Compact Substrates Research Articles

PEDOT: PSS/PC71BM with various Rubrene doping levels for the production of Organic/Inorganic hybrid silicon solar cells with enhanced yield efficiency

Polymer-based solar cells (PSCs) have garnered considerable interest due to their potential advantages over traditional organic/inorganic hybrid silicon solar cells, including reduced material and production costs, compact substrates, and lightweight finished photovoltaic cells. To explore this further, we examined the impact of Rubrene in the PEDOT: PC71BM hole transport layer within the bulk Heterojunction framework of solution-processable polymer photovoltaic cells. Cells were created by combining PEDOT: PSS and PC71BM, incorporating Rubrene at 6, 9, 12, and 15 wt% ratios. The device structure comprised Si/PEDOT: PSS/PC71BM: Rubrene: DMSO/Ag, with Ag serving as a cathode fabricated in a low-pressure chamber. Notably, employing a 6 wt% Rubrene solution yielded improved short-circuit current density (Jsc), open-circuit voltage (Voc), fill factor (FF), and power conversion efficiency (PCE) of 13.97 mA.cm−2, 514.80 mV, 40.97, and 2.948 %, respectively. These results demonstrate enhanced PCE with the addition of Rubrene compared to prior studies utilizing an active Rubrene surface.

Fossorial mammals emphasise the forelimb muscle moment arms used for digging: New indices for reconstruction of the digging ability and behaviours in extinct taxa.

Among fossorial mammals, forelimbs are major digging apparatuses for dwelling, sheltering and foraging underground. Forelimb-diggers have independently evolved in many lineages of mammals; thus, the method of digging with forelimbs varies by taxon. Therefore, the reconstruction of digging behaviours in extinct animals leads us to understand the evolutionary process of fossorial adaptation in each lineage. However, no morphological index was found to reconstruct if, or how, extinct taxa dug with forelimbs. In this study, we used the shoulder and elbow muscle moment arms in relation to the out-force lever on the manus as indices of the efficiency of motions. The mechanical advantage of two shoulder motions (medial rotation and retraction) and three elbow motions (extension, flexion and adduction) was measured in 381 extant mammal specimens representing 332 species, 279 genera, 103 families and 24 orders. Assuming that both forelimb-digging and -paddling in water require relatively high-output moment arm efficiency, the studied taxa were categorised into four groups based on the presence or absence of forelimb-digging and -paddling abilities. We found that the efficiencies of all five muscle moment arms in the forelimb-diggers and -paddlers were higher than those of the non-diggers and non-paddlers. Furthermore, among the forelimb-diggers, the taxa that dig compact substrates or frequently burrow tend to emphasise the muscle moment arms compared to the taxa that dig loose substrates or dig less frequently. The comparison among the 53 extant forelimb-diggers revealed that the efficiency marked among the five muscle moment arms reflects the difference in digging strategy: humeral rotation diggers emphasise the shoulder medial rotator and elbow adductor, hook-and-pull diggers emphasise the shoulder retractor and elbow flexor and scratch diggers emphasise the shoulder retractor and elbow extensor. We propose that these indices will be powerful tools for reconstructing the fossorial behaviours of extinct mammals. Applying these indices to extinct taxa, Ceratogaulus, Ernanodon, Metacheiromys and Prozaedyus are capable of more efficient forelimb-digging, and each may have adopted different digging strategies.

Laboratory research of solvent-assisted menthol sols as temporary consolidants in archaeological excavation applications

Temporary consolidation is a quite common practice during archeological excavations nowadays. Melts of cyclododecane or menthol are among the most used consolidants. When using melting protocol to consolidate fragile heritages in archaeological excavation sites, one of the most frequently encountered challenges is the poor penetration of the melt into the heritages, especially in cases of low environmental temperatures, high water content or compact substrates. In this work, we explore the possibility of using solvent-assisted menthol sols as temporary consolidant. Six common organic liquids are individually introduced into menthol at a concentration of 9.1 wt% to formulate room temperature menthol sols. Their potentials as temporary consolidants are systematically investigated. Experimental data indicate that solvent polarity is the most important feature for temporary consolidation purpose and ethanol with medium polarity is among the most appropriate solvents. Laboratory research results show that much better penetration behavior and good consolidation performances can be achieved in menthol-ethanol sol. The as-prepared menthol-ethanol sol is applied in Liangzhu archeological excavation site with satisfactory outcomes. This work shows that menthol-ethanol sol is an excellent temporary consolidation material for archaeological excavation purpose especially in extremely wet condition.

