Optimal Design of Multilayer Fog Collectors Azeem, Musaddaq; Guérin, Adrien; Dumais, Thomas ...
ACS applied materials & interfaces,
02/2020, Volume:
12, Issue:
6
Journal Article
Peer reviewed
Open access
The growing concerns over desertification have spurred research into technologies aimed at acquiring water from nontraditional sources such as dew, fog, and water vapor. Some of the most promising ...developments have focused on improving designs to collect water from fog. However, the absence of a shared framework to predict, measure, and compare the water collection efficiencies of new prototypes is becoming a major obstacle to progress in the field. We address this problem by providing a general theory to design efficient fog collectors as well as a concrete experimental protocol to furnish our theory with all the necessary parameters to quantify the effective water collection efficiency. We show in particular that multilayer collectors are required for high fog collection efficiency and that all efficient designs are found within a narrow range of mesh porosity. We support our conclusions with measurements on simple multilayer harp collectors.
This study analyzed the chemical composition of
essential oil from Puebla, México, assessed its antioxidant activity, and evaluated in silico protein-compound interactions related to central nervous ...system (CNS) physiology. GC-MS analysis identified myrcene (8.76%), Z-geranial (27.58%), and E-geranial (38.62%) as the main components, with 45 other compounds present, which depends on the region and growing conditions. DPPH and Folin-Ciocalteu assays using the leaves extract show a promising antioxidant effect (EC
= 48.5 µL EO/mL), reducing reactive oxygen species. The bioinformatic tool SwissTargetPrediction (STP) shows 10 proteins as potential targets associated with CNS physiology. Moreover, protein-protein interaction diagrams suggest that muscarinic and dopamine receptors are related to each other through a third party. Molecular docking reveals that
-geranial has higher binding energy than M1 commercial blocker and blocks M2, but not M4 muscarinic acetylcholine receptors, whereas
-pinene and myrcene block M1, M2, and M4 receptors. These actions may positively affect cardiovascular activity, memory, Alzheimer's disease, and schizophrenia. This study highlights the significance of understanding natural product interactions with physiological systems to uncover potential therapeutic agents and advanced knowledge on their benefits for human health.
The potential of additive manufacturing to produce architected lattice structures is remarkable, but restrictions imposed by manufacturing processes lead to practical limits on the form and dimension ...of structures that can be produced. In the present work, the capabilities of fused filament fabrication (FFF) to produce miniature lattices were explored, as they represent an inexpensive option for the production of polymer custom-made lattice structures. First, fused filament fabrication design guidelines were tested to assess their validity for miniature unit cells and lattice structures. The predictions were contrasted with the results of printing tests, showing some discrepancies between expected outcomes and resulting printed structures. It was possible to print functional 3D miniature open cell polymer lattice structures without support, even when some FFF guidelines were infringed, i.e., recommended minimum strut thickness and maximum overhang angle. Hence, a broad range of lattice structures with complex topologies are possible, beyond the cubic-type cell arrangements. Nevertheless, there are hard limits in 3D printing of miniature lattice structures. Strut thickness, length and orientation were identified as critical parameters in miniature lattice structures. Printed lattices that did not fully comply with FFF guidelines were capable of bearing compressive loads, even if surface quality and accuracy issues could not be fully resolved. Nevertheless, 3D printed FFF lattice structures could represent an improvement compared to other additive manufacturing processes, as they offer good control of cell geometry, and does not require additional post-processing.
In this paper, we study the capabilities of two additive manufacturing technologies for the production of lattice structures, namely material extrusion and vat photopolymerization additive ...manufacturing. A set of polymer lattice structures with diverse unit cell types were built using these additive manufacturing methods and tested under compression. Lattice structures built using material extrusion had lower accuracy and a lower relative density caused by the air gaps between layers, but had higher elastic moduli and larger energy absorption capacities, as a consequence of both the thicker struts and the relatively larger strength of the feedstock material. Additionally, the deformation process in lattices was analyzed using sequential photographs taken during the compression tests, evidencing larger differences according to the manufacturing process and unit-cell type. Both additive manufacturing methods produced miniature lattice structures with similar mechanical properties, but vat polymerization should be the preferred option when high geometrical accuracy is required. Nevertheless, as the solid material determines the compressive response of the lattice structure, the broader availability of feedstock materials gives an advantage to material extrusion in applications requiring stiffer structures or with higher energy absorption capabilities.
•The meteorology is controlled by interacting circulations and dynamical instabilities from the planetary scale down to the microscale.•The northern winter season is unique; the air mass in the ...crater mixes with external crater air due to the breaking of large amplitude mountain waves.•At other seasons, the mixing between the air in the floor of Gale Crater and air external to the crater may be more limited.•It is difficult to reconcile the putative methane detection with the Gale Crater circulation.
Numerical modeling results from the Mars Regional Atmospheric Modeling System are used to interpret the landed meteorological data from the Rover Environmental Monitoring Station onboard the Mars Science Laboratory rover Curiosity. In order to characterize seasonal changes throughout the Martian year, simulations are conducted at Ls 0, 90, 180 and 270. Two additional simulations at Ls 225 and 315 are explored to better understand the unique meteorological setting centered on Ls 270. The synergistic combination of model and observations reveals a complex meteorological environment within the crater. Seasonal planetary circulations, the thermal tide, slope flows along the topographic dichotomy, mesoscale waves, slope flows along the crater slopes and Mt. Sharp, and turbulent motions all interact in nonlinear ways to produce the observed weather. Ls 270 is shown to be an anomalous season when air within and outside the crater is well mixed by strong, flushing northerly flow and large amplitude, breaking mountain waves. At other seasons, the air in the crater is more isolated from the surrounding environment. The potential impact of the partially isolated crater air mass on the dust, water, noncondensable and methane cycles is also considered. In contrast to previous studies, the large amplitude diurnal pressure signal is attributed primarily to necessary hydrostatic adjustments associated with topography of different elevations, with contributions of less than 25% to the diurnal amplitude from the crater circulation itself. The crater circulation is shown to induce a suppressed boundary layer.
