create microstructurally distinct regions within each stripe, which are then placed within the active channel region of a device. It is shown that when the stripes are sufficiently narrow (less than 2 µm), a bi-crystal microstructure is observed. This is explained based on the change in the interface morphology as a consequence of enhanced heat flow at the edges of the stripe. It is suggested that this bi-crystal formation is beneficial to the approach, as it increases the effective number of stripes within the active channel region. One issue of fundamental and technological significance that is nearly always encountered in laser crystallization is the formation of structural defects, in general, and in particular, twins. Due to the importance of reducing the density of these defects in order to increase the performance of transistors, this thesis investigates the formation mechanism of twins in rapidly laterally solidified Si thin films. These defects have been characterized and examined in the past, but a physically consistent explanation has not yet been provided. To address this situation, we have carried out experiments using a particular version of SLS, namely dot-SLS. This specific technique is chosen because we identify that it is endowed with a fortuitous combination of experimental factors that enable the systematic examination of twinning in laterally grown Si thin films. Based on extensive microstructural analysis of dot-SLS-crystallized regions, we propose that it is the energetics associated with forming a new atomic layer (during growth) in either a twinned or non-twinned configuration heterogeneously at the oxide/film interface that dictate the formation (or absence) of twins. The second method presented in this thesis is that of advanced MPS. The basic MPS approach was originally conceived as a way to generate Si films for solar cells as it is capable of producing large, intragrain-defect-free regions that are predominantly (100) surface-textured. However, the location of the grain boundaries of these equiaxed grains is essentially random, and hence, transistors placed within the interior of the grains would exhibit differing performance compared to those that are place across the grain boundaries. To address this, advanced MPS is introduced and demonstrated as a means to manipulate solidification by seeding from {100} surface-oriented regions and to induce limited directional growth. This is accomplished using a continuous-wave laser with a Gaussian-shaped beam profile wherein a central, completely molten region is surrounded by a ``mixed-phase-region'' undergoing MPS. The technique creates quasi-directional material that consists of large, elongated, parallel, {100} surface-oriented grains. This material is an improvement over previously generated directionally solidified materials, and can allow one to build devices without high angle grain boundaries that are within, and oriented perpendicular to, the active channel. The resulting microstructure is explained in terms of the non-uniform energy density distribution generated by the Gaussian-shaped laser beam, and the corresponding shape and growth of the solid/liquid interface. Based on the observations and considerations from these results, we propose and demonstrate a related scheme whereby a flash-lamp annealing system is utilized in order to induce the advanced MPS condition. This method can potentially time-efficiently crystallize, and create in the process, well-defined regions that are microstructurally suitable for the fabrication of 3D-ICs

Culture optimization for the emergent zooplanktonic model organism Oikopleura dioica

The pan-global marine appendicularian, Oikopleura dioica, shows considerable promise as a candidate model organism for cross-disciplinary research ranging from chordate genetics and evolution to molecular ecology research. This urochordate, has a simplified anatomical organization, remains transparent throughout an exceptionally short life cycle of less than 1 week and exhibits high fecundity. At 70 Mb, the compact, sequenced genome ranks among the smallest known metazoan genomes, with both gene regulatory and intronic regions highly reduced in size. The organism occupies an important trophic role in marine ecosystems and is a significant contributor to global vertical carbon flux. Among the short list of bona fide biological model organisms, all share the property that they are amenable to long-term maintenance in laboratory cultures. Here, we tested diet regimes, spawn densities and dilutions and seawater treatment, leading to optimization of a detailed culture protocol that permits sustainable long-term maintenance of O. dioica, allowing continuous, uninterrupted production of source material for experimentation. The culture protocol can be quickly adapted in both coastal and inland laboratories and should promote rapid development of the many original research perspectives the animal offers

Extrait des physiques de Mr. Ganot [Material gráfico proyectable]

Contenido parcial: 1328. Microscope photo-electriqueContiene ilustraciones procedentes de los tratados de física de Adolphe Ganot.Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 2015En la etiqueta de cada placa consta "Extrait des physiques de Mr. Ganot avec autorisation spéciale", el número y tít. de la imagen.En la etiqueta de cada placa consta "Molteni / Paris"Estas colecciones se publican en la segunda mitad del s. XIX

Ergodicity breaking and lack of a typical waiting time in area-restricted search of avian predators

Movement tracks of wild animals frequently fit models of anomalous rather than simple diffusion, mostly reported as ergodic superdiffusive motion combining area-restricted search within a local patch and larger-scale commuting between patches, as highlighted by the L\'evy walk paradigm. Since L\'evy walks are scale invariant, superdiffusive motion is also expected within patches, yet investigation of such local movements has been precluded by the lack of accurate high-resolution data at this scale. Here, using rich high-resolution movement datasets ($>\! 7 \times 10^7$ localizations) from 70 individuals and continuous-time random walk modeling, we found subdiffusive behavior and ergodicity breaking in the localized movement of three species of avian predators. Small-scale, within-patch movement was qualitatively different, not inferrable and separated from large-scale inter-patch movement via a clear phase transition. Local search is characterized by long power-law-distributed waiting times with diverging mean, giving rise to ergodicity breaking in the form of considerable variability uniquely observed at this scale. This implies that wild animal movement is scale specific rather than scale free, with no typical waiting time at the local scale. Placing these findings in the context of the static-ambush to mobile-cruise foraging continuum, we verify predictions based on the hunting behavior of the study species and the constraints imposed by their prey.Comment: 27 pages, 8 figure