Distinct roles of adipose triglyceride lipase and hormone‐sensitive lipase in the catabolism of triacylglycerol estolides

Branched esters of fatty acids and hydroxy fatty acids (FAHFAs) belong to a wide range group of lipids, some of which have anti-inflammatory and anti-diabetic properties. FAHFAs themselves belong to oligomeric FA esters, known as estolides. Depending on structure, they are divided in subfamilies (e.g. palmitic acid esters of hydroxy stearic acid, PAHSAs) including several regioisomers with different position of the branching position (e.g. 9-PAHSA). In human and mice tissue, glycerol-bound FAHFAs in triacylglycerols (TAGs), named TAG estolides, serve as metabolite reservoir of FAHFAs mobilized by lipases upon demand. Here, we studied the role of two major metabolic lipases, adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL), in TAG estolide and FAHFA degradation. We synthesized a panel of twenty TAG estolide isomers with different FAHFAs groups varying in branching position, chain length, saturation grade, and position on the glycerol backbone. An in silico mass spectra library was developed of all predicted catabolic intermediates. Homogenates of HEK293T cells overexpressing ATGL, or HSL were used for the determination of TAG estolide hydrolase activity of HSL and ATGL in the presence or absence of comparative gene identification-58 (CGI-58). White adipose tissue from ad libitum fed and fasted wild-type and global HSL knock-out mice was collected and TAG estolides were quantified. We found that ATGL alone or coactivated by CGI-58 efficiently liberated FAHFAs from TAG estolides with a preference for more compact substrates where the estolide branching point is located near the glycerol ester bond. ATGL also participated in transesterification and remodeling reactions leading to the formation of TAG estolides with alternative acyl compositions. HSL represented a much more potent estolide bond hydrolase for both TAG estolides and free FAHFAs. FAHFA and TAG estolide accumulation in white adipose tissue of mice lacking HSL argued for a functional role of HSL in estolide catabolism in vivo. Our data show that ATGL and HSL participate in the metabolism of estolides and TAG estolides in distinct manners and are likely to affect the lipokine function of FAHFAs.

Distinct roles of adipose triglyceride lipase and hormone-sensitive lipase in the catabolism of triacylglycerol estolides

Branched esters of palmitic acid and hydroxy stearic acid are antiinflammatory and antidiabetic lipokines that belong to a family of fatty acid (FA) esters of hydroxy fatty acids (HFAs) called FAHFAs. FAHFAs themselves belong to oligomeric FA esters, known as estolides. Glycerol-bound FAHFAs in triacylglycerols (TAGs), named TAG estolides, serve as metabolite reservoir of FAHFAs mobilized by lipases upon demand. Here, we characterized the involvement of two major metabolic lipases, adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL), in TAG estolide and FAHFA degradation. We synthesized a library of 20 TAG estolide isomers with FAHFAs varying in branching position, chain length, saturation grade, and position on the glycerol backbone and developed an in silico mass spectra library of all predicted catabolic intermediates. We found that ATGL alone or coactivated by comparative gene identification-58 efficiently liberated FAHFAs from TAG estolides with a preference for more compact substrates where the estolide branching point is located near the glycerol ester bond. ATGL was further involved in transesterification and remodeling reactions leading to the formation of TAG estolides with alternative acyl compositions. HSL represented a much more potent estolide bond hydrolase for both TAG estolides and free FAHFAs. FAHFA and TAG estolide accumulation in white adipose tissue of mice lacking HSL argued for a functional role of HSL in estolide catabolism in vivo. Our data show that ATGL and HSL participate in the metabolism of estolides and TAG estolides in distinct manners and are likely to affect the lipokine function of FAHFAs.

Impedance spectroscopy of water splitting reactions on nanostructured metal-based catalysts

Hydrogen production by water splitting using nanomaterials as electrocatalysts is a promising route enabling replacement of fossil fuels by renewable energy sources. In particular, the development of inexpensive non-noble metal-based catalysts is necessary in order to replace currently used expensive Pt-based catalysts. We report a detailed impedance spectroscopy study of Ni-Mo and Ni-Fe based electrocatalytic materials deposited onto porous and compact substrates with different conductivities. The results were interpreted by a critical comparison with equivalent circuit models. The reaction resistance displays a strong dependence on potential and a lower substrate dependence. The impedance behaviour can also provide information on the dominating reaction mechanism. An optimized Ni-Fe based catalyst showed very promising properties for applications in water electrolysis.