Fused deposition modeling represents a flexible and relatively inexpensive alternative for the production of custom-made polymer lattices. However, its limited accuracy and resolution lead to ...geometric irregularities and poor mechanical properties when compared with the digital design. Although the link between geometric features and mechanical properties of lattices has been studied extensively, the role of manufacturing parameters has received little attention. Additionally, as the size of cells/struts nears the accuracy limit of the manufacturing process, the interaction between geometry and manufacturing parameters could be decisive. Hence, the influence of three geometric and two manufacturing parameters on the mechanical behavior was evaluated using a fractional factorial design of experiments. The compressive behavior of two miniature lattice structures, the truncated octahedron and cubic diamond, was evaluated, and multilinear regression models for the elastic modulus and plateau stress were developed. Cell size, unit cell type, and strut diameter had the largest impact on the mechanical properties, while the influence of feedstock material and layer thickness was very limited. Models based on factorial design, although limited in scope, could be an effective tool for the design of customized lattice structures.
The accumulation of particles in a turbulent flow of incompressible air with mono-dispersed solid particles inside a 90° pipe bend was simulated using ANSYS® Fluent (CFD), taking into account the ...effect of gravity, drag force and a bidirectional fluid-particle coupling. An analysis of the geometrical parameters and the structures of the secondary flow generated in a curved pipe (Dean vortices) was developed, thus determining the characteristic time scales of the flow. Four Stokes numbers (Stk) were formulated, whose values are calculated and studied from the numerical simulations performed. Two different particle sizes (d1 = 50 μm y d2 = 150 μm), at two different flow conditions (Re1 = 61,500 y Re2 = 173,972), and for three curvature ratios Rc/R = 1, 4 and 8 were studied. The flow was solved using a Eulerian–Lagrangian approach with a RNG k-ε turbulence model. Once the multiphase flow was solved and validated, the distribution and maximum particle concentration inside the 90° bend were presented. Additionally, the Stk numbers were calculated to estimate the possible particle concentration level for the different system configurations (dp, Re and Rc/R). It is concluded that, if all Stk numbers are less than one, relative concentration levels reach a minimum, while for Stk numbers larger than one, an increase in the maximum concentration inside the pipe bend was noticed.
Electric scooters are used as alternative ways of transport because they easily make travel faster. However, the batteries can take around 5 h to charge and have an autonomy of 30 km. With the ...presence of the hydrogen cell, a hybrid system reduces the charging times and increases the autonomy of the vehicle by using two types of fuel. An increase of up to 80% in maximum distance and of 34% in operating times is obtained with a 1:10 scale prototype with the hydrogen cell; although more energy is withdrawn, the combined fuel efficiency increases, too. This suggests the cell that is used has the same behavior as some official reported vehicles, which have a long range but low power. This allows concluding that use of the cell is functional for load tests and that the comparison factor obtained works as input for real-scale scooter prototypes to compete with the traditional electric scooters.
The primary aim of this study was to evaluate the readability, understandability, suitability and actionability of online psoriasis patient educational materials. A secondary aim was to identify ...areas for improvement.
We conducted an evaluation study to assess online psoriasis patient educational materials from the American Academy of Dermatology and National Psoriasis Foundation available in July 2017. We used two validated assessment tools specific to online healthcare materials. Outcomes were expressed as percentages, where higher percentages corresponded to higher quality materials.
Overall, the educational materials had a mean understandability score (72.7%) that was understandable; a suitability score (58.8%) that was adequate; a reading grade level (10.5) that was not readable; and an actionability score (54.7%) that was not actionable. Areas of improvement include reading grade level, visual aids, word choice, specific steps for actions and cultural appropriateness.
Online psoriasis patient educational materials are understandable and suitable, but they are written above the American Medical Association and National Institutes of Health's recommended 6th-8th grade reading level and are not actionable. Materials can benefit from decreasing reading grade level, including more visual elements, incorporating more actionable items and being culturally inclusive.
investigación surge del interés de la labor docente dentro y fuera del aula con miras al cambio, la flexibilización y la transformación de realidades. Su objetivo general es determinar el efecto ...diferencial de variaciones en los parámetros de retroalimentación para el acierto y error, en el aprendizaje de competencias básicas del área de inglés, en estudiantes de grado Octavo de una Institución Educativa Municipal al suroccidente colombiano. Se desarrolló bajo el paradigma cuantitativo, de tipo explicativo y diseño factorial con tres variables independientes: latencia, especificidad y valencia de la retroalimentación. Se realizó una prueba piloto, la cual permitió el fortalecimiento de la estrategia de manipulación de variables independientes y la aplicación de instrumentos. Se estimó la fiabilidad de los instrumentos utilizados, mediante Alfa de Cronbach para la pre prueba y la post prueba de inglés, arrojando índices de 0,77 y 0,76 respectivamente. El componente de especificidad interactúa con la latencia, para que la condición de retroalimentación específica y corta, sea la combinación de componentes que genera el mayor aprendizaje de competencias. Además, la retroalimentación corta mantuvo la motivación por la tarea de manera constante a lo largo de las diferentes instancias de evaluación de aprendizaje.
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