The Cdc48 unfoldase prepares well-folded protein substrates for degradation by the 26S proteasome

Cdc48/p97 is an essential and highly conserved AAA+ ATPase that uses its protein-unfoldase activity to extract ubiquitinated polypeptides from macromolecular complexes and membranes. This motor has also been implicated in protein-degradation pathways, yet its exact role in acting upstream of the 26S proteasome remains elusive. Ubiquitinated proteins destined for degradation by the proteasome require an unstructured initiation region to engage with the proteasomal translocation machinery, and Cdc48 was proposed to generate these unfolded segments, yet direct evidence has been missing. Here, we used an in vitro reconstituted system to demonstrate the collaboration of Cdc48 and the 26S proteasome from S. cerevisiae in degrading ubiquitinated, well-folded proteins that lack unstructured segments. Our data indicate that a critical role for Cdc48 in the ubiquitin-proteasome system is to create flexible initiation regions in compact substrates that otherwise would be refractory to engagement and degradation by the proteasome.

How moles destroy your lawn: the forelimb kinematics of Eastern moles in loose and compact substrates

The interplay between morphological specialization and kinematic flexibility is important for organisms that move between habitats within different substrates. Burrowing is energetically expensive and requires substantial interaction with soil to dislodge and transport it. True moles (Talpidae) have extraordinary forelimb morphologies and a unique ability to dig in loose as well as compact soils, yet we know little of how moles coordinate their forelimb joint kinematics when digging in soils of different compactness. Using marker-based X-ray Reconstruction of Moving Morphology (XROMM), we tested the hypothesis that moles burrow using different forelimb kinematics in loose and compact substrates. We predicted that moles raise mounds of loose soil by performing powerful compacting strokes mainly with long-axis rotation of the humerus (i.e. pronation/supination), but shear compact soil away by performing scratching strokes involving amplified elbow extension, similar to most scratching diggers. We also predicted that in both types of substrate, moles displace soil rearward like other mammalian diggers. Our results support our hypothesis but not the predictions. Eastern moles (Scalopus aquaticus) move substrates upward using compacting strokes in loose substrates and outward from the body midline using scratching strokes in compact substrates; unlike the digging strokes of most mammalian forelimb diggers, the power-stroke of moles itself does not displace substrates directly rearward. Compacting and scratching strokes involve similar ranges of humeral pronation and retraction at the scapulohumeral (shoulder) joint, yet the movements at the elbow and carpal joints differ. Our results demonstrate that the combination of stereotypic movements of the shoulder joint, where the largest digging muscles are located, and flexibility in the elbow and carpal joints makes moles extremely effective diggers in both loose and compact substrates.

Glass Packaging for RF MEMS

Abstract In recent years, advancements in High Performance Computing and Photonics are driving towards high density semiconductor packaging requirements that are creating a need for the adoption of novel material sets. Glass has many attractive properties that help address product level challenges such as low height, and smaller, packages. Glass also offers high resistivity, low dielectric constant, adjustable coefficient of thermal expansion (CTE), and low electrical loss. These properties can also be leveraged for RF and Mobile applications where battery life is paramount. To further utilize glass' material properties for interposers and compact substrates, it is necessary to form precision or Through Glass Vias (TGVs). Mobile cellular networks are rapidly evolving towards fifth generation (5G), which is set to exploit a wider spectrum of frequencies that range into millimeter wave (mmWave). RF MEMS technology is a promising approach to addressing RF Switches, which are key building blocks into Radio Frequency Front Ends (RFFE). In this paper, we show the usage of glass based packaging solutions and TGVs to offer low form factor, broadband RF MEMS switches.

Effects of recycled glass and different substrate materials on the leachate quality and plant growth of green roofs

Green roofs are a key component to building sustainable cities because of their multiple environmental benefits, but without the proper level of care, the leachate from green roofs might contain pollutants and become a new nonpoint pollution source in urban areas. Because its leachate quality is affected by the substrates and plants used, the objective of this study is to evaluate the effects of the substrates and plants with the aim of improving green roof applications. This study tested 3 materials – normal cultivated (C) substrate, commercial green roof (L) substrate, and mixed C and recycled glass (R) substrate – with a focus on using recycled glass materials in the green roof system. Recycled glass is a lightweight and porous material that improves pollutant absorption and water quality purification. Three different types of plants were tested: a sedum, a fern, and a shrub. Therefore, this study evaluated 9 combinations, each with 3 replicates. The differences in the substrates exerted significant effects on the chemical oxygen demand (COD) and phosphorous (P) concentrations. The nitrogen (N) concentrations were affected by differences in both the substrates and the plants. The changes in the observed water quality with time implied that compact substrates and mature plants reduced pollutant concentrations, except for N concentrations, in the outflow. The L substrate contained high levels of nutrients, and the plants grew better in this substrate than in the other two substrates; however, the L substrate also produced higher pollution concentrations. The R substrate, with recycled glass, performed well in the neutralization of acid rain but did not significantly reduce the levels of other pollutants. To enhance the purification ability of the recycled glass, the mixing ratio between the recycled glass and organic substances and the placement in the substrate are important factors.

Wetting and reaction characteristics of crystalline and amorphous SiO2 derived rice-husk ash and SiO2/SiC substrates with Al–Si–Mg alloys

A study of the wetting behavior of three substrate types (SiC, SiO2-derived RHA and SiC/SiO2-derived RHA) by two Al–Si–Mg alloys using the sessile drop method has been conducted, using amorphous and crystalline SiO2 in the experiment. Mostly, there is a transition from non-wetting to wetting contact angles, being the lowest θ values achieved with the alloy of high Mg content in contact with amorphous SiO2. The observed wetting behavior is attributed to the deposited Mg on the substrates. A strong diffusion of Si from the SiC/Amorphous RHA substrate into the metal drop explains the free Si segregated at the drop/substrate interface and drop surface. Although incorporation of both SiO2-derived RHA structures into the SiC powder compact substrates increases the contact angles in comparison with the SiC substrate alone, the still observed acute contact angles in RHA/SiC substrates make them promising for fabrication of composites with high volume fraction of reinforcement by the pressureless infiltration technique. The observed wetting characteristics, with decrease in surface tension and contact angles is explained by surface related phenomena. Based on contact angle changes, drop dimensions and surface tension values, as well as on the interfacial elemental mapping, and XRD analysis of substrates, some wetting and reaction pathways are proposed and discussed.

The Effect of Titanium Oxide Substrate on the Film Morphology and Photoluminescence Properties of Organometal Halide Perovskites

ABSTRACTWe have investigated the film morphology and photoluminescence properties of spin-coated CH3NH3PbI3-xClx films on mesoporous and compact TiO2 substrates. We observe that the perovskite film deposited on the mesoporous substrate composed of 20 nm TiO2 nanopaticles exhibits relatively uniform grain size, while the films deposited on the compact TiO2 substrate and the mesoporous substrate with large TiO2 nanoparticles (200 nm) show highly heterogeneous film morphology. The heterogeneity of film morphology has significant effect on the photoluminescence spectra and lifetime of the perovskite films. The result of time-resolved confocal microscopy unveils the relation between film structure and photoluminescence properties.

Mechanical Properties Improvement of Waterborne Polyurethane Coating Films After Rewetting and Drying

Drying behavior of waterborne polyurethane coating under ambient conditions displays the typical three-stage drying process on compact hard substrates. When the naturally dried samples are further dried at thermal condition of 105°C, the loss of residual water was accompanied with an increase in the hardness of the films. When the coating films were immersed in water and dried at ambient condition again, the hardness and modulus increased significantly. After 180-min immersion followed by natural drying, the hardness of the film increased to almost 10 times that of the initial value. The possible reason is that the interaction between water and the hydrophobic amorphous phase of polyurethane led to a compacted amorphous phase, which decreased the free volume of the films, resulting in the increase in the hardness and modulus of the coating films.

Topology of Smectic Order on Compact Substrates

Smectic orders on curved substrates can be described by differential forms of rank one (1-forms), whose geometric meaning is the differential of the local phase field of density modulation. The exterior derivative of the 1-form is the local dislocation density. Elastic deformations are described by superposition of exact differential forms. Applying this formalism to study smectic order on a torus as well as on a sphere, we find that both systems exhibit many topologically distinct low energy states that can be characterized by two integer topological charges. The total number of low energy states scales as the square root of the substrate area. For a smectic on a sphere, we also explore the motion of disclinations as possible low energy excitations, as well as its topological implications.

Kinetics of diffusion-limited reactions with biased diffusion in percolating to compact substrates

We study through Monte Carlo simulations, the kinetics of the two-species diffusion-limited reaction model with same species excluded volume interaction in substrates embedded on a square lattice ranging in occupancy from a fractal percolating structure to the compact limit. We study the time evolution of the concentration of single-particle species for various values of substrate occupancies, 0.5927460, 0.61, 0.63, 0.65, 0.7, 0.8, and 1, where the first value corresponds to the percolating probability of the square lattice. We show that in the diffusion-limited reaction regime, the kinetics strongly depends on the presence of a bias along a particular square lattice direction, representing the net effect of a driving field. We were able to explain the slow dynamics at high values of the driving field in terms of traps appearing in diluted substrates, particularly at the percolation threshold.

Canopy recovery after drought dieback in holm‐oak Mediterranean forests of Catalonia (NE Spain)

AbstractClimate change is likely to produce more frequent and longer droughts in the Mediterranean region, like that of 1994, which produced important changes in the Quercus ilex forests, with up to 76% of the trees showing complete canopy dieback. At the landscape level, a mosaic of responses to the drought was observed, linked to the distribution of lithological substrates. Damage to the dominant tree species (Q. ilex) and the most common understorey shrub (Erica arborea) was more noticeable on the compact substrates (breccia) than on the fissured ones (schist). This result was consistent with observations documenting deeper root penetration in schist than in breccia materials, allowing the plants growing on fissured substrates to use water from deeper soil levels. Smaller plants were more vulnerable to drought than larger plants in the trees, but not in the shrubs. Overall, Q. ilex was more affected than E. arborea. The resilience of the system was evaluated from the canopy recovery 1 year after the episode. Stump and crown resprouting was fairly extensive, but the damage pattern in relation to substrate, plant size, and species remained similar. The effect of recurrent drought episodes was studied on vegetation patches of Q. ilex located on mountain slopes and surrounded by bare rock. We observed that plants that resprouted weakly after a previous drought in 1985 were more likely to die or to produce poor regeneration in 1995 than plants that had resprouted vigorously. Vegetation patches located on the lower part of the slope were also less damaged than patches situated uphill. The study provides evidence of relevant changes in forest canopy as a consequence of extreme climate events. The distribution of this effect across the landscape is mediated by lithological substrate, causing patchy patterns. The results also support the hypothesis that recurrent droughts can produce a progressive loss of resilience, by depleting the ability of surviving plants to regenerate.

Coarsening in diluted systems

We investigate domain growth after a quench to the unstable region of the phase diagram on a lattice lacking translational invariance due to the presence of voids. The dynamical process is analyzed using a Ginzburg-Landau model with Langevin dynamics, studied numerically by means of a cell dynamical simulation in d = 2 for conserved order parameter at T F = 0. We find that for short times ordering proceeds as on compact substrates (L(t) ∼ t 1/3 ): later on, when L(t) becomes comparable to the typical distance separating voids, coarsening occurs only via activated processes and for T F = 0 the system freezes out of equilibrium.

Morphology and anatomy ofCaloplaca coralligera (Teloschistaceae) as adaptation to extreme environmental conditions in the maritime Antarctic

The anatomical and morphological structure of the lichenCaloplaca coralligera (Hue.)Zahlbr. was investigated in connection with mechanisms of colonization and adaptation to the special conditions of maritime Antarctic.Caloplaca coralligera seems to be endemic to the antarctic region. The lichen is unique in its morphology, growing like a crustose lichen with a prothallus, but the very thallus being composed of many vertical, frutescent branches not higher than large isidia. Due to fusions of the distal parts of the branches the morphology is characterized by air-filled cavities between the erect thallus parts where the phycobionts are located only close to the outermost surface. But also anatomically a system of air-filled cavities is developed by a net-like structure of hyphae. This may result in an insulation from temperature exchanges with the rocky substrate. It is speculated that this peculiar thallus structure might be advantageous to a lichen growing on compact substrates by buffering the diurnal temperature extremes which are characteristic for rocks under a strong radiation exchange with the atmospheric surrounding.